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Tech Industry

SA tips digital TV plans

Products will include digital TV cable set-top boxes that translate HDTV signals.

Scientific-Atlanta, one of the largest suppliers of communications equipment to the cable TV industry, today laid out plans for helping cable networks bring digital television to its customers.

Scientific-Atlanta (SA) intends to offer products ranging from cable set-top boxes capable of translating high-definition digital television (HDTV) signals for display on digital TVs to transmission equipment that sends digital TV signals to set-tops. In doing so, the firm is looking to "meet early market demand for HDTV," the company said.

Services now marketed as "digital TV" by cable companies such as Tele-Communications Incorporated only offer more channels for traditional, analog TVs. True digital TV, on the other hand, promises the ability to display content with greater picture quality than is possible now.

Digital broadcasts are slated to begin in some U.S. markets this November, but the issue of providing these broadcasts to millions of cable subscribers has been clouded by a variety of technical and political issues that have yet to be settled. Because of its role as a key supplier, Scientific-Atlanta's plans offer some insights into how digital television will--or in some cases won't--reach consumers.

Some 41 over-the-air broadcasters are slated to begin transmitting digital TV signals by November 1, according to the National Association of Broadcasters (NAB), but these signals are transmitted in a different format than the one used by cable operators to send signals to cable set-top boxes. The problem is between 60 and 67 percent of U.S. citizens get TV signals from the cable companies instead of an antenna.

TV format wars
HDTV: High-definition television

1080i: Offers 1,080 lines of resolution. Displays images using interlaced scanning, which first transmits all the odd lines on the TV screen and then the even lines. Most bandwidth-intensive signal.

720p: Offers 720 lines of resolution. Displays images using progressive scanning, which transmits each line from top to bottom. This offers image quality close to that of 1080i. More bandwidth-"friendly."

SDTV: Standard-definition television

480p: Offers 480 lines of resolution scanned one after another onto the screen. Bandwidth-friendly; allows for transmission of either multiple programs in the space of one channel or data services such as Internet access.

SA said that it will offer technology based on its PowerVu HD and Plus TV hardware to translate signals into the appropriate format, called QAM (quadrature amplitude modulation), so that cable companies can send to set-top boxes using SA's "Digital Transport" system.

SA claimed cable operators can put up to eight times the data on a single fiber-optic cable with its technology, which is important because there has been much debate about whether or not cable operators would carry bandwidth-intensive HDTV signals.

All of this equipment will initially send digital TV signals to an updated version of SA's Explorer 2000 set-top box, which includes technology for translating the cable system's QAM signal back into the format used by the new, expensive digital TV sets.

Some analysts have predicted that it would be at least 2000 before such set-tops appear on the market, whereas SA said its system will be available in January 1999. However, the company did not provide information on how much such a set-top box would cost. For perspective, some television manufacturers are said to be working on a "decoder" box separate from the cable set-top that can do this--for around $1,000 to $3,000.

New DTV sets, costing upward of $5,000, can't directly receive digital signals from the cable set-top converter boxes now found in 65 percent of U.S. homes. As it stands, consumers will have to rely on antennas hooked up to their television sets to get DTV signals in their pristine, high-resolution state.

A more cost-effective solution for the problem is in the works, but technical issues have not been settled yet. TV and set-top makers are looking to the Institute of Electrical and Electronics Engineers' 1394, or "FireWire," technology for connecting cable set-top boxes to digital television sets, but it won't be available in the first generation of DTV.

SA said it will manufacture set-tops with FireWire interconnects once the specifications have been finalized. The company said it has already demonstrated prototype devices with the technology.