HD Radio development Stasis

I have been working on an HD Radio installation these last few days.  This particular installation was manufactured by Broadcast Electronics.  Some 13 years into the HD Radio development cycle and the implementation still seems like a kluge to me.  To get some idea; to transmit a digital HD Radio with added sub-channels, the following equipment is needed:

  • HD Data importer, off the shelf computer with a sound card and specific software from iBquity.  This is used to import the audio for the HD-2 and HD-3/4 channels.  Runs on Windows (Win 7), Linked to the exporter via IP ethernet
  • HD Radio exporter, another specialized computer with a sound card.  Frames the HD Radio data and adds PID, etc.  Runs on Mandrake Linux, communicates with the exciter via data connection.
  • HD Radio exciter; like other exciters, generates RF and modulates it.
  • HD Radio transmitter; essentially an FM transmitter designed to run as a linear amplifier.

The HD Transmitter part can come in several configurations, including low level combining, high level combining or using a separate antenna for digital and analog signals.

Broadcast Electronics HD Radio transmission system
Broadcast Electronics HD Radio transmission system

None of this is news, of course.  My point is, after ten years, there does not seem to be any further development in HD Radio technology.  In the mean time, competitors are not standing still.  The mobile wireless industry has evolved several times during the same time period; 3G, 4G and LTE have been successfully deployed and widely adopted by mobile phone users.  Truly, mobile data is the real competition to terrestrial broadcasting.

The HD Radio transmission process is an overly complicated patchwork of hardware and software.  The importer in particular seems substandard.  It’s function is to run a bunch of small programs, each doing some small part of the importing process.  The web-admin used Internet Explorer, who uses Internet Explorer anymore?

Since the HD Radio inception, little or no further development seems to have taken place.  There are features, such as album art, program data, traffic data, etc but the system interface is weak, the hardware clunky, the data paths fragile, the operating system outdated, the typical installation is a compromise between cost and available floor space at the transmitter site.

HD Radio is also expensive to deploy and proprietary.  There is little compelling reason to listen to HD-1 channels because the programming is identical to the main analog channel.  HD-2, 3 and 4 channels seem to be mostly used to generate translator feeds, which again, are available with an analog radio.  This use of HD Radio actually damages uptake because, If all the HD Radio sub channels are available on FM analog frequencies, then why even bother with an HD Radio receiver?

Thus the forces at work in the development of HD Radio seem to have reached equilibrium:

Consumer apathy + expensive deployment = 16% uptake on FM and 6% uptake on AM1

The digital radio roll out has been stuck at those levels for many years.  Unless something changes, FM HD Radio will be limited to translator program origination and distribution.  AM HD Radio will go the way of AM Stereo.

1: FCC data on HD Radio deployment; 1,803 of 10,727 FM stations and 299 of 4,708 AM stations have installed HD Radio as of December 31, 2014.

AM revitalization comments

I have been reading the comments regarding the FCC’s NPRM (13-249).  Clearly, many people are interested in keeping the AM broadcasting band both active and relevant.  Some of these suggestions have merit, but are unlikely to be adopted by the FCC.  Others are viable and could alleviate at least a few of the technical shortcomings of the AM band.  The rest fall along expected positions.  Here is a brief rundown:

  • Clear Channel, iBiquity: Allow stations to transmit in all digital mode.  Likelihood: Possible.  The hybrid version of AM HD Radio has been a failure on several fronts; added interference to adjacent channels, self interference, poor adoption, wonky CODECs, etc.  However, letting stations choose to broadcast in all digital AM HD Radio may decide the issue once and for all.  As long as the all digital carriers fall within the current analog channels, this would be fine.  Actually, I would add that station transmitting in all digital be allowed to choose DRM as well as HD Radio
  • REC Networks, MMTC: Move AM stations to former TV channels 5 and 6.  Likelihood: Unlikely.  It would be a neat solution, however, there are currently many full and low power TV stations still using those frequencies.
  • Clear Channel, SBE, MMTC, Crawford, et al: Allow AM stations a special translator filing window.  Likelihood: Almost assured.  This has been broached by the FCC itself.  I would add that Class D and Class C stations be given priority.
  • SBE, du trial, Lundin and Rackely, MMTC et. al: Remove the “ratchet rule,” reduce antenna efficiency requirements and city of license contour requirements.  Likelihood: probable.  Over the years, the FCC’s rules and regulations designed to help AM broadcasting’s technical product have done the opposite in many cases.  This is especially true of the “ratchet rule.”
  • SBE, du Trial, Lundin and Rackely, MMTC: MDCL (Modulation Depended Carrier Level) Likelihood: Possible.  MDCL does not do much to improve AM signal quality, but it can save the station owner some money on the electricity bill.
  • Alabama Broadcaster’s Association, et al: Better FCC enforcement.  Likelihood: Not very.  This is another area were interference and AM noise problems can be fixed.  Given Ajit Pai’s desire for “non-regulatory” relief, stepped up enforcement seems to be a non-starter.
  • Hatfield and Dawson: Eliminate substandard AM stations.  Likelihood: Not very.  Getting rid of substandard stations and let the remaining AM stations enjoy a little breathing room is actually a big step in the right direction.  H&D notes that the FCC should petition congress for tax relief for those stations that choose to surrender their licenses.  Unfortunately, it does not appear likely that the FCC, congress and the current station owners would go for it.
  • du Treil, Lundin and Rackely: Do away with skywave protection for class A stations  Likelihood: Possible.  The argument goes; skywave listening represents a very small number of mostly hobbyists (AM DXers) as other, better methods for program distribution exist for serious listeners.  Sad but true.
  • du Treil, Lundin and Rackely: No more new AM stations.  Likelihood: Possible.  There is a cogent argument to be made regarding the overcrowding of the AM band.  Stopping any further crowding is a good idea.
  • SBE, Cohen, Dippell and Everist, et al: Tighten regulations on electrical noise emitters.  Likelihood: Unlikely.  The FCC does not have the mettle to tighten regulations against powerful manufacturing and technology lobbies.
  • iBiquity: Do not let anything get in the way of the HD Radio rollout.  Likelihood: Is it possible to get in the way of something that is standing still?

Talking amongst engineers and AM broadcasters, many of these ideas have merit.  The real question is, will any of this bring more listeners?

CES 2014 and the Digital Radio question

I have been busy of late, however, still keeping abreast of the news of the day.  Along with that, CES 2014 wrapped up recently.  No huge developments, especially when it comes to Broadcasting.  However, there was one item of interest; the updated technical specifications of IEEE 802.11ac.

It is of interest here because of the implications of the mobile/portable data developments and their impact on traditional AM and FM broadcasting. The new specification calls for 1.2 Gbp/s per device in the initial release, increasing that throughput to 6 Gbp/s in later releases.  These data rates are for overall transmission, including the WiFi overhead.  Actual usable application data (layer 5-7) would be about 20 to 30 percent less.  Even so, 900 Mbp/s is a phenomenal data rate.  Truely I say to you; this is the future of digital broadcasting.  HD Radio™; it may well prove that the “HD” stood for “Huge Distraction.”

The new 802.11ac specification uses MU-MIMO, high density modulation, larger channel bandwidths, and beamforming technology in the 5 GHz WiFi spectrum.  Of course, the question is, at what distances will this system work?  If it is like conventional WiFi, then 100-200 feet is about all that can be expected.  However, there are also many people interested in wireless broadband (WiMAX) service as an alternative to traditional wired ISPs. For that application, having many outdoor 802.11ac nodes connected by a backbone could potentially blanket a city or campus with free high speed wireless data.

Example of cjdns network
Example of cjdns network

Along the same lines, there are many people involved in creating mesh networks of various types; be they ad-hoc mobile networks, darknets, bitclouds, etc. Mesh networking is a very interesting topic, for me at least.  The network protocols are getting better and more secure.  WiFi hardware is becoming less expensive and more reliable.  As more and more people put effort into developing protocols like cjdns, local mesh networks will become wide spread, unless they are outlawed.  You know; because of teh terrorism!!1!!

As it stands today, I can drive for two hours in mostly rural upstate NY and CT streaming my favorite radio programs and have nearly seamless hand offs and very few dropouts.  This is on my three year old, beat up 3G HTC android phone sitting in the passenger seat of my car.

Digital Radio is here, it is simply not the In Band On Channel system that legacy broadcaster’s have chosen.

A few updates

UPDATE: I notice that Radio World has a little star rating system on their articles. According to the rating, twenty one people think I suck… That is okay, but when I started looking around at all of the other articles on the website, I noticed most have but one or two votes.  It seems odd to me that my little opinion piece would have so many negative votes, especially in light of the e-mails, phone calls and personal interactions I have received supporting my position. 

Perhaps a few of you could run over there, read the article then objectively decide what you think… Here is the link: AM Efforts Should Include Tech Solutions

I am deeply immersed in all things networking, yet again. I regret the sparse posts, but there are a few things of note:

  1. It appears the the WYFR shortwave site in Okeechobee has been sold to the operators of WRMI (Radio Miami International).  This is a good turn of events for shortwave broadcasting.  WRMI programmed mostly to the Caribbean and were difficult to hear in these parts.
  2. Nielsen Radio, formerly Arbitron, says it will increase the sample size for the PPM program.  This is good, larger sample size means better accuracy and fewer extrapolation related errors and strange rating spikes.
  3. I published an commentary in Radio World Commentary: AM Efforts Should Include Tech Solutions. What do you think? Should the industry be looking at something other than HD Radio?
  4. Then, from across the pond there is this:

    Which is a digital radio promotion from the BBC. It seems Great Brittan is trying to force an all digital transition. A glimpse of things to come?

  5. In spite of the lack of posts, the blog continues to grow, averaging 550 to 600 page views per day with about 180 RSS subscribers.  As far as content goes, I can assume more of the same will suffice.

As time becomes available, I will post more.