Broadcasters Battle over Standards

Cable World,  April 17, 2000  by Jim Barthold

• E-mail
• Print
• Link

Apparently when the broadcasting community married the 8 Vestigial Side Band (8VSB) digital modulation standard, it was not for better or for worse.

Continued concerns about 8VSB reception strength bubbled to the surface last week during the National Association of Broadcasters (NAB) convention in Las Vegas. At least one broadcaster said the industry should revisit the coded orthogonal frequency division multiplex (COFDM) format that was previously dismissed.

Cable is a big reason why broadcasters want better digital reception. Cable's preferred digital modulation scheme -- Quadrature Amplitude Modulation (QAM) -- was considered as a broadcast standard, but rejected in favor of 8VSB.

The cable industry has proposed remodulating broadcast signals into QAM for its digital set-tops. TV sets with 8VSB receivers cannot accept those signals without modification, so the industries are trying to agree how that will be done. Since 8VSB consumes more bandwidth than QAM, cable is balking at passing through broadcast signals as it does analog NTSC to so-called "cable-ready" TVs.

COFDM, with its stronger reception capabilities, could give broadcasters a stance against cable by offering "free, over-the-air" reception to consumers in much the way analog television works.

"We are very impatient," said Nat Ostroff, VP-new technology for Sinclair Broadcast Inc.

Admitting that Sinclair is "agnostic to the standard," Ostroff said he backed COFDM because it provided a "robust, easily-received signal" for viewers using in-home antennas and portable video units.

"We cannot -- must not -- rely on cable and satellite" to deliver broadcast digital signals, he said. "We must be able to maintain our pipeline to the audience."

Ostroff said his patience has worn thin.

"We need it now, not two years from now, because I've heard two years from now for two years," he said.

8VSB, he said, is a "problem in capitals" that is "not doing the job."

Ostroff pointed to results being achieved by the Digital Video Broadcast (DVB) project using COFDM and DVB, the generally accepted transmission standard outside North America.

"This is a level of performance we have established as a benchmark in DTV," he said. "I don't think U.S. broadcasters can afford to lose their over-the-air audience."

Answering the challenge, Royal Philips NV unit, Philips Research USA, said it would join with News Corp.'s Fox TV to study ways to improve 8VSB reception. Other partners include Cornell University and the Australian National University.

Philips will contribute algorithmic and architectural modifications to improve 8VSB receiver performance while Fox provides channel characterization, data and laboratory and field analysis from its 22 owned-and-operated local TV stations already offering digital service.

The project's goal is to enhance what exists, said Tom Patton, VP-government relations for Philips Electronics North America.

"The standard that was adopted is working splendidly." he insisted. "Early adopters of our first and second generations of TV sets are absolutely satisfied with the reception capabilities they're receiving."

Consumers don't have the reception flexibility of analog NTSC television, Patton admitted.

"There are some reception issues," he said. "Some have rooftop antennas, some have cable, stone have satellite, some are enjoying DVD players on their high-definition television sets. The modulation scheme, the technology, the standard, is not the problem. There are reception issues which are being addressed."

Ostroff suggested that set makers could solve the problem by adding "a little bit more silicon" to their sets to make them COFDM-capable.

Patton rejected the idea.

"COFDM was considered as a modulation scheme and was rejected by the Advanced Television Systems Committee - ATSC. It doesn't mean that COFDM was bad; it's optimized for different things. Done different ways, it could work. We could make a system work using COFDM."

But ... "We don't have to."

Sony president Ed Grebow hopes the issue is resolved soon. Grebow, while extolling Sony's goal to be the "digital broadband network company," noted he is "increasingly frustrated" with the industry's "sluggish" move to digital.

Although one industry insider said it was unlikely the ATSC would revisit the standards issue, Gregory Rohde, assistant secretary of commerce-communications and information, lent credence to the complaints.

"The dispute over a transmission standard is certainly becoming more complex again as your engineers take another look at the COFDM standard," he admitted. "We know these problems exist, and I don't want to minimize them."

He said he wouldn't dwell on the problems either "because I believe they will be worked out eventually."

COPYRIGHT 2000 Access Intelligence, LLC
COPYRIGHT 2008 Gale, Cengage Learning