Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : LAST MILE TECHNOLOGIES - Let's Discuss Them Here -- Ignore unavailable to you. Want to Upgrade?

To: Raymond Duray who wrote (7656)	7/16/2000 9:12:46 PM
From: ftth	Respond to of 12823

Hi Ray, re:I seem to recall that there was some discussion of the V.90 modem protocol violating "Shannon's Law" I think someone didn't understand the V.90 downstream, and how it differs from V.34 and earlier modems. The same conditions for capacity calculations don't exist in V.90 vs. V.34 or lower, so the roughly 35kbps limit doesn't apply to V.90 downstream. Even V.90 doesn't reach it's theoretical maximum. I think 3com had a pretty good, and fairly short paper about this. I'll see if I can find it later.

To: Raymond Duray who wrote (7656)	7/16/2000 9:15:30 PM
From: Frank A. Coluccio	Respond to of 12823

Ray, if I may, an aside that speaks to the V.90 matter in case anyone is left wondering why Shannon didn't apply. When V.90 appeared on the radar the general knee-jerk perception was that it would be limited to the confines of a standard ~4000 Hz common carrier channel, i.e., using channel units that modulated and demodulated, through one scheme or another, signals within the limits of d.c. (or ~ 300 Hz) through ~ 4000 Hz. And of course, in that case the Shannon argument would most likely have applied: "I seem to recall that there was some discussion of the V.90 modem protocol violating "Shannon's Law" at the time that it was being initially investigated." But the higher speeds attained over V.90 depend its ability to transmit bipolar digital data in the downstream direction (as opposed to ordinary analog modem tones that have been modulated by QAM, say) directly onto copper facilities, not the standard carrier grade 4000 Hz channels. The copper facilities bandwidth, in the absence of load coils, is rated in the multi-Megahertz range, translating to Mb/s. For this reason 56 k is feasible for V.90, just as it was for 1.544 Mb/s T1 carrier over metallic spans, and DDS circuits over metallic loops, before it. FWIW. FAC

To: Raymond Duray who wrote (7656)	7/17/2000 2:55:50 PM
From: Bernard Levy	Read Replies (1) \| Respond to of 12823

re. NVEI, I recall they claimed to be using soliton technology. Yet, references to solitons have disappeared from recent press releases, which is probably wise given that a literature search could not turn up any reference to soliton propagation on copper wires. It is also worth noting that the first PR claimed experimental results showing 50Mbps transmission to 3.5kft. Subsequent PRs indicated they planned to go to 8.5kft by September and 15kft by next year. My rating of NVEI is a strong sell.

To: Raymond Duray who wrote (7656)	7/17/2000 8:14:24 PM
From: Bill Pearson	Read Replies (1) \| Respond to of 12823

Ray – Unfortunately, you seem to present one face in your private messages (admittedly a more pleasant face), and another in the public forum. I've been sincere and have behaved fairly with everyone on this board, but enough is enough. The "POS" reference puts an end to my attempt to share what the "public" facts do not at this time accurately depict. Thanks to those who have corresponded with me privately. Your kind words and efforts are appreciated. Fortunately, skepticism and cynicism will not effect the validity of the hard science behind the NVEI tech. The bar just keeps getting raised higher and higher.