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
May 31, 2007
June 16, 2005
March 8, 2005
July 9, 2004
April 20, 2004
April 15, 2004
April 14, 2004
March 17, 2004
March 20, 2003
October 11, 2002
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.
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.
Technical information about IBOC can be found on Ibiquity's website, http://www.ibiquity.com/.
Quality of IBOC Digital Radio |
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.
Documents pertaining to IBOC digital radio operation are available on the FCC's
Internet site at http://www.fcc.gov/mb/audio/decdoc/engrser.html#IBOC.
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.
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