Revised NRSC IBOC Standard Now Public - Radio World

Revised NRSC IBOC Standard Now Public

The National Radio Systems Committee has published its updated IBOC technical standard.
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The National Radio Systems Committee has published its updated IBOC technical standard.

As we’ve reported, NRSC-5-B specifies the requirements for broadcasting digital audio and ancillary data signals in the AM and FM radio bands. The NRSC last revised the standard in 2005 when it added the data requirements.

NRSC members described the most recent changes as minor when they voted on them at the recent 2008 NAB Show in Las Vegas; and NAB engineers wrote in their Radio TechCheck this week that “this latest version includes substantive (but relatively minor) changes as well as editorial revisions designed to make the document easier to understand and more complete. None of these changes are expected to cause any backwards compatibility issues with HD Radio receivers.”

The updated version makes clear that the system supports three distinct data services, and discusses spectral emission limits for both AM and FM IBOC.

For Revision B, the NRSC was chaired by Milford Smith of Greater Media; the DRB Subcommittee was co-chaired by Michael Bergman of Kenwood and Andy Laird of Journal Broadcasting; and the IBOC Standards Development Working Group was chaired by Dom Bordonaro of Cox Broadcasting.

Download the standard at


NRSC Surround Report Now Available

As reported here earlier, the National Radio Systems Committee has released an educational document about surround, “Broadcasting Surround Sound Audio over IBOC Digital Radio - Issues and Resources for FM Broadcasters.”

NRSC Looks to November for Next IBOC Step

The standards-setting body made up of broadcasters and manufacturers, the National Radio Systems Committee, has set a tentative date of Nov. 29 for its DAB evaluation working group to report to the DAB Subcommittee its review of FM test results submitted by Ibiquity Digital Corp.