TelcoTV: Telcos need analog turnoff prep, says Tandberg

ANAHEIM, Calif. – While over-the-air TV subscribers in the US need to be preparing for the Feb. 17, 2009 end to analog TV broadcasting, telco TV providers have their own preparations to make, to ensure they can continue providing broadcast channels to their subscribers.

At TelcoTV, Tandberg Television, a unit of Ericsson, is demonstrating the kind of change required at an IPTV headend. “A lot of the channels that telcos are receiving they get right off the air,” said Craig Knudsen, director of business development for IPTV at Tandberg. “What we have done is build a receiver, the Tandberg 8320, that is purpose-built for the analog shutoff. This is something we have done for cable, but it has jumped up in visibility just recently for IPTV players.”

Today local broadcast signals based on the NTSC analog video standard come into NTSC-based receivers at the telco headend that demodulate the incoming analog signals and pass them to MPEG encoders, which produce the digital signal for IPTV systems. Receivers in the telco headend based on the ATSC digital video standard demodulate incoming digital TV broadcast signals and pass them through as MPEG-2 signals or decode the ATSC signal to baseband so it can be re-encoded as MPEG-4 AVC.

After the NTSC signals are shut off, telcos will have to rely on the digital signals from broadcasters, some of which have decided to only broadcast their digital high-definition signals and not continue a standard-definition signal, according to Tandberg. That means telcos will need to have HD ATSC -to-NTSC (DTV-to-analog) conversion devices in their headends, either as standalone devices or integrated into MPEG-2 t0 MPEG-4 AVC transcoders. Tandberg’s approach is to use an integrated solution designed to tackle the multiple issues of the analog shutoff, Knudsen said.

Those issues include performing picture aspect ratio conversion, color space correction, audio processing and program loudness adjustment, according to Tandberg. Other concerns are extraction of DTV closed captions, embedded extended data service information and other ancillary data.