From technical ingenuity to political intrigue, a tumultuous drama has unfolded over the last eight to 12 months in the digital-TV arena. The lead roles were played by the cable, television, consumer-electronics, and broadcast industries—with the help of some "gentle" FCC directing. The action almost seemed like a pilot for a new series of exciting technological advances that will grace our living rooms in the coming years.
The drama began as early as last April, when the market caught the first of the latest second-generation, 8-level, vestigial-sideband (8-VSB) demodulators for the reception of terrestrial DTV signals. Competitive announcements quickly followed, but all fell under a cloud of suspicion as a result of a claim by a certain broadcasting company. It stated that the American Television Standards Committee (ATSC) may have erred in judgement when it selected 8-VSB over the alternative, namely coded, orthogonal frequency-division multiplexing (COFDM). If true, that mistake could have cost millions to correct. The cost of the delays to the timely rollout of DTV, however, would have been inestimable.
While hearing these arguments, the FCC was busy trying to unite the consumer electronics and cable industries. By working together, they could bring about standards for low-cost, DTV-over-cable, in-the-clear reception within the receiver itself. This would eliminate the need for an external set-top box (STB). The FCC also was working on broadcasters, encouraging them to realize 60% market penetration of DTV signals by the end of 1999. This critical mass had to be reached if consumers were to start shelling out cold hard cash for the relatively expensive DTV sets.
Reaching that mark would be moot if quality content wasn't there. Sports and primetime TV were ramping up, but movie studios were loathe to allow the digital transmission of their properties. The scene was reminiscent of the introduction of the first VCRs. Only now the argument was that digital recordings are almost perfect and don't wear out. Some kind of copy protection, then, had to be inherent to a DTV setup before the movie properties would be transmitted. Protection was not technically difficult, with the 5C (named for the five companies behind it) standard already pretty much defined. It was just a matter of getting everyone to agree on it. That's where the fun started.
All of this was playing out against the backdrop of the consumers. As a group, they're almost blissfully unaware of the actual benefits of DTV. This truth could potentially scuttle all of the above efforts.
Sanity Prevails
Fortunately, sanity has prevailed for many reasons, not the least of which is the amount of money that has been invested in DTV. There's also the money that stands to be made. It will work.
The light at the end of the tunnel started to appear after William Kennard, chairman of the FCC, took the podium during a luncheon at January's Consumer Electronics Show in Las Vegas, Nev. After extolling the virtues of DTV and all of its potential, he made it clear that the FCC would no longer stand idly by and watch the cable and consumer-electronics industries squabble over standards.
In essence, he threatened to take over the process in the interests of the consumer. He would have the FCC decide how cable compatibility should be achieved. The threat of the FCC taking control was enough motivation for Robert Sachs, president and CEO of the National Cable Television Association (NCTA). On Feb. 22, he and Gary Shapiro, president and CEO of the Consumer Electronics Association (CEA), signed an agreement to achieve compatibility between consumer digital receivers and cable TV systems.
That agreement has four parts. First, the groups settled on the technical requirements for the network interface specifications that permit direct connection of consumer digital receivers to cable TV systems. They also agreed to carry Program and System Information Protocol (PSIP) data on cable systems. This would include virtual channel tables and event information data (up to 12 hours ahead) to support navigation functions in digital receivers.
As labeling was not finalized, they opted to continue discussions to devise appropriate naming when marketing various digital receivers designed to work with cable systems (cable ready versus cable compatible, etc.). Finally, the fourth part of the agreement calls for joint testing of interoperability between cable systems and consumer receivers.
Putting those particulars aside, the agreement basically states that through cable, TVs off the shelf and with the appropriate demodulators can now receive in-the-clear NTSC and digital programming. Using a point-of-deployment (POD) module, security will be supplied by the cable company to allow viewing of conditional-access programming, such as pay per view and subscription programs. This can be authorized by one-way downstream data transmission to the POD module (Fig. 1).
That module came about as part of the OpenCable specification. It calls for an out-of-band (OOB) channel to carry the PSIP. That OOB has a two-way feed, downstream and upstream, dubbed the forward data channel (FDC) and reverse data channel (RDC), respectively. The data rate on the FDC specified in the agreement can be 1.544, 3.088, or 2.048 Mbits/s to accommodate current standards and implementations. As a PC-card plug-in, the module can go into both the set-top box (STB) and receiver. But the agreement anticipates that it will now go directly into the TV.
Some minor technical issues do remain be solved. Yet manufacturers are confident that they'll have POD modules ready for retail availability by the FCC's July deadline.
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