The High-Bandwidth SDH optical networks are yet to fulfill their potential.
Before the big "fall" of the optical networking market, there was a big rush to develop faster and denser optical connection (10Gb/s & 40Gb/s and using WDM and DWDM). This was driven by the ever "dreaming" public and investers but the reality was much different:
Buisness - wise:
a) 70% of the intalled fibers were DARK - meaning no optical trafic went trough.
b) Most of the "Light" through the fibers was monochromatic (why invest in WDM optical components if the 2.5Gb/s is enough).
c) The fall of Napstar - reduced the internet trafic by arround 40% the same day.... the same happens when Kazaa is dropping in use.
d) No "Killer Application" - there is not yet an aopplication that will require a major increas in Traffic.
e) The higher bandwidth connections are the "Back-Bone" while there FTTH is just now beeing installed - in the US. There is a relationship between the two - the correct development of bandwidth is in pyramid form!
Technical Consideration:
a) COST: 2.5Gb/s is proven technology - and mature - therefore cost less! - Much less
b) The higher bandwidth you install - the shorter Span is possible (span - distance between repeater/base stations). While 2.5Gb/s can go 200Km - easily higher very possible - 10Gb/s can go 80Km - but it will cost you.. more is possible - but it is extreem technology (if you want I can elaborate), 40Gb/s is normative for ~40km...
c) Higher Bit-rate - less dense is the WDM.... and more nonlinear optical distortion (SPM, Four-wave-Mixing, PMD ets...)
Considering all these options - the BIG PUSH - toward 10Gb and 40Gb - was ahead of its time, companies spent too much money expecting - "short term investment return" and actually it was a "long term investment" - drove many "knolage centers" to dissolve. That worked against the correct development speed - and actually slowed the progress.
It should say the optical IC design is almost dying.Most large companies has cancelled their design projects just because of the boasting of the market demands.And as said before by Shutterman,now the 2.5G IC is more than enough for the current market.Even,many small companies even sell only for 622Mbps(OC-12) for good profits because they are in great need of.
The socalled 40Gbps is still far ahead of the real demands.Unless the VOD is the real market trends, like HDTV or other online video games,the product will be in the expreimental stage.
All of the products are depend on the MARKET!! No market,no money!! In brief,10m/100mb is enough for most people,so the "Gigabits" network is dispensable.
By the way,if you want to replace "cable" with "optical",there are so many stuffs necessary to be changed...But my reserch topic is about CDR...haha
That's narror definition, CDRs are extensively applied in many area,especially Receiver....etc