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 : Ciena (CIEN) -- Ignore unavailable to you. Want to Upgrade?

To: Maverick who wrote (1288)	2/20/1998 1:32:00 PM
From: Gary Korn	Read Replies (13) \| Respond to of 12623

Maverick, Great to see you posting on the CIEN thread. What are your thoughts on the recent stumble? Some of my thoughts: 1. Backbone demand is doubling every 3.6 months, so companies like WCOM, etc. are going to need capacity. 2. LU may have some new product, but there remains a lot of backbone demand out there, hence room for multiple suppliers (much like ATM and ASND, NN, NT etc.). 3. The financial position of CIEN is excellent. With half the shares, it has net income of almost as much per quarter as ASND (and I like ASND quite a lot). Also like ASND, it has no debt. Also like ASND, it has a lot of cash. I could go on. Anyway, your thoughts? Gary Korn

To: Maverick who wrote (1288)	2/20/1998 2:46:00 PM
From: Maverick	Respond to of 12623

WDM: NA, part VII The Role of EDFAs in Making WDM Economical The erbium-doped fiber amplifier (EDFA), as important an enabling technology as any other in current optical networks, enables direct amplification of optical signals without the use of electronic regenerators. This gain only exists in the 1550 nm region (where traditional single-mode fiber has lowest attenuation, but also has significant dispersion -- a fact that still causes significant engineering challenges in deploying high-speed and WDM systems in long spans). These optical amplifiers have come to replace most applications of the regenerators that were part and parcel of the fabric of long distance fiber networks, and now are found on many long fiber spans, typically about 120 km apart (and at the transmitters and receivers on long routes). One of the EDFA's most desirable features is the fact that it offers relatively flat gain across a quite large wavelength spread. What this means is that a single EDFA can provide gain for a nearly arbitrary number of wavelengths simultaneously, thereby replacing multiple fibers and regenerators. Thus, an EDFA used to extend the link length of a transmission path can be used for multiple signals, as long as they are each on different wavelengths. Then, with current WDM systems already supporting 16 wavelengths and heading to 32, the cost benefit from using WDM can be significant: To carry 32 OC-48 paths using OC-48 systems (without WDM) requires 32 separate fiber pairs, and 32 pairs of EDFAs at each amplifier site: typically, there is not enough fiber available to consider this approach. To carry 32 OC-48 paths using OC-192 systems (without WDM) requires eight separate fiber pairs, and eight pairs of EDFAs at each amplifier site. To carry 32 OC-48 paths using 32-wavelength WDM requires just one fiber pair and one pair of EDFAs at each site. Equivalently, to carry 32 OC-48 paths using eight wavelengths, each OC-192, again requires one fiber pair and one pair of EDFAs at each site. The result is that using WDM, either alone or in combination with a TDM upgrade, is an essential element in containing EDFA costs. Consequently, at least in long routes, WDM is easy to justify as an important ingredient of the upgrade path, either alone or in conjunction with a TDM upgrade. The cost equation for use of WDM in long distance networks is seemingly simple. This has fueled the exceptionally rapid (and relatively uniform) adoption of the technology by long distance carriers throughout North America. However, this equation is, at least as described here, sensitive to link distance, and it is not at all clear from the above analysis that WDM is a cost-effective solution in short-haul networks.