FCC Empowers Short-Range Radars in the 60 GHz Band, 47384-47395 [2023-15367]

Agencies

• FEDERAL COMMUNICATIONS COMMISSION

[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 [www.gpo.gov]
[FR Doc No: 2023-15367]



[[Page 47384]]

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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 [email protected].

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: https://docs.fcc.gov/public/attachments/FCC-23-35A1.pdf. Alternative formats are available 
for people with disabilities (Braille, large print, electronic files, 
audio format) by sending an email to [email protected] 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 [email protected] 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

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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

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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

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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 (Amazon.com 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