Before the
FEDERAL COMMUNICATIONS
COMMISSION
Washington, DC 20554
In the Matter of Revision of
Parts 2 and 15 of the Commission’s Rules to Permit Unlicensed
National Information Infrastructure (U‑NII) Devices in the 5 GHz Band |
) ) ) ) ) ) ) |
ET Docket No. 03-122 RM - 10371 |
COMMENTS OF THE NATIONAL
TELECOMMUNICATIONS
AND INFORMATION
ADMINISTRATION
Michael D. Gallagher Kathy
D. Smith
Acting Assistant
Secretary for Chief
Counsel
Communications and
Information
Fredrick R. Wentland
Associate
Administrator
Office of Spectrum
Management
Charles T. Glass
Telecommunications
Specialist
Office of Spectrum
Management
Edward F. Drocella
Robert L. Sole
Electronics
Engineers
Office of Spectrum
Management National
Telecommunications and
Information
Administration
U.S.
Department of Commerce
Room
4713
1401
Constitution Avenue, N.W.
Washington,
DC 20230
(202)
482-1816
October 1, 2003
TABLE OF CONTENTS
Section
EXECUTIVE SUMMARY . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . .
I. INTRODUCTION . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . .
II. NTIA SUPPORTS THE COMMISSION’S PROPOSAL TO
CHANGE
THE U.S. TABLE OF FREQUENCY
ALLOCATIONS TO
ACCOMMODATE
THE NEEDS OF FEDERAL AND NON-FEDERAL
GOVERNMENT RADIO
SERVICES OPERATNG IN THE 5 GHZ
FREQUENCY RANGE. .
. . . . . . . . . . . .
III. NTIA SUPPORTS THE COMMISSION’S PROPOSAL TO
MODIFY
THE
PART 15 RULES TO ACCOMMODATE EXPANDED USE OF
U-NII
DEVICES. . . . . . . . . . . . . . . . . .
IV. NTIA SUPPORTS THE COMMISSION’S PROPOSAL TO
REQUIRE
U-NII
DEVICES OPERATING IN THE 5.25-5.35 GHZ AND
5.47-5.725
GHZ FREQUENCY BANDS TO EMPLOY DFS TO AVOID
INTERFERING WITH
CRITICAL FEDERAL RADAR OPERATIONS .
V. NTIA IS LEADING A PROJECT TEAM WITH GOVERNMENT
AND
INDUSTRY REPRESENTATIVES TO DEVELOP COMPLIANCE
MEASUREMENT PROCEDURES
FOR DFS ENABLED U-NII
DEVICES.
. . . . . . . . . . . . . .
VI. NTIA SUPPORTS IMPLEMENTING TPC IN BOTH THE
5.25-5.35 GHZ
AND 5.47-5.725 GHZ
FREQUENCY BANDS .
VII. NTIA RECOMMENDS THAT U-NII DEVICES OPERATING
IN
THE 5.25-5.35 GHZ
FREQUENCY BAND THAT ARE
IMPORTED
SHOULD ADHERE TO THE COMMISSION’S
PROPOSED
TRANSITION SCHEDULE FOR DOMESTIC DEVICES
VIII. IN ORDER TO AVOID CONFUSION, NTIA RECOMMENDS
THAT ADDITIONAL
DEFINITIONS BE INCLUDED IN THE
COMMISSION’S
RULES FOR U-NII DEVICES .
IX. CONCLUSION
. . . .
DESCRIPTION OF RADAR USAGE IN THE 5 GHZ
FREQUENCY
RANGE . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . APPENDIX A
DRAFT MEASUREMENT PROCEDURES FOR DFS EQUIPPED
U-NII DEVICES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . APPENDIX B
SCHEDULE OF PROJECTED MILESTONES FOR 5 GHZ
PROJECT
TEAM . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . APPENDIX C
The National Telecommunications and
Information Administration (NTIA) commends the Federal Communications
Commission (Commission) for initiating this proceeding to expand the
options for unlicensed device use, and particularly, linking such
expanded use to adoption of new technologies for active
interference-avoidance. NTIA agrees with
the Commission regarding the significant benefits to the economy,
businesses, consumers, and government agencies that could be gained by
allowing unlicensed devices to operate in the 5.47-5.725 GHz frequency
range, provided that such operation is tied to effective implementation
of active interference-avoidance techniques. NTIA
would also like to commend the Commission for its careful consideration
and review of existing Part 15 Rules in the 5.25-5.35 GHz band as well
as consideration of the federal government and private sector spectrum
requirements in the 5 GHz frequency range. NTIA
provides the following comments to specific issues raised in the
Unlicensed-National Information Infrastructure (U-NII) Notice of
Proposed Rulemaking (NPRM) that may have an impact on critical federal
systems used for scientific research, aviation, and national defense.
NTIA
supports the Commission’s proposals to upgrade the frequency
allocations of federal government Radiolocation Service, and federal
and non-federal government Space Research Service (active) and the
Earth Exploration-Satellite Service (active) in the 5 GHz frequency
range. Upgrading these allocations is
consistent with the allocations adopted internationally, and will
provide the necessary protection to federal systems supporting national
defense as well as federal and non-federal commercial and scientific
operations. In addition to the allocation
upgrades in the 5 GHz frequency range, several footnotes were adopted
at the World Radiocommunication Conference 2003 (WRC-2003). There were also modifications made to several
existing footnotes in the 5 GHz frequency range. The
Commission’s proposal to modify the U.S. Table of Frequency Allocations
did not include the new footnotes or the modifications to existing
footnotes that were adopted at WRC-2003. NTIA
believes that the modifications to the U.S. Table of Frequency
Allocations should include the appropriate new footnotes and
modifications to existing footnotes adopted at WRC-2003. NTIA
believes that the inclusion of these new footnotes and the
modifications to existing footnotes are necessary because of the
complex sharing arrangements that exist between the diverse federal and
non-federal government radio services operating in the 5 GHz frequency
range.
NTIA
supports the Commission’s proposal to modify the Part 15 Rules to allow
U-NII devices to operate in the 5.47-5.725 GHz band on a
non-interference basis. Utilization of the
mitigation measures proposed in the NPRM along with the additional 255
MHz of spectrum for U-NII devices to spread across will provide
protection to vital government systems. The
Commission’s proposal will also meet current industry needs as well as
future growth in the radio local area network radio local area network
(RLAN) industry which has proven to be one of the few technology
success stories in the current economy.
NTIA
concurs with the Commission’s proposal that Dynamic Frequency Selection
(DFS) should be required in the existing 5.25-5.35 GHz U-NII band as
well as the proposed U-NII 5.47-5.725 GHz band. NTIA
also concurs with the technical limits on DFS proposed by the
Commission. Comprehensive studies carried
out jointly between NTIA, Department of Defense, and private industry
with Commission representatives has proven the requirement for these
technical limits. Specifically, NTIA
considers the proposed power limits, detection threshold, move time,
and non-occupancy period as fundamental for the protection of
government radars and no relaxation in the proposed values can be
accepted based on the studies cited above. DFS
is an integral part of the protection measures that allows for sharing
between the U-NII devices and existing primary government users. NTIA is of the opinion that the DFS mechanism
should be required to detect a single radar pulse present during
coincidence of the transmitted radar pulse and the dedicated listen
period of the DFS mechanism between each packet/frame. The
requirement should be for detection of a single pulse during this
coincidence period. In addition, the DFS
mechanism should be allowed to average received power over successive 1
microsecond periods during the dedicated listen period. Given
the typical pulse widths and pulse repetition rates of the radars
operating in these bands, as well as the average power levels
transmitted by these radars, the DFS mechanism should have no problems
detecting single radar pulses during coincidence. This
will not allow for radar signal detection and instead forces the DFS to
rely on signal detection above the DFS detection threshold no matter
the source. This provides further
protection of radar systems given the high probability of masking of
radar signals from adjacent, competing U-NII devices.
NTIA’s
Office of Spectrum Management is leading a government/industry project
team to develop proposed compliance measurement procedures for DFS
equipped U-NII devices. This project team
will be responsible for addressing technical issues related to the
generation of radar signals and the techniques to reliably measure
these signals. NTIA believes that this
government/industry project team has the expertise to provide guidance
to the Commission in the development of the compliance measurement
procedures for DFS equipped U-NII devices. A
first draft of the proposed compliance measurement procedures is
provided as part of these comments. There
are plans in the November 2003 timeframe for manufacturers to bring DFS
equipped devices to NTIA’s Institute for Telecommunication Sciences to
validate the draft measurement procedures. This
testing will be dependent on the availability of DFS equipped U-NII
devices. NTIA will submit a report to the
Commission documenting the results of these measurements and any
modifications to the draft procedures. NTIA
believes that providing the draft measurement procedures to the
Commission as part of the public record will allow other parties that
are not participating in the government/industry project team to review
and provide comments on the proposed measurement procedures.
The
current Institute of Electrical and Electronics Engineers (IEEE) 802.11
standards require Transmitter Power Control (TPC) in both the 5.25-5.35
GHz and 5.47-5.725 GHz bands as a means to facilitate sharing among
U-NII devices. Therefore, NTIA believes
that it should not create a burden on industry to implement TPC in both
bands. NTIA believes that TPC will provide
a mitigation factor of at least 3 dB within the EESS/SRS satellite
footprint providing additional protection for these critical government
operations.
NTIA
agrees with the Commission’s transition schedule for domestically
manufactured U-NII devices operating in the 5.25-5.35 GHz band. NTIA believes that this approach will lessen
the burden on manufacturers by allowing them adequate time to redesign
their devices to comply with the DFS and TPC requirements necessary to
protect federal systems. NTIA recommends
that the Commission require that imported U-NII devices operating in
the 5.25-5.35 GHz band adhere to the Commission’s Rules (e.g., DFS and
TPC), one year after the date of publication of the Report and Order in
the Federal Register.
Finally, NTIA recommends that the Commission
include additional definitions in their rules for U-NII devices. The additional definitions proposed by NTIA
are consistent with the terminology employed by the RLAN industry, and
will help to avoid confusion that may arise when developing compliance
measurement procedures for U-NII devices.
COMMENTS OF THE NATIONAL TELECOMMUNICATIONS
AND INFORMATION ADMINISTRATION
The National Telecommunications and
Information Administration (NTIA), an Executive Branch agency within
the Department of Commerce, is the President’s principal adviser on
domestic and international telecommunications policy, including
policies relating to the Nation’s economic and technological
advancement in telecommunications. Accordingly,
NTIA makes recommendations regarding telecommunications policies and
presents Executive Branch views on telecommunications matters to the
Congress, the Federal Communications Commission (Commission), and the
public. NTIA, through the Office of
Spectrum Management, is also responsible for managing the Federal
Government’s use of the radio frequency spectrum. NTIA
respectfully submits the following comments in response to the
Commission’s Notice of Proposed Rulemaking (NPRM) in the
above-captioned proceeding.[1]
The U-NII NPRM is seeking comments on the
feasibility of allowing unlicensed devices to operate in additional
frequency bands. Specifically, the NPRM
proposes to amend Part 15 of the Commission’s Rules governing the
operation of Unlicensed National Information Infrastructure (U‑NII)
devices, including Radio Local Area Networks (RLANs), to make available
an additional 255 megahertz of spectrum in the 5.47–5.725 GHz
band, and on the technical requirements that would be necessary to
ensure that such devices do not cause interference to authorized
services operating within the 5.25-5.35 GHz and 5.47-5.725 GHz bands.[2] The Commission also proposes other changes to
the United States (U.S.) Table of Frequency Allocations to accommodate
the needs of other radio services operating in the 5 GHz region of the
spectrum. Finally, the Commission proposes
to modify certain technical requirements for U‑NII devices in the Part
15 Rules to protect various radio services against harmful interference.[3] These proposals are consistent with the
outcome of the World Radiocommunication Conference 2003 (WRC-2003) and
the subsequent changes to the international Radio Regulations.
NTIA commends the Commission for initiating
this proceeding to expand the options for unlicensed device use and
particularly, linking such expanded use to adoption of new technologies
for active interference avoidance. NTIA
agrees with the Commission regarding the significant benefits to the
economy, businesses, consumers, and government agencies that could be
gained by allowing unlicensed devices to operate in the 5.47-5.725 GHz
frequency range, provided that such use is tied to effective
implementation of active interference avoidance techniques. NTIA would also like to commend the Commission
for its careful consideration and review of existing Part 15 Rules in
the 5.25-5.35 GHz band as well as consideration of the federal
government and private sector spectrum requirements in the 5 GHz
frequency range. NTIA provides the
following comments in response to specific issues raised in the U-NII
NPRM.
II. NTIA
SUPPORTS THE COMMISSION’S PROPOSAL TO CHANGE THE U.S. TABLE OF
FREQUENCY ALLOCATIONS TO ACCOMMODATE THE NEEDS OF FEDERAL AND
NON-FEDERAL GOVERNMENT RADIO SERVICES OPERATING IN THE 5 GHZ FREQUENCY
RANGE.
In
the U-NII NPRM, the Commission proposes to modify the U.S. Table of
Frequency Allocations to upgrade the status
of the federal government Radiolocation Service to primary in the
5.46–5.65 GHz band.[4] The Commission further proposes to add primary
allocations for the federal government and secondary allocations for
the non-federal government Space Research Service (active) (SRS) in the
5.35-5.57 GHz band and the Earth Exploration-Satellite Service (active)
(EESS) in the 5.46‑5.57 GHz band.[5] The Commission also proposes to upgrade the
allocation status of non-federal government Radiolocation to primary in
the 5.47-5.65 GHz band.[6]
The
Department of Defense (DoD) operates numerous radars in the 5.25-5.925
GHz frequency range in support of national defense, military test range
surveillance and instrumentation operations, airborne radar
transponders, battlefield missile surveillance and tracking, weather
radar observations, shipborne missile and gunfire control, and
navigational aids to assist precision positioning of ships.[7] Non-military government radar operations in
the 5.25-5.925 GHz frequency range include support for airborne weather
and navigation, weather phenomena research studies, and airport
terminal Doppler weather radars.[8] Appendix A provides a description of radar
usage in the 5 GHz frequency range.
The
primary factors driving the need for additional radar spectrum include
changes in requirements, missions, and technology which result in the
use of narrow pulse widths, and wide emission bandwidths to achieve the
resolution necessary to detect smaller and less reflective targets in
the presence of background clutter.[9] Given the increasing demands for spectrum in
the 5.25-5.925 GHz frequency range to support radar system development,
there is a need to upgrade the allocations of the federal government
radiolocation spectrum allocated on a secondary basis to primary. Upgrading the allocation from secondary to
primary in the 5.46-5.65 GHz frequency range will provide the same
regulatory protection throughout the entire tuning range of these radar
systems. This upgrade to primary
allocation is necessary to safeguard the operation of existing and
future radar operations in the 5 GHz frequency range from potential
interference resulting from the increased sharing demands to
accommodate new licensed and unlicensed radio services.
Active
sensing is the measurement on board a spacecraft of signals transmitted
by a sensor and then reflected, refracted, or scattered by the Earth’s
surface or its atmosphere. Prior to
WRC-2003, the U.S. Government identified a requirement to expand the
bandwidth available for spaceborne altimeters and synthetic aperture
radars (SARs) operating in the EESS (active) in the 5.25-5.46 GHz band
from 210 MHz to 320 MHz (5.25-5.57 GHz). This
increase in spectrum is necessary to satisfy a requirement for
altimeter height measurements with a standard deviation of 1 to 2.5
centimeters and a SAR requirement for measurements with enhanced ground
resolution of 1 meter. The higher quality
data collected using wideband SARs will allow scientist to gain new
insights into the prediction of climatic changes. These
wideband SARs will also provide the higher resolution necessary for
commercial applications, such as high-resolution surface mapping. For example, by increasing the bandwidth
available to SARs it will be possible to precisely map the boundary of
oil spills to a resolution of 1 meter.
NTIA
supports the Commission’s proposals to upgrade the frequency
allocations of federal government Radiolocation, and federal and
non-federal government SRS (active) and EESS (active) in the 5 GHz
frequency range. Upgrading these
allocations is consistent with the allocations adopted internationally,
and will provide the necessary protection to federal systems supporting
national defense as well as federal and non-federal commercial and
scientific operations. NTIA notes that the
U-NII NPRM does not include the new footnotes or the modifications to
existing footnotes that were adopted at WRC-2003.[10] NTIA believes that the modifications to the
U.S. Table of Frequency Allocations should include the appropriate new
footnotes and modifications to existing footnotes adopted at WRC-2003. NTIA recommends that the Commission include
the following new footnotes in the U.S. Table of Frequency Allocations:
USXXX--Federal Government stations in the radiolocation
service operating in
the
band 5350-5470 MHz, shall not cause harmful interference to, nor claim
protection
from, Federal stations in the aeronautical radionavigation service
operating
in accordance with No. 5.449.
USYYY--Federal Government stations in the radiolocation
service operating in
the
band 5470-5650 MHz, with the exception of ground based radars used for
meteorological
purposes operating in the band 5600-5650 MHz, shall nor cause
harmful
interference to, nor claim protection from, Federal Government stations
in the maritime radionavigation service.
USZZZ--Federal Government stations in the space research
service (active)
operating
in the band 5350-5460 MHz shall not cause harmful interference to nor
claim
protection from Federal Government and non-Federal Government stations
in
the aeronautical radionavigation service nor Federal Government
stations in the
radiolocation
service.
NTIA
also recommends that the following modifications adopted at WRC-2003 to
international footnotes 5.448A and 5.448B be reflected in the U.S.
Table of Frequency Allocations:
5.448A --The
use of the frequency band 5250-5350 MHz by the earth exploration-
satellite
(active) and space research (active) services shall not constrain the
future
development
and deployment of the radiolocation service. The
Earth
exploration-satellite
(active) and space research (active) services in the
frequency
band 5250-5350 MHz shall not claim protection from the
radiolocation
service.
5.448B--The earth exploration-satellite (active)
service operating in the band
5350-5460
MHz shall not cause harmful interference to, or constrain the use and
development
of, the aeronautical radionavigation service. The Earth
exploration-satellite
service (active) operating in the band 5350-5570 MHz
and
space research service (active) operating in the band 5460-5570 MHz
shall
not cause harmful interference to the aeronautical radionavigation
service
in the band 5350-5460 MHz, the radionavigation service in the
band
5460-5470
MHz and the maritime radionavigation service in the band 5470-
5570
MHz.
NTIA believes that the inclusion of these new
footnotes and the modifications to existing footnotes are necessary
because of the complex sharing arrangements that exist between the
diverse federal and non federal government radio services operating in
the 5 GHz frequency range. These new
footnotes and modifications to the existing footnotes were supported as
the U.S. position for WRC-2003.
III. NTIA SUPPORTS THE COMMISSION’S PROPOSAL TO MODIFY THE PART
15
RULES TO ACCOMMODATE EXPANDED USE OF U-NII DEVICES.
The
Commission is proposing to modify the Part 15 rules to allow U-NII
devices to
operate in the 5.47-5.725 GHz band on a
non-interference basis. This proposal will
increase the
available spectrum available for U-NII
devices by 255 MHz, facilitating the development of a
wide range of new and innovative unlicensed
devices. The Commission seeks comment on
this
proposal.[11]
NTIA
supports the Commission’s proposal to modify the Part 15 Rules to allow
U-NII devices to operate in the 5.47-5.725 GHz band on a
non-interference basis. Utilization of the
mitigation measures proposed in the NPRM along with the additional 255
MHz of spectrum for U-NII devices to spread across will provide
protection of the vital government systems. The
Commission’s proposal will also meet current industry needs as well as
future growth in the RLAN industry which has proven to be one of the
few technology success stories in the current economy.
IV. NTIA
SUPPORTS THE COMMISSION’S PROPOSAL TO REQUIRE U-NII DEVICES
OPERATING IN THE 5.25-5.35 GHZ AND 5.47-5.725 GHZ FREQUENCY
BANDS TO EMPLOY DFS TO AVOID INTERFERING WITH CRITCAL
FEDERAL RADAR OPERATIONS.
In order to ensure protection of existing
radar operations, the Commission is
proposing that U-NII devices authorized to
operate in the 5.25-5.35 GHz and 5.47-5.725
GHz bands employ a listen-before-talk
mechanism referred to as Dynamic Frequency Selection
(DFS). DFS
is an interference avoidance mechanism, that when employed in a U-NII
device, will monitor the radio environment for the presence of a radar.[12] For systems, where multiple devices operate
under a central controller, the Commission is proposing that only the
central controller have DFS capability. The
Commission is seeking comment on requiring U-NII devices to have DFS
and how to identify remote units that operate under the control of a
central controller.[13] The Commission is also seeking comment on the
minimum number of pulses needed for a DFS system to reliably detect a
radar signal.[14]
NTIA
concurs with the Commission’s proposal that DFS should be required in
the existing 5.25-5.35 GHz U-NII band as well as the proposed U-NII
5.47-5.725 GHz band. NTIA also concurs
with the technical limits on DFS proposed by the Commission. Comprehensive studies carried out jointly
between NTIA, DoD, and private industry with Commission representatives
have proven the requirement for these technical limits. Specifically,
NTIA considers the proposed power limits, detection threshold, move
time, and non-occupancy period as fundamental for the protection of
government radars and no relaxation in the proposed values can be
accepted based on the studies cited above. DFS
is an integral part of the protection measures that allows for sharing
between the U-NII devices and existing primary government users. NTIA is of the opinion that the DFS mechanism
should be required to detect a single radar pulse present during
coincidence of the transmitted radar pulse and the dedicated listen
period of the DFS mechanism between each packet/frame. Setting
a specific hard number of pulses before detection is difficult given
that coincidence between a radar pulse and listen period is statistical
in nature based on packet/frame length and probability of a radar pulse
being present during the listen period as based on radar pulse width
and pulse repetition rate as well as antenna pointing angle (radar
antenna scan function) with respect to the U-NII device. The
requirement should be for detection of a single pulse during this
coincidence period. In addition, the DFS
mechanism should be allowed to average received power over successive 1
microsecond periods during the dedicated listen period. Given
the typical pulse widths and pulse repetition rates of the radars
operating in these bands, as well as the average power levels
transmitted by these radars, the DFS mechanism should have no problem
detecting single radar pulses during coincidence. This
will not allow for radar detection and instead forces the DFS to rely
on signal detection above the DFS detection threshold no matter the
source. This provides further protection
of radar systems given the high probability of masking of radar signals
from adjacent, competing U-NII devices.
Internationally,
there is also a requirement for a dedicated 10 minute monitoring period
as part of the required non-occupancy period for channels on which the
detection threshold is exceeded in the 5.6-5.65 GHz band. NTIA
concurs with the Commission in excluding this from the domestic
rulemaking. The joint studies clearly show
that the required 30 minute non-occupancy period that was included in
the U-NII NPRM is sufficient to provide protection to circular scanning
weather radars that require protection using the non-occupancy period.
V. NTIA
IS LEADING A PROJECT TEAM WITH GOVERNMENT AND INDUSTRY REPRESENTATIVES
TO DEVELOP COMPLIANCE MEASUREMENT PROCEDURES FOR DFS ENABLED U-NII
DEVICES.
Determining
whether or not a U-NII device with DFS capability can reliably detect a
radar signal will require very specialized
compliance measurement procedures, that are beyond
the measurement procedures currently found in
the Commission’s Part 15 Rules. In order
to
address this issue the Commission is seeking
comment on the appropriate measurement
procedures to ensure compliance with the
requirements for DFS.[15]
NTIA
recognizes the difficulties encountered in reliably detecting radar
signals. NTIA’s
Institute for Telecommunication Sciences
(ITS) has many years of experience in detecting and
measuring radar signals. These
measurements require very specialized measurement instruments
and
measurement techniques that take into account the characteristics of
the signals being measured (e.g., pulse width, pulse
repetition frequency, antenna scan rate). The
test facilities that perform the Commission’s equipment compliance
measurements will in all likelihood not have this specialized
measurement equipment or have experience in generating the radar
signals that are necessary to determine whether or not DFS equipped
U-NII devices comply with the Commission’s Rules. NTIA
believes that the measurement procedures developed must correctly
determine compliance with the Commission’s Rules without undermining
the protection effects of DFS. However, the
measurement procedures should not unnecessarily cause manufacturers to
incur undue costs or delays in the deployment of equipment.
In
preparing for WRC-2003, the government (NTIA, Commission, and DoD)
worked
closely with industry representatives to reach agreement on the United States’ 5 GHz proposals for the conference. A similar approach will be employed to develop a proposal for the compliance measurement procedures for DFS equipped U-NII devices. NTIA’s Office of Spectrum Management is leading a government/industry project team to develop proposed compliance measurement procedures. This project team will be responsible for addressing technical issues related to the generation of radar signals and the techniques to reliably measure these signals. NTIA believes that this government/industry project team has the expertise to provide guidance to the Commission in the development of the compliance measurement procedures. A first draft of the compliance measurement procedures is provided in Appendix B. There are plans in the November 2003 timeframe for manufacturers to bring DFS equipped devices to ITS to validate the draft measurement procedures in Appendix B. This testing will be dependent on the availability of DFS equipped U-NII devices. NTIA will submit a report to the Commission documenting the results of these measurements and any modifications to the draft procedures in Appendix B. NTIA believes that providing the draft measurement procedures to the Commission as part of the public record will allow other parties that are not participating in the government/industry project team to review and provide comments on the measurement procedures. A schedule of the project team’s projected milestones is provided in Appendix C.
VI. NTIA
SUPPORTS IMPLEMENTING TPC IN BOTH THE 5.25-5.35 GHZ AND 5.47-5.725 GHZ
FREQUENCY BANDS.
The
Commission is proposing to require a transmit power control (TPC)
mechanism in the 5.47-5.725 GHz frequency band to further reduce the
potential impact on EESS and SRS operations. Consistent
with the U.S. proposals to the WRC-03, the Commission is proposing that
U-NII devices employ a TPC mechanism that will ensure a 6 dB drop in
power when triggered. The Commission seeks
comment the appropriate triggering mechanism and whether TPC should
keep a receiver parameter such as received signal strength, bit error
rate, or block error rate below a certain threshold. The
Commission also seeks comment on whether it will be necessary to
require U-NII devices to employ TPC if their maximum power is 3 dB or
more below the maximum permitted under the rules.[16]
In
the U-NII NPRM the Commission proposes that U-NII devices employ a TPC
mechanism that will ensure a 6 dB drop in the transmit power when
triggered.[17] However, NTIA believes that the correct amount
of reduction should be a 3 dB drop in system power when triggered. Further, NTIA is of the opinion that recent
changes to the international regulations regarding TPC suggest that a 3
dB drop in system power should be considered for both the 5.25-5.35 GHz
band and the 5.47-5.725 GHz band. The
international regulations require:
that in the bands 5250-5350 MHz and 5470-5725 MHz, systems in
the mobile service shall
either employ transmitter power control to provide, on average, a
mitigation factor of
at least 3 dB on the maximum average output power of the systems, or,
if transmitter power
control is not in use, then the maximum mean e.i.r.p. shall be reduced
by 3 dB. [18]
An
analysis of this language, taken in context of likely RLAN deployment
shows that for domestic regulations there should be a requirement for
devices to have TPC capability or, a maximum power no greater than 3 dB
below the standard maximum transmit power, for both bands. Any
further definition or requirement with respect to TPC is not required
given that the great preponderance of U-NII devices operate at power
levels greater than 6 dB below the maximum transmit power and this will
always provide, on average, a mitigation factor of at least 3 dB within
the EESS/SRS satellite footprint. Moreover,
NTIA believes that since the current Institute of Electrical and
Electronics Engineers (IEEE) 802.11 standards require TPC in both of
these bands as a means to facilitate sharing among U-NII devices it
should not create a burden on industry to implement TPC in both the
5.25-5.35 GHz and 5.47-5.725 GHz frequency bands.
VII. NTIA RECOMMENDS THAT U-NII
DEVICES OPERATING IN THE 5.25-5.35 GHZ BAND THAT ARE IMPORTED SHOULD
ADHERE TO THE COMMISSION’S PROPOSED TRANSITION SCHEDULE FOR DOMESTIC
DEVICES.
The
NPRM acknowledges that U-NII devices are currently operating in the
5.25-5.35
GHz band without DFS capability. To
address this issue the Commission proposes that all U-NII devices
certified one year after the Report and Order is published in the
Federal Register must employ DFS. The
Commission also proposes that all U-NII devices operating in the
5.25-5.35 GHz band that are imported or shipped in the interstate
commerce on or after two years from the date of publication in the
Federal Register must comply with these standards.[19]
NTIA
agrees with the Commission’s transition schedule for domestically
manufactured U-NII devices operating in the 5.25-5.35 GHz band. NTIA believes that this approach will lessen
the burden on manufacturers by allowing them adequate time to redesign
their devices to comply with the DFS and TPC requirements that are
necessary to protect federal systems. NTIA
recommends that the Commission require that imported U-NII devices
operating in the 5.25-5.35 GHz band also adhere to the Commission’s
Rules (e.g., DFS and TPC), one year after the date of
publication of the Report and Order in the Federal Register.
VIII. IN
ORDER TO AVOID CONFUSION, NTIA RECOMMENDS THAT ADDITIONAL
DEFINITIONS BE INCLUDED IN THE COMMISSION’S RULES FOR
U-NII DEVICES.
In the U-NII NPRM, the Commission proposes
that when multiple devices operate under a central control that only
the central controller be required to employ DFS capability, however,
the Commission does not provide a definition for the controller.[20] In §15.407(h)(2)(a)(i) and (ii) of the
proposed rules, the Commission makes reference to master and slave
operational modes of the U-NII devices, without providing definitions
for either operational mode.[21] NTIA believes that based on the terminology
used by the RLAN industry that the controller is a Master Device. The RLAN industry uses very specific
terminology to describe U-NII devices and the operating relationship
between these devices. Understanding the
relationship between the different operational modes of U-NII devices is
important when applying the DFS technical requirements specified in the
Commission’s Rules. NTIA believes that in
order to avoid confusion, the following definitions should be included
in the Commission’s Rules in Section 15.403 for U-NII devices:
Channel: amount of spectrum
used by a single U-NII device operating on one of the specific
carrier frequencies.
Client Device: a U-NII
device operating in Client mode.
Client Mode: operating mode
in which the transmissions of the U-NII device are under
the
control of the Master. A U-NII device in
Client mode is not able to initiate a network.
Master Device: a U-NII
device operating in Master mode.
Master Mode: operating mode
in which the U-NII device has the capability to transmit
without
receiving an enabling signal. In this mode
it is able to select a channel and
initiate a network by sending
enabling signals to other U-NII devices. A
U-NII network
has at
least one device operating in Master mode.
NTIA
also believes that Section 15.407(h)(2)(a)(i) and (ii) of the
Commission’s Rules should be amended as follows:
a) Operational Modes. The
DFS requirement applies to the following operational
modes:
i) The requirement for channel availability check
time applies in themaster operational
mode Master
Mode.
ii) The requirement for channel move time applies
in both the master
and slave operational modes Master Mode and Client Mode.
NTIA
believes that these definitions are consistent with the terminology
employed by the RLAN industry, and including them in the Commission’s
Rules will help to avoid confusion that may arise when applying the DFS
technical requirements.
NTIA
commends the Commission for initiating this proceeding to expand the
options for unlicensed device use. NTIA
agrees with the Commission regarding the significant public benefits
that could be gained by increasing the spectrum available for
unlicensed devices, provided that such use is tied to effective
implementation of active interference avoidance techniques. NTIA
will continue to work with the Commission and industry to resolve the
technical issues surrounding the successful implementation of DFS
equipped U-NII devices in an effort to continue the workable
arrangement of facilitating the development and deployment of
unlicensed wireless devices while protecting critical federal systems.
Respectfully
submitted,
Michael D. Gallagher Kathy
D. Smith
Acting Assistant
Secretary for Chief
Counsel
Communications and
Information
Fredrick R. Wentland National
Telecommunications
Associate
Administrator and
Information Administration
Office of Spectrum
Management U.S.
Department of Commerce
Room
4713
Charles T. Glass 1401
Constitution Avenue, N.W.
Telecommunications
Specialist
Washington, DC 20230
Office of Spectrum
Management (202)
482-1816
Edward F. Drocella
Robert L. Sole
Electronics
Engineers
Office of Spectrum
Management
October 1, 2003
DESCRIPTION OF RADAR USAGE IN
THE
5 GHZ FREQUENCY RANGE
There is a presumption that all Federal
Government radar systems operating in the 5 GHz frequency bands have
the same technical characteristics and operate on military
installations geographically separated from heavily populated areas. This section of the report provides a
description of the federal radar usage in the 5 GHz frequency bands. To describe the radar usage in the 5 GHz
frequency range, the four distinct frequency bands will be considered. The four frequency bands are: 5250-5350
MHz, 5470-5600 MHz, 5650-5670 MHz, and 5650-5725 MHz. The
spectral occupancy and the anticipated future development of radars in
the 5250-5725 MHz frequency range are also discussed.
The Federal Government radar systems
operating in the 5250-5350 MHz band are primarily used by the military. These military radars have the operational
capability to tune across the entire 5250-5725 MHz frequency range. The military radars that operate in this include both target search and tracking radars
that can use a single frequencies or can employ frequency hopping using
frequencies across the entire band. In the
past these radars have been limited to operating on or near military
installations. However, this was based on
the military’s usage prior to the terrorist attacks on September 11,
2001. One of the areas of concern in
assessing interference to military radars regards future radar
deployments and the expanding role of military radars in support of
homeland defense. This expanded role could
result in a requirement to deploy military radars in cities and near
highways.
The radars that operate in the 5470-5500 MHz
band used by military systems that are capable of tuning across the
entire 5400-5900 MHz frequency range. The
5470-5600 MHz frequency band is also used by marine radars that are
used for maritime navigation. The marine
radar provides ships with surface search, navigation capabilities, and
tracking services, particularly in inclement weather. These
navigation radars are used by all categories of commercial and
Government vessels, including foreign and U.S. flagged cargo, oil
tankers and passenger ships operating in U.S. waters, and is vital
sensor for safe navigation of waterways. The
marine navigation radar provides indications and data on surface craft,
obstructions, buoy markers, and navigation marks to assist in
navigation and collision avoidance. Emissions
from maritime radionavigation radars are observable at distances of at
least several kilometers inland. The
emissions are strong in the vicinity of the shoreline, on bridges near
waterways, and coastlines.
The 5600-5650 MHz band is used by Terminal
Doppler Weather Radar (TDWR) which provides quantitative measurements
of gusts, wind shear, micro bursts, and other weather hazards for
improving the safety of operations at major airports in the United
States. In addition to TDWR,
non-Government meteorological radars operate throughout the 5350-5625
MHz frequency range. In general weather
surveillance radars operate near populated areas.
The radars that operate in the 5650-5725 MHz
band are used primarily by military systems that are capable of tuning
across the entire 5400-5900 MHz frequency range. The
radars operating in this band segment can be either mobile or
transportable and are used for surveillance and test range
instrumentation. Test range
instrumentation radars are used for to provide highly accurate position
data on space launch vehicles and aeronautical vehicles undergoing
developmental and operational testing. Periods
of operation can last from minutes up to 4-5 hours, depending upon the
test program that is being supported. Operations
are conducted at scheduled times 24 hours per day, 7 days a week. One of the areas of concern in assessing
interference to military radars regards future radar deployments and
the expanding role of military radars in support of homeland defense. This expanded role could result in a
requirement to deploy military radars in cities and near highways.
SPECTRUM
OCCUPANCY IN THE 5250-5725 MHZ BAND
Spectrum occupancy measurements in the
5250-5925 MHz band were performed by NTIA near the cities of San Diego,
Los Angles, San Francisco, and Colorado.1 The activity in the 5250-5925 MHz band in all
of these areas was highly dynamic. Radar
measurement personnel have noted that, during the past 25 years of
spectrum survey measurements in the band 5250-5925 MHz, weather and
diurnal cycles have had a strong effect on the levels of occupancy in
the band. Based on the measured spectral
occupancy measurements, it is clear that in the frequency range between
5470-5725 MHz, the maximum observed signal levels are much higher as
compared to levels in the other parts of the 5 GHz frequency range.
ANTICIPATED
FUTURE RADAR DEVELOPMEMT TRENDS AT 5 GHZ
It is not currently known what new radar
systems will be developed for use in the 5250-5725 MHz frequency range
in the next few decades. But the limited
amounts of spectrum available for future radar development makes it
likely that new radar systems will be developed in the 5 GHz frequency
range. Current trends in advanced radar
design can provide some guidance as to the likely emission
characteristics of such radar systems. To
the extent that these new designs can be anticipated new services
should be designed to be electromagnetically compatible with future
radar systems.
Advanced
radar designs are tending toward increased use of modulated
compressed-pulse waveforms. These
approaches include various types of phase coding (e.g., Barker codes,
minimum shift keying, etc.) and frequency modulation (e.g., chirping). Assuming that this trend toward incorporating
larger amounts of information in radar pulses continues, it can be
expected that even compressed pulse lengths will increase. Already,
some 3 GHz radars are transmitting pulse lengths on the order of 50
microseconds and 100 microseconds pulses are foreseeable. Longer
pulses will tend to increase the average power output of the advanced
radar transmitters. The trend is also
toward solid state power output devices which will have lower peak
power levels, resulting in lower detected power in the receiver systems.
DRAFT MEASUREMENT PROCEDURES
FOR DFS EQUIPPED U-NII DEVICES
The
purpose of this appendix is to define procedures for testing of the
radar detection capability referred to as Dynamic Frequency Selection
(DFS) of unlicensed U-NII equipment operating in the frequency bands
5250 MHz to 5350 MHz and 5470 MHz to 5725 MHz. These
procedures will be used to test the efficacy of DFS as an interference
mechanism as formulated by the International Telecommunication
Union-Radiocommunications Sector (ITU-R) and documented in
Recommendation ITU-R M.1652 and called for in the U-NII Notice of
Proposed Rulemaking (NPRM).1 A major source for the content of this
document is the European Telecommunication Standards Institute (ETSI)
draft EN 301 893 version 1.2.2, which is the approved final European
conformance standard for 5GHz operation. Using
ETSI EN 301 893 and its associated reference documents as baseline for
developing this test plan does not infer that the United States confers
with all of the standards, practices, procedures, and tolerances set
within them.
The
scope of this document includes an overview of DFS operational
requirements, the detection and response criteria and methods of
measuring compliance with these criteria. The
methods include calibration and test procedures for conducted and
radiated measurements. Conducted
measurements are preferred over radiated measurements because they are
more precise and contain less measurement errors. Equipment
with an integral antenna may be equipped with a temporary antenna
connector in order to facilitate the conducted tests. When
the antenna can not be separated from the device and a radio frequency
(RF) test port is not provided, radiated measurements may be performed.
General
information about test sites and measurement techniques are assumed to
be known and not covered here.
Procedures
for equipment submission; certification and other regulatory aspects
are not covered in this document.
[1] Draft New
Recommendation ITU-R M.1652
[2] Draft EN
301 893 ETSI (RLAN Radio Conformance Test standard)
For
the purposes of the present document, following terms and definitions
apply.
5 GHz
U-NII bands: Frequency ranges: 5150 - 5250 MHz, 5250 - 5350 MHz, 5470 - 5725 MHz and 5725 - 5825 MHz.
Association: an active relationship between two wireless
devices in which one device (referred to as “Master device” in this
document) exercises certain control functions to which the other device
(referred to as “Client device” in this document) has to respond.
Burst: a period during which radio waves are
intentionally transmitted, preceded and succeeded by periods during
which no intentional transmission is made.
Channel: amount of spectrum used by a single
unlicensed U-NII device
operating on one of the specified carrier frequencies
Channel Availability Check Time: the time during which a channel
shall be checked for the presence of a radar signal with a level above
the Interference Detection
Threshold. No transmissions shall occur
during this time.
Channel Closing Transmission Time: the aggregate duration of
transmissions of control information by unlicensed U-NII devices during the Channel Move Time which starts upon detection of an interfering signal above the
Interference Detection Threshold. The aggregate duration of all
transmissions shall not count quiet periods
in between transmissions.
Channel
Move Time: the time taken by an unlicensed U-NII device to cease all transmissions on the current channel upon detection of an
interfering signal above the Interference
Detection Threshold.
Client Device: an unlicensed U-NII device operating in
Client mode.
Client mode: operating mode in which the transmissions of
the unlicensed U-NII device are under control of the Master. An unlicensed
U-NII device in Client mode is not able to initiate a network.
[djs1]In-Service Monitoring: a mechanism to check a channel
in use by the unlicensed U-NII device for the
presence of a radar signal with a level above the Interference
Detection Threshold.
Interference
Detection Threshold is the
level to be used by the DFS function to detect radar interference.
Master Device: an unlicensed U-NII device operating in
Master mode.
Master mode: operating mode in which the unlicensed U-NII device has the
capability to transmit without receiving an enabling signal. In
this mode it is able to select a channel and initiate a network by sending enabling signals to other unlicensed U-NII devices. An unlicensed U-NII network
always has at least one unlicensed device operating in Master mode.
Simulated Radar
burst: a series of periodic
radio wave pulses, separated by a period during which no pulses are
transmitted.
For the purposes of the present document, the
following symbols apply:
A Measured
power output (dBm)
B Radar
burst period
Chf Channel
free from radars
Chr Channel
occupied by a radar
D Measured
power density
E Field
strength
Eo Reference
field strength
fc Carrier
frequency
G Antenna
gain (dBi)
L Radar
burst length
n Number
of channels
PH Calculated
EIRP at highest power level
PL Calculated
EIRP at lowest power level
PD Calculated
power density
R Distance
Ro Reference
distance
S0 Signal
power
T0 Time
instant
T1 Time
instant
T2 Time
instant
T3 Time
instant
W Radar
pulse width
x Observed
duty cycle
For the purposes of the present document, the
following abbreviations apply:
DFS Dynamic
Frequency Selection
EMC Electro-Magnetic
Compatibility
EIRP Equivalent
Isotropic Radiated Power
LV Low
Voltage
PRF Pulse
Repetition Frequency
RE Radio
Equipment
UUT Unit
Under Test
An
unlicensed U-NII network shall employ a DFS function to:
· detect interference from other systems and to
avoid co-channel operation with these systems, notably radar systems.
· provide on aggregate a uniform loading of the
spectrum across all devices by selecting at startup, at random, on one
of the channels that the unlicensed device is capable of operating.
The
DFS function as described in the present document is not tested for its
ability to detect frequency agile radars. Within
the context of the operation of the DFS function, an unlicensed U-NII
device shall operate in either Master mode or Client mode. Unlicensed
devices operating in Client mode (Client device) can only operate in a
network controlled by a unlicensed U-NII device operating in Master
mode (Master device).
The
operational behavior and individual DFS requirements that are
associated with these modes are as follows:
a) The Master device shall use a Radar
Interference Detection function in order to detect radar
signals with a level above the Interference Detection
Threshold in the frequency ranges 5250 - 5350 MHz and 5470 - 5725 MHz. Radar
detection is not required in the frequency range 5150 - 5250 MHz or 5725 - 5825 MHz.
b) The Master device initiates an unlicensed
U-NII network by transmitting control signals that will enable other
unlicensed U-NII devices to Associate (participate in a wireless
network) with the Master device.
c) Before initiating a network on a Channel, the
master shall perform a Channel Availability Check for a certain
duration (Channel Availability Check Time) to ensure that there
is no radar operating on the Channel, using the Radar Interference
Detection function described under a).
d) During normal operation, the Master shall
monitor the operating channel (In-Service Monitoring) to ensure that there is no radar operating on the channel,
using the Radar Interference Detection function described under a).
e) If the Master device has detected a radar signal, during In-Service Monitoring as described under d),
the operating Channel of the unlicensed U-NII network is made
unavailable. The Master shall instruct all
Associated devices to stop transmitting on this Channel, which they
shall do within the Channel Move Time. The
Aggregate Transmissions during the Channel Move Time should be
limited to the Channel Closing Transmission Time.
f) A Master device shall not attempt to initiate
a network on a Channel in the frequency range 5600-5650 MHz during a
period defined as the Non-Occupancy Period after a
radar has been detected in that Channel, regardless of the outcome of
any In-Service Monitoring or Channel Availability Check procedures. The Non-Occupancy Period
commences at the time the radar was detected in the Channel.
a) An unlicensed U-NII Client device shall not
transmit before having received an appropriate enabling signal from a
Master device.
b) An unlicensed U-NII Client device shall stop
all its transmissions whenever instructed by a Master device to which
it is associated. The device shall not
resume any transmissions until it has again received enabling signals
from a Master device.
c) An unlicensed U-NII Client device that
incorporates a Radar Interference Detection function shall inform the
Master device and stop its networks transmission if it detects a radar.
The
Master device may implement the Radar Interference Detection function
referred to under a) using another device Associated with the Master. In such a case, the combination should be
tested against the requirements applicable to the Master.
In
Tables 1 and 2 shown below, the applicability of DFS requirements prior
to use of a channel (Channel Availability Check) and during
normal operation (In-Service Monitoring) for each of the above
mentioned operational modes.
The
manufacturer shall state whether the UUT is capable of operating as a
Master and/or as a Client. If the UUT is
capable of operating in more than one operating mode then each
operating mode shall be tested separately.
Table 1:
Applicability of DFS requirements prior to use of a channel
Requirement |
Operational
Mode |
||
Master |
Client (without
radar detection) |
Client (with
radar detection) |
|
Non
–occupancy period (required
for band 5600-5650 MHz) |
P |
Not required |
P |
Interference
Detection Threshold |
P |
Not required |
P |
Channel
Availability Check Time |
P |
Not required |
Not required |
Uniform
Spreading |
P |
Not required |
Not required |
Table
2: Applicability of DFS requirements during normal operation
Requirement |
Operational
Mode |
||
Master |
Client (without
radar detection) |
Client (with
radar detection) |
|
Interference
Detection Threshold |
P |
Not required |
P |
Channel
Closing Transmission Time |
P |
P |
P |
Channel Move
Time |
P |
P |
P |
The following tables give the DFS thresholds
for Master devices and for Client devices.
Table 3A:
Interference Threshold values, Master
Maximum
Transmit Power |
Value (see
note) |
³200 mW |
-64
dBm |
<200 mW |
-62
dBm |
Note: This
is the level at the input of the receiver assuming a 0 dBi receive
antenna |
Table 3B:
Interference Threshold values, Client
Maximum
Transmit Power |
Value |
³200 mW |
-64
dBm |
<200 mW |
-62
dBm |
Note: This
is the level at the input of the receiver assuming a 0 dBi receive
antenna |
The
following table gives the response requirements for DFS implementation.
Table 4: DFS
Response requirement values
Parameter |
Value |
Non-occupancy
period |
30 minutes |
Channel
Availability Check Time |
60 s |
Channel
Move Time |
10 s |
Channel
Closing Transmission Time |
260 ms |
The
DFS test signals shown in Table 5 shall be used.
Table 5:
Parameters of DFS test signals[djs3]
Radar
test signal |
Pulse
repetition frequency PRF [pps] |
Pulse
width W [µs] |
Burst
length L [ms] / No. of pulses (Note
1) |
Burst
Period B [sec] (Note 2) |
Hopping Rate (Note
4) |
Fixed
Frequency Radar signal 1 |
700 |
1 |
26 / 18 |
10 |
Na |
Fixed
Frequency Radar signal 2 |
1800 |
1 |
5 / 10 |
2 |
Na |
Frequency
Hopping Radar |
3000 |
1 |
100/300 |
10 |
1 kHz |
Note 1: This represents the number of pulses
seen at the unit under test (UUT) per radar scan N = [{antenna
beamwidth (deg)} x {pulse repetition rate (pps)}] / [{scan rate
(deg/s)}]
Note 2: Burst period represents the time
between successive scans of the radar beam
B = 360/{scan rate (deg/s)}
Note 3: Radar bandwidth is less than that of
the unlicensed U-NII device.
Note 4: The characteristics of this frequency
hopping radar do not correspond to any specific system. It can hop
across the 5250-5725 MHz band. The
frequencies will be selected by using a random without replacement
algorithm until all 475 frequencies have been used. After all have been
used, the pattern is reset and a new random set is generated.
Figure 1:
General structure of the DFS test transmission sequences
The
conformance requirements given in the section on Technical Requirements
for DFS shall be verified under normal
operating conditions, and in each of the stated
frequency range(s), and with each of the applicable radar signals
defined in Table 5.
For
a UUT with antenna connector(s) and using external antenna(s), or for a
UUT with integral antenna(s) but with a temporary antenna connector
provided, conducted measurements shall be used. In
this case, and if the UUT has a Radar Interference Detection Function,
the output power of the signal generator producing the radar test
signals shall provide a received signal power at the antenna connector
of the UUT with a level equal to (Interference Detection
Threshold + G), see Tables 3A and 3B. ParameterG [dBi] corresponds to the gain of the antenna assembly stated
by the manufacturer. If more than one
antenna assembly is intended, the gain of the antenna assembly with the
lowest gain shall be used.
For
a UUT with integral antenna(s) and without temporary antenna connector,
radiated measurements shall be used. In
this case, and if the UUT has a Radar Interference Detection Function,
the output power of the signal generator shall provide a signal power
at the antenna with a level equal to Interference Detection
Threshold.
Some
of the tests may be performed more readily if the channel selection
mechanism for the uniform spreading requirement can be disabled, for
example, to ensure selection of a channel outside the 5150-5250 MHz and
5725-5825 MHz bands.
It
should be noted that once a UUT is powered on, it will not start its
normal operating functions immediately, as it will have to finish its
power-up cycle first (Tpower_up). As
such, the UUT, as well as any other device used in the set-up, may be
equipped with a feature that will indicate its status during the
testing, including, for example, power-up mode, normal operation mode,
channel check status and radar detection event.
The
sections below contain simplified block diagrams that focus on the
radar signal injection path for each of the different conducted set-ups
to be used. The basic set-up is identical
for all cases. Full details of this setup,
including calibration, can be found in Annex B to this document.
When
the UUT is an unlicensed device operating as a Master, the test set-up,
further referred to as ‘Set-up A’ shall be used.
‘Set-up A’
consists of a signal generator connected to the UUT and an unlicensed
device operating as a Client. The latter is assumed to Associate with
the UUT (Master).
Figure
2 shows a block diagram for ‘Set-up A.’
Figure
2: Conducted Set-Up where UUT is a Master and Radar Test Signals
are injected into the Master
When
the UUT is an unlicensed device operating as a Client, with or without
a Radar Interference Detection Function (RIDF), the test set-up,
further referred to as ‘Set-up B’ shall be used.
‘Set-up
B’ consists of a signal generator
connected to a unlicensed device operating as a Master and the UUT. The
latter is assumed to Associate with the Master.
Figure
3 shows an example for ‘Set-up B.’ The
set-up used shall be documented in the test report.
Figure
3: Conducted Set-Up B where UUT is a Client and Radar Test Signals
are injected into the Master
When
the UUT is an unlicensed device operating as a Client with a Radar
Interference Detection Function (RIDF), the tests described in the
section on Test of DFS Function of the Client need to be repeated using
a set-up, further referred to as ‘Set-up C.’
‘Set-up
C’ consists of a signal
generator connected to the UUT (Client).
Figure 4 shows an example for ‘Set-up
C.’
Figure
4: Conducted Set-Up C - where UUT is a Client and Radar Test Signals
are injected into the Client
For
the purposes of the test, the UUT as well as other unlicensed U-NII
devices used in the set-up may be equipped with a specific user
interface to allow monitoring of the behavior of the different devices
of the set-up during the tests.
[MP4]The
UUT is capable of transmitting a test transmission sequence. The signal generator is capable of generating
any of the radar test signals defined in Table 5. Adequate
measurement equipment, e.g., spectrum analyzer, shall
be used to measure the aggregate transmission time of the UUT.
The
conformance requirements given in the section on Technical Requirements
for DFS shall be verified under normal operating conditions, and in each of the stated frequency range(s), and with each
of the applicable radar signals defined in Table 5.
For
a UUT with integral antenna(s) and without temporary antenna connector,
radiated measurements shall be used. In
this case, and if the UUT has a Radar Interference Detection Function,
the output power of the signal generator shall provide a signal power
at the antenna with a level equal to Interference Detection
Threshold .
Some
of the tests may be performed more readily if the channel selection
mechanism for the uniform spreading requirement can be disabled, for
example, to ensure selection of a channel outside the 5150-5250 MHz and
5725-5825 MHz bands. It should be noted
that once a UUT is powered on, it will not start its normal operating
functions immediately, as it will have to finish its power-up cycle
first (Tpower_up). As such, the
UUT, as well as any other device used in the set-up, may be equipped
with a feature that will indicate its status during the testing,
including, for example, power-up mode, normal operation mode, channel
check status and radar detection event.
The
sections below contain simplified block diagrams that focus on the
radar signal injection path for each of the different radiated set-ups
to be used. The basic set-up is identical
for all cases. Full details of this setup,
including calibration, can be found in Annex C to this document.
When
the UUT is an unlicensed U-NII device operating as a Master, the test
set-up, further referred to as ‘Set-up A’ shall be
used.
‘Set-up
A’ consists of a signal generator
connected to the UUT and an unlicensed U-NII device operating as a
Client. The latter is assumed to be associated with the UUT (Master).
Figure
5 shows a block diagram for ‘Set-up A.’
Figure
5: Radiated Set-Up where UUT is a Master and Radar Test Signals
are injected into the Master
When
the UUT is an unlicensed U-NII device operating as a Client, with or
without a RIDF, the test set-up, further referred to as ‘Set-up
B’ shall be used.
‘Set-up
B’ consists of a signal generator
connected to an unlicensed U-NII device operating as a Master and the
UUT. The latter is assumed to be associated with the Master.
Figure
6 shows an example for ‘Set-up B.’ The set-up used
shall be documented in the test report.
Figure
6: Radiated Set-Up B where UUT is a Client and Radar Test Signals
are injected into the Master
When
the UUT is an unlicensed U-NII device operating as a Client with a
RIDF, the tests described in Test of DFS Functions as the Client need
to be repeated using a set-up, further referred to as ‘Set-up
C.’
‘Set-up
C’ consists of a signal
generator connected to the UUT (Client).
Figure 7 shows an example for ‘Set-up
C.’
Figure
7: Radiated Set-Up C - where UUT is a Client and Radar Test Signals
are injected into the Client
For
the purposes of the test, the UUT as well as other unlicensed U-NII
devices used in the set-up may be equipped with a specific user
interface to allow monitoring of the behavior of the different devices
of the set-up during the tests.
The
UUT is capable of transmitting a test transmission sequence. The signal
generator is capable of generating any of the radar test signals defined
in Table 5.
Adequate
measurement equipment, e.g., spectrum analyzer, shall
be used to measure the aggregate transmission time of the UUT.
Detailed
set-up and instructions for calibration are given in Annexes B and C.
This
section describes the verification procedure for the Channel
Availability Check to be performed at initialization of an unlicensed
U-NII device. See section on DFS overview.
One
channel, outside the 5150-5250 MHz and 5725-5825 MHz range, is selected
from the stated operating frequency range(s) of the UUT. This
channel is designated as Chr (channel occupied by a radar).
The UUT shall be configured to select Chr
as the first operating channel.
Tch_avail_check is the minimum
Channel Availability Check Time as specified in Table 4.
The
different steps below define the procedure to verify
the response behavior parameters when a radar burst is generated on the
selected channel at the beginning or at the end of the Channel
Availability Check Time.
The steps below define the procedure to
verify successful radar detection on the selected channel during a
period equal to the Channel Availability Check Time and
avoidance of operation on that channel when a radar burst with a level
equal to the Interference Detection Threshold occurs at the
beginning of the Channel Availability Check Time.
a) The signal generator and UUT are connected
using the applicable test set-ups described in section on Conducted
Tests and the power of the UUT is switched off.
b) The UUT is powered on at T0. T1 denotes the instant when the UUT has
completed its power-up sequence (Tpower_up). The channel
availability check is expected to commence on Chr at instant
T1 and is expected to end no sooner than T1 + Tch_avail_check unless
a radar is detected sooner.
c) Radar bursts are generated on Chr
using one of the test patterns defined in Table 5. Radar
bursts should commence at time T1 and should continue for
approximately 6 seconds.
d) Visual indication on the UUT of successful
detection of the radar burst (if indication is available) should be
recorded. Observation of Chr shall
continue until the UUT starts transmitting on another channel. (In
the example given below, the UUT performs a channel
availability check on a new channel after it has
detected a radar on Chr). It
shall be verified and recorded that during the above steps no
transmissions occurred on Chr.
e) A timing trace or description of the observed
timing and behavior of the UUT should be reported.
The
steps below define the procedure to verify successful radar detection
on the selected channel during a period equal to the Channel
Availability Check Time and avoidance of operation on that channel
when a radar burst with a level equal to the Interference Detection
Threshold occurs at the end of the Channel Availability Check Time.
a) The signal generator and UUT are connected
using the applicable test set-ups referred to in section on Conducted
Test Configurations and the power of the UUT is switched off.
b) The UUT is powered up at T0.
T1 denotes the instant when the UUT has completed its power-up sequence
(Tpower_up). The channel
availability check is expected to commence on Chr at instant
T1 and is expected to end no sooner than T1 + Tch_avail_check unless
a radar is detected sooner.
c) Radar bursts are generated on Chr
using one of the test patterns defined in section 5.1 at a level defined
in the DFS Overview section. Radar bursts
should commence near the end of the minimum required Channel
Availability Check Time at time T1 + Tch_avail_check – 6
[sec] and should continue for the duration of this test.
d) Visual indication on the UUT of successful
detection of the radar burst (if indication is available) should be
recorded. Observation of Chr shall
continue until the UUT starts transmitting on another channel. (In
the example given below, the UUT performs a channel availability check
on a new channel after it has detected a radar on Chr). It shall be verified and recorded that during
the above steps no transmissions occurred on Chr.
e) A timing trace or description of the observed
timing and behavior of the UUT should be recorded.
Figure 9:
Example of timing for radar testing towards the end of
the Channel Availability Check Time
These
tests define how the following DFS parameters can be verified during
In-Service Monitoring
- Interference Detection Threshold
- Channel Closing Transmission Time
- Channel Move Time
- Non-Occupancy Period
The
steps below define the procedure to determine the above
mentioned parameters when a radar burst with a level equal to the Interference
Detection Threshold is generated on the channel of operation of the
unlicensed U-NII device (In- Service Monitoring).
a) A channel outside 5150-5250 MHz and 5725-5825
MHz bands is selected from the stated operating frequency range(s).
b) In case the UUT is an unlicensed U-NII device
operating as a Client (with or without Radar Interference Detection
Function), an unlicensed U-NII device operating as a Master will be
used to allow the UUT to associate with the Master. In
case the UUT is a Master, an unlicensed U-NII device operating as a
Client will be used and it is assumed that the Client will associate
with the UUT (Master). In both cases, the
signal generator shall be connected to the Master.
c) The UUT transmits a test transmission
sequence on the selected channel.
d) At a certain time T0
the signal generator starts generating one of the radar test patterns
defined in Table 5 at a level defined in the section on Response
Requirements on the selected channel. T1 denotes the end of the first radar
burst.
e) The transmissions of the UUT following
instant T1 on the selected channel shall be observed for a duration of
at least 10 seconds. The
aggregate duration of all transmissions from the UUT during the
observation time (Channel Closing Transmission Time) shall be
noted and compared to the limit defined in Table 4. Note:
the aggregate duration of all transmissions of the UUT does not include
quiet periods in between transmissions of the UUT.
f) T2 denotes the instant when the UUT has
ceased all transmissions on the channel. The
time difference between T1 and T2 shall be measured. This value (Channel Move Time)
shall be noted and compared with the limit defined in Table 4.
g) When the UUT is an unlicensed U-NII device
operating as a Master, following instant T2, the selected channel shall
be monitored for an additional 30 minutes (Non-Occupancy Period)
until instant T3, to verify that the UUT does not resume any
transmissions on this channel.
h) The test shall be repeated using each of the
radar signals defined in the section on Testing for Compliance with
Technical Requirements;
i) In case the UUT is an unlicensed U-NII device
operating as a Client with a Radar Interference Detection Function, the
steps a) to h) shall be repeated with the generator connected to the
UUT.
Figure 10:
Channel Closing Transmission Time & Channel Clearing Time
The
following information shall be stated by the manufacturer in order to
facilitate the execution of the test suites:
a) the operating frequency range(s) of the
equipment;
b) the operating modes (Master and/or Client)
c) the highest and the lowest possible power
level (equivalent isotropically radiated power (EIRP)) of the equipment;
d) the intended antenna assemblies and their
corresponding gains;
e) [djs5]the test sequences or messages
used for communication between Master and Client devices.
Interpretation
of the measurement results
The
interpretation of the results recorded in a test report for the
measurements described in the present document shall be as follows:
- the measured value related to the
corresponding limit will be used to decide whether an equipment meets
the requirements of the present document;
- the value of the measurement uncertainty for
the measurement of each parameter shall be included in the test report;
- the recorded value of the measurement
uncertainty shall be, for each measurement, equal to or lower than the
figures in Table A.1;
- the shared risk approach shall be applied for
the interpreting of all measurement results.[djs6]
Table
A.1: Maximum measurement uncertainty
Parameter |
Uncertainty |
RF frequency |
±1
x 10-5 |
RF power
conducted |
±1.5
dB |
RF power
radiated |
±2
dB |
Spurious
emissions, conducted |
±3
dB |
Spurious
emissions, radiated |
±2
dB |
Time |
±5
% |
Weighting of data test file
Packet size |
Weight |
|
Data rate (Mbit/s) |
Weight |
64 |
0.6 |
|
6 |
0.1 |
538 |
0.2 |
|
12 |
0.1 |
1 500 |
0.2 |
|
18 |
0.1 |
|
|
|
24 |
0.3 |
|
|
|
36 |
0.3 |
|
|
|
54 |
0.1 |
Conducted Test
Set-up and Calibration
Conducted
measurements are the preferred method to perform these tests. In this
method, cables are used to supply the unlicensed U-NII device signals
to/from the devices under test and the test equipment. Equipment
with an integral antenna may be equipped with a temporary antenna
connector in order to facilitate the conducted tests. Figure
B1 shows a detailed set-up for performing conducted measurements.
Figure
B1: Conducted DFS Measurements - Test Set-Up
It
is important to note that the Signal Generator used should have the
‘Short Pulse’ option to guarantee that the Automatic Level Control
circuitry can also deal with short pulses (this will be verified during
the calibration part.). It might be
possible that the function of the Delay/Trigger unit is part of the
features of Spectrum Analyzer #1.
The
value of the attenuator #1 and attenuator #2 are chosen in such a way
that the received unlicensed U-NII signal (unlicensed U-NII device #2)
at the input of the UUT (unlicensed U-NII device #1) is minimum about
20 dB above the threshold level to be tested (the received unlicensed
U-NII device signal should be much stronger as the radar test signals).
The duty cycle of
the unlicensed U-NII device transmissions should be sufficiently high.
Also the duration of the unlicensed U-NII device transmissions should
be sufficiently high to allow the measurements to be repeated a number
of times (e.g., 10 times). In order to allow some of
the tests to be repeated on the same channel, it may be required for
the diagnostic software to disable the ‘move to a new channel feature’
after a radar pulse was detected the first time, otherwise the whole
set-up need to be re-calibrated on the new frequency.
1) During this calibration, there are no
transmissions initiated by the UUT.
2) For calibrating the test set-up (exact
threshold level at the UUT, unlicensed device #1), the UUT is replaced
by a Spectrum Analyzer with an accurate power level measurement
feature.
3) The Spectrum Analyzer #2 is switched to Zero
Span’ mode and to the ‘Time Domain’ mode and it shall be verified if
the level of each of the Radar pulses is identical. This is required to
verify the proper functioning of ALC circuit of the Signal Generator
for short pulses. For each of the tests (different radar test signals),
the level of the Signal Generator is adjusted until the appropriate
level (e.g. -62 dBm) is measured by the Spectrum Analyzer #2.
4) The Spectrum Analyzer #1 is switched to ‘Zero
Span’ mode and to the ‘Time Domain’ mode with an adaptive sweep time.
The time base of the Spectrum Analyzer is externally triggered by the
Pulse Generator through a delay circuit so that the sweep is already
started a few ms before the first pulse of the Signal Generator appears.
This will bring the radar burst clearly within the view window of the
analyzer.
5) A reference point, indicating the start of
the first pulse of the radar test signal (often equal to the time of
the external trigger) should be set (marker T1) before any UUT
transmissions are initiated.
6) The Radar Test Signal is switched off.
· The Monitor/Diagnostic Device (PC#2) starts
transmissions between the 2 unlicensed U-NII devices.
· The Control Device #2 will switch on the
Radar Test Signal at the instances indicated in the procedures in
section 5
· The screen will now show the behavior of the
unlicensed U-NII devices to the Radar Test Signal.
Note: it should be possible, with the above described set-up, to distinguish (on the spectrum analyzer screen) (1) the Radar Test Signals, (2) U-NII
Radiated Test Set-up and
Calibration
Block
Diagram
Radiated
tests may be performed when the antenna of the unlicensed U-NII device
is integral (i.e., the antenna cannot be separated from the device) and
an external antenna port is not provided. Figure
C1 shows a detailed set-up for performing the radiated test
measurements.
Figure C-1.
Calibration procedure
During this calibration, there are no
transmissions initiated by the UUT.
1) For calibrating the test set-up (exact
threshold level at the UUT) Spectrum analyzer #2 will be used to
measure the power output of the radar signal simulator for each type of
signal in Table 5.
2) Spectrum Analyzer #2 will be set to zero span
mode with the RMS detector at the frequency of the chosen unlicensed
device channel. The resolution and video bandwidth will be set to 1
MHz. The unlicensed device integration time as defined by the ITU is 1
microsecond. In order to achieve this integration time, the sweep time
of the analyzer must be set appropriately as follows. If the analyzer
has 1000 points or “bins” across its display, the sweep time is equal
to that number multiplied by 1 microsecond, or 1 millisecond. For 8000
points (the maximum on the Agilent E440 analyzer) the sweep time would
be set to 8 milliseconds.
3) The radar signal
generator will be turned on (for each radar type) and be allowed to
“free run.” The pulses will be constantly
on and not generated in bursts. Note that the frequency hopping radar
will be set to a fixed frequency.
4) The step attenuator will be used to adjust
the power level at Spectrum Analyzer #2 to the level that is required
for the tests.
This value must be adjusted for the gain of
the horn antenna connected to the analyzer and adjusted once again if
the antenna on the unlicensed U-NNII device has gain.
The techniques for measuring pulsed emissions
from radars can be found in ITU-R M.1177-2.
5) After the attenuator has been adjusted to
achieve the proper power level the RF output of the simulator will be
turned off.
Taking
Measurements
Fixed
Frequency Radar Simulator
1) The power level (-64, -62, -55 dBm) of the
radar signal will be calibrated for the appropriate radar signal type
in Table 5 at the antenna of the unlicensed U-NII device. The
higher power level (-55 dBm) will be used to test the DFS functionality
of the unlicensed device before the ITU detection thresholds are tested.
2) The unlicensed U-NII devices will be turned
on and be instructed to operate on the appropriate unlicensed U-NII
channel that must incorporate DFS functions. Attenuators or some type
of power control will be used to set the power of the unlicensed link
[to be determined] dB above the radar simulator power.
3) The radar simulator will be turned on and
emulate one of the two fixed frequency radars in Table 5 with the
appropriate parameters (pulsewidth, burst length, and burst period).
4) Spectrum analyzer #1 and a diagnostic
computer/monitor will be used to monitor the output of the unit under
test (UUT) to observe that its behavior is consistent with the channel
occupancy and move times of ITU-R M.1652.
5) If the UUT does not properly detect the
simulated radar pulses in [to be determined] minutes the device will
not pass the test.
Note that both
types of Fixed frequency radars from Table 5 will be tested.
Frequency
Hopping Radar Simulator
1) The power level (-64, -62, -55 dBm) of the
radar signal will be calibrated for the frequency hopping radar signal
type in Table 5 at the antenna of the unlicensed U-NII device. The higher power level (-55 dBm) will be used
to test the DFS functionality of the unlicensed device before the ITU
detection thresholds are tested.
2) The unlicensed U-NII devices will be turned
on and be instructed to operate on the appropriate U-NII channel that
must incorporate DFS functions. Attenuators or some type of power
control will be used to set the power of the unlicensed link [to be
determined] db above the radar simulator power.
3) The radar simulator will be turned on and
emulate the frequency hopping radar in Table 5 with the appropriate
parameters (pulsewidth, burst length, burst period, and hopping rate).
4) Spectrum analyzer #1 and a diagnostic
computer/monitor will be used to monitor the output of the unit under
test (UUT) to observe that its behavior is consistent with the channel
occupancy and move times of ITU-R M.1652.
5) The UUT will be monitored for [to be
determined] minutes to determine if it can detect the frequency hopping
radar.
SCHEDULE OF PROJECTED
MILESTONES
FOR 5 GHZ PROJECT TEAM
Task_Name |
Duration |
Start_Date |
Finish_Date |
Status |
Bench
Test Procedures |
116 days |
9-Jun-03 |
14-Nov-03 |
Incomplete |
Draft
Bench Test Procedures |
39 days |
9-Jun-03 |
31-Jul-03 |
Yes |
Draft
Deadline |
1 day |
31-Jul-03 |
31-Jul-03 |
Yes |
DFS
Project Team Meeting |
1 day |
15-Aug-03 |
15-Aug-03 |
Yes |
Finalize
Bench Test Procedures |
11 days |
18-Aug-03 |
31-Aug-03 |
Yes |
Bench
Test Procedure Deadline |
1 day |
31-Aug-03 |
31-Aug-03 |
Yes |
FCC
NPRM Comment Reply Deadline |
1 day |
3-Sep-03 |
3-Sep-03 |
Yes |
Bench
Testing |
10 days |
3-Nov-03 |
14-Nov-03 |
Confirmed |
|
|
|
|
|
Bench
Test Report |
76 days |
17-Nov-03 |
1-Mar-04 |
Incomplete |
Draft
Report |
66 days |
17-Nov-03 |
16-Feb-04 |
Pending |
DFS
Project Team Meeting |
1 day |
15-Jan-04 |
15-Jan-04 |
Pending |
DFS
Project Team Meeting |
1 day |
2-Feb-04 |
2-Feb-04 |
Pending |
Submit
to FCC |
1 day |
1-Mar-04 |
1-Mar-04 |
Pending |
|
|
|
|
|
Field
Test Procedures |
100 days |
1-Mar-04 |
15-Jul-04 |
Incomplete |
Outline
Field Test Procedures |
34 days |
1-Mar-04 |
15-Apr-04 |
Pending |
Draft
Field Test Procedures |
22 days |
16-Apr-04 |
16-May-04 |
Pending |
Draft
Deadline |
1 day |
16-May-04 |
16-May-04 |
Pending |
DFS
Project Team Meeting |
1 day |
5-May-04 |
5-May-04 |
Pending |
Radar
Asset Confirmation Deadline |
1 day |
31-May-04 |
31-May-04 |
Pending |
DFS
Project Team Meeting |
1 day |
1-Jun-04 |
1-Jun-04 |
Pending |
Finalize
Field Test Procedures |
11 days |
1-Jun-04 |
15-Jun-04 |
Pending |
Field
Test Procedures Deadline |
1 day |
15-Jun-04 |
15-Jun-04 |
Pending |
Field
Testing |
11 days |
1-Jul-04 |
15-Jul-04 |
Pending |
|
|
|
|
|
Field
Test Report |
66 days |
16-Jul-04 |
15-Oct-04 |
Incomplete |
Draft
Report |
13 days |
16-Jul-04 |
3-Aug-04 |
Pending |
DFS
Project Team Meeting |
1 day |
31-Jul-04 |
31-Jul-04 |
Pending |
DFS
Project Team Meeting |
1 day |
3-Aug-04 |
3-Aug-04 |
Pending |
Submit
to FCC |
1 day |
15-Oct-04 |
15-Oct-04 |
Pending |
|
|
|
|
|
Comprehensive
NTIA Report |
65 days |
19-Oct-04 |
17-Jan-05 |
Incomplete |
Draft
Report |
57 days |
19-Oct-04 |
5-Jan-05 |
Pending |
Report
Deadline |
1 day |
3-Jan-05 |
3-Jan-05 |
Pending |
Submit
to FCC |
1 day |
17-Jan-05 |
17-Jan-05 |
Pending |
|
|
|
|
|
ITU
Methodology |
296 days |
15-Mar-04 |
29-Apr-05 |
Incomplete |
Draft
DFS Testing Question |
192 days |
15-Mar-04 |
6-Dec-04 |
Pending |
Drafting
of DFS Test Question |
106 days |
15-Mar-04 |
6-Aug-04 |
Pending |
Submit
to U.S. Preparatory Process |
1 day |
11-Aug-04 |
11-Aug-04 |
Pending |
Submit
to ITU-R WP 8A |
1 day |
1-Sep-04 |
1-Sep-04 |
Pending |
Draft
New Question Deadline |
1 day |
6-Dec-04 |
6-Dec-04 |
Pending |
Draft
Methodology Recommendation |
207 days |
15-Jul-04 |
29-Apr-05 |
Pending |
Drafting
of DFS Recommendation |
45 days |
15-Jul-04 |
15-Sep-04 |
Pending |
Submit
to U.S. Preparatory Process |
1 day |
17-Sep-04 |
17-Sep-04 |
Pending |
Submit
to ITU-R WP 8A |
1 day |
1-Oct-04 |
1-Oct-04 |
Pending |
Draft
New Recommendation Deadline |
1 day |
29-Apr-05 |
29-Apr-05 |
Pending |
[1] Revision of Parts 2 and 15 of the Commission’s
Rules to Permit Unlicensed National
Information Infrastructure (U-NII) Devices in the 5 GHz Band, Notice of Proposed Rulemaking, ET Docket No. 03-122,
(released June 4, 2003) (“U-NII NPRM”).
[2] See 47 C.F.R. Part 15 Subpart E – Unlicensed National Information Infrastructure Devices. U-NII devices are “[i]ntentional radiators operating in the frequency bands 5.15-5.35 GHz and 5.725-5.825 GHz that use wideband digital modulation techniques and provide a wide array of high data rate mobile and fixed communications for individuals, businesses, and institutions.” 47 C.F.R. §15.403(i).
[3] The rules being proposing are those deemed necessary to protect incumbent users from interference. Industry standards being developed by the Institute for Electrical and Electronics Engineers (IEEE) or others may contain more detailed technical requirements.
[4] The U.S. Table of Frequency Allocations is set forth in Section 2.106 of the Commission’s Rules, 47 C.F.R. § 2.106.
[5] The Commission previously proposed primary Federal Government EESS (active) and SRS (active) allocations in the 5.25-5.35 GHz band and a Federal Government EESS (active) allocation in the 5.35-5.46 GHz band. See Amendment of Parts 2, 25, and 87 of the Commission’s Rules to Implement Decisions from World Radio Communication Conferences Concerning Frequency Bands Between 28 MHz and 36 GHz and to Otherwise Update the Rules in this Frequency Range, Notice of Proposed Rulemaking, ET Docket No. 02-305, 17 F.C.C. Rcd. 19756 (2003).
[6] U-NII NPRM at ¶ 13.
[7] NTIA Special Publication 00-40, Federal Radar Spectrum Requirements, National Telecommunications and Information Administration, at 19 (May 2000).
[8] Id.
[9] To detect smaller targets narrower pulse widths are necessary. The bandwidth of a pulsed signal is related to the inverse of the pulse width (e.g., smaller pulse widths result in wider emission bandwidths).
[10] World Radiocommunication Conference 2003 (WRC-03) Final Acts (Provisional) as published on 4 July 2003, International Telecommunication Union (Revision 1), at 28 (Sept. 4, 2003).
[11] U-NII NPRM at ¶ 14.
[12] Id. at ¶ 20.
[13] Id. at ¶ 22.
[14] Id. at ¶ 23.
[15] Id. at ¶ 25.
[16] Id. at ¶ 24.
[17] Id.
[18] World Radio Conference Resolution 229 Resolves 7 (2003).
[19] U-NII NPRM at ¶ 26.
[20] Id. at ¶ 22.
[21] Id. at Appendix B.
1 NTIA Report 97-334, Broadband Spectrum Survey at San Diego, California, National Telecommunications and Information Administration (Dec. 1996); NTIA Report 97-336, Broadband Spectrum Survey at Los Angeles, California National Telecommunications and Information Administration (May 1997); NTIA Report 99-367, Broadband Spectrum Survey at San Francisco, California May-June 1995, National Telecommunications and Information Administration (July 1999); NTIA Report 95-321, Broadband Spectrum Survey at Denver, Colorado, National Telecommunications and Information Administration (Sept. 1995).
1 Revision of Parts 2 and 15 of the Commission’s Rules to Permit Unlicensed National Information Infrastructure (U-NII) Devices in the 5 GHz Band, Notice of Proposed Rulemaking, ET Docket No. 03-122, (released June 4, 2003) (“U-NII NPRM”).
[djs1]FCC does not ask for environmental conditions for these tests.
[djs3]Deleted
radar signal 3 – too close to Signal 1 to be of real value given the
use of a 6s window and testing at the beginning and end of the Channel
Availability Check time.
[MP4]Should this also be included in sections 5.2.1.2.1.2 and 5.2.1.4.1.2?
[djs5]Deletions are because FCC does not require environmental profiles.
[djs6]What is the shared risk model?
1) a measurement specification
should contain a maximum uncertainty (MU) defined for each measurement.
2) a measurement report should
specify the achieved measurement uncertainty
3) if the measured MU ≤specified
MU, then
a) when
the measured value does not exceed the limit value the equipment under
test meets the requirements of the standard;
b) when
the measured value exceeds the limit value the equipment under test
does not meet the requirements of the standard;
4) if measured MU > specified MU
then
a) when
the measured value plus the difference between the maximum allowable
measurement uncertainty and the measurement uncertainty calculated by
the test technician does not exceed the limit value the equipment under
test meets the requirements of the standard;
b) when
the measured value plus the difference between the maximum allowable
measurement uncertainty and the measurement uncertainty calculated by
the test technician exceeds the limit value the equipment under test
does not meet the requirements of the standard;
The heart of the matter is that
measurement uncertainty plays a role that is defined in terms of the
required measurement uncertainty. Shared
risk means nothing if there is no stated maximum allowable measurement
uncertainty.
In DFS testing, the matter is
complicated because the RF power level used is not a measured test
value but an input value. The test output
is - in principle - a binary value. Shared
Risk means nothing in the radar detection test. However,
it may be useful in the test time measurements.