MPEG-4 Gives DBS Room
The trick of delivering 1,700 broadcast signals
By Russell Shaw -- Broadcasting & Cable, 6/25/2006 8:00:00 PM
In order to provide a comprehensive offering of stations' high-definition signals in most markets, both DirecTV and EchoStar are upgrading their infrastructure from MPEG-2 compression to MPEG-4 to gain maximum efficiency from satellite capacity.
“When we started looking at the transmissions that support HDTV, we decided that none of the old boxes would be able to process them,” says Romulo Pontual, executive VP/chief technology officer, DirecTV Inc. “MPEG-4 offers a much better compression rate that can be used to improve quality.”
DirecTV is broadcasting local HD content using the H.264/MPEG-4 AVC codec while employing a newer transmission protocol (DVB-S2) over its new Spaceway-1 and Spaceway-2 satellites. This allows DirecTV to squeeze much more HD programming over its satellite signal than would be possible with the older MPEG-2 compression and DSS protocol it has been using.
Most HD channels today are compressed at a bitrate of 12 to 18 megabits per second (Mbps) using MPEG-2 technology. Compression manufacturers say the newer MPEG-4 codecs can slice that bitrate in half.
“The biggest technology challenge is the sheer amount of bandwidth necessary to carry up to 1,700 local-broadcast signals,” says Lisa Hobbs, senior director of business development for satellite & broadcast with Tandberg Television. “MPEG-4 is twice as efficient,” she adds, noting that it is capable of a 6- to 8-Mbps bitrate for HD.
“The need is being driven by the explosion of new content,” says Jimmy Schaeffler, chairman and senior analyst, Carmel Group. “More bandwidth enables more content down the same pipe.”
Of the two main DBS providers, DirecTV has been the more vocal about its plans. According to Pontual, some 36 markets covering approximately 68% of U.S. households will have been enabled for MPEG-4 by the end of this month, with a target of 50 markets and more than 65% of U.S. household penetration by the end of 2006.
EchoStar's Dish Network is also proceeding rapidly toward widespread MPEG-4 delivery of local broadcast high-def. The service started Feb. 1 with New York, Los Angeles, Chicago and Boston among the first to get the signals of the local ABC, CBS, Fox and NBC affiliates. EchoStar CEO Charlie Ergen has said that 50% of U.S. TV households will be covered with MPEG-4 by the end of 2006.
For both DirecTV and Dish, nationwide deployment of MPEG-4 will require a substantial outlay of capital, widely believed to be, collectively, well into the hundreds of millions of dollars.
“The main challenge is the cost of the encoders and the cost to change out set-top boxes,” says Schaeffler. “The satellites and multiplexers all stay the same.”
DirecTV customers can receive local HD channels by purchasing the company's new H20 HD receiver and a satellite dish able to receive programming from five orbital locations. DirecTV is offering a $100 mail-in rebate to new customers who purchase a DirecTV HD receiver.
Receiving equipment is available at major consumer-electronics retailers, such as Best Buy and Circuit City, as well as through DirecTV. Existing customers are eligible for a $99 upgrade to the new H20 receiver and dish, plus $99 for each additional HD receiver.
NEED MORE BIRDS
Bob Wilson, CEO of MPEG-4 compression supplier Modulus Video, notes that both EchoStar and DirecTV are starting to make the investment—one he believes will be complete within two years. “The good news is that all of the other equipment—the satellites, the transponders—is going to stay the same.”
Well, when it comes to satellites, not everything will stay the same. While the satellites currently in orbit will be able to handle MPEG-4, the sheer demand of all these extra national and local HD channels drives the need for more birds.
“We cannot [fully] convert to MPEG until we launch two other satellites in the first quarter of next year,” says DirecTV's Pontual. He believes that, with these new birds up, the total of four satellites (the two existing Spaceways plus DirecTV 10 and DirecTV 11) in 2007 should enable more or less full conversion to MPEG-4 within about a year.
VIEWERS WILL NOTICE
Modulus' Wilson believes that, when this conversion happens en masse, viewers will notice.
“MPEG-4 is about 10 times more computation-intensive, with more algorithms and tools,” he says. “As a result,” he adds, “the picture looks great or better than MPEG-2 but with a lot less noticeable blocks showing up in fast-motion images.”
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