Rule2023-15367
FCC Empowers Short-Range Radars in the 60 GHz Band
Primary source
Metadata and text below are from the Federal Register, a public-domain U.S. government work. Always verify the official published version before relying on it for any legal matter.
Published
July 24, 2023
Effective
August 23, 2023
Issuing agencies
Federal Communications Commission
Abstract
In this document, the Federal Communications Commission (Commission) revises its rules to provide new opportunities for unlicensed field disturbance sensor (FDS) devices (e.g., radars) to operate in the 57-71 GHz band (60 GHz band) while still ensuring coexistence with other unlicensed technologies in the band. The Commission's decision is a significant step in the continuing expansion and evolution of its rules and will supercharge the development and deployment of new and innovative radar operations--including valuable safety applications that detect unattended children in vehicles and which previously could only be permitted through a waiver of the rules.
Full Text
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[Federal Register Volume 88, Number 140 (Monday, July 24, 2023)]
[Rules and Regulations]
[Pages 47384-47395]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2023-15367]
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FEDERAL COMMUNICATIONS COMMISSION
47 CFR Part 15
[ET Docket No. 21-363; FCC 23-35; FR ID 153948]
FCC Empowers Short-Range Radars in the 60 GHz Band
AGENCY: Federal Communications Commission.
ACTION: Final rule.
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SUMMARY: In this document, the Federal Communications Commission
(Commission) revises its rules to provide new opportunities for
unlicensed field disturbance sensor (FDS) devices (e.g., radars) to
operate in the 57-71 GHz band (60 GHz band) while still ensuring
coexistence with other unlicensed technologies in the band. The
Commission's decision is a significant step in the continuing expansion
and evolution of its rules and will supercharge the development and
deployment of new and innovative radar operations--including valuable
safety applications that detect unattended children in vehicles and
which previously could only be permitted through a waiver of the rules.
DATES: Effective August 23, 2023.
FOR FURTHER INFORMATION CONTACT: Anh Wride, Office of Engineering and
Technology, (202) 418-0577 or <a href="/cdn-cgi/l/email-protection#3b7a5553156c49525f5e7b5d5858155c544d"><span class="__cf_email__" data-cfemail="19587771374e6b707d7c597f7a7a377e766f">[email protected]</span></a>.
SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Report
and Order, ET Docket No. 21-264; FCC 23-35, adopted on May 18, 2023 and
released on May 19, 2023. The full text of this document is available
for public inspection and can be downloaded at: <a href="https://docs.fcc.gov/public/attachments/FCC-23-35A1.pdf">https://docs.fcc.gov/public/attachments/FCC-23-35A1.pdf</a>. Alternative formats are available
for people with disabilities (Braille, large print, electronic files,
audio format) by sending an email to <a href="/cdn-cgi/l/email-protection#34727777010400745257571a535b42"><span class="__cf_email__" data-cfemail="eaaca9a9dfdadeaa8c8989c48d859c">[email protected]</span></a> or calling the
Commission's Consumer and Governmental Affairs Bureau at (202) 418-0530
(voice), (202) 418-0432 (TTY).
Procedural Matters
Final Regulatory Flexibility Analyses. The Regulatory Flexibility
Act of 1980, as amended (RFA), requires that an agency prepare a
regulatory flexibility analysis for notice and comment rulemakings,
unless the agency certifies that ``the rule will not, if promulgated,
have a significant economic impact on a substantial number of small
entities.'' Accordingly, the Commission has prepared a Final Regulatory
Flexibility Analysis (FRFA) concerning the possible impact of the rule
changes and/or policy contained in the Report and Order on small
entities. As required by the RFA, an Initial Regulatory Flexibility
Analysis (IRFA) was incorporated in the Notice of Proposed Rulemaking
(NPRM) (86 FR 46661, August 19, 2021). The Commission sought written
public comment on the proposals in the NPRM, including comments on the
IRFA. No comments were filed addressing the IRFA. Accordingly, the
Commission has prepared a Final Regulatory Flexibility Analysis (FRFA)
concerning the possible impact of the rule changes contained in the
document on small entities. The present FRFA conforms to the RFA and
can be viewed under Appendix C of the Report and Order.
Congressional Review Act. The Commission has determined, and the
Administrator of the Office of Information and Regulatory Affairs,
Office of Management and Budget, concurs, that this rule is non-major
under the Congressional Review Act, 5 U.S.C. 804(2). The Commission
will send a copy of this Report & Order to Congress and the Government
Accountability Office pursuant to 5 U.S.C. 801(a)(1)(A).
Paperwork Reduction Act Analysis. This Report and Order does not
contain new or modified information collections subject to the
Paperwork Reduction Act of 1995 (PRA), Public Law 104-13 (44 U.S.C.
3501-3520). In addition, it does not contain any new or modified
information collection burden for small business concerns with fewer
than 25 employees pursuant to the Small Business Paperwork Relief Act
of 2002, Public Law 107-198, see 44 U.S.C. 3506(c)(4).
People with Disabilities: To request materials in accessible
formats for people with disabilities (braille, large print, electronic
files, audio format), send an email to <a href="/cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="8ee8ededbbbebacee8ededa0e9e1f8">[email protected]</a> or call the
Consumer & Governmental Affairs Bureau at 202-418-0530 (voice), 202-
418-0432 (tty).
Synopsis
As discussed in greater detail below, the rules the Commission
adopts set forth distinct technical and operational provisions for
unlicensed use in different segments of the band. They will permit new
fixed and mobile FDS devices to implement pulse or frequency-modulated
continuous-wave (FMCW) techniques to facilitate new use cases including
installation on low-flying unmanned aircraft. Importantly, novel use
cases that support safety, such as vehicle occupant detection, chest
movement detection to determine breathing patterns, and eye lid
movement detection to determine driver alertness are also expected to
see widespread deployment. This approach recognizes evolution in the
proceeding as different unlicensed interests provided information on
the wide array of potential uses for FDS devices and developed a
consensus approach for accommodating these innovative applications. The
Commission's decision is especially well suited to stimulate the rapid
development of new products and services in such important areas as
healthcare monitoring, personal safety, autonomous vehicles, home and
industrial automation, and environmental control.
Background
In 2021, the Commission issued a Notice of Proposed Rulemaking
(NPRM) that proposed to change the rules in Sec. 15.255 to permit FDS
devices to operate at higher power limits and provide a more expansive
range of applications than the rules currently allow. The proposals,
recognizing the burgeoning interest in allowing the use of mobile
radars in the band for innovative and life-saving functions,
represented the latest evolution in a band in which unlicensed
operations have been permitted for more than 20 years. The Commission
attributed this newfound interest to the availability of affordable,
mass-produced chipsets that are capable of operating in the band, as
well as the prospect of marketing and operating these mobile radar
devices on a broad international scale. The NPRM noted, for example,
that interested parties had formed a 60 GHz Coexistence Study Group
that was ``looking into ways to accommodate both unlicensed
communications device and FDS operations in the band,'' and whose
members had ``encouraged [the Commission] to initiate a rulemaking
proceeding to review . . . the rules with a goal of putting in place a
new framework to promote further innovation in the 60 GHz band by both
unlicensed communications and FDS operations.'' It also recognized that
the FCC's 2020 Technological Advisory Council (TAC) panel recommended
that the Commission initiate a rulemaking proceeding to examine the
unlicensed rules governing 60 GHz operations.
Radars operate by transmitting radiofrequency (RF) signals at
targets and analyzing the subsequent reflections to determine the
targets' speed, range, and direction. Based on the record before us and
prevalent technologies, the two common types of radars the Commission
anticipates will
[[Page 47385]]
operate in the 60 GHz band are FMCW radars and pulse radars. An FMCW
radar transmits a continuous sinusoid signal (chirp) whose frequency
changes linearly in time to sweep over a defined frequency band. A
collection of evenly spaced chirps constitutes an FMCW radar frame. On
the other hand, pulse radars typically transmit nanosecond-long pulses
in the time domain that instantaneously spread frequencies across a
wide bandwidth. As discussed in greater detail below, the rules adopted
herein by the Commission are broad enough to account for use of these
radar types.
In the 60 GHz band, radars are regulated under Sec. 15.255 of part
15 of the Commission's rules. The part 15 rules permit low-power
intentional radiators (popularly known as ``unlicensed devices'') to
operate without an individual license where such use is not anticipated
to cause harmful interference to authorized users of the radio
spectrum. Unlicensed devices in the 60 GHz band generally include
indoor/outdoor communication devices such as WiGig, wireless local area
networks (WLANs), outdoor fixed point-to-point communication links, and
FDS--which includes radar operations. Unlicensed device users protect
the operations of authorized Federal and non-Federal users in the band.
These users operate under a variety of allocations, including the
Mobile, Fixed, Inter-Satellite, Earth-Exploration Satellite Service
(EESS), Space Research, Mobile-Satellite, Radiolocation,
Radionavigation, and Radionavigation-Satellite services.
When it first adopted Sec. 15.255 in 1995, the Commission stated
its intent to develop the 60 GHz band's potential to achieve
communications capabilities similar to fiber and coaxial cable; thus,
it originally prohibited FDS operation in the band. When it finalized
the rules by adopting a spectrum etiquette three years later, it also
included a provision that permitted only fixed FDS operation in the
band. In 2016, the Commission expanded unlicensed device use in the
band to permit limited mobile radar operations and to extend the use of
fixed field disturbance sensors to the 64-71 GHz band. Specifically,
the Commission's decision permitted the ``narrow application of mobile
radars for short-range interactive motion sensing'' (SRIMS) at reduced
power levels to ensure that they would successfully co-exist with co-
channel communications devices already permitted to operate in the
band. While the Commission did not adopt a specific definition for
SRIMS, in permitting narrow use of short-range mobile radars it
discussed the work of Google LLC (Google) in developing its ``Soli''
sensor technology, which envisioned that smartphones and other personal
devices would be able to sense hand gestures when a user is located at
a very short distance from the device to perform functions such as
controlling web pages or answering phone calls.
Since 2016, the Commission's Office of Engineering and Technology
(OET) has granted focused rule waivers to support discrete radar
applications, all based on an increased interest in FDS operation in
the 60 GHz band. First, in 2018, OET granted Google a waiver of the
emission limits to allow Soli radar devices to operate at a higher
output power level than what had been authorized in the rulemaking. The
waiver permitted Google to deploy its Soli sensor technology at 10 dBm
peak transmitter conducted output power, 13 dBm peak EIRP level, and 13
dBm/MHz power spectral density, with a maximum 10% duty cycle in any 33
ms interval. More recently, in 2021, OET granted waivers to several
parties to permit vehicle cabin-mounted radars as well as health-care
related and other applications in the 57-64 GHz range at the same power
levels as those granted to Google in 2018. These narrowly tailored
waivers support an especially compelling public interest--using radar
technology to monitor for children left in dangerously hot cars, and to
trigger alerts that could save lives. In addition, OET granted a waiver
to Leica Geosystems AG in July 2020 that allows a limited number of
radars to operate in the 60-64 GHz band on specialized unmanned
aircraft for the specific purpose of avoiding collisions with
structures, supporting wires, or other fixed objects during structure
visual inspection operations.
Under the current rules, FDS operations are limited to fixed
operation or when used for SRIMS. While FDS devices are limited to a
maximum transmitter conducted output power not to exceed -10 dBm and a
maximum EIRP level not to exceed 10 dBm, a fixed FDS device with an
occupied bandwidth fully contained within the 61.0-61.5 GHz Industrial,
Scientific, and Medical Equipment (ISM) band may operate with average
output power levels up to 40 dBm and peak output power levels up to 43
dBm. Finally, operations are prohibited on-board aircraft, except on
aircraft that are equipped with a high RF attenuation body (e.g.,
commercial airliners) while forming a ``closed exclusive on-board
communication networks within the aircraft.''
At the time the NPRM was issued, there was no uniform consensus for
how best to accommodate new FDS radar applications in the 60 GHz band
while ensuring coexistence with incumbent unlicensed uses.
Nevertheless, the Commission found that the extensive analysis
associated with the waiver requests, the widespread consumer use of
Google's Soli-equipped devices without reported cases of harmful
interference, and the ongoing industry interest in promoting
coexistence gave it confidence ``that there is now sufficient
information for us to build a record to expand unlicensed mobile radar
use beyond the toehold the Commission first provided in 2016 and the
narrow waivers that have been issued to date.''
As such, the NPRM offered a high level proposal that would have
provided for all FDS devices, mobile or fixed, to operate in the 57-64
GHz portion of the band at a maximum of 20 dBm average EIRP, 13 dBm/MHz
average EIRP power spectral density, and 10 dBm transmitter conducted
output power, along with a maximum 10% duty cycle restriction within
any 33 ms interval; allowed fixed and mobile FDS devices to operate
across the 57-71 GHz band at the existing 10 dBm EIRP and -10 dBm
conducted output power limits specified in the rules, without any duty
cycle limitations; and asked about other methods to potentially enhance
coexistence in the band. The Commission did not propose any rule
revisions that would apply to existing unlicensed communication devices
such as WiGig, WLAN, or fixed point-to-point wireless links that
currently operate in the 57-71 GHz band. The NPRM further recognized
that operation at higher power than specified in the Commission's
existing rules has been allowed in Europe under general rules for
short-range devices, and considered how the Commission might be able to
harmonize any revisions with applicable European Telecommunications
Standards Institute (ETSI) standards to the extent appropriate.
Throughout the NPRM, the Commission asked questions about its specific
proposals, and also specifically ``s[ought] input on the work results
of any other coexistence standards activities (international and
domestic) and/or cooperative works between communications and FDS study
groups that may have taken place, and how such work may inform its
proposals to expand unlicensed use of the band.''
In the time since the NPRM was released on July 14, 2021, the
record has reflected evolving views on how the Commission can
accomplish the goals of the rulemaking. The comment cycle initially
showed prevalent disagreements between the radar and
[[Page 47386]]
communication proponents, with parties from each group opposing
different aspects of the proposals. The large number of ex parte
filings following the close of the comment period reflect how both
sides, individually and jointly, have been engaged in ongoing attempts
to resolve their differences with various proposals for power levels
and duty cycles/radar transmission off-times based on different
segmentations of the 57-64 GHz band. Two recent submissions document
the fruit of these labors, and are significant milestones in the
history of this proceeding: the Industry Consensus Agreement submitted
February 27, 2023 that addresses the interests of both FMCW radars and
communications devices, and a separate Pulse Radar Joint Agreement
submitted November 10, 2022 that describes technical parameters
suitable for pulse radar operations.
Discussion
The targeted changes to the part 15 rules the Commission is
adopting are optimized to encourage the development of important
innovative FDS applications while promoting the growth of equally
important innovative immersive communication applications. Taking into
account the record as a whole, including the Industry Consensus
Agreement and the Pulse Radar Joint Agreement, as well as the filings
in response thereto, the Commission finds that these two types of
unlicensed technologies (i.e., radar and communications) can
successfully co-exist and expand the applications available in the 60
GHz band under the Commission's revised rules.
First, the Commission clarifies the relationship between radars and
FDS applications. The Commission also modifies its rules to expand
mobile FDS operations within the 60 GHz band, including within the
61.0-61.5 GHz sub band, where higher powered operations are permitted
but only for fixed use; with these modifications, the Commission
retires the specific provisions that had been established for SRIMS.
Second, for FDS devices that limit their operating frequencies to
the 57-64 GHz portion of the 57-71 GHz band, the Commission permits
various EIRP levels along with specific duty cycle restrictions related
to specific segmentations of the band. The Commission finds that these
distinctions, described in greater detail below, offer the best
opportunity for new and existing unlicensed devices to successfully co-
exist in the 60 GHz band. In conjunction with these rules, the
Commission addresses the applicability of additional technologies and
technical approaches that were discussed in the NPRM.
Third, the Commission permits FDS operation on-board unmanned
aircraft (UA) flying at altitudes less than 121.92 meters (400 feet)
above ground level, limited to the 60-64 GHz band, at up to 20 dBm peak
EIRP subject to a 50% duty cycle, and discusses how the Commission's
new rules for FDS devices relate to existing provisions for limited in-
cabin aeronautical use. The Commission also addresses matters related
to compliance testing and use of equipment that currently operates
under waivers of its existing rules.
Definitional Clarification and Mobile Use Expansion
Definition of FDS/Radar. In the NPRM, the Commission stated that,
although Sec. 15.3(l) of its rules provides a definition for ``field
disturbance sensor,'' one must look to the general part 2 rules to find
a definition for ``radar.'' It asked whether the rules related to
``field disturbance sensors'' in Sec. 15.255 are sufficiently broad
and flexible to accommodate the classes of devices that parties
anticipate will be developed to operate in the 57-71 GHz band and
whether the definition contained in part 15 of the rules should be
modified to provide greater clarity regarding the relationship between
FDS and radars.
The Commission clarifies that radars are a sub-category of FDS as
defined in both Sec. Sec. 15.3(l) and 2.1 of its rules. The Commission
further finds that the radar definition in Sec. 2.1 of its rules is
sufficiently broad when used in conjunction with the FDS definition of
Sec. 15.3(l) to accommodate the types of FDS applications envisioned
for the 60 GHz band. The Commission agrees with both Texas Instruments
(TI) and IEE Sensing that its rules must allow for the detection of
static persons or objects and cover all cases of motion/presence
detection, regardless of the particular radar topologies employed, and
the Commission finds that modifying the definition in Sec. 15.3(l) of
the rules to include radars will achieve this objective. The final
rules are set forth, infra.
Mobile Use of FDS Devices. The Commission's history of expanding
unlicensed use of the 60 GHz band has focused on fixed FDS use, with
limited and relatively recently adopted provisions for mobile use. In
the NPRM, the Commission sought comment on how it should interpret
``fixed'' and whether it should incorporate a specific definition for
that term into the part 15 rules. The Commission further observed that
a review of the 1998 Report and Order that first permitted fixed FDS
use in the band suggests the Commission was anticipating a narrow set
of applications for industrial settings where the equipment would
rarely if ever be moved. In the NPRM of this proceeding and with
respect to the 61.0-61.5 GHz band in particular, the Commission
tentatively concluded that fixed FDS operations should be interpreted
as those instances where an FDS device is stationary and is operating
at a discrete location for an indefinite--i.e., more than mere
transitory--period. It also sought comment on whether there is a bright
line rule to differentiate fixed and mobile FDS operations.
Many commenters express support for eliminating the distinction
between fixed and mobile FDS use or ask the Commission to take an
agnostic use case approach. Among the commenters that suggest specific
definitions, Vayyar says the Commission should interpret ``fixed'' in
an expansive manner, such as ``remaining at same geographical location
while operating,'' allowing moving the sensor within the premises or to
other premises (e.g., within an apartment, hospital, ship, etc.).
Google suggests keeping the high power allowed in the 61.0-61.5 GHz
band and recommends interpreting ``fixed'' FDS operations as those
instances where an FDS device is stationary and is operating at a
discrete location for an indefinite period, and Bosch suggests
distinguishing between fixed and mobile based on whether the device is
mounted on a structure (e.g., building, streetlight, or tower) or
connected to permanent infrastructure.
The Commission finds that the record illustrates radar use cases
that can be ubiquitous and sufficiently fluid in space (such as on a
vehicle, or a hospital equipment cart), such that to fully realize the
potential benefits of the band, many radar applications will have
mobile characteristics even if they are affixed to equipment that can
remain stationary in a particular location while the radar is in
operation. Thus, the Commission concludes that the best course is to
broadly expand mobile use throughout the band so that fixed and mobile
distinctions are generally not relevant for operating under the revised
rules. For this reason, the Commission is not adding a specific
``fixed'' definition in its rules for unlicensed FDS devices.
For purposes of the 61.0-61.5 GHz ISM band segment, existing Sec.
15.255(c)(2) of the rules permits a fixed FDS device to operate at up
to 40
[[Page 47387]]
dBm average EIRP and at up to 43 dBm peak EIRP. Under this rule, a
fixed FDS device's occupied bandwidth must be fully contained within
the 500-megahertz bandwidth of the 61.0-61.5 GHz band; and it must
attenuate its signals outside the 61.0-61.5 GHz band, but still within
the 57-71 GHz band, to less than 10 dBm average EIRP and 13 dBm peak
EIRP. Google has observed that the high power allowed in this 500-
megahertz band would be useful to FDS using narrow bandwidth
applications, and the Industry Consensus Agreement recommends retaining
the existing power levels permitted in the 61.0-61.5 GHz band while
opening the band to mobile applications. Applying the Commission's
decision to this band, it removes the ``fixed'' restriction applicable
to FDS operation in Sec. 15.255(c)(2). This is consistent with the
Commission's intentions to permit both fixed and mobile applications to
be deployed within the entirety of the 60 GHz band.
Removal of the SRIMS Designation. Consistent with the Commission's
decision to permit fixed and mobile radars to operate throughout the 60
GHz band, the Commission adopts the proposal to remove the term
``short-range interactive motion sensing'' (SRIMS) from the rules. The
Commission acknowledges that there has been much confusion on which 60
GHz mobile and fixed radar applications qualify under the SRIMS
designation, and notes that commenters unanimously supported the
removal of the SRIMS terminology from the rules. Because the FDS rules
the Commission is adopting herein will apply to all manners of fixed
and mobile technologies operating under Sec. 15.255, and because the
SRIMS designation was crafted for a limited type of mobile radar (i.e.,
short-range motion sensing radar), it is no longer necessary.
Accordingly, the Commission removes this designation and associated
relevant requirements from the rules.
Expanded Use of FDS Devices Operating in the 57-64 GHz Band
In response to notice that the Commission was considering rules
that would promote co-existence between communication devices--
especially new immersive technologies--and FDS/radars in the 60 GHz
spectrum, the record reflects the disagreements, debates, and ultimate
consensus opinions that arose between communications and radar
proponents. The rules the Commission is adopting balance the abilities
of radar and communication devices to access the same spectrum. The
Commission adopts a band plan and associated technical rules that arise
from the Commission's original proposals and accounts for the results
of a multi-month negotiated agreement between major parties within both
the communications and the radar industries, and that no party has
opposed.
Under the Commission's revised Sec. 15.255 rules, which are set
forth below, the Commission permits the following for FDS devices: (1)
up to 20 dBm peak EIRP for indoor operation, and up to 30 dBm peak EIRP
for outdoor operation, including all vehicular applications, within the
57.0-59.4 GHz band; (2) up to 3 dBm peak EIRP for all operations within
the 57.0-61.56 GHz band; (3) up to 20 dBm peak EIRP for all operations
within the 57.0-61.56 GHz band subject to a 50% duty cycle; (4) up to
14 dBm peak EIRP for all operations within the 57-64 GHz band subject
to a 22.7% duty cycle; and (5) up to 20 dBm peak EIRP for fixed outdoor
operations or vehicular applications (except in-cabin vehicular use
cases) within the 57-64 GHz band subject to a 50% duty cycle. In
addition, for FDS devices that have a maximum pulse duration of 6 ns,
the Commission permits the following: (a) the average EIRP shall not
exceed 13 dBm and the transmit duty cycle shall not exceed 10% during
any 0.3 [micro]s time window; (b) the average integrated EIRP within
the frequency band 61.5-64.0 GHz shall not exceed 5 dBm in any 0.3
[micro]s time window; and (c) peak emissions shall not exceed 20 dB
above the maximum permitted average emission limit applicable to the
equipment under test. The Commission addresses unlicensed device use
while airborne in the portion of this summary titled ``Operation On-
board Aircraft,'' infra. The adoption of the above technical rules is
supported by two industry joint agreements, the Industry Consensus
Agreement and the Pulse Radar Joint Agreement which are discussed in
greater detail, below. The Commission finds that these different EIRP
limits and the respective associated band segmentations along with the
different duty cycle limits would provide expanded opportunities for
various use cases based on radars' bandwidth usage while ensuring
successful co-existence with other users of the band. This approach,
proposed by the industry agreements, effectively improves on the
Commission's simpler approach of having a single EIRP limit across the
entire band as proposed in the NPRM. The Commission notes that these
EIRP limits are lower than the limits permitted to general
communication devices in the band.
Consensus Agreements
Industry Consensus Agreement. The February 27, 2023 Industry
Consensus Agreement represents a significant breakthrough, as it
resolves longstanding disagreements among various industry segments
regarding equitable spectrum access. The Industry Consensus Agreement
represented by radar proponents (<a href="http://Amazon.com">Amazon.com</a> Services LLC, Continental
Corporation, Garmin International, Inc., Google LLC, IEE Sensing Inc.,
Infineon Technologies Americas Corp., Texas Instruments Incorporated
and Vayyar Imaging Ltd.) and unlicensed communications proponents
(Intel Corporation, Meta Platforms Inc. and Qualcomm Incorporated), all
of whom have been active participants throughout the course of the
rulemaking proceeding, represents a viable compromise that has support
from both interest groups.
The Industry Consensus Agreement proposes ``soft segmentations'' of
the 57-64 GHz band that follows the WiGig channelization scheme to
promote communications devices' access to an alternative channel if a
radar device is transmitting on the remaining channel(s). The Industry
Consensus Agreement also proposes long periods of radar transmission
off-times (at least 2 ms in duration) under certain parameters to
permit communications devices' necessary access to the same spectrum,
thus resolving one of the more highly contested issues within the
proceeding--whether and for how long the rules should require FDS
devices to adhere to specific time periods of non-transmission.
Finally, the Industry Consensus Agreement proposes different EIRP
limits in different sub-bands to further ensure successful co-existence
between FDS and communications devices while allowing varying EIRP
levels necessary to successfully provide different radar applications
in each sub-band.
The Industry Consensus Agreement responds to the NPRM by proposing
more expansive radar operations in portions of the 57-64 GHz band than
the Commission proposed, while explaining how the Commission can still
meet its goal of ensuring fair sharing with communications operations.
For example, the proposal allows radars with 2-gigahertz bandwidth
(operating in the 57.0-59.4 GHz band) to transmit at 20 dBm peak EIRP
without any transmitter off-time limitations. In place of the prior 2
ms minimum radar transmitter off-time requirement imposed in multiple
waivers approved in July 2021, the Industry Consensus Agreement allows
FDS/radar devices
[[Page 47388]]
with 4.5-gigahertz bandwidth (operating in the band 57.0-61.56 GHz) and
7-gigahertz bandwidth (operating across the entire 57-64 GHz band) to
operate with transmission bursts that occupy 50% and 22.7% of the
airtime, respectively, but requires the FDS devices to implement
continuous silent intervals to prevent non-stop radar transmissions
bursts that could severely impact communications devices' latency, as
described in the record of the proceeding, supra.
Pulse Radar Joint Agreement. Acconeer, the primary proponent for 60
GHz pulse radar technologies in the Commission's record, engaged in
lengthy discussions with major communications device proponents
represented by Intel, Meta Platforms and Qualcomm to develop technical
parameters particular to pulse radars to enable successful co-existence
in the 57-64 GHz band. On November 10, 2022, these parties responded to
the Commission's NPRM by submitting the Pulse Radar Joint Agreement
that sets forth specific technical parameters applicable to pulse-style
radars that are distinct from those submitted by the Industry Consensus
Agreement, and requests that the Commission adopts these parameters
into the rules.
As described supra, pulse radars typically transmit nanosecond-long
pulses that instantaneously spread across the wide intended band.
Pulses are emitted in sweeps and multiple sweeps constitute a frame.
Acconeer describes that its ``pulse radar transmits in short
nanosecond-long pulses that can co-exist with [IEEE] 802.11ad/ay
[compliant devices] with low impact on throughput, as the error
correction coding of the communication systems are able to cope with
the pulse radar in the channel, even under extreme signal-to-
interference ratio (SIR)'' conditions unlike other types of radar
devices using different coding schemes, such as FMCW radars, ``which
perform sweeps continuously during tens of microseconds to tens of
milliseconds, making it difficult for [IEEE] 802.11ad/ay [compliant]
systems to rely on error correction coding to maintain a high data rate
during the slot occupied by the FMCW radar.'' Acconeer further explains
that the peak power spectral density for its pulse radar, as measured
over an IEEE 802.11ad/ay device's communication channel, is
significantly lower than FMCW radars, which decreases potential harmful
interference decreasing the likelihood that the listen-before-talk
(LBT) mechanism of the IEEE 802.11ad/ay compliant system less will be
triggered. Acconeer thus believes that its pulse radar technology,
which uses spread spectrum techniques over a wide bandwidth,
necessitates different provisions from what may be appropriate for
other types of radar technologies.
Discussion. The Commission finds that the technical proposals
included in the Industry Consensus Agreement in response to those on
which the Commission sought comment provides a reasonable compromise
that is well suited to foster its fundamental goal of opening the 60
GHz spectrum to innovative applications while promoting successful
sharing between communications and FDS technologies. The Industry
Consensus Agreement offers a path for realizing the band's potential to
host a wider range of unlicensed users without increasing the risk for
harmful interference to authorized users of the band. The Commission
notes that parties outside of the signatories to the Agreement,
including the Auto Innovators and Robert Bosch LLC have expressed
support for the Industry Consensus Agreement. Moreover, because the
Industry Consensus Agreement was the product of negotiations between
leading stakeholders with interests in both radar and unlicensed
communications devices, on balance, the economic benefits experienced
by band users will outweigh economic costs. Accordingly, the
Commission's final rules draw favorably from this filing.
While the NPRM made a specific proposal for expanding the use of
the band for FDS use, it also sought comment more broadly on rules that
would enable the successful sharing between FDS and communications
uses. For example, the NPRM proposed to expand FDS operations in the
57-64 GHz band, but alternatively sought comment on allowing the FDS
operations across the entire band or some other segment. The NPRM
proposed that FDS devices be limited to 20 dBm average EIRP while also
seeking comment on permitting up to an average power of 40 dBm EIRP and
on specifying a peak power rather than an average power. The NPRM
proposed FDS devices be limited to a duty cycle of 10% based on a
maximum 3.3 ms transmission time in every 33 ms interval but also
discussed the concerns parties have expressed with the proposed duty
cycle and timeframe. The NPRM also sought comment on frameworks
suggested by the 60 GHz Coexistence Study Group which included taking a
channelization approach to radars in the 60 GHz band and having
different operating parameters for radars when they are operating in a
vehicle, indoors, or outdoors, or between implementations that are
fixed, mobile, or portable.
To facilitate use by all technologies, the Commission agrees with
Acconeer that because pulse radars necessitate wide bandwidths to
accommodate their spread spectrum technique, the Commission must also
consider rules that are not solely predicated on using the small
partitioned bands outlined in the Industry Consensus Agreement.
Although Acconeer appears to be the only pulse radar provider that
participated in the proceeding, many commercial parties plan to
incorporate the Acconeer pulse radar chip into their finished products
and other manufacturers may have plans for similar systems, thus making
it likely that pulse FDS devices will see widespread use in the 57-64
GHz band. By adopting technical parameters that are compatible with the
Pulse Radar Joint Agreement, the Commission will further enhance the
potential for innovative product deployments in the 60 GHz spectrum
without increasing the potential for causing harmful interference to
authorized users. Because the Pulse Radar Joint Agreement represents
the interests of proponents of pulse radar and leading communications
device stakeholders, on balance, the economic benefits experienced by
band users will outweigh economic costs. Accordingly, the rules the
Commission is adopting also recognize the approach set forth in the
Pulse Radar Joint Agreement.
Technical Considerations
Frequency range. In the NPRM, based on the parameters in the
multiple waiver grants that pertain to FDS use of the 60 GHz band, the
Commission proposed to limit operation of FDS devices operating under
the proposed rules to the 57-64 GHz band to be consistent with the
European ETSI Harmonized Standard EN 305 550 that restricts short-range
devices, e.g., radars, to the 57-64 GHz band. While the Commission
proposed to retain FDS operation in the 64-71 GHz band at the existing
low-power limits in the rules, it sought comment on allowing use across
the entire 57-71 GHz frequency range at higher power limits in
conjunction with a specified duty cycle. In addition, in the NPRM, the
Commission noted the work of the 60 GHz Co-existence Study Group on
developing ``a consensus approach'' to a suitable co-existence
framework, with discussions concerning duty cycles; transmission on-
and off-times; operating bandwidth and channelization.
Initially, interested parties were unable to achieve consensus on
what
[[Page 47389]]
frequency range would be most appropriate for expanded FDS use. For
instance, Google suggested that limiting operating frequencies for FDS
devices to the 57-64 GHz band, consistent with the EN 305 550 standard,
would reserve the upper 7 gigahertz of the band for future potential
use cases, while both Acconeer and Amazon supported extending the
proposed higher power limits to the entire 14-gigahertz spectrum in the
57-71 GHz band to promote more FDS deployment. Other parties addressed
potential harmonization benefits in use of the 57-64 GHz band, and
suggested that minimizing the level of interference from FDS devices
used outdoors in hand-held devices would be useful to facilitate
compatibility with future generations of point-to-point radios that are
expected to feature the band segment. To protect communications
devices' ability to access the spectrum amidst radars' repetitive
transmission bursts, a Joint Comment from Intel Corporation, Meta
Platforms Inc. and Qualcomm Incorporated proposed that FDS devices
limit their operating bandwidth to certain partitions of the 57-64 GHz
band if using higher power levels and subject to strict duty cycles.
The radar industry initially opposed this approach.
Ultimately, parties representing both FDS and communications
interests found common ground in a soft segmentation approach to the
57-64 GHz band. As discussed above, the Industry Consensus Agreement
proposes three segments within the 57-64 GHz band, corresponding
respectively to WiGig Channel 1 (57.0-59.4 GHz), WiGig Channels 1-2
(57.0-61.56 GHz), and WiGig Channels 1-3 (57-64 GHz). The Pulse Radar
Joint Agreement also envisions use of the 57-64 GHz band, but under
separate provisions designed to accommodate the technical
characteristics of pulse radars. Adopting rules for use of the 57-64
GHz band that account for the existing WiGig channelization plan is
preferable to the initial NPRM proposal because it provides a level of
compatibility among unlicensed device types without imposing uniformly
low power levels and band-wide duty cycle limitations that parties
indicated would retard continued use and development of the band.
Therefore, the Commission is adopting the soft segmentation plan as
specified in the Industry Consensus Agreement and the technical
parameters for pulse radars as specified in the Pulse Radar Joint
Agreement.
EIRP Limits. In the NPRM, the Commission proposed allowing FDS
devices to operate at no more than 20 dBm average EIRP and asked
parties that opposed those limits to propose appropriate parameters.
This proposed EIRP limit is higher than the existing limit in the rules
which permits fixed FDS devices to operate at no more than 10 dBm peak
EIRP and is also higher than the level requested in the multiple
waivers that were granted, but is consistent with ETSI EN 305 550. All
of the granted waivers permit operation at 13 dBm peak EIRP to provide
greater accuracy and finer resolution imaging than the 10 dBm permitted
in the rules. The waiver requesters argued that such higher power is
necessary to achieve the necessary accuracy needed to detect small-size
targets due to poor signal-to-noise ratio conditions. For example,
these radars are intended to detect movement or objects in the sub-
millimeter range such as the breathing patterns of a child in a car
seat, or as in the case of Leica Geosystems AG, thin cables as small as
2.5 mm in diameter.
Radar proponents strongly supported the proposed 20 dBm average
EIRP power limit, claiming it is needed to provide the range and
sensing detail necessary for many applications, including those that
support health and safety. In addition, many of these parties submitted
technical studies purporting to demonstrate that radars operating at
higher power than currently allowed in the rules would not cause
harmful interference to communication devices in the band. On the other
hand, Facebook/Intel Corporation/Qualcomm Incorporated (FB et al.)
argue that radar operations at the proposed 20 dBm EIRP level greatly
increase the radar device's zone of interference to communications
devices and significantly increases the likelihood that multiple radar
devices will interfere with communications devices, and suggested that
the Commission adopts a 13 dBm peak EIRP limit, the same as that
granted in the waivers. Finally, Blu Wireless opposed the Commission's
proposals, arguing that regulatory changes are unnecessary because the
native IEEE 802.11ad protocol can be used to perform radar sensing
under the existing rules. However, Google disputed that use of this
standard and argued that it would produce unsatisfactory outcomes for
many of the anticipated new use cases for reasons including
performance, complexity and cost.
The Commission finds that the power limits endorsed in the Industry
Consensus Agreement, represents the best way forward. Initial comments
demonstrated the parties' contention that the Commission's ``one size
fits all'' approach would not result in a satisfactory product
performance to support anticipated use models. The Commission agrees
with the Industry Consensus Agreement that establishing power levels
for each band segment of the 57-64 GHz is a better solution for
fostering both unlicensed FDS and communications operations in the 60
GHz band while enabling a band sharing approach that can support the
capabilities envisioned by the commenters. With respect to the Blu
Wireless comments, the Commission notes that operations that were
permitted under its existing rules can continue under the revised rules
and parties may continue operating under the IEEE 802.11ad protocol if
they choose to. However, the Commission finds that there is a strong
public benefit in expanding its rules to support the many innovative
applications identified by the commenters, and that setting one power
limit for all applications is not necessary.
The Commission notes that thorough technical analyses were
conducted in 2022 in joint efforts by a Technical Interchange Group
(TIG) between the Commission, the National Oceanic and Atmospheric
Administration (NOAA), the National Aeronautics and Space
Administration (NASA), the Department of the Navy, and the National
Telecommunications and Information Administration (NTIA). NTIA supports
the TIG's consensus conclusion that 60 GHz FDS/radars operating at
ground level with the proposed power limits in the NPRM would not
result in harmful interference to passive EESS sensors in this band
because of the high level of atmospheric attenuation that exists
between transmitters on the surface of the Earth and the passive
sensors in this frequency band. The Commission observes that in the
NPRM, the Commission proposed a limit of 20 dBm average EIRP without
any limit on the peak EIRP, but sought comment on whether requiring a
peak power limit might be necessary. The technical parameters adopted
herein place a limit on the peak EIRP, which is a more stringent
requirement that enhances the protection of authorized services and
minimizes any potential risk that these operations would cause
instantaneous harmful interference. Therefore, the Commission is
adopting the EIRP limits provided by Industry in the Industry Consensus
Agreement and consistent with the analysis provided by the TIG.
Duty Cycle Limit. One area of particular contention throughout the
proceeding has been whether, where, and how to impose a duty cycle
limit on FDS operations. There are two components to the duty cycle,
the percentage or ratio of the time during
[[Page 47390]]
which the transmitter is active versus the time during which there is
no transmission and the total period or reference interval during which
this ratio is considered. The Commission proposed to require the same
10% duty cycle restriction associated with the multiple waiver grants
based on a maximum 3.3 ms total transmission time in every 33 ms
interval (which was derived from Google's 2018 final agreement with
stakeholders from the WLAN communications industry whose technology
operates in the 60 GHz spectrum), and sought comment on whether that or
some other duty cycle would be most appropriate.
Radar proponents opposed a duty cycle requirement for FDS
operations, stating that it would unnecessarily constrain the radars
sensor's capabilities. Parties further claim that limiting transmission
time to a maximum of 3.3 ms in every 33 ms interval would be
problematic for radars, because isochronous chirp transmission is
essential to attain proper measurements. Infineon states that relaxing
the 10% duty cycle imposed in the waiver orders would allow the use of
more transmit (TX) antennas (generating more virtual antennas) with the
same number of chirps for each TX antenna, which in turn would allow
higher angular resolution, improving and expanding the radars
applications that can be provided in automotive, residential, business,
and industrial contexts.
On the other hand, FB et al. state that even the 10% duty cycle
limit on radar operations by itself does not ensure fair coexistence
with communications applications, because radars operate with very
short pulses (i.e., radar ``on times'') sent in rapid succession with
off times that are at least 90% longer but still unusable by
communication systems. These parties argue that communication system
transmissions or acknowledgment messages can be either blocked or
repeatedly interrupted and corrupted by radars operating with short
transmission gaps. The communications proponents advocated for a duty
cycle restriction in conjunction with a limit on the duration between
radar chirps/pulses (minimum transmitter off-time) to allow for
sufficient silent periods during which the spectrum may be accessed--or
re-accessed--by communication devices.
In the NPRM, the Commission also observed that certain parties had
recommended modifying the duty cycle restriction adopted in the waivers
to read that ``any radar off-time period between two successive radar
pulses that is less than 2 ms shall be considered `on time' for
purposes of computing the duty cycle.'' These parties expressed concern
that the duty cycle requirement in the waivers, if expanded to the
rules, would not promote coexistence with communications operations,
including immersive augmented reality/virtual reality/extended reality
(AR/VR/XR) applications, which require very high data throughput and
very low latency. In their comments, radar interests claimed that such
a rule would impair radar deployment and prevent their ability to
meaningfully operate in the band. FB et al. offered a contrasting
perspective, arguing that communication transmissions or acknowledgment
messages would either be blocked or repeatedly interrupted if such a
standard is not adopted. They claim that under a 10% duty cycle
requirement, radars transmitting short bursts of micro/nano-second
durations followed by similarly short silent periods during the entire
total 33 ms interval would result in too short of a quiet interval for
60 GHz immersive virtual reality communication devices to effectively
access the spectrum--even though such radars would be in technical
compliance with the rules. This outcome would be especially harmful for
the virtual-reality-enabled headsets and eyewear and other real-time
audiovisual applications anticipated for 57-64 GHz band, due to the
strict latency they need to operate successfully.
Based on the record, the Commission concludes that a uniform duty
cycle requirement as proposed in the NPRM will not promote the
Commission's interest in expanding the types of unlicensed devices that
are able to operate in the 60 GHz band. Both radar and communications
interests offer convincing reasons why adopting such a requirement
could jeopardize their ability to make productive use of the band.
Instead, the Commission notes that the Industry Consensus Agreement
provides for frequency band segmentation along with associated EIRP
levels and duty cycle/radar transmission off-time solutions that
resolves the parties' previous impasse. With respect to pulse radar
operations, the duty cycle expressed in the Pulse Radar Joint Agreement
provides similar assurances to all parties. Because this duty cycle
satisfies the goals the Commission have in the proceeding, the
Commission is adopting rules consistent with the provisions of those
agreements. Finally, the Commission recognizes that the final rules it
is adopting do not follow the duty cycle requirements associated with
the ETSI standards.
Transmitter Conducted Output Power Limit. In the NPRM, the
Commission proposed to allow a maximum (peak) conducted output power
for FDS devices, consistent with the waivers the Commission had already
granted in the band, but also asked whether a transmitter conducted
output limit was necessary for 60 GHz transmitters, including
communications and radar devices. The Commission also sought input on
whether it should consider adopting an average transmitter conducted
output power limit and what impact this would have on the different
types of FDS devices (e.g., FMCW, pulse, etc.) envisioned for the band.
The Commission finds that, based on the technical analyses
submitted into the record, radars operating in this band typically use
a relatively wide antenna beamwidth to detect scattered small objects
and fine movements (e.g., chest movements on a patient, hand gestures,
obstructive objects, etc.). The Commission agrees with Valeo and Vayyar
that modern chip technologies for 60 GHz devices incorporate antenna
arrays such that the transmitter output port is difficult to access and
thus output power is difficult to directly measure. In such cases,
transmitter conducted output power limits are typically calculated for
compliance purposes based on the applicant's provided antenna gain
information, thereby making such a requirement difficult to enforce.
The Commission also observes that the Industry Consensus Agreement
suggests completely removing the conducted output power limit from FDS
devices operating in specific segments of the 57-64 GHz band. The
Commission notes that the rules must address use cases that involve FDS
devices that employ wide beamwidth antennas over the entire 57-71 GHz
band, in addition to those FDS devices that limit their operation to
certain portions of the band. For these reasons, the Commission
declines to specify a conducted output power limit in the rules it is
adopting for frequency-segmented FDS devices; however, to limit
potential harmful interference, the Commission continues to maintain
the conducted output power limit for devices that operate over the
entire 57-71 GHz band. Similarly, the Commission declines to adopt an
antenna gain requirement for FDS devices in lieu of a conducted power
limit as such a requirement would result in more complex measurements.
Power Spectral Density Limit. The existing rules do not restrict
the power
[[Page 47391]]
spectral density for 60 GHz devices. In the NPRM, the Commission
proposed to require a 13 dBm/MHz EIRP power spectral density on FDS
devices, to be consistent with the ETSI limit. This is the same
restriction placed on Google and other parties operating FDS devices
pursuant to Commission-issued waivers. However, the Commission sought
input on the ramifications of not adopting a PSD limit, and instead,
relying on the EIRP limits to avoid harmful interference. The
Commission notes that a power spectral density limit is not well
matched to the nature of radar transmissions--which are in bursts, or
chirps. Accordingly, the Commission finds that adopting a power
spectral density limit is unnecessary. Commenters have pointed out that
while the Commission proposed such a limit with the primary intent to
be consistent with ETSI, subsequent changes in the EU regulations have
made the Commission's proposal incompatible with that standard. The
Commission also agrees with Google that a power spectral density limit
may be too restrictive for certain radar use cases with narrow
bandwidths. The Commission therefore will not adopt this requirement
into the final rules.
Use of Spectrum Sensing Technologies. Although the Commission did
not suggest allowing FDS operation at the proposed higher power limits
throughout the entire 57-71 GHz band in the NPRM, it noted that the
Technical Advisory Committee (TAC) suggested the possibility of
allowing radars that incorporate a sensing technology such as listen-
before-talk (LBT) to operate at the same emission limits as WLAN
devices in the band, i.e., 40 dBm EIRP and 27 dBm transmitter conducted
output power. Commenters had different reactions to the concept.
Acconeer, for example, argued that LBT generally does not provide
efficient coexistence among different systems in high millimeter wave
frequencies such as the 60 GHz band, where transmissions have high
directivity. WISPA further states that LBT would only complicate
devices and add latency, driving up equipment costs and forcing a re-
design and retrofitting of equipment already deployed in hundreds, if
not thousands, of locations. Other parties suggested the Commission
could allow FDS devices to operate with power limits as high as those
accorded to communication devices (i.e., up to 40 dBm EIRP) if they
incorporated spectrum sharing techniques.
Given the Commission's decision to adopt final rules as described
above, the Commission sees no need to further pursue the use of
spectrum sensing technologies in the 60 GHz band at this time. Nothing
in the Commission's decision should be read to preclude standards
bodies from developing industry voluntary standards for consideration
by the Commission if they determine it is appropriate to do so.
Operation On-Board Aircraft
In the NPRM, the Commission stated that it did not anticipate
altering the existing restrictions in Sec. 15.255(b) of the rules
relating to the use of 60 GHz band unlicensed devices on-board
aircraft, but nevertheless sought comment as to whether it should
expand the situations where such use is permissible. These restrictions
prohibit operation on-board aircraft, except on aircraft that are
equipped with a high RF attenuation body (e.g., commercial airliners)
while forming ``closed exclusive on-board communication networks within
the aircraft,'' such as entertainment systems that deliver movies and
music to passengers on-board commercial aircraft. The rule specifically
prohibits 60 GHz transmitters from operating on unmanned aircraft,
because these types of aircraft do not provide substantial RF
shielding. The Commission observed that it has only authorized 60 GHz
radars to operate on board aircraft beyond the uses permitted in the
rules via waiver in two limited situations in conjunction with specific
use cases.
Operation On-Board Unmanned Aircraft (UA)
In its comments, Amazon requests that the final rules allow FDS
device use cases on board aircraft in the 60-64 GHz segment of the 60
GHz band for unmanned aircraft. Amazon states that it would like to
deploy 60 GHz radar on unmanned aircraft (UA) for obstacle avoidance
and situational awareness similar to the use cases the Commission have
previously permitted via waiver to Leica Geosystems AG. Amazon states
that using 60 GHz radars on drones would enable it and other companies
to develop and deploy Near Surround Detection (NSD) systems to enhance
the drone's ability to sense and avoid persons and obstacles in and
near its ascent and descent path, thereby improving aviation safety as
NSD systems provide situational awareness that help prevent collisions.
Amazon further claims that authorized drone operations conducted below
121.92 meters (400 feet) above ground level (AGL) in the 60-64 GHz band
can coexist with, and will not cause harmful interference to, adjacent
Earth-Exploration Satellite Service (EESS) and Radio Astronomy Service
(RAS) operations.
Over the course of the rulemaking, the Commission have seen
increasing interest in, and support of, Amazon's position. For
instance, the General Aviation Manufacturers Association (GAMA)
believes that airborne FDS radars operating in the 60 GHz band will not
cause harmful interference to other spectrum users, arguing that
``radar devices in this frequency range operate at a relatively low
EIRP; the nearest frequency band that is used on aircraft is 24 GHz;
and there is existing communications equipment using this same band at
the same power where no harmful interference has been observed.'' The
Consumer Technology Association, CTIA, Information Technology Industry
Council (ITI), NetChoice, TechNet and the U.S. Chamber of Commerce, in
a joint comment, assert that allowing the use of this band for low-
altitude drone operations would enable systems that sense and avoid
obstacles and provide situational awareness to develop; these parties
argue that this would help enhance aviation safety and reduce the risk
to both people and property on the ground and other airspace users.
The Commission finds that the rules could accommodate 60 GHz FDS
operations on UA provided that these operations are limited to the 60-
64 GHz sub-band while airborne at low altitudes (less than 121.92
meters (400 feet) above ground level (AGL)) without increasing the
potential for interference to authorized services in this band. As the
Commission stated in the Leica Waiver Order, limiting operation to the
60-64 GHz frequency band (instead of the entire 57-71 GHz band) avoids
the passive EESS band by providing a natural 700-megahertz guard band
between the EESS passive service at 57-59.3 GHz and the device's
operating band at 60-64 GHz, thus protecting EESS users. The Commission
further stated that ``[r]egarding RAS, for which there is no allocation
in the 57-71 GHz band, its strict out-of-band limits in the rules
already prevent any increase in potential harmful interference caused
by the device's operation.'' The Commission also observed that the high
oxygen attenuation at frequencies around 60 GHz, added to the fact that
the UA is mostly in motion, will serve to mitigate any potential for
harmful interference to other users. The Commission further noted that,
because fixed outdoor point-to-point 60 GHz transmitters generally use
narrow antenna beams, the likelihood that a UA equipped with a 60 GHz
radar would be located within the antenna beamwidth of these
transmitters is very small,
[[Page 47392]]
thereby mitigating any potential increase in harmful interference. The
Commission agrees with the logic of these prior assessments, and based
on the absence of interference complaints from the Leica deployments
since 2020 and support in the record, the Commission finds that 60-64
GHz FDS devices can operate on UA at altitudes less than 121.92 meters
(400 feet) above ground level without increasing the potential for
harmful interference to authorized services. The Commission also notes
that the Federal Aviation Administration (FAA) part 107 rules limit
operation of small unmanned aircraft to 121.92 meters (400 feet) AGL.
The rules the Commission is adopting herein address the operation of
unlicensed FDS devices in the 60 GHz band that may be used on UA and do
not alter any obligations under applicable FAA regulations.
Power Levels. With respect to power levels for FDS devices
operating on UA, the Commission notes that the Industry Consensus
Agreement proposes such operations be limited to 20 dBm peak EIRP with
a 50% duty cycle. These EIRP and duty cycle limits are consistent with
those permitted in the Leica Waiver Order, and the 60-64 GHz frequency
range selected for FDS devices operating on UA avoids the EESS passive
band at 57-59.3 GHz with a 700-megahertz guard band, consistent with
NTIA's support of the TIG's efforts regarding FDS co-channel use of the
EESS band. Accordingly, the Commission is authorizing these parameters
for 60-64 GHz FDS operating on-board UA, limited to flying altitudes
less than 121.92 meters (400 feet) above ground level. Operations on UA
at these power levels will enable more expansive use to deliver new
innovative services to the American public without increasing the
potential of causing harmful interference to incumbent users.
Operation On-Board Aircraft Other Than UA
As indicated above, Sec. 15.255(b)(2) prohibits operation on
aircraft, unless the device is part of ``closed exclusive on-board
communication networks within the aircraft.'' However, in 2018, the
Commission waived this rule to allow the Google Soli radar incorporated
into a smartphone to operate on aircraft without being part of the
aircraft's communication network. In the NPRM, the Commission noted
that compliance options exist for portable electronic devices that may
be brought aboard airplanes; these could include, for example,
requiring ``airplane mode'' to be activated during flight.
CORF argues that there is no publicly available data on the effect
that 60 GHz networking devices on aircraft have on EESS remote sensing
in the 57-59.3 GHz band. Therefore, CORF believes it is unreasonable to
loosen the standards and allow additional devices such as 60 GHz radars
on aircraft. The Frequency Allocation on Remote Sensing (FARS)
Committee agrees with CORF's concerns about the accuracy of Google's
report on the total reflection of radar signals off of an aircraft
window and the absence in Google's report of any discussion regarding
the effect of radar signals reflections off of the aircraft wings, and
requests that the Commission does not expand airborne use of radars.
Conversely, Google states that ``the 2018 Google study did take the
effect of radar reflections off of airplane wings into account.''
Google argues that the Soli radar emissions at issue in Google's study
are beamed out of the front of the phone; therefore, a user would have
to point the phone out of the aircraft window and downward. In such a
scenario, ``the user would have difficulty viewing the screen in this
configuration, let alone using hand gestures to control any interaction
with content on the screen.''
As indicated supra, NTIA supports the consensus conclusion of the
TIG that the high level of atmospheric attenuation between 60 GHz FDS/
radars operating at ground level and the passive EESS sensors operating
in the 57.0-59.3 GHz band would not result in any harmful interference
to EESS sensors in this band. However, NTIA requests that, if alternate
deployment scenarios are considered in the future whereby the
atmospheric absorption loss may be different (particularly,
aeronautical deployments), further analysis be conducted.
The Commission recognizes and supports the vital interest in
protecting the passive EESS services in the 57.0-59.3 GHz band. The
Commission also acknowledges that, consistent with NTIA's request,
further analysis is being undertaken at this time by the TIG regarding
the potential to deploy radars on aircraft in this band. The Commission
therefore will only allow FDS/radar operation on aircraft other than UA
in the 59.3-71 GHz band at this time, limited to installations within
personal portable electronic devices such as smartphones, laptop
computers, etc. These radar operations would not need to be part of the
on-board communication system within the aircraft.
Implementation Considerations--Compliance Testing
In the NPRM, the Commission proposed to exempt FMCW and other
similar swept-frequency radars from the Sec. 15.31(c) requirement to
stop the frequency sweep when measuring the relevant technical
parameters. The Commission explained that stopping the sweep is
physically impractical for most of these devices and can result in
inaccurate measurements. In addition, the Commission proposed to remove
the Sec. 15.255(c)(4) requirement to use an RF detector with a
detection bandwidth that encompasses the 57-71 GHz frequency range for
performing peak power measurements. The Commission stated that this
requirement has been superseded by the more recent inclusion of Sec.
15.255(i), which sets out a flexible approach toward measurement that
can be adapted more effectively as device technology and test
instrumentation evolve. Finally, the Commission proposed to specify
that the provision of Sec. 15.35(c) that requires calculating average
field strength over a complete pulse train or 100 ms is not applicable
to pulsed or burst radars that operate in the 60 GHz band. The
Commission explained that this measurement requirement was originally
designed for low frequency pulse-code modulated devices such as garage
door openers and would not be appropriate for high frequency radars.
Bosch proposes that instead of measuring transmitter conducted
output power, the Commission should consider the equivalent requirement
of the total radiated power (TRP), which may be considered and
specified as described in ETSI EN 303 883-1 Version 1.2.1 clause 5.6.
Bosch argues that this is the only feasible option for measuring the
total radiated power of FDS devices. Acconeer argues that using a 20 dB
bandwidth to measure wideband pulse systems is challenging, because the
low spectral density is usually below the noise flow of the measurement
equipment. Additionally, Acconeer proposes that the same method used
for evaluating the bandwidth of ultra-wideband (UWB) devices in the
3.1-10.6 GHz band be applied to radar devices in the 60 GHz band.
Infineon states that, given that the goal is to establish an average
EIRP for purposes of increased compatibility with other 60 GHz Band
devices, and different devices may have different cycle periods, a more
objective standard that is uniform over all affected radar and FDS
devices is appropriate; Infineon proposes that an absolute temporal
measure be used, specifically 100 ms. Valeo suggests that
[[Page 47393]]
transmission bandwidth should be expressed as a measured occupied
bandwidth. If the transmission bandwidth would be specified only by the
chirp specification, it could happen that a chirp timing constraint
(e.g., maximum chirp slope) may occur. Valeo suggests that the occupied
bandwidth be measured, including the overshoots caused by the slew rate
of the chirp and the return ramp. Vayyar supports removing the
requirement that the sweep is stopped during parts of the compliance
testing. The Auto Innovators recommend that compliance measurements
should allow evaluation over at least five repetition cycles of the
equipment under test (EUT), as it believes this will simplify testing.
The Commission finds that exempting FMCW and other swept-frequency
radars from Sec. 15.31(c) is necessary for performing meaningful
compliance measurements. In addition, the Commission finds it
appropriate to remove Sec. 15.255(c)(4). This rule section was
intended to address legacy spectrum analyzers' limited capability for
measuring radar waveforms at these frequencies, which is no longer an
issue with modern spectrum analyzers. Additionally, the anticipated
FMCW and pulsed radar waveforms will likely exceed the 10 MHz video
bandwidth specification, resulting in some degree of video averaging.
Further, Sec. 15.255(c)(4) specifies that average emission
measurements be performed only over a period of active transmission.
Retaining such a requirement will prohibit application of a duty cycle
correction in determining the average radar transmit power. Finally,
the Commission finds that the provision of Sec. 15.35(c) that requires
calculating average field strength over a complete pulse train or 100
ms is not applicable to FMCW or to pulsed radar in the 60 GHz band. The
Commission disagrees with Bosch's suggestion to consider TRP instead of
EIRP. TRP measurements require substantial sampling over the 4[pi]
steradian space, thus leading to significant complications in
performing compliance measurements. Furthermore, potential interference
is essentially driven by the maximum EIRP in the direction of the
victim, and due to the highly directional nature of radars, EIRP
measurement is correspondingly a more appropriate and efficient
compliance measurement. With respect to transmission bandwidth, the
Commission agrees with Valeo that the occupied bandwidth be measured as
part of the compliance measurements. Doing so will ensure fidelity to
the requirements specified in Sec. 2.1049 as required by Sec.
15.201(b). The Commission disagrees with Acconeer's justification for
applying the same method used for evaluating the bandwidth of UWB
devices to radar bandwidth measurements. UWB devices are held to a very
low fundamental power level and thus warrant bandwidth measurement
based upon the 10 dB down points to accommodate measurement sensitivity
challenges. The higher power limits provided to 60 GHz radar will
permit the measurement of occupied bandwidth, even in a radiated
measurement, with adequate sensitivity.
Operation of Equipment Subject to Prior Waivers and Transition
Provisions
As noted above, a number of parties have been granted waivers of
certain provisions of Sec. 15.255 to permit operation of innovative
radar devices in the 60 GHz band. In the NPRM, the Commission noted
that, to the extent that the rules are modified to expand unlicensed
FDS device operations in the 60 GHz band, all future 60 GHz FDS
operations would be conducted subject to the Commission's modified
rules. The Commission proposed to terminate all previously granted 60
GHz FDS waivers and FDS device manufacturers would be expected to
conform their operations to its rules as revised.
Most commenters agree that if the adopted 60 GHz technical and
operational rules are more stringent than existing FDS waiver
conditions, the Commission should grandfather the existing, more
flexible waivers for approved radar devices or, at minimum, provide a
reasonable transition period for waiver holders to bring their
technology into compliance with more rigorous regulatory standards. The
Industry Consensus Agreement suggests a six-month transition period
applicable only to new certifications under the terms of the waivers.
The Pulse Radar Joint Agreement suggested that Acconeer be permitted to
continue to market and sell pulse radars under its existing waiver for
two years after the effective date of new rules.
The Commission agrees that it is appropriate to afford parties that
are operating unlicensed 60 GHz band FDS equipment under waivers a
period of time to transition to the new rules and to sell products that
they have produced under the terms of their waivers, but the Commission
also wants to encourage parties to begin producing equipment that
complies with the new rules in a timely manner, notwithstanding whether
their existing waivers are more restrictive than the newly adopted
rules. The Industry Consensus Agreement shows that manufacturers are
comfortable that a relatively short, six-month, period is a realistic
and manageable transition time period. The Commission agrees that this
is an appropriate timeframe, given that it is important to begin the
transition to the new rules as soon as practicable. Accordingly, in
these cases where a waiver has previously been granted, the Commission
will require that all new FDS/radar devices that are approved by
Telecommunication Certification Bodies (TCBs) beginning six months
after the effective date of the rules adopted in the proceeding must
comply with the new rules. The Commission terminates the 60 GHz band
waivers that are currently in effect at the conclusion of this
transition period. However, the Commission specifies that so long as a
60 GHz FDS/radar does not cause harmful interference, it can continue
to operate until its natural replacement. Any equipment currently
operating pursuant to a waiver that is subsequently modified, however,
must be brought into compliance with the new rules.
Ordering Clauses
Accordingly, it is ordered that, pursuant to the authority
contained in sections 4(i), 302, 303(b), (c), (e), (f), (r), and 307 of
the Communications Act of 1934, as amended, 47 U.S.C. 154(i), 302a,
303(b), (c), (e), (f), (r), 307, this document is hereby adopted.
It is further ordered that part 15 of the Commission's rules is
amended as specified in below, and such rule amendments will become
effective 30 days after the date of publication in the Federal
Register.
It is further ordered that the 60 GHz waivers currently in effect,
as granted in DA 18-1308, DA 20-795, DA 21-407, DA 21-811, DA 21-812,
DA 21-813, DA 21-814, DA 21-815, and DA 21-816 are terminated effective
six months after the effective date of the rule amendments adopted
herein unless expressly extended by the Chief, Office of Engineering
and Technology. However, a device that was certified to be marketed and
to operate under waiver on or before six months after the effective
date of the rule amendments adopted herein may continue to be marketed
and operate in accordance with the terms of its certification so long
as the device does not cause harmful interference.
It is further ordered that the Commission's Consumer and
Governmental Affairs Bureau, Reference Information Center, shall send a
copy of the Report and Order, including the
[[Page 47394]]
Final Regulatory Flexibility Analyses, to the Chief Counsel for
Advocacy of the U.S. Small Business Administration.
It is further ordered that the Commission shall send a copy of this
Report and Order in a report to be sent to Congress and the Government
Accountability Office pursuant to the Congressional Review Act, see 5
U.S.C. 801(a)(1)(A).
List of Subjects in 47 CFR Part 15
Communications equipment, Computer technology, Field Disturbance
Sensor, Radar, Radio, and Telephone.
Federal Communications Commission.
Marlene Dortch,
Secretary.
Final Rules
For the reasons discussed in the preamble, the Federal
Communications Commission amends 47 CFR part 15 as follows:
PART 15--RADIO FREQUENCY DEVICES
0
1. The authority citation for part 15 continues to read as follows:
Authority: 47 U.S.C. 154, 302a, 303, 304, 307, 336, 544a, and
549.
0
2. Amend Sec. 15.3 by revising paragraph (l) to read as follows:
Sec. 15.3 Definitions.
* * * * *
(l) Field disturbance sensor. A device that establishes a radio
frequency field in its vicinity and detects changes in that field
resulting from the movement of persons or objects within its range. A
radar operating pursuant to the definition for radiodetermination
station in Sec. 2.1 of this chapter is an example of a field
disturbance sensor.
* * * * *
0
3. Amend Sec. 15.31 by revising paragraph (c) to read as follows:
Sec. 15.31 Measurement standards.
* * * * *
(c) Except as otherwise indicated in Sec. Sec. 15.255 and 15.256,
for swept frequency equipment, measurements shall be made with the
frequency sweep stopped at those frequencies chosen for the
measurements to be reported.
* * * * *
0
4. Amend Sec. 15.35 by revising paragraph (c) to read as follows:
Sec. 15.35 Measurement detector functions and bandwidths.
* * * * *
(c) Unless otherwise specified, e.g., Sec. Sec. 15.255 and
15.256(l)(5), when the radiated emission limits are expressed in terms
of the average value of the emission, and pulsed operation is employed,
the measurement field strength shall be determined by averaging over
one complete pulse train, including blanking intervals, as long as the
pulse train does not exceed 0.1 seconds. As an alternative (provided
the transmitter operates for longer than 0.1 seconds) or in cases where
the pulse train exceeds 0.1 seconds, the measured field strength shall
be determined from the average absolute voltage during a 0.1 second
interval during which the field strength is at its maximum value. The
exact method of calculating the average field strength shall be
submitted with any application for certification or shall be retained
in the measurement data file for equipment subject to Supplier's
Declaration of Conformity.
0
5. Amend Sec. 15.37 by adding paragraph (r) to read as follows:
Sec. 15.37 Transition provisions for compliance with this part.
* * * * *
(r) Field disturbance sensor/radar devices being marketed or
operating in the frequency band 57-64 GHz approved by Telecommunication
Certification Bodies as being in compliance with previously adopted
rules or waivers thereof on or before [six months after the effective
date of the rules] may continue to be marketed and operate in
accordance with their certifications. All other field disturbance
sensor/radar devices shall comply with the requirements in Sec.
15.255.
0
6. Amend Sec. 15.255 by:
0
a. Removing paragraphs (a)(1) and (2) and revising paragraph (a);
0
b. Adding a subject heading to the introductory text of paragraph (b);
0
c. Revising paragraph (b)(2)(ii);
0
d. Adding paragraphs (b)(2)(iii) and (b)(3);
0
e. Revising the introductory text of paragraphs (c) and (c)(1) and
paragraphs (c)(2) through (4);
0
f. Revising paragraph (d) introductory text to be an italicized subject
heading;
0
g. Revising paragraph (e) introductory text, (e)(1) and (2), and
removing paragraph (e)(3);
0
h. Adding a subject heading to paragraphs (g) and (h); and
0
i. Revising paragraph (i).
The revisions and additions read as follows:
Sec. 15.255 Operation within the band 57-71 GHz.
(a) General. Operation under the provisions of this section is not
permitted for equipment used on satellites.
(b) Operation on aircraft. * * *
(2) * * *
(ii) Except as permitted in paragraph (b)(3) of this section,
equipment shall not be used on aircraft where there is little
attenuation of RF signals by the body/fuselage of the aircraft.
(iii) Field disturbance sensor/radar devices may only operate in
the frequency band 59.3-71.0 GHz while installed in passengers'
personal portable electronic equipment (e.g., smartphones, tablets) and
shall comply with paragraph (b)(2)(i) of this section, and relevant
requirements of paragraphs (c)(2) through (c)(4) of this section.
(3) Field disturbance sensors/radar devices deployed on unmanned
aircraft may operate within the frequency band 60-64 GHz, provided that
the transmitter not exceed 20 dBm peak EIRP. The sum of continuous
transmitter off-times of at least two milliseconds shall equal at least
16.5 milliseconds within any contiguous interval of 33 milliseconds.
Operation shall be limited to a maximum of 121.92 meters (400 feet)
above ground level.
(c) Radiated power limits. Within the 57-71 GHz band, emission
levels shall not exceed the following equivalent isotropically radiated
power (EIRP):
(1) Devices other than field disturbance sensors shall comply with
one of the following power limits, as measured during the transmit
interval:
* * * * *
(2) Field disturbance sensors/radars shall not exceed -10 dBm peak
conducted output power and 10 dBm peak EIRP except that field
disturbance sensors/radars that limit their operation to all or part of
the specified frequency band may operate without being subject to a
transmitter conducted output power limit if they operate in compliance
with paragraph (b)(3) of this section or with one or more of the
provisions below:
(i) 57.0-59.4 GHz: the peak EIRP level shall not exceed 20 dBm for
indoor operation or 30 dBm for outdoor operation;
(ii) 57.0-61.56 GHz: the peak EIRP shall not exceed 3 dBm except
that the peak EIRP shall not exceed 20 dBm if the sum of continuous
transmitter off-times of at least two milliseconds equals at least 16.5
milliseconds within any contiguous interval of 33 milliseconds;
(iii) 57.0-64.0 GHz:
(A) The peak EIRP shall not exceed 14 dBm, and the sum of
continuous transmitter off-times of at least two milliseconds shall
equal at least 25.5 milliseconds within any contiguous interval of 33
milliseconds, except as specific in paragraph (c)(2)(iii)(B) of this
section;
[[Page 47395]]
(B) The peak EIRP shall not exceed 20 dBm, and the sum of
continuous transmitter off-times of at least two milliseconds shall
equal at least 16.5 milliseconds within any contiguous interval of 33
milliseconds when operated outdoors:
(1) As part of a temporary or permanently fixed application; or
(2) When being used in vehicular applications to perform specific
tasks of moving something or someone, except for in-cabin applications;
(iv) A field disturbance sensor may operate in any of the modes in
the above sub-sections so long as the device operates in only one mode
at any time and does so for at least 33 milliseconds before switching
to another mode.
(v) 61.0-61.5 GHz: For field disturbance sensors/radars that occupy
500 MHz bandwidth or less that are contained wholly within the
frequency band 61.0-61.5 GHz, the average power of any emission,
measured during the transmit interval, shall not exceed 40 dBm, and the
peak power of any emission shall not exceed 43 dBm. In addition, the
average power of any emission outside of the 61.0-61.5 GHz band,
measured during the transmit interval, but still within the 57-71 GHz
band, shall not exceed 10 dBm, and the peak power of any emission shall
not exceed 13 dBm.
(3) For pulsed field disturbance sensors/radars operating in the
57-64 GHz band that have a maximum pulse duration of 6 ns, the average
EIRP shall not exceed 13 dBm and the transmit duty cycle shall not
exceed 10% during any 0.3 [micro]s time window. In addition, the
average integrated EIRP within the frequency band 61.5-64.0 GHz shall
not exceed 5 dBm in any 0.3 [micro]s time window. Peak emissions shall
not exceed 20 dB above the maximum permitted average emission limit
applicable to the equipment under test. The radar bandwidth is the
frequency band bounded by the points that are 10 dB below the highest
radiated emission, as based on the complete transmission system
including the antenna.
(4) The provisions in Sec. 15.35(b) and (c) that require emissions
to be averaged over a 100 millisecond period and that limits the peak
power to 20 dB above the average limit do not apply to devices
operating under paragraphs (c)(2) and (3) of this section.
(d) Limits on spurious emissions. * * *
(e) Limits on transmitter conducted output power.
(1) Except as specified in paragraph (e)(2) of this section, the
peak transmitter conducted output power of devices other than field
disturbance sensors/radars shall not exceed 500 mW. Depending on the
gain of the antenna, it may be necessary to operate the intentional
radiator using a lower peak transmitter output power in order to comply
with the EIRP limits specified in paragraph (c) of this section.
(2) Devices other than field disturbance sensors/radars with an
emission bandwidth of less than 100 megahertz must limit their peak
transmitter conducted output power to the product of 500 mW times their
emission bandwidth divided by 100 megahertz. For the purposes of this
paragraph, emission bandwidth is defined as the instantaneous frequency
range occupied by a steady state radiated signal with modulation,
outside which the radiated power spectral density never exceeds 6 dB
below the maximum radiated power spectral density in the band, as
measured with a 100 kilohertz resolution bandwidth spectrum analyzer.
The center frequency must be stationary during the measurement
interval, even if not stationary during normal operation (e.g., for
frequency hopping devices).
* * * * *
(g) Radio frequency radiation exposure. * * *
(h) Group installation. * * *
(i) Compliance measurement. Measurement procedures that have been
found to be acceptable to the Commission in accordance with Sec. 2.947
of this chapter may be used to demonstrate compliance.
(1) For purposes of demonstrating compliance with this section,
corrections to the transmitter conducted output power may be made due
to the antenna and circuit loss.
(2) Compliance measurements of frequency-agile field disturbance
sensors/radars shall be performed with any related frequency sweep,
step, or hop function activated.
[FR Doc. 2023-15367 Filed 7-21-23; 8:45 am]
BILLING CODE 6712-01-P
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