[Federal Register Volume 64, Number 216 (Tuesday, November 9, 1999)]
[Proposed Rules]
[Pages 61054-61056]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-29270]


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FEDERAL COMMUNICATIONS COMMISSION

47 CFR Part 73

[MM Docket No. 99-325; FCC 99-327]


Digital Audio Broadcasting Systems and Their Impact on the 
Terrestrial Radio Broadcast Service

AGENCY: Federal Communications Commission.

ACTION: Notice of proposed rulemaking.

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SUMMARY: In this document, the Commission considers alternative 
approaches to introduce Digital Audio Broadcasting (DAB) to the 
American public. This document is intended to help the Commission 
determine whether an in-band, on-channel (IBOC) model or a model 
utilizing new spectrum would be the best means to promptly introduce 
DAB service. This document intends to foster development of both 
models, help DAB system proponents identify design issues, and 
encourage modifications to advance Commission's policy objectives. This 
document is in response to USA Digital Radio's (USADR) Petition for 
rulemaking, which requested initiation of a proceeding to implement 
IBOC DAB technology.

DATES: Comments are due on or before January 24, 2000, and reply 
comments are due on or before February 22, 2000.

ADDRESSES: Parties who choose to file comments by paper should address 
their comments to Magalie Roman Salas, Office of the Secretary, TW-
A306, Federal Communications Commission, 445 12th Street, SW., 
Washington, DC 20554 and should also submit comments on 3.5 inch 
diskette using Microsoft Word or compatible software addressed to 
William J. Scher, Federal Communications Commission, 445 12th Street, 
SW., Room 2-A445, Washington, DC 20554. Electronic comments may also be 
submitted using the Commission's electronic comment filing system via 
the Internet to <http://www.fcc.gov/e-file/ecfs.html>.

FOR FURTHER INFORMATION CONTACT: Peter Doyle or William Scher at (202) 
418-2780 or [email protected] or [email protected].

SUPPLEMENTARY INFORMATION:
    1. IBOC DAB. IBOC systems allow simultaneous broadcast of analog 
and digital radio signals in the AM and FM bands without disruption to 
existing analog service. IBOC DAB systems have not been conclusively 
proven to be technically viable, but recent advances hold real promise. 
In the hybrid operational mode, IBOC systems transmit lower power 
digital signal sidebands positioned on either side of the host analog 
signal. Digital signals would be interleaved (station A's upper digital 
sideband would be between 1st adjacent channel station B's lower and 
upper digital sidebands, and adjoining station B's carrier frequency). 
The presence of digital sidebands would reduce the separation between 
the host analog signal and 2nd and 3rd adjacent channel digital 
signals. IBOC proponents believe digital signal processing techniques 
will permit transmission of a digital ``pair'' of each analog signal in 
the AM and FM bands, without disrupting existing analog service.
    2. In the IBOC all-digital mode, the system proposed by USADR would 
continue to divide the digital signal into sidebands, boost power by 
tenfold, and use the channel center for lower-power auxiliary services. 
The increased power of the signal sidebands likely would interfere with 
1st adjacent channel analog signals. Therefore, USADR proposes to use 
the hybrid mode for 12 years and then sunset protection of analog 
signals. At that time, it proposes to implement the all digital mode. 
The system proposed by Lucent Technologies (``Lucent'') consolidates 
the digital signal in the channel center in the all-digital mode, and 
proposes to use the 1st adjacent for auxiliary services. No sunset of 
protection for analog signals would be necessary because Lucent's model 
conforms to the Commission's current analog technical rules.
    3. DAB Public Policy Objectives. In this Notice, the Commission's 
public policy objectives to introduce DAB are (1) to provide vastly 
improved radio service to the public, (2) to permit broadcasters and 
listeners to realize fully the superior technical performance 
capabilities of DAB; (3) to support a vibrant and vital terrestrial 
radio service for the public and create DAB opportunities for existing 
radio broadcasters; (4) to ensure that the introduction of DAB does not 
weaken the vitality of our free, over-the-air radio broadcast service; 
(5) to provide all broadcasters with the opportunity to provide DAB 
service. The Commission will favor systems that are spectrum efficient, 
that do not require burdensome investments in new broadcast 
transmission equipment, and that provide broadcasters with incentives 
to convert to DAB.
    4. Tentative Selection Criteria. The Commission proposes to apply 
the following evaluative criteria to determine which DAB model and/or 
system would best promote the public policy objectives: (1) enhanced 
audio fidelity; (2) robustness to interference and other signal 
impairments; (3) compatibility with existing analog service; (4) 
spectrum efficiency; (5) flexibility; (6) auxiliary capacity; (7) 
extensibility; (8) accommodation for existing broadcasters; (9) 
coverage; and (10) implementation costs/affordability of equipment.
    5. Enhanced Audio Fidelity/ Robustness. DAB system proponents 
anticipate that AM IBOC DAB systems will offer sound quality comparable 
to today's stereo FM systems, and that FM IBOC DAB systems will deliver 
near-CD quality sound. As to robustness, DAB systems may improve 
reception by using techniques that protect digital signals from 
interference that affects analog signals. The Commission seeks comment 
of these selection criteria, including the specific standards that 
should be used to compare competing systems.
    6. A comparison of IBOC and new-spectrum alternatives must consider 
the time frame to achieve all-digital operations and short-term 
performance advantages of a hybrid IBOC system over analog. The 
Commission seeks comment on the issue. The Commission also seeks 
comment on appropriate ways to compare IBOC and new-spectrum DAB 
alternatives under this selection criteria.
    7. Compatibility. The Commission tentatively concludes that IBOC 
systems should minimize interference to host and adjacent-channel 
analog signals in hybrid mode including interference to FM subcarriers. 
The opportunity to introduce new ancillary services is tied to 
initiation of all-digital operations. A system which permits rapid 
implementation to all-digital radio service (such as Lucent's) may 
serve the public interest better than a system which relies on a longer 
transition period with a fixed sunset of analog protection (such as 
USADR's). The Commission seeks comment on whether all-digital 
compatibility with analog signals should be an evaluative criteria for 
IBOC systems.
    8. The Commission seeks comment on how a DAB system could be 
designed to protect a possible future LPFM service. The Commission 
seeks comment on the

[[Page 61055]]

potential for enhancing the robustness of IBOC systems to reject 
undesired 2nd and 3rd adjacent channel signals and the likely impact on 
such modifications.
    9. Spectrum Efficiency. Spectrum efficiency considers not only 
whether a DAB technology would not require additional spectrum, but 
also the additional value that results from the transition from analog 
to digital transmission service. The added value of spectrum is the 
product of several factors, including the capacity to transmit greater 
data per hertz, enhanced flexibility, the lesser likelihood of digital 
signals to cause interference, less susceptibility to interference, and 
more robust with respect to multi-path fading and non-radio noise 
sources, and the capacity to provide a listenable service at relatively 
low signal strength levels. The Commission wants to examine if digital 
receivers could provide additional protection against interference. 
What would the cost be to consumers and, besides cost, are there other 
considerations?
    10. The Commission seeks comment on possible DAB efficiency 
standards. Are any of the Eureka-147 and/or satellite DARS signal 
bandwidth and interference protection standards relevant in 
establishing DAB spectrum efficiency standards? What bandwidth is 
necessary for CD-quality signals? What are the spectrum implications of 
recent advances in coding and multistreaming technologies? What are the 
quantifiable trade-offs between bandwidth and signal robustness? What 
trade-offs should the Commission consider in balancing the needs of 
incumbents and new entrants? Should there be different data capacity 
criteria during and after transition? Would transition be slowed if 
incumbents were assigned less bandwidth for all digital operations? Is 
preserving (or expanding) bandwidth assignments necessary?
    11. Flexibility/auxiliary capacity. The Commission tentatively 
concludes that ancillary services must not technically impair reception 
of DAB programming. The Commission seeks comment on whether the Digital 
Television (DTV) framework is appropriate for radio and what limits if 
any, the Commission should establish for ancillary services.
    12. Extensibility. The Commission tentatively concludes that 
extensibility (ability of a DAB system to adapt to future technological 
advances) is crucial to preserving of free broadcast in a digital 
environment and ensuring that listeners fully benefit from DAB. The 
Commission seeks comment.
    13. Accommodation. The Commission tentatively concludes that a DAB 
system should, to the maximum extent possible, accommodate all existing 
broadcasters wanting to initiate DAB and that placing AM and FM on 
equal footing is not essential. The Commission seeks comment.
    14. Coverage. Broadcasters argue that a DAB system should be able 
to replicate existing coverage areas, which tend to be greater than 
``interference-free'' areas protected under Commission's rules. While 
the Commission recognizes that preserving existing coverage areas may 
be important, it tentatively concludes that the public interest is best 
served by a digital assignment policy based on analog protected service 
contours. Service contours reflect a balance between providing adequate 
service areas and expanding the number of station assignments. The 
Commission requests comment.
    15. IBOC DAB Model. The Commission believes that IBOC would be 
superior to a new spectrum model because it would not require new 
spectrum, it would permit a fast transition to DAB while preserving 
benefits of analog service, and may achieve certain spectrum 
efficiencies. To ensure a smooth initiation to DAB, the Commission 
tentatively concludes that if IBOC is adopted, IBOC DAB licenses will 
not count as distinct authorizations for purposes of local ownership 
rules and seeks comment on that view.
    16. The Commission seeks comment on the spectrum efficiency 
concerns inherent in the IBOC model and whether a model proposing to 
switch digital audio transmission from sidebands to a center band in 
the all digital mode would be more spectrally efficient than one which 
continues to carry the main audio signal in digital sidebands. The 
proposed IBOC systems would double the bandwidth licensed to AM and FM 
stations to 20 kHz and 400 kHz respectively, spectrum which is 
currently included in analog ``emission masks'' and the Commission 
seeks comment on whether spectrum may be returned at the end of the 
licensees' IBOC transition to an all-digital operating environment. The 
Commission seeks comment on how to balance the need to provide 
broadcasters with sufficient incentive to transition rapidly to DAB 
with the need to respond to unmet demand for new entrants. The 
Commission seeks analyses of minimum power levels needed to preserve 
service within protective service areas in a digital environment, and 
alternatively, the levels that would result in significant disruption 
to current listening patterns.
    17. New Spectrum DAB Model. As an alternative to IBOC, the 
Commission requests comment on whether the six MHz of spectrum at 82-88 
MHz (now TV Ch. 6) could be reallocated to DAB at the end of the DTV 
transition. The Commission seeks comment on any possible adverse 
affects on DTV implementation and television service in general. The 
earliest the spectrum could be available is 2007; however, the 
availability of this spectrum is tied to the end of the DTV transition 
period and could be significantly later. The Commission requests 
comment on all aspects of the new spectrum option and asks whether 
there are other frequency bands to consider. IBOC and new spectrum 
options are not mutually exclusive and could be complementary.
    18. The Commission seeks comment on whether new spectrum models, 
which are independent of the existing analog AM and FM radio systems, 
would provide greater flexibility to plan and implement DAB, and 
whether compared to IBOC in hybrid mode, it would operate at a higher 
data rate and support higher audio quality and enhanced ancillary 
services. At the time when an 82-88 MHz DAB system proves successful, 
analog stations licensed to frequencies in the existing 88-108 MHz 
could convert to DAB. The transition could result in significant 
service disruptions, unless listeners have digital receivers. The 
Commission seeks comment on such transition issues.
    19. The Commission seeks comment on whether to maintain the same 
channel bandwidth assignment scheme currently used with FM service and 
if this approach would facilitate conversion to DAB and a common FM/DAB 
radio receiver design in the 82-108 MHz band. The Commission seeks 
comment on whether to adopt a consistent service area approach which 
follows the plan of existing classes of FM stations (Class A, B1, B, 
C3, C2, C1 and C) or should all DAB stations be provided a common 
service area?
    20. The Commission seeks comment on whether all AM and FM 
broadcasters should be eligible for a DAB license, whether DAB licenses 
should be excluded from local ownership limits and whether new channels 
should be reserved for educational use and new entrants. The Commission 
seeks comment on whether it should limit the number of DAB licenses in 
each market and whether issuing DAB licenses would implicate statutory 
auction requirements.
    21. The Commission seeks comment on whether to allot DAB channels 
to communities in proportion to the

[[Page 61056]]

number of AM and FM channels operating or based on initial expression 
of interest by applicants, and whether either approach is consistent 
with 47 U.S.C. 307(b). The Commission requests comment on whether to 
use minimum geographic spacing distances or other engineering criteria 
to assess technical acceptability of new DAB allotments and 
modifications.
    22. The Commission seeks comment on whether Channel 6 should be 
used to ensure adequate new entrant DAB opportunities and whether the 
Commission may give preferences to LPFM licensees in assigning Channel 
6 spectrum, and if so, whether it should do so.
    23. DAB Transmission Standard. The Commission tentatively concludes 
that it is in the public interest for the Commission to take a role in 
DAB standards development with the advice and involvement of all 
sectors of the industry. The Commission seeks comment on how likely the 
broadcast industry is to establish a de facto standard without 
Commission action and whether there is anything the Commission can do 
short of mandating a standard to assist the industry? The Commission 
lacks sufficient information at this time to conclude that a 
Commission-mandated transmission standard is necessary and seeks 
comment on whether a single mandated standard is desirable. The 
Commission seeks comment on whether there is a high degree of 
compatibility among the several DAB systems. It also seeks comment on 
whether developments in digital signal processors (DSPs) and DSP chip 
technology make a standard unnecessary, whether an ``open 
architecture'' approach is feasible, and what impact such an approach 
would have on the development and costs of receivers.
    24. Models for IBOC DAB System Testing and Evaluation. The 
Commission believes that it is necessary to rely to some degree on the 
expertise of the private sector for DAB system evaluations and 
ultimately, recommendations for a transmission standard. However, it 
believes it is premature to select an approach at this time. The NRSC 
has set a deadline of December 15, 1999 for proponents to submit system 
test results and the Commission requests that the parties also submit 
the reports to the Commission as part of this proceeding. The 
Commission would give great weight to a fair and thorough NRSC testing 
process and any industry consensus the NRSC may achieve. However, the 
Commission will act promptly to provide an alternative mechanism if the 
current process breaks down. The Commission will revisit the 
effectiveness of the NRSC approach once the Commission reviews the NRSC 
report on IBOC tests expected the first quarter of 2000. The Commission 
seeks comment on evaluative models.
    25. Initial Regulatory Flexibility Analysis. The Commission has 
prepared an Initial Regulatory Flexibility Analysis of the possible 
significant economic impact on small entities by the policies and rules 
proposed in this Notice. Comments are requested on this IRFA and must 
be identified as responses to the IRFA. The proposed rules and policies 
potentially will apply to all AM and FM radio broadcasting licensees 
and potential licensees. The SBA defines a radio broadcasting station 
that has no more than $5 million in annual receipts as a small 
business. A radio broadcasting station is an establishment primarily 
engaged in broadcasting aural programs by radio to the public, 
including commercial, religious, educational, and other radio stations. 
As of December 31, 1998, official Commission records indicate that 
12,472 radio stations were operating, of which 4,793 were AM stations. 
Thus, the proposed rules will affect 12,472 radio stations, 11,973 of 
which are small businesses. These estimates may overstate the number of 
small entities since the revenue figures on which they are based do not 
include or aggregate revenues from non-radio affiliated companies. In 
addition, any entity that seeks or desires to obtain a DAB license may 
be affected by the proposals. The number of entities that seek to 
obtain a DAB radio broadcast license is unknown. The Commission invites 
comment on such number. The Notice sets forth policy objectives and 
proposes criteria for the selection of alternative DAB models and/or 
systems that will promote the interests of small entities and minimize 
the economic impact on such entities of a transition to DAB service.

Federal Communications Commission.
Magalie Roman Salas,
Secretary.
[FR Doc. 99-29270 Filed 11-8-99; 8:45 am]
BILLING CODE 6712-01-U