Level One unveiling version of DSL

Electronic News, Feb 24, 1997

Sacramento--Ready or not, another digital subscriber loop (DSL) technology is on the way. Level One Communications is now offering its own personal flavor--MDSL, or Multi-rate Digital Subscriber Loop. A derivative of HDSL (High-speed DSL), MDSL features a variable data rate, in addition to a claimed longer reach over standard copper wiring.

The company said it released into production its MDSL data pump chipset, targeted for Internet access providers, as a way to give consumers faster Internet access than current analog modems at a comparable price.

The chipset is designed for lower power consumption (500 milliwatts) that will in turn allow the design of higher-density central office DSL line cards without overheating problems. ADC Telecommunications, a long-time HDSL development partner, last week revealed the MDSL chipset is at the heart of its Soneplex central office router and Cellworx access modem.

Housed in separate PLCC packages, the chipset consists of an integrated analog front-end and a dedicated, pre-programmed digital signal processor (DSP) back-end. The 44-pin SK70720 MDSP and 28-pin SK70721 IAFE pair is available in volume quantities priced under $20.

Only Brooktree, with its $20 Zipwire (Bt8960) offers a direct merchant market competitor. The Zipwire is designed for sub-rate HDSL, up to 416 kilobits-per-second (kps), and has been shipping since the beginning of the year.

According to Will Strauss of Forward Concepts, both products hit the sweet spot of the HDSL chip market, which he estimates at $47 million this year overall, or about 554,000 units. Mr. Strauss projected the market will be close to double that by the year 2000.

In 1994, Level One developed what is considered the first three-chip HDSL data pump, as part of a consortium with ADC, Siemens and other telecom equipment vendors. But the company eventually concluded that HDSL, delivering more than a megabit-per-second, was bandwidth overkill and too expensive for most users, while ISDN, considered the low-end xDSL standard at 160 kilobits-per-second (Kps), was often not enough bandwidth for a graphics-intensive networking experience.

Attempting to fill a perceived need somewhere between HDSL and ISDN is MDSL, offering a variable data rate from 272 to 784Kps and maintaining a solid data path up to a claimed 22,000 feet at 272Kps. The current HDSL standard allows 784Kps for up to 18,000 feet.

Mr. Strauss sees HDSL as a "hot market," with MDSL targeting a particular segment--namely, Internet access.

"Very soon, we will start to see RBOCs (local telephone companies) start to become Internet service providers (ISPs), and this technology allows them to get something at a much higher rate than ISDN, and much cheaper than ISDN," he said.