Jim,
I can't tell you if this is related and I didn't look at my watch, but it seems to me it was shortly after 3:00 when Kim Maxwell said that the ANSI committee had ruled that there was not a consensus that CAP should be added as a standard. I did note that some cell phones were activated at the break.
Kim Maxwell did give a nice presentation though I found the after 4:30 discussions more interesting. To continue the CAP vs. DMT discussion, there seemed to be a consensus by the some of the ADSL players at the meeting that: Performance isn't that significant of an issue DMT has advantages, CAP has advantages.
From the briefing
DMT benefits:
32kbps rat granularity (CAP at 320kbps)
Probably works on more lines
Greater immunity to impulse noise
Spectral management tool
ANSI standard (ergo 5 silicon efforts underway)
CAP benefits:
Dominated field trials to date
Higher level of integration now
Well understood
Supported by some major players
Interoperable with QAM
Remember one thing, the ADSL forum has to remain neutral on line coding and Kim stated that several times, but I like the DMT benefits list better than the CAP benefits list ... your choice.
CAP has had most of the deployment to date approx. 9,000 of 10,000 worldwide and will continue to probably have the significant share of near term market. So CAP won't be going away real soon. But there seemed to be an indication that once the DMT design integration occurred DMT would begin moving in.
Other notable items from the presentation
Projections for ADSL modem lines = 20 million by 2000
RBOCS are gaining momemtum on ADSL.
ADSL is ideal for internet access and certainly usable for VOD at 3Mbps. At 6 Mbps for Broadcast TV, ADSL isn't the ideal choice since it ties up the entire bandwidth available and only serves one TV.
At breaks and after the meeting 4:30 - 5:30:
Bell Atlantic will not be running all ADSL modems from the CO they are planning on cost reductions through elimination of some COs and running fiber closer to the subscriber and increasing the percentage of subscriber access. Challenges that ADSL has to overcome are distance, bridge taps and subscriber wiring. The BA ADSL deployment takes care of the first two.
Five vendors are developing highly integrated DMT chips or chip sets, TI, Orckit, Motorola, ADI and ...I'll remember later. CAP supporters say it's harder to do DMT integration than it is to do rate adaptive for CAP (see below) but the DMT supporters say there are five vendors doing DMT integration ....
Right now the DMT designs are not highly integrated .... but there are no CAP modems which are rate adaptive which has become a requirement from the RBOCS. By the time CAP modems become rate adaptive and the DMT designs become highly integrated, there will only be a few months that separate them from delivery early next year. Once the DMT designs are integrated there should be no difference in cost.
What to look forward to next year.... more trials ... sales in the hundreds to thousands .... problems found in deploying in the real world .... the press will report that ADSL is unraveling ... the problems will be solved and life (ADSL) will go on.
Rumor has it that the 4 RBOCS made there decision on the vendors on 3 Sep, but aren't telling anyone.
Kim was asked about why NorTel went with QAM .... he has no idea why they are doing that.
I'll look over my notes/presentation and post again if warranted.
Hope this was useful and didn't ramble too much.
Regards,
Jim
P.S. Kim Maxwell is a co-founder of Amati and has a financial interest in Amati. |
