AT&T Plans LightSpeed Trip to High-Tech TV3/17/2006 7:00 PM Eastern
AT&T Inc. and three key vendors — Alcatel, Microsoft Corp. and Scientific-Atlanta Inc. — are working on what would be, if successful, the largest Internet protocol television service in the world.
The service, expected to be fully deployed in about three years, could prove to be a key differentiator for AT&T in the marketplace. It will provide:
Delivery of only the channel a subscriber requests at any given time;
Seamless changeover when consumers switch channels;
The ability to view multiple pictures on one screen; and
Search capability for video-on-demand offerings.
Alcatel is supplying much of the infrastructure for AT&T’s Project LightSpeed, including fiber, switches and routers. Microsoft is providing servers and key pieces of software, while S-A is supplying video headend equipment and set-top boxes.
AT&T is building two super headend offices to serve the eventual 18 million homes to be passed by Project LightSpeed.
“The super headend offices are the points of ingest for all national broadcast content,” said Steve West, director in the strategic solutions area in Alcatel’s chief technology office. “They will ingest content just like cable.”
The cable channels will be encoded into MPEG-4 (Moving Picture Experts Group) and placed in Internet protocol packets for transmission to 41 video hub offices in major markets that AT&T is building.
The content passes through a server, West said, “where we separate content from the metadata and where digital rights management first gets applied.”
For instance, on-demand content from Hollywood studios carries with it metadata such as information about the movie, its rating and the cast. Microsoft’s digital rights-management software protects the movies from being pirated or copied, starting at the national super headend offices all the way through the network to the home.
“It’s unique to the Microsoft-Alcatel solution,” West said. “At no place is the content in the clear,” meaning once content hits the super headend office, no outside party can steal it.
Once the content is properly protected, it will be shipped over AT&T’s national backbone to one of 41 video hub offices.
Instead of delivering 200 channels to the home like cable, AT&T will only deliver to the home the single channel a subscriber requests through their remote control. Whereas a single MPEG-4 standard-definition channel requires 1 million to 2 million bits per second, an MPEG-4 HD signal would require 6 million to 8 million. AT&T is working to guarantee 24 million bits per second to the home — enough to handle one HD feed, one SD TV signal, a phone call and a video download to a computer at 3 million to 5 million bits per second.
“There will be different demands inside each household,” West said. “A power family user may demand up to three streams of HD at any one time. AT&T can set priorities,” he said, on which homes get how much bandwidth.
The video hub office also contains Microsoft servers where the software for the Microsoft guide and its video-on-demand opening screen is stored, said Ed Graczyk, director of marketing for Microsoft.
Content is shipped from the video hub offices, through AT&T’s Project LightSpeed fiber plant to hundreds of central offices in any one community. The central office contains the Alcatel switch, local on-demand servers for the most popular content and Microsoft servers that provide the key “instant” channel change software that Microsoft believes will be a major differentiator for AT&T.
The entire channel lineup is sent from the video hub offices to the Alcatel switch in the central office. The Microsoft server is constantly pulling live channels from the switch and buffering three to five seconds of video in its server. When a subscriber changes channels, the buffered video is sent to the home from the server. As the first few seconds of video is sent down, the Alcatel switch receives a command from the server to send the rest of the live signal from the switch to the home. The changeover is seamless to the viewer, who can switch channels in the blink of an eye, compared to the two- to three-second delay with digital cable.
“The signals sit in the Ethernet switch, available to be served up,” West said.
According to Graczyk, “the round trip is 300 milliseconds” from the time the subscriber hits the remote control button and the time the TV signal shows up on the stream.
In addition to a text grid, the Microsoft guide includes “a video thumbnail window,” so subscribers can “see” what’s playing on one channel, while viewing their main channel. Microsoft’s software also allows for four to six pictures to be displayed on one screen at the same time.
“And the whole video-on-demand experience is different,” Graczyk said. “We have branded store fronts, movie art and branded colors,” he said. “We have a search capability.”
The software searches the TV lineup, the on demand library, even the content stored on a digital video recorder.
West and Graczyk believe that using Internet protocol will help AT&T, as well as other telcos, differentiate themselves in the marketplace. “It makes those integrated services in the home a lot easier to put together,” West said.