Getting xDSL off the ground

Electronic News, Feb 2, 1998 by Will Wade

San Jose, Calif.--Scores of the major players in the communications market have rushed to voice their support for a trilateral initiative to push standards for digital subscriber line (xDSL) products. The Universal ADSL Working Group (UAWG), spearheaded by Intel, Microsoft and Compaq Computer, was officially announced at last week's ComNet trade show in Washington, D.C. The team effort to design an open standard for the high-speed digital data communication protocol has also been endorsed by GTE and all five Baby Bell telephone companies, an unprecedented show of cooperation between the computer and phone industries.

While the technical specifications for this xDSL standard are not expected to be released until later this year, the group has already announced they will use DMT technology, and that transfer rates will likely reach 1.5 megabits-per-second downstream into the home, and a bit less than half that for the upstream journey. This asymmetric DSL (ADSL) format settles what has been one of the persistent debates hindering an ADSL standard: whether to use DMT, or a competing and incompatible CAP format.

In the past week, members of every segment of the telecommunications segment, including chipmakers, systems companies and carriers, have been falling over themselves in the rush to endorse the UAWG effort. At last report, nearly a dozen semiconductor makers have announced their entry into the UAWG, including Texas Instruments, Lucent Technologies, Analog Devices, Cirrus Logic, Siemens and Rockwell Semiconductor Systems. Systems companies are also supporting the effort, with Northern Telecom, 3Com, Westell Technologies and Cisco Systems among some of the entries. And along with all the major phone carriers, Sprint, U.S. West and Covad Communications are just some of the companies which intend to help iron out a standard and deploy ADSL systems.

More To Follow

Analysts predict even more companies will follow. For companies that had been using CAP-based technology, adopting a DMT-based format requires a complete reversal in their development strategies. However, some executives have said switching gears is worth the effort because working with the UAWG may lead to a robust ADSL market this year, while there is currently no significant market for any ADSL technology. Early predictions see ADSL devices aimed at the consumer on retail shelves by Christmas, with supporting infrastructure in place at the telephone carrier central offices. Compaq has already announced plans to install the digital modem hardware in some of its Presario systems, perhaps as early as spring.

These announcements, especially the support from the telephone carriers, represent a huge shot in the arm for ADSL deployment. Until recently, it appeared that cable modem systems had achieved a slam dunk in the race to dominate the broadband consumer communication market, but it now seems that ADSL may be able to close the gap. Digital subscriber lines offer digital data transfers over existing copper telephone wiring. There are several varieties, differentiated primarily by transfer rate, but all of them are much faster than existing analog modems. The technology also allows users to remain connected to the Internet at all times, much like with a corporate LAN, while using the same line to make standard voice calls.

The format being pushed by this alliance is one of the slowest, offering an asymmetric rate of 1.5M downstream and a slower upstream rate upstream, probably about 300K to 650K. This is aimed at the average home-based Internet surfer who downloads large web files and uploads smaller E-mail messages.

This format also has the advantage of easy installation; faster xDSL protocols require the installation of a line splitter at the home, while this slower version requires nothing more complicated than plugging the modem into a standard wall jack.

Seeking An Open Standard

Intel said the company's main goal was to promote an open standard that would lead to higher bandwidth services wired into the home. The company is not expected to design or manufacture ADSL chips, but Jon Jackson, a spokesman for the Intel Architecture Labs said the company would benefit indirectly.

"Our focus is on making sure the PC is ready to accept and utilize DSL technology," said Mr. Jackson. "If we can increase bandwidth, PC users will experience quicker access to the Internet. The PC consumer will benefit from that, the PC industry will benefit from that, and that means Intel will benefit as well." The technology behind ADSL lines is not new, but so far has seen very limited deployment because there is no industry-wide standard. Telephone carriers have been reluctant to purchase and install expensive ADSL systems that may not work with other carriers or with all consumer systems. While the industry has been slowly plodding towards a standard in the International Telecommunications Union and the American National Standards Institute, progress has been slow and nothing was expected to emerge this year.