FCC Rejects Sinclair COFDM Petition; NBC Validates COFDM's Superiority But Stands Behind 8-VSB

by Naina Narayana
WASHINGTON, D.C.
Despite more evidence indicating that 8-VSB is inadequate for digital broadcasting, the FCC - as well as a major network that documented poor reception as late as January - have steadfastly refused to abandon the transmission standard. FCC commissioners voted "on circulation" Feb. 4 to reject Sinclair Broadcasting Group's petition seeking to allow COFDM as a second transmission standard. The decision came a few weeks after NBC conducted tests in Philadelphia that confirmed Sinclair's concerns over 8-VSB's indoor reception performance in urban environments. Though NBC reported its preliminary findings to the FCC (just after the vote), the network still supports the 8-VSB standard. NBC said it found, despite its concerns over 8-VSB, that COFDM was not a viable alternative.

"It's no use saying the standard doesn't work or we're going someplace else unless you have a real option to go to," said Peter Smith, vice president of Technical Planning and Engineering at NBC "There has to be a realistic option." The network's support for 8-VSB came at a MSTV board of directors meeting in early February. Smith added, though, that NBC will continue to work to improve both 8-VSB reception and find a configuration of COFDM for U.S. broadcasters that would not require the FCC to change its DTV Table of Allotments, which assigned digital channels to the nation's 1,600 broadcasters.

FCC REASONING
According to the commission statement, studies were conducted that demonstrated NTSC replication "is attainable under the 8-VSB standard." In the statement it released, the commission said that rather than demonstrating that 8-VSB is an inadequate transmission method, the concerns raised in the Sinclair petition have "done no more than demonstrate a shortcoming of early DTV receiver implementation." The FCC's Office of Engineering and Technology (OET) analyzed the merits of the two standards and concluded that the "benefits of changing the DTV transmission standard to COFDM would not outweigh the costs of making such a revision." The commission does plan, however, to revisit the ATSC standard in an
upcoming biennial review of the digital rollout.

A DIFFERENT PERSPECTIVE
In responding to the FCC decision, Sinclair President David Smith put a positive spin on the announcement. "Although the commission dismissed our petition, we welcome their larger interest and intent to investigate all aspects of DTV and its fundamental failure to date," he said. The broadcast group also accepted the commission's invitation to take part in OET DTV receiver tests. "We look forward to working with OET, MSTV and the NAB ... to develop DTV receiver standards that will replicate ease-of-reception of analog TV," said Mark Hyman, Sinclair vice president of Corporate Relations. Meanwhile, Sinclair is still pressing forward with its petition on Capital Hill. While the FCC commissioners were still making their decisions, the broadcast group mounted a counteroffensive on Capitol Hill earlier this month by asking legislators to urge the FCC to put its petition out for public comment. In early February, Sinclair engineers set up an 8-VSB demonstration for House staffers and plan to hold another at the Senate later this month.

THE BATTLE RAGES ON
Even as the regulatory wheels began to turn in Washington, the battle over 8-VSB and COFDM continued in the private sector. One of the inventors of the 8-VSB standard, Zenith Electronics Corp., lobbied against any changes to the DTV modulation standard. In early February, Zenith held a public demonstration comparing COFDM and 8-VSB and urged FCC staffers to recommend the dismissal of the Sinclair petition. Using previously recorded programming and third-generation chips - expected to be available in DTV consumer sets by this October - Zenith officials said the COFDM receivers failed first in the presence of white, phase and impulsive noise as well as high multipath conditions. Sinclair engineers, however, asserted that the Zenith tests were "meaningless" because Zenith operated one of the COFDM receivers above its design threshold. By operating COFDM receivers from NDS and Nokia at -30 dBmV to compensate for the wider 8 MHz bandwidth - the same level that the first, second and third-generation 8-VSB receivers were running - Zenith was operating the Nokia receiver at almost four times the amount of power that it is designed to operate, said Mark Aitken, Sinclair New Technology Group engineer. But Zenith technologists believe neither COFDM receiver was overloaded and defends the company's decision to conduct the simulated demonstration. "Using an off-air signal doesn't make it as controlled," said Senior Vice President of Technology and Research Richard Lewis, citing a better handling of ghosts, timing and multiple impairments in a controlled environment. Several 8-VSB proponents claim finances, not technology, is the motivation behind Sinclair's push for COFDM. The broadcast group has denied the assertion, saying although its financial performance is poor right now, Sinclair neither has a lack of resources or a desire to delay the DTV transition. "We want digital to be a success," Aitken said. "We invested in a transmitter company [Acrodyne] to be available to reap the benefits of that success. But that investment is overshadowed by the need to ensure there is a return on that investment. And we see no return with an investment based upon 8-VSB."

Copyright 2000 IMAS Publishing Group