[Federal Register Volume 87, Number 93 (Friday, May 13, 2022)]
[Proposed Rules]
[Pages 29248-29271]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-09938]


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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Parts 15, 20, 22, 24, 25, 27, 30, 73, 74, 76, 78, 80, 87, 
90, 95, 96, and 101

[ET Docket No. 22-137; FCC 22-29 FRS 85531]


Promoting Efficient Use of Spectrum Through Improved Receiver 
Interference Immunity Performance

AGENCY: Federal Communications Commission.

ACTION: Proposed rule.

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SUMMARY: This document invites comments from all stakeholders in 
connection with the development of an up-to-date record on the role of 
receivers in spectrum management and how the Federal Communications 
Commission (Commission or FCC) might best promote improvements in 
receiver interference immunity performance that would serve the public 
interest. The Commission seeks to build upon the progress, including 
technological advances, in recent years that has enabled better 
receiver interference immunity performance, and the Commission seeks 
comment on where those efforts and advances have been most successful. 
The Commission also seeks to learn lessons from recent Commission 
proceedings in which receiver performance concerns have been prominent, 
to better inform the Commission as it considers how to ensure valuable 
and innovative services are able to thrive across the frequency range.

DATES: Comments are due on or before June 27, 2022, and reply comments 
are due on or before July 27, 2022.

FOR FURTHER INFORMATION CONTACT: Paul Murray of the Office of 
Engineering and Technology, at <a href="/cdn-cgi/l/email-protection#0e7e6f7b6220637b7c7c6f774e686d6d20696178"><span class="__cf_email__" data-cfemail="522233273e7c3f272020332b123431317c353d24">[email protected]</span></a> or (202) 418-0688, 
or Michael Ha of the Office of Engineering and Technology, at 
<a href="/cdn-cgi/l/email-protection#573a3e343f36323b793f361731343479303821"><span class="__cf_email__" data-cfemail="0b666268636a6e6725636a4b6d6868256c647d">[email protected]</span></a> or (202) 418-2099.

SUPPLEMENTARY INFORMATION: This is a summary of a document in, ET 
Docket No. 22-137, FCC 22-29, released April 21, 2022 (Notice of 
Inquiry). The full text of the document is available for inspection and 
copying during normal business hours in the FCC Reference Center (Room 
CY-A257), 45 L Street NE, Washington, DC 20554. The full text may also 
be downloaded at: https://www.fcc.gov/document/fcc-launches-proceeding-promoting-receiver-performance-0. People with Disabilities: To request 
materials in accessible formats for people with disabilities (braille, 
large print, electronic files, audio format), send an email to 
<a href="/cdn-cgi/l/email-protection#6d0b0e0e585d592d0b0e0e430a021b"><span class="__cf_email__" data-cfemail="f4929797c1c4c0b4929797da939b82">[email protected]</span></a> or call the Consumer & Governmental Affairs Bureau at 
(202) 418-0530 (voice), (202) 418-0432 (tty).

Synopsis

    In this document, the Commission takes a fresh look at the role of 
receiver performance in its spectrum management responsibilities, with 
the goal of facilitating new opportunities for use of its nation's 
spectrum resources. Forward-facing spectrum management necessitates 
that the Commission continuously promote more efficient spectrum use to 
enable the introduction of valuable new wireless services that benefit 
the American people. As spectrum use across the radio frequencies (RF) 
becomes more intensive, and services are packed more closely together, 
Commission spectrum management policies must consider potential 
efficiencies across all aspects

[[Page 29249]]

of wireless systems, not just transmitters but receivers as well. While 
the Commission has typically focused its rules on the transmitter side 
of radio systems, as several recent Commission proceedings have 
underscored, receivers and receiver interference immunity performance 
play an increasingly critical role in enabling more efficient spectrum 
use.
    The Commission seeks through this document to develop an up-to-date 
record on the role of receivers in spectrum management and how it might 
best promote improvements in receiver interference immunity performance 
that would serve the public interest. The Commission seeks to build 
upon the progress, including technological advances, in recent years 
that has enabled better receiver interference immunity performance, and 
the Commission seeks comment on where those efforts and advances have 
been most successful. The Commission also seeks to learn lessons from 
recent Commission proceedings in which receiver performance concerns 
have been prominent, to better inform the Commission as it considers 
how to ensure valuable and innovative services are able to thrive 
across the frequency range. To further assist the Commission's efforts, 
it also seeks to consider anew the efforts, reports, studies, and 
recommendations, including several of the Commission's Technological 
Advisory Council (TAC) White Papers, that have been proffered in recent 
years regarding the kinds of actions that the Commission should 
consider.
    In sum, the Commission begins the process of developing potential 
pathways for improvements in receiver performance, where and as 
appropriate, that will aid in making spectrum management more effective 
and provide more benefits to the American public. As the Commission 
discusses below, it recognizes that a variety of approaches may be 
appropriate, whether through industry-led voluntary measures, 
Commission policy and guidance, or rule requirements where other 
approaches would be insufficient. In this important first step the 
Commission seeks to compile a comprehensive record on the various 
issues that the Commission should consider, inviting broad comment from 
all stakeholders as the Commission considers these issues. The 
Commission looks forward to reviewing the record that develops from 
this Inquiry to inform us regarding possible next steps that the 
Commission may take in the future to promote efficient spectrum 
management in the public interest.

Background

    In 2003, the Commission adopted a Notice of Inquiry (NOI) to begin 
``consideration of incorporating receiver interference immunity 
performance specifications into its spectrum policy on a broader 
basis'' (68 FR 23677 (May 5, 2003)) (NOI on Receiver Performance 
Specifications). The Commission noted that incorporating receiver 
performance specifications could promote more efficient spectrum use 
and create opportunities for new and additional use of radio 
communications services by the American public. The Commission 
indicated that consideration of receiver interference performance 
specifications could be in the form of incentives, guidelines, or 
regulatory requirements (or a combination of these) in particular 
frequency bands, services or across bands and services.
    The 2003 NOI sought information, comment, and research concerning 
the immunity performance and interference tolerance of existing 
receivers, the possibilities for improving the level of receiver 
immunity in the various radio services, and potential impacts of 
receiver standards on innovation and the marketplace. In particular, 
the Commission sought comment on the following issues--receiver 
performance parameters (e.g., selectivity, sensitivity, dynamic range, 
automatic RF gain control, shielding, modulation method, and signal 
processing); the current RF environment and receiver interference 
immunity performance; various approaches that the Commission should 
consider for incorporating receiver interference immunity performance 
guidelines into spectrum policy (including voluntary industry 
standards, guidelines promulgated by the Commission, and mandatory 
standards); receiver performance in various radio services; the 
potential impact of receiver performance specification on innovation 
and the marketplace; and the treatment of existing receivers and the 
transition pathways to improved receivers.
    Several commenters responding to the 2003 NOI supported the 
Commission's further exploring interference immunity performance 
standards and agreed that improved receiver performance can help 
improve spectrum efficiency and ensure greater access to spectrum for 
all users; they differed, however, regarding the appropriate 
approach(es) and how to implement them with respect to particular 
bands. In 2007, the Commission terminated the proceeding ``without 
prejudice to its substantive merits.'' The Commission stated that, with 
the passage of time, the record had become outdated and that, to the 
extent that receiver interference immunity performance specifications 
are desirable, they could be addressed in proceedings that are 
frequency band or service specific.

Commission Rules on Receiver Performance Requirements

    As a general matter, the Commission's regulation of transmitters 
has at least implicitly provided for an RF environment that affects 
receiver performance insofar as the technical characteristics of 
receivers are expected to process those transmissions to successfully 
establish communications. The overall objective of that regulation has 
been to provide, through limits on power levels, in-band and out-of-
band emission limits, operational requirements regarding antennas, 
etc., an RF environment that facilitates those communications as much 
as possible. In some limited circumstances, the Commission has more 
directly addressed regulated receiver performance, both through 
performance standards and performance incentives, only in limited 
circumstances, such as in the examples that follow.
    800 MHz Band Public Safety Re-banding. In the 800 MHz public safety 
re-banding proceeding, minimum receiver performance was a major 
consideration when establishing whether a licensee operating in the 
band could claim entitlement to protection against ``unacceptable 
interference.'' Specifically, the Commission established a bright-line 
test for determining if a licensee is fully eligible to claim 
protection against ``unacceptable interference'' based on, among other 
factors, the characteristics of the receiver being employed by the 
licensee seeking protection.
    900 MHz Band. The Commission adopted for the 900 MHz band 
interference criteria similar to those established for the 800 MHz 
band. Like in the 800 MHz band, the Commission established a definition 
of ``unacceptable interference'' to 900 MHz narrowband licensees from 
900 MHz broadband licensees and established technical parameters 
including a receiver intermodulation rejection ratio, adjacent channel 
rejection ratio, and reference sensitivity.
    Digital Television. Improved receiver performance was a major 
consideration as the Commission prepared for the digital television 
(DTV) transition. Prior to that transition, the Commission adopted a 
series of decisions intended to help address issues regarding the 
conversion of analog TV to digital TV, a transition that was finalized 
in 2009. In planning for the DTV transition, the

[[Page 29250]]

Commission had anticipated the need for certain minimal receiver 
specifications. Several interested parties had recognized that 
voluntary transition might not be sufficient, and the Commission 
agreed, mandating receiver specifications for TV broadcast receivers in 
2002 that would go into effect after a specified phase-in period to 
ensure a smooth transition.
    Part 96 Citizens Broadband Radio Service. The Commission adopted 
rules in the 3.55-3.7 GHz Band governing reception limits for Citizens 
Broadband Radio Service users and incumbents that established 
``acceptable levels'' of in-band and adjacent band interference for 
operations. These limits apply to Priority Access Licensees, incumbent 
Fixed Satellite Service (FSS) earth stations in the 3.6-3.7 GHz band, 
and adjacent band FSS earth stations used for telemetry, tracking, and 
control. The Commission also established received signal strength 
limits for Citizens Broadband Service Devices (CBSDs) and required 
Spectrum Access System administrators to manage transmissions to ensure 
that aggregate signal strength remains below a fixed threshold between 
geographically adjacent service areas held by different licensees.
    Part 27 Broadband Radio Service/Educational Broadband Service. The 
Commission established rules that specify the minimum signal level 
below which Broadband Radio Service/Educational Broadband Service base 
station receivers in the 2496-2690 MHz band do not receive interference 
protection from co-channel base station transmitters not exceeding the 
height benchmark.
    Part 27 3.7 GHz Service. When authorizing the 3.7-3.98 GHz Band for 
flexible use, the Commission adopted rules to protect incumbent FSS 
earth stations from out of band emissions and blocking interference; 
these rules that require that transmitters are separated from FSS earth 
station receivers by 20 megahertz and meet both in-band and out-of-band 
power-flux density (PFD) limits as measured at each incumbent FSS earth 
station antenna and established specific protection criteria for earth 
stations used for telemetry, tracking, and control. The Commission also 
adopted rules that required passband filters to be installed on 
incumbent FSS earth station antennas and established a transition 
process to, in part, ensure that such filters are acquired and 
installed at each antenna.
    Part 80 Maritime Service. The Commission adopted several technical 
requirements, such as sensitivity and/or stability requirements, for 
certain receivers in the Maritime Services. It also has incorporated by 
reference standards for Global Maritime Distress and Safety System 
operations which include receiver operational and performance 
requirements.
    Part 87 Aviation Service. To maintain the accuracy of critical 
location information for applications such as aircraft precision 
landings, part 87 Aviation Service rules specify performance 
requirements for differential global positioning system (GPS) receivers 
(in the presence of undesired VHF-FM broadcast signals) relied upon for 
aviation safety purposes.
    Part 95 Personal Radio Services. To ensure that life-saving 
Personal Locating Beacons and Maritime Survivor Locating Beacons 
operate properly and do not further endanger those in distress and/or 
rescue personnel, these devices must meet technical standards 
incorporated by reference in the rules which include receiver 
operational and performance standards.

Recent Proceedings

    In several recent Commission proceedings, the receiver interference 
immunity performance associated with incumbent services operating in 
spectral proximity to new users or services has been a major 
consideration. In these cases, the ability of incumbent service 
receivers to reject signals outside their intended band has been 
directly relevant to the timing and scope of the introduction of new 
services.
    For example, in both the Ligado and the 3.7 GHz Band proceedings, 
the Commission adopted operating conditions and rules to enable the 
introduction of new operations into frequency bands with various 
incumbent users operating under different service allocations in the 
same band, adjacent band, or other spectrally proximate frequency 
bands. Although the factual circumstances of these two proceedings 
differ, both illustrate the challenges that systems face to co-exist 
and successfully operate when the spectral environment changes 
especially when incumbent systems may have been designed based on 
different assumptions about the RF environment in adjacent bands or 
other nearby frequency bands. These proceedings demonstrate that having 
accurate and timely information about receiver characteristics can be 
helpful in the Commission's analysis of potential harmful interference 
concerns and also highlight several other spectrum management issues 
that can arise with respect to receiver interference immunity 
performance, including receiver interference susceptibility, receiver 
selectivity, the impact of technological advancements (including 
filtering), and legacy devices.

Technological Advisory Council (TAC) White Papers and Workshops

    In recent years, the Commission's Technological Advisory Council 
(TAC) also has been engaged in examining various technical issues 
concerning receiver performance in several of the White Papers that the 
TAC has issued. In addition, the TAC has made several recommendations 
for the Commission's consideration on potential ways to promote the 
development and deployment of receivers that are more resilient to 
interference and could enable more efficient use of the Nation's 
spectrum resources.
    White Paper on Spectrum Efficiency Metrics. In 2011, the 
Commission's TAC issued a White Paper on ``spectrum efficiency 
metrics,'' which it viewed as an important factor in the Commission's 
spectrum management decisions. The TAC took an ``integrated systems 
approach'' in its evaluation of spectrum efficiency metrics, and noted 
that every component of a radio based communications system involved 
with either the transmission and/or reception of a signal has to be 
considered as part of efficiency. The TAC recognized a close 
relationship between spectrum efficiency and receiver standards/
guidelines or performance.
    White Papers on Interference Limits Policy and Harm Claim 
Thresholds. In 2013, the TAC issued a White Paper on Interference 
Limits Policy in which it explored potential policy--an ``interference 
limits policy,'' including harm claim thresholds--that it believed 
could promote more transparent consideration of receivers in spectrum 
management and promote better receiver performance. The TAC believed 
that the Commission could increase service density, reduce regulatory 
risk, and encourage investment with adoption of rules that make clear 
in which situations receivers and transmitters each will have the 
responsibility for mitigating any harmful interference, and doing so 
up-front rather than after lengthy post-dispute proceedings. This 
approach would state explicitly when receivers may claim harmful 
interference as a necessary complement to existing transmitter 
regulation that could facilitate more intensive frequency use by 
providing more clarity about the baseline regulatory and radio 
interference context going forward. In 2014, the TAC followed with 
issuing its White Paper on Harm Claim Thresholds, which provided 
additional discussion on an interference limits

[[Page 29251]]

policy focusing on harm claim threshold approaches.
    White Paper on Risk-informed Interference Assessment. In 2015, the 
TAC issued its White Paper on Risk-informed Interference Assessment. 
The TAC recommended that the Commission adopt risk-informed 
interference assessment and statistical service rules more widely to 
help improve its spectrum management decision-making. As risk-informed 
interference assessment would consider likelihood/consequence 
combinations for potential interference hazard scenarios involving 
transmitters and receivers; this tool could serve to complement a more 
static ``worst case'' analysis that considers the single scenario with 
the most severe consequence regardless of its likelihood.
    White Paper on Basic Principles for Assessing Compatibility of New 
Spectrum Allocations. In 2015, the TAC released another White Paper on 
Basic Principles for assessing compatibility of new spectrum 
allocations. It believed that a set of basic principles could be 
helpful for all involved parties to consider and could serve to 
establish clearer expectations of incumbent services as well as new 
services entering the spectrum. Several of the basic principles 
directly related to expectations regarding both transmitters and 
receivers. As contemplated, these principles sought to promote ``good 
neighbor policies'' among spectrum users that more effectively enable 
users to ``get along.''
    Commission workshops. In 2012, as part of the Commission's efforts 
to develop more effective spectrum management approaches that promote 
greater spectrum efficiency, the Commission's Office of Engineering and 
Technology, in conjunction with the Wireless Telecommunications Bureau 
and the Office of Strategic Planning, hosted a workshop on ``Spectrum 
Efficiency and Receiver Performance.'' In the workshop, the Offices and 
Bureaus pointed out that receiver performance has historically arisen 
in the context of conflicts between legacy stakeholders and new 
entrants, where deployments of new technologies and services threatens 
to adversely impact an incumbent or place restrictions on the new 
entrant. In 2014, the Commission's Office of Engineering and Technology 
(OET), in conjunction with the International Bureau (IB), Public Safety 
and Homeland Security Bureau (PSHSB), and Wireless Telecommunications 
Bureau (WTB), hosted another workshop, this one on ``GPS Protection and 
Receiver Performance.

Other Relevant Studies, Analyses, and Memoranda

    NTIA Report on Receiver Standards. In 2003, the same year that the 
Commission issued its NOI on Receiver Performance Specifications, the 
National Telecommunications and Information Administration (NTIA) 
issued a report on ``Receiver Spectrum Standards'' as part of its 
effort to explore promoting more interference-robust receivers. NTIA 
suggested several reasons why interference and efficiency problems were 
becoming more important. These included the dramatic increase in 
spectrum use, the introduction of new services and systems without 
standards needed for electromagnetic compatibility, design tradeoffs 
that favored inexpensive radio equipment rather than good performance, 
reduction in available guard bands, equipment manufacturers' lack of 
knowledge of characteristics of equipment operating in the same or 
adjacent bands, and increased receiver front-end bandwidth of 
receivers.
    CSMAC Report on Fostering Spectrum Sharing and Improving Spectrum 
Efficiency. In 2010, the Commerce Spectrum Management Advisory 
Committee (CSMAC) issued a report that among other things underscored 
the importance of receivers as tools in achieving greater spectrum 
efficiency. CSMAC recommended developing incentives for promoting 
better receivers and transmitters, promoting awareness of interference 
characteristics of receivers and transmitters, improving filter 
performance, promoting certainty and appropriate consideration of 
legacy devices, and taking technological advances into account 
regarding legacy equipment.
    Kwerel and Williams Paper on ``Forward Looking Interference 
Regulation.'' In 2011, Evan Kwerel and John Williams published a paper 
proposing that the Commission should provide better incentives to build 
more interference-robust systems in future allocations by moving away 
from a general interference protection model in spectrum management 
that often provides incumbent users protection against any interference 
resulting from subsequent rule changes. The paper asserted that the 
adjacent band interference protection for incumbents should not be 
static and recommended that incumbents be incentivized to ``self-
protect'' their wireless operations (including their receivers) against 
interference from adjacent bands (e.g., assuming that the adjacent band 
would be used for flexible use). The paper also noted certain market 
failures (e.g., lack of clarity regarding rights, holdout problems, 
transaction costs) that prevented efficient resolution of interference 
problems between incumbent users and new licensees through negotiation.
    Silicon Flatirons Reports--on Efficient Interference Management and 
on Receivers. In 2012 and 2013, the Silicon Flatirons Center issued two 
reports on spectrum management and receiver performance drawn from its 
roundtable conferences comprised of government, industry, and policy 
experts. The 2012 report on ``Efficient Interference Management: 
Regulation, Receivers, and Right Enforcement'' noted that receiver 
performance dramatically affects the coexistence of adjacent services, 
and further noted that while transmitters are required to control out-
of-band and spurious emissions to minimize interference, receivers are 
not generally required to minimize interference from such emissions. 
The report identified several recurring problems that should be 
addressed (e.g., incumbents not accounting for a changing RF 
environment, ``poor knowledge transfer'' among all of the affected 
parties regarding receiver interference problems that could enable 
potential resolution), and stated that it would be helpful if 
regulators could better anticipate the needs at band edges and provide 
proper notice to affected parties on the need for better receivers and 
that phase-in of any receiver regulation would be important. The second 
Silicon Flatirons report, ``Receivers, Interference, and Regulatory 
Options,'' also identified several problems that have made it difficult 
to improve receiver performance, including: Externalities (since the 
party who would bear the cost of improving receivers is not the party 
who benefits); ``asymmetric information'' (between incumbent users and 
adjacent band users seeking to mitigate interference but lacking 
information needed to effectively reduce interference); general lack of 
information for some of the parties affected; the need to understand 
costs and benefits (which could help enable creation of an incentive 
structure to improve receiver performance); and the need for more 
clarity about the RF environment. That report recommended improving 
transparency among operators and consumers creating more incentives to 
build more robust receivers (e.g., through issuance of a policy 
statement). Several on the panel also supported use of multi-
stakeholder groups to develop appropriate technical solutions. Finally, 
the report

[[Page 29252]]

recommended appropriate notice to stakeholders of any proposed changes 
and development of a transition plan.
    PCAST Report on Spectrum Sharing. In 2012, the President's Council 
of Advisors on Science and Technology (PCAST) issued a report that 
dedicated significant discussion to the important role of receivers and 
receiver performance for spectrum management and promoting more 
efficient use of spectrum. In particular, given that receiver 
characteristics can be a significant factor in limiting operations in 
adjacent spectrum bands, the report underscored the importance of 
knowing receiver characteristics for spectrum management among 
operations in adjacent bands. PCAST also made several observations and 
recommendations regarding receivers. It believed that different types 
of receivers may require different approaches to receiver management. 
It also supported consideration of the harm claims threshold approach 
for receiver interference limits.
    GAO Report on Receiver Performance. In 2013, the Government 
Accountability Office (GAO) issued its report, observed that while the 
Commission and NTIA have historically focused on transmitters, 
receivers also can play an important role in better spectrum 
management. GAO identified challenges related to improving receiver 
performance, including the lack of coordination across industries when 
developing voluntary standards, the lack of incentives for 
manufacturers or spectrum users to incur costs associated with using 
more robust receivers, and the difficulty of accommodating a changing 
spectrum environment. GAO also identified various options for 
consideration, including developing voluntary industry standards, 
creating a ``safe harbor'' in which compliance with industry standards 
would be a pre-requisite to claim harmful interference; mandatory 
standards, interference limits, and gathering additional information on 
spectrum use and the characteristics of systems (which it thought on 
the one hand could enable more informed decision-making while on the 
other raise concerns about disclosure of proprietary or classified 
information).
    Presidential Memorandum on Wireless Innovation. In 2013, President 
Obama issued a Presidential memorandum on ``Wireless Innovation,'' 
which included a section on receiver performance that encouraged the 
Commission, in consultation with NTIA, where appropriate, the industry, 
and other stakeholders, to develop to the fullest extent of its legal 
authority a program of performance criteria, ratings, and other 
measures, including standards, to encourage the design, manufacture, 
and sale of radio receivers such that emission levels resulting from 
reasonable use of adjacent spectrum will not endanger the functioning 
of the receiver or seriously degrade, obstruct, or repeatedly interrupt 
the operations of the receiver.
    International developments. Finally, the Commission note that 
international regulators and intergovernmental organizations also have 
discussed the importance of ensuring that receivers are appropriately 
designed in order to promote more efficient use of spectrum. For 
example, the International Telecommunication Union (ITU) ``Radio 
Regulations'' include several provisions that concern ``technical 
characteristics of stations'' associated with transmitter and receiver 
equipment and performance with respect to each other and in the context 
of promoting more efficient and effective use of spectrum, including 
Radio Regulations (RR) Nos. 3.3, 3.9, 3.11, 3.12, and 3.13. In 2014, 
the European Union (EU) issued Radio Equipment Directive 2014/53/EU, 
which recognized the important role of transmitter and receiver radio 
equipment in spectrum management. Among the Radio Equipment Directive 
``Essential Requirements'' is that radio equipment should be 
constructed so as to ensure ``an adequate level of electromagnetic 
compatibility'' and in a manner that ``both effectively uses and 
supports the efficient use of radio spectrum in order to avoid harmful 
interference.'' Additionally, the United Kingdom Ofcom's 2021 spectrum 
management strategy statement states that it is essential to encourage 
spectrum users to be more resilient to interference, and that operators 
should not generally expect Ofcom to take action on interference if it 
is a result of the poor performance of receivers or wider systems.

Discussion

    The Commission begins by discussing the critical role that receiver 
performance plays with regard to spectrum management and enabling more 
efficient use of spectrum. The Commission then inquires about a wide 
range of approaches that the Commission might consider to promote more 
efficient use of spectrum that will enable greater access to the 
Nation's spectrum resources for new services that will benefit 
Americans.

The Critical Role of Receiver Performance in Spectrum Management

    The Commission issues this document with the goal of considering 
various approaches that will enable us to reorient its spectrum 
management lens--from focusing primarily on the transmitter side of 
wireless networks to focusing on both the transmitter and receiver 
sides of wireless systems. Both are vital to the innovative and 
efficient use of spectrum. While the Commission has long relied on 
rules establishing particular transmitter requirements to promote 
spectrum efficiency and more intensive use, receiver performance also 
can significantly affect the Commission's ability to introduce new 
services in the same or nearby frequencies. In particular, receivers 
without sufficient interference immunity performance can diminish 
opportunities for innovative spectrum uses that drive economic growth, 
competition, security, and innovation. They can put constraints on what 
is possible in the evolving wireless world.
    Considering additional ways to promote more efficient use of 
spectrum by focusing on the role of both transmitters and receivers is 
even more important today than it was when the Commission initiated its 
earlier NOI on receiver performance in 2003. Continuous growth of and 
high demand for spectrum-based services makes this examination of 
receiver performance critical to more effective Commission spectrum 
management going forward. Greenfield spectrum--open and cleared for 
use--is hard to find in the current spectral environment. To make 
spectrum available for new and expanded services, existing spectrum 
users are packed into a more congested environment, as transmitters and 
receivers increasingly are situated in closer spectral and geographic 
proximity. In this congested environment, it is challenging to meet the 
demands for spectrum availability by simply relying on spectrum 
management tools used in the past. As the RF environment continues to 
change, receiver performance necessarily assumes greater importance in 
enabling more efficient spectrum use and effective spectrum management.
    In this document, the Commission inquires about the role of 
receivers as part of its broader exploration of policy tools that can 
harness new technologies and promote expanded and efficient spectrum 
use. The Commission seeks to develop a record on receiver performance 
across the RF spectrum, and on how the Commission might consider 
options that can promote more

[[Page 29253]]

efficient spectrum use, where and as appropriate, that can best serve 
the public interest. The Commission invites broad comment on the 
various approaches and questions posed in this document. The Commission 
encourages commenters to focus on risk-based assessments and science-
driven policy. As discussed below, the Commission recognizes that a 
variety of approaches may be appropriate, including industry-led 
voluntary measures, clearer Commission policy and guidance, and, where 
other approaches may be insufficient, requiring specified levels of 
performance. Different approaches may be appropriate depending on the 
particular circumstances, including the types of services involved, and 
the Commission invites comment to help guide the Commission's 
considerations. The Commission anticipates that commenters will discuss 
a range of options for possible industry and government actions, 
including those described below, as well as how best to implement any 
new policies in a manner that establishes clearer interference-related 
rights and responsibilities among spectrum users that can promote more 
efficient spectrum use while also driving innovation and serving the 
public interest.

Considerations for Promoting Receiver Interference Immunity Performance

    As set forth below, the Commission inquires about a number of 
different considerations as the Commission evaluates approaches for 
promoting improved receiver interference immunity performance. The 
Commission invites comment on each of these approaches while also 
recognizing that some approaches may be more effective than others for 
addressing receiver performance concerns in particular situations, and 
that some mix of approaches may best serve the public interest.

Receiver Performance Parameters

    Inquiring about receiver performance parameters, or how they, along 
with transmitter parameters define the RF environment, is essential to 
understanding what actions, if any, the Commission should consider 
taking. In the 2003 NOI on Receiver Performance Specifications, the 
Commission similarly sought comment on what receiver performance 
parameters the Commission should consider. As the NOI on Receiver 
Performance Specifications recognized, a radio receiver's immunity to 
interference is dependent on a number of factors in its technical 
design and, in addition, the characteristics of the signals it 
receives; these factors may be closely related and interdependent, and 
a receiver's performance in one factor may often affect its performance 
in others. The NOI then identified several parameters--including 
selectivity, sensitivity, dynamic range, automatic RF gain control, 
shielding, modulation method, and signal processing--and requested 
comment and information on these or any other factors and how they are 
related that should be considered.
    Subsequent efforts identified additional receiver parameters and 
engaged in further discussion on how such parameters could or should be 
considered by the Commission as it evaluates steps that it might take 
to promote receiver performance. These include, for instance, 
discussion in TAC White Papers, including the White Paper on 
Interference Limits Policy, the White Paper on Harm Claim Thresholds, 
and the White Paper on Risk-informed Interference Assessment, as well 
as the PCAST Report. CSMAC also emphasized the importance of developing 
more information on receiver filter performance, including working with 
the filter technology community on improving filter performance.
    Discussion. In this document, the Commission seeks information on 
receiver performance parameters that the Commission should consider, 
including those identified in the Commission's earlier NOI or others 
that commenters consider relevant, as the Commission continues to 
examine whether the Commission should consider ways to promote receiver 
performance where appropriate. In particular, the Commission seeks to 
update and refresh the information presented in any earlier Commission 
proceeding or studies identified above, as well as any other relevant 
information (studies, analyses, reports, etc.) or past experience that 
could be useful as the Commission considers receiver parameters and 
receiver performance matters.
    As the Commission previously noted, interference immunity is 
dependent on several factors in the receiver's technical design as well 
as the characteristics of the signal it receives. In considering 
approaches to advance receiver performance in ways that take receiver 
performance parameters into greater consideration, what specific 
parameters (e.g., selectivity, sensitivity, dynamic range, automatic RF 
gain control, shielding, modulation method, signal processing) should 
be considered? The Commission asks that commenters identify the various 
parameters (including but not limited to those listed here) as well as 
their typical ranges, that the Commission should consider.
    The Commission invites comment on whether there are specific 
receiver performance parameters that are more critical for allowing 
introduction of new services in the adjacent or neighboring bands 
without causing unacceptable interference. Are there any special 
hardware designs, software methodologies, or new technologies available 
that would significantly enhance receiver immunity performance? Are 
there techniques that can be used to improve these receiver performance 
parameters? How are various parameters interrelated? Are there factors 
that could or should be considered as a group and not independently due 
to their cross interactions or relationships with other factors? For 
example, to what extent does a receiver's selectivity and sensitivity 
affect its dynamic range? What are the various trade-offs that must be 
considered when optimizing these parameters when designing a receiver? 
Can receiver interference immunity parameters be ranked or rated in 
accordance with their level of importance to performance? If the 
Commission were to take action, what performance levels should be 
associated with each parameter? Should requirements differ by service? 
If so, how should they differ for various services? Should performance 
levels be required to change over time (i.e., require increased 
interference tolerance on a specified timescale or based on some 
triggering event)? Commenters advocating such an approach should 
provide details as to which parameters should change and over what 
timeframe or what the triggering events should be. What procedures or 
criteria should be used to determine how to trade off the level of 
receiver performance with the practical issues of cost and 
implementation?
    The Commission seeks comment on any recent technical advancements 
in receiver design that the Commission should consider. What is the 
state of the art currently and what advances are anticipated? Are there 
advancements that have made receivers more resilient or susceptible to 
interference? If so, the Commission requests comments on changes in 
design that improved or degraded interference immunity. What specific 
receiver parameters were affected? Are there organizations or 
industries that are particularly helpful in developing such technical 
advancements? What current or planned research projects, either 
industry or academia based, are focused on receiver

[[Page 29254]]

improvements? How can these organizations and projects help inform the 
Commission as it seeks to identify receiver parameters which, if 
changed, would lead to the greatest improvement in receiver 
performance? Is there any ongoing research related to how receiver 
design could affect or influence regulatory and policy issues and 
various approaches that the Commission could consider during rulemaking 
proceedings? Would it be appropriate or feasible for industry 
stakeholders to maintain a library of specifications, best practices, 
and trends of receiver interference immunity performance levels?
    The Commission requests comment on how receiver performance factors 
are related to frequency and operating power, and are these factors are 
influenced by the nature of the RF environment (e.g., how does 
anticipate in-band and out-of-band power affect receiver performance 
and influence design choices)? To what extent, and in what way, are 
certain factors that affect interference immunity relatively more 
important than others across different types of receivers used in 
different radio services or across devices that receive signals 
transmitted using different methods of modulation?
    In identifying the various receiver parameters on which the 
Commission or industry should focus, the Commission notes that there 
must be standard techniques to evaluate receivers to ensure that they 
meet any voluntary or required regulatory (including mandatory) 
benchmarks. The Commission further notes that unlike transmitter 
characteristics, many receiver parameters are inherently difficult to 
measure. The Commission seeks information on how receiver performance 
parameters can be measured, validated, and rated. Is there a subset of 
receiver performance parameters that can be easily measured and that 
also provide a reasonable characterization of receiver performance? Are 
there any industry standards for these types of measurements, created 
by standardization bodies such as the American National Standards 
Institute (ANSI), Institute of Electrical and Electronic Engineers 
(IEEE), 3rd Generation Partnership Project (3GPP), or European 
Telecommunications Standards Institute (ETSI) that could be helpful as 
the Commission considers various approaches for promoting receiver 
performance?

The RF Environment

    Understanding the RF environment in which radio services operate, 
both today and as anticipated in the future, provides important context 
for the Commission's considerations regarding how best to understand 
options that could promote better receiver interference immunity 
performance as part of improved spectrum management. The Commission 
seeks comment on the RF environment and how it should be factored into 
consideration.
    In the 2003 NOI, the Commission noted that ``existing receivers 
are, for the most part, built to provide interference immunity as 
determined necessary by their designer/manufacturer to provide 
satisfactory service'' which has ``resulted a wide range of immunity 
performance across products used within the same services and across 
services.'' Accordingly, the Commission sought comment and information 
on the interference immunity characteristics of receivers used in 
various radio services and how receivers performed in those services; 
as part of its inquiry, it requested information about how many units 
were at that time in service and about the expected service life of the 
receivers in various services. It also inquired about different 
receiver specifications that should be considered depending on the 
environment in which a receiver operates, or whether instead there 
should be a ``generic'' environment in which all receivers should be 
expected to perform adequately.
    Several studies and recommendations have emphasized the importance 
of the Commission and spectrum users to have knowledge of the 
characteristics of both transmitters and receivers in order to promote 
more efficient spectrum management. The TAC White Paper on Basic 
Principles for Assessing Compatibility of New Spectrum Allocations, for 
instance, included a principle that radio services would be ``expected 
to disclose the relevant standards, guidelines, and operating 
characteristics of their systems if they expect protection from harmful 
interference. Another report identified the need for more clarity about 
the RF environment, which could help inform operators about the type of 
systems they need to deploy; it also pointed out that not knowing 
system characteristics created a problem of ``asymmetric information'' 
insofar as the interference protection enjoyed by a receiving system in 
one band affects the ability of an adjacent service provider to 
operate, but that service provider usually does not have all the 
information needed to make choices that will reduce interference). That 
report also called for improving transparency for operators, including 
the sharing of more information on the characteristics of their 
neighbors' adjacent operations, establishing a device performance 
registry, and otherwise incentivizing operators to divulge helpful 
information.
    The CSMAC and PCAST reports also discussed the importance of having 
more information on receiver characteristics. CSMAC believed that new 
services acquiring or accessing spectrum should be made aware of the 
interference characteristics of receiving and transmitting equipment 
operating on frequencies that will be shared or used in adjacent bands. 
PCAST noted that, given that receiver characteristics can be a 
significant factor in limiting operations in adjacent spectrum bands, 
the report underscored the importance of knowing receiver 
characteristics for spectrum management among operations in adjacent 
bands. Further, GAO recognized that one option for helping improve 
spectrum management and decision-making would be for the Commission to 
gather more information on spectrum use and the characteristics of the 
systems, including receivers, although GAO thought that this would 
raise concerns about disclosure of proprietary or classified 
information.
    Finally, recent Commission proceedings have underscored the 
importance of having better information on receiver characteristics as 
the Commission exercises its spectrum management responsibilities. This 
information could enable the Commission to provide greater access to 
spectrum for new services, promote more efficient use of spectrum, and 
find ways to better understand the nature and extent of potential 
interference concerns that may arise with respect to the introduction 
of new services. It also could enable consideration of pathways to 
address legacy receivers that may raise particular concerns (e.g., 
identifying, modifying, repairing, replacing through transitions).
    The Commission requests comment on the current RF environment in 
which various services operate. What is the impact of that environment 
on the ability for adjacent and nearby operations? Have interference 
concerns been addressed effectively or ineffectively with regard to 
adjacent band services (e.g., use of guard bands, technical rules, 
etc.), or are there other relevant considerations regarding the current 
RF environment that can inform its consideration in the proceeding?
    As the Commission noted in the 2003 NOI, the receiver interference 
environment and demands placed on receiver performance have often been 
dependent on the specific type of

[[Page 29255]]

service provided on neighboring frequency bands. In that NOI, it sought 
comment on various operational environments and characteristics of the 
different types of services at that time (nearly 20 years ago)--
including satellite, public safety, mobile, fixed, and broadcast 
services--as they affected minimum receiver performance needs. It also 
noted that the types of operations and services occupying neighboring 
frequency bands often are a significant factor in the environment in 
which a receiver operates, and the Commission sought information on 
receiver performance issues of specific types of service and operations 
relating to both the in-band and out-of-band environments.
    The Commission again seeks comment on the current RF environment 
with respect to particular services--including various mobile services 
(terrestrial, aeronautical, satellite, maritime), fixed services 
(point-to-point microwave, point-to-multipoint, satellite), public 
safety services, broadcast services (fixed and mobile), and other 
services such as radionavigation, radiolocation, and sensing services 
used for scientific applications. The Commission is particularly 
interested in obtaining information on whether the RF environment and 
receiver interference immunity performance may have changed because of 
technological advancements, evolved spectrum management challenges, or 
changing spectrum use requirements in seeking to promote more efficient 
use of spectrum and greater access to spectrum for the introduction of 
new services. In asking about particular services, the Commission also 
invites comment on the extent to which considerations about receiver 
immunity performance parameters should be grouped based on these 
different service groupings, or whether instead some other analytical 
approach should be considered. Should there be different approaches to 
the Commission's consideration of receiver performance based on the 
particular services associated with the receiver, how the receiver 
might be integrated into other systems, and/or which services operate 
in adjacent or nearby bands?
    In seeking comment below, the Commission notes that significant 
effort over the last few years has been devoted to providing more 
broadband services to the American public. In making allocation 
decisions and crafting service rules to accommodate this evolving 
landscape, spectrum use has intensified and the Commission has 
increasingly explored ways to provide for these valuable services by 
creating adjacencies that, in the past, would never have been 
contemplated. As an example, in the 3.7 GHz Report and Order (85 FR 
22804 (April 23, 2020)), the Commission repurposed fixed satellite 
downlink spectrum for terrestrial mobile broadband services resulting 
in separation of relatively high power terrestrial services from 
sensitive satellite earth stations by only a 20-megahertz guard band. 
This decision necessitated a thorough examination of the new RF 
environment and adoption of appropriate rules to ensure the satellite 
services could coexist with the new terrestrial operations.
    In satellite services, receivers must be very sensitive to 
successfully receive the low level signals emanating from very distant 
satellites. As such, these receivers can be adversely affected by 
communications systems operating in adjacent or nearby bands. They may 
also experience interference from low level ambient noise sources that 
are below the minimum sensitivity level of typical receivers used in 
other radio services where the desired signal is significantly 
stronger. Whether satellite receivers could experience harmful 
interference effects from systems operating outside of the satellite 
bands depends on a variety of factors related to the types of 
operations in neighboring bands (e.g., fixed versus mobile) and the 
technical operating parameters of those services (e.g., power levels, 
out-of-band emissions (OOBE) limits, etc.), as well as the actual 
receiver interference immunity performance. The Commission invites 
comment on RF environment considerations with respect to satellite 
bands and adjacent or nearby band operations. What are the most 
important parameters to consider for services in adjacent bands to 
ensure compatibility with satellite services? The Commission seeks how 
best to characterize the adjacent band RF environment in reasonable 
performance metrics for satellite receivers. Is it anticipated that 
satellite receivers could improve their interference immunity? Over 
what time frame? How should the Commission characterize the RF 
environment for satellite services and the various trade-offs that are 
associated with providing full flexibility for services to operate in 
adjacent or nearby bands often with relatively higher power? What 
differences should be accounted for when considering fixed vs mobile 
and/or geosynchronous versus non-geosynchronous satellite operations? 
With today's demands for spectrum access to support new and innovative 
technologies, it is becoming increasingly necessary for the Commission 
to group unlike services adjacent to each other. To what extent, with 
today's technologies, is it necessary for the Commission to group like 
services adjacent to each other? As the Commission seeks to make more 
spectrum available for introduction of new services, including 
terrestrial services, what concerns and approaches should the 
Commission consider with respect to promoting improved receiver 
interference immunity to better accommodate the existing and 
anticipated future RF environment created by adjacent or nearby band 
operations?
    Public safety operations often have stringent operational 
requirements to assure users such as police, fire and emergency medical 
service providers whose missions often involve safety of life, that 
their RF-based systems will function reliably in all circumstances. 
Given these requirements, what should the Commission take into account 
when making allocation or service rule decisions for bands adjacent to 
and nearby frequency bands used for public safety? How should these 
requirements be considered given the receiver immunity characteristics 
of today's public safety radios? How is such receiver immunity 
anticipated to change in the future and how would that affect the 
Commission's flexibility to make spectrum allocation and service rule 
decisions in adjacent and nearby bands as the RF environment changes? 
The Commission invites comment on how public safety services operate in 
today's RF environment, including how receivers operate effectively 
without experiencing harmful interference from adjacent or nearby band 
services. Are there special considerations regarding the RF environment 
in which public safety services operate that the Commission should take 
into account as it considers approaches to promote receiver performance 
for these services?
    The Commission seeks similar information as it pertains to various 
mobile services, fixed services, broadcast services, and other 
services. Each service category presents different use cases with 
different dependencies on the RF environment. Mobile services include 
commercial mobile cellular networks that are characterized by a high 
degree of station and user density as well as movement of end-user 
devices in the vicinity of sectorized base stations with both fixed and 
steerable high gain antennas, public land mobile radio systems with 
comparatively lower density base stations and user devices but higher 
elevation base station antennas, and myriad other services

[[Page 29256]]

with distinct configurations and parameters. Fixed services are often 
characterized by highly directional (e.g., point-to-point microwave) 
transmit and receive antennas, engineered to meet very high link 
reliability requirements. Broadcast services are often characterized by 
very tall antennas radiating high-powered signals to user terminals, 
either mobile or in fixed locations over large distances. Transmitters 
and receivers that serve location (position), navigation, timing, and 
space-based sensing services also may have particular RF performance 
characteristics. While receivers used in all of these services perform 
similar functions (e.g., filtering, amplification, frequency 
conversion, etc.), the varied RF environment and applications for each 
service affect receiver design. How does the RF environment from 
adjacent and nearby bands affect the ability of users in each of these 
services to operate? What are the characteristics of current receivers 
that enable this coexistence and what is anticipated for future 
improvements? How does the current RF environment affect these services 
and how would more intensive spectrum use in the future change this RF 
environment? What steps can the Commission take to allocate services or 
assign users within and amongst these services with less spectral 
separation? What can users in these services do to adapt to the 
changing RF environment? Are there aspects of any of these services 
that may necessitate particular approaches to receiver performance, and 
if so what steps can be taken to ensure that receivers in any such 
service are sufficiently immune to interference from adjacent and 
nearby operations as the RF environment continues to change? Finally, 
the Commission asks if it should consider international implications 
for services that may have large international components, such as 
international flights or cargo shipping? Are there specific issues the 
Commission needs to consider regarding receivers that need to operate 
in a multitude of countries and territories? Commenters should address 
any international regulations (e.g., for aviation safety) that should 
be taken into account.
    Finally, the Commission invites comment on any other services that 
commenters believe have particular concerns not addressed above, and on 
which particular considerations should be given by the Commission with 
respect to RF environment.

Information on Transmitters and Receivers

    The Commission inquires below about what information is currently 
available regarding existing incumbent wireless systems--with respect 
to transmitter characteristics, receiver characteristics, and an 
``integrated systems analysis'' approach and receiver interference 
immunity performance concerns. In addition, the Commission requests 
comment below on the changing RF environment, including what kinds of 
changes are anticipated that the Commission might better prepare for, 
and how the Commission might establish its approaches that can 
effectively help ensure that receiver interference immunity performance 
concerns are addressed as the Commission takes future actions affecting 
the current RF environment to enable greater access to spectrum for new 
services and more efficient spectrum use.

Specific Information on Transmitter Characteristics

    The Commission notes that, under the its long-standing approach to 
providing for the introduction of new services, the Commission and 
relevant stakeholders generally already have much significant 
information already available to them about transmitter characteristics 
based on the Commission's existing regulatory framework in which 
transmitters in particular services are required to meet various 
technical parameters (e.g., power limits, antenna height, OOBE, etc.). 
This information is available for the transmitter operations whether 
authorized pursuant to rules associated with the licenses or authorized 
on an unlicensed basis (under part 15 rules). These rules often have 
been the primary means by which the Commission protects adjacent and 
nearby band operations, including incumbent receiver operations, from 
harmful interference.
    As the Commission discusses in this document, efficient spectrum 
management seeks to optimize the ability of different types of services 
to operate in different allocations under specified rules in a manner 
that does not cause harmful interference to others' operations. As the 
Commission considers approaches to promoting receiver interference 
immunity performance, both transmitter and receiver characteristics are 
important for its consideration. This information is useful on a range 
of spectrum management issues, including adjacent band interference 
concerns, interference limits policies such as harm claim thresholds, 
quantitative risk-based assessment of interference, legacy devices, and 
cost-benefits, among others.
    Discussion. The Commission invites comment on transmitter 
characteristics, as well whether more information would be useful as it 
pertains to the inquiry into receiver immunity performance.
    The Commission seeks comment on the availability of information on 
transmitter characteristics in various frequency bands and the 
different services allocated to those bands. The Commission notes, of 
course, that its rules already provide limits for transmitters (e.g., 
maximum power, OOBE limits, etc.), but the Commission seeks information 
on how typical operating values, both median and maximum levels, might 
differ from those regulatory limits. In cases where transmitters may 
typically operate below the regulatory limits, what factors influence 
those operating parameters? The Commission seeks this information for 
conducted and radiated power as well as for OOBE. How does the choice 
of antenna affect operational levels?
    The Commission also inquires about additional transmitter 
characteristics that might be helpful to the Commission as it considers 
spectrum management options to improve receiver performance. How can 
the Commission implement an integrated systems approach that could 
promote spectrum policy that balances the burdens on transmitters and 
receivers and promotes improved receiver interference immunity 
performance where appropriate? In this context, the Commission notes 
that transmitters and receivers in different radio services (e.g., 
fixed, mobile, satellite, broadcast, radio astronomy, etc.) have 
differing requirements. Should different metrics be used when 
evaluating systems in different services? What factors should the 
Commission take into account? In some instances, the Commission has 
used tools such as requiring PFD or field strength limits at various 
geographic boundaries or specific locations. Should the Commission use 
these techniques more often to provide additional protection to 
receivers? Likewise, are there requirements that can be placed on 
receivers if PFD, field strength limits, or other limits are placed on 
transmitters that would improve their immunity to harmful interference? 
What is the right balance for requiring either or both transmitters and 
receivers to comply with certain standards?

[[Page 29257]]

Specific Information on Receiver Characteristics

    The Commission requests up-to-date information on what is currently 
known about receiver characteristics with respect to different services 
and operations across the radio spectrum bands. As noted in the TAC 
White Paper on Interference Limits Policy and TAC White Paper on Risk-
informed Interference Assessment, relevant knowledge of both 
transmitter and receiver characteristics would be crucial for 
implementation of those approaches. Similarly, the White Paper on Basic 
Principles for Assessing Compatibility of New Spectrum Allocations 
recommended that services under Commission jurisdiction that seek 
protection from harmful interference should be expected to disclose the 
relevant standards, guidelines, and operating characteristics of their 
systems. While the Commission notes that several commenting parties 
supported gathering additional information on receiver characteristics, 
others opposed this based on proprietary and other concerns.
    In addition, some reports have emphasized the importance of clarity 
about the RF environment and how the lack of information (often in the 
form of asymmetric information) available to relevant stakeholders, 
particularly with regard to receiving systems, can impede the ability 
of parties seeking to introduce new services to make appropriate 
choices to reduce potential interference, and have recommended 
improving transparency for operators by requiring the sharing of more 
information on technical characteristics that affect adjacent band 
operations. GAO also identified a lack of sharing among different 
industries when developing receiver specifications, and noted that one 
option for the Commission would be to gather additional information on 
the characteristics of the different systems, including receiver 
characteristics. CSMAC also believed that new entrants accessing 
spectrum should be made aware of the interference characteristics of 
receiving and transmitting equipment, and noted that filter performance 
of both receivers and transmitters were important considerations. Both 
GAO and CSMAC suggested consideration of establishing a repository or 
clearinghouse of information. Several reports, including GAO's, also 
have noted that, were the Commission to consider requiring that more 
information on receiver characteristics be made available, such a 
requirement raises concerns about confidential, proprietary, or 
classified information.
    Discussion. The Commission invites comment on whether the 
Commission should consider requiring that more information about 
receiver characteristics be made available. Are there certain 
circumstances in which having additional information available to the 
Commission and relevant stakeholders would be helpful to introducing 
new services in adjacent or nearby bands? Could this information help 
serve the Commission's goal of providing for more efficient use of 
spectrum so that there is greater access to spectrum for new services? 
The Commission asks that commenters help the Commission as it considers 
whether to require additional information on receiver characteristics. 
If commenters support the availability of more information, the 
Commission invites commenters to indicate the types of information on 
receiver interference immunity performance would be most helpful in 
serving its goals of promoting more efficient use of spectrum and how 
best to manage the information.
    The Commission requests that commenters discuss particular contexts 
in which having more information on receiver characteristics would be 
helpful, provided of course that any proprietary or classified concerns 
can be effectively addressed. As discussed elsewhere in this document, 
having sufficient relevant information regarding both transmitters and 
receivers is seen as a critical ingredient to promoting more efficient 
use of spectrum and providing a more effective pathway for addressing 
issues related to legacy receivers. With regard to voluntary approaches 
in which potential adjacent band use is under consideration, 
information on receiver characteristics could be helpful to all 
relevant stakeholders in order to address interference concerns.
    The Commission seeks comment on whether there are services or bands 
in which commenters believe that additional information on receiver 
characteristics is not necessary, such as bands where necessary 
incentives are already in place for promoting receiver performance? On 
the other hand, what services or bands have insufficient available 
information on receiver characteristics, especially where the 
incentives are not sufficient with regard to promoting receiver 
performance? The Commission asks that commenter provide their thoughts 
about what factors the Commission might consider if it were to consider 
requiring the availability of more information on receiver 
characteristics.
    Also, as noted, if the Commission were to consider requiring that 
more information be provided regarding receiver characteristics, how 
should the Commission address concerns around proprietary information, 
or other concerns? As for propriety concerns, would, for instance, the 
Commission's existing procedures for addressing parties' proprietary 
concerns in proceedings be an appropriate model? The Commission invites 
commenters to assist the Commission as it considers any potential 
requirements regarding information on receiver characteristics and the 
need to protect information that should not be publicly disclosed.

Integrated Systems Analysis

    Understanding whole systems--both transmitters and receivers and 
their interaction under current rules and requirements can be an 
important consideration as the Commission seeks comment on the current 
RF environment. Two TAC White Papers proposed that the Commission focus 
more on an ``integrated systems'' approach as part of its spectrum 
management activities. An integrated systems approach takes into 
account every component of a radio based communication system involved 
with either the transmission and/or reception of a signal. The White 
Paper on Spectrum Efficiency Metrics discusses the potential role of an 
``integrated systems'' approach in more effectively evaluating spectrum 
efficiency metrics. The White Paper on Risk-informed Interference 
Assessment recommends that the Commission should seek to include in its 
assessment of harmful interference a quantitative risk analysis, one 
which considers the various likelihood/consequence combinations for 
multiple different potential interference hazard scenarios among 
transmitters and receivers, which would complement the Commission's 
evaluation of other assessments as it determines how best to serve the 
public interest. Both of these approaches require that relevant 
information on potentially affected radio systems be available--
including characteristics of both transmitters and receivers.
    As the Commission has noted above, several reports have called for 
more transparency with respect to relevant information on both 
transmitters and receivers. Some also have called for developing a 
repository of information on transmitters and receivers.
    Discussion. The Commission invites comment on whether the 
Commission should consider developing more of an integrated systems 
approach to spectrum management. What kinds of

[[Page 29258]]

information regarding transmitters and receivers would be relevant and 
helpful? Is there some way that more information on transmitters and 
receivers should be made more transparent and more readily available 
for the Commission or relevant stakeholders? To what extent would some 
form of repository be appropriate and helpful? If so, how would 
commenters suggest that any proprietary concerns be addressed.

Managing the Changing RF Environment

    As the Commission has discussed, the RF environment continues to 
change in face of the need for greater access to spectrum for new uses. 
Given this, it is critical to address considerations affecting 
potential adjacent and nearby band interference concerns in an 
appropriate and timely fashion. It is important that as the Commission 
anticipates these changes the relevant stakeholders (e.g., incumbents 
adjacent or nearby to bands that may be reallocated) are notified so 
that appropriate steps can be taken to address those stakeholders 
potentially affected. If improved receiver interference immunity 
performance would be appropriate, several also have recommended that 
the Commission provide for an appropriate transition or phase-in 
approach. GAO noted the lack of predictability about the changing 
future spectrum environment made it more difficult to accommodate 
repurposed uses of spectrum, and that it could take significant time 
and effort to upgrade and replace receivers where necessary.
    Discussion. The Commission seeks comment on how the Commission can 
promote smoother and more effective transitions among potentially 
affected users as the RF environment continues to change to accommodate 
greater access to spectrum that serve the public interest. What steps 
should be taken to provide for greater predictability or transparency 
for potentially affected stakeholders, including those whose receivers 
may potentially be affected? How much advance notice from the 
Commission might be appropriate to provide to potentially affected 
stakeholders as the RF environment continues to change? In what ways 
should such advance notice be provided? What steps should the 
Commission consider to identify and inform potentially affected 
incumbent operators? To the extent that commenters believe that any 
particular past experiences regarding particular steps that either were 
taken, or could or should have been helpful if taken, the Commission 
asks that commenters offer their thoughts and recommendations for the 
Commission's consideration as it seeks to develop policies and take 
actions that promote better transitions in the future.
    Also, considering that the RF environment can be anticipated to 
continue to change, the Commission seeks comment to whether and how the 
Commission could best clarify expectations for the performance of all 
radio equipment--both transmitters and receivers--in a changing RF 
environment. The Commission also invites comment on the importance of 
promoting more spectrally efficient devices that are designed to 
anticipate or assume that potential new uses of spectrum might occur in 
adjacent or nearby spectrum.
    The Commission notes that it also raises some of these issues in a 
separate section below on potential Commission policy and guidance. In 
that section, the Commission requests comment on whether the Commission 
should consider providing additional policy or guidance specifically as 
to expectations that would apply to transmitters and receivers in 
adjacent band operations, including regarding expectations relating to 
receiver interference immunity performance.

Approaches for Promoting Improved Receiver Interference Immunity 
Performance

    As the Commission seeks comment on various approaches to consider 
as it moves forward, it is important to provide an overall framework 
for considering how the Commission might incorporate receiver 
performance considerations into its spectrum management decision-
making. The Commission inquires about whether and how to factor 
receiver interference immunity performance into spectrum policy in the 
form of incentives, guidelines, or regulatory requirements. These could 
include industry-led voluntary approaches, such as industry-developed 
guidelines and standards. They also could include additional Commission 
guidance, whether in terms of clarifying Commission policy, issuing a 
policy statement, or considering ways to advance approaches such as an 
interference limits policy, and/or a harm claim threshold approach 
where that might be helpful. The Commission also notes that in 
particular circumstances it might want to consider adopting specific 
rule requirements if other approaches would not be sufficient.
    The Commission invites interested parties to provide their up-to-
date views, observations, and recommendations on these different types 
of approaches that it discuss below. The Commission envisions that 
these approaches could include industry-led voluntary guidelines and 
efforts, additional Commission policy or guidelines, and specific 
mandatory requirements, and can be part of the solution in promoting 
improved receiver performance where that may be appropriate. The 
Commission seeks general comment here as to how these different 
approaches can work together to help optimize the promotion of receiver 
performance and other system design measures that would reduce 
susceptibility to interference and best serve the public interest. The 
Commission invites comments on how it might find an appropriate balance 
or mix of these different approaches.

Industry-Led Voluntary Approaches

    In this section, the Commission requests that commenters provide 
up-to-date information on various industry-led voluntary approaches, 
including standards and guidelines, that currently promote receiver 
performance. The Commission requests comment on where voluntary 
approaches are effective, where they could be more effective, and what 
the Commission could consider in order to enhance the effectiveness of 
voluntary approaches.
    The Commission notes that in the 2003 NOI on Receiver Performance 
Specifications the Commission expressed a general preference for 
relying primarily on voluntary approaches and guidelines that are 
supported and managed by industry, in conjunction with user groups as 
appropriate, believing this approach is most flexible and responsive to 
changes in technology, consumer desires, and economic conditions. The 
Commission believes that spectrum users such as commercial spectrum 
licensees often have the requisite incentives to reach voluntary 
agreements that provide for additional spectrum use. At the same time, 
however, it recognized that a purely voluntary approach may produce an 
incumbency problem if owners of non-conforming receivers limit 
efficient use of spectrum. The Commission inquired specifically about 
various voluntary approaches at that time, and many commenters in that 
proceeding generally supported a voluntary approach to improving 
receivers (such as through development of industry standards and 
guidelines). Since that time, many have continued to assert that 
voluntary approaches are the most efficient and effective means of 
promoting receiver performance and promote more efficient use of 
spectrum.

[[Page 29259]]

    The Commission continues to believe that the development and 
implementation of various voluntary approaches, taken together 
throughout the wireless sector, in many situations can provide the best 
and most effective means of promoting interference immunity in the most 
efficient and effective way. The Commission seeks detailed comment on 
the various ways in which voluntary standards and guidelines have, and 
will continue to, serve its goal of promoting improvements in receiver 
performance that will enable greater access to spectrum. To what extent 
are voluntary approaches sufficient to ensure that minimum receiver 
interference immunity performance can be achieved in some or all bands?
    As the Commission considers voluntary standards and guidelines, the 
Commission also notes that several studies and commenters have pointed 
out challenges that may be associated with the development of voluntary 
approaches in certain situations, either because the necessary 
incentives may not be present or the necessary information may not be 
available. While describing several voluntary efforts have helped 
improve receiver interference immunity performance, GAO also noted that 
in many situations there were challenges that affect the development of 
voluntary standards, including the lack of coordination across 
industries when developing voluntary standards (e.g., while standards 
may be developed by a single industry, these standards may not be 
coordinated with representatives of others that could be affected, such 
as adjacent band users). GAO also noted that there could be a lack of 
incentives for manufacturers and spectrum users to incur costs 
associated with using more robust receivers (noting that there may be 
few incentives for users in one band to incur costs to improving 
receivers for operations if the adjacent band users gain the benefits); 
it concluded that, even though there can be sufficient incentives for 
addressing receiver performance within the same service, such 
incentives often do not exist for different services or adjacent band 
services.
    Several reports and commenters have suggested that voluntary 
approaches could benefit from the use of multi-stakeholder groups in 
helping develop appropriate voluntary standards. Several also noted, 
however, that oftentimes not all of the relevant stakeholders (e.g., 
those potentially affected by the development of voluntary standards, 
including those with interests associated with adjacent band use), 
participated in the development of voluntary standards.
    GAO also noted that a compendium of current industry standards or 
guidance may not always be available, and could help facilitate 
knowledge on any standards or guidelines. Finally, GAO pointed out 
that, while voluntary standards and guidelines could help promote 
receiver performance, the extent to which they are in fact used is 
generally unknown.
    Discussion. In this document, the Commission invites comment from 
interested parties to provide up-to-date information on the various 
voluntary approaches, including industry-led approaches, that currently 
serve to promote better receiver performance and generally more 
interference-resistant system designs. The Commission inquires about 
their views on the role of voluntary standards and guidelines to 
promote improved receiver performance by providing greater resilience 
to harmful interference, promote more efficient use of spectrum, and 
enable innovative new services to be introduced. The Commission also 
inquires about the steps it might take to promote development and use 
of voluntary standards and guidelines.
    The Commission invites comment on whether voluntary standards and 
guidelines that have previously existed or currently exist serve as an 
effective means of promoting receiver performance. What are these 
standards and guidelines, and how effective have they been in promoting 
receiver performance? Which industries helped to establish them, and 
which stakeholders were involved in their development? Are these 
standards or guidelines publicly available? The Commission invites 
broad comment on where these approaches work well and help promote 
receiver performance in today's RF environment and could help promote 
improvements in a changing RF environment. The Commission asks 
commenters to comment on the extent to which the necessary incentives 
are in place to develop effective voluntary approaches.
    The Commission requests comment on whether there could be 
improvements in the ways that voluntary approaches can be developed and 
used. To what extent have such efforts included relevant stakeholders? 
If additional stakeholders could help improve such voluntary efforts, 
how might they be involved in future efforts.
    The Commission also requests comment on situations or cases in 
which current voluntary approaches may not be sufficient with respect 
to promote improved receivers in certain situations and contexts (e.g., 
addressing adjacent band compatibility issues). The Commission asks 
that commenters identify and discuss situations in which voluntary 
approaches may not promote improvements in receiver performance where 
that would help promote more efficient use of spectrum. Are there ways 
to ensure that there are appropriate incentives for promoting effective 
voluntary approaches?
    The Commission invites comment as to the appropriate role for 
multi-stakeholder groups in this process. Are there particular 
situations in which commenters believe a multi-stakeholder group 
involvement would be appropriate? If so, which stakeholders should be 
involved, and how?
    As discussed elsewhere in this document, the Commission is seeking 
comment about both transmitter and receiver characteristics as it 
considers approaches to improving receiver performance. The Commission 
seeks comment on whether more transparent or available information on 
transmitters and receivers could help promote more effective voluntary 
approaches.
    Finally, the Commission requests comment on whether and how it 
could help promote effective voluntary approaches.

Commission Policy and Guidance

    In this section, the Commission inquire about the kinds of policy 
and guidance that could be helpful as the it considers whether and how 
to incorporate receiver performance more directly into spectrum 
management decisions. The Commission recognizes that such policy and 
guidance could take many forms, and some mix of approaches may be 
appropriate; the Commission invites commenters to help as it considers 
these various approaches.
    Many contend that the Commission's general spectrum management 
policy on the role of receiver interference immunity performance should 
be clarified. Some have suggested that the Commission's approach to 
date on receiver performance is not been sufficiently conducive to 
promoting more efficient spectrum use or promoting greater access to 
the spectrum resources for new services and uses. For instance, in the 
White Paper on Interference Limits Policy the TAC Working Group 
suggested that expectations of receiver performance have almost always 
been implicit and often based solely on the ability of the receiver to 
perform its desired function in the existing spectral environment, 
which has led to conflicts due to a change in the RF environment and/or 
a

[[Page 29260]]

differing understanding of requisite receiver performance. Authors in 
one paper recommended that, in order to provide better incentives to 
build more interference-robust systems in future allocations and put 
more spectrum to its highest and best use, the Commission should move 
away from any general interference protection model in spectrum 
management that, when considering permitting new services in adjacent 
bands, often provides incumbent users (those licensed first) protection 
against any interference resulting from subsequent rule changes. They 
stated that adjacent band interference protection for incumbents should 
not be static, and that incumbents should be incentivized to improve 
their systems' interference resilience in the most cost-effective way, 
including the use of receivers that are more interference-immune to 
interference exposure from adjacent bands.
    One report observed that certain assumptions that many spectrum 
users make are not conducive to promoting more efficient use of 
spectrum--including that operators of wireless systems tend to rely on 
their neighbors being quiet, often do not account for changes in the RF 
environment, and often do not realize that receivers are a part of the 
problem (and instead assume that the neighboring transmitters are the 
problem). That report also concluded that there is ``poor knowledge 
transfer'' among all affected parties regarding the interference 
problems related to receiver performance and potential resolution, and 
suggested that regulators could provide more helpful notice to 
operators regarding the need for better receivers. Another report 
recommended improved transparency for operators (e.g., sharing more 
information on the characteristics of their neighbors' adjacent 
operations, establishing a device performance registry, incentivizing 
operators to divulge the required information); they also stated that 
more incentives should be provided for promoting more robust receivers, 
possibly including issuance of a Commission Policy Statement (e.g., to 
the effect that receivers would no longer be protected if they do not 
include appropriate receiver selectivity).
    GAO also noted in its report that current practices and policies 
related to receiver performance may in effect constrain repurposing of 
spectrum, and that the lack of predictability about future spectrum 
management also could be a hindrance to a more effective spectrum 
policy. CSMAC stated that spectrum managers should consider incentives, 
rules, and policies to improve the capability of receiving devices to 
reject adjacent channel interference. The Commission also notes that 
the Presidential Memorandum on Wireless Innovation encouraged the 
development of measures concerning receivers that would promote design 
and deployment of receivers that are protected from harmful 
interference from adjacent band operations in cases where there is 
``reasonable use'' of adjacent band spectrum. Several have emphasized 
that as the Commission considers developing new policies or guidance, 
it also considers whether some transition or phase-in period would be 
appropriate.
    Below the Commission considers several possible approaches and 
invite comment. These include (1) providing clearer Commission policy 
guidance on the role of receivers and expectations about their 
performance; (2) gathering relevant information on receiver 
characteristics; (3) issuing a policy statement; and (4) promoting an 
interference limit policy such as harm claim threshold approaches where 
that might be appropriate. The Commission also inquires about whether 
it should consider any of these approaches, a transition or phase-in of 
some kind might be appropriate.

General Policy Guidance

    The Commission first seeks comment on whether it should consider 
establishing clearer guidance on Commission policies relating to 
receivers and receiver performance in spectrum management going 
forward. The Commission inquires whether such policy guidance could 
serve to establish clearer expectations for all spectrum users as to 
receiver performance, including in the future as the Commission seeks 
to enable greater access to spectrum for new users and promote more 
efficient use of spectrum by receivers. The Commission also inquires 
whether and how a clearer policy could help incentivize a more forward-
looking approach to the role of improved receiver performance in a 
changing RF environment.
    The Commission offers possible approaches below and seeks comment. 
The Commission also invites commenters to identify other approaches 
regarding Commission policy that it should consider.
    Establishing clearer expectations about the extent to which 
incumbent receivers will receive interference protection as new 
services are introduced. As noted above, some have suggested that in 
order to promote greater access to spectrum and promote more efficient 
use of spectrum, the Commission should establish clearer policies on 
the extent to which incumbent receivers will be protected in the future 
regardless of spectrum efficiency concerns. In particular, some state 
that the Commission should be more transparent that incumbent receiver 
operators should not simply assume that the introduction of 
transmitters in adjacent or nearby bands is the entire focus for 
addressing interference compatibility issues or that receiver 
performance will not be considered in the Commission's spectrum 
management decisions. The Commission invites comment on whether it 
should establish a clearer or explicit policy regarding the extent to 
which incumbent receivers will receive interference protection as the 
RF environment continues to change and new services are introduced into 
adjacent or nearby bands. The Commission also requests that, to the 
extent commenters believe such policy clarification would be 
beneficial, they suggest the types of clarifications that the 
Commission should consider. To what extent would such a policy-based 
expectation require clarification of incumbent users' spectrum rights 
and responsibilities?
    The Commission also invites comment on how such a policy 
clarification might be implemented with regard to incumbent users. When 
might such a policy make sense? How might such a policy be implemented 
with respect to adjacent band operations, including when both services 
have primary allocations? As to implementation of such an approach, 
what kinds of factors and timeframes should be considered? For 
instance, should the amount of time an adjacent band incumbent has been 
operating be a factor in considering what action the Commission should 
take? Should the expected life (e.g., average useful life) of receivers 
in the affected band be considered to reduce the potential for stranded 
investments?
    Clarifying the importance of assigned frequency bands and 
allocations with respect to receiver performance. Several have 
suggested or recommended that one component of better spectrum 
management would include Commission clarification of the respective 
responsibilities associated with both transmitters and receivers in 
spectrum allocations and assignments, and that this could include being 
more explicit regarding whether receiver interference immunity 
performance should be tied to the allocation or assignment under which 
the receivers are authorized. In the 2003 NOI on Receiver Performance 
Specifications, for instance, the Commission specifically

[[Page 29261]]

inquired about how receiver performance should be related to the 
management of spectrum and uses in adjacent bands, including whether 
the definition of assigned frequency bands and areas already provided 
``substantial definition to the interference environment in which 
licensees must design their systems.''
    The Commission also notes that the TAC's White Paper on Basic 
Principles for Assessing Compatibility of New Spectrum Allocations 
proposed that the Commission consider establishing ``Basic Principles'' 
regarding both transmitters and receivers with respect to spectrum 
allocations, and specifically proposed as one principle that 
``[r]eceivers are responsible for mitigating interference outside their 
assigned channels'' (while it also proposed that ``[t]ransmitters are 
responsible for minimizing the amount of their transmitted energy that 
appears outside their assigned frequencies and licensed areas''). 
Further, the Commission notes that ITU Radio Regulations, for instance, 
recognize the importance of expectations regarding receiver 
performance, and provide that receivers should provide adequate 
performance such that they do not suffer from interference from 
transmitters operating at a reasonable distance. Also, as the 
Commission has discussed above, recent proceedings have highlighted the 
relationship of receiver performance vis-[agrave]-vis assigned 
frequency bands and allocations, as well as expectations on receiver 
performance regarding interference from adjacent or nearby operators.
    Accordingly, the Commission inquires whether the Commission's 
spectrum management policy should clarify that, as a general matter of 
the spectrum regulatory policy, receiver manufacturers and operators 
are expected to take into account their allocation and assignment, or 
take into consideration designing and using receivers that include 
interference immunity parameters that would ensure coexistence with 
transmitters operating with reasonable spectral separation from the 
band in which the receivers are authorized to operate. To the extent 
that commenters believe that policy guidance is appropriate, the 
Commission asks that they propose specifics about the guidance they 
think appropriate, explain why, and, depending upon the guidance they 
suggest, indicate the extent to which a transition period may be 
appropriate.
    Development of performance criteria or ratings. The Commission also 
invites comment on whether it should consider developing particular 
receiver performance criteria, or some form of ratings, that would 
serve to encourage the design, manufacturer, and deployment of 
receivers that promote receiver interference immunity and adequately 
protect the receivers from interference from current and future uses of 
adjacent band spectrum. If the Commission were to consider developing 
performance criteria or ratings, how would these be developed? With 
regard to performance criteria, what specific metric(s) should the 
Commission consider? For instance, should the criteria be tied to a 
certain level of performance at the edge of the allocation? The 
Commission asks that commenters suggest specific criteria and explain 
their rationale for such criteria. Similarly, the Commission invites 
comment on whether some form of ratings should be considered. If so, 
what would comprise the ratings, how many levels of ratings would be 
appropriate, and how would the ratings be determined? Can ratings 
effectively be designed that would aide operators and consumers in 
using more interference immune receivers? Could particular receiver 
performance criteria or ratings be developed that could be incorporated 
into voluntary standards or Commission requirements? How might 
performance criteria or ratings best be implemented?
    Informing relevant stakeholders of any Commission forthcoming 
policy guidance. If the Commission were to provide additional policy 
guidance, the Commission recognizes that it would be important that 
potentially affected stakeholders are apprised of the guidance. The 
Commission asks for comment on how the means by which it and others 
could most effectively identify and communicate such policy guidance.
    Transitions. If the Commission were to consider providing 
additional policy guidance, the Commission invites comment on the 
considerations that would be associated with policy implementation. 
Depending on the policy guidance, are there particular transition 
concerns that the Commission should take as to receivers that may need 
to be repaired, modified, or replaced? Would such considerations depend 
on the particulars involved as to specific situations and bands? The 
Commission asks that commenters help it take into account the various 
factors that should be considered.
    Other policy guidance. The Commission invites commenters to offer 
other ideas or measures for Commission consideration regarding further 
guidance. Commenters should explain their suggestions and provide 
detailed discussion of why such policy guidance would be appropriate 
and how the Commission might consider implementing such guidance.

Policy Statement

    In this section the Commission invites comment on whether the 
Commission should consider issuing a policy statement to establish a 
clear and transparent Commission policy that can help bring receiver 
interference immunity performance into fuller consideration in spectrum 
management decisions, as some have suggested. The Commission first 
inquires generally whether a policy statement would be constructive. 
The Commission then inquires about possible models for a policy 
statement.
    Issuing a policy statement. Through the years, the Commission has 
issued various policy statements to guide public considerations and to 
advance spectrum management pursuits. For instance, in 1999 the 
Commission issued a Policy Statement on ``Principles for Reallocation 
of Spectrum to Encourage Development of Telecommunications Technologies 
for the New Millennium,'' in which the Commission noted the 
unparalleled growth of wireless services in the 1990s and ``set forth 
guiding principles for the Commission's spectrum management 
activities''--including ways to promote greater efficiency in spectrum 
markets, make more spectrum available, and identify new bands for 
spectrum reallocation--as the Commission engaged in spectrum management 
in 2000 and beyond. In 2000, the Commission issued its Policy Statement 
on ``Principles for Promoting the Efficient Use of Spectrum by 
Encouraging the Development of Secondary Markets,'' in which it set 
forth the Commission's vision and plans for facilitating secondary 
markets for radio spectrum that will allow and encourage licensees to 
make all or portions of their assigned frequencies or service areas 
available to other entities and uses. Both Policy Statements helped lay 
the foundation for the Commission's forthcoming rulemakings 
implementing some of the enunciated policies in the early 2000s.
    In recommending that the Commission create more incentives for 
building more robust receivers, Silicon Flatirons suggested that 
issuance of a policy statement could be useful. Also, as discussed 
above, many commenters and reports have called for greater Commission 
clarity on how receiver performance considerations should be factored 
into the Commission's spectrum management in ways that would provide 
clearer expectations and

[[Page 29262]]

greater predictability for all spectrum users in the future.
    The Commission seeks comment on whether it should consider issuing 
a policy statement to more directly and transparently incorporate 
relevant and appropriate focus on receivers as part of a balanced 
approach--i.e., considering the important role of both transmitters and 
receivers--to promoting more efficient spectrum use in the Commission's 
spectrum management decision-making. Would adoption of a policy 
statement be helpful in promoting the Commission's efforts to 
incorporate receiver interference immunity performance considerations 
and promote more efficient spectrum use in the current and evolving RF 
environment? What purposes could be served by issuance of a policy 
statement? Would a policy statement, for instance, help establish 
clearer expectations and greater predictability for spectrum users 
going forward?
    If the Commission were to consider issuing a policy statement, what 
specific framework, features, factors, or statements should be 
included? The Commission asks that commenters in favor of the issuance 
of a policy statement set forth their recommendations, including 
discussion of the various goals of the policy statement, any suggested 
language, and the reasons for such language.
    Possible models for a policy statement. The Commission invites 
comment on possible models for crafting a policy statement. Commenters 
should identify any such models, and any specific framework or language 
in those models that they believe should be considered.
    In particular, the Commission inquires whether the TAC's White 
Paper on Basic Principles for Assessing Compatibility of New Spectrum 
Allocations or some modification or variant of that framework, could 
supply a possible and constructive framework for consideration in 
developing a future Commission policy statement. As the TAC explained:

    Basic principles of spectrum utilization are important for all 
involved parties to consider, not just the regulatory authorities. 
Realization of certain facts of communications technology will 
temper the expectations of the incumbent services using spectrum 
resources as well as the new services that are trying to gain entry 
into the spectrum.

    As contemplated, with the nine ``basic principles'' the TAC sought 
to promote ``good neighbor policies'' among spectrum users (generally 
found at spectral boundaries) that better enable adjacent and nearby 
spectrum users to ``get along'' with each other. Several of these 
principles directly related to expectations about both transmitters and 
receivers. Given the many differences between the requirements of 
various types of systems, the TAC did not expect the application of 
these principles to result in a concrete set of regulations that fit 
all radio services in the same way, but nonetheless believed that the 
principles can be applied to all systems and result in an optimal 
solution for each service. As discussed in the basic principles below, 
several of the principles focused on establishing expectations and 
responsibilities concerning receiver performance within the larger 
context of spectrum management, including establishing that harmful 
interference is affected by the characteristics of both a transmitting 
service and a nearby receiving service, that receivers are responsible 
for mitigating interference outside their assigned channels, and that 
services under the FCC's jurisdiction are expected to disclose the 
relevant standards, guidelines and characteristics of their systems if 
they expect protection from harmful interference.
    The basic principles identified by the TAC Working Group included 
three functional groups--``Interference Realities'' (realities of 
interference everyone must accept), ``Responsibilities of Services'' 
(responsibilities that services have to mitigate their interaction with 
other services), and ``Regulatory Requirements and Actions'' 
(requirements for, and actions that should be taken by, regulatory 
authorities with respect to spectrum allocations):
    Interference Realities--
    <bullet> Principle 1: Harmful interference is affected by the 
characteristics of both a transmitting service and a nearby receiving 
service in frequency, space or time.
    <bullet> Principle 2: All services should plan for 
non[hyphen]harmful interference from signals that are nearby in 
frequency, space or time, both now and for any changes that occur in 
the future.
    <bullet> Principle 3: Even under ideal conditions, the 
electromagnetic environment is unpredictable. Operators should expect 
and plan for occasional service degradation or interruption. The 
Commission should not base its rules on exceptional events.
    Responsibilities of Services.
    <bullet> Principle 4: Receivers are responsible for mitigating 
interference outside their assigned channels;
    <bullet> Principle 5: Systems are expected to use techniques at all 
layers of the stack to mitigate degradation from interference; and
    <bullet> Principle 6: Transmitters are responsible for minimizing 
the amount of their transmitted energy that appears outside their 
assigned frequencies and licensed areas.
    Regulatory Requirements and Actions.
    <bullet> Principle 7: Services under FCC jurisdiction are expected 
to disclose the relevant standards, guidelines and operating 
characteristics of their systems to the Commission if they expect 
protection from harmful interference;
    <bullet> Principle 8: The Commission may apply Interference Limits 
to quantify rights of protection from harmful interference.
    <bullet> Principle 9: A quantitative analysis of interactions 
between services shall be required before the Commission can make 
decisions regarding levels of protection.
    The Commission notes that several commenters expressed interest in 
having it explore these principles insofar as they pertained to 
expectations and responsibilities associated with receivers and 
receiver interference immunity performance, while others expressed 
particular concern about particular principles and their application to 
certain types of receivers. The Commission invites comment on the 
principles in the White Paper as they concern a Commission policy 
statement. Commenters should discuss their views and concerns on 
particular principles, and whether revisions or clarifications on any 
of the principles or on their applicability should be considered.
    The Commission also asks whether there are other models that the 
Commission could draw from as it considers a policy statement. For 
instance, would ITU Radio Regulations (RR) or relevant ITU-R 
publications (e.g., ITU-R recommendations) that pertain to receiver 
performance (along with transmitter performance) provide a useful 
framework or particular language for consideration? As discussed above, 
several provisions in the Radio Regulations concern ``technical 
characteristics of stations'' associated with both the transmitter and 
receiver equipment and performance with respect to each other and in 
promoting more efficient and effective use of spectrum. As regards 
receivers in particular, the ITU provided regulations on several 
aspects on the role of receiver design and performance that would that 
serve to promote more efficient use of spectrum--including receiver 
design (RR No. 3.3--taking into account technical measures to reduce 
susceptibility to interference), bandwidth considerations (RR No. 3.9--

[[Page 29263]]

keeping bandwidths at lowest values that the service permits), spectrum 
efficiency (RR No. 3.11--receivers should promote efficient use of 
spectrum), technical characteristics (RR No. 3.12--receiver selectivity 
that ensures efficient utilization of spectrum), and performance 
characteristics (RR No. 3.13--sufficient levels of receiver 
interference immunity performance so that receivers do not suffer from 
interference from transmitters operating at ``a reasonable distance''). 
Would any of these ITU references provide helpful guidance for 
consideration to be included in a Commission policy statement? 
Similarly, would the European Union Radio Equipment Directive provide 
useful guidance? That Directive also recognized the important role of 
both transmitter and receiver equipment in spectrum management. The 
Directive further indicated that ``Essential Requirements'' includes a 
requirement that radio equipment (both transmitters and receivers) 
should be constructed so as to ensure ``an adequate level of 
electromagnetic compatibility'' and in a manner that ``both effectively 
uses and supports the efficient use of radio spectrum in order to avoid 
harmful interference.
    Finally, the Commission invites comment on any other models or 
other sources (e.g., proposals, reports, studies, etc.) that could 
provide useful discussion for Commission consideration about a policy 
statement and specific features or language that should be included.

Interference Limits Policy, Including Harm Claim Thresholds

    In the White Paper on Interference Limits Policy issued in 2013, 
the TAC discussed an interference limits policy as well as one 
particular form of such a policy, harm claim thresholds. In 2014, the 
TAC followed up this discussion with its White Paper on Harm Claim 
Thresholds. The TAC Working Groups authoring these two White Papers 
believed that an interference limits policy would promote more 
transparent consideration of receivers in spectrum management and 
promote better receiver performance policy in a more flexible manner if 
the Commission adopted receiver performance mandates. As discussed 
below, many commenters were in favor of the Commission further 
exploring interference limits policy, and harm claim thresholds in 
particular.
    The Commission summarizes at a high level these approaches below--
but it direct commenters to review and address the details set forth in 
the two White Papers themselves. The Commission invites comment on 
whether and how an interference limits policy, and a harm claim 
thresholds approach in particular, should be considered by the 
Commission.
    In these papers, the TAC working groups noted that, in order to 
meet the growing demand for wireless service, the number of wireless 
systems that operate in close proximity in frequency, space, and time 
need to increase, and that while there are many benefits derived from 
packing wireless systems among these dimensions (i.e., higher system 
density), there is also an increased risk of service disruption due to 
inter-service interference. The TAC stated that implementing an 
interference limit policy would bring receivers into the spectrum 
management picture, and do so with minimal regulatory intervention. As 
explained in the White Paper on Interference Limits Policy:

    Increased density requires more care in optimizing the whole 
wireless system structure, particularly regarding the interactions 
between transmitters and receivers on either side of band 
boundaries. . . . [R]eceivers that cannot reject interfering signals 
transmitted outside their assigned frequencies can preclude or 
constrain new allocations in adjacent bands. A holistic system view 
that facilitates trade-offs between receiver and transmitter 
performance requirements is needed.
    Receivers can be brought into the policy picture with minimal 
regulatory intervention by introducing an ``interference limits'' 
policy; that is, the establishment of ceilings, called harm claim 
thresholds, on in-band and out-of-band interfering signals that must 
be exceeded before a radio system can claim that it is experiencing 
harmful interference. Manufacturers and operators are left to 
determine whether and how to build receivers that can tolerate such 
interference, or even determine that they will choose to ignore 
these limits. Harm claim thresholds thus allow the FCC to provide 
guidance on the optimization of receiver performance without unduly 
restricting technical and commercial choice.

    The TAC contemplated rules that explicitly state when receivers may 
and may not claim harmful interference. Such rules would be a necessary 
complement to existing transmitter regulation that could facilitate the 
transition to more intensive frequency use by providing more clarity to 
service providers about the baseline regulatory and radio interference 
context going forward. The TAC stated that harm claim thresholds could 
be particularly useful in bands with many diverse and frequently 
emerging new technologies. As envisioned, the approach would delegate 
decisions about system design, including receiver performance, to 
manufacturers and operators, giving operators the flexibility to decide 
best how to deal with the RF environment (i.e., signal levels in 
adjacent or nearby bands which may be viewed as interference) they need 
to tolerate, whether by improving receiver selectivity, deploying more 
base stations, using internal guard bands, or accepting occasional 
service degradation given their choice of receiver design. Further, 
under such an approach, the private sector would play a key role in 
developing receiver specifications and standards that ensure adequate 
performance given the harm claim thresholds of a particular allocation. 
The TAC also recognized, however, that a harm claim threshold approach 
may require special consideration in cases where receivers are not 
controlled by a license holder or for life-safety systems like aviation 
and public safety.
    As the White Paper on Harm Claim Thresholds explained, the goal of 
a harm claim threshold is to reduce the uncertainty among radio system 
operators regarding the level of interference that one operator is 
entitled to impose on another operator, and that a related goal has 
been to find ways the Commission could encourage more efficient radio 
service coexistence, including ways to encourage receiver performance 
improvement without mandating receiver performance specifications. As 
articulated in the White Paper on Interference Limits, a guiding 
principle of this approach is that the number of interference disputes 
that require Commission resolution could be reduced if the 
responsibility to mitigate interference is more clearly assigned (i.e., 
if lines are more clearly drawn between the rights of transmitters and 
receivers).
    The TAC recommended that the Commission develop, where necessary, 
the expertise and that multi-stakeholder groups form to investigate 
interference limits policy at suitable high-value inter-service 
boundaries and suggested potential ways about implementing an 
interference limits policy. The TAC suggested introducing a harm claim 
thresholds approach on a gradual basis and suggested a three-step 
process for how the Commission might roll out rules and regulations on 
an interference limits policy, including harm claim thresholds. First, 
the Commission could identify frequency allocation boundaries where 
harm claim thresholds would bring immediate value, such as adjacent 
allocations where intensified use is anticipated. Second, the 
Commission would initiate a consultation process involving stakeholders 
in multiple services that span band boundaries.

[[Page 29264]]

Such multi-stakeholder groups could work collectively to develop 
options at these spectrum boundaries (e.g., methods for determining 
harm claim thresholds, enforcement and conflict adjudication 
mechanisms) as well as develop guidelines (and perhaps standards) for 
receiver performance parameters such as receiver sensitivity, 
selectivity, intermodulation rejection, and dynamic range, that, 
together with the transmitter power, signal modulation and deployment 
assumptions applicable to a particular service, would ensure that 
conformant receivers would operate satisfactorily within an RF 
environment where signal levels are no greater than the harm claim 
threshold. Third, the Commission would monitor the progress of the 
multi-stakeholder process, representing the interests of future 
licensees and other absent stakeholders while also ensuring that the 
record developed provides a thorough basis for a rulemaking should that 
be appropriate.
    Many commenters on the White Paper on Interference Limits Policy 
believed that the concepts deserved further consideration. Others, 
while acknowledging the need to consider an interference limits 
approach, opposed applying such an approach to particular services 
(e.g., aviation safety, safety-of-life services, amateur radio, or 
commercial mobile services) stating that a one-size-fits-all approach 
would not be appropriate. Some commenters, noting the difficult 
methodological and administrative implementation issues associated with 
this approach, stated that the Commission should explore and promote 
industry receiver performance measurements and some thought it 
important to develop appropriate enforcement mechanisms for any limits 
adopted. Many supported use of multi-stakeholder groups for formulating 
possible interference limits provided that appropriate representatives 
would participate. Some commenters supported the Commission using a 
pilot project to explore the approach in an appropriate band.
    In addition to the TAC, other entities recommended that the 
Commission further explore an interference limits policy, including 
harm claim threshold approaches. These included reports noting 
panelists' consensus that a protection limits approach generally was 
preferable to adoption of receiver standards, and a later report 
largely supportive of developing an interference limits policy 
approach, including harm claim thresholds approach along with using 
multi-stakeholder groups to help develop appropriate technical 
solutions. One paper has proposed a specific harm claims threshold 
approach in which the threshold would be based on the interference 
environment associated with flexible use in the adjacent bands. PCAST 
also supported the harm claims threshold approach for receiver 
interference limits, which it contrasted with use of ``heavy regulation 
of spectrum and devices'' to solve receiver-driven interference issues. 
It believed that such an approach would provide a framework for 
defining harmful interference, could provide clarity on the 
requirements that a new entrant must meet to co-exist with legacy 
systems in adjacent bands, and would give device manufacturers freedom 
to address those requirements as they see fit. GAO also noted one of 
the Commission's clear options for promoting receiver performance was 
further consideration of an interference limits approach.
    Discussion. In this document, the Commission seeks to develop an 
up-to-date record on whether the Commission should further explore 
implementing an interference limits policy, and in particular, a harm 
claim thresholds approach. The Commission ask that commenters review 
the two TAC whitepapers, and offer their thoughts on the details 
discussed there, the issues and concerns raised, and how the Commission 
might proceed in consideration of interference limits policy and harm 
claim thresholds. In particular, the Commission seeks comment on how 
such an approach would fit into today's spectrum environment 
characterized by much more intensive use compared to when these 
recommendations were developed. How could this approach alleviate 
spectrum issues the Commission is currently addressing as well as 
anticipated trouble spots as the Commission continues to examine 
opportunities for reallocating spectrum for higher valued uses? Should 
the Commission consider adopting any rules to implement such a policy?
    The Commission notes that the TAC recommended in the White Paper on 
Interference Limits Policy that the Commission issue a Notice of 
Inquiry seeking public comment on interference limits policy. First, 
the Commission seeks comment on the use of an interference limits 
policy at service boundaries in general, including the tradeoffs 
between interference limits policy and three alternatives to an 
interference limits policy that were noted in the White Paper on 
Interference Limits Policy. To focus this inquiry quantitatively, the 
Commission seeks comment on the use of an interference limits policy at 
service boundaries where there are legacy receivers for one of the 
radio services for which there are no published or industry-standard 
minimum out-of-band blocking threshold(s). Commenters should identify 
inter-service boundaries where there are some legacy receivers that are 
unable, for example, to tolerate fundamental signal levels outside 
their receive band that are more than 2%-10% displaced from the legacy 
receiver band edge and less than -15 dBm at the receiver input port 
(after antenna losses, prior to RF filter attenuation). Commenters that 
support different metrics for examining inter-service boundaries are 
encouraged to provide such metrics along with detailed explanations to 
support their choices as well as the boundaries where they should 
apply. The Commission is interested in knowing where legacy receivers 
are deployed that are designed and compliant with widely accepted 
industry receiver standards that include minimum out-of-band blocking 
(i.e., overload) tolerance specifications (e.g., radio receivers such 
as 3GPP base stations, user devices, aviation certified GPS receivers, 
etc.). Similarly, the Commission seeks information on where receivers 
are deployed that are not built to such standards, yet seek protection 
from signals outside their band. And the Commission requests that 
commenters identify the types of legacy receivers that are in the 
category identified by the TAC where interference limit policies may 
not be necessary at all. The Commission's goal is to build a 
quantitative record based on commenters' experience and spectrum 
viewpoints to inform the Commission where they believe high-value 
interservice boundaries exist and where interference problems can be 
foreseen that could benefit from proactively implementing a harm claim 
threshold approach to specify licensees' responsibilities for 
interference risk mitigation.
    Second, the Commission seeks comment on institutional approaches 
for implementing harm claim thresholds, including the use of multi-
stakeholder processes, rulemaking, and in particular, inter-industry 
standards setting processes. The Commission seeks comment on specific 
tasks or reports that a multi-stakeholder group should address that 
would aid it if it were to further examine implementing a harm claim 
threshold approach. For example, would a multi-stakeholder group be 
able to evaluate any high value interservice boundaries identified by 
commenters and provide consensus insight into which spectrum 
allocations

[[Page 29265]]

should be addressed first or which would provide the largest benefits? 
Additionally, could a multi-stakeholder group compile data and produce 
a report or database regarding relevant technical specifications of 
deployed receivers including, but not limited to relative and absolute 
dynamic range, out-of-band blocking tolerance, and selectivity, where 
public owners of such receivers, other potentially affected spectrum 
users, and the Commission, do not have transparent insight? Such 
information could inform policy decisions and actions to balance 
transmitter emission power with receiver reception limits. What other 
tasks could a multi-stakeholder group tackle to help this process?
    Similarly, how can industry standards processes be leveraged to 
provide for improved receiver performance to support a harm claim 
threshold approach? In this regard, the Commission is not seeking to 
build a record to mandate the ``design'' of receivers that could chill 
technology evolution, but instead, the Commission is seeking ideas on 
how the importance of good receiver design can more effectively be 
represented in the lifecycle of receiver development and product 
evolution processes. For example, for receivers that require protection 
from fundamental signals in adjacent or nearby spectrum bands, the 
minimum undesired out-of-band power at which those receivers can 
operate without a degradation metric exceeding a low minimum, could be 
specified in an industry standard. The Commission notes that this is 
already done in some standards groups. Alternatively, specific receiver 
requirements can be specified as a receiver mandate in the Commission's 
rules or absent such specificity, left to industry to meet a harm claim 
threshold signal strength or power flux over-the-air specification 
(i.e., signal-in-space) which could be codified in its rules. The 
Commission seeks comment on these alternatives and their tradeoffs.
    Third, the Commission seeks comment on suitable parameters for harm 
claim thresholds, engineering methods to determine their values, and 
ongoing reporting, analysis, and enforcement challenges. For example, 
should the Commission consider whether to adopt a standard ``reference 
value of far out-of-band blocking power'' to evaluate inter-radio-
service interference scenarios. If so, what value would be appropriate? 
Would a standard reference value such as -15 dBm at the input to a 
receiver's front-end filter, be useful in the early identification of 
suitable harm claim thresholds; i.e., identifying harm claim thresholds 
that may be ``at,'' ``above,'' or ``below'' a standard reference value? 
If this value is inappropriate, what value would be appropriate? Should 
different values be specified for different radio services? If so, the 
Commission requests that commenters justify their position and provide 
detailed comment regarding recommended values and which radio services 
are applicable. Are there instances in which the harm claim threshold 
should be set based on assuming that the allocation in the adjacent 
band would be flexible use? How can the Commission incentivize industry 
segments where there are no consensus receiver standards, yet there is 
a desire for ``protection'' from inter-band interference? Since the 
responsibility for spectrum coexistence lies with both transmitters and 
receivers, can these (or other) harm claim threshold parameters be used 
to achieve the Commission's policy goals?
    The Commission also seeks comment on whether a harm claim threshold 
approach should incorporate two parameters that 3GPP has used to study 
the balance of transmitter impairments with receiver impairments: 
Adjacent Channel Leakage Ratio (ACLR) and Adjacent Channel Selectivity 
(ACS). These parameters are used to analyze and determine the balance 
between transmitter and receiver impairments within spectrum bands 
shared between multiple mobile broadband service providers using a 
basic formulation called Adjacent Channel Interference Ratio (ACIR). 
While the Commission is unaware of anyone applying this concept 
``between inter-service spectrum bands'' (i.e., between different radio 
services) to assess whether out-of-band transmitter impairments or out-
of-band blocking receiver filter impairments dominate the interference 
equation between spectrum bands, it seeks comment on whether these 
concepts can be used in this context. For commenters that support such 
an approach, the Commission requests specific information regarding how 
these concepts could be applied and what values should be considered 
for evaluation purposes for various radio services.
    Are there specific engineering methods or analysis tools that lend 
themselves to analyses necessary to support a harm claim threshold 
approach? In particular, a harm claim threshold approach may require 
specifying an ``over the air'' power flux or field strength threshold, 
over which ``claims of harm'' could be made, and under which claims of 
harm could not be made. Spatial and temporal variables associated with 
transmitters and receivers, especially mobile radio, present a 
statistical challenge to assess probabilistic bounds versus 
deterministic bounds (e.g., a receiver dynamic range certification 
requirement). Moreover, radio propagation is highly variable and radio 
waves are ``polarized'' and ``directional'' creating more statistical 
uncertainty. Further, technology advancements such as 5G Advanced 
Antenna Systems (AAS) enable more effective ``directionality'' to 
optimize wireless network coverage and performance, but technologies 
such as AAS also pose a dimension of uncertainty (e.g., RF emissions 
`below the horizon' versus `above the horizon'). How can these 
probabilistic variables be accounted for in analyses to produce trusted 
results agreed upon by interested parties? Can a standard methodology 
and modeling tools be used to implement these processes?
    The Commission also seeks comment on whether a standard reporting 
or measurement scale can be developed to categorize levels of 
interference or impairment. For example, most people are familiar with 
the Fujita (tornadoes), Saffir-Simpson (hurricanes), and Richter 
(earthquakes) scales, that stratify the consequences of undesired 
environmental effects in a manner that is understandable by the public. 
Can something similar be developed for spectrum and RF interference? 
Currently, some parties point to a relative change in the noise floor 
as a single indicator of harmful interference. However, given the 
orders of magnitude of variation between transmitter and receiver 
impairment conditions for different services and situations, a single-
value relative change metric may not be meaningful. Moreover, under a 
harm claim threshold approach, there should be flexibility to determine 
a range of relevant values and associated responsibilities or ability 
to claim inference protection. Should the Commission establish a few 
basic and standard reference categories of interference, to enable 
quantitative/statistical risk assessment? As with the examples above, 
the absolute values of the scale can be different between different 
radio services. There is no ``one size fits all.'' However, the notion 
here is that ``sizes'' (or ranges of power) are potentially describable 
and more meaningful to the public. What categories and levels do 
commenters believe would be both easy to describe and lend relevance to 
this approach?
    The Commission seeks comment on how a harm claim threshold could be 
enforced given the spatial and temporal

[[Page 29266]]

variations of various radio systems. The Commission seeks comment on 
how persistent and intermittent interference would or could be 
detected, reported, and used to identify a ``claim'' of interference? 
How would such a process distinguish external sources of interference 
from self-interference sources such as ``cross coupling'' between the 
transmit and receive paths within a radio transceiver, which could be 
misinterpreted as interference from an external source? How would 
sources of intermodulation interference be detectable and analyzed to 
distinguish (a) intermodulation interference generated from within a 
receiver, from (b) intermodulation products from the receiver's antenna 
system, from (c) intermodulation interference from the local 
environment (e.g., rusty bolts, corroded metal infrastructure nearby), 
from [d] intermodulation interference generated from high power nearby 
RF emissions (e.g., fundamental signals F<INF>1</INF> and F<INF>2</INF> 
can create interference at F<INF>3</INF> = 2 * F<INF>2</INF>-
F<INF>1</INF>) when impressed on a nonlinear element can cause co-
channel interference within a receiver? The Commission seeks comment on 
these and other relevant interference reporting processes and best-
practices that can be employed for specific radio services, regardless 
of whether receiver performance minimum expectations are established by 
industry standards or harm claim threshold methods. What other factors 
need to be addressed to effectively enforce a harm claim threshold? 
Commenters should be specific regarding what they and industry 
stakeholders can proactively and specifically do, and what role the 
Commission should undertake to enforce a harm claim threshold approach, 
especially in maintaining a ``light touch'' regulatory approach.
    Finally, the Commission inquires about whether a harm claim 
thresholds approach should be expected to evolve as receiver 
performance improves over time. Should receivers that may meet a 
standard when they are deployed be upgraded or replaced in the future 
to merit interference protection under the Commission's rules if new 
receiver standards are developed that provide increased interference 
immunity? The Commission notes that different systems have different 
expected lifecycles. The Commission requests comment on whether it 
should consider a specified time frame from the date a receiver was 
deployed after which it should be expected to meet newer standards. 
Similarly, the Commission invites comment on whether limits should be 
reevaluated periodically and adjusted based on newer technology 
standards and capabilities, or whether receiver protection should be 
tied to certain required maintenance or replacement schedules.

Receiver Performance Mandates

    As noted above, the Commission has not generally imposed 
requirements on receiver performance and relies instead on establishing 
technical and operational rules associated with transmitters. As to 
receiver performance, the Commission has relied largely on market 
forces rather than mandatory requirements to provide incentives for 
manufacturers to produce equipment with good receivers, though better 
performing receivers may come with increased cost. As discussed above, 
there have been a number of occasions in which the Commission has 
adopted rules that either promote receiver performance or require that 
receivers meet certain minimal technical performance capabilities, 
including situations involving repurposed spectrum where receiver 
performance specifications were required for future operations (DTV 
tuner requirements), developing acceptable levels of in-band and 
adjacent band interference for services (800 and 900 MHz bands), and 
safety-of-life services (maritime and location services). Some 
commenters or studies have indicated that in certain types of 
situations rules promoting receiver performance may be appropriate, 
such as in the case where the licensee does not have sufficient control 
over receiver performance.
    Discussion. The Commission requests comment on whether and under 
what circumstances it might be appropriate for it to consider adopting 
rules promoting receiver performance or specifying minimal receiver 
requirements. The Commission also invites comment on possible 
regulatory approaches that promote receiver performance without 
specifying technical requirements.
    The Commission seeks comment on whether it should consider 
expanding its receiver rules to encompass more radio services or to 
apply rules generally across all radio services. To what extent to do 
the Commission's limited existing requirements on receivers provide 
guidance as it considers this issue? How successful were those efforts 
at balancing the need for a rule requirement without imposing undue 
costs that might be associated with such a regulatory approach? Should 
a particular approach already adopted by the Commission for one 
particular situation be appropriate for considering in an analogous 
situation? Are there particular services or situations today that 
suggest that the Commission should consider adopting a rule on receiver 
performance to serve the public interest? Why would such an approach be 
appropriate?
    If a commenter suggests that the Commission should consider 
adopting a rule requirement in particular situation(s), it seeks 
comment on why and how the rules could be applied. How specific would 
the requirements need to be? For example, the Commission could take a 
light touch regulatory approach and simply require equipment to meet 
certain industry standards or it could require receivers to meet 
certain benchmarks or a combination of the two based on radio service 
or type of equipment. Because some Commission licensees, such as mobile 
phone providers approve and certify specific phone models for use on 
their networks, should the Commission consider whether to adopt a 
requirement that those licensees ensure that their customers' equipment 
meets some minimal standards (e.g., 3GPP standards)? Would a rule 
specifying such a requirement suffice? Or would specific minimum 
benchmarks be needed?
    The Commission seeks comment on whether there are certain cases 
where a regulatory approach should be considered because the receivers 
associated with a particular service are not sufficiently under the 
control of the licensee or may not be designed to meet particular 
industry specifications. The Commission notes, for instance, that in 
many cases consumers have a wide variety of equipment choices (e.g., 
in-home access point equipment, devices for use with a licensed or 
unlicensed services such as radar or satellite receivers), and the 
purchase decision is entirely in the consumer's hands without any 
licensee providing the role of gatekeeper on receiver performance. 
Would regulatory requirements to ensure minimal performance be 
appropriate in certain situations such as those? What are the costs and 
benefits of such an approach? Commenters should provide detailed 
justification for what type of requirements should apply to which 
services or user classes, if the Commission were to consider amending 
its rules to implement receiver requirements.
    To what extent might it be appropriate for the Commission to 
consider requiring certain disclosure to consumers, and owners/
operators of equipment and systems with embedded receivers or 
transceivers, so that they make a more informed choice about the 
equipment they purchase. The

[[Page 29267]]

Commission invites comment on whether it should require radio equipment 
information disclosure, for example through a labeling requirement, or 
key metrics regarding the receiver. Would such a requirement be useful 
to consumers and owners/operators of integrated systems that employ 
receivers? If so, what type of information would be most helpful to 
inform consumers and operators to make an educated decision (e.g., 
selectivity, dynamic range, etc.)? Would such a requirement be 
beneficial across the board for all equipment or only for equipment 
designed for certain services or user bases? What would be the best way 
to disclose this information (e.g., on packaging, in the manual, etc.)? 
What burden and costs would a disclosure requirement place on 
manufacturers? Would this increase product costs? If so, by how much? 
Commenters should provide details regarding who would benefit most from 
such disclosures and for what type of equipment for which rule parts or 
portions thereof. The Commission also seeks comment on how, if it deems 
such rules are warranted, they should be enforced? Should it be part of 
the equipment certification process where the Commission already 
imposes certain labelling requirements? Finally, the Commission asks if 
such a disclosure requirement would incentivize manufacturers to build 
better receivers? Are there any other factors or policy issues that the 
Commission should consider as it pertains to the potential for 
requiring receiver labeling information?
    If the Commission were to pursue consideration of possible 
mandatory requirements, it requests comment on possible technical 
specifications or other requirements that would need to be considered. 
For example, could the rules tie a filtering requirement to the 
expected emissions in adjacent or nearby bands to ensure resiliency 
from out-of-band emissions or blocking interference? What about 
requirements regarding to spurious emissions or intermodulation 
interference? How could such requirements be implemented? What factors 
should go into determining such filter and other requirements? Is there 
a frequency separation that should be considered, either absolute or as 
a function of bandwidth that should be considered to adequately protect 
receivers against blocking interference? Should there be a required 
margin built in, to future proof receivers against future Commission 
actions that might affect the nearby RF environment? If so, how much of 
a margin is realistic? What issues need to be considered that affect 
the attenuation roll-off performance of filters? How should such 
requirements be contemplated for differing operational requirements 
(e.g., requirement differences in fixed, mobile, satellite, 
broadcasting, radiolocation services, etc.)?
    In the event a regulatory requirement is considered, the Commission 
seeks comment on what consideration should be given for services where 
the expected equipment lifetime differs. For example, certain 
industrial equipment is expected to work for 10 or 20 years or more 
while consumer mobile devices are typically replaced every few years. 
What other technical requirements would need to be specified? How 
should different receivers be categorized? Can a rating scale be 
developed to easily assess how much additional interference protection 
one receiver may have over another? Should any categorization be tied 
to characteristics of the desired transmitters? Or the undesired 
transmitters in adjacent and nearby bands?
    In addition, the Commission seeks comment on how rules specifying 
particular receiver protection criteria may affect receiver 
architecture, particularly concerning implementation complexity, size, 
performance, form factors, number of external components, power 
consumption, impacts on other systems, and cost.
    The Commission seeks comment on what type of tests may be needed if 
it were to consider specific requirements. Should such testing be part 
of the equipment approval process? Which receiver parameters should be 
examined? How should tests for these parameters be designed and 
conducted? Commenters should provide information regarding specific 
test details. Is there other information the Commission should 
consider, if it were to implement rule requirements for all or certain 
receivers?
    Finally, the Commission requests comment on any other regulatory 
approaches the Commission should consider that would promote improved 
receiver interference immunity performance where that would be 
appropriate. The Commission asks that commenters provide sufficient 
explanation of their ideas and rationale for why they would be 
appropriate for consideration of such a regulatory approach as the best 
means of promoting its goal of promoting more efficient use of spectrum 
through improved receiver performance.

Innovation and the Marketplace

    As part of the Commission's overall spectrum management goals, the 
Commission seeks to promote innovative new technologies and uses of 
spectrum. The Commission requests that commenters address the various 
considerations and approaches that have been discussed in this 
document, and inform the Commission about how best to promote 
innovation.
    The Commission recognizes that receiver interference immunity 
performance specifications have the potential to impact receiver 
markets in various ways depending on how they are implemented. As 
discussed above, the Commission is examining three general types of 
approaches to promoting improved receiver performance--promoting 
industry-led voluntary approaches, providing additional Commission 
guidance, and possibly adopting mandatory requirements, or some 
combination of each. The Commission inquire as to how innovation and 
the marketplace would be affected by the approaches it is considering, 
and how best to consider the weighing of each approach as well as a 
balanced combination.
    The Commission notes, for instance, that receivers with improved 
interference immunity performance features may create product 
differentiation that is generally desirable for consumers/users. As for 
voluntary approaches, voluntary industry guidelines and standards that 
promote development of receivers that are better or more desirable 
would create product differentiation. At the same time, however, the 
cost of producing such receiver devices might be higher than the cost 
of producing less resilient receivers, resulting in higher prices. In 
such a case, consumers/users would ultimately determine whether the 
receivers with greater interference immunity are ultimately deployed 
(compared to less resilient receivers), and would generally be based on 
whether the users would be willing to pay any higher prices that might 
be charged. The Commission seeks comment on how it might assess 
voluntary approaches in the context of innovation and the marketplace, 
and which approaches would be most or least effective when it comes to 
facilitating innovation while promoting improved receiver performance.
    The Commission next seeks comment on how the various approaches 
discussed regarding potential Commission guidance would affect 
innovation and the marketplace. The Commission asks that commenters

[[Page 29268]]

address particular types of potential its policy guidance discussed 
herein--including general policy guidance, a policy statement, or an 
interference limits policy such as harm claim thresholds--and how those 
particular approaches affect innovation and the marketplace. Which 
approaches would be most or least effective as to facilitating 
innovation while promoting improved receiver performance? For instance, 
would clarification of Commission policy as to the integral role that 
receiver interference immunity performance plays in spectrum 
management, and clearer guidance about receiver responsibilities 
associated with developing and deploying receivers that protect against 
adjacent and nearby spectrum uses, help promote innovations in improved 
receiver design, and how should the Commission consider crafting such 
guidance in order to promote innovation in the marketplace? The 
Commission also notes that proponents of the development of an 
interference limits policy or harm claim threshold approaches note many 
benefits of such an approach, including that it could serve as a better 
alternative to adopting particular mandatory requirements in the rules. 
The Commission invites comment on how an interference limits policy or 
harm claim thresholds approaches affect innovation and the marketplace.
    The Commission also invites comment on the adoption of regulatory 
requirements or rules (including standards) that require minimal levels 
of receiver interference immunity performance as the means for 
achieving its public interest goals. The Commission notes that 
mandatory standards would be expected to ensure development and 
deployment of receivers with a minimal level of interference immunity 
performance that would help achieve particular Commission goals 
regarding particular spectrum bands, including addressing issues 
relating to enabling greater access to adjacent band spectrum for other 
spectrum users. At the same time, the Commission notes that there may 
be instances in which regulatory adoption of specification standards 
could stifle innovation by restricting the introduction of products 
with otherwise desirable new features that are inconsistent with the 
standards, or might not be the most efficient at achieving the 
Commission's goals for ensuring a minimal level of receiver 
performance. The Commission asks for comment on how particular 
mandatory approaches may affect innovation and the marketplace. If a 
class of receivers are expected to be protected without a minimum 
knowable level of self-protection (selectivity) designed-in the 
receiver, how can protection be ensured?
    With regard to each of the approaches discussed above, the 
Commission requests comment on the impacts of receiver interference 
immunity performance as to the following questions. What effects would 
interference immunity performance specifications have on innovation in 
equipment design, performance (especially as to performance not 
addressed by specifications) and features? What effects would 
particular approaches have on receiver markets in terms of cost of 
production, price and availability of equipment, and user demand? What 
aspects of specifications would have the greatest impacts on innovation 
and markets and what steps could be taken to minimize or mitigate their 
impacts? Since receiver filters to block OOB signals are generally a 
small fraction of the cost and complexity of a receiver, and generally, 
such components do not constrain the high-level innovative functions of 
a receiver, commenters should be specific and describe the impact on 
innovation, if any, of establishing basic minimum power reception 
limits from signals outside of a receiver's allocated spectrum band. 
Finally, to what extent should assessments of the impact on innovation 
and markets be a factor in the Commission's consideration of the 
various approaches for promoting improved receiver interference 
immunity performance discussed in this document?
    In addition, the Commission inquires as to how it might evaluate an 
appropriate mix or balance among the various approaches that are 
discussed in this document as regards innovation and the marketplace. 
Commenters should offer their views on how the Commission might find 
that appropriate mix or balance. The Commission also invites comment on 
how these approaches might affect innovation in spectrum utilization. 
For example, how might these measures affect the development and costs 
and benefits of innovation associated with new wireless use cases? 
Compared to the Commission's approach to receiver performance to date, 
how might any of the approaches discussed above potentially serve to 
promote innovation in spectrum use, including not only in receiver but 
in transmitter design and performance as well?
    Finally, the Commission invites comment on any other considerations 
that it should take into account on how best to promote innovation as 
it evaluates possible approaches to promoting improved receiver 
performance as part of its spectrum management in the future.

Legacy Receivers and Transition Pathways

    There are many billions of receivers currently in use in various 
different radio services for a multitude of purposes. Depending on the 
types of approaches that industry and the Commission might take into 
promoting improvements in receiver performance, many of these existing 
``legacy'' receivers may be impacted. Many receivers presumably already 
operate efficiently and include robust interference immunity, whether 
it is because they comply with voluntary industry guidelines, 
manufacturer designs are efficient, regulatory requirements are in 
place, or for other reasons. Many other receivers may currently not 
include the latest technologies or designs that could make the 
receivers more immune to interference, but also may be in the process 
of being replaced fairly quickly over the next few years, as is the 
case for consumer mobile devices over generally a five to ten year 
period. Then there are receivers in many different services, that may 
not be as immune to interference as they could be, particularly insofar 
as the receivers (or some subset of them) used in a particular service 
may be susceptible to interference from other operations in adjacent or 
nearby bands, or could experience interference with the introduction of 
new services in adjacent or nearby bands, in part because these 
receivers (or some subset of them) have not been designed to be more 
immune to interference.
    As the Commission observed in its 2003 NOI on receiver performance, 
in situations where the Commission adopted spectrum policies that 
assumed receivers performed in accordance with a given set of 
interference immunity specifications, it is likely that many of the 
existing receivers could continue to provide satisfactory service. 
Further, interference conditions that would necessitate the use of 
receivers meeting the applicable guidelines/standards would not be 
present everywhere, and they may operate in locations where potentially 
interfering signals were not present or were present at levels within 
the capabilities of existing receivers. Such receivers could provide 
satisfactory service in many situations where industry or the 
Commission adopted spectrum policies that promote

[[Page 29269]]

receiver performance. Accordingly, the NOI noted that one approach 
would be to simply allow users to change to new receivers as they 
encountered interference. The Commission also identified another 
situation, such as where the service would be of more critical 
importance, and suggested that it might be necessary to require 
replacement of receivers, including the case in which a transition is 
being mandated for the replacement of receivers. The Commission asked 
about how to treat existing receivers that do not comply with any new 
receiver immunity specifications that may be developed, and how the 
size of the installed receiver base should affect development of 
receiver guidelines/standards, what criteria should be used by the 
Commission if it were to take action to require replacement of 
receivers (either rapidly on a transitional basis) in particular 
services, and what would be an appropriate phase-in period.
    Regarding the potential replacement of legacy receivers, the GAO 
report noted both the lack of predictability about the future spectrum 
environment, and that it can take significant time and effort to 
upgrade and replace receivers once deployed. Silicon Flatirons 
suggested that it would be helpful if regulators could better 
anticipate the needs at band edges and provide proper notice (e.g., 10 
years) regarding the need for better receivers, and further noted that 
in order to help manage costs development of a phase-in of receiver 
regulation would be important. CSMAC discussed the need for future 
spectrum planning to give due consideration to legacy equipment and not 
to unnecessarily strand such equipment due to new services or devices 
that cause interference. It believed that when developing future 
spectrum sharing policies and considering technological advancements 
that enable improvements in legacy equipment, spectrum managers should 
also consider the replacement rate of existing transmitting and 
receiving equipment. This would avoid the potential for unnecessary 
stranded investment in this equipment, and balance the cost of this 
investment with the public benefits of more spectrum access to both 
Federal Government and other users.
    The Commission further notes that the matter of how best to address 
legacy receivers and transition to less susceptible receivers in order 
to allow new operations in adjacent or nearby bands continues to be an 
important consideration as it seeks to enable new uses of spectrum and 
promote more efficient use of spectrum. The Commission anticipates that 
issues concerning legacy receivers that are not as interference-
resilient as they could or should be may continue to arise, and 
consideration to potential pathways for addressing legacy receivers and 
any transitions to better performing receivers is important.
    Discussion. What is the state of receiver performance across the 
commercial sector, including public safety, aviation and maritime 
safety, and Federal spectrum users? The Commission requests comment and 
suggestions on the range of issues and considerations that it should 
take into account as it considers the treatment of existing receivers 
that may not comply with any new approaches or policies adopted in the 
future (e.g., improved receiver minimum interference immunity 
performance where that might be appropriate). The Commission notes that 
the issues include those relating to how it or others might determine 
the size of the installed base and identify existing or legacy 
receivers that potentially may be subject to approaches that lead to 
improved interference immunity performance. As discussed above, the 
Commission recognizes that in many instances, receivers are replaced 
fairly often, and that improved receiver performance in those cases 
could be achieved in a relatively rapid fashion, while there may be 
other situations in which other approaches (as discussed herein) may be 
appropriate. The Commission invites comment on each of these types of 
situations, including specific comment on whether and how to factor in 
the anticipated useful life of existing receivers.
    The Commission also requests comment on considerations that it 
should take into account related to transitions (e.g., repair or 
replacement) from use of legacy receivers to receivers that are more 
interference-immune in situations where that is deemed appropriate. Are 
there, for instance, particular approaches in previous or current 
Commission proceedings that provide some guidance that the Commission 
should consider? What are the complexities of introducing receiver 
requirements or harm claim thresholds in bands with existing spectrum 
allocations and service rules? What are realistic timelines for 
products in existing bands to adapt to a harm claim threshold or other 
regulatory actions to improve receiver performance? The Commission 
invites broad comment on relevant issues pertaining to legacy receivers 
and potential transition approaches, including timelines for 
transitioning that may be appropriate, the impact on global 
competitiveness, and consideration to regulatory actions that other 
nations have taken. Are there approaches that the Commission should 
consider that would enable smooth transitions? Should the Commission 
consider approaches that could facilitate any transition deemed 
appropriate that would minimize the costs that would be incurred? In 
sum, the Commission asks that commenters help it identify and consider 
the range of issues and concerns that should be taken into account with 
regard to addressing legacy receivers and transitioning to systems with 
improved receiver interference immunity performance that would serve 
the public interest.

Costs and Benefits

    There are both costs and benefits that are associated with the 
implementation of the various approaches discussed in this document for 
the Commission's consideration as it seeks to promote improved receiver 
interference immunity performance in appropriate ways. The Commission 
recognizes that there could be a range of tradeoffs to consider. The 
Commission invites comment on ways to minimize the costs, optimize the 
benefits, and otherwise balance the costs and benefits, as steps are 
taken in the future to improve receiver interference immunity 
performance as part of its overall spectrum management goals in those 
situations in which doing so would serve the public interest.
    The Commission notes that the TAC, in its White Paper on Risk-
informed Interference Assessment, recommended that it include in its 
decision-making evaluation a quantitative risk-informed interference 
assessment (e.g., comparing various likelihood/consequence combinations 
for multiple different potential interference hazard scenarios among 
the potentially affected operators) as it considers the interests of 
incumbents, new entrants, and the public. Others have noted that better 
understanding of the costs and benefits associated with improved 
receiver interference immunity performance could be help ``inform how 
to develop an incentive structure that would actually improve receiver 
selectivity.'' CSMAC indicated that in considering costs, spectrum 
managers should take into account changes and improvements in legacy 
equipment that will occur in the marketplace, and try to minimize the 
cost of stranded investments. Several other reports have focused on 
considerations related to the costs associated with any new guidance or 
policy promoting improved receiver performance, and discussions of the

[[Page 29270]]

need for an appropriate phase-in depending on the situation.
    Discussion. The Commission invites comment on how it should 
consider the associated costs and benefits of the various approaches 
that are discussed in this document for promoting improved receiver 
interference immunity performance--including voluntary approaches, 
Commission guidance (e.g., policy clarification, policy statement, 
interference limits policies), or regulatory approaches such as 
adoption of mandatory requirements for specified services.
    The Commission also invites comment on how it might consider a 
phased-in approach when promoting improved receiver interference 
immunity performance in particular bands. As the Commission considers 
costs and benefits, what are the kinds of costs and the kinds of 
benefits that should be considered? The Commission asks that commenters 
discuss not only financial impacts but also considerations relating to 
competition as well as public safety and national security concerns. 
For example, would improvements in receiver interference immunity 
performance (e.g., selectivity to reject unwanted emissions) enhance 
the ability of receivers to reject jamming and spoofing attempts? How 
might the Commission best consider the trade-offs concerning 
potentially affected stakeholders?

Legal Authority

    As the Commission considers possible approaches to explore further, 
it seeks comment on its legal authority concerning the kinds of 
approaches it may be considering. In the 2003 NOI on Receiver 
Performance Specifications, the Commission stated its belief that it 
had the ``necessary statutory authority to promulgate receiver immunity 
guidelines and standards under sections 4(i), 301, 302(a), 303(e), (f), 
and (r) of the Communications Act, as amended.'' Several commenting 
parties generally agree, while others suggested that the Commission's 
authority could be limited.
    Discussion. The Commission continues to believe that it has the 
necessary statutory authority to promulgate receiver immunity 
guidelines and standards under sections 4(i), 301, 302(a), 303(e), (f), 
and (r) of the Communications Act, as amended. The Commission requests 
comment on the assessment of its authority. The Commission also invites 
comment on other sources of authority as it considers the various 
approaches concerning receiver performance as discussed in this 
document. The Commission seeks comment in this document on whether the 
extent and limits of its statutory authority and enforcement mechanisms 
should affect its consideration of the possible approaches.
    The Communications Act provides it with broad spectrum management 
authority, including authority under Title III of the Act to manage the 
use of radio spectrum and to prescribe the nature of wireless services 
to be rendered. In particular, section 303(e) allows the Commission to 
``regulate the kind of apparatus to be used with respect to its 
external effects and the purity and sharpness of the emissions from 
each station and from the apparatus,'' section 303(f) directs the 
Commission to ``[m]ake such regulations not inconsistent with law as it 
may deem necessary to prevent interference between stations and to 
carry out the provisions of the chapter,'' and section 303(r) provides 
the Commission with general rulemaking authority. In the past, the 
Commission has drawn on its authority under section 303 to adopt 
requirements designed to protect receiving devices from interference 
from incoming signals by defining the conditions that constitute 
interference, including the operating parameters of the equipment 
causing and receiving the interference. For example, as discussed 
above, in both the 800 MHz public safety service and 900 MHz Business 
and Industrial/Land Transportation (B/ILT) service the Commission 
adopted regulations that required licensees claiming protection from 
unacceptable interference to use receivers capable of distinguishing 
wanted signals from unwanted signals. More recently, the Commission 
adopted rules for commercial use of the 3.5 GHz Band that included 
protection limits afforded to receivers, although in that proceeding 
the Commission found it was unnecessary to mandate receiver performance 
specifications.
    In addition to the Commission's clear authority to regulate 
receivers by defining the conditions that constitute interference, the 
Title III mandate to prevent interference ``between stations'' may also 
authorize it to regulate the operations of a receiving station with 
respect to its compliance with technical parameters designed to ensure 
that it is capable of screening out certain levels of RF energy that 
would otherwise interfere with its reception of desired signals. The 
Commission invites commenters to provide an assessment of the extent of 
its Title III authority over receivers. Can section 303(f) be 
interpreted to authorize the regulation of either the transmission or 
reception of the undesired signal in order to prevent interference? 
Does section 303(f), together with sections 4(i), 301, 302(a), 303(e), 
and (r), provide a sufficient basis for the Commission to establish 
interference protection rights for licensees or other authorized users 
of licensed devices, contingent on their devices meeting certain 
threshold performance requirements? Do these or other statutory 
provisions also provide authority for the Commission to adopt 
requirements that specify interference-rejection capabilities for 
wireless receivers or to impose direct controls on receiver devices 
that lack sufficient capacity to reject incoming interfering signals? 
Are such regulations reasonably ancillary to the Commission's broad 
authority to ensure efficient use of radio spectrum? Prohibiting the 
manufacture or use of devices that are particularly susceptible to 
interference would prevent interference under the terms of section 
303(f), insofar as that provision empowers the Commission to adopt 
regulations to prevent interference ``between stations.'' If Congress 
had intended to limit the Commission's authority to the regulation of 
the transmission of the undesired signal, it could have made that 
intent clear by stating in section 303(f) that the Commission has 
authority to adopt regulations to prevent stations from ``causing 
interference to other stations.'' By using the phrase ``between 
stations,'' however, Congress arguably provided the Commission with the 
flexibility to address interference problems at both the transmitting 
and receiving ends. Do commenters agree? The Commission seeks comment 
on the scope of the statutory definition of ``stations'' in the 
context, including how to interpret the definition of ``radio 
communication'' or ``radio transmission of energy,'' the former of 
which includes ``all instrumentalities, facilities, apparatus, and 
services (among other things, the receipt, forwarding, and delivery of 
communications) incidental to such transmission.''
    What is the Commission's authority to impose direct regulation on 
device manufacturers--i.e., to prohibit the manufacture or marketing of 
devices that fail to conform to minimum performance standards for 
resisting interference? Section 302(a)(2) of the Communications Act 
gives the Commission authority to ``establish[ ] minimum performance 
standards for home electronic equipment and systems to reduce their 
susceptibility to interference from radio frequency energy'' and 
provides that ``[s]uch regulations shall be applicable to the 
manufacture, import, sale, use, offer for

[[Page 29271]]

sale, or shipment of such devices and home electronic equipment and 
systems, and to the use of such systems.'' While the Commission has 
clear authority to adopt performance standards for receivers used as 
home electronic equipment under section 302(a)(2), the Commission seeks 
comment on the scope of the Commission's authority pursuant to the 
provision. To what extent does the Commission's authority extend to 
receivers used in commercial applications, such as on airplanes, 
commercial delivery trucks, or tractors on industrial-scale farms? Can 
consumer-facing devices used outside of the home, such as GPS devices 
used as navigation aids, be regulated under the authority?
    The Commission invites comment on any other sources of authority it 
could rely on for the actions it considers here. Commenters should 
explain in detail why they do or do not believe the Commission have 
authority to act if it chooses to do so. Commenters should also address 
whether the kinds of efforts or approaches that the Commission may 
ultimately take (e.g., gathering more information on receiver 
characteristics, developing and implementing harm claim threshold 
approaches, requiring transitions) would affect the analysis of the 
Commission's authority or of its ability to enforce its rules 
effectively.

Other Possible Approaches and Issues

    The Commission invites comment on other possible approaches for its 
consideration. For instance, would convening Commission-led workshops 
comprised of a variety of experts from industry and government be 
helpful? Would any pilot project be appropriate, and if so, with what 
particular frequency band(s) should be considered. Are there further 
studies that could help inform the Commission on important 
considerations with regard to improving receiver interference immunity 
performance? Are there other studies, efforts, analyses that the 
Commission should consider in the proceeding? If so, the Commission 
asks that commenters identify them and explain why they should be 
considered.
    Digital Equity and Inclusion. Finally, the Commission, as part of 
its continuing effort to advance digital equity for all, including 
people of color, persons with disabilities, persons who live in rural 
or Tribal areas, and others who are or have been historically 
underserved, marginalized, or adversely affected by persistent poverty 
or inequality, invites comment on any equity-related considerations and 
benefits (if any) that may be associated with the various approaches 
and issues discussed herein. Specifically, the Commission seeks comment 
on how the various approaches that it may consider may promote or 
inhibit advances in diversity, equity, inclusion, and accessibility, as 
well the scope of the Commission's relevant legal authority.

Procedural Matters

    Ex Parte Rules. The proceeding shall be treated as a ``permit-but-
disclose'' proceeding in accordance with the Commission's ex parte 
rules. Persons making ex parte presentations must file a copy of any 
written presentation or a memorandum summarizing any oral presentation 
within two business days after the presentation (unless a different 
deadline applicable to the Sunshine period applies). Persons making 
oral ex parte presentations are reminded that memoranda summarizing the 
presentation must (1) list all persons attending or otherwise 
participating in the meeting at which the ex parte presentation was 
made, and (2) summarize all data presented and arguments made during 
the presentation. If the presentation consisted in whole or in part of 
the presentation of data or arguments already reflected in the 
presenter's written comments, memoranda, or other filings in the 
proceeding, the presenter may provide citations to such data or 
arguments in his or her prior comments, memoranda, or other filings 
(specifying the relevant page and/or paragraph numbers where such data 
or arguments can be found) in lieu of summarizing them in the 
memorandum. Documents shown or given to Commission staff during ex 
parte meetings are deemed to be written ex parte presentations and must 
be filed consistent with Rule Sec.  1.1206(b), 47 CFR 1.1206(b). 
Participants in the proceeding should familiarize themselves with the 
Commission's ex parte rules.
    Comment Filing Procedures. Pursuant to Sec. Sec.  1.415 and 1.419 
of the Commission's rules, 47 CFR 1.415, 1.419, interested parties may 
file comments and reply comments on or before the dates indicated on 
the first page of the document. Comments may be filed using the 
Commission's Electronic Comment Filing System (ECFS) or by paper. All 
filings must be addressed to the Commission's Secretary, Office of the 
Secretary, Federal Communications Commission.
    [ssquf] Electronic Filers: Comments may be filed electronically by 
accessing ECFS at https://www.fcc.gov/ecfs.
    [ssquf] Paper Filers: Parties who choose to file by paper must file 
an original and one copy of each filing. Paper filings can be sent by 
hand or messenger delivery, by commercial overnight courier, or by 
first-class or overnight U.S. Postal Service mail.
    [ssquf] Effective March 19, 2020, and until further notice, the 
Commission no longer accepts any hand or messenger delivered filings. 
This is a temporary measure taken to help protect the health and safety 
of individuals, and to mitigate the transmission of COVID-19.
    [ssquf] Commercial overnight mail (other than U.S. Postal Service 
Express Mail and Priority Mail) must be sent to 9050 Junction Drive, 
Annapolis Junction, MD 20701.
    [ssquf] U.S. Postal Service first-class, Express, and Priority mail 
must be addressed to 45 L Street NE, Washington, DC 20554.
    Availability of Documents. Comments, reply comments, and ex parte 
submissions will be publicly available online via ECFS. These documents 
will also be available for public inspection during regular business 
hours in the FCC Reference Information Center, when FCC Headquarters 
reopen to the public.
    People with Disabilities. To request materials in accessible 
formats for people with disabilities (braille, large print, electronic 
files, audio format), send an email to <a href="/cdn-cgi/l/email-protection#b9dfdada8c898df9dfdada97ded6cf"><span class="__cf_email__" data-cfemail="680e0b0b5d585c280e0b0b460f071e">[email protected]</span></a> or call the 
Consumer & Governmental Affairs Bureau at 202-418-0530 (voice), 202-
418-0432 (tty).

Ordering Clauses

    Accordingly, it is ordered that, pursuant to sections 4(i), 301, 
302(a), 303(e), 303(f), and 303(r) of the Communications Act of 1934, 
as amended, 47 U.S.C. 154(i), 301, 302(a), 303(e), 303(f), and 303(r), 
the Notice of Inquiry is adopted.

Federal Communications Commission.
Marlene Dortch,
Secretary.
[FR Doc. 2022-09938 Filed 5-12-22; 8:45 am]
BILLING CODE 6712-01-P


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