Broadband Bound

International DSL standard improves business services

International experts are set to ratify the first standard technology for offering business-class broadband services over Digital Subscriber Lines later this month. Once approved, the deployment of such services will be simpler, cheaper and more efficient than todays methods.

Symmetric High Bit Rate Digital Subscriber Line, or G.SHDSL, is the latest flavor of DSL, and one of its most anticipated. Telecommunications industry research firm RHK reports the market for G.SHDSL will expand from 400,000 lines in 2000, to 1.7 million lines in service by 2004.

Although the standard is only being ratified this month by the International Telecommunications Union, the G.SHDSL buzz has been circulating for two years. Until now, other than a few deployments of lesser-known DSL variants, Symmetric DSL (SDSL) has been the only game in town for providing business-class services.

Asymmetric DSL (ADSL) is used primarily in consumer deployments because the download speed is much faster than the upload speed, theoretically between 1.5 megabits per second and 9 Mbps down and between 16 kilobits per second and 800 Kbps up. SDSL, however, can provide speeds up to 2 Mbps in both directions. This enables services like video and voice-over-DSL (VoDSL), virtual private networking, and data access to more than one person in one deployment.

The problem is SDSL is not a standard, but instead what one industry insider called "an American solution" to providing business-class DSL services. While SDSL certainly worked to get those services rolling months ago, instead of waiting until after the G.SHDSL ratification, equipment providers have been in a quandary because they dont have any standards to design to, thereby rendering multi-vendor SDSL deployments difficult, if not impossible.

G.SHDSL is a solution developed by the ITUs Telecommunications Standards Sector (ITU-T), based in Geneva. Its members come from around the world and include most of the household names in the U.S. telecom equipment market.

Double Duty

NOT ONLY IS G.SHDSL FASTER THAN SDSL, but it can be deployed to customers farther away from the carriers central office, where the DSL equipment is placed. SDSL is available within 18,000 feet of the central office, while G.SHDSL can almost double that. G.SHDSL can also provide broadband speeds of 2.3 Mbps, compared to the 2.0 Mbps from SDSL.

"Itll take some time before I can tell you [G.SHDSL] is fully baked and rock solid," says Chy Chuawiwat, vice president of sales at Celsian Technologies, one of the smaller data equipment providers hoping to take advantage of an open standard.

"G.SHDSL is a standard that will allow carriers to use our modem, and use all kinds of central office equipment and it will all work together," Chuawiwat explains.

But G.SHDSL isnt in the clear just yet. Once its ratified this month, someone has to deploy it, and its still not clear whos going to do that. Since the Bell companies, such as Verizon Communications, focus almost entirely on residential DSL, theres no assurance theyll deploy it anytime soon.

So far, its been the independent carriers, like Covad Communications and Rhythms NetConnections, that have targeted businesses, but the financial markets have left those carriers so cash strapped, its difficult to fill a purchase order for staplers, let alone brand new G.SHDSL equipment, especially when they already have SDSL installed.

But dont count the Bell companies out of business-class DSL just yet, says Adam Guglielmo, an analyst at telecommunications research firm TeleChoice. "I do think you are seeing the [Bell companies] start to move into symmetric services or business services so they will be [purchasing] more," Guglielmo says. "I think now that they have a standardized symmetric service, some of the big guys might deploy more with G.SHDSL."

Even a "standard" DSL technology doesnt necessarily get deployed right away, however. The G.Lite DSL standard was approved by the ITU-T nearly two years and has yet to reach wide-scale use. A form of ADSL, G.Lite was expected to make installing DSL so easy that by the end of 2000, everyone would be buying DSL modems at retail stores and having service installed within a week.

But even though G.Lite is a standard, it still doesnt perform the way it was designed to. Industry experts say its unlikely the same could thing happen with G.SHDSL.