The FCC decided in 1997 when it launched the transition to digital TV to review progress every two years.

While the review was scheduled, it comes as several key technical and legal issues remain unresolved. Among them are improving indoor reception of DTV signals, whether cable operators will be required to carry digital TV signals and what copy-protection mechanism will be used to encrypt digital TV signals. Some of those issues have been excluded from the FCC examination.

The review will revisit the ongoing controversy over the best modulation scheme for digital broadcasting despite an early agency ruling that it would not consider reopening the U.S. digital standard, vestigial sideband (VSB). Some broadcasters would prefer the FCC to consider an alternative scheme, called coded orthogonal frequency division multiplexing.

The FCC said it would seek comments on "progress being made to improve indoor DTV reception under this standard, and manufacturers' efforts to implement DTV design or chip improvements."

Opponents of the VSB spec have complained that next-generation receivers do little to address indoor reception problems that they warned will slow the digital transition. Sinclair Broadcasting Group Inc. (Hunt Valley, Md.) is leading the opposition to VSB. "We are withholding comment until such time as we have seen and have reviewed the FCC notice," a Sinclair spokesman said.

Some broadcasters have recommended the FCC address broadcast signal reception by setting receiver standards. Therefore, regulators asked for industry comments on whether the FCC has authority to set minimum performance levels for DTV receivers and, if so, how such requirements should be structured.

Few technical problems

While broadcasters faced early problems in launching digital TV services, the FCC said, "stations are facing relatively few technical problems in building digital facilities, and that problems encountered by some stations with tower availability and/or local zoning issues do not seem to be widespread."

According to the Commission, 92 digital TV stations were on the air as of Feb. 23.

On another front, the DTV review will seek industry comments on whether broadcasters can secure transmitter tower locations and how zoning disputes and a lack of resources are affecting the digital transition.

The review will also consider whether regulators should adopt a requirement to replicate their National Television Standards Committee service area with digital service, and whether replication should be based on population or service area. Some broadcasters, seeking to recoup high up-front investments in digital TV equipment, have asked to relocate stations closer to population centers.

The target date for completing the conversion to digital TV is 2006. The FCC said it is too early in the transition process to review the target date. Skeptics doubt whether analog broadcasts can end by 2006, and some U.S. stations in rural areas are seeking an extension of the target date.

Comments on the digital TV review are due by May 17, the agency said.