**Before the**

**Federal Communications Commission**

**Washington, D.C. 20554**

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| In the matter of                 | *  | IB Docket No. 01-185         |
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| Flexibility for Delivery of      | ** |                              |
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| Communications by Mobile         | *  |                              |
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| Service Providers in the 2 GHz   |    |                              |
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| L-Band, and the 1.6/2.4 GHz      | ** |                              |
| Bands                            |    |                              |
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**Memorandum Opinion and Order and**

**Second Order on Reconsideration**

**Adopted: February 10, 2005 Released: February 25, 2005**

By the Commission: Commissioner Copps approving in part, concurring in
part, and issuing a separate statement.

**TABLE OF CONTENTS**

Heading Paragraph No.

I. INTRODUCTION 1

II\. executive summary 2

III\. background [3](#background)

IV\. discussion [8](#discussion)

A. Gating Criteria [8](#gating-criteria)

1\. Substantial Satellite Service 20

2\. Integrated Service 24

3\. Dual-Mode Devices 28

4\. ATC-Only Subscriptions 32

5\. Band-Specific Gating Criteria 33

6\. Geographic Coverage 34

B. Uplink Interference in the L-Band 36

1\. Interference Standard 40

2\. Other Issues 46

C. Downlink Interference in the L-Band 50

1\. ATC Base Station Power Levels 51

2\. Protection of Airports and Waterways 59

3\. Overhead Gain Suppression 63

4\. Protection of the Radionavigation Satellite Service 65

5\. Protection of Search-and-Rescue Satellite Service (SARSAT) 70

6\. Non-Forward Band Operation 71

D. Licensing Issues 72

1\. Assignment of Licenses by Competitive Bidding 72

2\. Public Notice of Licensing Actions 77

3\. Conditional Licenses 79

4\. Demonstrations of Compliance 83

E. Uplink Interference in the Big LEO Band. 87

1\. Out-of-Band Emissions 87

2\. Protection of Broadcast Auxiliary Service 89

V. conclusion 91

VI\. procedural matters 92

VII\. ordering clauses 94

Appendix A: Test Report - Inmarsat Terminal Interference Susceptibility
Testing

Appendix B: Final Rules

Appendix C: List of Commenting Parties

# INTRODUCTION

1.  By this *Memorandum Opinion and Order and Second Order on
    Reconsideration*, the Commission revises the rules adopted in 2003
    for flexibility in the provision of Mobile Satellite Service (MSS)
    communications, permitting the addition of ancillary terrestrial
    components (ATC) to MSS systems. We reaffirm that ATC is a part of,
    and ancillary to, MSS. We reconsider and substantially change
    certain technical standards for ATC in the L-band, in order to
    permit MSS/ATC licensees flexibility in designing and operating
    their ATC while at the same time preventing harmful interference
    from ATC to co-primary MSS licensees in the L-band. We also allow
    certain increases in ATC base station power because it has been
    demonstrated that these increases will not cause harmful
    interference. Finally, we amend the rules for authorizing MSS
    operators to add ATC to their networks.

# executive summary

2.  This *Memorandum Opinion and Order and Second Order on
    Reconsideration* addresses eight petitions for reconsideration of
    prior Commission decisions regarding ATC operations. These decisions
    fall into four areas: (1) gating criteria, (2) uplink
    interference, (3) downlink interference, and (4) licensing issues.

3.  Gating criteria are conditions that an MSS operator must meet in
    order to receive authorization to operate ATC. This *Memorandum
    Opinion and Order and Second Order on Reconsideration*:

    ● Affirms our prior decision not to require a specific percentage of
    MSS system capability to be reserved for MSS operation, and

    ● Clarifies that all MSS/ATC equipment must be able to communicate
    via both MSS and ATC, and that services must be available through
    both MSS and ATC.

4.  Uplink interference issues address the protection of other
    co-primary MSS operators in the L-band from harmful interference
    from ATC operations. This *Memorandum Opinion and Order and Second
    Order on Reconsideration* changes the basis of interference
    protection from a list of specific technical requirements to a limit
    on the increase in interference an MSS/ATC network can cause to
    other MSS operators' satellites, leaving MSS/ATC operators free to
    design and operate their systems as they consider best, within the
    interference standards.

5.  Downlink interference issues address the protection of MSS earth
    stations from interference from ATC. This *Memorandum Opinion and
    Order and Second Order on Reconsideration*:

    ● Raises the limits on ATC base station power, while continuing to
    protect other MSS operators' earth stations,

    ● Allows higher ATC signal strength near airports and waterways,
    while continuing to protect other MSS operators' earth stations, and

    ● Relaxes overhead gain limits for ATC base stations.

6.  Licensing issues address how MSS operators will be granted ATC
    authority. This *Memorandum Opinion and Order and Second Order on
    Reconsideration*:

    ● Reaffirms that MSS/ATC authority is ineligible for competitive
    bidding,

    ● Reaffirms that public notice and comment will be provided in
    consideration of applications for ATC authority, and

    ● Declines to grant conditional authority, requiring instead that
    MSS operators be in compliance with all gating criteria before they
    can be authorized to provide ATC.

# background

7.  MSS is a radiocommunication service involving transmission between
    mobile earth stations and one or more space stations.[^1] The
    Commission has allocated and assigned spectrum in several bands to
    MSS.[^2] MSS systems can provide communications in areas where it is
    difficult or impossible to provide communications coverage via
    terrestrial base stations, such as remote or rural areas and
    non-coastal maritime regions.[^3] A disadvantage of MSS is the fact
    that the satellite link is susceptible to blocking by structural
    attenuation, particularly in urban areas and inside buildings.[^4]

8.  After receiving applications from MSS operators requesting authority
    to re-use their assigned spectrum to provide terrestrially-based
    service, we began this proceeding to consider permitting MSS
    operators to integrate terrestrial services into their satellite
    networks, in order to augment coverage in areas where their
    satellite signals are largely unavailable due to blocking.[^5] After
    receiving voluminous public comment on whether to permit MSS
    operators to operate ATCs, and under what restrictions such
    operations should be permitted, we released a *Report and Order*
    that permits MSS operators to provide integrated ATC within their
    assigned MSS spectrum, and adopted rules pertaining to the licensing
    and operation of ATC systems.[^6]

9.  *[MSS Flexibility R&O]{.underline}*. In deciding to permit MSS
    operators to integrate ATC into their MSS systems, we stated that
    "permitting MSS licensees to enhance spectrum efficiency through ATC
    represents a superior choice to continuing with the regulatory
    status quo."[^7] Further, we found that MSS/ATC would expand the
    consumer market MSS is capable of serving, leading to economies of
    scale and lower prices for consumers.[^8] Granting authority for
    integrated MSS/ATC would also allow MSS operators to offer the
    capability of receiving calls via both satellite and terrestrial
    radio links with a single dual-mode handset and a single telephone
    number, whereas current dual-capability MSS/Commercial Mobile Radio
    Service (CMRS) handsets require separate numbers for MSS and CMRS
    services.[^9] Moreover, MSS/ATC would eliminate operational and
    transactional difficulties and costs for MSS operators in
    negotiating separate terrestrial roaming agreements with various
    terrestrial CMRS operators within the MSS operators' service
    areas.[^10] Finally, we found that MSS/ATC would enhance the ability
    of the national and global telecommunications systems to protect the
    public by offering ubiquitous service to law enforcement, public aid
    agencies, and the public,[^11] and would strengthen competition in
    the telecommunications market.[^12]

10. We concluded that our decision to permit MSS operators to acquire
    ATC authority did not establish the requisite conditions for
    assigning licenses through competitive bidding under section 309(j)
    of the Communications Act of 1934, as amended (Communications
    Act).[^13] We also concluded that granting ATC authority by
    modifying MSS operators' rights under their existing authorizations
    and declining to authorize separate terrestrial authorizations in
    MSS bands precluded the filing of mutually exclusive applications, a
    requirement for assigning licenses by competitive bidding.[^14]
    Further, we found that granting ATC authority under the conditions
    we prescribed would not unjustly enrich MSS operators because MSS,
    even with ATC, is not a close substitute for terrestrial CMRS for
    most customers, and will not compete with CMRS directly.[^15] With
    regard to licensing, we decided to implement geographic area
    licensing of ATC base stations generally, and individual licensing
    of ATC base stations in situations where the stations could pose
    threats of adverse effects to the environment, public health, scenic
    and historic locations, tribal lands, aviation, or related
    concerns.[^16] We also decided that applications for ATC authority
    would be treated as minor modifications to the MSS operators' space
    station licenses.[^17] Further, foreign-licensed MSS operators
    permitted to offer service in the United States under a Letter of
    Intent (LOI) would apply for ATC authority by modification of the
    LOI.[^18] We specified that ATC construction and testing may not
    begin until after an ATC authorization has been issued, but may
    begin prior to commencement of the provision of MSS services.[^19]
    Finally, we decided to license MSS ATC handsets by our equipment
    certification procedure under Part 2, Subpart J of the rules.[^20]

11. To protect other users of MSS spectrum, both satellite and
    terrestrial, from harmful interference from ATC, we adopted a number
    of technical rules for ATC. These rules vary for the three MSS
    bands, and apply power limits for ATC base stations and MSS
    handsets, and require separation distances from airports or
    navigable waterways for ATC base stations.[^21] The MSS/ATC operator
    is also required to resolve any harmful interference to other
    services caused by its ATC base stations or handsets.[^22]

12. *[Sua Sponte Order]{.underline}*. On July 3, 2003, we released an
    *Order on Reconsideration (Sua Sponte Order)*, in which we
    reconsidered and clarified certain aspects of the *MSS Flexibility
    R&O* on our own motion.[^23] Because we had decided in the *MSS
    Flexibility R&O* that we would not grant ATC authority to any MSS
    operator until that MSS operator satisfied all of several
    preconditions for operating ATC, collectively known as gating
    criteria,[^24] we clarified that we will allow preoperational ATC
    construction and testing in accordance with the technical rules, at
    any time after physical construction of the MSS satellites has
    begun. Such construction and testing is to be at the MSS operator's
    risk, and does not presuppose authorization to operate an ATC.[^25]
    Further, we clarified that we would consider ATC applications before
    each of the gating criteria was met, provided the MSS operator
    applying for ATC authorization makes a substantial showing that its
    MSS and ATC operations will meet the gating criteria.[^26] Also in
    our *Sua Sponte Order*, we specified that no ATC authority will be
    granted until we are satisfied that each of the gating criteria has
    been met or will be met at the same time the application is
    granted.[^27] As a result of this decision, we also eliminated the
    rule requiring MSS operators to have a conditioned ATC authorization
    before engaging in preoperational constructing and testing, instead
    allowing such construction and testing at any time after an MSS
    operator has begun construction of satellites and has informed us of
    its intent to construct and test ATC facilities.[^28] Finally, we
    required all initial applications for ATC authority to be placed on
    public notice, in order to allow interested parties to comment on
    the applications. Such public notice will contain a statement that
    any party objecting to an application for ATC authority bears the
    burden of demonstrating that the applicant's proposed ATC is not
    consistent with the rules.[^29]

13. Seven parties filed petitions for reconsideration and/or
    clarification of the *MSS Flexibility R&O*.[^30] One party filed a
    petition for reconsideration of the *Sua Sponte Order*.[^31] Eight
    parties filed oppositions to or comments on the petitions for
    reconsideration or clarification,[^32] and six parties filed replies
    to oppositions or comments.[^33]

14. On July 8, 2003, AT&T Wireless Services, Inc. and Cellco
    Partnership, doing business as Verizon Wireless, petitioned the U.S.
    Circuit Court of Appeals for the District of Columbia Circuit for
    review of the *MSS Flexibility R&O*.[^34] The petitioners in that
    action challenge our decision to allow ATC in MSS spectrum as
    unreasoned decisionmaking and not in accordance with the law.[^35]

15. [MSV's ATC License]{.underline}. On November 18, 2003, MSV applied
    for authority to provide ATC in the United States in conjunction
    with its provision of MSS in the United States via satellites
    licensed by the Commission and Industry Canada.[^36] MSV requested
    waiver of many of our technical rules for L-Band ATC operation,
    arguing that the flexibility afforded by such waivers would permit
    it to operate more efficiently without impairing its own MSS
    operations or causing harmful interference to other MSS
    systems.[^37] MSV contended that grant of its ATC applications and
    the associated waiver requests would enable it, for the first time,
    to offer a ubiquitous, high-quality, integrated mobile service
    throughout the United States.[^38] On February 9, 2004, the
    International Bureau issued a public notice that these ATC
    applications were accepted for filing, specifying a schedule for
    filing comments, petitions to deny, and reply pleadings.[^39]

16. Inmarsat filed comments in opposition to MSV's ATC applications,
    raising concerns about the potential interference that the proposed
    ATC operation could cause to Inmarsat's current and next-generation
    MSS networks.[^40] The National Telecommunications and Information
    Administration (NTIA) also submitted written comments on the ATC
    applications. For protection of Aeronautical Mobile Satellite
    (Route) Service (AMS(R)S) and Global Maritime Distress and Safety
    System (GMDSS) operations, NTIA recommended that MSV's waiver
    requests pertaining to power limits for ATC base stations be granted
    only in part, subject to restrictions on operation in the vicinity
    of navigable waterways and limits on out-of-channel emissions. NTIA
    also recommended use of a certain measurement technique in
    compliance testing to ensure that out-of-band emissions from MSV's
    ATC mobile terminals will not interfere with reception of satellite
    radionavigation signals in the 1559-1610 MHz band.[^41] Other
    interested parties filed comments that expressed no opinion on the
    merits of MSV's waiver requests but urged us to grant the ATC
    application or promptly take action on it.[^42]

17. On August 2, 2004, MSV filed a request for expedited action on its
    application.[^43] MSV acknowledged in this filing that some of the
    issues raised by its waiver requests were closely intertwined with
    issues raised in its petition for reconsideration of the *MSS
    Flexibility R&O*. Nevertheless, MSV asked the Bureau to grant "core
    elements" of its ATC application in advance of our disposition of
    the petitions for reconsideration in the ATC rulemaking proceeding.

18. On November 8, 2004, the International Bureau granted MSV's
    applications for ATC authority in part, granting some of its waiver
    requests, denying others, and deferring resolution of some issues
    that were also raised in the petitions for reconsideration in this
    proceeding*.*[^44]

# discussion

## Gating Criteria

19. [Background]{.underline}. In the *MSS Flexibility R&O*, we
    established several prerequisites that MSS operators would be
    required to meet in order to be allowed to offer ATC. These
    prerequisites have been collectively called "gating criteria." To
    ensure that ATC will be ancillary to provision of MSS, we adopted a
    requirement that MSS operators must provide substantial satellite
    service to be eligible for ATC authorization.[^45] We defined
    substantial satellite service as the capability of providing
    continuous satellite service over the entire geographic area of
    satellite coverage required in our rules,[^46] maintenance of spare
    satellites to replace destroyed or degraded satellites
    expeditiously,[^47] and commercial availability of service, meaning
    offering MSS service to the general public for a fee, throughout the
    mandatory geographic coverage area.[^48] We also required the offer
    of MSS and ATC services to be integrated. To demonstrate integrated
    service, MSS/ATC operators could demonstrate that all handsets
    offered were dual-mode (MSS and ATC), or could submit individualized
    substantial showings to demonstrate integrated service.[^49]
    Finally, we required MSS operators to offer ATC only in the
    frequency bands in which they are authorized to provide MSS.[^50] We
    considered and rejected proposals from commenters to require that
    MSS traffic be quantitatively "primary" or "predominant" in MSS/ATC
    systems,[^51] to require that all MSS/ATC calls be routed through a
    satellite;[^52] to require that MSS operators demonstrate a
    technical inability to serve proposed ATC areas by satellite as a
    condition of ATC;[^53] and to impose additional fees for MSS
    operators who wish to provide ATC.[^54] Three petitions filed in the
    instant proceeding request that we reconsider various aspects of the
    gating criteria for ATC and require MSS/ATC operators to dedicate a
    certain amount of capacity exclusively for MSS;[^55] require MSS/ATC
    handsets to always attempt to communicate via the satellite
    first;[^56] clarify that all MSS/ATC handsets must be dual-mode to
    qualify for our "safe harbor" demonstration of integrated MSS/ATC
    service;[^57] forbid ATC-only service subscriptions;[^58] clarify
    that gating criteria must be met for each band in which an MSS
    operator seeks authority to provide ATC;[^59] and clarify that our
    geographic coverage requirement applies only to the extent
    technically feasible.[^60]

### Substantial Satellite Service

20. We deny petitioners' requests to require that a specific percentage
    of an MSS/ATC operator's capacity be reserved exclusively for
    MSS.[^61] We note that we refuted similar arguments regarding
    "primary" or "predominant" satellite service in the *MSS Flexibility
    R&O*[^62] for reasons that we fully reaffirm, and that the
    petitions, oppositions, and replies do little more than simply
    rehash those arguments. We deny these requests because, as we stated
    in the *MSS Flexibility R&O*, we are unable to impose a quantitative
    criterion of MSS service in an MSS/ATC system that would not be
    arbitrary. First, the percentage of spectrum used by MSS and ATC
    will vary drastically in the different areas served by the
    satellites. In a rural area with a low population density and
    considerable terrain folding and other challenges to terrestrial
    system propagation, the MSS/ATC system will use most or all of its
    channels and time for MSS. In a densely-populated urban area with
    tall buildings whose structures prevent MSS service inside and block
    the communications path between handsets in the immediate vicinity
    and MSS satellites, the MSS/ATC system could use the large majority
    of its channels and time for ATC. Thus, we deny CTIA's proposal of
    allowing only 20% of the available channels in any spot beam to be
    used for ATC[^63] because it would result in a grossly inefficient
    use of spectrum in many areas.

21. Similarly, we cannot predict what eventualities may cause traffic
    loading to increase or decrease, or how such loads will be
    distributed between ATC transmitters and MSS handsets. As Globalstar
    points out, considerations for allocating spectrum between MSS and
    ATC vary by time and geography.[^64] Further, in a natural or other
    disaster, the higher efficiency of ATC may be crucial to providing
    telecommunications for the public. It is equally possible that such
    a disaster could damage or destroy the capacity of ATC, and possibly
    of terrestrial mobile communications as well. In such a
    circumstance, MSS would become critical even in an area where MSS is
    usually not the most efficient method of communication. Neither
    CTIA's recommendation of allowing a maximum of 20% of MSS capacity
    for ATC nor Cingular's recommendation that we require MSS/ATC
    operators to reserve at least 50% of their capacity for MSS service
    at all times[^65] explains why these numbers are reasonable.

22. Such imponderables as MSS usage and ATC usage in different parts of
    the country under different circumstances render any attempt to
    establish a single, fixed percentage of capacity that must be
    reserved for MSS highly problematic and uncertain. Further, such a
    requirement would substantially negate the value of dynamic
    frequency assignment in improving spectrum efficiency. We agree with
    commenters that assert that MSS/ATC operators will have an incentive
    to continue providing substantial satellite service.[^66] Should we
    specify a fixed percentage of an MSS/ATC operator's spectrum that
    must be reserved for MSS operations, the MSS/ATC operator would
    probably have to permanently assign a certain number of channels in
    each spot beam for MSS traffic only, reducing the options available
    for dynamic frequency assignment. Imposition of a rigid percentage
    of MSS/ATC capacity that must be reserved for MSS would not be
    conducive to either business success or providing the best possible
    service to the public.

23. In addition, we find no basis in the record to conclude that MSS/ATC
    operators would surrender their single most valuable system feature,
    complete ubiquity of coverage, in order to compete with the already
    well developed and heavily financed terrestrial mobile systems.
    Rather, two factors strongly favor substantial satellite service in
    an MSS/ATC system. First, MSS/ATC customers will likely be drawn to
    MSS because of its ubiquity. Specifically, MSS, with or without ATC,
    will appeal most strongly to customers who expect to need
    communications in areas currently unserved by terrestrial mobile
    providers, such as rural areas, underpopulated areas, areas with
    significant hindrances to terrestrial radio propagation, and marine
    areas where terrestrial mobile base stations cannot be installed.
    Thus, customer demand will do much to ensure continuing substantial
    satellite service. Second, our rules require MSS/ATC licensees to
    retain capacity for providing MSS throughout their mandatory
    geographic coverage areas.[^67] Nevertheless, we reiterate and
    reaffirm that the terrestrial service is to be offered on an
    *ancillary* basis by satellite licensees. The gating criteria we
    have adopted are intended to ensure compliance with this ancillary
    requirement. To the extent we receive specific complaints about a
    particular system, we will examine the totality of the services
    being offered to ensure that the terrestrial service is in fact
    ancillary to the satellite service. For these reasons, we again
    decline to establish a specific, additional requirement for
    substantial satellite service.

### Integrated Service

24. We deny Cingular's request that we adopt a requirement that any
    MSS/ATC handset first attempt to place a call through the MSS
    component of the service and only call through the ATC if the
    satellite signal is unavailable or unreliable.[^68] The *MSS
    Flexibility R&O* required that MSS/ATC providers offer a single,
    integrated service. We disagree with Cingular and CTIA that such a
    requirement is the only way to ensure integrated service.[^69]

25. We addressed this issue in the *MSS Flexibility R&O*, stating that
    "requiring satellite-routing would defeat most of the benefits of
    authorizing ATC in the first instance."[^70] None of the parties
    seeking reconsideration presented new facts or arguments to change
    our analysis. We agree with MSV and Globalstar that adding a
    requirement that the MSS/ATC handset attempt to acquire the
    satellite first would impair operational efficiency.[^71]

26. We also agree with Boeing that all modern wireless communications
    networks involve continuous instructions to handsets regarding the
    location and type of base stations assigned, and that the
    efficiencies of dynamic frequency assignment would be hampered by a
    firm rule that handsets must try to acquire the MSS communications
    path first.[^72] Any "satellite first-look" requirement would
    involve the use of extra time and power in the handset, and would
    complicate control signals from the MSS satellite and ATC base
    stations to the handsets. Such a requirement would increase the cost
    of providing service, hinder call completion, and ultimately reduce
    system efficiency. Further, any such requirement could ultimately
    force a weaker satellite signal on consumers in areas where a
    stronger ATC signal was available, but a satellite signal was also
    available. We find no significant public interest benefit to offset
    these serious disadvantages.

27. We can see no reason why an MSS/ATC operator would install ATC base
    stations in any area where customer demand can be adequately
    accommodated by the operator's satellite system. On the contrary,
    the MSS/ATC operators' interest in avoiding unnecessary capital
    expenditures would deter them from installing ATC base stations in
    non-urban areas where traffic is light enough to be handled by MSS
    alone. Thus, we believe that MSS/ATC operators will only install ATC
    base stations in areas where the satellite signal is substantially
    affected by blocking or where consumers demand more communications
    paths than the satellite can provide. These are the precise
    situations for which we authorized ATC. Therefore, we disagree with
    CTIA's contention that MSS/ATC handsets will always attempt to
    acquire ATC first, and that as a result ATC will not be ancillary to
    MSS.[^73] On the contrary, we presume that an MSS/ATC handset will
    be in constant communication with the MSS/ATC network, and will
    choose the best communication path available to it, whether MSS or
    ATC. We therefore decline to add an artificial and spectrally
    inefficient requirement to the MSS/ATC rules.

### Dual-Mode Devices

28. [Background]{.underline}. In the *MSS Flexibility R&O*, we stated
    that a "safe harbor" method by which MSS operators could demonstrate
    MSS/ATC system integration without specific, detailed showings of
    system integration is to provide ATC services via dual-mode handsets
    that can also be used for communication via the provider's satellite
    system.[^74] Cingular requests that we clarify that the integrated
    service "safe harbor" can be satisfied only by a dual-mode handset
    that "actually incorporates the capability to communicate with both
    the satellite and the ATC base stations."[^75] MSV responds to this
    request, asking that we clarify that "component kits" consisting of
    a handset with all of the hardware and software necessary for access
    to both ATC and MSS, and a separate antenna booster needed for
    communicating with MSV's current generation satellite meets the
    definition of a dual-mode handset.[^76]

29. [Discussion]{.underline}. We clarify that a "dual-mode handset," for
    the purposes of 47 C.F.R. § 25.149(b)(4)(i) shall consist of a
    handset which, when sold to the customer, contains all the hardware
    and software necessary to acquire and communicate via both the
    operator's MSS system's signal and its ATC system's signal, either
    within the casing or permanently affixed to the casing in such a
    fashion that no part of the equipment would ordinarily be detached
    from the casing unless defective and in need of replacement.
    Specifically, we will not ordinarily consider "component kits" as
    described by MSV to be dual-mode handsets. Any handset that requires
    a supplementary attachment to acquire and use both the MSS and the
    ATC signal will not be considered dual-mode.

30. We also extend this clarification to apply to personal digital
    assistants (PDAs), laptop computers, and other digital devices
    communicating via MSS/ATC. In the *MSS Flexibility R&O*, we exempted
    such devices from the dual-mode "safe harbor" demonstration of
    integrated service for MSS/ATC.[^77] Cingular requests that we
    eliminate this exception or clarify its scope, claiming that
    otherwise potentially significant terrestrial services could be
    provided on a stand-alone basis.[^78]

31. We agree with Cingular that "there is no clear definition of what
    constitutes a PDA at a time when handsets have begun to incorporate
    various computer and Internet access functions, along with voice
    capability."[^79] By exempting such devices from our safe harbor, we
    would generate considerable confusion over precisely what devices
    would qualify for safe harbor by being dual-mode. We also agree with
    other parties that argue that digital devices should not necessarily
    be required to be dual-mode.[^80] These parties, however, ignore the
    fact that dual-mode devices are not required under our gating
    criteria, they are merely required to qualify for the safe harbor
    demonstration of integrated service. Any MSS/ATC operator that
    chooses not to make its handsets or digital devices dual-mode can
    satisfy our integrated service gating criterion by presenting
    sufficient evidence demonstrating that they will offer integrated
    service. For example, ICO expresses its intention to offer digital
    voice and data through satellite air-interface repeaters that
    provide service links to satellites, claiming that such repeaters
    could be attached to a number of devices, making it unnecessary to
    make each individual device satellite-capable.[^81]

32. We agree with Cingular and CTIA that there is no clear distinction
    between PDAs and handsets that is relevant to our ATC rules. For
    this reason, we grant Cingular's request to the extent of finding
    that devices providing ATC, including PDAs and other digital
    devices, must be dual-mode, as defined above, for purposes of the
    "safe harbor" method of demonstrating integrated MSS/ATC
    service.[^82] MSS/ATC operators choosing to use handsets or digital
    devices that are not dual-mode will be required to demonstrate that
    they offer integrated service.[^83]

### ATC-Only Subscriptions

33. We clarify that "integrated service" as used in this proceeding and
    required by 47 C.F.R. § 25.149(b)(4) forbids MSS/ATC operators from
    offering ATC-only subscriptions.[^84] We reiterate our intention not
    to allow ATC to become a stand-alone system. The purpose of ATC is
    to enhance MSS coverage, enabling MSS operators to extend service
    into areas that they were previously unable to serve, such as the
    interiors of buildings and high-traffic density urban areas. We will
    not permit MSS/ATC operators to offer ATC-only subscriptions,
    because ATC systems would then be terrestrial mobile systems
    separate from their MSS systems. We therefore clarify that
    "integrated service" as used in this proceeding and required by 47
    C.F.R. § 25.147(b)(4) forbids MSS/ATC operators from offering
    ATC-only subscriptions.[^85]

### Band-Specific Gating Criteria

34. We clarify that any MSS operator wishing to incorporate an ATC
    component into its system must meet the gating criteria for each
    spectrum band in which it wishes to provide ATC. We agree with
    Cingular and CTIA that we did not make this requirement explicit in
    the rules.[^86] Accordingly, we require MSS operators seeking ATC
    authorization to meet the gating criteria in each band in which an
    MSS operator intends to provide ATC. The rules specify that in each
    of the 2 GHz MSS band, the Big LEO band, and the L-band, MSS/ATC is
    limited to the frequencies authorized for MSS communication.[^87]
    Further, as we have made clear, an ATC is ancillary to the MSS
    system it supports. These requirements have the effect of obligating
    MSS operators to fulfill the gating criteria in each band in which
    the seek to provide ATC. Therefore we clarify that our gating
    criteria must be met in each band in which an MSS operator seeks
    authorization to provide ATC.

### Geographic Coverage

35. We clarify our geographic coverage requirement by adding the phrase
    "if technically feasible" to the gating criteria for the 2 GHz MSS
    band in the MSS/ATC service rules. We agree with Boeing that the
    difference between our coverage requirements as an MSS/ATC gating
    criterion and our general requirement for GSO 2 GHz MSS operators is
    critical because it is not technically possible to provide MSS to
    all of Alaska using a GSO satellite system.[^88]

36. The meaning of the phrase "consistent with the coverage requirements
    for 2 GHz MSS GSO operators" in the MSS/ATC gating criteria is that
    the MSS/ATC "coverage requirement" gating criterion is satisfied by
    a showing that the coverage requirements of the 2 GHz MSS service
    rules, including the exemption for technical infeasibility, are met.
    We therefore agree with Boeing that the technical feasibility clause
    should be in the rules.

## Uplink Interference in the L-Band

37. [Background]{.underline}. In the *MSS Flexibility R&O*, we
    extensively discussed and analyzed proposed technical rules for
    MSS/ATC, with the goal of adopting a flexible set of technical rules
    that would prevent harmful interference while permitting the rapid
    and economically efficient development of ATC. We addressed issues
    of self-interference, *i.e.*, the interference an ATC could cause to
    the MSS system of which it is a part; inter-system interference,
    *i.e.*, the interference an ATC could cause to other MSS systems;
    and out-of-band interference that ATC could cause to services other
    than MSS.

38. In the L-band,[^89] unlike other MSS bands, each MSS operator is
    licensed for the entire band, but must coordinate with other users
    of the L-band to determine which channels each MSS operator may use.
    Under an international agreement known as the Mexico City Memorandum
    of Understanding (Mexico City MoU), five L-band MSS operators are to
    coordinate their use of the L-band, meeting annually to re-negotiate
    their coordination agreement. These negotiations have not occurred
    since 1999, and the 1999 coordination agreement remains in
    effect.[^90] Because the channels used by the L-band MSS operators
    are interleaved,[^91] inter-system interference protection is a
    significant challenge.

39. In the *MSS Flexibility R&O*, we based our analysis of interference
    potential on MSV's proposed ATC. MSV's proposal provided specific
    system features for us and parties to evaluate.[^92]

40. We began our uplink interference analysis in the *MSS Flexibility
    R&O* with the level of interference that MSV claimed was appropriate
    for its next generation satellite to accept from its own ATC, or
    self-interference.[^93] The analysis assumed that MSV's
    self-interference would increase no more than 0.25 dB with an ATC
    active and that, by using very general assumptions, the expected
    interference into an Inmarsat satellite receiver would be about the
    same, or less than, the interference received by MSV.[^94] We
    concluded that "the total noise increase in the Inmarsat-4 receiver
    would be on the order of 1.4%. The noise increase for the Inmarsat-3
    satellite receiver would be on the order of 0.1%.[^95] Neither of
    these noise increases should hinder the Inmarsat operations."[^96]
    Accordingly, we adopted technical rules for L-band ATC that mandated
    adherence to the assumed design parameters,[^97] which were largely
    consistent with MSV's ATC design proposal at that time.[^98] Based
    on this data, we calculated MSV's satellite gain, receiver noise
    temperature, degradation of signals, and a number of other factors
    in the system design, and established a set of rules to ensure that
    ATC would not cause harmful interference to MSV's own satellite
    operations or to Inmarsat. These rules included a limitation on ATC
    base stations of 1725 nation-wide on any one channel,[^99] a
    requirement for power reduction from MSS/ATC handsets when they
    operate outside buildings (structural attenuation),[^100] limits on
    base station power and antenna gain,[^101] and out-of-channel
    emissions limits.[^102] Several parties petitioned for changes to
    these rules.

### Interference Standard

41. Upon review of the arguments in petitions and oppositions, we change
    the basis of the rules for uplink interference in the L-band. As a
    result, an MSS/ATC operator in the L-band may increase the noise
    level of another co-primary MSS system by no more than 6% ΔT/T from
    the MSS/ATC operator's entire system, both MSS and ATC, without a
    specific coordination agreement being accepted by all affected
    parties. Three separate factors inform this decision. First, through
    the course of this proceeding, MSV has changed its ATC design
    substantially, and may do so again. In using MSV's
    originally-proposed ATC specifications as a basis for its technical
    analysis of interference, we intended to ground our analysis, and
    therefore its rules, in real-world considerations. It was not our
    intention to design our rules for MSV's proposed system, but rather
    to establish rules for all potential ATC systems in the L-band.
    Second, we agree with MSV's contention that we should not impose
    restrictions designed to limit self-interference. A more appropriate
    basis for interference limits is the interference an MSS/ATC system
    may cause to another MSS system in the L-band. Third, we note that
    Inmarsat provides both AMS(R)S and GMDSS communications.[^103] In
    addition to our statutory mandate to prevent harmful
    interference,[^104] we are determined to ensure that these safety
    and emergency communications suffer no degradation due to harmful
    interference.

42. We conclude that interference to other MSS systems is a better basis
    for our technical rules than self-interference. The International
    Telecommunication Union (ITU) has standards in place to protect GSO
    MSS systems from interference, in addition to well-defined methods
    to calculate the level of interference.[^105] These standards permit
    an MSS provider to increase the noise level of another co-primary
    MSS provider's satellite receivers up to a level of 6% ΔT/T without
    coordinating.[^106] An MSS provider in the L-band wishing to operate
    at a higher level of interference to co-primary MSS systems must
    coordinate and receive consent to do so from other MSS
    providers.[^107] These standards have been effective in preventing
    harmful interference between L-band MSS providers.[^108] Inmarsat
    urges us to reject the claims of an MSS licensee that it can
    withstand a self-interference level higher than 0.25 dB, which
    equates to 6% ΔT/T. Inmarsat argues that if an MSS/ATC operator were
    to exceed this level, the MSS/ATC operator would be required to
    either limit its ATC service, contrary to its business interests, or
    degrade its satellite performance.[^109] We agree with MSV that
    interference to other MSS systems, rather than self-interference, is
    the appropriate concern upon which to base our interference rules.
    We also agree with Inmarsat that we should not allow an ATC, by
    itself, to interfere with another MSS system to a level of 6% ΔT/T.

43. We adopt a requirement that the permitted level of interference from
    one L-band MSS system into the satellite receivers of another L-band
    MSS system shall be no greater than 6% ΔT/T without a coordination
    agreement among the affected parties. Because ATC is an ancillary
    component of an MSS system, we consider interference caused by ATC
    operation as part of the 6% ΔT/T level of interference allowed from
    an MSS system without coordination, rather than allowing an MSS
    system with ATC a greater capacity to cause interference without
    coordination than an MSS system without ATC. Therefore, on any
    L-band channel an MSS/ATC system is entitled to use under the
    current L-band coordination agreement, and where another MSS system
    has a satellite within the visible arc from the MSS/ATC operator's
    area of coverage, the MSS/ATC operator may cause no more than a 6%
    ΔT/T increase in the system noise of the other co-primary operator's
    satellite system, unless the parties to the coordination agreement
    have coordinated to allow a higher level of interference, in which
    case the coordinated level serves as the baseline for permissible
    aggregate interference from all of the MSS/ATC provider's
    operations.

44. The current coordination agreement under which Inmarsat and MSV
    share L-band spectrum was finalized in 1999. Ideally, the L-band MSS
    operators should renegotiate their coordination agreement every
    year. Indeed, changes to the existing coordination agreement could
    help avoid some of the potential interference issues that could
    arise from deployment of MSS/ATC.[^110] At the same time, however,
    we acknowledge that it could take a great deal of time and effort to
    conduct further coordination negotiations. For this reason, in the
    case of any L-band frequency that is currently the subject of a
    coordination agreement and is shared between an MSS operator and an
    MSS/ATC operator, we will permit an MSS/ATC to cause a small
    increase in interference to another MSS operator's system above the
    coordinated interference level when the coordinated interference
    level is already greater than 6% ΔT/T. This measure accounts for the
    reality that MSS is currently operating in the L-band, and that it
    may be necessary and appropriate to allow a slightly higher level of
    interference than currently coordinated levels allow in order to
    permit ATC to begin operations. When L-band MSS operators enter into
    a new coordination agreement, this additional interference allowance
    will no longer apply, and MSS/ATC operators will be required to
    operate its ATC within the limits coordinated by the parties.

45. Permitting interference from MSS/ATC operations in the United States
    to co-primary MSS systems on shared channels at the 1% ΔT/T level
    will allow MSS/ATC operators to implement ATC without undue risk of
    harmful interference, until such time as a new coordination
    agreement can be reached that considers interference from both MSS
    and ATC. This interim allowance of an additional 1% ΔT/T is higher
    than the 0.7% ΔT/T limit upon which we based our interference
    analysis in the *MSS Flexibility R&O*. We conclude that this value
    is reasonable because, as MSV points out, our conclusion in the *MSS
    Flexibility R&O* was that an increase of 0.7% ΔT/T in interference
    from the United States, and another 0.7% ΔT/T from outside the
    United States, would not hinder Inmarsat's MSS operations.[^111] Our
    analysis therefore accepted aggregate system-wide interference at a
    level of 1.4% ΔT/T.[^112] MSV points out that it plans to deploy 80%
    of its ATC in the United States, and only 20% in Canada.[^113] This
    is reasonable because of the much higher population of the United
    States. Thus, 80% of the total of 1.4% ΔT/T, or 1.12% ΔT/T, can be
    expected to emanate from MSV's ATC in the United States. We round
    this figure down to 1% ΔT/T to ensure that interference from ATC
    does not rise to a level that would interfere with MSS operations,
    while still allowing ATC to be rapidly deployed.

46. In summary, we adopt three interference limits for MSS/ATC
    operations in the L-band, varying with the channels in question.

    ● In any channel that is coordinated for the exclusive use of an
    MSS/ATC operator, and where there is no other MSS operator's
    satellite within the visible arc as seen from the ATC geographic
    coverage area, the MSS/ATC operator is limited only by in-band and
    out-of-band emissions limits and the need to control
    self-interference sufficiently to maintain substantial satellite
    service.

    ● In any channel which is coordinated for shared use between the
    MSS/ATC operator and another MSS operator, the MSS/ATC operator is
    permitted to cause interference to the other MSS operator up to a
    level of 6% ΔT/T from its entire MSS/ATC network.

    ● In any channel which is coordinated for shared use between the
    MSS/ATC operator and another MSS operator, and is coordinated to
    permit a level of interference from the MSS/ATC operator higher than
    6% ΔT/T, the MSS/ATC operator's ATC may raise the interference to
    the other MSS operator an additional 1% ΔT/T without further
    coordination.[^114]

47. This approach has several benefits. First, it allows MSS/ATC
    operators freedom to design their systems to meet a limit on uplink
    interference in the manner that they think best promotes the
    efficiency and utility of their service offering. They are in a
    better position to make decisions regarding the interference
    trade-offs between MSS and ATC that will produce the best service.
    Second, under this approach, L-band MSS/ATC providers will have a
    strong incentive to innovate, in order to get the maximum possible
    coverage and efficiency within their interference "budget" by using
    interference reduction techniques. We cannot predict what techniques
    may be invented or where such techniques will prove most effective,
    in the MSS component or the ATC of an MSS/ATC system. Finally, our
    revised approach supports and encourages private coordination
    agreements among the interested parties in the band. Private
    negotiations between expert parties with their business interests at
    heart are more likely to produce the most efficient interference
    levels than regulations based on largely hypothetical cases. We
    therefore will permit interference levels above 6% ΔT/T where the
    parties have reached coordination agreements. We note that the
    Mexico City MoU contemplated such coordination sessions on an annual
    basis.

### Other Issues

48. Because of the change in our interference standard, and the
    elimination of certain technical rules, we dismiss as moot several
    requests for changes to those technical rules. MSV petitioned for an
    increase in the number of base stations each MSS/ATC operator is
    permitted on two separate grounds.[^115] Our overall limit on the
    interference an MSS/ATC operator may cause to other MSS systems
    obviates the need for a numerical limit on ATC base stations. MSV
    also requests that we amend the rules to allow the use of half-rate
    vocoders and channels, as opposed to quarter-rate vocoders and
    channels.[^116] This rule is also rendered unnecessary by our new
    interference standard.

49. Inmarsat requests that we require MSS/ATC applicants to provide a
    full description of their ATC architecture.[^117] Inmarsat also
    requests that the restriction we applied limiting the number of
    simultaneously-transmitting ATC handsets to 90,000 be inserted into
    the rules, noting that the restriction is in the text of the *MSS
    Flexibility R&O*, but not in the rules.[^118] We are also removing
    these requirements from our rules, replacing them with an overall
    limitation on the amount of interference an MSS/ATC system can cause
    to another MSS system in the L-band. For this reason, we dismiss
    Inmarsat's requests as moot.

50. Because we are allowing MSS/ATC providers to apportion their
    interference budget between MSS and ATC according to their own
    designs and business plans, and to change those apportionments
    without further approval as long as the sum of the ATC and MSS
    interference remains below the levels required, we have little basis
    for limiting the number of base stations or mobile handsets, so we
    will eliminate these limits. The intent of these rules was to limit
    the total interference caused by ATC. These specific numerical
    limits were based on an analysis of MSV's proposed ATC. Many of the
    values proposed by MSV have changed. More importantly, we believe
    that it is important to allow MSS/ATC licensees flexibility to
    design their ATC in accordance with technical and market demands. We
    have decided that a better way to achieve this goal is to limit the
    total interference that an ATC may cause, rather than dictating
    system design features.

51. While we are eliminating many of our more detailed technical rules
    on uplink interference, we expect MSS/ATC providers will use, and be
    able to document compliance with, realistic technical parameters
    when calculating the increase in uplink interference (*i.e.*, ΔT/T)
    to other MSS systems. For example, if a party relies on an 18 dB
    structural attenuation link budget during coordination, it must be
    able to demonstrate how its system will ensure compliance with that
    parameter. Similar demonstrations would be needed for other key
    parameters, such as the vocoder/power relationship, number of mobile
    users, etc. We retain the authority to request the values used for
    these factors and the demonstrations used to justify them.[^119]

## Downlink Interference in the L-Band

52. [Background]{.underline}. Where uplink interference protection is
    concerned with interference into the satellite receiver of an MSS
    system, downlink interference protection ensures that receivers on
    or near the surface of the Earth are able to receive signals without
    harmful interference. As we stated in the *MSS Flexibility R&O*, the
    potential for interference may exist in four ways: (1) overload of
    the land-based mobile earth terminal (MET) receiver[^120] from
    in-band emissions when in close proximity to ATC base stations; (2)
    out-of-band interference to the land-based MET from ATC base
    stations; (3) aggregate interference to the airborne MET from
    multiple ATC base stations; and (4) overload of the airborne MET
    from an ATC base station.[^121] To protect METs from overload, we
    established a power limit on ATC base stations of 19.1 dBW per
    carrier with no more than three carriers per sector,[^122] and 14.1
    dBW EIRP per carrier toward the horizon.[^123] To protect land-based
    METs from out-of-band interference, we adopted an out-of-band
    emission limit of -57.9 dBW/megahertz for ATC base stations.[^124]
    To protect airborne METs from out-of-band interference, we
    established overhead gain limits for ATC base stations dependent on
    the angle of maximum gain from the base station antenna.[^125] We
    determined that airborne receiver overload was not expected to
    occur, and so established no technical limits on this basis.

### ATC Base Station Power Levels

53. We grant a request from MSV to reconsider the power limits on base
    stations, and generally allow an 8dB increase in base station
    power.[^126] With an added 15 dB of margin, MSV claims that we can
    increase the permitted EIRP of ATC base stations from 23.9 dBW to
    38.9 dBW, with an aggregate peak EIRP in any direction from all base
    station sectors of no more than 53.9 dBW, and the EIRP toward the
    horizon from 18.9 dBW to 33.9 dBW per sector.[^127] Inmarsat
    disputes MSV's contention, asserting that it has provided reports
    from two separate manufacturers of Inmarsat METs, demonstrating that
    a receiver overload threshold of at most -75 dBm is necessary to
    protect Inmarsat from out-of-band interference from ATC base
    stations[^128]

54. We are presented with two opposing propositions from MSV and
    Inmarsat. MSV states that the appropriate MET receiver overload
    threshold upon which to base our downlink interference calculations
    is -45 dBm. Inmarsat claims that the appropriate threshold is -75
    dBm. Both parties provide reports and measurements to support their
    assertions. Faced with the need to decide among these two
    alternatives or the -60 dBm threshold we used in our downlink
    interference calculations in the *MSS Flexibility R&O*, the staff
    conducted tests of the overload thresholds of representative METs,
    supplied by MSV and Inmarsat. The report of these tests is attached
    as Appendix A.

55. The testing indicates that most of the Inmarsat receivers tested
    outperform the overload limit of -60 dBm used in our analysis in the
    *MSS Flexibility R&*O. From the test data, we conclude that Inmarsat
    receivers can tolerate another 8 dB increase in power when the
    interfering signal is more than approximately two megahertz removed
    from the desired signal.[^129] This tolerance is 8 dB better than
    the assumed tolerance of -60 dBm upon which we based our ATC base
    station power limits. We also note that in an *ex parte* filing, MSV
    requested a waiver of our rules to allow an additional 8 dB of base
    station power, both generally and near airports and waterways,[^130]
    in place of the 15 dB increase MSV requested in its petition. For
    this reason, we grant MSV's request to change the power limits on
    base stations, as follows. Generally in the L-band, the EIRP of ATC
    base stations shall be limited to 31.9 dBW, and the EIRP toward the
    horizon shall be limited to 26.9 dBW per base station sector. This
    represents an 8 dB increase over the current power limits that apply
    when three carriers are used within an antenna sector.

56. The testing our staff conducted also indicates that in cases where
    the interfering signal is less than approximately two megahertz
    removed from the desired signal, our assumption of Inmarsat MET
    receiver tolerance of -60 dBm was correct. Generally, we do not
    regulate the susceptibility of receivers to interference from
    transmissions on nearby frequencies. Rather, we rely on the
    marketplace -- manufacturers and service providers -- to decide how
    much susceptibility to interference will be acceptable to consumers.
    In addition, we generally do not limit one party's ability to use
    the spectrum based on another party's choice regarding receiver
    susceptibility. In this situation, it is clear from our testing and
    our knowledge of receiver design that Inmarsat can deploy receivers
    in the future that can be less susceptible to interference from
    transmissions on nearby frequencies. We recognize, however, that it
    is important to provide some amount of protection to current
    receivers used by Inmarsat in the L-band because some of Inmarsat's
    operations are safety-related, though these safety-related
    transmissions are likely to be limited in quantity. Furthermore, it
    is not clear that there will be great usage of Inmarsat MSS signals
    near urban areas where MSS ATC L-band transmitters will be deployed.
    This is because: 1) MSS signals are often obstructed by buildings
    and the environment in general, and 2) there are other more reliable
    and cheaper modes of communication that are more likely to be used
    (e.g., VHF air traffic control, VHF marine, CMRS communications, and
    landline). As such, we conclude that it is inefficient and
    unnecessary for us to limit MSS ATC deployment at higher power
    levels on all frequencies in the L-band.

57. The 1544-1545 MHz sub-band, within the MSS L-band allocation, is
    limited to distress and safety communications.[^131] Thus, it is
    reasonable to provide greater protection against interference in
    this particular sub-band. In reviewing our receiver test results, as
    discussed earlier, we found that current Inmarsat receivers can
    generally tolerate increased ATC power levels and power flux density
    (PFD) levels provided they are more than approximately two megahertz
    away in frequency from the desired signal. After reviewing the
    current frequency sharing agreement governing use of the L-band in
    North America by MSS licensees, we conclude that distress and safety
    communications should have adequate protection from critical
    interference due to increased ATC transmitted power and increased
    PFD limits if we limit such increases to spectrum outside the
    1541.5-1547.5 MHz band (that is, 2.5 megahertz away from the band
    edges of the 1544-1545 MHz sub-band). We recognize that some
    consumers may wish to transmit non-safety traffic through an MSS
    system even when located in urban areas near MSS/ATC transmitters,
    and that those transmissions would have to be on frequencies outside
    the 1544-1545 MHz sub-band. Nevertheless, it appears that Inmarsat
    and other MSS operators should have adequate ability to support such
    operations, either by providing those users with receivers that are
    less susceptible to interference or by directing non-safety traffic
    to frequencies that are adequately removed from higher-power ATC
    transmissions in a particular area. In this regard, we note that
    under the current frequency sharing agreement, MSV's operations are
    limited to significantly fewer frequencies than Inmarsat's
    operations. Furthermore, parties to coordination negotiations that
    will be needed in the L-band for next-generation satellite
    deployment and large-scale deployment of ATC can accommodate ATC
    operations in their negotiations. In order to protect the safety
    functions of Inmarsat operations, our rules, based on a receiver
    tolerance of interference at -60 dBm, will remain in place for the
    portion of the L-band at 1541.5-1547.5 MHz.[^132]

58. Our testing also revealed another potential source of interference
    to Inmarsat METs: third-order intermodulation interference.
    Third-order intermodulation interference occurs when two
    frequencies, both removed from the frequency carrying the desired
    signal, interact to cause interference to the frequency carrying the
    desired signal.[^133] Our testing indicates that Inmarsat's
    receivers may be vulnerable to intermodulation interference,
    depending upon the combined power of the two unwanted signals. Our
    testing showed that the four terminals tested will not experience
    third-order intermodulation difficulties if the combined power at
    the receiver from the two unwanted signals is less than -70
    dBm.[^134]

59. To resolve third-order intermodulation problems, we require any
    MSS/ATC operator to notify the affected MSS operator in any case
    where a single base station or multiple base stations will transmit
    on frequencies that can produce third-order intermodulation products
    that overlap a frequency assigned to the affected MSS operator in
    the 1525-1559 MHz band, where such transmissions will result in a
    signal level of -70 dBm or higher for the combined signals at the
    output of the affected MSS operator's terminal's receiving
    antenna.[^135] The MSS/ATC operator and the affected MSS operator
    must work together to resolve the interference problem. We note that
    careful selection of base station frequencies by the MSS/ATC
    operator can minimize the number of situations in which this problem
    will arise, as could aggregating the channels used by the different
    MSS operators through the coordination process.

60. The rules specify the maximum permitted EIRP per carrier and limit
    to three the number of carriers per ATC base station sector.[^136]
    MSV requests that we eliminate the restriction on the number of
    carriers per sector.[^137] Because it is the total EIRP produced
    within an ATC base station sector that can cause receiver overload,
    the number of carriers used to generate that EIRP level is
    inconsequential. An ATC base station could be implemented with a few
    high power carriers or many low power carriers. As long as the EIRP
    resulting from the different implementations was the same, the
    interference potential would be the same. Therefore, we grant MSV\'s
    request and remove the limitations on the number of carriers per ATC
    base station sector from the rules.[^138]

### Protection of Airports and Waterways

61. [Background]{.underline}. In the special case of ATC base stations
    near airport runways or waterways, we grant an 8 dB increase in PFD
    limits, with certain restrictions. Our testing of Inmarsat METs
    found that they were able to tolerate 8 dB more interference than we
    assumed in the *MSS Flexibility R&*O, which justifies an 8 dB
    increase in PFD. In the *MSS Flexibility R&*O, we determined that
    these areas required additional protection for METs, due to the fact
    that they tend to be open, with few buildings, where signal
    propagation from ATC base stations will be closer to \"free-space\"
    conditions than it would be in urban areas with heavy concentrations
    of buildings and other obstructions.[^139] We decided that
    protection of METs from interference in these situations required a
    physical separation for ATC base stations of a minimum of 470 meters
    from any runway or aircraft stand area.[^140] To further protect
    aircraft METs from interference, we also required ATC base stations
    to produce a PFD of no more than -73.0 dBW/m² per 200 kilohertz
    channel at the edge of airports.[^141] In the case of waterways, we
    required that ATC base stations be separated by 1.5 kilometers (0.9
    miles) if there is a clear view of the water, and that ATC base
    stations could produce a PFD of no more than -64.6 dBW/m² per 200
    kilohertz channel at the edge of navigable waterways.[^142]

62. Asserting that these protection requirements are unnecessarily
    stringent, MSV requests that we allow an additional 15 dB of PFD at
    the edges of airports and navigable waterways, based on its
    measurements of Inmarsat MET receiver front-end one-dB compression
    points that purportedly demonstrates that the proper overload
    threshold is -45 dBm, rather than the -60 dBm we used in our
    calculations.[^143] Further, MSV contends that our approach of
    requiring both separation distances and PFD limits in the case of
    airports and waterways deprives ATC providers of flexibility and is
    unnecessary to protect METs from interference.[^144]

63. [Discussion]{.underline}. Because of the results of our testing, we
    deny Inmarsat's request that we recalculate the PFDs and separation
    distances relevant to airports and waterways based on an overload
    threshold for Inmarsat METs of -75 dBm, rather than the -60 dBm or
    -50 dBm that we used in calculating these limits. The analysis of
    PFDs at edges of airports and waterways is contained in Appendix C2
    of the *Flexibility R&O*. That analysis assumed that Inmarsat
    maritime METs could tolerate an unwanted signal level of -60 dBm
    while Inmarsat airborne METs could tolerate an unwanted signal
    levels of -50 dBm. Because our tests indicated that Inmarsat MET
    receivers are capable of tolerating an interference level of -52
    dBm, a level 8 dB higher than the -60 dBm we assumed in setting PFD
    limits near waterways, we will permit an increase of 8 dB in the PFD
    permitted at the edges of waterways.

64. With respect to airports, we use the results of our tests and base
    PFDs on an interference level of -52 dBm. Inmarsat indicates that
    theoretical calculations predict that receiver overload should occur
    at levels around -54 dBm for its "Aero H" receivers and -60 dBm for
    its higher data-rate "S64" receivers.[^145] We believe, however,
    that these calculations represent a worst-case situation that is
    several dB worse than would be expected in real-world receivers.
    While we did not test an airborne MET receiver, we have no reason to
    believe that airborne receivers, which must meet stringent
    government testing and approval standards, would perform worse with
    respect to receiver overload than the other MET receivers that we
    did test. As with our decision to increase the limits on ATC base
    station power generally, the PFD limits that we adopted in the *MSS
    Flexibility R&O* will remain in force for the sub-band at
    1541.5-1547.5 MHz, except that the PFD limits for airports will be
    reduced by 2 dB to reflect the results of our testing. We
    acknowledge Inmarsat's concern that METs aboard aircraft are part of
    a safety service, as well as the statement of Aeronautical Radio,
    Inc. and the Air Transport Association of America (ARINC/ATA) that
    AMS(R)S communications use the Inmarsat space segment, and that
    these communications are time-critical, safety communications that
    require protection under ITU regulations.[^146] However, continuance
    of the more stringent PFD limits in the 1541.5-1547.5 MHz sub-band
    adequately assures the protection of safety and emergency
    communications in the 1544-1545 MHz sub-band. Accordingly, we change
    the PFD limit for ATC base stations at the edges of airports to
    -56.8 dBW/m^2^/200 kilohertz, summed over all carriers in a sector
    for the full 1525-1559 MHz band, [^147] and for ATC base stations at
    the edges of waterways to -56.6 dBW/m^2^/200 kHz, summed over all
    carriers in a sector, for carriers outside the sub-band at
    1541.5-1547.5 MHz. [^148] For carriers within the 1541.5-1547.5 MHz
    sub-band, our original PFD limits for ATC base stations at the edges
    of waterways of -64.6 dBW/m^2^/200 kHz, summed over all carriers in
    a sector, will remain in effect.

65. We also agree with MSV that the dual requirements of PFD limits and
    physical separations of ATC base stations from airports and
    waterways is unnecessary. The separation distance we established
    provides a critical additional protection for safety services,
    according to Inmarsat.[^149] While we recognize this argument, the
    determinative factor in preventing interference to METs is PFD, not
    separation. Therefore, we will eliminate the distance requirements
    in the rules, and require only that ATC base stations meet the PFD
    limits in the rules. Compliance may be demonstrated by either actual
    measurement of PFD at the edge of the airport or waterway, or by
    calculations using free-space loss.[^150] The separation distances
    remain a good general indicator of necessary distances for design
    purposes. We also note ARINC/ATA's observation that there is no need
    for ATC base stations within 470 meters of an airport, because
    airports are generally free of obstructions and MSS satellites
    should be in view at all times. This factor, however, is more
    appropriate as a system design consideration. Our PFD requirement
    remains the critical factor in preventing harmful interference.

### Overhead Gain Suppression

66. We grant MSV's request that we increase the overhead gain limits by
    10 dB in elevation angles from 55° to 145° and by 8 dB in elevation
    angles from 30° to 55°. We agree with MSV's claim that ATC base
    stations can operate with 10 dB more gain in elevation angles from
    55° to 145° and 8 dB more gain in elevation angles from 30° to 55°
    without causing an increase in interference greater than 0.3 dB
    based upon the aggregate interference model used in the *MSS
    Flexibility R&O* Technical Appendix.[^151]

67. We find that MSV is correct in its assertion that the increases in
    overhead gain limits it requests will cause only a minimal increase
    in interference to co-primary MSS operators. We note that Inmarsat
    states that the overhead gain limits in the *MSS Flexibility R&O*
    were based on MSV's own statement that it would use a "specially
    designed antenna" that would perform to the specifications in its
    application for ATC authority, and that Inmarsat previously
    commented that MSV was unlikely to achieve these
    specifications.[^152] We find this argument unpersuasive in light of
    the fact that an increase in interference of 0.3 dB is negligible.
    In measuring interference, a difference of 0.3 dB is difficult to
    measure, and in any event is highly unlikely to be a significant
    rise in interference. We find that there is no serious threat of
    harmful interference in relaxing the overhead gain suppression
    limits as requested by MSV, and therefore grant the request.

### Protection of the Radionavigation Satellite Service

68. [Background]{.underline}. In the *MSS Flexibility R&O*, we
    considered the need to protect reception of Radionavigation
    Satellite Service (RNSS) signals in the1559-1610 MHz band from
    out-of-band interference from ATC transmitters.[^153] We decided
    that ATC mobile terminals and base stations should operate in
    compliance with the same limits on emissions in the 1559-1610 MHz
    band that we had previously prescribed for MSS METs in the *Global
    Mobile Personal Communications by Satellite (GMPCS)*
    proceeding.[^154] MSS terminals transmitting on assigned frequencies
    in the 2 GHz MSS band must limit the EIRP density of out-of-band
    emissions in the 1559-1610 MHz frequency range to -70 dBW/megahertz
    or less, averaged over two milliseconds of active transmission; and
    must limit the EIRP of discrete emissions of less than 700 hertz
    bandwidth in the 1559-1610 MHz band to -80 dBW, also averaged over
    two milliseconds.[^155] Similar out-of-band emission limits apply to
    operation of Big LEO MSS terminals and MSS terminals transmitting on
    assigned frequencies in the 1626.5-1660.5 MHz band.[^156] We
    accordingly adopted rule provisions that likewise require ATC
    handsets and base stations to meet an EIRP density limit of -70
    dBW/megahertz and a narrowband EIRP limit of -80 dBW on out-of-band
    emissions in the 1559-1610 MHz RNSS band.[^157]

69. Prior to our adoption of the *MSS Flexibility R&O*, NTIA stressed
    that the out-of-band emission limits adopted in the *GMPCS*
    proceeding were devised to protect aircraft reception of RNSS
    signals and contended that stricter limits should be imposed on ATC
    transmitters in order to protect ground-based RNSS receivers as
    well.[^158] We noted in this regard that MSV had reached an
    agreement with the GPS Industry Council, in which it promised to
    limit the EIRP density from its proposed ATC base stations to -100
    dBW/megahertz in the 1559-1605 MHz band, and limit the EIRP density
    of emissions in that band from ATC handsets to -90
    dBW/megahertz.[^159] NTIA provided a technical analysis proposing
    out-of-band emission levels that were consistent with those agreed
    to by MSV and the GPS Industry Council.[^160] We did not, however,
    adopt NTIA's proposed out-of-band emission levels for L-band ATC
    base stations and mobile terminals because we disagreed with certain
    assumptions made in its analysis.[^161] Although we recognize that
    NTIA disagreed with our assessment of its technical analysis, we
    declined to adopt stricter RNSS-band emission limits for ATC
    transmitters than we had previously adopted for MSS terminals in the
    *GMPCS* proceeding, however, because we did not find a sufficient
    basis in the record to support adoption of such stricter
    limits.[^162] We stated that we planned to consider possible changes
    in our protection requirements for RNSS in a future rulemaking
    proceeding.[^163] The GPS Industry Council filed a Petition for
    Reconsideration urging the Commission to amend the ATC rules to
    require all L-band ATC transmitters to operate within the stricter
    out-of-band emissions limits that MSV has agreed to meet.[^164]

70. [Discussion]{.underline}. We do not act on the GPS Industry
    Council's petition at this time. While we agree with the GPS
    Industry Council, NTIA, and other government agencies that it is
    essential to ensure that GPS does not suffer harmful
    interference,[^165] it is also important to ensure that new
    technologies are not unnecessarily constrained. In this regard, we
    recognize that the President's new national policy for space-based
    positioning, navigation, and timing (PNT) directs the Secretary of
    Commerce to protect the radio frequency spectrum used by GPS and its
    augmentations through appropriate domestic and international
    spectrum management regulatory practices.[^166] The PNT policy also
    directs the Secretary of Commerce, in cooperation with the Chairman
    of the FCC, to take the appropriate and legally permissible actions
    required to mitigate interference to GPS. Furthermore, the
    President's PNT policy calls for the establishment of an
    inter-agency Executive Committee, on which the Chairman of the FCC
    will be invited to participate as a liaison, and a National
    Space-Based PNT Coordination Office. It is our intention to
    establish discussions with other agencies, through the PNT Executive
    Committee and Coordination Office as appropriate, to better
    understand what protection levels for GPS are warranted. The results
    of those discussions may lead to future rulemaking proposals in
    order to ensure that all FCC services provide adequate protection to
    GPS, and produce a more complete record upon which to establish
    final GPS protection limits for MSS ATC licensees.

71. In the interim, the only MSS/ATC licensee, MSV, has agreed to comply
    with the tighter limits requested by the GPS Industry Council, and
    we have made compliance with these limits a condition of its
    license. If MSV requests a change to this condition, we will
    initiate a notice and comment period, and coordinate any change with
    NTIA and other government agencies. If additional ATC applications
    are filed, we will coordinate any ATC authority grant with NTIA,
    pursuant to the general notification process, to assure adequate
    protection of the GPS.

72. On our own motion, we amend the RNSS-band emission limits for ATC
    handsets and base stations in sections 25.252-25.254 to eliminate
    several minor, unintended discrepancies between those limits and
    corresponding emission limits in sections 25.216, in keeping with
    our previously stated intention to limit ATC emissions in the
    1559-1610 MHz band to the same extent as emissions from MSS
    terminals.[^167] We also amend section 25.216(i) pertaining to
    carrier-off-state emissions to delete language that is inconsistent
    with our intention that the limit should restrict average EIRP
    density.[^168] Because this amendment is merely clarifying, rather
    than substantive, prior public notice and comment is unnecessary.

### Protection of Search-and-Rescue Satellite Service (SARSAT)

73. We deny a request from MSV to change the language defining
    coordination zones around SARSAT earth stations. In the *MSS
    Flexibility R&*O, we required ATC providers to "provide the
    Commission with sufficient information to complete coordination of
    any ATC base station placed within 27 km from one of the \[SARSAT
    earth station locations\] and within the radio horizon of the SARSAT
    earth station prior to operation."[^169] MSV claims that this
    language could be confusing, and requests that we amend the rules so
    that this requirement is "for any ATC base station located within 27
    km of a SARSAT and within radio horizon of the SARSAT station
    \[sic\]."[^170] No other party addresses this issue.[^171] We find
    this request to be without substance because MSV's proposed language
    has the same effect as the language currently in the rules.

### Non-Forward Band Operation

74. We grant a request from MSV to clarify a note to section 25.253 that
    modifies the rule in section 25.149(a)(1) requiring operation in the
    forward-band mode.[^172] The note to section 25. 253 states that our
    L-band technical rules are based on GSM/TDMA 800 or GSM 1800 system
    architecture, and that an L-band MSS/ATC operator may implement an
    alternate system architecture upon demonstrating that the alternate
    system architecture would produce no greater potential interference
    than the rules allow. [^173] MSV requests that we clarify that the
    note to sections 25.253 applies to section 25.149(a)(1) so that an
    MSS/ATC applicant may implement a non-forward band system
    architecture upon demonstrating that such a system architecture will
    cause no greater interference than the rules permit.[^174] We agree
    with MSV that L-band MSS operators should be able to implement a
    non-forward band system architecture if they demonstrate that such a
    system architecture will cause no greater interference to other MSS
    systems in the L-band than the rules permit.

## Licensing Issues

### Assignment of Licenses by Competitive Bidding

75. [Background]{.underline}. In the *MSS Flexibility R&O*, we concluded
    that under our decision to permit the grant of ATC authority to
    previously licensed MSS operators through the modification of their
    MSS authorizations, certain conditions for assigning licenses by
    competitive bidding pursuant to section 309(j)(1) of the
    Communications Act would not be met. Specifically, we found that our
    decision precluded the filing of mutually exclusive
    applications,[^175] and that license modifications associated with
    ATC would not be modifications so different in kind or so large in
    scope as to warrant treatment as "initial" licenses subject to
    Section 309(j)(1).[^176] We also concluded that allowing MSS
    operators to incorporate ATC without going through a competitive
    bidding process would not be inequitable to CMRS carriers or
    unjustly enrich MSS operators such that the modification of their
    authorizations should be treated as initial licenses.[^177] We based
    this conclusion on the fact that we placed strict limitations on the
    ATC authority that would be available to MSS operators and the
    significant costs of launching and maintaining satellite
    operations.[^178] We also found that restricting eligibility for ATC
    authority to licensed MSS operators was consistent with our
    obligations under Section 309(j)(3), which include promoting the
    deployment of new technologies and services in rural areas and
    ensuring efficient and intensive use of the spectrum.[^179]

76. Cingular argues that the decision to award terrestrial rights to 2
    GHz MSS licensees without an auction is contrary to Section 309(j)
    of the Communications Act and is wrong as a matter of law and
    policy.[^180] More specifically, according to Cingular, the record
    demonstrates that segmentation of the spectrum would be more
    efficient than integrated MSS-terrestrial operations and therefore
    "an auction is compelled by statute."[^181] In support of this
    assertion, Cingular cites a study by Telcordia Technologies
    (Telcordia), which Cingular states concluded that the spectrum
    efficiencies through dynamic frequency control claimed possible by
    MSS/ATC proponents were unlikely to be realized, that ATC would
    degrade MSS performance, and that any terrestrial use of MSS
    spectrum would probably be accomplished through band segmentation,
    in which case there would be no loss of efficiency if the
    terrestrial and satellite operations were performed by different
    parties.[^182] Cingular also claims that the Commission's finding
    that MSS operators would not be unjustly enriched by its decision to
    make ATC authority available to them was unsupported and does not
    withstand scrutiny.[^183]

77. [Discussion]{.underline}. We deny Cingular's request to assign ATC
    authority by competitive bidding. Contrary to Cingular's contention,
    the Telcordia study does not demonstrate that MSS/ATC frequency
    sharing is infeasible. Specifically, the study fails to consider
    techniques for reducing self-interference that MSV proposes to
    incorporate into its ATC system, and that other ATC providers could
    also employ. The Telcordia study concludes that band sharing between
    MSS and ATC, even with dynamic frequency sharing, will only permit
    the use of very few ATC handsets in very large areas, on the order
    of fewer than 100 handsets in areas larger than the State of
    Texas.[^184] According to Telcordia and Cingular, band sharing is
    not feasible and band segmentation is the only means by which ATC
    can be provided in MSS bands. However, we also have before us
    studies and a plan that concludes that thousands or millions of ATC
    handsets can operate in the United States without causing harmful
    interference to MSS, including a highly developed plan from MSV for
    ATC in the L-band. This plan offers the possibility of MSS/ATC band
    sharing using dynamic frequency assignment. We have chosen to credit
    the analyses and plans showing that MSS/ATC band sharing is
    possible, because MSV's plan for ATC indicates that frequency
    sharing is possible without harmful interference. If Telcordia and
    Cingular are correct, there presumably will be no ATC, for we see
    little business sense in building an ATC to serve fewer than 100
    handsets in an area larger than Texas. If, however, MSS/ATC
    proponents are correct, ATC will help to expand communications
    options to the American public and will use spectrum more
    efficiently and intensively.

78. Because we reject Telcordia's conclusion that the only means by
    which MSS/ATC can be accomplished is band segmentation, we are not
    persuaded that our decision to make ATC authority in the 2 GHz MSS
    band available only to previously licensed MSS operators was in
    error, and we again conclude that it would not be in the public
    interest to grant terrestrial rights in this band to entities other
    than MSS operators. We addressed Cingular's argument in favor of
    band segmentation and authorizing separate entities to provide MSS
    and terrestrial service in the *MSS Flexibility R&O.* There we
    stated that band segmentation would amount to reallocation of a
    portion of the MSS bands, and decided that such reallocation would
    be unreasonable and unwarranted.[^185] Further, as we stated in our
    discussion of substantial satellite service,[^186] MSS and ATC usage
    will vary by area of the country. Allocating some portion of the MSS
    bands for terrestrial use could cause those portions to be underused
    in rural and remote areas. Similarly, allocating some portion of the
    MSS bands exclusively for MSS use would continue the current
    situation, in which MSS is not available in some areas, particularly
    urban areas with significant blockage of the satellite communication
    path.

79. We conclude that band segmentation would not be an "efficient and
    intensive use of the electromagnetic spectrum."[^187] Thus, we are
    not persuaded that we should make ATC authority available by means
    of a licensing process that permits the filing of mutually exclusive
    applications for initial licenses, and we affirm our conclusion in
    the *MSS Flexibility R&O* that our decision to permit MSS operators
    to acquire ATC authority does not establish the requisite conditions
    for assigning terrestrial licenses in the MSS bands through
    competitive bidding.

80. Cingular's argument regarding unjust enrichment also does not lead
    us to conclude that we should adopt a licensing process that would
    make ATC authority available to entities other than MSS operators.
    First, we find Cingular's argument that MSS operators would be
    unjustly enriched to be flawed because it is based on a valuation of
    spectrum that is largely irrelevant to the heavily restricted ATC
    authority we authorized in the *MSS Flexibility R&O*. Second, we do
    not agree that the *Seventh CMRS Competition Report* includes
    "findings" that satellite operators are in direct competition with
    terrestrial wireless operators.[^188] While that report includes
    satellite operators as "other types of operators that are competing
    in the mobile telephone segment,"[^189] the discussion is merely a
    brief description of how satellite telephony works and the services
    and products offered. The text of the report makes clear that prices
    for satellite services, in particular handset prices, are not
    competitive with currently offered CMRS wireless plans; nor does the
    report extend the competitive analysis undertaken for CMRS providers
    (including discussions of churn, subscriber growth, market
    penetration, etc.) to satellite operators, as would be consistent
    with an assertion that these operators compete directly with
    terrestrial providers. Third, our decision to modify MSS operators'
    licenses to include ATC authority is consistent with other decisions
    in which the Commission has extended licensees additional operating
    rights without accepting competing applications that might have been
    mutually exclusive and required an auction.[^190]

81. Finally, Cingular ignores the fact that we must consider and balance
    all of the objectives of Section 309(j)(3) in identifying classes of
    licenses to be auctioned, including "the development and rapid
    deployment of new technologies, products, and services for the
    benefit of the public, including those residing in rural
    areas"[^191] and "efficient and intensive use of the electromagnetic
    spectrum. . ."[^192] We concluded in the *MSS Flexibility R&O* that
    our decision to restrict terrestrial rights in the bands used by MSS
    operations to the provision of ATC by MSS operators only, and our
    concomitant decision not to accept terrestrial applications from
    other parties, is consistent with these goals.[^193] Cingular's
    arguments do not persuade us that the objective of efficient,
    intensive spectrum use would be better served by band segmentation;
    nor has Cingular demonstrated how the other goals of Section
    309(j)(3) such as the rapid deployment of services to rural areas
    would be better achieved by making terrestrial rights in the 2 GHz
    MSS band available to parties other than MSS operators. We therefore
    decline to reverse our decision to make ATC authority available to
    MSS operators through the modification of their MSS authorizations.

### Public Notice of Licensing Actions

82. We indicated in the *MSS Flexibility R&O* that applications for ATC
    authority that meet certain requirements will be treated as
    applications for minor modifications to the MSS license.[^194]
    Inmarsat claims that this is a departure from past Commission
    practice and that a minor modification is one that does not have the
    potential to increase interference.[^195] Inmarsat requests that all
    applications for ATC authority be open to public notice and comment,
    to provide the opportunity for affected parties to evaluate the
    applications and comment on them .[^196] Further, Inmarsat requests
    that we require ATC licensees to notify us when they commence ATC
    operations, and issue a public notice to announce the start of the
    18-month limited deployment period specified in the rules.[^197]
    Inmarsat also requests that we require MSS/ATC operators to keep
    complete records of the locations of ATC base stations and the
    number of MSS/ATC handsets deployed, and to file that information
    with us every six months, to allow affected parties to be apprised
    of the scope of deployment.[^198] Finally, Inmarsat requests that we
    place on public notice "any waiver requests made by an ATC operator
    after deployment of its ATC operations," arguing that any such
    waiver or modification of an ATC system could cause interference
    that was not considered in the *MSS Flexibility R&O.*[^199]

83. In the *Sua Sponte Order*, we stated that "we require that the
    Commission place on notice for public comment any initial
    application for authority to add an ATC component to an eligible
    satellite network."[^200] We therefore dismiss as moot Inmarsat's
    request that we make applications for ATC authority open to public
    notice and comment. We deny Inmarsat's request to issue a public
    notice at the start of the 18-month limited deployment period, and
    the request for specific information to be filed with us every six
    months. We have the authority to require MSS/ATC operators to file
    such information as we think necessary to evaluate the interference
    potential of ATC. We will seek analysis and comment from interested
    parties, and will make available to those parties the evidence
    needed to make their analyses and comments. It is impossible to
    determine at this point precisely what information will be
    necessary, and we therefore decline to require the filing of
    information that may not be necessary.

84. For the same reasons, we decline to adopt a rule requiring all
    waiver requests to be placed on notice for public comment. We agree
    with MSV's position that we should maintain the flexibility to
    decide whether waiver requests should be put on public notice
    individually, because some waiver requests may be innocuous, and
    inviting public comment would merely waste time.[^201] Further,
    providing full notice and comment on minor or innocuous waiver
    requests would run the risk of allowing frivolous objections
    calculated merely to harass and delay ATC deployment. We will be
    able to determine those situations where public comment and the
    input of affected parties is needed. We are not persuaded that any
    useful purpose would be served by eliminating *ad hoc* discretion in
    this regard.

### Conditional Licenses

85. Boeing requests reconsideration of the *Sua Sponte Order*. Boeing
    states that we initially adopted licensing rules for ATC under which
    we would grant MSS operators seeking to offer ATC conditional
    authorizations that prohibited them from offering ATC prior to
    meeting ATC gating criteria and MSS implementation milestones.[^202]
    Boeing argues that the approach taken in the *Sua Sponte Order* will
    not provide greater clarity, but will cause substantial uncertainty
    in the process of incorporating an ATC into an MSS network.[^203]
    According to Boeing, the licensing system adopted in the *MSS
    Flexibility R&O*, on the other hand, allowed MSS operators to
    control the timing of their business plans by scheduling each step
    on the way to providing MSS and ATC to customers.[^204] Boeing
    contends that administrative convenience is the only justification
    we offered for changing the licensing system, and claims that the
    new approach will not be easier to administer, because we will still
    accept applications submitted by MSS licensees that have not met the
    gating criteria, and then will have to review additional submissions
    demonstrating that each gating criterion has been met. To avoid
    inconvenience and uncertainty, as well as time-consuming delays,
    Boeing requests that we return to the licensing regime adopted in
    the *MSS Flexibility R&O*.[^205]

86. We deny Boeing's request. We made it clear in the *Sua Sponte Order*
    that an MSS operator is prohibited from conducting commercial ATC
    operations until the operator has received authorization to do so.
    As we stated in that *Order*, granting ATC authorization
    "conditioned upon" meeting the gating criteria could be interpreted
    as meaning that we authorized the commencement of commercial ATC
    operations prior to satisfaction of all the gating criteria.[^206]
    It is also possible that an MSS/ATC operator, in possession of a
    conditional authority, could begin commercial operations before all
    the gating criteria were met to our satisfaction. In such
    circumstances, customers could be deprived of service for which they
    had contracted if we found that the gating criteria had not been met
    and required the MSS/ATC operator to cease operations pending
    satisfaction of the gating criteria.

87. At the same time, we realize that the optimum time to begin ATC
    operations is as soon as the MSS system meets all the gating
    criteria, and that delays are harmful to the business operations of
    MSS/ATC operators. The licensing regime we adopted in the *Sua
    Sponte Order* recognized this and built in the flexibility to allow
    an MSS/ATC applicant that needs extra time for consideration of
    complex issues to seek a pre-authorization ruling that some gating
    criteria have been met.[^207] We also provided the opportunity for a
    licensee to receive ATC authority upon a showing that our geographic
    and temporal coverage, replacement satellite, and commercial service
    criteria have been met, provided "the MSS ATC applicant makes a
    satisfactory, prospective, substantial showing that its ATC
    operations will meet our integrated service and other gating
    criteria."[^208] This amounts to the conditional authority Boeing
    requested, while at the same time ensuring that we maintain control
    of the authorizing process and that applicants show substantial
    progress toward meeting the gating criteria before receiving a grant
    of ATC authority. Beyond these limited circumstances, we decline to
    grant ATC authority to an applicant that has not yet met the gating
    criteria.

### Demonstrations of Compliance

88. In the alternative, Boeing requests that we adopt an application
    approval process for non-operational MSS systems similar to the
    approach in the *Sua Sponte Order*. Specifically, we stated in the
    *Sua Sponte Order* that "we will grant ATC authority to an operating
    MSS system in actual compliance with our MSS system geographic and
    temporal coverage, replacement satellite, and commercial service
    gating criteria if the MSS ATC applicant makes a satisfactory,
    prospective, substantial showing that its ATC operations will meet
    our integrated service and other gating criteria."[^209] Boeing
    contends that this provision allows operational MSS operators a
    streamlined approval process, while non-operational MSS operators
    will be handicapped by the time needed to construct and launch its
    satellite network, and by the delay of securing authority to provide
    ATC.[^210] Boeing requests that we permit non-operational MSS
    operators able to make certain demonstrations that they will be
    within compliance with the gating criteria within one year.[^211]
    Further, Boeing requests that we clarify how MSS operators can
    demonstrate that they have satisfied the gating criteria[^212]

89. We agree with Boeing's argument that we should grant non-operational
    MSS applicants for ATC authority the opportunity to demonstrate that
    they will be in compliance with the gating criteria in the near
    future. We see no reason why an MSS operator should not be able to
    begin ATC operation at the same time it begins MSS operation. A
    non-operational MSS operator, like an operational MSS operator, is
    free to "without further authority from the Commission and at its
    own risk, engage in pre-operational build-out and conduct equipment
    tests" on an ATC.[^213] It is subject to precisely the same
    conditions as an operational MSS operator, *i.e.*, it may not
    provide ATC service until its MSS system and ATC service meet our
    gating criteria. Therefore, we will grant a non-operational MSS
    operator the same sort of authority that we will grant operational
    MSS operators. Upon a satisfactory, prospective and substantial
    showing that a non-operational MSS licensee will soon meet the
    gating criteria, we will grant the MSS operator ATC authority to
    begin ATC operations upon actually meeting the gating criteria.

90. We decline, however, to grant the clarifications Boeing requests.
    Boeing's proposed demonstrations lack the specificity we intend to
    require. Terms such as "predicted spacecraft antenna gain,"[^214]
    "arrangements for the construction of a replacement
    satellite,"[^215] and "letters from its suppliers of user terminals,
    or letters from customers that have contracted for . . .
    services"[^216] are too vague to be granted the status of conclusive
    demonstrations. We will require detailed showings in any case where
    an MSS/ATC applicant claims that it is near to meeting our gating
    criteria. Although all of the factors Boeing lists will be relevant
    to our review of applications and may be conclusive, we reserve the
    right to require additional detail and certainty. Therefore, we deny
    Boeing's requested clarification.

## Uplink Interference in the Big LEO Band.

### Out-of-Band Emissions

91. Inmarsat states that it raised concerns about potential interference
    to its L-Band MSS system from future deployment of ATC in the Big
    LEO band, and that we did not address this issue in the *MSS
    Flexibility R&O*. Inmarsat requests that we consider its earlier
    arguments and adopt out-of-band emissions limits for ATC in the Big
    LEO band to protect MSS systems in the adjacent L-band.[^217]

92. We find that we adequately addressed the potential for out-of-band
    interference in the Big LEO uplink band in the *MSS Flexibility
    R&O*. Specifically, we adopted out-of-channel emissions limits of
    -44.1 dBW per 30 kilohertz for ATC base stations in the Big LEO
    band,[^218] and -57.1 dBW per 30 kilohertz for handsets in the Big
    LEO band.[^219] We consider these limits sufficient to protect
    Inmarsat's satellites in the superjacent 1626.5-1660.5 MHz band. We
    also note that Inmarsat's only reference to possible interference to
    L-band MSS from Big LEO band ATC was a single paragraph which
    claimed only that Big LEO band ATC could cause harmful interference
    to Inmarsat's MSS in the L-band.[^220] Because we adequately
    addressed the potential for out-of-band interference from ATC in the
    Big LEO band, we deny this request.

### Protection of Broadcast Auxiliary Service

93. SBE requests that we reconsider the decision to allow ATC base
    stations in the Big LEO band. In the *MSS Flexibility* *R&O*, we
    noted that some Broadcast Auxiliary Service (BAS) operations are
    permitted on BAS Channel A10 (2483.5-2500 MHz) on a "grandfathered"
    basis, but stated that the records indicate that there are no BAS
    facilities licensed in this band. SBE points out that there are 87
    licenses currently authorized for BAS Channel A10, according to our
    Universal Licensing System, though ten of these licenses are listed
    as "expired" or "cancelled."[^221] SBE requests that we reconsider
    the decision to allow ATC in the Big LEO band to protect BAS Channel
    A10 operations. In the alternative, SBE requests that we require any
    Big LEO MSS operator that seeks authority to operate ATC to pay the
    reasonable costs of converting BAS equipment to digital operation on
    three narrower channels in what are currently BAS Channels A8 and
    A9.[^222]

94. We will take measures to protect licensees on BAS Channel A10. The
    number of active BAS Channel A10 users is sufficiently small that
    Big LEO MSS licensees desiring ATC authorization will be able to
    coordinate with BAS licensees to avoid causing harmful interference
    to BAS Channel A10. Therefore, we note that BAS licensees using BAS
    Channel A10 are "grandfathered," and are entitled to operate without
    interference from MSS/ATC operations. Big LEO band MSS operators
    seeking to add ATC to their systems will be required to coordinate
    their use of the 2483.5-2500 MHz band with BAS licensees, or may
    negotiate with those licensees for relocation or some other solution
    to potential interference problems. To that extent, we grant SBE's
    request. We will not, however, mandate a relocation scheme for BAS
    Channels A8, A9, and A10, despite Globalstar's willingness to
    consider relocation of BAS licensees under certain, limited
    conditions.[^223]

# conclusion

95. The actions we take in this *Memorandum Opinion and Order and Second
    Order on Reconsideration* will facilitate the development of
    MSS/ATC. By replacing certain uplink interference rules with a
    standard of interference, we allow MSS/ATC operators the freedom to
    design their systems to meet their customers' needs while protecting
    other MSS systems from harmful interference. By revising base
    station power limits in the L-band downlink, we allow MSS/ATC
    operators to build more powerful base stations while ensuring that
    they do not exceed the measured tolerance of MSS METs for
    interfering signals. Finally, by modifying the licensing rules, we
    provide equal opportunity for operational and non-operational MSS
    systems to add ATC without undue delay. These actions will advance
    the Commission's goal of ensuring efficient and intensive use of the
    spectrum, and will bring more options for high-quality
    communications at reasonable cost to all Americans.

# procedural matters

96. *Final Regulatory Flexibility Certification* The Regulatory
    Flexibility Act of 1980, as amended (RFA),[^224] requires that a
    regulatory flexibility analysis be prepared for notice-and comment
    rule making proceedings, unless the agency certifies that "the rule
    will not, if promulgated, have a significant economic impact on a
    substantial number of small entities."[^225] The RFA generally
    defines the term "small entity" as having the same meaning as the
    terms "small business," "small organization," and "small
    governmental jurisdiction."[^226] In addition, the term "small
    business" has the same meaning as the term "small business concern"
    under the Small Business Act.[^227] 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).[^228]

97. As required by the RFA, an Initial Regulatory Flexibility Analysis
    (IRFA) was incorporated in the *Flexibility Notice,* and no parties
    responded to the IRFA. [^229] After a review of the policies and
    rules adopted in the *Flexibility Order*, the Commission determined
    that there would be no significant impact on a substantial number of
    small entities. Thus, a Final Regulatory Flexibility Certification
    was included in the *Flexibility Order.*[^230]

98. In addressing the issues raised by the parties seeking
    reconsideration of the *Flexibility Order,* no parties commented on
    the regulatory flexibility certification. For the reasons described
    below, we certify that the policies and rules adopted in the
    *Memorandum Opinion and Order and Second Order on Reconsideration*
    will not have a significant impact on a substantial number of small
    entities.

99. We are incorporating the Final Regulatory Analysis Certification
    contained in the *Flexibility Order* into this proceeding. In our
    reconsideration of the petitions in this proceeding, we modify our
    rules to permit the addition of ATC to MSS systems. We change
    certain technical standards for ATC in the L-band, in order to
    permit MSS/ATC licenses flexibility in designing and operating their
    ATC while at the same time preventing harmful interference from ATC
    to co-primary MSS licensees in the L-band. In addition, we will
    allow certain increases in ATC base station power. We also modify
    the rules for authorizing MSS operators to add ATC to their
    networks. We expect that these changes will facilitate the
    development of MSS/ATC. We believe that all entities, both large and
    small, will have the flexibility to design their systems to meet
    their customers\' needs. The policies and rules adopted in this
    proceeding are essentially technical changes that will provide equal
    opportunity for operational and non-operational MSS systems to add
    ATC without undue delay.

100. We believe that the policies and rules adopted in this proceeding
     -- which brings additional flexibility to existing MSS licensees
     \-- will not affect a substantial number of small entities. There
     are currently five 2 GHz MSS licensees, two Big LEO MSS licensees
     and three L-band MSS licensees authorized to provide service in the
     United States. Although at least one of the 2 GHz MSS system
     licensees and one of the Big LEO licensees are small businesses,
     small businesses often do not have the financial ability to become
     MSS system operators because of the high implementation costs
     associated with satellite systems and services. We expect that, by
     the time of MSS ATC system implementation, these current small
     businesses will no longer be considered small due to the capital
     requirements for launching and operating a proposed system.

101. Therefore, we certify that the requirements of the Memorandum
     *Opinion and Order and Second Order on Reconsideration* will not
     have a significant economic impact on a substantial number of small
     entities.

102. The Commission will send a copy of the *Memorandum Opinion and
     Order and Second Order on Reconsideration,* including a copy of
     this Final Regulatory Flexibility Certification, in a report to
     Congress pursuant to the Congressional Review Act.[^231]

103. *Final Paperwork Reduction Act Analysis*. This item does not
     contain proposed information collections subject to the Paperwork
     Reduction Act of 1995 (PRA), Public Law No. 104-13. It also,
     therefore, does not contain any new or modified "information
     collection burden for small business concerns with fewer than 25
     employees," pursuant to the Small Business Paperwork Relief Act of
     2002, Public Law No. 107-198, *see* 44 U.S.C. § 3506(c)(4).

# ordering clauses

104. IT IS ORDERED that, pursuant to sections 4(i), 7, 302, 303(c),
     303(e), 303(f) and 303(r) of the Communications Act of 1934, as
     amended, [47 U.S.C. sections
     154(i)](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS154&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
     [157](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS157&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
     [302](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS302&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
     [303(c)](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS303&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
     [303(e)](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS303&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
     [303(f)](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS303&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw)
     and
     [303(r)](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS303&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
     this Memorandum Opinion and Order and Second Order on
     Reconsideration IS ADOPTED and that Part 25 of the Commission's
     Rules IS AMENDED, as specified in Appendix B, effective 30 days
     after publication in the Federal Register.

105. IT IS FURTHER ORDERED that the Petition for Reconsideration filed
     by Cingular Wireless LLC IS GRANTED in part to the extent described
     above and IS DENIED in all other respects.

106. IT IS FURTHER ORDERED that the Petition for Reconsideration filed
     by the Society of Broadcast Engineers, Inc. IS GRANTED in part to
     the extent described above and IS DENIED in all other respects.

107. IT IS FURTHER ORDERED that the Petition for Reconsideration filed
     by Mobile Satellite Ventures Subsidiary LLC IS GRANTED in part to
     the extent described above, IS DISMISSED as moot in part to the
     extent described above, and IS DENIED in all other respects.

108. IT IS FURTHER ORDERED that the Petition for Reconsideration filed
     by Inmarsat Ventures PLC IS GRANTED in part to the extent described
     above, IS DISMISSED as moot in part to the extent described above,
     and IS DENIED in all other respects.

109. IT IS FURTHER ORDERED that the Petition for Reconsideration filed
     by the Cellular Telecommunications & Internet Association IS
     GRANTED in part to the extent described above and IS DENIED in all
     other respects.

110. IT IS FURTHER ORDERED that the Petition for Reconsideration of the
     MSS Flexibility R&O filed by the Boeing Co. IS GRANTED in part to
     the extent described above and IS DENIED in all other respects.

111. IT IS FURTHER ORDERED that the Petition for Reconsideration of the
     Sua Sponte Order filed by the Boeing Co. IS GRANTED in part to the
     extent described above and IS DENIED in all other respects.

112. IT IS FURTHER ORDERED that the Final Regulatory Flexibility
     Certification, as required by section 604 of the Regulatory
     Flexibility Act, IS ADOPTED.

113. IT IS FURTHER ORDERED that the Commission's Consumer Information
     Bureau, Reference Information Center, SHALL SEND a copy of this
     Memorandum Opinion and Order and Second Order on Reconsideration,
     including the Final Regulatory Flexibility Certification, to the
     Chief Counsel for Advocacy of the Small Business Administration.

     FEDERAL COMMUNICATIONS COMMISSION

     Marlene H. Dortch

     Secretary

**APPENDIX A**

**Test Report**

**Inmarsat Terminal Interference Susceptibility Testing**

#  {#section .unnumbered}

# 1. Introduction {#introduction-1 .unnumbered}

1.1. In the *MSS Flexibilty R&O*, we assumed a saturation level of -50
dBm for Inmarsat airborne terminals and -60 dBm for mass-produced
terrestrial receivers, and used these levels to calculate protection
criteria for Inmarsat mobile earth terminal (MET) receivers from signals
from ATC base stations in the 1525-1559 MHz band.[^232] We subsequently
received filings in petitions for reconsideration from MSV and from
Inmarsat regarding signal power levels that would cause harmful
interference to Inmarsat METs receivers by signals from MSV's ATC base
stations. MSV stated, based on tests it had performed, that the signal
power level required to cause harmful interference through the mechanism
of receiver overload[^233] is -45 dBm at the input to the receiver
low-noise amplifier.[^234] In support of its argument, MSV presented
data on the 1 dB compression point[^235] of the front ends[^236] of
several Inmarsat MET receivers.[^237] Inmarsat stated that MSV's 1 dB
compression point technique is not a proper way to determine the harmful
interference threshold of Inmarsat MET receivers.[^238] Inmarsat also
stated that the correct value for the harmful interference threshold in
its MET receivers is -75 dBm.[^239] Furthermore, Inmarsat claimed that
Inmarsat MET receivers could be susceptible to intermodulation product
interference[^240] at signal levels much lower than those required to
produce receiver overload.[^241]

1.2. In order to understand and resolve the 30 dB difference (-45 dBm
versus -75 dBm) between the harmful interference threshold values
proposed by MSV and Inmarsat, we decided to conduct independent tests on
Inmarsat METs. The International Bureau asked Inmarsat to supply METs
and the special test equipment required to simulate the link from the
METs through its satellites to its land earth stations. The Bureau asked
MSV to supply the METs on which it had conducted receiver front-end 1 dB
compression point measurements.

1.3. Inmarsat arranged to have its equipment manufacturers supply four
METs for testing. One of these METs is an Inmarsat Fleet 77 marine
terminal, one is designed for vehicular mounting and is based on a
similar Inmarsat Fleet 55 marine terminal, and two are portable METs.
These METs are all capable of receiving 64 kilobit per second (kbps)
16-state quadrature-amplitude modulation (16QAM), as is used in
Inmarsat\'s Global Area Network (GAN). All have a 64 kbps Integrated
Services Digital Network (ISDN) interface, which were used to conduct
bit-error-rate (BER) tests on the METs.

1.4. Inmarsat's equipment manufacturers did not provide an airborne MET.
Inmarsat held some informal discussions with Bureau staff regarding
visiting an airborne MET manufacturer to conduct tests on an airborne
Inmarsat MET, stating that the specialized test equipment required to
test an airborne MET should not be moved from the manufacturer's
facility. However, these discussions did not progress to an on-site
test, so no airborne METs were tested.

1.5. * *We also held informal discussions with Inmarsat regarding
testing Inmarsat\'s higher data rate B-GAN terminals.  Inmarsat
informed our staff that the B-GAN terminal was in the prototype stage
and that the prototype terminal would not be ready for interference
testing until sometime in October, 2004, several weeks after we had
planned to complete the testing.  In addition, Inmarsat told our staff
that it would be necessary to conduct the tests at the facility of
Inmarsat\'s manufacturing partner, Hughes Network Systems, in San Diego,
CA.  We were of the opinion that testing a prototype terminal in a
facility not under the Commission\'s control could result in
questionable test data.  Inmarsat has recently disclosed that the B-GAN
terminal is still in the prototype stage, i.e., it is not yet a
commercially-available production item like the other terminals we
tested for susceptibility to interference from simulated ATC base
station signals.

1.6. We did not test the METs supplied by MSV due to lack of proper test
equipment and test software for these particular METs.[^242]

# 2. Methodology {#methodology .unnumbered}

2.1. We conducted the tests on the METs supplied by Inmarsat's equipment
manufacturers in accordance with the test plan shown in Annex 1 of this
report. We used specialized test equipment supplied by Inmarsat to
generate the simulated Inmarsat satellite signals and to conduct
bit-error-rate (BER) tests on the METs. Synthesized signal generators
with built-in arbitrary waveform generators generated simulated
interfering signals. We tested the receivers with three different types
of signals: an unmodulated sine wave (CW) signal, a simulation of a
variant of the Global System for Mobile communications (GSM)
forward-link signal proposed by MSV ("MSV's GSM"), and a simulated
cdma2000^®^[^243] signal. The CW signal would not be transmitted by an
ATC base station (except perhaps for testing the base station
transmitter), but it was included for reference purposes. The simulated
interfering signals were combined with the simulated Inmarsat satellite
signals using a two-way radiofrequency (RF) power combiner.

2.2. We used a spectrum analyzer to measure the cable and other losses
from the signal generators to a convenient signal monitoring point in
the test setup, and the cable losses to the point of connection to the
Inmarsat METs receivers. These loss measurements used the signal
generators to generate a CW signal in 250 kHz steps across the 1525-1559
MHz band, and used the spectrum analyzer to record the signal level
every 250 kHz. We recorded the spectrum analyzer measurements on a
floppy disk and imported into a spreadsheet. We then used the spectrum
analyzer to measure the interfering signal levels at the monitoring
point, and recorded the measured values using the spreadsheet. We used
the spreadsheet to calculate the level of the interfering signals at the
input to the Inmarsat MET receivers.

2.3. For all tests, we maintained the simulated Inmarsat signal at 1530
MHz at a C/N~0~ level 2 dB higher than that required to achieve a BER of
approximately 1 x 10^-5^ when the simulated ATC base station signal was
turned off. For the single-carrier harmful interference susceptibility
tests, we varied the frequency of the simulated interfering signal
frequency over the 1525 to 1559 MHz band. For the third-order
intermodulation product harmful interference susceptibility tests, we
used the pairs of frequencies shown in the tables in section 5 of the
test plan. We maintained the two signals generating the third-order
intermodulation products within 1 dB of the same power level at the
input to the Inmarsat MET receiver. We recorded the simulated
interfering signal power levels required to achieve a BER of
approximately 1 x 10^-4^.

# 3. Summary of Results {#summary-of-results .unnumbered}

3.1. In presenting the results of the testing, we will not identify the
four Inmarsat METs staff tested by manufacturer and model number,
because this information is not essential for understanding the test
results. Instead, we will identify the METs as \"Inmarsat Terminal A,
Inmarsat Terminal B, Inmarsat Terminal C, and Inmarsat Terminal D\".
Inmarsat Terminal B is what Inmarsat calls a \"Fleet 77\" MET, and
Inmarsat Terminal D is the land-mobile MET derived from what Inmarsat
calls a \"Fleet 55\" MET. Inmarsat Terminals A and C are portable MET.

3.2. Our staff found that three of the four Inmarsat MET receivers
tested were more resistant to harmful interference from single simulated
ATC base station forward-link signals than MSV's proposed -45 dBm
overload threshold, if the interfering signal was offset in frequency by
at least 5 MHz from the desired Inmarsat signal. These three METs
exhibited harmful interference thresholds above -40 dBm when the
interfering signals were sufficiently offset in frequency from the
desired Inmarsat signal. One MET had a harmful interference threshold of
approximately -52 dBm. Figure 1 shows the power levels of the simulated
ATC base station signals that resulted in harmful interference to the
Inmarsat MET receivers. Note that some datapoints are missing because
the level of the simulated interfering signal required to cause harmful
interference to the Inmarsat MET receiver exceeded the limitations of
the test equipment. The ordinate of each plot is labeled with the level
of the interfering signal that caused a BER of approximately 1x10^-4^
when the simulated Inmarsat satellite signal was maintained at a C/N~0~
level 2 dB higher than that required to produce a BER of 1x10^-5^ when
no interference was present. The abscissa of each plot is labeled with
the frequency of the interfering signal; the simulated Inmarsat
satellite signal was maintained at 1530 MHz.

![](media/image1.png){width="5.6090277777777775in"
height="4.504861111111111in"}

Figure 1: Inmarsat Terminal Single-Carrier Harmful Interference Levels.

3.3. The results show that in general, the simulated cdma2000 waveform
resulted in harmful interference at lower root-mean-square (rms) power
levels than MSV\'s GSM signal or the CW signal. This might be due to the
higher peak-to-average power ratio[^244] of the cdma2000 waveform as
compared to the offset quadrature-phase-shift keyed (OQPSK) waveform
used in MSV\'s GSM and as compared to the CW signal, which is a
constant-envelope signal.[^245]

3.4. Our staff found all four of the Inmarsat MET receivers to be
susceptible to harmful interference from third-order intermodulation
products of pairs of simulated ATC base station signals at much lower
interfering signal levels than the levels required for harmful
interference from a single simulated ATC base station signal. For the
simulated MSV's GSM signals, the levels that caused harmful interference
due to third-order intermodulation products ranged from approximately
-50 dBm for the receiver most resistant to interference from third-order
intermodulation products to approximately -75 dBm for the receiver least
resistant to interference from third-order intermodulation products,
when both of the two signals generating the intermodulation product were
offset from the simulated Inmarsat satellite signal at 1530 MHz by 1 MHz
or more. Note that these levels are the combined power of two signals
contributing to the third-order intermodulation product \-- each signal
is 3 dB lower than the combined power level.

3.5. Figure 2 shows the combined power levels of two interfering signals
contributing to the third-order intermodulation product that resulted in
harmful interference to the Inmarsat MET receivers. The ordinate of
Figure 2 is labeled with the combined power level of the pair of
interfering signals that creates a third-order intermodulation product
at 1530 MHz. The abscissa of Figure 2 is labeled with the frequency of
f2, where the intermodulation product is at 1530 MHz = 2f1-f2.

![](media/image2.png){width="5.626388888888889in"
height="4.499305555555556in"}

Figure 2: Inmarsat Terminal Third-Order Intermodulation Product Harmful
Interference Levels.

3.6. The results show that in general, a pair of CW signals produces
harmful interference due to third-order intermodulation products at a
lower level than a pair of simulated MSV\'s GSM signals. A pair of
simulated MSV\'s GSM signals produces harmful interference due to
third-order intermodulation products at a lower level than a pair of
simulated cdma2000 signals. The difference in level might be due to the
fact that the simulated Inmarsat satellite signal that is being
interfered with has a bandwidth of approximately 40 kHz, while a pair of
CW signals produce an intermodulation product that is (at least
theoretically) 0 Hz wide, a pair of simulated MSV\'s GSM signals produce
an intermodulation product that is approximately 600 kHz wide, and a
pair of cdma2000 signals produce an intermodulation product that is
approximately 3.75 MHz wide. Therefore, all the energy of the
intermodulation product produced by the pair of CW signals falls within
the bandwidth of the simulated Inmarsat satellite signal. But the
intermodulation product produced by a pair of simulated MSV\'s GSM
signals is spread over a bandwidth approximately 15 times (11.8 dBHz) as
wide as the simulated Inmarsat satellite signal, and the intermodulation
product produced by a pair of simulated cdma2000 signals is spread over
a bandwidth approximately 93.75 times (19.7 dBHz) as wide as the
simulated Inmarsat satellite signal.

3.7. One might therefore expect MSV\'s GSM signal to need to be 11.8 dB
stronger and the cdma2000 signal to need to be 19.7 dB stronger than a
CW signal to produce the same harmful interference as the CW signal,
since the third-order intermodulation product is spread over a wider
bandwidth than the simulated Inmarsat satellite signal, but this is not
the case. The difference is on the order of 2 to 3 dB between the CW
signal and MSV\'s GSM signal, and the same amount between MSV\'s signal
and the cdma2000 signal. One reason this might happen is that the higher
peak-to-average ratios of MSV\'s GSM signal compared to the CW signal,
and the cdma2000 signal compared to both MSV\'s GSM signal and the CW
signal, may result in higher levels of interference from cdma2000 and
MSV's GSM signals than that which results from a constant-envelope
signal. The signal peak power levels are significantly higher than their
rms powers for MSV's GSM and cdma2000. The Inmarsat satellite receiver
amplifiers may experience overloading on the signal peaks. Another
possible explanation is that the bandpass filters in the Inmarsat MET
receivers allow some energy to come in from the frequency bands adjacent
to the simulated Inmarsat satellite signal.

3.8. Figure 3 below shows the composite single-carrier harmful
interference levels (top figure) and the composite third-order
intermodulation product harmful interference levels for all four
Inmarsat METs and for MSV's GSM and cdma2000 modulation. Solid lines in
both figures show the harmful interference signal levels for MSV's GSM;
dot-dashed lines show the harmful interference signal levels for
cdma2000.

![](media/image3.png){width="5.9944444444444445in"
height="3.933333333333333in"}

Figure 3: Single-signal and Third-Order Intermodulation Signal Pair
Harmful Interference Levels for MSV's GSM and cdma2000 Modulation for
Four Inmarsat Terminal Receivers

# Results for Each MET {#results-for-each-met .unnumbered}

3.9. The ordinate of each even-numbered figure below is labeled with the
level of the interfering signal that caused a BER of approximately
1x10^-4^ when the simulated Inmarsat satellite signal was maintained at
a C/N~0~ level 2 dB higher than that required to produce a BER of
1x10^-5^ when no interference was present. The abscissa of these figures
is labeled with the frequency of the interfering signal; the simulated
Inmarsat satellite signal was maintained at 1530 MHz.

3.10. The ordinate of the odd-numbered figures below is labeled with the
combined power level of the pair of interfering signals that creates a
third-order intermodulation product at 1530 MHz. The abscissa of these
figures is labeled with the frequency of f2, where the intermodulation
product is at 1530 MHz = 2f1-f2.

3.11. [Inmarsat Terminal A]{.underline}

3.11.1. Inmarsat Terminal A is a portable Inmarsat MET. The
single-carrier harmful interference susceptibility levels for this MET
are shown in Figure 3. The third-order intermodulation product harmful
interference susceptibility levels for this MET are shown in Figure 4.

3.11.2. Referring to Figure 4 below, one can see that the level of the
CW signal that causes harmful interference to the Inmarsat Terminal A
receiver is about -50 dBm at 1526 MHz, falling to about -68 dBm at
1529.5 MHz. It rises from about -66 dBm at 1530.5 MHz to about -52 dBm
at 1533 MHz. The level stays in the range of about -51 to -52 dBm from
1533 MHz to about 1546 MHz, then rises to about -47 dBm at 1552 MHz and
remains at this level until 1559 MHz. The simulated MSV's GSM
interfering signal level closely tracks the CW signal level, except that
it is somewhat lower at small frequency offsets relative to the 1530 MHz
simulated Inmarsat satellite signal. The simulated cdma2000 interfering
signal level is about -58 dBm at 1526 MHz, falling to about -78 dBm at
1529 MHz. It rises from about -72 dBm at 1531 MHz to about -52 dBm at
1536 MHz, and remains at this level until about 1546 MHz. It rises to
about -49 dBm at about 1552 MHz, and remains at this level until 1559
MHz.

![](media/image4.png){width="3.751388888888889in"
height="2.995833333333333in"}

Figure 4: Inmarsat Terminal A Single-Carrier Harmful Interference
Levels.

3.11.3. Referring to Figure 5 below, one can see that the combined power
level of a pair of CW signals that causes harmful interference due to
third-order intermodulation products in the receiver of Inmarsat
Terminal A ranges from a low of about -85 dBm to a high of about -70
dBm. The level of the interfering pair of simulated MSV's GSM signals is
typically about 2 to 3 dB higher than that of the CW signal pair. The
level of the interfering pair of simulated cdma2000 signals is typically
about 2 to 3 dB higher than that of the MSV's GSM signal pair.

![](media/image5.png){width="3.734722222222222in"
height="2.997916666666667in"}

Figure 5: Inmarsat Terminal A Third-Order Intermodulation Product
Harmful Interference Levels.

3.12. [Inmarsat Terminal B]{.underline}

3.12.1. Inmarsat Terminal B is an Inmarsat Fleet 77 marine terminal. The
single-carrier harmful interference susceptibility levels for this MET
are shown in Figure 6. The third-order intermodulation product harmful
interference susceptibility levels for this MET are shown in Figure 7.

3.12.2. Figure 6 is missing many data points because it was not possible
to measure them due to limitations in the test equipment, primarily in
the signal generator, because of the high power level of the interfering
signal required to cause harmful interference to this terminal\'s
receiver. The interfering level of the CW signal was measurable from
1525 to 1529.5 MHz and from 1530.5 MHz through 1535 MHz, and at 1542
MHz. The simulated MSV's GSM interfering signal level was measurable at
1527, 1528, 1529, 1531, 1532, and 1533 MHz, and from 1540 MHz through
1559 MHz. The simulated cdma2000 interfering level was only measurable
at 1528, 1529, 1531, and 1532 MHz. Elsewhere, the signal generator noise
at the levels required to measure the interfering signal level was too
high to permit accurate measurements

3.12.3. In Figure 6 below, one can see that the level of the CW signal
that causes harmful interference to the Inmarsat Terminal B receiver is
about -38 dBm frequency offsets of ± 500 kHz from the simulated Inmarsat
satellite signal at 1530 MHz. This level rises to about -26 dBm at 1525
MHz and 1533 MHz. Beyond 1535 MHz, the only data point that could be
measured (due to equipment limitations) was about -24 dBm at 1542 MHz.
The simulated MSV's GSM interfering level fell from about -36 dBm at
1526 MHz to about -43 dBm at 1529 MHz, and rose from about -42 dBm at
1531 MHz to about -35 dBm at 1533 MHz. From 1540 MHz through 1559 MHz,
except at 1546 MHz, the level required for the simulated MSV's GSM
signal to interfere with the simulated Inmarsat satellite signal was
about -32 to -33 dBm. The dip to -40 dBm at 1546 MHz is unexplained, but
was repeatable. The simulated cdma2000 interfering signal level is about
-49 dBm at 1528 MHz, falling to about -58 dBm at 1529 MHz. It rises from
about -58 dBm at 1531 MHz to about -48 dBm at 1532 MHz.

![](media/image6.png){width="3.7159722222222222in" height="3.0in"}

Figure 6: Inmarsat Terminal B Single-Carrier Harmful Interference
Levels.

3.12.4. In Figure 7 below, one can see that the combined power level of
a pair of CW signals that causes harmful interference due to third-order
intermodulation products in the receiver of Inmarsat Terminal B ranges
from a low of about -73 dBm to a high of about -58 dBm. The level of the
interfering pair of simulated MSV's GSM signals is typically about 2 dB
higher than that of the CW signal pair. The level of the interfering
pair of simulated cdma2000 signals is typically about 2 dB higher than
that of the MSV's GSM signal pair.

![](media/image7.png){width="3.7305555555555556in"
height="3.001388888888889in"}

Figure 7: Inmarsat Terminal B Third-Order Intermodulation Product
Harmful Interference

3.13. [Inmarsat Terminal C]{.underline}

3.13.1. Inmarsat Terminal C is a portable Inmarsat MET. The
single-carrier harmful interference susceptibility levels for this MET
are shown in Figure 8. The third-order intermodulation product harmful
interference susceptibility levels for this terminal are shown in Figure
9. This MET appears to be particularly susceptible to interfering
signals offset by about 21.4 MHz. This might be due to the use of a
superheterodyne receiver with an intermediate frequency (IF) in the
vicinity of 10.7 MHz, and poor image rejection in the receiver.[^246]

3.13.2. In Figure 8 below, one can see that the level of the CW signal
that causes harmful interference to the Inmarsat Terminal C receiver is
about -42 dBm at 1525 MHz. The CW interfering signal level remains in
the range of -42 to -45 dBm until 1529 MHz. Beyond 1531 MHz, the CW
interfering signal level gradually rises to about -35 dBm at 1529 MHz.
There are two dips in the CW interfering signal level, one at 1542 MHz,
and one at 1550 MHz. These dips are unexplained. The simulated MSV's GSM
interfering level tracks the CW interfering signal level to within about
2 dB over most of the 1525-1559 MHz frequency range. The simulated
cdma2000 interfering signal level is about -47 dBm at 1526 MHz, falling
to about -63 dBm at 1529 MHz. It rises from about -62 dBm at 1531 MHz to
about -35 dBm at 1545 MHz, which is the highest level it attains.

![](media/image8.png){width="3.7159722222222222in" height="3.0in"}

Figure 8: Inmarsat Terminal C Single-Carrier Harmful Interference
Levels.

3.13.3. In Figure 9 below, one can see that the combined power level of
a pair of CW signals that causes harmful interference due to third-order
intermodulation products in the receiver of Inmarsat Terminal C ranges
from a low of about -69 dBm to a high of about -65 dBm. The level of the
interfering pair of simulated MSV's GSM signals is typically about 2 to
3 dB higher than that of the CW signal pair. The level of the
interfering pair of simulated cdma2000 signals is typically about 2 to 3
dB higher than that of the MSV's GSM signal pair.

![](media/image9.png){width="3.734722222222222in" height="3.0in"}

Figure 9: Inmarsat Terminal C Third-Order Intermodulation Product
Harmful Interference

3.14. [Inmarsat Terminal D]{.underline}

3.14.1. Inmarsat Terminal D is a land-mobile Inmarsat MET, designed to
be mounted on the roof of a motor vehicle. It is derived from its
manufacturer\'s similar Inmarsat Fleet 55 MET. Terminal D has two
connections between its Duplexer + LNA Block and its antenna,
necessitating a minor modification to the test setup shown in Section
4.1 of the Test Plan. See Figure 12 for the test setup for Terminal D.
The single-carrier harmful interference susceptibility levels for this
MET are shown in Figure 10. The third-order intermodulation product
harmful interference susceptibility levels for this MET are shown in
Figure 11. Note that some of the datapoints for MSV's GSM and most of
the datapoints for cdma2000 are missing due to test equipment
limitations in generating signals strong enough to cause harmful
interference to this MET using these modulation techniques.

3.14.2. Figure 10 below shows that the level of the CW signal that
causes harmful interference to the Inmarsat Terminal C receiver is about
-32 dBm at 1525 MHz. The CW interfering signal level falls to about -42
dBm at 1529 MHz. From about -42 dBm at 1531 MHz, the CW interfering
signal level gradually rises to about -32 dBm at 1534 MHz. The CW
single-signal interfering level remains in the range of -28 to -35 dBm
from 1535 MHz to 1559 MHz, reaching its highest level at 1559 MHz. The
simulated MSV's GSM interfering level tracks the CW interfering signal
fairly closely except for two unexplained dips at 1539 MHz and 1542 MHz.
The simulated cdma2000 interfering signal level was only measurable at
1529 MHz and 1531 MHz because at all other frequencies, the signal
generator was unable to output this signal format at a high enough level
to cause the BER to degrade to 1 x 10^-4^. The level at these two
frequencies was about -59 dBm.

![](media/image10.png){width="3.734722222222222in"
height="3.0006944444444446in"}

Figure 10: Inmarsat Terminal D Single-Carrier Harmful Interference
Levels.

3.14.3. Figure 11 below shows that the combined power level of a pair of
CW signals that causes harmful interference due to third-order
intermodulation products in the receiver of Inmarsat Terminal D ranges
from a low of about -61 dBm to a high of about -53 dBm. The level of the
interfering pair of simulated MSV's GSM signals is typically about 3 dB
higher than that of the CW signal pair. The level of the interfering
pair of simulated cdma2000 signals is typically about 2 dB higher than
that of the MSV's GSM signal pair.

![](media/image11.png){width="3.736111111111111in"
height="3.001388888888889in"}

Figure 11: Inmarsat Terminal D Third-Order Intermodulation Product
Harmful Interference

![](media/image12.wmf){width="5.986111111111111in"
height="3.879861111111111in"}

Figure 12: Test Setup for Inmarsat Terminal D

#  {#section-1 .unnumbered}

# Annex 1 {#annex-1 .unnumbered}

# Test Plan {#test-plan .unnumbered}

**Inmarsat Terminal**

**Interference Susceptibility Testing**

#  {#section-2 .unnumbered}

# 1. Scope {#scope .unnumbered}

The purpose of the Inmarsat MET interference susceptibility testing is
to determine the levels of interference from MSS/ATC Base Stations (BS)
that will result in harmful interference to Inmarsat METs. This document
defines the methods of determining interference susceptibility of
Inmarsat METs submitted to the Federal Communications Commission for
interference susceptibility testing.

# 2. Applicable Documents {#applicable-documents .unnumbered}

-   Protocol and Traffic Tester Reference Manual, Inmarsat, 28 July 2004

-   Physical Layer Tester Hardware Manual, DC-190304 V1.2, Square Peg
    Communications, Inc., 18 August 2003

# 3. Equipment Required {#equipment-required .unnumbered}

## 3.1. Inmarsat-supplied test equipment {#inmarsat-supplied-test-equipment .unnumbered}

### Physical Layer Tester

### Protocol and Traffic Tester

### SYNC and RF interconnect cables

## 3.2. Commercial Test Equipment {#commercial-test-equipment .unnumbered}

### Agilent E4438C Vector Signal Generator

### Agilent E4437B Vector Signal Generator

### Agilent E4440A Spectrum Analyzer

### Mini-Circuits ZAPD-2-N Power Combiner/Divider (3 ea.)

### 0-100 dB Step Attenuator, 0.1 dB steps (2 ea.)

### Tunable L-Band Filter

### Appropriate RF interconnect cables and adapters

### ISDN and LAN interconnect cables

## 3.3. Equipment-Under-Test {#equipment-under-test .unnumbered}

### Inmarsat terminals with required accessories

# 4. Equipment Setup and Inmarsat Receiver Overload Tests {#equipment-setup-and-inmarsat-receiver-overload-tests .unnumbered}

## 4.1. Equipment Setup {#equipment-setup .unnumbered}

Connect the equipment as shown in Figure 1, Equipment Setup Block
Diagram. Connect the 100W, 30 dB attenuator (and diplexer, if
applicable) to the Inmarsat terminal as recommended by the terminal
manufacturer. Connect the tunable filter if/as required.

![](media/image13.wmf){width="5.998611111111111in"
height="3.926388888888889in"}

Figure 1: Equipment Setup Block Diagram

## 4.2. Level Calibration {#level-calibration .unnumbered}

The purpose of this step is to gather data on the signal level losses
through the test setup so that interference levels at the input to the
Inmarsat terminal receiver can be easily calculated.

### 4.2.1. With the step attenuator on the output of the two-way power combiner set to 0 dB, measure and record the power losses from the E4438C vector signal generator and the E4437B vector signal generator through the power dividers/combiners, step attenuator, tunable filter (if used), PLT, and 100W, 30 dB attenuator to the Inmarsat terminal diplexer antenna port over the band 1525 MHz to 1559 MHz. {#with-the-step-attenuator-on-the-output-of-the-two-way-power-combiner-set-to-0-db-measure-and-record-the-power-losses-from-the-e4438c-vector-signal-generator-and-the-e4437b-vector-signal-generator-through-the-power-dividerscombiners-step-attenuator-tunable-filter-if-used-plt-and-100w-30-db-attenuator-to-the-inmarsat-terminal-diplexer-antenna-port-over-the-band-1525-mhz-to-1559-mhz. .unnumbered}

## 4.3. Signal Generator Noise Floor Measurement and Compensation {#signal-generator-noise-floor-measurement-and-compensation .unnumbered}

The E4438C and E4437B vector signal generators have a signal-to-noise
ratio that varies as a function of modulation type (CW, MSV's GSM,
cdma2000) and frequency offset. If the signal generators are required to
generate higher-powered signals, the noise floor of the signal generator
output within the bandwidth of the desired Inmarsat signal generated by
the Inmarsat PLT may be high enough to raise the noise floor at the
Inmarsat receiver input and degrade the C/N~0~ level of the desired
signal.

If this is the case, there are two techniques that can be employed to
mitigate the effects of the signal generator noise:

If the frequency offset between the signal generator's simulated
interfering signal and the desired signal is high enough, the tunable
filter can be employed to reduce the noise level in the bandwidth of the
desired signal. If this technique is used, the level calibration
described in section will need to include the effects of the tunable
filter.

If the frequency offset between the signal generated by the signal
generator and the desired signal is small enough so that the tunable
filter cannot be used, or if the noise introduced by the signal
generator within the bandwidth of the desired signal is relatively low,
the desired signal can be increased in power to maintain a constant
C/N~0~ despite the signal generator noise.

For all tests, monitor the noise floor using the E4440A spectrum
analyzer set as follows: Center Frequency: 1529.9 if the interfering
signal frequency is less than 1530 MHz, or 1530.1 MHz if the interfering
signal frequency is greater than 1530 MHz; Span: 100 kHz; Reference
Level: -70 dBm; Attenuator: 0 dB; Measure: Channel Power; Channel Power
Integration Bandwidth: 40 kHz. Record the power spectral density
measured by the spectrum analyzer with the vector signal generator RF
outputs turned off. Monitor the power spectral density that occurs as
tests are run, and calculate the resulting increase in the Inmarsat
receiver noise floor. As long as the Inmarsat receiver noise floor
increases by 1.0 dB or less, it is permissible to increase the power of
the Inmarsat signal at 1530 MHz so as to maintain a constant C/N~0~
level of the Inmarsat signal. If an increase of more than 1.0 dB is
required, determine whether the tunable filter can be used to reduce the
signal generator noise at the Inmarsat signal frequency. If neither
technique can be used, record this fact and the maximum interfering
signal levels that can be attained.

## 4.4. Baseline minimum desired signal level vs. BER tests {#baseline-minimum-desired-signal-level-vs.-ber-tests .unnumbered}

The purpose of this step is to determine the minimum desired signal
levels required for the terminal to achieve a bit error rate (BER) of
10^-5^ and 10^-4^, given the noise floor of the receiver, measured with
a minimum of 100 errors.

### 4.4.1. Set the PTT/PLT for a transmit frequency of 1530 MHz for the carrier against which BER tests will be run. Set the PTT and PLT up to perform BER tests on the Inmarsat terminal. Turn off the RF outputs of the vector signal generators. Set the Tx step attenuator on the PLT and the step attenuator in the Tx IF loopback signal path for a signal level that will result in a C/N~0~ about 3 dB higher than that specified by Inmarsat as being required to achieve a BER of 1 x 10^-5^. {#set-the-pttplt-for-a-transmit-frequency-of-1530-mhz-for-the-carrier-against-which-ber-tests-will-be-run.-set-the-ptt-and-plt-up-to-perform-ber-tests-on-the-inmarsat-terminal.-turn-off-the-rf-outputs-of-the-vector-signal-generators.-set-the-tx-step-attenuator-on-the-plt-and-the-step-attenuator-in-the-tx-if-loopback-signal-path-for-a-signal-level-that-will-result-in-a-cn0-about-3-db-higher-than-that-specified-by-inmarsat-as-being-required-to-achieve-a-ber-of-1-x-10-5. .unnumbered}

### 4.4.2. Start the BER test. Ensure that the terminal synchronizes to the forward-link signal and that the BER is less than 1 x 10^-5^.  {#start-the-ber-test.-ensure-that-the-terminal-synchronizes-to-the-forward-link-signal-and-that-the-ber-is-less-than-1-x-10-5. .unnumbered}

### 4.4.3. Reduce the PLT forward-link power until the BER is approximately 1 x 10^-5^. Run the test until at least 100 bit errors occur. Fine-tune the forward-link power to achieve the desired BER. Record the step attenuator settings and the measured BER at which this occurs. {#reduce-the-plt-forward-link-power-until-the-ber-is-approximately-1-x-10-5.-run-the-test-until-at-least-100-bit-errors-occur.-fine-tune-the-forward-link-power-to-achieve-the-desired-ber.-record-the-step-attenuator-settings-and-the-measured-ber-at-which-this-occurs. .unnumbered}

### 4.4.4. Reduce the PLT forward-link power until the BER is approximately 1 x 10^-4^. Run the test until at least 100 bit errors occur. Fine-tune the forward-link power to achieve the desired BER. Record the step attenuator settings at which this occurs, the measured BER, and the difference between the settings for a BER of approximately 1 x 10^-5^ and a BER of approximately 1 x 10^-4^.  {#reduce-the-plt-forward-link-power-until-the-ber-is-approximately-1-x-10-4.-run-the-test-until-at-least-100-bit-errors-occur.-fine-tune-the-forward-link-power-to-achieve-the-desired-ber.-record-the-step-attenuator-settings-at-which-this-occurs-the-measured-ber-and-the-difference-between-the-settings-for-a-ber-of-approximately-1-x-10-5-and-a-ber-of-approximately-1-x-10-4. .unnumbered}

### 4.4.5. Increase the forward-link power by 2 dB from the level at which the BER was approximately 1 x 10^-5^. Maintain this setting except as required by section 4.3. {#increase-the-forward-link-power-by-2-db-from-the-level-at-which-the-ber-was-approximately-1-x-10-5.-maintain-this-setting-except-as-required-by-section-4.3. .unnumbered}

## 4.5. Interference tests with a CW signal {#interference-tests-with-a-cw-signal .unnumbered}

The purpose of these tests is to characterize the susceptibility of the
Inmarsat MET receiver to harmful interference from a CW (unmodulated
carrier) signal over a range of interfering signal frequency offsets and
power levels.

### 4.5.1. Set the E4438C vector signal generator up to generate a CW signal. Set the E4438C frequency to 1525 MHz. Set the output power level of the E4438C to its minimum value, and turn on the RF output. Turn off the RF outputs of the E4437B vector signal generator. Set the step attenuator on the output of the two-way power combiner to 0 dB. {#set-the-e4438c-vector-signal-generator-up-to-generate-a-cw-signal.-set-the-e4438c-frequency-to-1525-mhz.-set-the-output-power-level-of-the-e4438c-to-its-minimum-value-and-turn-on-the-rf-output.-turn-off-the-rf-outputs-of-the-e4437b-vector-signal-generator.-set-the-step-attenuator-on-the-output-of-the-two-way-power-combiner-to-0-db. .unnumbered}

### 4.5.2. Increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs. .unnumbered}

### 4.5.3. Reduce the E4438C output power level by at least 3 dB. Change the E4438C frequency by +1.0 MHz. Then increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#reduce-the-e4438c-output-power-level-by-at-least-3-db.-change-the-e4438c-frequency-by-1.0-mhz.-then-increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs. .unnumbered}

### 4.5.4. Repeat the preceding step until the signal generator frequency reaches 1529.0 MHz. {#repeat-the-preceding-step-until-the-signal-generator-frequency-reaches-1529.0-mhz. .unnumbered}

### 4.5.5. Set the E4438C frequency to 1559 MHz. Set the output power level of the E4438C to its minimum value, and turn on the RF output. {#set-the-e4438c-frequency-to-1559-mhz.-set-the-output-power-level-of-the-e4438c-to-its-minimum-value-and-turn-on-the-rf-output. .unnumbered}

### 4.5.6. Increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-1 .unnumbered}

### 4.5.7. Reduce the E4438C output power level by at least 3 dB. Change the E4438C frequency by -1.0 MHz. Then increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#reduce-the-e4438c-output-power-level-by-at-least-3-db.-change-the-e4438c-frequency-by--1.0-mhz.-then-increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs. .unnumbered}

### 4.5.8. Repeat the preceding step until the signal generator frequency reaches 1531 MHz. {#repeat-the-preceding-step-until-the-signal-generator-frequency-reaches-1531-mhz. .unnumbered}

## 4.6. Interference tests with a single-carrier simulated GSM signal {#interference-tests-with-a-single-carrier-simulated-gsm-signal .unnumbered}

The purpose of these tests is to characterize the susceptibility of the
Inmarsat MET receiver to harmful interference from MSV's ATC Base
Stations transmitting a simulated GSM forward-link signal over a range
of interfering signal frequency offsets and power levels.

### 4.6.1. Set the E4438C vector signal generator up for a simulated GSM signal having the same data rate and time slot structure as a standard GSM signal, but using a 135.40 ksps symbol rate, OQPSK modulation, and a Root-Nyquist baseband filter with alpha = 0.3. Set the E4438C frequency to 1526 MHz. Set the output power level of the E4438C to its minimum value, and turn on the RF output. Turn off the RF outputs of the E4437B vector signal generator. Set the step attenuator on the output of the two-way power combiner to 0 dB. {#set-the-e4438c-vector-signal-generator-up-for-a-simulated-gsm-signal-having-the-same-data-rate-and-time-slot-structure-as-a-standard-gsm-signal-but-using-a-135.40-ksps-symbol-rate-oqpsk-modulation-and-a-root-nyquist-baseband-filter-with-alpha-0.3.-set-the-e4438c-frequency-to-1526-mhz.-set-the-output-power-level-of-the-e4438c-to-its-minimum-value-and-turn-on-the-rf-output.-turn-off-the-rf-outputs-of-the-e4437b-vector-signal-generator.-set-the-step-attenuator-on-the-output-of-the-two-way-power-combiner-to-0-db. .unnumbered}

### 4.6.2. Increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-2 .unnumbered}

### 4.6.3. Reduce the E4438C output power level by at least 3 dB. Change the E4438C frequency by +1.0 MHz. Then increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#reduce-the-e4438c-output-power-level-by-at-least-3-db.-change-the-e4438c-frequency-by-1.0-mhz.-then-increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-1 .unnumbered}

### 4.6.4. Repeat the preceding step until the signal generator frequency reaches 1529 MHz. {#repeat-the-preceding-step-until-the-signal-generator-frequency-reaches-1529-mhz. .unnumbered}

### 4.6.5. Set the E4438C frequency to 1558.5 MHz. Set the output power level of the E4438C to its minimum value, and turn on the RF output. {#set-the-e4438c-frequency-to-1558.5-mhz.-set-the-output-power-level-of-the-e4438c-to-its-minimum-value-and-turn-on-the-rf-output. .unnumbered}

### 4.6.6. Increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-3 .unnumbered}

### 4.6.7. Reduce the E4438C output power level by at least 3 dB. Change the E4438C frequency by -1.0 MHz. Then increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#reduce-the-e4438c-output-power-level-by-at-least-3-db.-change-the-e4438c-frequency-by--1.0-mhz.-then-increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-1 .unnumbered}

### 4.6.8. Repeat the preceding step until the signal generator frequency reaches 1531 MHz. {#repeat-the-preceding-step-until-the-signal-generator-frequency-reaches-1531-mhz.-1 .unnumbered}

## 4.7 Interference tests with a simulated single-carrier cdma2000 signal {#interference-tests-with-a-simulated-single-carrier-cdma2000-signal .unnumbered}

The purpose of these tests is to characterize the susceptibility of the
Inmarsat MET receiver to harmful interference from MSV's ATC Base
Stations transmitting a simulated cdma2000 forward-link signal over a
range of interfering signal frequency offsets and power levels.

### 4.7.1. Set the E4438C vector signal generator up for a cdma2000 signal with a 1.25 MHz bandwidth (SR1) and at least nine channels. Set the E4438C frequency to 1526 MHz. Set the output power level of the E4438C to its minimum value, and turn on the RF output. Turn off the RF outputs of the E4437B vector signal generator. Set the step attenuator on the output of the two-way power combiner to 0 dB. {#set-the-e4438c-vector-signal-generator-up-for-a-cdma2000-signal-with-a-1.25-mhz-bandwidth-sr1-and-at-least-nine-channels.-set-the-e4438c-frequency-to-1526-mhz.-set-the-output-power-level-of-the-e4438c-to-its-minimum-value-and-turn-on-the-rf-output.-turn-off-the-rf-outputs-of-the-e4437b-vector-signal-generator.-set-the-step-attenuator-on-the-output-of-the-two-way-power-combiner-to-0-db. .unnumbered}

### 4.7.2. Increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-4 .unnumbered}

### 4.7.3. Reduce the E4438C output power level by at least 3 dB. Change the E4438C frequency by +1.0 MHz. Then increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#reduce-the-e4438c-output-power-level-by-at-least-3-db.-change-the-e4438c-frequency-by-1.0-mhz.-then-increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-2 .unnumbered}

### 4.7.4. Repeat the preceding step until the E4438C frequency reaches 1529 MHz. {#repeat-the-preceding-step-until-the-e4438c-frequency-reaches-1529-mhz. .unnumbered}

### 4.7.5. Set the E4438C frequency to 1558 MHz. Set the output power level of the E4438C to its minimum value, and turn on the RF output. {#set-the-e4438c-frequency-to-1558-mhz.-set-the-output-power-level-of-the-e4438c-to-its-minimum-value-and-turn-on-the-rf-output. .unnumbered}

### 4.7.6. Increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-5 .unnumbered}

### 4.7.7. Reduce the E4438C output power level by at least 3 dB. Change the E4438C frequency by -1.0 MHz. Then increase the output power level of the E4438C until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C frequency and the output power level at which this occurs. {#reduce-the-e4438c-output-power-level-by-at-least-3-db.-change-the-e4438c-frequency-by--1.0-mhz.-then-increase-the-output-power-level-of-the-e4438c-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-frequency-and-the-output-power-level-at-which-this-occurs.-2 .unnumbered}

### 4.7.8. Repeat the preceding step until the E4438C frequency reaches 1531 MHz. {#repeat-the-preceding-step-until-the-e4438c-frequency-reaches-1531-mhz. .unnumbered}

# 5. Third-Order Intermodulation Product Tests {#third-order-intermodulation-product-tests .unnumbered}

## 5.1. Purpose {#purpose .unnumbered}

The purpose of these tests is to determine the susceptibility of the
Inmarsat MET receiver to interference from third-order intermodulation
products from pairs of MSS ATC BS emissions with frequencies that result
in a third-order intermodulation product at the same frequency as the
desired Inmarsat space-to-Earth signal.

## 5.2. Equipment Setup {#equipment-setup-1 .unnumbered}

For these tests, the equipment is set up the same way as is shown in
Figure 1 above. The two signal generators will each be set to provide a
0 dBm signal at the output of the two-way power combiner. Level
calibration data from paragraph can be used. The noise compensation
technique described in paragraph should be used, except that the tunable
filter should not be used.

## 5.3. CW Third-Order Intermodulation Product Tests {#cw-third-order-intermodulation-product-tests .unnumbered}

The purpose of these tests is to characterize the susceptibility of the
Inmarsat MET receiver to harmful interference from a pair of CW
(unmodulated carrier) signals at pairs of frequencies that result in
third-order intermodulation products at the same frequency as the
Inmarsat signal (1530 MHz).

### 5.3.1. Set the E4438C and E4437B vector signal generators up to generate a CW signal. Set the E4438C frequency to 1538 MHz, and the E4437B frequency to 1546 MHz. Turn off the RF output of the other E4437B vector signal generator. Disconnect the output of the two-way power combiner from the step attenuator and connect the spectrum analyzer to the output of the two-way power combiner. Set the power level of the two vector signal generators such that the rms power level at the output of the two-way power combiner is 0 dBm for each signal. Set the step attenuator to provide at least 90 dB of attenuation, and reconnect the equipment as shown in Figure 1. {#set-the-e4438c-and-e4437b-vector-signal-generators-up-to-generate-a-cw-signal.-set-the-e4438c-frequency-to-1538-mhz-and-the-e4437b-frequency-to-1546-mhz.-turn-off-the-rf-output-of-the-other-e4437b-vector-signal-generator.-disconnect-the-output-of-the-two-way-power-combiner-from-the-step-attenuator-and-connect-the-spectrum-analyzer-to-the-output-of-the-two-way-power-combiner.-set-the-power-level-of-the-two-vector-signal-generators-such-that-the-rms-power-level-at-the-output-of-the-two-way-power-combiner-is-0-dbm-for-each-signal.-set-the-step-attenuator-to-provide-at-least-90-db-of-attenuation-and-reconnect-the-equipment-as-shown-in-figure-1. .unnumbered}

### 5.3.2. Set the E4438C frequency to 1525 MHz, and the E4437B frequency to 1527.5 MHz. Reduce the step attenuator setting until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C and E4437B frequencies and the output power level at which this occurs. {#set-the-e4438c-frequency-to-1525-mhz-and-the-e4437b-frequency-to-1527.5-mhz.-reduce-the-step-attenuator-setting-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-and-e4437b-frequencies-and-the-output-power-level-at-which-this-occurs. .unnumbered}

### 5.3.3. Repeat the preceding step for each of the following pairs of frequencies (all in MHz): {#repeat-the-preceding-step-for-each-of-the-following-pairs-of-frequencies-all-in-mhz .unnumbered}

  ----------------------------------- -----------------------------------
  1526 , 1528                         1530.25, 1530.5

  1527, 1528.5                        1530.5, 1531

  1528, 1529                          1531, 1532

  1529, 1529.5                        1532, 1534

  1529.5, 1529.75                     1533, 1536

  1534, 1538                          1540, 1550

  1535, 1540                          1541, 1552

  1536, 1542                          1542, 1554

  1537, 1544                          1543, 1556

  1538, 1546                          1544, 1558

  1539, 1548                          

                                      
  ----------------------------------- -----------------------------------

## 5.4. MSV's GSM Third-Order Intermodulation Product Tests {#msvs-gsm-third-order-intermodulation-product-tests .unnumbered}

The purpose of these tests is to characterize the susceptibility of the
Inmarsat MET receiver to harmful interference from a pair of MSV's GSM
signals at pairs of frequencies that result in third-order
intermodulation products at the same frequency as the Inmarsat signal
(1530 MHz).

### 5.4.1. Set the E4438C and E4437B vector signal generators up to generate a GSM signal with OQPSK modulation, Root-Nyquist baseband filtering with alpha = 0.3, and a symbol rate of 135.44 ksps. Set the E4438C frequency to 1538 MHz, and the E4437B frequency to 1546 MHz. Turn off the RF output of the other E4437B vector signal generator. Disconnect the output of the two-way power combiner from the step attenuator and connect the spectrum analyzer to the output of the two-way power combiner. Set the power level of the two vector signal generators such that the rms power level at the output of the two-way power combiner is 0 dBm for each signal. Set the step attenuator to provide at least 90 dB of attenuation, and reconnect the equipment as shown in Figure 1. {#set-the-e4438c-and-e4437b-vector-signal-generators-up-to-generate-a-gsm-signal-with-oqpsk-modulation-root-nyquist-baseband-filtering-with-alpha-0.3-and-a-symbol-rate-of-135.44-ksps.-set-the-e4438c-frequency-to-1538-mhz-and-the-e4437b-frequency-to-1546-mhz.-turn-off-the-rf-output-of-the-other-e4437b-vector-signal-generator.-disconnect-the-output-of-the-two-way-power-combiner-from-the-step-attenuator-and-connect-the-spectrum-analyzer-to-the-output-of-the-two-way-power-combiner.-set-the-power-level-of-the-two-vector-signal-generators-such-that-the-rms-power-level-at-the-output-of-the-two-way-power-combiner-is-0-dbm-for-each-signal.-set-the-step-attenuator-to-provide-at-least-90-db-of-attenuation-and-reconnect-the-equipment-as-shown-in-figure-1. .unnumbered}

### 5.4.2. Set the E4438C frequency to 1525 MHz, and the E4437B frequency to 1527.5 MHz. Reduce the step attenuator setting until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C and E4437B frequencies and the output power level at which this occurs. Then increase the step attenuator setting by at least 10 dB. {#set-the-e4438c-frequency-to-1525-mhz-and-the-e4437b-frequency-to-1527.5-mhz.-reduce-the-step-attenuator-setting-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-and-e4437b-frequencies-and-the-output-power-level-at-which-this-occurs.-then-increase-the-step-attenuator-setting-by-at-least-10-db. .unnumbered}

### 5.4.3. Repeat the preceding step for each of the following pairs of frequencies (all in MHz): {#repeat-the-preceding-step-for-each-of-the-following-pairs-of-frequencies-all-in-mhz-1 .unnumbered}

  ----------------------------------- -----------------------------------
  1526 , 1528                         1535, 1540

  1527, 1528.5                        1536, 1542

  1528, 1529                          1537, 1544

  1529, 1529.5                        1538, 1546

  1530.5, 1531                        1539, 1548

  1531, 1532                          1541, 1552

  1532, 1534                          1542, 1554

  1533, 1536                          1543, 1556

  1534, 1538                          1544, 1558
  ----------------------------------- -----------------------------------

## 5.5. cdma2000 Third-Order Intermodulation Product Tests {#cdma2000-third-order-intermodulation-product-tests .unnumbered}

The purpose of these tests is to characterize the susceptibility of the
Inmarsat MET receiver to harmful interference from a pair of cdma2000
signals at pairs of frequencies that result in third-order
intermodulation products at the same frequency as the Inmarsat signal
(1530 MHz).

### 5.5.1. Set the E4438C up to generate a single-carrier nine-channel cdma2000 signal, and the E4437B vector signal generator up to generate a single-carrier 32-channel IS-95A signal. Set the E4438C frequency to 1538 MHz, and the E4437B frequency to 1546 MHz. Turn off the RF output of the other E4437B vector signal generator. Disconnect the output of the two-way power combiner from the step attenuator and connect the spectrum analyzer to the output of the two-way power combiner. Set the power level of the two vector signal generators such that the rms power level at the output of the two-way power combiner is 0 dBm for each signal. Set the step attenuator to provide at least 90 dB of attenuation, and reconnect the equipment as shown in Figure 1. {#set-the-e4438c-up-to-generate-a-single-carrier-nine-channel-cdma2000-signal-and-the-e4437b-vector-signal-generator-up-to-generate-a-single-carrier-32-channel-is-95a-signal.-set-the-e4438c-frequency-to-1538-mhz-and-the-e4437b-frequency-to-1546-mhz.-turn-off-the-rf-output-of-the-other-e4437b-vector-signal-generator.-disconnect-the-output-of-the-two-way-power-combiner-from-the-step-attenuator-and-connect-the-spectrum-analyzer-to-the-output-of-the-two-way-power-combiner.-set-the-power-level-of-the-two-vector-signal-generators-such-that-the-rms-power-level-at-the-output-of-the-two-way-power-combiner-is-0-dbm-for-each-signal.-set-the-step-attenuator-to-provide-at-least-90-db-of-attenuation-and-reconnect-the-equipment-as-shown-in-figure-1. .unnumbered}

### 5.5.2. Set the E4438C frequency to 1525 MHz, and the E4437B frequency to 1527.5 MHz. Reduce the step attenuator setting until the Inmarsat terminal BER increases to approximately 1 x 10^-4^. Record the E4438C and E4437B frequencies and the output power level at which this occurs. Then increase the step attenuator setting by at least 10 dB. {#set-the-e4438c-frequency-to-1525-mhz-and-the-e4437b-frequency-to-1527.5-mhz.-reduce-the-step-attenuator-setting-until-the-inmarsat-terminal-ber-increases-to-approximately-1-x-10-4.-record-the-e4438c-and-e4437b-frequencies-and-the-output-power-level-at-which-this-occurs.-then-increase-the-step-attenuator-setting-by-at-least-10-db.-1 .unnumbered}

### 5.5.3. Repeat the preceding step for each of the following pairs of frequencies (all in MHz): {#repeat-the-preceding-step-for-each-of-the-following-pairs-of-frequencies-all-in-mhz-2 .unnumbered}

  ------------------------------------- ---------------------------------
  1526 , 1528                           1538, 1546

  1527, 1528.5                          1539, 1548

  1532, 1534                            1540, 1550

  1533, 1536                            1541, 1552

  1534, 1538                            1542, 1554

  1535, 1540                            1543, 1556

  1536, 1542                            1544, 1558

  1537, 1544                            
  ------------------------------------- ---------------------------------

**APPENDIX B**

**Final Rules**

For the reasons discussed above, the Federal Communications Commission
amends 47 C.F.R. part 25 as follows:

**PART 25 -- SATELLITE COMMUNICATIONS**

1\. The authority citation for Part 25 continues to read as follows:

Authority: 47 U.S.C. 701-744. Interprets or applies Sections 4, 301,
302,303, 307, 309 and 332 of the Communications Act, as amended, 47
U.S.C. Sections 154, 301, 302, 303, 307, 309, 332, unless otherwise
noted.

2\. Section 25.149 is amended by revising paragraph (a)(1) to read as
follows:

**§ 25.149 Application requirements for ancillary terrestrial components
in the mobile-satellite service networks operating in the 1.5/1.6 GHz,
1.6/2.4 GHz and 2 GHz mobile-satellite service.**

\(a\) \* \* \*

\(1\) ATC shall be deployed in the forward-band mode of operation
whereby the ATC mobile terminals transmit in the MSS uplink bands and
the ATC base stations transmit in the MSS downlink bands in portions of
the 2000-2020 MHz/2180-2200 MHz bands (2 GHz band), the 1626.5-1660.5
MHz/1525-1559 MHz bands (L-band), and the 1610-1626.5 MHz/2483.5-2500
MHz bands (Big LEO band).

Note to § 25.149(a)(1):

An L-band MSS licensee is permitted to apply for ATC authorization based
on a non-forward-band mode of operation provided it is able to
demonstrate that the use of a non-forward-band mode of operation would
produce no greater potential interference than that produced as a result
of implementing the rules of this section.

\* \* \* \* \*

3\. Section 25.149 is amended by revising paragraph (b)(1)(i) to read as
follows:

**§ 25.149 Application requirements for ancillary terrestrial components
in the mobile-satellite service networks operating in the 1.5/1.6 GHz,
1.6/2.4 GHz and 2 GHz mobile-satellite service.**

\* \* \* \* \*

\(b\) \* \* \*

\(1\) \* \* \*

\(i\) For the 2 GHz MSS band, an applicant must demonstrate that it can
provide space-segment service covering all 50 states, Puerto Rico, and
the U.S. Virgin Islands one-hundred percent of the time, unless it is
not technically possible, consistent with the coverage requirements for
2 GHz MSS GSO operators.

\* \* \* \* \*

3\. Section 25.201 is amended by revising the following definition to
read as follows:

**§ 25.201 Definitions**

\* \* \* \* \*

*Ancillary terrestrial component.* The term "ancillary terrestrial
component" means a terrestrial communications network used in
conjunction with a qualifying satellite network system authorized
pursuant to these rules and the conditions established in the Orders
issued in IB Docket No. 01-185, *Flexibility for Delivery of
Communications by Mobile Satellite Service Providers in the 2 GHz Band,
the L-Band, and the 1.6/2.4 GHz Band.*

4\. Section 25.216 is amended by revising paragraph (i) to read as
follows:

**§ 25.216 Limits on emissions from mobile earth stations for protection
of aeronautical radionavigation-satellite service.**

\* \* \* \* \*

\(i\) The e.i.r.p density of carrier-off state emissions from mobile
earth stations manufactured more than six months after Federal Register
publication of the rule changes adopted in FCC 03-283 with assigned
uplink frequencies between 1 and 3 GHz shall not exceed −80 dBW/MHz in
the 1559-1610 MHz band averaged over any two millisecond interval.

5\. Section 25.252 is amended by revising paragraph (a)(7) and (b)(3) as
follows:

**§ 25.252 Special requirements for ancillary terrestrial components
operating in the 2000--2020 MHz/2180--2200 MHz bands.**

\(a\) \* \* \*

\(7\) Generate EIRP density, averaged over any two millisecond active
transmission interval, greater than −70 dBW/MHz in the 1559--1610 MHz
band. The EIRP, measured over any two millisecond active transmission
interval, of discrete out-of-band emissions of less than 700 Hz
bandwidth from such base stations, shall not exceed −80 dBW in the
1559-1610 MHz band. A root-mean-square detector function with a
resolution bandwidth of one megahertz or equivalent and no less video
bandwidth shall be used to measure wideband EIRP density for purposes of
this rule, and narrowband EIRP shall be measured with a root-mean-square
detector function with a resolution bandwidth of one kilohertz or
equivalent.

\* \* \* \* \*

\(b\) \* \* \*

\(3\) Not generate EIRP density, averaged over any two-millisecond
active transmission interval, greater than −70 dBW/MHz in the 1559-1610
MHz band. The EIRP, measured over any two-millisecond active
transmission interval, of discrete out-of-band emissions of less than
700 Hz bandwidth from such mobile terminals shall not exceed −80 dBW in
the 1559-1610 MHz band. The EIRP density of carrier-off-state emissions
from such mobile terminals shall not exceed −80 dBW/MHz in the 1559-1610
MHz band, averaged over a two-millisecond interval. A root-mean-square
detector function with a resolution bandwidth of one megahertz or
equivalent and no less video bandwidth shall be used to measure wideband
EIRP density for purposes of this rule, and narrowband EIRP shall be
measured with a root-mean-square detector function with a resolution
bandwidth of one kilohertz or equivalent.

\* \* \* \* \*

6\. Section 25.253 is amended in its entirety to read as follows:

**§ 25.253 Special requirements for ancillary terrestrial components
operating in the 1626.5-1660.5 MHz/1525-1559 MHz bands.**

(a) An ancillary terrestrial component in these bands shall:

```{=html}
<!-- -->
```
(1) In any band segment coordinated for the exclusive use of an MSS
    Applicant within the land area of the U.S., where there is no other
    L-Band MSS satellite making use of that band segment within the
    visible portion of the geostationary arc as seen from the ATC
    coverage area, the ATC system will be limited by the in-band and
    out-of-band emission limitations contained in this section and the
    requirement to maintain a substantial MSS service.

(2) In any band segment that is coordinated for the shared use of the
    Applicant\'s MSS system and another MSS operator, where the
    coordination agreement existed prior to February 10, 2005 and
    permits a level of interference to the other MSS system of less than
    6% ∆T/T, the Applicant\'s combined ATC and MSS operations shall
    increase the system noise level of the other MSS to no more then 6%
    ∆T/T. Any future coordination agreement between the parties
    governing ATC operation will supersede this paragraph.

(3) In any band segment that is coordinated for the shared use of the
    Applicant\'s MSS system and another MSS operator, where a
    coordination agreement existed prior to February 10, 2005 and
    permits a level of interference to the other MSS system of 6% ∆T/T
    or greater, the Applicant\'s ATC operations may increase the system
    noise level of the other MSS system by no more than an additional 1%
    ∆T/T. Any future coordination agreement between the parties
    governing ATC operations will supersede this paragraph.

(4) In a band segment in which the Applicant has no rights under a
    coordination agreement, the Applicant may not implement ATC in that
    band.

\(b\) ATC base stations shall not exceed an out-of-channel emissions
measurement of −57.9 dBW/MHz at the edge of a MSS licensee\'s authorized
and internationally coordinated MSS frequency assignment.

\(c\) An applicant for an ancillary terrestrial component in these bands
shall:

\(1\) Demonstrate, at the time of application, how its ATC network will
comply with the requirements of footnotes US308 and US315 to the table
of frequency allocations contained in § 2.106 of this chapter regarding
priority and preemptive access to the L-band MSS spectrum by the
aeronautical mobile-satellite en-route service (AMS(R)S) and the global
maritime distress and safety system (GMDSS).

\(2\) Coordinate with the terrestrial CMRS operators prior to initiating
ATC transmissions when co-locating ATC base stations with terrestrial
commercial mobile radio service (CMRS) base stations that make use of
Global Positioning System (GPS) time-based receivers.

\(3\) Provide, at the time of application, calculations that demonstrate
the ATC system conforms to the ΔT/T requirements in subparagraphs (a)(2)
and (a)(3) of this section, if a coordination agreement that
incorporates the ATC operations does not exist with other MSS operators.

\(d\) Applicants for an ancillary terrestrial component in these bands
must demonstrate that ATC base stations shall not:

\(1\) Exceed a peak EIRP of 31.9 -10\*log(number of carriers)
dBW/200kHz, per sector, for each carrier in the 1525-1541.5 MHz and
1547.5- 1559 MHz frequency bands;

\(2\) Exceed an EIRP in any direction toward the physical horizon (not
to include man-made structures) of 26.9 -10\*log(number of carriers)
dBW/200 kHz, per sector, for each carrier in the 1525-1541.5 MHz and
1547.5-1559 MHz frequency bands;

\(3\) Exceed a peak EIRP of 23.9 -10\*log(number of carriers) dBW/200
kHz, per sector, for each carrier in the 1541.5-1547.5 MHz frequency
band;

\(4\) Exceed an EIRP toward the physical horizon (not to include
man-made structures) of 18.9 - 10\*log(number of carriers) dBW/200 kHz,
per sector, for each carrier in the 1541.5-1547.5 MHz frequency band;

(5) Exceed a total power flux density level of −56.8 dBW/m^2^/200 kHz at
    the edge of all airport runways and aircraft stand areas, including
    takeoff and landing paths from all carriers operating in the
    1525-1559 MHz frequency bands. The total power flux density here is
    the sum of all power flux density values associated with all
    carriers in a sector in the 1525-1559 MHz frequency band, expressed
    in dB(Watts/m^2^/200 kHz). Free-space loss must be assumed if this
    requirement is demonstrated via calculation;

(6) Exceed a total power flux density level of −56.6 dBW/ m^2^/200 kHz
    at the water's edge of any navigable waterway from all carriers
    operating in the 1525-1541.5 MHz and 1547.5-1559 MHz frequency
    bands. The total power flux density here is the sum of all power
    flux density values associated with all carriers in a sector in the
    1525-1541.5 MHz and 1547.5-1559 MHz frequency bands, expressed in
    dB(Watts/m^2^/200 kHz). Free-space loss must be assumed if this
    requirement is demonstrated via calculation;

\(7\) Exceed a total power flux density level of −64.6 dBW/ m^2^/200 kHz
at the water\'s edge of any navigable waterway from all carriers
operating in the 1541.5-1547.5 MHz frequency band. The total power flux
density here is the sum of all power flux density values associated with
all carriers in a sector in the 1541.5-1547.5 MHz frequency band,
expressed in dB(Watts/m^2^/200 kHz). Free-space loss must be assumed if
this requirement is demonstrated via calculation;

\(8\) Exceed a peak antenna gain of 16 dBi;

\(9\) Generate EIRP density, averaged over any two-millisecond active
transmission interval, greater than −70 dBW/MHz in the 1559--1605 MHz
band or greater than a level determined by linear interpolation in the
1605--1610 MHz band, from −70 dBW/MHz at 1605 MHz to −46 dBW/MHz at 1610
MHz. The EIRP, averaged over any two-millisecond active transmission
interval, of discrete out-of-band emissions of less than 700 Hz
bandwidth from such base stations shall not exceed −80 dBW in the
1559--1605 MHz band or exceed a level determined by linear interpolation
in the 1605-1610 MHz band, from −80 dBW at 1605 MHz to −56 dBW at 1610
MHz. A root-mean-square detector function with a resolution bandwidth of
one megahertz or equivalent and no less video bandwidth shall be used to
measure wideband EIRP density for purposes of this rule, and narrowband
EIRP shall be measured with a root-mean-square detector function with a
resolution bandwidth of one kilohertz or equivalent.

\(e\) Applicants for an ancillary terrestrial component in these bands
must demonstrate, at the time of the application, that ATC base stations
shall use left-hand-circular polarization antennas with a maximum gain
of 16 dBi and overhead gain suppression according to the following:

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Angle from direction of maximum gain, Antenna discrimination pattern
(dB)

in vertical plane, above antenna (degrees)

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

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Gmax

5\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\....
Not to Exceed Gmax -5

10\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\.....
Not to Exceed Gmax -19

15 to
55\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\.....
Not to Exceed Gmax -27

55 to
145\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...
Not to Exceed Gmax -30

145 to
180\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\...\....
Not to Exceed Gmax -26

\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\-\--

Where: Gmax is the maximum gain of the base station antenna in dBi.

\(f\) Prior to operation, ancillary terrestrial component licensees
shall:

\(1\) Provide the Commission with sufficient information to complete
coordination of ATC base stations with Search-and-Rescue Satellite-Aided
Tracking (SARSAT) earth stations operating in the 1544--1545 MHz band
for any ATC base station located either within 27 km of a SARSAT
station, or within radio horizon of the SARSAT station, whichever is
less.

\(2\) Take all practicable steps to avoid locating ATC base stations
within radio line of sight of Mobile Aeronautical Telemetry (MAT)
receive sites in order to protect U.S. MAT systems consistent with ITU-R
Recommendation ITU-R M.1459. MSS ATC base stations located within radio
line of sight of a MAT receiver must be coordinated with the Aerospace
and Flight Test Radio Coordinating Council (AFTRCC) for non-Government
MAT receivers on a case-by-case basis prior to operation. For government
MAT receivers, the MSS licensee shall supply sufficient information to
the Commission to allow coordination to take place. A listing of current
and planned MAT receiver sites can be obtained from AFTRCC for
non-Government sites and through the FCC\'s IRAC Liaison for Government
MAT receiver sites.

\(g\) ATC mobile terminals shall:

\(1\) Be limited to a peak EIRP level of 0 dBW and an out-of-channel
emissions of -67 dBW/4 kHz at the edge of an MSS licensee's authorized
and internationally coordinated MSS frequency assignment.

\(2\) Be operated in a fashion that takes all practicable steps to avoid
causing interference to U.S. radio astronomy service (RAS) observations
in the 1660--1660.5 MHz band.

\(3\) Not generate EIRP density, averaged over any two-millisecond
active transmission interval, greater than −70 dBW/MHz in the 1559--1605
MHz band or greater than a level determined by linear interpolation in
the 1605--1610 MHz band, from −70 dBW/MHz at 1605 MHz to −46 dBW/MHz at
1610 MHz. The EIRP, averaged over any two-millisecond active
transmission interval, of discrete out-of-band emissions of less than
700 Hz bandwidth from such mobile terminals shall not exceed −80 dBW in
the 1559--1605 MHz band or exceed a level determined by linear
interpolation in the 1605-1610 MHz band, from −80 dBW at 1605 MHz to −56
dBW at 1610 MHz. The EIRP density of carrier-off-state emissions from
such mobile terminals shall not exceed −80 dBW/MHz in the 1559--1610 MHz
band, averaged over a two-millisecond interval. A root-mean-square
detector function with a resolution bandwidth of one megahertz or
equivalent and no less video bandwidth shall be used to measure wideband
EIRP density for purposes of this rule, and narrowband EIRP shall be
measured with a root-mean-square detector function with a resolution
bandwidth of one kilohertz or equivalent.

\(h\) When implementing multiple base stations and/or base stations
using multiple carriers, where any third-order intermodulation product
of these base stations falls on an L-band MSS band coordinated for use
by another MSS operator with rights to the coordinated band, the MSS ATC
licensee must notify the MSS operator. The MSS operator may request
coordination to modify the base station carrier frequencies, or to
reduce the maximum base station EIRP on the frequencies contributing to
the third-order intermodulation products. The threshold for this
notification and coordination is when the sum of the calculated signal
levels received by an MSS receiver exceeds -70 dBm. The MSS receiver
used in these calculations can be assumed to have an antenna with 0 dBi
gain. Free-space propagation between the base station antennas and the
MSS terminals can be assumed and actual signal polarizations for the ATC
signals and the MSS system may be used.

7\. Section 25.254 is amended by revising paragraph (a)(4) and (b)(4) as
follows:

**§ 25.254 Special requirements for ancillary terrestrial components
operating in the 1610--1626.5 MHz/2483.5--2500 MHz bands.**

\(a\) \* \* \*

\(4\) Base stations operating in frequencies above 2483.5 MHz shall not
generate EIRP density, averaged over any two-millisecond active
transmission interval, greater than −70 dBW/MHz in the 1559--1610 MHz
band. The EIRP, averaged over any two-millisecond active transmission
interval, of discrete out-of-band emissions of less than 700 Hz
bandwidth from such base stations shall not exceed −80 dBW in the
1559--1610 MHz band. A root-mean-square detector function with a
resolution bandwidth of one megahertz or equivalent and no less video
bandwidth shall be used to measure wideband EIRP density for purposes of
this rule, and narrowband EIRP shall be measured with a root-mean-square
detector function with a resolution bandwidth of one kilohertz or
equivalent.

\* \* \* \* \*

\(b\) \* \* \*

\(4\) ATC mobile terminals operating in assigned frequencies in the
1610-1626.5 MHz band shall not generate EIRP density, averaged over any
two-millisecond active transmission interval, greater than −70 dBW/MHz
in the 1559--1605 MHz band or greater than a level determined by linear
interpolation in the 1605--1610 MHz band, from −70 dBW/MHz at 1605 MHz
to −10 dBW/MHz at 1610 MHz. The EIRP, averaged over any two-millisecond
active transmission interval, of discrete out-of-band emissions of less
than 700 Hz bandwidth from such mobile terminals shall not exceed −80
dBW in the 1559--1605 MHz band or exceed a level determined by linear
interpolation in the 1605-1610 MHz band, from −80 dBW at 1605 MHz to −20
dBW at 1610 MHz. The EIRP density of carrier-off-state emissions from
such mobile terminals shall not exceed −80 dBW/MHz in the 1559--1610 MHz
band, averaged over a two-millisecond interval. A root-mean-square
detector function with a resolution bandwidth of one megahertz or
equivalent and no less video bandwidth shall be used to measure wideband
EIRP density for purposes of this rule, and narrowband EIRP shall be
measured with a root-mean-square detector function with a resolution
bandwidth of one kilohertz or equivalent.

\* \* \* \* \*

**APPENDIX C: LIST OF COMMENTING PARTIES**

**[Petitions for Reconsideration of the *MSS Flexibility
R&O*]{.underline}:**

The Boeing Company

The Cellular Telecommunications & Internet Association

Cingular Wireless LLC

Inmarsat Ventures PLC

Mobile Satellite Ventures Subsidiary LLC

The Society of Broadcast Engineers, Inc.

The U.S. GPS Industry Council

**[Petitions for Reconsideration of the *Sua Sponte
Order*]{.underline}:**

The Boeing Company

**[Oppositions to and Comments on Petitions]{.underline}:**

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

AT&T Wireless Services, Inc.; Cingular Wireless LLC; Verizon Wireless
(the Wireless Carriers)

Delta Air Lines, Inc.

Globalstar, L.P. and Globalstar USA, LLC

ICO Global Communications (Holdings) Limited

Inmarsat Ventures PLC

Mobile Satellite Ventures Subsidiary LLC

The Society of Broadcast Engineers, Inc.

**[Replies to Oppositions and Comments]{.underline}:**

The Cellular Telecommunications & Internet Association

Cingular Wireless LLC

Inmarsat Ventures PLC

Mobile Satellite Ventures Subsidiary LLC

The U.S. GPS Industry Council

**[*Ex Parte* Comments and Letters]{.underline}:**

Air Trak

AOS, Inc.

American Petroleum Institute/United Telecom Council

Ass'n for Maximum Service Television

The Boeing Company

California Space Authority

The Cellular Telecommunications & Internet Association

Central Communications & Electronics, Inc.

Cingular Wireless LLC

Continental Mobile Communications

The Department of Defense

Geologic Solutions Inc.

GEOSat Solutions, Inc.

Global Communications Solutions Inc.

Globalstar, L.P. and Globalstar USA, LLC

Glocom

Hughes Supply Co.

Inmarsat Ventures PLC

Intel Corporation

International Satellite Services, Inc.

J.E.S. & Sons, Inc.

Level 3 Communications LLC

Mercedes-Benz USA

Mobile Equipment International

Mobile Satellite Ventures Canada Inc.

Mobile Satellite Ventures Subsidiary LLC

Motient, Inc.

National Ass'n of Broadcasters

Nera, Inc.

NexTel, Inc.

Office of Communications of the United Kingdom

Radio-Television News Directors Ass'n

Remote Satellite Systems, International

Satcom Direct

Sky Blitz, Inc.

Space Systems Loral

The Society of Broadcast Engineers, Inc.

Thrane & Thrane Inc.

The U.S. GPS Industry Council

Verizon Wireless

Wells Communications

The Wi-Fi Alliance

Wireless Matrix Corporation

**SEPARATE STATEMENT OF**

**COMMISSIONER MICHAEL J. COPPS**

**Approving in Part, Concurring in Part**

Re: *In the Matter of Flexibility for Delivery of Communications by
Mobile Satellite Service Providers in the 2 GHz Band, the L-Band, and
the 1.6/2.4 GHz Bands; Review of the Spectrum Sharing Plan Among
Non-Geostationary Satellite Orbit Mobile Satellite Service Systems in
the 1.6/2.4 GHz Bands; IB Docket No. 01-185, IB Docket No. 02-364.*

I agree with today's decision in most respects. I believe that ATC is a
vital tool for the MSS industry. It holds the promise of allowing MSS
operators to bring improved service and new competition to most of the
country through their satellite networks. Satellite has a critically
important role to play in bringing the wonders of the digital era to our
citizens, especially in hard-to-reach areas. ATC also allows these
carriers to serve areas that cannot be reached by satellite through a
terrestrial network. I place great stock in the analysis of the FCC's
engineers on the interference dispute that we resolve today, and my
support of this item is based on their analysis and recommendation.

When we granted ATC authority, however, I argued that the Commission
should consider the importance of fees for satellite carriers who choose
to use their un-auctioned satellite spectrum licenses for terrestrial
uses. We must ensure that the American people are adequately compensated
for private use of a public resource and that all spectrum users have
the incentive to use spectrum intensively. Because the Commission again
fails to do explore spectrum fees, I must concur in part.

[^1]: *See* 47 C.F.R. § 2.1(c).

[^2]: MSS is allocated spectrum at 1525-1559 MHz (space-to-Earth),
    1610-1660.5 MHz (Earth-to-space), 2483.5-2500 (space-to-Earth),
    2000-2020 MHz (Earth-to-space), and 2180-2200 MHz (space-to-Earth).
    *See* 47 C.F.R. § 2.106.

[^3]: *Flexibility for Delivery of Communications by Mobile Satellite
    Service Providers in the 2 GHz Band, the L-Band, and the 1.6/2.4 GHz
    Bands; Amendment of Section 2.106 of the Commission's Rules to
    Allocate Spectrum at 2 GHz for Use by the Mobile Satellite Service,*
    IB Docket No. 01-185, ET Docket No. 95-18, Notice of Proposed
    Rulemaking, FCC 01-225, 16 FCC Rcd 15,532 at ¶ 1 (2001) (*MSS
    Flexibility NPRM*).

[^4]: *See id.*

[^5]: *See* *id.*

[^6]: *See Flexibility for Delivery of Communications by Mobile
    Satellite Service Providers in the 2 GHz Band, the L-Band, and the
    1.6/2.4 GHz Bands; Review of the Spectrum Sharing Plan Among
    Non-Geostationary Satellite Orbit Mobile Satellite Service Systems
    in the 1.6/2.4 GHz Bands*, IB Docket Nos. 01-185 and 02-364, Report
    and Order and Notice of Proposed Rulemaking (*MSS Flexibility R&O*),
    FCC 03-15, 18 FCC Rcd 1962 (2003). The Notice of Proposed Rulemaking
    portion of the document initiated the new IB Docket No. 02-364
    regarding spectrum sharing in the Big LEO bands and is not relevant
    to the discussion herein.

[^7]: *See id.* at 1974, ¶ 22.

[^8]: *See id.* at 1975, ¶ 24.

[^9]: *See id.* at 1976, ¶ 25.

[^10]: *See id.* at 1977, ¶ 26.

[^11]: *See MSS Flexibility R&O*, 18 FCC Rcd at 1978, ¶ 28.

[^12]: *See id.* at 1979, ¶ 30.

[^13]: *See id* at 2068, ¶ 219.

[^14]: *See id.* at 2068-69, ¶ 221.

[^15]: *See id.* at 2072, ¶ 229.

[^16]: *See id.* at 2076-77, ¶ 239.

[^17]: *See MSS Flexibility R&O*, 18 FCC Rcd at 2077, ¶ 240.

[^18]: *See id.* at 2080, ¶ 245.

[^19]: *See id.* at 2082-83, ¶ 250.

[^20]: *See id.* at 2082, ¶ 248. *See also* 47 C.F.R. Part 2, Subpart J.

[^21]: *See* 47 C.F.R. §§ 25.147(c), 25.252-25.254.

[^22]: *See* 47 C.F.R. § 25.255.

[^23]: *Flexibility for Delivery of Communications by Mobile Satellite
    Service Providers in the 2 GHz Band, the L-Band, and the 1.6/2.4 GHz
    Bands*, IB Docket No. 01-185, Order on Reconsideration (*Sua Sponte
    Order*), FCC 03-162, 18 FCC Rcd 13,590 (2003).

[^24]: Gating criteria are designed to ensure that MSS operators may not
    operate terrestrial services unrelated to their satellite
    operations. For a detailed discussion of gating criteria, see
    *infra.*

[^25]: *See Sua Sponte Order* at 13,593, ¶ 7.

[^26]: *See id.* at 13,594-95, ¶ 10; 47 C.F.R. § 25.149(f). This will
    allow us to consider granting ATC authority while the construction
    and testing of the MSS system is ongoing.

[^27]: *See Sua Sponte Order* at 13,594-95, ¶ 10.

[^28]: *See id.* at 13,595-96, ¶ 13.

[^29]: *See id.* at 13,596, ¶ 14.

[^30]: Petitions for reconsideration and/or clarification were filed by
    the Society of Broadcast Engineers, Inc. (SBE); the U.S. GPS
    Industry Council (GPSIC); Mobile Satellite Ventures Subsidiary LLC
    (MSV); the Cellular Telecommunications & Internet Association
    (CTIA), Inmarsat Ventures PLC (Inmarsat); the Boeing Co. (Boeing);
    and Cingular Wireless LLC (Cingular).

[^31]: Boeing filed a petition for reconsideration of the *Sua Sponte
    Order.*

[^32]: Oppositions to petitions were filed by Boeing; MSV; Inmarsat;
    Globalstar, L.P. (Globalstar); ICO Global Communications (Holdings)
    Limited (ICO); and AT&T Wireless Services, Inc., Cingular, and
    Verizon Wireless (jointly the Wireless Carriers). Comments on the
    petitions were filed by Aeronautical Radio, Inc. and the Air
    Transport Association (ARINC/ATA) and Delta Airlines, Inc. (Delta).

[^33]: Replies to oppositions were filed by Boeing, SBE, MSV, Cingular,
    and CTIA. GPSIC filed a reply to comments.

[^34]: *See AT&T Wireless Services, Inc. and Cellco Partnership d/b/a
    Verizon Wireless v. FCC*, Case No. 03-1191 (D.C.Cir. filed Jul. 8,
    2003) (stayed pending exhaustion of administrative remedies).

[^35]: *See id.*, Petitioners' Non-Binding Statement of Issues to be
    Raised 2 (filed Aug. 8, 2003).

[^36]: In accordance with instructions in the *MSS Flexibility R&O*, MSV
    filed three applications for ATC authority on November 18, 2003: an
    application for authority to provide ATC in conjunction with MSS via
    MSV's currently operational satellite, AMSC-1; an amendment to MSV's
    pending application for license authority for a second-generation
    L-band MSS satellite, requesting authority to provide ATC in
    conjunction with provision of MSS via that satellite; and an
    application for modification of MSV's blanket license for provision
    of MSS in the United States via a Canadian-licensed L-Band MSS
    satellite operated by an affiliated company, MSV Canada, for
    authority to offer ATC in the United States in conjunction with its
    provision of MSS via that satellite.

[^37]: Application for Minor Modification and Amendment filed Nov. 18,
    2003 ("MSV ATC Application"), at 2.

[^38]: *Id.*

[^39]: Public Notice, Report No. SPB-200 (Feb. 9, 2004).

[^40]: Opposition of Inmarsat Ventures Ltd, filed March 25, 2004
    ("Inmarsat Opposition").

[^41]: *See* 47 C.F.R. § 25.253(g)(3).

[^42]: *See* letter from Raul R. Rodriguez, counsel for the U.S. GPS
    Industry Council, to Marlene Dortch, Secretary, FCC, IB Docket
    01-185 (dated Mar. 24, 2004) (advocating grant); letter from Eric
    Epley, Executive Director, Southwest Texas Regional Advisory Council
    For Trauma, to Marlene Dortch, Secretary, FCC, IB Docket 01-185
    (dated Apr. 14, 2004) (advocating expeditious action); letter from
    Karl-Heinz Ziwica, Vice President for US Engineering, BMW of North
    America LLC, to Marlene Dortch, Secretary, FCC, IB Docket 01-185
    (dated Apr. 23, 2004) (advocating grant); letter from Kenneth B.
    Taylor, Director, North Carolina Department of Crime Control and
    Public Safety, Division of Emergency Management, to Marlene Dortch,
    Secretary, FCC, IB Docket 01-185 (dated Apr. 20, 2004) (advocating
    expeditious action); letter from Conrad Burns, U.S. Senator, to
    Michael Powell, Chairman, FCC, IB Docket 01-185 (dated May 21, 2004)
    (advocating expeditious action); letter from Tom Davis, U.S.
    Representative, to Michael Powell, Chairman, FCC, IB Docket 01-185
    (dated Jun. 3, 2004) (advocating expeditious action); letter from
    Howard McConnell, Chairperson, Yurok Tribe, to Marlene Dortch,
    Secretary, FCC, IB Docket 01-185 (dated Jun. 14, 2004) (advocating
    grant).

[^43]: Letter from Lon C. Levin, Vice President, MSV, to Marlene Dortch,
    Secretary, FCC, IB Docket 01-185 (Aug. 2, 2004) (MSV Aug. 2 *Ex
    Parte* letter), filed as attachment to letter from Henry Goldberg,
    counsel for Motient, Inc., to Marlene Dortch, Secretary, FCC, IB
    Docket 01-185 (dated Aug. 2, 2004). Also see letter from Lon C.
    Levin, Vice President, MSV, to Marlene Dortch, Secretary, FCC, IB
    Docket 01-185 (dated Oct. 4, 2004) (modifying request for expedited
    action).

[^44]: *See Mobile Satellite Ventures Subsidiary LLC Application for
    Minor Modifications of Space Station License for AMSC-1; Minor
    Amendment to Application for Authority to Launch and Operate a
    Next-Generation Replacement MSS Satellite, Application for Minor
    Modification of Blanket License for Authority to Operate Mobile
    Earth Terminals with MSAT-1*, File Nos. SAT-MOD-20031118-00333,
    SAT-AMD-2003-1118-00332, SES-MOD-20031118-01879, Order and
    Authorization, DA 04-3553 (rel. Nov. 8, 2004) *(ATC License Order)*.
    On December 8, 2004, Inmarsat filed an *Application for Review* of
    this Order and Authorization. The *Application for Review* is
    currently under consideration.

[^45]: *See MSS Flexibility R&O* at 2001-02, ¶ 72.

[^46]: *See id*. at 2003-04, ¶ 75. We required MSS providers seeking to
    provide ATC to demonstrate coverage: for the 2 GHz MSS band, of all
    50 states, Puerto Rico, and the U.S. Virgin Islands 100% of the
    time; for the L-band, of 50 states, Puerto Rico, and the U.S. Virgin
    Islands 100% of the time unless technically impossible from the
    orbit position(s) of the satellite(s); for the Big LEO band, of all
    locations between 70º North latitude and 55º South latitude for at
    least 75% of every 24-hour period and on a continuous basis
    throughout all 50 states, Puerto Rico, and the U.S. Virgin Islands.
    *See also* 47 C.F.R. 25.147(b)(1).

[^47]: *See MSS Flexibility R&O* at 2007, ¶ 83. We required operational
    NGSO MSS providers wishing to provide ATC to maintain at least one
    spare satellite in orbit, and operational GSO MSS providers wishing
    to provide ATC to maintain a spare satellite on the ground within
    one year of commencing operations and to launch the spare satellite
    in the first commercially reasonable launch window following
    satellite failure. *See also* 47 C.F.R. § 25.147(b)(2).

[^48]: *See MSS Flexibility R&O* at 2008, ¶ 86. *See also* 47 C.F.R. §
    25.147(b)(3).

[^49]: *See MSS Flexibility R&O* at 2008-09, ¶¶ 87-88. *See also* 47
    C.F.R. § 25.147(b)(4).

[^50]: *See MSS Flexibility R&O* at 2011-12, ¶ 93. In the 2 GHz MSS
    band, ATC is limited to the MSS provider's selected assignment. In
    the Big LEO band, ATC is limited to no more than 5.5 megahertz of
    spectrum in each direction of operation, and must conform to Big LEO
    MSS band-sharing arrangements. In the L-band, ATC is limited to the
    frequencies available for the providers of MSS operations under
    coordination in accordance with the Mexico City Memorandum of
    Understanding and successor agreements. *See also* 47 C.F.R. §
    25.147(b)(5).

[^51]: *See MSS Flexibility R&O* at 2014-15, ¶ 99.

[^52]: *See id.* at 2015, ¶ 100.

[^53]: *See id.* at 2015, ¶ 101.

[^54]: *See id.* at 2015-16, ¶ 102.

[^55]: *See* Cingular, *Petition for Reconsideration* at 3; CTIA,
    *Petition for Reconsideration* at 3-4.

[^56]: *See* Cingular *Petition* at 10-11.

[^57]: *See* *id.* at 11.

[^58]: *See* CTIA *Petition* at 6.

[^59]: *See* Cingular *Petition* at 15; CTIA *Petition* at 8.

[^60]: *See* Boeing, *Petition for Reconsideration of the Boeing
    Company* at 2.

[^61]: Cingular asserts that our rules requiring substantial satellite
    service are merely cosmetic and reflect unreasoned decisionmaking.
    *See* Cingular *Petition* at 3. Cingular and CTIA request that we
    adopt a specific percentage of satellite capacity that must be
    reserved for MSS operations. Cingular requests that we require
    MSS/ATC operators to reserve at least 50% of their capacity for MSS
    service at all times. *See id.* at 9-10. CTIA agrees that a
    numerical limit on ATC is needed, stating that "a reasonable
    criterion would be that the capacity in any satellite antenna beam
    is never reduced by more than 20% from what it would be in the
    absence of an \[ATC\]." CTIA *Petition* at 4. *See also* letter from
    Diane Cornell, CTIA, to Marlene Dortch, Secretary, FCC, IB Docket
    01-185, Appx. at 5 (dated Feb. 2, 2005) (CTIA Feb. 2 *Ex Parte*
    letter).

[^62]: *See MSS Flexibility R&O* at 2013-14, ¶¶ 98-99.

[^63]: *See* CTIA *Petition* at 3-4.

[^64]: *See* Globalstar, *Consolidated Opposition of Globalstar, L.P.*
    at 5.

[^65]: *See id.* at 9-10.

[^66]: ICO asserts that MSS operators will have an incentive to continue
    to provide robust satellite service because they have invested large
    sums of money in satellites, agreeing with our reasoning that MSS
    operators are "unlikely 'to abandon satellite services merely for
    the opportunity to compete only in the market for terrestrial mobile
    services where much larger, better financed competitors already
    engage in "'competitive, intense \[and\] aggressive price
    competition.'" *See* ICO, *Consolidated Opposition of ICO Global
    Communications (Holdings) Limited* at 5-6 (quoting *MSS Flexibility
    R&O* at 1982-83, ¶ 35). *See also* letter from Suzanne Hutchings
    Malloy, ICO, to Marlene Dortch, Secretary, FCC, IB Docket 01-185 at
    2 (dated Feb. 3, 2005) (ICO Feb. 3 *Ex Parte* letter). Boeing
    concurs, stating that the business plan of MSS/ATC operators must be
    to provide mobile services in all locations in the United States,
    especially those locations unserved or underserved by terrestrial
    operators, and that MSS operators will invest in the additional cost
    of ATC transmitters only where the MSS signal is not available or in
    heavily populated "bottleneck" locations. *See* Boeing, *Opposition
    of the Boeing Company* at 5. MSV states that its system would meet a
    gating factor that restricts ATC from significantly decreasing
    satellite capacity but that such a gating criterion is unnecessary
    and could hinder MSS/ATC operators in seeking financing. *See* MSV,
    *Consolidated Opposition to and Comments on Petitions for
    Reconsideration* at 15-16. *See also* letter from Lon. C. Levin,
    Vice President MSV, to Marlene Dortch, Secretary, FCC, IB Docket
    01-185 at 2-4 (dated Feb. 3, 2005).

[^67]: *See* 47 C.F.R. § 25.149(a)(2), (6).

[^68]: *See* Cingular *Petition* at 10-11.

[^69]: *See id.* *See also* CTIA Feb. 2 *Ex Parte* letter at 5.

[^70]: *MSS Flexibility R&O* at 2015, ¶ 100.

[^71]: *See* MSV *Opposition* at 16. Globalstar adds that such a
    requirement is spectrally inefficient, and would require handsets to
    attempt to use the MSS communications path whenever the MSS signal
    was above a certain threshold, regardless of actual communications
    traffic, leading to denials of service when the users could use ATC
    to complete their calls. *See* Globalstar *Opposition* at 7.

[^72]: *See* Boeing *Opposition* at 8.

[^73]: *See* CTIA *Reply* at 5. *See also* CTIA Feb. 2 *Ex Parte* letter
    at 5.

[^74]: *See* *MSS Flexibility R&O* at 2008-09, ¶ 87. Applicants for
    MSS/ATC may prove integrated service by demonstrating "\[t\]he
    MSS/ATC operator will use a dual-mode handset that can communicate
    with both the MSS network and the MSS/ATC to provide the proposed
    ATC service," or by an alternate showing establishing that the
    MSS/ATC service is integrated. *See* 47 C.F.R. § 25.147(b)(4).

[^75]: Cingular *Petition* at 11. Cingular states that MSS/ATC
    proponents "sought flexibility to offer 'dual mode' phones where the
    capability to access the satellite was merely a component available
    at the point of sale." *Id.*

[^76]: *See* MSV *Opposition* at 17-18.

[^77]: *See MSS Flexibility R&O* at 2009, n.229.

[^78]: *See* Cingular *Petition* at 12.

[^79]: Cingular *Petition* at 12. CTIA also points out that there are
    PDAs and other digital devices available on the market in the United
    States today incorporating voice and data capabilities. *See* CTIA
    *Petition* at 7. *See also* CTIA Feb. 2 *Ex Parte* letter at 6.

[^80]: *See, e.g.,* Inmarsat *Opposition* at 3-4

[^81]: *See* ICO *Opposition* at 3-4. *See also* ICO Feb. 3 *Ex Parte*
    letter at 3.

[^82]: Because MSS is the basic service to which ATC is ancillary, we
    see no reason why we should prohibit or restrict MSS-only devices.

[^83]: For example, the International Bureau authorized MSV's use of a
    dual-mode handset with a separate antenna booster for its current
    generation satellites. The Bureau found that MSV had demonstrated
    satisfaction of the integrated service requirement, and that its
    proposal to use the separate antenna booster with a dual-mode
    handset designed to communicate with MSV's next generation satellite
    without a booster to be a reasonable temporary solution that will
    enhance economic efficiency. *See* *ATC License Order* at ¶ 21.

[^84]: CTIA requests that we forbid MSS/ATC operators to offer
    "ATC-only" subscriptions to customers, stating that such a
    requirement would ensure that MSS/ATC operators would offer ATC only
    as part of an integrated system with MSS as the primary component.
    *See* CTIA *Petition* at 6; CTIA Feb. 2 *Ex Parte* letter at 5. No
    party explicitly opposes this request, but Globalstar states that a
    "customer should have the option of taking an ATC-only service at a
    high data rate" in urban areas where the customer does not expect to
    leave the ATC-covered area. Globalstar *Opposition* at 8-9.

[^85]: Because MSS is the basic service to which ATC is ancillary, we
    will not prohibit or restrict MSS-only service subscriptions.

[^86]: Cingular states that "\[w\]hile the Commission has made it clear
    that it does not intend to allow gaming of its ATC rules \[footnote
    omitted\], the failure to explicitly state that satisfaction of the
    gating criteria is license/band-specific and not licensee-specific
    presents that opportunity." Cingular *Petition* at 15. CTIA adds
    that it believes the Commission intended to make satisfaction of
    gating criteria a precondition to the grant of ATC authority for
    each MSS license, but that MSS operators should not be allowed to
    avoid their satellite obligations in one band by claiming they have
    met those obligations in another band. *See* CTIA *Petition* at 8;
    *see also* CTIA Feb. 2 *Ex Parte* letter at 7. *But see* ICO
    *Opposition* at 10 (arguing that Cingular's and CTIA's request is
    frivolous because the requirement of band-specific satisfaction of
    gating criteria is explicit in the rules) (citing *MSS Flexibility
    R&O* at 2011-12, ¶ 93; 47 C.F.R. 25.149(b)(5). *See also* Globalstar
    *Opposition* at 9.

[^87]: *See* 47 C.F.R. § 25.149(b)(5).

[^88]: *See* Boeing *Petition* at 2. Our ATC rules state that a
    geostationary orbit (GSO) 2 GHz MSS operator must demonstrate that
    its system "can provide space-segment service covering all 50
    states, Puerto Rico, and the U.S. Virgin Islands one-hundred percent
    of the time, consistent with the coverage requirements for 2 GHz MSS
    GSO operators." 47 C.F.R. § 25.149(b)(1)(i). By contrast, the
    service rules for GSO 2 GHz MSS systems require the systems to be
    "capable of providing mobile satellite services on a continuous
    basis throughout the 50 states, Puerto Rico, and the U.S. Virgin
    Islands, *if technically feasible*." 47 C.F.R. § 25.143(b)(2)(iv)
    (emphasis supplied).

[^89]: The L-band consists of the bands assigned by the Commission in
    the United States for MSS operations: 1525-1544 MHz and 1545-1559
    MHz for downlinks, and 1626.5-1645.5 MHz and 1646.5-1660.5 MHz for
    uplinks. *See* 47 C.F.R. § 2.106.

[^90]: The five operators in the L-band and their authorizing countries
    are MSV (United States), TMI (Canada), Inmarsat (United Kingdom),
    Solidaridad (Mexico), and Volna-More (Russia). *See MSS Flexibility
    R&O* at 1994, n.144.

[^91]: In the L-band, all licensees have equal rights to all channels in
    the band. The licensees coordinate their channel usage so that each
    licensee has some channels it uses exclusively, some it is not
    entitled to use, and some that it shares with other licensees. By
    contrast, in the Big LEO and 2 GHz MSS bands, each licensee has
    exclusive rights to a block of spectrum.

[^92]: *See MSS Flexibility R&O* at 2031-32, ¶ 132. Inmarsat, which
    could receive harmful interference from MSV's ATC, has had the
    opportunity to evaluate and comment upon MSV's proposal, as has
    NTIA. NTIA is the agency responsible for the telecommunications of
    the Federal government, including defense communications, aviation
    communications, and the Global Positioning System (GPS), among other
    systems and services. The Commission therefore works with NTIA in
    evaluating the potential for interference to, and the need for
    protection of, systems operated by the Federal government.

[^93]: *See id.* at 2033, ¶ 136. *See also* letter from Bruce Jacobs,
    counsel for MSV, to Marlene Dortch, Secretary, FCC, IB Docket 01-185
    at 11 (dated Mar. 28, 2002), Table *SS Link Margin Degradation to
    Accommodate Intra-System Effect of ATC*.

[^94]: *See id.* at 2033, ¶ 137.

[^95]: The total radio "noise," or power that can interfere with the
    reception of desired signals, can be expressed as a "system
    temperature," which includes both the noise received from all
    sources by the system's antennas and the noise added by the system's
    own operation. The system noise temperature (T) of Inmarsat's
    satellite receivers is 600K. ΔT/T represents the rise in that noise
    temperature caused by a new source of noise, such as ATC. The
    equation calls for dividing the increase in the system noise
    temperature (Δ) by the noise temperature without the new source of
    noise (T). Thus, 36 ÷ 600 = 6%, so 6% ΔT/T in this case would be
    sufficient additional noise to raise the system temperature of
    Inmarsat's satellite receivers by 36 degrees Kelvin.

[^96]: *MSS Flexibility R&O* at 2170, Appx. C2, ¶ 2.1.1. Inmarsat-3
    refers to the current generation of Inmarsat satellites. Inmarsat
    has planned to construct and launch Inmarsat-4 satellites in the
    future. These satellites will feature much higher receiver
    sensitivity and many more antenna beams, each covering a smaller
    area of the Earth's surface. These different characteristics
    required the Commission to evaluate the impact of potential
    interference on both the current and the planned Inmarsat
    satellites.

[^97]: "Below, we. . . provide an individual assessment of the potential
    for interference from MSV's ATC operations to Inmarsat's networks. .
    . ." *MSS Flexibility R&O* at 2143, Appx. C2. For a description of
    MSV's ATC, *see Application of Motient Services Inc.*, File Nos.
    SAT-LOA-19980702- 00066, SAT-AMD-20001214-00171 & SAT-AMD-20010302.
    *See also* Public Notice, Report No. SAT-00066 at 2 (rel. Mar. 19,
    2001) (MSV Application). MSV later indicated that it would seek to
    use the same ATC network with its current-generation MSS system.
    *See* Letter from Carson E. Agnew, President and Chief Operating
    Officer, and P. Karabinis, Chief Technical Officer, MSV, to Marlene
    Dortch, Secretary, FCC, IB Docket 01-185 (dated Dec. 16, 2002).

[^98]: *See* 47 C.F.R. § 25.253.

[^99]: *See id.* at § 25.253(c).

[^100]: *See id.* at § 25.253(a)(8).

[^101]: *See id.* at § 25.253(d)(1-2).

[^102]: *See id.* at § 25.253(d)(7).

[^103]: *See, e.g.,* 47 C.F.R. § 80.1187 (Inmarsat as part of GMDSS); §
    87.187(q) (AMS(R)S) .

[^104]: *See* 47 U.S.C. § 303(f).

[^105]: *See* ITU-R RR Appendix 8 (rev. WRC-03).

[^106]: *See* ITU-R Rec. M.1086 which stipulates that the procedures of
    ITU-R Appendix 29 (now Appendix S8) be used in determining the ∆T/T
    between two geostationary MSS satellites, and that the satellite
    systems coordinate operations if the calculated value of ∆T/T is
    greater than 6%.

[^107]: *See* ITU-R Rec. M.1086.

[^108]: Inmarsat states that the interference tolerance of satellites is
    limited and does not account for terrestrial uses such as ATC.
    Inmarsat designs an interference allowance of approximately 25% ΔT/T
    in its system, and uses 6% ΔT/T from any one other satellite system
    as the basis for coordination. If MSV's ATC alone were allowed to
    create 6% ΔT/T, Inmarsat claims that this would consume almost a
    quarter of its entire interference margin, which would significantly
    constrain its ability to provide L-band MSS. Inmarsat stresses that
    ATC is merely an ancillary component of MSS, and claims that the
    interference caused by ATC should be included in the interference
    allowance for MSS systems. ATC interference must be kept at a low
    level, as our rules currently require, in order to ensure effective
    coordination and spectrum efficiency in the L-band, according to
    Inmarsat. *See* Inmarsat, *Inmarsat Opposition to Petition for
    Partial Reconsideration and Clarification of Mobile Satellite
    Ventures Subsidiary LLC* at 8-11. *See also* letter from John P.
    Janka, counsel for Inmarsat, to Marlene Dortch, Secretary, FCC, IB
    Docket 01-185, Appx. 1 at 5 (dated Feb. 3, 2005) (Inmarsat Feb 3 *Ex
    Parte* letter).

[^109]: *See* Inmarsat *Petition* at 13-14.

[^110]: Such renegotiation could also facilitate the efficient usage and
    protection of new satellites that will be deployed over the next few
    years by both Inmarsat and MSV. While we encourage such
    renegotiation to occur at the earliest possible opportunity, we
    recognize that the existing agreement, which identifies frequencies
    available to each operator from specific orbital locations and
    antenna beams, and in some cases, interference levels coordinated
    between the operators, provides a basis under which current MSS
    operators can continue to operate as well as deploy and use new
    satellites and MSS/ATC.

[^111]: *See* MSV *Petition* at 6 (citing *MSS Flexibility R&O* at 2170,
    Appx. C, ¶ 2.1.1).

[^112]: *See id.*

[^113]: *See id.*

[^114]: We note that the existing coordination agreement does not
    specify current ΔT/T protection levels. However, such levels can be
    calculated using either ITU-R Appendix 8 (Rev.WRC-03) or the
    methodology that was presented in our *MSS Flexibility R&O.* We
    would expect both parties to approach the development of a new
    coordination agreement in good faith and to apply good engineering
    judgment to determine the various factors and trade-offs that must
    go into the evaluation of sharing between an MSS system and an
    MSS/ATC system. The methodology that was presented in our *MSS
    Flexibility R&O* could be used as an example of the different
    factors that could be taken into account in determining the
    interference from an MSS/ATC system into an MSS system.

[^115]: MSV requested that we increase the limit on co-channel base
    stations in the United States from 1725 to 2760 based on the fact
    that we assumed in the *MSS Flexibility R&O* that MSV would deploy
    one-half of its ATC network in the United States. Therefore,
    according to MSV, we intended to limit co-channel base stations to
    3450 network-wide, half in the United States and half outside the
    United States. Because it plans to deploy approximately 80% of its
    ATC network within the United States, MSV requested that we increase
    the permitted number of co-channel base stations in the United
    States to 80% of the network-wide total, or 2760. *See* MSV
    *Petition* at 5-6 (citing 47 C.F.R. § 25.253(c)). MSV also requests
    that we increase the number of permitted co-channel base stations to
    14,785 based on its argument that ATC should be allowed to interfere
    with co-primary MSS systems to a level of 6% ΔT/T. *See id.* at 15.

[^116]: A vocoder converts the caller's voice into a digital signal for
    transmission and converts the received digital signal back into
    intelligible voice. By reducing the rate of the vocoder, the
    transmitter can reduce the interference caused by the transmission,
    at the expense of voice quality. MSV states that in the *MSS
    Flexibility R&O*, we assumed that MSV would use a quarter-rate
    vocoder and channel and that this would reduce the effective
    isotropic radiated power of MSV's ATC handsets by 3.5 dB. MSV claims
    that this reduction in EIRP will be achieved with a half-rate
    vocoder. *See* MSV *Petition* at 14. Contrary to MSV's assertions,
    47 C.F.R. § 25.253(a)(2) requires the use of a variable-rate
    vocoder, not a quarter-rate or half-rate vocoder.

[^117]: Inmarsat requests that we require such a description to include
    a detailed demonstration that the cell structure of the ATC includes
    an 18 dB link margin for structural attenuation and that this margin
    will be used only for service to mobile handsets indoors. *See*
    Inmarsat *Petition.* at 11. *See also* Inmarsat Feb 3 *Ex Parte*
    letter at Appx. 5.

[^118]: Inmarsat seeks clarification that this limit applies to all
    MSS/ATC operators in the L-band, not to each such operator, because
    it claims that the latter interpretation would have no relation to
    the assumptions underlying our interference analysis. *See* Inmarsat
    *Petition* at 13.

[^119]: MSV is the only L-band MSS provider currently authorized to
    provide ATC. Our elimination of some technical rules here does not
    affect the terms of MSV's ATC authorization. MSV must conform to all
    the terms of its ATC authorization unless it applies for
    modification of its license and demonstrates that the modifications
    it proposes would be consistent with the limits on interference we
    adopt here.

[^120]: Overload occurs when the total input power to the receiver
    drives the receiver from its operational linear state to a
    non-linear state, which results in distortion of the desired input
    signal or, in the case of severe overload, the inability of the
    receiver to operate.

[^121]: *See MSS Flexibility R&O* at 2038, ¶ 148.

[^122]: *See MSS Flexibility R&O* at 2038, ¶ 148; 47 C.F.R. §
    25.253(d)(1).

[^123]: *See MSS Flexibility R&O* at 2039, ¶ 152; 47 C.F.R. §
    25.253(d)(2).

[^124]: *See MSS Flexibility R&O* at 2041, ¶ 157; 47 C.F.R. § 25.253(b).

[^125]: *See MSS Flexibility R&O* at 2042, ¶ 160; 47 C.F.R. § 25.253(e).

[^126]: MSV claims that it submitted "uncontroverted evidence" that the
    overload threshold for Inmarsat METs is -45 dBm, instead of the -60
    dBm value we used in our calculation. MSV submits measurements it
    conducted of the 1 dB compression point of the receiver front-ends
    in Inmarsat's land-based and maritime METs produced by a variety of
    manufacturers. This data purports to demonstrate that "even an
    in-band signal level of -45 dBm does not overload an Inmarsat
    land-based or maritime MET." *See* MSV *Petition* at 16-17; Appx. C.

[^127]: *See id.* at 17-18. The peak EIRP level of 19.1 dBW per carrier,
    with no more than three carriers per sector, specified in 47 C.F.R.
    § 25.253(d)(1) equates to an aggregate EIRP per sector of 23.9 dBW.
    The EIRP level of 14.1 dBW toward the horizon per carrier specified
    in 47 C.F.R. § 25.253(d)(2) equates to an aggregate EIRP toward the
    horizon per sector of 18.9 dBW.

[^128]: Specifically, Inmarsat claims that the overload threshold of its
    METs is -72 dBm at a one megahertz frequency offset, and lower still
    at offsets of less than one megahertz. For this reason, Inmarsat
    requests that we recalculate the ATC base station power limits based
    on an overload threshold of -75 dBm, instead of the -60 dBm we used
    in our calculation. *See* Inmarsat *Petition* at 15-17; Inmarsat
    *Opposition* at 16.

[^129]: *See* Appx. A, § 3.

[^130]: *See* MSV Aug. 2 *Ex Parte* letter at 1.

[^131]: *See* 47 C.F.R. § 2.106, n.5.356.

[^132]: In this portion of the band, ATC base stations will be limited
    to a peak EIRP of 19.1 dBW per carrier and 14.1 dBW toward the
    physical horizon per carrier. *See* 47 C.F.R. § 25.253(d).

[^133]: Determining the frequencies whose interactions can cause
    intermodulation to the desired frequency is accomplished by applying
    the formula 2 f~1~ -- f~2~ = X, where f~1~ and f~2~ are the
    frequencies producing the intermodulation, and X is the desired
    frequency.

[^134]: *See* Appx. A, Figure 3. The single exception occurs in the
    tests of Terminal C with cdma2000 modulation where sensitivity to
    having one of the two unwanted signals near 1552 MHz occurred. This
    sensitivity was probably due to an image rejection problem in the
    receiver as discussed in Attachment A, n.19.

[^135]: For the purpose of determining when a signal at the output of an
    MSS terminal antenna is greater than -70 dBm, a calculation based on
    free-space propagation, and omni-directional antenna, and the actual
    polarizations used by the ATC base station and the MSS system may be
    used. Unless otherwise justified, the MSS terminal should be assumed
    to be at ground level.

[^136]: *See* 47 C.F.R. § 25.535(d)(1).

[^137]: *See* letter from David S. Konczal, counsel for MSV, to Marlene
    Dortch, Secretary, FCC, IB Docket 01-185, Appx. at 18 (dated Mar.
    10, 2004).

[^138]: We note that in implementing a multiple-carrier base station,
    the EIRP level of each carrier can be expressed as the total EIRP
    divided by the number of carriers. Alternately, expressed in
    decibels, the EIRP per carrier will be the peak EIRP-10\*log(number
    of carriers). *See* Appx. B, § 25.253.

[^139]: *See MSS Flexibility R&O* at 2178, Appx C2, ¶ 2.2.1.3.

[^140]: *See* *id.* at 2040, ¶ 154; 47 C.F.R. § 25.253(d)(3).

[^141]: *See MSS Flexibility R&O* at 2040, ¶ 154; 47 C.F.R. §
    25.253(d)(4).

[^142]: *See MSS Flexibility R&O* at 2040, ¶ 154; 47 C.F.R. §
    25.253(d)(5).

[^143]: *See* MSV *Petition* at 19.

[^144]: MSV contends that ATC providers should be able to site base
    stations outside the separation distances without having to measure
    the PFD produced, and that alternately, ATC providers should be
    allowed to site their base stations within the separation distances
    if they measure the PFD at the edges of airports and waterways, and
    those PFDs are within the limits in the rules. *See* *id.* at 20-21;
    MSV *Reply* at 9.

[^145]: *See* Inmarsat Feb 3 *Ex Parte* letter at 42-49.

[^146]: *See* ARINC/ATA *Comments* at 2.

[^147]: MSV correctly pointed out that there was a numerical error in
    the calculation of the PFD at the edge of a airport contained in
    Attachment C2 of the *MSS Flexibility R&O*, although the calculation
    supplied by MSV was also incorrect. We base the PFD calculated here
    on the following parameters: an Inmarsat terminal receive gain of 0
    dBi, a polarization isolation of 0 dB, a frequency of 1542 MHz
    (center of the band), and an interference tolerance level of -52
    dBm. *See* letter from Bruce Jacobs, counsel for MSV, to Marlene
    Dortch, Secretary, FCC, IB Docket 01-185 at 1-2 (dated Nov. 18,
    2003).

[^148]: We base this PFD calculation for waterways for the band
    1541.5-1547.5 MHz on the following parameters: a n Inmarsat terminal
    receive gain of 7.5 dBi, a polarization isolation of 8 dB, a
    frequency of 1544.5 MHz and an interference tolerance level of -52
    dBm.

[^149]: Noting that Inmarsat METs aboard aircraft are part of a safety
    service, Inmarsat explains that the PFD limits quantify the level at
    which aircraft METs will experience harmful interference, but that
    PFD limits can be difficult to measure accurately. *See* Inmarsat
    *Opposition* at 18-19.

[^150]: 47 U.S.C. § 25.253. *See* Appendix B.

[^151]: MSV asserts that the benefit of the overhead gain suppression
    levels we adopted in the *MSS Flexibility R&O* is far outweighed by
    the cost of implementing these levels of overhead gain suppression.
    *See* MSV *Petition* at 19-20; MSV *Reply* at 8.

[^152]: Inmarsat argues that the standards derived from analyses of
    overhead gain suppression that relied on MSV's statements cannot be
    changed without further detailed study. *See* Inmarsat *Opposition*
    at 17-18.

[^153]: *See MSS Flexibility R&O* at 2028-29, ¶¶ 124-126; 2051-53, ¶¶
    180-184. The RNSS includes the Global Positioning System (GPS)
    operating in a portion of the 1559-1610 MHz band. *See MSS
    Flexibility R&O* at 2028, ¶ 124.

[^154]: *See Amendment of Parts 2 and 25 to Implement the Global Mobile
    Personal Communications by Satellite (GMPCS) Memorandum of
    Understanding and Arrangements (GMPCS Order)*, IB Docket No. 99-67,
    Report and Order and Further Notice of Proposed Rulemaking, 17 FCC
    Rcd 8309 (2002) (modified in *GMPCS*, Second Report and Order, IB
    Docket No. 99-67, 18 FCC Rcd 24423 (2003)).

[^155]: *See* 47 C.F.R. § 25.216(e).

[^156]: *See* 47 C.F.R. § 25.216(a)-(d), (f)-(h).

[^157]: *See* 47 C.F.R. §§ 25.252(a)(7), (b)(3); 25.253(a)(6), (c)(7);
    25.254(a)(4), (b)(4).

[^158]: *See MSS Flexibility R&O* at 2029, ¶ 125.

[^159]: *See id.* at 2053, ¶ 184. Further, MSV promised that the EIRP
    density of ATC handsets activated five years or more after the
    commencement of its proposed ATC operation would be limited to -95
    dBW/megahertz in the 1559-1610 MHz band.

[^160]: *See* letter from Fredrick R. Wentland, Acting Associate
    Administrator, Office of Spectrum Management, NTIA, to Donald
    Abelson, Chief, International Bureau, FCC, IB Docket 01-185 (dated
    Nov. 12, 2002).

[^161]: For example, we did not agree that a 3 dB allowance for base
    station interference allotment for aviation GPS receivers was
    necessary. We also were not persuaded to establish interference
    standards based on a two meter separation distance.

[^162]: *See id.* at 2029, ¶ 126; 2052-53, ¶ 182.

[^163]: *See id.* at 2029, ¶ 126; 2053, ¶ 184.

[^164]: The GPS Industry council states that these stricter limits were
    broadly supported and endorsed by NTIA, and asserts that we must
    make decisions based on the facts in the record, and must
    "articulate a satisfactory explanation for \[our\] action including
    a rational connection between the facts found and the choice made."
    *See* GPS Industry Council *Petition* at 3-4 (quoting *Motor Vehicle
    Mfrs. Assn. v. State Farm Mutual Auto. Inc. Co.*, 463 U.S. 29, 43
    (1983); *Citizens to Preserve Overton Park, Inc. v Volpe*, 401 U.S.
    402, 416 (1971)).

[^165]: *See id.* at 4. *See also* ARINC/ATA *Comments* at 2-3; Delta
    Airlines *Comments* at 1-2.

[^166]: *See* U.S. Space-Based Positioning, Navigation, and Timing
    Policy, December 15, 2004, Fact Sheet, available on the World-Wide
    Web at
    www.ostp.gov/html/FactSheetSPACE-BASEDPOSITIONINGNAVIGATIONTIMING.pdf.

[^167]: These discrepancies arose because the MSS terminal limits in
    sections 25.216 were revised in some respects after the adoption of
    the ATC rules. In order to correct these discrepancies, we will
    amend sections 25.252, 25.253, and 25.254 to specify measurement
    intervals as two milliseconds in place of the current 20
    milliseconds, change the permitted EIRP density of emissions in the
    1605-1610 MHz band from ATC terminals and base stations operating in
    the L-Band, specified in section 25.253(d)(7) and (g)(3) from -10
    dBW/megahertz to -46 dBW/megahertz, amend section 25.254(a)(4) to
    change the permitted EIRP density of emissions in the 1605-1610 MHz
    band from ATC base stations with assigned frequencies above 2483.5
    MHz to -70 dBW/megahertz, establish narrowband EIRP limits in the
    1605-1610 MHz segment for all ATC terminals, and prescribe stricter
    limits on EIRP density in the 1559-1610 MHz band for ATC terminals
    when in the carrier-off state.

[^168]: *See GMPCS*, Second Report and Order, IB Docket No. 99-67, 18
    FCC Rcd 24,423, 24,455-56, ¶ 97 (2003).

[^169]: *MSS Flexibility R&O* at 2049-50, ¶ 177.

[^170]: MSV states that this requirement was intended to require
    coordination only when the planned ATC base station was both within
    27 km of a SARSAT earth station and within the radio horizon of the
    SARSAT earth station, but notes that the rule itself applies this
    requirement to any planned ATC base station "located either within
    27 km of a SARSAT station, or within the radio horizon of the SARSAT
    station, whichever is less." MSV *Petition*, Appx. E at 3.

[^171]: We note that the value of 27 km mentioned above is dependent on
    the EIRP of ATC base stations. MSV has requested a change in the
    base station EIRP. If the base station EIRP changes this value will
    also change.

[^172]: *See* MSV *Petition* at 23.

[^173]: *See* 47 C.F.R. § 25.253 at note.

[^174]: *See* MSV *Petition* at 23.

[^175]: *See MSS Flexibility R&O* at 2068-69, ¶ 221.

[^176]: *See id.* at 2070, ¶¶ 224-225; 47 U.S.C. § 309(j)(1).

[^177]: *See MSS Flexibility R&O* at 2071, ¶ 226.

[^178]: *See id.* We also found that MSS operators with ATC authority
    would not compete directly with terrestrial CMRS. *See id.* at 2072,
    ¶ 229.

[^179]: *See id.* at 2071-72, ¶ 228 (citing 47 U.S.C. § 309(j)(3)(A) &
    (D)).

[^180]: *See* Cingular *Petition* at 1. Cingular also claims that the
    decision to award terrestrial rights to 2 GHz MSS licensees without
    an auction is contrary to "the FCC's decision in the licensing
    orders to allow 2 GHz MSS applicants to succeed or fail . . . on the
    basis of a satellite-only authorization," *See also* Cingular
    *Reply* at 2.

[^181]: *See* Cingular *Petition* at 2.

[^182]: *Id.* at 16-19.

[^183]: *Id.* at 22-23. *See also* letter from Brian F. Fontes, Vice
    President, Federal Relations, Cingular, to Marlene Dortch,
    Secretary, FCC, IB Docket 01-185 at 5 (dated Jan. 28, 2005). Section
    309(j)(3)(C) states that the Commission shall seek to recover for
    the public "a portion of the value of the public spectrum resource
    made available for commercial use and avoidance of unjust enrichment
    through the methods employed to award uses of that resource." 47
    U.S.C. § 309(j)(3)(C).

[^184]: *See* letter from Brian F. Fontes, Vice President, Federal
    Relations, Cingular, to Don Abelson, Chief, International Bureau,
    FCC, IB Docket 01-185 at 2-3 and Attachment A (dated May 13, 2002).

[^185]: "The Commission has identified MSS as an important component of
    our overall mix of spectrum allocations. The "separate-band,
    separate-operator" approach, however, would, in essence, reallocate
    spectrum from MSS to other uses. We believe that reconsideration of
    the spectrum-management decision to allocate resources to MSS is
    unreasonable and unwarranted. . . ." *See MSS Flexibility R&O* at
    1996, ¶ 58.

[^186]: *See supra* ¶ 20.

[^187]: 47 U.S.C. § 309(j)(3)(D).

[^188]:
    > *See* Cingular *Petition* at 23 (citing *Implementation of Section
    > 6002(B) of the Omnibus Budget Reconciliation Act of 1993(Seventh
    > CMRS Competition Report)*, Seventh Report, FCC 02-179, 17 FCC Rcd
    > 12,985, 12997, 13025-28 (2002).

[^189]: *See Seventh CMRS Competition* Report at 13,025.

[^190]:
    > *See, e.g*., *Amendment of the Commission's Rules to Permit
    > Flexible Service Offerings in the Commercial Mobile Radio Services
    > (CMRS Flexibility Report and Order)*, First Report and Order and
    > Further Notice of Proposed Rulemaking, WT Docket 96-6[, 11 FCC Rcd
    > 8965, 8979-80, ¶
    > 33](http://web2.westlaw.com/find/default.wl?DB=4493&SerialNum=1996297313&FindType=Y&ReferencePositionType=S&ReferencePosition=8979&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw)
    > (deleting footnotes US330 and US331, which prohibited PCS
    > licensees from providing fixed service, without triggering the
    > competitive bidding requirements of [Section
    > 309(j)](http://web2.westlaw.com/find/default.wl?DB=1000546&DocName=47USCAS309&FindType=L&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw));
    > *Amendment of Parts 21 and 74 to Enable M**ultipoint Distribution
    > Service and Instructional Television Fixed Service Licenses to
    > Engage in Fixed Two-Way Transmissions*, MM Docket 97-217, 13 FCC
    > Rcd 19,112 (1998), [recon., 14 FCC Rcd 12,764
    > (1999)](http://web2.westlaw.com/find/default.wl?DB=4493&SerialNum=1999288043&FindType=Y&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw),
    > [further recon., 15 FCC Rcd 14,566
    > (2000)](http://web2.westlaw.com/find/default.wl?DB=4493&SerialNum=2000463059&FindType=Y&AP=&RS=WLW4.10&VR=2.0&FN=_top&SV=Split&MT=Westlaw)
    > (permitting both MDS and ITFS licensees to provide two-way
    > services and increasing flexibility on permissible modulation
    > types and channelization). In both the CMRS and MDS/ITFS context,
    > the Commission did not consider accepting competing applications
    > from non-incumbents because of the difficulties of coordinating
    > new fixed uses with existing mobile uses in CMRS and coordinating
    > fixed two-way transmissions with existing one-way uses in
    > MDS/ITFS. Although we sought comment on the possibility of
    > coordination with respect to MSS spectrum, we have concluded that,
    > as in those prior cases, there is no practical means by which a
    > new licensee could coordinate terrestrial uses with existing
    > satellite rights in the spectrum. *See MSS Flexibility R&O* at
    > 2070-71, ¶225.

[^191]: 47 U.S.C. § 309(j)(3)(A).

[^192]: 47 U.S.C. § 309(j)(3)(D).

[^193]: *See MSS Flexibility R&O* at 2071-72, ¶¶ 227-228.

[^194]: *See* 47 C.F.R.§ 25.150(a)(3) and (a)(4).

[^195]: Inmarsat states that an "amendment will be deemed to be a major
    amendment. . . \[i\]f the amendment increases the potential for
    interference. . . ." *See* Inmarsat *Petition* at 19 (quoting 47
    C.F.R. § 25.116(b)).

[^196]: *See id.* at 20-23.

[^197]: *See* 47 C.F.R. § 25.253(c).

[^198]: *See* Inmarsat *Petition* at 23-24.

[^199]: *Id.* at 24.

[^200]: *Sua Sponte Order* at 13,596, ¶ 14. *See also* 47 C.F.R. §
    25.117(f).

[^201]: *See* MSV *Opposition* at 12.

[^202]: *See* Boeing *Petition* at 4-5. Under the approach we adopted in
    the *Sua Sponte Order*, according to Boeing, MSS operators will
    still be permitted to file applications for ATC authority before
    meeting all gating criteria, but we will not grant ATC
    authorizations until the MSS operator has demonstrated that it has
    met all of the gating criteria. We justified this change on the
    basis that such a system would be easier to administer and would
    provide a clear standard for when an MSS/ATC operator may begin
    commercial operations. *See id.* at 5-7.

[^203]: The process of reviewing and considering licenses applications
    can be long and complex, and we have offered only to endeavor to act
    on each application within 90 days, but made no guarantees. As a
    consequence, MSS operators will be unable to advise potential
    customers when ATC will be available, to the detriment of MSS
    service offerings, contends Boeing. *See id.* at 6-7.

[^204]: With conditional authority to offer ATC, MSS operators could
    even outline their ATC plans, demonstrating that each of the gating
    criteria would be met on a date certain, and ATC operations could
    then commence immediately upon meeting the gating criteria. *See
    id.* at 7-8.

[^205]: Multiple filings, each with its own set of comments and
    petitions in response to public notice, will make the licensing
    process complex and time consuming, argues Boeing. *See id.* at 8-9.

[^206]: *See* *Sua Sponte Order* at 13,594-95, ¶ 10.

[^207]: *See id.* at 13,593, ¶ 7.

[^208]: *See id.* at 13,595, ¶ 11.

[^209]: *Sua Sponte Order* at 13,595, ¶ 11.

[^210]: *See* Boeing *Petition* at 10.

[^211]: The non-operational MSS operator making a "satisfactory,
    prospective and substantial showing that its ATC service will
    satisfy sections 25.149(b)(4) and (b)(5) of the Commission's rules"
    should be granted an ATC authorization conditioned on the operator
    coming into compliance with sections 25.149(b)(1) (geographic and
    temporal coverage), (b)(2) (replacement satellites), and (b)(3)
    (commercial availability).^?^ Boeing states that we should allow
    impending satisfaction of geographic and temporal coverage
    requirements to be demonstrated by a submission of predicted antenna
    gain contours, replacement satellite requirements to be satisfied by
    submission of a contract or certification of a satellite
    manufacturer listing a scheduled completion date, and the commercial
    availability requirement by submission of letters from handset
    suppliers or from customers who have contracted for service. *See
    id.* at 11-13. *See also* C.F.R. § 25.149(b)(1) -- (3).

[^212]: Specifically, Boeing requests that we clarify that the
    demonstrations it advocated can be used to satisfy the geographical
    and temporal coverage, replacement satellite, and commercial
    availability, and that a certificate of compliance from the MSS/ATC
    operator will satisfy the in-band operation requirement of section
    25.149(b)(5) of the rules. *See* Boeing *Petition* at 18-19. *See
    also* 47 C.F.R. § 25.149(b)(5).

[^213]: 47 C.F. R. §§ 25.136(g), 25.143(j).

[^214]: Boeing *Petition* at 15.

[^215]: *Id.* at 17.

[^216]: *Id.* at 18.

[^217]: *See* Inmarsat *Petition* at 15.

[^218]: *See* 47 C.F.R. § 25.254(a)(2).

[^219]: *See* 47 C.F.R. § 25.254(b)(3).

[^220]: *See* Inmarsat, *Comments of Inmarsat Ventures PLC* 20-21 (dated
    Oct. 19, 2001) (in response to the *MSS Flexibility NPRM*).

[^221]: *See* SBE, *Petition for Reconsideration (Petition)* at 1-2.

[^222]: *See id.* at 2-3.

[^223]: *See* Globalstar *Opposition* at 3-5.

[^224]: The RFA, *see* 5 U.S.C § 601-612, has been amended by the Small
    Business Regulatory Enforcement Fairness Act of 1996 (SBREFA), pub.
    L. No. 104-121, Title II, 110 Stat. 857 (1996).

[^225]: 5 U.S.C. § 605(b).

[^226]: 5 U.S.C. § 601(6).

[^227]: 5 U.S.C. § 601(3) incorporating by reference the definition of
    "small-business concern" in the Small Business Act, 15 U.S.C. §
    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."

[^228]: 15 U.S.C. § 632.

[^229]: *MSS Flexibility Notice*, 16 FCC Rcd 15,532 at 15,565-67, ¶¶
    85-93.

[^230]: *MSS* *Flexibility R&O*, 18 FCC Rcd 1962 at 2214-15, Appendix D,
    ¶ 2.

[^231]: *See* 5 U.S.C. § 801(a)(1)(A).

[^232]: *See MSS Flexibility R&O* at Appendix C2, ¶ 1.12.

[^233]: Receiver overload occurs when a signal at the input of a
    receiver's amplifier reaches an amplitude sufficient to cause the
    amplifier to attempt to exceed its maximum possible output level,
    consequently distorting the output signal waveform. If a strong
    signal from a nearby ATC base station overloads the amplifier in an
    Inmarsat terminal receiver, the amplifier will distort the waveforms
    of both the ATC signal and a concurrently-received Inmarsat
    satellite signal. The amplifier's distortion of the satellite-signal
    waveform will cause demodulation errors and resultant errors in the
    receiver's output.

[^234]: MSV *Petition* at 16-17.

[^235]: When an amplifier is operated in its linear range, the gain of
    the amplifier is constant as the input signal level is varied, i.e.
    the output signal level is always G dB higher than the input signal
    level, where G is the gain of the amplifier in dB. As the input
    signal level is increased beyond the linear range of the amplifier,
    the 1 dB compression point of the amplifier is the input signal
    power level at which the gain of the amplifier becomes G-1 dB.

[^236]: The "front end" of a receiver typically comprises the first RF
    amplifier and some frequency-selective components that together
    establish the noise figure and RF bandwidth of the receiver.

[^237]: MSV *Petition* at Appendix C.

[^238]: Inmarsat *Opposition* at A-8.

[^239]: *Id.* at 16.

[^240]: Intermodulation products occur when two or more signals at
    different frequencies combine in a receiver or other device to
    create signals at frequencies that are the sums and differences of
    integer multiples of the original signals. Intermodulation product
    frequencies are calculated by: f~IM~=n\*f~1~ ± m\*f~2,~ where f~IM~
    is the frequency of the intermodulation product, f~1~ and f~2~ are
    the interfering signal frequencies, and n and m are integers greater
    than zero. If an intermodulation product is created by two MSV ATC
    base station signals on a frequency being used by an Inmarsat
    receiver, harmful interference to the Inmarsat receiver may occur,
    depending on the levels of the ATC base station signals at the input
    to the Inmarsat receiver. The strongest intermodulation products
    occur when m + n = 3, i.e. when m = 1 and n = 2, or m = 2 and n = 1.
    These are known as "third-order" intermodulation products.

[^241]: Inmarsat *Opposition* at A-8.

[^242]: A question of handling was also raised about these METs.

[^243]: cdma2000^®^ is a registered trademark of the Telecommunications
    Industry Association (TIA-USA) in the United States.

[^244]: Peak-to-average power ratio is the ratio of the instantaneous
    peak power of a signal to its time-averaged power. A CW signal has a
    peak-to-average power ratio of 1:1, or 0 dB. A standard GSM signal
    using Gaussian minimum-shift keying (GMSK) also has a
    peak-to-average power ratio of 0 dB. MSV's GSM signal has a
    peak-to-average power ratio of about 3.8 dB, and a nine-channel
    cdma2000 signal has a peak-to-average power

[^245]: A constant-envelope signal is one in which the RF envelope of
    the signal has constant amplitude, and the peak-to-average power
    ratio is 0 dB.

[^246]: In a superheterodyne receiver, the desired RF signal is
    converted to an intermediate frequency (IF) signal by mixing it with
    a signal from a local oscillator (LO). The mixing process converts
    signals at frequencies of both LO-RF and LO+RF to the same IF. For
    example, suppose the desired RF signal is centered at 1530 MHz.
    Suppose the LO is at 1540.7 MHz. Mixing the desired RF signal at
    1530 MHz with the 1540.7 MHz LO will produce an IF signal at 10.7
    MHz. However, if a signal is present at 1551.4 MHz, mixing this
    signal with the 1540.7 MHz LO will also produce an IF signal at 10.7
    MHz.