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IBOC Digital Radio Broadcasting
for AM and FM Radio Broadcast Stations
The FCC has approved In-Band On-Channel (IBOC) digital radio operation for
AM (daytime and nighttime) and FM broadcast stations.
To obtain a list of stations authorized for "hybrid" operation (analog + digital signals),
select one of the following links:
[ AM | FM ]
Digital Radio Headlines
October 2, 2007
Clarification of Notification Procedures for Dual Antenna Hybrid Digital Operation,
Public Notice, DA 07-4114, released October 2, 2007.
[ PDF | Word ].
Effective date of the new notification procedures for dual antenna hybrid systems was September 14, 2007.
May 31, 2007
Digital Audio Broadcasting Systems and Their Impact on the Terrestrial Radio Broadcasting Service ,
Second Report and Order, First Order on Reconsideration and Second Further Notice of Proposed Rulemaking, MM Docket 99-325 , FCC 07-33, released May 31, 2007.
[ PDF | Word ].
Comments due 60 days after the publication of this item in the Federal Register, reply comments due 90 days after publication of this item in the Federal Register.
Martin: [ PDF | Word ].
Copps: [ PDF | Word ].
Adelstein: [ PDF | Word ].
Tate: [ PDF | Word ].
McDowell: [ PDF | Word ].
June 16, 2005
Comment Sought on National Radio System Committee's "In-Band/On-Channel Digital Radio Broadcasting Standard NRSC-5",
Public Notice,
DA 05-1661, released June 16, 2005.
[ PDF | Word ].
Comments sought by July 18, 2005; reply comments sought by August 17, 2005.
March 8, 2005
Commission Clarifies Policy Regarding
Multiple Audio Streams in IBOC Transmissions, MM Docket 99-325, DA 05-609,
released March 8, 2005.
[ PDF | Word ].
Experimental authority must be requested.
July 9, 2004
Digital Audio Broadcasting Systems
and Their Impact on the Terrestrial Radio Broadcast Service,
Order, MB Docket 99-325, DA 04-2073, released July 9, 2004.
[ PDF | Word ].
Extension of time until August 2, 2004 to file reply comments.
[ Link to proceeding in ECFS ].
April 20, 2004
Digital Audio Broadcasting Systems And
Their Impact on the Terrestrial Radio Broadcast Service,
Further NPRM and NOI, MM Docket 99-325, released April 20, 2004.
[ PDF | Word ].
Comments due by June 16, 2004; reply comments due July 16, 2004. Statements by
Powell:
[ PDF | Word ],
Copps:
[ PDF | Word ],
Adelstein:
[ PDF | Word ].
April 15, 2004
FCC Explores Rules
for Digital Audio Broadcasting,
News Release, released April 15, 2004.
[ PDF | Word ].
Statements from Chairman Powell
[ PDF | Word ]
and Commissioner Copps
[ PDF | Word ]. .
April 14, 2004
Comment Sought on Use of Digital
AM Transmissions During Nighttime Hours,
Public Notice, DA 04-1007, released April 14, 2004.
[ PDF | Word ].
Comments due by June 14, 2004; reply comments due July 14, 2004.
March 17, 2004
Use of Separate Antennas to
Initiate Digital FM Transmissions Approved,
Public Notice, DA 04-712, released March 17, 2004.
[ PDF | Word ]
Special temporary authority must be requested and granted before digital
operations can commence.
March 20, 2003
IBOC Notification Procedures
Effective Immediately,
Public Notice, DA 03-831, released March 20. 2003.
[ PDF |
Word ]
AM or FM stations implementing IBOC hybrid digital operation must notify the
FCC in writing within 10 days of commencing such operation. The
sample notification letter in this Public Notice
may be used for this purpose.
October 11, 2002
Digital Audio Broadcasting Systems
and Their Impact on the Terrestrial Radio Broadcast Service,
First Report and Order, FCC 02-286, 17 FCC Rcd 19990,
released October 11, 2002.
[ PDF |
Word ]
FM IBOC Specifications (Appendix B):
[ PDF |
Word ]
AM IBOC Specifications (Appendix C):
[ PDF |
Word ]
What is IBOC Digital Radio?
IBOC refers to the method of transmitting a digital radio broadcast signal
centered on the same frequency as the AM or FM station's present
frequency. For FM stations, the transmission of the digital signal occupies the
sidebands above and below the center FM frequency (e.g., 97.9 MHz).
AM band transmissions also place the digital signal in sidebands above and
below the existing AM carrier frequency. By this means, the AM or FM station
digital signal is transmitted in addition to the existing analog signal.
In both instances, the digital emissions fall within the spectral emission
mask of the AM or FM channel (see 47 CFR Sections 73.44 and 73.317).
The present IBOC system is referred to as a "hybrid" since it is neither fully
analog nor fully digital. During hybrid operation, existing receivers still continue
to receive the analog (non-digital) signal. New
receivers being developed are expected to incorporate both modes of reception,
where receiver will automatically switch to the analog signal if the digital
signal cannot be decoded or is lost by the receiver.
IBOC digital radio is expected to provide near CD
quality reception for stations operating in the FM broadcast band. For AM
stations, IBOC digital radio is expected to provide reception approximately
equal to today's analog FM reception. Minimal impact is anticipated on
reception of existing service.
Where Can I Obtain a
Digital Receiver?
The pace of development of IBOC digital receivers for consumers depends
on a number of factors, including how fast and how many
AM and FM stations commence digital broadcasting, and how soon receiver
manufactures can produce radio receivers. Check with local electronics
suppliers from time to time for digital radio receivers!
How Do I Know Whether A Station
Transmits a Digital Signal?
An AM or FM licensee is required to provide written notification to the FCC
within 10 days of commencing digital/analog hybrid operation. Notice must
be provided using the attachment in the Commission's March 20, 2003
Public Notice
[ PDF | Word ]. As
notifications are received, they will be entered into the Media Bureau's
Consolidated DataBase System (CDBS).
A "Digital Status" search field has been implemented within the
Station Information form in CDBS, to
help you identify which stations are operating in hybrid mode.
Also, an AM or FM station itself will announce if its operations
include transmission of the digital signal.
E-mailed questions may be referred to
Ann Gallagher or
Charles Miller in the Audio Division.
The telephone number of the Audio Division is 202-418-2700.
