Microsoft IPTV is still fuzzy but promising

Several big telecommunications operators and, in particular, the world's largest software maker, Microsoft, hope to sway many couch potatoes to zap their old-fashioned notions about television and tune into the convergence of TV and the Internet.

Internet TV, or IPTV, is arguably one of the hottest new technologies in the communications sector. A handful of operators are already offering service with their own, largely home-grown systems, but many eyes are glued to the screen to see what Microsoft is concocting together with some big-name carriers.

Using the same DSL (digital subscriber line) high-speed connection that offers customers broadband Internet access over copper telephone lines, Microsoft-aligned operators such as BT Group PLC, Telecom Italia SpA, SBC Communications Inc. and India's Reliance Infocomm Ltd. aim to add television to their product offerings to achieve the much-cited "triple play" of bundled voice, data and video services. Their motto: if -- in our age of the digital packet -- documents, images, music and even phone calls can be broken up into bits, thrust through networks and reassembled at the other end by the Internet protocol, why not TV?

It's a legitimate question, and one that telephone companies -- painfully aware that the days of their cash-cow circuit-switched telephone business are numbered as cheap VOIP (voice over IP) services go mass market -- aim to answer, despite their failed TV attempts in the past.

More than a decade ago, several big carriers, such as Deutsche Telekom AG, tried unsuccessfully to deliver TV service over analog lines. Now, with digital technology, operators are more likely to succeed, according to Laura Behrens, principle research media analyst at Gartner Inc. "Delivery of anything digital into the consumer home is so much more reliable and less costly at the operating level than anything operators ever dreamt of in the analog era," she said.

The quality of the digital stream into the home, however, is a big factor and one that operators say will distinguish IPTV from video streamed to a PC over the Internet. On the public Internet, packets can be delayed or lost entirely, explaining why Web video can be so jerky and low resolution. IPTV, by comparison, is engineered for end-to-end delivery of high-quality video as good as any digital cable or satellite feed.

One of the components necessary to provide this quality of delivery is a dedicated transmission path. Another is a high-performance set-top box. And still another, software that unites all the pieces.

For instance, under the IPTV service that French network operator France Télécom SA has been offering over its DSL lines since March 2004, live TV programs and video-on-demand are transmitted as MPEG2 streams over an IP connection, but the video streams and normal Internet traffic are kept from interfering with one another by separating them at the ATM (Asynchronous Transfer Mode) layer. They are transmitted in separate virtual channels over the same piece of copper between the DSLAM (DSL access multiplexer) and the DSL modem in the subscriber's home. France Télécom uses the SmartVision Internet TV system from Thales SA.

IPTV set-top boxes offer new encoding technology designed to highly compress video. Such compression can reduce not only network congestion but also the jumpiness of video simply because the signal will take up less network capacity, and allow the delivery of TV over narrower channels than would otherwise be possible.