By Jeffrey Krauss, Looney Tuner and President of Telecommunications and Technology Policy

The FCC decided that all new TV sets will have to have digital tuners, and the outraged consumer electronics industry is going straight to court. Which way will the court rule? It's very close–you can flip a coin. I think the FCC should lose, but that will happen only if the court examines the guts of a digital TV receiver. And frankly, that isn't very likely.

Here is the basis for the disagreement. The FCC took a close look at the 1962 All Channel Receiver Act (ACRA) and decided that Congress intended it to apply to digital TVs. The TV set makers disagreed, saying that Congress could not have known anything about digital TVs in 1962.

Here's what that law says: The FCC shall have the authority "to require that apparatus designed to receive television pictures broadcast simultaneously with sound be capable of adequately receiving all frequencies allocated by the Commission to television broadcasting." This language now appears as Section 303(s) of the Communications Act.

So what do you think these words "adequately receiving all frequencies" mean? Do you need a tuner? Do you need an MPEG decoder? Do you need a display? The FCC says "yes" to all three.

In order to watch an off-air digital TV broadcast, first you need a device with a filter that passes a particular 6 MHz channel and then combines it with a local oscillator signal to extract a stream of compressed MPEG video packets. That device is called a tuner. Then you need a device to transform the MPEG packets into an uncompressed digital video bitstream. That device is called an MPEG decoder. And finally, you need a display device.

Is that what the Congress had in mind in writing the ACRA? In 1962, the problem was that TV sets were being manufactured and sold that contained tuners that only covered the VHF frequencies, 54 to 216 MHz, corresponding to TV channels 2 to 13. During the late '50s and early '60s, the FCC started handing out licenses for TV stations on the UHF frequencies, 470 to 890 MHz, corresponding to TV channels 14 to 83, but most TV sets could not tune the UHF frequencies. Of course, you could always buy a converter box that converted UHF channels to a VHF frequency, but that was an extra cost that put UHF broadcasters at a disadvantage. The purpose of the law, back in 1962, was to make it as easy to watch a UHF channel as a VHF channel.

In those days, complying with ACRA was simply a matter of adding a UHF tuner. No additional decoder was needed, because both VHF and UHF broadcasters used the same signal format, known as vestigial sideband AM (VSB-AM). The same VSB-AM demodulator that converted a VHF signal into pictures could be used to convert a UHF signal into pictures. The only difference between a VHF TV receiver and an all-channel TV receiver is the frequency range covered by the tuner.

But that is not the case for digital TV. In fact, analog TVs and digital TVs cover exactly the same frequency range. They differ in two significant respects. The digital tuner must demodulate 8-level vestigial sideband (8-VSB) signals rather than VSB-AM. And it must decompress the MPEG packets. Analog TV does not use any compression.

Now, the demodulator is not an expensive addition. Cable modems have digital demodulators, admittedly using quadrature amplitude modulation (QAM) rather than 8-VSB, but the two digital modulation methods are closely related, and the cost of a demodulator that can handle both 8-VSB and QAM signals should be only a little more than the QAM demodulator in a cable modem. And complete cable modems, with upstream as well as downstream capabilities, are now selling for less than $100.

But the MPEG decoder is a bit more pricey. So this is the real point of contention between the FCC and the TV set guys.

But, funny thing, the FCC decision never even mentioned MPEG decoders. It never distinguished between a stream of compressed MPEG packets and a stream of decompressed pictures. The closest the FCC came was this: "to suggest that the statutory requirements are somehow satisfied simply where a receiver picks up the frequency but is incapable of displaying the signal in a viewable format strikes us as an absurd reading of the ACRA."

Assuming that the ACRA even applies to digital television, will the court think the words "adequately receiving all frequencies" requires that the receiver have both an 8-VSB demodulator and an MPEG decoder to make pictures, or just an 8-VSB demodulator which produces an MPEG packet bitstream? Do the words "adequately receiving" mean that the device must be able to produce an MPEG packet stream, or a stream of pictures?

My opinion is that if the device can produce MPEG packets, then the signal has been adequately received. But this argument may be too complicated for the court, and too complicated for what many believe is a purely political decision by the FCC. Stay tuned.

Have a comment? Contact Jeff via e-mail at: jkrauss@cpcug.org