Big Picture

Next summer, broadcasters in major urban areas will start transmitting TV programs using a new technology adopted by the federal government earlier this year following an agreement among the major players.

The system is called high-definition television (HDTV). And though few viewers who benefit from the dramatically improved picture and sound that HDTV offers will be aware of it, MIT played an important role in creating the system. “We had a strong voice in all the technical decisions that were made,” says Jae Lim, professor of electrical engineering and computer science, and head of the Institute’s Advanced Television Research Program.

Most viewers also won’t know that the system emerged after a decade-long battle that engaged some of the world’s best-known companies. Lim, one of those at the front lines, says it was a hugely absorbing effort, taking him to countless meetings that sometimes seemed to overlap one another.

“I remember returning from one trip,” he says, “and my wife brought a suitcase with my next week’s clothes to Logan Airport. I then took off again for another round of meetings somewhere else.”

Still, he feels that his–and MIT’s–efforts were well worth it.

Great Pictures

HDTV images can have more fives times as many picture elements as those in conventional TV broadcasts, which vastly improves the the images’ clarity. If you have a conventional system with a two-foot high screen, you have to sit at least 14 feet away to avoid the appearance of horizontal lines. With an HDTV system, you can be as close as six feet–meaning large-screen TVs will now work well in an average-sized room.

Lim says HDTV’s picture quality is better than watching a film in a theater. “When you see a spectacular movie like the ‘Sound of Music’ or a colorful sporting event on an HDTV system, it can be quite moving,” he says. “I find it hard to go back to regular TV.”

But a clearer picture is only part of the story. Broadcasters will be able to deliver CD-quality multichannel sound along with the images they transmit. There’ll also be ample capacity to broadcast everything from stock quotes to publications. “You’ll be able to read your local paper on the screen,” notes Lim.

Art buffs, meanwhile, will get to display digitized images of favorite masterworks, and change these at will. And in time, computer-game aficionados will be able to use their HDTV screens as large-scale arenas for solving vexing crimes or crushing devious foes.

Still, Lim’s motivation wasn’t so much how the system would be used as its technological and industrial implications. “If you need a certain kind of chip for an HDTV receiver,” he notes, “that could mean 250 million of those chips will be made, because that’s approximately how many TV sets there are in America.”

MIT’s Role

The Institute was the only university to play a role throughout the battle over HDTV. After the retirement of the Media Lab’s Professor William Schreiber, who began the effort, Lim took over the Advanced Television Research Program. He felt that the Institute should keep its hand in, and that the only way to do this was to take part in the system’s design.

“It’s easy to try to be a referee because it doesn’t cost anything, but no one will listen to you,” he notes. “If you want to make an impact, you have to be a system proponent.”

Hence, followers of the issue were treated to the spectacle of MIT facing off against concerns like AT&T and Phillips. With a pricetag for participating as high as $100 million, though, most participants combined their efforts with one or more partners. MIT linked up with a firm called General Instruments Corp.

GI had submitted its own system, but it also worked with MIT on a joint entry. “The system was approximately half ours and half theirs,” notes Lim. And it fared well in the competition, with the Federal Communications Commission choosing it as one of four finalists.

The Right Thing

The HDTV competition involved seemingly arcane issues–for example, whether broadcasts should be “interlaced,” with the odd-numbered lines in an image all being broadcast in succession followed by the even, as is currently done; or “progressive,” with all the lines being transmitted in succession over a 60th of a second. (The ultimate decision allowed both.) Yet with billions of dollars at stake, it was also intense.

“In many cases, I saw people pushing for a certain technical element not because it was the best, but because it was in their company’s financial interest,” says Lim.

The MIT group made key technical contributions to the HDTV standard. But Lim says MIT’s participation was also personally invaluable to him because he learned about how the nation’s policies on technological issues are shaped.

“When you look at the outcome,” he explains, “I’d say it’s 80 to 90 percent of the way to an optimal system. So despite the self-interest of many of the players, in the end we somehow did the right thing for the country.”

by Richard Anthony

On Topic: electrical engineering+electronics, faculty, technology+society