Federal Register / Vol. 86, No. 158 / Thursday, August 19, 2021 / Proposed Rules 46661 

■ 6. Amend § 2.911 by adding paragraph 

(d)(5) to read as follows: 

§ 2.911 Application requirements. 

* * * * * 

(d) * * * 

(5) The applicant shall provide a 

written and signed certification that, as 

of the date of the filing of the 

application, the equipment for which 

the applicant seeks equipment 

authorization through certification is 

not ‘‘covered’’ equipment on the 

Covered List established pursuant to 

§ 1.50002 of this chapter. 

* * * * * 

■ 7. Amend § 2.1033 by revising 

paragraph (b)(1) to read as follows: 

§ 2.1033 Application for certification. 

* * * * * 

(b) * * * 

(1) The identification, by name, 

mailing address and telephone number 

or internet contact information, of the 

manufacturer of the device, the 

applicant for certification, and the 

responsible party as defined in § 2.909. 

The responsible party must be located 

within the United States. 

* * * * * 

[FR Doc. 2021–16085 Filed 8–18–21; 8:45 am] 

BILLING CODE 6712–01–P 

FEDERAL COMMUNICATIONS 

COMMISSION 

47 CFR Part 15 

[ET Docket No. 21–264; FCC 21–83; FR ID 

41217] 

FCC Seeks To Enable State-of-the-Art 

Radar Sensors in 60 GHz Band 

AGENCY: Federal Communications 

Commission. 

ACTION: Proposed rule. 

SUMMARY: In this document, the 

Commission proposes to revise the 

Commission’s rules to provide 

expanded operational flexibility to 

unlicensed field disturbance sensor 

(FDS) devices (e.g., radars) that operate 

in the 57–64 GHz band (60 GHz band). 

The Commission’s proposal recognizes 

the increasing practicality of using 

mobile radar devices in the 60 GHz 

band to perform innovative and lifesaving functions, including gesture 

control, detection of unattended 

children in vehicles, and monitoring of 

vulnerable medical patients, and it is 

designed to stimulate the development 

of new products and services in a wide 

variety of areas to include, for example, 

personal safety, autonomous vehicles, 

home automation, environmental 

control, and healthcare monitoring, 

while also ensuring coexistence among 

unlicensed FDS devices and current and 

future unlicensed communications 

devices in the 60 GHz band. 

DATES: Comments are due on or before 

September 20, 2021; reply comments are 

due on or before October 18, 2021. 

ADDRESSES: You may submit comments, 

identified by ET Docket No. 21–264, by 

any of the following methods: 

• Electronic Filers: Comments may be 

filed electronically using the internet by 

accessing the ECFS: http://apps.fcc.gov/ 

ecfs/. 

• Paper Filers: Parties who choose to 

file by paper must file an original and 

one copy of each filing. 

• Filings can be sent by commercial 

overnight courier, or by first-class or 

overnight U.S. Postal Service mail. All 

filings must be addressed to the 

Commission’s Secretary, Office of the 

Secretary, Federal Communications 

Commission. 

• Commercial overnight mail (other 

than U.S. Postal Service Express Mail 

and Priority Mail) must be sent to 9050 

Junction Drive, Annapolis Junction, MD 

20701. 

• U.S. Postal Service first-class, 

Express, and Priority mail must be 

addressed to 45 L Street NE, 

Washington, DC 20554 

• Effective March 19, 2020, and until 

further notice, the Commission no 

longer accepts any hand or messenger 

delivered filings. This is a temporary 

measure taken to help protect the health 

and safety of individuals, and to 

mitigate the transmission of COVID–19. 

See FCC Announces Closure of FCC 

Headquarters Open Window and 

Change in Hand-Delivery Policy, Public 

Notice, DA 20–304 (March 19, 2020). 

https://www.fcc.gov/document/fcccloses-headquarters-open-window-andchanges-hand-delivery-policy. 

People with Disabilities: To request 

materials in accessible formats for 

people with disabilities (braille, large 

print, electronic files, audio format), 

send an email to fcc504@fcc.gov or call 

the Consumer & Governmental Affairs 

Bureau at 202–418–0530 (voice), 202– 

418–0432 (TTY). 

FOR FURTHER INFORMATION CONTACT: Anh 

Wride, Office of Engineering and 

Technology, 202–418–0577, anh.wride@

fcc.gov, or Thomas Struble at 202–418– 

2470 or Thomas.Struble@fcc.gov 

SUPPLEMENTARY INFORMATION: This is a 

summary of the Commission’s Notice of 

Proposed Rulemaking (NPRM), in ET 

Docket No. 21–264, FCC 21–83, adopted 

on July 13, 2021 and released on July 

14, 2021. The full text of this document 

is available for public inspection and 

can be downloaded at: https://

www.fcc.gov/document/fcc-seeksenable-state-art-radar-sensors-60-ghzband-0 or by using the search function 

for ET Docket No. 20–382 on the 

Commission’s ECFS web page at 

www.fcc.gov/ecfs. 

Synopsis 

Discussion. 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 

networking (WLAN) devices, outdoor 

fixed point-to-point communication 

links, and field disturbance sensors 

(FDS)—which includes radar 

operations. Unlicensed device users 

must account for the operations of 

authorized Federal and non-Federal 

users in the band, who operate under a 

variety of co-primary allocations. These 

allocations, which vary by band 

segment, consist of the Mobile, Fixed, 

Inter-Satellite, Earth-Exploration 

Satellite Service (EESS), Space 

Research, Mobile-Satellite, 

Radiolocation, Radionavigation, and 

Radionavigation-Satellite services. 

Section 15.255 of the rules stipulates 

operational policies and technical 

parameters for the 60 GHz band. The 

rule limits FDS operations to fixed 

operation or when used as short-range 

devices for interactive motion sensing 

(SRIMS). Furthermore, a fixed FDS with 

an occupied bandwidth fully contained 

within the 61.0–61.5 GHz band may 

operate with average output power 

levels up to 40 dBm and peak output 

power levels up to 43 dBm, while all 

other FDS devices (including those 

being used for SRIMS) are limited to a 

maximum transmitter conducted output 

power not to exceed –10 dBm and a 

maximum EIRP level not to exceed 10 

dBm. 

When it first adopted § 15.255 in 

1995, the Commission stated that its 

intent was to foster the potential of the 

60 GHz band ‘‘for allowing the 

development of short-range wireless 

radio systems with communications 

capabilities approaching those . . . 

achievable only with coaxial and optical 

fiber cable.’’ When it finalized the rule 

by adopting a spectrum etiquette three 

years later, it also included a provision 

that permitted fixed FDS operation in 

the band. 

In 2016, the Commission further 

expanded unlicensed device use in the 


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band to permit limited mobile radar 

operations and to extend the use of 

fixed field disturbance sensors to the 

64–71 GHz band. At that time, the 

Commission recognized that wireless 

innovation included the development of 

gesture-recognition technology using 

short-range radars that would allow 

users to interact with devices without 

needing to touch them. It thus decided 

to permit SRIMS radars while also 

noting that the record before it was 

insufficient to allow for the unfettered 

operation of mobile radars in the band. 

Specifically, the Commission’s decision 

permitted the ‘‘narrow application of 

mobile radars for short-range interactive 

motion sensing’’ 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. Furthermore, 

while the Commission specifically 

rejected comments calling on it to 

completely eliminate restrictions on 

FDS use, it also stated that it might 

consider allowing higher power levels 

in the future after it had acquired more 

experience with the devices it was 

permitting at that time. 

Since the 2016 decision, there has 

been continued interest in developing 

mobile radar applications that use the 

60 GHz band. To date, the Commission’s 

Office of Engineering and Technology 

(OET) has granted focused waivers of 

the rules to support discrete 

applications. First, Google requested 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, arguing 

that it had determined that higher 

power levels were necessary for the 

radar sensor to provide sufficient 

resolution to engage in effective 

interactions. In its 2018 order granting 

that waiver, which was limited to use of 

the specific Soli sensor described in 

Google’s request, OET found that 

allowing Google Soli sensors to operate 

at the requested power levels would not 

materially change the operating 

environment in the 57–64 GHz band 

from the perspective of the other users 

in the band. Specifically, it determined 

that the higher-power Google Soli 

device would be able to cooperatively 

share this spectrum with all users. 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 

milliseconds (ms) interval. This 

represented a lesser peak power limit 

than Google had originally sought, as it 

had revised its request following 

discussions with other parties who had 

interests in using the band for 

unlicensed operations, such as 

Facebook, in an effort to facilitate 

coexistence between unlicensed users in 

the band. 

Recently, OET granted waivers to 

several parties to permit the operation of 

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 dangerous, hot cars and to trigger 

alerts that could save lives. While radars 

operating under these waivers must be 

installed within the vehicle cabin and 

have the primary function of preventing 

children from inadvertently being left 

unattended in rear car seats, they are 

also expected to provide additional 

passenger safety and theft prevention 

benefits. 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 the visual 

inspection of structures. 

Applications such as the use of incabin automotive radars represent one 

of the many uses that parties have 

identified as being well suited for 

development in the 57–71 GHz band if 

the § 15.255 rules were amended to 

permit expanded mobile radar use. The 

Commission has received additional 

waiver requests asking for permission, 

for example, to install a radar on the 

exterior of a vehicle to enable closure of 

a door by the detection of foot 

movement or hand gestures; to operate 

60 GHz radars in robotic lawn mowers, 

or in personal safety wall-mount devices 

to detect changes in a person’s gait or a 

fall, and in 3D imaging equipment in 

healthcare environments. In general, 

these requests have been consistent with 

the same technical parameters as the 

waiver granted to Google and are 

represented to occupy the same 

‘‘spectrum footprint’’ as the Soli device. 

The increased interest in use of the band 

and accompanying breadth of potential 

applications that parties have identified 

is a relatively recent development, 

attributable at least in part, the 

Commission believes, to the availability 

of 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. 

To that end, the Commission notes 

that operation at higher power than 

specified in the Commission’s rules has 

been allowed in Europe under general 

rules for short-range devices. A 

European Telecommunications 

Standards Institute (ETSI) standard, 

which has been in effect since 2014, 

permits short-range devices to operate 

in a portion of the 57–71 GHz band at 

power levels that exceed those for 

FDS—including those operating as 

SRIMS—under § 15.255 of the 

Commission’s rules. Specifically, ETSI 

Standard EN 305 550 permits operation 

of short-range devices in the 57–64 GHz 

band at up to 20 dBm mean EIRP, while 

§ 15.255(c)(3) presently specifies that 

the peak EIRP level for FDS devices 

shall not exceed 10 dBm. ETSI EN 305 

550 also permits a maximum transmitter 

output power of 10 dBm, which is 20 dB 

greater than the level that § 15.255(c)(3) 

permits in this band. There are some 

additional differences between the US 

and European approaches. For example, 

the ETSI power limits are based on 

average measurements, whereas the 

Commission’s limits are based on peak 

power measurements. In addition, ETSI 

EN 305 550 also requires short-range 

devices in the 57–64 GHz band to 

comply with a power spectral density 

(PSD) limit of 13 dBm/MHz, which the 

Commission’s rules do not include. 

Finally, unlike the U.S, ETSI does not 

have a separate provision that allows for 

higher EIRP levels of up to 40 dBm for 

FDS in the 61.0–61.5 GHz band, nor 

does it provide for operation in the 64– 

71 GHz band. 

The protocols for wireless systems 

operating in the 60 GHz band within the 

U.S. have been established by the 

Institute of Electrical and Electronics 

Engineers (IEEE) 802.11 Standards 

Committee. These protocols are often 

referred to as ‘‘WiGig,’’ named for the 

former Wireless Gigabit Alliance which 

advocated for their development. The 

current IEEE 802.11ad standard allows 

for channel sizes of up to 2.16 gigahertz 

in the 60 GHz band, which support a 

data rate of up to 8 gigabits per second 

and permits a total of six channels in 

the 57–71 GHz band available in the 

United States. Furthermore, there are 


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IEEE 802.11 working groups with 

ongoing activities to define the channel 

access protocols to enable the same 60 

GHz system transmitting 

communication signals to transmit radar 

signals. 

The ongoing interest in expanding the 

scope of permissible unlicensed 

operations in the 60 GHz band has 

prompted interested parties to form a 60 

GHz Coexistence Study Group that has 

been looking into ways to accommodate 

both unlicensed communications device 

and FDS operations in the band. This 

group, which has attracted the active 

participation of many key members of 

the industry and meets on a regular 

basis, operates independently of the 

Commission. Members of this group, 

however, have submitted comments and 

ex parte filings in conjunction with 

many of the recent waiver proceedings. 

In general, these submissions have 

documented the parties’ interest in 60 

GHz unlicensed operations and have 

encouraged us to initiate a rulemaking 

proceeding to review § 15.255 of the 

Commission’s rules with a goal of 

putting into place a new framework to 

promote further innovation in the 60 

GHz band by both unlicensed 

communications and FDS operations. 

Finally, the 2020 panel of the FCC’s 

Technological Advisory Council (TAC) 

took notice of the 60 GHz Coexistence 

Study Group when its Future of 

Unlicensed Operations working group 

examined ways to improve regulations 

for the 60 GHz band. As part of the 

TAC’s January 14, 2021 meeting, the 

working group recommended that the 

Commission initiate a rulemaking 

proceeding to examine the 60 GHz rules 

in § 15.255 to address issues raised by 

the numerous waiver requests that had 

been filed. 

Discussion. The Commission believes 

that there are significant benefits in 

initiating this rulemaking proceeding, 

and the Commission agrees with the 

TAC and other parties that have urged 

us to comprehensively evaluate 

unlicensed operations under § 15.255 of 

the Commission’s rules. The 

Commission realizes that past 

individual waivers have served as an 

important ‘‘relief valve’’ that allow for 

unique types of operations that have 

important public interest benefits and 

that do not result in harmful 

interference to incumbent licensed users 

or jeopardize coexistence with other 

unlicensed users but do not comply 

with the Commission’s rules. However, 

they are an inappropriate mechanism 

for providing the type of broad-based 

relief that the Commission considers 

here. Together, the overwhelming 

interest in FDS operations in the 60 GHz 

band, the breadth of deployments that 

parties have identified, and the 

opportunities for innovation that will be 

made possible by the availability of 

relatively inexpensive applicationagnostic FDS-capable chipsets make the 

Commission’s initiation of a rulemaking 

proceeding both timely and appropriate. 

In recognition that unencumbered 

unlicensed operation has proven to be 

an especially powerful engine for 

innovation and economic growth, the 

Commission’s proposals are designed to 

expand the opportunities for unlicensed 

FDS operations in the band to the 

greatest extent possible. At the same 

time, the Commission’s proposals are 

also designed to provide assurance that 

the unlicensed communications devices 

that have been permitted to use the 

band since it was first made available 

for unlicensed operations will be able to 

coexist with these new unlicensed 

operations. And, in all cases, the 

Commission’s proposals remain true to 

the bedrock principle that unlicensed 

devices, regardless of type, must not 

cause harmful interference to authorized 

users of the band. 

In this NPRM, the Commission 

proposes targeted changes to § 15.255 of 

the Commission’s rules to expand 

unlicensed FDS device operations in the 

60 GHz band. First, the Commission 

proposes that all FDS devices that limit 

their operating frequencies to the 57–64 

GHz portion of the band would be 

permitted to transmit 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. FDS devices will be able 

to continue to operate across the entire 

57–71 GHz band at the 10 dBm EIRP 

and –10 dBm conducted output power 

limits specified in the Commission’s 

existing rules. By streamlining the 

Commission’s rules in this manner, the 

Commission would no longer need the 

special provisions for short-range 

interactive motion-sensing mobile 

radars (i.e. SRIMS) that are contained in 

the Commission’s existing rules. 

Second, the Commission also proposes 

to retain and potentially to expand on 

the provision of § 15.255(c)(2) allowing 

fixed FDS devices that contain their 

operating bandwidth to the 61.0–61.5 

GHz band to transmit at 40 dBm average 

EIRP and 43 dBm peak EIRP. Finally, 

the Commission seeks comment on 

methods to enhance coexistence (e.g., 

listen-before-talk or other spectrum 

sensing/contention avoidance 

capabilities) that could be used to allow 

the same power level for FDS devices as 

is currently permitted for 60 GHz 

communication devices (up to 40 dBm 

EIRP) across the entire 57–71 GHz band. 

The Commission is not proposing any 

rule revisions for existing unlicensed 

communication devices such as WiGig 

WLAN or fixed point-to-point wireless 

links that currently operate in the 57– 

71 GHz band. However, the Commission 

seek comment on whether there are 

particular provisions that the 

Commission is proposing for FDS 

operation, such as an antenna gain limit 

instead of a conducted power limit and 

requiring use of a spectrum sensing 

mechanism, that should be more 

broadly applied to all Part 15 devices 

operating in the 57–71 GHz band. 

The Commission notes that the TAC’s 

Future of Unlicensed Operations 

working group suggested the 

Commission seek comment on whether 

the rules should allow greater radiated 

power for radar applications, if the 

parameters of the Google Soli waiver 

should be incorporated into the rules, 

and whether there are changes to the 

conditions and technical requirements 

set forth in the recent waivers that 

would improve sharing with 

communications applications. It further 

suggested that the Commission ask 

whether the use of a contention-based 

protocol should be required, and 

whether 60 GHz band unlicensed radar 

applications should be allowed to use 

the same power levels as 

communications applications in the 

band if they incorporate listen-beforetalk procedures. The Commission 

invites commenters to address these 

specific questions. 

As an initial matter, given that the 

Commission refers to both FDS and 

radars extensively throughout this 

document, the Commission addresses 

the relationship between the two terms. 

Field disturbance sensors broadly 

include radar operations. Although 

§ 15.3(l) of the Commission’s rules 

provides a definition for ‘‘field 

disturbance sensor,’’ it does not provide 

a definition for ‘‘radar,’’ and instead 

parties must look to the radar definition 

contained in § 2.1 of the Commission’s 

rules. The Commission seeks comment 

on whether the rules related to ‘‘field 

disturbance sensors’’ in § 15.255 are 

sufficiently broad and flexible to 

accommodate the class(es) of devices 

that parties anticipate will be developed 

to operate in the 57–71 GHz band. The 

Commission also seeks comment on 

whether the Commission should modify 

the definitions contained in Part 15 of 

the Commission’s rules to provide 

greater clarity about the relationship 

between FDS and radars and, if so, how? 

Commenters that support modifying the 


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existing Part 15 definitions should also 

address whether such modifications 

would require adjustments elsewhere in 

the rules. 

As noted above, a number of parties 

have been granted waiver of certain 

provisions of § 15.255 to permit 

operation of innovative radar devices in 

the 60 GHz band. To the extent the 

Commission modifies its rules in this 

proceeding to expand unlicensed FDS 

device operations in the 60 GHz band, 

the Commission expects that all future 

60 GHz FDS operations would be 

conducted subject to the Commission’s 

modified rules. Accordingly, the 

Commission proposes that if the 

Commission adopts such modifications 

to the Commission’s rules in this 

proceeding, the previously granted 60 

GHz FDS waivers would be terminated 

and FDS device manufacturers would be 

expected to conform their operations to 

the Commission’s rules as revised. The 

Commission seeks comment on this 

proposal. 

The Commission first proposes to 

modify § 15.255 of the Commission’s 

rules to afford greater opportunities for 

fixed and mobile FDS devices operating 

in the 57–64 GHz portion of the 60 GHz 

band. The extensive analysis that has 

accompanied the multiple waiver 

requests that have been submitted to the 

Commission, the widespread consumer 

use of Google’s Soli-equipped devices 

without reported cases of harmful 

interference and the ongoing efforts of 

the industry and standards groups to 

identify model coexistence practices for 

unlicensed users gives us 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. The 

Commission’s baseline proposals draw 

from the technical and operating 

conditions incorporated into the 

waivers granted to Google for its Soli 

device and to automobile manufacturers 

and suppliers for in-cabin radars to 

detect children left in cars, with 

additional modifications to account for 

harmonization with international 

provisions governing operation in the 

band. 

As discussed below, the Commission 

proposes to: Focus device operation to 

the 57–64 GHz portion of the 60 GHz 

band; allow operations at higher power 

levels than were permitted in the 

waivers but consistent with the wellestablished ETSI standards; and require 

a duty cycle that is consistent with what 

was established in the Google waiver, 

with the possibility of mandating a 

minimum off-time between cycles. 

Based on the Commission’s review of 

the multiple waiver requests that 

pertain to FDS use of the 60 GHz band, 

parties designing and manufacturing 

radars to operate in the 60 GHz band 

have proposed to restrict their spectrum 

usage to frequencies below 64 GHz 

(constituting the 60–64 GHz or 57–64 

GHz band segments, depending on the 

filing), although § 15.255 permits 

operation across the 57–71 GHz band for 

fixed FDS and SRIMS devices such as 

the Google Soli. The Commission 

surmises that the requests seek to limit 

operation to the lower portion of the 57– 

71 GHz band to align operations and 

devices with international standards 

such as the European ETSI Harmonized 

Standard EN 305 550 that restrict shortrange devices, e.g., radars, to the 57–64 

GHz band. The Commission seeks 

comment on this assumption. 

The Commission notes that a proposal 

has been submitted to IEEE 802.11 to 

define a channel access protocol to 

enable the same 60 GHz systems to 

transmit signals that can be used both 

for communications and radar purposes 

to be decoded by a similar system at the 

receiving end. Equipment designs for 60 

GHz transmitters are thus considering 

radar transmissions alongside 

communication transmissions in the 

same transmitter or chip. While the 

IEEE efforts in this area may be 

considering the entire 57–71 GHz band, 

the Commission proposes to limit 

operation of FDS devices operating 

under the Commission’s proposed 

higher power limits (20 dBm EIRP) to 

the 57–64 GHz band. As discussed 

above, limiting the Commission’s 

proposal in this way provides for 

devices that are consistent with the 

international standards, which only 

specify FDS operation in the 57–64 GHz 

band. The Commission seeks comment 

on this proposal. Would limiting 

operation of higher power FDS devices 

to the 57–64 GHz band benefit 60 GHz 

WLAN systems operating in close 

proximity to FDS devices by leaving the 

64–71 GHz band clear of higher power 

FDS operations? The Commission seeks 

comment on whether, alternatively, the 

Commission should allow the proposed 

FDS operation across all of the 57–71 

GHz band or some other segment of the 

band. If the Commission were to allow 

the proposed FDS operation across the 

entire 57–71 GHz frequency range under 

the proposed requirements discussed 

below—which include a duty cycle 

limit—should the Commission remove 

the current provision that permits 

operation in this band at 10 dBm EIRP 

with no duty cycle limit? Should the 

Commission modify the Commission’s 

rules in any other respect? The 

Commission also seeks comment on the 

benefits or costs of these proposed 

changes with respect to 60 GHz 

authorized users. Parties that oppose 

these proposed rules should cite 

specific harms that they believe would 

result from changing the rules. 

EIRP Limits. The current rules permit 

FDS devices to operate at a maximum 

10 dBm EIRP. All of the waiver requests 

the Commission received requested a 

maximum of 13 dBm EIRP to provide 

greater accuracy and finer resolution 

imaging. Subsequent waiver requests to 

Google’s waiver described the intended 

target detection to be either in the submillimeter 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; 

thus, requesters argue that 60 GHz FDS 

devices need higher power than 

specified in the rules, because the 

existing power levels do not allow the 

devices to provide the necessary 

accuracy in detection of small-size 

targets due to poor signal-to-noise ratio. 

The Commission proposes to allow 

FDS devices to operate at no more than 

20 dBm average EIRP. This proposed 

EIRP limit is higher than the level 

requested in the multiple waivers that 

the Commission received; however, it is 

consistent with ETSI EN 305 550. The 

Commission believes this EIRP level 

will promote additional growth for new 

FDS applications beyond those 

anticipated to be deployed under the 

Commission’s issued and pending 

waiver requests. The Commission also 

believes that harmonization with other 

regions will likely increase efficiency 

for American manufacturers by reducing 

design and manufacturing costs. The 

Commission further believes that this 

EIRP limit will not cause harmful 

interference to authorized services in 

the band. These radars will operate at a 

comparatively much lower EIRP level 

than what is already permitted for 

communication devices (indoors and 

outdoors) in the same frequency band. 

Communication devices such as 60 GHz 

WLAN devices can operate at up to 40 

dBm EIRP, as compared to the 20 dBm 

EIRP limit that the Commission is 

proposing for radars. The Commission 

notes that a WLAN device may already 

have to operate in the presence of 

signals from neighboring WLAN devices 

and other Part 15 devices operating at 

similar power levels; thus the proposed 

lower EIRP limit for FDS devices should 

have little or no effect on the 

operational environment that WLAN 

devices can expect under the 

Commission’s rules. The Commission 

also observes that 60 GHz WLAN 


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devices have operated at this EIRP limit 

(i.e., 40 dBm average/43 dBm peak) for 

several years without causing harmful 

interference to other authorized 

services, such as the Passive EESS 

operating at 57–59.3 GHz. In addition, 

the IEEE 802.11 standards group’s 

activity to define channel access 

protocols to allow transmission of radar 

signals alongside communication 

signals may allow coexistence of both 

signals in the 60 GHz band. The 

Commission seeks comment on the 

proposed EIRP level for FDS devices 

and on the Commission’s tentative 

interference assessment. The 

Commission also seeks comment on the 

state of standards development — 

specifically, with respect to coexistence 

issues between radar signals and 

communications signals. Should the 

Commission specify any coexistence 

measures or requirements, such as 

listen-before-talk in its rules? Does the 

fact that many radars are mobile mean 

that they will not be used in close 

proximity to communication devices for 

extended periods of time, thus limiting 

any potential for causing interference to 

short durations? Further, the 

Commission seeks comment on the 

benefits or costs of the proposed change 

to the EIRP limit with respect to 60 GHz 

authorized users. How would this 

change, if adopted, benefit stakeholders, 

consumers and others? Parties that 

oppose these proposed rules should: 

Cite specific harms that they believe 

will result from changing the rules in 

the manner proposed, estimate the costs 

of such potential harms, and specify 

under what parameters they believe 

radar systems can coexist with 

communications systems in the band. 

Because 60 GHz FDS devices will 

need to coexist with 60 GHz 

communications devices, the 

Commission also seeks comment on the 

state of development in the 60 GHz 

communications device ecosystem. 

What is the current state of deployment 

of 60 GHz communications systems? 

What use cases are supported by 60 GHz 

communications systems today, and 

what use cases are contemplated for 

these systems in the future? Do 60 GHz 

communications systems generally take 

advantage of the higher EIRP limits 

permitted under the Commission’s 

rules? Facebook, Intel, and Qualcomm 

assert that the 60 GHz band will be used 

by unlicensed devices for latencysensitive augmented reality/virtual 

reality/extended reality (AR/VR/XR) 

applications. Is this likely to be a 

widely-deployed use case in the 60 GHz 

band? Do AR/VR/XR applications 

present distinct interference scenarios 

or raise other considerations compared 

to other 60 GHz WLAN applications? Do 

60 GHz unlicensed communications 

systems operate throughout the entirety 

of the 60 GHz band? Could these 

systems operate effectively in a 

subsection of the overall band, for 

example, the 64–71 GHz band segment? 

Transmitter Conducted Output Power 

Limit. The rules currently permit FDS 

devices to operate at a maximum –10 

dBm transmitter conducted output 

power, whereas 60 GHz WLAN devices 

are allowed up to 27 dBm. The 

Commission proposes to allow FDS 

devices to operate at a maximum 10 

dBm conducted output power, 

consistent with the waivers the 

Commission has already granted in the 

band. The Commission notes that the 

ETSI standard specifies the conducted 

output power as a mean (average) limit, 

rather than a peak limit as the 

Commission’s rules do. The 

Commission seeks input on whether the 

Commission should consider average 

transmitter conducted output power 

limit and what impact this would have 

on the different types of FDS devices 

(e.g., FMCW, pulse, etc.). On the other 

hand, the Commission notes that for 60 

GHz transmitters, including 

communications and radar devices, that 

are implemented at the chip level, 

access to the transmitter output port 

may not be available, rendering a 

demonstration of compliance to this 

requirement burdensome. The 

Commission seeks input on whether 

this requirement is necessary in view of 

the technological evolution of such 

system-on-chip devices. A 10 dBm 

transmitter conducted output power 

limit along with a 20 dBm EIRP limit 

implies a limit on transmit antenna 

gain. The Commission inquires as to 

whether the transmitter conducted 

output power limit instead should be 

replaced by an antenna gain limit. If so, 

what limit would be appropriate? 

Should an antenna gain limit be applied 

to all 60 GHz transmitters, including 60 

GHz communication devices, since 

these devices also have transmitters 

implemented at the chip level, and thus 

would encounter the same measurement 

difficulties? The Commission also seeks 

comment on whether a transmitter 

conducted output limit is necessary for 

60 GHz transmitters, including 

communications and radar devices. The 

Commission seeks input on this issue in 

order to develop a comprehensive 

record. The Commission also seeks 

comment on the benefits or costs of the 

proposed change to the transmitter 

conducted output power with respect to 

60 GHz authorized users. Proponents of 

such a change should provide specific 

details regarding measurement 

difficulties than might be encountered 

for system-on-a-chip devices as well as 

details on what maximum antenna gain 

they believe should be specified and 

whether there are circumstances under 

which that gain can be exceeded (e.g., 

with a corresponding EIRP reduction). 

Power Spectral Density Limit. The 

existing rules do not restrict the power 

spectral density for 60 GHz devices. The 

Commission proposes 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 the Commission placed on 

Google and other parties operating FDS 

devices pursuant to Commission issued 

waivers. The Commission seeks 

comment on the proposed power 

spectral density limit. Is there a need for 

a power spectral density limit, and if so, 

what is the appropriate limit and for 

which types of devices should it apply? 

For example, would a power spectral 

density limit be necessary for FDS 

devices using frequency-modulated 

continuous wave (FMCW), or pulse/ 

impulse transmissions? Although the 

Commission is mindful of harmonizing 

the technical rules that the Commission 

adopts with the existing ETSI standards, 

the Commission seeks input and 

technical analyses on the utility of this 

proposed requirement. FMCW sensors 

generally modulate their transmission 

over a frequency band in order to obtain 

the necessary target resolution. At any 

given time, FMCW sensor emissions are 

limited to a small portion of the 

spectrum. As such, implementing a PSD 

limit appears to be an appropriate 

measure for spectrum sharing for these 

types of sensors. The Commission seeks 

comment on whether a PSD limit alone 

is a sufficient power limit to facilitate 

sharing between field disturbance 

sensors and communication devices. 

Are there other FDS modulation 

techniques that would benefit from a 

power spectral density limit? The 

Commission also seeks comment on the 

benefits or costs of the proposed power 

spectral density limit for FDS devices 

with respect to 60 GHz authorized users. 

If the Commission does not adopt a 

power spectral density limit, what are 

the ramifications if devices are 

permitted to operate with all of their 

energy concentrated in a narrow 

bandwidth? Parties that oppose these 

proposed rules should cite specific 

harms that they believe would result by 

imposing a power spectral density 

requirement. 

The Commission notes that the EIRP, 

transmitter conducted output power, 

and power density limits proposed here 


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are consistent with those stipulated by 

the ETSI standard EN 305 550. This 

standard has been in existence since 

2014, thus these limits have been tested 

and deployed in other geographic 

regions with similar spectrum 

allocations. In fact, ETSI released an 

updated draft of this standard in 2017 

and did not recommend changes to the 

limits. Thus, it appears that these 

proposed power levels have been 

successful in providing an environment 

that supports robust sharing of the 60 

GHz spectrum among various users as 

the Commission is proposing to allow 

here. The Commission seeks comment 

on this view. The Commission also 

seeks input on the development status 

of the draft 2017 ETSI EN 305 550 

Standard with respect to the technical 

parameters the Commission is 

proposing herein. The Commission 

understands that ETSI is undertaking a 

major revision of EN 305 550 to address 

receiver performance parameters, which 

the 2014 Harmonized version did not 

address. The Commission seek comment 

on the status of this revision and what 

changes to the specification are 

anticipated. In light of this ongoing 

revision, are changes to the 

Commission’s proposed rules 

warranted? To develop a comprehensive 

record, the Commission seeks input on 

current or planned standards, both 

domestic and international, regarding 

operation of FDS devices in the 57–71 

GHz band, or any subset frequency band 

thereof. In addition, because radar 

resolution is generally dependent on 

bandwidth, the Commission seeks 

comment on whether the proposed rules 

will provide the sufficient resolution 

over the ranges needed for the 

applications envisioned for radars in the 

60 GHz band. 

Peak vs. Average Power Limits. The 

Commission notes that, except for fixed 

FDS devices that contain their operating 

bandwidth within the 61.0–61.5 GHz 

band, the existing rules for FDS devices 

do not specify an average power limit, 

but instead only a peak or maximum 

power limit, unlike the power limits for 

60 GHz communications devices, where 

the Commission specifies both an 

average EIRP and a peak EIRP of 3 dB 

above the average limit. The 

Commission observes that 60 GHz FDS 

and radar devices will mostly use 

constant-amplitude continuous-wave 

(CW), frequency-modulated continuous 

wave (FMCW), or pulse/impulse 

transmissions. If the limits are applied 

only during active transmission (i.e., 

only over the chirp or pulse duration), 

then the peak and the average signals 

will be equivalent. The Commission 

further notes that by specifying the 

limits only in terms of average power, 

potential measurement instrument 

desensitization phenomena can be 

avoided. The Commission proposes to 

define the power limits for FDS/radar 

devices in terms of average power and 

seek comment on the benefits of such a 

measurement. Are there consequences 

to specifying average power 

measurements rather than peak with 

respect to the potential to cause harmful 

interference to authorized users, or for 

unlicensed radar systems to coexist with 

unlicensed communications systems? 

Those who believe that such a change 

might result in harmful interference 

should estimate the costs of such 

interference. Would this change impact 

passive EESS users in the 57–59.3 GHz 

band? Are there are other possible FDS/ 

radar modulation techniques that would 

make requiring a peak power limit 

necessary? 

The existing rules do not place a duty 

cycle restriction on 60 GHz devices. 

Similarly, the ETSI EN 305 550 standard 

does not stipulate a duty cycle limit for 

60 GHz short-range devices; however, 

the standard does specify requirements 

for 60 GHz receivers to ensure that they 

can adequately handle interferer signals. 

The Commission imposed a 10% duty 

cycle limit in the Google Waiver Order 

and subsequent waivers for 60 GHz FDS 

devices operating under higher emission 

limits than permitted in the rules. This 

10% duty cycle is based on a maximum 

3.3 ms transmission time in every 33 ms 

interval and was derived from Google’s 

2018 final agreement with stakeholders 

from the WLAN communications 

industry whose technology operates in 

the 60 GHz spectrum. The Commission 

proposes to require the same duty cycle 

restriction as that imposed in the 

multiple waivers. 

However, the Commission notes that 

in some of the waiver requests, parties 

asked for a longer transmission time 

frame. The Commission further notes 

certain parties recommend 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 express concern that the duty 

cycle requirement in the waivers will 

not promote coexistence with 

communications applications, including 

AR/VR/XR communication devices 

which require very high data 

throughput and very low latency. They 

point out that the 10% duty cycle 

requirement could lead to certain radars 

transmitting very short bursts (in microsecond durations) followed by similarly 

short silent periods (also in the microsecond durations) during the entire total 

33 ms interval. This would result in 

interspersed, non-contiguous microsecond short silent intervals during 

which 60 GHz AR/VR communication 

devices may have difficulty accessing 

the spectrum due to the briefness of the 

radars’ quiet intervals; yet, when added 

together, the total amount of 

transmission time and silent intervals 

would comply with the ‘‘10% on, 90% 

off’’ definition of a 10% duty cycle. 

On the other hand, other parties 

indicate that ‘‘regulatory guarantees of 

such latency targets would substantially 

degrade performance of FMCW radars, 

which generally need to transmit 

frequent chirps (to prevent velocity 

aliasing) and span a sufficient burst time 

to enable good velocity resolution.’’ 

These parties argue that a duty cycle 

rule restricting radars to ‘‘guarantee that 

at least 99% of WiGig packets 

experience on-air latency of no more 

than a few milliseconds’’ would be 

unnecessary due to ‘‘radars’ low 

transmission power, low potential to 

generate interference, and antenna 

directionality, as well as propagation 

loss in the 60 GHz band.’’ A regulatory 

latency target will have a similar impact 

on pulse radars as well, as the radar’s 

observable maximum velocity and 

velocity resolution both depend on the 

pulse repetition frequency. As such, 

should duty cycle be defined differently 

for radar systems with different 

modulation techniques (FMCW, pulse, 

etc.) operating on different time scales? 

On the other hand, in view of these 

apparent limitations with respect to 

maximum velocity and velocity 

resolution, is duty cycle a suitable 

parameter for regulation? Can limiting 

peak and average power within a 

defined band be a better approach than 

specifying a duty cycle? If regulating the 

duty cycle is necessary, then how 

should it be defined? The Commission 

seeks comment and technical input on 

appropriate parameters for regulation 

including definition/characterization of 

the duty cycle with respect to radar 

devices. The Commission seeks input 

on this issue to maximize the efficiency 

of both communications and radar 

operations without unduly degrading 

the operating environment for 

unlicensed users of the band or causing 

harmful interference to authorized users 

in the band. The Commission also seeks 

comment on whether radar signals 

could mimic the spectrum access 

protocols of communications devices to 

appear like any other communication 

signal thereby making a duty cycle 

restriction unnecessary. The 


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Commission seeks comment on whether 

the recent activities in the IEEE 

standards group examining channel 

access protocols that would enable the 

same 60 GHz system transmitting 

communication signals to transmit radar 

signals address this issue. Commenters 

should provide technical detail, studies 

and analyses supporting their position 

on how a duty cycle requirement for 

FDS devices should be specified. 

The Commission notes that the 60 

GHz Co-existence Study Group’s 

activities have been geared toward 

developing ‘‘a consensus approach’’ to a 

framework for a potential Commission 

rulemaking, with discussions 

concerning duty cycles; transmission 

on- and off-times; operating bandwidth 

and channelization (e.g., radar 

implementations with 2-gigahertz, 4- 

gigahertz, 7-gigahertz-bandwidth); 

contention-based protocols; transmit 

power; and antenna gain.’’ Although 

representatives from the 60CSG recently 

informed us that the group has yet to 

achieve consensus on a recommended 

regulatory approach to accomplish 

coexistence among the diverse 

operations in the 60 GHz band, they also 

described several potential 

‘‘frameworks’’ for further unlicensed 

development in this frequency range. 

These include establishing a single rule 

for radar operations in the 57–64 GHz 

portion of the 60 GHz band, establishing 

a rule based on average power and/or 

average PSD limits that draws from the 

ETSI EN 305 550 standard, taking a 

channelization approach to radars in the 

60 GHz band, and amending the rules to 

reflect different categories of 

technologies that operate in the 60 GHz 

band, such as allowing for different 

operating parameters when operating in 

a vehicle, indoors, or outdoors, or 

between implementations that are fixed, 

mobile, or portable. The Commission 

seeks comment on the 60 GHz CSG 

filing. What are the technical trade-offs 

and cost/benefits for each framework? 

What parts of these four frameworks can 

the Commission incorporate into the 

Commission’s final rules to optimize the 

benefits and minimize the costs to all 

authorized 60 GHz users, and help us 

achieve the Commission’s objective of 

fostering a greater variety of unlicensed 

uses in the 60 GHz band? The 

Commission also seeks 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 the 

Commission’s proposals to expand 

unlicensed use of the band. 

Because the Commission is proposing 

to permit fixed and mobile radars to 

operate in the 60 GHz band, the 

Commission believes it is no longer 

necessary to qualify an application as 

SRIMS to operate as a mobile radar 

under § 15.255. The Commission 

therefore proposes to remove this 

designation from the rules and replace 

it with the general designation of FDS 

devices for both fixed and mobile 

radars. As indicated, when adopting the 

rule for SRIMS, the Commission stated 

that it intended it to be a narrow 

application of mobile radar use, while 

continuing to prohibit general mobile 

radar use in § 15.255. As such, the 

Commission did not adopt a definition 

for SRIMS. Over the last few years, there 

has been much confusion on which 60 

GHz mobile and fixed radar applications 

should qualify under the SRIMS 

designation. The Commission also 

requested input in response to the 

multiple 60 GHz waiver requests but 

was not able to make a bright-line 

determination for certain applications. 

The Commission seeks comment on the 

proposal to remove the SRIMS 

exception from § 15.255 and replace it 

with general rules covering all FDS 

devices. The Commission also seeks 

comment on the benefits or costs of this 

proposal with respect to 60 GHz 

authorized users. Parties that oppose 

removing the SRIMS designation from 

the rules should cite specific harms that 

they believe would result from making 

this change to the rules. 

The Commission next addresses 

§ 15.255(c)(2) of its rules, which permits 

a fixed FDS device to operate at up to 

40 dBm average EIRP and at up to 43 

dBm peak EIRP in the 61.0–61.5 GHz 

band segment. 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. The Commission 

believes that this rule is valuable insofar 

that it permits the operation of fixed 

FDS devices at power levels as high as 

communication devices, albeit restricted 

to a more narrow operating bandwidth, 

without being restricted to a specific 

duty cycle limit. As such, the 

Commission proposes to retain 

§ 15.255(c)(2) but also seeks comment 

on whether the Commission should 

expand this provision to apply to both 

fixed and mobile FDS applications. The 

Commission seeks comment on how 

useful this 500-megahertz bandwidth 

provision has been in practice in 

facilitating FDS device deployment, 

given that radars typically achieve better 

resolution with a wider bandwidth. 

What FDS applications currently are 

being enabled using the higher power 

levels permitted in the 61.0–61.5 GHz 

band? Could the Commission expect 

that expanding § 15.255(c)(2) would 

result in new mobile FDS applications, 

and if so would they perform functions 

that otherwise would not be possible 

under the existing rules? How would 

expanding the rule affect the spectrum 

environment for all users of the band? 

What costs and benefits would be 

associated with such an action? In 

particular, the Commission seeks 

comment and technical analyses on 

these issues to develop a comprehensive 

record. 

Section 15.255(c)(2) requires the 

average power of any emission outside 

of the 61.0–61.5 GHz band, measured 

during the transmit interval, to be less 

than or equal to 10 dBm, and similarly 

the peak power of any emission to be 

less than or equal to 13 dBm. Because 

no measurement bandwidth is currently 

specified in the rule, the Commission 

seeks comment on whether this 

requirement is sufficiently specific. 

Should these limits be specified in 

terms of power spectral density (PSD)? 

If so, what are the required peak and 

average power densities outside of the 

61.0–61.5 GHz band? The reference 

bandwidth that the Commission often 

uses for specification of the spurious 

domain emission levels for frequency 

bands above 1 GHz is 1 megahertz. The 

Commission seeks comment on the 

appropriate reference bandwidth for 

PSD for emission outside of the 61.0– 

61.5 GHz band. Are any other additional 

requirements necessary? 

To the extent that the Commission 

retains provisions in § 15.255 that 

specifically permit fixed FDS 

operations, the Commission seeks 

comment on how the Commission 

should interpret ‘‘fixed’’ and whether 

the Commission should incorporate a 

specific definition for the term into the 

Commission’s Part 15 rules. When OET 

granted the automotive waivers, it noted 

that the Commission did not specifically 

address whether the rule permits 

something that is inherently mobile 

(such as an automobile) to be treated as 

fixed in certain circumstances, and left 

any determination of what constitutes 

‘‘fixed’’ and ‘‘mobile’’ operation under 

the rule for separate consideration. A 

review of the 1998 Report and Order 

that first permitted fixed FDS use in the 

band would suggest that the 

Commission was anticipating a narrow 

set of applications that would be used 

in industrial settings where the 


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equipment would rarely if ever be 

moved. However, in light of the wide 

range of potential FDS applications that 

now have been identified for the 60 GHz 

band and the Commission’s general 

inclination to provide as expansive an 

opportunity for unlicensed operations 

in a particular band as is practical, the 

Commission tentatively concludes that a 

broader view is appropriate. The 

Commission tentatively concludes that 

the Commission should interpret fixed 

FDS operations 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. The Commission 

envisions this interpretation would 

allow for a device that is used in a 

household and easily moved from room 

to room to operate in different parts of 

the residence, but that an automotivemounted radar that operates when the 

car is stopped while the ignition is 

engaged would be too transitory to 

qualify. The Commission seeks 

comment on this proposal. Does it 

provide a sufficient bright-line rule for 

device operation? Will it provide other 

unlicensed and authorized users in the 

60 GHz band with sufficient confidence 

that they will be able to identify and 

resolve any degradation of the 

operational environment caused by 

these fixed users? Are there other 

interpretations that are more 

appropriate for defining fixed FDS 

operations? 

The Commission’s third area of 

discussion relates to whether the 

Commission could permit FDS devices 

to operate at a higher power throughout 

the entire 57–71 GHz band. In its 

recommendation, the TAC suggests that 

the Commission explores the possibility 

of allowing radars that incorporate a 

sensing technology such as listenbefore-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. 

The Commission seeks input regarding 

the effect such higher power levels 

would have on authorized users who are 

entitled to interference protection, as 

well as how those power levels would 

affect the ability of unlicensed radar 

systems to coexist with unlicensed 

communications systems. Are these 

EIRP and transmitter conducted output 

power levels appropriate for radar 

applications, given the implied high 

antenna gain/directivity? What antenna 

gain do radars need in various 

applications? Are mobile radar 

applications limited by power 

consumption such that they would not 

be able to leverage these higher 

emission limits? With spectrum sensing 

capabilities, would a duty cycle 

restriction be necessary? The 

Commission seeks input and feedback 

as well as recommendations on these 

issues. Commenters should provide 

technical details and/or studies to show 

that it is practical for radars to operate 

at up to 40 dBm EIRP without causing 

harmful interference to existing 

authorized services in the band. The 

Commission notes that the 2021 TAC 

Recommendation only mentions the 

listen-before-talk technique. Are there 

other spectrum contention avoidance 

techniques that would serve the same 

purpose and how effective are they? 

What are the costs and benefits of such 

techniques? Have there been any 

completed or ongoing studies regarding 

coexistence between radars and 

authorized 60 GHz users and, if so, what 

are the results and recommendations? 

Should the same spectrum sensing 

technique be required for all devices 

operating in the 57–71 GHz band with 

the average power limit of 40 dBm 

EIRP? Have industry standards groups 

such as the 802.11 Standards Committee 

considered the use of spectrum sensing 

techniques for 60 GHz unlicensed 

devices? Will there be a need to regulate 

energy detection and observation time 

for LBT sensing? If so, what are the 

appropriate limits? Will usage of LBT 

provide higher aggregate capacity? If so, 

does it justify the higher complexity 

necessary to support LBT? The 

Commission solicits input on these 

issues to develop a comprehensive 

record on these matters. 

The Commission does not propose to 

alter the existing restrictions relating to 

the use of 60 GHz band unlicensed 

devices on board aircraft which are 

contained in § 15.255(b) of its rules, but 

the Commission nevertheless seeks 

comment as to whether the Commission 

should expand the situations where 

such use is permissible. Currently, such 

operation is limited to when the aircraft 

is on the ground, and, for airborne use, 

only in closed exclusive communication 

networks within the aircraft. To account 

for the important interest in protecting 

passive EESS users that operate in the 

57–59.3 GHz band, the rule limits this 

use to aircraft with a high RF 

attenuation body (e.g., commercial 

airliners), and cannot be used in 

wireless avionics intra-communication 

applications where external structural 

sensors or external cameras are mounted 

on the outside of the aircraft structure. 

The Commission does not believe that 

retaining the existing provisions 

regarding in-aircraft use of unlicensed 

devices would hinder the initial 

successful deployment of new 

applications and devices under the 

Commission’s proposed rules. Many of 

the use opportunities that have been 

identified to date—such as inside and 

outside vehicles, and in personal safety, 

medical imaging, home automation, 

environmental control, and robotic 

appliances devices, for example—are 

not dependent on use on board an 

aircraft. Compliance options also exist 

for portable electronic devices that may 

be brought aboard airplanes. These 

could include, for example, activation of 

‘‘airplane mode’’ during flight or the use 

of sensors to disable operations when 

the device is above a particular height 

above ground. The Commission seeks 

comment on this tentative 

determination. 

Currently the Commission has only 

authorized 60 GHz radars to operate on 

board aircraft beyond the uses permitted 

in the rules via two limited situations. 

Both were in conjunction with waiver 

grants that carefully evaluated how 

specific devices would be deployed in 

well-defined use cases. Leica 

Geosystems AG may operate a 60–64 

GHz radar on an unmanned aircraft, but 

with very restrictive conditions on the 

number of deployed devices. The 

Google Soli radar incorporated into a 

smartphone (e.g., the Google Pixel) 

allows control of a smartphone via 

gestures without touching the phone, 

and is not intended to be part of the 

aircraft communication network. 

Although the Commission proposes to 

retain the existing rule, the Commission 

nevertheless seeks comment on whether 

the Commission should allow for 

expanded use of 60 GHz radars on board 

aircraft and, if so, with what 

requirements and restrictions. Given 

that the Commission’s fundamental 

consideration has been and remains 

how to ensure that passive EESS 

operations in the 57–59.3 GHz band 

continue to be protected from harmful 

interference that could be caused by 

airborne use of unlicensed 60 GHz 

devices, could airborne radar use be 

permitted above 59.3 GHz? The 

Commission is not aware of any reports 

of harmful interference being caused by 

Google Soli devices during airborne use. 

Could the Commission permit 60 GHz 

radars to operate on board aircraft for 

limited uses such as when incorporated 

into smartphones or similar portable 

electronic devices that may be carried 

by air travelers? Would the Commission 

need to limit such use to the power 

levels associated with the Google Soli 

waiver, which operates at lower power 

levels than those the Commission is 

proposing for 60 GHz radars? Are there 

other narrow use cases that the 

Commission should allow? For 


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example, could the Commission’s rules 

be modified to allow an aircraft’s 

entertainment system’s in-seat display 

monitors to incorporate radars that 

could be controlled remotely by air 

travelers’ gestures? Commenters 

addressing expanded airborne use 

should provide detailed technical 

analyses, research, studies, etc. 

supporting potential recommendations 

to address whether harmful interference 

to authorized users in the band would 

result or if such systems can coexist and 

under what conditions. Would any 

adverse effects be anticipated from 60 

GHz radars operating on aircraft? Would 

the risk of harmful interference 

occurring to passive EESS be minimal 

from radars in aircraft with high RF 

attenuation characteristics? What are the 

cost and benefits of such use? 

In addition, the Commission seeks 

comment on the ramifications of 

permitting unlicensed 60 GHz radar 

operation on board aircraft with little or 

no RF attenuation characteristics, such 

as unmanned aerial systems (UAS)/ 

drones and light and personal aircraft. 

The Commission has given a limited 

waiver to Leica Geosystems AG to 

operate a radar in the 60–64 GHz band 

on board a UAS to provide visual 

inspection of structures in engineering 

and scientific applications to prevent 

the UAS from colliding with the 

structure or other fixed objects that it is 

surveying. The Commission has also 

received informal inquiries indicating 

an interest in deploying unlicensed 60 

GHz radar for applications involving, as 

an example, use on board crop-spraying 

aircraft. Commenters who support 

expanding the types of aircraft upon 

which unlicensed 60 GHz devices could 

be deployed should address how such 

use would not undermine the objective 

of preventing harmful interference to 

EESS operations in the 57–59.3 GHz 

portion of the band. 

Compliance testing of modulated CW 

(e.g., FMCW) and pulse/impulse-based 

radar devices can be complex and 

typically requires careful consideration 

to ensure the proper characterization of 

technical parameters such as transmit 

bandwidth, output power and unwanted 

emissions levels in the out-of-band and 

spurious domains. As such, the 

Commission seeks comment on 

methodologies for performing such tests 

to obtain the data necessary to 

demonstrate compliance with the 

specified technical requirements for the 

types of radars anticipated to operate 

under § 15.255 rules. For example, 

should transmission bandwidth be 

represented only by the chirp or pulse 

specifications or should it be expressed 

as a measured occupied bandwidth, 20- 

dB bandwidth, or other representation? 

Similarly, should peak power 

measurements be avoided to eliminate 

potential for inaccurate amplitude 

results due to measurement 

instrumentation desensitization? 

Measured power levels for radio 

frequency (RF) pulses that are frequency 

modulated (chirped) vary as a function 

of the bandwidth in which the 

measurement is performed; if chirped 

pulses cause RF interference, the power 

levels of the pulses in victim receivers 

will likewise vary as a function of 

receiver bandwidth. NTIA Technical 

Report TR–12–488 provides both 

heuristic and rigorous derivations of the 

relationships among chirped pulse 

parameters and the measured peak and 

average power levels of chirped pulses 

as a function of measurement 

bandwidth. These relationships may be 

best understood via a single graph 

(Figure 3) presented in this report. This 

report supplements NTIA Technical 

Reports TR–05–420, TR–10–465 and 

TR–10–466, in which the formula for 

minimum bandwidth needed for 

measurement of full peak power in 

chirped pulses is presented but not 

derived. The Commission seeks 

comment on NTIA’s technical report 

and its applicability to measurements of 

chirped signals. 

The Commission proposes to exempt 

FMCW and other similar sweptfrequency radars from the § 15.31(c) 

requirement to stop the frequency 

sweep when measuring the relevant 

technical parameters. Stopping the 

sweep is physically impractical for most 

of these types of devices and can result 

in inaccurate measurements. In 

addition, the Commission proposes to 

remove the § 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 believes that this 

requirement is superseded by the more 

recent inclusion of § 15.255(i), which 

sets out a flexible approach toward 

measurement that can be adapted more 

effectively as the technology of devices 

and test instrumentation evolve. Finally, 

the Commission proposes to specify that 

the provision of § 15.35(c) that requires 

calculating average field strength over a 

complete pulse train or 100 

milliseconds is not applicable to pulsed 

or burst radars that operate in the 60 

GHz band. This measurement 

requirement was originally designed for 

low frequency pulse-code modulated 

devices such as garage door openers and 

the Commission believes it is not 

appropriate for high frequency radars. 

The Commission seeks comment on 

these proposals. 

Initial Regulatory Flexibility Act. The 

Regulatory Flexibility Act of 1980, as 

amended (RFA), requires that a 

regulatory flexibility analysis be 

prepared for notice and comment 

rulemaking proceedings, 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 an Initial 

Regulatory Flexibility Analysis (IRFA) 

concerning potential rule and policy 

changes contained in this Notice of 

Proposed Rulemaking. 

Initial Paperwork Reduction Act 

Analysis. This Notice of Proposed 

Rulemaking does not contain potential 

new or revised information collection 

requirements subject to the Paperwork 

Reduction Act of 1995, Public Law 104– 

13. In addition, therefore, it does not 

contain any proposed 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). 

Ex Parte Rules—Permit-But-Disclose. 

This proceeding shall be treated as a 

‘‘permit-but-disclose’’ proceeding in 

accordance with the Commission’s ex 

parte rules. Ex parte presentations are 

permissible if disclosed in accordance 

with Commission rules, except during 

the Sunshine Agenda period when 

presentations, ex parte or otherwise, are 

generally prohibited. Persons making ex 

parte presentations must file a copy of 

any written presentation or a 

memorandum summarizing any oral 

presentation within two business days 

after the presentation (unless a different 

deadline applicable to the Sunshine 

period applies). Persons making oral ex 

parte presentations are reminded that 

memoranda summarizing the 

presentation must (1) list all persons 

attending or otherwise participating in 

the meeting at which the ex parte 

presentation was made, and (2) 

summarize all data presented and 

arguments made during the 

presentation. Memoranda must contain 

a summary of the substance of the ex 

parte presentation and not merely a 

listing of the subjects discussed. More 

than a one or two sentence description 

of the views and arguments presented is 

generally required. If the presentation 

consisted in whole or in part of the 

presentation of data or arguments 

already reflected in the presenter’s 

written comments, memoranda or other 

filings in the proceeding, the presenter 

may provide citations to such data or 

arguments in his or her prior comments, 


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46670 Federal Register / Vol. 86, No. 158 / Thursday, August 19, 2021 / Proposed Rules 

1 5 U.S.C. 603. The RFA, 5 U.S.C. 601–612, has 

been amended by the Small Business Regulatory 

Enforcement Fairness Act of 1996 (SBREFA), Public 

Law 104–121, Title II, 110 Stat. 857 (1996). 

2 5 U.S.C. 603(a). 

3 Id. 

4 5 U.S.C. 603(b)(3). 

5 5 U.S.C. 601(6). 

6 5 U.S.C. 601(3) (incorporating by reference the 

definition of ‘‘small-business concern’’ in the Small 

Business Act, 15 U.S.C. 632). Pursuant to 5 U.S.C. 

601(3), the statutory definition of a small business 

applies ‘‘unless an agency, after consultation with 

the Office of Advocacy of the Small Business 

Administration and after opportunity for public 

comment, establishes one or more definitions of 

such term which are appropriate to the activities of 

the agency and publishes such definition(s) in the 

Federal Register.’’. 

7 15 U.S.C. 632. 

8See U.S. Census Bureau, 2017 NAICS Definition, 

‘‘334220 Radio and Television Broadcasting and 

Wireless Communications Equipment 

Manufacturing,’’ https://www.census.gov/naics/ 

?input=334220&year=2017&details=334220. 

9 Id. 

10See 13 CFR 121.201, NAICS Code 334220. 

11See U.S. Census Bureau, 2012 Economic 

Census of the United States, Table ID: EC1231SG2, 

Manufacturing: Summary Series: General 

Summary: Industry Statistics for Subsectors and 

Industries by Employment Size: 2012, NAICS Code 

334220, https://data.census.gov/cedsci/table?text=

EC1231SG2&n=334220&tid=ECNSIZE2012.

EC1231SG2&hidePreview=false. 

12 Id. The available U.S. Census Bureau data does 

not provide a more precise estimate of the number 

of firms that meet the SBA size standard. 

memoranda, or other filings (specifying 

the relevant page and/or paragraph 

numbers where such data or arguments 

can be found) in lieu of summarizing 

them in the memorandum. Documents 

shown or given to Commission staff 

during ex parte meetings are deemed to 

be written ex parte presentations and 

must be filed consistent with § 1.1206(b) 

of the rules. In proceedings governed by 

§ 1.49(f) of the rules or for which the 

Commission has made available a 

method of electronic filing, written ex 

parte presentations and memoranda 

summarizing oral ex parte 

presentations, and all attachments 

thereto, must be filed through the 

electronic comment filing system 

available for that proceeding, and must 

be filed in their native format (e.g., .doc, 

.xml, .ppt, searchable .pdf). Participants 

in this proceeding should familiarize 

themselves with the Commission’s ex 

parte rules. 

Additional Information. For 

additional information on this 

proceeding, contact Anh T. Wride, 

anh.wride@fcc.gov, (202) 418–0577, 

Office of Engineering and Technology, 

Technical Rules Branch; or Thomas 

Struble at (202) 418–2470 or 

Thomas.Struble@fcc.gov, Office of 

Engineering and Technology, Office of 

the Chief Engineer. 

Initial Regulatory Flexibility Analysis. 

As required by the Regulatory 

Flexibility Act of 1980, as amended 

(RFA),1 the Commission has prepared 

this present Initial Regulatory 

Flexibility Analysis (IRFA) of the 

possible significant economic impact on 

a substantial number of small entities by 

the policies and rules proposed in this 

Notice of Proposed Rule Making 

(NPRM). Written public comments are 

requested on this IRFA. Comments must 

be identified as responses to the IRFA 

and must be filed by the deadlines for 

comments on the NPRM provided in the 

item. The Commission will send a copy 

of the NPRM, including this IRFA, to the 

Chief Counsel for Advocacy of the Small 

Business Administration (SBA).2 In 

addition, the NPRM and IRFA (or 

summaries thereof) will be published in 

the Federal Register.3

A. Need for, and Objectives of, the 

Proposed Rules 

The NPRM addresses issues raised in 

multiple waiver requests by various 

field disturbance sensor (FDS)/radar 

manufacturers and is partly in response 

to a recommendation from the 

Technical Advisory Committee (TAC) 

that the Commission modify the rules 

for unlicensed 60 GHz devices in a 

number of respects. The TAC 

recommends that the FCC initiates a 

rulemaking proceeding addressing 

potential areas of concern in the 60 GHz 

band by requesting comment and 

response to the following questions: (1) 

Should FCC rules allow greater radiated 

power for radar applications than 

currently permitted?; (2) Should the 

parameters for Google Soli, for which 

other entities have filed ‘‘me-too’’ 

requests, be included in the rules?; (3) 

What changes to the recent waiver 

parameters are needed to improve 

sharing with communications 

applications?; (4) Should the FCC 

require 60 GHz communication 

applications (and radar applications) to 

use a contention-based protocol?; and 

(5) Should radar applications that 

perform listen-before-talk be allowed to 

use the same power levels as 

communications applications in this 

band? 

B. Legal Basis 

The proposed action is taken pursuant 

to sections 4(i), 201, 302, and 303 of the 

Communications Act of 1934, as 

amended, 47 U.S.C. 154(i), 201, 302a, 

303. 

C. Description and Estimate of the 

Number of Small Entities to Which the 

Proposed Rules Will Apply 

The RFA directs agencies to provide 

a description of, and where feasible, an 

estimate of the number of small entities 

that may be affected by the proposed 

rules, if adopted.4 The RFA generally 

defines the term ‘‘small entity’’ as 

having the same meaning as the terms 

‘‘small business,’’ ‘‘small organization,’’ 

and ‘‘small governmental jurisdiction.’’ 5

In addition, the term ‘‘small business’’ 

has the same meaning as the term 

‘‘small business concern’’ under the 

Small Business Act.6 A ‘‘small business 

concern’’ is one which: (1) Is 

independently owned and operated; (2) 

is not dominant in its field of operation; 

and (3) satisfies any additional criteria 

established by the Small Business 

Administration (SBA).7

Radio and Television Broadcasting 

and Wireless Communications 

Equipment Manufacturing. The 

proposed rules pertain to manufacturers 

of unlicensed communications devices. 

The appropriate small business size 

standard is that which the SBA has 

established for radio and television 

broadcasting and wireless 

communications equipment 

manufacturing. This industry comprises 

establishments primarily engaged in 

manufacturing radio and television 

broadcast and wireless communications 

equipment.8 Examples of products made 

by these establishments are: 

Transmitting and receiving antennas, 

cable television equipment, GPS 

equipment, pagers, cellular phones, 

mobile communications equipment, and 

radio and television studio and 

broadcasting equipment.9 The SBA has 

established a small business size 

standard for this industry of 1,250 

employees or less.10 U.S. Census Bureau 

data for 2012 show that 841 

establishments operated in this industry 

in that year.11 Of that number, 828 

establishments operated with fewer than 

1,000 employees, 7 establishments 

operated with between 1,000 and 2,499 

employees and 6 establishments 

operated with 2,500 or more 

employees.12 Based on this data, we 

conclude that a majority of 

manufacturers in this industry are 

small. 

D. Description of Projected Reporting, 

Recordkeeping, and Other Compliance 

Requirements for Small Entities 

Unlicensed 60 GHz devices operating 

in the 57–71 GHz frequency band are 

regulated under section 15.255 of the 

Commission’s rules. The proposed rules 

in this NPRM pertain to field 

disturbance sensors (i.e., radar devices) 

that may be fixed or mobile. The 

proposed rules increase the allowable 

transmitted power levels to promote 


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Federal Register / Vol. 86, No. 158 / Thursday, August 19, 2021 / Proposed Rules 46671 

13 47 CFR 2.907. The Commission or a TCB may 

test a sample of a device to verify that it complies 

with the rules before granting approval for the 

equipment to be marketed. Examples of devices 

subject to certification include, but are not limited 

to, mobile phones; wireless local area networking 

equipment, remote control transmitters; land 

mobile radio transmitters; wireless medical 

telemetry transmitters; cordless telephones; and 

walkie-talkies. 

14 47 CFR 15.31(c). 

15 47 CFR 15.255(c)(4). 

16 47 CFR 15.35(c). 

17 5 U.S.C. 603(c)(1)–(c)(4). 

short-range radar applications without 

application restriction on operating 

environments, i.e., they may operate 

indoors or outdoors, in fixed or mobile 

applications, and be incorporated into 

any device, e.g., personal safety, 

industrial and consumer robotics, 

home/transportation automation (e.g., 

autonomous vehicles), environmental 

control, health care monitoring. 

Specifically, the NPRM: (1) Proposes to 

permit field disturbance sensors in the 

57–64 GHz band to operate with up to 

20 dBm average EIRP, 10 dBm 

transmitter conducted output power, 13 

dBm/MHz average EIRP power spectral 

density and a 10% duty cycle in every 

33 millisecond (ms) interval; (2) 

investigates the potential for mobile 

FDS devices to operate in the 61.0–61.5 

GHz band at the same 40 dBm EIRP at 

which fixed FDS devices currently are 

permitted to operate; (3) ask whether the 

Commission could permit radar devices 

that incorporate listen-before-talk, 

spectrum sensing, or other methods of 

co-existence, to operate across the entire 

57–71 GHz band at the same power 

level (i.e., 40 dBm EIRP) as currently is 

permitted for 60 GHz communication 

devices; and (4) ask whether any of the 

provisions proposed for FDS operation 

should be more broadly applied to all 

Part 15 devices operating in the 57–71 

GHz band. 

Most RF transmitting equipment, 

including 60 GHz devices, must be 

authorized through the certification 

procedure. Certification is an equipment 

authorization issued by a designated 

Telecommunication Certification Body 

(TCB) based on an application and test 

data submitted by the responsible party 

(e.g., the manufacturer or importer).13

Existing FDS devices operating under 

section 15.255 of the Commission’s 

rules are already subject to the 

Certification procedure. The NPRM does 

not propose to change the authorization 

procedure for 60 GHz devices, but it 

does seek comment on methodologies 

for performing tests to obtain the data 

necessary to demonstrate compliance 

with the technical requirements for the 

types of radars anticipated to operate 

under the modified rules. In addition, 

the NPRM proposes to exempt 

frequency-modulated continuous wave 

and other swept frequency radars from 

the section 15.31(c) requirement to stop 

the frequency sweep when measuring 

the relevant technical parameters; 14 (2) 

remove the section 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; 15 and (3) not apply the 

provision of section 15.35(c) that 

requires calculating average field 

strength over a complete pulse train or 

100 milliseconds to pulsed or burst 

radars that operate in the 60 GHz 

band.16

E. Steps Taken To Minimize the 

Significant Economic Impact on Small 

Entities, and Significant Alternatives 

Considered 

The RFA requires an agency to 

describe any significant, specifically 

small business, alternatives that it has 

considered in reaching its proposed 

approach, which may include the 

following four alternatives (among 

others): ‘‘(1) the establishment of 

differing compliance or reporting 

requirements or timetables that take into 

account the resources available to small 

entities; (2) the clarification, 

consolidation, or simplification of 

compliance and reporting requirements 

under the rule for such small entities; 

(3) the use of performance rather than 

design standards; and (4) an exemption 

from coverage of the rule, or any part 

thereof, for such small entities.’’ 17

The rule changes proposed in the 

NPRM for higher power to field 

disturbance sensors and radars would 

provide greater flexibility to 60 GHz 

device operations. As these proposed 

changes provide greater flexibility, the 

Commission does not believe they will 

have a significant negative impact on 

small entities. In fact, the proposed 

rules could benefit small entities. As 

operation of 60 GHz devices do not 

require a license, small entities are able 

to operate 60 GHz devices without the 

cost or inconvenience of obtaining a 

license. In addition, the proposed rules 

partly align the technical parameters for 

FDS/radar devices with international 

standards, which could save cost to 

small entities who would now be able 

to avoid having to create region-specific 

product designs. 

F. Federal Rules That May Duplicate, 

Overlap, or Conflict With the Proposed 

Rules 

None. 

Ordering Clauses. It is ordered, 

pursuant to the authority found in 

sections 4(i), 201, 302, and 303 of the 

Communications Act of 1934, as 

amended, 47 U.S.C. 154(i), 201, 302a, 

303, and §§ 1.407 and 1.411 of the 

Commission’s rules, 47 CFR 1.407 and 

1.411, that this Notice of Proposed 

Rulemaking is adopted, as set forth 

above. 

It is further ordered that the 

Commission’s Consumer and 

Governmental Affairs Bureau, Reference 

Information Center, shall send a copy of 

this Notice of Proposed Rulemaking, 

including the Initial Regulatory 

Flexibility Analysis, to the Chief 

Counsel for Advocacy of the Small 

Business Administration. 

List of Subjects in 47 CFR Part 15 

Communications equipment. 

Federal Communications Commission. 

Marlene Dortch, 

Secretary. 

Proposed Rules 

For the reasons discussed in the 

preamble, the Federal Communications 

Commission proposes to amend 47 CFR 

part 15 as follows: 

PART 15—RADIO FREQUENCY 

DEVICES 

■ 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. 

■ 2. Section 15.31 is amended by 

revising paragraph (c) to read as follows: 

§ 15.31 Measurement standards. 

* * * * * 

(c) Except as otherwise indicated in 

§§ 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. 

* * * * * 

■ 3. Section 15.35 is amended by 

revising paragraph (c) to read as follows: 

§ 15.35 Measurement detector functions 

and bandwidths. 

* * * * * 

(c) Unless otherwise specified, e.g., 

§§ 15.255(c), 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 


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46672 Federal Register / Vol. 86, No. 158 / Thursday, August 19, 2021 / Proposed Rules 

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. 

■ 4. Section 15.255 is amended by 

revising the introductory text of 

paragraphs (a), (c), and (c)(1), revising 

paragraph (c)(3), removing paragraph 

(c)(4), paragraphs (e) introductory text 

and (e)(2) and adding paragraph (e)(4) to 

read as follows: 

§ 15.255 Operation within the band 57–71 

GHz. 

(a) Operation under the provisions of 

this section is not permitted for 

equipment used on satellites. 

* * * * * 

(c) Radiated Power Limits. Within the 

57–71 GHz band, emission levels shall 

not exceed the following equivalent 

isotropically radiated power (EIRP): 

(1) Products other than field 

disturbance sensors shall comply with 

one of the following power limits, as 

measured during the transmit interval: 

* * * * * 

(3) Field disturbance sensors other 

than those operating under the 

provisions of paragraph (c)(2) of this 

section shall comply with the following, 

as measured during the transmit 

interval: 

(i) For field disturbance sensors that 

limit their operation to the 57–64 GHz 

frequency band, the average power shall 

not exceed 20 dBm and the average 

power spectral density shall not exceed 

13 dBm/MHz. The transmit duty cycle 

shall not exceed 10% during any 33 ms 

interval (i.e., the device shall not 

transmit longer than a total of 3.3 ms). 

(ii) For field disturbance sensors 

operating over the entire 57–71 GHz 

frequency band, the average power shall 

not exceed 10 dBm. 

* * * * * 

(e) Limits on transmitter conducted 

output power. Except as specified 

paragraph (e)(1) of this section, the peak 

transmitter conducted output power 

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) Field disturbance sensors 

operating under the provisions of 

paragraph (c)(3) of this section shall 

comply with the following: 

(i) For field disturbance sensors that 

limit their operation to the 57–64 GHz 

frequency band, the peak transmitter 

conducted output power shall not 

exceed 10 mW. 

(ii) For field disturbance sensors 

operating over the entire 57–71 GHz 

frequency band, the peak transmitter 

conducted output power shall not 

exceed 0.1 mW. 

* * * * * 

(4) Compliance measurements of 

frequency-agile field disturbance 

sensors shall be performed with any 

related frequency sweep, step, or hop 

function activated. 

* * * * * 

[FR Doc. 2021–16637 Filed 8–18–21; 8:45 am] 

BILLING CODE 6712–01–P 


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