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Public Comment to FCC 02-302

The Notice of Proposed Rule Making (NPRM) Regarding WT Docket No. 01-90
and ET Docket

No. 02-302 "Regarding Dedicated Short-Range Communication Services in
the 5.850-5.925 GHz Band (5.9 GHz Band)"

**Prepared by:**

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**The Johns Hopkins University**

**Applied Physics Laboratory**

**11000 Johns Hopkins Road**

**Laurel, Maryland 20723-6099**

**Public Comment to FCC 02-302**

Approved By: *[Original signed by:]{.underline}*\_\_\_\_\_\_\_\_ Date
[March 17, 2003]{.underline}\_\_\_

Kim E. Richeson

Program Area Manager

Transportation Systems Program Area

Strategic Systems Department

The Johns Hopkins University

> Applied Physics Laboratory

Approved By: *[Original signed by:]{.underline}*\_\_\_\_\_\_\_\_ Date
[March 17, 2003]{.underline}\_\_\_

Ronald K. Char

CVISN Program Manager

Strategic Systems Department

The Johns Hopkins University

> Applied Physics Laboratory

Approved By: *[Original signed by:]{.underline}*\_\_\_\_\_\_\_\_ Date
[March 17, 2003]{.underline}\_\_\_

Robert T. Soranno

Strategic Systems Department

The Johns Hopkins University

> Applied Physics Laboratory

1.  **SCOPE**

The Johns Hopkins University Applied Physics Laboratory (JHU/APL), under
contract to the Federal Highway Administration (FHWA), is a noted
member[^1] of the joint American Society for Test and Measurement (ASTM)
E17.51 Subcommittee and the Institute of Electrical and Electronic
Engineers (IEEE) SCC32 committee that comprise the Dedicated Short Range
Communications (DSRC) Standards Writing Group. The Laboratory endorses
the ITS America submittal to the FCC, regarding DSRC use of the 5.850 to
5.925 GHz band. Technical information is provided to demonstrate that
this plan represents a flexible design that supports interoperable
deployment of public safety applications. This plan implements the
recommendations of the FCC Spectrum Policy Task Force, as stated in
Report ET Docket No. 02-135, dated November 2002[^2]

This document discusses how the proposed Channeling Plan conforms to the
mandates of ET Docket. No. 02-135. The interaction between public safety
applications and private services is described. Recommendations are made
to govern licensing of DSRC. These recommendations include: "license by
rule" for On Board Units (OBUs), Site licensing for Road Side Units
(RSUs) instead of licensing by geographic area, and the prohibition of
Part 15 devices. Answers to specific questions raised by The Commission
in FCC 02-302 are also provided.

2.  **902-928 MHz Location and Monitoring Service Band**

    1.  **Background**

Paragraphs 24 through 29 in Section C of FCC 02-302, entitled
"Interoperability," highlight the problems associated with the
allocation of a frequency band for public applications, without
mandating a national communications standard. The proliferation of
multiple equipment protocols has led to isolated, non-interoperable
service areas throughout the U. S. Users enrolled in more than one
program and long-distance travelers have been forced to purchase
multiple transponders (onboard units), in order to receive service.
Particularly hard hit has been the commercial vehicle operator,
providing interstate transport or nationwide services. Not only are
equipment costs multiplied, but performance and reliability degrades as
the potential for interference increases. In some cases, two or more
transponders of identical manufacture are required onboard the vehicle,
because systems are not interoperable, despite deploying identical
roadside communications equipment. Imagine the public outcry, if
multiple car stereo systems were required, in order to receive AM/FM
broadcast service, in different cities.

Lack of interoperability, through a common communications standard, also
increases deployment and operating costs to state agencies and private
sector operators. Programs are forced to build and maintain redundant
transponder distribution and service capabilities. New service startup
costs are higher, as new programs must account for these
transponder-related costs, without being able to leverage a large,
existing national customer base. Many potential new services, and their
value-added benefits to the nation, are not realized because of this
increased entry cost.

The success, to date, of electronic toll collection (ETC), electronic
screening (E-Screening) and other DSRC-based applications illustrate the
value and utility of the technology. Of particular note is the
overwhelming success of the E-ZPass^sm^ system in the Northeast region.
The E-ZPass^sm^ program allows customers to pay tolls electronically in
multiple states using a single transponder. The widespread acceptance of
E-ZPass^sm^ demonstrates the importance of interoperability.

Because of the tremendous amounts of sunken capital investment in DSRC
hardware and related infrastructure, the possibility of remedying the
current situation without a national standard is virtually impossible.
If the proposed 5.9 GHz DSRC standard was adopted, then systems could
migrate to the new interoperable devices, during the course of the
normal equipment replacement cycle. Without an accepted national
standard, the variety of non-interoperable devices will remain, and the
situation will not improve.

2.  **Collocation of Existing DSRC Systems**

JHU/APL has conducted numerous tests and technical studies into the
possibility of collocating existing 902-928 MHz DSRC devices with
different communications protocols. The results confirmed the obvious.
It is physically impossible for two products, operating at or near the
same frequency, with no timing coordination or other compensation
mechanism, to effectively operate, without interfering with each other.
The passive/backscatter DSRC systems utilize beacons that continuously
provide a signal, even when the transponder is responding. Active
protocol DSRC systems have powered transponders that initiate
transmissions. Thus, backscatter systems interfere with active
transponders by increasing the noise floor. Conversely, active
transponder transmissions create interference to the backscatter
beacons. The problem is even worse when considering the case of two
different active protocol systems, where the transmissions are
sufficiently similar to result in a jamming effect.

Another problem in co-deploying DSRC equipment, both operating in the
902-928 MHz frequency band, occurs for lane-based applications, such as
at ETC plazas. The effective radiated power (ERP) of the beacon
transmissions results in RF spillage into adjacent lanes. The existing
antennas are not physically large enough to support the necessary
directivity, so, a combination of methods, including controlled power
levels, timing, and transaction zone sizing, are used to keep the system
from interfering with itself. Add a second DSRC system, operating in the
same frequency band, and the problem becomes virtually impossible.

3.  **Migration of Existing DSRC Systems from 902-928 MHz to 5.9 GHz**

FHWA has taken a first step toward national interoperability of DSRC
systems, by proposing a standard for Commercial Vehicle Operations (CVO)
deployments[^3]. This proposal would require CVO projects receiving
federal highway funds to adhere to a new 902-928 MHz DSRC standard,
commonly referred to as the "Sandwich Specification." The 902-928 MHz
DSRC Sandwich Specification is based on existing active-protocol product
design, but also incorporates a new application layer standard, IEEE
1455-1999.

IEEE 1455-1999 describes how communications are conducted between the
Roadside Unit (RSU) and the Onboard Unit (OBU). Data access is
controlled using various service tables. Message types and formats are
also specified in IEEE 1455-1999.

The IEEE 1455-1999 standard also defines the application layer for the
proposed 5.9 GHz DSRC standards. This commonality between the 902-928
MHz DSRC Sandwich Specification and the proposed 5.9 GHz DSRC standards
would ease the migration from deployed to new equipment. Since message
types and formats would be unchanged, interfaces to the roadside
equipment would remain the same and back-office systems unchanged.

Discussion presented in Paragraph 83, "Location and Monitoring Service,"
expresses concern about premature adoption and migration to the 5.9 GHz
band (see Section K, Other Matters). Presentations at the DSRC Standards
Writing Group meetings show that these concerns may be overstated.
Several states, including Florida, Texas and New York, are already
planning and making preparations for early transition to 5.9 GHz.

The International Bridge, Tunnel and Thruway Association (IBTTA), a
member of the DSRC Standards Writing Group representing the major ETC
systems, also supports the proposed 5.9 GHz DSRC Standard effort. IBTTA
has also been studying migration strategies to 5.9 GHz DSRC.

3.  **5.850 to 5.925 GHz DSRC Band**

    1.  **Design Considerations**

The Executive Summary of the Task Force Major Findings and the
Recommendations sections of ET Docket No. 02-135, assert that:

-   "The Commission should pursue a balanced spectrum policy that
    includes both the granting of exclusive spectrum usage rights
    through market-based mechanisms and creating open access to spectrum
    'commons', with command-and-control regulation used in limited
    circumstances."[^4]

-   Public safety is identified as an interest objective.

-   "Common Elements of Spectrum Policy" include "(p)olicies that
    encourage grouping of spectrum neighbors" with technically
    compatible characteristics.[^5]

-   Interference management in a dense mobile arena is tantamount.

-   "Command-and-control regulation should be reserved only for
    situations where prescribing spectrum use by regulation is necessary
    to accomplish important public interest objectives or to conform to
    treaty obligations."[^6]

-   "Public safety users should have the ability to lease excess
    capacity for other uses through time sharing of spectrum or other
    mechanisms."[^7]

All of these objectives are recognized and agreed to by the DSRC
Standards Writing Group. The proposed 5.9 GHz standards and the
Channeling Plan developed by the DSRC Standards writing Group satisfies
these objectives.

In order to select the modulation type that fully supports the public
safety requirement, the DSRC Standards Writing Group 9 GHz used the
following guidelines:

-   Maximum data rate should support existing and future requirements

-   Robust modulation scheme to reduce multi-path and fading

-   Use proven or promising emerging technology

-   No limitations on supported public safety applications (exclude
    capability of two-way, real-time voice communications link)

-   Minimal implementation cost

-   Minimum implementation risk

-   Maximum flexibility of features (i.e. channeling, interfacing,
    message lengths, etc.)

-   Open architecture to be freely available to multiple suppliers

-   Diagnostic outputs to assist in performance evaluation

-   Provide for growth to support future applications

-   Detailed specifications and acceptance tests will be defined

-   Licensing procedure will be developed to ensure standard,
    interchangeable and interoperable products.

The DSRC Standards Writing Group performed extensive research and
analysis in order to develop the best solution and optimize use of the
frequency band. These activities included:

-   Examination of the Japanese and European DSRC standards in order to
    adopt the best features of each, and learn from their shortcomings

-   Extensive testing of competing technologies under realistic
    conditions.

-   Multi-path testing was conducted in a parking garage, between
    buildings and at a toll plaza.

-   Two-way data link testing was conducted on highways and at a test
    track at speeds up to 120 mph to determine if sufficient time was
    available to meet transaction requirements.

-   Simulations were developed to characterize the propagation channel
    for DSRC environments[^8] and to model the effects of delay spread,
    antenna height, Doppler and path loss.

Data link simulations were the basis for the DSRC band requirements to
use 10 MHz channels, half the 802.11a data rates, and system clock
requirements with twice the stability of the 802.11a clock. These
requirements reduce the potential for performance degradation due to
multi-path and fading. Also, transmit mask, transmission power level
control and the Received Signal Strength Indication (RSSI) levels are
increased in the DSRC standard, in order to reduce the potential for
interference. This design does not allow for Part 15 devices to
cohabitate in this band with licensed DSRC equipment.[^9]

1.  **DSRC Relationship to Adjacent Frequency Bands**

As noted in Paragraph 29 of FCC 02-302, the DSRC Standards Writing
Group, on August 24, 2001, cast a nearly unanimous decision to select
Orthogonal Frequency Division Multiplexing (OFDM) and IEEE 802.11a
technology as the basis for the new 5.9 GHz DSRC standard. This
selection allowed DSRC to leverage the technology adopted for its
neighbor, the Unlicensed National Information Infrastructure (U-NII)
band. Thus, DSRC now fulfills the Spectrum Policy Task Force Requirement
to "encourage grouping of spectrum 'neighbors' with technically
compatible characteristics."[^10] Selection of the 802.11a technology
opens the market to the large number of chip vendors producing 802.11a
products, and ultimately, significantly reducing development and
manufacturing costs.

Much of the upper layer architecture development effort is designed to
be consistent with relevant International Standards Organization (ISO)
and other IEEE standards. ISO Working Group 16 is developing the
Communication Air Interface Long and Short Media (CALM) architecture.
CALM covers the frequency spectrum from 4.9 to 5.9 GHz, and mandates
total system interoperability at all levels.

To meet the CALM requirements, the DSRC architecture adopted IPV6 as the
method of handling upper layer applications. This design allows DSRC to
use standard internet protocols to handle message traffic in all
channels except the DSRC Control Channel. DSRC is therefore consistent
with the Spectrum Policy Task Force recommendation to develop a
"...balanced spectrum policy that includes both the granting of
exclusive spectrum usage rights through market-based mechanisms and
creating open access to spectrum 'commons', with command-and-control
regulation used in limited circumstances."[^11]

FCC has ruled that the 4.5 GHz band will be provided to emergency
services for communications. Specifically, the 4.5 GHz band will be
restricted to voice and data communications between police, fire, and
other emergency services. DSRC at 5.9 GHz complements this function by
providing for public safety notification and broadcasts. In fact, the
DSRC proposed channeling plan augments the 4.5 GHz capability, by
allowing emergency services to also operate at 5.9 GHz, albeit under the
same rules of usage as the general public[^12].

4.  **DSRC CHANNELING PLAN**

The channeling plan developed by the DSRC Standards Writing Group fully
exploits all IEEE 802.11a, IEEE 802.11 and U-NII band technologies. The
Command Channel concept is based on existing 902-928 MHz DSRC products,
and fully supports the requirement for public safety to be the primary,
but not the only user of the 5.9 GHz band. Section D of FCC 02-0302,
provides a description of this concept. Additional detail is provided
below.

The Control Channel is designated to provide "command-and-control
regulation used in limited circumstances."[^13] It is the "(e)fficient
and reliable enforcement mechanism(s) to ensure regulatory compliance by
all spectrum users."[^14] As stated in Paragraph 37 of FCC 02-302, this
channel ***must*** be accessed on a periodic basis by ***every*** unit
operating in the DSRC band. This channel is used by both RSUs and OBUs
to transmit public safety information and also to advertise the
availability of other licensed services. In order to maintain the
integrity of the Control Channel and ensure the performance necessary to
support public safety functions, it is imperative that only approved
DSRC hardware should operate in this 5.9 GHz frequency band. Other
non-conforming equipment would generate interference since timing on
channels could not be coordinated[^15].

The Spectrum Policy Task Force recommended that, "...command-and-control
regulation should be reserved only for spectrum uses that provide clear,
non-market public interest benefits or that require regulatory
prescription to avoid market failure."[^16] The proposed DSRC Channeling
plan implements this recommendation by supporting the public safety
functions using the Control Channel while also permitting other private
sector services to operate.

The ability to fully support, and grant priority to all public safety
messages is required for all RSUs. Otherwise, the RSUs may be operated
to provide services without interference to other users. Licensing of
RSUs is critical because this design could be exploited to provide
priority to non-critical transmissions, and therefore, interfere with
public safety and other legitimate services.

OBUs are required to listen to the Control Channel every few hundred
milliseconds[^17], in order to check for public safety messages. The
messages on the Control Channel are of variable length, but are
generally kept short, to permit maximum access to the channel. Licensing
of both RSUs and OBUs is necessary to prevent excessive use of the
Control Channel. OBUs should be licensed by rule, since these devices
are mobile and can operate across the nation communicating with any
other DSRC devices within range[^18].

Control Channel access will be performed via a standard 802.11a feature,
Carrier Sense Multiple Access with Collision Detection (CSMA/CD). All
devices when tuned to the Control Channel, by default listen for a
transmission. If a DSRC device desires to transmit, but detects another
message being broadcast on the Control Channel, it must wait before
attempting to transmit. A request to send (RTS) is initiated and time is
granted first to high priority (public safety) broadcasts, then to lower
priority transmissions. If a device leaves the Control Channel, to
communicate on another channel, a timer is activated to indicate when to
return to the Control Channel.

The same Control Channel is used for roadside-to-vehicle,
vehicle-to-roadside and vehicle-to-vehicle communications. This design
exploits the fact that DSRC has limited range. Simulations indicate that
even in high density areas, reliable service can be provided. Additional
simulations are being developed to refine the detailed specification of
the Control Channel.

Since the Control Channel will be fixed throughout the nation, all DSRC
devices will be designed to access those services. ASTM Standard
E2213-02 now requires that every DSRC device to power-up in a default
state[^19] to listen on the Control Channel. Note that only Control
Channel services are required for all devices. Therefore, a wide range
of DSRC products can be developed, with low-cost devices only providing
access to the services residing on the Control Channel, which includes
public safety. High-end, more expensive devices will be able to support
additional DSRC and U-NII channels and deliver the full capability of
DSRC.

5.  **LICENSING ISSUES**

    1.  **Onboard Units (OBUs)**

By definition, an OBU is any mobile device that participates in the DSRC
band and conforms to the DSRC rules while in motion. As the Commission
points out in Paragraph 51 of Section 2.0 of FCC 02-302 entitled "On
Board Units," there are basically two types of OBUs. The Public Safety
OBUs are equipped with enhanced capabilities to support public safety
and emergency services[^20]. The second classification, entitled "OBUs
associated with a specific system," is contrary to the proposed DSRC
concept and not in the best interest of the nation. Since OBUs are
general purpose devices, supporting a wide range of both private and
public services, throughout the nation, it is impossible to associate
these OBUs with a single specific system. Instead the DSRC proposal
defines "private OBUs," which are "licensed by rule" devices, intended
for use by the general public. These devices freely operate with
multiple systems, across the nation.

DSRC is designed to capitalize upon the significant advantages offered
by current spectrum-based radio smart technologies. Smart technologies
sense the spectrum environment to dynamically adapt and adjust
operations. "...Increasing access to the spectrum for smart
technologies, such as software-controlled radios, can improve
utilization, through more efficient access, of the radio spectrum
without detriment to existing spectrum users."[^21] DSRC devices are
software-controlled and incorporate these smart technologies. Extensive
power control features used in both transmission and RSSI reporting
conforms to both the "commons" model and the "command-and-control" model
of the Spectrum Policy Task Force. They also allow DSRC devices to
afford the maximum amount of interference protection[^22] and permits
"power levels to be adjusted to match the environment of the transmitter
and the intended service area."[^23]

Private OBUs will be limited to 23 dBm maximum effective radiated output
power. Power levels for transmission will be adjusted automatically, as
part of the communications. When a receiving device detects
point-to-point transmissions, its RSSI determines the appropriate output
power adjustment for the transmitting device. The required output power
information is sent back to the transmitting device, via a reply
message. And, likewise, the appropriate output power adjustment for the
return link is also communicated in the opposite direction. In this
manner, transmission power levels can be optimized and the number of
DSRC devices sharing the spectrum can be maximized. This design affords
the "Maximum Flexibility of Spectrum Use"[^24] in a frequency band
"...in which regulating spectrum use on a command-and-control basis may
continue to be necessary to achieve certain public interest
objectives."[^25]

Conformance with these highly-advanced DSRC design requirements can not
be ensured by Part 15 regulation. Part 15 does not mandate adequate
power, power control, clock stability or channel control to satisfy the
proposed DSRC architecture. If Part 15 devices were permitted to operate
without coordination, it would have the effect of increasing the noise
floor and otherwise interfering with DSRC devices. Allowing
limited-capability Part 15 devices to operate in the 5.9 GHz band,
without requiring the additional DSRC requirements would reduce the
overall performance and reliability of the frequency band.

DSRC OBUs should be licensed by rule and mandated to participate on the
Control Channel while moving. License by rule satisfies the requirement
of the Spectral Policy Task Force for "(e)fficient and reliable
enforcement mechanisms to ensure regulatory compliance by all spectrum
users."[^26] Requiring all devices in the 5.9 GHz band to operate in
accordance with the DSRC standards is necessary, to reliably support
public safety functions and other services.

Public Safety OBUs are permitted higher output power levels on specific
channels to ensure that safety transmissions reach their intended
audience[^27]. Additional features are also included to allow emergency
vehicles to perform safety functions such as traffic signal control and
emergency message broadcast. In order to prevent this privileged
capability from being abused or counterfeited, special security measures
are necessary. Licensing and regulation of these Public Safety OBUs is
absolutely required.

Finally, in regard to the issue The Commission raises in Paragraph 53 of
FCC 02-302, "we seek comment on whether OBUs not associated with an RSU
should be permitted to operate under Part 15." All OBUs associate with
RSUs for Control Channel information. All RSUs are required to transmit
public safety information to all OBUs in range. Therefore, OBUs are
always associated with any RSU within range. As discussed earlier, Part
15 operations, whether by dedicated devices, or as a feature of OBUs,
should not be permitted due to degradation in the overall performance
and reliability of the frequency band.

2.  **Roadside Units (RSUs)**

An RSU is a device that operates in the DSRC band from a stationary
position. The same rules of Control Channel utilization used for OBUs
also apply to RSUs.

There are two types of RSUs, fixed and portable. Fixed RSUs are affixed
to a structure or otherwise installed at a stationary location. Portable
RSUs are public safety devices that can be temporarily placed near a
danger zone, and operated in a stationary manner. These Portable RSUs
can perform functions similar to the variable message signs currently
used by highway authorities. Only authorized agencies will be allowed to
own Portable RSUs, and their operations restricted to public safety
functions.

RSU installations are similar to cellular towers in that it has a
communication zone dictated by the RF environment. The RSU controls
communications/transactions between OBUs within its zone. It may have
hardwired connections to external resources, permitting data transfer
and coordination of message traffic with other RSUs and back office
applications. Unlike cellular towers, large/tall structures are not
required as DSRC communication ranges are very limited. RSUs should be
non-interference devices without overlapping communication zones in the
5.9 GHz DSRC band.

While geographic licensing works best for cellular service, it is not
the correct solution for DSRC. Cellular service is best operated in
large continuous coverage areas served by a few providers. In contrast,
DSRC is envisioned to encompass a multitude of services, provided by a
number of enterprises, each with localized communications zones. In many
cases, DSRC operations, and the associated communications zones may be
restricted to the property boundaries of the private enterprise (i.e.
restaurants, gas stations, parking facilities, banks, etc...).

Although geographic licensing may be initially successful at getting
some DSRC services rapidly deployed, as noted by The Commission in
Paragraph 48 of FCC 02-302, it would not serve the long term interests
of the nation. Geographic licensing would inhibit the multitude of
services that could be provided. It would be a windfall for the luck few
that get in first, and an economic barrier or burden for all that
follow. The overall success of the 5.9 GHz DSRC frequency band may be
jeopardized because of the minimal value added by only a limited number
of services. Site licensing is the best way to act on the recommendation
of the Spectrum Policy Task Force found in "The Case for Spectrum
Reform," whereby "(t)he Commission should also strive, wherever
possible, to eliminate regulatory barriers to increased spectrum
access."[^28]

High-technology "smart antennas"[^29] further support deployment through
site licensing. Use of high frequency/short wavelength combined with new
higher dielectric microwave materials permits tiny, inexpensive antenna
arrays, and patches to be customized to service any communication zone
requirement[^30]. Coverage initially granted to an RSU to serve a broad
area could later be adjusted when new RSUs enter the area. Also
additional RSUs may be able to target specific communications zones, in
the vicinity of, but otherwise uncovered by existing RSUs. Time Division
Multiple Access (TDMA) with CSMA-CD and channel limits methods could
also be used to prevent interference of operations in close proximity.

Public safety services would have priority for site licenses. Other
services, including private sector providers would require site
licensing, to guarantee a level of service and to ensure that they do
not interfere with other users. Note that all licensees would be
required to be licensed for the control channel in addition to specific
service channels."[^31]

Private users could lease underutilized capacity from public safety
installations or other facilities to assure maximum, efficient
utilization of spectrum. Leased services and other users could be
preempted whenever public safety broadcast is required. That is one
scenario, but not the only, where public safety capabilities would
propagate, fueled by private sector resources.

6.  **SPECIFIC ISSUES**

This section provides discussion on the specific issues raised by the
FCC. These items are addressed in the order in which they were presented
in the NPRM.

1.  **Paragraph 14: The Definition of DSRC**

In response to The Commission's question regarding the definition of
DSRC, information is already provided throughout the NPRM, and
specifically in the questions and discussions presented by The
Commission through Paragraph 23. Although many applications have been
identified, the DSRC Standards Writing Group is unable to list all of
the potential applications for DSRC, because such a compilation would
incomplete. Since the channel plan and DSRC hardware are being designed
to support a twenty plus year life cycle, it would be short-sighted to
generate a list from the current perspective.

Specifically, The Commission asks whether or not DSRC should handle the
audio component of the "Emergency Vehicle Video Relay." The 4.940-4.990
GHz band, under the plan proposed by ETA[^32], is a more appropriate
place for this application to reside. It should not be explicitly
excluded from DSRC, and could reside there if so desired. In general,
the definition of "data transfer" should remain as flexible as possible
and not exclude specific applications where possible.

As pointed out in Paragraph 15, DSRC is not designed to be a real-time,
two-way communication system to compete with the cellular system, or for
mobile video applications. Under stationary conditions, the throughput
rates would support real-time data transfer.

The best answer to the question regarding a definition of DSRC, is that
DSRC has been purposely designed to be integrated into the CALM
architecture. CALM seeks to utilize the best resource for an
application, subject to the guidelines and restrictions for the devices.
If DSRC best satisfies the requirements of an application, then it
should be used.

2.  **Paragraph 16: Changing the Service Definition from "Including
    Commercial Environments" to "A Variety of Environments":**

Instead of either of these two options, we support the ITS America
application to change the definition to "private environments." The term
"variety" could be interpreted to permit the use of unlicensed
equipment. The ITS America recommendation that the 5.9 GHz band 'be
designated for shared public safety and private services"[^33] is
correct and precise.

3.  **Paragraph 19: Public Safety Radio Services**

The 4.940-4.990 GHz band, with no interference from private and
commercial users, is the appropriate location for these services. The
DSRC Standards Writing Group has purposely excluded point-to-point
direct emergency service communications and has listed it under
"exemptions."

4.  **Paragraphs 22 and 23: Non-public Safety Uses**

In these paragraphs The Commission asks if private users should be
permitted to use the public safety DSRC band. The Commission also asks
if non-public safety applications should be permitted in the band.

The DSRC proposal would allow private users to provide services though
the 5.9 GHz band without compromising support of public safety services.
The Control Channel and licensing requirements guarantee that the DSRC
band will "preserve and protect the ability of public safety entities to
do their important jobs in light of the increasing spectrum
demands."[^34]

5.  **Paragraph 31: Interoperability**

The DSRC Standards Writing Group shares the Commission's concerns and is
taking a number of steps to ensure interoperability.

A test plan to verify compliance with ASTM E2213-02 is being developed.
This document, "Standard Test Method for Telecommunications and
Information Exchange Between Roadside and Vehicle Systems Specific
Requirements -- 5 GHz Band Dedicated Short Range Communications (DSRC)
Medium Access Control (MAC) and Physical Layer (PHY) Standard Test
Method," verifies that products conform to ASTM E2213-02. Specifically,
interoperability at the lower layers of the communications stack, is
being checked.

Interoperability requirements extend beyond the lower layers. The DSRC
Standards Writing Group expects that all DSRC operations should conform
to the IEEE standards documents governing the upper layers of
communication stack. A letter has been drafted by the DSRC Standards
Writing Group to the FHWA and ITS America informing them of this
additional requirement.

To ensure interoperability, all DSRC hardware devices must be certified
to operate in the band. The DSRC Standards Writing Group also recommends
"(p)eriodic review and revision of spectrum rules to account for
technological advances and other changes."[^35] This action is necessary
to accommodate changing requirements throughout the life cycle.

6.  **Paragraphs 35 to 39: Band Plan**

Detail discussion regarding the design of the band and channeling plans
are provided in Sections 3 and 4 of this document. The channel size was
developed to support DSRC in a mobile, high multi-path environment while
taking full advantage of the 802.11a U-NII Band with technically
compatible characteristics."[^36] Channels smaller than 10 MHz would not
have met the performance requirements for DSRC.

In Paragraph 39, The Commission requests inputs regarding the structure
of the channeling plan and the possibility of subdividing it. The DSRC
Control Channel is a single channel, accessible throughout the country.
All DSRC devices must be able to operate on the Control Channel.
Restricting operations on selected other channels to specific types of
operations could accomplish the same effect as subdivision while
retaining interoperability among DSRC devices.

7.  **Licensing Plan, Road Side Units and On Board Units**

RSUs should be regulated using site licensing. OBUs should be governed
using license by rule. Part 15 devices should not be allowed. Detailed
discussions on each of these recommendations can be found in Section 5
of this document

8.  **Treatment of Incumbent Services**

There exists a potential problem for DSRC to interfere with the Fixed
Satellite Service. The noise floor could increase for satellite
receiving antennas as a result of DSRC operations at the same or
adjacent frequencies. If such a problem is identified, then using the
flexible channeling plan, operations at or near those frequencies could
be avoided. The satellite stations are treated as primary users to be
protected in the band. Site licensing protects the satellite services as
well as other radar users.

7.  **SUMMARY**

The Johns Hopkins University Applied Physics Laboratory, under contract
to the Federal Highway Administration endorses the ITS America submittal
to the FCC, regarding DSRC use of the 5.850 to 5.925 GHz band. Technical
information is provided to demonstrate that this plan implements the
recommendations of the FCC Spectrum Policy Task Force, as stated in
Report ET Docket No. 02-135, dated November 2002[^37]

The ASTM E2213-02 lower layer standard and its associated test plan,
represent an integrated package for 5.9 GHz DSRC hardware development,
integration and interoperability in North America. Combined with the
IEEE upper layer standards, the DSRC products should be interoperable
and interchangeable.

DSRC licensing should be handled as follows:

-   OBUs should be licensed by rule devices.

-   RSUs should be required to obtain site licenses.

-   Part 15 devices should be prohibited.

As proposed, DSRC would satisfy the recommendations of the Spectrum
Policy Task Force. Specifically, DSRC:

-   ensures effective public safety operations,

-   supports efficient band utilization,

-   minimizes interference through controlled management of resources,

-   matches up with neighbors with technically compatible
    characteristics,

-   provides a clear definition of spectrum user's rights and
    responsibilities,

-   supports leasing of spectrum capacity during low-use periods, and

-   conforms to the Spectrum Rights "Command-and-Control" model.[^38]

The DSRC proposal should be adopted as it reliably, efficiently and
effectively supports both public safety and private sector services.

[^1]: Section C, Paragraph 28 entitled, "ITS America and the Standards
    Writing Group" of FCC 02-0302

[^2]: Federal Communications Commission Spectrum Policy Task Force
    Report ET Docket No. 02-135, November, 2002.

[^3]: Department of Transportation, Federal Highway Administration, 23
    CFR Part 945, FHWA Docket No. FHWA 99-5844, RIN 2125-AE63,
    "Dedicated Short Range Communications in Intelligent Transportation
    Systems (ITS) Commercial Vehicle Operations.

[^4]: Reference 2, Page 3.

[^5]: Ibid, Page 4.

[^6]: Ibid, Page 5.

[^7]: Ibid, Page 17.

[^8]: "DSRC Physical Channel Characterization", Final Report, prepared
    for CALTRANS TCFI by TechnoCom Corporation, June 30, 2000.

[^9]: Response to question posed by The Commission in Paragraph 50 of
    Reference 1 regarding shared usage of DSRC and Part 15 equipment in
    the DSRC band.

[^10]: Reference 2, Page 16.

[^11]: Reference 2, Page 3.

[^12]: With the exception of being allowed higher effective radiated
    power for applications on Channel 184.

[^13]: Reference 2, Page 3.

[^14]: Ibid, Page 4.

[^15]: See footnote 16.

[^16]: Ibid, Page 41.

[^17]: The exact access time will be determined via simulations

[^18]: OBU-to-OBU communications would be an enhancement function over
    the low cost, baseline OBU product

[^19]: ASTM E2213-02, [Standard Specification for Telecommunications and
    information exchange between roadside and vehicle systems, Specific
    requirements -- 5 GHz Band Dedicated Short Range Communications
    (DSRC) Medium Access Control (MAC) and Physical Layer (PHY)
    specifications,]{.underline} Section 6.4.1.

[^20]: Ibid, Sections 8.9.1.6 and 8.9.1.7.

[^21]: Reference 2, Page 15.

[^22]: Ibid, page 18.

[^23]: Ibid, page 19.

[^24]: Ibid, Page 16.

[^25]: Ibid, Pages 16 and 41.

[^26]: Reference 2, Page 4.

[^27]: For example, traffic signals, cars, etc. within their intended,
    extended communication zone.

[^28]: Reference 2, Page 4.

[^29]: See, for example, "Smart Antennas: The Freedom to Choose",
    Wireless Design and Development Magazine, November 2002, Pages
    20-22.

[^30]: For the technology competition, JHU/APL was required to produce
    antennas for RSU and OBU operations. For the RSU, a helix antenna
    was constructed, measuring approximately 6 inches in length by 2.5
    inches at the base. This antenna had as good a pattern as the 36
    inch by 36 inch antennas currently used for ETC beacons and could be
    manufactured for a fraction of the cost.

[^31]: Reference 1, Paragraph 46, Pages 29-30.

[^32]: "Wireless Communications Systems for Public Safety 4.9 GHz --
    Leveraging 5.9 GHz DSRC to 4.9 GHz PS by Engineering Technology of
    America, Inc., December 2002.

[^33]: Reference 2, Paragraph 17, page 13.

[^34]: Ibid, Page 3.

[^35]: Reference 2, Page 4.

[^36]: Ibid, Page 4.

[^37]: Federal Communications Commission Spectrum Policy Task Force
    Report ET Docket No. 02-135, November, 2002.

[^38]: Reference 2, Page 5.