[Federal Register Volume 88, Number 161 (Tuesday, August 22, 2023)]
[Proposed Rules]
[Pages 57033-57043]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2023-17423]



[[Page 57033]]

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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Part 73

[MB Docket No. 22-405; FCC 23-61; FR ID 161601]


Rules for FM Terrestrial Digital Audio Broadcasting Systems

AGENCY: Federal Communications Commission.

ACTION: Proposed rule.

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SUMMARY: In this document, the Federal Communications Commission 
(Commission or FCC) adopted a Notice of Proposed Rulemaking, in which 
it seeks comment on proposals to change the digital audio broadcasting 
technical rules that would permit additional FM stations to increase FM 
hybrid digital effective radiated power (FM Digital ERP) beyond the 
existing levels without the need for individual Commission 
authorization, as well as allowing asymmetric digital sideband 
operation. These specific rule changes were proposed based on two 
consolidated Petitions for Rule Making filed in 2019 and 2022.

DATES: Comments may be filed on or before September 21, 2023 and reply 
comments may be filed on or before October 6, 2023.

ADDRESSES: You may submit comments, identified by MB Docket No. 22-405, 
by any of the following methods:
     Electronic Filers: Federal Communications Commission's 
website: http://apps.fcc.gov/ecfs//. Follow the instructions for 
submitting comments.
     Paper Filers: Parties who choose to file by paper must 
file an original and one copy of each filing.
     Filings can be sent by commercial overnight courier, or by 
first-class or overnight U.S. Postal Service mail (although the 
Commission continues to experience delays in receiving U.S. Postal 
Service mail). All filings must be addressed to the Commission's 
Secretary, Office of the Secretary, Federal Communications Commission.
     Commercial overnight mail (other than U.S. Postal Service 
Express Mail and Priority Mail) must be sent to 9050 Junction Drive, 
Annapolis Junction, MD 20701.
     U.S. Postal Service first-class, Express, and Priority 
mail must be addressed to 45 L Street NE, Washington, DC 20554.
     Effective March 19, 2020, and until further notice, the 
Commission no longer accepts any hand or messenger delivered filings. 
This is a temporary measure taken to help protect the health and safety 
of individuals, and to mitigate the transmission of COVID-19.
     During the time the Commission's building is closed to the 
general public and until further notice, if more than one docket or 
rulemaking number appears in the caption of a proceeding, paper filers 
need not submit two additional copies for each additional docket or 
rulemaking number; an original and one copy are sufficient.
    People with Disabilities: Contact the FCC to request reasonable 
accommodations (accessible format documents, sign language 
interpreters, CART, etc.) by email: [email protected] or phone: 202-418-
0530 or TTY: 888-835-5322.

FOR FURTHER INFORMATION CONTACT: Albert Shuldiner, Chief, Media Bureau, 
Audio Division, (202) 418-2700; Thomas Nessinger, Senior Counsel, Media 
Bureau, Audio Division, (202) 418-2700. For additional information 
concerning the Paperwork Reduction Act (PRA) information collection 
requirements contained in this document, contact Cathy Williams at 202-
418-2918, or via the internet at [email protected].

SUPPLEMENTARY INFORMATION: This is a summary of the Commission's Order 
and Notice of Proposed Rulemaking (NPRM), MB Docket No. 22-405; FCC 23-
61, adopted on July 31, 2023, and released on August 1, 2023. The full 
text of this document is available for public inspection and copying 
via ECFS at http://apps.fcc.gov/ecfs and the FCC's website at https://docs.fcc.gov/public/attachments/FCC-23-61A1.pdf. Documents will be 
available electronically in ASCII, Microsoft Word, and/or Adobe 
Acrobat. Alternative formats are available for people with disabilities 
(Braille, large print, electronic files, audio format), by sending an 
email to [email protected] or calling the Commission's Consumer and 
Governmental Affairs Bureau at (202) 418-0530 (voice), (202) 418-0432 
(TTY).

Initial Paperwork Reduction Act of 1995 Analysis

    The NPRM in document FCC 23-61 seeks comment on proposed rule 
amendments that may result in modified information collection 
requirements. If the Commission adopts any modified information 
collection requirements, the Commission will publish another notice in 
the Federal Register inviting the public to comment on the 
requirements, as required by the Paperwork Reduction Act, Public Law 
104-13; 44 U.S.C. 3501-3520. In addition, pursuant to the Small 
Business Paperwork Relief Act of 2002, the Commission seeks comment on 
how it might further reduce the information collection burden for small 
business concerns with fewer than 25 employees. Public Law 107-198; 44 
U.S.C. 3506(c)(4).

Synopsis

    1. Power Increase Petition; History of Digital FM Power Limits. In 
2002, the Commission selected in-band, on-channel (IBOC) technology, at 
the time developed and manufactured by iBiquity, to enable radio 
broadcast stations to commence digital broadcasting. At that time, the 
Commission adopted notification procedures allowing existing FM radio 
stations to begin digital transmissions immediately on an interim basis 
using the IBOC system. The iBiquity FM IBOC digital system includes 
several hybrid modes and separate all-digital modes. In the hybrid and 
extended hybrid modes, a station simultaneously transmits both the 
analog and digital signals. In the all-digital modes, the station drops 
the analog signal and is able to increase the capacity of the digital 
signal. The Commission initially limited digital operations to the 
hybrid digital mode, which permits the simultaneous transmission of 
both the analog and digital signals within the current spectral 
emissions mask of a single FM channel, placing redundant blocks of 
digital information in the sidebands on both sides of and immediately 
adjacent to the analog signal.
    2. iBiquity and several independent parties conducted extensive 
field and laboratory tests of the IBOC system prior to Commission 
adoption. Based on the National Radio Systems Committee's (NRSC) 
evaluation of those test results, in December 2001 the NRSC approved 
the NRSC-5 standard, which specifies a digital FM effective radiated 
power (ERP) equal to one percent of authorized analog FM power (20 
decibels below carrier or -20 dBc). Subsequently, the Commission 
adopted this as the maximum digital power level for the hybrid digital 
mode of the FM IBOC system. In 2010, the Commission's Media Bureau 
(Bureau) released an Order increasing the allowable power level of the 
FM station's digital sidebands from -20 dBc to -14 dBc, upon electronic 
notification to the Commission. The Bureau further allowed certain FM 
stations to increase digital power above -14 dBc, to up to -10 dBc, 
upon a showing that such power increase would comply with the formula 
in the Bureau's 2010 order, and therefore would not cause harmful

[[Page 57034]]

interference to adjacent analog FM stations.
    3. Petitioners in this rulemaking proceeding state that digital FM 
receiver penetration continues to grow: according to petitioners, there 
are over 90 million autos in the U.S. with digital receivers; receiver 
penetration has exceeded 40% in some markets; and almost 60% of new 
automobiles sold in the U.S. are equipped with digital IBOC receivers. 
Petitioners National Association of Broadcasters (NAB) and Xperi 
(successor to iBiquity) contend, however, that many stations have 
resisted adopting IBOC technology due to the inability to replicate 
their analog signal coverage with digital coverage, owing to the limits 
placed on digital sideband power. They maintain that the Commission, by 
its own admission, overprotected adjacent-channel FM analog stations 
when implementing the allowable FM digital power table set forth in the 
2010 Bureau Order, and further state that 12 years of experience with 
the current FM digital power levels has yielded few if any complaints 
of interference from hybrid digital FM transmissions. As evidence for 
its contentions, petitioners NAB and Xperi attached an analysis of 
existing digital FM stations transmitting at the current allowable 
limit of -14 dBc, but whose digital signal substantially overlaps that 
of adjacent analog FM stations. They assert that in none of these real-
world situations have there been any instances of digital-to-analog 
interference. NAB and Xperi further attached the results of their own 
field test, conducted under experimental authority, using three 
stations in the New York market, two adjacent ``interfering'' stations 
and one ``interfered with'' station. In this study the adjacent-channel 
digital stations operated first with FM digital signals at -14 dBc, and 
then at -10 dBc, while recordings were made of the adjacent channel 
analog station under each condition. According to a panel of 
listeners--consisting of NAB and Xperi employees--who evaluated the 
recordings, there was ``no significant change or degradation of the 
desired [FM analog] signal when the 1st-adjacent channel interferer 
went from -14 dBc to -10 dBc'' even though these stations were 
operating at levels far in excess of the levels permitted under the 
current methodology.
    4. Asymmetric Sideband Petition. The Commission's existing rules 
assumed that digital power would be the same on both digital sidebands. 
NAB, Xperi, and National Public Radio (NPR), in the 2019 Asymmetric 
Sideband Petition, assert that with asymmetric sidebands a digital FM 
station could protect one adjacent analog FM station while concurrently 
increasing power on the other sideband frequency in order to expand its 
digital coverage and building penetration. These petitioners conducted 
a study that they state demonstrates that many more digital FM stations 
could increase power above -14 dBc on at least one sideband. Out of 
10,875 digital FM stations studied, petitioners contend that 6,120 
could increase power to -10 dBc under the current rules, whereas if 
asymmetric sidebands were allowed, an additional 3,496 stations could 
increase one sideband to -10 dBc, with another 532 being able to 
increase one sideband's power to between -14 and -10 dBc. These 
petitioners also noted that, under the current rules, stations may only 
request asymmetric sidebands under an experimental authorization. They 
argued that the need to request experimental authorization, and the 
temporary nature of such authorizations, discourages use of asymmetric 
sidebands, which in turn limits digital FM stations to the power level 
needed to protect the closer or higher-powered adjacent-channel analog 
FM station. Petitioners thus requested that the Commission amend its 
rules to allow FM stations to operate with asymmetric digital 
sidebands, without having to request experimental authorization to do 
so, in order to remove unnecessary regulatory barriers and promote 
broader adoption of terrestrial digital FM broadcasting. The Bureau 
sought comment on the consolidated Power Increase Petition and 
Asymmetric Sideband Petition in a Public Notice released November 28, 
2022.
    5. After review of the two consolidated petitions for rulemaking 
(Power Increase Petition and the Asymmetric Sideband Petition), and the 
comments filed in response, the Commission concluded that the record 
discloses sufficient reasons to justify the institution of a rulemaking 
proceeding seeking further comment on these proposals. The Commission 
tentatively concluded that the proposals in both the Power Increase 
Petition and the Asymmetric Sideband Petition represent steps toward 
improving the terrestrial digital FM broadcast radio service. The 
Commission seeks comment on its proposal to allow additional stations 
to increase FM digital power levels, to authorize asymmetric sideband 
power levels without the need for experimental authorization, and to 
rely on existing interference mitigation and remediation processes, and 
notification procedures.
    6. Power Increase Petition. The Commission proposed to amend its 
rules to change its power increase methodology and notification 
procedures, consistent with the Petition. Specifically, it proposed to 
change the methodology used by digital FM stations to determine whether 
they are eligible to increase digital FM power up to -10 dBc, or 10% of 
analog power. It also proposed that such increases be allowed without 
the need for additional individual special authorization, but upon 
basic notification to the Commission. It further proposed that stations 
notify the Commission of a power increase up to -10 dBc in the Bureau's 
Licensing and Management System (LMS), using the same notification 
procedures as currently used to notify the Commission of digital 
operation up to -14 dBc.
    7. Maximum Permissible FM Digital ERP Table. The Commission 
proposed to amend its rules to modify the methodology a digital FM 
station must use to determine whether it is eligible to increase its 
power above -14 dBc. This modification, if adopted, would allow more 
stations to increase power up to -10 dBc without the requirement of 
submitting a contour analysis. Secondary services such as LPFM and FM 
translators are eligible to operate in hybrid mode. To the extent that 
such a secondary service station seeks to increase its digital power, 
it would use the same methodology set forth herein. As summarized 
above, currently a digital FM station may operate with digital power up 
to -14 dBc. Additionally, a digital FM station could apply to operate 
with power of up to -10 dBc (10% of analog power), pursuant to the 
current methodology. Petitioners asserted that the intervening dozen 
years of experience with the established 2010 power limits, as well as 
follow-up field tests and other studies, demonstrate that most digital 
FM stations should be able to operate at power levels of up to -10 dBc 
without special Commission authorization, and without causing 
interference to adjacent channel FM facilities. They proposed an 
updated table for determining maximum permissible FM Digital ERP as 
follows:

------------------------------------------------------------------------
 Proponent analog F(50,10) field strength
   at first adjacent station's analog 60       Maximum permissible FM
   dB[micro] F(50,50) contour (symmetric             digital ERP
            sideband operation)
------------------------------------------------------------------------
57.9 dB[micro] and above..................  -14 dBc
56.5 dB[micro] to 57.8 dB[micro]..........  -13 dBc
55.6 dB[micro] to 56.4 dB[micro]..........  -12 dBc
54.1 dB[micro] to 55.5 dB[micro]..........  -11 dBc
54.0 dB[micro] or less....................  -10 dBc
------------------------------------------------------------------------


[[Page 57035]]

    8. Currently, a licensee desiring FM Digital ERP in excess of -14 
dBc must calculate the station's analog F(50,10) field strength at all 
points on the 60 dB[micro] F(50,50) contour of a potentially affected 
first-adjacent channel analog FM station. This calculation must be done 
using each station's licensed analog facilities and the standard FCC 
contour prediction methodology. Once the most restrictive analog 
F(50,10) field strength of the proponent station has been determined, 
the licensee will use the updated table to determine the proponent 
station's maximum permissible FM Digital ERP.
    9. Petitioners studied pairs of stations in which the digital FM 
station operated at -14 dBc, yet the station's signal strength at the 
protected contour of the adjacent analog FM station is greater than 
that allowed by the current methodology. Despite this, petitioners 
stated that none of the studied analog FM stations reported any 
significant interference from the digital FM stations, in spite of 
signal strengths higher than permitted by the current methodology. The 
Commission noted that it had not received any interference complaints 
from any of the adjacent channel stations most likely to experience 
interference from the stations that petitioners studied, with greater-
than-normal power ratios. The Commission requests comment on the 
methodology or interpretation of petitioners' studies, and whether they 
support petitioners' claim that use of the proposed revised table will 
not result in harmful interference.
    10. The majority of commenters supported the proposals set forth in 
the Power Increase Petition. Most agreed with petitioners that allowing 
more stations to increase digital power would assist FM digital 
stations to expand their digital service areas, as well as improve 
building signal penetration. Two commenters expressed concern about the 
effect of increased digital FM power on Low-Power FM (LPFM) and smaller 
Class A FM stations, contending that such stations serve listeners 
outside the protected 60 dB[micro] contour.
    11. The Commission tentatively concluded that the record collected 
to date supports the proposed methodology change. The Commission 
initiated the process of authorizing digital broadcast operations in 
1999 with the eventual goal of moving terrestrial broadcasting from an 
all-analog to an all-digital world. Although it stated repeatedly that 
there is no timetable for this eventual change to all-digital broadcast 
radio, and did not alter that stance in the NPRM, its objective is to 
advance the progress of digital radio without causing harmful 
interference or disruption to existing analog operations. This is 
especially true given the record evidence of increased digital FM 
receiver penetration, even while recognizing that such receivers are 
far from ubiquitous, and that the record was less complete with regard 
to non-automotive digital FM receiver penetration. It is this desire to 
encourage continued adoption of digital FM broadcast technology that 
informed the Commission's tentative conclusions and proposals in this 
NPRM.
    12. The Commission tentatively concluded that the proposals set 
forth in the Power Increase Petition support the goal of furthering the 
progress of digital FM broadcast radio. It therefore proposed to amend 
its rules to change the methodology used by digital FM stations to 
determine whether they are eligible to operate with allowable IBOC 
power up to and including -10 dBc, and to permit any existing FM 
digital station currently operating with power below -10 dBc that 
satisfies the table proposed to be adopted herein, to increase 
allowable IBOC power without seeking prior Commission authorization and 
without the requirement of submitting a contour overlap analysis. It 
further proposed to adopt the petitioners' table for calculating 
maximum allowable FM IBOC power set forth above. The Commission seeks 
comment on this proposal. Are the contours and power levels set forth 
in the Maximum Permissible FM Digital ERP Table reasonable from an 
engineering standpoint? If not, how would commenters modify the table? 
To the extent that any such modifications are proposed, the Commission 
requests that commenters detail the engineering rationale underlying 
any such modifications. If commenters generally support providing 
greater flexibility for stations to increase their FM digital power but 
disagree with the use of the Maximum Permissible FM Digital ERP Table, 
what other methods would they suggest for calculating maximum FM 
digital power?
    13. Interference and Proposed Interference Remediation Procedures. 
The Commission also seeks comment on whether changing the power 
increase methodology will create an unacceptable risk of interference 
to adjacent-channel stations. Most commenters agreed with petitioners 
that interference has not been and would not be an issue with the 
proposal to broaden the number of stations eligible to increase digital 
power levels. Petitioners, and those who concurred with them, based 
their contentions on the technical analyses and field studies they 
cited. Some commenters, however, expressed caution surrounding digital 
interference to FM analog stations, especially smaller stations. These 
commenters argued that the proposed change to the methodology could 
harm smaller stations such as Class A FM stations, LPFM stations, and 
FM translators and AM stations rebroadcasting over FM translators, as 
well as other entities beside FM stations, such as broadband providers.
    14. The Bureau previously set forth detailed procedures to identify 
and remedy complaints of digital-to-analog FM interference among full-
service FM broadcast stations. Those procedures require, first, that an 
analog FM station receiving verifiable listener complaints of digital 
interference within its protected contour contact the digital FM 
station, and that the stations cooperate to confirm the interference 
and attempt to eliminate it using voluntary tiered FM digital power 
reductions. If the stations are unable to agree on appropriate 
interference remediation measures, the affected analog FM licensee may 
file a complaint with the Bureau. Bureau staff will review each 
complaint and order appropriate action within 90 days of filing the 
complaint. If the Bureau has not acted within 90 days, the interfering 
station must reduce its digital power, and ongoing complaints of 
interference may require subsequent stepped reductions of digital 
power.
    15. Like the petitioners and commenters, the Commission has noted 
few interference complaints from full-service analog FM stations 
resulting from adjacent-channel digital transmissions. Given the 
paucity of interference complaints, the Commission tentatively 
concluded that the interference remediation procedures outlined above 
will continue to suffice to handle such digital-to-analog interference 
complaints as may arise between full-service FM stations. These 
interference mitigation and remediation procedures would therefore 
remain in place to guard against any instances of actual interference 
to other facilities. The Commission seeks comment on this tentative 
conclusion. To the extent that commenters believe that these current 
procedures would be inadequate to deal with the increased power levels 
proposed in this NPRM, they are asked to state specifically where the 
current system is deficient, and describe in detail the interference 
identification and remediation measures they feel are needed.
    16. As secondary services LPFM and FM translators stations are not 
eligible for the interference remediation

[[Page 57036]]

procedures outlined herein. Because secondary services are not 
protected from interference from full-service stations, the Commission 
did not propose to modify this approach such that secondary services 
can use these interference remediation procedures to claim interference 
from full-service stations. However, although the number of secondary 
service stations employing hybrid digital operation to date is small, 
the Commission invites comment as to whether it should adopt any 
digital interference remediation procedures for secondary service 
analog stations claiming interference from secondary service digital 
stations. All full-service stations, including Class A stations, may 
take advantage of the interference remediation procedures proposed 
herein.
    17. Commenters may wish to address whether the station complaints 
described above should be based on objective criteria such as ``agreed-
upon [mathematical] formulas,'' rather than listener reports. Should 
the number of reports of ongoing interference required (currently six) 
be increased or decreased? Should a complaining station be allowed 
instead to submit studies and/or measurements demonstrating that the 
digital FM signal within the complaining station's protected contour 
exceeds allowable limits? Additionally, how should a digital FM station 
that has increased its digital power be treated if and when an 
adjacent-channel analog FM station subsequently increases its analog 
power, and/or moves its facilities closer to the digital FM station? 
Should we give precedence to the analog FM signal? Alternatively, 
should the digital FM facility that now seeks a power increase be 
protected over a subsequent facility modification by an adjacent-
channel analog FM station?
    18. Two commenters raised the issue of how a digital FM station 
power increase would affect protection to incumbent stations, 
expressing concern about its impact on LPFM and other smaller stations. 
They argued that protection to the 60 dB[micro] contour is insufficient 
for analog FM stations on adjacent channels that, they contend, have 
listenership well beyond that contour. The Commission tentatively 
concluded that there is no need to provide protection from actual 
interference outside the protected contour of an analog FM station from 
the digital signal of a full-service FM station, and seeks comment on 
this conclusion. Should protection of incumbent analog FM stations on 
adjacent channels be increased beyond the 60 dB[micro] contour and, if 
so, to what contour? Commenters are asked to give detailed evidence for 
or against increasing the level of protection to analog FM stations on 
adjacent channels from increased FM digital sideband power proposals. 
Commenter Press Communications, LLC (Press), offered a number of 
proposals to remedy what it sees as the problems the Power Increase 
Petition would cause to smaller, coastal FM stations, including: (i) 
allowing such stations to move up to three miles inland under certain 
conditions; (ii) adopting a universal analog 60 dB[micro] protection in 
Zone I for all co-, first-, and second-adjacent analog Class A to Class 
B station-to-station separations; and (iii) extending protection beyond 
the 60 dB[micro] contour for Class A stations to the 45 dB[micro] 
contour or even a 50 dB[micro] Longley-Rice contour. While noting that 
Press's proposed solutions appear to be geographically targeted and 
class-specific, the Commission invites comment on Press's proposals. 
Finally, the Commission invites comment as to the potential effect of 
the proposed change in the methodology for calculating digital FM power 
levels on all stakeholders utilizing the 88-108 MHz frequency band, 
whether they are broadcasters or providers of other services.
    19. Superpowered FM Stations. The Commission proposed to continue 
to limit the power level for previously authorized superpowered FM 
stations to the station's class maximum. One commenter noted that 
allowing a legacy digital superpowered FM station meeting the proposed 
new table to increase its digital ERP up to -10 dBc, or 10% of the 
analog ERP could allow certain stations to increase digital power to 
above the class maximum, resulting in harmful interference. The 
Commission tentatively concluded that a superpowered station's digital 
ERP should continue to be limited to the class maximum provided in 47 
CFR 73.211 and 73.511. Thus, it proposed that a superpowered FM station 
seeking to increase its digital power above -14 dBc may request 
experimental authorization or special temporary authorization (STA) to 
do so, and the staff would review such requests on a case-by-case 
basis. The Commission solicits comment on this conclusion and proposal, 
and requests that commenters opposing this view detail the reasons why 
they believe that a digital FM station whose power greatly exceeds its 
class maximum will not cause excessive interference to adjacent channel 
analog facilities.
    20. Notification of FM Digital Power Increase. The Commission seeks 
comment on the type of notification, if any, that should be required of 
a digital FM station increasing digital power, and whom should be 
notified. One commenter urged that any adopted notification procedures 
also include a provision that the FM digital station increasing power 
notify the licensees of first-adjacent channel FM stations at least 30 
days prior to implementation of the power increase, but in no event 
after the power increase has already taken place. The International 
Association of Audio Information Services (IAAIS), representing radio 
reading services that use analog FM station sub-carriers to provide 
audio versions of publications for print-disabled individuals, likewise 
requested that a host station increasing digital power to -10 dBc 
provide written notification to any radio reading services on that host 
station's sub-carriers, as well as to all radio reading services 
broadcasting over any adjacent channel stations' sub-carriers.
    21. Under the current system, stations increasing symmetric digital 
sideband power to levels up to -14 dBc need to submit LMS Form 2100, 
Schedule 335-FM, FM Digital Notification (Schedule 335-FM), without any 
further showings or analysis to be submitted to the staff for approval. 
The digital FM station must electronically notify the Media Bureau of 
increased power FM digital operation within 10 days of commencement of 
operations at increased power. Although these notifications are 
available to the public from the FCC's database, the staff takes no 
action on the notifications, and they do not appear in the Commission's 
public notices of broadcast applications or broadcast actions. 
Symmetric digital operation at power levels between -14 dBc and -10 dBc 
currently require both notification on Schedule 335-FM and a showing 
that the contours generated do not overlap with the protected contours 
of adjacent-channel FM stations. Such showings are confirmed by the 
staff. Under the Commission's proposal herein, such showings would no 
longer be required for power increases up to -10 dBc--the station 
seeking a power increase would only have to provide notification by 
filing Schedule 335-FM, and the staff would neither grant nor deny such 
notification. The Commission tentatively concluded that this 
notification-only procedure should be sufficient for digital FM 
stations increasing digital sideband power the additional 4 dB it 
proposes to allow in the NPRM, and seeks comment on this conclusion. It 
likewise tentatively concluded that Schedule 335-FM notification should 
be required for any digital FM station permanently reducing

[[Page 57037]]

digital power, and further tentatively concluded that any such 
notification of digital FM power reduction be accompanied by a short 
statement of the reason(s) for the power reduction (e.g., interference 
complaints, inadequate signal coverage, etc.), and seeks comment on 
this tentative conclusion.
    22. Although the filing of Schedule 335-FM does not generate a 
separate LMS Public Notice, all filed LMS forms are searchable, and are 
thus available to the public using the LMS ``Search'' function. The 
Commission thus seeks comment on whether this accessibility should 
provide adequate notice to other stations and interested parties that a 
first-adjacent channel FM digital station is increasing its digital 
power. It seeks comment on whether Schedule 335-FM filings in LMS will 
provide adequate notice or if it should adopt any other notification 
procedure. Commenters holding differing views should explain why the 
Commission should require additional specific notice, i.e., to first-
adjacent stations or entities other than the Commission, than is 
currently required. Should it require direct notice to all potentially 
affected first-adjacent channel FM stations in addition to that 
provided by the notification filed in LMS? Should potential direct 
notice to first-adjacent channel FM stations be given a certain period 
of time, such as 30 days, before the digital station is allowed to 
implement the digital power increase? In the alternative, should the 
station increasing digital power be required not only to file Schedule 
335-FM, but further be obliged to wait a certain period of time before 
implementing the power increase, so as to give interested parties an 
opportunity to comment and/or object? The Commission asks that 
commenters provide reasons for their positions regarding notice, and 
further to provide specifics as to both the type of notice that should 
be given and the key recipients of that notice.
    23. IAAIS expressed concerns about digital FM sideband power and 
its effects on radio reading services. Radio reading services, using 
primarily volunteer staff, provide valuable services by reading daily 
and weekly newspapers, magazines, current books, and other programs of 
interest to blind, visually impaired, physically disabled, and other 
print-disabled persons, who cannot easily access or consume written 
media. While these important services employ a variety of methods to 
deliver their content, the majority of IAAIS members broadcast over 
analog FM radio subcarriers. With regard to IAAIS's concerns about the 
effect of increased digital FM sideband power on such subcarriers, even 
absent a general requirement of direct notice of digital power increase 
to potentially affected stations, should such radio reading services 
receive special notification from the station proposing to increase 
digital power, whether that is the station hosting the radio reading 
service or a nearby adjacent channel station? If so, what form should 
that direct notice take? If, after reviewing comments, the Commission 
determines that a station increasing digital power must notify all 
first-adjacent channel stations of the increase, should it further 
require that any first-adjacent channel station receiving such notice 
notify any radio reading service(s) that it hosts?
    24. Asymmetric Sideband Petition. The Commission proposed to grant 
blanket authorization to digital FM stations to originate digital 
transmissions at different power levels on the upper and lower digital 
sidebands without having to request experimental authorization. As with 
any digital FM power increase resulting from the proposed revised power 
table, discussed above, it proposed that a digital FM station need only 
notify us of asymmetric sideband operation by filing notification 
(Schedule 335-FM) in the Bureau's LMS database.
    25. Asymmetric Sideband Operation/Interference Issues. Currently, 
digital FM stations must use the same ERP on both the upper and lower 
digital sidebands. Thus, as pointed out by petitioners, any digital FM 
station's digital power was limited to that needed to protect the 
nearer of the adjacent channel analog FM stations, regardless of 
whether there was a need to limit power on the other sideband. 
Petitioners contended that allowing calculation of the maximum 
allowable digital FM ERP on a per-sideband basis allows such stations 
to optimize their digital signal coverage while still protecting analog 
FM stations on adjacent channels. For example, a digital FM station 
with an analog station only on the first adjacent channel above its 
frequency could selectively reduce power on the upper sideband to avoid 
causing interference, while maintaining or even increasing digital ERP 
on the lower sideband to enhance signal coverage without interfering 
with a nearby station. Alternatively, a digital FM station in the same 
situation could maintain its digital ERP on the upper sideband while 
increasing power on the lower sideband. The 2022 Power Increase 
Petition proposed a new formula to calculate maximum digital power per 
sideband, updated to comport with the Power Increase Petition proposal. 
The proposed new method for calculating per-sideband FM Digital ERP 
yields the following table:

------------------------------------------------------------------------
 Proponent analog F(50,10) field strength
   at first adjacent station's analog 60       Maximum  permissible FM
  dB[micro] F(50,50) contour (asymmetric             digital ERP
            sideband operation)
------------------------------------------------------------------------
54.9 dB[micro] and above..................  -14 dBc
53.5 dB[micro] to 54.8 dB[micro]..........  -13 dBc
52.6 dB[micro] to 53.4 dB[micro]..........  -12 dBc
51.1 dB[micro] to 52.5 dB[micro]..........  -11 dBc
51.0 dB[micro] or less....................  -10 dBc
------------------------------------------------------------------------

    26. When operating in symmetric mode, each digital sideband 
contributes exactly half of the total authorized digital power for that 
station. For example, a station that is authorized to operate in 
symmetric mode with a total digital power of -10 dBc operates with half 
that power (-13 dBc) in each digital sideband. When a station operates 
in asymmetric mode with one digital sideband having more power than the 
other, it is necessary to ensure that each sideband is limited to the 
appropriate contour-limited value from the table, and that the total 
digital power in both sidebands together does not exceed the total 
amount of digital power that would be authorized if the station were 
operating in symmetric mode. Accordingly, the Effective Radiated Power 
at each sideband must be adjusted so that the total sideband powers do 
not exceed the total power that would be authorized for that station 
operating in symmetric sideband mode.
    27. Those commenters that addressed the Asymmetric Sideband 
Petition uniformly supported it, although Press, which filed ex parte 
presentations after the commenting period expired, questioned whether 
these proposals, if adopted, would actually protect adjacent FM analog 
stations to the extent it believed is required. Many of the supporters 
noted that eliminating the need to seek experimental authorization for 
asymmetric sideband operation would encourage more stations to adopt 
this operational mode.
    28. Given the general lack of commenter objection and the record as 
presented by the petitioners and certain commenters, the Commission 
proposed to authorize asymmetric sideband operation for FM digital 
broadcasters operating at any power level, without the need first to 
seek experimental authorization. As with any potential FM digital power 
increase, the Commission proposed that a digital FM station seeking to 
operate with asymmetric sidebands must notify the Bureau using Schedule 
335-FM. It reiterated that the filing of Schedule 335-FM with the

[[Page 57038]]

Commission does not trigger the release of a separate Public Notice in 
LMS, but that, like all LMS forms, the filing is searchable and thus 
available to members of the public using the LMS ``Search'' function. 
The Commission therefore seeks comment on whether notification to the 
Commission should suffice to provide notice to other interested 
parties, including adjacent channel stations. To the extent that 
commenters believe that more or different notice should be required, it 
asks that they specify the type of notice and the reasons why form 
availability in LMS is not sufficient. It further tentatively concluded 
that Schedule 335-FM notification should be required for any digital FM 
station that permanently reverts to symmetric sideband operation from 
asymmetric sideband operation, and further tentatively conclude that 
any such notification of return to symmetric sideband operation be 
accompanied by a short statement of the reason(s) for this action. The 
Commission seeks comment on this tentative conclusion.
    29. Likewise, the Commission believed that the interference 
mitigation and remediation procedures established in 2010 should be 
sufficient to remedy any reports of inter-station interference as a 
result of asymmetric sideband operation. It observed that asymmetric 
sideband operation per se should not cause an increase in interference 
or complaints thereof, as stations employing such operation are already 
protecting the closer of the adjacent stations to their sideband 
frequencies, and the only power increases should be toward adjacent 
channel stations that are more distant, either physically or by 
frequency. To the extent that commenters believe that more stringent 
interference mitigation and remediation procedures are required, the 
Commission asks that such commenters detail the measures they deem 
necessary as well as the precise reasons why the current procedures are 
inadequate.
    30. Other Issues: 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 
proposals and issues discussed herein. The term ``equity'' is used here 
consistent with Executive Order 13985 as the consistent and systematic 
fair, just, and impartial treatment of all individuals, including 
individuals who belong to underserved communities that have been denied 
such treatment. Such individuals include Black, Latino, and Indigenous 
and Native American persons, Asian Americans and Pacific Islanders and 
other persons of color; members of religious minorities; lesbian, gay, 
bisexual, transgender, and queer (LGBTQ+) persons; persons with 
disabilities; persons who live in rural areas; and persons otherwise 
adversely affected by persistent poverty or inequality. Section 1 of 
the Communications Act of 1934 as amended provides that the FCC 
``regulat[es] interstate and foreign commerce in communication by wire 
and radio so as to make [such service] available, so far as possible, 
to all the people of the United States, without discrimination on the 
basis of race, color, religion, national origin, or sex.''. 
Specifically, the FCC seeks comment on how its proposals 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

    31. The proceeding this NPRM initiates shall be treated as a 
``permit-but-disclose'' proceeding in accordance with the Commission's 
ex parte rules, 47 CFR 1.1200 et seq. Persons making ex parte 
presentations must file a copy of any written presentation or a 
memorandum summarizing any oral presentation within two business days 
after the presentation (unless a different deadline applicable to the 
Sunshine period applies). Persons making oral ex parte presentations 
are reminded that memoranda summarizing the presentation must (1) list 
all persons attending or otherwise participating in the meeting at 
which the ex parte presentation was made, and (2) summarize all data 
presented and arguments made during the presentation. Memoranda must 
contain a summary of the substance of the ex parte presentation and not 
merely a listing of the subjects discussed. More than a one or two 
sentence description of the views and arguments presented is generally 
required. If the presentation consisted in whole or in part of the 
presentation of data or arguments already reflected in the presenter's 
written comments, memoranda or other filings in the proceeding, the 
presenter may provide citations to such data or arguments in his or her 
prior comments, 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 47 CFR 
1.1206(b). In proceedings governed by 47 CFR 1.49(f) or for which the 
Commission has made available a method of electronic filing, written ex 
parte presentations and memoranda summarizing oral ex parte 
presentations, and all attachments thereto, must be filed through the 
electronic comment filing system available for that proceeding, and 
must be filed in their native format (e.g., .doc, .xml, .ppt, 
searchable.pdf). Participants in this proceeding should familiarize 
themselves with the Commission's ex parte rules.

Initial Regulatory Flexibility Analysis

    32. The Regulatory Flexibility Act of 1980, as amended (RFA), 
requires that a regulatory flexibility analysis be prepared for notice 
and comment rule making proceedings, unless the agency certifies that 
``the rule will not, if promulgated, have a significant economic impact 
on a substantial number of small entities.'' The RFA generally defines 
the term ``small entity'' as having the same meaning as the terms 
``small business,'' ``small organization,'' and ``small governmental 
jurisdiction.'' In addition, the term ``small business'' has the same 
meaning as the term ``small business concern'' under the Small Business 
Act. A ``small business concern'' is one which: (1) is independently 
owned and operated; (2) is not dominant in its field of operation; and 
(3) satisfies any additional criteria established by the Small Business 
Administration (SBA).
    33. As required by the RFA, the Commission has prepared this 
Initial Regulatory Flexibility Analysis (IRFA) of the possible 
significant economic impact on a substantial number of small entities 
by the policies proposed in the Notice of Proposed Rulemaking (NPRM). 
Written public comments are requested on this IRFA. Comments must be 
identified as responses to the IRFA and must be filed by the deadlines 
for comments on the NPRM provided on the first page of the NPRM. The 
Commission will send a copy of this entire NPRM, including this IRFA, 
to the Chief Counsel for Advocacy of the Small Business Administration 
(SBA). In addition, the NPRM and the IRFA (or summaries thereof) will 
be published in the Federal Register.

[[Page 57039]]

A. Need For, and Objectives of, the Proposed Rules

    34. In the NPRM, the Commission proposes to revise its methodology 
for determining whether a digital FM station may increase the effective 
radiated power (ERP) on its digital sidebands; to allow a digital FM 
station to implement or increase digital ERP from 14 dB below the 
analog carrier ERP (expressed as -14 dBc) to -10 dBc, without the need 
to do more than notify the Commission of such operation by FCC form; 
and to allow a digital FM station to operate with different power 
levels on its upper and lower digital sidebands, without first having 
to seek experimental authorization for such operation. The Commission 
initiated the NPRM in response to two Petitions for Rulemaking that 
were consolidated by the Media Bureau (Bureau) because the proposed 
rule changes both relate to improving digital FM signal quality and 
minimizing the effect of the digital FM station signal on adjacent 
channel FM transmissions. In the earlier of the two petitions, filed 
December 9, 2019, petitioners National Association of Broadcasters 
(NAB), Xperi Corporation (Xperi), and National Public Radio (NPR) 
request blanket authorization to set digital power at different levels 
on each digital sideband, thus allowing a digital FM station to 
protect, for example, an analog FM station on a lower first adjacent 
channel, while enabling an increase in digital power on the upper 
sideband where there is no adjacent analog FM station or a more distant 
adjacent station. In the second petition, filed October 26, 2022, NAB 
and Xperi request that the FCC adopt an updated methodology to 
determine digital FM power levels for stations seeking to exceed the 
currently authorized FM digital effective radiated power (ERP) of -14 
dBc. The Commission seeks comment on whether the rule changes proposed, 
based on the Asymmetric Sideband Petition and Power Increase Petition, 
would serve the public interest by providing digital FM stations with 
the ability to increase power and, concomitantly, increase coverage 
area, building penetration, and provide a more robust digital signal. 
Petitioners, and most commenters on the petitions, maintain that the 
current method for determining digital FM power overprotects analog FM 
stations on adjacent frequencies from digital interference, and that 
higher digital FM power levels would enable digital FM stations to more 
closely replicate their analog FM coverage with digital coverage. With 
regard to the Asymmetric Sideband Petition, petitioners contend that 
allowing calculation of the maximum allowable digital FM power on a 
per-sideband basis allows such stations to optimize their digital 
signal coverage while still protecting analog FM stations on adjacent 
channels. For example, a digital FM station with an analog station only 
on the first adjacent channel above its frequency could selectively 
reduce power on the upper sideband to avoid causing interference, while 
maintaining or even increasing digital power on the lower sideband to 
enhance signal coverage without interfering with a nearby station. 
Alternatively, a digital FM station in the same situation could 
maintain its digital power on the upper sideband while increasing power 
on the lower sideband.
    35. The Commission seeks comment on the following issues relating 
to digital FM station operations: (1) to change the methodology used by 
digital FM stations to determine whether they are eligible to increase 
digital FM ERP up to -10 dBc, or 10% of analog power, upon basic 
notification to the Commission and without the need for additional 
individual special authorization; (2) to allow a power increase up to -
10 dBc by notifying the Commission in the Bureau's Licensing and 
Management System (LMS), utilizing the same notification procedures as 
currently used; (3) whether changing the method for calculating whether 
a digital FM station can increase its digital power will create an 
unacceptable risk of interference to adjacent-channel stations; (4) 
whether to continue to limit the power level for previously authorized 
superpowered FM stations to their class maximum; (5) the type of 
notification, if any, we should require of a digital FM station 
increasing digital power, and whom should be notified; (6) whether the 
interference mitigation and remediation procedures currently used for 
inter-station digital FM interference should be sufficient to remedy 
any reports of interference to FM broadcast stations or other spectrum 
users as a result of a station's increase in its digital power; (7) 
whether to grant blanket authorization to digital FM stations to 
originate digital transmissions at different power levels on the upper 
and lower digital sidebands without having to request experimental 
authorization; and (8) whether the interference mitigation and 
remediation procedures currently used for inter-station digital FM 
interference should be sufficient to remedy any reports of inter-
station interference as a result of asymmetric sideband operation.

B. Legal Basis

    36. The proposed action is authorized pursuant to sections 1, 4(i), 
4(j), 301, 302a, 303, 307, 308, 309, 316, 319, and 324 of the 
Communications Act of 1934, as amended, 47 U.S.C. 151, 154(i), 154(j), 
301, 302a, 303, 307, 308, 309, 316, 319, and 324.

C. Description and Estimate of the Number of Small Entities to Which 
the Proposed Rules Will Apply

    37. The RFA directs agencies to provide a description of, and where 
feasible, an estimate of the number of small entities that may be 
affected by the proposed rules, if adopted. 5 U.S.C. 603(b)(3). The RFA 
generally defines the term ``small entity'' as having the same meaning 
as the terms ``small business,'' ``small organization,'' and ``small 
governmental jurisdiction.'' In addition, the term ``small business'' 
has the same meaning as the term ``small business concern'' under the 
Small Business Act. A small business concern is one which: (1) is 
independently owned and operated; (2) is not dominant in its field of 
operation; and (3) satisfies any additional criteria established by the 
SBA.
    38. Radio Stations. This industry is comprised of ``establishments 
primarily engaged in broadcasting aural programs by radio to the 
public.'' Programming may originate in their own studio, from an 
affiliated network, or from external sources. The SBA small business 
size standard for this industry classifies firms having $41.5 million 
or less in annual receipts as small. U.S. Census Bureau data for 2017 
show that 2,963 firms operated in this industry during that year. Of 
this number, 1,879 firms operated with revenue of less than $25 million 
per year. Based on this data and the SBA's small business size 
standard, we estimate a majority of such entities are small entities.
    39. The Commission estimates that as of March 31, 2023, there were 
4,472 licensed commercial AM radio stations and 6,681 licensed 
commercial FM radio stations, for a combined total of 11,153 commercial 
radio stations. Of this total, 11,151 stations (or 99.98%) had revenues 
of $41.5 million or less in 2022, according to Commission staff review 
of the BIA Kelsey Inc. Media Access Pro Database (BIA) on April 7, 
2023, and therefore these licensees qualify as small entities under the 
SBA definition. In addition, the Commission estimates that as of March 
31, 2023, there were 4,219 licensed noncommercial (NCE) FM radio 
stations, 1,999 low power FM (LPFM) stations, and 8,939 FM translators 
and

[[Page 57040]]

boosters. The Commission however does not compile, and otherwise does 
not have access to financial information for these radio stations that 
would permit it to determine how many of these stations qualify as 
small entities under the SBA small business size standard. 
Nevertheless, given the SBA's large annual receipts threshold for this 
industry and the nature of radio station licensees, we presume that all 
of these entities qualify as small entities under the above SBA small 
business size standard.
    40. We note, however, that in assessing whether a business concern 
qualifies as ``small'' under the above definition, business (control) 
affiliations must be included. Our estimate, therefore, likely 
overstates the number of small entities that might be affected by our 
action, because the revenue figure on which it is based does not 
include or aggregate revenues from affiliated companies. In addition, 
another element of the definition of ``small business'' requires that 
an entity not be dominant in its field of operation. We are unable at 
this time to define or quantify the criteria that would establish 
whether a specific radio or television broadcast station is dominant in 
its field of operation. Accordingly, the estimate of small businesses 
to which the rules may apply does not exclude any radio or television 
station from the definition of a small business on this basis and is 
therefore possibly over-inclusive. An additional element of the 
definition of ``small business'' is that the entity must be 
independently owned and operated. Because it is difficult to assess 
these criteria in the context of media entities, the estimate of small 
businesses to which the rules may apply does not exclude any radio or 
television station from the definition of a small business on this 
basis and similarly may be over-inclusive.
    41. Low Power FM Stations. The SBA small business size standard for 
Radio Stations applies to low power FM stations. The Radio Stations 
industry comprises establishments primarily engaged in broadcasting 
aural programs by radio to the public. Programming may originate in 
their own studio, from an affiliated network, or from external sources. 
The SBA small business size standard for this industry classifies firms 
having $41.5 million or less in annual receipts as small. U.S. Census 
Bureau data for 2017 show that 2,963 firms in this industry operated 
during that year. Of this number, 1,879 firms operated with revenue of 
less than $25 million per year. Therefore, based on the SBA's size 
standard we conclude that the majority of low power FM stations are 
small.
    42. Additionally, according to Commission data as of March 31, 
2023, there were 1,999 Low Power FM licensed broadcast stations and 
8,939 FM Translator Stations. The Commission does not compile and 
otherwise does not have access to financial information for these 
stations that would permit it to determine how many of the stations 
would qualify as small entities under the SBA size standard. However, 
given that low power FM stations and FM translators and boosters are 
very small and limited in their operations and unlikely to have annual 
receipts anywhere near the SBA small size standard, we will presume 
that these licensees qualify as small entities under the SBA size 
standard.

D. Description of Projected Reporting, Recordkeeping and Other 
Compliance Requirements

    43. In this section, we identify the reporting, recordkeeping, and 
other compliance requirements proposed in the NPRM and consider whether 
small entities are affected disproportionately by any such 
requirements. As discussed above, the NPRM seeks comment on changes to 
the Commission's rules governing digital FM broadcast stations. 
Allowing some broadcasters that are small entities to increase digital 
FM power, or to operate with asymmetric sideband power, as proposed in 
the NPRM would be a voluntary process. Each FM station that meets the 
proposed requirements can make an individual decision about whether 
operating with higher digital power and/or asymmetric sideband power is 
a feasible technical and economic upgrade option. The Commission does 
not propose to compel, but rather merely to authorize, the proposed 
digital power increases and operations. The NPRM proposes new mandatory 
reporting, recordkeeping, and compliance requirements for small 
entities that are FM licensees and choose to increase their power and/
or adopt asymmetric sideband operation. We note that the adoption of 
the proposed rules may require modification of current requirements and 
processes for small entities that choose to implement these operational 
changes, and may require modification of FCC forms, including but not 
limited to, FCC Form 2100, Schedule 335-FM, which is the form currently 
used to notify the Commission of the initiation of digital operations. 
The NPRM thus may impose additional obligations or expenditure of 
resources on small businesses that elect to modify their digital 
service, and may require small entities to hire professionals to comply 
with the proposed rules.
    44. The NPRM seeks comment on the notification and interference 
mitigation and remediation obligations of digital FM stations, 
including small entities. For example, the proposal to amend the 
Commission's rules to modify the methodology a digital FM station must 
use to determine whether it is eligible to increase its power above -14 
dBc, if adopted, would reduce compliance obligations for small entities 
by allowing them to increase power up to -10 dBc without submitting a 
contour analysis. Small entity stations that seek to increase digital 
sideband power by the addition of 4 dB would need to notify the 
Commission by filing Schedule 335-FM. At this time the Commission 
cannot quantify the cost of compliance for small entities that choose 
to modify their operations pursuant to the NPRM proposals. However, the 
Commission expects the information it receives in comments to help it 
identify and evaluate relevant compliance matters for small entities, 
including compliance costs and other burdens that may result from 
potential changes discussed in the NPRM.

E. Steps Taken To Minimize Significant Impact on Small Entities, and 
Significant Alternatives Considered

    45. The RFA requires an agency to describe any significant, 
specifically small business, alternatives that it has considered in 
reaching its proposed approach, which may include the following four 
alternatives (among others): ``(1) the establishment of differing 
compliance or reporting requirements or timetables that take into 
account the resources available to small entities; (2) the 
clarification, consolidation, or simplification of compliance and 
reporting requirements under the rule for such small entities; (3) the 
use of performance, rather than design standards; and (4) an exemption 
from coverage of the rule, or any part thereof, for such small 
entities.''
    46. The NPRM considers a voluntary process by which some FM 
stations may operate at increased digital power and/or with differing 
power levels on each digital sideband. According to commenters, the 
proposal would benefit digital FM broadcasters and listeners alike by 
promoting greater adoption of FM digital transmission systems. 
Commenters also assert that adoption of the NPRM proposals would 
increase the robustness of the digital FM broadcast service by 
improving stations' signal quality, including building penetration and 
allowing a digital FM licensee to

[[Page 57041]]

expand its digital service area to approximate more closely its analog 
service area. Other commenters caution that the proposed change may 
harm small entities by causing surrounding interference for smaller 
stations such as Class A FM stations, LPFM stations, and stations 
broadcasting over FM translators.
    47. In the NPRM, the Commission considers specific steps it could 
take and alternatives to the proposed rules that could minimize 
potential economic impact on small entities that might be affected by 
the proposed rule change, as well as any other rule changes that may be 
required. For example, to avoid increasing burdens on digital FM 
broadcasters, the Commission proposes that any notification of 
increases in digital FM ERP and/or initiation of asymmetric sideband 
operation be made by filing FCC Form 2100, Schedule 335-FM, in the 
searchable LMS database. This is the same form currently used to notify 
the Commission of the initiation of digital operations. Under the 
proposed rule changes fewer stations would be required to submit a 
contour study with Schedule 335-FM, as is currently the case for 
digital FM stations proposing digital power levels above -14 dBc. 
Therefore, the administrative impact of the proposed rule changes will 
be similar to that of existing digital FM service, will be less 
burdensome for most digital FM broadcasters, and thus is not likely to 
have an additional adverse economic impact on small entities.
    48. The Commission also considers alternatives to its current 
interference remediation procedures, including whether station 
complaints should be assessed based on listener complaints or based on 
studies and/or measurements demonstrating that a digital FM signal 
within the complaining station's protected contour exceeds allowable 
limits. Another alternative considered in relation to interference that 
may impact small entities is whether protection of incumbent analog FM 
stations on adjacent channels should be increased beyond the 60 
dB[micro] contour. The Commission tentatively concluded that this 
protection is not necessary, however, it also considered whether this 
protection should be increased and, if so, to what contour. The 
Commission expects to more fully consider the economic impact and 
alternatives for small entities following the review of comments filed 
in response to the NPRM.

F. Federal Rules Which Duplicate, Overlap, or Conflict With, the 
Commission's Proposals

    49. None.
    50. To request materials in accessible formats for people with 
disabilities (Braille, large print, electronic files, audio format), 
send an email to [email protected] or call the Consumer and Governmental 
Affairs Bureau at 202-418-0530 (voice), 202-418-0432 (TTY).

Ordering Clauses

    51. Accordingly, it is ordered, pursuant to Sec.  1.407 of the 
Commission's rules, 47 CFR 1.407, that the Petition for Rulemaking of 
the National Association of Broadcasters, Xperi Corporation, and 
National Public Radio filed on Dec. 9, 2019 and the Petition for 
Rulemaking of the National Association of Broadcasters and Xperi 
Corporation filed on Oct. 26, 2022 are granted.
    52. it is further ordered that, pursuant to the authority contained 
in sections 1, 4(i), 4(j), 301, 302a, 303, 307, 308, 309, 316, 319, and 
324 of the Communications Act of 1934, as amended, 47 U.S.C. 151, 
154(i), 154(j), 301, 302a, 303, 307, 308, 309, 316, 319, and 324 this 
Notice of Proposed Rulemaking is adopted.
    53. it is further ordered that the Commission's Office of the 
Secretary, Reference Information Center, shall send a copy of this 
Notice of Proposed Rulemaking, including the Initial Regulatory 
Flexibility Analysis, to the Chief Counsel for Advocacy of the Small 
Business Administration.

List of Subjects in 47 CFR Part 73

    Radio, Reporting and recordkeeping requirements.


Federal Communications Commission.
Katura Jackson,
Federal Register Liaison Officer.

Proposed Rules

    For the reasons discussed in this preamble, the Federal 
Communications Commission proposes to amend 47 CFR part 73 as follows:

PART 73--RADIO BROADCAST SERVICES

0
1. The authority citation for part 73 continues to read as follows:

    Authority: 47 U.S.C. 154, 155, 301, 303, 307, 309, 310, 334, 
336, 339.

0
2. Amend Sec.  73.310 by revising paragraphs (a) and (b) to read as 
follows:


Sec.  73.310  FM technical definitions.

    (a) Frequency modulation. The following definitions pertain to 
frequency modulation, as defined in Sec.  73.310(a)(17).
    (1) Antenna height above average terrain (HAAT). HAAT is calculated 
by: determining the average of the antenna heights above the terrain 
from 3 to 16 kilometers (2 to 10 miles) from the antenna for the eight 
directions evenly spaced for each 45[deg] of azimuth starting with True 
North (a different antenna height will be determined in each direction 
from the antenna): and computing the average of these separate heights. 
In some cases less than eight directions may be used. (See Sec.  
73.313(d).) Where circular or elliptical polarization is used, the 
antenna height above average terrain must be based upon the height of 
the radiation of the antenna that transmits the horizontal component of 
radiation.
    (2) Antenna power gain. The square of the ratio of the root-mean-
square (RMS) free space field strength produced at 1 kilometer in the 
horizontal plane in millivolts per meter for 1 kW antenna input power 
to 221.4 mV/m. This ratio is expressed in decibels (dB). If specified 
for a particular direction, antenna power gain is based on that field 
strength in the direction only.
    (3) Auxiliary facility. An auxiliary facility is an antenna 
separate from the main facility's antenna, permanently installed on the 
same tower or at a different location, from which a station may 
broadcast for short periods without prior Commission authorization or 
notice to the Commission while the main facility is not in operation 
(e.g., where tower work necessitates turning off the main antenna or 
where lightning has caused damage to the main antenna or transmission 
system) (See Sec.  73.1675).
    (4) Center frequency. The term ``center frequency'' means:
    (i) The average frequency of the emitted wave when modulated by a 
sinusoidal signal.
    (ii) The frequency of the emitted wave without modulation.
    (5) Composite antenna pattern. The composite antenna pattern is a 
relative field horizontal plane pattern for 360 degrees of azimuth, for 
which the value at a particular azimuth is the greater of the 
horizontally polarized or vertically polarized component relative field 
values. The composite antenna pattern is normalized to a maximum of 
unity (1.000) relative field.
    (6) Composite baseband signal. A signal which is composed of all 
program and other communications signals that frequency modulates the 
FM carrier.
    (7) Effective radiated power. The term ``effective radiated power'' 
means the product of the antenna power

[[Page 57042]]

(transmitter output power less transmission line loss) times:
    (i) The antenna power gain, or
    (ii) the antenna field gain squared. Where circular or elliptical 
polarization is employed, the term effective radiated power is applied 
separately to the horizontal and vertical components of radiation. For 
allocation purposes, the effective radiated power authorized is the 
horizontally polarized component of radiation only.
    (8) Equivalent isotropically radiated power (EIRP). The term 
``equivalent isotropically radiated power (also known as ``effective 
radiated power above isotropic) means the product of the antenna input 
power and the antenna gain in a given direction relative to an 
isotropic antenna.
    (9) FM Blanketing. Blanketing is that form of interference to the 
reception of other broadcast stations which is caused by the presence 
of an FM broadcast signal of 115 dB[micro] (562 mV/m) or greater signal 
strength in the area adjacent to the antenna of the transmitting 
station. The 115 dB[micro] contour is referred to as the blanketing 
contour and the area within this contour is referred to as the 
blanketing area.
    (10) FM broadcast band. The band of frequencies extending from 88 
to 108 MHz, which includes those assigned to noncommercial educational 
broadcasting.
    (11) FM broadcast channel. A band of frequencies 200 kHz wide and 
designated by its center frequency. Channels for FM broadcast stations 
begin at 88.1 MHz and continue in successive steps of 200 kHz to and 
including 107.9 MHz.
    (12) FM broadcast station. A station employing frequency modulation 
in the FM broadcast band and licensed primarily for the transmission of 
radiotelephone emissions intended to be received by the general public.
    (13) Field strength. The electric field strength in the horizontal 
plane.
    (14) Free space field strength. The field strength that would exist 
at a point in the absence of waves reflected from the earth or other 
reflecting objects.
    (15) Frequency departure. The amount of variation of a carrier 
frequency or center frequency from its assigned value.
    (16) Frequency deviation. The peak difference between modulated 
wave and the carrier frequency.
    (17) Frequency modulation. A system of modulation where the 
instantaneous radio frequency varies in proportion to the instantaneous 
amplitude of the modulating signal (amplitude of modulating signal to 
be measured after pre-emphasis, if used) and the instantaneous radio 
frequency is independent of the frequency of the modulating signal.
    (18) Frequency swing. The peak difference between the maximum and 
the minimum values of the instantaneous frequency of the carrier wave 
during modulation.
    (19) Multiplex transmission. The term ``multiplex transmission'' 
means the simultaneous transmission of two or more signals within a 
single channel. Multiplex transmission as applied to FM broadcast 
stations means the transmission of facsimile or other signals in 
addition to the regular broadcast signals.
    (20) Percentage modulation. The ratio of the actual frequency 
deviation to the frequency deviation defined as 100% modulation, 
expressed in percentage. For FM broadcast stations, a frequency 
deviation of 75kHz is defined as 100% modulation.
    (21) Previously authorized superpowered FM station. An FM station 
authorized to operate with facilities that exceed the Effective 
Radiated Power/Height Above Average Terrain limitations of Sec. Sec.  
73.211 or 73.511 for their specific class.
    (b) Stereophonic sound broadcasting. The following definitions 
pertain to stereophonic sound broadcasting, as defined in Sec.  
73.310(b)(8).
    (1) Cross-talk. An undesired signal occurring in one channel caused 
by an electrical signal in another channel.
    (2) FM stereophonic broadcast. The transmission of a stereophonic 
program by a single FM broadcast station utilizing the main channel and 
a stereophonic subchannel.
    (3) Left (or right) signal. The electrical output of a microphone 
or combination of microphones placed so as to convey the intensity, 
time, and location of sounds originating predominately to the 
listener's left (or right) of the center of the performing area.
    (4) Left (or right) stereophonic channel. The left (or right) 
signal as electrically reproduced in reception of FM stereophonic 
broadcasts.
    (5) Main channel. The band of frequencies from 50 to 15,000 Hz 
which frequency-modulate the main carrier.
    (6) Pilot subcarrier. A subcarrier that serves as a control signal 
for use in the reception of FM stereophonic sound broadcasts.
    (7) Stereophonic separation. The ratio of the electrical signal 
caused in sound channel A to the signal caused in sound channel B by 
the transmission of only a channel B signal. Channels A and B may be 
any two channels of a stereophonic sound broadcast transmission system.
    (8) Stereophonic sound. The audio information carried by plurality 
of channels arranged to afford the listener a sense of the spatial 
distribution of sound sources. Stereophonic sound broadcasting 
includes, but is not limited to, biphonic (two channel), triphonic 
(three channel) and quadrophonic (four channel) program services.
    (9) Stereophonic sound subcarrier. A subcarrier within the FM 
broadcast baseband used for transmitting signals for stereophonic sound 
reception of the main broadcast program service.
    (10) Stereophonic sound subchannel. The band of frequencies from 23 
kHz to 99 kHz containing sound subcarriers and their associated 
sidebands.
* * * * *
0
3. Amend Sec.  73.402 by adding paragraph (i) to read as follows:


Sec.  73.402  Definitions.

* * * * *
    (i) Asymmetric sideband operation. For digital FM stations, the use 
of different power levels on the upper and lower digital sidebands in a 
hybrid or extended hybrid DAB system.
0
4. Amend Sec.  73.404 by adding paragraphs (e) through (g) to read as 
follows:


Sec.  73.404  IBOC DAB operation.

* * * * *
    (e) All FM stations transmitting hybrid IBOC signals may operate 
with total effective radiated power of up to -14 dBc. No station may 
operate its digital carriers with a total effective radiated power in 
excess of -10 dBc. A station using symmetric sidebands planning to 
operate with a total radiated power in excess of -14 dBc must confirm 
compliance with Table 1 below by calculating the signal strength of its 
analog signal at the first adjacent station's 60 dB[mu] contour. All 
calculations must be made using the standard FCC contour prediction 
methodology.

    Table 1 to Paragraph (e)--Maximum Permissible FM Digital ERP for
                      Symmetric Sideband Operation
------------------------------------------------------------------------
                                                              Maximum
    Proponent analog F(50,10) field strength at first     permissible FM
  adjacent station's analog 60 dB[mu] F(50,50) contour      digital ERP
             (symmetric sideband  operation)                   (dBc)
------------------------------------------------------------------------
57.9 dB[mu] and above...................................             -14
56.5 dB[mu] to 57.8 dB[mu]..............................             -13
55.6 dB[mu] to 56.4 dB[mu]..............................             -12
54.1 dB[mu] to 55.5 dB[mu]..............................             -11
54.0 dB[mu] or less.....................................             -10
------------------------------------------------------------------------

    (f) FM stations may transmit hybrid IBOC signals with asymmetric 
power on

[[Page 57043]]

the digital sidebands, as defined in Sec.  73.402(i). Where asymmetric 
operation is used, the Effective Radiated Power at each sideband must 
be adjusted so that the total sideband powers do not exceed the total 
power that would be authorized for the station operating in symmetric 
sideband mode. A station using asymmetric sidebands planning to operate 
with a radiated power in excess of -17 dBc on either sideband (upper or 
lower) must confirm compliance with Table 1 below by calculating the 
signal strength of its analog signal at the respective (upper or lower) 
first adjacent station's 60 dB[mu] contour. All calculations must be 
made using the standard FCC contour prediction methodology.

    Table 1 to Paragraph (f)--Maximum Permissible FM Digital ERP for
                      Asymmetric Sideband Operation
------------------------------------------------------------------------
                                                              Maximum
                                                          permissible FM
                                                            digital ERP
Proponent analog F(50,10) field strength at the upper or      for the
     lower first adjacent station's analog 60 dB[mu]        respective
    F(50,50) contour  (asymmetric sideband operation)        (upper or
                                                              lower)
                                                          sideband (dBc)
------------------------------------------------------------------------
54.9 dB[mu] and above...................................             -17
53.5 dB[mu] to 54.8 dB[mu]..............................             -16
52.6 dB[mu] to 53.4 dB[mu]..............................             -15
51.1 dB[mu] to 52.5 dB[mu]..............................             -14
51.0 dB[mu] or less.....................................             -13
------------------------------------------------------------------------

    (g) The digital effective radiated power of a previously authorized 
superpowered FM station, as defined in Sec.  73.310(a)(7) and (a)(21), 
must be limited to the class maximum set forth in Sec. Sec.  73.211 and 
73.511.
0
5. Amend Sec.  73.406 by adding paragraphs (d)(5) through (8) to read 
as follows:


Sec.  73.406  Notification.

* * * * *
    (d) * * *
    (5) If applicable, for FM stations planning to operate with 
symmetric sidebands in excess of -14 dBc, a certification that the 
proposed FM digital Effective Radiated Power is permitted, using the 
table set forth in Table 1 to Sec.  73.404(e). Certifications must be 
based on the most restrictive analog field strength of the proponent at 
any nearby first-adjacent channel station's 60 dB[mu] contour.
    (6) If applicable, for FM stations employing asymmetric sideband 
operation as defined in Sec.  73.402(i), a certification that the 
proposed digital sideband power on each sideband conforms to the 
Maximum Permissible FM Digital ERP set forth in Table 1 to Sec.  
73.404(f), and that the total digital sideband power will not exceed 
the total power if the digital sideband operation were symmetric.
    (7) Any digital FM station permanently reducing digital power must 
notify the Commission of such digital power reduction on Form 2100, 
Schedule 335-FM. Any such notification of digital FM power reduction 
must include a short statement of the reason(s) for the power 
reduction.
    (8) Any digital FM station permanently discontinuing asymmetric 
sideband operation and returning to symmetric sideband operation must 
notify the Commission of such return to symmetric sideband operation on 
Form 2100, Schedule 335-FM. Any such notification of discontinuing 
asymmetric sideband operation must include a short statement of the 
reason(s) for such action.

[FR Doc. 2023-17423 Filed 8-21-23; 8:45 am]
BILLING CODE 6712-01-P