Before the

**Federal Communications Commission**

**Washington, D.C. 20554**

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| In the matter of                 | *  | ET Docket 98-153             |
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| Revision of Part 15 of the       | ** |                              |
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| Regarding Ultra-Wideband         | *) |                              |
| Transmission ) ET Docket 98-153  | ** |                              |
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**FIRST REPORT AND ORDER**

**Adopted: February 14, 2002 Released: April 22, 2002**

**By the Commission:** Commissioners Copps and Martin issuing separate
statements.

Page

I. introduction [2](#introduction)

II\. executive summary [3](#executive-summary)

III\. BACKGROUND [4](#background)

IV\. discussion [7](#discussion)

A. Authorization and Regulatory Treatment of UWB
[7](#authorization-and-regulatory-treatment-of-uwb)

B. UWB Definition [12](#uwb-definition)

C. Frequency Bands and Operational Requirements for UWB Devices
[16](#frequency-bands-and-operational-requirements-for-uwb-devices)

1\. Imaging Systems [18](#imaging-systems)

2\. Other UWB Devices [23](#other-uwb-devices)

D. Analyses of Interference Studies
[27](#analyses-of-interference-studies)

1\. NTIA, DOT and TDC Analyses of Potential Interference to GPS
[28](#ntia-dot-and-tdc-analyses-of-potential-interference-to-gps)

2\. NTIA Analyses of Interference to Various U.S. Government Systems:
[44](#ntia-analyses-of-interference-to-various-u.s.-government-systems)

3\. U.S. Department of Defense Analysis of Interference to the SGLS
[53](#u.s.-department-of-defense-analysis-of-interference-to-the-sgls)

4\. ARRL Analysis of Noise Floor Increase in Amateur Radio Bands
[53](#arrl-analysis-of-noise-floor-increase-in-amateur-radio-bands)

5\. Analyses of Potential Interference to PCS
[54](#analyses-of-potential-interference-to-pcs)

6\. Cisco Analysis of Potential Interference to MMDS
[57](#cisco-analysis-of-potential-interference-to-mmds)

7\. XM Analysis of Potential Interference to DARS
[58](#xm-analysis-of-potential-interference-to-dars)

8\. Summary of Tests and Analyses [59](#summary-of-tests-and-analyses)

E. Emission Limits [60](#emission-limits)

1\. General [60](#general)

2\. Average and Quasi-peak Emission Levels
[62](#average-and-quasi-peak-emission-levels)

3\. Imaging Systems Including GPRs [65](#imaging-systems-including-gprs)

4\. Other Applications [66](#other-applications)

5\. Emission Levels above 1990 MHz [70](#emission-levels-above-1990-mhz)

6\. Dithering and Other Noise-Like Emission Requirements
[71](#dithering-and-other-noise-like-emission-requirements)

7\. Emissions from Incorporated Digital Devices
[72](#emissions-from-incorporated-digital-devices)

8\. Peak Emission Limits [72](#peak-emission-limits)

9\. AC Power Line Conducted Limits [77](#ac-power-line-conducted-limits)

10\. Summary of Emission Limits Being Adopted in this Report and Order
[77](#summary-of-emission-limits-being-adopted-in-this-report-and-order)

F. Cumulative Impact [79](#cumulative-impact)

G. Measurement Procedures [81](#measurement-procedures)

1\. Quasi-peak and Average Measurements
[82](#quasi-peak-and-average-measurements)

2\. Peak Measurements [84](#peak-measurements)

3\. Frequency Range of Measurement [86](#frequency-range-of-measurement)

H. Prohibition Against Class B, Damped Wave Emissions
[87](#prohibition-against-class-b-damped-wave-emissions)

I. Other Matters [88](#other-matters)

1\. Operation of Wide Bandwidth Systems under the Existing Rules
[88](#operation-of-wide-bandwidth-systems-under-the-existing-rules)

2\. Transition Provisions [89](#transition-provisions)

3\. Existing Waivers [90](#existing-waivers)

4\. Miscellaneous Issues [90](#miscellaneous-issues)

5\. Other Matters [91](#other-matters-1)

V. PROCEDURAL MATTERS [92](#procedural-matters)

VI\. ORDERING CLAUSES [94](#ordering-clauses)

APPENDIX A: Commenting Parties

APPENDIX B: Comments in Response to NTIA's Study of Potential
Interference to Non-GPS Systems

APPENDIX C: Comments in Response to Studies of Potential Interference to
GPS Systems and to Personal Communications Services

APPENDIX D: Changes to the Regulations

APPENDIX E: Peak in a Specific Bandwidth vs. Average in a 1 MHz
Bandwidth vs. PRF

APPENDIX F: Measurement Procedures

# introduction

1.  By this action, we are amending Part 15 of our rules to permit the
    marketing and operation of certain types of new products
    incorporating ultra-wideband (\"UWB\") technology. UWB devices
    operate by employing very narrow or short duration pulses that
    result in very large or wideband transmission bandwidths. UWB
    technology holds great promise for a vast array of new applications
    that we believe will provide significant benefits for public safety,
    businesses and consumers. With appropriate technical standards, UWB
    devices can operate using spectrum occupied by existing radio
    services without causing interference, thereby permitting scarce
    spectrum resources to be used more efficiently. This First Report
    and Order ("Order") includes standards designed to ensure that
    existing and planned radio services, particularly safety services,
    are adequately protected. We are proceeding cautiously in
    authorizing UWB technology, based in large measure on standards that
    the National Telecommunications and Information Administration
    ("NTIA") found to be are necessary to protect against interference
    to vital federal government operations. These UWB standards will
    apply to UWB devices operating in shared or in non-government
    frequency bands, including UWB devices operated by U.S. Government
    agencies in such bands. We are concerned, however, that the
    standards we are adopting may be overprotective and could
    unnecessarily constrain the development of UWB technology.
    Accordingly, within the next six to twelve months we intend to
    review the standards for UWB devices and issue a further rule making
    to explore more flexible technical standards and to address the
    operation of additional types of UWB operations and technology.

2.  This has been an unusually controversial proceeding involving a
    variety of UWB advocates and opponents. These parties have been
    unable to agree on the emission levels necessary to protect
    Government-operated, safety-of-life and commercial radio systems
    from harmful interference. It is our belief that the standards
    contained in this Order are extremely conservative. These standards
    may change in the future as we continue to collect data regarding
    UWB operations. The analyses and technical standards contained in
    this Order are unique to this proceeding and will not be considered
    as a basis for determining or revising standards for other radio
    frequency devices, including other Part 15 devices.

3.  The following text first provides an executive summary of the major
    actions taken in this item. Next, a background section describing
    Part 15 of the Commission\'s rules and the history of this
    proceeding is provided. A comprehensive discussion section
    consisting of several parts is also included. The first section of
    the discussion focuses on regulatory treatment and the Commission\'s
    definition of ultra wideband technology. The next part of the
    discussion provides analyses of studies submitted by several parties
    assessing the interference potential of ultra wideband devices to
    existing services. This section is followed by a discussion of the
    emission limits established for ultra wideband deployment. Also
    included in the discussion section are assessments of the cumulative
    impact of ultra wideband devices and procedures for measuring the
    emissions from ultra wideband devices. Finally, the discussion
    concludes with a section on other matters that impact the
    authorization of UWB technology.

# executive summary

4.  Upon consideration of the record, we continue to believe that UWB
    technology offers significant benefits for Government, public
    safety, businesses and consumers. However, we recognize that these
    substantial benefits could be outweighed if UWB devices were to
    cause interference to licensed services and other important radio
    operations. Our analysis of the record and the various technical
    studies submitted indicate that UWB devices can be permitted to
    operate on an unlicensed basis without causing harmful interference
    provided appropriate technical standards and operational
    restrictions are applied to their use.

5.  To ensure that UWB devices do not cause harmful interference, this
    Order establishes different technical standards and operating
    restrictions for three types of UWB devices based on their potential
    to cause interference. These three types of UWB devices are: 1)
    imaging systems including Ground Penetrating Radars (GPRs) and wall,
    through-wall, surveillance, and medical imaging devices, 2)
    vehicular radar systems, and 3) communications and measurement
    systems. Generally, we are adopting unwanted emission limits for UWB
    devices that are significantly more stringent than those imposed on
    other Part 15 devices; limiting outdoor use of UWB devices to
    imaging systems, vehicular radar systems and hand held devices; and,
    limiting the frequency band within which certain UWB products will
    be permitted to operate. The frequency band of operation is based on
    the --10 dB bandwidth of the UWB emission. This combination of
    technical standards and operational restrictions will ensure that
    UWB devices coexist with the authorized radio services without the
    risk of harmful interference while we gain experience with this new
    technology. In the meantime, we plan to expedite enforcement action
    for any UWB products found to be in violation of the rules we are
    adopting and will act promptly to eliminate any reported harmful
    interference from UWB devices. Specifically, the Order takes the
    following actions:

-   ***Imaging Systems***: Provides for the operation of GPRs and other
    imaging devices under Part 15 of the Commission's rules subject to
    certain frequency and power limitations. All imaging systems are
    subject to coordination with NTIA through the FCC. NTIA has
    indicated that coordination will be as expeditious as possible,
    requiring no longer than 15 business days, and may be expedited in
    emergency situations. The operators of imaging devices must be
    eligible for licensing under Part 90 of our rules, except that
    medical imaging devices may be operated by a licensed health care
    practitioner. Imaging systems include:

-   ***Ground Penetrating Radar Systems*:** GPRs must be operated below
    960 MHz or in the frequency band 3.1-10.6 GHz. GPRs operate only
    when in contact with, or within close proximity of, the ground for
    the purpose of detecting or obtaining the images of buried objects.
    The energy from the GPR is intentionally directed down into the
    ground for this purpose. Operation is restricted to law enforcement,
    fire and rescue organizations, to scientific research institutions,
    to commercial mining companies, and to construction companies.

-   ***Wall Imaging Systems*:** Wall imaging systems must be operated
    below 960 MHz or in the frequency band 3.1-10.6 GHz. Wall-imaging
    systems are designed to detect the location of objects contained
    within a "wall," such as a concrete structure, the side of a bridge,
    or the wall of a mine. Operation is restricted to law enforcement,
    fire and rescue organizations, to scientific research institutions,
    to commercial mining companies, and to construction companies.

-   ***Through-wall Imaging Systems*:** These systems must be operated
    below 960 MHz or in the frequency band 1.99-10.6 GHz. Through-wall
    imaging systems detect the location or movement of persons or
    objects that are located on the other side of a structure such as a
    wall. Operation is limited to law enforcement, fire and rescue
    organizations.

-   ***Surveillance Systems*:** Although technically these devices are
    not imaging systems, for regulatory purposes they will be treated in
    the same way as through-wall imaging systems used by police, fire
    and rescue organizations and will be permitted to operate in the
    frequency band 1.99-10.6 GHz. Surveillance systems operate as
    "security fences" by establishing a stationary RF perimeter field
    and detecting the intrusion of persons or objects in that field.
    Operation is limited to law enforcement, fire and rescue
    organizations, to public utilities and to industrial entities.

-   ***Medical Systems*:** These devices must be operated in the
    frequency band 3.1-10.6 GHz. A medical imaging system may be used
    for a variety of health applications to "see" inside the body of a
    person or animal. Operation must be at the direction of, or under
    the supervision of, a licensed health care practitioner.

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-   ***Vehicular Radar Systems*:** Provides for the operation of
    vehicular radar in the 22-29 GHz band using directional antennas on
    terrestrial transportation vehicles provided the center frequency of
    the emission and the frequency at which the highest radiated
    emission occurs are greater than 24.075 GHz. These devices are able
    to detect the location and movement of objects near a vehicle,
    enabling features such as near collision avoidance, improved airbag
    activation, and suspension systems that better respond to road
    conditions. Attenuation of the emissions below 24 GHz is required
    above the horizontal plane in order to protect space borne passive
    sensors operating in the 23.6-24.0 GHz band.

-   ***Communications and Measurement*** ***Systems*:** Provides for use
    of a wide variety of other UWB devices, such as high-speed home and
    business networking devices as well as storage tank measurement
    devices under Part 15 of the Commission's rules subject to certain
    frequency and power limitations. The devices must operate in the
    frequency band 3.1-10.6 GHz. The equipment must be designed to
    ensure that operation can only occur indoors or it must consist of
    hand held devices that may be employed for such activities as
    peer-to-peer operation.

# BACKGROUND

6.  Part 15 of our rules permits the operation of authorized low power
    radio frequency (RF) devices without a license from the Commission
    or the need for frequency coordination.[^1] The technical standards
    contained in Part 15 are designed to ensure that there is a low
    probability that these unlicensed devices will cause harmful
    interference to other users of the radio spectrum.[^2] Part 15
    intentional radiators, *i.e.*, radio transmitters, are permitted to
    operate under a set of general emission limits[^3] or under
    provisions that allow higher emission levels in certain frequency
    bands.[^4] Part 15 intentional radiators generally are not permitted
    to operate in certain sensitive[^5] or safety-related frequency
    bands that are designated as restricted bands,[^6] or in the
    frequency bands allocated for television ("TV") broadcasting. Only
    out-of-band or spurious emissions from Part 15 transmitters are
    permitted in these restricted bands.

7.  UWB radio systems typically employ pulse modulation where extremely
    narrow (short) bursts of RF energy are modulated and emitted to
    convey information. Because of the very short duration of these
    pulses, the emission bandwidths from these systems are large and
    often exceed one gigahertz.[^7] In some cases, "impulse"
    transmitters are employed where the pulses do not modulate a
    carrier. Instead, the radio frequency emissions generated by the
    pulses are applied to an antenna, and the resonant frequency of the
    antenna determines the center frequency of the radiated emission.
    The frequency response characteristics of the antenna provide
    band-pass filtering, further affecting the shape of the radiated
    signal. UWB devices can be used for precise measurement of distances
    or locations and for obtaining the images of objects buried under
    ground or behind surfaces. UWB devices can also be used for wireless
    communications, particularly for short-range high-speed data
    transmissions suitable for broadband access to networks.

8.  The current Part 15 rules pose two primary obstacles to the
    implementation of UWB technology. First, the wide bandwidth that is
    intrinsic to the operation of UWB devices can result in transmission
    of the intentional emissions into restricted frequency bands or into
    the TV broadcast frequency bands, which is prohibited under the Part
    15 rules. Second, the current emission measurement procedures
    specified in our Part 15 rules were developed for relatively
    narrowband systems and may be inappropriate for, and pose
    unnecessary restrictions to, UWB technology, particularly impulse
    systems. For example, the Part 15 measurement procedures require the
    application of a pulse desensitization correction factor.[^8] The
    application of this correction factor is not appropriate for very
    wideband systems and may can cause UWB systems to exceed the peak
    emission limits currently specified under the Part 15 rules.[^9]

9.  The Federal Government operates safety-of-life and other critical
    systems in several of the restricted frequency bands and has raised
    concerns about the potential for UWB devices to interfere with these
    operations. The National Telecommunications and Information
    Administration (NTIA) at the U.S. Department of Commerce is
    responsible for managing the Federal Government\'s use of the radio
    frequency spectrum. In this capacity, NTIA conducted measurements
    and analysis of potential interference to a range of Federal systems
    including, for example, the Global Positioning System, Search and
    Rescue Satellite System, Air Traffic Control System, and
    Meteorological Radar System. NTIA and the FCC have worked closely
    throughout this proceeding to ensure that the public interest is
    best served by the implementation of UWB technology. Specifically,
    the two agencies have worked together to develop a regulatory
    paradigm that permits the deployment of promising new UWB technology
    while adequately safeguarding both Government and non-government
    operations.

10. On May 10, 2000, the Commission adopted a *Notice of Proposed Rule
    Making* ("*Notice*") that proposed rules to allow the operation of
    UWB transmission systems under the Part 15 regulations.[^10] In the
    *Notice*, the Commission requested comments on various aspects of
    UWB operation, including applications, general characteristics,
    operation on an unlicensed basis, how UWB should be defined, the
    frequency ranges of operation, appropriate emission levels,
    cumulative impact concerns, and measurement procedures. In addition,
    the Commission requested comments concerning the existing
    prohibition against Class B, damped wave emissions, the operation of
    wide bandwidth transmitters under the existing Part 15 rules, and
    the transition provisions that should be applied. In response to the
    *Notice*, the Commission received 159 comments and 80 reply
    comments, as shown in Appendix A.[^11]

11. Subsequent to the *Notice*, the Commission, on January 24, 2001,
    requested comments on two studies presented NTIA regarding the
    potential for UWB transmission systems to cause harmful interference
    to U. S. Government radio operations between 400 MHz and 6000
    MHz.[^12] In response to these studies, the Commission received 16
    comments and 7 reply comments, as shown in Appendix C. Subsequent to
    the NTIA filing, the Commission, on March 26, 2001, requested
    comments on additional studies addressing potential interference
    from UWB operation to the Global Positioning System (GPS) and to the
    Personal Communications Services (PCS) telephones.[^13] Time
    Domain,[^14] NTIA,[^15] and the Department of Transportation[^16]
    submitted GPS interference studies. Qualcomm submitted the PCS
    study.[^17] In response to these studies, the Commission received 22
    comments and 16 reply comments, as shown in Appendix D.[^18]

# discussion

## Authorization and Regulatory Treatment of UWB

12. In the *Notice*, we stated that UWB technology holds significant
    promise for a vast array of new applications and devices, which may
    offer significant benefits for public safety, businesses, consumers,
    and could enhance competition and the economy. In addition, we
    indicated that UWB technology might enable increased use of scarce
    spectrum resources by sharing frequencies with other services
    without causing interference. We noted that most of the near-term
    applications for UWB technology involve relatively low powers and
    short operating ranges. Further, most UWB devices are intended to be
    mass marketed to businesses and consumers making it impractical to
    individually license each device. We observed that these
    characteristics are largely consistent with devices that operate on
    an unlicensed basis under Part 15 of the rules. Accordingly, we
    tentatively concluded that regulating UWB devices under Part 15 of
    the Commission's rules would be appropriate.[^19]

13. A large number of parties filed comments in response to the *Notice*
    supporting the authorization of UWB technology and suggesting
    applications for its use. While many of these endorsements did not
    provide technical comments on the operating parameters that should
    be applied to UWB devices, they do provide significant insight into
    the public interest and demand for the wide array of products that
    could be developed using UWB techniques. Several UWB applications
    including ground penetrating radar (GPR) systems, wall-imaging
    systems, automotive collision avoidance systems, radar level gauges
    used in storage tanks, and communications systems received
    significant support. Intel, for example, believed that the greatest
    potential use is short-range communications in the home or business,
    allowing equipment mobility and high data rates to facilitate
    information sharing.[^20] Fantasma noted similar applications for
    supplying simultaneous video, audio, and Internet use throughout
    homes, schools, libraries, medical and elder-care facilities, and
    businesses.[^21] AT&T expressed interest in providing high
    throughput, short-range voice, data and video services on premises
    and campus environments. [^22] National Safe Skies Alliance believed
    UWB could be used to detect airport runway incursions and provide
    data distribution within airport terminals, personnel location, and
    other features.[^23] Siemens Automotive ZF suggests using UWB
    technology for forward looking and lane change collision avoidance
    systems, backup warning systems, and airbag proximity
    measurements.[^24] TDC noted the potential for using UWB devices in
    dozens of applications.[^25]

14. Most parties supporting UWB also support authorization of UWB
    technology under Part 15 unlicensed operations. Delphi, Endress
    Hauser, Lucent and Bosch note that they intend to mass-market UWB
    devices to businesses and consumers. They argue that licensing UWB
    devices would be impractical and unwieldy and would increase costs
    to consumers.[^26] Valeo Electronics supports unlicensed operations
    for UWB but also suggests that higher-powered UWB use should be
    permitted with individual licensing or under product-specific
    waivers.[^27] Similarly, Zircon, while supporting unlicensed
    operation for UWB devices complying with the 47 C.F.R. § 15.209
    emission limits, indicated that UWB devices that comply with the
    limits for Class A digital devices should be minimally encumbered by
    any licensing requirements.[^28]

15. In general, the commenting parties associated with authorized radio
    services are opposed to authorization of UWB technology in their
    frequency bands of operation or suggest that UWB only be allowed on
    a licensed basis. For example, Cingular and other PCS operators
    suggest that UWB devices be limited to spectrum above 6 GHz or below
    1 GHz for GPRs only.[^29] The U.S. GPS Industry Council asserts that
    it is inappropriate for communications applications of UWB to be
    regulated under Part 15, as these are intentional emitters that
    experience very high peak powers.[^30] ARINC and ATA state that
    licensed UWB operation would provide protection to existing users
    through frequency coordination, but recognize that another rule
    making proceeding would be required to address the table of
    frequency allocations.[^31] Alloy states that licensing is essential
    until UWB is found to be non-interfering.[^32] MSSI, while a
    proponent of UWB operation, states that GPRs are inappropriate for
    unlicensed operation because of their high power level requirements
    and limited market.[^33]

16. Boeing requests that a new rule part be established under which UWB
    devices would be licensed.[^34] Boeing expresses concern that the
    potential aggregate impact of UWB devices is too significant to
    permit unless there is sufficient means to control the number of UWB
    devices in use. Under Boeing's proposal, the UWB manufacturers would
    obtain from the Commission authority to manufacture and market a
    fixed number of UWB devices under specific technical and operating
    conditions, such as limiting distribution to only public safety
    officials. Similarly, Lockheed states that the Commission needs to
    establish a regulatory regime that allows it to limit the number of
    devices that can operate at one time in the same area.[^35]
    Professor Peha suggests a scheme where the Commission would issue
    permits for UWB devices and allow only a fixed number of devices to
    be introduced per year. Professor Peha argues that this approach
    would allow the Commission to track usage and the number of devices
    deployed.[^36] SIA and Sirius also request that we implement some
    form of blanket licensing to limit the number of devices that can be
    operated in one area.[^37] Sirius believes that licensing enables
    potentially affected services to receive advance notice of the
    proposed UWB use and to comment on those proposals. Kohler opposes
    licensing and the use of permits stating that the Commission does
    not have the authority to implement this method of licensing. Kohler
    argues that such an approach would create mutual exclusivity by
    designating the number of UWB devices that could be authorized per
    year and would not comport with 47 U.S.C. 309(j).[^38]

17. Based on our review of the record, we continue to believe that UWB
    technology offers significant benefits for public safety, businesses
    and consumers. We anticipate that the authorization of UWB
    technology will create new business opportunities for manufacturers,
    distributors and vendors that will enhance competition and the
    economy. We also find that the use of this technology would promote
    spectrum efficiency by sharing frequencies with other services
    without causing interference. We also note that authorization of UWB
    is consistent with Section 7 of the Communications Act of 1934, as
    amended, which requires the Commission \"... to encourage the
    provision of new technologies and services to the public.\"[^39]

18. We are cognizant; however, that the substantial benefits of UWB
    technology could be outweighed if UWB devices were to cause
    interference to licensed services and other important radio
    operations. Our analysis of the record and the various technical
    studies submitted indicates that UWB devices can be permitted to
    operate without causing harmful interference if appropriate
    technical standards and operational restrictions are applied to
    their use. In this regard, we are establishing different technical
    standards and operating restrictions for different types of UWB
    equipment based on their potential to cause interference. As
    discussed below, we are, *inter alia,* adopting emission limits for
    UWB that are generally more stringent than those imposed on other
    Part 15 devices and limiting the frequency range below which certain
    UWB products will be permitted to operate. We believe that this
    combination of technical standards and operational restrictions will
    enable UWB devices to coexist with the authorized radio services
    without the risk of harmful interference.

19. We also continue to believe that unlicensed operation under Part 15
    of our rules is the most appropriate manner in which to authorize
    UWB devices at this time. These products, in general, will operate
    with very low power making licensing unnecessary. In this regard, we
    are not permitting UWB devices to be employed in higher power
    applications, such as wide-area mobile radio services. Instead, we
    are adopting emission limits that are designed to ensure that
    harmful interference to the authorized radio services is minimized,
    including interference from the cumulative effect of multiple UWB
    devices. We also are placing several restrictions on how and where
    UWB devices may be operated to ensure that harmful interference is
    not caused by these operations. We do not believe that requiring
    licensing is appropriate. However, we are implementing a
    coordination requirement for imaging devices, as requested by
    NTIA.[^40] We also do not believe that it is practical to limit the
    number of devices being produced by a manufacturer. We anticipate
    that many of these devices will be small or portable and therefore
    any such limits would not necessarily limit the number of
    transmitters concentrated in any specific location. We believe that
    regulating UWB through power restrictions and other technical
    requirements is sufficient and has worked successfully for other
    Part 15 devices. Accordingly, we see no benefits, commensurate with
    the added costs to the public and manufacturers, from requiring
    individual operators to obtain a license or from attempting to limit
    the yearly production of individual UWB manufacturers. Thus, we are
    promulgating the regulations for UWB operation under Part 15 of our
    rules.

20. For regulatory purposes, we have categorized UWB devices into three
    types: 1) imaging systems (including GPRs), 2) vehicular radar
    systems, and 3) communications and measurement systems. We believe
    that these categories provide a logical way to address the various
    technical characteristics of the different applications. Most
    imaging systems emit energy that is largely absorbed by the material
    against which they are placed. A GPR operates only when in contact
    with or within close proximity to the ground for the purpose of
    detecting or obtaining the images of buried objects. Imaging systems
    can be used to detect objects within or on the other side of walls.
    A wall imaging system is designed to detect the location of objects
    contained within a "wall," such as a concrete structure, the side of
    a bridge, or the wall of a mine. A through-wall imaging system
    detects the location or movement of persons or objects that are
    located on the other side of a structure such as a wall or a
    ceiling. A surveillance system is a stationary radar system used for
    security purposes by establishing an RF perimeter and detecting the
    movement of persons or objects within that perimeter. Vehicular
    radar systems are able to detect the location and movement of
    objects near a vehicle, enabling features such as near collision
    avoidance, improved airbag activation, and suspension systems that
    better respond to road conditions. Communications and measurement
    systems consist of indoor and hand held devices that can encompass a
    wide variety of applications including high-speed home and business
    networking devices.[^41] The term "hand held devices," as used in
    this Order, refers to portable devices, such as a lap top computer
    or a PDA, that are primarily hand held while being operated and that
    do not employ a fixed infrastructure when operating outdoors.

21. We have established different standards for these devices based on
    their individual operating characteristics and potential for causing
    interference to the authorized radio services. We recognize that our
    initial restrictions on applications, operating frequencies and
    emission levels may limit some UWB applications. However, we believe
    that we should be cautious until we have gained further experience
    with this technology. Once additional experience has been gained
    with UWB operation, we may consider whether more flexible standards
    are appropriate. Within their permitted bands of operation, UWB
    devices may operate at the emission limits specified in 47 C.F.R. §
    15.209. The other basic operating parameters for these devices are
    summarized below:

-   ***Imaging Systems***: Imaging systems include GPRs, wall imaging
    systems, through-wall imaging systems, surveillance systems and
    medical systems. All imaging systems are subject to coordination
    with NTIA through the FCC. NTIA has indicated that coordination will
    be as expeditious as possible, requiring no longer than 15 business
    days, and may be expedited in emergency situations. Except for
    medical imaging systems, the operators of imaging devices must be
    eligible for licensing under Part 90 of our rules. The standards for
    the different imaging systems are as follows:

-   ***Ground Penetrating Radar Systems*:** GPRs must be operated with
    their --10 dB bandwidth below 960 MHz or in the frequency band
    3.1-10.6 GHz. GPRs operate only when in contact with, or within
    close proximity of, the ground for the purpose of detecting or
    obtaining the images of buried objects. The energy from the GPR is
    intentionally directed down into the ground for this purpose.
    Operation is restricted to law enforcement, fire and emergency
    rescue organizations,[^42] to scientific research institutions, to
    commercial mining companies, and to construction companies.

-   ***Wall Imaging Systems*:** Wall imaging systems must be operated
    with their --10 dB bandwidth below 960 MHz or in the frequency band
    3.1-10.6 GHz. Wall-imaging systems are designed to detect the
    location of objects contained within a "wall," such as a concrete
    structure, the side of a bridge, or the wall of a mine. Operation is
    restricted to law enforcement, fire and emergency rescue
    organizations, to scientific research institutions, to commercial
    mining companies, and to construction companies.

-   ***Through-wall Imaging Systems*:** These systems must be operated
    with their --10 dB bandwidth below 960 MHz or in the frequency band
    1.99-10.6 GHz. Through-wall imaging systems detect the location or
    movement of persons or objects that are located on the other side of
    a structure such as a wall. Operation is limited to law enforcement,
    fire and emergency rescue organizations.

-   ***Surveillance Systems*:** Although technically these devices are
    not imaging systems, for regulatory purposes they will be treated in
    the same way as through-wall imaging systems used by police, fire
    and rescue organizations and will be permitted to operate with their
    --10 dB bandwidth in the frequency band 1.99-10.6 GHz. Surveillance
    systems operate as "security fences" by establishing a stationary RF
    perimeter field and detecting the intrusion of persons or objects in
    that field. Operation is limited to law enforcement, fire and
    emergency rescue organizations, to public utilities and to
    industrial entities.[^43]

-   ***Medical Systems*:** These devices must be operated with their
    --10 dB bandwidth in the frequency band 3.1-10.6 GHz. A medical
    imaging system is used to detect the location or movement of objects
    within the body of a person or animal. Operation must be at the
    direction of, or under the supervision of, a licensed health care
    practitioner.

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-   ***Vehicular Radar Systems*:** Provides for the operation of
    vehicular radar systems using directional antennas on terrestrial
    transportation vehicles provided the center frequency of the
    emission and the frequency at which the highest radiated emission
    occurs are greater than 24.075 GHz. The -10 dB bandwidth must be
    between 22 and 29 GHz. These devices are able to detect the location
    and movement of objects near a vehicle, enabling features such as
    near collision avoidance, improved airbag activation, and suspension
    systems that better respond to road conditions. Attenuation of the
    emissions below 24 GHz is required above the horizontal plane in
    order to protect space borne passive sensors operating in the
    23.6-24.0 GHz band.

-   ***Communications and Measurement*** ***Systems*:** Provides for use
    of a wide variety of other UWB devices, such as high-speed home and
    business networking devices as well as storage tank measurement
    devices under Part 15 of the Commission's rules subject to certain
    frequency and power limitations. The devices must operate with their
    --10 dB bandwidth in the frequency band 3.1-10.6 GHz. The equipment
    must be designed to ensure that operation can only occur indoors or
    it must consist of hand held devices that may be employed for such
    activities as peer-to-peer operation. The limits on unwanted
    emissions are more stringent for hand held devices than they are for
    indoor-only systems.

## UWB Definition

22. [Proposal]{.underline}. In the *Notice*, the Commission proposed to
    adopt a modified version of the UWB definition established by the
    OSD/DARPA UWB radar review panel.[^44] Specifically, the Commission
    proposed to define a UWB device as any device where the fractional
    bandwidth is greater than 0.25 or occupies 1.5 GHz or more of
    spectrum.[^45] The formula proposed by the Commission for
    calculating fractional bandwidth is 2(f~H~-f~L~)/(f~H~+f~L~) where
    f~H~ is the upper frequency of the --10 dB emission point and f~L~
    is the lower frequency of the --10 dB emission point. The center
    frequency of the transmission was defined as the average of the
    upper and lower --10 dB points, i.e., (f~H~+f~L~)/2.[^46] The
    Commission proposed to base its modified definition of an UWB device
    on --10 dB bandwidth, rather than the --20 dB bandwidth used by
    OSD/DARPA, because under the Part 15 limits, UWB devices operate so
    close to the noise floor that in many cases it may not be possible
    to measure the --20 dB bandwidth. The Commission also proposed that
    the bandwidth be determined using the antenna that is designed to be
    used with the UWB device. Comments were requested on: 1) the
    proposed definition; 2) whether the fractional bandwidth should be
    changed to account for the narrower bandwidth that would be measured
    using the --10 dB emission points instead of the --20 dB points; 3)
    whether we should use some other method to determine the emission
    bandwidth, such as a calculated bandwidth based on pulse width; 4)
    whether we should define UWB devices as limited to devices that
    solely use pulsed emissions where the bandwidth is directly related
    to the pulse width;[^47] and 5) whether extremely high speed data
    systems that comply with the UWB bandwidth requirements only because
    of the high data rate employed, as opposed to meeting the definition
    solely from the narrow pulse width, should be permitted. In the
    *Notice*, the Commission indicated it would pursue a conservative
    initial approach until more experience was gained with UWB
    operations.

23. [Comments]{.underline}. The commenting parties generally supported
    basing the definition of UWB either on a fractional bandwidth or
    some minimum emission bandwidth.[^48] They disagreed, however, on
    the specific values that should be applied for a device to be
    defined as UWB. There was also disagreement among the parties with
    regard to limiting the modulation to pulsed modulation, and
    requiring that the bandwidth be directly related to the narrow pulse
    width instead of the data rate. There were no objections to
    determining the bandwidth of the UWB emission using the antenna
    designed to be employed with the UWB transmitter.[^49]

24. A number of commenting parties supported the proposal in the
    *Notice* to use the --10 dB emission points to determine the
    fractional bandwidth. Bosch, for example, stated that the definition
    of UWB should be based solely on bandwidth using the --10 dB
    emission points.[^50] It stated that the --20 dB emission points
    were too near the noise floor to be measured reliably. Bosch also
    noted that the --20 dB emission points would be ambiguous as such
    points appear on both the fundamental lobe and the side lobes.
    Similar concerns about use of the --20 dB emission points were
    echoed by Valeo,[^51] Kohler,[^52] and others.

25. Objections to the use of the --10 dB emission points to determine
    the fractional bandwidth were filed by NBAA. It stated that the --10
    dB fractional bandwidth was arbitrary and asserts that it would
    ignore emission components that "could account for peak powers of
    hundreds of watts."[^53] NBAA suggests that the bandwidth of the
    device be more than 5 percent of its center frequency. AOPA requests
    that the bandwidth be based on the --20 dB points stating that
    emission levels vary too much to use the --10 dB points.[^54] ARRL
    requests that the bandwidth be determined using the --23 dB points
    believing that this would be consistent with other Commission
    regulations on spurious and out-of-band emissions.[^55]

26. Several parties requested that the fractional bandwidth of 0.25 and
    minimum bandwidth of 1.5 GHz limit be reduced from that proposed in
    the *Notice* due to the use of --10 dB rather than the --20 dB
    emission points.[^56] SME and Valeo, for example, requested a
    fractional bandwidth of around 0.17 and an upper bandwidth limit of
    one gigahertz.[^57] Siemens requests that the fractional bandwidth
    be reduced to 0.15 with a 1 GHz upper bandwidth limit.[^58] Bosch
    requests a fractional bandwidth of 0.15-0.20 and a minimum bandwidth
    of one to 1.5 gigahertz.[^59] ANRO and Kohler request a fractional
    bandwidth of 0.20.[^60] Daimler Chrysler requested an upper
    bandwidth limit of one gigahertz.[^61]

27. Delphi requested that a minimum bandwidth of 500 MHz be used to
    define UWB, regardless of center frequency, and that all forms of
    modulation be permitted.[^62] It added that absent such changes
    manufacturers producing radar devices under the current regulations
    would be disadvantaged because they would not be permitted to
    operate their equipment within the restricted bands. M/A-Com
    objected to Delphi's request stating that the Commission is not
    promoting the operation of narrowband systems in restricted
    bands.[^63] On the other hand, MSSI stated that UWB systems should
    be permitted with bandwidths as low as 200 MHz, indicating that UWB
    devices could be constructed with bandwidths as narrow as 20-30
    MHz.[^64]

28. With regard to the use of modulation types other than pulsed or
    impulse emissions, AOPA expressed concern that such proposals to
    expand the definition of UWB would open the door for additional
    types of devices.[^65] These additional devices could have different
    interference characteristics. Similarly, TDC did not believe that
    all devices above a certain minimum fractional bandwidth or upper
    bandwidth limit should be characterized as UWB, stating that most of
    the benefits of UWB come from having very few cycles within the
    pulse envelopes, not the duration of the pulse envelope itself.[^66]
    TDC also raised concerns that minimal information exists regarding
    the interference potential and applicable measurement procedures for
    stepped and swept frequency systems.[^67] Endress Hauser and USGPSIC
    also expressed concerns about permitting the operations of linear
    sweep systems and chirped systems respectively. [^68] On the other
    hand, ARRL agreed with Delphi that all modulation types should be
    permitted provided proper peak, average and power spectral density
    limits are met.[^69] CSSIP[^70], Krohne[^71], Siemens[^72] and
    Valeo[^73] specifically requested that stepped frequency or swept
    frequency systems be permitted under the UWB definition. Krohne
    argued that there is sufficient information on measurement
    procedures and emission limits for these devices.

29. Bosch stated that basing the definition on the use of a narrow pulse
    width to achieve a wide emission bandwidth could impede the
    development of novel pulse or modulation schemes, including
    high-speed data systems.[^74] XSI stated that we should include
    extremely high-speed data systems that comply only because of the
    high-speed data rate and not because of narrow pulse width.[^75] XSI
    stated that the threat of harmful interference depends primarily on
    the average and peak emissions and the location of significant
    spectral lines and is affected little, if at all, by the nature of
    the modulating signal. AOPA objected indicating that other
    modulation techniques, such as chirping, are likely to have
    different interference potential characteristics.[^76]

30. [Discussion]{.underline}. We are adopting our proposal to use the
    --10 dB emission points to determine the bandwidth and the center
    frequency of the UWB emission. As pointed out by Bosch and others,
    the --20 dB emission points could be so near the noise floor that
    making accurate measurements would be difficult or impractical.
    Similarly, it would be impractical to specify the --23 dB points
    recommended by ARRL. In addition, we agree that the minimum required
    fractional bandwidth should be reduced given that the use of the
    --10 dB bandwidth measurement points will result in a smaller
    measured bandwidth.[^77] Accordingly, we are reducing the --10 dB
    fractional bandwidth from 0.25 to 0.20. For this same reason, we
    also are reducing the minimum bandwidth limit from the 1.5 gigahertz
    proposed in the *Notice* to a limit of 500 megahertz for UWB
    devices.[^78] A minimum bandwidth limit of 500 megahertz should
    accommodate most of the proponents in this proceeding. While some
    parties have suggested that we could eliminate all restrictions on
    fractional bandwidth and minimum bandwidth, we disagree. In the
    absence of a minimal bandwidth requirement, many devices could be
    designed to operate in restricted bands even though they have no
    need to do so. For example, devices such as radio control toys
    typically employ bandwidths of 25 kHz or less and there are ample
    provisions to operate such devices outside of the restricted bands.

31. We also do not believe that there is any justification for reducing
    the minimum bandwidth to 200 MHz, as sought by MSSI. One of the
    major regulations being addressed in this proceeding is the
    operation of Part 15 devices in the restricted bands described in 47
    C.F.R. § 15.205. We are amending the rules in this Report and Order
    to permit UWB devices to emit in certain restricted bands because
    the bandwidths employed by those systems are so wide that they have
    difficulty finding spectrum to operate without transmitting in one
    or more of the restricted bands. We do not find a similar difficulty
    finding 200 MHz of contiguous spectrum outside of the restricted
    bands. For example, unlicensed Part 15 operation at, or higher than,
    the emission levels being permitted for UWB devices currently is
    permitted in the frequency bands 1722.2-2200 MHz, 2900-3260 MHz,
    3359-3600 MHz, 5150-5350 MHz, 5460-7250 MHz, etc. Further, Part 15
    devices operating in these bands could be employed for any purpose
    without having to comply with the additional standards that are
    being adopted for UWB devices. At this time, we do not wish to open
    the restricted bands for operation by any Part 15 device that can
    operate satisfactorily between the restricted bands. Accordingly, we
    are limiting the minimum bandwidth limit to 500 MHz. Once additional
    experience has been gained with UWB operation, we may revisit these
    values.

32. We agree with Bosch and XSI that transmission systems should not be
    precluded from the UWB definition simply because the bandwidth of
    the emission is due to a high speed data rate instead of the width
    of the pulse or impulse. We also agree with ARRL and Delphi that
    various modulation types should be permitted as long as the products
    comply with all of the technical standards that are being adopted in
    this proceeding. Thus, as long as the transmission system complies
    with the fractional bandwidth or minimum bandwidth requirements at
    all times during its transmission, we agree that it should be
    permitted to operate under the UWB regulations. We recognize that
    this may preclude certain types of modulations, such as swept
    frequency (*e.g.*, FMCW), stepped frequency or frequency hopping
    systems. The current measurement procedures require that
    measurements of swept frequency devices be made with the frequency
    sweep stopped.[^79] The sweep is stopped because no measurement
    procedures have been proposed or established for swept frequency
    devices nor has the interference aspects of swept frequency devices
    been evaluated based on the different measurement results that would
    be obtained from measurements taken with the sweep active.
    Similarly, measurements on a stepped frequency or frequency hopping
    modulated system are performed with the stepping sequence or
    frequency hop stopped. With the sweep, step function or hopping
    stopped, it is unlikely that swept frequency (linear FM or FMCW) or
    stepped frequency modulated emissions would comply with the
    fractional bandwidth or minimum bandwidth requirements. It also is
    unlikely that frequency hopping systems would comply unless an
    extremely wide bandwidth hopping channel is employed.[^80]

## Frequency Bands and Operational Requirements for UWB Devices

33. [Proposal]{.underline}. In the *Notice*, the Commission indicated
    that it considered a number of factors in addressing which frequency
    bands should be made available for UWB devices. First is the need to
    protect from interference the vitally important and critical safety
    systems operating in the restricted frequency bands, including GPS
    operations. Second, there are a broad variety of potential
    applications for UWB technology, each of which has unique spectrum
    attributes and requirements. Third, various regions of the spectrum
    have different propagation characteristics. To realize the full
    benefits of this technology, the Commission indicated that it should
    establish as few restrictions as possible on UWB operating
    frequencies, except as necessary to protect existing services
    against interference.

34. The Commission noted that it had a number of concerns about
    generally permitting the operation of UWB devices in the region of
    the spectrum below approximately 2 GHz. This is perhaps the most
    heavily occupied region of the spectrum and is used for public
    safety, aeronautical and maritime navigation and communications, AM,
    FM and TV broadcasting, private and commercial mobile
    communications, medical telemetry, amateur communications, and GPS
    operations. Further, 41 of the 64 restricted frequency bands are at
    or below 2 GHz, not counting the TV broadcast bands. Of particular
    concern is the impact of any potential interference to the GPS band
    at 1559-1610 MHz. The Commission also expressed concern about
    interference to any additional frequencies allocated to GPS, *e.g.*,
    the planned L5 frequency in the 960-1215 MHz band. GPS will be
    increasingly relied upon for air navigation and safety, and is a
    cornerstone for improving the efficiency of the air traffic system.
    GPS also may be used by commercial mobile radio E-911 services to
    enable police and fire departments to quickly locate individuals in
    times of emergency. Moreover, businesses and consumers are now
    employing GPS for various applications, such as for navigation by
    automobiles, boats and other vehicles, surveying, hiking, and
    geologic measurements. Therefore, any harmful interference to GPS
    could have a serious detrimental impact on public safety, businesses
    and consumers. In addition, propagation losses are not as great
    below 2 GHz, and services in this region of the spectrum tend to
    employ omnidirectional antennas that do not discriminate against
    undesired signals. These factors tend to increase the risks of
    interference below 2 GHz.

35. In light of these factors, the Commission expressed concern about
    the operation of UWB devices, except for GPRs and possibly
    through-wall imaging devices, in the region of the spectrum below
    approximately 2 GHz. Comments were invited on whether UWB devices
    should be restricted from operating on frequencies below 2 GHz, and
    the impact such a restriction would have on the potential
    applications for UWB technology. Comments also were requested as to
    the precise frequency below which the operation of UWB devices may
    need to be restricted.[^81] For example, should operation be
    restricted below the GPS band at 1610 MHz, or below the restricted
    band at 1718.8 - 1722.2 MHz, or below the Personal Communication
    Service band at 1850 - 1990 MHz, or below some other frequency?

36. Notwithstanding the above concerns, the Commission noted that GPRs
    must operate at frequencies in the region below 2 GHz in order to
    obtain the penetration depth and resolution necessary to detect and
    obtain the images of buried objects. It noted, however, that the
    risk of interference from GPRs is low because the majority of their
    energy is directed into the ground. In addition, GPRs are expected
    to have a low proliferation and usually operate at infrequent
    intervals. Accordingly, the Commission proposed to allow GPRs to
    operate in any part of the spectrum. It proposed to define a GPR as
    an UWB device that is designed to operate only when in contact with,
    or in close proximity to (*i.e.*, within 1 meter), the ground for
    the purpose of detecting or obtaining the images of buried objects.
    It also proposed to require GPRs to include a switch or other
    mechanism to ensure that operation occurs only when the device is
    activated by an operator and is aimed directly down at the ground.

37. In the *Notice*, the Commission also indicated it is unclear whether
    the same considerations apply to other imaging devices used to
    detect or obtain the images of objects inside or behind walls or
    other surfaces. [^82] For example, in contrast to GPRs where signals
    are aimed at the ground, wall imaging and through-wall imaging
    devices could aim their energy in any direction. While the wall
    structure could attenuate these signals, the amount of attenuation
    can vary widely depending on the composition of the wall. The
    Commission noted, however, that it expected that such systems would
    have a low proliferation and would be operated infrequently. Thus,
    the Commission indicated that one option would be to treat all
    imaging devices the same way as GPRs. Alternatively, it indicated
    that it could restrict the operation of such devices to bands below
    a certain frequency or apply other restrictions to such devices.
    Comments were invited on: 1) these and other approaches for GPRs and
    imaging systems; 2) the provisions needed to ensure that these
    systems operate only when they are in contact with a wall; 3)
    whether the operation of through-wall imaging systems should be
    limited to parties eligible for licensing under the Public Safety
    Pool of frequencies in Part 90 of our rules, as required under the
    earlier waiver to Time Domain;[^83] and, 4) whether through-wall
    imaging systems should be required to incorporate automatic power
    control features that would reduce power levels to the minimum
    necessary to function based on the composition of the surface and
    its absorption of RF energy.

38. The Commission observed that it appears that most other applications
    of UWB technology could satisfactorily operate in a variety of
    regions of the spectrum. It further observed that UWB devices
    generally can operate compatibly with other radio services in the
    region of the spectrum above approximately 2 GHz without causing
    harmful interference to other radio services for two main
    reasons: 1) the UWB signals will quickly fall off to levels below
    the background noise because of the high propagation losses at 2 GHz
    and above; and 2) most radio services operating above 2 GHz use
    directional antennas that generally discriminate against reception
    of undesired signals. Accordingly, the Commission proposed to allow
    the operation of all types of UWB devices on frequencies above
    approximately 2 GHz, subject to the general limits on technical
    operation set forth elsewhere herein.

39. The Commission also requested comment on alternative approaches to
    restricting or prohibiting operations in the frequency bands below 2
    GHz. It noted that certain UWB applications might be feasible using
    extremely low signal levels. Comments were invited as to whether and
    at what levels, if any, operation should be permitted in the
    restricted bands below 2 GHz for devices that can operate using
    extremely low signal levels. While UWB technology generally cannot
    completely notch out certain frequency bands, comments were
    requested as to the viability of establishing a general emission
    limit for UWB devices below 2 GHz, and whether a more stringent
    limit, or notch, should be applied to the GPS band.

40. [Discussion]{.underline}. As discussed above, we are establishing
    different technical standards and operating restrictions for three
    categories of UWB devices based on their potential to cause
    interference. These three categories of UWB devices are 1) imaging
    systems including ground penetrating radar (GPR), wall,
    through-wall, surveillance, and medical imaging devices, 2)
    vehicular radar systems, and 3) communications and measurement
    systems. The discussion below sets forth the frequency and
    operational limitations that will apply to each of these device
    categories.

### Imaging Systems

41. Most of the commenting parties support allowing GPRs to operate in
    all frequency bands provided that certain conditions are met, such
    as requiring a switch to avoid unattended operation and ensuring
    that they are operated in close proximity to the ground. The
    commenting parties expressed differing views, however, with regard
    to other types of imaging systems. Some parties state that imaging
    systems need to operate across a broad range of frequencies in order
    to accommodate the wide range of applications and to allow imaging
    sensors to effectively penetrate a wide variety of materials. Other
    commenting parties are concerned that imaging systems may be more
    likely to cause interference to licensed services. These parties
    suggest limiting imaging systems to certain frequency bands and
    applying other restrictions on their use.

42. The ARRL, for example, states that it does not object to permitting
    GPRs to operate anywhere in the spectrum, subject to appropriate
    emission limits.[^84] It states that these devices are expected to
    be deployed in limited numbers and will direct their signals towards
    the ground. ARINC, ARRL, and ATA state that limiting UWB operations
    in restricted bands to GPRs that direct most of their energy into
    the ground may serve to minimize the impact of any harmful
    interference to GPS and other safety-of-life operations.[^85] Nortel
    states that GPRs are unlikely to cause significant interference to
    communications systems as the energy is directed into the ground and
    extraneous radiation is low.[^86] Nortel also agreed that a switch
    or other mechanism should be required to ensure operation only when
    activated by the operator and aimed at the ground. The USGPSIC also
    requested that GPRs be equipped with a switch to shut off the
    transmitter if it was not in contact with the ground.[^87] Sirius
    requested that GPRs operate exclusively below 2 GHz so as to avoid
    the DARS frequency band.[^88] Aether Wire indicated that the use of
    frequencies below 1 GHz is optimal for transmitting through walls,
    pavement, debris, earth, water, snow, etc.[^89] The Colorado School
    of Mines stated that, depending on soil conditions, GPR operation
    may be in the 100 MHz to 2 GHz region.[^90] On the other hand,
    USGPSIC stated that there is no valid reason why GPRs can not
    operate above 3 GHz.[^91]

43. AOPA questioned permitting GPRs to operate one meter from the
    ground. It argued that one meter represents a half-wavelength of
    about 150 MHz and indicates that GPRs can emit significant energy
    above this frequency and states that there is the possibility of
    substantial "coupling leakage" and reflection from the ground's
    surface.[^92] Alloy requested that GPRs be limited to a maximum
    one-foot separation from the ground, requiring the GPR to be as
    close to the ground as possible, since metal objects could reflect
    the RF signal.[^93] Peter Annan objected to requiring an automatic
    switch permitting operation only when the GPR is pointed at the
    ground, indicating that GPRs may be operated on steep slopes, into
    the sides of cliffs, or retaining walls, in underground pipes, and
    at other locations.[^94] Mr. Annan requested that GPRs be permitted
    to have an override switch, *e.g.*, a press to operate switch. He
    also requested that certification of GPRs not be required since the
    interference potential from GPRs is low.

44. With regard to imaging systems, Bosch argued that the emission
    limits for UWB should ensure that there is no interference to other
    services and that the use of wall contact switches as well as
    automatic power control are unnecessary.[^95] It pointed out that
    automatic power control is impracticable because it is not possible
    to predict the exact attenuation of every wall. TDC indicated that
    the best center frequency for through-wall sensors is 2 GHz due to
    the ability at this frequency to penetrate construction
    materials.[^96] TDC also expressed concern regarding the requirement
    for a wall contact switch, noting that there may not always be flat
    surfaces, *e.g.*, walls in a collapsed building.[^97] TDC also noted
    that police would prefer the ability to operate these devices
    remotely for the safety of their personnel. Zircon stated that its
    UWB radar operates between 200 MHz and 4 GHz, adding that the use of
    frequencies below 2 GHz is necessary to obtain through-wall imaging
    definition of narrow objects.[^98] While Zircon stated that it does
    not oppose a contact switch in principle it needs an override
    mechanism to permit a few seconds of calibration or to pass closely
    over uneven surfaces that might not always permit direct contact.
    [^99] XM stated that it is unlikely that imaging systems would pose
    a significant threat of interference to DARS. [^100]

45. Nortel noted that caution is needed with systems that are designed
    to penetrate walls or floors as emissions from these systems could
    interfere with in-building communications systems.[^101] Alloy
    expressed concern that through-wall-imaging systems could be aimed
    at CMRS antennas and wants these devices activated only if they are
    in direct contact with a wall surface and equipped with automatic
    power control. [^102] USGPSIC requested that the use of through-wall
    imaging systems be restricted to public safety applications or to
    the protection of life or property in order to avoid proliferation
    of the equipment.[^103] It also stated that these devices must be
    required to meet all of the conditions established by NTIA for UWB
    devices operating under a waiver from the Commission.[^104] These
    conditions mandate the keeping of records of all parties to whom the
    equipment is marketed, coordination by the equipment users of
    detailed areas of operation with the Frequency Assignment
    Subcommittee of the Interdepartmental Radio Advisory Committee under
    NTIA, and other requirements. TDC stated that the operation of
    through-wall systems should not be limited to law enforcement and
    public safety even though the more sophisticated versions were
    likely to be used by these groups.[^105] TDC noted that similar
    technology could provide high security sensors for commercial and
    residential applications. Zircon also requested that the Commission
    not restrict the operation of imaging systems to safety-of-life or
    property as its customers would be contractors and remodelers who
    would not be permitted to use the equipment under these conditions.
    [^106]

46. [Discussion]{.underline}. Based on the record and recommendations
    from NTIA,[^107] we find that imaging systems can be permitted to
    operate in most regions of the frequency spectrum without causing
    harmful interference provided appropriate technical standards and
    operational restrictions are applied to their use. With regard to
    GPRs, we find that these devices must operate over a range of
    frequencies, including in the region below 2 GHz, in order to obtain
    the penetration depth and resolution necessary to detect and obtain
    the images of buried objects. We also agree with the majority of the
    commenting parties that the risk of interference from GPRs is low
    since the energy from these devices is directed into the ground,
    where most of the energy is absorbed, and emissions in other
    directions can be shielded without affecting the operating
    characteristics of the GPR. Further, we expect that GPRs will have a
    low proliferation and usually operate at infrequent intervals. In
    addition, the low heights at which GPRs are operated and the low
    duty cycles employed by GPRs[^108] ensure that there is a minimal
    risk of interference from these devices.

47. GPRs must operate only when directed at the ground and in contact
    with, or in close proximity (*e.g.*, 1 meter) to, the ground for the
    purpose of detecting or obtaining the images of buried objects, and
    we will require that they be tested at their operational height.
    This will ensure that any emissions due to leakage or to reflections
    can be detected. We do not agree with Alloy that reflections that
    may occur from infrequent metal objects that may appear under the
    GPR would increase the potential for interference. Such objects
    would likely be quite small and would reflect the signal low to the
    ground where it would quickly be attenuated with distance and by
    intervening objects. To ensure that operation occurs only when the
    GPR is directed towards the ground, we are requiring that the device
    be equipped with a switch accessible by the operator. The switch
    shall be manually operated and shall cause the transmitter to cease
    operation within 10 seconds of being released by the operator. It is
    permissible for the switch to be operated by remote control provided
    the GPR system ceases transmission within 10 seconds of the remote
    switch being released by the operator.

48. We reject the request to exempt GPRs from the Commission's equipment
    certification procedure. This procedure was established as a method
    to ensure that RF products comply with the appropriate standards
    before they are imported, marketed or used. We do not have
    sufficient experience with this equipment at this time to ensure
    that such devices do, or will continue to, meet our technical
    standards.

49. We recognize that wall, through-wall, and medical imaging systems
    generally do not direct their energy into the ground and therefore
    present a somewhat greater risk of interference. However, it is
    desirable for these imaging systems to operate across a broad range
    of frequencies in order to accommodate different applications and to
    effectively penetrate a wide variety of materials. We believe that
    sufficient protection from harmful interference can be achieved by a
    combination of technical requirements and operational restrictions
    on imaging systems. We are therefore designating three classes of
    imaging systems, each subject to different technical standards and
    operational restrictions.

50. *Low-frequency imaging systems.* The first class of imaging systems
    includes all imaging systems operating with a --10 dB bandwidth that
    is wholly contained below 960 MHz. These systems will be permitted
    to operate at the emission limits contained in §15.209. They are
    also required to meet the following out-of-band emission limits:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -65.3                         |
|                                      |                               |
| 1610-1990                            | -53.3                         |
|                                      |                               |
| Above 1990                           | -51.3                         |
+--------------------------------------+-------------------------------+

51. We are restricting the use of this class of equipment to parties
    eligible for licensing under the provisions of Part 90 of the FCC's
    rules. We also are requiring that the operators of imaging systems
    in this class complete a coordination procedure with the Government.
    These devices radiate energy in arbitrary directions and operate in
    the vicinity of materials that may provide, in some instances, very
    little energy absorption. While the record showed that the GPS and
    other authorized services are generally robust against interference
    from devices, such as GPRs, with low PRFs, the record did not
    directly support extending this conclusion to all systems operating
    in this low frequency range. Other technical and operational
    requirements for low-frequency imaging systems are contained in new
    Section 15.509 in Appendix D. The specifics of the coordination
    process are detailed in the Section 15.525 contained in Appendix D
    of this Order.

52. *High-frequency Imaging Systems*. The second class of imaging
    systems are those that operate with a -10 dB bandwidth between 3.10
    GHz and 10.6 GHz.[^109] Emission levels from this category of device
    must meet an emissions mask for the appropriate frequency bands. The
    emission limits are as follows:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| Below 960                            | 15.209 limits                 |
|                                      |                               |
| 960-1610                             | -65.3                         |
|                                      |                               |
| 1610-1990                            | -53.3                         |
|                                      |                               |
| 1990-3100                            | -51.3                         |
|                                      |                               |
| 3100-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -51.3                         |
+--------------------------------------+-------------------------------+

53. The high-frequency imaging system class includes GPRs, wall, and
    medical imaging devices. As with the low-frequency imaging systems,
    Government coordination is required for the operation of these
    devices, following the procedures described in Section 15.525 in
    Appendix D. Specific technical and operational requirements for
    high-frequency UWB devices are contained in Section 15.513 in
    Appendix D.

54. *Mid-frequency Imaging Systems.* This class of imaging systems
    consists solely of through-wall and surveillance systems. These
    devices operate with a -- 10 dB bandwidth between 1990 MHz and
    10,600 MHz. Higher unwanted emission limits than those applied to
    the other classes of imaging devices are permitted. The emission
    limits are as follows:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| Below 960                            | 15.209 limits                 |
|                                      |                               |
| 960-1610                             | -53.3                         |
|                                      |                               |
| 1610-1990                            | -51.3                         |
|                                      |                               |
| 1990-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -51.3                         |
+--------------------------------------+-------------------------------+

55. Parties seeking to operate this mid-frequency class of devices must
    be eligible for licensing under the provisions of Part 90 of the
    FCC's rules. The systems in this class are considered to pose a
    greater risk for harmful interference because of the lower frequency
    of the fundamental emission and the higher power levels reflected in
    the less conservative emissions mask; however, consideration of the
    substantial benefits to the public safety and the limited user base
    tend to mitigate the interference concerns. This class of UWB
    imaging systems requires Government coordination. This coordination
    will provide for operation in a pre-approved geographic area, with
    perhaps, certain restrictions on specific locations identified by
    the Government. This should provide maximum flexibility to safety
    services while still assuring that the risk for harmful interference
    is appropriately minimized. Surveillance systems will operate only
    at fixed locations such that harmful interference can be avoided
    through coordination. In addition, if harmful interference were to
    occur the source can be readily identified and corrected. See
    Section 15.511 for the specific technical provisions for
    mid-frequency UWB devices.

56. The limits specified above for imaging systems reflect an abundance
    of caution to protect the GPS and PCS services, and the passive
    bands employed in radio astronomy and by satellite sensors. We
    believe that by restricting the parties and requiring coordination
    before the device is used that the proliferation of these systems
    will be limited and the use controlled to a narrow range of
    applications that should not present interference concerns. We
    believe that the requirement for coordination will have a minimal
    impact on UWB equipment users as NTIA must complete its coordination
    efforts within 15 business days of its receipt of the request for
    routine UWB operations. Special temporary operations may be handled
    with a much faster turn-around time when circumstances warrant.
    Further, the operation of UWB systems in emergency situations can be
    commenced immediately pursuant to the notification procedures
    specified in 47 C.F.R. Section 2.405(a)-(e). We believe that these
    technical requirements and operational restrictions will ensure that
    imaging systems do not cause harmful interference.

57. We agree with Bosch, TDC and Zircon that there is no need for a wall
    contact switch or automatic power control for imaging devices.
    However, as with GPRs, we are requiring that wall imaging systems be
    equipped with a manually operated switch, the release of which
    causes the transmitter to cease operation within no more than 10
    seconds. Recognizing that police and other public safety officials
    may employ these systems in hostile situations, we will permit this
    switch to operate by remote control. We do not agree with the
    request from USGPSIC to require detailed record keeping such as that
    which was required by NTIA for the UWB manufacturers that obtained
    waivers from the Commission.

### Other UWB Devices

58. [Comments]{.underline}. The comments from parties associated with an
    authorized radio service generally objected to the operation of UWB
    devices in "their" spectrum regardless of the emission level. For
    example, objections to the operation of UWB were filed by ARRL
    regarding the amateur bands, Cisco regarding MMDS operations,
    Motorola and Sprint PCS regarding operation in the PCS band, Sprint
    on several services including MDS, ITFS, PCS and LMDS, XM and Sirius
    regarding operation in the SDARS band, Nortel regarding PCS,
    UNII[^110] and fixed wireless access systems, AT&T on UNII
    operation, MCHI regarding MSS, and several others.[^111] Based on
    these objections, several different frequencies were suggested in
    the comments below which UWB devices should not be permitted to
    operate. For example, Nortel requested that UWB systems not be
    permitted to operate below 5.9 GHz.[^112] Sirius requested that UWB
    systems not be permitted to operate below 2.9 GHz, with a possible
    exception for GPRs and wall imaging systems.[^113] Lockheed Martin
    requested that UWB systems be excluded from operating below 2.9 GHz
    due to the sensitive nature of many operations conducted in
    restricted bands used for military and public safety applications
    and other sensitive uses.[^114] MCHI requested that UWB devices,
    other than certain ground radars, not be permitted below 3
    GHz.[^115] Rockwell requested that UWB devices be prohibited from
    operating below 5.15 GHz, except for GPRs and wall imaging systems,
    in order to accommodate radio altimeters at 4.2-4.4 GHz and MLS
    receivers at 5.03-5.09 GHz.[^116] ARRL requested that non-GPRs be
    located above 2.5 GHz.[^117] XM requested that UWB devices be
    prohibited from operating below 3 GHz in order to provide protection
    to DARS.[^118] Alloy wants all UWB devices, except GPRs, to operate
    above 2.7 GHz.[^119] ARINC & ATA want UWB operation permitted only
    above 5.5 GHz and then only outside of the existing restricted
    bands.[^120] ATA and several other industry representatives stated
    later that UWB operation must be above 6 GHz.[^121] American Trans
    Air stated that UWB devices should not be permitted to operate in
    any of the safety-of-life bands.[^122] M/A-Com noted that the bands
    within which Motorola, Sprint, Nortel, Cisco and others requested
    that UWB systems be prohibited from operating are not restricted
    bands and may already be used by Part 15 devices.[^123]

59. TDC stated that the best center frequencies are as follows: 2 GHz
    for wireless local area networks with precision tracking, precision
    tracking systems, buried victim rescue radar, and security fences; 4
    GHz for RF identification tags, medical telemetry tags, short range
    high resolution radar, and short range data links; and 8 GHz for
    automotive pre-crash sensors, airbag deployment sensors,
    construction inspection equipment, and high resolution radars.[^124]
    Fantasma indicated that it could operate above 2 GHz.[^125] MSSI
    stated that UWB should initially be allowed above 3.1 GHz.[^126] XSI
    indicated that its UWB equipment could operate with a center
    frequency above 3.1 GHz. Valeo Electronics stated that it expects
    automotive radars to be designed at frequencies above 4 GHz as
    antenna aperture is proportional to wavelength and space is
    limited.[^127] Daimler Chrysler wants to operate its vehicular radar
    systems with a center frequency at 24.125 GHz.[^128]

60. XM noted that radio receivers for several services operating above 2
    GHz do not rely on directional antennas, but added that most radio
    receivers operating above 3 GHz do rely on directional
    antennas.[^129] MSSI noted that fifty percent of the U.S. Government
    radio operations and forty percent of non-government radio
    operations occur below 3.1 GHz and requested that UWB operation be
    permitted above this frequency.[^130] NTIA, in its analysis of
    potential interference from UWB systems to non-GPS systems,
    concluded that the operation of UWB devices is feasible in portions
    of the spectrum between about 3.1 and 5.65 GHz at heights of about 2
    meters with some operating constraints but that operation below 3.1
    GHz would be quite challenging.[^131] This statement by NTIA was
    echoed in several of the comments filed in response to the NTIA
    analysis.

61. Aether Wire stated that rather than confining operation to above 2
    GHz we should set reasonable limits in the GPS bands consistent with
    noise sources that already exist and let manufacturers choose how to
    meet these limits.[^132] It added that an outright ban to UWB
    operation below 2 GHz would be dictating a political solution to an
    engineering problem and would favor some UWB systems over others.
    The USGPSIC requested that we require UWB transmitters to be
    equipped with filters to protect the GPS band, stating that it is
    impossible to prevent significant changes in the frequency and
    bandwidth of a UWB emitter due to accidental or intentional changes
    to the UWB antenna.[^133] It attached a new element to a UWB antenna
    and removed a radiating element from another UWB device to
    demonstrate that the UWB transmitter could be made to change
    frequency.

62. [Discussion]{.underline}. We recognize that the UWB proponents wish
    to build various types of UWB devices oriented towards the general
    consumer marketplace. However, we also are concerned about harmful
    interference absent sufficient constraints. As noted earlier, we
    believe that a cautious approach is needed during the initial stages
    of UWB development. For that reason, we are adopting very
    conservative emission limits for consumer UWB applications for three
    categories of devices: vehicular radar systems; indoor; and
    hand-held, short range, peer-to-peer systems.

63. *Vehicular Radar Systems.* We are limiting vehicular radar systems
    to operation with a center frequency greater than 24.075 GHz.[^134]
    Further, we are requiring that the frequency at which the highest
    radiated emission level occurs also must be greater than 24.075 GHz
    and that the -10 dB bandwidth be contained between 22-29 GHz. This
    is high enough in frequency to ensure antenna directionality along
    with a high level of signal attenuation with increasing distance and
    intervening objects. It also is high enough in frequency to permit
    the use of an antenna small enough to be mounted on an automobile.
    Further, by requiring the center frequency to be this high the
    emissions appearing within the frequency bands below 10.6 GHz that
    were investigated by NTIA and others should be similar to spurious
    emissions from conventional Part 15 transmitters or to emissions
    from digital devices and of no greater interference threat.
    Consistent with our cautious approach, we are requiring that
    emissions below 960 MHz be at or below the § 15.209 limits and that
    emissions appearing above 960 MHz conform to the following emissions
    mask:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -75.3                         |
|                                      |                               |
| 1610-22,000                          | -61.3                         |
|                                      |                               |
| 22,000-29,000                        | -41.3                         |
|                                      |                               |
| 29,000-31,000                        | -51.3                         |
|                                      |                               |
| Above 31,000                         | -61.3                         |
+--------------------------------------+-------------------------------+

64. While we believe that the emission mask that we are adopting will
    prevent harmful interference to radio systems operating in these
    bands, out of an abundance of caution we also are requiring that
    vehicular radar systems employ directional antennas or other methods
    that will attenuate the emissions 38 degrees or higher above the
    horizontal plane in the 23.6-24.0 GHz band by at least 25 dB below
    the Part 15 general emission limits.[^135] As requested by NTIA, and
    as discussed in paragraphs 195-197 of this Order, this level of
    attenuation will be increased in steps such that emissions 30
    degrees or higher above the horizontal plane in the 23.6-24.0 GHz
    band must be attenuated 35 dB below the Part 15 general emission
    limits by January 1, 2014. Since we expect vehicular radar to become
    as essential to passenger safety as air bags for motor vehicles, the
    greater number of vehicles using these systems could pose an
    increased risk to terrestrial passive sensing by satellites.
    Therefore, we are adopting the additional emission requirements. See
    Section 15.515 in Appendix D for the specific provisions for
    vehicular radars.

65. *Indoor UWB Systems*. Devices operating under this category must
    demonstrate that the system units will fail to operate if they are
    removed from the indoor environment. One acceptable procedure may be
    to show that the transmitting unit requires AC power to function.
    Based on the concerns expressed by NTIA and others regarding
    operation below 3.1 GHz, we are requiring that --10 dB bandwidth of
    indoor UWB systems must lie between 3.1 GHz and 10.6 GHz. We are
    adopting a very conservative out of band emission mask to address
    the concerns of companies which make or market indoor electronic
    equipment. In the frequency band below 960 MHz these devices are
    permitted to emit at or below the § 15.209 limits, and emissions
    appearing above 960 MHz will conform to the following emissions
    mask:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -75.3                         |
|                                      |                               |
| 1610-1990                            | -53.3                         |
|                                      |                               |
| 1990-3100                            | -51.3                         |
|                                      |                               |
| 3100-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -51.3                         |
+--------------------------------------+-------------------------------+

66. An additional requirement for indoor UWB devices is that they may
    transmit only when operating with a receiver. A device connected to
    AC power is not constrained to reduce or conserve power by ceasing
    transmission, so this restriction will eliminate unnecessary
    emissions. In addition, if a device is designed to operate pointed
    downwards in an enclosed structure such as a metal or underground
    storage tank, it may operate at the levels allowed in this section.
    See Section 15.517 in Appendix D. We are convinced that the
    conservative emission limits and restrictions we are adopting for
    UWB indoor devices will prevent harmful interference. Not only will
    indoor operation provide additional attenuation due to surrounding
    structure, the signals from the UWB transmitters would no longer be
    directly in the beam of high gain antennas, such as MMDS antennas
    mounted on rooftops or aeronautical antennas at airports. Indeed,
    the majority of interference problems reported by NTIA in its
    analyses of interference to non-GPS systems concerned outdoor
    systems and especially outdoor systems operating at an elevation of
    30 meters.[^136] These provisions will ensure that even nearby RF
    devices, including devices that also may operate indoors, will not
    receive interference.

67. *Hand Held UWB Systems.* Section 15.519 of Appendix D contains the
    provisions for miscellaneous UWB devices that are primarily hand
    held and intended to operate in a peer-to-peer mode without
    restriction on location. Operation among peer-to-peer devices is
    expected to be a strong driver for the development of UWB
    technology. We recognize that the greatest concerns of interference
    in the record were centered about the potential for uncontrolled
    proliferation of these devices. Therefore, out of an abundance of
    caution the limits that we are adopting here are the most stringent
    for UWB operation. We are requiring that these devices operate with
    a --10 dB bandwidth between 3.1 GHz and 10.6 GHz. We are adopting an
    extremely conservative out of band emission mask to address the
    concerns of the great majority of commenters. In the frequency band
    below 960 MHz these devices are permitted to emit at or below the §
    15.209 limits, and emissions appearing above 960 MHz must conform to
    the following emissions mask:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -75.3                         |
|                                      |                               |
| 1610-1900                            | -63.3                         |
|                                      |                               |
| 1900-3100                            | -61.3                         |
|                                      |                               |
| 3100-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -61.3                         |
+--------------------------------------+-------------------------------+

68. Further, we also require that these devices transmit only when in
    communication with an associated receiver. The transmitter will
    cease transmission within 10 seconds unless it receives an
    appropriate acknowledgment from the associated receiver, and the
    acknowledgment will continue during the transmission at 10-second
    intervals. Devices operating under these emission levels should
    result in battery operated, hand held units with a viable range of
    about 10 to 15 meters. The out of band emissions are reduced by 10
    dB below the requirement for indoor devices except in the GPS bands
    where the limit is already approaching the practical bound on our
    ability to verify compliance by measurement. We are adopting these
    requirements out of an abundance of caution and we believe that
    these emission levels and restrictions address the majority of the
    concerns and analyses in the record. See Section 15.519 in Appendix
    D for the specific technical requirements for these devices.

69. We find no validity to the statement from USGPSIC that an operator
    would modify the UWB antenna to change operating frequency or
    bandwidth or that equipment that has been damaged in such a fashion
    would continue to be operated. We are aware that the emitted
    frequency of an impulse system is a function not only of the pulse
    width and shape but also of the resonant frequency of the antenna.
    Any major modification to the antenna could result in the UWB
    transmitter operating at a different frequency. However, such a
    significant change would also render the equipment unusable as the
    associated receiver would now be on the wrong frequency. Significant
    phase errors likely would be introduced as well. Because of this, we
    expect that UWB manufacturers would design equipment with some
    serious thought to protecting the antenna from damage. Accordingly,
    we find no basis to require UWB transmitters to be equipped with
    filters.

## Analyses of Interference Studies 

70. [Proposal]{.underline}. In the *Notice*, the Commission noted that
    NTIA and others were planning experimental programs to study the
    interference potential of UWB devices. The Commission encouraged
    these testing programs, believing that the information they yielded
    would be important for developing emission limits for UWB devices.
    The establishment of emissions limits requires a firm understanding
    of the characteristics of UWB signals, their impact on victim
    receivers, and the minimum separation distance between UWB devices
    and victim receivers. Thus, the Commission requested parties
    performing interference tests to consider and provide information on
    receiver susceptibility to UWB signals along with the spatial
    geometries assumed for evaluating potential interference.

71. [Submissions]{.underline}. Several parties submitted analyses of
    potential interference to various radio services from UWB devices.
    NTIA[^137], NTIA on behalf on DOT[^138], and TDC^.^[^139] provided
    reports addressing potential interference to GPS receivers.[^140]
    NTIA presented two studies regarding the potential for UWB
    transmission systems to cause harmful interference to U. S.
    Government radio operations between 400 MHz and 6000 MHz. [^141] In
    addition, DOD provided a mathematical analyses of possible
    interference from UWB operation to its Space-Ground Link Subsystem
    (SGLS) at 2.2-2.3 GHz.[^142] The following additional reports were
    filed: ARRL calculated increases to receiver noise floors for
    receivers located at 420 MHz and 2500 MHz;[^143] Motorola,[^144]
    Sprint PCS, Telcordia Technologies and Time Domain
    Corporation,[^145] and Qualcomm[^146] performed analyses and testing
    of potential interference to PCS systems; Cisco presented an
    analysis of interference to MMDS systems;[^147] and XM calculated
    the impact on Satellite DARS systems.[^148] Comments were
    specifically requested on the NTIA, DOT, TDC, and Qualcomm
    reports.[^149] In the following section, we summarize each of these
    analyses and present our findings.

### NTIA, DOT and TDC Analyses of Potential Interference to GPS

72. NTIA, DOT, TDC, and Qualcomm performed measurements and analyses to
    determine the UWB emission levels necessary to prevent interference
    to GPS operation. Qualcomm conducted UWB interference test on a GPS
    receiver that is intended to provide location information for E-911
    services. The information below summarizes various measurement
    reports on UWB interactions with GPS receivers.

73. *Measurements*: Initially, NTIA tested two GPS receivers, a
    coarse/acquisition (C/A) code tracking receiver architecture that is
    representative of most GPS applications, and a semi-codeless
    receiver architecture used for applications that are less dynamic
    and require more precision such as surveying. In a follow-on
    measurement effort, NTIA also performed measurements on a GPS
    receiver employing a narrowly spaced correlator architecture and an
    aviation GPS receiver compliant with FAA Technical Standard
    Order-C129a (TSO-C129a) also employing the C/A code receiver
    architecture.[^150] The performance criteria used to define and
    assess interference to receiver operations were: (a) break-lock
    (BL), a condition that causes a loss of signal lock between the GPS
    receiver and the satellite, and (b) increase in reacquisition time
    (RQT), the amount of time it takes a receiver tracking a GPS signal
    to reacquire the signal after it has been momentarily removed. NTIA
    also developed a representative set of impulse waveform parameters
    to characterize the UWB emission environment. The parameters
    included four PRFs of 0.1, 1, 5, and 20 MHz; four modulation types
    consisting of constant PRF, On-Off keying, 2% relative reference
    dither, and 50% absolute dither; and two types of signal gating -
    100% and 20%; resulting in 32 permutations. These permutations
    identified the single source UWB signal structure. An additional set
    of 5 aggregate signal structures was developed to investigate how
    several UWB devices acting together would affect the GPS receiver
    performance.

74. NTIA performed testing to determine the interference thresholds of
    the GPS receiver. A GPS simulator was used to establish the GPS
    receiver operational state. In the test constellation, GPS signals
    from a four satellite constellation (five satellites were used for
    the TSO-C129a compliant receiver in order to meet receiver
    autonomous integrity monitoring requirements) based on ephemeris
    data taken from an actual GPS constellation present on December
    16, 1999. For the measurements performed on the C/A code,
    narrowly-spaced correlator, and TSO-C129a receivers the simulator
    power of the satellite being monitored was set to the minimum
    specification level of --130 dBm at the GPS receiver input.[^151]
    The simulator power of the satellite being monitored for the
    semi-codeless receiver was set to --133 dBm at the GPS receiver
    input. One commenter states that using the minimum guaranteed signal
    power represents an overly worst-case scenario.[^152] The commenter
    also provides a detailed discussion of the difficult propagation
    conditions that GPS receivers must operate in.[^153] Tracking and
    acquiring/reacquiring satellites in an open field with no
    obstructions is relatively straightforward. The challenge comes when
    there is a partial blockage that reduces the amount of signal energy
    that reaches the receiver. As pointed out by the commenter, the key
    factors that characterize the GPS signal propagation include
    multipath and blockage from buildings and foliage. These factors
    reduce the received GPS signal level in urban and suburban areas
    where GPS receivers are used in land-based applications. The
    received GPS signal levels from unobstructed satellites can be as
    much as 7 dB higher, than the guaranteed minimum signal level;
    however, it is the difficult propagation environment for land-based
    GPS receiver applications that justifies the use of the minimum
    signal level in the establishment of regulatory limits.

75. Conducted measurements were used to evaluate the interference levels
    on the GPS receivers, and radiated measurements, using an anechoic
    chamber to determine whether the GPS antennas altered the UWB
    radiated signals before they reached the GOS receiver. The results
    of the radiated measurements confirmed that the GPS antenna does not
    cause any effects to the portion of the UWB signal within the GPS
    operating band beyond that of amplifying the signal by the antenna
    gain in the direction of the UWB device. One commenter criticized
    the NTIA and DOT measurements programs for not including outdoor
    radiated measurements in assessing the impact of UWB devices on GPS
    receivers.[^154] We believe that conducted measurements that are
    repeatable in a controlled environment are more appropriate at this
    stage where we are trying to set conservative limits for a new
    technology. Since the ambient noise environment and the
    contributions from multi-path will change for each geographic
    location, outdoor, radiated measurements performed in a specific
    location are more difficult to interpret for establishing regulatory
    limits and that we have an inadequate record at this time for basing
    standards on such measurements.

76. The measurements performed by NTIA also included collecting
    amplitude probability distribution (APD) statistics, which, together
    with results from the interference measurements of the GPS
    receivers, were used to classify the UWB signal interference effects
    in the GPS receiver into 3 categories; pulse-like, CW-like, and
    noise-like. The pulse-like category was defined by received UWB
    pulses that were independent,[^155] and low duty cycle (low PRF),
    and could not cause a GPS break-lock condition within the available
    power of the UWB test generator. The CW-like category was defined by
    a received UWB environment composed of dominant spectral lines,
    which produced severe disruption in GPS receiver performance when
    one spectral line aligned with a C/A code line in the received GPS
    signal. The noise-like category was defined as UWB spectra without
    dominant lines and with repeatable measured values for GPS receiver
    reacquisition thresholds. The UWB signals and GPS noise measured
    signals were expressed in terms of a 20-MHz bandwidth (centered at
    1575.42 MHz), and power measurements were expressed as RMS power
    levels. The measurements produced values of the RMS power level for
    interference using BL and RQT thresholds for all of the 32 UWB
    signal variations and 5 aggregate UWB signal cases.

77. NTIA's classification of the UWB signals, as they existed in the GPS
    receivers tested, is similar to classifications for general
    interference to GPS made by the RTCA (pulsed, CW, and broadband
    noise) and the ITU-R (CW and broadband noise).[^156]. The ITU-R and
    the RTCA have both derived permissible interfering signal limits for
    each of these classes of GPS interference. For the case of in-band
    pulsed interference, the RTCA derived limit is a peak power of +20
    dBm for pulse widths less than 1 ms and pulse duty cycles less than
    10%. For the in-band CW interference case, both the RTCA and the
    ITU-R interference limits are defined as --120.5 dBm for GPS
    receivers operating in the tracking mode.[^157] For in-band
    broadband noise interference, both the RTCA and the ITU-R limits are
    -110.5 dBm/MHz for GPS receivers operating in the tracking
    mode.[^158] The NTIA measurement and analysis results are consistent
    with these values. These RTCA and ITU-R limits are based on a
    minimum available GPS C/A code signal level of --130 dBm with the
    GPS receiver antenna gain assumed to be -4.5 dBi.[^159] The RTCA and
    ITU-R interference limits are based on a Minimum Operational
    Performance Standard for GPS receivers used for Category I/II/III
    precision approaches.

78. NTIA demonstrated that independent UWB pulses of sufficient
    amplitude would saturate one or more elements in the GPS receiver
    during the pulse period. If the pulses are relatively short, and
    produce an impulse response at the output of the filter, and are of
    a relatively low duty cycle, they will not seriously degrade GPS
    performance. Further, the interference effect is independent of the
    pulse amplitude as long as the amplitude is below the receiver peak
    pulse power limit (approximately +20 dBm). NTIA concluded that GPS
    performance is relatively robust to pulse-like UWB emissions. The
    NTIA measurements for the C/A code receiver architecture show that a
    UWB signal with a PRF of 100 kHz[^160] causes a low-duty cycle
    pulse-like interference effect that does not degrade GPS receiver
    performance. The measurements performed by NTIA for the narrowly
    spaced correlator and TSO-C-129a receivers, which use the C/A code
    architecture, also show this low duty cycle, pulse-like interference
    effect.

79. NTIA also performed measurements of UWB interference to a
    semi-codeless GPS receiver. The measured susceptibility values,
    based on the RQT performance criterion, are for a variety of UWB
    characteristics. The GPS receiver performance criterion for RQT is a
    "sharp" increase in the average time to reacquire a GPS signal that
    has been interrupted for ten seconds. This average time was
    determined by measuring the reacquisition time for each of ten
    trials (for the same set of test conditions) and then computing the
    average time of the successful reacquisitions. That is, if the
    receiver was not able to reacquire within the time allowed for a
    trial, this trial was not considered in the determination of average
    reacquisition time. The RQT threshold value was determined by
    engineering judgment by observing a plot of average reacquisition
    time and deciding at what UWB input signal level there was a sharp
    increase in reacquisition time. In general, this sharp increase was
    more evident for the UWB signals involving higher PRFs (*i.e*., 5
    and 20 MHz) and was more a judgment for the lower PRF
    conditions.[^161]

80. The DOT sponsored measurements considered a UWB signal with a PRF of
    100 kHz and came to the same conclusion as NTIA. Thus as long as the
    PRF of the UWB emission is no greater than, 100 kHz, and the output
    level of the UWB emission is low enough so as not to overload the
    front end of the GPS receiver, interference to GPS from UWB
    operation is unlikely. Based on the test data, UWB devices could
    operate at the Part 15 general emission limits, provided the PRF
    does not exceed 100 kHz, without causing interference to GPS
    reception. Thus from the GPS protection viewpoint, GPRs with PRFs
    less than 100 kHz are not an interference concern.

81. For the measurements of the C/A code receiver architecture, NTIA
    classified 19 of the 32 UWB signal permutations in the pulse-like
    category. The majority of the PRF values were 100 kHz (8 cases) and
    1 MHz (7 cases), however two of the 5 MHz PRF (2% relative and 50%
    absolute dither with 20% gate), and one 20 MHz PRF (2% relative
    dither, 20% gate) produced pulse-like interference effects. The NTIA
    measurements confirmed, as theory would predict, that there is a
    relationship between the interference effect and the receiver
    bandwidth. For example, some of the UWB signals (particularly among
    the 1 MHz PRF signals) that produced pulse-like interference effects
    in the wider band GPS receivers (the 10 MHz C/A code and 16 MHz
    narrowly-spaced correlator receivers) produced a response
    characteristic of the more disruptive noise-like or CW-like
    interference effects in the narrower bandwidth receiver (2 MHz
    TSO-C129a). As the PRF of the UWB emission increases above 1 MHz,
    the interference to the GPS receiver can be classified as either
    noise-like or CW-like. The noise like signal permutations included
    the 5 and 20 MHz PRF, 100% gated waveform with 2% relative or 50%
    absolute dithering. Among these four noise-like cases, the
    worst-case measured interference threshold for the C/A code receiver
    was --95 dBm/20 MHz (‑108 dBm/MHz) corresponding to the 20 MHz PRF,
    with 50% absolute dithering signal. Nine of the 32 UWB signal
    permutations were categorized as CW-like. There were four 5 MHz and
    four 20 MHz PRF cases and one 1 MHz PRF signal set that resulted in
    CW-like GPS interference effects. Among these 9 CW-like cases, the
    worst-case interference threshold measured for the C/A code receiver
    was --99.5 dBm/20 MHz. The adjustments to convert this value to the
    power level for a single spectral line in a one MHz bandwidth
    include a 3 dB reduction for the division of power between discrete
    spectral lines and the continuous spectrum for on-off keying (OOK),
    a 7 dB reduction to account for the 20% gate-on time relative to
    total time of 20 milliseconds, and a 7 dB reduction to adjust for a
    single spectral line that is modulated by a sinc function by the
    gating period, producing --116.5 dBm.[^162] The measured level at
    which interference occurred to the GPS C/A code receiver was 8 dB
    less for a CW-like UWB signal than for the noise-like UWB
    signal.[^163] This measured difference is in agreement with the RTCA
    and ITU-R standards noted above which identify a 10 dB difference
    for the two interference effects.

82. *Analysis*: In order to calculate the maximum allowable EIRP for a
    UWB device, a source-path-receiver analysis must be performed. The
    basic parameters that must be defined for this type of analysis are
    the receiver interference threshold, the source output power and
    antenna gain, the propagation path between the transmitter and
    receiver, and the antenna gain of the receiver in the direction of
    the source transmitter. The data obtained from the measurements
    performed by NTIA define the interference threshold level at the
    input of the GPS receiver as a function of UWB signal structure
    (*e.g.*, power, PRF, modulation scheme) for each of the GPS receiver
    architectures examined. The EIRP of an UWB device can be estimated
    by the Part 15 emission limit to which it is subject. However, this
    EIRP thus derived is in most practical cases an overestimate,
    particularly when the receiver of interest has a bandwidth which is
    narrow compared to the difference between the upper and lower
    frequency of a emission limit.

83. In the case of the emission limits in Appendix D, the bracket
    containing the GPS band is 960-1610 MHz with a total bandwidth of
    650 MHz. Part 15 devices are measured for approval purposes using
    the methodology contain in ANSI Standard C63.4.[^164] This
    methodology checks the limit, expressed in field strength units,
    over the whole bandwidth of the bracket and over a surface 3 meters
    away from the device under test with measurement height ranging from
    1 to 4 meters. Furthermore, the device is measured over a conducting
    surface that causes reflections of emissions to reach the antenna in
    addition to direct rays from device under test. This multipath
    contribution to the measured field strength means that the measured
    field strength corresponds to an EIRP 4-5 dB higher than a
    mathematical conversion from field strength to EIRP would indicate.
    Furthermore the fact that the highest field strength measurement
    over a cylinder 3 meters in radius and 3 meters high and over the
    whole bandwidth of a bracket is used for compliance comparison,
    leads to an additional overestimate compared with the signal that
    might be emitted from a UWB device in a specific direction and at a
    specific frequency measurement with a 1 MHz bandwidth. For the
    following analysis to determine UWB emission limits we will use the
    worst case, but probably unrealistic, assumption that the EIRP in
    the direction of the GPS receiver or any other victim receiver is
    the same as implied by compliance measurement. This is necessary at
    this time because we do not have reliable information in the record
    concerning the evenness of the spectral emissions over frequency and
    the variability of UWB antenna patterns with frequency and
    direction.

84. In order to make reasonable assumptions regarding the remaining
    values needed for the analysis, information regarding how the
    transmitter and receiver can interact within their operating
    environment is necessary. Collectively, this information defines an
    operational scenario, which establishes how close the two systems
    may come to one another under actual operating conditions, and the
    likely orientation of the antennas. This information is then used to
    compute the propagation loss and the receive antenna gain in the
    direction of the transmitter. The operational scenario can also be
    used to determine the applicability of factors such as building
    attenuation, multiple transmitters, and safety margins.

85. NTIA, RTCA, and the USGPSIC performed analysis to compute the
    maximum allowable EIRP for the UWB devices with the GPS receiver and
    UWB device for different operational scenarios. NTIA hosted a series
    of open public meetings to develop operational scenarios to be
    considered. The meetings were announced in the *Federal Register*
    and participation was encouraged within the UWB and GPS communities
    and among the interested Federal agencies. Specific proposals for
    operational scenarios to be considered included GPS receivers used
    in the following applications: land-based (*e.g.*, public safety,
    emergency response vehicle navigation, geographic information
    systems, precision machine control); maritime navigation (in
    constricted waterways, harbors, docking, and lock operations);
    railway operations (positive train control); surveying; and aviation
    (en-route navigation and non-precision approach). The input received
    at the public meetings was used by NTIA to develop the operational
    scenarios considered in their analysis. RTCA Working Group 6
    developed operational scenarios for GPS receivers used in Category
    I, II, and III precision approach landings. The USGPSIC developed an
    operational scenario for an E-911 GPS receiver. Since the *Notice*
    did not specify any operating restrictions for UWB devices, the
    operational scenarios considered both indoor and outdoor operation
    of UWB devices. These operational scenarios are the developers' best
    estimates of acceptable geometries between GPS receivers and UWB
    devices. However, the scenarios do not have the legal status of law
    or regulation and our willingness to use them for this analysis is
    based mostly on the absence of other standards that reflect a broad
    consensus and a balancing of all public interests. Spectrum
    management is a complex subject and interference protection goals in
    general must consider both the benefits of authorizing new emitters
    as well as the interference risk to other systems.

86. There are two operational scenarios proposed on the record that
    serve as the limiting scenarios for establishing the emission limits
    for UWB devices operating indoors: 1) the land-based multiple UWB
    device operational scenario developed by NTIA and 2) the E-911
    operational scenario developed by the USGPSIC. The following
    paragraphs provide a detailed discussion of these operational
    scenarios.

87. The first limiting operational scenario for the indoor use of UWB
    devices is where there are several UWB devices operating inside of a
    building and the GPS receiver is operating outdoors. The following
    table provides an overview of the technical factors for noise-like
    interfering UWB signals considered in the analysis for this
    operational scenario. In order to err on the conservative side,
    worst case assumptions have been used for most parameters, as
    advocated and explained by NTIA.

    Table 1 Technical Factors Considered for Indoor UWB Interference to
    GPS

+--------------------------------------------+-----------+------------+
| Parameter                                  | Value     | Value      |
+============================================+===========+============+
| GPS Receiver Interference Susceptibility   | -102.5    | -108       |
| (dBm/MHz)                                  |           |            |
|                                            | (BL)      | (RQT)      |
| (Performance Metric)                       |           |            |
+--------------------------------------------+-----------+------------+
| Propagation Loss (dB)                      | 55        | 55         |
|                                            |           |            |
| (Minimum Distance Separation (m))          | (8.6)     | (8.6)      |
+--------------------------------------------+-----------+------------+
| GPS Receive Antenna Gain (dBi)             | -3        | -3         |
+--------------------------------------------+-----------+------------+
| UWB Device Interference Allotment (dB)     | -3        | -3         |
|                                            |           |            |
| (Percentage UWB)                           | \(50\)    | \(50\)     |
+--------------------------------------------+-----------+------------+
| Allotment for Multiple UWB Devices (dB)    | -6        | -6         |
|                                            |           |            |
| (Number of Devices)                        | \(4\)     | \(4\)      |
+--------------------------------------------+-----------+------------+
| Manufacturer Variation (dB)                | -3        | -3         |
+--------------------------------------------+-----------+------------+
| Average Building Attenuation (dB)          | 9         | 9          |
+--------------------------------------------+-----------+------------+
| Allowance for Acquisition (dB)             | -6        | 0          |
+--------------------------------------------+-----------+------------+
| Maximum Allowable EIRP (dBm/MHz)           | -59.5     | -59        |
+--------------------------------------------+-----------+------------+
| 47 C.F.R.§15.209 Emission Limit (dBm/MHz)  | -41.3     | -41.3      |
+--------------------------------------------+-----------+------------+
| Additional Attenuation Required (dB)       | 18.2      | 17.7       |
+--------------------------------------------+-----------+------------+

88. The UWB emission limit recommended in the above table is calculated
    by adding the values in the columns. As shown in the table, for
    noise-like UWB signals an additional 18 dB of attenuation below the
    47 C.F.R.§15.209 emission limit is necessary to protect the GPS
    receiver under the conservative assumptions in this operational
    scenario. The following paragraphs will provide a detailed
    discussion of each of the technical factors considered in this
    operational scenario.

89. The GPS interference susceptibility levels used in this analysis
    correspond to the break-lock and reacquisition performance metrics
    of the GPS receiver. As discussed earlier, the GPS receiver
    interference susceptibility referenced to the input of the receiver
    was obtained from the single source measurements performed by NTIA.
    The values used in this analysis are based on the UWB signal
    structure that causes the most susceptible noise-like interference
    threshold that was measured by NTIA.

90. The propagation loss is computed using the minimum distance
    separation between the GPS receiver and the UWB device as defined by
    the operational scenario considered. For this operational scenario
    the minimum distance separation is computed from the slant range
    with the GPS receiver located 5 meters from the building and the UWB
    device 7 meters above the GPS receiver. The computed minimum
    distance separation is 8.6 meters. For this distance separation the
    free space propagation model is applicable. One commenter suggests
    that a factor for loss due to vegetation be included in the
    analysis.[^165] Although such a factor may be applicable in other
    operational scenarios, NTIA does not believe that it is appropriate
    in this case and that it should not be included in the analysis. The
    commenter also suggests that a factor be included for scattering
    loss that would result from the fact that most of the world is
    cluttered with objects that will reflect the UWB signals and create
    frequency selective nulls.[^166] Signal scattering similar to the
    effects of multi-path is difficult to predict and are highly
    dependent on the surrounding obstacles. Since there is no way to
    accurately predict the types of obstacles that exist in a given
    area, the inclusion of such a factor in this analysis may not be
    appropriate given the lack of operational experience with UWB.

91. The UWB devices, which are indoors, in this operational scenario,
    are located above the GPS receiver, which is outside. The antenna
    model used by NTIA for the GPS receiver indicates that the receive
    antenna gain is 3 dBi. The antenna for the UWB device is assumed to
    be omnidirectional. One commenter suggested that the antenna gain of
    the UWB device in the direction of the GPS receiver be reduced by 2
    dB to account for off-axis antenna alignment.[^167] Another
    commenter stated that in the analysis of aggregate interference to
    airborne GPS receivers it is appropriate to reduce the gain of the
    UWB device based on the elevation angle.[^168] The commenter states
    that most UWB applications will employ omnidirectional antennas that
    will provide essentially uniform coverage in the horizontal
    direction and in the vertical direction for low elevation
    angles.[^169] The commenter recommends that the antenna gain of the
    UWB device be reduced by approximately 40 dB to 4 dB respectively
    for elevation angles from the vertical down to 45 degrees.[^170] At
    the lower elevation angles, the commenter does not recommend a
    reduction in the UWB device antenna gain. We agree that it would be
    appropriate to include such a factor if the UWB devices were
    employing directional antennas and the locations of the devices were
    known. However, it may not be appropriate to include an off-axis
    antenna alignment factor in the analysis of this operational
    scenario, where omnidirectional antennas might to be employed.
    Off-axis discrimination is typically employed when analyzing
    stations in the fixed radio service, for example, where the
    locations of the transmitters and antenna pointing angles are known.
    Since the locations, the types of antennas being employed, and the
    antenna pointing angles of the UWB devices are all unknowns; it may
    be inappropriate to include a factor for off-axis antenna alignment
    in this analysis. An off-axis antenna alignment factor could be
    applied in an operational scenario examining aggregate interference
    to an airborne receiver from a large number of land-based UWB
    devices, such as in an en-route navigation operational scenario.
    However, it may not be appropriate to include such a factor in the
    analysis of this operational scenario based on the record.

92. One commenter states that antenna polarization mismatch loss should
    be included in the analysis to minimize the interference effects of
    UWB devices to GPS receivers.[^171] Polarization mismatch loss, also
    referred to as polarization discrimination or polarization
    isolation, is the ratio at a receiving point between received power
    in the expected polarization and received power in a polarization
    orthogonal to it from a wave transmitted with a different
    polarization. Polarization mismatch is a common technique used in
    sharing the same frequency for fixed point-to-point microwave
    systems and fixed satellite earth stations. The key factor being
    that the transmitter and receiver antennas are fixed and their
    polarization are known. Moreover, the polarization of an antenna
    remains relatively constant throughout the main lobe of the antenna
    pattern, but varies considerably in the minor lobes.[^172] In
    practice, polarization of the radiated energy varies with the
    direction from the center of the antenna, such that different parts
    of the antenna pattern and different sidelobes have different
    polarizations.[^173] This is also true for GPS antennas where in the
    mainbeam the polarization is circular, but outside the mainbeam in
    the lower elevation angles the polarization is nearly linear. Since
    the locations of the UWB devices, and polarizations are unknown at
    this time we do not believe that a factor for polarization mismatch
    loss should be included in the analysis.

93. In addition to the potential interference from UWB devices, several
    other potential sources of interference to GPS receivers have been
    identified. These potential sources of interference include but are
    not limited to: 1) adjacent band interference from mobile-satellite
    service Mobile Earth Terminals (METs); 2) harmonics from television
    transmitters; 3) spurious emissions from 700 MHz public safety base,
    mobile, and portable transmitters; and 4) spurious emissions
    including harmonics from 700 MHz commercial base, mobile, and
    portable transmitters. Multiple sources of interference, which might
    individually be tolerated by a GPS receiver, may combine to create
    an aggregate interference level that could prevent the reliable
    reception of the GPS signal. The emission limit of the MSS METs, 700
    MHz public safety and commercial transmitters is --40 dBm/MHz for
    noise-like interference. The zone of interference of each of these
    transmitters could be as much as a circle of 30-meter (100-foot)
    radius, if it emits out-of-band radiation at the limit. The emission
    from digital television (DTV) transmitters is --110 dBc and will
    result in a zone of interference that is as much as a circle of 270
    meters (884-foot) radius at the same height as the antenna. As a
    consequence these transmitters do not have to be located next to a
    GPS receiver to disrupt signal reception in land-based applications.
    In this conservative operational scenario one half of the total
    allowable interference budget is allotted to UWB devices and the
    other half is allotted to all other interfering sources combined.
    The factor for UWB device interference allotment is computed from 10
    Log (UWB interference allotment ratio). For a UWB device
    interference allotment of 50% (a ratio of 0.5), a 3 dB factor is
    included in this analysis. One commenter argued against including a
    factor for interference allotment in the analysis.[^174] However,
    their argument is at odds with their other comments, wherein they
    acknowledge that there may be sources of interference such as
    incidental and unintentional radiators, as well as licensed
    transmitters with spurious emissions in the GPS bands.[^175] The use
    of allotments for multiple sources of interference is not a new
    concept in studies examining interference from one radio service to
    another. For example, ITU-R Recommendation F.1094-1 specifies an
    interference allotment of 89% for transmitters of the same radio
    service, an interference allotment of 10% for radio transmitters in
    other radio services, and a 1% interference allotment for all other
    sources (*e.g.*, unlicensed transmitters).[^176] This is also
    consistent with ITU-R Recommendation M.1477, which states that when
    there is a potential for more than one source of interference at the
    same time, it will be necessary to apportion the interference
    threshold among the potential interference sources.[^177] Since the
    GPS/UWB measurements that are part of the public record in this
    proceeding did not include other potential sources of interference,
    it may be appropriate to include a factor in the analysis to take
    them into account. Out of an abundance of caution, we shall do so
    here but may request comments in future proceedings on appropriate
    interference modeling.

94. The factor for multiple UWB devices was obtained from the multiple
    source (aggregate) measurements performed by NTIA. The measurements
    performed by NTIA verified that if the individual signals cause an
    interference effect that is noise-like, the interference effect of
    the multiple noise-like signals is noise-like. Based on the
    measurements, for UWB signal permutations that have been
    characterized as causing noise-like interference, a factor of 10 Log
    (number of UWB devices) is included in the analysis. Based on the
    record, it is unclear whether this modeling of cumulative effects of
    multiple spatially separated UWB devices will be representative of
    typical UWB environments. However, erring again on the side of
    conservatism in order to protect GPS in the near future we are
    accepting NTIA's analysis of multiple UWB device effects at this
    time.

95. One commenter recommends that an activity factor of 3 dB be included
    in the analysis to account for the fact that UWB devices will not be
    transmitting continuously.[^178] The factor of 3 dB would indicate
    that each UWB device is transmitting 50% of the time. The inclusion
    of an activity factor may be appropriate when there are a large
    number of UWB devices considered in the operational scenario. The
    activity factor is also dependent upon the UWB application. Since
    there are only four UWB devices in this operational scenario and it
    is not possible to accurately estimate representative values of
    activity factors at this time, we will not use an activity factor in
    this analysis (*i.e.,* the UWB devices will be continuously
    transmitting).

96. A 2001 GPS Receiver Survey lists 64 different manufacturers of GPS
    receivers.[^179] The survey lists approximately 500 different models
    of GPS receivers representing the C/A code, semi-codeless, and
    narrowly spaced correlator receiver architectures. The NTIA
    measurements included one receiver from each of the three GPS
    architectures. Based on the NTIA measurements, the results of the
    other measurement efforts, and the analyses of the data that is part
    of the public record in this proceeding, initial engineering
    modeling of the interference effects of UWB signals on the different
    GPS receiver architectures has emerged. However, the number of
    different models of GPS receivers and manufacturers considered in
    the current measurement efforts may not completely represent the
    performance of all the GPS receivers currently being manufactured.
    There may be differences in hardware, firmware,[^180] or software
    (*e.g*., tracking and acquisition algorithms) employed in the
    receivers that were not considered in the current measurement
    efforts. There may be differences in the models produced by the same
    manufacturer as well as between receivers produced by different
    manufacturers. Therefore, the inclusion of a factor in the analysis
    to account for these possible differences is reasonable at this
    time. Based on an analysis performed by NTIA of the data that is on
    the public record in this proceeding, the range of data indicates
    that the more susceptible interference thresholds are within 3 dB of
    the median.[^181] One commenter objected to the inclusion of the 3
    dB factor for manufacturer variation.[^182] The commenter stated
    that the industry would not accept a 3 dB variance from the
    stringent specifications required by the aviation and surveying
    receivers.[^183] With the exception of the aviation community, NTIA
    indicates that it is unaware of any specifications for GPS
    receivers. The NTIA analysis included this factor to take into
    account the small number of GPS receivers considered in all of the
    measurement efforts. The analysis performed by JHU/APL also
    acknowledged that there are differences in GPS receivers.
    Specifically JHU/APL concluded that variations in the measurements
    of performance due to different GPS receivers are greater than those
    due to the operating modes of the UWB tested devices. JHU/APL
    further concluded that the impact of UWB devices on all GPS
    receivers could not be assessed using a single GPS receiver.[^184]
    Based on the analysis performed by NTIA, the absence of detailed
    information on receiver variability in the record, and the
    conclusions reached in the JHU/APL analysis, we are applying a value
    of 3 dB in this analysis for manufacturer variation.

97. As part of a separate measurement effort, NTIA has conducted
    building attenuation loss measurements at 912, 1920, and 5990
    MHz.[^185] The measurements were performed for different buildings
    representing typical residential and high-rise office construction.
    Based on the results of these measurements, an average building
    attenuation of 9 dB in the range 960-1610 MHz in which GPS operates
    is used in this analysis. The standard deviation for the
    measurements, however, is on the same order of magnitude as the
    value of building attenuation loss.[^186]

98. The NTIA measurements did not consider the acquisition of a new
    satellite in the presence of a UWB signal. The acquisition threshold
    is known to be more sensitive than the tracking threshold, which
    can, in part, be attributed to the time and frequency search
    performed by the GPS receiver as part of the satellite acquisition
    scheme. As part of the satellite acquisition process, the loop
    filter bandwidths are increased, which causes the noise (N) to
    increase reducing the effective carrier-to-noise ratio (C/N). The
    acquisition mode of the GPS receiver is extremely difficult to
    measure, because it is highly dependent on manufacturer-specific
    acquisition algorithms. A 6 dB factor is typically used in GPS
    interference analyses to account for the greater sensitivity of
    satellite acquisition.[^187] This 6 dB reduction in the interfering
    signal power level only provides protection of 2.5 dB in C/N+I,
    which is a critical factor in GPS receiver performance. Since the
    performance metric of break-lock is related to the tracking
    performance of the GPS receiver, including the acquisition factor in
    the analysis when the interference susceptibility is based on the
    break-lock performance is appropriate.

99. The second limiting operational scenario to be considered for UWB
    devices is the indoor use of E-911 GPS receivers. Because buildings
    and other structures attenuate the received GPS satellite signals,
    indoor reception has been not been possible previously. However,
    Global Locate and Snap Track (Qualcomm) have developed technologies
    that permit indoor, enhanced GPS reception for E-911 applications.
    These technologies rely on enhancing the signal processing of the
    E-911 received GPS signal with information provided from a separate
    GPS receiver located at the base station. This supplemental
    information provides Doppler and code shift data to allow
    acquisition and tracking of low level GPS signals. In addition,
    information involving phase shifts caused by the GPS navigation
    signal is provided to allow coherent integration of the E-911 GPS
    signal for a period longer than 20 milliseconds. The enhanced GPS
    receiver integrates the satellite signal over a longer time period,
    allowing the receiver to obtain a 20 to 30 dB higher processing gain
    than a conventional GPS receiver. [^188] This higher processing gain
    permits the reception of a GPS signal that is significantly below
    the receiver noise floor in a 1 MHz bandwidth.[^189]

100. This processing, to determine location of the E-911 receiver, can
     be carried out at the E-911 receiver using supplemental data from
     the base station that is provided via the phone connection. An
     alternative is to do the final processing at the base station. For
     example, a snapshot (in time) of the signals (in the GPS band)
     received at the E-911 receiver is forwarded to the base station via
     the phone connection where the signal and supplemental information
     is processed to determine location of the E-911 receiver. These
     processing technologies require that the E-911 receiver not be on a
     platform that is moving rapidly. Significant motion could, for
     example, invalidate the supplemental Doppler information and/or
     invalidate the final position solution, which involves some time
     latency due to the signal processing procedure. At this time, it is
     expected that the E-911 position determination would not be invoked
     until the emergency (911) call is placed.

101. Regardless of the processing gain or the bandwidth of the tracking
     loop, the minimum level of the GPS signal that can be used for an
     E-911 position determination will be determined by the receiver
     system noise density. An interfering signal that adds to the system
     noise density will necessitate a higher GPS signal level thus
     decreasing the indoor coverage of the E-911 position determination
     capability. Thus, we believe that an analysis of an indoor UWB
     transmitter and an E-911 GPS receiver provides the more stringent
     interference example. The USGPSIC provided an operational scenario
     for an E-911 GPS receiver.[^190] The following table provides an
     overview of the technical factors considered in the USGPSIC
     analysis for this operational scenario.

     Table 2 USGPSIC Analysis of UWB Indoor Interference to E-911 Indoor
     System

+----------------------------------------------------+-----------------+
| Parameter                                          | Value           |
+----------------------------------------------------+-----------------+
| Receiver Susceptibility Mask (dBm/MHz)             | -111.5          |
|                                                    |                 |
| (Broadband Noise)                                  |                 |
+----------------------------------------------------+-----------------+
| Public Safety Margin (dB)                          | -6              |
+----------------------------------------------------+-----------------+
| Multiple System Allotment (Excluding MSS) (dB)     | -3              |
+----------------------------------------------------+-----------------+
| Single Emitter Allotment                           | -6              |
+----------------------------------------------------+-----------------+
| GPS Antenna Gain in Direction of RFI Source (dBi)  | 0               |
+----------------------------------------------------+-----------------+
| Propagation Loss (dB)                              | 46              |
|                                                    |                 |
| (Minimum Distance Separation (meters))             | \(3\)           |
+----------------------------------------------------+-----------------+
| Noise-Like RFI Emission Limit (dBm/MHz)            | -80.5           |
+----------------------------------------------------+-----------------+
| 47 C.F.R.§15.209 Emission Limit (dBm/MHz)          | -41.3           |
+----------------------------------------------------+-----------------+
| Additional Attenuation Required (dB)               | 39.2            |
+----------------------------------------------------+-----------------+

102. The UWB emission limit recommended in the above table is calculated
     by adding the values in the columns. As shown in the table, the
     USGPSIC states that for noise-like interference, UWB signals must
     be 39 dB below the 47 C.F.R.§15.209 emission limit to protect the
     GPS receiver under the conditions in this operational scenario. The
     following paragraphs will examine and assess the viability of each
     of the technical factors considered in this operational scenario.

103. The interference susceptibility level specified by the USGPSIC is
     --111.5 dBm/MHz, which is equal to an interference density of
     --171.5 dBm/Hz. The typical receiver system noise density of a GPS
     receiver is --171.5 dBm/Hz for a 3 dB receiver noise figure.[^191]
     Therefore the specified interference susceptibility represents an
     I/N of 0 dB or a 3 dB increase in the system noise density. This
     means that interference at this level can cause a 100% increase in
     the GPS receiver system noise density. As stated earlier, the
     receiver system noise density determines the minimum level of the
     GPS signal that can be used for an E-911 position determination.
     Therefore, an interfering signal that adds to the system noise
     density will limit the GPS signal level that can be tracked by the
     receiver. Conventional GPS receivers require a relatively high
     C/N~0~ because of the wide loop bandwidths that are employed. In
     contrast GPS receivers used in E-911 applications can take full
     advantage of communication network support to obtain and remove the
     GPS navigation data and to stabilize the receiver clock. In
     addition, it is assumed that the dynamics are very low (e.g., the
     user is walking). As a result, the tracking bandwidth can be
     narrowed very substantially, thus maintaining a positive
     signal-to-noise ratio in the tracking loop at much lower C/N~0~
     values. Receivers are being designed today which can track with a
     20 dB C/N~0~, and the industry is striving to track with a C/N~0~
     of 10 dB. Based on the system noise density of --171 dBm/Hz, a 20
     dB C/N~0~ represents a received signal level of --151 dBm, and a 10
     dB C/N~0~ represents a received signal level of --161 dBm. There
     are existing GPS receivers that are capable of tracking signals
     that are 21 dB weaker than the signal levels considered in the
     measurement efforts that are part of the public record in this
     proceeding. If improvements permit tracking at a C/N~0~ of 10 dB,
     the tracked signal level would be 31 dB weaker than the signal
     levels considered in the measurement efforts. Based on the lower
     received signal levels that can be tracked by GPS receivers, a 100%
     increase in the system noise may not be acceptable. We are
     therefore limiting at this time the increase in system noise caused
     by noise-like UWB signals to 50%, which equates to an I/N of --3
     dB. Based on the I/N of --3 dB the interference susceptibility
     level used in the analysis will be --114.5 dBm/MHz.

104. ITU-R M.1477 specifies a 6 dB safety margin to account for
     uncertainties on the aviation side of the link budget that are real
     but not quantifiable, which include but are not limited to:
     multipath of the GPS signal; receiver implementation losses;
     antenna gain variations; and approach path deviation. Since the GPS
     signal level cannot be increased, the aviation safety margin is
     implemented by lowering the allowable interference. In Annex 5 of
     ITU-R M.1477 the need for an aviation safety margin is justified by
     citing examples of other aviation systems such as the Instrument
     Landing System, and the Microwave Landing System that both use a
     safety margin. ITU-R M.1477 specifies a 6 dB margin for aviation
     safety of life applications employing GPS receivers. Therefore, it
     is not appropriate to apply this margin to non-aviation safety of
     life applications using GPS receivers, and the public safety margin
     of 6 dB specified by the USGPSIC should not be used in the E-911
     operational scenario analysis.

105. The USGPSIC defined E-911 GPS receiver operational scenario
     includes a 3 dB factor for multiple interfering systems allotment,
     excluding MSS. This factor is used for the composite of all UWB and
     future radio frequency interference sources. The 3 dB factor is
     equivalent to a 50% interference allotment to UWB devices. The
     remaining 50% is to account for all other potential sources of
     interference. Since the GPS receiver is operating indoors this will
     minimize the potential for interference from other sources such as
     700 MHz commercial and pubic safety mobile and base stations
     transmitters and harmonics from DTV stations. Furthermore, as shown
     in the table above, the minimum distance separation is 3 meters.
     For operational scenarios where the minimum distance separation
     between the GPS receiver and UWB devices is on the order of several
     meters, the UWB device is expected to be the dominant source of
     interference. Therefore, for the E-911 GPS receiver operational
     scenario it is not appropriate to include a factor for other
     sources of interference.

106. The USGPSIC defined E-911 GPS receiver operational scenario
     includes a factor for multiple UWB devices. As shown in the table
     there is a factor that accounts for 4 UWB devices causing noise
     like interference each operating at the minimum separation distance
     of 3 meters. Although this minimum distance separation may be
     acceptable when assessing interference from a single UWB device, we
     believe that it is not appropriate when assessing interference from
     multiple UWB devices. Therefore, for this operational scenario, it
     is not appropriate to consider multiple UWB devices operating at
     such a close distance. When considering interference to GPS E-911
     receivers from a single indoor system, NTIA employed a minimum
     separation distance of 2 meters in this analysis. We have employed
     the antenna model specified in the NTIA analysis, using an antenna
     gain of 0 dBi in the direction of the UWB device. We also have
     employed NTIA's use of the free space propagation model to compute
     the propagation loss.

107. The table below shows the amount of additional attenuation below
     the current 47 C.F.R.§15.209 emission limits that is needed to
     protect an E-911 GPS receiver under the revised conditions.

     Table 3 Analysis of Indoor E-911 Using Revised Conditions

+---------------------------------------------+------------------------+
| Parameter                                   | Value                  |
+---------------------------------------------+------------------------+
| Receiver Susceptibility Mask (dBm/MHz)      | -114.5                 |
|                                             |                        |
| (Broadband Noise)                           |                        |
+---------------------------------------------+------------------------+
| GPS Antenna Gain in Direction of RFI Source | 0                      |
| (dBi)                                       |                        |
+---------------------------------------------+------------------------+
| Propagation Loss (dB)                       | 42.4                   |
|                                             |                        |
| (Minimum Distance Separation (meters))      | \(2\)                  |
+---------------------------------------------+------------------------+
| Noise-Like RFI Emission Limit (dBm/MHz)     | -72.1                  |
+---------------------------------------------+------------------------+
| 47 C.F.R.§15.209 Emission Limit (dBm/MHz)   | -41.3                  |
+---------------------------------------------+------------------------+
| Additional Attenuation Required (dB)        | 30.8                   |
+---------------------------------------------+------------------------+

108. As shown in the table above, for noise-like interference, UWB
     signals should be 31 dB below the 47 C.F.R.§15.209 emission limit
     to protect the GPS receiver in this operational scenario. This
     conclusion is based on limited quantitative information that was
     inserted recently into the record by NTIA. Out of an abundance of
     caution to protect the newly emerging GPS-based indoor E-911
     systems and their safety implications from UWB devices with which
     we also have minimal operational experience, we are basing our UWB
     rules on this analysis.

109. Qualcomm submitted an *ex parte* presentation for the public record
     reporting on a series of test to assess the impact of UWB emissions
     on the performance of a GPS enabled PCS phone.[^192] This type of
     GPS receiver is designed to provide location information for E-911
     callers in compliance with our E-911 mandate. The Qualcomm
     measurements used a GPS signal level at the input to the receiver
     that resulted in a C/N~0~ of 34 dB-Hz.[^193] The noise figure of
     the GPS receiver was 4 dB.[^194] This results in a receiver noise
     density level of --170 dBm/Hz (-110 dBm/MHz) and a GPS signal level
     of -136 dBm for a 34 dB-Hz condition. Qualcomm selected the 34
     dB-Hz level as it represented a value exceeded in 5% of the test
     cases for within building applications.[^195] The UWB signal was
     then input to the GPS receiver and the location accuracy determined
     as a function of UWB signal level. For dithered (noise-like) UWB
     signals the 50^th^ percentile position accuracy increased to 50 m
     at -97.5 dBm/2 MHz or -100.5dBm/MHz. This interference level is
     9.5dB above receiver noise (I/N = 9.5dB). However, our requirement
     for E-911 performance includes a specification for 95% of the
     calls. Using the Qualcomm cumulative distribution plots for C/N~0~,
     a value that would be exceeded in 95% of the cases can be
     determined.[^196] This value is 22.5 dB-Hz and is 11.5 dB below the
     value for 5% of the cases. That is the carrier (GPS signal) is 11.5
     dB weaker. GPS performance is related to the
     carrier-to-interference ratio so that an 11.5 dB decrease in
     carrier level should result in a requirement to lower the UWB
     interference level by approximately 11.5 dB to maintain the
     required position accuracy. Relating this to the measured I/N of
     9.5dB would indicate an I/N of -2dB would be required for 95^th^
     percentile C/N~0~ level.

110. Similarly, the Qualcomm test effort evaluated UWB signals with a
     constant PRF resulting in a UWB spectrum with CW lines. As
     previously discussed in paragraph 82, *supra*, GPS can be more
     susceptible to CW-like interference than to noise-like
     interference. The Qualcomm test results showing 50^th^ percentile
     position errors for noise-like and CW-like interference cases show
     very similar position error versus UWB power level performance
     characteristics. This could be interpreted that there was no
     difference in susceptibility for noise-like and CW-like
     interference. This could be explained by considering the accuracy
     performance is a 50^th^ percentile value and one would not expect
     the alignment of GPS and interference spectral lines to occur in a
     significant number of cases considering the narrow loop bandwidths
     used in the E-911 GPS receivers and the fairly short length of time
     to determine position. A few instances of CW line alignment would
     not seriously impact the 50^th^ percentile position error. As shown
     in the test report an 800-meter position error was used as a
     default value when there is not sufficient information to obtain a
     position measurement[^197]. Examination of the UWB impact versus
     time information shows 5 cases of 800-meter errors in approximately
     50 calls.[^198] Some of these 800-meter errors could have been
     caused by CW-like interference, which is expected to be a low
     probability event for E-911 service. In addition some E-911 GPS
     receivers are reportedly using processing techniques that in effect
     converts CW energy into broadband interference. It is not known
     whether the Qualcomm receiver includes such processing. We believe,
     therefore, that the Qualcomm test data is inconclusive in the area
     of increased susceptibility of the GPS receiver tested to CW-like
     interference as compared to noise-like interference.

111. Based on the above analysis, of the two limiting operational
     scenarios for the indoor use of UWB devices, a UWB signal level 31
     dB below the Part 15 general emission limits would be required for
     noise-like UWB emissions in the 960-1610 MHz range. Based on the
     various uncertainties at this time and the lack of operational
     experience with UWB systems, we believe that an additional
     attenuation of 3 dB is reasonable giving a total attenuation of 34
     dB below the §15.209 emission limit. This attenuation will be
     required for all indoor and outdoor non-imaging UWB systems,
     including vehicular radars and hand held systems.

112. We are permitting imaging systems, vehicular radar systems and hand
     held devices to operate outdoors, at any PRF provided the emissions
     in the GPS bands are below the Part 15 general emission limit. The
     limiting operational scenario considered for the outdoor use of GPS
     and imaging systems is given in the table below.

     Table 4 Outdoor Analysis for Imaging System Interference to GPS

+-----------------------------------------------+----------------------+
| Parameter                                     | Value                |
+-----------------------------------------------+----------------------+
| GPS Receiver Interference Susceptibility      | -114.5               |
| (dBm/MHz)                                     |                      |
|                                               |                      |
| (Broadband Noise)                             |                      |
+-----------------------------------------------+----------------------+
| Propagation Loss (dB)                         | 49.5                 |
|                                               |                      |
| (Minimum Distance Separation (m))             | (4.5 m)              |
+-----------------------------------------------+----------------------+
| GPS Receive Antenna Gain (dBi)                | 0                    |
+-----------------------------------------------+----------------------+
| Maximum Allowable EIRP (dBm/MHz)              | -65                  |
+-----------------------------------------------+----------------------+
| 47 C.F.R. §15.209 Emission Limit (dBm/MHz)    | -41.3                |
+-----------------------------------------------+----------------------+
| Additional Attenuation Required (dB)          | 23.7                 |
+-----------------------------------------------+----------------------+

113. As shown in the table above, a signal level 24 dB below the Part 15
     general emission limit is required for noise-like emissions in the
     960-1610 MHz frequency range from imaging systems under the
     conservative assumptions we are using based on the record. We also
     believe that imaging systems typically will emit RF energy only for
     short periods of time, so any possible interference from operation
     at closer distance separations should be transient.

114. In limited cases involving public safety uses of UWB imaging where
     there are positive public safety benefits from the UWB use and
     where coordination can be used to limit the risk of interference to
     safety-related uses of GPS, we believe that 12 dB less attenuation,
     resulting in an emission level 12 dB below the §15.209 emission
     limit, represents the appropriate balancing of public interests.

115. The limiting operational scenario considered for the outdoor use of
     GPS and vehicular radar systems is given in the table below.

     Table 5 Analysis for Vehicular Radar System Interference to GPS
     Receivers

+----------------------------------------------------+-----------------+
| Parameter                                          | Value           |
+----------------------------------------------------+-----------------+
| Receiver Susceptibility Mask (dBm/MHz)             | -114.5          |
|                                                    |                 |
| (Broadband Noise)                                  |                 |
+----------------------------------------------------+-----------------+
| GPS Antenna Gain in the Direction of UWB Device    | 4.5             |
| (dBi)                                              |                 |
+----------------------------------------------------+-----------------+
| Propagation Loss (dB)                              | 45.9            |
|                                                    |                 |
| (Minimum Distance Separation (meters))             | \(3\)           |
+----------------------------------------------------+-----------------+
| Allotment for Multiple UWB devices (dB)            | -7.8            |
+----------------------------------------------------+-----------------+
| Noise-Like Emission Limit (dBm/MHz)                | -71.9           |
+----------------------------------------------------+-----------------+
| 47 C.F.R. § 15.209 Emission Limit (dBm/MHz)        | -41.3           |
+----------------------------------------------------+-----------------+
| Additional Attenuation Required (dB)               | 30.6            |
+----------------------------------------------------+-----------------+

116. The typical implementation of the vehicular radar systems will
     consist of multiple radar systems (as many as 12 per vehicle) that
     are mounted on the bumpers and fenders of the vehicle. Vehicular
     radar systems will also employ directional antennas and will be
     installed at a height of approximately 0.5 meters.[^199] Based on
     anticipated operational use of vehicular radar systems the antenna
     discrimination of a GPS antenna in the direction of the vehicular
     radar systems and interference from multiple vehicular radar
     systems must be considered in the analysis.

117. Since the vehicular radar systems are mounted at a height of
     approximately 0.5 meters they will typically be below the GPS
     antenna. Based on the antenna model provided by NTIA, the GPS
     receive antenna gain in the direction of the vehicular radar
     systems would be --4.5 dBi. In order to determine the location of
     vehicles and objects that surround the vehicle multiple vehicular
     radar systems employing directional antennas will be employed. In
     this analysis it will be assumed that there are six vehicular radar
     systems transmitting in the direction of the GPS receiver and a
     factor of 10 Log (6) or 7.8 dB will be included in the analysis.

118. The calculations shown in Table 5 lead to a conclusion that a
     signal level 31 dB below the Part 15 general emission limit is
     required for noise-like emissions from vehicular radar systems in
     the 960-1610 MHz frequency range based on the conservative
     assumptions and limited record on operational experience that we
     are using at this time. Because of the present uncertainties in
     predicting interference from UWB devices for which we have no
     operational experience and our concern about certain safety-related
     applications of GPS, we agree to employ the additional safety
     margin applied by NTIA to the receiver susceptibility mask,
     resulting in an emission level 34 dB below the Part 15 limits.

119. The previous discussion has focused on interference from noise-like
     UWB emissions to GPS. UWB emissions can also have discrete spectral
     lines or CW-like emissions in addition to noise-like emissions
     depending on the statistical details of time spacing between
     adjacent pulses.[^200] Now will we consider limits on these CW-like
     emissions.

120. The measured level at which interference occurred to the GPS C/A
     code receiver was 8 dB less for a CW-like UWB signal than for the
     noise-like UWB signal. As also indicated, this measured difference
     is in agreement with the RTCA and ITU-R standards, which specify a
     10 dB difference for the two interference effects. Accordingly, we
     agree that UWB emissions appearing within the 960-1610 MHz
     frequency range due to narrowband CW-like interference signals
     should be 10 dB below the emission power level measured in a 1 MHz
     bandwidth permitted for noise-like emissions. As discussed in the
     section addressing emission limits, we are implementing this by
     requiring that the UWB transmitters be demonstrated to comply with
     this limit when measured with a spectrum analyzer employing a
     resolution bandwidth no less than 1 kHz.[^201] The above
     requirements for UWB emission levels appearing in the 960-1610 MHz
     frequency range also will be satisfactory for GPS receivers that
     work with satellite-based augmentation systems (SBAS) and ground
     based augmentation systems (GBAS). ITU-R Recommendation M.1477
     provides receiver specifications for an SBAS air navigation
     receiver to be used in Category I precision approach operations and
     a GBAS air navigation receiver to be used with Category II/III
     precision approach operations. In both instances, the minimum
     required power level at the input is specified at --131 dBm, only
     one dB lower than the specification for the C/A code GPS receiver.
     In both cases, the specified receiver aggregate wideband
     interference threshold in track and acquisition mode is identical
     to the RTCA and ITU-R thresholds for the C/A code GPS receiver.
     Hence, the conclusions above will apply to SBAS or GBAS and GPS
     receivers.

121. The semi-codeless GPS receivers have more stringent requirements on
     GPS received signal levels (3 dB lower) than the C/A code GPS
     receivers, and the wideband interference requirements for tracking
     mode is 6 dB lower than the C/A code GPS receiver.[^202] The
     wideband interference requirement for acquisition is the same for
     both classes of receiver. Because the semi-codeless receiver works
     with the GPS P-signal, which has essentially no spectral line
     content, this receiver is not sensitive to the spectral lines in
     the CW-type UWB emissions, as demonstrated by NTIA's measurements
     for the C/A code receiver architecture. NTIA's measurements also
     demonstrated the same robust operations for low PRF signals as the
     C/A code receiver. The NTIA measurements supported an increased
     sensitivity to noise-like UWB emissions than for the C/A code
     receiver architecture. Nevertheless, the operational scenarios
     examined by NTIA involving surveying applications that employ the
     semi-codeless architecture receiver produced interference levels
     that were higher than the terrestrial operational scenarios. In any
     case, since the semi-codeless receiver relies on the C/A code for
     initial acquisition and it typically defaults to C/A code operation
     if the P-signal becomes unavailable the C/A code receiver
     performance drives the UWB threshold limits for all receiver types
     discussed earlier.

### NTIA Analyses of Interference to Various U.S. Government Systems:

122. NTIA analyzed the interactions between UWB transmitters and a
     number of U.S. Government radio communication systems to determine,
     *inter alia,* the maximum UWB emission levels that could be allowed
     without causing interference. These analyses were based on an
     extensive laboratory measurement program at the Institute for
     Telecommunication Sciences, in Boulder, CO. The measurement program
     identified various methods being currently used to generate UWB
     signals and characterized the essential parameters of UWB systems
     provided by various UWB manufacturers. The ITS verified how filters
     of varying bandwidths respond to numerous types of UWB signals and
     determined measurement techniques that correctly measure the
     emission spectra of UWB devices. The ITS also performed a
     measurement program to determine the nature of the aggregation of
     UWB signals.[^203] NTIA also initiated a measurement program
     consisting of field measurements of radiated UWB signals at the FAA
     Aeronautical Center in Oklahoma City, OK to determine the effects
     of one UWB device operating at the current Part 15 limits on Air
     Route Surveillance Radars (ARSR), and Airport Surveillance Radars
     (ASR) in order to validate the prediction models used in the
     analysis. In its reports, NTIA provided quantitative values for UWB
     emission limits involving federal systems for the following: RMS
     power limits for a UWB device located at 2 m and at 30 m above the
     ground for 15 systems (and peak power limits for two of the
     systems); and developed a computer model for assessing the impact
     of aggregate UWB interference. The NTIA interference analyses of
     the effects of RMS and peak power were based on a link budget
     equation involving the system threshold for interference, as
     determined using standard established interference protection
     criteria, actual antenna elevation gain patterns for the victim
     receivers, the smooth earth option of the Irregular Terrain Model
     for propagation loss, estimated system losses, and the empirically
     determined correction factors for bandwidth to determine the UWB
     limits in power per megahertz (dBm/MHz).

123. The NTIA analysis was performed for 7 UWB PRFs ranging from 1 kHz
     to 500 MHz for both dithered and undithered signals. The NTIA study
     used the current Part 15 limit, an RMS EIRP of ‑41.3 dBm/MHz at
     frequencies above 1 GHz, as the baseline for the study. The study
     determined the allowable UWB emission levels and did not
     specifically address the 12 dB reduction from the current Part 15
     level in the bands below 2 GHz as proposed in the *Notice*. The
     analysis also assumed that the UWB devices were located out of
     doors. The following is a summary of NTIA's report. A more detailed
     analysis has been placed in the docket file for this proceeding.

     Table 6 Maximum UWB EIRP for Outdoor Use of UWB at 2m & 30 m

+-----------------+-------------+-----------------+------------------+
| System          | Frequency   | Maximum UWB     | Maximum UWB      |
|                 |             |                 |                  |
|                 | (MHz)       | EIRP            | EIRP             |
|                 |             |                 |                  |
|                 |             | (dBm/MHz)       | (dBm/MHz)        |
|                 |             |                 |                  |
|                 |             | UWB             | UWB              |
|                 |             |                 |                  |
|                 |             | Outdoors        | Outdoors         |
|                 |             |                 |                  |
|                 |             | 2 m height      | 30 m height      |
+-----------------+-------------+-----------------+------------------+
| DME,            | 960-1215    | -47             | Not Applicable   |
| Interrogator    |             |                 |                  |
+-----------------+-------------+-----------------+------------------+
| DME,            | 1025-1150   | -64             | -57              |
| Transponder     |             |                 |                  |
+-----------------+-------------+-----------------+------------------+
| ATCRBS,         | 1030        | -44             | Not Applicable   |
| Transponder     |             |                 |                  |
+-----------------+-------------+-----------------+------------------+
| ATCRBS,         | 1090        | -31             | -45              |
| Interrogator    |             |                 |                  |
+-----------------+-------------+-----------------+------------------+
| ARSR-4          | 1240-1370   | -61             | -82              |
+-----------------+-------------+-----------------+------------------+
| SARSAT          | 1544-1545   | -69             | -66              |
+-----------------+-------------+-----------------+------------------+
| ASR-9           | 2700-2900   | -46             | -66              |
+-----------------+-------------+-----------------+------------------+
| NEXRAD          | 2700-2900   | -42             | -76              |
+-----------------+-------------+-----------------+------------------+
| Marine Radar    | 2900-3100   | -56             | -57              |
+-----------------+-------------+-----------------+------------------+
| FSS, 20 degrees | 3700-4200   | -36             | -42              |
+-----------------+-------------+-----------------+------------------+
| FSS, 5 degrees  | 3700-4200   | -51             | -77              |
+-----------------+-------------+-----------------+------------------+
| CW Altimeters   | 4200-4400   | 25              | Not Applicable   |
+-----------------+-------------+-----------------+------------------+
| Pulsed          | 4200-4400   | 14              | Not Applicable   |
| Altimeter       |             |                 |                  |
+-----------------+-------------+-----------------+------------------+
| MLS             | 5030-5091   | -54             | Not Applicable   |
+-----------------+-------------+-----------------+------------------+
| TDWR            | 5600-5650   | -35             | -63              |
+-----------------+-------------+-----------------+------------------+

124. NTIA investigated the potential interactions of proposed UWB
     systems on 15 U.S. Government systems operating between the
     frequencies of 960 and 5650 MHz. The systems investigated included
     Distance Measuring Equipment (DME) interrogator airborne receiver,
     DME ground transponder receiver, Air Traffic Control Radio Beacon
     System (ATCRBS) air transponder receiver, ATCRBS ground
     interrogator receiver, ARSR), Search and Rescue Satellite (SARSAT)
     ground station land user terminal, ASR, Next Generation Weather
     Radar (NEXRAD), Maritime Radar, Fixed Satellite Service (FSS) earth
     stations, CW and Pulsed Radar Altimeters, Microwave Landing Systems
     (MLS), and Terminal Doppler Weather Radar (TDWR). Table 6 denotes
     these systems and their frequency band of operation and summarizes
     NTIA's conclusions of emission limits necessary to preclude
     interference from a UWB transmitter operating at a height of 2 or
     30 meters. The maximum UWB EIRP is the maximum signal level that
     NTIA calculated at which a UWB transmitter could operate without
     causing interference to the system when the UWB is allowed
     unrestricted outdoor operation independent of the UWB's pulsewidth,
     PRF, or other modulation schemes or the nature of it's intended
     operation (e.g. radio determination or communication). Where there
     was a difference due to the PRF of the UWB emission, we have
     included the results from the PRF that required the UWB emissions
     to be reduced to the lowest level. In the column for 30 meters,
     "Not Applicable" indicates that the particular scenario would
     involve a UWB transmitter on a fixed antenna tower at the same
     altitude as the airborne victim, which would not be likely.

125. The NTIA protection criteria for most of the systems were
     determined from International Civil Aeronautical Organization
     (ICAO), RTCA and ITU-R standards developed from system spectrum
     sharing criteria. The protection levels for the DME interrogator,
     the ATCRBS systems, and the MLS were based, however, on specific
     system performance specifications and on additional protection
     margins recommended by the FAA's Spectrum Management and Policy
     Program Division. NTIA chose to use international and national
     sharing and coordination criteria partly because harmful
     interference is a subjective criterion. Moreover, these are
     well-established critical operations, many involving safety of life
     situations. Therefore, NTIA believes that it is appropriate to
     provide them protection from interference rather than ensuring that
     harmful interference is unlikely. We recognize that there is
     usually more than one valid approach to interference analysis. In
     several of the analyses discussed below, we present a short
     discussion of the rationale for less conservative values also
     identified in the record. However, out of an abundance of caution,
     we have deferred to NTIA's experience with these systems and used
     NTIA's conservative analyses to develop the requirements for UWB
     operations. The following discussion examines these protection
     criteria for each of the examined systems.

126. *DME, Interrogator*. This system is used to provide civil and
     military aircraft pilots with the distance from a specific ground
     beacon, the transponder, for navigational purposes. In Appendix A
     of its report, NTIA referenced the RTCA specification[^204] for a
     70 percent reply efficiency at a --83 dBm receiver sensitivity, and
     calculated that the interference threshold should be set at --115
     dBm, which is an I/N of -7 dB as shown by Table A-9. [^205] NTIA
     concluded that for all conditions studied and proposed, a UWB EIRP
     of --47 dBm is adequate to protect the operations of the DME
     interrogator receiver.

127. Our evaluation of the NTIA approach used the --99 dBm RTCA
     protection criterion but found no basis for including the
     additional 16 dB of safety margin suggested by NTIA. NTIA indicates
     they applied a partitioning of total interference allowing 10
     percent for UWB (a -10 dB factor) and 6 dB for an aeronautical
     safety margin directly to the -99 dBm RTCA protection criterion
     calculating that the interference threshold should be -115 dBm.
     Employing a -99 dBm protection criterion appears to be consistent
     with NTIA's analysis of the ATCRBS systems where a very similar set
     of operational conditions applies, and where we agree with the NTIA
     methodology. We concluded that this system would not experience
     interference from a UWB device operating at the Part 15 general
     emission level.

128. *DME, Transponder*. This device responds to interrogations from the
     DME airborne component. NTIA applied a 10 dB UWB partitioning and 6
     dB aeronautical safety margin directly to the --106 dBm receiver
     thermal noise level calculating that the interference threshold
     should be--122 dBm. The NTIA initial study of the DME transponder
     showed that an EIRP of --64 dBm was necessary to protect its
     operations from UWB emissions with the additional caveat that no
     UWB could come as close as 15 meters. NTIA's analysis also showed
     that an EIRP of --41.3 dBm would be adequate to protect the
     transponder; however, it would be necessary to ensure that UWB
     devices not operate any closer than 260 meters, which cannot be
     guaranteed. The operational limits required for the protection of
     the GPS will also be adequate to protect DME operations.

129. We question the applicability of the 10 dB value NTIA applied for
     "UWB partitioning." However, applying NTIA's 16 dB protection
     criterion directly against the --94 dBm receiver sensitivity,
     similar to the analysis applied to the DME interrogator, resulted
     in an interference criterion of --110 dBm, which is 4 dB below the
     receiver thermal noise floor. We concluded that a UWB EIRP of --52
     dBm provides an adequate protection threshold for the DME
     interrogator receiver and that the 260-m separation distance
     determined by NTIA was a conservative value. We note that the
     protection criterion employed by NTIA for this system was based on
     a CW-type interfering signal level. Thus, we believe that NTIA's
     analysis results in a conservative protection value since UWB
     emissions are designed to be predominantly noise-like. We agree
     with NTIA that the operational limits for GPS protection will
     protect DME operations.

130. *ATCRBS Transponder and Interrogator*. These systems are used in
     conjunction with the ASR and ARSR and other air traffic control
     radars to provide controllers with the location, altitude, and
     identity of civil and military aircraft through an interrogate and
     reply operation. The protection criteria employed by NTIA were
     based on the minimum triggering levels, that is the minimum input
     power levels supplied to the sensor RF port that results in a 90
     percent reply ratio for the transponder, -77 dBm, and a 90 percent
     reply ratio for the interrogator, -79 dBm. Both the interrogator
     and the transponder must be able to demodulate and decode 90
     percent of the interrogations (replies) with a S/I of 12 dB.[^206]
     NTIA used the power level for 90 percent reply detection as the
     system threshold and applied the RTCA and FAA 12 dB S/I criterion
     to these values to determine the interference thresholds. NTIA's
     final system interference thresholds are 11 dB above the receiver
     thermal noise floor for the interrogator system and 9 dB above the
     receiver noise floor for the transponder system. We agree with the
     NTIA analysis and note that ATCRBS transponder and interrogator
     operations will be protected from harmful interference at the
     emission limits being established to protect to other nearby
     systems (*e.g*., ARSR-4, and GPS).

131. *ARSR-4*. This system is used by the FAA and DOD to monitor
     aircraft during enroute flight to distances of beyond 465 km (250
     nautical miles). NTIA used a protection criterion of an
     interference-to-thermal noise ratio of -10 dB, *i.e.*, I/N = -10
     dB, while the current protection criteria in ITU-R Recommendation
     M.1463 is for an I/N of --6 dB for both radionavigation and
     radiolocation applications of radar.[^207] NTIA calculated that low
     PRF operations of UWB devices, even near ground level, must be
     limited to ‑60 dBm EIRP to protect the ARSR-4. We note that the
     emission limits being required for emissions in the GPS bands are
     adequate to protect ARSR-4 operations.

132. We noted in our analysis that the ITU-R rationale for I/N = -6 dB
     relates to the desensitization of the radar receiver for noise-type
     interference due to the increases in the apparent noise floor that
     the receiver perceives. This desensitization effect results in a
     decrease of the maximum working range of the radar (about 6 %) for
     the smallest cross section target that the radar can detect. The
     effect occurs only at the distance where the signal to noise (S/N)
     of the radar is marginal for normal performance, which is at the
     boundaries of an azimuthal angular section of about half the
     azimuthal beam width in the direction of the UWB source. We also
     noted that radar range decreases by much larger amounts due to
     atmospheric effects such as rain. We believe that the specific
     events that could cause this effect, such as UWB device location
     and antenna orientation with respect to the radar, and the
     relatively mild nature of this effect greatly reduce the risk of
     interference. We further note that the NTIA analysis did not
     include an effect due to the scanning beam of the operating radar.
     TDC stated that because the antenna's main lobe is actually
     tapered, the response signals being integrated could not have the
     UWB transmitter fixed at the maximum of the lobe; instead, it
     appears smeared over the beamwidth of the antenna.[^208] TDC also
     stated that beam shape losses raise the level of the noise in a
     typical radar receiver by at least 1.6 dB above the thermal noise
     floor and possibly as high as 3 dB.[^209] We concluded that the
     potential for UWB interference to the ARSR-4 was more limited than
     the NTIA analysis suggests. However, a more detailed analysis would
     involve statistical estimates and require information specific to
     individual radar sites. Therefore, we deferred to the NTIA analysis
     values for this system. These remarks also apply to the ASR-9 and
     the Marine radar.

133. *SARSAT-LUT*. This system provides distress alert and location
     information to appropriate public safety rescue authorities for
     maritime, aviation, and land users in distress. NTIA used a
     protection criterion of I/N = -9 dB. The NTIA SARSAT-LUT analysis
     was based on the SARSAT receive antenna operating at an elevation
     angle of 0 degrees, *i.e.*, the receive antenna is pointed directly
     at the horizon. At this elevation angle, the large gain of the
     antenna amplifies emissions from a UWB device at 2 m height. TDC
     and XSI correctly noted that the performance specification for
     SARSAT dictates acquiring the satellite when it reaches an
     elevation angle of 5º above the horizon where there is 10 dB less
     gain provided by the SARSAT-LUT antenna than at 0º.[^210] However,
     the acquisition process begins at, or near 0º elevation. The
     SARSAT-LUT antenna is scanned to a lower elevation angle to permit
     faster acquisition of the COSPAS/SARSAT satellites as they appear
     above the horizon. Thus NTIA concluded that use of the maximum
     antenna gain is appropriate. Of the UWB operations proposed,
     outdoors use will have the greatest potential to interfere with
     SARSAT operations.

134. Our analysis of the SARSAT noted that the NTIA protection criterion
     was not referenced from a specific standard or recognized criteria.
     SARSAT is a digital communications system, and we do not consider
     it necessary to protect communications systems from signals that
     are below the noise floor. These systems operate at some margin
     above the noise floor to account for aging components, adverse
     propagation conditions, and other system degradations. Hence, we
     used the noise floor as the protection level, *i.e.*, an I/N of 0
     dB. We also used the angle of 5º above the horizon based on the
     SARSAT specification. We concluded that a UWB EIRP of --50 dBm was
     an adequate protection threshold for the SARSAT system for UWB
     emissions at a height of 2m. Further, we noted that the NTIA
     analysis values are critically dependent on the height of the
     SARSAT antenna used in the analysis (NTIA used an average height).
     Since there are only 7 SARSAT systems mostly located on Government
     installations, we believed that each system could have been
     addressed individually and that this approach would have shown that
     UWB operations would not cause interference to SARSAT operations.

135. *ASR-9*. This radar monitors the location of civil and military
     aircraft in and around airports to a range of 110 km (60 nautical
     miles). NTIA stated that the protection criterion for this radar
     was an I/N of --10 dB. The U.S. Submission to ITU-R Working Party
     8B proposed this level in a revision to ITU-R M.1464, which is
     under consideration by ITU-R Study Group 8 and is an official US
     position. There is also a proposal by Working Party 8B to decrease
     the I/N to --12 dB involving an evaluation of expected interference
     to radars from systems using Orthogonal Frequency Division
     Multiplex (OFDM) modulation methods. The proposal to change the I/N
     to --12 dB also includes noise like interference sources, and is
     not solely based on an OFDM type emission.[^211] However, the --10
     dB level is the agreed upon U.S. position with the ITU and is
     appropriate for this analysis. In calculating the required emission
     limits for UWB devices to protect the ASR-9, NTIA used average
     antenna heights and antenna tilt angles. Only indoor UWB operation
     in a 30 m building exceeds the predicted protection limit for the
     ASR-9. The ASR-9 requires a limitation of the EIRPs of UWB devices
     operating inside buildings to --57 dBm, while the proposed limit
     for indoor UWB devices in this band is --51.3 dBm. Further
     calculations show that if the protection level is --51.3 dBm, the
     required separation distance for a UWB operating at this EIRP level
     is 270 meters. This 3.7 dB difference effectively would reduce the
     I/N from --10 to --6 for this system and would increase the noise
     floor by 1 dB instead of ½ dB. While NTIA indicates that this would
     diminish the capabilities of this radar in the same azimuth of the
     building, NTIA concluded that it is not as severe a problem as the
     reduction of the coverage in this azimuth due to the physical
     line-of-sight blockage caused by a 10-story building within 270
     meters of an ASR-9.

136. *NEXRAD*. This radar provides quantitative and automated real-time
     information on storms, precipitation, hurricanes, tornadoes, and a
     host of other important weather information. We note that NTIA
     refers to ITU-R M.1464, the same specification called out for the
     ASR-9 but uses a level of --6 dB below the noise floor as the
     applicable protection level since the NEXRAD radar is used for
     meteorological purposes. Only indoor UWB operation in a 30 m
     building less than 760 meters away exceeds the predicted protection
     limit for the NEXRAD. The NEXRAD requires a limitation of the EIRPs
     of UWB devices operating inside buildings to ‑57.3 dBm, while the
     proposed limit for indoor UWB devices in this band is --51.3 dBm.
     Given the 0.5-degree minimum elevation angle of the antenna
     mainbeam, the beam would only be 6.6 meters above the ground at 270
     meters. The building itself would at least partially obstruct the 3
     dB beam width of the mainbeam and be the limiting factor along the
     given azimuth and not the UWB's EIRP. An elevation angle of greater
     than 2 degrees is required to clear a 30-meter obstacle at a
     distance of 270 meters.

137. Our analysis of this weather radar examined the possible locations
     of the UWB devices that were required to produce an interference
     level --6 dB below the radar noise floor. At these locations, we
     computed the field strength emitted by the radar. We concluded that
     UWB devices would not be found at these locations because the radar
     fields were large enough to disrupt the operation of standard
     electronic devices. We also were informed of NOAA's siting
     criteria[^212] that requires a large exclusion area around the
     radar to assure operational capability. We were unable to confirm
     that such exclusion areas actually exist as required due to the
     absence of site specific data showing the distance and location of
     large buildings around the radar sites. Therefore, we deferred to
     the NTIA analysis values for this system. These remarks also apply
     to the TDWR weather radar.

138. *Marine Radionavigation Radar*. These S-band radars provide
     information on surface craft locations, obstructions, buoy markers,
     and navigation marks, *e.g.*, shore-based beacons and radar beacons
     to assist in navigation and collision avoidance. NTIA employed an
     I/N protection criterion of --10 dB, indicating that this level is
     contained in a proposed revision to ITU-R M.1313-1 under
     consideration by ITU-R Study Group 8 and entitled, *Technical
     Characteristics of Maritime Radionavigation Radars.* Only the level
     proposed for UWB indoor operation at 30 meters height exceeds the
     calculations for maritime radar. Indoor UWB operations in this band
     will be limited to --51.3 dBm. The level computed for protection of
     marine radar was --56 dBm. The distance at which a UWB with an EIRP
     of --51.3 dBm satisfies the protection criteria equation is 370
     meters. At such a close separation distance, it does not appear
     that marine radionavigation radar systems would receive harmful
     interference from UWB operations. As shipboard UWB operation is
     prohibited at the request of NTIA, marine radar systems must be
     less than 370 meters from land in order to receive interference
     from UWB systems. At this distance, the return signal from the
     target being detected by the marine radar would be considerably
     higher than the signal received from the UWB device. Accordingly,
     no harmful interference would occur.

139. *FSS*. These 4-GHz earth stations are used to receive downlink
     transmissions from geosynchronous satellites for a variety of
     applications including voice, data, and video services for
     Government agencies. NTIA examined interactions with FSS systems
     employing antenna elevation angles of 20 degrees and 5 degrees.
     NTIA used an I/N protection criterion of --10 dB based on a general
     discussion of factors affecting the sensitivity of digital
     communication systems. Only the level proposed for UWB indoor
     operation at 30-meter heights exceeds the calculations for
     protection of receivers in the fixed satellite service with an
     elevation angle of 8º. Emissions from indoor UWB operations in this
     band will be limited to --51.3 dBm. The level computed for
     protection of FSS receivers with an elevation angle of 8 degrees
     was --67 dBm. For the proposed level of --51.3 dBm, the required
     separation distance to satisfy the protection criterion, a
     separation distance of 240 meters must be maintained. For the given
     scenario of an FSS earth station with an 8º elevation angle, if the
     separation distance is less than 240 meters, a 30 meter building
     would at least partially obstruct the 3 dB beamwidth of the
     mainbeam of the earth station antenna based purely on the geometry
     of the scenario. Hence the level --41.3 dBm appears adequate.

140. Our analysis of the FSS noted that the NTIA protection criterion
     was not referenced from a specific standard or recognized
     criterion. FSS is a digital communications system, and as discussed
     in the SARSAT analysis, we believe the noise floor should be
     applied as the protection level, *i.e.*, an I/N of 0 dB. We applied
     the analysis procedure found in the Radio Regulations of the
     ITU[^213] and concluded that for an I/N of 0 dB, UWB interference
     would not be allowed to occur for more than 2.5% of the time
     without requiring coordination. We considered that UWB devices in
     tall buildings would not be an interference risk for the FSS
     terminals. The FSS antenna would not point at a building since the
     building would block signals from the satellite. We were unable to
     confirm this conjecture because of the absence of site specific
     data showing the distance and location of large buildings around
     the FSS sites. Therefore, we defer to the NTIA analysis values for
     this system.

141. *CW and Pulsed Radar Altimeters*. These systems provide pilots of
     civil and military aircraft and, through them, air traffic
     controllers with information on the height of an aircraft above
     ground level. NTIA's investigation demonstrated that UWB devices
     operating at the Part 15 general emission limits would not result
     in interference to these operations. For that reason, we have not
     investigated these systems in any greater detail.

142. *Microwave Landing Systems*. These systems are used for precision
     approach and landing of civilian and military aircraft. The MLS
     ground station supports navigation and guidance out to a range of
     43 km at an altitude of 20,000 feet. NTIA stated that RF
     interference could lead to errors in the estimation of time
     intervals associated with beam passage of the MLS transmitting
     station's antenna beam.[^214] It added that, depending on the
     frequency components of the error process and the aircraft flight
     control system guidance loop bandwidth, this could lead to the
     physical displacement of the aircraft relative to the desired
     approach path. NTIA added that the ICAO specified the maximum
     permissible interference power into a MLS receiver as --130 dBm to
     prevent this from occurring.[^215] NTIA subtracted 4 dB from the
     ICAO threshold "to partition the UWB interference into the link
     budget," resulting in NTIA's maximum permissible UWB interference
     level of --134 dBm, a level that is 22 dB below the thermal noise
     floor of the MLS receiver and 31 dB below the sensitivity of the
     MLS receiver. NTIA employed a 5-dBi gain antenna, the maximum
     available to the aircraft at an angle of about 30 degrees below the
     horizontal.

143. Our analysis of the MLS focused on two approaches. First, the
     receiver noise floor is --112 dBm, and the ICAO maximum
     interference level is --130 dBm. This interference level is 18 dB
     below the noise floor and 27 dB below the sensitivity level of the
     receiver. An interfering signal at 18 dB below the noise floor
     would result in an increase to the MLS receiver noise floor of only
     0.07 dB. Such a small increase in the noise floor is not detectable
     by the receiver or by measurement instrumentation. We believe that
     employing the ICAO value as a protection criterion is overly
     conservative for this system. Further, we do not agree with the
     comments from Rockwell stating that the 4 dB additional safety
     margin added by NTIA is inadequate for MLS operation in a Category
     III approach. Rockwell did not provide any justification for an
     additional safety margin. Indeed, we believe that the ICAO
     threshold, even without the 4 dB additional safety margin applied
     by NTIA, is too conservative. Second, we note that NTIA calculated
     that harmful interference would be caused to MLS from a UWB
     transmitter operating at the Part 15 general emission limits at a
     maximum separation distance of 160 meters. We also note that the
     expected operating range of the MLS system is 43 km at an altitude
     of 20,000 feet. There is little likelihood that at this range from
     the MLS transmitter the aircraft will be within 160 meters of a UWB
     transmitter. As the aircraft approaches the ground, it will come
     much closer to the MLS transmitter, increasing the level of the
     received signal to the point that the MLS signal would be
     considerably greater than the signal level from a UWB transmitter
     operating at the Part 15 general limits.[^216] NTIA also stated
     that its calculations were based on the aircraft being at a height
     of 30 meters. At this height, the aircraft would be near the MLS
     transmitter, whose signal level would override any potential
     interference.

144. *TDWR*. These radars operate in the 5600-5650 MHz band and provide
     measurements of gust fronts, microbursts, and other weather hazards
     at for improving safety operations at major airports in the United
     States. They are located within 24 kilometers (15 miles) of
     airports and need to have a clear line-of-sight (LOS) at the runway
     to observe weather phenomena for aircraft approaches and landings.
     Indoor UWB operation is the only UWB operation not directly
     protected by the proposed limits. The proposed UWB EIRP level for
     this band is --41.3 dBm which is 8 dB above the calculated EIRP. To
     achieve the required protection for the TDWR, a UWB located in a
     30-meter building would have to be located 1370 meters away. Given
     the 0.2º minimum elevation angle of the antenna mainbeam, the beam
     would only be 5 meters above the horizon. The building itself would
     at least partially obstruct the 3 dB beamwidth of the mainbeam and
     be the limiting factor along the given azimuth and not the UWB's
     EIRP. An elevation angle of greater than 1.25 degrees is required
     to clear a 30-meter obstacle at a distance of 1370 meters.
     Therefore, the geometry of the TDWR is the limiting factor for this
     scenario, not the EIRP of the UWB.

     Table 7. Maximum UWB EIRP for UWB Use Indoors

+-------------------+---------+-----------+----------------+----------+
| System            | Fr      | Maximum   | Maximum UWB    | Average  |
|                   | equency |           |                |          |
|                   |         | UWB EIRP  | EIRP           | Building |
|                   | (MHz)   |           |                |          |
|                   |         | (dBm/MHz) | (dBm/MHz)      | Att      |
|                   |         |           |                | enuation |
|                   |         | UWB       | UWB            | Losses   |
|                   |         |           |                | [^217]   |
|                   |         | Indoors   | Indoors        | (dB)     |
|                   |         |           |                |          |
|                   |         | 2 m       | 30 m height    |          |
|                   |         | height    |                |          |
+-------------------+---------+-----------+----------------+----------+
| DME, Interrogator | 9       | -38       | Not            | 9        |
|                   | 60-1215 |           | Ap             |          |
|                   |         |           | plicable[^218] |          |
+-------------------+---------+-----------+----------------+----------+
| DME, Transponder  | 10      | -55       | -48            | 9        |
|                   | 25-1150 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| ATCRBS,           | 1030    | -35       | Not Applicable | 9        |
| Transponder       |         |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| ATCRBS,           | 1090    | -22       | -35            | 9        |
| Interrogator      |         |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| ARSR-4            | 12      | -52       | -73            | 9        |
|                   | 40-1370 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| SARSAT            | 15      | -60       | -57            | 9        |
|                   | 44-1545 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| ASR-9             | 27      | -37       | -57            | 9        |
|                   | 00-2900 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| NEXRAD            | 27      | -33       | -67            | 9        |
|                   | 00-2900 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| Marine Radar      | 29      | -34       | -45            | 12       |
|                   | 00-3100 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| FSS, 20 degrees   | 37      | -24       | -30            | 12       |
|                   | 00-4200 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| FSS, 5 degrees    | 37      | -39       | -65            | 12       |
|                   | 00-4200 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| CW Altimeters     | 42      | 37        | Not Applicable | 12       |
|                   | 00-4400 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| Pulsed Altimeters | 42      | 26        | Not Applicable | 12       |
|                   | 00-4400 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| MLS               | 50      | -42       | Not Applicable | 12       |
|                   | 30-5091 |           |                |          |
+-------------------+---------+-----------+----------------+----------+
| TDWR              | 56      | -23       | -51            | 12       |
|                   | 00-5650 |           |                |          |
+-------------------+---------+-----------+----------------+----------+

145. The above table reflects NTIA's calculation of the maximum signal
     levels that could be permitted for UWB devices operated indoors.
     The possibility of restricting most applications of UWB technology
     to indoor use but imaging and vehicular radar applications was not
     considered in the NTIA analysis because it was not specifically
     proposed in the *Notice*. Thus, the constraints NTIA's analysis
     originally concluded were necessary to protect government receivers
     from outdoor use of UWB devices must be reformulated to account for
     the indoor use of UWB devices and the inherent additional expected
     propagation attenuation. This is done by simply adding a term for
     the value of expected building attenuation as a function of
     frequency to the link budget analysis model described earlier. The
     column on the far right contains the average building attenuation
     factor. NTIA analyzed UWB devices operating in-doors at heights of
     2 meters (roughly equivalent to ground level) and 30 meters
     (roughly equivalent to the tenth floor in a typical suburban,
     office building) and calculated the maximum allowable UWB EIRP. The
     building attenuation level was subtracted from the values NTIA
     obtained in Table 6 to obtain the indoor limits at a 2 meter
     height. The results of the NTIA analyses are summarized in Table 7.

146. *UWB Interference due to Peak Emission Levels*. NTIA also performed
     a limited analysis of potential interference to SARSAT and FSS
     stations due to the peak level of the UWB transmitter. However,
     NTIA did not consider the proposed limits on peak power levels in
     the *Notice,* since their measurements did not show a need for such
     limits for analog systems and only very limited measurements were
     made on digital systems*.* No conclusion can be made from the peak
     power analysis due to the non-linear nature of the digital systems,
     unique error correcting schemes, and unknown characteristics of
     individual UWB systems operating in these bands. The actual impact
     to a digital wideband system from the peak power received from a
     UWB device will depend on many receiver parameters not generally
     available such as modulation scheme, and bit error rates. As a
     result, the peak values NTIA used for its analysis are far in
     excess of the levels the Commission proposed in the *Notice*.[^219]
     Consequently, we do not envision interference problems from peak
     emissions from UWB devices if the peak power limits proposed in the
     *Notice* are embraced.

### U.S. Department of Defense Analysis of Interference to the SGLS

i.  DOD provided a mathematical analysis of possible interference from
    UWB operation to its Space-Ground Link Subsystem (SGLS) at 2.2-2.3
    GHz.[^220] DOD applied free space attenuation without intervening
    objects, assumed a noise-like UWB emission, and applied SGLS receive
    antenna gains ranging from 6 to 26 dB corresponding to antenna
    elevation angles ranging from 20 to 3 degrees. Interference was
    defined with I/N ranging from +17.5 dB to --5.4 dB. It calculated
    minimum separation distances ranging from 19 meters to 1.522 km.

ii. Few details were included with the DOD analysis. We do not agree
    that it is appropriate to use free space analysis or to assume the
    lack of intervening objects in determining propagation attenuation.
    We also do not believe that these DOD satellite receive stations
    will be located in areas were UWB devices would be sufficiently
    close to cause interference problems, especially with the
    operational constraints we are adopting in this proceeding.
    Similarly, as with the SARSAT and FSS stations, these antennas will
    not be directed at buildings or other structures that would block
    reception of the satellite transmissions.

### ARRL Analysis of Noise Floor Increase in Amateur Radio Bands

iii. The ARRL presented analyses of potential increases in the noise
     floor in the Amateur Radio Service frequency bands at 420-450 MHz
     (420 MHz) and 2400-2450 MHz (2450 MHz). ARRL performed calculations
     to show that an amateur radio receiver operating in the 420 MHz
     band, using a 20 dBi receive antenna gain and a receiver bandwidth
     of 1 kHz would experience a 56.5 dB increase in the noise floor at
     a distance of 30 meters from an UWB transmitter operating with an
     average EIRP of --80 dBm/Hz (0 dBm/100 MHz). Similar calculations
     were performed showing that an amateur radio receiver operating in
     the 2450 MHz band using a 0 dBi or a 20 dBi receive antenna gain
     and a receiver bandwidth of 1 kHz would experience a 11.4 and 31 dB
     increase, respectively, in the noise floor at a distance of 30
     meters from a UWB transmitter operating with an average EIRP of
     --90 dBm/Hz (0 dBm/GHz).[^221] Additional calculations showed that
     the increase in the receiver noise floor did not change if the
     receiver bandwidth was increased from 1 kHz to 10 kHz or from 1 kHz
     to 50 MHz.[^222]

iv. We find that ARRL's calculations overestimate the potential increase
    in the noise floor to amateur radio receivers from UWB devices. As
    an initial matter, the use of the thermal noise floor of a receiver
    is not a reasonable approach for evaluating whether or not harmful
    interference may occur. The thermal noise floor represents the
    minimum signal level that can be received under ideal conditions. In
    practice, the actual received signal levels are typically well above
    the thermal noise floor of the receiver. ARRL assumed that the UWB
    transmitter would be operating at an average EIRP of --80 dBm/Hz at
    420 MHz or at --90 dBm/Hz at 2500 MHz. The specific limits proposed
    in the *Notice* were 200 uV/m, as measured at 3 meters with a
    quasi-peak detector, for 420 MHz and 500 uV/m, as measured at 3
    meters with an average detector and a 1 MHz resolution bandwidth,
    for 2450 MHz. These limits are equivalent to an EIRP of 12 nW/120
    kHz[^223] or --49.2 dBm/120 kHz or --100 dBm/Hz at 420 MHz and to an
    EIRP of 75 nW/MHz or --41.25 dBm/MHz or --101.25 dBm/Hz at 2450 MHz.
    Therefore, the levels ARRL applied to the UWB emissions are 11 to 20
    dB higher than those proposed in the *Notice*. We also believe that
    it is extremely unlikely that the UWB emission would be in the main
    beam of a 20 dBi gain antenna, particularly given the operating
    restrictions we are applying to UWB devices.[^224] Adjusting ARRL's
    analyses to take these factors into account substantially reduces
    ARRL's estimate of the increase in the noise floor of the receivers.

v.  In addition, we note that Part 15 devices already operate in the
    2400-2450 MHz band used by the amateur radio service at considerably
    higher power levels that those proposed in the *Notice*. For
    example, frequency hopping spread spectrum transmitters are
    permitted to operate at a signal level of 36 dBm/MHz and at even
    higher signal levels for fixed point-to-point links. Similarly,
    microwave ovens and other Part 18 devices are permitted to operate
    on a primary basis within this frequency band without a limit on the
    level of their emissions. Nevertheless, amateurs have coexisted
    successfully with these devices. This leads us to conclude that it
    is unlikely that UWB devices will have any significant impact on
    Amateur operations in this spectrum. We find nothing in the ARRL
    analysis that leads us to conclude that the existing Part 15
    emissions limits are inadequate to control interference from UWB
    devices to the Amateur Radio Service.

### Analyses of Potential Interference to PCS

vi. Several parties performed tests and analysis of potential
    interference to PCS systems operating in the 1850 -- 1910 MHz and
    1930 -1990 MHz bands.[^225] These studies are discussed in the
    following paragraphs.

vii. *Motorola Analysis.* Motorola performed mathematical analyses of
     potential interference from UWB devices to PCS systems. Motorola
     bases its definition of harmful interference on a PCS receiver as
     any signal that causes a 1 dB rise in the receiver thermal noise
     floor, *i.e.*, resulting from an UWB device that produces signal in
     the PCS receiver that is 6 dB below the thermal noise floor.
     Motorola assumed that the receiver would have a 10 dB noise figure
     and an antenna with --8 dBi of gain. Using free space attenuation,
     it calculated that the UWB and the PCS receiver must be separated
     by at least 13 meters. It then demonstrated how this separation
     distance increased with increasing antenna gain such that the
     minimum separation distance becomes 65 meters when the receiving
     antenna gain is increased to +6 dBi, *i.e.*, the antenna employed
     with a base station.

viii. Protecting the PCS receiver to a level 6 dB below the thermal
      threshold of the receiver is not reasonable because it represents
      the ideal performance of the receiver and is not representative of
      typical operating conditions. In practice, PCS receivers will
      normally receive signals well above the thermal threshold of the
      receiver. Thus, Motorola's analysis affects receivers operating at
      the fringe of a reception area. In addition, it is likely that
      intervening objects would provide significant attenuation to UWB
      emissions. Thus, we do not believe that Motorola's calculations
      provide a reasonable representation of the interference potential
      of UWB to PCS operations.

ix. *Sprint PCS, Time Domain Corporation and Telcordia Analyses.* Sprint
    PCS and TDC jointly submitted two documents. The first was a
    theoretical model developed by Telcordia Technologies to analyze the
    impact of UWB on the forward link on a CDMA PCS network. The second
    summarized tests conducted by Sprint PCS, Time Domain and Telcordia.
    These tests included laboratory evaluations, over the air
    transmissions in an anechoic chamber, and field simulations. The
    over-the-air test conducted in an anechoic chamber demonstrated the
    following[^226]: (1) free space attenuation is appropriate for this
    type of test; (2) the PCS handset had an antenna gain of --4.6
    dBi;[^227] (3) the RSSI measured by the handset was 3 dB different
    from computed values;[^228] (4) the measured E/N for the onset of
    frame errors was 5 dB, consistent with expectations; (5) the handset
    power varied by 1.5 to 2.5 dB due to antenna polarization and by 12
    to 15 dB use to "head loss", *i.e.*, signal blocking by the user;
    and (6) the effect of UWB IX appears to be the same as Gaussian
    noise.[^229] Much of the data from the open field tests was
    lost.[^230] The available test data employed an RSSI (total forward
    power received by the handset) of between --92 dBm and --96 dBm. As
    only a single test cell was activated, no account was taken of
    potential interference from other nearby cells. The minimum UWB
    separation distance to avoid interference at that signal level was
    found to be about 0.35 to 0.56 meters. The call was dropped when the
    UWB emitter was moved to within about 0.3 meters of the PCS
    handset.[^231] It also was noted that with a fully loaded system
    this distance range would apply with the RSSI at about 7 dB greater,
    *i.e.*, at --85 dBm to --89 dBm. Several comments were filed in
    response to this test.

x.  Sprint PCS stated that these tests confirm that a UWB emission at a
    level 12 dB below the general limits in 47 C.F.R. § 15.209 will
    cause interference to a PCS CDMA system, resulting in the handset,
    operating with a PCS received signal of --100 dBm, requesting 50
    percent more power when only 2 meters from the UWB
    transmitter.[^232] It added that a separate effect of UWB
    interference is call blocking such that if between one in twenty and
    one in five PCS customers are within 2 meters of active UWB
    transmitters 2 percent to 7.9 percent of calls will be dropped or
    call attempts will be blocked.[^233]

xi. On the other hand, TDC believes that the theoretical model of
    Telcordia does not accurately describe the results of real world
    open field testing, adding that it is not possible for the PCS
    receivers to detect UWB emissions even at separation distances less
    than 1 meter.[^234] It stated that the PCS phone performance was
    dramatically better in an anechoic chamber than in an open field
    even through the base station was clearly visible to the handset and
    the propagation path was unobstructed.[^235] According to TDC, the
    model developed by Telcordia predicted that in an anechoic chamber
    IS-95 cellphones should not experience frame error rates greater
    than 2 percent at received signals levels as low as --105 dBm;
    however, in the open field the FER would jump momentarily to as much
    as 8 percent even when the received signal was as great at --85 dBm.
    TDC adds that extrapolation from testing suggests that the impact of
    the UWB emission on PCS might be observable when the PCS signal is
    marginal, at --95 dBm, and the UWB device is continually
    transmitting and within 1.5 meters.[^236] However, it concluded that
    this was a conservative estimate since during the open field testing
    with a PCS received signal level of between --92 dBm and --95 dBm no
    impact from the UWB emission was seen until the UWB emitter was less
    than 1 meter from the PCS cellphone.

xii. XSI also believes that the earlier Sprint PCS/TDC tests
     demonstrated that UWB devices would not cause substantial harmful
     interference to PCS, stating that the claim of interference is
     based on numerous unrealistic assumptions and conflicting
     results.[^237] XSI stated that it is important to note that the
     anechoic chamber eliminated all external RF noise and any potential
     interference due to other CDMA cells or multi-path which it says
     are the most important factors in understanding potential
     interference for a PCS network.[^238] The test that was performed
     at an outdoor facility showed that the PCS handset exhibited a rise
     in traffic channel power and then dropped a call only when a UWB
     transmitter was moved to within approximately 0.3 meters of the
     handset.[^239] XSI noted that the Sprint model did not consider
     non-line-of-sight propagation effects, nor did it provide an
     allowance for interference from other base stations although this
     effect is shown to be significant, resulting in as much as a 5 dB
     rise in the effective noise floor.[^240] XSI concluded that the
     live testing by Sprint PCS showed that effects such as
     interference, noise, and Rayleigh fading were severe enough to mask
     any effects predicted by the analytical model until the UWB emitter
     was moved to within approximately 0.3 meters of the PCS
     handset.[^241]

xiii. We find that the testing in the anechoic chamber permitted the PCS
      receiver to function properly down to the thermal noise floor of
      the receiver. Once this equipment was placed outdoors in a
      simulated environment, the UWB emissions had no significant
      interference effect except at distances less than one meter. We
      find that it is extremely unlikely that UWB devices will be
      located this close to a PCS receiver, particularly given the
      operating restrictions we are applying to UWB devices. Further, we
      do not believe it is appropriate to use such a close separation
      distance as the basis for controlling harmful interference. Any
      interference at close distances can be easily remedied by moving
      the devices a short distance apart.

xiv. *Qualcomm Analysis.* Qualcomm performed a mathematical analysis
     accompanied by laboratory testing using a PCS simulator. Based on
     its mathematical analysis, Qualcomm asserts that a PCS mobile unit
     would need to be at least 24 meters from a UWB transmitter
     operating at the 47 C.F.R. § 15.209 limit in order not to receive
     harmful interference. A more detailed discussion of the Qualcomm
     analysis has been placed in the docket file for this proceeding.

xv. We observe that Qualcomm's mathematical analysis is based on
    defining harmful interference as any UWB emission that is greater
    than 6 dB below the thermal noise floor of the PCS receiver. While
    such an analysis can determine if a signal will increase the
    receiver noise floor in situations where no RF background noise
    exists, this is not indicative of harmful interference to a
    communications system. Modifying the antenna gain to --4.6 dBi to
    reflect the measured data from the Sprint analysis, and using free
    space to recalculate the minimum separation distance necessary to
    prevent harmful interference to a PCS system, we find that a UWB
    transmitter must be 3.2 meters from the PCS receiver if the UWB
    transmitter operates at the limit in 47 C.F.R. § 15.209 and 0.8
    meters if the UWB transmitter operates at 12 dB below the limit in
    47 C.F.R. § 15.209, as proposed in the *Notice*. These separation
    distances are based on worst case conditions as they do not assume
    that there is additional attenuation of the UWB emissions due to
    intervening objects, mismatched antenna polarizations, head loss, or
    other effects. They also assume that the UWB transmitter is
    operating at its maximum emission limit with the emission directed
    at the PCS receiver.

xvi. The laboratory measurements performed by Qualcomm demonstrated that
     a S/I of about a 6 dB is required to prevent interference to a PCS
     system. We believe that a PCS received signal level of --96
     dBm/1.25 MHz adequately characterizes a low level PCS signal level
     based on real world applications.[^242] Using free space analysis,
     this PCS signal level and a 6 dB S/I for the UWB emission, we find
     that the UWB transmitter must be 7.2 meters from the PCS receiver
     if the UWB transmitter operates at the limit in 47 C.F.R. § 15.209
     and 1.8 meters if the UWB transmitter were to operate at 12 dB
     below the limit in 47 C.F.R. § 15.209. Again, these separation
     distances are based on worst case conditions as they do not assume
     that there is additional attenuation of the UWB emissions due to
     intervening objects, mismatched antenna polarizations, head loss,
     or other effects. They also assume that the UWB transmitter is
     operating at its maximum emission limit with the emission directed
     at the PCS receiver.

xvii. *Summary of findings of analyses of interference to PCS*. Upon
      review of the various tests and analyses submitted in the record,
      we do not believe that UWB devices will present a significant risk
      of harmful interference to PCS, particularly when evaluated under
      actual operating conditions instead of in a laboratory
      environment. Nevertheless, given that we are applying a reduction
      of at least 12 dB in emissions in the GPS frequency band, which is
      in close proximity to the PCS band, in an abundance of caution we
      will require this reduction to extend through the PCS band to 1990
      MHz. We do not believe this will have any significant impact on
      the viability of UWB devices. Further, this will ensure against
      interference to PCS even under extremely close separation
      distances.

### Cisco Analysis of Potential Interference to MMDS

xviii. Cisco presented mathematical analyses to demonstrate that a
       single UWB transmitter would cause a significant increase to the
       noise floor of a MMDS receiver located several hundred meters
       away. Attachment 2 to its comments addressed UWB peak emissions,
       and Attachment 3 to its comments addressed UWB average emissions.
       With regard to peak emissions, Cisco calculated, based on the
       proposal in the *Notice* for a limit on total peak power, that a
       UWB transmitter operating with a pulse width of one nanosecond
       and possessing a 1.5 gigahertz --10 dB bandwidth will have a
       total peak emission 49.4 dB greater than the average limit. It
       then calculated that for a UWB system to comply with a 49.4 dB
       peak to average ratio it must operate with a pulse repetition
       frequency of 11.5 kHz.[^243] As this is less than the 12 MHz
       bandwidth employed by the MMDS receiver, Cisco calculated that
       the peak power received by the 12 MHz wide receiver will be 44.1
       dB greater than the average UWB received power.

xix. We find that in calculating the --10 dB bandwidth of the UWB
     transmitter Cisco assumed the use of a perfect antenna. It is
     unlikely that an antenna, which acts as a band-pass filter, would
     pass all of the energy over a 1.5 gigahertz bandwidth centered on
     the UWB emission. The actual total peak signal, based on the
     proposal in the *Notice*, may be lower due to the narrower
     transmitted bandwidth. Cisco also assumed that the UWB transmitter
     had to meet a peak-to-average ratio whereas our proposal was to
     establish an average limit and a peak limit with the latter
     consisting of two parts: a total peak power based on the bandwidth
     of the emission and a peak power limit based on a 50 MHz bandwidth.
     In actual practice, a UWB transmitter will be subject to the
     average limit or to the peak limit but not both. Systems with low
     PRFs will be governed by the peak limits and systems with high PRFs
     will be governed by the average limits.

xx. With regard to average power levels, Cisco modeled a 2.5 GHz
    sinusoidal carrier modulated by a one nanosecond pulse with a PRF of
    20 MHz. Cisco then assumed that the UWB transmitter operated at the
    maximum limit and was pointed directly at a 20 dBi antenna employed
    by the MMDS receiver. Cisco also assumed that its MMDS operation
    should be protected to at least a level of 10 dB below the thermal
    noise floor of the MMDS receiver without adjusting the noise floor
    for line losses and the receiver noise figure. With free space
    attenuation, this resulted in Cisco calculating a minimum separation
    distance of 380 meters. Cisco then assumes that 10 or 100 UWB
    transmitters all are emitting at the maximum allowable emission
    limit at 2.5 GHz and are all pointed directly at the MMDS antenna to
    show how, using free space attenuation, the required separation
    distances increase to 1.2 km and 3.9 km.

xxi. We find that the protection of the MMDS receiver to a level 10 dB
     below the thermal threshold of the receiver is not
     reasonable.[^244] Second, we note that the actual thermal noise
     floor of the MMDS receiver would be higher than that calculated by
     Cisco once line losses and the receiver noise figure are included.
     Unfortunately, these values are not provided by Cisco to permit the
     calculations to be redone. Third, at the distances employed free
     space is not a practical method to calculate path loss. At these
     distances, intervening objects would provide significant
     attenuation to UWB emissions. Fourth, it is extremely unlikely that
     the UWB emission could be pointed at the main beam of a high-gain
     MMDS antenna because such antennas generally are mounted outside on
     roof tops or on the sides of buildings. Because of this antenna
     placement, it is highly unlikely that a UWB transmitter would be
     close to an MMDS station or have its emissions directed within the
     mean beam of the MMDS receiving antenna. As with the SARSAT and FSS
     stations, MMDS antennas will not be directed at buildings or other
     structures that would block reception of the MMDS transmissions. We
     also note that millions of other RF products, such as spread
     spectrum transmitters operating in the 2400-2483.5 MHz band under
     the provisions of 47 C.F.R. § 15.247, already are permitted to
     place spurious emissions in the MMDS bands at the emission level
     proposed in the *Notice*. The spread spectrum spurious emissions
     must be attenuated to--41.25 dBm/MHz,[^245] the same level proposed
     for UWB emissions.

### XM Analysis of Potential Interference to DARS 

xxii. XM performed an analysis of potential interference to its
      satellite digital audio radio service operating in the 2332.5 --
      2345 MHz band. XM stated that its satellite receiver operates with
      a received signal of --109 dBm to --90 dBm with a noise figure of
      1.2 dB and a thermal noise of --110 dBm/2 MHz.[^246] XM then
      calculated, using free space, the required separation distances
      between a UWB device and a DARS receiver in order to ensure that
      the UWB emissions are below the thermal noise floor of the DARS
      receiver. At a level of --41.25 dBm/MHz, XM calculated that the
      UWB device must be 35 meters from the DARS receiver.[^247] XM also
      stated\` that the required S/N for its receiver is 3 dB, the I/N
      is 67 dB and the minimum distance from an interference source must
      be based on 1 meter. Accordingly, XM requests that the emissions
      from UWB devices in its 2332.5-2345 MHz band be limited to --70
      dBm.

xxiii. As discussed above, harmful interference is not caused to a
       receiver from a radio signal that is below the thermal noise
       floor of a victim radiocommunications receiver. If we assume that
       the UWB signal, emitting at --41.25 dBm/MHz, may not exceed the
       DARS receiver thermal noise floor of --110 dBm/2 MHz, an
       attenuation of 71.75 dB is required. Free space at 2340 MHz
       achieves this attenuation at a separation of around 39 meters. If
       we take into account the 3 dB loss between XM's circular
       polarized antenna and the linear polarization expected from UWB
       operation, the separation drops to 27.9 meters. If only 10 dB of
       attenuation is applied to the UWB emission, the minimum
       separation distance decreases to 8.8 meters. This is not an
       excessive separation distance for a receiving system that
       generally is expected to be mounted outside of a transportation
       vehicle or on the roof or side of a building. Under practical
       operating conditions, there would be further attenuation of the
       UWB emissions due to the presence of intervening objects,
       misalignment of the UWB transmitting and DARS receiving antennas,
       and other factors. Further, the DARS signal normally would be
       above the minimum received level employed in this calculation. It
       also is likely that the UWB emissions would be somewhat below the
       maximum level permitted under the rules. These factors would
       considerably shorten the calculated interference distance.
       Vehicle mounted UWB radar systems, which will be located closest
       to DARS receivers, are being required to operate in a
       considerably higher frequency band than that used by DARS. This
       should result in emissions appearing in the DARS band that would
       be no more of an interference threat than emissions from
       conventional Part 15 devices.[^248] In any event, emissions from
       the vehicular radar systems would likely be pointed in a
       direction other than at the DARS antenna. Further, since vehicle
       manufacturers will provide DARS and UWB radar systems in the same
       vehicle the vehicle manufacturer would engineer these systems to
       ensure that there is no mutual interference. We also note that
       DARS will be supplemented in major metropolitan areas with high
       powered terrestrial broadcasting stations, further reducing the
       potential for harmful interference.

### Summary of Tests and Analyses

147. The protection levels established in this Order primarily are those
     determined in the NTIA analyses of Government systems. The UWB
     emissions level NTIA developed for the GPS bands provides a
     conservative protection level for all of the government and
     commercial systems operating between 960 MHz and 1610 MHz. We find
     that the various analyses were generally based on overly
     conservative and worst case conditions. For example, tests were
     performed in some cases using UWB signals with characteristics
     designed to cause the greatest interference effect. While we
     recognize this could occur, in practice many UWB devices will have
     emission characteristics that are more benign relative to
     particular receivers. We also note that several of the analyses
     seek to protect radiocommunications systems to levels below the
     receiver thermal noise floor. This is a level of performance that
     does not generally occur under actual operating conditions due to
     the presence of other sources of radio noise. Further, the fact
     that the noise floor may increase does not necessarily indicate
     that harmful interference will occur.

148. Certain of the analyses applied only free space attenuation to
     determine propagation losses and did not consider the effects of
     intervening objects. Some commenting parties sought to ensure that
     no interference would occur at unreasonable separation distances,
     such a having the victim receiver within one meter of, or
     co-located with, the UWB transmitter. In some cases additional
     protection margins were added to further ensure conservative
     protection levels. We observe that these various studies and
     analyses have been useful in serving to illuminate the record in
     this proceeding. However, we do not believe our regulations for
     controlling interference from UWB devices should be based on a
     series of worst case assumptions. Instead, we find that the various
     studies demonstrate conclusively that UWB devices can be permitted
     under the proper set of standards without causing harmful
     interference to other radio operations.

## Emission Limits

### General

i.  [Proposal]{.underline}. In order to control harmful interference
    from UWB devices, appropriate emission limits must be established.
    The current Part 15 rules are based on the equivalent of a power
    spectral density, *i.e.*, a field strength limit is specified along
    with a measurement bandwidth. These emission limits were chosen to
    protect various classes of receivers from interference at certain
    separation distances. The radiated limits below 1 GHz are based on
    measurements employing a quasi-peak detector that effectively
    provides an average reading with some weighting for peak signal
    levels. The radiated emissions limits for both intentional and
    unintentional radiators above 1 GHz are based on measurements using
    an average detector. However, intentional radiators also are subject
    to a requirement that the total peak levels of emissions above 1 GHz
    must be no greater than 20 dB above the average limits.[^249] Higher
    peak levels could lead to an increased risk of interference to
    certain receivers. For example, if the pulse repetition frequency of
    the UWB signal is much greater than the bandwidth of a receiver, the
    emission may appear to be random noise, the effect of which is
    proportional to the average power in the UWB signal within the
    receiver's bandwidth. However, if the PRF is much less than the
    receiver's bandwidth, the UWB signal may appear to the receiver as
    impulsive noise and the effect would be proportional to the peak
    power of the UWB signal. In addition, UWB devices spread their
    emissions over a wide bandwidth as compared to most current
    intentional and unintentional radiators. As a result, receivers that
    use wide bandwidths are likely to receive more total energy from UWB
    devices than from most other existing Part 15 devices.

ii. In the *Notice*, the Commission concluded that it is necessary to
    regulate both the peak and average emission levels above 1 GHz and
    the quasi-peak emission levels below 1 GHz from UWB transmitters,
    just as it regulates these emission levels for most other types of
    Part 15 transmission systems. The impact of UWB signals on a
    receiver appears to depend on the randomness of the UWB signal and
    the relationship between the pulse repetition frequency (PRF) of the
    UWB signal and the bandwidth of the receiver.[^250] If the UWB
    pulses are spaced evenly in time and each pulse is exactly the same
    (as in many radar systems), then classic communications theory shows
    that the spectrum consists of narrow spectral lines spaced at the
    PRF. The impact of these signals on a receiver can be modeled by
    treating each spectral line as a narrowband conventional signal.
    This gives rise to one possible way to increase protection to GPS
    receivers from UWB GPR and through-wall imaging devices. Since
    repetitive identical pulses are often applicable to GPRs and
    through-wall imaging devices, the Commission noted that it might be
    possible for designers to select system parameters to avoid GPS
    signal bands and thus avoid co-channel interference. It also may be
    possible to space the UWB signal's spectral lines in places within
    the GPS band where GPS receivers are less sensitive to interference.
    Comments were requested on whether this technique is applicable to
    all types of GPRs and through-wall imaging devices and the cost
    implication of using a stable frequency reference to ensure the PRF
    creates a signal avoiding the GPS bands.

iii. For UWB communications systems, the emitted spectrum depends on the
     information being sent. If the information is unchanging, such as a
     steady string of zeroes in the case of digital information, the
     transmitted signal may become a set of spectral lines that has
     different interference potential than the noise‑like spectrum that
     would be produced under normal modulation. Depending on exactly
     where these spectral lines are, the interference potential may
     increase. This could be avoided by using scrambler technology,
     often used in digital wireline and optical communications systems,
     which prevents long strings of unchanging bits. The Commission
     sought comment on whether it should require such scrambler
     technology for UWB communications systems or, alternatively, a
     performance requirement that would show that the transmitted
     spectrum remains noise-like in the case of unchanging input data.

iv. [Comments]{.underline}. The comments generally indicated that the
    proposal to place spectral lines outside of critical frequency bands
    should not be implemented. For example, as noted by AOPA doppler
    shifts due to movements of the GPS satellites and to movements of
    planes would negate any ability to avoid the GPS band.[^251] AOPA
    added that the frequency stability of the circuitry used to generate
    the PRF would have to be very stable raising cost concerns. A. Peter
    Annan stated that this is an impractical solution for GPRs that have
    low PRFs that make it impossible to space the spectral lines far
    enough apart to avoid the GPS bands.[^252] ARRL noted that selecting
    PRFs to avoid generating signals in certain bands would add a layer
    of regulatory complexity that could perhaps be better addressed
    through other means.[^253] On the other hand, Aether Wire indicates
    that it may be possible for its equipment to avoid the GPS L1 and L2
    bands by adjusting the spaces between the impulse doublets and
    between the impulses in each doublet of its transmission, noting
    that the oscillation would have sufficient stability through the use
    of temperature stabilization.[^254]

v.  With regard to scrambler technology, the comments supported
    requiring UWB signals to be noise-like in certain bands,
    particularly GPS. AOPA noted that sufficient dithering or scrambling
    of the interference signal spectral lines in the instantaneous time
    or frequency domains would decrease the probability of harmful
    interference but could increase aggregate interference.[^255] Aether
    Wire stated that a UWB system that lacks coding for channelization
    is severely limited in its capabilities and that such a system it
    the only one for which scrambler technology is applicable.[^256] It
    added that a performance requirement that shows that the transmitted
    spectrum remains noise-like in the case of unchanging input data is
    appropriate.

vi. [Discussion]{.underline}. We have come to the conclusion that there
    is no need to establish design criteria for UWB systems, such as
    specifying where spectral lines may be placed or requiring the
    application of scrambler technology. Rather, we believe that we
    should specify only the emission limits that are necessary to
    prevent interference to the authorized radio services. It will be up
    to the manufacturers of UWB devices to determine how they will
    comply with these standards. A discussion of the emission levels we
    are adopting follows. As will be noted, we are adopting a
    requirement to limit the power level of the spectral lines that
    appear in the GPS frequency bands.

### Average and Quasi-peak Emission Levels

vii. [Proposal]{.underline}. The Commission stated in the *Notice* that
     the Part 15 general emission limits[^257] have a long and
     successful history of controlling interference to other radio
     operations. However, the general emission limits were never
     designed to protect against all possibilities of harmful
     interference. Rather, these limits were designed to protect
     neighbors from causing interference to each other.[^258] These
     limits were designed as a reasonable compromise to protect the
     authorized radio services from receiving harmful interference
     without requiring an analysis of the individual needs of every type
     of receiver design used in every radio service. The Commission
     reiterated that it remains committed to protecting the authorized
     radio services from receiving harmful interference from Part 15
     devices, adding that it was especially concerned about protecting
     radio services used for safety-of-life applications, such as GPS,
     from such interference. Accordingly, the Commission indicated in
     the *Notice* that the general emission limits contained in 47
     C.F.R. Section 15.209 appear appropriate for UWB operations. These
     emission limits are already based on a spectral power density,
     measuring signal level per unit bandwidth.[^259] It also proposed
     that additional protection be provided below approximately 2 GHz
     for emissions from UWB devices. For emissions from UWB devices
     other than GPRs and, possibly, through-wall imaging systems, it
     proposed that emissions that appear below approximately 2 GHz be
     attenuated by at least 12 dB below the general emission limits.
     This attenuation below the general emission levels would provide
     additional protection to the congested spectrum below 2 GHz without
     affecting the viability of UWB operations. Comments were requested
     on whether additional attenuation below 2 GHz is necessary.
     Comments were also sought on whether the proposed reduction in the
     emission levels should apply to all emissions below 2 GHz or only
     to emissions below 2 GHz that fall within the restricted bands
     shown in 47 C.F.R. § 15.205. Comments also were requested on
     whether UWB devices other than GPRs, and possibly through-wall
     imaging systems, should be permitted to operate below 2 GHz
     provided they comply with these reduced emission levels. Finally,
     the Commission indicated that the emission limits that were
     proposed in the *Notice* were a reasonable starting point for
     establishing standards. As equipment continues to be developed and
     additional experience is gained with this equipment, future changes
     to the standards would be considered.

viii. [Comments/Discussion]{.underline}.[^260] A considerable number of
      comments were filed concerning the levels of emissions that should
      be permitted for UWB transmitters. Most of the comments supported
      the continued application of quasi-peak limits on radiated
      emissions below 1000 MHz and of average and peak limits on
      radiated emissions above 1000 MHz.[^261] NTIA, however, requested
      that average and peak emission limits apply to all emissions above
      960 MHz. Some commenting parties requested that we implement
      limits on spectral power density.[^262] However, the quasi-peak
      and average limits currently contained in the Part 15 rules
      already are based on spectral power densities. For example, the
      quasi-peak limits for emissions between 30 MHz and 1000 MHz are
      based on the emissions that appear in a 120 kHz [+]{.underline} 20
      kHz bandwidth. The emission limits above 1000 MHz are based on the
      emissions that appear in a 1 MHz bandwidth.[^263]

ix. There was no concurrence in the comments with regard to the emission
    limits that should be adopted. The ARRL stated that the Part 15
    general emission limits have not been adequate to protect all
    amateur operations; however, it could, with some reluctance, accept
    the idea that permitting UWB operation at those levels is not much
    different in kind from the types of operation permitted under the
    Part 15 rules.[^264] It added that the impact on amateur receivers
    from UWB signals that are noise-like would be determined by the
    average power present in the victim receiver bandwidth whereas for
    UWB signals with low PRFs, the noise may appear as impulse and/or
    multiple discrete signals within the receiver passband where the
    peak limit would be more important.[^265] Lucent also agreed that
    the proposed peak and average limits were sufficient for
    interference protection provided average measurements are
    clarified.[^266] On the other hand, parties such as XM requested
    that the emission levels in the satellite DARS band be reduced to an
    EIRP of --100 dBW, about 29 dB below the existing Part 15 emission
    limit.[^267] Parties such as Siemens Automotive and others want the
    Part 15 emission levels increased at the higher frequencies.[^268]

x.  With the exception of GPR manufacturers, a few comments requested
    increases in the Part 15 emission levels for UWB devices. MSSI
    wished to operate with a one watt peak output into a 6 dBi
    antenna.[^269] While MSSI equated its UWB operation to the
    regulations for spread spectrum operation, the current rules
    designate specific frequency bands for spread spectrum
    operation.[^270] Implementation of this same power level for
    operation in other frequency bands was not supported by the earlier
    test data or comments. Bosch, Saab, Siemens and Valeo requested that
    the higher frequency bands be permitted increased signal levels due
    to increased attenuation.[^271] We agree that higher attenuation
    applies to RF emissions as frequency increases and that this may
    prove to be an acceptable approach to modifying the Part 15 emission
    limits. However, we do not believe that initial UWB operations
    should begin with a power increase.

xi. As noted by TDC, the issue of what constitutes reasonable levels of
    emissions outside of defined bands confronts the Commission every
    time a new licensed or unlicensed service is proposed.[^272]
    However, several tests and analyses, discussed earlier, have been
    performed in this proceeding that permit us to determine the
    appropriate emission limits. As noted earlier, there were only a few
    instances where UWB systems operating at the limits in 47 C.F.R. §
    15.209 demonstrated a clear potential to cause harmful interference
    to the authorized radio services. In most of these instances, the
    UWB transmitter and the victim receiver were required to be in
    extremely close proximity to each other before harmful interference
    could occur.

xii. As discussed earlier, the interference analyses performed by NTIA
     and others allowed us to determine the emission limits that should
     be applied to UWB devices operating under various worst case
     conditions. Based on the limited information in the record and our
     lack of operation experience with UWB devices, we believe it best
     to proceed with an abundance of caution in establishing emission
     limits. The limits we are adopting were coordinated with NTIA, as
     well as with several other U.S. Government agencies. [^273] These
     limits are an appropriate first step in introducing UWB devices.
     The following table specifies the average emission limits, in terms
     of dBm EIRP as measured with a one megahertz resolution bandwidth,
     that we are implementing for UWB operation.

     **Table 8 Average Emission Limits Applicable to UWB Operation**

  ------------- --------- --------------- ----------- -------------- ----------- -----------
  Frequency     Imaging   Imaging,        Imaging,    Indoor         Hand held,  Vehicular
  Band (MHz)    below 960 Mid-Frequency   High        applications   including   radar
                MHz                       frequency                  outdoor     

  0.009-960     §15.209   §15.209         §15.209     §15.209        §15.209     §15.209

  960-1610      -65.3     -53.3           -65.3       -75.3          -75.3       -75.3

  1610-1990     -53.3     -51.3           -53.3       -53.3          -63.3       -61.3

  1990-3100     -51.3     -41.3           -51.3       -51.3          -61.3       -61.3

  3100-10600    -51.3     -41.3           -41.3       -41.3          -41.3       -61.3

  10600-22000   -51.3     -51.3           -51.3       -51.3          -61.3       -61.3

  22000-29000   -51.3     -51.3           -51.3       -51.3          -61.3       -41.3

  Above 29000   -51.3     -51.3           -51.3       -51.3          -61.3       -51.3
  ------------- --------- --------------- ----------- -------------- ----------- -----------

149. Mid-frequency imaging, consisting of through-wall imaging systems
     and surveillance systems, must operate with the --10 dB bandwidth
     within the frequency band 1990-10,600 MHz. High frequency imaging
     systems, equipment that will be operated exclusively indoors, and
     hand held UWB devices that may operate anywhere, including outdoors
     and for peer-to-peer applications, must operate with the --10 dB
     bandwidth within the frequency band 3100-10,600 MHz. All other
     imaging systems must operate with the --10 dB bandwidth below 960
     MHz. Vehicular radar systems must operate with the -10 dB bandwidth
     within the frequency band 22-29 GHz and with a carrier frequency
     greater than 24.075 GHz. To further ensure that the operation of
     these UWB devices does not result in harmful interference, we also
     are requiring coordination with NTIA through the Commission of the
     imaging systems. The operators of these devices will be required to
     provide us with their address, the characteristics of the UWB
     device, and a detailed record of the areas in which the equipment
     will be operated. The information submitted to the Commission will
     be forwarded to NTIA for notification purposes. The operators of
     UWB imaging systems must complete this coordination and
     authorization procedure before initial operation of the equipment
     in a particular area. As noted previously, in emergency situations
     a notification process may be used in lieu of coordination.[^274]
     Further, depending on the specific location it may be necessary for
     the operators to coordinate day-to-day operations with nearby radio
     stations within their operating area. The manufacturers of these
     devices will be required to inform the users of the equipment of
     these requirements. Because of the tighter emission limits being
     employed, coordination is not being required for indoor equipment,
     hand held devices, or vehicular radar systems.

### Imaging Systems Including GPRs

i.  As noted throughout this Report and Order, we are taking a cautious
    approach to the standards for UWB devices. One method of reducing
    interference potential is to restrict the applications for using UWB
    devices and the locations where UWB devices may be operated. These
    devices will have a low proliferation and would be used
    infrequently. Further, the primary energy from a GPR is directed
    into, and absorbed by, the ground. In addition, the energy radiated
    by the GPR is at a low elevation where it should attenuate
    rapidly.[^275] To ensure that the proliferation remains low, we are
    restricting the parties that may operate GPRs to law enforcement,
    fire and emergency rescue organizations, to scientific research
    institutes, to commercial mining companies, and to construction
    companies. As used in this Order, law enforcement, fire and
    emergency rescue organizations refers to parties eligible to obtain
    a license from the FCC under the eligibility requirements specified
    in Section 90.20(a)(1) of this chapter. All users of GPRs must be
    eligible for licensing under Part 90 of our rules, and these users
    must coordinate with the FCC, which in turn will coordinate with
    NTIA, before operation.

ii. Peter Annan stated that GPRs need special consideration on emission
    limits with more power needed at lower frequencies, particularly for
    operation below 250 MHz.[^276] He requested that GPRs be permitted
    to operate at an average power limit of 500 mW below 50 MHz and 20
    mW above 250 MHz with a logarithmic progression between these power
    levels between 50 MHz and 250 MHz. GSSI and Sensors & Software, in
    extremely late filed comments, requested that GPRs operating with
    PRFs lower than 500 MHz and at frequencies below 500 MHz be
    permitted to exceed the 47 C.F.R. § 15.209 limits, up to a maximum
    level of 95 dBuV/m below 30 MHz.[^277] These companies did not
    indicate how or at what distance the revised emission limit should
    be measured, but we believe, based on their October 2, 2001, meeting
    with the staff of our Office of Engineering and Technology, that
    they desired these limits to be based on an average measurement.

iii. Subsequent to the October 10, 2001, filing by GSSI and Sensors and
     Software, a late filed comment was submitted on October 16, 2001,
     by Mr. Steven Koppenjan *et al*, identifying themselves as the
     general chairs of the 6^th^, 7^th^, 8^th^ and 9^th^ International
     Conferences on Ground Penetrating Radar. Mr. Koppenjan *et al*
     indicated that new GPR products are being developed that will
     comply with the limits proposed in the *Notice*. They add that
     pulse compression schemes can provide both low peak-to-average
     power ratios in the time domain and low spectral power density in
     compliance with the proposals.

iv. Sufficient notice was not provided to the other parties interested
    in this proceeding to permit us to address a relaxation to the
    emission limits below 500 MHz. In addition, the request to allow
    certain GPR devices to operate at higher emissions levels was filed
    very late, which did not afford an opportunity for analysis by other
    parties. We also note that GSSI did not provided any interference
    analysis to support its proposals, other than a statement that
    existing GPRs have operated benignly with these emission
    characteristics for 30 years. It appears that the basis of the
    proposals from GSSI and from Sensors & Software is to accommodate
    existing equipment designs.[^278] It also appears, based on the
    comment from Mr. Koppenjan *et al*, that it may be possible for GPRs
    to be designed to comply with the radiated emission limits proposed
    in the *Notice*. Thus, we are not persuaded that higher emission
    levels are prudent especially in the early stages of UWB standards
    development. Such higher limits could overpower the front end of a
    nearby receiver or result in harmful interference to nearby
    television broadcast reception.

v.  In contrast to GPRs, other types of imaging systems may be used for
    a variety of applications where the energy is aimed horizontally
    along the earth. We anticipate that the walls, buildings or other
    objects against which the imaging system may be placed may absorb
    most of the energy.[^279] However, we recognize that with imaging
    systems other than GPRs there is an increased risk that some of the
    energy would not be absorbed and could be radiated in the direction
    of authorized radio services. Thus, as a cautious approach we are
    restricting the use of imaging systems. Wall imaging systems may be
    employed only by law enforcement, fire and emergency rescue
    organizations, by scientific research institutes, by commercial
    mining companies, and by construction companies. Only law
    enforcement, fire or emergency rescue organizations may use
    through-wall imaging systems. Further, the operators of through-wall
    and wall imaging systems must be parties that are eligible to obtain
    licensing under the provisions in Part 90 of our rules. Finally,
    medical imaging systems may be used only at the direction of, or
    under the supervision of, a licensed health care practitioner. This
    will allow the introduction of the compelling uses for UWB imaging
    systems cited by the commenters, such as for hostage rescue, law
    enforcement, inspection of building walls and foundations, and
    detecting objects inside walls when performing construction. At the
    same time, by limiting the applications for UWB imaging we will
    minimize the risk of interference by controlling the proliferation
    of these devices. The applications for UWB imaging systems will be
    controlled through our equipment authorization program. In addition,
    the grantees of equipment authorization will be responsible for
    ensuring that the marketing and distribution of these products is
    consistent with the restrictions on use.

### Other Applications

vi. While we believe that some of the interference levels characterized
    by the commenters may not represent real-world situations, we agree
    that the initial UWB regulations should be implemented cautiously.
    Accordingly, we are implementing a reduction to the Part 15 general
    emission levels over certain frequency bands to ensure that our
    introduction of UWB devices causes the least possible impact to the
    authorized radio services. We investigated different standards for
    UWB devices depending on whether they are operated outdoors or
    indoors. We believe that the combined operating conditions and
    emissions standards will prevent harmful interference. The operation
    of UWB devices at the EIRP levels being adopted in this proceeding
    should provide sufficient attenuation to protect authorized services
    from harmful interference from UWB systems operating nearby or in
    elevated locations, such as inside buildings.

vii. With regard to GPS, we are particularly concerned about protecting
     E-911 applications. As noted above, GPS systems can experience
     harmful interference if they are within a few meters of a UWB
     system operating at the general limits in 47 C.F.R. § 15.209. The
     emission limits being adopted in this proceeding within the GPS
     frequency bands, ranging from 12 to 34 dB below the Part 15 general
     limits, were found to be more than sufficient to protect GPS from
     harmful interference. Further, we note that GPS operates in the
     same frequency region as DME transponders, the ARSR-4, and SARSAT
     systems.[^280] We also note that the emission limits we are
     applying to the GPS bands are more than sufficient to prevent
     harmful interference to all Government systems operating in the
     960-1610 MHz band.

viii. We also concluded from our analysis of the Qualcomm submission
      that it could be advantageous to provide additional protection to
      PCS operation in the 1850-1990 MHz band due to its potential use
      in E-911 applications. The 12 dB of attenuation below the Part 15
      general emission limits appears more than sufficient to provide
      this protection, as described in our discussion of the Qualcomm
      analyses. We do not believe that additional attenuation is needed
      for UWB emissions falling in the Cellular Radiotelephone Service
      bands at 824-849 MHz and 869-894 MHz bands. In the first place,
      the Part 15 general emission limits for the cellular frequency
      band, unlike those for the PCS band, are expressed as a quasi-peak
      limit. The modulation employed by UWB devices will tend to be
      measured in the cellular band as a peak spectral power density
      whereas the cellular receiver will respond to the average signal
      level from the UWB transmitter. This should provide sufficient
      additional protection to cellular reception. Second, only imaging
      systems will operate at the low frequency employed for cellular
      operation. Third, the emissions from cellular transmitters that
      fall within the band used by the mobile receiver are permitted at
      a level of --80 dBm, as measured at the antenna connector.[^281]
      This is the level of interference that a cellular mobile
      transmitter may cause to its own receiver. This also is the level
      that would be produced by a UWB transmitter, operating at the Part
      15 general emission limits, at a separation distance of about 4
      meters using free space attenuation with no intervening objects.
      Thus, the separation distance between a UWB transmitter operating
      at the general emission limits and a cellular receiver is about
      the same as that of a UWB transmitter operating at 12 dB below the
      general emission limits and a PCS receiver. Accordingly, we find
      that no additional attenuation in the cellular band is required.

ix. Based on the above, we are applying a 12 dB reduction below the
    general emission limits over the frequency range 1610 MHz to 1990
    MHz.[^282] We also have applied a 10 dB reduction below the general
    emission limits for emissions between 1990 and 3100 MHz to ensure
    protection from harmful interference to the U.S. Government
    operations within this band as well as the operation of DARS and
    other communications systems operating within this band.

x.  One of the largest potential outdoor uses of UWB technology is
    vehicular radar. However, we do not believe that the proliferation
    of such devices will result in increased interference concerns at
    the emission levels and frequency range being adopted. We are
    requiring that the -10 dB bandwidth be between 22-29 GHz and that
    the center frequency be greater than 24.075 GHz.[^283] In addition,
    there is a high probability that other intervening objects, *e.g.*,
    other vehicles, will cause the emissions to rapidly attenuate,
    especially at the higher frequencies. Emissions far removed from the
    center frequency, *e.g.*, emissions appearing below 10 GHz, should
    appear similar to spurious emissions from other types of Part 15
    devices.[^284] Because we are requiring the lower frequency
    emissions to be attenuated below the Part 15 general emission
    limits, the interference potential from vehicular radar systems to
    lower frequency radio systems will be less than the interference
    potential of conventional Part 15 devices.

xi. Our primary interference concern with vehicular radar systems is
    cumulative interference to passive sensing systems operating in the
    23.6 to 24.0 GHz band on low earth orbiting satellites, including
    meteorological satellites.[^285] NTIA indicated that it performed an
    analysis of the potential interference to EESS passive satellite
    receivers.[^286] NTIA states that a potential for harmful
    interference to EESS receivers would exist if emissions below 24.0
    GHz were permitted at the Part 15 general emission limits. NTIA
    based its analysis on a 22 to 23 dB antenna discrimination at
    elevation angles above 30 degrees above the horizon. It concluded
    that the emissions from vehicular radar systems in the 23.6-24.0 GHz
    band must be 35 dB below the Part 15 general emission limits at
    elevation angles greater than 30 degrees above the horizon.[^287]
    NTIA indicated that an attenuation of 25 dB at elevation angles of
    greater than 30 degrees could be achieved at the present time. NTIA
    indicated that the radars would be placed on transportation vehicles
    over a period of time and agreed to allowing a phased-in approach to
    obtain the additional attenuation. It agreed to permit UWB vehicular
    radar systems provided these systems attenuate emissions appearing
    within the 23.6-24.0 GHz band at greater than 30 dB elevation above
    the horizontal plane by the following amounts below the Part 15
    general emission limits: 25 dB by January 1, 2005; 30 dB by January
    1, 2010, and 35 dB by January 1, 2014.

xii. We believe that the analysis performed by NTIA may be overly
     conservative.[^288] However, to ensure that the cumulative impact
     of the potentially tens of thousands of transportation vehicles
     employing these radar devices does not result in harmful
     interference to the passive satellite receivers we are requiring
     that the emissions 38 degrees or higher above the horizontal plane
     in the 23.6-24.0 GHz band from properly installed vehicular radar
     systems be attenuated by more than 25 dB below the Part 15 general
     emission limit. The attenuation can be due to antenna
     directionality, a lowered transmitter power level or whatever
     combination produces this desired result. For equipment authorized,
     manufactured or imported on or after January 1, 2005, this
     attenuation below the Part 15 general emission limit must be
     increased to 25 dB at 30 degrees or greater elevation. This
     attenuation at elevations greater than 30 degrees shall increase to
     30 dB by January 1, 2010, and to 35 dB by January 1, 2014. We
     intend to review these standards as additional experience is
     gained. In addition, we note that this limit on the emissions from
     a vehicular radar in the vertical direction results in the
     emissions radiated towards the passive satellite sensors to appear
     as spurious emissions. Thus, we are exempting Part 15 UWB devices
     from the provisions contained in US Footnote 246 to the frequency
     allocation table.[^289]

xiii. We were able to reduce considerably the potential for harmful
      interference from UWB systems by limiting outdoor devices to
      imaging and vehicular radar applications. These devices will
      likely use directional antennas that reduce the probability that a
      UWB transmitter will be pointed at any particular victim receiver.
      However, the UWB proponents indicated a desire to provide many
      other types of UWB systems, especially communications systems.
      These systems likely would operate at high PRFs with
      omnidirectional antennas in the lower frequency bands, *e.g.*,
      with a center frequency lower than 5 to 7 GHz. Further,
      manufacturers indicated their desire to permit these operations
      with minimal restrictions on who may use the equipment or on
      licensing. Indeed, some proponents requested that we establish an
      emission limit that permits general outdoor operation.

xiv. XSI, in its *ex parte* filing of October 22, 2001, among others,
     requested that we prohibit outdoor infrastructure or establish
     lower emission limits to permit outdoor applications.[^290] XSI
     stated that it would be willing to attenuate the emissions from its
     UWB communications systems to below the Part 15 general emission
     limits by 12 dB over the band 2 GHz to 1.6 GHz, 18 dB below 1.6
     GHz, and 35 dB in the GPS band with an additional 10 dB in the GPS
     band for spectral lines. In its *ex parte* filing of November 5,
     2001, XSI suggested that the Commission require an additional
     reduction of 9 to 12 dB in emissions below 3.1 GHz from
     peer-to-peer devices to provide the same attenuation that would be
     provided indoor operation due to building shielding.[^291]

xv. Based on our coordination with NTIA and other concerned U.S.
    Government agencies, we believe that limited outdoors operation,
    including general peer-to-peer operations, can be permitted provided
    the emissions from the UWB devices within the 1610-3100 MHz band and
    above 10.6 GHz are attenuated by at least 10 dB below the emission
    levels being permitted for indoor applications. However, we remain
    concerned that permitting UWB devices to be used outdoors could
    result in the development of large communications systems that could
    adversely impact the authorized services. For that reason, we are
    prohibiting the use of antennas attached to outside structures or
    any form of fixed outdoor infrastructure. To further prevent use of
    these products as fixed outdoor systems, we are requiring that these
    devices be hand held products. Further, to ensure that these
    products do not emit energy when they are not transmitting
    information to an associated receiver, we are requiring that hand
    held UWB devices be designed to cease transmission within ten
    seconds unless an acknowledgment is received from the associated
    receiver that the transmission is being received. This
    acknowledgment of reception must continue to be received by the UWB
    transmitter at least every ten seconds in order for the UWB
    transmitter to continue transmission. This will ensure that the UWB
    device transmits only when it is sending information to an
    associated receiver. Finally, to further limit the proliferation of
    these products we are prohibiting the use of UWB devices for the
    operation of toys.[^292] We believe that these conditions reflect
    our desire to proceed cautiously with the introduction of UWB
    equipment.

xvi. Except for toys, we are permitting indoor systems to be used for
     any type of application, including communication systems, provided
     emissions are not intentionally directed outside, *e.g.*, through a
     window or doorway to perform an outside function such as the
     detection of persons about to enter a building. We also are
     prohibiting the use of fixed outdoor antennas, such as antennas
     mounted on the side or top of a building, or other outdoors
     infrastructure. The --10 dB UWB bandwidth, encompassing both the
     center frequency of operation and the frequency at which the
     highest radiated emission occurs, must be greater than 3.1 GHz.
     This will remove the highest emission level components away from
     the more sensitive radio services operating below this frequency.
     Building shielding combined with the emission limits being adopted
     should prevent interference to the authorized services, including
     the indoor operation of cellular, PCS and GPS systems employed in
     E-911 applications.[^293] However, because indoor systems will be
     permitted to operate at higher emission levels than outdoor
     systems, we find that we must adopt a regulation that states that
     the UWB equipment, by the nature of its design, must be capable of
     operation only indoors. If a manufacturer were to design a system
     that permits peer-to-peer operation to function only indoors, we
     will permit it. An example would be where peer-to-peer operation
     can occur only when an emission from an associated base station
     also is detected. A necessity to operate with a fixed indoor
     infrastructure also may be sufficient to demonstrate indoors only
     operation. This action is consistent with the method we used with
     unlicensed PCS to ensure that portable devices were not introduced
     into areas that had not yet been cleared of existing licensed
     users.[^294]

xvii. We also note that TDC expressed specific interest in permitting
      the use of UWB for surveillance systems.[^295] These are radar
      devices that establish a stationary RF perimeter field, similar to
      that of a half-bubble, that is used for security purposes to
      detect the intrusion into a designated area by persons or objects.
      We believe that TDC's request has merit but remain concerned about
      the potential for the proliferation of these devices. Accordingly,
      we are requiring the same coordination procedures that we applied
      to imaging devices. In addition, we are limiting the operation of
      surveillance systems to law enforcement, fire and emergency rescue
      organizations, to public utilities and to industrial entities.
      These parties must be eligible for licensing under Part 90 of our
      rules.

### Emission Levels above 1990 MHz

xviii. We previously discussed the analyses of potential interference to
       U.S. Government radio operations, amateur operation at 2450 MHz,
       MMDS operation around 2500 MHz, and satellite DARS at 2320-2345
       MHz. The comments also addressed concerns regarding possible
       harmful interference to several other radio operations. AT&T
       requests that additional attenuation be provided as high as 2600
       MHz to protect possible future 3G operations and also requests
       that UNII operation at 5 GHz be protected.[^296] Lucent also
       requests additional protection for future 3G systems.[^297]
       Motorola lists several operations above 2 GHz that should be
       protected from UWB operations, such as 3G, MDS, WCS, and others,
       but does not provide any information to demonstrate that UWB
       devices operating on these frequencies would be a problem.[^298]

xix. We note that the 10 dB of attenuation below the Part 15 general
     emission limits that are being provided in the frequency range of
     1990-3100 MHz to protect various U.S. Government radio operations
     appears to be more than sufficient to protect non-Government
     operations from harmful interference. The only UWB operations not
     subject to this additional 10 dB of attenuation are through-wall
     imaging systems used by public safety organizations and
     surveillance systems employed by public safety organizations and by
     public utilities and industrial entities. As used in this Order,
     the reference to public utilities and industrial entities refers to
     the manufacturers licensees, petroleum licensees or power licensees
     defined in 47 C.F.R. § 90.7. We believe that the requirement for
     surveillance systems to operate at the Part 15 general emission
     limits in combination with the coordination procedures are
     sufficient to alleviate concerns of harmful interference.

xx. Except for imaging devices operating below 960 MHz, through-wall
    systems, surveillance systems and vehicular radars, all other UWB
    devices are being required to operate with their --10 dB bandwidth
    between 3.1-10.6 GHz. Above 3.1 GHz, it appears that the Part 15
    general emission limits are sufficient to protect the various
    authorized radio services from harmful interference. The upper
    frequency limit of 10,600 MHz provides additional protection to the
    passive satellite receiving system frequency band at 10,600-10,700
    MHz. Only vehicle radar systems are being permitted to operate with
    their -10 dB bandwidth between 22-29 GHz. Further, as requested by
    NTIA we are requiring that unwanted emissions from vehicle radar
    systems be attenuated 20 dB below the Part 15 general limits if they
    are outside the 22-31 GHz band and 10 dB below the Part 15 general
    limits if they are in the band 29-31 GHz. The filing from SARA
    indicated that their equipment could comply with such an emission
    limit.[^299]

### Dithering and Other Noise-Like Emission Requirements

xxi. As discussed earlier, the measured level at which interference
     occurred to a GPS C/A code receiver was 8 dB lower for a CW-like
     UWB emission than that at which interference occurred from a
     noise-like UWB emission. This 8 dB difference is in agreement with
     the international standards, which specify that CW-like emissions
     necessitate 10 dB of additional interference protection.[^300]
     Because a CW-like emission consists of narrow spectral lines, the
     standard is specified as the signal level contained within a 700 Hz
     bandwidth.

xxii. We concur with the test data and international standards that an
      additional 10 dB of protection should be provided to GPS emissions
      from CW-like, narrowband emissions produced by the UWB
      transmitter. However, we note that a 700 Hz bandwidth setting is
      not available on the measurement instrumentation, such as a
      spectrum analyzer. XSI agreed with USGPSIC that this 10 dB of
      suppression could be demonstrated using a 10 kHz resolution
      bandwidth.[^301] We also agree that a 10 kHz resolution bandwidth
      could be used to demonstrate that the CW-like emissions are
      suppressed 10 dB below the limits applicable to noise-like
      emissions.[^302] However, we wish to specify the measurement
      bandwidth as close as possible to the specification employed in
      the ITU-R recommendation. While a 700 Hz resolution bandwidth is
      not available, the use of a 1 kHz resolution bandwidth is adequate
      for this measurement. A CW-like emission will have the same
      emission level whether it is measured with a 1 kHz, a 10 kHz or a
      1 MHz resolution bandwidth. Thus, we are requiring the average
      emissions appearing within the GPS frequency bands, 1164-1240 MHz
      and 1559-1610 MHz, when measured with a resolution bandwidth of no
      less than 1 kHz, to be attenuated by 10 dB below the average limit
      specified for a 1 MHz resolution bandwidth, *i.e.*, the noise-like
      emission limit. Specifying the resolution bandwidth for the
      CW-like measurement as no less than 1 kHz permits noise-like UWB
      systems to be tested with a wider bandwidth so that testing time
      may be reduced.[^303]

### Emissions from Incorporated Digital Devices

xxiii. We note that many UWB transmission systems will incorporate
       digital devices that, by themselves, will radiate RF emissions.
       We also note that requiring the emissions from these digital
       devices to comply with some of the reduced levels being adopted
       in this proceeding may make production infeasible. We see no
       reason, based on the submissions in this proceeding, that
       emissions from associated digital circuitry should be required to
       have any greater attenuation than required under the current
       rules. To do so may make it technically infeasible or overly
       expensive to design UWB devices. However, we note that the
       digital circuitry used with a transmitter for the purpose of
       enabling the operation of the transmitter is not defined as a
       digital device but is considered to be part of the transmitter.
       Thus, this digital circuitry would normally be subject to the
       emission limits applicable to the transmitter. Under the current
       rules, emissions from digital circuitry used to enable the
       operation of the transmitter are not required to be reduced below
       the general limits in 47 C.F.R. § 15.209. We see no reason to
       change this existing provision. Accordingly, we are permitting
       the emissions from digital circuitry used to enable the operation
       of an UWB device to operate at the limits contained in 47 CFR §
       15.209 provided it can be clearly demonstrated that those
       emissions are due solely to emissions from the digital circuitry
       and are not intended to be radiated from the antenna. We are not
       addressing distinctions between Class A and B digital devices as
       this is not considered in the current regulations. However, if
       the digital circuitry is used to control additional functions or
       capabilities, *i.e.*, it complies with the definition in 47
       C.F.R. § 15.3(k) for a digital device, that aspect of the digital
       circuitry may comply with the standards for a Class A digital
       device or a Class B digital device, as applicable, in accordance
       with the current rules.

### Peak Emission Limits

xxiv. [Proposal]{.underline}. In the *Notice*, the Commission noted that
      the peak output level does not directly impact the interference
      seen by a narrowband receiver. It is the power spectral density of
      the pulse and the pulse repetition frequency that are important
      for controlling potential interference. However, a limit on peak
      emissions is necessary to reduce the potential for UWB emitters to
      cause harmful interference to radio operations above 1 GHz. The
      Commission proposed two methods of measuring peak emission
      levels: 1) the peak level of the emission when measured over a
      bandwidth of 50 MHz which is comparable to the widest victim
      receiver that is likely to be encountered, and 2) the absolute
      peak output of the emission over its entire bandwidth. Comments
      were requested on the suitability of these two measurements with
      regard to the potential for interference from UWB transmitters to
      wideband receivers used in the licensed radio services.

xxv. In the case of the first definition of peak level, *i.e.*, the peak
     signal strength measured over a 50 MHz bandwidth, the Commission
     proposed to apply a 20 dB limit with respect to the maximum
     permitted average emission level.[^304] This limit is consistent
     with the limit currently contained in 47 C.F.R. § 15.35(b). It also
     proposed that the absolute peak limit for the emission over its
     entire bandwidth be variable based on the amount the --10 dB
     bandwidth of the UWB emission exceeds 50 MHz. The Commission
     proposed to use the following formula to calculate the amount that
     the absolute peak emission level over the entire bandwidth of the
     UWB emission would be permitted to exceed the Part 15 average
     emission limit: \[20 + 20log~10~(-10 dB bandwidth of the UWB
     emission in Hertz/50 MHz)\] dB with the further stipulation that
     the absolute peak emission level not be permitted to exceed the
     average limit by more than 60 dB.[^305] This 60 dB limit is
     comparable with the limit permitted under the waivers recently
     issued to Time Domain Corporation, U.S. Radar Inc. and Zircon
     Corporation.[^306] Comments were requested on whether wideband
     receivers used in the licensed services are sensitive to peak
     signal level in a unit bandwidth, such as the 50 MHz referenced
     above, or to the total peak emission produced by the USB device,
     and whether both peak limits are needed to reduce potential
     interference to the authorized radio services. If only one peak
     limit is needed, the comments should indicate which limit is
     appropriate. The Commission indicated that it intended to rely
     heavily on submitted test data in determining what peak emission
     standards should apply to UWB products.

xxvi. The Commission requested comments as to whether the higher
      absolute peak limit will cause increased interference problems,
      especially using the proposed measurement procedures and the
      limitations on frequency bands of operation. Comments were
      requested on the proposed method of varying the absolute peak
      emission limit and whether other features, such as the excess
      bandwidth, *i.e.*, the amount of the occupied bandwidth/effective
      data rate exceeds a specified level such as 10 dB, should be
      employed in calculating a peak limit.

xxvii. [Comments]{.underline}. Several of the comments agreed with our
       specifying a peak limit over a 50 MHz bandwidth. As stated by
       AOPA, 50 MHz is ample for current GPS, GLONASS and AMS(R)S
       receivers which have a front end bandwidth of about 30 MHz.[^307]
       NBAA agreed that a 50 MHz bandwidth is appropriate for protection
       of the current radio services.[^308] AOPA and NBAA noted the
       possibility that wider bandwidths may be needed in the future if
       UWB is found to have operational and spectrum efficiency
       advantages that make it desirable for use in aeronautical
       communications. Similarly, Valeo Electronics stated that the
       proposal to measure peak over 50 MHz is appropriate and
       comparable to the worst case of a likely victim receiver. [^309]
       It also noted that adoption of this standard would make it
       unnecessary to specify a limit on the total peak signal level.
       TDC also objected to a limit on total peak signal level as it
       would be relevant only to receivers that have a bandwidth wide
       enough to receive the entire UWB transmission.[^310] Nortel noted
       that future software-defined receivers will use wider bandwidths
       and that a 50 MHz bandwidth would not seem unreasonable in a few
       years.[^311] Bosch also agreed that a 50 MHz bandwidth was a
       practical standard for a wideband receiver.[^312]

xxviii. ANRO requested a limit on the total peak level, noting that peak
        measurements over a 50 MHz BW would be difficult and citing an
        uncertainty as to where in the spectrum 50 MHz measurements
        should be made.[^313] On the other hand, Kohler noted that the
        proposal to establish an absolute peak limit based on the
        bandwidth of the UWB transmission would encourage manufacturers
        to employ as wide a bandwidth as possible in order to increase
        the peak limit and result in greater UWB intrusion into a
        broader range of frequencies.[^314] SiRF Technology, Inc. &
        Trimble Navigation request that peak power be measured on a
        "per-nanosecond basis."[^315] USGPSIC also requested that peak
        power be measured on a "per nanosecond basis" believing that
        otherwise UWB devices would be permitted to emit peak power
        levels in excess of a megawatt.[^316] XSI noted that the
        calculation by USGPSIC requires the use of an impractical PRF of
        1 second and that the average level employed by USGPSIC is 50 dB
        higher than that proposed in the *Notice* for emissions in the
        GPS band.[^317]

xxix. The commenters did not agree on the peak signal limit that should
      be employed. TDC, noting that the absence of peak limits would
      allow UWB systems operating at low PRFs to emit enormous pulse
      levels, stated that it was not clear how a 50 MHz measurement
      bandwidth and a limit of 20 dB above the average limit were
      indicative of interference potential and that there was no
      justification provided for these values.[^318] TDC later requested
      that the peak power in a 50 MHz band be limited to 0 dBm
      EIRP.[^319] Kohler notes that its system operates at an average
      level of --47.3 dBm/MHz and a total peak signal of +7 dBm.[^320]
      XSI stated that its equipment operates with a 5 dB peak to average
      ratio.[^321] CSSIP requested that a peak limit apply below 1000
      MHz.[^322] This limit, as measured in a 6 MHz bandwidth, would be
      20 dB greater than the quasi-peak limit.

xxx. [Discussion]{.underline}. There are two reasons for imposing a peak
     emission limit on UWB devices. The first, and most obvious, is to
     keep from overloading the front end of a nearby victim receiver.
     For example, the interference protection level for C/A-code GPS
     receivers from low duty cycle pulse-like emissions is +20 dBm peak
     pulse power at the receiver input.[^323] This is considerably
     higher than the signal levels we are considering in this
     proceeding. The second reason is because pulsed emissions with low
     PRFs have high peak-to-average ratios and victim receivers will
     respond to the peak signal level produced by the UWB transmitter if
     their bandwidth is wider than the UWB PRF. Thus, we need to address
     the potential total peak power that will be received in the
     bandwidth employed by the victim receiver. The total peak power
     produced by the UWB device is not relevant to interference
     potential as there are no receivers employed with the authorized
     radio services that operate at the bandwidths employed by UWB
     emissions. For that reason, we are not adopting a limit on total
     peak power. The comments generally agreed that 50 MHz is about the
     widest bandwidth that would be employed by victim radio receivers.
     Thus, there appears to be no reason to measure peak power across a
     wider bandwidth.

xxxi. The low proliferation, infrequent operation, operation near the
      ground, rapid attenuation of emitted signals, and general
      operation in the presence of surrounding objects that would
      further attenuate the emissions should result in a low
      interference potential from GPRs and other imaging systems.[^324]
      Vehicular radar systems operate above 24 GHz where the emissions
      will attenuate rapidly with distance and there is a high
      probability of intervening objects further attenuating the UWB
      emissions and reducing the probability of harmful interference. We
      expect that most indoor and hand held systems would operate at
      high PRF levels, resulting in potential victim receivers reacting
      only to the average emission levels produced by the UWB devices.
      However, some UWB devices may be designed to operate at a low PRF
      with a resulting high peak-to-average ratio. This could result in
      the peak power level being a controlling factor in potential
      interference to other receivers. Accordingly, we believe that a
      peak limit is needed to ensure that nearby victim receivers are
      not affected.

xxxii. In the *Notice*, the Commission proposed a peak power limit in a
       50 MHz band equal to 20 dB greater than the maximum permitted
       average limit. The average limit is 500 uV/m, as measured at 3
       meters with a 1 MHz resolution bandwidth. This is equivalent to
       an EIRP of --41.25 dBm/MHz.[^325] Thus, the peak power limit
       proposed in the *Notice* was equivalent to an EIRP of --21.25
       dBm/50 MHz. The comments generally did not address interference
       at the peak limits being considered. Because of this, we
       performed our own analysis on the effect of peak power to a
       generic communications receiver.[^326] We found that a suitable
       peak EIRP power limit for a transmitter placed 3 meters away
       would be --33.7 dBm/MHz. For a transmitter placed 10 meters away,
       the peak EIRP limit would be --23.3 dBm/MHz. We also note that
       the peak limit needs to be applied at only one location, *i.e.*,
       centered on the frequency at which the highest level emission
       occurs.[^327]

xxxiii. As noted in the section on Measurement Procedures, we find that
        peak measurements based on a 50 MHz (resolution) bandwidth may
        not be feasible. The widest readily available resolution
        bandwidth that can be employed for peak measurements is 3 MHz.
        Consequently, we prepared a comparison of the differences in
        peak-to-average ratios, based on an average signal measured with
        a 1 MHz resolution bandwidth (RBW), as the PRF of the UWB
        emission and the RBW of the measuring instrument are
        varied.[^328] These graphs, shown in Appendix E to this Report
        and Order, compare emissions from conventional pulsed
        transmissions and dithered (Gaussian) pulsed transmissions.

xxxiv. As shown in the graph, the peak EIRP signal level of --21.25
       dBm/50 MHz [^329] that was proposed in the *Notice* results in
       non-dithered pulsed emissions being average-limited if the PRF is
       greater than 11.11 MHz and all dithered UWB emissions being
       peak-limited.[^330] If the RBW is reduced to 3 MHz, the
       relationship is based on a 20 log factor resulting in a decrease
       in the peak level allowed with a 50 MHz RBW by 24.44 dB. This
       results in an allowable peak level of --45.69Bm/3 MHz, a level
       that is 4.44 dB lower than the permissible average limit with a 1
       MHz RBW. Reducing this further to measurement with a 1 MHz RBW
       lowers the permissible peak level to --55.23 dBm/MHz, 14 dB below
       the average limit. In actual practice, we would not specify a
       peak level lower than the average limit. It should be noted that
       a conventional pulsed modulated emission would not have a peak
       emission higher than the average limit at PRFs greater than the
       RBW employed divided by 0.45.

xxxv. Based on the above, we believe that our proposal to permit a peak
      emission within a 50 MHz RBW of only --21.25 dBm EIRP is too
      conservative. We believe that the peak emission level of 0 dBm/50
      MHz, equivalent to 58 mV/m at 3 meters, requested by TDC would not
      result in harmful interference problems to communications systems.
      This level translates to a peak EIRP of --24.44 dBm/3 MHz or 3.6
      uW/3 MHz, or to a peak field strength of 3.46 mV/m at measured at
      3 meters with a 3 MHz RBW. This peak level is 16.8 dB higher than
      the average level determined with a 1 MHz RBW and is 3.2 dB lower
      than the peak limit permitted under the current Part 15 rules.
      [^331] It results in dithered and non-dithered UWB emissions being
      average-limited for PRFs greater than 1 MHz and peak-limited for
      PRFs below 1 MHz.

xxxvi. Our conversion from a 50 MHz resolution bandwidth to a 3 MHz
       resolution bandwidth is based on the worse case assumption that
       changes in the peak levels changes follow the square of the
       change in the resolution bandwidth. That is, the change in the
       allowable peak limit at 50 MHz to a peak limit at 3 MHz was based
       on 20 log (3/50) dB. We recognize that this could penalize some
       UWB operations, particularly those operating with PRFs greater
       than around 6.7 MHz. According, we are adopting a peak limit
       based on a sliding scale dependent on the actual resolution
       bandwidth employed in the measurement. The peak EIRP limit being
       adopted in this Report and Order is 0 dBm when measured with a
       resolution bandwidth of 50 MHz and 20 log (RBW/50) dBm when
       measured with a resolution bandwidth ranging from 1 MHz to 50
       MHz. RBW is the resolution bandwidth, in megahertz, actually
       employed. The minimum resolution bandwidth that may be employed
       is 1 MHz; the maximum resolution bandwidth that may be employed
       is 50 MHz.

### AC Power Line Conducted Limits

xxxvii. In the *Notice*, the Commission proposed to retain the existing
        limit in 47 CFR Section 15.207 for controlling the amount of
        energy permitted to be conducted onto the AC power lines as a
        reasonable starting point for establishing standards until
        additional experience can be gained with this equipment.[^332]
        None of the comments objected to retaining the existing Part 15
        limits on RF energy conducted onto the AC power lines.[^333] We
        concur and are adopting a limit of 250 uV over the frequency
        range of 450 kHz to 30 MHz, as proposed in the *Notice*.

### Summary of Emission Limits Being Adopted in this Report and Order

xxxviii. As stated in the *Notice*, the establishment of emission limits
         requires a firm understanding of the characteristics of UWB
         signals, their impact on victim receivers, and the minimum
         separation distance between UWB devices and victim receivers;
         almost any transmitter will cause interference if it is too
         close to a receiver.[^334] We have attempted to apply the data
         submitted in the various comments, tests and analyses to
         determine what emission limits are acceptable for UWB
         operation. Our task was to determine limits based on
         reasonable, real-world applications and not just on the results
         of laboratory measurements conducted in anechoic chambers.
         While such measurements are necessary to determine if further
         investigations are necessary or additional caution should be
         applied, they demonstrate the possible performance capabilities
         of products in the absence of other RF noise sources. In some
         cases, we have adjusted the levels determined from the various
         analyses to reflect our desire and the desire of NTIA to
         proceed cautiously.[^335]

xxxix. The limits we are adopting in this proceeding are considerably
       lower in some frequency ranges than the current Part 15 levels.
       While these limits may prove to be lower than what is necessary,
       we believe that such caution is needed in the early stages of UWB
       implementation. Once additional experience is gained with this
       equipment and a better understanding develops regarding operating
       frequency and allowable emissions levels, we may be able to
       revisit these limits. In the interim, the following summarizes
       the emission limits being adopted in this Report and Order.

xl. Based on the proceeding discussion, we are adopting the following
    emission limits for UWB devices:

-   Coordinated GPRs, wall imaging and through-wall imaging systems may
    operate with the --10 dB bandwidth below 960 MHz at the Part 15
    general emission limits provided emissions in the 960-1610 MHz band
    are attenuated below the general limits by 24 dB; narrowband
    emissions in the GPS bands are attenuated below the general limits
    by 34 dB; emissions in the 1610-1990 MHz are attenuated below the
    general limits by 12 dB; and emissions above 1990 MHz are attenuated
    below the general limits by 10 dB. There are usage restrictions and
    a labelling requirement.

-   Coordinated through-wall imaging systems and surveillance systems
    may operate with the --10 dB bandwidth within the band 1990 MHz to
    10,600 MHz at the Part 15 general emission limits provided emissions
    below 960 MHz do not exceed the general limits; emissions in the
    960-1610 MHz band are attenuated below the general limits by 12 dB;
    narrowband emissions in the GPS bands are attenuated below the
    general limits by 22 dB; emissions in the 1610-1990 MHz band are
    attenuated below the general limits by 10 dB; and emissions above
    10,600 MHz are attenuated below the general limits by 10 dB. There
    are usage restrictions and a labelling requirement.

-   Coordinated GPRs, wall imaging and medical imaging systems may
    operate with the --10 dB bandwidth within the band 3100 MHz to
    10,600 MHz at the Part 15 general emission limits provided emissions
    below 960 MHz do not exceed the general limits; emissions in the
    960-1610 MHz band are attenuated below the general limits by 24 dB;
    narrowband emissions in the GPS bands are attenuated below the
    general limits by 34 dB; emissions in the 1610-1990 MHz band are
    attenuated below the general limits by 12 dB; emissions in the
    1990-3100 MHz band are attenuated below the general limits by 10 dB;
    and emissions above 10,600 MHz are attenuated below the general
    limits by 10 dB. There are usage restrictions and a labelling
    requirement.

-   Indoor-only systems may operate with the --10 dB bandwidth within
    the band 3100 MHz to 10,600 MHz provided emissions below 960 MHz do
    not exceed the general limits; emissions in the 960-1610 MHz band
    are attenuated below the general limits by 34 dB; narrowband
    emissions in the GPS bands are attenuated below the general limits
    by 44 dB; emissions in the 1610-1990 MHz band are attenuated below
    the general limits by 12 dB; emissions in the 1990-3100 MHz band are
    attenuated below the general limits by 10 dB; and emissions above
    10,600 MHz are attenuated below the general limits by 10 dB. There
    is a labelling requirement.

-   Hand held systems may operate with the --10 bandwidth within the
    band 3100 MHz to 10,600 MHz provided emissions below 960 MHz do not
    exceed the general limits; emissions in the 960-1610 MHz band are
    attenuated below the general limits by 34 dB; narrowband emissions
    in the GPS bands are attenuated below the general limits by 44 dB;
    emissions in the 1610-1990 MHz band are attenuated below the general
    limits by 22 dB; emissions in the 1990-3100 MHz band are attenuated
    below the general limits by 20 dB; and emissions above 10,600 MHz
    are attenuated below the general limits by 20 dB.

-   Vehicular radar systems may operate with the -10 dB bandwidth within
    the 22-29 GHz and with the center frequency and the frequency at
    which the maximum emission occurs both located above 24.075 GHz
    provided emissions below 960 MHz do not exceed the general limits;
    emissions in the 960-1610 MHz band are attenuated below the general
    limits by 34 dB; narrowband emissions in the GPS bands are
    attenuated below the general limits by 44 dB; emissions in the
    1610-22,000 MHz band and in the band above 31 GHz are attenuated
    below the general limits by 20 dB; and emissions between 29 GHz and
    31 GHz are attenuated below the general limits by 10 dB.

150. For all UWB devices, emission limits below 960 MHz are based on the
     use of a CISPR quasi-peak detector and average emissions above 960
     MHz are based on the use of an RMS average detector with a 1 MHz
     resolution bandwidth. For systems operating above 960 MHz, there is
     a limit on the peak emission level contained within a 50 MHz
     bandwidth centered on the frequency, f~M~, at which the highest
     radiated emission occurs. That limit is 0 dBm EIRP. A different
     resolution bandwidth of between 1 MHz and 50 MHz may be employed
     for the peak measurement provided the peak EIRP level does not
     exceed 20 log (RBW/50) dBm where RBW is the resolution bandwidth in
     megahertz. Only one peak measurement, centered on f~M~, is
     required. If the UWB transmitter connects to the AC power lines,
     there is a quasi-peak limit of 250 uV over the frequency range of
     450 kHz to 30 MHz.[^336]

## Cumulative Impact

a.  [Proposal]{.underline}. While the Commission indicated that further
    testing and analysis is desirable on this issue, it stated in the
    *Notice* that it appeared that cumulative impact is negligible at
    the power levels and with the modulation types being proposed,
    especially when compared to the interference potential from a single
    land mobile transmitter. Thus, the Commission believed that only the
    closest transmitter placing an emission on the frequency of concern
    would be of importance, obviating the need for additional
    attenuation to compensate for cumulative effects. However, it added
    that the cumulative impact of several UWB devices might be different
    depending on their individual emission and transmission
    characteristics. For example, how does the cumulative impact of
    those UWB transmitters that emit a line spectrum compare to those
    that have a high level of random pulse positioning or dithering and
    may appear as Gaussian noise?[^337] Further, what is the
    relationship between pulse repetition frequency and the cumulative
    impact of a number of UWB devices? The Commission noted that the
    emission limits were established based on the potential interference
    from a single Part 15 device and do not take into account cumulative
    effects that could occur if a number of devices are located closely
    together. Comments and test data were requested along with relevant
    input from the Commission's Technical Advisory Council.

b.  [Comments]{.underline}. There was no agreement among the comments.
    It is obvious that emissions from multiple UWB transmitters are
    additive to some extent. As the UWB emissions become more noise
    like, they tend to add directly, as would be expected with noise
    emissions. This was demonstrated in the University of Texas tests
    using multiple UWB transmitters.[^338] Other commenting parties have
    advanced various mathematical models of UWB system configurations to
    demonstrate whether the major impact is caused by the closest UWB
    emitter or is caused by the cumulative effect of all surrounding
    emitters.

c.  XSI argued that there is little cumulative effect from multiple UWB
    devices even when they are concentrated in a small area.[^339] XSI
    added that UWB devices could not add over distances greater than
    about 10 meters because of poor indoor propagation.[^340] XSI noted
    that devices located within about 10 m of each other share a common
    RF channel and so must reduce power, duty cycle, or both to avoid
    mutual interference. As stated by Aether Wire, a local network of
    UWB devices will generally have only one device transmitting at any
    time.[^341] Similarly, Sprint PCS stated that many types of UWB
    devices will not transmit continuously, but rather will transmit
    burst or packets as necessary.[^342] Sprint PCS added that in that
    case it would not be realistic to sum interference contributions
    from multiple UWB transmitters that normally would not all be
    transmitting simultaneously.

d.  Motorola stated that it expected that the UWB devices closest to the
    victim receiver would dominate due to typical path losses.[^343] Its
    Monte Carlo analysis demonstrated that the vast majority of the time
    more than 90 percent of the interference is coming from the closest
    one to five UWB transmitters. Thus, Motorola concluded that even
    with 1000 surrounding transmitters the effect of cumulative
    interference was not as severe as the effect from the closest
    transmitters. Motorola's analysis found that a cumulative effect was
    more prevalent where the victim receiver was a base station with no
    nearby UWB transmitters. Under this condition, it took a
    considerably greater number of transmitters to contribute 90 percent
    of the interference power, using UWB emission contributions from as
    far away as 600 m.[^344] As stated by AT&T, the important issue is
    how many transmitters operating simultaneously within a specified
    range will cause an additive power problem.[^345]

e.  NTIA employed a mathematical analysis using successive, equally
    spaced rings containing UWB emitters with their energy maximized in
    the direction of the victim receiver to demonstrate that high
    concentrations of UWB transmitters could result in cumulative
    interference. [^346] However, XSI demonstrated that if only one UWB
    transmitter was placed within the inner ring used in NTIA's analysis
    the emission from that single UWB transmitter would dominate the
    signal at the victim receiver.

f.  DOD provided mathematical analyses of possible cumulative
    interference from UWB operation to its SEEK Skyhook radar system,
    operating at 3.15 GHz and at 3.23 GHz.[^347] The SEEK Skyhook is a
    surveillance radar positioned 12,000 feet above mean sea level
    operating with a range of 278 km at an altitude of 3660 meters. It
    currently is used to detect low flying aircraft for drug
    interdiction at Cudjoe Key, Florida and operates with a narrow 40
    dBi antenna tilted at --1.5 degrees. Based on these specifications,
    DOD calculated the ground area illuminated by the radar antenna and
    the distance to the center of that range to determine how many UWB
    emitters could be permitted per square kilometer based on I/N levels
    ranging from --3 dB to --10 dB.[^348] It concluded that a UWB
    emission level of --53 dBm covers most of the interference
    situations it analyzed and that mitigating factors from UWB antenna
    patterns, intermittent operation, building attenuation, and obstacle
    attenuation would permit a higher signal level.

g.  ARRL stated that while more distant radiators would create less
    noise, this would be offset by the fact that there are more of them
    seen by the victim receiver.[^349] It added that the large antennas
    used by amateur operators at UHF and higher frequencies would see a
    cumulative effect when overlooking urban areas. ARRL added that a
    single UWB emitter may dominate if the interference extended only
    for tens of meters, but as demonstrated by Motorola the interference
    could extend for hundreds of meters.[^350] TDC argued that the
    closest UWB transmitter would produce the greatest impact as signals
    from more distant devices would be subsumed by the noise floor.

h.  [Discussion]{.underline}. We agree with ARRL that a single UWB
    emitter will dominate if the interference extends for only a few
    tens of meters. Earlier in this Report and Order, we demonstrated
    that the interference impact of a single UWB device is on the order
    of "tens of meters" or less with the exception of a few sensitive
    receivers that operate at the noise floor and employ high gain
    antennas, such as the ARSR-4 system.[^351] The ARSR-4 would not be
    particularly prone to cumulative interference as it views only a
    narrow ground segment at any given time.[^352] Systems prone to
    receiving cumulative interference are those that employ high gain
    receiving antennas directed over large geographical areas. Examples
    are airborne systems and receivers located on orbiting satellites.
    Wide coverage area cellular and PCS base stations also may
    experience some cumulative impact although it should be considerably
    less than that received by airborne receivers.

i.  We have implemented considerable restraints on the technical and
    operational standards for UWB equipment to ensure that cumulative
    interference will not occur. Primarily, we have limited outdoor
    applications to imaging, hand held and vehicle radar systems. The
    directional antennas employed by imaging and vehicle radar systems
    make it unlikely that the maximum emission components would be
    directed towards a victim receiver. Thus, directional antennas
    prevent the occurrence of multiple UWB emitters from producing
    equally received emission levels even if they are equally distant
    from the victim receiver. Also, the majority of the UWB radar
    devices being authorized direct their emissions into the ground or
    horizontally, away from airborne or satellite receivers. In
    addition, limiting the applications to systems that operate at
    ground level[^353] ensures that the emissions attenuate more rapidly
    with distance and have a higher probability of obstructions between
    the UWB transmitter and the victim receiver. Most of the imaging UWB
    devices will operate only infrequently and will be far apart such
    that it is unlikely they will cause any cumulative effect. We also
    implemented constraints on the frequency bands in which the
    equipment is permitted to operate. Limiting devices to operate above
    certain frequency bands ensures that the maximum emissions will not
    occur in lower frequency bands where greater propagation may occur.
    Finally, we required UWB devices to operate at reduced emission
    levels between 960 MHz and 1990 MHz or higher, significantly
    reducing the range over which the UWB emissions in this band can be
    detected. All of these features combine to ensure that UWB systems
    will not result in a cumulative interference problem. While it is
    possible that indoor UWB devices, operating in an omnidirectional
    mode, could be sufficiently concentrated in a small area to cause a
    cumulative effect, XSI, Sprint PCS and others have already
    demonstrated that these devices will not operate
    simultaneously.[^354] It is more likely that any high concentration
    of UWB devices operating indoors would be an interlinked system with
    a low overall duty cycle so as to avoid mutual interference.

## Measurement Procedures

j.  In the *Notice*, we proposed to continue to employ quasi-peak
    measurements for emissions below 1 GHz and average and peak
    measurements for emissions above 1 GHz, as under the current
    rules.[^355] Quasi-peak measurements provide a weighted average over
    a specified measurement bandwidth while average measurements above 1
    GHz are based on the use of a 1 MHz resolution bandwidth ("RBW").
    Comments were sought regarding the specific measurement procedures
    that should be employed.

### Quasi-peak and Average Measurements

i.  For measuring average emissions, we proposed in the *Notice* that
    spectrum analyzer video averaging with a video bandwidth (\"VBW\")
    of no greater than 10 kHz or less than 10 Hz be used in conjunction
    with peak hold to determine the average level as a function of
    frequency. Alternative techniques that can be shown to give
    comparable or more accurate results would be considered. Comments
    were requested on applying the measurement procedures specified in
    HP Application Note 150-2. Under this note, if there was no
    dithering of the pulse position or pulse position modulation, the
    average level of the fundamental and harmonic emissions would be
    measured using a spectrum analyzer adjusted to produce a line
    spectrum with the VBW equal to or greater than the RBW. This
    requires that the RBW be less than, or equal to, 0.3 times the pulse
    repetition frequency. The level of the highest line in the emission
    line spectrum being measured would be the average level. If the
    dithering or pulse position modulation could not be turned off, the
    emission would be measured with the spectrum analyzer settings
    adjusted to obtain a true pulse spectrum. A pulse desensitization
    correction factor, based on the calculations provided in HP
    Application Note 150-2, would be added to the measurement to obtain
    a peak level, and the average would be calculated using the duty
    cycle factor in dB.

ii. [Comments]{.underline}. Quasi-peak and average emission measurements
    are well understood, and ANSI[^356] and others have established
    appropriate measurement procedures. ANRO, Bosch and Zircon supported
    the proposed average measurement techniques.[^357] There were,
    however, several requests for variations from our measurement
    procedures. NTIA requested that we apply an average limit based on
    an RMS average rather than a logarithmic average, such as would be
    obtained from a spectrum analyzer employing a low video
    bandwidth.[^358] It stated that the average logarithm is largely
    insensitive to energy contained in low duty cycle, high amplitude
    signals. It added that no single average detector function
    adequately describes the interference effects of UWB signals but the
    RMS average better quantifies this. NTIA also wished to apply the
    average emission limits above 960 MHz instead of 1000 MHz.[^359]

iii. On the other hand, Lucent requested that the VBW employed for an
     average measurement be greater than 10 Hz because of the
     possibility of burst transmissions.[^360] Lucent was concerned that
     a 10 Hz VBW, approximating averaging over a 100 millisecond period,
     would result in too low a measured value, permitting the actual
     radiated emission to exceed our average limits. Lucent requested
     that the VBW be set no lower than 10 kHz or that an undefined
     "correction factor" be applied when the transmitter operating time
     was less than the averaging time of the measurement. Metricom
     requested that average measurements be made using a RBW of 50 MHz,
     just like the peak measurements.[^361] A narrower VBW would be
     employed to average the emission.

iv. Most of the comments were directed not towards the actual
    measurement instrumentation settings but to the test setup itself.
    With regard to GPRs, A. Peter Annan expressed concern that GPRs may
    not be perfectly coupled with the ground, suggesting that the GPRs
    be measured while suspended in the air and 20 to 40 dB be subtracted
    from the results.[^362] Mr. Annan also requested that GPRs operating
    below 250 MHz be measured with a resistive load substituted for the
    antenna. CSSIP requested that GPRs be measured with the antennas in
    contact with, or in close proximity to, the ground using a suitable
    media of dry sand, freshwater, salty-water or concrete made from
    specified materials.[^363] An *ex parte* filing by Sensors &
    Software and GSSI requested the use of a concrete slab, at least 8
    inches thick, the size of the GPR transducer and installed over 12
    inches of gravel, be used as the absorptive material for a
    GPR.[^364] No metal or fiberglass reinforcing bar would be used in
    this base material.

v.  TDC also suggested several provisions for the test set-up for UWB
    measurements.[^365] TDC requested that we permit measurements at 1
    meter due to the need for the measured emission to be at least 10 dB
    above the noise level of the spectrum analyzer for accuracy
    purposes. Bosch suggested the use of a corrugated horn antenna for
    measuring emissions above 1 GHz as these antennas have a fixed phase
    center and may be used over a wide bandwidth.[^366]

vi. [Discussion]{.underline}. There is no apparent difficulty in
    performing measurements of quasi-peak or average emission levels.
    Such procedures are well documented in the current FCC test
    procedures and the application notes published by spectrum analyzer
    manufacturers. There are, however, a few areas where we need to
    provide clarification of the measurement procedures. A measurement
    procedure applicable to UWB devices is attached as Appendix F. The
    following discussion provides the reasons for several of the
    features we are including in these procedures.[^367]

vii. We concur with NTIA's request that logarithmic averaging not be
     permitted for UWB average measurements. We currently do not permit
     a logarithmic average to be employed for any Part 15 measurements
     with one exception: if the peak-to-average ratio of an emission is
     low and the measured emission is well below our limits, we have
     permitted the use of logarithmic averaging in order to facilitate
     measurements. While we normally perform measurements of emissions
     from Part 15 devices with the detector on the spectrum analyzer set
     in the linear mode[^368], we recognize that the test data and
     analyses in this proceeding were performed based on RMS average
     emission levels. In keeping with our conservative approach to
     implementing UWB operation, we are adopting NTIA's suggestion to
     specify the average emission limits in terms of RMS average. A 1
     MHz resolution bandwidth would be employed with an RMS detector and
     an averaging time of 1 millisecond or less. Appendix F also
     describes an alternative method that can be used to measure RMS
     average emission levels using spectrum analyzers that do not have
     an RMS detector. We also are implementing NTIA's request to begin
     RMS average emission limits, based on the use of a 1 MHz resolution
     bandwidth, beginning at 960 MHz.

viii. We do not agree with Lucent that a minimum VBW of 10 kHz needs to
      be established[^369] or that a "correction factor" needs to be
      applied to average emission measurements of short burst
      transmissions. Lucent has not provided any information to
      demonstrate why the application of a 10 Hz VBW, representing an
      averaging period of 100 milliseconds, to a burst UWB transmission
      would result in a higher interference potential. We agree that
      burst transmissions would have a low average measurement because
      of their short period of operation. However, the peak levels we
      are establishing would limit such transmissions. A UWB system with
      a high peak-to-average ratio would be peak-limited, resulting in
      the measured average emission level being well below our limits.
      We also reject the proposal by Metricom to employ a 50 MHz RBW for
      average measurements. Metricom did not provide any justification
      as to why such a large RBW is necessary for average measurements.
      It appears that Metricom wanted the use of a wider RBW, without a
      corresponding increase in permitted signal level, solely to reduce
      the levels of the radiated emissions. We also note that
      measurement equipment employing such a wide RBW is not commonly
      available in laboratory environments, and we are unsure about the
      repeatability of measurements made using such equipment.

ix. In most cases, measurements will follow the procedures specified in
    47 C.F.R. §15.31(a)(6). However, we believe that the measurement
    procedures applied to UWB devices also should address the manner in
    which the equipment is designed to be operated. For example,
    through-wall imaging systems are intended to transmit through a wall
    that may not dissipate much of the energy. Thus, these systems may
    be tested with a ½ inch section of gypsum board in front of the
    transmitting antenna. No attenuating material would be employed in
    front of medical imaging systems, vehicle radar systems, indoor
    systems, or hand held devices.[^370] On the other hand, GPRs and
    wall imaging systems are designed to dissipate their transmitted
    energy into the ground or other structure into which they are
    radiating. Testing these devices over a ground plane would cause the
    transmitted energy to be reflected back into the air. Thus, we agree
    with CSSIP, Sensors & Software and GSSI that GPRs and wall imaging
    systems should be tested over an absorptive material. We are
    specifying that the transmitted emission from a GPR or a wall
    imaging system is to be directed towards 20 inches of dry sand. We
    believe that the use of dry sand will be easier to establish than a
    concrete/gravel test bed and would not contain the discontinuity at
    8 inches as would occur with the concrete/gravel interface. This dry
    sand bed shall be at least the width and length of the GPR or wall
    imaging system being tested. Further, no ground plane shall be
    located under this dry sand bed. GPRs shall be suspended above this
    material at the height above ground at which the equipment is
    intended to operate. Wall imaging systems shall be suspended above
    this material at the separation distance at which they are intended
    to operate from a wall. Recognizing that the use of this absorptive
    material will prevent the use of a turntable, measurements must be
    taken at a sufficient number of radials to ensure that the measured
    emission levels are maximized.

x.  Because of the lack of ground plane material in the test bed used
    for GPRs and wall imaging systems, we are establishing a test
    procedure than may be used for any UWB device as an option to using
    a ground plane. We will permit RF absorptive material, such as that
    found in an anechoic chamber, to be employed between the equipment
    under test and the measuring instrumentation. However, if this
    absorptive material is used 4.7 dB must be added to the obtained
    measurement results to simulate the effect of an additive signal
    reflected from the ground plane. In addition, measurements may be
    made at a closer distance, as requested by TDC, following the
    existing procedures in 47 C.F.R. § 15.31(f). However, measurements
    may not be made in the near field.

### Peak Measurements

xi. [Proposal]{.underline}. In the *Notice*, we recognized that the
    measurement of peak power based on a 50 MHz measurement bandwidth
    can not be performed with normal commercial EMC test equipment. We
    noted that microwave receivers designed for radar interception and
    analysis are available with such characteristics and have costs
    comparable to normal EMC test equipment. Further, the IF output of a
    microwave receiver that uses a wide bandwidth, *e.g.*, 50 MHz, could
    be analyzed using a conventional oscilloscope in order to measure
    the peak level of the waveform in the time domain. Comments were
    sought on the feasibility of this testing technique as well as its
    utility as a model for the interference potential of peak UWB
    levels. As we are not adopting a standard for total peak power,
    there is no need to discuss a corresponding measurement
    procedure.[^371] Similarly, there is no need to reiterate the
    discussion on antennas suitable for extreme bandwidth measurements.

xii. [Comments/Discussion]{.underline}. Several of the comments
     responded to the systematic problems of measuring a peak emission
     level over a 50 MHz bandwidth. TDC supplied a detailed measurement
     procedure for accomplishing this.[^372] We appreciate the efforts
     of the commenting parties. Unfortunately, upon reflection we do not
     believe that peak measurements employing a 50 MHz bandwidth are
     practical using currently available equipment. As has become
     obvious from the comments, there are considerable difficulties
     maintaining phase accuracy over a 50 MHz bandwidth making
     calibration of the setup of the test bed and the measurements of
     the radiated emissions difficult. Further, the choice of the
     variable-frequency filter used to perform measurements over a 50
     MHz bandwidth is extremely critical. It is unlikely that
     measurements over a 50 MHz bandwidth would be repeatable from one
     test site to another.

xiii. Siemens suggested measuring the peak emission level using the
      maximum RBW available on the instrumentation and calculating the
      peak emission at 50 MHz.[^373] Valeo proposed a method of
      integrating a measurement from a spectrum analyzer over 50
      MHz.[^374] As stated by Fantasma, the existing rules employing a 1
      MHz RBW are simple and straight forward.[^375] While USGPSIC
      argued against the use of a spectrum analyzer, stating that
      spectrum analyzers sample at too low a rate to capture the peak
      power of UWB signals[^376], we believe that a spectrum analyzer
      can provide a realistic view of the peak emission level as it
      would be viewed by a receiver employing a similar bandwidth.

xiv. We believe that there is a simpler method of measuring peak
     emission levels in a manner that also takes into account the
     interference potential of the equipment. In order to perform a peak
     measurement on a spectrum analyzer, the VBW must be at least as
     large as the RBW. The largest VBW on a spectrum analyzer is about 7
     MHz. Thus, the widest RBW that could be employed is 3 MHz. However,
     there are several receivers used by the authorized radio services
     that employ greater bandwidths. Thus, the concern is how to ensure
     that peak measurements performed with a 3 MHz RBW will protect
     receivers that employ a wider bandwidth from harmful interference.

xv. Appendix E attached to this Report and Order demonstrates the
    theoretical peak-to-average relationship of a pulsed emission and a
    dithered emission that appears like Gaussian noise as the PRF is
    varied. In these graphs, the average is based on measurements
    performed with a 1 MHz RBW. The peak measurements are based on
    measurements performed with a RBW of 1 MHz, 3 MHz and 50 MHz. As can
    be seen, the major differences between changes in RBW are not based
    on a 10 log relationship. Rather, they are based on a 20 log
    relationship.[^377] We established a peak emission limit of 0 dBm as
    measured over a 50 MHz bandwidth. Under these conditions, reducing
    the RBW from 50 MHz to 3 MHz results in an attenuation of the peak
    limit of 20 log (3/50) or --24.44 dBm.[^378] Reducing the allowed
    peak limit to an EIRP of --24.44 dBm when measured with a 3 MHz RBW
    ensures that the emission would be no greater than 0 dBm if it was
    measured with a 50 MHz RBW. Peak measurements using a spectrum
    analyzer with a 3 MHz RBW are relatively straight-forward and can be
    performed using existing measurement procedures. It also is expected
    that these measurements should be reproducible between different
    measurement sites. For these reasons, we are adopting a peak
    measurement procedure employing a 3 MHz resolution bandwidth. This
    measurement must be performed centered on the frequency of emission
    on which appears the highest average level emission.

xvi. As stated earlier, our conversion from a 50 MHz resolution
     bandwidth to a 3 MHz resolution bandwidth is based on the worse
     case assumption that changes in the peak levels changes follow the
     square of the change in the resolution bandwidth. That is, the
     change in the allowable peak limit at 50 MHz to a peak limit at 3
     MHz was based on 20 log (3/50) dB. We also recognized that this
     could penalize some UWB operations, particularly those operating
     with PRFs greater than around 6.7 MHz. To compensate for this, peak
     limits were established based on a sliding scale that is dependent
     on the actual resolution bandwidth employed in the measurement. The
     peak EIRP limit is 20 log (RBW/50) dBm when measured with a
     resolution bandwidth between 1 MHz and 50 MHz.[^379] RBW is the
     resolution bandwidth in megahertz actually employed. This bandwidth
     must be centered on the frequency at which the highest radiated
     emission occurs.

xvii. We intend to employ at our laboratory a measurement procedure
      using a 3 MHz resolution bandwidth. However, we will permit
      responsible parties to test their UWB products using different
      resolution bandwidths ranging from 1 MHz to as high as 50 MHz. The
      use of a higher resolution bandwidth may be particularly helpful
      for measuring a system operating at a higher PRF. If a resolution
      bandwidth greater than 3 MHz is employed, the application for
      certification filed with the Commission must contain a detailed
      description of the test procedure, calibration of the test setup,
      and the instrumentation employed in the testing.

### Frequency Range of Measurement

xviii. [Proposal]{.underline}. For impulse systems, the Commission
       proposed that the center frequency of the emission bandwidth, as
       determined by the --10 dB points, should be used as the reference
       for determining the upper frequency range over which emissions
       should be measured.[^380] Noting that the emission spectrum will
       change depending on the specific measurement procedures employed,
       *e.g.*, the use of average versus peak measurements, comments
       were requested on any specific measurement procedures that should
       be employed to determine the center frequency. For a carrier
       modulated system, the Commission proposed that the carrier
       frequency should continue to be used as the reference for
       determining the upper frequency range over which emissions should
       be measured. However, the Commission expressed concern that a
       manufacturer could employ a low frequency carrier with an
       extremely narrow pulse or a narrow pulse impulse system could be
       used with a low frequency antenna, resulting in emissions
       extending far beyond the tenth harmonic, the normal upper range
       of measurement. Accordingly, comments were requested on whether a
       different method of determining the frequency measurement range
       should be employed, *e.g.*, a system based on pulse rise time and
       width. In addition, it was noted that the lower frequency range
       of measurements would continue to be determined by the lowest
       radio frequency generated in the device. Comments were requested
       on whether the pulse repetition frequency, pulse dithering
       frequency, modulating frequency or other factors would permit the
       investigation of a low enough frequency range to address possible
       amplification of the emitted signal due to antenna resonances
       below the fundamental emission.

xix. [Comments/Discussion]{.underline}. There were no pertinent comments
     regarding the proposed frequency range over which measurements
     should be performed. Valeo stated that the measurement ranges are
     appropriate as referenced to the carrier or center frequency.[^381]
     Our primary concern is that a sufficient frequency range be
     investigated to ensure that the emitted signals are no greater than
     the limits contained in Part 15 so that harmful interference is not
     caused to other users of the spectrum

xx. UWB operation is unique with regard to the possible range of
    emissions that could be radiated from the transmitter. The generated
    pulse could result in a fundamental emission that is several
    gigahertz wide. Similarly, the side lobes also could be several
    gigahertz wide with the amplitude of the secondary lobe(s) only
    attenuated slightly below the level of the fundamental emission. It
    is the resonant frequency of the antenna employed with the UWB
    transmitter that determines the relative amplitudes of the radiated
    emissions.[^382] The antenna can be resonant on several frequencies
    over a wide range both low and high. Thus, it is difficult to
    precisely state a frequency range of measurement.

xxi. We would rather proceed cautiously for these initial standards. We
     believe that the frequency range over which radiated emissions are
     investigated should include at least the fundamental emission and
     the secondary lobe regardless of the center frequency. This can be
     accomplished by requiring that the emissions be measured up to at
     least the center frequency added to three divided by the width of
     the pulse in seconds. Of course, we recognize that there is no need
     to require the emissions to be measured beyond 200 GHz, as could
     otherwise be required for extremely short pulses.[^383] On the
     other hand, we do not wish to overburden equipment manufacturers
     with extensive measurement ranges that may not be necessary.
     Accordingly, we believe that we can compromise by establishing the
     following parameters. The radio spectrum produced by a UWB
     transmitter shall be investigated from the lowest frequency
     generated within the device, without going below 9 kHz, up to the
     frequency range shown in 47 C.F.R. § 15.33(a) or to the center
     frequency added to three divided by the pulse width in seconds,
     whichever is higher. The frequency range in 47 C.F.R. § 15.33(a)
     shall be based on the center frequency unless a higher frequency,
     *e.g.*, a carrier frequency, is generated within the UWB device.
     There is no requirement to measure emissions beyond 40 GHz provided
     the center frequency is less than 10 GHz; beyond 100 GHz if the
     center frequency is at or above 10 GHz and below 30 GHz; or beyond
     200 GHz if the center frequency is at or above 30 GHz.[^384]

## Prohibition Against Class B, Damped Wave Emissions

k.  The rules prohibit the use of Class B, damped wave emissions.[^385]
    This prohibition stems from a similar International
    Telecommunication Union regulation and is a throwback to the days
    when spark gap transmitters were employed.[^386] There is no longer
    a clear definition of a Class B, damped wave emission.[^387] The
    Commission proposed to eliminate the prohibition against Class B,
    damped wave emissions indicating that this prohibition does not
    appear to be relevant at the power levels being proposed for UWB
    transmissions. These levels appear to be low enough to prevent
    harmful interference to other users of the spectrum. Further, unlike
    conventional damped wave transmissions it is likely that the
    receivers associated with UWB transmitters would attempt to recover
    as much of the transmitted bandwidth as possible for information
    processing purposes.

l.  [Comments]{.underline}. Few comments were filed in response to this
    proposal. TDC agreed with our proposal stating that the prohibition
    against damped wave emissions does not appear relevant to the
    current UWB technologies.[^388] On the other hand, USGPSIC objected
    to removing the prohibition against employing damped wave emissions
    stating that there is no assurance that all future UWB applications
    will employ low power levels.[^389] USGPSIC stated that it is
    prudent to retain the prohibition until a regulatory environment can
    be established that ensures stability of the national information
    infrastructure.

m.  [Discussion]{.underline}. The objection from USGPSIC has no
    technical basis. The regulations being adopted address the emission
    limits from UWB devices, ensuring that these devices will not
    operate at power levels that could cause harmful interference to the
    authorized radio services. Accordingly, our original supposition has
    been satisfied, and we are eliminating the prohibition against
    damped wave operation for UWB devices.

## Other Matters

### Operation of Wide Bandwidth Systems under the Existing Rules

i.  [Proposal]{.underline}. In the *Notice*, we proposed specific
    regulations regarding the frequency of operation and emission levels
    that would apply to UWB devices. We expressed concern that UWB
    manufacturers would wish to operate their products under a
    combination of both the UWB regulations and the existing Part 15
    regulations in 47 C.F.R. §§ 15.217-15.255. This would result in a
    transmitter that has an extremely wide bandwidth attempting also to
    operate under standards that were developed for narrowband
    operation. An example would be a UWB device that operates at 5800
    MHz attempting to demonstrate compliance with 47 C.F.R. § 15.245
    over the frequency range 5785-5815 MHz while demonstrating
    compliance with the UWB emission limits outside of that frequency
    band. To prevent this method of cross-rule operation, the Commission
    proposed to amend 47 C.F.R. § 15.215(c) to state that intentional
    radiators operated under the provisions of 47 C.F.R. §§
    15.217-15.255 or Subpart E of the current regulations must be
    designed to ensure that the main lobe or the necessary bandwidth,
    whichever is less, is contained within the frequency bands
    designated in those rule section under which the equipment is
    operated. The requirement to contain the fundamental emission within
    one of the specified frequency bands would include the effects from
    frequency sweeping, frequency hopping and other modulation
    techniques that may be employed as well as the frequency stability
    of the transmission over variations in temperature and supply
    voltage. If a frequency stability were not specified, the regulation
    would continue to recommend that the fundamental emission be kept
    within at least the central 80 percent of the band in order to
    minimize the possibility of out-of-band operation.

ii. [Comments]{.underline}. Interlogix expressed concern on how to
    compute the necessary bandwidth and measurements of the fundamental
    lobe.[^390] It requested that the determination of whether an
    emission was contained within one of the frequency bands specified
    in 47 C.F.R. § 15.217-15.255 should be based on the 20 dB bandwidth
    of the emission. Bosch requested that higher emission levels be
    permitted for UWB devices if the emission is located in one of the
    ISM bands.[^391] TDC requested that we not prohibit dual mode
    devices provided each mode of operation qualifies separately under
    the pertinent regulations.[^392] Valeo and SARA also requested the
    ability for dual mode operation.[^393] In addition, Delphi and SARA
    requested that higher UWB emissions be permitted if the emissions
    are located in the ISM bands.[^394]

iii. [Discussion]{.underline}. We agree with Interlogix that the 20 dB
     bandwidth of an emission is an appropriate method of determining if
     an emission is operating within one of the frequency bands
     specified in 47 C.F.R. §§ 15.217-15.255 and are adopting this
     suggestion.[^395] We also agree that dual mode operation is not
     prohibited provided each mode of operation can be distinguished and
     demonstrated to comply separately under the pertinent
     regulations.[^396] However, we see no basis for permitting
     emissions from UWB devices to exceed the standards being adopted in
     this proceeding simply because the emissions happen to appear in an
     ISM band. There are a significant number of other radio services
     and devices operating within the ISM bands, some of which are
     allocated spectrum for this purpose. Examples include Location
     Monitoring Service systems in the 915 MHz band, Amateur Radio
     Service and land mobile systems operating in the 2450 MHz band, and
     police radar systems operating in the 24.125 GHz band. These are
     authorized radio services and are protected against harmful
     interference from the operation of Part 15 devices, regardless of
     whether they are located within ISM bands. The commenting parties
     have not provided information demonstrating that their products
     could operate without causing harmful interference to these
     authorized services. Even so, we are not persuaded that higher
     emission limits for UWB operation are prudent at this time. Once we
     have gained additional experience with the operation of UWB devices
     and their interference potential, additional changes to the rules
     could be considered.

### Transition Provisions

iv. In the *Notice*, we proposed that the regulations being adopted in
    this Report and Order become effective 60 days from its date of
    publication in the Federal Register. USGPS objected to our proposal,
    stating that it is premature to permit the regulations to become
    effective within 60 days of publication in the Federal
    Register.[^397] USGPSIC added that additional proposals are needed,
    and that these would be major rule changes requiring congressional
    review.

v.  We recognize that this proceeding is considered to be a major action
    and that the effective date is delayed for 60 days under the
    Contract with America Advancement Act of 1996.[^398] This provides
    Congress with sufficient time to review our decisions, if it so
    desires. Absent adoption of a petition for stay or a court-order
    stay of this proceeding, we see no justification for delaying
    further the effective date.

### Existing Waivers

vi. The Commission has issued four waivers to permit the manufacture of
    UWB devices. Three of the waivers were issued on June 25, 1999. TDC
    was issued a waiver for UWB systems that would be used by public
    safety personnel for high resolution imaging of persons and objects
    behind walls or under debris. Zircon was issued a waiver for UWB
    radar systems that would be used by the construction industry to
    detect objects hidden inside walls or other building materials. U.S.
    Radar was issued a waiver for ground penetrating radar systems. A
    fourth waiver was issued on August 6, 2001, to Kohler Co. to permit
    it to market UWB toilet ventilating devices. These waivers were
    scheduled to terminate upon the effective date of the Report and
    Order in this proceeding.

vii. On August 16, 2001, Kohler filed a request to permit it to continue
     to market its product under the waiver until one year from the
     effective date of this Report and Order. Kohler, noting that the
     adopted rules may be different than those under which the waiver
     was granted, cited the time necessary to redesign its product, to
     test the redesigned device and to modify its tooling. We sympathize
     with Kohler's concerns and believe that these problems also would
     affect other companies marketing equipment under a waiver.
     Accordingly, we are extending the cut-off dates of the waivers
     issued to Time Domain Corp., to U.S. Radar, to Zircon, and to
     Kohler for a period of one year from the effective date of this
     Report and Order.

### Miscellaneous Issues

viii. *Further Notice of Proposed Rule Making*. A number of parties
      requested that the Commission issue a further notice of proposed
      rule making before adopting final rules.[^399] They argue,
      generally, that the *Notice* was inadequate because it did not
      include the text of the proposed rules. They also claim that the
      Commission must update the proposals to take into account the
      information contained in the various test reports filed in the
      record. As stated by ARRL, the *Notice* included no proposed
      rules, listed a few generalized tentative conclusions about UWB,
      and was more akin to a Notice of Inquiry.[^400] Contrary to these
      comments, Fantasma and XSI asserted that each regulatory measure
      was contemplated in the *Notice* and can be implemented without a
      further notice of proposed rule making.[^401]

ix. It is true that the *Notice* did not include the precise language of
    the rules we are adopting today. However, the Commission did provide
    a general picture of what it intended to do and that is legally
    adequate under the Administrative Procedure Act.[^402] In
    *California Citizens Band Association* v. *U.S.*, 375 F 2d 43, 48-49
    (9^th^ Cir. 1967), *cert. denied*, 389 U.S. 844 (1967), the court
    held that the Administrative Procedure Act "\...does not require an
    agency to publish in advance every precise proposal which it may
    ultimately adopt as a rule. \...\[A\] notice of rulemaking is
    sufficient if it provides a description of the subjects and issues
    involved." Similarly, the court in *Forester* v. *Consumer Product
    Safety Com'n*, 559 F 2d 774, 787 (D.C. Cir. 1977) held that "Section
    553(b) does not require that interested parties be provided precise
    notice of each aspect of the regulations eventually adopted. Rather,
    notice is sufficient if it affords interested parties a reasonable
    opportunity to participate in the rulemaking process\..." Additional
    legal citations were provided by Fantasma in its filing of April 2,
    2001, and by XSI in its filing of April 12, 2001.

x.  Several hundred comments have been filed in this proceeding,
    including comments on the various technical reports and analyses. It
    is clear from this record that the commenters well understood the
    regulations under consideration for amendment and the scope of
    proposed changes under consideration. We find that there is
    sufficient information in the record to make initial decisions at
    this time that provide for the introduction of UWB technology based
    on standards that are extremely conservative in protecting radio
    services against harmful interference. We recognize, however, that
    as this technology develops and we gain experience with the
    potential interference of UWB devices, it is appropriate to
    reexamine these rules. Accordingly, within the next six to twelve
    months we intend to review the standards for UWB devices and issue a
    further rule making to explore more flexible technical standards and
    to address the operation of additional types of UWB operations and
    technology. In the meantime, we plan to expedite enforcement action
    for any UWB products found to be in violation of the rules we are
    adopting and will act promptly to eliminate any reported harmful
    interference from UWB devices.

xi. *Delphi and Other Automotive Radar Systems*. Delphi requested that
    we include its radar system operating at 24.125 GHz under our
    provisions for UWB operation.[^403] Delphi indicated that it
    operates at 17 GHz and at 24.125 GHz and uses several different
    modulation types, including swept frequency modulation. However, it
    is the 24.125 GHz system operating with a pseudo-noise direct
    sequence binary phase shift key waveform that Delphi requested for
    inclusion. This system transmits in the restricted band below 24 GHz
    at the limit in 47 C.F.R. § 15.209. SARA also has expressed interest
    in a similar technology.[^404] We find that the SARA and Delphi
    systems, excluding the swept frequency modulated system, fall under
    the definition being adopted in this proceeding and that no further
    action is necessary.

### Other Matters

xii. *Operation in the PCS Bands*. Sprint objected to the basic concept
     of UWB operation, stating that the Commission does not have a legal
     right to convert Sprint's licenses into non-exclusive licenses and
     to require Sprint PCS to share its spectrum with others, much less
     share it for free.[^405] Sprint PCS added that it spent over \$3
     billion for exclusive PCS licenses and that Commission
     authorization of new users constitutes breach of contract and an
     unlawful modification of licenses for which the Government would be
     liable for damages.[^406] However, no such contractual exclusivity
     exists. This spectrum is not, and has never been, exclusive to
     Sprint or to any other licensee or user. While Sprint PCS has been
     provided some exclusivity in operating licensed PCS systems within
     specified geographic areas, Part 15 transmitters currently are
     permitted to operate within the PCS and cellular frequency bands at
     considerably higher emission levels than those being adopted in
     this Report and Order.[^407] In addition, there are countless other
     devices that emit radio emissions within these bands. In any event,
     we have not in this proceeding permitted any UWB devices to
     deliberately emit in the PCS bands. Much as we have done for other
     RF devices, we have simply established limits on out-of-band and
     spurious emissions from UWB devices that are designed to reduce the
     probability that harmful interference would be caused.

xiii. *Exemption of Unlicensed PCS Transmitters from the Restricted
      Bands*. Under the current rules, unlicensed PCS transmitters
      operating under Subpart D of Part 15 are not subject to the
      restricted band provisions in 47 C.F.R. § 15.205. The
      cross-reference in Subpart D to other applicable Part 15
      regulations, as specified in 47 C.F.R. § 15.309, does not include
      Subpart C of Part 15 or any of the individual regulations
      contained in that subpart. Thus, 47 C.F.R. § 15.205, which is
      contained in Subpart C, does not apply to unlicensed PCS
      transmitters.[^408] We are taking the opportunity provided by this
      Report and Order to clarify this current standard in our amendment
      to 47 C.F.R. § 15.205. As this amendment to the rules only
      clarifies an existing regulation, prior notice and comment are
      unnecessary.[^409]

xiv. *U.S. Government Operation of UWB Devices*. When the Part 15
     regulations were amended in 1989,[^410] the Commission opened
     several frequency bands for unlicensed operation even though those
     bands were allocated for exclusive operation by the U.S.
     Government. The Commission took this action following an informal
     agreement with NTIA that similarly permitted it to operate
     equipment in exclusive non-government bands under the same Part 15
     standards.[^411] We will continue this policy, permitting the U.S.
     Government to operate in non-government frequency bands and in
     shared frequency bands under the Part 15 standards. Accordingly, as
     a condition of their use of these bands U.S. Government
     specifications for UWB devices operated by the U.S. Government
     agencies in non-government or in shared frequency bands must
     conform to the standards and operating conditions that are being
     adopted in this Order.[^412] We believe that this will result in a
     greater number of UWB devices operating under the same parameters,
     facilitating our studies to readdress the appropriateness of the
     UWB standards within the next six to 12 months.

# PROCEDURAL MATTERS

151. [Paperwork Reduction Act of 1995 Analysis]{.underline}. This Report
     & Order contains modified information collection subject to the
     Paperwork Reduction Act of 1995 (PRA), Public Law 104-13. It will
     be submitted to the Office of Management and Budget (OMB) for
     review under Section 3507(d) of the PRA. OMB, the general public,
     and other Federal agencies are invited to comment on the modified
     information collection contained in this proceeding.

152. [Final Regulatory Flexibility Certification]{.underline}. The
     Regulatory Flexibility Act of 1980, as amended (RFA)[^413] requires
     that a regulatory flexibility analysis be prepared for rulemaking
     proceedings, unless the agency certifies that \"the rule will not
     have a significant economic impact on a substantial number of small
     entities.\"[^414] The RFA generally defines \"small entity\" as
     having the same meaning as the terms \"small business,\" \"small
     organization,\" and \"small governmental jurisdiction.\"[^415] In
     addition, the term \"small business\" has the same meaning as the
     term \"small business concern\" under the Small Business Act.[^416]
     A small business concern is one which: (1) is independently owned
     and operated; (2) is not dominant in its field of operation;
     and (3) satisfies any additional criteria established by the Small
     Business Administration (SBA).[^417]

153. In this First Report and Order, we are amending Part 15 of our
     rules to permit the marketing and operation of new products
     incorporating ultra-wideband (\"UWB\") technology. UWB devices
     operate by employing very narrow or short duration pulses that
     result in very large or wideband transmission bandwidths. UWB
     devices have the capability to provide for significant benefits for
     public safety, businesses and consumers. With appropriate technical
     standards, UWB devices can operate on spectrum occupied by existing
     radio services without causing interference, thereby permitting
     scarce spectrum resources to be used more efficiently.

154. We note that the Aircraft Owners and Pilots Association (AOPA)
     along with the National Business Aviation Association (NBAA)
     commented that the impact on small entities could not be estimated
     at this time.[^418] They added that their constituency
     substantially consists of small entities, comprising individuals
     and small businesses that are aircraft owners and operators. AOPA
     and NBAA expressed concern that there would be a severe and lengthy
     impact to aeronautical operations should the UWB standards prove to
     be inadequate to protect aeronautical communications, navigation
     and surveillance functions. However, as demonstrated in our
     analyses of the interference studies on GPS there should be no
     impact to aeronautical radio operations from UWB devices operating
     under the technical limits and operational requirements we are
     adopting. Therefore, we find that our action will have no negative
     impact on this industry and in fact will have a positive impact.
     Further, as noted in the text we currently are limiting the
     expansion of UWB, out of an abundance of caution, until such time
     as we gain additional experience. Thus, we expect that our actions
     do not amount to a significant economic impact at this time.
     Accordingly, we certify that the rules being adopted in this Report
     and Order will not have a significant economic impact on a
     substantial number of small entities.

155. We will send a copy of the First Report and Order, including a copy
     of this final certification, in a report to Congress pursuant to
     the Congressional Review Act.[^419] In addition, the First Report
     and Order and this certification will be sent to the Chief Counsel
     for Advocacy of the Small Business Administration, and will be
     published in the Federal Register.[^420]

# ORDERING CLAUSES

156. IT IS ORDERED that Part 15 of the Commission's Rules and
     Regulations IS AMENDED as specified in Appendix D, effective 60
     days after publication in the Federal Register. This action is
     taken pursuant to Sections 4(i), 302, 303(e), 303(f), 303(r), 304
     and 307 of the Communications Act of 1934, as amended, 47 U.S.C.
     Sections 154(i), 302, 303(e), 303(f), 303(r), 304 and 307.

157. IT IS FURTHER ORDERED that the waivers issued on June 25, 1999, to
     Time Domain Corporation, to U.S. Radar Inc., and to Zircon Corp.
     and the waiver issued on August 6, 2001, to Kohler Co. to permit
     the manufacture and marketing of their UWB devices remain in effect
     until one year from the effective date of this Report and Order.

158. IT IS FURTHER ORDERED that the Commission's Consumer and
     Governmental Affairs Bureau, Reference Information Center, SHALL
     SEND a copy of this *Report and Order*, including the Final
     Regulatory Flexibility Analysis, to the Chief Counsel for Advocacy
     of the Small Business Administration.

159. For further information regarding this *Report and Order*, contact
     John A. Reed, Office of Engineering and Technology, (202) 418-2455,
     <jreed@fcc.gov>.

     FEDERAL COMMUNICATIONS COMMISSION

     Marlene H. Dortch

Secretary

APPENDIX A

Commenting Parties

Parties filing comments:

1.  Aeronautical Radio, Inc. & the Air Transport Association of America,
    Inc.

2.  Aether Wire & Location, Inc.

3.  Aircraft Owners and Pilots Association

4.  Alzheimer's Association, Coastal Carolina Chapter

5.  Alzheimer's Association, Middle Mississippi Chapter

6.  The Amyotropic Lateral Sclerosis Association, Keith Worthington
    Chapter

7.  The Amyotropic Lateral Sclerosis Association, Western Ohio Chapter

8.  A. Peter Annan

9.  ANRO Engineering, Inc.

10. Senator Bill Armistead, Alabama State Senate

11. Arc of Tennessee

12. ARRL, The National Association for Amateur Radio

13. Arthur D. Little, Inc.

14. The Associated General Contractors of America

15. Assistance of Independent Living, Inc.

16. Astatula Police Department (Florida)

17. AT&T Wireless Services, Inc.

18. Ball & Associates

19. Berwyn Fire Department (Illinois)

20. A/Prof. Marek Bailkowski, University of Queensland

21. Boeing Company

22. Burbank Fire Department

23. Centre for Sensor Signal and Information Processing

24. Cisco Systems, Inc.

25. Colingo, Williams, Heidelberg, Steinberger & McElhaney, P.A. (2)

26. Comprehensive Cancer Institute

27. Thomas J. Cooper

28. Congressman Bud Cramer, *et al.*

29. Daniel Group

30. Decatur Police Department, Criminal Investigation Division (Alabama)

31. Delphi Automotive Systems Corporation

32. Deutsche Bank Securities Inc.

33. William E. N. Doty

34. Dulac Fire Protection District 4-A (Louisiana)

35. DVP Incorporated

36. Endress + Hauser GmbH & Co.

37. Envoy Corporation

38. Fairlawn Fire Department (Ohio)

39. Fantasma Networks, Inc.

40. Farmington Department of Public Safety (Michigan)

41. Federal Law Enforcement Wireless Users Group

42. Federal Republic of Germany, Liaison Office for Defense Materiel
    USA/Canada

43. Florida Adult Day Care Association

44. Gordon E. Fornell

45. Charles Alton Forsberg

46. Fraternal Order of Police

47. Frontier Capital, LLC

48. Garmin International, Inc.

49. General Electric Company

50. Globe Fire Department (Arizona)

51. Golf-Domain

52. Groveland Police Department (Florida)

53. The Heart Center, P.C.

54. Helena Fire Department (Montana)

55. Hewlett-Packard Company

56. Houma Police Department (Louisiana)

57. Houston Police Department (Texas)

58. Representative Mike Hubbard, Alabama House of Representatives

59. Iberia Parish Council on Aging, Inc. (Louisiana)

60. Intelligent Automation, Inc.

61. Interlogix, Inc.

62. International Association of Fire Chiefs

63. International Brotherhood of Electrical Workers

64. Irmo Fire District (South Carolina)

65. Jore Corporation

66. Joseph Decosimo and Company

67. Kohler Co.

68. Krohne America Inc.

69. L-3 Communications

70. Laborers' International Union of North America

71. Leesburg Fire Department (Florida)

72. Lockheed Martin Corporation

73. Lockheed Martin Information Systems

74. Los Angeles County Sheriff's Department (California)

75. Senator Trent Lott

76. Lucent Technologies Inc.

77. M/A-COM

78. Maricopa County Emergency Management (Arizona)

79. McNeese State University

80. Metricom, Inc.

81. Metro Area Agency on Aging (W. Virginia)

82. Mobile Communications Holdings, Inc.

83. Moose Hill Enterprises, Inc.

84. Motorola, Inc.

85. Multispectral Solutions, Inc.

86. National Alliance for the Mentally Ill, Illinois

87. National Alliance for the Mentally Ill, Kansas

88. National Alliance for the Mentally Ill, South Dakota

89. National Association of Broadcasters

90. National Business Aviation Association, Inc.

91. National Safe Skies Alliance

92. National Telecommunications and Information Administration

93. National Thoroughbred Racing Association

94. National Volunteer Fire Council

95. Noro-Moseley Partners (2)

96. Nortel Networks Inc.

97. Ohio Statewide Independent Living Council

98. OnScene, Inc.

99. Plymouth Township Police Department (Michigan)

100. Professor Jon M. Peha, Carnegie Mellon University

101. Qualcomm Incorporated

102. Rainbow/PUSH Coalition

103. Redwood City Fire Department (California)

104. Richards Lighting

105. Roane County Committee on Aging, Inc. (W. Virginia)

106. Robert Bosch Gmbh

107. Rockwell Collins, Inc.

108. Saab Marine Electronics

109. San Mateo County, Office of the Sheriff (California)

110. Satellite Industry Association

111. James J. Schaffer

112. Professor Robert Scholtz, University of Southern California

113. Science Applications International Corporation

114. Senior Citizens, Inc.

115. Senior Companion Program, Van Buren Community Development and
     Services Board (Tennessee)

116. Senator Jeff Sessions, U.S. Senate

117. Siemens Automotive

118. Siemens Corporation

119. Sierra Monolithics, Incorporated

120. Singing River Hospital (Mississippi)

121. Sioux Falls Fire Rescue (South Dakota)

122. SiRF Technology, Inc.

123. Sirius Satellite Radio Inc.

124. Sony Corporation

125. South Dakota Coalition of Citizens with Disabilities

126. Sprint

127. Sprint Corporation

128. Staenberg Private Capital, LLC

129. Stanford University, Department of Aeronautics and Astronautics

130. STEP Inc.

131. Stephens Inc.

132. Steven T. Suess

133. Tacoma-Pierce County Chamber of Commerce (Washington)

134. Tallahassee Senior Center (Florida)

135. Congressman Billy Tauzin, *et al.*

136. Tennessee Disability Coalition

137. Terrebonne Parish Sheriff's Office (Louisiana)

138. Time Domain Corporation

139. Peter W. Torode

140. Tri-City Fire District (Arizona)

141. UCI

142. University of Mississippi, Office of the Chancellor

143. Upper East Tennessee Human Development Agency, Inc.

144. U.S. Department of Justice, Federal Bureau of Prisons

145. U.S. Department of the Navy, Office of the Assistant Secretary

146. U.S. Department of Transportation

147. U.S. GPS Industry Council

148. Valeo Electronics

149. Virginia Task Force One

150. Virtual Education, Inc.

151. Wakefield Police Department (Massachusetts)

152. Congressman Curt Weldon

153. West Virginia Department of Health and Human Resources

154. Wheeling Jesuit University, Office of Law Enforcement Technology
     Commercialization (West Virginia)

155. Lt. Governor Steve Windom, State of Alabama

156. Wireless Communications Association International, Inc. ("WCA")

157. XM Radio Inc.

158. XtremeSpectrum, Inc.

159. Zircon Corporation

Parties filing reply comments:

1.  Aeronautical Radio, Inc. and the Air Transport Association of
    America, Inc.

2.  Aerospace Industries Association

3.  Aerospace States Association (ASA)

4.  Aircraft Owners and Pilots Association (AOPA)

5.  Alliance for Telecommunications Industry Solutions (ATIS)

6.  Alloy LLC

7.  American Association of People with Disabilities

8.  American Telemedicine Association

9.  American Trans Air, Inc.

10. Apple Valley Fire Protection District, California

11. ARRL, The National Association for Amateur Radio

12. AT&T Wireless Services, Inc.

13. Aviation Management Associates, Inc. (AMA)

14. Clovis Firefighters' Association

15. Colorado School of Mines, Department of Geophysics

16. Community Technology Centers' Network (CTCNet)

17. Computer & Communications Industry Association (CCIA)

18. Consortium for School Networking (CoSN)

19. Consumers Union and the Consumer Federation of America

20. Council of Chief State School Officers (D.C.)

21. Daimler Chrysler Research and Technology North America

22. Dain Rauscher Wessels

23. Delphi Automotive Systems Corporation

24. Disability Rights Education and Defense Fund, Inc.

25. Dr. William E. English

26. Fantasma Networks, Inc.

27. Fraternal Order of Police (Albuquerque, New Mexico)

28. Garmin International, Inc.

29. Dr. Jim Grigsby

30. Hays Medical Center (Kansas)

31. Iberia Medical Center (Louisiana)

32. Intel Corporation

33. Interagency GPS Executive Board (IGEB)

34. Interlogix Inc.

35. IPEG Corporation

36. iTelehealth, Inc.

37. Kohler Co.

38. Krohne, Inc.

39. Lockheed Martin Corporation (2)

40. Lucent Technologies Inc.

41. M/A-COM

42. Motorola, Inc.

43. Multispectral Solutions, Inc.

44. National Alliance for the Mentally Ill, Tennessee

45. National Association of County and City Health Officials

46. National Business Aviation Association, Inc.

47. National Catholic Educational Association

48. National Safe Skies Alliance

49. National Spectrum Managers Association

50. NAV Canada, SatNav

51. NovAtel Inc.

52. Robert Bosch Gmbh

53. Rockwell Collins, Inc.

54. Rural Wisconsin Health Cooperative

55. Rush Advanced Technology & International Health

56. Satellite Industry Association (SIA)

57. SBK Capital, LLC

58. Nancy J. Sharp

59. Don Siegelman, Governor, State of Alabama

60. SiRF Technology, Inc. & Trimble Navigation Limited

61. Sirius Satellite Radio Inc.

62. Sprint

63. Sprint PCS

64. STMicroelectronics (ST)

65. Stroud Engineering Services, Inc.

66. Time Domain Corporation (2)

67. United States Catholic Conference

68. U. S. Department of Defense

69. U. S. Department of Transportation

70. U. S. GPS Industry Council

71. University NAVSTAR Consortium

72. University of Arkansas for Medical Sciences, Rural Hospital Program

73. Verizon Telephone Companies

74. Dr. John Michael Williams

75. John A. Williamson, Sr.

76. Steve Windom, Lieutenant Governor, State of Alabama

77. Worldcom, Inc.

78. XM Radio Inc.

79. XtremeSpectrum, Inc.

80. Zircon Corporation

    Appendix B

    Comments in Response to NTIA's Study of Potential

Interference to non-GPS Systems

Parties filing comments:

1.  Aeronautical Radio, Inc. and the Air Transport Association of
    America, Inc. (ARINC/ATA)

2.  AT&T Wireless Services, Inc. (AT&T)

3.  Cingular Wireless LLC (Cingular)

4.  Fantasma Networks, Inc. (Fantasma)

5.  Federal Law Enforcement Wireless Users Group (FLEWUG)

6.  Nickolaus E. Leggett

7.  Lockheed Martin Corporation (LMC)

8.  Multispectral Solutions, Inc. (MSSI)

9.  National Association of Broadcasters (NAB)

10. Dr. Gary R. Olhoeft

11. Rockwell Collins, Inc.

12. Sirius Satellite Radio Inc. (Sirius)

13. Sprint Corporation

14. 3Com Corporation

15. Time Domain Corporation

16. U.S. GPS Industry Council

Parties filing reply comments:

1.  AT&T Wireless Services, Inc. (AT&T)

2.  Fantasma Networks, Inc. (Fantasma)

3.  Multispectral Solutions, Inc. (MSSI)

4.  Sirius Satellite Radio Inc. (Sirius)

5.  Time Domain Corporation

6.  XM Radio Inc.

7.  XtremeSpectrum, Inc.

    Appendix C

    Comments in Response to Studies of Potential Interference to GPS
    Systems and to PCS

Parties filing comments:

1.  Aeronautical Radio, Inc. and The Air Transport Association of
    America, Inc. (ARINC/ATA)

2.  ANRO Engineering, Inc. (ANRO)

3.  ARRL, The National Association for Amateur Radio (ARRL)

4.  The Boeing Company (Boeing)

5.  Centre for Sensor Signal and Information Processing (CSSIP)

6.  Conexant Systems Inc.

7.  Geophysical Survey Systems, Inc. (GSSI) (x2)

8.  The Ground Penetrating Radar Circle of Finland

9.  Johns Hopkins University Applied Physics Laboratory

10. Lockheed Martin Corporation (LMC)

11. Motorola, Inc.

12. Nokia, Inc.

13. Sirius Satellite Radio Inc. (Sirius) (x2)

14. Dr. Lee Slater

15. Sprint Corporation (Sprint)

16. Sprint Spectrum (Sprint PCS)

17. Dr. Ben K. Sternberg

18. Technos, Inc.

19. Time Domain Corporation (TDC)

20. U.S. GPS Industry Council

21. Dr. David L. Wright

22. XtremeSpectrum, Inc. (x2)

Parties filing reply comments:

1.  Aeronautical Radio, Inc. and The Air Transport Association of
    America, Inc. (ARINC/ATA)

2.  Dr. A. Peter Annan

3.  ARRL, The National Association for Amateur Radio (ARRL)

4.  Cingular Wireless

5.  Common Ground Alliance

6.  Geophysics Community

7.  Interagency GPS Executive Board (IGEB)

8.  Johns Hopkins University Applied Physics Laboratory

9.  Mercedes-Benz USA (MBUSA)

10. Qualcomm Incorporated

11. Sirius Satellite Radio, Inc.

12. Society of Exploration Geophysicists (SEG)

13. Time Domain Corporation (TDC)

14. U.S. GPS Industry Council

15. XM RadioInc.

16. XtremeSpectrum, Inc.

    Appendix D

    Changes to the Regulations

Title 47 of the Code of Federal Regulations, Part 15, is amended as
follows:

1.  The authority citation for Part 15 continues to read as follows:

    AUTHORITY: 47 U.S.C.154, 302, 303, 304, 307 and 544A.

2.  Section 15.35 is amended by revising paragraph (b) to read as
    follows:

    Section 15.35 [Measurement detector function and
    bandwidth]{.underline}.

\* \* \* \* \*

\(b\) Unless otherwise stated, on any frequency or frequencies above
1000 MHz the radiated limits shown are based upon the use of measurement
instrumentation employing an average detector function. When average
radiated emission measurements are specified in the regulations,
including emission measurements below 1000 MHz, there also is a limit on
the radio frequency emissions, as measured using instrumentation with a
peak detector function, corresponding to 20 dB above the maximum
permitted average limit for the frequency being investigated unless a
different peak emission limit is otherwise specified in the rules,
*e.g.*, see Sections 15.255, 15.509 and 15.511. Unless otherwise
specified, measurements above 1000 MHz shall be performed using a
minimum resolution bandwidth of 1 MHz. Measurements of AC power line
conducted emissions are performed using a CISPR quasi-peak detector,
even for devices for which average radiated emission measurements are
specified.

\* \* \* \* \*

3.  Section 15.205 is amended by adding a new subparagraph (d)(6), to
    read as follows:

    Section 15.205 [Restricted bands of operation]{.underline}.

\* \* \* \* \*

(d)(6) Transmitters operating under the provisions of Subparts D or F of
this Part.

\* \* \* \* \*

4.  Section 15.215 is amended by revising (c) and by removing paragraph
    (d), to read as follows:

    Section 15.215 [Additional provisions to the general radiated
    emission limitations]{.underline}.

\* \* \* \* \*

\(c\) Intentional radiators operating under the alternative provisions
to the general emission limits, as contained in Sections 15.217 *et
seq.* and in Subpart E of this part, must be designed to ensure that the
20 dB bandwidth of the emission is contained within the frequency band
designated in the rule section under which the equipment is operated.
The requirement to contain the 20 dB bandwidth of the emission within
the specified frequency band includes the effects from frequency
sweeping, frequency hopping and other modulation techniques that may be
employed as well as the frequency stability of the transmitter over
expected variations in temperature and supply voltage. If a frequency
stability is not specified in the regulations, it is recommended that
the fundamental emission be kept within at least the central 80% of the
permitted band in order to minimize the possibility of out-of-band
operation.

5.  Part 15 is amended by adding a new Subpart F, to read as follows:

    **SUBPART F -- ULTRA-WIDEBAND OPERATION**

    Section 15.501 [Scope]{.underline}.

    This subpart sets out the regulations for unlicensed ultra-wideband
    transmission systems.

    Section 15.503 [Definitions]{.underline}.

\(a\) [UWB Bandwidth]{.underline}. For the purpose of this subpart, the
UWB bandwidth is the frequency band bounded by the points that are 10 dB
below the highest radiated emission, as based on the complete
transmission system including the antenna. The upper boundary is
designated f~H~ and the lower boundary is designated f~L~. The frequency
at which the highest radiated emission occurs is designated f~M~.

\(b\) [Center frequency]{.underline}. The center frequency, f~C~, equals
(f~H~ + f~L~)/2.

\(c\) [Fractional bandwidth]{.underline}. The fractional bandwidth
equals 2(f~H~ - f~L~)/ (f~H~ + f~L~).

\(d\) [Ultra-wideband (UWB) transmitter]{.underline}. An intentional
radiator that, at any point in time, has a fractional bandwidth equal to
or greater than 0.20 or has a UWB bandwidth equal to or greater than 500
MHz, regardless of the fractional bandwidth.

\(e\) [Imaging system]{.underline}. A general category consisting of
ground penetrating radar systems, medical imaging systems, wall imaging
systems through-wall imaging systems and surveillance systems. As used
in this subpart, imaging systems do not include systems designed to
detect the location of tags or systems used to transfer voice or data
information.

\(f\) [Ground penetrating radar (GPR) system]{.underline}. A field
disturbance sensor that is designed to operate only when in contact
with, or within one meter of, the ground for the purpose of detecting or
obtaining the images of buried objects or determining the physical
properties within the ground. The energy from the GPR is intentionally
directed down into the ground for this purpose.

\(g\) [Medical imaging system]{.underline}. A field disturbance sensor
that is designed to detect the location or movement of objects within
the body of a person or animal.

\(h\) [Wall imaging system]{.underline}. A field disturbance sensor that
is designed to detect the location of objects contained within a "wall"
or to determine the physical properties within the "wall." The "wall" is
a concrete structure, the side of a bridge, the wall of a mine or
another physical structure that is dense enough and thick enough to
absorb the majority of the signal transmitted by the imaging system.
This category of equipment does not include products such as "stud
locators" that are designed to locate objects behind gypsum, plaster or
similar walls that are not capable of absorbing the transmitted signal.

\(i\) [Through-wall imaging system]{.underline}. A field disturbance
sensor that is designed to detect the location or movement of persons or
objects that are located on the other side of an opaque structure such
as a wall or a ceiling. This category of equipment may include products
such as "stud locators" that are designed to locate objects behind
gypsum, plaster or similar walls that are not thick enough or dense
enough to absorb the transmitted signal.

\(j\) [Surveillance system]{.underline}. A field disturbance sensor used
to establish a stationary RF perimeter field that is used for security
purposes to detect the intrusion of persons or objects.

\(k\) [EIRP]{.underline}. Equivalent isotropically radiated power,
*i.e.*, the product of the power supplied to the antenna and the antenna
gain in a given direction relative to an isotropic antenna. The EIRP, in
terms of dBm, can be converted to a field strength, in dBuV/m at 3
meters, by adding 95.2. As used in this subpart, EIRP refers to the
highest signal strength measured in any direction and at any frequency
from the UWB device, as tested in accordance with the procedures
specified in Sections 15.31(a) and 15.523 of this chapter.

\(l\) [Law enforcement, fire and emergency rescue
organizations]{.underline}. As used in this subpart, this refers to
those parties eligible to obtain a license from the FCC under the
eligibility requirements specified in Section 90.20(a)(1) of this
chapter.

\(m\) [Hand held]{.underline}. As used in this subpart, a hand held
device is a portable device, such as a lap top computer or a PDA, that
is primarily hand held while being operated and that does not employ a
fixed infrastructure.

Section 15.505 [Cross reference]{.underline}.

\(a\) Except where specifically stated otherwise within this subpart,
the provisions of Subparts A and B and of Sections 15.201 through 15.204
and Section 15.207 of Subpart C of this part apply to unlicensed UWB
intentional radiators. The provisions of Sections 15.35(c) and 15.205 do
not apply to devices operated under this subpart. The provisions of
Footnote US 246 to the Table of Frequency Allocations contained in
Section 2.106 of this chapter does not apply to devices operated under
this subpart.

\(b\) The requirements of Subpart F apply only to the radio transmitter,
*i.e.*, the intentional radiator, contained in the UWB device. Other
aspects of the operation of a UWB device may be subject to requirements
contained elsewhere in this chapter. In particular, a UWB device that
contains digital circuitry not directly associated with the operation of
the transmitter also is subject to the requirements for unintentional
radiators in Subpart B of this chapter. Similarly, an associated
receiver that operates (tunes) within the frequency range 30 MHz to 960
MHz is subject to the requirements in Subpart B of this chapter.

Section 15.507 [Marketing of UWB equipment]{.underline}.

In some cases, the operation of UWB devices is limited to specific
parties, *e.g.*, law enforcement, fire and rescue organizations
operating under the auspices of a state or local government. The
marketing of UWB devices must be directed solely to parties eligible to
operate the equipment. The responsible party, as defined in Section
2.909 of this chapter, is responsible for ensuring that the equipment is
marketed only to eligible parties. Marketing of the equipment in any
other manner may be considered grounds for revocation of the grant of
certification issued for the equipment.

Section 15.509 [Technical requirements for low frequency imaging
systems]{.underline}.

\(a\) The UWB bandwidth of an imaging system operating under the
provisions of this Section must be below 960 MHz.

\(b\) Operation under the provisions of this section is limited to the
following:

\(1\) GPRs and wall imaging systems operated by law enforcement, fire
and emergency rescue organizations, by scientific research institutes,
by commercial mining companies, or by construction companies.

\(2\) Through-wall imaging systems operated by law enforcement, fire or
emergency rescue organizations.

\(3\) Parties operating this equipment must be eligible for licensing
under the provisions of Part 90 of our rules.

\(4\) The operation of imaging systems under this section requires
coordination, as detailed in Section 15.525 of this chapter.

\(c\) An imaging system shall contain a manually operated switch that
causes the transmitter to cease operation within 10 seconds of being
released by the operator. In addition, it is permissible to operate an
imaging system by remote control provided the imaging system ceases
transmission within 10 seconds of the remote switch being released by
the operator.

\(d\) The radiated emissions at or below 960 MHz from a device operating
under the provisions of this section shall not exceed the emission
levels in Section 15.209 of this chapter. The radiated emissions above
960 MHz from a device operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of 1 MHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -65.3                         |
|                                      |                               |
| 1610-1990                            | -53.3                         |
|                                      |                               |
| Above 1990                           | -51.3                         |
+--------------------------------------+-------------------------------+

\(e\) In addition to the radiated emission limits specified in the above
table, UWB transmitters operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of no less than 1 kHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 1164-1240                            | -75.3                         |
|                                      |                               |
| 1559-1610                            | -75.3                         |
+--------------------------------------+-------------------------------+

\(f\) There is a limit on the peak level of the emissions contained
within a 50 MHz bandwidth centered on the frequency at which the highest
radiated emission occurs, f~M~. That limit is 0 dBm EIRP. It is
acceptable to employ a different resolution bandwidth, and a
correspondingly different peak emission limit, following the procedures
described in Section 15.521 of this chapter.

\(g\) Imaging systems operating under the provisions of this section
shall bear the following or similar statement, as adjusted for the
specific provisions in paragraph (b) of this section, in a conspicuous
location on the device:

Operation of this device is restricted to law enforcement, fire and
rescue officials, scientific research institutes, commercial mining
companies, and construction companies. Operation by any other party is a
violation of 47 U.S.C. § 301 and could subject the operator to serious
legal penalties.

Section 15.511 [Technical requirements for mid-frequency imaging
systems]{.underline}.

\(a\) The UWB bandwidth of an imaging system operating under the
provisions of this section must be contained between 1990 MHz and 10,600
MHz.

\(b\) Operation under the provisions of this section is limited to the
following:

\(1\) Through-wall imaging systems operated by law enforcement, fire or
emergency rescue organizations.

\(2\) Fixed surveillance systems operated by law enforcement, fire or
emergency rescue organizations or by manufacturers licensees, petroleum
licensees or power licensees as defined in Section 90.7 of this chapter.

\(3\) Parties operating under the provisions of this section must be
eligible for licensing under the provisions of Part 90 of our rules.

\(4\) The operation of imaging systems under this section requires
coordination, as detailed in Section 15.525 of this chapter.

\(c\) A through-wall imaging system shall contain a manually operated
switch that causes the transmitter to cease operation within 10 seconds
of being released by the operator. In addition, it is permissible to
operate an imaging system by remote control provided the imaging system
ceases transmission within 10 seconds of the remote switch being
released by the operator.

\(d\) The radiated emissions at or below 960 MHz from a device operating
under the provisions of this section shall not exceed the emission
levels in Section 15.209 of this chapter. The radiated emissions above
960 MHz from a device operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of 1 MHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -53.3                         |
|                                      |                               |
| 1610-1990                            | -51.3                         |
|                                      |                               |
| 1990-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -51.3                         |
+--------------------------------------+-------------------------------+

\(e\) In addition to the radiated emission limits specified in the above
table, UWB transmitters operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of no less than 1 kHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 1164-1240                            | -63.3                         |
|                                      |                               |
| 1559-1610                            | -63.3                         |
+--------------------------------------+-------------------------------+

\(f\) There is a limit on the peak level of the emissions contained
within a 50 MHz bandwidth centered on the frequency at which the highest
radiated emission occurs, f~M~. That limit is 0 dBm EIRP. It is
acceptable to employ a different resolution bandwidth, and a
correspondingly different peak emission limit, following the procedures
described in Section 15.521 of this chapter.

\(g\) Imaging systems operating under the provisions of this section
shall bear the following or similar statement, as adjusted for the
specific provisions in paragraph (b) of this section, in a conspicuous
location on the device:

> Operation of this device is restricted to law enforcement, fire and
> rescue officials, public utilities, and industrial entities. Operation
> by any other party is a violation of 47 U.S.C. § 301 and could subject
> the operator to serious legal penalties.

Section 15.513 [Technical requirements for high frequency imaging
systems]{.underline}.

\(a\) The UWB bandwidth of an imaging system operating under the
provisions of this section must be contained between 3100 MHz and 10,600
MHz.

\(b\) Operation under the provisions of this section is limited to the
following:

\(1\) GPRs and wall imaging systems operated by law enforcement, fire or
emergency rescue organizations, by scientific research institutes, by
commercial mining companies, or by construction companies.

\(2\) Medical imaging systems used at the direction of, or under the
supervision of, a licensed health care practitioner.

\(3\) Parties operating GPRs or wall imaging systems must be eligible
for licensing under the provisions of Part 90 of our rules.

\(4\) The operation of imaging systems under this section requires
coordination, as detailed in Section 15.525 of this chapter.

\(c\) An imaging system shall contain a manually operated switch that
causes the transmitter to cease operation within 10 seconds of being
released by the operator. In addition, it is permissible to operate an
imaging system by remote control provided the imaging system ceases
transmission within 10 seconds of the remote switch being released by
the operator.

\(d\) The radiated emissions at or below 960 MHz from a device operating
under the provisions of this section shall not exceed the emission
levels in Section 15.209 of this chapter. The radiated emissions above
960 MHz from a device operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of 1 MHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -65.3                         |
|                                      |                               |
| 1610-1990                            | -53.3                         |
|                                      |                               |
| 1990-3100                            | -51.3                         |
|                                      |                               |
| 3100-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -51.3                         |
+--------------------------------------+-------------------------------+

\(e\) In addition to the radiated emission limits specified in the above
table, UWB transmitters operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of no less than 1 kHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 1164-1240                            | -75.3                         |
|                                      |                               |
| 1559-1610                            | -75.3                         |
+--------------------------------------+-------------------------------+

\(f\) There is a limit on the peak level of the emissions contained
within a 50 MHz bandwidth centered on the frequency at which the highest
radiated emission occurs, f~M~. That limit is 0 dBm EIRP. It is
acceptable to employ a different resolution bandwidth, and a
correspondingly different peak emission limit, following the procedures
described in Section 15.521 of this chapter.

\(g\) Imaging systems, other than medical imaging systems, operating
under the provisions of this section shall bear the following or similar
statement in a conspicuous location on the device:

Operation of this device is restricted to law enforcement, fire and
rescue officials, scientific research institutes, commercial mining
companies, and construction companies. Operation by any other party is a
violation of 47 U.S.C. § 301 and could subject the operator to serious
legal penalties.

Section 15.515 [Technical requirements for vehicular radar
systems]{.underline}.

\(a\) Operation under the provisions of this section is limited to UWB
field disturbance sensors mounted in terrestrial transportation
vehicles. These devices shall operate only when the vehicle is
operating, *e.g.*, the engine is running. Operation shall occur only
upon specific activation, such as upon starting the vehicle, changing
gears, or engaging a turn signal.

\(b\) The UWB bandwidth fo a vehicular radar system operating under the
provisions of this section shall be contained between 22 GHz and 29 GHz.
In addition, the center frequency, f~C~, and the frequency at which the
highest level emission occurs, f~M~, must be greater than 24.075 GHz.

\(c\) Following proper installation, vehicular radar systems shall
attenuate any emissions within the 23.6-24.0 GHz band that appear 38
degrees or greater above the horizontal plane by 25 dB below the limit
specified in paragraph (d) of this chapter. For equipment authorized,
manufactured or imported on or after January 1, 2005, this level of
attenuation shall be 25 dB for any emissions within the 23.6-24.0 GHz
band that appear 30 degrees or greater above the horizontal plane. For
equipment authorized, manufactured or imported on or after January 1,
2010, this level of attenuation shall be 30 dB for any emissions within
the 23.6-24.0 GHz band that appear 30 degrees or greater above the
horizontal plane. For equipment authorized, manufactured or imported on
or after January 1, 2014, this level of attenuation shall be 35 dB for
any emissions within the 23.6-24.0 GHz band that appear 30 degrees or
greater above the horizontal plane. This level of attenuation can be
achieved through the antenna directivity, through a reduction in output
power or any other means.

\(d\) The radiated emissions at or below 960 MHz from a device operating
under the provisions of this section shall not exceed the emission
levels in Section 15.209 of this chapter. The radiated emissions above
960 MHz from a device operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of 1 MHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -75.3                         |
|                                      |                               |
| 1610-22,000                          | -61.3                         |
|                                      |                               |
| 22,000-29,000                        | -41.3                         |
|                                      |                               |
| 29,000-31,000                        | -51.3                         |
|                                      |                               |
| Above 31,000                         | -61.3                         |
+--------------------------------------+-------------------------------+

\(e\) In addition to the radiated emission limits specified in the above
table, UWB transmitters operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of no less than 1 kHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 1164-1240                            | -85.3                         |
|                                      |                               |
| 1559-1610                            | -85.3                         |
+--------------------------------------+-------------------------------+

\(f\) There is a limit on the peak level of the emissions contained
within a 50 MHz bandwidth centered on the frequency at which the highest
radiated emission occurs, f~M~. That limit is 0 dBm EIRP. It is
acceptable to employ a different resolution bandwidth, and a
correspondingly different peak emission limit, following the procedures
described in Section 15.521 of this chapter.

Section 15.517 [Technical requirements for indoor UWB
systems]{.underline}.

\(a\) Operation under the provisions of this section is limited to UWB
transmitters employed solely for indoor operation.

\(1\) Indoor UWB devices, by the nature of their design, must be capable
of operation only indoors. The necessity to operate with a fixed indoor
infrastructure, *e.g.*, a transmitter that must be connected to the AC
power lines, may be considered sufficient to demonstrate this.

\(2\) The emissions from equipment operated under this section shall not
be intentionally directed outside of the building in which the equipment
is located, such as through a window or a doorway, to perform an outside
function, such as the detection of persons about to enter a building.

\(3\) The use of outdoor mounted antennas, *e.g.*, antennas mounted on
the outside of a building or on a telephone pole, or any other outdoors
infrastructure is prohibited.

\(4\) Field disturbance sensors installed inside of metal or underground
storage tanks are considered to operate indoors provided the emissions
are directed towards the ground.

\(5\) A communications system shall transmit only when the intentional
radiator is sending information to an associated receiver.

\(b\) The UWB bandwidth of a UWB system operating under the provisions
of this section must be contained between 3100 MHz and 10,600 MHz.

\(c\) The radiated emissions at or below 960 MHz from a device operating
under the provisions of this section shall not exceed the emission
levels in Section 15.209 of this chapter. The radiated emissions above
960 MHz from a device operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of 1 MHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -75.3                         |
|                                      |                               |
| 1610-1990                            | -53.3                         |
|                                      |                               |
| 1990-3100                            | -51.3                         |
|                                      |                               |
| 3100-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -51.3                         |
+--------------------------------------+-------------------------------+

\(e\) In addition to the radiated emission limits specified in the above
table, UWB transmitters operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of no less than 1 kHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 1164-1240                            | -85.3                         |
|                                      |                               |
| 1559-1610                            | -85.3                         |
+--------------------------------------+-------------------------------+

\(f\) There is a limit on the peak level of the emissions contained
within a 50 MHz bandwidth centered on the frequency at which the highest
radiated emission occurs, f~M~. That limit is 0 dBm EIRP. It is
acceptable to employ a different resolution bandwidth, and a
correspondingly different peak emission limit, following the procedures
described in Section 15.521 of this chapter.

\(g\) UWB systems operating under the provisions of this section shall
bear the following or similar statement in a conspicuous location on the
device or in the instruction manual supplied with the device:

This equipment may only be operated indoors. Operation outdoors is in
violation of 47 U.S.C. § 301 and could subject the operator to serious
legal penalties.

Section 15.519 [Technical requirements for hand held UWB
systems]{.underline}.

\(a\) UWB devices operating under the provisions of this section must be
hand held, *i.e.*, they are relatively small devices that are primarily
hand held while being operated and do not employ a fixed infrastructure.

\(1\) A UWB device operating under the provisions of this section shall
transmit only when it is sending information to an associated receiver.
The UWB intentional radiator shall cease transmission within 10 seconds
unless it receives an acknowledgement from the associated receiver that
its transmission is being received. An acknowledgment of reception must
continued to be received by the UWB intentional radiator at least every
10 seconds or the UWB device must cease transmitting.

\(2\) The use of antennas mounted on outdoor structures, *e.g.*,
antennas mounted on the outside of a building or on a telephone pole, or
any fixed outdoors infrastructure is prohibited. Antennas may be mounted
only on the hand held UWB device.

\(3\) UWB devices operating under the provisions of this section may
operate indoors or outdoors.

\(b\) The UWB bandwidth of a device operating under the provisions of
this Section must be contained between 3100 MHz and 10,600 MHz.

\(c\) The radiated emissions at or below 960 MHz from a device operating
under the provisions of this section shall not exceed the emission
levels in Section 15.209 of this chapter. The radiated emissions above
960 MHz from a device operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of 1 MHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 960-1610                             | -75.3                         |
|                                      |                               |
| 1610-1900                            | -63.3                         |
|                                      |                               |
| 1900-3100                            | -61.3                         |
|                                      |                               |
| 3100-10600                           | -41.3                         |
|                                      |                               |
| Above 10600                          | -61.3                         |
+--------------------------------------+-------------------------------+

\(d\) In addition to the radiated emission limits specified in the above
table, UWB transmitters operating under the provisions of this section
shall not exceed the following average limits when measured using a
resolution bandwidth of no less than 1 kHz:

+--------------------------------------+-------------------------------+
| Frequency in MHz                     | EIRP in dBm                   |
+--------------------------------------+-------------------------------+
| 1164-1240                            | -85.3                         |
|                                      |                               |
| 1559-1610                            | -85.3                         |
+--------------------------------------+-------------------------------+

\(e\) There is a limit on the peak level of the emissions contained
within a 50 MHz bandwidth centered on the frequency at which the highest
radiated emission occurs, f~M~. That limit is 0 dBm EIRP. It is
acceptable to employ a different resolution bandwidth, and a
correspondingly different peak emission limit, following the procedures
described in Section 15.521 of this chapter.

Section 15.521 [Technical requirements applicable to all UWB
devices]{.underline}.

\(a\) UWB devices may not be employed for the operation of toys.
Operation onboard an aircraft, a ship or a satellite is prohibited.

\(b\) Manufacturers and users are reminded of the provisions of Sections
15.203 and 15.204 of this chapter.

\(c\) As noted in Section 15.3(k) of this chapter, digital circuitry
that is used only to enable the operation of a transmitter and that does
not control additional functions or capabilities is not classified as a
digital device. Instead, the emissions from that digital circuitry are
subject to the same limits as those applicable to the transmitter. If it
can be clearly demonstrated that an emission from a UWB transmitter is
due solely to emissions from digital circuitry contained within the
transmitter and that the emission is not intended to be radiated from
the transmitter's antenna, the limits shown in Section 15.209 of this
chapter shall apply to that emission rather than the limits specified in
this section.

\(d\) Within the tables in the above rule sections, the tighter emission
limit applies at the band edges. Radiated emission levels at and below
960 MHz are based on measurements employing a CISPR quasi-peak detector.
Radiated emission levels above 960 MHz are based on RMS average
measurements over a 1 MHz resolution bandwidth. The RMS average
measurement is based on the use of a spectrum analyzer with a resolution
bandwidth of 1 MHz, an RMS detector, and a 1 millisecond or less
averaging time. If pulse gating is employed where the transmitter is
quiescent for intervals that are long compared to the nominal pulse
repetition interval, measurements shall be made with the pulse train
gated on. Alternative measurement procedures may be considered by the
Commission.

\(e\) The frequency at which the highest radiated emission occurs, f~M~,
must be contained within the UWB bandwidth.

\(f\) Imaging systems may be employed only for the type of information
exchange described in their specific definitions contained in Section
15.503 of this chapter. The detection of tags or the transfer or data or
voice information is not permitted under the standards for imaging
systems.

\(g\) When a peak measurement is required, it is acceptable to use a
resolution bandwidth other than the 50 MHz specified in this subpart.
This resolution bandwidth shall not be lower than 1 MHz or greater than
50 MHz, and the measurement shall be centered on the frequency at which
the highest radiated emission occurs, f~M~. If a resolution bandwidth
other than 50 MHz is employed, the peak EIRP limit shall be 20 log
(RBW/50) dBm where RBW is the resolution bandwidth in megahertz that is
employed. This may be converted to a peak field strength level at 3
meters using E(dBuV/m) = P(dBm EIRP) + 95.2. If RBW is greater than 3
MHz, the application for certification filed with the Commission must
contain a detailed description of the test procedure, calibration of the
test setup, and the instrumentation employed in the testing.

\(h\) The highest frequency employed in Section 15.33 of this chapter to
determine the frequency range over which radiated measurements are made
shall be based on the center frequency, f~C~, unless a higher frequency
is generated within the UWB device. For measuring emission levels, the
spectrum shall be investigated from the lowest frequency generated in
the UWB transmitter, without going below 9 kHz, up to the frequency
range shown in Section 15.33(a) of this chapter or up to f~C~ + 3/(pulse
width in seconds), whichever is higher. There is no requirement to
measure emissions beyond 40 GHz provided f~C~ is less than 10 GHz;
beyond 100 GHz if f~C~ is at or above 10 GHz and below 30 GHz; or beyond
200 GHz if f~C~ is at or above 30 GHz.

\(i\) The prohibition in Sections 2.201(f) and 15.5(d) of this chapter
against Class B (damped wave) emissions does not apply to UWB devices
operating under this subpart.

\(j\) Responsible parties are reminded of the other standards and
requirements incorporated by reference in Section 15.505 of this
chapter, such as a limit on emissions conducted onto the AC power lines.

Section 15.523 [Measurement procedures]{.underline}.

Measurements shall be made in accordance with the procedures specified
by the Commission.

Section 15.525 [Coordination requirements]{.underline}.

\(a\) UWB imaging systems require coordination through the FCC before
the equipment may be used. The operator shall comply with any
constraints on equipment usage resulting from this coordination.

\(b\) The users of UWB imaging devices shall supply detailed operational
areas to the FCC Office of Engineering and Technology who shall
coordinate this information with the Federal Government through the
National Telecommunications and Information Administration. The
information provided by the UWB operator shall include the name, address
and other pertinent contact information of the user, the desired
geographical area of operation, and the FCC ID number and other
nomenclature of the UWB device. This material shall be submitted to the
following address:

Frequency Coordination Branch., OET

Federal Communications Commission

445 12^th^ Street, SW

Washington, D.C. 20554

ATTN: UWB Coordination

\(c\) The manufacturers, or their authorized sales agents, must inform
purchasers and users of their systems of the requirement to undertake
detailed coordination of operational areas with the FCC prior to the
equipment being operated.

\(d\) Users of authorized, coordinated UWB systems may transfer them to
other qualified users and to different locations upon coordination of
change of ownership or location to the FCC and coordination with
existing authorized operations.

\(e\) The NTIA/FCC coordination report shall include any needed
constraints that apply to day-to-day operations. Such constraints could
specify prohibited areas of operations or areas located near authorized
radio stations for which additional coordination is required before
operation of the UWB equipment. If additional local coordination is
required, a local coordination contact will be provided.

\(f\) The coordination of routine UWB operations shall not take longer
than 15 business days from the receipt of the coordination request by
NTIA. Special temporary operations may be handled with an expedited
turn-around time when circumstances warrant. The operation of UWB
systems in emergency situations involving the safety of life or property
may occur without coordination provided a notification procedure,
similar to that contained in Section 2.405(a)-(e) of this chapter, is
followed by the UWB equipment user.

APPENDIX E

Peak in a Specific Bandwidth vs. Average in a 1 MHz Bandwidth vs. PRF

![](media/image1.png){width="6.503472222222222in"
height="4.877777777777778in"}

**APPENDIX F**

**Measurement Procedures**

This appendix is intended to provide general guidance for compliance
measurements of UWB devices. The procedures herein are based on the
Commissions current understanding of UWB technology. Modifications may
be necessary as measurement experience is gained.

Except as otherwise described herein, measurements shall be made in
accordance with the procedures specified in Section 15.31(a)(6) of Title
47 of the Code of Federal Regulations.

(1) Ground penetrating radars (GPRs) and wall imaging systems shall be
    tested under conditions that are representative of actual operating
    conditions. UWB devices intended for these types of application
    shall be compliance tested with the transducer at an operationally
    representative height above a twenty-inch thick bed of dry sand. The
    use of this medium, particularly for larger GPRs (e.g., those that
    are towed behind vehicles), will likely preclude the use of a
    turntable in the measurement procedure. For these cases,
    directionality gradients shall be analyzed and measurements shall be
    performed at a sufficient number of radials around the equipment
    under test to determine the radial at which the field strength
    values of the radiated emissions are maximized.

(2) Field strength measurements of through-wall imaging systems may be
    made with a ½" thick gypsum or drywall board placed between the UWB
    device antenna and the measurement system antenna.

(3) RMS average field strength measurements, required for all
    frequencies above 960 MHz, shall be made using techniques to obtain
    true RMS average. This can be accomplished by using a spectrum
    analyzer that incorporates a RMS detector. The resolution bandwidth
    of the analyzer shall be set to 1 MHz, the RMS detector selected,
    and a video integration time of 1 ms or less is to be used. If the
    transmitter employs pulse gating, in which the transmitter is
    quiescent for intervals that are long compared to the nominal pulse
    repetition interval, all measurements shall be made while the pulse
    train is gated on. Alternatively, a true RMS level can be measured
    using a spectrum analyzer that does not incorporate a RMS detector.
    This approach requires a multiple step technique beginning with a
    peak detection scan of the UWB spectrum with a RBW of 1 MHz and a
    VBW of no less than 1 MHz. The resulting trace is to be used to
    identify the frequency and bandwidth of the five highest peaks in
    the spectrum. The analyzer is then to be placed in a "zero span"
    mode, with a RBW of 1 MHz, a video bandwidth equal to or greater
    than 1 MHz, and a detector selected that does not distort or smooth
    the instantaneous signal levels (e.g., a "sample" detector). With
    these settings, a minimum of ten independent instantaneous points,
    representing the highest amplitude readings, are to be obtained
    during the time that a pulse is present, in each 1 MHz frequency bin
    across the bandwidth of each of the five highest peaks identified in
    the previous step. Note that when the PRF of the device under test
    is less than the measurement bandwidth of 1 MHz, a significant
    number of samples may be required to ensure that a minimum of 10
    samples with the pulse present are obtained. The data obtained from
    these measurements must then be post-processed to determine true RMS
    average power levels. The post-processing of the data can be
    performed manually or with the aid of appropriate software.

(4) On any frequency or frequencies below or equal to 960 MHz, the field
    strength shall be measured with equipment employing a CISPR
    quasi-peak detector function and related measurement bandwidths,
    unless otherwise specified.

(5) In the frequency bands 1164-1240 MHz and 1559-1610 MHz, average
    radiated field strength measurements shall be made with a resolution
    bandwidth of no less than 1 kHz, using techniques as described
    previously for determining true RMS average power levels.

(6) Peak radiated emission measurements shall be made using a spectrum
    analyzer with a 3 MHz resolution bandwidth and no less than a 3 MHz
    video bandwidth. The analyzer should be used in a maximum-hold trace
    mode. The peak power level expressed in a 3 MHz bandwidth and the
    frequency at which this level was measured shall be reported in the
    application for certification. A different resolution bandwidth
    between 1 MHz and 50 MHz may be employed with appropriate changes to
    the standard. If a resolution bandwidth greater than 3 MHz is
    employed, a detailed description of the test procedure, calibration
    of the test setup, and the instrumentation employed in the testing
    must be submitted to the Commission. It is recommended that
    measurements using a resolution bandwidth greater than 3 MHz be
    coordinated with the Commission's laboratory staff in advance of the
    submission for certification.

(7) Field strength measurements may be performed without the use of a
    ground plane; however, a factor of 4.7 dB must be added to the
    measurement results thus obtained.

(8) To the extent practicable, the device under test should be measured
    at the distance specified in the appropriate rule section. However,
    in order to obtain an adequate signal-to-noise ratio in the
    measurement system, radiated measurements may have to be made at
    distances less than specified. In these cases, measurements may be
    performed at a distance other than what is specified, provided:
    measurements are not made in the near field of the measurement or
    device under test antenna, except where it can be shown that near
    field measurements are appropriate due to the characteristics of the
    device; and, it can be demonstrated that the signal levels
    necessitated a measurement at the distance employed in order to be
    accurately detected by the measurement equipment.

(9) To the maximum extent possible, field strength measurements should
    be performed with the equipment under test positioned as it is
    intended to be used in actual operating conditions.

(10) Radiated field strength measurements must be made using the antenna
     to be employed with the UWB device under test. The measurement
     antenna must be sufficiently broad band to cover the frequency
     range of the measurements, and the use of multiple measurement
     antennas may be required. All measurement antennas used must be
     accurately calibrated and must demonstrate low phase dispersion
     over the frequency range of measurement. The orientation of the
     measurement antenna shall be varied to determine the polarization
     that maximizes the measured field strength.

(11) The spectrum to be investigated should include at least the
     fundamental emission and the secondary lobe regardless of the
     center frequency. In order to accomplish this, the frequency
     spectrum shall be investigated from the lowest frequency generated
     within the device, without going below 9 kHz, up to the frequency
     range shown in Section 15.33(a) of the FCC rules or up to an upper
     frequency defined by adding three divided by the pulse width in
     seconds to the center frequency in Hz, whichever is greater. The
     frequency range in Section 15.33(a) is based on the center
     frequency unless a higher frequency, *e.g.*, a carrier frequency,
     is generated within the device. There is no requirement to measure
     emissions beyond 40 GHz provided the center frequency is less than
     10 GHz; beyond 100 GHz if the center frequency is at or above 10
     GHz and below 30 GHz; or beyond 200 GHz if the center frequency is
     at or above 30 GHz.

     SEPARATE STATEMENT OF

     COMMISSIONER MICHAEL J. COPPS

February 14, 2002

RE: Revision of Part 15 of the Commission's Rules Regarding
Ultra-Wideband Transmission Systems (ET Docket No. 98-153)

I believe that ultra-wideband ("UWB") technologies are destined to play
a significant role across America's communications landscape. UWB
devices will save firefighters' and policemen's lives, prevent
automobile accidents, assist search-and-rescue crews in seeing through
the rubble of disaster sites, enable broadband connections between our
home electronics, and allow exciting new forms of communications in the
years ahead. Indeed, the U.S. Government already uses UWB extensively to
make our soldiers, airport runways, and highway bridges safer, and so
much more is on the horizon.

But opinion differs greatly on the interference effect of the widespread
use of UWB technologies by the public. If interference does occur, it
could conceivably affect critical government and non-government spectrum
users. Our national defense and several safety-of-life systems depend on
bands that have the potential to be impacted by UWB devices.

Because the effects of widespread use of UWB are not yet fully known,
and interference could impact critical spectrum users, I will support,
albeit somewhat reluctantly, the ultra-conservative ultra-wideband step
we take today. The limits we place on UWB are designed to reduce the
interference risks associated with the technology to levels far, far
below those placed on technologies that place energy into narrower
portions of the spectrum. These limits are intentionally at the extreme
end of what FCC engineers -- the best spectrum engineers in the country
-- believe necessary. They were agreed to because of the unique and
novel impact of this technology, and should not be taken as precedent
for any other interference dispute -- involving other Part 15 devices,
government bands, or other new technologies.

I strongly support the Commission's decision to initiate a further NPRM
within 6 to 12 months. My hope is that we can phase in this exciting new
technology with some sense of urgency, proceeding through the conduct of
expeditious step-by-step authorizations from the Commission for
applications that are waiting in line. We owe it to our citizens and our
businesses to determine, just as quickly as we prudently can, whether we
can loosen the ultra-conservative restrictions we put in place today. So
I urge all parties, especially our government colleagues, to start
collecting data immediately so we can have as much data as possible,
including information about their own use of UWB and how UWB effects
their other uses of the spectrum, in a timely manner.

Delay, even when advisable, still has costs. If we find that our rules
are too restrictive and we fail to correct them promptly, the price may
be that the United States loses its leadership role in ultra-wideband.
The technology could easily move overseas, where, I wager, would-be
competitors are only too eager to get a step ahead of the USA. Let's be
cognizant, too, of the need to proceed so as to inflict minimal harm on
U.S. commercial interests. Some companies may be seriously inhibited by
the limitations being announced. We should not expect that they can
afford to stand patiently by while testing and approval proceeds at
glacial pace. I hope that all of us, whether in government or the
private sector, will approach our nation's deployment of ultra-wideband
with the sense of urgency that it so clearly merits.

Finally, I want to welcome Ed Thomas to the FCC. He started with
ultra-wideband -- a trial by fire! I look forward to working with you. I
also want to thank Julie Knapp and the whole OET team for their
dedication and hard work on this item. Lots of weekends and late nights
went into this Order. Thank you.

SEPARATE STATEMENT OF COMMISSIONER

KEVIN J. MARTIN

RE: Revision of Part 15 of the Commission's Rules Regarding
Ultra-Wideband Transmission Systems, First Report and Order (ET Docket
No. 98-153).

Spectrum management decisions are always complex and challenging. In an
environment where the amount of unencumbered spectrum is decreasing
while demand continues to grow, it is even more critical we make
interference and sharing decisions that do not waste this precious
natural resource. Inevitably, we will depend more and more on sharing
the spectrum currently available to avoid such waste. Sharing decisions
are made particularly difficult in the context of the "fiefdom"
mentality that seems to characterize players who fervently guard their
spectrum "turf," regardless of whether additional use can be
accommodated. Unfortunately, the result is often unrealized potential
that can never be recaptured.

I am excited that ultrawideband technology, which operates at powers
10,000 times lower than PCS handsets, will allow us to take sharing to
new levels, and help avoid such waste. These sophisticated applications
can potentially co-exist with spectrum users in any frequency, while
promising a host of exciting military, public safety, medical and
consumer uses. Firefighters, police officers and emergency personnel can
make use of this technology to detect and image objects that are behind
walls, buried underground or even inside the human body. Automotive
applications such as collision avoidance and improved airbag mechanisms
will have a direct consumer safety impact. Consumers also stand to
benefit from enhanced laptops, phones, video recorders, and personal
digital assistants that can wirelessly send and receive streams of
digital video, audio and data.

Most importantly, ultrawideband challenges the notion that use of
particular frequencies or bands is necessarily mutually exclusive. In
defiance of our traditional allocation paradigm that often forces us to
pick "winners and losers" in the face of competing demands, this
technology seems to allow more winners all around.

I am disappointed that we did not, at this time, adopt more flexible
limits that may have allowed for even more widespread use of this
technology. I look forward to re-examining the technical parameters
established in this order once we have more data that will address the
interference concerns expressed by NTIA.

I am optimistic that future technological developments will provide the
Commission with more such opportunities to insist on increasingly
efficient use of current spectrum. Ultimately, the amount of available
spectrum and our ability to use it is perhaps limited only by
technology. Today, however, we must act rationally to make the best
choices within the spectrum constraints that face us now.

[^1]: Devices are permitted to operate after they have been verified to
    comply with existing operational restrictions. *See* 47 C.F.R.
    Chapter 2, Subpart J. & 47 C.F.R. §§ 15.1 *et seq*.

[^2]: In addition to the limiting technical constraints, one of the
    primary operating conditions under Part 15 are that the operator
    must accept whatever interference is received and must correct
    whatever interference is caused. Should harmful interference occur,
    the operator is required to immediately correct the interference
    problem, even if correction of the problem requires ceasing
    operation of the Part 15 system causing the interference. *See* 47
    C.F.R. § 15.5.

[^3]: *See* 47 C.F.R. § 15.209.

[^4]: *See* 47 C.F.R. §§ 15.215-15.407. In some cases, operation at the
    higher emission levels within these designated frequency bands is
    limited to specific applications.

[^5]: The sensitive bands referenced here are bands employed by radio
    services that must function, as a nature of their operation, using
    extremely low received signal levels. These systems may be passive,
    such as radio astronomy, or active, such as satellite down links and
    wildlife tracking systems.

[^6]: *See* 47 C.F.R. § 15.205.

[^7]: Typical pulse widths used by UWB devices currently are on the
    order of 0.1-2 nanoseconds, or less, in width. The emission spectrum
    appears as a fundamental lobe with adjacent side lobes that can
    decrease slowly in amplitude. The rise time of the leading edge of
    the pulse and the passband of the radiating antenna are major
    factors in determining the bandwidth of the UWB emission.

[^8]: HP Application Note 150-2 specifies the use of a pulse
    desensitization correction factor.

[^9]: *See* 47 C.F.R. §§ 15.35(b) and 15.209. UWB systems that operate
    with a low duty cycle would have peak levels that are quite high
    compared to the average emission levels.

[^10]: *See Notice of Proposed Rule Making* in ET Docket No. 98-153, 65
    Fed. Reg.37332, June 14, 2000,
    [http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/Notices/2000/fcc00163.doc](http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/fedreg/63/50184.pdf).
    *See*, also, *Notice of Inquiry* in ET Docket No. 98-153, 63 Fed.
    Reg. 50184, September 21, 1998,
    <http://www.fcc.gov/Bureaus/Engineering_Technology/Documents/fedreg/63/50184.pdf>.

[^11]: A large number of late filed comments and *ex parte* comments
    continued to be filed in this proceeding long after the end of the
    comment period. While these comments were examined and evaluated,
    the commenting parties are not shown in Appendix A. A list of all
    parties filing comments in this proceeding can be found by
    referencing the Commission's Electronic Comment Filing System
    located at
    [www.fcc.gov/e-file/ecfs.html](http://www.fcc.gov/e-file/ecfs.html).

[^12]: *See* NTIA Special Publication 01-43, *Assessment of
    Compatibility between Ultrawideband Devices and Selected Federal
    Systems*, January 2001, and NTIA Report 01-383, *The Temporal and
    Spectral Characteristics of Ultrawideband Signals*, January 2001.
    *See*, also, Public Notice of January 24, 2001, DA 01-171.

[^13]: *See* Public Notice of March 26, 2001, DA 01-753.

[^14]: *See* Time Domain's submission of March 9, 2001, *Final Report
    UWB-GPS Compatibility Analysis Project*, 8 March 2001, prepared by
    Strategic Systems Department, The Johns Hopkins University/Applied
    Physics Laboratory. The study consists of testing performed by the
    University of Texas along with an analysis by the Applied Physics
    Laboratory of Johns Hopkins University.

[^15]: *See* NTIA Special Publication 01-45, *Assessment of
    Compatibility between Ultrawideband (UWB) Systems and Global
    Positioning System (GPS) Receivers*, February 2001, and NTIA Report
    01-384, *Measurements to Determine Potential Interference to GPS
    Receivers from Ultrawideband Transmission Systems*, February 2001,
    submitted to the Commission on March 9, 2001.

[^16]: *See* the study submitted March 21, 2001, by NTIA on behalf of
    the Department of Transportation regarding tests performed by
    Stanford University.

[^17]: *See* the March 5, 2001, submission of Qualcomm.

[^18]: As with the *Notice*, a number of late filed comments and *ex
    parte* comments were filed in this proceeding regarding the
    potential for UWB transmission systems to cause interference to GPS
    receivers. While these comments were examined and evaluated, the
    commenting parties are not shown in Appendix D. A list of all
    parties filing comments in this proceeding can be found by
    referencing the Commission's Electronic Comment Filing System
    located at
    [www.fcc.gov/e-file/ecfs.html](http://www.fcc.gov/e-file/ecfs.html).

[^19]: While the Commission recognized that UWB technology may be
    developed for higher power applications such as wide-area mobile
    radio services, it found that such applications raised many new and
    novel questions, such as consistency with the international and
    domestic table of frequency allocations, and how such services might
    be licensed to share spectrum across broad frequency ranges used by
    multiple existing services and licensees. As there was insufficient
    information in the record to address such issues, no proposals were
    made to allow high power UWB devices to operate under Part 15 or on
    a licensed basis.

[^20]: Intel reply comments at pg. 3.

[^21]: Fantasma comments at pg. 2.

[^22]: AT&T comments at pg. 5-6.

[^23]: National Safe Skies Alliance comments at pg. 1.

[^24]: Siemens Automotive ZF comments at pg. 1. *See*, also, M/A-COM
    comments at pg. 2.

[^25]: TDC reply comments at pg. 4-19.

[^26]: Delphi comments at pg. 7, Endress Hauser comments at pg. 2,
    Lucent comments at pg. 2, and Bosch comments at pg. 2 and reply
    comments at pg. 1.

[^27]: Valeo Electronics comments at pg. 4.

[^28]: Zircon comments at pg. 2. It should be noted that the Commission
    already declined to permit UWB devices to operate at the Class A
    digital device limits contained in 47 C. F.R. § 15.109(b). *See
    Notice*, *op cit.*, at para. 40.

[^29]: See, for example, Cingular *ex parte* comments filed August 20,
    2001.

[^30]: USGPSIC comments at pg. 29-30.

[^31]: ARINC and ATA joint comments at pg. 9 and 10. Also, ATA *et al*
    *ex parte* comments of 6/6/01, 5/18/01.

[^32]: Alloy reply comments at pg. 6-9. Alloy also believed that the
    first round of equipment to be authorized under the rules would be
    restricted to ground penetrating radars and through-wall imaging
    systems employed mostly by professionals.

[^33]: MSSI comments at pg. 12. MSSI subsequently cosigned the ATA *et
    al* *ex parte* comments of 6/6/01, 5/18/01.

[^34]: Boeing comments at pg. 13-14.

[^35]: Lockheed reply comments at pg. 5. Lockheed suggested that
    unlicensed operation could be considered only on frequencies where
    there is no reasonable interference concerns for safety services.

[^36]: Prof. Peha comments at pg. 6.

[^37]: SIA reply comments at pg. 5. Sirius reply comments at pg. 3, 11
    and 18.

[^38]: Kohler reply comments at pg. 5-6.

[^39]: *See* 47 U.S.C. § 157(a) (1998).

[^40]: *See* letter of February 13, 2002, from William T. Hatch,
    Associate Administrator, Office of Spectrum Management, U.S.
    Department of Commerce to Edmond J. Thomas, Chief, Office of
    Engineering and Technology, FCC. A copy of the letter is on file in
    this proceeding.

[^41]: Indoor systems, because of the additional shielding provided by
    building walls, are able to operate with slightly higher levels of
    unwanted emissions.

[^42]: As used in this Order, law enforcement, fire and emergency rescue
    organizations refers to parties eligible to obtain a license from
    the FCC under the eligibility requirements specified in Section
    90.20(a)(1) of this chapter.

[^43]: As used in this Order, the reference to public utilities and
    industrial entities refers to the manufacturers licensees, petroleum
    licensees or power licensees defined in 47 C.F.R. § 90.7.

[^44]: *Assessment of Ultra-Wideband (UWB) Technology*, OSD/DARPA,
    Ultra-Wideband Radar Review Panel, R-6280, Office of the Secretary
    of Defense, Defense Advanced Research Projects Agency, July 13,
    1990.

[^45]: Under the proposed definition of an UWB device, the 1.5 GHz
    maximum bandwidth limit would only apply where the center frequency
    is greater than 6 GHz.

[^46]: In some UWB systems, there is no clear center frequency as with
    other modulation techniques, such as AM and FM. Furthermore, the
    shape of the transmitted spectrum may be significantly modified by
    the frequency response of the antenna such that even the carrier
    frequency, where employed, may not represent the center frequency.

[^47]: Other types of modulation, such as linear sweep FM, could be
    employed to produce UWB equipment.

[^48]: *See*, *e.g.*, the comments of Aether Wire and Location at pg. 7,
    ANRO at pg. 1, CSSIP at pg. 1, Delphi at pg. 10, Endress Hauser at
    pg. 3, Lucent at pg. 5, M/A-Com at pg. 1, Bosch at pg. 2, TDC at pg.
    21, and Zircon at pg. 2. We have used the term "minimum bandwidth"
    in this proceeding to reference the bandwidth above which a product
    qualifies as a UWB device regardless of its fractional bandwidth.

[^49]: As noted by Aether Wire and Location, the antenna is an integral
    part of the system that affects the radiated bandwidth and the phase
    response. Aether Wire and Location comments at pg. 7.

[^50]: Bosch comments at pg. 2-3 and reply comments at pg. 1-2.

[^51]: Valeo comments at pg. 4.

[^52]: Kohler comments at pg. 4.

[^53]: The limits being adopted in this proceeding do not permit peak
    emissions approaching this amplitude.

[^54]: AOPA comments at pg. 4.

[^55]: ARRL comments at pg. 18. It should be noted that these emission
    points are representative of the attenuation requirements for the
    authorized radio services where the radiated emission levels are
    powerful enough to be easily measured.

[^56]: ARRL requested that a minimum frequency bandwidth be applied to
    the UWB definition since a 0.25 fractional bandwidth would not
    result in a very wide emission for a system operating at, say, 3.5
    MHz. *See* ARRL comments at pg. 13. However, ARRL did not suggest a
    lower limit. We did not address this issue in this proceeding since
    UWB systems, other than GPRs and certain imaging systems are
    required to operate in considerably higher frequency ranges. GPRs
    and imaging systems need to operate at frequencies higher than 3.5
    MHz in order to obtain the needed object resolution.

[^57]: SME comments at pg. 2 and 4. Valeo comments at pg. 4.

[^58]: Siemens comments are pg. 2.

[^59]: Bosch comments at pg. 2-3 and reply comments at pg. 1-2.

[^60]: ANRO comments at pg. 1. Kohler comments at pg. 4.

[^61]: *Ex parte* filing of Daimler Chrysler on July 31, 2001.

[^62]: Delphi comments at pg. 9-17. Delphi later amended its proposal to
    include only pseudo-noise direct sequence binary phase shift key
    type of modulation. Delphi *ex parte* filing of July 13, 2001.

[^63]: M/A-Com reply comments at pg. 2.

[^64]: MSSI comments at pg. 15.

[^65]: AOPA reply comments at pg. 10-11.

[^66]: TDC comments at pg. 21.

[^67]: TDC comments at pg. 25.

[^68]: Endress Hauser comments at pg. 3-4 and USGPSIC comments at pg. 2
    of Attachment A.

[^69]: ARRL reply comments at pg. 9.

[^70]: CSSIP comments at pg. 1.

[^71]: Krohne comments at pg. 4.

[^72]: Siemens comments at pg. 2.

[^73]: Valeo comments at pg. 5.

[^74]: Bosch comments at pg. 3.

[^75]: XSI comments at pg. 8.

[^76]: AOPA comments at pg. 5.

[^77]: The fractional bandwidth value of 0.25, or 25 percent, was
    established by the OSD/DARPA UWB radar review panel based on the use
    of a --20 dB emission bandwidth.

[^78]: As noted, UWB devices would be required to have a --10 dB
    fractional bandwidth of at least 0.20 or a --10 dB bandwidth of at
    least 500 MHz. The effect of this change is that UWB systems with a
    center frequency greater than 2.5 GHz need to have a --10 dB
    bandwidth of at least 500 megahertz while UWB systems operating with
    a center frequency below 2.5 GHz need to have a fractional bandwidth
    of at least 0.20.

[^79]: *See* 47 C.F.R. §15.31(c).

[^80]: We note that NTIA recently agreed that a waiver could be issued
    to Krohne to permit the Part 15 operation of its level measuring
    radar system in steel tanks. This should alleviate Krohne's concerns
    in the UWB proceeding. *See* letter of September 5, 2001, from
    William Hatch of NTIA to Bruce Franca, Acting Chief, OET, FCC.
    *See*, also, letter of October 26, 2001, from Bruce A. Franca to
    Fish & Richardson granting Krohne its waiver request.

[^81]: Our concerns apply to all emissions within the --10 dB bandwidth
    of the UWB signal, not just at the center frequency.

[^82]: Time Domain's through-wall imaging system, authorized under a
    waiver issued on June 29, 1999, by the Chief, Office of Engineering
    and Technology, operates over a frequency band ranging from a few
    hundred Hertz to greater than 4 GHz. Through-wall imaging systems
    are limited to products that detect objects located on the other
    side of a wall. Under the waiver, operation was limited to parties
    eligible for licensing under the Public Safety Pool of frequencies
    in Part 90 of this chapter.

[^83]: Waivers were issued on June 29, 1999, to Time Domain Corporation,
    Zircon, and U.S. Radar and on August 6, 2001, to Kohler Co. to
    permit the limited marketing of UWB devices.

[^84]: ARRL comments at pg. 16.

[^85]: ARINC & ATA comments at pg. 13.

[^86]: Nortel comments at pg. 7.

[^87]: USGPSIC comments at pg. 23-24.

[^88]: Sirius comments at pg. 15.

[^89]: Aether Wire comments at pg. 6.

[^90]: Colorado School of Mines reply comments at pg. 3-4.

[^91]: USGPSIC reply comments at pg. 10.

[^92]: AOPA comments at pg. 7. NBAA comments at pg. 8. Sirius comments
    at pg. 19-20.

[^93]: Alloy reply comments at pg. 14.

[^94]: A. Peter Annan comments at pg. 3. The Colorado School of Mines on
    page 4 of its reply comments also noted that GPRs are sometimes used
    to investigate cliff faces and overhangs.

[^95]: Bosch comments at pg. 3 and reply comments at pg. 2.

[^96]: TDC comments at pg. 11.

[^97]: TDC comments at pg. 26.

[^98]: Zircon comments at pg. 1 and 5.

[^99]: Zircon reply comments at pg. 3.

[^100]: XM reply comments at pg. 6, footnote 8.

[^101]: Nortel comments at pg. 7.

[^102]: Alloy reply comments at pg. 14-16.

[^103]: USGPSIC comments at pg. 23-34.

[^104]: *See* letter of June 15, 1999, from William T. Hatch of NTIA to
    Dr. Dale Hatfield, Chief, OET, FCC.

[^105]: TDC comments at pg. 26.

[^106]: Zircon reply comments at pg. 3.

[^107]: *See* letter of February 13, 2002, from William Hatch, *supra.*

[^108]: GPRs generally operate at low PRFs as they must pause between
    pulses to give the signal transmitted into the ground sufficient
    time to be reflected and to return to the receiver.

[^109]: It should be noted that GPRs are a specialized application of
    imaging systems and can operate under this second category of
    imaging systems using any PRF provided, however, that they comply
    with all of the other technical and operational restrictions
    associated with this equipment category.

[^110]: UNII devices operate under Part 15 of our rules and are not
    provided any protection from harmful interference. *See* 47 C.F.R. §
    15.5.

[^111]: ARRL comments at pg. 2-3. Cisco comments at pg. 3. Motorola
    comments at pg. 11-30. Sprint PCS reply comments at pg. 2. Sprint
    comments at pg.3. XM comments at pg. 10. Sirius comments at pg.
    7-10. Nortel comments at pg. 6. AT&T comments at pg. 5. MCHI
    comments at pg. 1-2. We note that UNII is a Part 15 operation and is
    provided no protection from harmful interference. *See* 47 C.F.R. §
    15.5.

[^112]: Nortel comments at pg. 6.

[^113]: Sirius comments at pg. ii and 7-10.

[^114]: Lockheed Martin comments at pg. 8.

[^115]: MCHI comments at pg. 4.

[^116]: Rockwell comments at pg. 5.

[^117]: ARRL comments at pg. 17.

[^118]: XM comments at pg. 1 and 10.

[^119]: Alloy reply comments at pg. 16.

[^120]: ARINC & ATA reply comments at pg. 7.

[^121]: ATA *et al* *ex parte* comments of 6/6/01, 5/18/01.

[^122]: American Trans Air reply comments at pg. 2.

[^123]: M/A-Com reply comments at pg. 2.

[^124]: TDC comments at pg. 11.

[^125]: Fantasma comments at pg. 3.

[^126]: MSSI comments at pg. 2.

[^127]: Valeo Electronics comments at pg. 7.

[^128]: Daimler Chrysler *ex parte* filing of 7/31/01.

[^129]: XM comments at pg. 10.

[^130]: MSSI comments at pg. 10 and reply comments at pg. 2.

[^131]: NTIA Special Publication 01-43, *supra*, at pg. x. We note that
    NTIA, in performing its analysis leading up to this statement, did
    not consider the 12 dB reduction below the Part 15 general emission
    limits that was proposed in the *Notice*.

[^132]: Aether Wire comments at pg. 7.

[^133]: USGPSIC comments of 7/25/01. XSI in its comments of 7/25/01 at
    pg. 4 and 9 noted that its antenna can not be manipulated in such a
    manner. The Commission also previously recognized that UWB devices
    might not be able to notch out frequency bands that are a subset of
    their operating frequencies. *See Notice*, *supra*, at para. 23 and
    30.

[^134]: Most comments supporting UWB operation for vehicles wished to
    operate above 24 GHz.

[^135]: The angle above the horizontal plane is based on measurements
    from a properly installed vehicle radar system with the vehicle
    resting horizontally.

[^136]: NTIA Special Publication 01-43, *supra*.

[^137]: *See* NTIA Special Publication 01-45, *supra*, and NTIA Report
    01-384, *supra*.

[^138]: NTIA, on behalf of DOT, also submitted a preliminary version of
    this report on October 30, 2000.

[^139]: The study consists of testing performed by the University of
    Texas along with an analysis by the Applied Physics Laboratory of
    Johns Hopkins University.

[^140]: *See* Public Notice of March 26, 2001, DA 01-753.

[^141]: *See* NTIA Special Publication 01-43, *supra*, and NTIA Report
    01-383, *supra*. *See*, also, Public Notice of January 24, 2001, DA
    01-171, requesting additional comments on this study.

[^142]: Filing of U.S. Department of Defense submitted 10/1/00,
    Attachment 2.

[^143]: ARRL comments at Appendix A.

[^144]: *See* Motorola comments at pg. 11-38.

[^145]: Sprint PCS and TDC joint comments at Attachments 1 and 2.

[^146]: *See* Public Notice of March 26, 2001, DA 01-753.

[^147]: Cisco comments, Attachments 2 and 3.

[^148]: XM comments, Technical Appendix.

[^149]: Other parties indicated that test reports would be filed with
    the Commission, but these have not been forthcoming.

[^150]: See NTIA Report 01-389 Addendum to NTIA Report 01-384:
    Measurements to Determine Potential Interference to GPS Receivers
    from Ultrawideband Transmission Systems, September 2001.

[^151]: Global Positioning System Standard Positioning Service Signal
    Specification, Second Edition, GPS NAVSTAR (June 2, 1995) at pg. 18.

[^152]: TDC Comments in response to Public Notice at pg. 40.

[^153]: *Id* at pg. 49.

[^154]: *Id* at pg. 36.

[^155]: Pulses are independent when the filter bandwidth is greater than
    the pulse repetition rate. To remain independent the minimum pulse
    repetition period of a dithered signal must be greater than the
    duration of the filter impulse response.

[^156]: NTIA Special Publication 01-45, *supra*, at pg. 2-8.

[^157]: ITU-R Recommendation M. 1477, *Technical and Performance
    Characteristics of Current and Planned Radionavigation-Satellite
    Service (Space-to-Earth) and Aeronautical Radionavigation Service
    Receivers to Be Considered in Interference Studies in the Band
    1559-1610 MHz* (2000), at Tables 1 and 2. As noted in footnote 2 to
    these tables, the interference threshold already takes into account
    the effects of GPS intra-system interference based on random code
    analysis. This threshold value must account for all other aggregate
    interference.

[^158]: *Id*.

[^159]: Document Number RTCA/DO-229B, Minimum Operational Performance
    Standard for GPS/Wide Area Augmentation System Airborne Equipment
    (January, 1996). Recommendation ITU-R M.1477, *supra*, at ANNEX 1,
    Section 3-2.

[^160]: These low PRFs are found in most of the proposed GPR systems.

[^161]: Of particular concern for the interference protection of the
    semi-codeless GPS receiver is the reacquisition data point listed
    for the UWB signal with a 100 kHz, 2% relative dither and 20%
    gating. The listed value is -88 dBm/20 MHz. This single value would
    indicate the semi-codeless receiver is susceptible to low PRF UWB
    interference. This single value is at least 17 dB lower than the
    other listed values for a 100 kHz PRF UWB signal. This 17 dB
    difference includes a 7 dB adjustment to determine the average
    interference power for the 20% gated signal. Because this 17 dB
    difference is significant in determining interference protection
    requirements, a further review of this data point was carried out.
    The measured data plots for all the 100 kHz PRF, 20% gated UWB
    signal cases for the semi-codeless receiver tests were reviewed.
    This resulted in reviewing four data plots for reacquisition tests
    from the measured data report. As previously stated the
    reacquisition threshold was determined through a judgment as to the
    power level where a sharp increase in reacquisition time occurred.
    For three of the data plots, the previous judgment was that no sharp
    increase was observed over the range of measured interference power
    levels. Only in the case of concern (100 kHz with 2% relative dither
    and 20% gating) was a reacquisition threshold selected. In
    retrospect, because the curves are all similar, a comparative review
    of the data across the four cases would indicate that a
    reacquisition threshold should not have been selected over the range
    of UWB signal powers measured for the 100 kHz PRF, 2% relative
    dither and 20% gating case. Thus, the entry in Table 2-2 of NTIA
    Special publication 01-45 should be \[-66\] rather than -88. The
    \[-66\] shows that this was the limit of the power available in the
    test setup and the effect of interest (the reacquisition threshold)
    was not observed. This GPS receiver performance, in the presence
    with low PRF UWB interfering signals, is in agreement with the C/A
    code receiver architecture results.

[^162]: NTIA Special Publication 01-45, *supra*, at pg. 2-12.

[^163]: Our discussion in this section primarily is directed to
    noise-like UWB emissions. Additional protection will be provided to
    GPS reception of CW-like emissions to accommodate the 8 dB
    difference measured by NTIA and the 10 dB specified in the RTCA and
    ITU-R standards.

[^164]: *See 47 C.F.R. § 15.31(a)(6).*

[^165]: TDC Comments in Response to Public Notice at pg. 64.

[^166]: *Id.*

[^167]: *Id.*

[^168]: Comments of XtremeSpectrum, Inc., *On Issues of Interference
    Into Global Positioning System Receivers* (April 25, 2001) at pg.
    21.

[^169]: *Id.*

[^170]: *Id.*

[^171]: TDC Comments in Response to Public Notice at pg. 64.

[^172]: Antenna Engineering Handbook, R.C. Johnson, H. Jasik (Second
    Edition) at pg. 1-7.

[^173]: Antenna Analysis, E.A. Wolff (1966) at pg. 17

[^174]: TDC Comments in Response to Public Notice at pg. 56.

[^175]: *Id.* at pg. 44.

[^176]: ITU-R Recommendation F.1094-1, *Maximum Allowable Error
    Performance and Availability Degradations to Digital Radio-Relay
    Systems Arising from Interference from Emissions and Radiations from
    Other Sources*.

[^177]: ITU-R M.1477 at Annex 5.

[^178]: TDC Comments in Response to the Public Notice at pg. 64.

[^179]: *GPS World Receiver Survey,* GPS World Magazine, January 2001,
    at pg. 32.

[^180]: Firmware is software installed in a device that is typically
    stored in read only memory (ROM) or programmable read only memory
    (PROM).

[^181]: *See* NTIA Special Publication 01-47, *Assessment of
    Compatibility Between Ultrawideband (UWB) Systems and Global
    Positioning System (GPS) Receivers* (Report Addendum), November
    2001.at pg. 2-13.

[^182]: TDC Comments in Response to Public Notice at pg. 56.

[^183]: *Id.*

[^184]: JHU/APL Report at ES-2.

[^185]: NTIA Report 95-325, *Building Attenuation Measurements From
    Low-height Base Stations at 912, 1920, and 5990 MHz*, September
    1995, at pg. 43.

[^186]: *Id.* at pg. 36.

[^187]: *Understanding GPS Principles and Applications*, E. D. Kaplan
    (Editor), Artech House, 1996, pg. 211; ITU-R M.1477 at Annex 1

[^188]: Note that these are only estimates of what values of processing
    gain can be achieved and may vary depending on the implementation of
    the technology.

[^189]: No E-911 receivers were available for testing purposes. The
    information herein is based on our meeting with Qualcomm on 9/26/01.

[^190]: Stephen D. Baruch, Counsel for the U.S. GPS Industry Council,
    Written Ex Parte Presentation in ET Docket No. 98-153, June 21,
    2001, at pg. 11.

[^191]: The noise figure of a GPS receiver typically is in the range of
    2 to 4 dB.

[^192]: Written *Ex Parte* Presentation, ET Docket 98-153, Revisions of
    Part 15 of The Commission's Rules Regarding Ultra-Wideband
    Transmission Systems (January 11, 2002)

[^193]: *Id* at pg.12.

[^194]: *Id* at Fig 4-19

[^195]: *Id* at Fig 3-6

[^196]: *Id*

[^197]: *Id* at pg. 14

[^198]: *Id* at Fig 4-1

[^199]: BOSCH presentation to European Ultra Wideband Workshop*, Short
    Range Automotive Radar (SRR) ... another generic (ultra) wide band
    device at 24 GHz* (March 20, 2001) at. pg. 4.

[^200]: In theory these spectral lines could be eliminated, the
    requirement in practical systems to have a lower bound on the time
    between pulses leads to structure in the signal's autocorrelation
    function and therefore spectral lines of some magnitude.

[^201]: This is similar to an approach we have used to protect GPS from
    Mobile Satellite System (MSS) out-of-band emissions. *See* 47 C.F.R.
    25. \_\_\_\_

[^202]: ITU-R M1477 at Annex 1 Table 3.

[^203]: *See* NTIA Special Publication 01-43, *supra*, and NTIA Report
    01-384, *supra*.

[^204]: *Minimum Operational Performance Standards for Airborne Distance
    Measuring Equipment (DME) Operating within the Radio Frequency Range
    of 960-1215 MHz*, RTCA DO-189, at 2.2.11 (September 1985).

[^205]: NTIA Special Publication 01-43, *supra*, at page A-19, Table
    A-9.

[^206]: *Minimum Operational Performance Standards for Air Traffic
    Control Radar Beacon System/Mode Select (ATCRBS/MODE S) Airborne
    Equipment*, Radio Technical Commission for Aeronautics, RTCA
    DO-181A, at 2.2.8.1 (January 1992) and Federal Aviation
    Administration, US Department of Transportation, *Specification for
    Mode Select Beacon System (Modes) Sensor*, Amendment 2, FAA-E-2716
    (March 1993).

[^207]: An I/N of --6 dB translates to an increase in the noise floor of
    1 dB and a reduction in the maximum radar range of just under 6
    percent. A value of --10 dB translates to an increase in the noise
    floor of about 0.5 dB and a reduction in the maximum radar range of
    just under 3 percent

[^208]: TDC comments of February 23, 2001, at pg. 26-27. Also, Skolnik,
    M. I., *Introduction to Radar Systems*, (1980) at pg. 58-59.

[^209]: We believe that TDC means that the intensity of the received
    signal is reduced by 1.6 to 3 dB due to beam smearing.

[^210]: TDC comments of 3/12/01 at pg. 10, footnote 18. XSI comments of
    3/12/01 at pg. 7. *See COSPAS-SARSAT LEOLUT Performance
    Specifications and Design Guidelines*, Document C/S T.002, Issue 3,
    Rev. 1 (Oct. 1999) in Section 3.5 at 3-1. This states that the LUT
    shall be able to track the LEO SARSATs when they reach 5 degrees
    above the horizon.

[^211]: *Study on 2700-2900 MHz Frequency Band Sharing Between Existing
    Aeronautical Radar Equipment and Planned Digital ENG/OB and digital
    Aeronautical Telemetry Services*, EUROCONTROL, Edition Date
    29/05/2001.

[^212]: *See* XSI *ex parte* comments of February 4, 2002, at pg. 21-22.
    XSI also indicates that there are similar FAA siting requirements
    for its radar systems.

[^213]: Radio Regulations of the ITU, Appendix 7, *Method for the
    Determination of the Coordination Area Around an Earth Station in
    Frequency Bands Between 1 GHz and 40 GHz Shared Between Space and
    Terrestrial Radiocommunications Services*. Section 2.3, "Derivation
    and Tabulation of Interference Parameters," and Section 2.3.1,
    "Permissible Level of the Interfering Emission," was applied.

[^214]: NTIA Special Publication 01-43, *supra*, at pg. A-17.

[^215]: International Standards and Recommended Practices Annex 10 to
    the Convention of International Civil Aviation, Volume 1 (Radio
    Navigation Aids) Fifth Edition, July 1996.

[^216]: In order for the aircraft to be within 160 meters, horizontal,
    from the UWB transmitter at a receive angle of 30 degrees, as
    employed by NTIA in its calculations, the aircraft would be less
    than 93 meters above the ground.

[^217]: NTIA Report 95-325, Building Attenuation, at pg. 43.

[^218]: "Not Applicable" indicates that the particular scenario would
    involve an airborne receiver at the same altitude as a UWB
    transmitter, which should not occur.

[^219]: The primary effect of the Commission's peak power limits as
    proposed in the *Notice* is that the peak power limit provides the
    restriction at lower PRFs while the average power limit provides the
    restriction at higher PRFs. .

[^220]: Attachments to U.S. Department of Defense filing of 10/1/00.

[^221]: ARRL employed a receiver noise level of --141 dBm and a noise
    figure of 3 dB, resulting in a thermal noise floor of --139 dBm, for
    both 1 kHz bandwidth receivers used in its analyses.

[^222]: This would be expected with a constant envelope signal level.

[^223]: At the PRFs commonly employed by UWB transmitters, it is
    expected that a quasi-peak detector will tend to measure closer to
    the peak level as opposed to the average level. However, the amateur
    narrowband receiver would respond to the average level of the UWB
    emission. This could be considerably less than the peak level. In
    any event, the devices operating below 1 GHz will be extremely
    limited in number and scope and should not be a source of
    interference.

[^224]: While a 20 dBi Yagi antenna is feasible, such an antenna
    normally would be mounted high above a roof where it is unlikely
    that a nearby UWB transmitter would be directly in the main beam.

[^225]: It should be noted that the PCS frequency bands are not
    restricted bands. Part 15 devices currently are permitted to
    transmit in the PCS bands at a level equivalent to --41.25 dBm/MHz
    EIRP.

[^226]: *See* Sprint PCS comments of 9/12/2000 at Attachment 2, pg. 2-3.

[^227]: In the anechoic chamber test, it appeared that the antenna was
    optimized for the transmit band rather than the receive band
    resulting in a measured gain of --4.6 dBi.

[^228]: Thus, the losses between the antenna and the receiver are
    greater than those used in the above calculations.

[^229]: Qualcomm stated that for commercial CDMA receivers it does not
    matter if the in-band noise has spectral lines or is white spectrum;
    what matters is total power in a 1.2288 MHz bandwidth. *See*
    Qualcomm comments of 5/10/01 at pg. 14.

[^230]: Sprint PCS comments of 9/12/2000 at Attachment 2, pg. 4.

[^231]: Sprint PCS comments of 9/12/2000 at Attachment 2, pg. 4.

[^232]: Sprint PCS comments of 4/6/01 at pg. 2.

[^233]: Sprint PCS comments of 4/6/01 at pg. 2-3.

[^234]: TDC comments of 4/25/01 at pg. 79.

[^235]: TDC comments of 4/25/01 at pg. 83-84.

[^236]: TDC comments of 4/25/01 at pg. 85.

[^237]: XSI comments of 5/10/01 at pg. 4.

[^238]: XSI comments of 5/10/01 at pg. 5-6.

[^239]: XSI comments of 5/10/01 at pg. 6.

[^240]: XSI comments of 5/10/01 at pg. 7-8.

[^241]: XSI comments of 5/10/01 at pg. 11.

[^242]: 47 C.F.R. § 24.236 states that the median field strength at any
    location on the border of the PCS service area shall not exceed 47
    dBuV/m. As this is the signal level established in the rules as what
    is necessary to prevent interference to an adjacent license, it
    appears likely that PCS systems are designed to operate at this
    level or higher. For a 50 ohm system, this emission level is
    equivalent to a received signal level of --96 dBm.

[^243]: No limit on the peak-to-average ratio was proposed in the
    *Notice*.

[^244]: *See*, for example, *Second Memorandum Opinion and Order* in WT
    Docket No. 99-168, 16 FCC Rcd. 1239 (2001), at para. 6-8.

[^245]: This is the limit for emissions appearing within the 2483.5-2500
    MHz band. The limit on emissions from spread spectrum transmitters
    appearing within the MMDS band above 2500 MHz is about +16 dBm but
    may be higher for high gain antennas used with point-to-point spread
    spectrum systems.

[^246]: Referencing the thermal noise to 290°K, the receiver noise level
    for a 2 MHz bandwidth is --110.97 dBm. A thermal noise referenced to
    290°K is appropriate as the omnidirectional antenna employed by the
    DARS receiver will encompass surrounding terrain.

[^247]: Sirius stated that with a typical noise figure of 2 dB, receiver
    performance would be degraded by 3 dB at 150 feet for line-of-sight
    and 25 feet for non-line-of-sight. Sirius comments of 4/25/01 at pg.
    3.

[^248]: Due to the extremely wide frequency separation, it is likely
    that emissions in the DARS band would be considerably lower than the
    Part 15 emission limits.

[^249]: *See* 47 C.F.R. § 15.35(b).

[^250]: This assumes that the UWB signal is far enough from the receiver
    that it does not overload the receiver causing nonlinear operation.
    The peak limits being considered in this proceeding will ensure that
    receiver overloading is not a concern.

[^251]: AOPA comments at pg. 13.

[^252]: A. Peter Anan comments at pg. 4.

[^253]: ARRL comments at pg. 14.

[^254]: Aether Wire comments at pg. 11.

[^255]: AOPA comments at pg. 13.

[^256]: Aether Wire comments at pg. 12.

[^257]: *See* 47 C.F.R. §§ 15.109(a) and 15.209.

[^258]: While it is possible to establish emission limits that protect a
    user from his own interference at separation distances on the order
    of one meter, such limits would significantly add to the cost of all
    Part 15 devices, including computers, cordless telephones and
    receivers.

[^259]: Emissions below 1 GHz are measured using a CISPR quasi-peak
    detector with a resolution bandwidth of 120 kHz [+]{.underline} 20
    kHz. Emissions above 1 GHz are measured using a 1 MHz resolution
    bandwidth. *See* 47 C.F.R. § 15.35.

[^260]: Some of the comments continued to propose that UWB devices be
    subject to the same emission limits as those applied to Class A
    digital devices. The Commission considered this issue in the
    *Notice* and declined to propose it. We find no new information in
    the comments that would cause us to reconsider. *See Notice*,
    *supra*, at para. 40.

[^261]: *See*, for example, the comments of AOPA at pg. 12, Lucent at
    pg. 1, and NBAA at pg. 13.

[^262]: *See*, for example, the comments of AT&T at pg. 6 and Cisco at
    pg. 6-9.

[^263]: *See* 47 C.F.R. § 15.35(b).

[^264]: ARRL comments at pg. 12.

[^265]: ARRL comments at pg. 14.

[^266]: Lucent comments at pg. 1.

[^267]: XM comments at pg. A6 and reply comments at pg. 8.

[^268]: *See*, for example, Bosch reply comments at pg. 3, SME comments
    at pg. 3, Siemens comments at pg. 2, and MSSI reply comments at pg.
    2.

[^269]: MSSI reply comments at pg. 2. Also, MSSI comments of 3/22/01 at
    pg. 4.

[^270]: *See* 47 C.F.R. § 15.247. The spread spectrum frequency bands
    are 902-928 MHz, 2400-2483.5 MHz, and 5725-5750 MHz.

[^271]: Bosch reply comments at pg. 4. Saab comments at pg. 3. Siemens
    comments at pg. 2. Valeo comments at pg. 5-6. Valeo actually
    requested a variable limit where the emission would be at thermal
    noise at 10 meters using free space, a 0 dBi antenna and a 3 dB
    receiver noise figure.

[^272]: TDC comments at pg. 19.

[^273]: *See* letter of February 13, 2002, from William Hatch, *supra.*

[^274]: We note that US Government radio stations may be operated
    without coordination under emergency circumstances. *See* *Manual of
    Regulations and Procedures for Federal Radio Frequency Management*,
    U.S. Department of Commerce, National Telecommunications and
    Information Administration, January 2000, at Section 7.3.1. We also
    note that no similar provision exists that would permit
    non-Government operation absent appropriate coordination. However,
    we are implementing a procedure similar to that contained in 47
    C.F.R. Section 2.405(a)-(e) to facilitate the emergency operation of
    UWB imaging devices.

[^275]: We expect that the emissions would attenuate with distance based
    on the cube of the inverse distance, not the square as employed with
    free space propagation.

[^276]: A. Peter Annan comments at pg. 3-5.

[^277]: GSSI and Sensors and Software comments of October 10, 2001. The
    maximum limit was expressed as 20 log (500MHz/testing frequency in
    MHz) dBuV/m. At, say, 20 MHz, the testing frequency is 9 kHz
    resulting in a signal level of 94.9 dBuV/m or 55,600 uV/m. The
    existing limit at 20 MHz is 30 uV/m, as measured at 30 meters with a
    quasi-peak detector, or 29.5 dBuV/m.

[^278]: The only UWB GPRs that have been certified by the Commission are
    those produced by U.S. Radar. U.S. Radar received a waiver from the
    Commission, subsequent to extensive coordinated with NTIA, to permit
    the marketing and use of its product. The marketing or use of any
    GPR that has not been certified, except under the conditions
    specified in 47 C.F.R. § 15.211, is in violation of 47 U.S.C. 301
    and 302 and is subject to the penalties described in 47 U.S.C.
    501-510.

[^279]: Similarly, we believe that medical imaging systems would be used
    indoors such that intervening walls would attenuate the emissions.

[^280]: GPS operation occurs at 1164-1215 MHz for the L5 band, 1215-1240
    MHz for the L2 band, and 1559-1610 MHz for the L1 band. DME
    transponders operate at 1025-1150 MHz; the ARSR-4 operates at
    1240-1370 MHz; and SARSAT operates at 1544-1545 MHz.

[^281]: 47 C.F.R. § 22.917(f). This standard originally was established
    by the cellular industry, working through the Electronics Industry
    Association, and was published in the Commission's OST Bulletin No.
    53, *Cellular System Mobile Station -- Land Station Compatibility
    Specification*, April 1981 at Section 2.2.3.1.1.

[^282]: As discussed elsewhere in this Order, an additional 8 dB of
    suppression has been applied to vehicular radar systems and an
    additional 10 dB has been applied to hand held devices at the
    request of NTIA.

[^283]: Part 15 radar systems currently are permitted to operate in the
    24.075-24.175 GHz band. *See* 47 C.F.R. § 15.245.

[^284]: The UWB antenna will act as a band-pass filter. Emissions
    appearing, say, 20 GHz below a transmitter operating with a center
    frequency above 24 GHz will be a random collection of cabinet
    radiation and antenna resonant frequencies.

[^285]: *See 47 C.F.R. § 2.106.*

[^286]: *See* letter of February 13, 2002, from William Hatch, *supra.*.

[^287]: We note that it does not make a difference as to whether this
    attenuation is achieved through antenna directivity, the suppression
    of emissions below 24 GHz or some other method.

[^288]: For example, NTIA did not provide any attenuation of the
    radiated emissions due to foliage, terrain, buildings, or other
    vehicles as would be expected at the low elevation angles involved.
    NTIA also assumed that each vehicle would have four radar
    transmitters directed towards the satellite, resulting in a 6 dB
    increase to the received level, with the emissions from these
    transmitters attenuated, due to antenna directivity, by 21.9 dB at
    an angle of 33.2 degrees, the lowest LOS elevation angle used in
    NTIA's analyses. NTIA concluded in its calculations that an
    additional 10 dB of attenuation is necessary, resulting in an
    antenna directivity of 31.9 dB at 33.2 degrees above the horizontal
    plane, of 33.2 dB at 35.2 degrees, or of 40 dB at 90 degrees,
    depending on which of its four analysis NTIA employed. However, NTIA
    then required that the antenna directivity be increased to an even
    tighter margin of 35 dB at an elevation of 30 degrees. NTIA did not
    provide any justification for its additional protection margin.

[^289]: *See 47 C.F.R. § 2.106.*

[^290]: Prior XSI comments indicated that UWB operation would be
    restricted to indoor systems. *See*, for example, XSI reply comments
    at pg. 5 where XSI states that indoors only operation should be
    required until the Commission has developed a full technical record.

[^291]: NTIA acknowledged building attenuation levels of 9 dB from
    960-3000 MHz, 12 dB from 3000-5650 MHz, and 14 dB from 5650-7250
    MHz. *See* NTIA Special Publication 01-43, *supra*, at pg. 5-31.

[^292]: This is consistent with our desire to proceed cautiously with
    the introduction of UWB devices. This is an area that we may wish to
    readdress in our further review of the UWB standards that is
    scheduled to occur in the next six to twelve months.

[^293]: Requiring the equipment to be operated indoors also should
    provide an effect similar to that of a directional antenna. RF
    emissions would not be directed skyward due to increased rooftop
    attenuation. Variable attenuation of the building walls and
    attenuation by randomly placed objects within the building will
    reduce the probability that emissions radiated from the building
    will be pointed in any particular direction.

[^294]: 47 C.F.R. § 15.307.

[^295]: *See*, for example, TDC's *ex parte* filing of November 20,
    2001.

[^296]: AT&T comments at pg. 7-8. UNII systems operate under Part 15 and
    are not entitled to protection from interference. *See* 47 C.F.R. §
    15.5.

[^297]: Lucent comments at pg. 7.

[^298]: Motorola comments at pg. 36. While Motorola in its comments
    requested that UWB systems be required to attenuate emissions 12 dB
    below the Part 15 general limits, it later requested that 18 dB of
    attenuation be required but supplied no data to support its request.
    Motorola reply comments at pg. 2 and 7.

[^299]: *See*, for example, the *ex parte* comments of December 5, 2001,
    from DaimlerChrysler and SARA on pg. 14.

[^300]: Recommendation ITU-R M.1477, *supra*.

[^301]: XSI comment of 7/25/01responding to the USGPSIC comment of
    6/21/01.

[^302]: If the signal is noise-like, the reduction from a 1 MHz
    resolution to a 10 kHz resolution bandwidth would cause a 20 dB
    reduction in the measured signal level.

[^303]: A true CW-like emission will have the same measured emission
    level regardless of the resolution bandwidth provided only one
    spectral line is contained within the bandwidth of the measuring
    instrument. A true noise-like emission will change by 10 dB for
    every 10 percent change in the measurement bandwidth, *i.e.*, a
    signal measured to be --30 dBm with a 1 MHz resolution bandwidth
    will be --60 dBm when measured with a 1 kHz resolution bandwidth.
    When noise-like and CW-like emissions are mixed, as with most UWB
    operations, the measured UWB emission will decrease logarithmically
    with the decrease in resolution bandwidth until the imbedded CW
    emissions begin to be detected and resolved.

[^304]: The average limit above 1000 MHz, 500 uV/m, as measured at 3
    meters, is equivalent to an equivalent isotropically radiated power
    (EIRP) of --41.25 dBm/MHz. Thus, the proposed peak limit in a 50 MHz
    band would be 5000 uV/m, as measured at 3 meters, or --21.25 dBm/ 50
    MHz EIRP. It appears that several of the commenters mistakenly
    believed that the Commission proposed to apply a limit to the
    peak-to-average ratio of the UWB transmission instead of to the peak
    emission level.

[^305]: This would be equivalent to a total peak EIRP of +18.75 dBm.

[^306]: *See* waivers issued on June 29, 1999, by the Chief, Office of
    Engineering and Technology. While the waivers stated that the
    maximum peak-to-average ratio was limited to 30 dB, these ratios
    were calculated using 10 log~10~\[(pulse width) x (pulse repetition
    frequency)\] dB. For conventional pulses, the calculation would have
    been based on a 20 log~10~ factor, resulting in a maximum 60 dB
    peak-to-average ratio.

[^307]: AOPA comments at pg. 14.

[^308]: NBAA comments at pg. 15.

[^309]: Valeo Electronics comments at pg. 11.

[^310]: TDC comments at pg. 34.

[^311]: Nortel comments at pg. 4.

[^312]: Bosch comments at pg. 5.

[^313]: ANRO comments at pg. 2. ANRO also requested peak limits of 2 kW
    for UWB systems using directional antennas.

[^314]: Kohler comments at pg. 5-6.

[^315]: SiRF Technology, Inc. & Trimble Navigation joint reply comments
    at pg. 3.

[^316]: USGPSIC comments at pg. 41-42. The USGPSIC stated that this high
    power would occur from the use of a 1 mW average UWB transmission
    using a pulse width of 1 nS.

[^317]: XSI reply comments at pg. 6.

[^318]: TDC comments at pg. 32-33.

[^319]: TDC comments of 3/12/01 at pg. 17.

[^320]: Kohler reply comments at pg. 2.

[^321]: XSI reply comments at pg. 5. It appears that the 5 dB peak to
    average applies to average and peak measurements over the same 1 MHz
    bandwidth.

[^322]: CSSIP comments at pg. 2. We note that the quasi-peak measurement
    closely approximates the peak level of a pulsed emission.
    Accordingly, we see no reason to apply a peak limit on top of a
    quasi-peak limit.

[^323]: NTIA Special Publication 01-45, *supra*, at pg. 4-3.

[^324]: We also note that many GPRs and imaging systems will operate
    below 1000 MHz where they are subject to a quasi-peak emission
    limit. The quasi-peak emission limit should closely approximate the
    peak levels produced by these devices.

[^325]: There is a direct correlation between EIRP and field strength.
    Field strength in dBuV/m at 3 meters equals EIRP (in dBm) plus 95.2.

[^326]: Our initial analysis of the effect on a QPSK system has been
    placed in the docket file for this proceeding.

[^327]: The bandwidth of the measuring instrument would be centered on
    this frequency.

[^328]: The formulas needed to perform this analysis are contained in
    NTIA Special Publication 01-43, *supra*, at pg. D-1 through D-2.

[^329]: This equates to a 20 dB peak-to-average level for the 50 MHz RBW
    curve.

[^330]: "Average-limited" means that the average emission level will be
    the determining standard on whether the equipment complies with the
    standards. If the emissions from the device meet the average limit,
    they will also meet the peak limit. "Peak-limited" is the counter to
    this where if the device meets the peak limit, it will also comply
    with the average limit. However, it must be noted that the graphs
    are based on ideal pulse characteristics. Because of extraneous
    emissions, *e.g.*, emissions from an associated digital device,
    antenna effects, different pulse shapes, and other factors it
    remains necessary to specify both peak and average emissions.

[^331]: The peak limit above 1000 MHz is 5 mV/m. This is equivalent to
    --21.25 dBm EIRP. *See* 47 C.F.R. §§ 15.33(b) and 15.209. However,
    it must be remembered that the peak limit in the current Part 15
    rules is based on the total peak emission level and not on a peak
    level over a specified bandwidth.

[^332]: The Commission proposed to modify the AC power line conducted
    emission limits in 47 C.F.R. § 15.207. *See Notice of Proposed Rule
    Making* in ET Docket No. 98-80, 64 Fed. Reg. 62159, November 16,
    1999,
    <http://www.fcc.gov/Bureaus/Engineering_Technology/Notices/1999/fcc99296.wp>.

[^333]: *See*, for example, the comments of ARRL at pg. 16, A. Peter
    Annan at pg. 7, and TDC at pg. 34. While Mr. Annan's comments
    address conducted limits applicable to digital devices, UWB devices
    are intentional radiators though they also may contain digital
    circuitry.

[^334]: *Notice*, *supra*, at para. 32.

[^335]: *See* letter of February 13, 2002, from William Hatch, supra.

[^336]: This limit could change in the future based on the *Notice of
    Proposed Rule Making* in ET Docket No. 98-80, *supra*.

[^337]: Most UWB transmitters produce a line spectrum while those
    employing high levels of random pulse positioning can appear more as
    Gaussian noise. For the former devices, the emission only appears as
    noise depending on the settings of the measurement instrumentation.

[^338]: *See* TDC submission of 3/9/01, *supra*.

[^339]: XSI *ex parte* response of 7/25/01 at pg. 3-4 and 5-6.

[^340]: XSI was promoting an indoor-only system.

[^341]: Aether Wire comments at pg. 12.

[^342]: Sprint PCS comments at Attachment 1, pg. 1-2.

[^343]: Motorola comments at pg. 10 and 20-21.

[^344]: Motorola comments at pg. 26-27.

[^345]: AT&T comments at pg. 6.

[^346]: NTIA Special Publication 01-43, *supra*, at pg. 5-1 through 5-34
    and B-1 through B-27.

[^347]: Filing of U.S. Department of Defense submitted 10/1/00,
    Attachment 1.

[^348]: We believe that the power levels being permitted for UWB
    operation would need to be considerably higher in order to
    transverse the hundreds of kilometers necessary to cause
    interference to the DOD SEEK Skyhook radar system.

[^349]: ARRL comments at pg. 13-14.

[^350]: ARRL reply comments at pg. 8.

[^351]: Interference to systems such as the ARSR-4 has been sufficiently
    addressed through the emission limits being adopted in this
    proceeding.

[^352]: The directional signal characteristics of the UWB systems also
    will reduce the number of UWB devices "visible" to the ARSR-4
    receiver.

[^353]: We expect that most handheld devices would be operated indoors
    or at ground level.

[^354]: As noted earlier, it will appear to outdoor receivers that
    indoor UWB systems are operating with directional antennas due to
    variable attenuation from building walls and randomly placed
    obstacles within the building.

[^355]: *See* 47 C.F.R. §§ 15.35(b) and 15.209(d). There are also
    certain rule sections that specify the application of a total peak
    power limit over a wider bandwidth. *See*, for example, 47 C.F.R. §§
    15.247(b) and 15.255(e).

[^356]: American National Standards Institute (ANSI) ANSI C63.4-1992,
    *Methods of Measurement of Radio-Noise Emissions from Low-Voltage
    Electrical and Electronic Equipment in the Range of 9 kHz to 40
    GHz*, is specified in the Part 15 regulations as the measurement
    procedure applicable to Part 15 devices. *See* 47 C.F.R. §
    15.31(a)(6).

[^357]: ANRO comments at pg. 2; Bosch comments at pg. 5; Zircon comments
    at pg. 4.

[^358]: *See* NTIA Report 01-383, *supra*, at pg. 6-18 through 6-25 and
    A-1 through A-21. *See*, also, NTIA Special Publication 01-43,
    *supra*, at pg. 2-1 through 2-2.

[^359]: One of the U.S. Government frequency bands starts at 960 MHz,
    not at 1000 MHz.

[^360]: Lucent comments at pg. 3. Burst transmissions are extremely
    short transmission intervals that have a low average emission level.

[^361]: Metricom comments at pg. 5.

[^362]: A. Peter Annan comments at pg. 7-8.

[^363]: CSSIP comments at pg. 2.

[^364]: Sensors & Software and GSSI *ex parte* filing of 10/10/01.

[^365]: TDC comments at pg. 36-42 and reply comments at pg. 59.

[^366]: Bosch comments at pg. 5.

[^367]: We noted under the discussion on emission limits the need to
    test for narrowband emission levels in the GPS frequency bands and
    the test procedure that would be applied.

[^368]: Linear averaging can be accomplished by using appropriate video
    averaging or by trace averaging.

[^369]: It is not necessary to specify a video bandwidth with an RMS
    detector.

[^370]: The type of material in front of these transmitters, if any,
    could vary. Thus, no attempt was made to categorize this material.

[^371]: The comments noted considerable difficulties in attempting to
    measure total peak output levels. *See*, for example, TDC comments
    at pg. 42-43.

[^372]: TDC reply comments at Appendix C.

[^373]: Siemens comments at pg. 1.

[^374]: Valeo comments at pg. 12.

[^375]: Fantasma reply comments at pg. 9.

[^376]: USGPSIC comments at pg. 45, footnote 81.

[^377]: The worst case comparison occurs when the PRF is less than
    RBW/0.45.

[^378]: If peak measurements were to be performed using a 1 MHz
    bandwidth, the peak limit would be decreased by 20 log (1/50) or to
    an EIRP of --34 dBm.

[^379]: This may be converted to a peak field strength level at 3 meters
    using E(dBuV/m) = P(dBm EIRP) + 95.2.

[^380]: While several references to the --20 dB emission points were
    made in the comments for defining UWB emissions, we believe that the
    --10 dB emissions points are more appropriate for determining the
    center frequency as it is unlikely that the --10 dB points would be
    below the noise floor of a spectrum analyzer.

[^381]: Valeo comments at pg. 13.

[^382]: Pulse shaping also could affect the characteristics and levels
    of the radiated emissions.

[^383]: With the exception of radar transmitters operating between 76-77
    GHz, 200 GHz is the current upper range of measurements for Part 15
    transmitters. *See* 47 C.F.R. § 15.33(a).

[^384]: At this time, we are not adopting regulations that would permit
    UWB systems to operate with a center frequency greater than 30 MHz.
    However, we see no reason not to adopt a general standard for the
    frequency range of measurement.

[^385]: *See* 47 C.F.R. §§ 2.201(f) and 15.5(d).

[^386]: *See* Chapter II, Article 5, Section 8 of the Radio Regulations
    of the International Telecommunication Union.

[^387]: The term "damped waves (Type B)" was last defined in Article 5,
    Section 1 of the 1938 version of the ITU regulations as "\[w\]aves
    composed of successive series of oscillations the amplitude of
    which, after obtaining a maximum, decreases gradually, the wave
    trains being keyed according to a telegraph code." A more modern
    version of the term "damped wave" is defined in the IEEE Standard
    Dictionary of Electrical and Electronic Terms, IEEE Std 100-1972, as
    "\[a\] wave in which, at every point, the amplitude of each
    sinusoidal component is a decreasing function of time."

[^388]: TDC comments at pg. 44.

[^389]: USGPSIC comments at pg. 47-48.

[^390]: Interlogix comments at pg. 4-5 and reply comments at pg. 2. We
    note that Interlogix redesigned its equipment in order to be
    certified under the provisions of 47 C.F.R. § 15.249.

[^391]: Bosch comments at pg. 5 and reply comments at pg. 5.

[^392]: TDC comments at pg. 44-45.

[^393]: Valeo comments at pg. 4; SARA *ex parte* filing of 11/14/01.

[^394]: Delphi comments at pg. 17-18; SARA *ex parte* filing of
    11/14/01. The "ISM" bands refer to the frequency bands under 47
    C.F.R. § 18.301, *e.g.*, the bands on which operation is permitted
    under 47 C.F.R. §§ 15.245-15.249.

[^395]: Any emissions appearing outside of the specified frequency band
    must continue to meet the emission limits even if those limits
    require an attenuation of greater than 20 dB. For example, a spread
    spectrum system operating at 2400-2483.5 MHz under 47 C.F.R. §
    15.245 must attenuate emissions in the 2483.5-2500 MHz band by
    significantly greater than 20 dB. We are using the 20 dB bandwidth
    only to determine that the emission is contained within the
    specified band.

[^396]: We do not believe that a specific regulation is required for
    this interpretation.

[^397]: USGPSIC comments at pg. 48-52.

[^398]: *See* 5 U.S.C. §§ 801 *et seq*.

[^399]: *See*, for example, ATA *et al* late filed comments of 3/27/01,
    and MSSI late filed comments of 10/9/01. MSSI rescinded its request
    in an *ex parte* filing of 11/12/01.

[^400]: ARRL comments at pg. 3.

[^401]: Fantasma late filed comments of 4/2/01; XSI late comments of
    4/12/01 and *ex parte* filing of 7/25/01.

[^402]: *See* 5 U.S.C. 553.

[^403]: *See* Delphi comments, reply comments and *ex parte* filings of
    4/24/01, 6/07/01, 7/13/01, and 9/20/01.

[^404]: SARA *ex parte* filing of 11/14/01. SARA also expressed concern
    regarding the residual carrier emission produced by its homodyne
    receiver. This issue will be addressed upon such time as the
    equipment is submitted for authorization under our certification
    procedure. However, we note that the levels of radiated emissions
    due to the local oscillator of a receiver operating above 960 MHz is
    not addressed under Part 15, other than the requirement that the
    emissions not cause harmful interference to other radio operations.
    *See* 47 C.F.R. § 15.101(b).

[^405]: Sprint reply comments at pg. 13-14 and comments of 4/25/01 at
    pg. 8.

[^406]: Sprint PCS comments of 4/6/01 at pg. 2.

[^407]: *See* 47 C.F.R. § 15.231.

[^408]: Unlicensed PCS transmitters operate in the bands 1910-1930 MHz
    and 2390-2400 MHz. The exemption from the restricted bands only
    affects the limits for some of the unwanted emissions. The unwanted
    emissions are required to comply with the limits in 47 C.F.R. §§
    15.321(d) and 15.323(d), as appropriate.

[^409]: *See* 47 U.S.C. 553(b)(B).

[^410]: *See* *First Report and Order* in GEN Docket No. 87-389, 4 FCC
    Rcd. 3493 (1989).

[^411]: *See Manual of Regulations and Procedures for Federal Radio
    Frequency Management*, U.S. Department of Commerce, National
    Telecommunications and Information Administration, January 2000, at
    Sections 7.8 and 7.9.

[^412]: The operation in non-government bands of UWB devices that are
    not in compliance with the technical and administrative provisions
    contained in this Order is not permitted without the concurrence of
    the FCC.

[^413]:   The RFA, *see* § 5 U.S.C. S 601 *et. seq*., has been amended
    by the Contract With America Advancement Act of 1996, Pub. L. No.
    104-121, 110 Stat. 847 (1996) (CWAAA). Title II of the CWAAA is the
    Small Business Regulatory Enforcement Fairness Act of 1996 (SBREFA).

[^414]:   5 U.S.C. § 605(b).

[^415]:   5 U.S.C. § 601(6).

[^416]:   5 U.S.C. § 601(3) (incorporating by reference the definition
    of \"small business concern\" in Small Business Act, 15 U.S.C. S §
    632). Pursuant to 5 U.S.C. § 601(3), the statutory definition of a
    small business applies \"unless an agency, after consultation with
    the Office of Advocacy of the Small Business Administration and
    after opportunity for public comment, establishes one or more
    definitions of such term which are appropriate to the activities of
    the agency and publishes such definition(s) in the Federal
    Register.\"

[^417]:   Small Business Act, § 15 U.S.C. S 632.

[^418]: AOPA comments at pg. 16-17; NBAA comments at pg. 17.

[^419]: *See* 5 U.S.C. § 801(a)(1)(A)

[^420]: *See* 5 U.S.C. § 605(b).