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: Bernard Levy who wrote (5450)	10/4/1999 8:21:00 PM
From: Frank A. Coluccio	Read Replies (2) \| Respond to of 12823

Bernard, thank you for that excellent but much too brief tutorial. The Times article I referenced earlier had the Russians working on an acoustic variant: piezo-like excitation of a treated carbon medium that could theoretically carry very high bit rates over long distances. A part of which, you've corroborated here: " These waves also exist in all media (I saw an acoustic demonstration), but they are not solitons, since they require a linear medium." What stuck out in my mind was the otherwise unlikely consideration for acoustic waves ever substituting for e-m, electron or photon flows. --- I, too, have come across numerous references to the planned use of solitons in future long haul submarine systems. Here's some additional information from Pioneer Consulting's report of last year which addresses such a use: pioneerconsulting.com "The table below lists the submarine systems planned with WDM technology. Pioneer Consulting predicts that 80% of the long-haul systems installed between 1997 and 2002 will employ WDM technology, while 35% of short-haul and repeaterless links will employ the technology. As the submarine market develops past 2002, long-haul systems will be using combinations of WDM and soliton technology to achieve bit rates over 100 Gbps. Short haul systems will more closely resemble domestic long distance networks, using a mixture of high speed SDH [SONET] technology to achieve 10 Gbps throughput over high-fiber-count cables and WDM technology to integrate long-haul submarine systems into domestic networks through dedicated wavelength routing and switching." The table which followed this snip was useful, btw. --- Regards, Frank Coluccio

To: Bernard Levy who wrote (5450)	10/5/1999 2:10:00 PM
From: Geof Hollingsworth	Read Replies (2) \| Respond to of 12823

Hi Bernard-further on Solitons A factoid which I know you are well aware but others may find of interest is that Solitons (like Bragg gratings) are not a new idea at all-they were first documented in 1834 by Scottish engineer John Scott Russell. Russell observed the Soliton wave phenomena in the water while studying the movement of canal boats. As you say, it is only since the development of EDFAs that there has been a commercial application for the technology. The Soliton applications I find of most interest are for high bit rate (OC 192) DWDM systems, where the traditional non-return to zero (NRZ) encoding for each wavelength starts to run out of gas because of the fiber non-linearity distortions and the intermodulation between the DWDM channels themselves (four-wave mixing). Soliton modulation takes advantage of fiber non-linearities potentially resulting in longer transmission distances, the elimination of some of the electrical equipment in the network, and higher power (Soliton return-to-zero pulses have higher peak power than NRZ pulses). In addition to Lucent, I know that Pirelli is working on this, and I understand that both Qtera and Algety are basing their products around applications of Soliton technology.