RE: RE: Re[2]: (SSIG) Taking the winning route
Dear Hzhong:
Regards,
Edward S. Chang
NetWorth Technologies, Inc.
EChang@xxxxxxxxxxxxxxxx
Tel: (610)292-2870
Fax: (610)292-2872
The new fiber, Gigaguide, is not a magic fiber. It is the product of a
logical engineering thought -- improving the defected refractive index
profile. As a result, it will work better, but it also a possibility to run
into DMD problem as the average installed fibers.
The best approach is to let the future market decide which is the most
cost-effective product, instead of a few of us. For the time being, keep
all viable options available for users.
-----Original Message-----
From: hzhong@xxxxxxxxxxxx [mailto:hzhong@xxxxxxxxxxxx]
Sent: Thursday, April 13, 2000 2:52 PM
To: edward.chang@xxxxxxxxxxxxxxxx; NetWorthTK@xxxxxxx;
giorgio@xxxxxxxxxx; david_cunningham@xxxxxxxxxxx
Cc: rtaborek@xxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
Subject: Re:RE: Re[2]: (SSIG) Taking the winning route
Dear Ed:
Not all effective modal bandwidth is 'much higher' than 500MHZ*km and
'normal'
(FDDI ) fiber cannot carry 1Ghz*km, only gigaguide fiber can. For the
'small'
amount of fiber needs donut, there will be no benefit of 'mass production'
savings. Add WDM to that just not fun.
Hailing Zhong
Lucent Technologies
Member of Technical Staff
hzhong@xxxxxxxxxx
508-347-8654
____________________Reply Separator____________________
Subject: RE: Re[2]: (SSIG) Taking the winning route
Author: "Edward Chang" <edward.chang@xxxxxxxxxxxxxxxx>
Date: 4/13/00 2:13 PM
Dear Hailing:
The OFL bandwidth of 500 MHz-km at 1300 nm is not realistic, because laser
sources are not OFL launch. The effective bandwidth is much higher than 500
MHz-km. Furthermore, the normal 62.5 um MM fiber can provide bandwidth of
more than 1 GHz-km.
However, the DMD, caused by imperfection of the refractive index profile,
can reduce bandwidth to less than 1 GHz-km. These defected DMD fibers can
be corrected by adding a mode conditioner, off-set, or Donut type. If these
devices become a mass production product, I believe, the unit price will be
in $15 to $30 range.
Only a very small portion of the installed MM fiber may need a mode
conditioner. The users are not recommended to use it, unless needed.
Regards,
Edward S. Chang
NetWorth Technologies, Inc.
EChang@xxxxxxxxxxxxxxxx
Tel: (610)292-2870
Fax: (610)292-2872
-----Original Message-----
From: owner-stds-802-3-hssg@xxxxxxxx
[mailto:owner-stds-802-3-hssg@xxxxxxxx]On Behalf Of hzhong@xxxxxxxxxxxx
Sent: Thursday, April 13, 2000 10:50 AM
To: NetWorthTK@xxxxxxx; giorgio@xxxxxxxxxx; david_cunningham@xxxxxxxxxxx
Cc: rtaborek@xxxxxxxxxxx; stds-802-3-hssg@xxxxxxxx
Subject: Re[2]: (SSIG) Taking the winning route
Ed,
I agree that it is possible the length can go longer than the standard has
specified on 62.5um at 1300nm in many cases. However, we need to be careful
with
our assumptions. For example, are you assuming that both offset patchcord
and
WDM to be used at the same time? That is a guaranteed to be expensive and a
lots
of hassle for the field tech.
Hailing Zhong
Lucent Technologies
Member of Technical Staff
hzhong@xxxxxxxxxx
508-347-8654
____________________Reply Separator____________________
Subject: Re: (SSIG) Taking the winning route
Author: <NetWorthTK@xxxxxxx>
Date: 4/12/00 9:43 PM
Dear Giorgio:
How did you get 280 meter to make shortage of 20 meter out of 300 meter
total, then claim it is failure. I do not believe the actual optical link
design can be that simplified. The real optical link does not behave as a
step function, rather a gradual change.
The fiber distance is very complex trade off among fiber effective
bandwidth,
transmitter rise time, receiver bandwidth, bit error rate, and power.
Even the new fiber cannot guarantee without DMD problem which will change
the
performance.
Regards,
Ed Chang
<< agree with you the Gigabit Ethernet model has been proven to be robust
and I congratulate with the work that has been done.
Based on a straightforward extension of that model, a 3.125 Gb/s link at
1.3um
can go approximately 280 m on installed MMF (62.5um 500MHz km).
This is below the objective of 300 m and does not consider additional
potential impairments introduced by the WDM process.
>>