Layer is vice president,
advanced engineering at National Association of Broadcasters. He is the
primary NAB staff person on NAB’s Radio Technology Committee and the National
Radio Systems Committee, a technical standards setting body co-sponsored by NAB
and the Consumer Technology Association. This interview is from the recent Radio World eBook “New
Directions for HD Radio.”
Radio World: You’ve watched HD Radio develop as closely as anyone
in the industry. What is the most important next step for the platform or
biggest question we should watch for in 2018?
Click on image to read it.
David Layer: NAB has been raising broadcaster
awareness regarding the importance of delivering a quality “metadata”
experience (for example, song title and artist, and album artwork for FM
broadcasters) to the digital dashboard. As part of this effort we have been
working with broadcasters on doing “station audits” to assess how well
individual stations look on the dashboard and to offer recommended practices on
what should be done. I am hopeful that in 2018 you will see more HD Radio
broadcasters deliver the very best experience they can on dashboards, which
will improve the listener experience and will better position radio to compete
with all of the other audio services becoming available in cars.
RW: The hardware for stations to implement HD Radio has
always been something of a complicated topic, but this seems to be changing.
What trends are you seeing that engineers should know about?
Layer: Over the last couple of years, equipment
manufacturers have been developing lower-cost solutions for broadcasters to
implement HD Radio, and one positive development for 2018 would be to see more
analog-only broadcasters deciding to “take the plunge” and start broadcasting
an HD Radio signal. This lower-cost equipment also provides a good opportunity
for existing HD Radio broadcasters to update their aging equipment.
David Layer speaks at a 2017 GM hackathon.
RW: Please update readers about the status of tests into
the possibility of “all-digital” operation for U.S. radio.
Layer: For background, currently the FCC only
authorizes the broadcast of “hybrid HD Radio” signals, which include both
legacy analog as well as digital components. (Note that I am discussing hybrid
HD Radio here, not to be confused with “hybrid radio” services like NextRadio
that combine over-the-air radio with mobile broadband content.)
all HD Radio receivers in the marketplace, however, will work not only with
these hybrid HD Radio signals but also with a more advanced, all-digital HD
Radio signal that offers higher digital throughput and greater robustness, but
is not receivable on analog-only radios. Looking to the future when the
penetration of HD Radio receivers in the marketplace is higher than it is today
and these all-digital services become feasible, NAB has been working with Xperi
and broadcasters to test these all-digital signals and develop a technical
record which is a necessary prelude to FCC authorization, and in addition to
raise awareness among broadcasters and the industry at-large as to the
capabilities and benefits of these all-digital services.
AM, a series of all-digital AM lab and field tests were conducted from 2012 to
2014. In early 2018, NAB plans to do some limited all-digital FM field testing,
and we plan to discuss this test program and share some results at the 2018 NAB
Show during the Broadcast Engineering and Information Technology Conference.
[Read more: "NAB Tests Address Digital AM Concerns," May 2016]
RW: How close are we to seeing voluntary all-digital
operation allowed for FM stations on a widespread basis? For AMs?
Layer: I do not foresee FCC authorization of
all-digital services in the near future simply because the penetration of HD
Radio receivers in the marketplace has not yet reached the level where it would
make sense for the broadcast industry to start transitioning from hybrid
digital to all-digital.
Having said that, I would not be
surprised to see requests for experimental authorization of all-digital
services by pioneering broadcasters who are looking to the future and whose
circumstances are such that experimentation makes sense.
example, an AM radio station that has an FM translator might be interested in
experimenting with an all-digital AM service, since they can use their AM
signal all-digital to reach listeners with HD Radio receivers, and still reach
listeners with analog radios with their FM translator signal.
am very excited about that kind of experimentation, it would be a great way to
raise consumer awareness as to the benefits of all-digital for AM, and it also
highlights how important FM translators can be for AM broadcasters in a
possible transition to an all-digital service.
RW: What other technical issues is the National Radio
Systems Committee or NAB watching with digital radio?
Layer: One exciting project the NRSC is working
on right now is an updating of the NRSC-G200 Guideline, “Harmonization of RDS and IBOC Program
Service Data (PSD),” to address the widespread use by radio broadcasters
of streaming their audio programs over the internet. It is important for
broadcasters to provide a good “metadata” experience not just on over-the-air
receivers but also to streaming audio players. The goal is for the updated NRSC
Guideline to help broadcasters understand the different metadata capabilities
of all platforms that radio listeners are using, and to offer information on
how to efficiently provide a premium metadata experience to all of these