The National Radio Systems Committee (NRSC) has adopted an updated version of its in-band/on-channel (IBOC) digital radio (HD Radio) broadcasting standard. An updated RF mask (the digital sidebands on either side of the analog carrier) detail requested by iBiquity Digital and the transmitter manufacturers is at the core of the standard. The NRSC is a technical standards-setting body co-sponsored by the NAB and the Consumer Electronics Association.
Milford “Smitty” Smith, VP/Radio Engineering with Greater Media and NRSC chairman, tells RBR it slightly changes the mask: “It puts some very small “skirts” at one point where there is a transition from one maximum allowable signal level to another. It changes the maximum allowable level that the waveform would be permitted to reach at a particular distance away from the [analog] carrier. It gives a little more headroom at the transition in the waveform [from analog to digital].”
“NRSC-5-B, In-band/on-channel Digital Radio Broadcasting Standard,” was adopted by the Digital Radio Broadcasting (DRB) Subcommittee, which is co-chaired by Andy Laird, vice president and chief technology officer, Journal Broadcast Group; and Mike Bergman, director of research and development, Digital Broadcast, Kenwood Americas Corporation. This latest version includes some editorial updates as well as a revised FM IBOC RF mask which was submitted to the NRSC by iBiquity Digital Corporation, developers of the HD Radio technology upon which NRSC-5-B is based.