NRSC Looks to November for Next IBOC Step
by Leslie Stimson
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.
The decision was made at a meeting of the DAB
Subcommittee at the NAB Radio Show in New Orleans.
The working group, led by the International
Broadcasting Bureau’s Dr. Don Messer, has begun reviewing
600 pages of FM test results that were submitted recently by Ibiquity
(Radio World, Sept. 12).
In its report, the working group will focus
on whether IBOC performs significantly better than analog and
whether IBOC has an acceptable impact to host analog stations
and adjacents.
If the report is favorable as determined by
members of the evaluation working group and the larger DAB Subcommittee,
the latter group likely would develop an FM IBOC standard, through
a formal process developed by NRSC members.
How long the standards-setting process could
take is uncertain. DAB Subcommittee Chairman Milford Smith said
the group would do its work quickly.
Once the subcommittee adopts the report, it
becomes public. This means the FCC, and anyone else, can see it.
How that would happen has not yet been made clear.
This process takes place independently of the
FCC, though commission employees observe the NRSC process and
attend meetings. Several sources said the commission would prefer
that industry, rather than regulators, do the "heavy lifting"
in evaluating the technology.
In its DAB Notice of Proposed Rule Making, the
FCC said it had confidence in the ability of the NRSC to evaluate
IBOC.
The commission must determine how to incorporate
IBOC into its pending rule making on DAB and what broadcasters
would need to do to comply with new rules. The agency has latitude
in how much it changes the rules to accommodate IBOC. Its options
range from changing the allowed digital carrier power levels to
re-licensing all U.S. radio stations. Sources said the commission
would not prefer the latter.
"The Ibiquity product has tremendous potential,"
said Keith Larson, FCC associate bureau chief for engineering
in the Mass Media Bureau. Two questions still to be answered,
he said, are "What is meaningful interference?" and
"What is the effect (of the system) on first adjacent channels?"
New concept
At the meeting of the full NRSC in New Orleans,
members also heard a presentation from three individuals who have
formed a company called JackHammer Digital (RW, Sept. 12, page
5).
The company believes it has a concept that could
work in conjunction with stations using FM analog or IBOC. JackHammer’s
theory is to use broadband technology to allow four digital stations
to operate within spectrum now allocated for one FM station. The
system is digital, but more like an in-band, adjacent-channel
(IBAC) system similar to one considered by the NRSC in the mid-1990s.
JackHammer believes its system would be compatible
with IBOC and that it could co-exist with future generations of
IBOC receivers.
The company said that, using its system, the
FM band could support 412 digital CD-quality channels at 240 kbps.
Sources said the higher data rate is more susceptible
to interference than, for example, the FM IBOC data rate at 96
kbps.
JackHammer has been privately funded so far.
It needs about $500,000 to complete a prototype system and approximately
$5 million to take the concept to reality. JackHammer is looking
for product development alliances among manufacturers that participate
in the NRSC.
The NRSC told JackHammer to keep it apprised
of its progress.
