January 2002

Delivering DSL

Broadband

By Mike May

Digital subscriber lines, or DSL, take advantage of telephone system infrastructure to give consumers broadband Internet access. But the service's availability is notoriously limited to certain neighborhoods. There may soon be help for the DSL-deprived, however: a new version of the technology nearly doubles its reach.

With conventional DSL, a device in a central switching facility connects a phone line to the Internet backbone, then uses high-frequency signals to communicate over that line with a DSL modem in the home. But if your home is one of the millions that's more than five kilometers from such a facility-as the wire wanders, not as the crow flies-you're out of luck; the signal degrades before it reaches you. The new DSL service, called G.SHDSL, combines a lower-frequency signal with software that reduces transmission errors to send the signal almost twice as far. Amplifiers on the line also help push the signal along, says Mark Peden, a board member for an industry consortium aimed at making DSL a mass-market technology.

The new DSL offers another advantage: it sends data as fast as it receives it, in contrast to most current residential systems, which limit upload speeds and cause problems if you're, say, using video-chatting software. Better yet, the technology is ready for deployment: a number of firms, including Cisco Systems, already offer complete systems. "Europe will probably adopt G.SHDSL within a year," says Ernie Bergstrom, a senior analyst at Cahners In-Stat Group in Scottsdale, AZ. "It will probably show up in the United States about a year later." The lucky few who already have broadband access, in other words, might soon have plenty of company.