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RE: PMD discussion

  I really meant what I said.  I think the operative objective for shorter 
reach is the unwritten objective, "<100 m on multi-mode fiber."  The real 
objective, "at least 100 meters on installed MMF," is tainted by the desire 
to use the horizontal wiring standard as a guide.  I haven't found anyone 
with more than a fiber or two in the horizontal space.  Do you know of any?  
If not, then the official objective is just a wimpy statement about what 
system suppliers really want: 300-m installed base support.  By the way, 
wimpy is ok as long as we realize what it really means.

   If you read to the bottom of my email, the real question was concerning 
1550.  If we get 1550 off the list (1310 serial works for 40km; 1550 suffers 
from dispersion on "normal" fiber) then we are instantly down to four PMDs 
without even trying.

Robert Marsland
Focused Research, Inc. (a New Focus company)
555 Science Dr.
Madison, WI 53711
(608) 238 2455
(608) 238 2656 FAX

-----Original Message-----
From:   owner-stds-802-3-hssg@xxxxxxxx 
[mailto:owner-stds-802-3-hssg@xxxxxxxx] On Behalf Of Jaime Kardontchik
Sent:   Tuesday, May 30, 2000 5:12 PM
To: 'Stds-802-3-Hssg@Ieee. Org'
Subject:    Re: PMD discussion


I would say that your second unwritten objective is very well written,
if it is stated correctly:

   2) at least 100 meters on installed MMF

which makes an 850nm 4-WDM solution very desirable.

Jaime E. Kardontchik
Micro Linear
San Jose, CA 95131

Rob Marsland wrote:

> Hello,
>   I am detecting three unwritten objectives.  These appear to be swaying our
> decision making process.  The point of this email is to point out the
> unwritten objectives and see if there is consensus that these should indeed
> be swaying our decisions:
> Unwritten Objectives:
> 1) 300-m over installed 62/125 multi-mode fiber (the "real" installed base)
> 2) <100-m over multi-mode fiber (cheap computer-room interconnects)
> 3) 80 to 100km over "new" single mode fiber (dark-fiber WAN applications)
> Unwritten objective number one means we must have 1300 WWDM.
> Unwritten objective number two means we must have an 850-nm solution
> Unwritten objective number three means we must have a 1550-nm solution
> I don't know what vote it takes to delete a non-objective, but eliminating
> number 3) above would allow 1300-nm serial to serve the 2 to 40-km space and
> rid us of two PMD variants (1550 serial and WDM).  Any takers?
> Rob
> ________________________________
> Robert Marsland
> Focused Research, Inc. (a New Focus company)
> 555 Science Dr.
> Madison, WI 53711
> (608) 238 2455
> (608) 238 2656 FAX