Published December 2008
Digital Video Transition And You
By Jerry Budge
It’s an FCC mandated opportunity.
If the date of February 17, 2009, does not mean anything to you yet, hopefully, you will equate the date with opportunity by the time you finish reading this. In an effort to reclaim and reallocate bandwidth, the Federal Communications Commission (FCC) mandated that all broadcasters must stop broadcasting in analog and may only broadcast in a digital format. On December 24, 1996, the FCC adopted major elements of the American Television Standards Committee Digital Television (ATSC DTV) standard, mandating its use for digital television broadcasts in the United States.
In 1997, the FCC adopted the companion DTV rules, assigning an additional 6MHz off-air television channel to the approximately 1600 full-power broadcasters in the United States. This ruling has allowed broadcasters to transmit analog and digital in parallel during the transition period, while consumers and facilities made the conversion to digital television receivers or set-tops.
So, where is the opportunity, you ask? If you know of facilities that rely on these free, off-air channels, they are going to have to do something in order to be able to continue to view programming. So, let’s talk about options. The obvious option is to sell them nice shiny digital sets to replace all of those perfectly fine analog sets that have nothing wrong with them. Oh, wait, I forgot, money doesn’t grow on trees! So, what is a more realistic option?
The best option to be able to preserve all of the existing analog televisions is to receive the local, digital standard or high-definition (8VSB) off-air broadcast programming that is available in the market and distribute it through the facility in a format that can be viewed by the existing analog televisions. There are two perfectly acceptable ways to accomplish this: a digital demod and analog modulator combination, or a digital-to-analog processor.
In the first scenario, the digital demodulator is the system component that receives the off-air digital channel and tunes to a particular program (within the channel) if multiple programs are transmitted. The digital demodulator provides analog, baseband (NTSC Composite) audio and video outputs. These analog, baseband outputs are then connected to an analog modulator. This analog modulator then creates the new channel that will be viewed by the existing analog televisions. It is common practice to re-modulate onto unused VHF or CATV channels to minimize distribution losses that occur at higher frequencies, and make it easier to construct and manage the distribution network.
The second scenario utilizes a single-box solution versus the multiple-box solution just detailed. A digital-to-analog processor will also receive the off-air digital channel and tune to a particular program (within the channel) if multiple programs are transmitted. This selected program is then processed to the desired output channel as an analog channel with stereo audio, if stereo was present in the selected program.
This single-box approach allows for the “swapping” out of the old analog, heterodyning processors that may already be in place. This type of single-box solution may come with “future proofing” options such as Active Format Description (AFD) or Asynchronous Serial Interface (ASI) outputs. AFD is a standard set of codes that carries information about the image aspect ratio and active picture characteristics. It can be used by television broadcasters to enable both 4:3 and 16:9 television sets to present pictures transmitted in either format optimally, or to dynamically control how down-conversion equipment formats widescreen 16:9 pictures for 4:3 displays.
ASI is a digital data stream output that has become a standard inter-stage format for the multiplexing and digital modulation of CATV channels. Processors that also have an ASI output will not be obsolete when all of the analog televisions have been replaced with digital versions because the ASI output is the standard input for CATV digital modulators and multiplexers.
Do it right the first time! Our customers/clients are commercial, educational or institutional facilities, so why would you install residential gear? Businesses and facilities are subject to a different set of rules and regulations that do not apply to residences. The residential digital demodulators that are common in the market today—the “$40 coupon” box—have many fatal flaws for commercial integrators and their customers. Most of these units have inferior power supplies that were never intended to operate 24/7/365. The devices almost never pass the closed captioning information, which is an Americans with Disabilities Act requirement, ADA Titles II and III.
Almost all of the residential-grade digital demodulators suffer from “lip sync” problems, in the form of a delay in the audio so it does not match the onscreen video, reminiscent of an old Japanese sci-fi movie where the English audio never matches the lip movement of the characters. Not the best way to preserve your hard-earned reputation and satisfy your customer’s needs.
Ensuring the highest quality and reliability for the end-user experience is of utmost importance. Good rules of thumb are only to use true commercial-quality electronics, and to judge the product quality on the warranty period that companies place on their gear. It is always better to stake your reputation on a product that has a multi-year warranty (three years) versus an end-of-driveway (90-day) warranty that is common in traditional consumer electronics.
So, now is the time to go back through your customer database and find all of the jobs that depended on, or used, the free off-air channels. These are immediate opportunities for upgrades in order to preserve all of their perfectly good analog viewing locations. If you should happen to encounter the rare customer who wants you to install hundreds of digital televisions, CONGRATULATIONS, but please let me know where their money tree is because we could all use it to spark up the economy!
Editor’s Note: The author, along with Jay Paul, CTS, of AVI-SPL, and Darren Cheshier, CTS-D, of SKC, can be seen on Sound & Communications VIEWpoint this month and next, discussing this, and related issues. Go to http://soundandcommunications.com/viewpoint.
Jerry Budge has been Director of Marketing and Product Management for Blonder Tongue Laboratories, Inc., since March 2007, and has been with the company since 1999. Prior to that, he was a founding partner of North American Cable Equipment, Inc. Budge first became involved with the cable and satellite television industries in 1988.