Linux takes on starring role

Sprint develops low-cost set-top using OS Despite a recent downturn in telco interest in providing entertainment services - particularly video - to residential customers, for the past two years Sprint has been running a test in Pacifica, Calif., that may change some minds.

One of the biggest issues in providing the next generation of advanced TV services is choosing an operating system (OS) for the set-top box. The decision, which generally is made early in the testing process, dictates which vendors operators can work with and also plays a major role in the cost of the set-top. Moreover, the question of what platform will be used to offer these services is far from being decided.

Microsoft's Windows CE is certain to play a major role - thanks in part to the software leviathan's $5 billion investment in AT&T, which, as the largest cable operator in the country, chose to use the OS. Proprietary platforms, while sometimes less expensive than Windows CE, carry with them the fear that operators will be tied to a single vendor.

Sprint, however, as part of its Pacifica broadband test, developed a set-top that it claims could lead to a low-cost alternative. Using an existing set-top product from Sigma Designs as its base, Sprint engineers at the Burlingame, Calif.-based Advanced Technology Laboratories chose to implement a Linux OS along with additional software.

"We went with Linux for the purposes of programmability," said Jay Cee Straley, a senior network architect with Sprint's service architecture group.

What makes Sprint's choice unique is the end result. Not only is the company putting a digital set-top in people's homes, it's putting a box with a 16 Mb/s hard drive, a DVD player, a 100 Mb/s Ethernet connection (plus a possible connection for a wireless LAN) and a routing point for IP-based phones.

"It's an open platform on which we can deploy all kinds of services," Straley said.

In Pacifica, Sprint is offering the service to 200 homes via a local provider. The test includes video-on-demand service, interactive games and high-speed Internet access.

When the test began, Sprint also considered enabling consumers to watch shows in the time slot of their choosing. However, legal issues involving broadcast rights and the ability of broadcasters to sell airtime in specific time slots led Sprint to abandon the service.

In fact, the technology for offering video services has become so flexible, it often raises questions in the minds of broadcasters, which fear that giving too much control to users would harm the value of their broadcasts. "How are the broadcasters going to handle all of these capabilities? That's a big question for them right now," said Frank DeNap, head of Sprint's ATL.

The trial also is testing several architectures, including fiber to the curb with an Ethernet connection into the home and fiber to the home running ATM all the way to the set-top box (see figure).

Almost as important is the cost. The set-top boxes can be built for about $300 in quantity - another major reason Sprint opted for Linux, Straley said. The entire box, which actually performs more like a residential gateway than a traditional set-top, is built from standard equipment.

"There's a real cost curve being driven by the enterprises that we wanted to take advantage of," Straley said.

Of course, Sprint isn't the first to use Linux in a set-top box. Caldera Thin Clients, an Orem, Utah-based Linux developer, announced last year that it would offer a set-top software solution based on a stripped-down version of Linux.

Several emerging residential broadband gateway vendors also are considering using Linux because of its openness and ease of adding new applications.

A number of other OSs were developed specifically for the video environment, including OpenTV and Java.

Next Level Communications, which provides set-top boxes and much of the network infrastructure for U S West's video services in Phoenix, is looking at using Linux as an option for its customer premises equipment, said a company spokeswoman. However, the company is not planning any Linux-based set-tops in the near future, she added.