DSL Prime: Standards Gains and Losses

While standards resolution results in redundancies at one chipmaker, an anonymous source says the next standards breakthrough is very near.

by Dave Burstein DSL Prime [June 8, 2004]

Infineon/Savan Victim of Standards War
Slews of good engineers looking for next job
Infineon's strategic decision to move to DMT for the next generation of VDSL chips made the engineering team in Israel redundant. Christoph Liedtke "Ethernet Access activities at Infineon Technologies Savan LTD. located in Netanya, Israel, were closed effective June 1, 2004. We are committed to the support of our large VDSL customer base and to further improve our product offerings. Therefore our VDSL Development will be concentrated in other existing Infineon locations to increase synergy effects. The site in Netanya will focus on the ongoing development of Ultra Wide Band technologies. This decision is related to the ongoing consolidation of the development and competence centers within Infineon's Business Group Wireline Communications and will help to further strengthen our Access business unit."

Meanwhile, DMT VDSL2 remains undefined in standards committees, with at least four conflicting proposals on the table and resolution unlikely this year. Some want very simple extensions to ADSL2+, similar to the Centillium Globespan chips already doing 40 million down for lucky Japanese. Others, led by John Cioffi, want chips optimized for DMT adaptability and DSM. A third group rejects that as too complex and delaying time to market, but wants some of the necessary performance improvement.

Ikanos (DMT) and Metalink (QAM) are soon going to ship 100 Mbps down, 30 Mbps up proprietary silicon. Francois Crepin of Metalink at Fast Net promised to demo 100 Mbps symmetric at next year's show. Those chips (well within theoretical possibilities for short loops), if they work well in the field, threaten to make the standard obsolete. Interested parties are trying to create a bandwagon around VDSL2, but in the real world carriers who can't wait three years remain ambivalent. One recently made sure to include QAM as part of the world's largest VDSL deployment, knowing the continued competition keeps prices down for all.

There's apparently also news from Paradyne's ex-Jetstream voice division, but I wanted to get firm confirmation before I published it.

On ADSL2+
What's working
This just in. "On condition of anonymity, I can tell you that 2+ is at the doorstep of reality. Anybody claiming to deliver it in volume 4 months ago is lying. Multi-chip interoperability has yet to be prime time, but chip makers are now (within the last month) delivering production builds and code loads to system vendors on both the CO and RT side. ~20Mbps is a reality over advertised loop lengths, and the chips work well in both 'old' ADSL mode and hip, new 2+ mode."

Chip vendors weren't pleased with my report last issue that ADSL2+ has few if any field results, especially testing all promised features. The article was inspired by comments from equipment makers. Before I published, I e-mailed six major chip vendors. None would tell me about real world results. Nearly all dodged questions about how 3 Meg symmetric mode, power-down, and similar promised features were faring in tests. Everyone advised pairing DSLAMs only with modems tested together if you need advanced features. Tested pairs, generally working outside the standard, have been delivering more than 20 Mbps to many users in Japan. Some comments:

From a DSLAM vendor "We began shipping our ADSL2+ DSLAM modules last month, and early field testing is consistent with what you reported."

From a chip vendor with "on-the-record" results "ADI is able to demonstrate that their ADSL2/2+ CPE chipset works well with the Broadcom CO chips in a best-selling DSLAM. Tony Zarola of ADI also has a second vendor's DSLAM in his office, which is working fine with his modem board. Based on lab data, he believes the Reach mode will extend 500K service another 2,000 feet."

From another chip vendor, who prefers to remain anonymous. "We have been ready to go on ADSL2+ since October last year. We have demonstrated interop with more than one CPE and data rates as high as 29Mbps in the labs of a major telco. It is true that some suppliers are WAY LATE with fully functional Silicon but maybe they have been eating to much BBQ...;-) The maturity is obvious at UNH." While he's putting things more positively than I did, this actually corresponds to what I reported: good lab tests, a few early successes, and little field-proven. I have since determined some limited bell field trials of the Alcatel/Broadcom are doing reasonably well.

Caution advised, therefore, but within limits. ADSL2+ is loaded with advantages.

Copyright 2004 Dave Burstein.
The DSL Prime Newsletter is reprinted with permission.

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