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RE: Why wrong LINE rate could cost dear


I agree with your position, especially your concluding statement.  Also, if
you allow the GaAs Industry the opportunity to compete with other
technologies in the same space (specification-wise), you will find we are
very cost-effective.  We need to hear more from the optics vendors on this
topic, and I suspect we will!

At 08:47 PM 6/28/99 -0700, Perkins, Drew wrote:
>It seems to me that we're drawing to a conclusion something like the
>Semiconductor technology is continuing to follow Moore's Law. That suggests
>that the next generation of silicon will support something in the
>neighborhood of 2.5 - 3.125 Gb/s since the current generation supports 1.25
>Gb/s. Some day, however, another generation (maybe the next) will support
>something in the neighborhood of 10 Gb/s. This may be using SiGe instead of
>Si. So, we should plan for two or more generations to occur: 2.5 - 3.125
>(G1) and 10 Gb/s (G2). Of course GaAs supports 10 Gb/s today, but is seen as
>being more expensive than Si or SiGe. So we probably want to specify a
>serial version of 10 Gb/s immediately as well, but we should expect that we
>may have to revise it when G2 becomes available.
>G1: For Generation 1, we will want to use a non-serial protocol
>implementation that leverages G1 silicon. This may be WWDM/CWDM/etc. and/or
>MAS. We may also need to do this because of fiber impairments that don't
>allow 10 Gb/s serial anyway. For G1, we may want to specify multiple
>standards, just like Gigabit Ethernet did. We may want equivalents of SX and
>LX. In fact, perhaps these two standards were well enough matched to market
>demands that we should copy the requirements and try to meet them. Also,
>these standards may have not set a good set of expectations that the market
>will force us to meet. I would propose that we take these two as baseline
>goals. I.e. let's use the same fiber types and lengths as our goals and try
>to work with them. This probably implies that we want an SX-like solution
>that uses 850 nm VCSELs, and an LX-like solution that uses 1310 nm FP
>G2: For Generation 2, we will want to use a serial protocol implementation
>that leverages G2 semiconductors on fiber that supports it. In fact, we
>probably want to specify and standardize a 10 Gb/s solution immediately as
>well for use with GaAs technology.
>Ciena Corporation                 Email: ddp@xxxxxxxxxxxx
>Core Switching Division                 Tel: 408-865-6202
>10201 Bubb Road                         Fax: 408-865-6291
>Cupertino, CA 95014              Cell/Pager: 408-829-8298
>-----Original Message-----
>From: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
>[mailto:owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx]On Behalf Of
>Sent: Monday, June 28, 1999 5:46 PM
>To: piers_dawe@xxxxxx; stds-802-3-hssg-speed@xxxxxxxx;
>Subject: Re: Why wrong LINE rate could cost dear
>In a message dated 6/28/99 2:41:48 PM Eastern Daylight Time, 
>piers_dawe@xxxxxx writes:
>> Why wrong LINE rate could cost dear
>>  1.	Cost JUMPS as bit rate goes up.
>>  Faster IC technologies, more heat, possibly substantial extra complexity
>>  around the optoelectronics.
>>  Lasers don't follow Moore's Law.
>>  Unlike transistors, there is no virtuous circle of smaller -> faster and
>>  cheaper -> better.  The guts of a laser are sized for the wavelength. 
>>  Laser speed has increased slowly and unevenly, but until now, they were
>>  fast enough (for 2.5 Gbit/s line rate).  Optical modulator type
>>  transmitters as used in OC-192 are very expensive.
>>  Picking a line rate that's faster than the state of the art will delay
>>  product availability and cause extra costs into the future (25% to 150%
>>  more? make your own guess).
>>  2.	Standards are good.
>>  Line clock ICs take time and money to design.  Other parts
>>  (multiplexers, receivers, whatever) may be in the market now for ~9.95
>>  Gbit/s, a very few at OC-192+FEC rates, none for 12.5 Gbit/s.  Analog
>>  parts are rarely right first time, respins add to the delays...
>>  Picking a non-standard line rate could cause delay and further fragment
>>  the market for parts which we believe are currently too expensive but
>>  where volumes are driving costs down.
>>  So, I believe that raising the line rate of optical transmitters
>>  four-fold is a worthwhile achievement, and then we attach ourselves to
>>  the nearest standard, the OC-192 line rate of 9.95328 Gbit/s.  Raising
>>  the line rate of optical transmitters five-fold, out ahead of the state
>>  of a slow-moving art and away from any standard, will cost money and
>>  delay and needs very good justification.  There's an obvious direct hit
>>  on link length too (dispersion limited) but what I'm talking about is
>>  more severe than that.
>>  Can we get back the difference between what's desired and what's
>>  affordable by looking at line codes, interframe gap or what?  Maybe
>>  settle for 95% of what we would like and get a good-enough job done on
>>  time and affordably?
>>  "Keep it simple, follow standards, keep it cheap."
>>  Piers Dawe
>>  -- 
>To all:
>I heartily agree with Piers'  recommendation!
>As a receiver manufacturer looking for better 10g amplifier solutions,
>it becomes clear very quickly that good IC's for anything above 10g
>are simply not readily available, while 10g components are receiving
>considerable attention from several suppliers, and are in fact providing 
>acceptable sensitivity performance at both 850 and 1310nm.
>Although the needs for FEC will be addressed by speciality products,
>this certainly will not be the main stream, and also will not reach the cost
>structure necessary for a viable product on the anticipated timeline.
>The most elegant, cost-effective, and especially, timely solution will 
>exploit those components that are already being developed for related 
>applications (OC-192).
>Common sense is a good thing.
>Janis Valdmanis
>Picometrix Inc.
>(734) 998-4502

Fred Weniger
Product Marketing Manager, Gigabit Products
Vitesse Semiconductor Corporation
741 Calle Plano, Camarillo, CA 93012
Phone: 805-388-7571   Fax: 805-987-5896
E-mail: weniger@xxxxxxxxxxx