[Federal Register Volume 85, Number 101 (Tuesday, May 26, 2020)]
[Rules and Regulations]
[Pages 31390-31414]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2020-11236]


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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Parts 0 and 15

[ET Docket No. 18-295 and GN Docket No. 17-183; FCC 20-51; FRS 16729]


Unlicensed Use of the 6 GHz Band

AGENCY: Federal Communications Commission.

ACTION: Final rule.

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SUMMARY: In this document, the Commission adopts rules designed to 
optimize unlicensed access by authorizing two types of unlicensed 
operations in the 6 GHz band while also protecting incumbent services 
so that they continue to thrive in the band. The Commission is 
authorizing unlicensed standard-power access points that will operate 
under the control of an automated frequency coordination system in 
portions of the 6 GHz band. The Commission is also opening the entire 6 
GHz band for unlicensed indoor low power access points. In addition, 
the Commission will permit unlicensed client devices to communicate 
with both the standard-power and low-power access points. These rules 
will provide opportunities for unlicensed operations to use up to 320-
megahertz channels to expand capacity and increase performance. This 
forward-looking action anticipates the next generation of the 
unlicensed devices and advances the U.S.'s role as an innovator and 
global spectrum policy leader.

DATES: Effective July 27, 2020.

ADDRESSES: Federal Communications Commission, 445 12th Street SW, 
Washington, DC 20554.

FOR FURTHER INFORMATION CONTACT: Mr. Nicholas Oros of the Office of 
Engineering and Technology, Policy and Rules Division, at (202) 418-
0636, or [email protected].

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Report 
and Order, ET Docket No. 18-295 and GN Docket No. 17-183, FCC 20-51, 
adopted April 23, 2020 and released April 24, 2020. The full text of 
this document is available for public inspection and copying during 
normal business hours in the FCC Reference Center (Room CY-A257), 445 
12th Street SW, Washington, DC 20554, or by downloading the text from 
the Commission's website at https://www.fcc.gov/document/fcc-opens-6-ghz-band-wi-fi-and-other-unlicensed-uses-0. 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).

Synopsis

Unlicensed Use of the 6 GHz Band

    1. The Commission adopts rules designed to optimize unlicensed 
access to the 6 GHz band while also protecting incumbent services so 
that they continue to thrive in the band. In doing so, the Commission 
accounts for the concerns raised by parties representing the various 
incumbent services that operate in the 6 GHz band, weighs the various 
technical studies presented by proponents of unlicensed operations as 
well as representatives of incumbent services, and addresses how the 
rules the Commission adopts will enable unlicensed operations to 
operate in the 6 GHz band and protect the various incumbent services 
that operate in the band.

Standard-Power Operations in U-NII-5 and U-NII-7 Bands

    2. The Commission adopts rules to permit standard power unlicensed 
operations in the U-NII-5 (5.925-6.425 GHz) and U-NII-7 (6.525-6.875 
GHz) bands to operate outdoors or indoors with similar power levels as 
permitted for unlicensed portions of the 5 GHz band through use of an 
automated frequency coordination (AFC) system to protect incumbent 
fixed microwave operations from harmful interference. Specifically, the 
Commission authorizes standard-power access points to operate in these 
bands at power levels up to 36 dBm EIRP (PSD of 23 dBm/MHz EIRP), and 
client devices to operate at up to 30 dBm EIRP (PSD of 17 dBm/MHz 
EIRP). The rules the Commission adopts for these unlicensed device 
operations will protect incumbent fixed microwave, radio astronomy, and 
fixed-satellite operations, add much needed capacity to meet the 
rapidly increasing demands of the wireless industry, and promote 
innovation and investment in new wireless unlicensed technologies. To 
protect incumbent fixed microwave operations from harmful interference, 
unlicensed access to these bands is only permitted on frequencies and 
locations determined by an AFC system based on the exclusion zones that 
it establishes. The Commission also protects certain radio astronomy 
observatories through the AFC system. Finally, in affirming the 
Commission's tentative conclusion that the AFC system is not necessary 
to protect incumbent fixed satellite service operations, the Commission 
also adopts a restriction on unlicensed standard-power access point to 
prevent them from pointing toward the space station receivers.

AFC-Based Access To Protect Fixed Microwave Services

    3. Consistent with the framework proposed in the Notice, the AFC 
mechanism, combined with the technical and operational rules that the 
Commission adopts, will protect incumbent fixed microwave operations 
from the potential of harmful interference from unlicensed standard-
power operations in the U-NII-5 and U-NII-7 bands. As noted by the 
Commission, the use of an automated system to control access to 
spectrum is not new. The Commission has previously used this approach 
to protect television reception from unlicensed white space devices in 
the TV bands and to protect satellite earth stations and government 
radars from devices of the Citizens Broadband Radio Service in the 
3550-3700 MHz band. A properly designed AFC system in the U-NII-5 and 
U-NII-7 bands will protect incumbent operations, though they often 
differ on particular design and features of that system.
    4. The AFC-based system for permitting unlicensed standard power 
operations in the 6 GHz bands will consist of several components which, 
when taken together, will determine the specific exclusion zones that 
will protect incumbent operations. These

[[Page 31391]]

components include (1) the framework, design, and operation of AFC 
system; (2) the operational requirements that the Commission 
establishes regarding standard-power access points (e.g., geolocation 
capabilities, antenna-related restrictions); and (3) the interference 
protection parameters that protect the incumbent fixed service 
operations.

The AFC System Framework and Database

    5. Centralized approach. The Commission requires the AFC to use a 
centralized model where each standard-power access point remotely 
accesses an AFC to obtain a list of available frequency ranges in which 
it is permitted to operate and the maximum permissible power in each 
frequency range. This is consistent with the centralized model the 
Commission has employed in other contexts, will facilitate Commission 
oversight of AFC operations, and reduces design complexity. Because the 
Commission is concerned that allowing both architectures (centralized 
and de-centralized) could create problematic or unforeseen 
complications in operational management of AFC systems and devices and 
thereby could delay unlicensed deployment in this band, it declines to 
permit use of a dual AFC architecture as some parties have suggested.
    6. Use of ULS for information on incumbent operations. the 
Commission requires that the AFC system rely on the Commission's 
Universal Licensing System (ULS) for fixed microwave link data when 
calculating and establishing the exclusion zones to protect those 
microwave links from harmful interference. The ULS is the official 
licensing database for microwave links in the U-NII-5 and U-NII-7 bands 
and contains extensive technical data for site-based licenses including 
transmitter and receiver locations, frequencies, bandwidths, 
polarizations, transmitter EIRP, antenna height, and the make and model 
of the antenna and equipment used. Thus, the ULS contains the 
information necessary for AFC systems to protect fixed service links. 
To ensure that AFC systems have the most recent information on fixed 
service links, the Commission requires AFC systems to download the 
database on a daily basis.
    7. The Commission recognizes the concerns of some parties that 
information used by the AFC systems must be accurate and up-to-date, 
and notes that there may currently be some inaccurate or incomplete 
data in the ULS database. Because ULS is the official Commission 
compendium of license records, licensees are obligated under the terms 
of their licenses to keep their information filed with the Commission 
current and complete. Thus, licensees have the responsibility, as well 
as significant incentive, to maintain the continued accuracy of data in 
the ULS to ensure that they are protected from harmful interference not 
only from new unlicensed devices, but also from new fixed microwave 
links that may access the band. To the extent licensees determine that 
their actual operations differ from the Commission's licensing records, 
they should modify those records to ensure they are properly protected 
from harmful interference from any other spectrum users, and the 
Commission directs the Wireless Telecommunications Bureau to issue a 
public notice reminding such licensees of the importance of maintaining 
accurate information in that system.
    8. Microwave links may begin operation prior to obtaining a license 
so long as certain criteria are met, such as completing successful 
frequency coordination and filing an application that appears in the 
ULS as pending. Because such a filing may indicate that a new station 
is operational, or soon will be, the Commission requires the AFC system 
to protect pending as well as granted facilities. In addition, 
temporary fixed microwave links may be authorized by a blanket 
authorization, in which case the licensee is not required to obtain 
approval from the Commission prior to operating at specific locations 
or report the technical details of their operation to the Commission. 
Because the AFC system must have knowledge of the location of temporary 
fixed links in order to protect them from harmful interference, the 
Commission requires the operators of temporary fixed stations to 
register the details of their operations (transmitter and receiver 
location, antenna height, antenna azimuth, antenna make and model, 
etc.) in the ULS prior to transmission if they desire to be protected 
from potentially receiving harmful interference from standard-power 
access points in the U-NII-5 and U-NII-7 bands. The capability to 
register temporary fixed links does not currently exist in the ULS. 
That functionality will be announced by Public Notice once developed. 
Because temporary fixed links are not mobile and intended to operate at 
a specified location for up to a year, the Commission does not believe 
this registration requirement poses a significant burden on licensees.
    9. Information on microwave operations in border areas near Canada 
and Mexico. As required by international agreements, and consistent 
with actions regarding white spaces and the CBRS, the Commission 
requires the AFC to protect microwave operations in Canada and Mexico 
near the United States border. The Commission recognizes that the ULS 
does not contain information on microwave operations in these 
countries. The Commission therefore intends to work with the 
governments of Canada and Mexico to obtain information on microwave 
systems in those countries and a method for providing it to AFC 
operators for incorporation into their systems.
    10. Information on location and antenna height of standard-power 
access points. The AFC system also will make use of data concerning the 
location and antenna height of standard-power access points when 
calculating the availability of frequencies and channels of operations. 
The Commission establishes particular operational requirements for 
access points that ensure the accuracy of this data.
    11. Use of specified interference protection parameters. The AFC 
system will apply the specified interference protection parameters 
established in this Order to protect fixed microwave operations from 
harmful interference. These include use of specified propagation models 
and a conservative interference protection criterion when calculating 
exclusion zones, and the methodology for addressing adjacent channel 
operations.
    12. Determining frequency and channel availability based on 
unlicensed device power levels. The Commission requires that the AFC 
have the capability to determine frequency availability at the maximum 
permissible power of 36 dBm for standard-power access points, as well 
as at lower power levels. Because the minimum required separation 
distance from a fixed service receiver, among other factors, is a 
function of the access point power, lower power devices do not have to 
meet as large a separation distance to provide the same level of 
protection as higher power devices. This means that more spectrum may 
be available for access points that operate with power levels below the 
maximum, especially in congested areas where spectrum is more heavily 
used by the fixed microwave services. This action is consistent with 
the Commission's white space rules in which white space devices 
operating at power levels less than the maximum have shorter required 
separation distances from protected services, and the white space 
database provides devices with a list of

[[Page 31392]]

available frequencies and the maximum permissible power on each.
    13. The Commission requires that the AFC system be capable of 
determining frequency availability in steps of no greater than 3 dB 
below the maximum 36 dBm permissible EIRP, down to a minimum level of 
21 dBm. The Commission believes 3 dB is an appropriate step size 
because it is large enough to be significant (i.e. a factor of two) and 
will allow the AFC to determine frequency availability at multiple 
power levels so a device can select its optimum frequency and power 
level combination. The Commission's requirement that an AFC only 
consider power levels as low as 21 dBm is predicated on the expectation 
that outdoor access points will generally operate at the higher power 
levels to maximize coverage area or throughput or both. However, 
because certain situations or applications may not need that much 
power, there may be a need for AFCs to evaluate additional power 
levels. The Commission will not preclude AFC operators from determining 
frequency availability at additional power levels, e.g., below 21 dBm 
or in smaller step sizes; it simply establishes minimum AFC performance 
requirements. Consistent with the white space rules, the AFC will 
provide a list of available frequencies and power levels to standard-
power access points but will not select the frequency or control the 
power level of a device. Rather, each access point will select its 
operating frequency and power level from the list provided by the AFC.

Operational Requirements for Access Points

    14. The AFC system requires a device's geographic coordinates--
along with the accuracy of those coordinates--and the device's antenna 
height above ground, in order to determine which frequencies are 
available for use at its location.
    15. Incorporated geo-location. The Commission requires all 
standard-power access points to include a geo-location capability to 
determine their geographic coordinates, rather than relying on a 
professional installer to determine them. Additionally, an incorporated 
geo-location capability provides a means for a device to automatically 
re-establish its coordinates if they are lost or altered due to a power 
outage or equipment reboot.
    16. The Commission requires a device's geo-location capability to 
determine its location uncertainty and report it to the AFC system, 
which will use this information to determine the minimum required 
separation distances from fixed service receivers. The Commission also 
requires that it be determined, in meters, with 95% confidence level, 
which is consistent with the rules for white space devices which 
operate with similar geo-location requirements to those the Commission 
adopts for AFC controlled standard-power access points. The 
Commission's experiences with this rule confirms that it reliably 
ensures protection against harmful interference, at reasonable cost.
    17. The Commission recognizes that geo-location technologies such 
as GPS do not work at locations where satellite signals are blocked by 
obstructions such as tall buildings and trees, or deep within 
buildings. To ensure that standard power access points can accurately 
determine their coordinates and provide them to the AFC in these 
situations, without the need for professional installation, the 
Commission provides additional flexibility for manufacturers and device 
operators by making provisions for standard-power access points that 
operate in locations where an incorporated geo-location capability may 
not work. The Commission allows standard-power access points to obtain 
their geographic coordinates through an external geo-location source 
when they are used at locations where an internal geo-location 
capability does not function. The Commission also allows an external 
geo-location source to be connected to an access point through either a 
wired or a wireless connection and will allow a single geo-location 
source to provide location information to multiple access points. The 
Commission requires that an external geo-location source be connected 
to an access point using a secure connection to ensure that only an 
external geo-location source approved for use with a device provides 
geographic coordinates to that device. Additionally, the Commission 
allows the use of extender cables to connect a remote receive antenna 
to a geo-location receiver within a fixed device. In cases where 
equipment uses a remote geo-location source, the separation distance 
between the access point transmit antenna and geo-location source must 
be included in the location uncertainty reported to the AFC system. 
This requirement will be enforced through the equipment certification 
process. Based on the Commission's experience, it believes these 
provisions will increase the manufacturers' flexibility to develop 
devices that can be used in a wide variety of locations while ensuring 
that devices accurately determine their location and report it to the 
AFC to prevent harmful interference to protected services.
    18. Considering the geo-location requirements, the Commission is 
not requiring professional installation. It is not necessary because 
manufacturers can incorporate a variety of location technologies into 
their devices; many of these, such as GPS, are widely available at low 
cost. Further, requiring professional installation of all standard-
power access points would be burdensome and that requiring devices to 
incorporate automatic geo-location will ensure that the information 
provided to the AFC system is accurate.
    19. Antenna height above ground. For the AFC to accurately 
calculate exclusion zones to protect fixed service receivers, it 
requires the antenna height above ground of a standard-power access 
point. Consistent with the rules for white space devices, the 
Commission permits this information to be provided to the AFC either 
automatically by the device, or manually by the installer or operator 
of the device but does not require it to be determined by a 
professional installer.
    20. Because automated geo-location methods such as GPS may not 
accurately provide height information in all cases, the Commission 
allows a device installer to manually determine the antenna height 
above ground and provide it to the AFC. As the Commission notes with 
respect to white space devices, installers with simple measuring 
equipment should be able to accurately determine antenna height above 
ground. However, because improvements in technology in the future could 
enable devices to automatically determine their antenna height above 
ground with more precision, there is also the option for standard-power 
access points to automatically do so. Industry groups are expected to 
work on developing methods for automatic height determination that 
could be used for standard-power access points or other applications 
where the antenna height above ground must be known.
    21. Frequency availability re-check interval. The Commission 
requires a standard-power access point to contact an AFC system at 
least once per day to obtain the latest list of available frequencies 
at its location. Once per day is an appropriate re-check interval 
because the ULS, from which the AFC system will obtain data, is updated 
on a daily basis. The Commission disagrees with suggestions that of a 
30-day re-check interval be instituted. While the likelihood is low 
that a new microwave link will become operational on any given day at a 
given location, when 6

[[Page 31393]]

GHz devices are widely deployed there will be situations where new 
microwave links are licensed in the vicinity of co-channel standard-
power access points. To ensure that an unlicensed device quickly ceases 
operation on a frequency that becomes licensed for a microwave link 
near its location, standard-power access points are required to re-
check their frequency availability on a daily basis, i.e., the same as 
the ULS update interval.
    22. The Commission recognizes that there may be situations when an 
AFC system is temporarily unavailable due to a sustained power loss, an 
internet outage, or other circumstances that disrupt a device's ability 
to contact an AFC system. Consistent with the Commission's actions in 
other proceedings, an access point that cannot contact the AFC system 
during any given day is permitted to continue operating until 11:59 
p.m. of the following day at which time it must cease operations until 
it re-establishes contact with the AFC system and re-verifies its list 
of available frequencies. The Commission does not believe that ais one-
day grace period is not likely to result in harmful interference to 
fixed service links because an access point being unable to contact the 
AFC system for a day is likely to be a relatively infrequent 
occurrence, and the probability that it will occur at the same time in 
the same place where a new microwave link commences operation is low.

Designating AFC Operators

    23. Operator approval and system certification process. Consistent 
with the Commission's actions regarding white spaces and the CBRS, the 
Commission directs the Chief of the Office of Engineering and 
Technology (OET) to designate AFC system operators and oversee 
operation of their systems.
    24. OET will designate AFC operators using a multi-stage review 
process similar to that it used for designating white space database 
and SAS administrators. As the first step, OET will issue a public 
notice inviting prospective AFC system operators to submit proposals 
describing how their systems would comply with all Commission AFC 
rules. The public will have an opportunity to review and comment on 
these AFC system proposals. OET will conditionally approve applicants 
that demonstrate that their proposed systems would comply with all AFC 
requirements. Applicants that receive a conditional approval will then 
be required to provide a test system that will be subject to a public 
trial period to provide interested parties an opportunity to check that 
it provides accurate results. This trial period will include thorough 
testing, both in a controlled environment (e.g., lab testing) and 
through demonstration projects (e.g., field testing).
    25. The Commission encourages formation of a multi-stakeholder 
group that will address issues specific to technical and operational 
issues associated with the AFC system, and intends to work with 
industry stakeholder groups as necessary to develop appropriate 
procedures for thoroughly testing AFC systems prior to use. The 
Commission will not grant final approval for an AFC system operator to 
begin providing service until after the operator satisfactorily 
demonstrates that standard-power access points can operate under the 
control of its system without causing harmful interference to fixed 
wireless services.
    26. Multiple AFC Operators. As proposed in the Notice and 
consistent with commenters' support and existing rules for white spaces 
and CBRS multiple AFC operators may be designated. As the Commission 
previously noted in regard to white spaces databases, this would 
prevent a single party from obtaining monopoly control over the AFC 
systems, could provide an incentive for AFC system operators to provide 
additional services beyond those required by the rules, and is more 
likely to result in lower costs to consumers.
    27. The Commission permits AFC functions, such as a data 
repository, registration, and query services, to be split among 
multiple entities, as is done for white spaces and the CBRS. No parties 
commented on this specific issue. This approach will allow greater 
flexibility in AFC system design and potential cost savings by allowing 
multiple operators to share the costs of running parts of an AFC 
systems. However, to ensure that the Commission can effectively oversee 
the AFC system operation, it requires that entities designated as AFC 
system operators be held accountable for all aspects of system 
administration, including any functions performed by third parties.
    28. Term of AFC Designation. To ensure a stable operating 
environment for standard-power access points and consistent with both 
the white space and CBRS rules, the Commission adopts a five-year term 
which, at the Commission's discretion, may be renewed. Similar to the 
requirements for the white space database and SAS administrators, in 
the event an AFC system operator does not wish to continue to provide 
services, or if its term is not renewed, the system operator will be 
required to transfer its database along with the information necessary 
to access the database to another designated AFC system and will be 
permitted to charge a reasonable fee for the transfer of this 
information. Transferring this information assures operational 
continuity for existing devices; otherwise in the event an AFC 
discontinues service, devices would be denied operating frequencies and 
cut-off from providing services until it established a connection to a 
new database. This action allows that new connection to occur 
automatically.
    29. The Commission disagrees that it would be burdensome for an AFC 
operator to transfer its registration data to another AFC system 
operator since the data that must be transferred (e.g., location, 
antenna height, device FCC ID and serial number) is relatively simple. 
The Commission also adopts the proposal that an AFC system operator 
must provide a minimum of 30 days' notice to the Commission when it 
plans to cease operation. Because standard-power access points must be 
able to access an AFC in order to operate, the Commission does not 
believe that the it should designate AFC system operators that could 
cease operation at any time with no notice as that could leave users 
with equipment that ceases operating unexpectedly.
    30. Fees. Consistent with the rules for white space database and 
CBRS SAS administrators and as supported in the record, the Commission 
permits AFC operators to charge fees for the provision of service. 
Because the Commission is allowing multiple AFC operators to be 
designated, the Commission believes that competition among them will 
serve to keep fees reasonable and will allow for multiple business 
models that could benefit consumers, e.g., device manufacturers or a 
trade association could fund an AFC system as part of its business and 
no individual transaction fees would be charged. However, as with white 
space databases and the CBRS SAS, the Commission permits parties to 
petition the Commission to review fees and require changes to the fees 
if they are found to be excessive.
    31. AFC to AFC synchronization requirements. The Commission 
concludes that, under the AFC system, there is no need to require AFC 
systems to synchronize their data with each other. Unlike white space 
database systems that must accept and share registration information 
from protected entities, e.g., cable headends and

[[Page 31394]]

licensed wireless microphone operators, that cannot be obtained from 
Commission databases, AFC systems will obtain their data on protected 
entities from a single source (the ULS). Therefore, there will be no 
need for AFC operators to synchronize protected entity information 
between different systems as NAB suggests. Additionally, because the 
Commission is not requiring AFC systems to consider aggregate 
interference from multiple standard-power access points when 
determining frequency availability, there is no need for the AFC 
systems to share information about registered standard-power access 
points.

Interference Protection Analyses and Parameters

    32. The Commission protects fixed microwave operations from harmful 
interference by using an AFC system that establishes location and 
frequency-based exclusion zones for standard-power unlicensed devices 
around fixed microwave receivers operating in the U-NII-5 and U-NII-7 
bands. Under this AFC system, individual unlicensed devices will not be 
permitted to operate on certain frequencies within the exclusion zone. 
Below, the Commission discusses technical parameters that the AFC 
system will use to calculate these exclusion zones.
    33. Propagation models. Evaluating potential harmful interference 
from U-NII-5 and U-NII-7 unlicensed standard-power access point devices 
depend on the propagation models assumed for both fixed microwave 
signals and unlicensed devices. The propagation model that the 
Commission adopts will, in turn, be used by the AFC system as one of 
the factors when determining the exclusion zones.
    34. The Commission believes an approach which combines different 
propagation models is most appropriate for evaluating necessary 
separation distances of 6 GHz unlicensed devices from fixed microwave 
links. More specifically, because propagation models have been 
developed to accommodate a variety of environments and over various 
distances, the Commission finds that using a combination of models 
optimized for the varying propagation conditions that will be 
encountered is the best way to balance unlicensed device access and 
incumbent protection in the 6 GHz band. That is, it is most appropriate 
to use a set of propagation models keyed to specific separation 
distances between an unlicensed device and a fixed service receiver to 
determine appropriate exclusion zone size. Under this approach, the 
Commission uses the free-space model for short distances, where it 
accurately predicts signal path loss, the WINNER II for medium 
distances, and the Irregular Terrain Model (ITM) for longer distances 
to more realistically account for terrain and clutter losses.
    35. Under our general approach, the Commission finds that for 
separation distances of 30 meters or less, the free space pathloss 
model is the appropriate model. Commenters generally assumed that 6 GHz 
unlicensed devices would not be placed within 30 meters of a microwave 
receiver and thus, did not suggest a propagation model for such short 
distances. Because, the potential for a direct line-of-sight between an 
unlicensed device and a microwave receiver is greatest at short 
distances, the Commission adopts the free space pathloss model for 
distances less than 30 meters. This model generates the greatest 
possible path loss to account for the possibility of direct line-of-
sight from a standard-power access point to a microwave receiver. The 
free space pathloss model though theoretically simple, has a limited 
range of applicability because it ignores environmental clutter and 
over long distances can result in extremely conservative calculations 
that under predict the amount of actual path loss.
    36. Incumbents generally recommend use of free space propagation 
model for all separation distances regardless of environment, while 
proponents of unlicensed operations advocate use of a combination of 
propagation models that specifically consider the propagation 
environment. Beyond 30 meters and up to one kilometer from an 
unlicensed device to a microwave receiver, the Commission finds that 
the most appropriate propagation model is the Wireless World Initiative 
New Radio phase II (WINNER II) model for urban, suburban, and rural 
environments. At these distances, the WINNER II model accounts for 
obstructions by urban and suburban clutter, which the free space model 
does not. The Commission makes this decision recognizing that the 
WINNER II model is one of the most widely used and well-known channel 
models in the world and was developed from measurements conducted by 
the WINNER organization, as well as results from academic literature 
and used by several commenters for analyses submitted to the record. 
The Commission requires the use of site-specific information, including 
buildings and terrain data, for determining the line-of-sight/non-line-
of-sight path component in the WINNER II model where this information 
is available. For evaluating paths where this data is not available, 
the Commission requires probabilistic combining of the line-of-sight 
and non-line-of-sight path into a single path-loss. When site-specific 
information regarding line-of-sight/non-line-of-sight is not available 
then path losses of line-of-sight(LOS) and non-line-of-sight(NLOS) 
paths can be combined into a single loss using the following formula: 
Path-loss (L) = [Sigma]i P(i) * Li = 
PLOS * LLOS + PNLOS * 
LNLOS, where PLOS is the probability of line-of-
sight, LLOS is the line-of-sight path loss, PNLOS 
is the probability of non-line-of sight, LNLOS is the non-
line-of-sight path loss, and L is the combined path loss. The WINNER II 
path loss models include a formula to determine PLOS as a 
function of antenna heights and distance. PNLOS is equal to 
(1-PLOS). Using the WINNER II propagation model for these 
separation distances will provide the best prediction of actual 
pathloss between unlicensed devices and fixed service receivers as it 
accounts for environmental information not considered in the free space 
model.
    37. The Irregular Terrain Model is a propagation model that 
specifically takes into account the effects of terrain on radio 
propagation but does not include clutter losses. The model accounts for 
transmission loss relative to free space loss for distances between 1 
km and 2,000 km. For separation distances greater than one kilometer, 
commenters suggest that the Irregular Terrain Model combined with a 
clutter model depending on the environment is the most appropriate 
model. The Commission agrees. Consistent with Commission use of 
propagation models in other proceedings, the Commission requires use of 
1 arc-second digital elevation terrain data and, for locations where 
such data is not available, the Commission requires use of the most 
granular digital elevation terrain data available. To account for the 
effects of clutter, such as from buildings and foliage, the Commission 
requires that the Irregular Terrain Model be combined with a 
statistical clutter model ITU-R P.2108 for urban and suburban 
environments, and ITU-R P.452-16 clutter model for rural environments. 
The appropriate clutter category that most closely represents the local 
morphology should be selected when using ITU-R P.452-16. However, if 
detailed local information is not available, the Commission believes 
the ``Village Centre'' clutter category should be used as a default 
because access points will generally be installed in or on buildings 
(i.e., in a village) and this category most closely represents that 
morphology. The Commission specifies

[[Page 31395]]

the Irregular Terrain Model because it has been widely available and 
accepted since the early 1980s, has been used by the Commission for 
interference prediction in other proceedings, is supported by the 
record, and in its experience has served reliably as a propagation 
model. The Irregular Terrain Model is the propagation model currently 
used to determine spectrum availability in the spectrum access systems 
(SAS) used to manage access to the 3550-3700 MHz band in the Citizens 
Broadband Radio Service.
    38. Interference protection criterion. The Commission requires the 
prescribed AFC system to use an I/N metric rather than C/I for 
determining the exclusion zones. The I/N ratio was used by most 
commenters in their analyses as the interference protection metric and 
is more straightforward to implement, and thus is more consistent with 
one of our major goals for the AFC system--simplicity of 
implementation. Use of a C/I ratio would entail additional 
implementation complexities. In particular, calculating the C/I ratio 
would require calculating the power arriving at the microwave receiver 
from its corresponding transmitter in addition to estimating the signal 
level from the access point. This would require knowledge of the 
microwave link characteristics including the instantaneous transmitted 
power as well as the modulation and coding scheme used, which is 
information that is not available in ULS.
    39. As for the specific interference protection criterion, the 
Commission specifies a I/N of -6 dB I/N. By specifying that AFC 
exclusion zone calculations will be based on this particular 
interference protection criterion, the Commission is taking a 
conservative approach to ensure that the potential for harmful 
interference is minimized and important fixed microwave services in the 
6 GHz band are protected. The Commission is not, however making a 
determination that any signal received with an I/N greater than -6 dB 
would constitute ``harmful interference.'' No commenter provides 
technical justification for using a particular I/N level as the actual 
level necessary to protect fixed microwave receivers against harmful 
interference. In determining to apply -6 dB I/N as the interference 
protection criterion, the Commission does not find the need to 
establish a specific industry multi-stakeholder group to establish the 
appropriate metric on this issue, as some have suggested.
    40. Aggregate interference. The Commission did not propose nor find 
that there is any need to consider the effect of aggregate interference 
from multiple access points to point-to-point microwave links. The risk 
of interference from large numbers of standard power access points 
would not be due to signal aggregation from multiple unlicensed 
devices, but from a single standard-power access point in or near the 
main beam of a microwave link receive antenna with little or no 
intervening clutter. In the event that two or more access points could 
cause interference to the same microwave receiver, the signal from the 
nearest would dominate over the others and make the others irrelevant 
to the analysis. The Commission does not require the AFC to consider 
aggregate interference when determining exclusion zones.
    41. Adjacent channel protection. Although the Commission believes 
that the risk of adjacent channel interference to fixed service 
microwave receivers is low, the Commission takes a conservative 
approach to enabling new unlicensed devices in the 6 GHz band. Thus, in 
addition to the AFC calculating a co-channel exclusion zone, the 
Commission also requires it to determine an adjacent channel exclusion 
zone. The adjacent channel exclusion zone defines a zone under which 
any standard power access point is prevented from operating adjacent to 
an FS receiver within one-half channel bandwidth of the access point. 
The Commission expects these adjacent channel zones will be small and 
not significantly impact the amount of spectrum available to unlicensed 
devices at any given location. Also, because the AFC will need to 
calculate co-channel exclusion zones for all nearby fixed service 
stations, the incremental burden to also calculate adjacent channel 
exclusion zones should be minimal. To this end, the Commission requires 
the AFC to determine an adjacent channel exclusion zone based on the 
out-of-band emission mask the Commission adopts for unlicensed devices 
which is designed to keep energy outside an unlicensed device's 
operating channel to low levels and the same protection criterion used 
to determine co-channel exclusion zones; that is the I/N ratio must be 
calculated to be -6 dB or less. This requirement will protect fixed 
microwave receivers from harmful interference due to unlicensed devices 
out-of-band emissions.

Other AFC System Issues

    42. Security Issues. The Commission requires that AFC systems and 
standard-power access points employ protocols and procedures to ensure 
that all communications and interactions between the AFC and standard-
power access points are accurate and secure and that unauthorized 
parties cannot access or alter the database or the list of available 
frequencies and power levels sent to an access point. These 
requirements are similar to those adopted for the white space database 
and the Citizens Broadband Radio Service spectrum access system.
    43. The Commission is not mandating specific security models. 
Instead, the Commission requires AFC system operators to use advanced 
security standards and demonstrate that their systems contain 
communication and information security features during the AFC system 
certification process. These security protocols will be subject to the 
Commission's review and approval. The Commission anticipates that an 
industry-wide multi-stakeholder group will take the lead on this 
process and develop security protocols that AFC administrators may 
consider for their operation, subject to Commission review and 
approval. The Commission also expects that security models will be 
updated as needed to reflect state-of-the-art protection against new 
security threats. The Commission will review any modifications or 
updates in the security protocols AFC system operators or a multi-
stakeholder group proposes to implement.
    44. AFC device registration. To further ensure the AFC ecosystem 
integrity, the Commission requires standard-power access points to 
register with the AFC system when requesting a list of available 
operating frequencies and power levels. Although the Commission 
recognizes that the AFC system would be simpler without a registration 
requirement, device registration provides another layer of protection 
by ensuring only authorized devices access the spectrum and by easing 
the process of mitigating harmful interference if it occurs. Because 
the registration information would be automatically provided by the 
access point or network proxy to the AFC system, the registration 
process will require little effort by the access point user.
    45. To register, a standard-power access point will be required to 
provide the AFC system--in addition to the technical information 
described above with the device's FCC identifier (FCC ID), and its 
serial number. Although the FCC ID or the access point's serial number 
are not required to calculate frequency availability, the AFC will use 
the information for two purposes. First, the information will be used 
to authenticate the device, to ensure that no rogue devices are 
operating in the

[[Page 31396]]

band. The AFC will verify the device's FCC ID by accessing the 
Commission's Equipment Authorization System. The AFC can retrieve the 
FCC IDs of certified standard-power access points from the Commission's 
equipment authorization database using an Application Program Interface 
(API) or another method and determine whether the FCC ID provided by a 
device during registration is valid. Access to the equipment 
authorization database and extracting FCC IDs is a process that is used 
by the CBRS SAS and white space data administrators. Second, the 
information will be used for interference mitigation and enforcement 
purposes to identify the source if harmful interference were to occur. 
In addition, the Commission requires that AFC systems have the capacity 
to deny spectrum access to a particular registered standard-power 
access point upon requests by the Commission, in the event of harmful 
interference caused by a particular device or type of device. The 
Commission also requires that AFC operators implement procedures to 
respond to requests from Commission personnel for information stored or 
maintained by the AFC, and that they establish and follow protocols to 
comply with enforcement instructions from the Commission, including 
discontinuance of access point operations in designated geographic 
areas. These requirements ensure that the Commission is able to 
ascertain the accuracy of information stored in the AFC, obtain 
information necessary to enforce the Commission's rules, and ensure 
that access points that do not comply with the rules are shut down in a 
timely manner.
    46. The Commission encourages formation of a multi-stakeholder 
group that would include representatives of unlicensed equipment 
manufacturers, equipment users and point-to-point microwave providers 
to develop additional procedures to resolve interference concerns. 
Regardless of the processes that stakeholders may develop for 
addressing interference, consistent with statute the Commission is the 
final arbiter regarding cases of harmful interference.
    47. Individual standard-power access points will not be required to 
interface with the AFC system if the required registration data is 
communicated by a proxy device or network control device. The network 
management device may be the point of interface with the AFC system for 
multiple access points. In other words, the registration information 
can be provided directly and individually by a single standard-power 
access point or by a network proxy representing multiple devices 
operating on the same network. The access point or its proxy must 
register with the AFC system via any communication link, wired or 
wireless, outside the U-NII-5 and U-NII-7 bands. The AFC system will 
then communicate back a list of permissible frequency range(s) and the 
maximum power in each range for standard-power access point operation. 
In the case of a proxy, each access point must still provide its exact 
location and will obtain a set of available frequencies for that 
location.
    48. The Commission requires the AFC system to store registered 
information in a secure database until an access point ceases operation 
at a location, which the Commission defines as a device not contacting 
the AFC to verify frequency availability information for more than 
three months. This requirement will ensure that the AFC database does 
not become cluttered with entries for devices that are no longer being 
used. To ensure the users' privacy, the AFC system will use the 
registered data and any other access point operational information only 
to protect incumbents and for potential interference mitigation.

Radio Astronomy Observatories

    49. Incumbent operations in the U-NII-7 band include several radio 
astronomy observatories, located in remote areas, that observe methanol 
spectral lines between 6.6500-6.675.2 GHz. The Commission recognizes 
the importance of these observations to the scientific community and 
will adopt exclusion zones to protect them from interference over the 
specified frequencies. In so doing, the Commission notes that there is 
no radio astronomy allocation for these observations requiring that 
they be protected from interference; the radio astronomy allocation 
table footnote merely provides that ``all practicable steps shall be 
taken to protect the radio astronomy service'' in this band from 
harmful interference). As these observatories are located in remote 
areas the Commission does not believe excluding standard-power access 
points from this 25.2 megahertz of spectrum in these areas will be a 
significant burden on unlicensed operations. The AFC system will 
determine the size of the exclusion zones by the radio line-of-sight 
distance between the radio astronomy antenna and the unlicensed access 
point. The radio line-of-sight should be determined using \4/3\ earth 
curvature using the following formula dkm_los = 4.12*(sqrt(Htx) + 
sqrt(Hrx)), where Htx and Hrx are the heights of the unlicensed access 
point and radio astronomy antenna in meters above ground level, 
respectively.

Fixed-Satellite Services

    50. The Commission adopts rules supporting the Commission's 
tentative conclusion that the AFC system is not needed to protect 
incumbent fixed-satellite operations from standard power access point 
operations in the U-NII-5 and U-NII-7 bands. Considering that the 
satellites receiving in these sub-bands are limited to geostationary 
orbits, approximately 35,800 kilometers above the equator, the 
Commission believes it unlikely that relatively low-power unlicensed 
devices would cause harmful interference to the space station 
receivers.
    51. The Commission declines to adopt Intelsat and SES Americom's s 
suggestion for an aggregate power limit from unlicensed devices to be 
enforced though the use of the AFC systems. As a precautionary measure, 
the Commission adopts a rule requiring outdoor standard-power access 
points to limit the maximum EIRP above a 30 degree elevation angle to 
21 dBm, which is similar to what the Commission requires in the U-NII-1 
band to protect fixed satellite services. The Commission adopts this 
restriction rather than an aggregate power limit for two reasons. 
First, outdoor access points have no reason to radiate significant 
power skyward, and so the Commission does not believe this requirement 
will impose a burden on standard-power access point manufacturers and 
users. Second, designing an AFC system to undertake aggregate power 
limit monitoring would be very complex, requiring the AFC to know how 
much energy is being emitted to each portion of the geostationary arc 
for each unlicensed device. That in turn would require the AFC to have 
knowledge of each outdoor access point's antenna pattern, orientation, 
actual transmit power levels, and percent of the time it transmits as 
well as similar information for unlicensed client devices operating 
outdoors. Given the skyward EIRP restrictions the Commission is placing 
on the AFC controlled outdoor unlicensed devices, the Commission see no 
reason to require this level of complexity in the AFC systems.

Additional Issues

    52. Authorizing standard-power access points to operate in the U-
NII-8 band. The Commission does not authorize standard-power access 
points to operate in the lower 100-megahertz portion of the U-NII-8 
band, which had been requested by some unlicensed

[[Page 31397]]

proponent. The Commission declines to do so for a number of reasons. 
The U-NII-8 band is used by both fixed and mobile broadcast auxiliary 
service services and the lower 25-megahertz portion of the band is 
available for Low Power Auxiliary Stations operations such as licensed 
wireless microphones. The geographic areas for these types of licensed 
operations are specified in a variety of fashions, including point/
radius, countywide, statewide and nationwide. The AFC system would not 
be able to allow standard-power access points to operate in the band 
while protecting licensed operations without additional information on 
their exact operating locations and times, and information on mobile 
operations can change frequently. Even if licensees were to provide 
additional operational information, this would increase the complexity 
of the AFC system and its interactions with unlicensed devices, and 
still may not adequately protect mobile operations. Accordingly, the 
Commission is not authorizing standard-power access points to operate 
in the lower 100 megahertz of the U-NII-8 band.
    53. Adopting an ``inclusion zone'' approach. The Commission also 
declines to adopt the suggested alternative to an AFC system. to permit 
unlicensed devices to operate in an ``inclusion zone'' around microwave 
transmitters. Under this approach, an applicant for a microwave license 
would conduct coordination for both the licensed link and unlicensed 
devices within the inclusion zone. In declining to adopt this approach, 
the Commission notes that its proposal is nearly identical to the 
concept of auxiliary stations, which the Commission considered as part 
of the Wireless Backhaul proceeding. The auxiliary station proposal 
contemplated placement of multiple lower power transmitters within the 
signal pattern of a microwave link. These auxiliary stations would be 
coordinated in advance of deployment and have secondary status. The 
Commission rejects this proposal, one of the reasons being that the 
proposal would create an incentive for microwave license applicants to 
propose excessive power or use more diffuse antenna patterns for their 
primary transmitters thereby precluding use of the spectrum by other 
microwave operators.

Low-Power Indoor Operations Across the Entire 6 GHz Band

    54. The Commission opens the entire 6 GHz band for unlicensed 
indoor operations without the need for AFC-controlled access. By doing 
so, the Commission creates new unlicensed use opportunities in these 
bands--including optimizing the potential for deployment of next 
generation Wi-Fi that makes use of 160 MHz channels--while protecting 
the various incumbent licensed services in the band, including fixed 
microwave services, various other fixed and mobile services, and fixed-
satellite services.
    55. Because there will be no AFC system to prevent interference to 
licensed services from occurring, the rules the Commission adopts three 
restrictions designed to prevent harmful interference. Devices are: (1) 
Limited to indoor operation; (2) required to use a contention-based 
protocol; and (3) subject to low-power operation.
    56. First, these low-power access points must operate only indoors. 
The signals transmitted by these unlicensed devices will be 
significantly attenuated when passing through the walls of buildings. 
The median signal loss from a traditionally constructed building is 17 
dB and newer, highly efficient buildings provide even higher signal 
attenuation. No commenters disagreed with the ITU median signal loss 
value for traditional construction. This attenuation is key to 
providing the necessary signal reduction to prevent harmful 
interference from occurring to incumbents.
    57. Second, the Commission requires that the indoor low-power 
devices, both access points and their associated client devices, employ 
a contention-based protocol. A contention-based protocol allows 
multiple users to share spectrum by providing a reasonable opportunity 
for the different users to transmit. Because the weighted average 
airtime utilization of Wi-Fi networks today is 0.4%, Wi-Fi devices 
share spectrum using a contention-based protocol. For IEEE's 802.11, a 
``listen-before talk'' medium access scheme based on the Carrier Sense 
Multiple Access with Collision Avoidance (CSMA/CA) protocol functions 
as a contention-based algorithm to provide access to all traffic. 
Before initiating any packet delivery, a station listens to the 
wireless medium and if the medium is idle, the station may transmit; 
otherwise the station must wait until the current transmission is 
complete before transmitting. To ensure efficient and cooperative 
shared use of the spectrum, the Commission requires all unlicensed 
indoor low power operations use technology that includes a contention-
based protocol.
    58. In addition to providing equal access to the spectrum for 
unlicensed devices, a contention-based protocol can also be used to 
avoid co-frequency interference with other services sharing the band. 
Thus, this requirement can be leveraged to facilitate spectrum sharing 
with incumbent fixed and mobile services in the band. In addition, 
requiring a contention-based protocol will limit the amount of time 
that the low-power unlicensed device will transmit because of the need 
to share the spectrum with other devices. This will limit the time 
periods during which interference could potentially occur.
    59. Third, the Commission limits the low-power indoor access points 
to lower power levels than the standard-power access points that 
operate under the control of an AFC. Consistent with the Commission's 
approach for the existing U-NII bands, the Commission specifies both a 
maximum power spectral density and an absolute maximum transmit power, 
both in terms of EIRP. Specifically, the Commission allows a maximum 
radiated power spectral density of 5 dBm per 1 megahertz and an 
absolute maximum radiated channel power of 30 dBm for the maximum 
permitted 320-megahertz channel (or 27 dBm for a 160-megahertz 
channel). In addition, to ensure that client devices remain in close 
proximity to the indoor access points, the Commission limits their PSD 
and maximum transmit power to 6 dB below the power permitted for the 
access points. In adopting these power levels in our rules, the 
Commission authorizes indoor unlicensed devices with adequate power to 
be useful to the public while also protecting the licensed services in 
the 6 GHz band from harmful interference. In accordance with the record 
developed in this proceeding, the Commission finds that this power 
level meets these twin goals.
    60. In the sections below, the Commission first discusses the 
provisions adopting to keep these low-power access points indoors. The 
Commission then discusses the technical parameters for indoor 
unlicensed operations in this band--the power levels different parties 
request, the rationale behind the power levels the Commission adopts 
today, and how the technical filings in this proceeding support our 
conclusion that the potential for harmful interference to incumbent 
services operating in the 6 GHz band is insignificant. The Commission 
then evaluates the probability of unlicensed devices causing harmful 
interference to the incumbent services in the 6 GHz band--fixed 
services, mobile services, FSS, and radio astronomy. The Commission 
discusses the technical studies submitted to the record, most of which 
employ different analysis methodologies with widely varying input 
assumptions leading to divergent conclusions.

[[Page 31398]]

Certain studies are based on statistical simulations while others are 
based on worst-case scenarios. In evaluating these studies, the 
Commission discusses the methodologies and the underlying assumptions 
regarding propagation models, building entry loss, antenna patterns, 
height of unlicensed devices, activity factor and the bandwidth overlap 
of incumbent and unlicensed services and the associated consequences 
and conclusions.

Indoor Operations

    61. The Commission first addresses measures designed to restrict 
these operations to indoor use. Because building attenuation is a key 
factor in minimizing the potential for harmful interference from indoor 
low-power access points to licensees' receivers, the Commission adopts 
reasonable and practical measures that will restrict low power access 
points to indoor operations. Specifically, the Commission adopts three 
equipment-related hardware requirements that are designed to keep these 
low-power access points indoors. First, as suggested by Boeing, the 
Commission requires that the access point devices cannot be weather 
resistant. Second, the Commission requires that the low-power access 
points have integrated antennas and prohibit the capability of 
connecting other antennas to the devices, which will prevent 
substituting higher gain directional antennas and make the devices less 
capable or suitable for outdoor use. Third, the Commission prohibits 
these low-power access points from operating on battery power. 
Furthermore, the Commission requires that the access points be marketed 
as ``for indoor use only'' and include a label attached to the 
equipment stating that ``FCC regulations restrict to indoor use only.'' 
The Commission also requires that this statement be placed in the 
device's user manual. This statement along with existing Commission 
requirements for Part 15 equipment will inform consumers of the 
appropriate use.
    62. The Commission finds that these requirements will make outdoor 
operations impractical and unsuitable, and disagree with those 
commenters that suggest either that no requirements are needed or that 
any requirements would be ineffective. The Commission declines to adopt 
a suggestion to use GPS to determine whether a device is indoors. 
Furthermore, the Commission is hesitant to require all devices to incur 
the cost of incorporating a GPS capability given that the effectiveness 
of this idea has not been demonstrated.

Power Spectral Density Limit

    63. In determining the appropriate power spectral density for low 
power indoor unlicensed devices in this band, the Commission has 
carefully reviewed the studies submitted into the record by all 
parties. Various analysis methodologies are used which fall into two 
main categories: (i) Monte Carlo simulations, which take into account 
probabilistic factors such as building entry loss, activity factor, and 
co-channel probability, and (ii) static link budgets with limited 
considerations of probabilistic dependencies. The studies submitted to 
the record result in widely varying conclusions. While the studies 
performed by the incumbents tend to assume worst case conditions and 
ignore the very low probabilities associated with such worst-case 
scenarios, the proponents of unlicensed usage tend to assume very low 
probabilities for the activity factor and high building entry losses. 
Other assumptions that vary between the models are building entry loss 
and propagation loss, with incumbents generally assuming line of sight 
free space propagation and unlicensed device proponents applying 
industry standard models that either inherently include clutter loss or 
treat such loss as an additive factor determined by a separate 
statistical clutter model appropriate for the environment.
    64. The Commission adopts a 5 dBm/MHz PSD. Based on our experience 
with unlicensed operations and interference analyses as well as our 
engineering judgment, the Commission finds that 5 dBm/MHz PSD will both 
adequately protect all incumbents in the band from harmful interference 
as well as offer enough power to unlicensed devices, commensurate with 
the levels in the other U-NII bands, to sustain meaningful applications 
especially when using wider bandwidths. At this power limit and with 
the other constraints imposed on these operations, the risk of harmful 
interference to incumbent operations is insignificant.
    65. With respect to unlicensed client devices, the Commission 
adopts the proposal and does not permit client devices to operate with 
the same power spectral density as access points. The Commission finds 
that client devices does not need the same power level due to the 
asymmetrical nature of traffic. An additional margin of 6 dB will 
provide protection to incumbents as client devices operate in the 
vicinity of access points. Accordingly, the Commission concludes that 
the appropriate maximum power spectral density for low power indoor 
client devices in this band is 6 dB below the limit for access points 
(or -1 dBm/MHz based on the adopted PSD limit).

Protecting Incumbent Operations

    66. Fixed Microwave Service. The Commission finds that fixed 
microwave receivers will be protected from harmful interference from 
unlicensed indoor low power devices operating at the power levels the 
Commission is authorizing. The Commission reaches this conclusion based 
on the examination of two representative technical studies submitted to 
the record. First, a Monte Carlo simulation submitted by CableLabs 
provides a strong basis for reaching this conclusion. This study 
assumes realistic operating conditions for both licensed incumbent 
services and unlicensed operations. Second, a link budget analysis for 
six particular cases submitted by AT&T illustrates that interference is 
not likely to occur with the proposed power levels when realistic 
assumptions are made regarding propagation losses and taking into 
account the probabilistic nature of unlicensed transmissions. Because 
these six cases represent microwave receiver/unlicensed device 
geometries that are challenging from an interference perspective, the 
results give us confidence that interference is unlikely to occur. The 
Commission explains in more detail the numerous other technical filings 
submitted and why they are not significant to the conclusion.
    67. Among several technical studies submitted by advocates of 
indoor low-power operations showing that the likelihood of interference 
to fixed microwave receivers is extremely low, the Commission finds the 
CableLabs study the most significant. These studies generally perform 
Monte Carlo computer simulations that model a random deployment of low-
power unlicensed devices and calculate statistics on the likelihood of 
interference occurring to microwave receivers. Advocates of indoor low-
power operations claim that fixed microwave links will not experience 
harmful interference from the unlicensed devices.
    68. In general, any technical study pertaining to spectrum sharing 
should take into consideration the specific behavior of services 
involved and the complexity of the propagation environment where the 
services operate. Studies that focus on static link budgets, for 
example, neglect the effects of the sporadic nature of most unlicensed 
transmissions (activity factor) and the probability of co-channel 
operation of

[[Page 31399]]

the unlicensed device and the licensed service (e.g., an 80-megahertz 
unlicensed channel covers less than 7% of the 6 GHz band). These 
factors reduce the probability of interference to the licensed service.
    69. CableLabs submitted a technical study that models the 
interference potential of low-power indoor unlicensed devices to 
microwave receivers. This Monte Carlo simulation explores the potential 
for interference to fixed links in the New York City area. The 
simulation uses the WINNER II urban propagation model, the propagation 
model the Commission adopts in this Report and Order for intermediate 
distances for AFC systems (By intermediate distances the Commission is 
referring to distances between 30 meters and 1 kilometer.). The 
CableLabs study selects a building entry loss between 10 dB and 30 dB, 
which is consistent with ITU recommendation P.2109. Furthermore, the 
simulation uses a distribution of airtime utilization based on data 
taken from 500,000 Wi-Fi access points to model how often each access 
point in the simulation transmits. The simulations showed that the I/N 
ratio is far below the conservative -6 dB I/N threshold. This is the 
same -6 dB threshold that the Fixed Wireless Communications Coalition, 
which represents the interest of the fixed microwave licensees, uses as 
a threshold for protecting against harmful interference to fixed 
microwave links.
    70. The Commission finds the CableLabs' study persuasive because it 
uses actual airtime utilization data for hundreds of thousands of Wi-Fi 
access points along with a statistical model for building entry loss. 
Rather than using a single average or median value to represent 
building entry loss the CableLabs' study uses attenuation values drawn 
from a probability distribution for each access point in the 
simulation. In this way the simulation more accurately models the 
variability of the building loss than using a single number for 
building loss such as the median or average.
    71. Wi-Fi is the predominant use of the U-NII bands, and is 
ubiquitous in both residences and businesses. The Commission expects 
that the majority of indoor unlicensed operations in the 6 GHz band 
will be for Wi-Fi as well. Additionally, while the adopted rules do not 
limit the activity factor, the Commission requires devices to use a 
contention-based protocol which will prevent devices from transmitting 
at extremely high duty cycles. For these reasons, the Commission finds 
that the CableLabs study is the best evidence in the record of the 
impact that unlicensed low-power indoor devices will have on incumbent 
operations--and it demonstrates that such operations will not cause 
harmful interference.
    72. AT&T offered six scenarios where an unlicensed device operates 
in close proximity to a fixed microwave receiver or where an unlicensed 
device operates relatively far from the microwave receiver but the 
terrain causes the unlicensed device to be in or close to the main 
receiver beam.
    73. AT&T's technical study attempts to overcome the limitation of 
simple deterministic interference calculations by introducing a 
probability distribution around building entry loss. AT&T claims that 
their examples properly apply building entry loss by treating it as a 
probabilistic quantity using the distribution from ITU-recommendation 
P.2109 and that prior analyses have oversimplified building entry loss 
into a single value. The Commisison concludes that this step does not 
fully remedy the limitation of a static link budget analysis 
limitations. Some of the most significant elements of the AT&T link 
budgets are also probabilistic quantities. AT&T's link budget makes the 
following assumptions: (a) An EIRP of 30 dBm in an 80 MHz channel (11 
dBm/MHz); (b) the maximum unlicensed device EIRP is in the direction of 
the microwave antenna; (c) free-space propagation for the interfering 
signal; (d) zero clutter loss; (e) that an unlicensed device at the 
specified location is capable of 6 GHz band operation and is operating 
co-frequency with the microwave receiver; and (f) the unlicensed device 
has a 100% duty cycle. Clearly, all of these parameters except for the 
EIRP have an associated probability distributions that are missing from 
AT&T's link budgets. For example, AT&T's use of a free-space 
propagation model ignores clutter that often surrounds the transmitter 
and receiver sites (and that may significantly reduce the risk of 
harmful interference). Recognizing that each of these factors can take 
on a range of values and that it is unlikely that each will be worst 
case at the same time and location, the Commission finds that AT&T 
overstates the potential for harmful interference.
    74. The Commission presents a detailed comparison in Table 1 for 
one of AT&T's examples (Example 2) The Commission does this because it 
gives a more useful indication of unlicensed device signal levels than 
only treating one factor in the calculation as a probabilistic quantity 
as AT&T has done in their examples. By treating only the building entry 
loss as a probabilistic quantity while not considering all the other 
statistical quantities, AT&T's examples exaggerate the likelihood of 
interference occurring.

                                             Table 1--AT&T Example 2
----------------------------------------------------------------------------------------------------------------
                                                 AT&T            Apple, Broadcom et al.            FCC
----------------------------------------------------------------------------------------------------------------
EIRP/BW..............................  30 dBm/80 MHz..........  30 dBm/160 MHz.........  24 dBm/80 MHz.
PSD..................................  11 dBm/MHz.............  8 dBm/MHz..............  5 dBm/MHz.
Antenna Gain.........................  37.9 dB................  37.9 dB................  37.9 dB.
Antenna Discrimination...............  -1.5 dB................  -2.538 dB..............  -1.5 dB.
RLAN/FS Antenna Mismatch.............  0 dB...................  -5 dB..................  -5 dB.
Clutter..............................  0 dB...................  -25.00 dB..............  -18.4 dB (using ITU-R
                                                                                          P.452 clutter model).
Path Loss............................  -118.96 dB (free space)  -118.92 dB (free space)  -120.12 dB (ITM P2P
                                                                                          model).
Bandwidth Mismatch...................  -3 dB (assuming 80 MHz   -7.27 dB (assuming 160   -4.26 (assuming 80 MHz
                                        channels).               MHz channels).           channels).
Noise Figure.........................  -3.0 dB................  -3.0 dB................  -3.0 dB.
Polarization Loss....................  -3.0 dB................  -3.0 dB................  -3.0 dB.
Feeder Loss..........................  0 dB...................  0 dB...................  0 dB.
Building Entry Loss (50%)............  -17.00 dB..............  -17.00 dB..............  -20.62 dB (70/30 mix).
Interference (I).....................  -78.76 dBm.............  -113.83 dBm............  -114 dBm.
Noise Floor (N)......................  -99 dBm................  -99 dBm................  -99 dBm.
I/N..................................  20.44 dB...............  -14.83 dB..............  -15.0 dB.
----------------------------------------------------------------------------------------------------------------


[[Page 31400]]

    75. The parameters in the above table were adjusted as follows:
    (i) EIRP/BW: The analysis assumes a nominal channel bandwidth of 80 
MHz, which results in a 5 dBm/MHz PSD limit.
    (ii) RLAN/FS Antenna mismatch: The Commission agrees with Apple, 
Broadcom et al. that there will be an antenna pattern mismatch between 
the unlicensed devices and the microwave antenna and that 5 dB is a 
reasonable assumed loss.
    (iii) Clutter: The Commission uses a standard clutter model (ITU-R 
P.452) to derive an 18.4 dB clutter loss.
    (iv) Path loss: The Commission believes that the ITM P2P path loss 
model is most appropriate for this scenario.
    (v) Bandwidth mismatch: The mismatch is based on an 80-megahertz 
bandwidth unlicensed channel. However, The Commission assumes that the 
mismatch factor should be -4.26 dB based on the ratio of the passband 
of AT&T's receiver and the bandwidth of the unlicensed channel.
    (vi) Building Entry Loss: The Commisison finds that a 70% 
traditional construction/30% energy efficient construction mix of 
building types for determining building entry loss is appropriate.
    76. Table 2 presents all of AT&T's six examples but substitutes 
more realistic technical parameters.

                                                       Table 2--FCC Analysis of the AT&T Examples
--------------------------------------------------------------------------------------------------------------------------------------------------------
                                      Example 1A          Example 1B           Example 2           Example 3           Example 4           Example 5
--------------------------------------------------------------------------------------------------------------------------------------------------------
EIRP Power Spectral Density (dBm/ 5.................  5.................  5.................  5.................  5.................  5.
 MHz).
Bandwidth (MHz).................  80................  80................  80................  80................  80................  80.
EIRP (dBm)......................  24................  24................  24................  24................  24................  24.
RLAN Antenna Discrimination (dB)  -5................  -5................  -5................  -5................  -5................  -5.
BW Mismatch.....................  -4.26.............  -4.26.............  -4.26.............  -4.26.............  -4.26.............  -4.26.
(80 MHz Chan.) (dB).............
Polarization Loss (dB)..........  -3................  -3................  -3................  -3................  -3................  -3.
Propagation Model...............  Winner II Urban     Winner II Urban     ITM P2P...........  ITM P2P...........  Winner II Suburban  Winner II Suburban
                                   LOS.                LOS.                                                        LOS.                LOS.
Propagation Loss (dB)...........  -103.6............  -99.5.............  -120.12...........  -122.7............  -96.1.............  -83.6.
Clutter Loss(dB)................  0.................  0.................  -18.4.............  -18.4.............  0.................  0.
MW Antenna Gain (dB)............  43.2..............  43.2..............  37.9..............  38.8..............  41.3..............  38.8.
MW Antenna Discrimination (dB)..  -36...............  -38...............  -1.5..............  -0.9..............  -38...............  -40.
Feeder Loss (dB)................  -2................  -2................  0.................  0.................  -2................  0.
Building Entry Loss (70T/30E)     -21.4.............  -21.9.............  -20.6.............  -20.6.............  -23.1.............  -24.0.
 50th Percentile (dB).
Noise (dBm).....................  -99.0.............  -99.0.............  -99.0.............  -99.0.............  -99.0.............  -99.0.
Noise Figure (dB)...............  3.................  3.................  3.................  3.................  3.................  3.
I/N (dB)........................  -12.06............  -10.46............  -15...............  -16.1.............  -10.1.............  -1.06.
--------------------------------------------------------------------------------------------------------------------------------------------------------

    77. Table 2 shows that when more realistic technical parameters 
than assumed by AT&T are used, the I/N ratio in all but one case now 
falls below the conservative -6 dB interference protection benchmark--
indicating that there is an insignificant risk of harmful interference 
in five of these cases, when considering a static link budget analysis. 
Significantly, because these examples represent cases where the 
unlicensed devices are close to the microwave receivers or have terrain 
features that place the unlicensed device squarely in the main beam, 
they are representative of the worst cases that are likely to occur. 
Accordingly, they do not serve to rebut the persuasive showing by 
CableLabs based on a reliable probabilistic assessment derived from 
measurements associated with hundreds of thousands of actual Wi-Fi APs.
    78. In only one case does a static link budget analysis suggest a 
nontrivial possibility of harmful interference (Case 5), and the 
Commission does not believe this one case poses a significant potential 
for actual harmful interference. That is in part because a -6 dB I/N 
interference protection criterion is a conservative approach to 
ensuring that the potential for harmful interference is minimized and 
in part because many statistical factors unaccounted for in this link 
budget analysis further make the potential for harmful interference 
much less likely. Combining the low probability of co-channel operation 
and low activity factor, the Commission concludes that based on a 5 
dBm/MHz EIRP, the low power indoor operation will have an insignificant 
chance of causing harmful interference to the microwave links for any 
of these six examples (or fixed microwave links more generally). If the 
EIRP where increased to 8 dBm/MHz, the I/N ratios for examples 1B, 4, 
and 5 in Table 5 would recalculate to -7.46 dB, -7.1 dB, and 1.94 dB 
respectively, which would create a higher risk of harmful interference 
(although still very low). As the Commission cannot conduct an analysis 
for every fixed station and each of their associated link paths, it 
chooses to adopt a conservative 5 dBm/MHz EIRP at this time to enable 
low-power indoor operations throughout the 6 GHz band with 
insignificant risk of harmful interference.
    79. CITA, Southern Company, the Critical Infrastructure Industry, 
and Apple, Broadcom et al. also submitted technical studies exploring 
the potential for harmful interference to fixed microwave receivers. 
The Commission examined these technical studies. These technical 
studies did not change the Commission's conclusion that unlicensed low-
power indoor operations would present an insignificant risk of harmful 
interference.
    80. Additional Considerations. The Commission is convinced, that as 
the Monte Carlo simulations involving extensive use of unlicensed 
devices in the band and examination of the link budget studies show, 
fixed microwave links will have an insignificant chance of experiencing 
harmful interference from indoor low-power unlicensed operations. 
Further, the non-continuous nature of the transmissions of the most 
widely used unlicensed systems today, like Wi-Fi makes the occurrence 
of harmful interference even less likely. And the Commission's rule 
requiring

[[Page 31401]]

that low-power indoor access points employ a contention-based protocol 
ensures that none of these unlicensed devices will employ continuous 
transmissions. The data that CableLabs submitted collected from 500,000 
Wi-Fi access points shows that 95% of access points have an activity 
factor of less than 2% and only 1% of access points are active more 
than 7% of the time. This illustrates that most of the time a 
particular access point will not be transmitting.
    81. The sporadic and bursty nature of Wi-Fi transmissions is 
significant for two reasons. First, it illustrates why discussions of 
aggregate interference from Wi-Fi devices cannot simply add the power 
received from the individual access points to calculate the received 
interference. Instead, to more accurately estimate aggregate 
interference a Monte Carlo simulation which accounts for the 
intermittent nature of the transmissions should be undertaken.
    82. Second, potential degradation of a microwave link will only 
occur if a deep atmospheric multipath fade occurs at the same time the 
microwave receiver receives an excessively high powered transmission 
from an unlicensed device, such that natural losses due to separation 
distance, clutter, and terrain do not sufficiently diminish the power 
received from the unlicensed device.
    83. The Commission disagrees with the Fixed Wireless Communications 
Coalition to the extent that it implies that our obligation regarding 
harmful interference from unlicensed devices goes beyond what is 
enumerated in our rules. While as general matter harmful interference 
is defined as ``[a]ny emission, radiation or induction that endangers 
the functioning of a radio navigation service or of other safety 
services or seriously degrades, obstructs or repeatedly interrupts a 
radiocommunications service operating in accordance with this 
chapter,'' the Part 15 rules apply this criteria on a case by case 
basis for different bands after careful consideration of the incumbent 
services in each band that ensures such harmful interference is 
unlikely to occur. The technical and operational limits the Commission 
adopts in this proceeding ensures that unlicensed devices will not have 
a significant potential for causing harmful interference to the users 
authorized to operate in the 6 GHz band.
    84. The Commission, however, is not required to refrain from 
authorizing services or unlicensed operations whenever there is any 
possibility of harmful interference. Indeed, such a prohibition would 
rule out virtually all services and unlicensed operations, given that 
there is virtually no type of RF-emitting device that does not have the 
potential for causing such interference if used incorrectly. NCTA notes 
that the Commission may promulgate rules for unlicensed operations in 
bands occupied by other users so long as unlicensed devices do not 
``transmit[ ] enough energy to have a significant potential for causing 
harmful interference.'' In rulemakings, the Commission may authorize 
operations in a manner that reduces the possibility of harmful 
interference to the minimum that the public interest requires, and it 
will then authorize the service or unlicensed use to the extent that 
such authorization is otherwise in the public interest. The Commission 
determines that the restrictions and requirements that it is 
establishing for indoor use of low power access points eliminates any 
significant risk of causing harmful interference.
    85. AT&T, CTIA, and others express concern that harmful 
interference nonetheless may occur, and the rules do not go far enough 
to ensuring that the interfering devices can be identified and the 
operation cease. Both AT&T and CTIA advocate use of an AFC system to 
address these concerns. While in certain bands the Commission has 
required database use, for other bands the Part 15 rules have no such 
requirement. Of particular relevance here, there is no spectrum 
management system in the 2400-2483.5 MHz band, where unlicensed devices 
share spectrum with the incumbent broadcast auxiliary service licensees 
and operate at higher powers than the indoor low-power access points 
authorized here. Nor are there such requirements in the 5 GHz band, 
which includes sensitive incumbent operations and where the unlicensed 
operations are similar to the kinds of low-power operations anticipated 
in the 6 GHz band. Wi-Fi devices have been deployed in these bands in 
abundance for well over 20 years, and the Commission expects that the 
deployment of 6 GHz devices will resemble the deployment of devices in 
these other bands, where instances of harmful interference have been 
effectively identified and addressed.
    86. The Commission disagrees with CTIA's contention that our rules 
will be ineffective in keeping the low-power indoor devices from being 
used outdoors. The Commission's Part 15 rules prohibited outdoor 
operation in the U-NII-1 band from 1997 until 2014 and currently 
prohibit outdoor operation for unlicensed devices in the 92-95 GHz band 
and many ultra-wideband devices. As outdoor operation of these indoor 
devices has not been a problem, the Commission's rules restricting 
devices to indoors cannot be categorized as ineffective. None of these 
existing and previous rules contain all of the restrictions the 
Commission adopts here to discourage outdoor use. As in the rules for 
those operations, the Commission concludes that the technical and 
operational rules will be sufficient to protect incumbent operations.
    87. In the unlikely event that harmful interference does occur, the 
Commission's Part 15 rules in section 15.5 (b)-(c) require that such 
operations cease, and the Commission's Enforcement Bureau has the 
ability to investigate reports of such interference and take 
appropriate enforcement action as necessary. Also, once interference to 
a protected service crosses the relevant threshold specified in section 
15.3(m) for harmful interference, it is immediately actionable for 
enforcement purposes. Any user causing interference may be required to 
cease operating the U-NII device, even if the device in use was 
properly certified and configured and will not be permitted to resume 
operation until the condition causing the harmful interference has been 
corrected.
    88. Here, as always, the Commission focuses on identifying and 
protecting against actual-use cases; were the Commission to act on 
every unrealistic or contrived situation that purports to show the 
potential for harmful interference, the Commission's rules would allow 
for few or no opportunities for sharing between unlicensed devices and 
licensed services; sharing that has allowed Wi-Fi to prosper along with 
continued licensed spectrum use. The Commission emphasizes, however, 
that under our long-established rules, Part 15 devices are not 
permitted to cause harmful interference. This fundamental principle 
stands regardless of the particular band- and application-specific 
rules adopted.

Mobile Services

    89. The 6 GHz band Mobile service allocation is limited to the U-
NII-6 (6.425-6.525 GHz) and U-NII-8 (6.875-7.125 GHz) bands. In these 
bands, the mobile service incumbents operate electronic news gathering 
and other Part 74 broadcast auxiliary services, as well as Part 78 
Cable Television Relay Service, and Part 101 Local Television 
Transmission Service. Incumbents operate portable camera relays to 
``jumbotron'' screens for major sporting events at stadiums and arenas, 
and at musical concerts at large venues, indoors and outdoors; use the 
spectrum bands for video relay to production

[[Page 31402]]

trucks at news events; and for video signal multi-hop mobile relay from 
newsworthy events to either a satellite news truck, a fixed receive 
site or a temporary relay site. Low Power Auxiliary Stations, also 
licensed in the U-NII-8 band, operate on an itinerant basis and 
transmit over distances of approximately 100 meters for uses such as 
wireless microphones, cue and control communications, and TV camera 
synchronization signals. Additional terrestrial uses of the band 
include short range video relay for video production at automobile and 
sailboat racing event, political conventions and golf tournaments. 
Because of the nature of their use--breaking news, event coverage, 
etc.--the use of particular portions of this band by these auxiliary 
services is unpredictable.
    90. NAB opposes allowing indoor unlicensed operations in the bands 
where there are broadcast auxiliary service operations (U-NII-6 and U-
NII-8), unless a ``robust, reliable mechanism is developed to 
coordinate'' the unlicensed operations with the licensed uses. To 
support of its position, NAB submitted a study which evaluates the 
impact of indoor and outdoor unlicensed operations in the U-NII-6 and 
U-NII-8 bands in three different use scenarios: (i) An electronic news 
gathering truck transmitting to a central receive site; (ii) portable 
cameras transmitting to an outdoor electronic news gathering truck 
receive site; and (iii) portable cameras transmitting to an indoor 
receive site.
    91. Though the NAB study provides some valuable information about 
the potential risk of harmful interference to electronic news gathering 
receive sites, the Commission disagrees with certain of its 
assumptions. The Commission disagrees with NAB's use of free-space path 
loss for all paths based on a predicted percentage of area that is 
line-of-sight when in fact unlicensed devices will be randomly located 
and could very well be in areas of buildings without line-of-sight to 
the electronic news gathering receiver. Under more realistic 
conditions, the Commission notes that NAB's use of a -10 dB I/N 
benchmark is rarely exceeded in the electronic news gathering truck 
receiver case. The Commission notes that the use of a conservative but 
more reasonable -6 dB would show much less likelihood of any potential 
for harmful interference. And taking into account the power-level and 
contention-based protocol limitations would show even less likelihood 
of harmful interference.
    92. NAB's study includes co-channel operation probability in its 
statistical study but bases this probability on unlicensed devices 
being restricted to the U-NII-6 and U-NII-8 bands. NAB's assumption 
increases the probability of co-channel operations and thus, over 
predicts the potential for harmful interference to electronic news 
gathering operations.
    93. Finally, NAB requests that the Commission authorize low power 
indoor operations in the U-NII-6 band altogether or alternatively to 
reserve 80 megahertz in the upper U-NII-8 band for ENG use only. As 
discussed below, low-power indoor operations will have little potential 
of causing harmful interference to ENG operations and decline to take 
this action. Moreover, eliminating the spectrum available for 6 GHz 
unlicensed devices could have the unintended effect of actually 
increasing the potential interference to other users as more unlicensed 
devices would have access to fewer channels.
    94. Outdoor electronic news gathering central receive sites. For 
the reasons outlined above, the Commission believes NAB's study 
overstates the potential of exceeding its chosen I/N criterion of -10 
dB and therefore also overstates the likelihood of exceeding the 
conservative and sufficiently protective I/N value of -6 dB. Apple, 
Broadcom et al. submitted a statistical study of the same scenarios but 
based on a combination of WINNER II and Irregular Terrain Model with 
the P.2108 propagation models. The Apple, Broadcom et al. study 
considers two activity factors and a 70/30 mix of building entry loss 
based on ITU Recommendation P.2109. The Apple, Broadcom et al. results 
indicate that aggregate signal level from indoor unlicensed devices 
will exceed a level 6 dB below the electronic news gathering central 
site receiver noise floor only 0.1% of the time. Thus, concluding that 
there is a negligible risk of harmful interference. The Commission 
finds that the Apple, Broadcom et al. study uses more appropriate 
propagation models and therefore more accurately represents the risk of 
harmful interference from indoor unlicensed devices to electronic news 
gathering central receive sites and find that risk to be insignificant.
    95. Interference to electronic news gathering truck receivers. 
Results of NAB's own study show that at the lower activity factor of 
0.44% indoor unlicensed devices are unlikely to cause the I/N to exceed 
-10 dB. At the 10% activity factor, the electronic news gathering truck 
receiver results showed that between 0.2 and 49.8% of the time the 
aggregate I/N exceeds the -10 dB I/N threshold. CableLabs' empirical 
activity factor data show a weighted distribution of 0.4%. The 
Commission concludes that it is highly unrealistic to assume that every 
unlicensed device in an area surrounding an electronic news gathering 
truck will be transmitting at the high 10% activity factor.
    96. The NAB study also concludes that the level of unwanted signal 
seen by the electronic news gathering truck receiver is dependent on 
the relationship between the height of the unlicensed device, the 
height of the electronic news gathering antenna and the height of the 
surrounding environment. The same relationship between local 
environment and antenna heights will exist for the desired link between 
the electronic news gathering transmitter and truck mounted receiver, 
except the electronic news gathering link can be planned and the 
electronic news gathering truck can be positioned to achieve the best 
possible signal between transmitter and receiver. Given the sensitivity 
of potential interference to geometry coupled with NAB's unrealistic 
assumption that every unlicensed device in an area surrounding an 
electronic news gathering truck will be transmitting at the high 
activity factor, the Commission concludes that the potential for 
harmful interference (using a more appropriate -6 dB threshold) is 
again insignificant for the scenario indicated.
    97. CableLabs and Apple, Broadcom et al. both submitted studies 
indicating that potential for harmful interference from indoor 
unlicensed devices to outdoor electronic news gathering truck receivers 
will be unlikely. The Commission agrees with CableLabs' and Apple, 
Broadcom et al.'s findings, that the risk of harmful interference to 
outdoor electronic news gathering receivers from indoor unlicensed 
devices is negligible. The Commission notes that the same conditions 
that cause signal variations in the electronic news gathering signal 
will also act upon a signal from an unlicensed device. CableLabs states 
that a 10 dB signal-to-interference-plus-noise provides an accurate 
basis for determining the impact of unlicensed indoor devices on 
broadcast auxiliary service signals. Apple, Broadcom et al. asserts 
``[n]ews truck operators will be able to improve their link budgets by 
slightly adjusting the positions of their trucks or shooting 
locations.'' The Commission also notes that both Apple, Broadcom et al. 
and CableLabs' studies assume a maximum of 30 dBm EIRP with at least an 
8 dBm/MHz PSD, and that it is permitting indoor unlicensed devices to 
transmit with only a maximum 5 dBm/MHz PSD. This 3 dB variance further 
reduces the probability of harmful interference to

[[Page 31403]]

electronic news gathering trucks from unlicensed devices.
    98. Interference to indoor electronic news gathering receivers. The 
final scenario studied by NAB is communication between indoor 
electronic news gathering transmitters, such as microphones and camera-
back transmitters, and indoor electronic news gathering receivers. The 
Commission is not permitting client devices to be used as hotspots and 
requires 6 GHz unlicensed devices to use a contention-based protocol. 
The Commission concludes that such a protocol will allow unlicensed 
devices to sense the energy from nearby indoor licensed operations and 
avoid using that channel. Apple, Broadcom et al. points out that the 
802.11 specification dictates that devices sense the energy in the 
channel and not transmit if they detect energy at a level greater than 
-62 dBm. To confirm that energy sensing could be used to mitigate 
interference to indoor electronic news gathering receivers, Apple, 
Broadcom et al. simulated the receive power level from electronic news 
gathering transmitters at 20 unlicensed access points operating within 
the US House of Representatives chamber. The results of this simulation 
demonstrate that, even at the lowest electronic news gathering transmit 
power level, all unlicensed access points would detect the electronic 
news gathering signal at greater than -62 dBm and therefore not 
transmit co-channel. While it is not requiring a specific technology 
protocol or contention method, the Commission concludes that the 
results of the Apple, Broadcom et al. study shows the likely potential 
of contention-based protocols to protect indoor mobile links, including 
electronic news gathering and Low Power Auxiliary Stations. Thus, the 
Commission concludes that the risk of harmful interference to indoor 
electronic news gathering receivers from indoor unlicensed devices is 
insignificant.

Fixed-Satellite Services

    99. The entire 6 GHz band is also home to a FSS allocation (Earth-
to-space), while U-NII-8 has a few space-to-Earth MSS feeder downlinks. 
The Commission agrees with Sirius XM, Intelsat, and SES that there will 
be negligible interference to satellite receivers from low-power indoor 
unlicensed devices. The low power levels of these devices as well as 
building attenuation will prevent harmful interference. With regard to 
earth station receivers, the Commission disagrees with Globalstar's 
analysis. As Apple, Broadcom et al. point out Globalstar's analysis 
represents an impossible worst-case scenario because it assumes that 
the earth station antenna is pointing at its minimum usable elevation 
angle in each of the interfering indoor access points resulting in the 
assumption that earth station antennas will simultaneously receive 
unlicensed device transmissions from all directions with the same 
antenna gain. Globalstar also assumes all unlicensed devices are 
operating at the same location where the incidence angle at the 
building wall is always zero, yielding the least building entry loss. 
Globalstar, uses a conservative 10% activity factor with all unlicensed 
activity concentrated at a small number of sites resulting in an 
unrealistic assumption that unlicensed transmission will always be 
subject to 7 dBi of earth station gain. However, it is unlikely that 
all indoor unlicensed devices will be operating at the same location 
and orientation with respect to the path between the device and the 
earth station receiver. Instead, the elevation angle at the building 
fa[ccedil]ade should be considered to be variable, resulting in 
incidence angles greater than zero, which would increase the building 
entry loss value and minimize the probability of interference. 
Globalstar assumes line-of-sight and free-space propagation for all 
paths. The Commission disagrees that line of sight and free-space 
propagation loss is appropriate in all cases between a randomly placed 
unlicensed device and Globalstar's earth station.
    100. Finally, Globalstar's analysis assumes all unlicensed devices 
are operating at the proposed maximum permissible power with the peak 
antenna gain directed toward its earth stations. The Commission is 
allowing unlicensed indoor devices to operate at a maximum 5 dBm/MHz 
PSD which represents at least a 3 dB/MHz reduction over the power 
levels assumed in the Globalstar analysis. Additionally, when 
considering random placement of unlicensed devices and variations in 
the unlicensed device antenna pattern, it is unlikely that the 
unlicensed device EIRP in the direction of the earth station will 
always be at maximum power, thus the risk of harmful interference is 
further reduced. For the reasons outlined here, the Commission finds 
that Globalstar's link budget analysis fails to fully consider all the 
probability factors that must align in order for interference to occur. 
The Commission therefore finds that the risk of harmful interference 
occurring to Globalstar's earth stations to be low.

Radio Astronomy

    101. The National Academy of Sciences Committee on Radio 
Frequencies requests that the Commission use the AFC system to protect 
four radio astronomy observatories located in remote areas. The 
Commission is not adopting any AFC-based requirements for unlicensed 
low-power indoor operations generally, and declines to adopt such a 
requirement here. The four radio observatories that receive in the 6 
GHz band are in remote locations and it is unlikely that indoor low-
power unlicensed devices will be operating nearby. Furthermore, these 
observatories can restrict installation of such devices at their 
facilities. The Commission believes that indoor unlicensed devices do 
not pose any risk of harmful interference to radio astronomy 
operations.

Multi-Stakeholder Group

    102. The Commission notes that many of the companies and 
organizations with interest in the 6 GHz band may not have previously 
participated in multi-stakeholder groups on matters related to specific 
Commission proceedings. Therefore, while the Commission takes no 
position on whether an existing organization could or should serve as 
host of the 6 GHz multi-stakeholder group, the Commission believes that 
any such multi-stakeholder group should be newly formed (not an 
offshoot of an existing group) and focus solely on issues relevant to 
the 6 GHz band. To ensure that all viewpoints are considered, the 
Commission encourages stakeholders comprising all sectors of the 6 GHz 
ecosystem to participate, including: wireless service providers with 
interest in providing service through standard-power and indoor low 
power devices, RLAN and network equipment manufacturers, potential AFC 
operators, fixed service vendors and operators, existing 6 GHz band 
incumbent licensees, ultrawideband equipment manufacturers, academic 
experts, testing organizations, and other 6 GHz band stakeholders. The 
Commission does not, however, take a position on the exact makeup or 
organizational structure of any such stakeholder group.
    103. The Commission encourages the multi-stakeholder group to 
address any issues it deems appropriate regarding interference 
detection and mitigation in the event that an incumbent licensee 
believes it may be experiencing harmful interference from standard-
power or indoor low-power operations. These issues would include 
procedures and

[[Page 31404]]

processes that could be followed if an incumbent licensee has, or 
potentially has, an interference complaint. For example, network 
operators of standard-power or indoor low-power operations could decide 
to make points of contact publicly available or to create a website to 
facilitate addressing concerns or for reporting complaints. The 
Commission also believes that the group should set a goal of creating a 
process through which the industry can effectively address and resolve 
interference claims without necessitating involvement of the 
Commission's Enforcement Bureau.
    104. While the Commission is not requiring general device testing 
as a gating criterion for devices before they begin operating in the 6 
GHz band, the Commission recognizes that it will take some time before 
devices can be designed, manufactured and made available to consumers. 
During this interim period, members of the multi-stakeholder group 
could work cooperatively to develop and test devices to aid in the goal 
of developing processes for introducing and operating devices across 
the 6 GHz band. As the Commission does not require the multi-
stakeholder group to conduct testing, the Commission also declines to 
set any timelines if any testing is conducted. Because the Commission 
does not expect widespread availability of 6 GHz unlicensed devices 
immediately, the Commission encourages the multi-stakeholder group, if 
conducting any testing related to developing procedures and processes 
regarding interference detection and mitigation, to set a goal of 
implementing any agreed-upon device-related features before unlicensed 
6 GHz devices reach consumers.
    105. The Commission also encourages the multi-stakeholder group to 
address any other issues that may be specific to standard-power 
operations or indoor low-power operations. In particular, the 
Commission encourages the group to address, as proposed in the Notice, 
AFC system development for standard power access points. Related tasks 
are expected to include any standards that are necessary for AFC 
operators, such as how to implement the required propagation models or 
whether common communications protocols are needed between standard 
power unlicensed devices and the AFC(s). Additionally, the Commission 
expects that the multi-stakeholder group will develop AFC system 
testing and certification procedures and processes for ensuring that 
AFC systems contain complete and up-to-date incumbent data.
    106. Finally, the Commission expects that the multi-stakeholder 
group will develop best practices and standards concerning standard-
power operations (and use of the AFC system) and for indoor low-power 
operations--practices that the Commission expects will benefit all 
users of the 6 GHz band, both incumbents that desire additional 
protection and new unlicensed users that want to use the spectrum more 
intensely. The Commission expects that these best practices will 
include such concerns as device and communication link security. These 
activities should be viewed as a starting point; participants of the 
multi-stakeholder group should tackle any issues they deem appropriate.
    107. The Commission's Office of Engineering and Technology (OET) 
will act as a liaison for the Commission with any such multi-
stakeholder group so formed. In particular, the Commission expects the 
Office to observe the functioning of any such group and the technical 
concerns that it is considering to ensure that the group's activities 
are useful and pertinent. OET will provide guidance to any such group 
on the topics on which it would be most helpful for the Commission to 
receive input and a sense of the time frames in which such input would 
be helpful.

Equipment Issues

    108. LAntenna Requirements. The Commission requires that all low 
power devices incorporate permanently attached integrated antennas. 
Requiring an integrated antenna makes it significantly more difficult 
for a party to replace a device's antenna with a higher gain antenna, 
which could increase a device's EIRP above the limit and therefore 
increase the potential for a device to cause harmful interference.
    109. The Commission does not, however, require a permanently 
attached antenna for standard-power access points. The Commission finds 
that a requirement to use a permanently attached antenna on standard 
power access points could be overly restrictive. These types of devices 
are typically used outdoors by parties such as schools, businesses and 
WISPs and are configured in a manner where the antenna is mounted on a 
mast or building and connected through a cable to a separately located 
transmitter. Such a requirement could be difficult to implement for 
these configurations. In addition, permitting such devices a choice of 
appropriate antennas will provide options for meeting the antenna 
pointing restrictions which limit outdoor devices to antenna elevation 
angles less than 30 degrees for devices transmitting more than 21 dBm 
EIRP to protect satellite operations in the band. Further, the 
Commission notes that devices in other U-NII bands do not have a 
requirement for permanently attached antennas, so adding a requirement 
for equipment in the 6 GHz bands could make it more difficult for 
manufacturers to develop devices that are capable of operating across 
multiple bands. Consistent with the existing Part 15 rules, applicants 
for standard-power access point equipment authorizations will be 
required to list all types of antennas that will be used with a device 
and demonstrate that the equipment complies with the EIRP limits with 
all types of antennas with which it is authorized.
    110. Maximum Channel Bandwidth. Because the Commission is setting a 
power spectral density limit of 5 dBm/MHz for low power indoor devices 
to limit their potential for causing interference to incumbent 
services, the Commission permits these devices to operate with a 
maximum channel bandwidth to 320 megahertz to permit a maximum power of 
up to 30 dBm. For consistency the Commission also specifies a maximum 
bandwidth of 320 megahertz for AFC controlled standard-power access 
points.
    111. The Commission finds that this bandwidth requirement is 
appropriate for several reasons. It will permit manufacturers to 
develop equipment under current standards with bandwidths of up to 160 
megahertz as a number of parties suggest. In addition, the Commission's 
understanding is that industry standards under consideration such as 
IEEE 802.11be will specify channel bandwidths of up to 320 megahertz. 
Thus, a 320 megahertz bandwidth limit will permit future equipment 
development under anticipated standards without a need for additional 
rule changes. However, the Commission is placing a 320-megahertz upper 
limit on bandwidth so as not to supplant the rules for wideband and 
ultrawideband operations in the 6 GHz band. These rules permit 
operation with bandwidths greater than 500 megahertz, but with a lower 
-41 dBm/MHz power spectral density. The Commission notes that 
unlicensed proponents have not requested channels bandwidths greater 
than 320 megahertz and that the Commission did not provide notice of 
any proposed changes to the wideband or ultrawideband rules.
    112. Standard power transmitted power levels in rural areas. The 
Commission does not at this time permit higher power limits in rural 
areas, nor make any specific provisions for higher power point-to-point 
or point-to-multipoint operations in the U-NII-5 and U-NII-7 bands as 
suggested by some commenters. While the Commission recognizes that 
establishing

[[Page 31405]]

a single power limit of 36 dBm for standard-power access points differs 
from the rules for the U-NII-1 and U-NII-3 bands that permit higher 
power for fixed point-to-point devices, and from the white space rules 
that permit higher power for fixed devices in ``less congested'' (e.g., 
rural) areas, the Commission is not adopting higher power limits for 
several reasons. The Commission first notes that the rules adopted does 
not place an upper limit on antenna gain; the transmit limits are based 
solely on EIRP, and manufacturers can use any combination of 
transmitter power and antenna gain to reach that limit. The Commission 
interprets parties' requests for higher antenna gain limits as requests 
for higher EIRP limits. While allowing higher power could encourage the 
provision of additional services in rural and other areas, it also 
increases the range at which harmful interference to incumbent users in 
the bands could potentially occur. Therefore, the Commission is taking 
a conservative approach at this time and not permitting power levels 
greater than 36 dBm for standard-power access points. In addition, 
permitting higher power in only certain areas would make the AFC 
implementation more complex because criteria for where to allow higher 
power operation would have to be defined and incorporated into the AFC. 
Also, taking into account the directivity of standard-power access 
point transmit antennas as some parties suggest would make AFC 
calculations more complex.
    113. Client Device Transmit Power Levels. The Commission is 
adopting rules that limit client devices to power levels 6 dB below the 
power limits for access points. The Commission concludes that this 6 dB 
reduction is necessary because when the client device is operating 
under the control of the access point, the client device may have a 
slightly different propagation path and interference potential to a 
victim receiver.
    114. The Commission generally declines to increase client device 
power levels to the same power levels as access points, as suggested by 
some commenters. The Commission recognizes commenters concerns 
regarding the power differential between access points and client 
devices. However, because a client device may be portable (e.g., a cell 
phone) and operate at different locations around its serving access 
point, the propagation path of its emissions could vary. This could, in 
turn, slightly change the potential for interference from any 
particular client device to incumbent operations within the area. Thus, 
the Commission declines to adopt power limits for client devices 
commensurate with access points. However, the Commission makes two 
limited exceptions to this requirement.
    115. First, to the extent that an access point and a client device 
are both permanently fixed and operate under the control of an AFC 
system that provides a list of available frequencies to each device, 
each may operate at up to the maximum 36 dBm level. In such cases, the 
Commission does treat the client device as another access point with 
respect to operational rules, provided it complies with all of the 
requirements for access points, including using an AFC to obtain a list 
of available channels, having a geolocation capability and complying 
with the limit on upward antenna radiation from outdoor devices (no 
greater than 21 dBm at more than 30 degrees above the horizon). To 
distinguish these devices from actual access points for equipment 
certification purposes (as they differ in not having a direct 
connection to the internet), the Commission defines them as fixed 
client devices.
    116. The Commission also adopts an exception to accommodate devices 
such as Wi-Fi extenders and mesh networking equipment intended to work 
in conjunction with an indoor access point and share the same 
propagation path and thus the same power requirements. The Commission 
also permits other devices under certain conditions to operate at the 
full 5 dBm/MHz power spectral density. The Commission permits such 
devices to operate at the same power levels as an access point provided 
that they comply with all the requirements set out for low power indoor 
access points (i.e., the device cannot be weather resistant, must have 
an integrated antenna and cannot have capability of connecting other 
antennas, cannot be capable of operating on battery power, and must 
include a label regarding proper usage) and the end unit obtains its 
own equipment certification. Under these requirements modules do not 
qualify for higher power. Further, such devices may only be used within 
a single structure and not to connect separate buildings or structures. 
The Commission believes such relief is a reasonable accommodation to 
keep most popular consumer devices less complex and more affordable 
without increasing the potential of harmful interference to incumbent 
licensees as these devices will be installed and used in a manner 
analogous to an access point.
    117. The Commission does not find it necessary to restrict the 
power radiated upward from client devices as required for standard-
power access points. The Commission believes it is unlikely that 
relatively low-power unlicensed devices will cause harmful interference 
to receivers on geostationary satellites approximately 36,000 km above 
the equator. The Commission is limiting upward power from standard-
power access points merely as a precautionary measure as they are more 
likely to operate outdoors and with higher power. The Commission notes 
that client devices can operate with EIRP as high as 30 dBm, but finds 
that they are less likely to cause interference to satellite receivers 
than similarly powered outdoor access points due to the nature of their 
operation. The Commission first notes that client devices are limited 
to a power level 6 dB lower than access points, but the Commission 
expects them to generally operate at much lower power levels to 
maximize battery life and comply with RF exposure limits. In addition, 
client devices communicate with access points in an asymmetric nature, 
in that relatively little data is transmitted in the uplink direction 
(i.e., from the client device) as compared to the downlink direction 
where any single access point may be serving many client devices. 
Moreover, client devices typically operate with omnidirectional 
antennas at low antenna heights and in a mobile or portable mode (i.e., 
not installed in permanent outdoor locations). Thus, the Commission 
expects that upwardly directed client device emissions will often be at 
low power levels and shielded to some extent by buildings, foliage, or 
other obstructions.
    118. Emission Mask and Out-of-Band Emission Limits. The Commission 
concludes that the emission mask suggested by RKF Engineering, with 
certain modifications, protects incumbent microwave links and other 
services operating in the adjacent channel to unlicensed devices within 
the U-NII-5 through U-NII-8 bands. Accordingly, the Commission requires 
emissions from standard power access points and low power indoor 
devices within the U-NII-5 through U-NII-8 bands to comply with the 
transmit emission mask proposed in the Notice. Specifically, the 
Commission is requiring 20 dB suppression of power spectral density at 
one megahertz outside of an unlicensed device's channel edge, 28 dB 
suppression of power spectral density at one channel bandwidth from an 
unlicensed device's channel center, and 40 dB suppression of power 
spectral density at one and one-half times the channel bandwidth

[[Page 31406]]

away from an unlicensed device's channel center. At frequencies between 
one megahertz outside an unlicensed device's channel edge and one 
channel bandwidth from the center of the channel, the limits must be 
linearly interpolated between 20 dB and 28 dB suppression, and at 
frequencies between one and one and one-half time an unlicensed 
device's channel bandwidth from the center of the channel, the limits 
must be linearly interpolated between 28 dB and 40 dB suppression. 
Emissions removed from the channel center by more than one and one-half 
times the channel bandwidth, but within the U-NII-5 and U-NII-8 bands, 
must be suppressed by at least 40 dB.
    119. The Commission adopts a -27 dBm/MHz limit for emissions from 
all 6 GHz unlicensed devices at frequencies below the bottom of the U-
NII-5 band (5.925 GHz) and above the upper edge of the U-NII-8 band 
(7.125 GHz), but will not require it between the sub-bands, i.e., 
between the U-NII-5 and U-NII-6, the U-NII-6 and U-NII-7, and the U-
NII-7 and U-NII-8 bands. The Commission believes that a limit of -27 
dBm/MHz is necessary to protect services outside the U-NII-5 and U-NII-
8 bands, including the Intelligent Transportation Service below the U-
NII-5 band and federal government operations above the U-NII-8 band. 
The Commission is not requiring devices to meet this emission limit 
between the sub-bands as suggested by Sony because it is seeking to 
maximize spectrum use and it would stifle innovation by precluding the 
use of wide bandwidth channels (up to 320 megahertz) that straddle sub-
bands. Standards bodies have generally developed channeling plans for 
unlicensed devices based on technical characteristics, including 
devices' out-of-band emissions. Manufacturers will have the freedom to 
determine how they will meet this limit either by reducing power 
levels, through filtering or through other means, such as not enabling 
channels closest to the U-NII-5 and U-NII-8 band edges.
    120. Finally, the Commission addresses the measurement procedures 
for 6 GHz unlicensed devices. To protect Intelligent Transportation 
Services in the band below 6 GHz, 5GAA states that the -27 dBm/MHz 
standard the Commission is adopting, when based on a root-mean-square 
(RMS) measurement, is sufficient to protect those services from indoor 
device OOBE. RLAN proponents agree that the OOBE should be verified 
using an RMS detector or other appropriate techniques for measuring 
average power. The Commission agrees and will provide guidance to the 
test labs and telecommunications certification bodies which conduct 
equipment approval measurements and oversight that 6 GHz unlicensed 
device measurements may be conducted based on using an RMS detector. 
Because RMS measurements represent the continuous power being generated 
from a device as opposed to peak power which may only be reached 
occasionally and for short periods of time, the Commission believes an 
RMS measurement is more appropriate. The Commission notes that this is 
a departure from the Commission's measurement guidance for similar 
devices in the 5 GHz band where the Commission specifies a peak 
measurement. However, that procedure was instituted to mitigate a known 
interference issue with federal radars in the 5 GHz band. No such 
situation exists in the 6 GHz band. The Commission will update its 
Knowledge Database guidance consistent with this decision.
    121. Client Device Restrictions. The Commission adopts a 
requirement that client devices operate either under the control of a 
standard-power access point or a low-power access point. The purpose of 
this requirement is to prevent client devices from transmitting 
outdoors at locations where they may cause interference to a microwave 
receiver or other incumbent. When client devices are under the control 
of a standard-power access point, they will be in close proximity to 
the access point and may transmit only on frequencies that the AFC 
system has determined will not cause interference to fixed microwave 
links. When a client device is under the control of a low-power indoor 
access point, it should also be indoors and in close proximity to the 
access point, and therefore avoid presenting an interference risk to 
licensed services. However, the Commission also adopts an exception to 
this general requirement to allow a client device to transmit brief 
messages (``probe requests'') to an access point when attempting to 
join its network as discussed below.
    122. The Commission recognizes the utility of permitting probe 
requests to enable client devices to join an access point's network. 
However, these probe requests have the potential to cause harmful 
interference to licensed operations. The Commission therefore only 
permits a client device to send a probe request to an access point 
after it has detected a transmission from the access point. The client 
device will be required to send the probe request on the same frequency 
as the access point's transmission. This is consistent with the white 
space rules that permit a fixed white space device establishing a 
network to make brief transmissions on a frequency that it detects is 
in use by another fixed device prior to receiving a list of available 
channels from a database. Under this exception, because the client 
device will have to detect an access point transmission, the client 
device will only transmit when it is close enough to an access point to 
be under its control and on a frequency on which the access point has 
permission to transmit. This will prevent harmful interference from 
occurring.
    123. The Commission prohibits the use of client devices as mobile 
hotspots that could authorize the operation of other client devices. 
The rules the Commission adopts for AFC controlled operation of 
unlicensed access points are designed to prevent harmful interference 
to licensed stations by only allowing operation at locations where an 
access point and client devices directly communicating with it would 
not cause interference to licensed stations. Permitting a client device 
operating under the control of an access point to authorize the 
operation of additional client devices could potentially increase the 
distance between these additional client devices and the access point 
and increase the potential for harmful interference to fixed service 
receivers or electronic news gathering operations. For standard-power 
devices in the U-NII-5 and U-NII-7 bands hotspot operation could allow 
the additional client devices to transmit in locations where the AFC 
otherwise would prevent operation to protect incumbent service 
operations. With regard to low-power indoor access points, our rules 
are designed to prevent the low-power access points from being used 
outdoors which should also keep the client devices indoors. In 
addition, as APCO states, allowing such portable access points could 
make identifying and resolving interference difficult.

Making Portions of the 6 GHz Band Available for New Licensed Services

    124. The Commission declines the requests to repurpose substantial 
portions of the 6 GHz band for new licensed services in place of new 
unlicensed operations and existing incumbents. Most importantly, the 
Commission believes that providing new opportunities for unlicensed 
operations across the entire 6 GHz band can help address the critical 
need for providing additional spectrum resources for unlicensed 
operations. Making the entire band available for these unlicensed 
operations enables use of wide swaths of spectrum, including several 
160-megahertz channels as well

[[Page 31407]]

as 320-megahertz channels, which promotes more efficient and productive 
use of the spectrum, and would also help create a larger ecosystem in 
the 5 GHz and 6 GHz bands for U-NII devices. Repurposing large portions 
of the 6 GHz band for new licensed services would diminish the benefits 
of such use to the American public. Accordingly, the Commission agrees 
with the unlicensed proponents to reject these requests. Similarly, 
repurposing substantial portions of the band, as CTIA and Ericsson 
request substantially affects existing licensed services in the band. 
This is contrary to the Commission's goal in this proceeding to ensure 
that existing incumbents can continue to thrive in the 6 GHz band. 
Representatives of the incumbent fixed microwave services also raise 
concerns about the reasonableness and practicality of relocation, and 
question whether other appropriate spectrum can be found. The fixed 
satellite service commenters also strongly reject the contention of 
CTIA and Ericsson that satellite services would not need to be 
relocated because new licensed services would not cause harmful 
interference to the satellite services. Further, there is no certain or 
clear path for achieving what CTIA and Ericsson propose, and it would 
take years. For all of these reasons, the Commission will not take the 
approach suggested by CTIA and Ericsson to repurpose this band. By the 
actions the Commission takes today to open the entire 6 GHz band for 
new unlicensed operations, the American public will begin to see the 
benefits in the near term.
    125. The Commission also declines to reconsider the approach it is 
taking to authorize unlicensed low-power operations in the U-NII-6 
band. Ericsson asked to make the U-NII-6 band available for licensed 
indoor use rather than permitting unlicensed indoor use as proposed in 
the Notice. The Commission has made the entire 6 GHz band available for 
indoor low-power operations under rules that will protect incumbent 
operations across the band while also enabling use of wide channels 
that promote efficient use of the entire band. These unlicensed devices 
can provide the IoT applications envisioned by Ericsson in the entire 6 
GHz band while protecting incumbent operators from harmful 
interference.

Mobile Operations and Use in Moving Vehicles

    126. General prohibition on mobile operations. The Commission does 
not at this time permit standard-power and low-power indoor access 
points in the 6 GHz band to operate while in motion, with one exception 
in the U-NII-5 band with respect to large passenger aircraft operating 
over 10,000 feet. The Commission declines to permit operation in 
vehicles because of the potential for increasing interference to 
incumbent services. As a result, the use of unlicensed access points 
shall not be permitted in moving vehicles such as cars, trains, ships, 
or small aircraft. Also, the Commission is prohibiting unlicensed 
devices in the 6 GHz band to be installed on unmanned aircraft systems.
    127. As commenters note, the white space rules do provide a method 
that could enable personal/portable devices to operate while in motion 
by obtaining channel availability information for multiple locations 
and using this information to define a geographic area of operation. 
However, no personal/portable white space devices have yet been 
certified and such devices are limited to a lower power level than 
other white space devices. The Commission is concerned that allowing 
standard-power access points to operate while in motion would add 
complexity to the AFC system as it would need to continuously update 
available frequency lists for such devices, and that this could add 
substantial congestion to links connecting devices to the AFC, 
potentially degrading the quality of service for the expected 
predominant fixed access point use. Given the lack of a record as to 
the power levels and operational requirements that would be needed to 
permit mobile operation, the Commission will not permit mobile 
standard-power access point operation at this time.
    128. Similarly, the Commission rejects the Wi-Fi Alliance's 
position that it should consider the signal attenuation provided by the 
vehicle or the user's body to establish appropriate power levels to 
enable mobile and transportable operations. Unlicensed devices will 
have no way to determine whether they are within a car, train, or plane 
and therefore would not be able to adjust their output power 
accordingly.
    129. While the Commission is prohibiting the use of 6 GHz access 
points while in motion, the Commission is not prohibiting transportable 
devices, which the rules define as devices that ``are not intended to 
be used in motion, but rather at stationary locations.'' However 
transportable access points will have to otherwise comply with the 
rules the Commission adopting. That is, they will either operate under 
the control of an AFC system or they will have to operate only indoors. 
Indoor transportable access points will have to comply with all of the 
restrictions the Commission is adopting to prevent outdoor use.
    130. The Commission is prohibiting use of access points in cars, 
trains, and small aircraft because of the complications of using an AFC 
to control frequency access while in motion and because of the 
uncertain attenuation properties of these vehicles. Use of 6 GHz 
devices on ships raises the same issues as use in cars, trains, and 
aircraft regarding use of the AFC systems to protect licensees and lack 
of building attenuation when access points are used indoors. To address 
these issues and protect the earth exploration satellite service 
operations over oceans, the Commission also prohibits standard-power 
and low-power indoor access points aboard ships and on oil platforms.
    131. The Commission prohibits unlicensed devices in the 6 GHz 
band--whether standard-power or low-power devices--from operating on 
unmanned aircraft systems. Unmanned aircraft systems pose similar 
issues as other vehicles with the added complication of operating at 
significant height, and the Commission has no technical bases in the 
record to enable an evaluation of the potential harmful interference 
concerns posed by these systems. For the reasons it is not permitting 
standard-power and low-power indoor devices generally in vehicles, the 
Commission is not permitting them in unmanned aircraft systems.
    132. Exception for large aircraft operating above 10,000 feet. 
Boeing requests that that the Commission permit unlicensed operations 
aboard large aircraft when flying above 10,000 feet. The Commission 
agrees with Boeing that the fuselage of large passenger aircraft will 
provide significant attenuation of signals from unlicensed in-flight 
entertainment systems. The measured average signal attenuation from the 
fuselage of a large aircraft at 5 gigahertz is 17 dB, which is 
comparable to a building of traditional construction. The Commission 
does not expect the aircraft fuselage signal attenuation at 6 GHz to 
differ significantly from 5 GHz given the closeness in frequency. In 
addition, large passenger aircraft normally fly at high altitudes which 
will provide additional signal attenuation preventing signals from 
reaching terrestrial fixed and mobile receivers. The only potential 
area of concern would be if an aircraft flew through the main beam of a 
microwave link during take-off or landing. To address this concern, the 
Commission limits the use of low-power

[[Page 31408]]

access points for in-flight entertainment systems in aircraft to above 
10,000 feet. Because the only data on the signal attenuation from 
aircraft fuselage submitted on the record is for large passenger 
aircraft, the Commission shall also limit use to this type of aircraft. 
Finally, to prevent harmful interference to radio astronomy and earth 
exploration satellite service, the Commission limits airborne use of 
low-power access points to the U-NII-5 band where such passive 
scientific operations do not occur.

Microwave Links in the Gulf of Mexico

    133. The Commission does not find RigNet's technical study 
regarding aggregate interference from indoor unlicensed devices 
convincing for several reasons. RigNet's study presents a link budget 
analysis of aggregate interference to each of ten microwave receivers 
located on land. In each of the link budget calculations the study 
assumes that a number of access points ranging from 2 to 100 are 
present. For each receiver all the access points are assumed to be at 
the same distance from the microwave receiver, but this distance varies 
from 250 m to 5 km for the different receivers. The reason for assuming 
these distances and number of access points is not explained. The study 
assumes that the access points would transmit power at a power spectral 
density of 23 dBm/MHz and that there would be 11 dB of building loss. 
Because the Commission is only permitting access points to transmit at 
5 dBm/MHz and, as discussed above, an appropriate assumption for 
building loss is 20.5 dB, the calculated signal from each access point 
should be 26.5 dB lower than what the study assumes. While the study 
does not discuss the propagation model used, from the pathloss shown in 
the link budgets it appears that free space was used for all cases. In 
addition, the study assumes that every access point was directly in the 
main beam of the microwave receiver, which is unrealistic considering 
the height of the microwave receivers compared to the likely height of 
the indoor access points. Thus, the Commission believes the calculated 
interference levels should be at least 50 dB lower than what RigNet's 
study finds. This is consistent with the Commission's conclusion that 
microwave receivers will not experience harmful interference from 
indoor access points. With respect to AFC-controlled devices, RigNet's 
microwave links will be protected by the AFC as would any other 
microwave link licensed in the 6 GHz band. RigNet's microwave network 
appears to be no different from any other microwave links, which our 
new unlicensed rules are designed to protect from harmful interference. 
Accordingly, the Commission's rules do not exclude the Gulf of Mexico 
from unlicensed operations.

Ultra-Wideband and Wideband

    134. The Commission declines to adopt specific provisions to 
provide special protections for ultra-wideband and wideband devices. As 
ultra-wideband and wideband devices operate under Part 15 unlicensed 
rules, taking such action would effectively provide those devices with 
a level of interference protection to which they are not entitled. 
Ultra-wideband and wideband devices are permitted to operate at a 
variety of power levels, all of which are below -41.3 dBm/MHz. These 
devices also operate over large bandwidths that are typically allocated 
to a variety of services.
    135. The Commission notes that ultra-wideband and wideband devices, 
as with all unlicensed devices operating under our Part 15 rules, are 
subject to the condition that they may receive interference--including 
interference from other unlicensed devices. Unlicensed Part 15 devices 
have no vested right in the continued use of any particular block of 
spectrum. Moreover, ultra-wideband and wideband devices operate across 
a varied spectrum landscape with different types of licensed services 
(in this case, microwave links and satellite uplinks) that are governed 
by differing service and technical rules. Thus, by their nature, 
wideband and wideband devices must be designed to tolerate varying 
levels of interference with no assurance of an interference-free 
operating environment.
    136. All of the provisions that the ultra-wideband and wideband 
advocates request would in effect reserve spectrum in a manner that the 
Commission has not previously contemplated or proposed for such 
devices. The Commission declines to let the spectrum provisions 
applicable to ultra-wideband and wideband devices preclude the 
provision of other services that the Commission has widely permitted 
under the unlicensed framework applicable to the U-NII bands. The 
Commission's experience with the 2.4 GHz and existing U-NII bands has 
shown that the adoption of technology neutral rules has resulted in an 
explosion of innovation and the widespread adoption of unlicensed 
technologies by consumers and businesses. The Commission expects a 
similar experience to occur in the 6 GHz band. If the Commission were 
to adopt the suggested limitations on power levels, available spectrum, 
and duty cycle it would limit the range and data rates of the new 
unlicensed devices in a way that limits their utility. The Commission 
finds that it would not be in the public interest to restrict the use 
of the 6 GHz band unlicensed devices in this way. However, the 
Commission notes that the contention-based protocol requirement it is 
adopting for low power indoor devices will limit the unlicensed device 
duty cycle and that it could also detect the presence of ultra-wideband 
and wideband devices. The Commission encourages ultra-wideband and 
wideband interests to work with standards bodies to explore protocols 
that may enhance those devices coexistence with new 6 GHz unlicensed 
devices.
    137. Additionally, the record provides compelling evidence of 
circumstances where unlicensed devices operating under both the 
existing and new rules will be able to peacefully co-exist. A study 
submitted by Broadcom indicates that wideband devices may be able to 
operate outdoors in areas immediately adjacent to locations where 
unlicensed devices operating indoors under the new rules are deployed 
and that, where devices are in close proximity, users will likely be 
able to promote co-existence by adjusting the positioning of UWB and 
RLAN devices. Thus, for ultra-wideband and wideband devices employed in 
industrial applications and other indoor locations, the facility owner 
will be able to exercise control over the use and placement of new 
unlicensed devices, and if necessary, can choose which devices to 
deploy to avoid unwanted interference. In addition, according to data 
submitted by CableLabs, the weighted average of the activity factor for 
Wi-Fi is 0.4% which is below the 0.5% activity factor suggested by the 
ultra-wideband and wideband proponents to enable co-existence. Thus, 
the Commission has reason to believe that in many cases ultra-wideband 
and wideband devices will be able to operate in the presence of new 
devices that will operate under the new 6 GHz unlicensed rules.

Synchronized Unlicensed Operation

    138. Qualcomm requests that the Commission adopt a rule which it 
claims will permit access points that use synchronized contention 
windows to operate without disadvantaging other technologies. The 
specific rule that Qualcomm requests would establish a synchronized 
mode for unlicensed devices with contention windows every 6 
milliseconds.

[[Page 31409]]

    139. The Commission has historically adopted rules that are 
technologically neutral and remains committed to this policy. This is 
reflected by our U-NII rules which do not require the use of a 
particular contention method for unlicensed devices to share access to 
spectrum. The Commission's embrace of technology neutrality has 
encouraged the development of a vast variety of unlicensed devices 
operating under our Part 15 rules. In fact, Qualcomm has endorsed our 
policy stating that this ``approach to both licensed and unlicensed 
spectrum bands has supported perpetual innovation by the entire 
wireless industry'' and that ``[t]here is no question that the FCC 
should continue its successful tech neutral policy to existing and 
future spectrum bands.'' While there may be ways to increase spectrum 
efficiency by synchronization as Qualcomm advocates, this would 
necessarily require restricting the flexibility that Part 15 has 
permitted to U-NII devices. The Commission does not believe that this 
would be an acceptable tradeoff and rejects Qualcomm's request.
    140. The Commission also does not find convincing Qualcomm's 
contention that granting its request would be in keeping with our 
technology neutral policy. The Commission agrees with HP Enterprise 
that ``far from being technologically neutral, the stated purpose of 
[Qualcomm's] proposal is to advantage one specific type of unlicensed 
technology over all others.'' The Commission also expects that 
technologies other than IEEE 801.11be (EHT) or 5G NR-U will be used by 
unlicensed devices in this band and do not see any reason to place 
limitations on their operation.

Digital Identifying Information

    141. The Commission declines to adopt a requirement that 6 GHz 
unlicensed devices transmit digital identifying information. To impose 
such a requirement requires the Commission to mandate a modulation 
format for the transmitted information, which necessarily imposes 
restrictions on the development of unlicensed technology in the band. 
Given that the record has provided no details on how this requirement 
will help resolve interference, the Commission does not believe that 
imposing this requirement can be justified. The Commission also agrees 
with those commenters who express concern that this requirement could 
intrude upon the privacy of device users by facilitating tracking of 
devices.

Benefits and Costs

    142. Making available 1200 megahertz of spectrum in the 6 GHz band 
for new types of unlicensed use will yield important economic benefits 
and will allow more extensive use of technologies such as Wi-Fi and 
Bluetooth by American consumers. Consumers are using more and more 
data, on average, and this is expected to continue to grow 
significantly. As demand for data increases, making more spectrum 
available for two types of unlicensed use--standard-power and low-power 
indoor--will provide economic benefits by relieving potential 
congestion, allowing more users to access these new bands, and 
potentially making new use cases possible. As noted above, the ability 
of unlicensed devices to use significant portions of this band may also 
complement new licensed 5G services by allowing providers to offer a 
full range of services to consumers and will help to secure U.S. 
leadership in the next generation of wireless services. One report 
cited by several commenters estimates that in 2018, the economic 
benefits associated with Wi-Fi in the United States was valued at 
almost $500 billion. A further report estimated that these new rules 
will produce over $150 billion in economic value. In some ways, 
unlicensed usage on the new spectrum will be more restricted than for 
current Wi-Fi usage due to the AFC and lower power limits. However, in 
the United States, Wi-Fi currently operates in different bands over 
nearly 700 megahertz of spectrum, none of which enables channels as 
large as 160 megahertz. Making an additional 1200 megahertz of 6 GHz 
spectrum available for unlicensed use, including enabling the use of 
160-megahertz channels that will lead to expanded throughput, capacity, 
and performance will have a significant economic benefit.
    143. The Commission notes, however, that the new rules for 
unlicensed spectrum use could impose some economic costs if harmful 
interference to incumbent services occurs. As explained above, the 
technical and operational rules are designed to minimize the potential 
interference to incumbent licensed uses. While under the rules there 
can be interference with ultra-wideband and wideband applications, 
these costs will be lower than the total U.S. economic value for ultra-
wideband and wideband products, which in turn, are lower than the total 
economic value of new unlicensed use. The CableLabs study gives reason 
to believe that interference with ultra-wideband and wideband will only 
be intermittent, so that coexistence with new users will be possible. 
Further, when ultra-wideband and wideband use is specific to an indoor 
facility, it will be feasible for facility owners to prevent 
interference by regulating use of unlicensed activity within the 
facility. Thus, in most cases, the full value of ultra-wideband or 
wideband will be preserved, with only management costs incurred by 
facility owners. While the Commission is unable to precisely estimate 
the value of U.S. ultra-wideband and wideband, one market research firm 
cited the global value of the ultra-wideband industry will be $85.4 
million in 2022. In addition, the Commission notes that revenues from a 
non-exhaustive list of U.S. firms producing ultra-wideband products, 
among others, imply that even if costs are incurred, they will be 
significantly less than the potential hundreds of billions of dollars 
of economic value created. Overall, while the Commission identifies 
some economic costs, the Commission believes that they are limited and 
do not outweigh the substantial economic benefits of making such a 
large amount of spectrum available for unlicensed use.

Procedural Matters

    144. Final Regulatory Flexibility Analysis.--As required by the 
Regulatory Flexibility Act of 1980 (RFA), as amended, the Commission 
has prepared a Final Regulatory Flexibility Analysis (FRFA) regarding 
the possible significant economic impact on small entities of the 
policies and rules adopted in this First Report and Order, which is 
found in Appendix B of the link provided in the beginning of this 
SUPPLEMENTARY INFORMATION section. The Commission's Consumer and 
Governmental Affairs Bureau, Reference Information Center, will send a 
copy of the Report and Order, including the FRFA, to the Chief Counsel 
for Advocacy of the Small Business Administration.
    145. Paperwork Reduction Act Analysis.--This document does not 
contain new or modified information collection requirements subject to 
the Paperwork Reduction Act of 1995 (PRA), Public Law 104-13. In 
addition, therefore, 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).
    146. Congressional Review Act.--The Commission has determined, and 
the Administrator of the Office of Information and Regulatory Affairs,

[[Page 31410]]

Office of Management and Budget, concurs that this rule is 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).

Ordering Clauses

    147. Accordingly, it is ordered, 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, and Section 1.411 of the Commission's Rules, 47 
CFR 1.411; that this Report and Order and Further Notice of Proposed 
Rulemaking, is hereby adopted.
    148. It is further ordered that the amendments of the Commission's 
rules as set forth in Appendix A are adopted, effective sixty days from 
the date of publication in the Federal Register.
    149. It is further ordered that the Commission's Consumer and 
Governmental Affairs Bureau, Reference Information Center, shall send a 
copy of this Report and Order and Further Notice of Proposed 
Rulemaking, including the Initial and Final Regulatory Flexibility 
Analyses, to the Chief Counsel for Advocacy of the Small Business 
Administration.
    150. It is further ordered that the Commission's Consumer and 
Governmental Affairs Bureau, Reference Information Center, shall send a 
copy of this Report and Order and Further Notice of Proposed 
Rulemaking, including the Initial and Final Regulatory Flexibility 
Analysis, 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

47 CFR Part 0

    Reporting and recordkeeping requirements, Telecommunications.

47 CFR Part 15

    Communications equipment, Radio.

Federal Communications Commission.
Cecilia Sigmund,
Federal Register Liaison Officer.

Final Rules

    For the reasons discussed in the preamble, the Federal 
Communications Commission amends 47 parts 0 and 15 as follows:

PART 0--COMMISSION ORGANIZATION

0
1. The authority citation for Part 0 continues to read as follows:

    Authority:  Secs. 5, 48 Stat. 1068, as amended; 47 U.S.C. 155.


0
2. Section 0.241 is amended by adding paragraph (k) to read as follows:


Sec.  0.241   Authority delegated.

* * * * *
    (k) The Chief of the Office of Engineering and Technology is 
delegated authority to administer the Automated Frequency Coordination 
(AFC) system and AFC system operator functions set forth in subpart E 
of part 15 of this chapter. The Chief is delegated authority to develop 
specific methods that will be used to designate AFC system operators; 
to designate AFC system operators; to develop procedures that these AFC 
system operators will use to ensure compliance with the requirements 
for AFC system operations; to make determinations regarding the 
continued acceptability of individual AFC system operators; and to 
perform other functions as needed for the administration of the AFC 
systems.

PART 15--RADIO FREQUENCY DEVICES

0
3. 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
4. Section 15.401 is revised to read as follows:


Sec.  15.401   Scope.

    This subpart sets out the regulations for unlicensed National 
Information Infrastructure (U-NII) devices operating in the 5.15-5.35 
GHz, 5.47-5.725 GHz, 5.725-5.85 GHz, and 5.925-7.125 GHz bands.

0
5. Section 15.403 is revised to read as follows:


Sec.  15.403   Definitions.

    Access Point (AP). A U-NII transceiver that operates either as a 
bridge in a peer-to-peer connection or as a connector between the wired 
and wireless segments of the network or as a relay between wireless 
network segments.
    Automated Frequency Coordination (AFC) System. A system that 
automatically determines and provides lists of which frequencies are 
available for use by standard power access points operating in the 
5.925-6.425 GHz and 6.525-6.875 GHz bands.
    Available Channel. A radio channel on which a Channel Availability 
Check has not identified the presence of a radar.
    Average Symbol Envelope Power. The average symbol envelope power is 
the average, taken over all symbols in the signaling alphabet, of the 
envelope power for each symbol.
    Channel Availability Check. A check during which the U-NII device 
listens on a particular radio channel to identify whether there is a 
radar operating on that radio channel.
    Channel Move Time. The time needed by a U-NII device to cease all 
transmissions on the current channel upon detection of a radar signal 
above the DFS detection threshold.
    Client Device. A U-NII device whose transmissions are generally 
under the control of an access point and is not capable of initiating a 
network
    Contention-based protocol. A protocol that allows multiple users to 
share the same spectrum by defining the events that must occur when two 
or more transmitters attempt to simultaneously access the same channel 
and establishing rules by which a transmitter provides reasonable 
opportunities for other transmitters to operate. Such a protocol may 
consist of procedures for initiating new transmissions, procedures for 
determining the state of the channel (available or unavailable), and 
procedures for managing retransmissions in the event of a busy channel.
    Digital modulation. The process by which the characteristics of a 
carrier wave are varied among a set of predetermined discrete values in 
accordance with a digital modulating function as specified in document 
ANSI C63.17-1998.
    Dynamic Frequency Selection (DFS) is a mechanism that dynamically 
detects signals from other systems and avoids co-channel operation with 
these systems, notably radar systems.
    DFS Detection Threshold. The required detection level defined by 
detecting a received signal strength (RSS) that is greater than a 
threshold specified, within the U-NII device channel bandwidth.
    Emission bandwidth. For purposes of this subpart the emission 
bandwidth is determined by measuring the width of the signal between 
two points, one below the carrier center frequency and one above the 
carrier center frequency, that are 26 dB down relative to the maximum 
level of the modulated carrier.
    Fixed client device. For the purpose of this subpart, a client 
device intended as customer premise equipment that is permanently 
attached to a structure, operates only on channels provided by an AFC, 
has a geolocation capability, and complies with antenna pointing angle 
requirements.

[[Page 31411]]

    Indoor Access Point. For the purpose of this subpart, an access 
point that operates in the 5.925-7.125 GHz band, is supplied power from 
a wired connection, has an integrated antenna, is not battery powered, 
and does not have a weatherized enclosure.
    In-Service Monitoring. A mechanism to check a channel in use by the 
U-NII device for the presence of a radar.
    Non-Occupancy Period. The required period in which, once a channel 
has been recognized as containing a radar signal by a U-NII device, the 
channel will not be selected as an available channel.
    Operating Channel. Once a U-NII device starts to operate on an 
Available Channel then that channel becomes the Operating Channel.
    Maximum Power Spectral Density. The maximum power spectral density 
is the maximum power spectral density, within the specified measurement 
bandwidth, within the U-NII device operating band.
    Maximum Conducted Output Power. The total transmit power delivered 
to all antennas and antenna elements averaged across all symbols in the 
signaling alphabet when the transmitter is operating at its maximum 
power control level. Power must be summed across all antennas and 
antenna elements. The average must not include any time intervals 
during which the transmitter is off or is transmitting at a reduced 
power level. If multiple modes of operation are possible (e.g., 
alternative modulation methods), the maximum conducted output power is 
the highest total transmit power occurring in any mode.
    Power Spectral Density. The power spectral density is the total 
energy output per unit bandwidth from a pulse or sequence of pulses for 
which the transmit power is at its maximum level, divided by the total 
duration of the pulses. This total time does not include the time 
between pulses during which the transmit power is off or below its 
maximum level.
    Pulse. A pulse is a continuous transmission of a sequence of 
modulation symbols, during which the average symbol envelope power is 
constant.
    RLAN. Radio Local Area Network.
    Standard Power Access Point. An access point that operates in the 
5.925-6.425 GHz and 6.525-6.875 GHz bands pursuant to direction from an 
Automated Frequency Coordination System.
    Subordinate Device. For the purpose of this subpart, a device that 
operates in the 5.925-7.125 GHz band under the control of an Indoor 
Access Point, is supplied power from a wired connection, has an 
integrated antenna, is not battery powered, does not have a weatherized 
enclosure, and does not have a direct connection to the internet. 
Subordinate devices must not be used to connect devices between 
separate buildings or structures. Subordinate devices must be 
authorized under certification procedures in part 2 of this chapter. 
Modules may not be certified as subordinate devices.
    Transmit Power Control (TPC). A feature that enables a U-NII device 
to dynamically switch between several transmission power levels in the 
data transmission process.
    U-NII devices. Intentional radiators operating in the frequency 
bands 5.15-5.35 GHz, 5.470-5.85 GHz, 5.925-7125 GHz that use wideband 
digital modulation techniques and provide a wide array of high data 
rate mobile and fixed communications for individuals, businesses, and 
institutions.

0
6. Section 15.407 is amended by:
0
A. Redesignating paragraphs (a)(4) and (5) as (a)(11) and (12);
0
B. Adding paragraphs (a)(4) through (10);
0
C. Revising newly redesignated paragraph (a)(12);
0
D. Redesignating paragraphs (b)(5) through (8) as (b)(7) through (10);
0
E. Adding paragraphs (b)(5) and (6), (d) and (k) through (n).
    The additions and revisions read as follows.


Sec.  15.407   General technical requirements.

    (a) * * *
    (4) For a standard power access point and fixed client device 
operating in the 5.925-6.425 GHz and 6.525-6.875 GHz bands, the maximum 
power spectral density must not exceed 23 dBm e.i.r.p in any 1-
megahertz band. In addition, the maximum e.i.r.p. over the frequency 
band of operation must not exceed 36 dBm. For outdoor devices, the 
maximum e.i.r.p. at any elevation angle above 30 degrees as measured 
from the horizon must not exceed 125 mW (21 dBm).
    (5) For an indoor access point operating in the 5.925-7.125 GHz 
band, the maximum power spectral density must not exceed 5 dBm e.i.r.p. 
in any 1-megahertz band. In addition, the maximum e.i.r.p. over the 
frequency band of operation must not exceed 30 dBm.
    (6) For a subordinate device operating under the control of an 
indoor access point in the 5.925-7.125 GHz band, the maximum power 
spectral density must not exceed 5 dBm e.i.r.p in any 1-megahertz band, 
and the maximum e.i.r.p. over the frequency band of operation must not 
exceed 30 dBm.
    (7) For client devices, except for fixed client devices as defined 
in this subpart, operating under the control of a standard power access 
point in 5.925-6.425 GHz and 6.525-6.875 GHz bands, the maximum power 
spectral density must not exceed 17 dBm e.i.r.p. in any 1-megahertz 
band, and the maximum e.i.r.p. over the frequency band of operation 
must not exceed 30 dBm and the device must limit its power to no more 
than 6 dB below its associated standard power access point's authorized 
transmit power.
    (8) For client devices operating under the control of an indoor 
access point in the 5.925-7.125 GHz bands, the maximum power spectral 
density must not exceed -1 dBm e.i.r.p. in any 1-megahertz band, and 
the maximum e.i.r.p. over the frequency band of operation must not 
exceed 24 dBm.
    (9) Access points operating under the provisions of paragraphs 
(a)(5) and (a)(6) of this section must employ a permanently attached 
integrated antenna.
    (10) The maximum transmitter channel bandwidth for U-NII devices in 
the 5.925-7.125 GHz band is 320 megahertz
* * * * *
    (12) Power spectral density measurement. The maximum power spectral 
density is measured as either a conducted emission by direct connection 
of a calibrated test instrument to the equipment under test or a 
radiated measurement. Measurements in the 5.725-5.85 GHz band are made 
over a reference bandwidth of 500 kHz or the 26 dB emission bandwidth 
of the device, whichever is less. Measurements in all other bands are 
made over a bandwidth of 1 MHz or the 26 dB emission bandwidth of the 
device, whichever is less. A narrower resolution bandwidth can be used, 
provided that the measured power is integrated over the full reference 
bandwidth.
    (b) * * *
    (5) For transmitters operating within the 5.925-7.125 GHz band: Any 
emissions outside of the 5.925-7.125 GHz band must not exceed an 
e.i.r.p. of -27 dBm/MHz.
    (6) For transmitters operating within the 5.925-7.125 GHz bands: 
Power spectral density must be suppressed by 20 dB at 1 MHz outside of 
channel edge, by 28 dB at one channel bandwidth from the channel 
center, and by 40 dB at one- and one-half times the channel bandwidth 
away from channel center. At frequencies between one megahertz

[[Page 31412]]

outside an unlicensed device's channel edge and one channel bandwidth 
from the center of the channel, the limits must be linearly 
interpolated between 20 dB and 28 dB suppression, and at frequencies 
between one and one- and one-half times an unlicensed device's channel 
bandwidth, the limits must be linearly interpolated between 28 dB and 
40 dB suppression. Emissions removed from the channel center by more 
than one- and one-half times the channel bandwidth must be suppressed 
by at least 40 dB.
* * * * *
    (d) Operational restrictions for 6 GHz U-NII devices. (1) Operation 
of standard access points, fixed client devices and indoor access 
points in the 5.925-7.125 GHz band is prohibited on oil platforms, 
cars, trains, boats, and aircraft, except that indoor access points are 
permitted to operate in the 5.925-6.425 GHz bands in large aircraft 
while flying above 10,000 feet.
    (2) Operation of transmitters in the 5.925-7.125 GHz band is 
prohibited for control of or communications with unmanned aircraft 
systems.
    (3) Transmitters operating under the provisions of paragraphs 
(a)(5), (a)(6), and (a)(8) of this section are limited to indoor 
locations.
    (4) In the 5.925-7.125 GHz band, indoor access points and 
subordinate devices must bear the following statement in a conspicuous 
location on the device and in the user's manual: FCC regulations 
restrict operation of this device to indoor use only. The operation of 
this device is prohibited on oil platforms, cars, trains, boats, and 
aircraft, except that operation of this device is permitted in large 
aircraft while flying above 10,000 feet.
    (5) In the 5.925-7.125 GHz band, client devices, except fixed 
client devices, must operate under the control of a standard power 
access point, indoor access point or subordinate devices; Subordinate 
devices must operate under the control of an indoor access point. In 
all cases, an exception exists for transmitting brief messages to an 
access point when attempting to join its network after detecting a 
signal that confirms that an access point is operating on a particular 
channel. Access points and subordinate devices may connect to other 
access points or subordinate devices. Client devices are prohibited 
from connecting directly to another client device.
    (6) Indoor access points, subordinate devices and client devices 
operating in the 5.925-7.125 GHz band must employ a contention-based 
protocol.
    (7) Fixed client devices may only connect to a standard power 
access point.
* * * * *
    (k) Automated frequency coordination (AFC) system. (1) Standard 
power access points and fixed client devices operating under paragraph 
(a)(4) of this section must access an AFC system to determine the 
available frequencies and the maximum permissible power in each 
frequency range at their geographic coordinates prior to transmitting. 
Standard power access points and fixed client devices may transmit only 
on frequencies and at power levels that an AFC system indicates as 
available.
    (2) An AFC system must be capable of determining the available 
frequencies in steps of no greater than 3 dB below the maximum 
permissible e.i.r.p of 36 dBm, and down to at least a minimum level of 
21 dBm.
    (3) An AFC system must obtain information on protected services 
within the 5.925-6.425 GHz and 6.525-6.875 GHz bands from Commission 
databases and use that information to determine frequency availability 
for standard power access points and fixed client devices based on 
protection criteria specified in paragraph (l)(2) of this section.
    (4) An AFC system must use the information supplied by standard 
power access points and fixed client devices during registration, as 
set forth in this section, to determine available frequencies and the 
maximum permissible power in each frequency range for a standard power 
access point at any given location. All such determinations and 
assignments must be made in a non-discriminatory manner, consistent 
with this part.
    (5) An AFC system must store registered information in a secure 
database until a standard power access point or fixed client device 
ceases operation at a location. For the purpose of this paragraph, a 
standard power access point or fixed client device is considered to 
have ceased operation when that device has not contacted the AFC system 
for more than three months to verify frequency availability 
information.
    (6) An AFC system must verify the validity of the FCC identifier 
(FCC ID) of any standard power access point and fixed client device 
seeking access to its services prior to authorizing the access point to 
begin operation. A list of standard power access points with valid FCC 
IDs and the FCC IDs of those devices must be obtained from the 
Commission's Equipment Authorization System.
    (7) The general purposes of AFC system include:
    (i) Enacting all policies and procedures developed by the AFC 
system operators pursuant to this section.
    (ii) Registering, authenticating, and authorizing standard power 
access point and fixed client device operations, individually or 
through a network element device representing multiple standard power 
access points from the same operating network.
    (iii) Providing standard power access points and fixed client 
devices with the permissible frequencies and the maximum permissible 
power in each frequency range at their locations using propagation 
models and interference protection criteria defined in paragraph (l) of 
this section.
    (iv) Obtaining updated protected sites information from Commission 
databases.
    (8) Standard power access points and fixed client devices:
    (i) Must register with and be authorized by an AFC system prior to 
the standard power access point and fixed client device's initial 
service transmission, or after a standard power access point or fixed 
client device changes location, and must obtain a list of available 
frequencies and the maximum permissible power in each frequency range 
at the standard power access point and fixed client device's location.
    (ii) Must register with the AFC system by providing the following 
parameters: Geographic coordinates (latitude and longitude referenced 
to North American Datum 1983 (NAD 83)), antenna height above ground 
level, FCC identification number, and unique manufacturer's serial 
number. If any of these parameters change, the standard power access 
point or fixed client device must provide updated parameters to the AFC 
system. All information provided by the standard power access point and 
the fixed client device to the AFC system must be true, complete, 
correct, and made in good faith.
    (iii) Must provide the registration information to the AFC system 
either directly and individually or by a network element representing 
multiple standard power access points or fixed client devices from the 
same operating network. The standard power access point, fixed client 
device or its network element must register with the AFC system via any 
communication link, wired or wireless, outside 5.925-6.425 GHz and 
6.525-6.875 GHz bands.
    (iv) Must contact an AFC system at least once per day to obtain the 
latest list of available frequencies and the

[[Page 31413]]

maximum permissible power the standard power access point or fixed 
client device may operate with on each frequency at the standard power 
access point and fixed client device's location. If the standard power 
access point or fixed client device fails to successfully contact the 
AFC system during any given day, the standard power access point or 
fixed client device may continue to operate until 11:59 p.m. of the 
following day at which time it must cease operations until it re-
establishes contact with the AFC system and re-verifies its list of 
available frequencies and associated power levels.
    (v) Must incorporate adequate security measures to prevent it from 
accessing AFC systems not approved by the FCC and to ensure that 
unauthorized parties cannot modify the device to operate in a manner 
inconsistent with the rules and protection criteria set forth in this 
section and to ensure that communications between standard power access 
points, fixed client devices and AFC systems are secure to prevent 
corruption or unauthorized interception of data. Additionally, the AFC 
system must incorporate security measures to protect against 
unauthorized data input or alteration of stored data, including 
establishing communications authentication procedures between client 
devices and standard power access points.
    (9) Standard power access point and fixed client device geo-
location capability:
    (i) A standard power access point and a fixed client device must 
include either an internal geo-location capability or an integrated 
capability to securely connect to an external geolocation devices or 
service, to automatically determine the standard power access point's 
geographic coordinates and location uncertainty (in meters), with a 
confidence level of 95%. The standard power access point and fixed 
client device must report such coordinates and location uncertainty to 
an AFC system at the time of activation from a power-off condition.
    (ii) An external geo-location source may be connected to a standard 
power access point or fixed client device through either a wired or a 
wireless connection. A single geo-location source may provide location 
information to multiple standard power access points or fixed client 
devices.
    (iii) An external geo-location source must be connected to a 
standard power access point or fixed client device using a secure 
connection that ensures that only an external geo-location source 
approved for use with a standard power access point or fixed client 
device provides geographic coordinates to that standard power access 
point or fixed client device. Alternatively, an extender cable may be 
used to connect a remote receive antenna to a geo-location receiver 
within a standard power access point or fixed client device.
    (iv) The applicant for certification of a standard power access 
point or fixed client device must demonstrate the accuracy of the geo-
location method used and the location uncertainty. For standard power 
access points and fixed client devices that may not use an internal 
geo-location capability, this uncertainty must account for the accuracy 
of the geo-location source and the separation distance between such 
source and the standard power access point or fixed client device.
    (10) An AFC system operator will be designated for a five-year term 
which can be renewed by the Commission based on the operator's 
performance during the term. If an AFC system ceases operation, it must 
provide at least 30-days' notice to the Commission and transfer any 
registration data to another AFC system operator.
    (11) The Commission will designate one or more AFC system operators 
to provide service in the 5.925-6.425 GHz and 6.525-6.875 GHz bands.
    (12) The Commission may permit the functions of an AFC system, such 
as a data repository, registration, and query services, to be divided 
among multiple entities; however, entities designated as AFC system 
operators will be held accountable for the overall functioning and 
system administration of the AFC system.
    (13) The AFC system must ensure that all communications and 
interactions between the AFC system and standard power access points 
and fixed client devices are accurate and secure and that unauthorized 
parties cannot access or alter the database, or the list of available 
frequencies and associated powers sent to a standard power access 
point.
    (14) An AFC system must implement the terms of international 
agreements with Mexico and Canada.
    (15) Each AFC system operator designated by the Commission must:
    (i) Maintain a regularly updated AFC system database that contains 
the information described in this section, including incumbent's 
information and standard power access points and fixed client devices 
registration parameters.
    (ii) Establish and follow protocols and procedures to ensure 
compliance with the rules set forth in this part.
    (iii) Establish and follow protocols and procedures sufficient to 
ensure that all communications and interactions between the AFC system 
and standard power access points and fixed client devices are accurate 
and secure and that unauthorized parties cannot access or alter the AFC 
system, or the information transmitted from the AFC system to standard 
power access points or fixed client devices.
    (iv) Provide service for a five-year term. This term may be renewed 
at the Commission's discretion.
    (v) Respond in a timely manner to verify, correct, or remove, as 
appropriate, data in the event that the Commission or a party presents 
to the AFC system Operator a claim of inaccuracies in the AFC system. 
This requirement applies only to information that the Commission 
requires to be stored in the AFC system.
    (vi) Establish and follow protocols to comply with enforcement 
instructions from the Commission, including discontinuance of standard 
power access point operations in designated geographic areas.
    (16) An AFC system operator may charge fees for providing service 
in registration and channel availability functions. The Commission may, 
upon request, review the fees and can require changes to those fees if 
the Commission finds them unreasonable.
    (l) Incumbent Protection by AFC system: Fixed Microwave Services. A 
standard power access point or fixed client device must not cause 
harmful interference to fixed microwave services authorized to operate 
in the 5.925-6.425 GHz and 6.525-6.875 GHz bands. Based on the criteria 
set forth below, an AFC system must establish location and frequency-
based exclusion zones (both co-channel and adjacent channel) around 
fixed microwave receivers operating in the 5.925-6.425 GHz and 6.525-
6.875 GHz bands. Individual standard power access points and fixed 
client devices must not operate co-channel to fixed microwave system 
frequencies within co-channel exclusion zones, or on adjacent channel 
frequencies within adjacent channel exclusion zones.
    (1) Propagation Models: Propagation models to determine the 
appropriate separation distance between a standard power access point 
or a fixed client device and an incumbent fixed microwave service 
receiver. For a separation distance:
    (i) Up to 30 meters, the AFC system must use the free space path-
loss model.
    (ii) More than 30 meters and up to and including one kilometer, the 
AFC system must use the Wireless World Initiative New Radio phase II 
(WINNER II) model. The AFC system must use site-specific information, 
including buildings and terrain data, for

[[Page 31414]]

determining the line-of-sight/non-line-of-sight path component in the 
WINNER II model, where such data is available. For evaluating paths 
where such data is not available, the AFC system must use a 
probabilistic model combining the line-of-sight path and non-line-of-
sight path into a single path-loss as follows:

Path-loss (L) = [Sigma]i P(i) * Li = 
PLOS * LLOS + PNLOS * 
LNLOS,


where PLOS is the probability of line-of-sight, 
LLOS is the line-of-sight path loss, PNLOS is the 
probability of non-line-of sight, LNLOS is the non-line-of-
sight path loss, and L is the combined path loss. The WINNER II path 
loss models include a formula to determine PLOS as a 
function of antenna heights and distance. PNLOS is equal to 
(1-PLOS). In all cases, the AFC system will use the correct 
WINNER II parameters to match the morphology of the path between a 
standard power access point and a fixed microwave receiver (i.e., 
Urban, Suburban, or Rural).
    (iii) More than one kilometer, the AFC system must use Irregular 
Terrain Model (ITM) combined with the appropriate clutter model. To 
account for the effects of clutter, such as buildings and foliage, that 
the AFC system must combine the ITM with the ITU-R P.2108-0 (06/2017) 
clutter model for urban and suburban environments and the ITU-R P.452-
16 (07/2015) clutter model for rural environments. The AFC system 
should use the most appropriate clutter category for the local 
morphology when using ITU-R P.452-16. However, if detailed local 
information is not available, the ``Village Centre'' clutter category 
should be used. The AFC system must use 1 arc-second digital elevation 
terrain data and, for locations where such data is not available, the 
most granular available digital elevation terrain data.
    (2) Interference Protection Criteria:
    (i) The AFC system must use -6 dB I/N as the interference 
protection criteria in determining the size of the co-channel exclusion 
zone where I (interference) is the co-channel signal from the standard 
power access point or fixed client device at the fixed microwave 
service receiver, and N (noise) is background noise level at the fixed 
microwave service receiver.
    (ii) The AFC system must use -6 dB I/N as the interference 
protection criteria in determining the size of the adjacent channel 
exclusion zone, where I (interference) is the signal from the standard 
power access point or fixed client device's out of channel emissions at 
the fixed microwave service receiver and N (noise) is background noise 
level at the fixed microwave service receiver. The adjacent channel 
exclusion zone must be calculated based on the emissions requirements 
of paragraph (b)(6) of this section.
    (m) Incumbent Protection by AFC system: Radio Astronomy Services. 
The AFC system must enforce an exclusion zones to the following radio 
observatories that observe between 6650-6675.2 MHz: Arecibo 
Observatory, the Green Bank Observatory, the Very Large Array (VLA), 
the 10 Stations of the Very Long Baseline Array (VLBA), the Owens 
Valley Radio Observatory, and the Allen Telescope Array. The exclusion 
zone sizes are based on the radio line-of-sight and determined using 
\4/3\ earth curvature and the following formula:

dkm_los = 4.12 * (sqrt(Htx) + sqrt(Hrx)),


where Htx is the height of the unlicensed standard power access point 
or fixed client device and Hrx is the height of the radio astronomy 
antenna in meters above ground level. Coordinate locations of the radio 
observatories are listed in section 2.106, notes US 131 and US 385 of 
this part.
    (n) Incumbent Protection by AFC system: Fixed-Satellite Services. 
Standard power access points and fixed client devices located outdoors 
must limit their maximum e.i.r.p. at any elevation angle above 30 
degrees as measured from the horizon to 21 dBm (125 mW) to protect 
fixed satellite services.

[FR Doc. 2020-11236 Filed 5-22-20; 8:45 am]
BILLING CODE 6712-01-P