Rockwell pushes into DSL development

Electronic News, Dec 1, 1997 by Will Wade

Newport Beach, Calif. -- Rockwell Semiconductor Systems has inked two deals aimed at pushing digital subscriber line (xDSL) technology further into the mainstream. The company has entered a joint development agreement with Orckit Communications to collaborate on high bit rate DSL products (HDSL), and has also announced intentions to work with Northern Telecom to make Rockwell's consumer DSL (CDSL) format interoperable with Nortel's similar 1-Meg Modem system. But just to cover all the options, Rockwell has announced its first chipset to support high-speed cable modems, seen as the main competition for xDSL lines in the consumer market.

Both xDSL relationships indicate Rockwell's strong support for technology, and are likely to further efforts to develop widely accepted standards for the two formats. "We see xDSL as the next wave of communication technology," said Raouf Halim, VP and general manager for Rockwell's network access division. "It's the future of our business."

Digital subscriber lines come in several different formats, but all of them offer high-speed digital data communication over existing twisted copper pair phone lines. Rockwell recently introduced CDSL, aimed at the home consumer market and delivering data rates of one megabit-per-second downstream and 128 kilobits-per-second upstream (EN, Nov. 3). Asymmetric DSL (ADSL) is beginning to initial testing in several markets, and is being aimed at consumers and telecommuters.

Widely Used Format

HDSL is currently the most widely deployed xDSL format, and its 1.5M symmetrical service is commonly used to move data over corporate T1 and E1 lines but requires two twisted-pair lines. Rockwell and Orckit will work together on HDSL2 products, which offers the same service over a single line.

Much of Rockwell's HDSL2 chip development efforts will emerge from the group formed when the company acquired Brooktree last year (EN, July 8, 1996). This deal renews an old partnership with Orckit, which worked with Brooktree prior to its acquisition. As in the previous relationship, Orckit will develop HDSL2 systems based on chips supplied by its partner. The two companies hope to sample complete consumer and central office equipment by mid-1998.

Although several other firms are also developing HDSL2 products, there is no current market for them because no telephone companies have agreed to deploy the technology. Mr. Halim said phone companies are likely to adopt HDSL2 because of its obvious performance advantage, but not until there is an established standard and working systems available from several vendors.

Nigel Cole, VP of business development at Orckit, said an HDSL2 standard is being developed by ANSI and is likely to be finalized by mid-1998. He predicted that phone companies would begin wide deployment of HDSL2 equipment by early 1999, and that many companies would migrate to the new systems. Phone companies especially should like the second version because it eliminates the need to run a second copper cable to support HDSL service. "The last thing a telco wants to do today is deploy more copper wire in the ground," he said.

Unlike these early xDSL formats with no established market, there are some 170,000 cable modem units in operation, and about 15 percent of the North American cable infrastructure can support two-way data traffic. Rockwell says its new cable modem chips include all the key components for the consumer end of the line, and the company plans to offer chips for the central office equipment as well by next fall.

Cable modems are seen as a key competitor for high-bandwidth digital phone services in the home market, and already have a significant headstart over xDSL. Cable wires can carry data at rates up to 36M downstream and 10M upstream. "Our entry into the cable modem IC market adds another high-speed Internet access solution to Rockwell's growing family of personal communications electronics technologies," said A.C. D'Augustine, VP and general manager of the company's digital infotainment division. "The addition of an even higher speed alternative than our recently announced CDSL technology allows us to support customers' demands with as many options as possible."

Rockwell's CDSL technology is also aimed at the home user, and is said to be very similar to Nortel's 1-Meg Modem format. Their partnership is aimed at creating an interoperable middle-ground and promoting this protocol as the basis for a new standard. Ultimately they want to persuade telephone companies to implement the system. Nortel will develop equipment for telephone central offices, while Rockwell will focus on the silicon and for the consumer modem equipment. The two companies said they will probably come up with a single name for the format sometime in the future.

Like HDSL2, there is no current market for CDSL devices and no systems in operation. "We could drive the technology without much effort because the consumers are dying for higher bandwidth," said Mike Henderson, marketing director for ADSL products at Rockwell. "But the real gateway is the telcos, and how quickly they implement the system."