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[10GBASE-T] a channel capacity estimation program for your evaluation

Hi, Bill and 10GBASE-T SG members,

Sorry for the so late response.  I was on a quite long vacation past
several week.

I have finished a Matlab program to distribute in the 10GBase-T SG for the
evaluation of the bottomline channel performance.  The channel simulation
is based on the models (return loss, FEXT, NEXT, insertion loss) provided
by Chris and a presentation (Alien NEXT) last Novermber.  Without
consideration of any implementation and modulation/coding, the Shannon
channel capacity can be calculated only based on the frequency-domain
channel model.   Please read the comments in the program for details

Unfortunately, based on the available channel models, even with a quite
optimistic belief in the achievable DSP power, the Shannon capacity tells
me that both CAT-5E and CAT-6 cables cannot support 10Gbps throughtput over
a distance of 100 meters.  Please read the comments in the program for

Surely, the calculation is completely based on the available channel
models.  I know more work is needed on setting up a channel model accepted
by all of us.  But unless some dramatic improvement can be achieved in the
alien NEXT suppression, the program tells us pretty much the story.

If you have any question about the program itself, you are more than
welcome to post on the group reflector for discussion.

Best regards,


(See attached file: i3e.m)

"William Jones" <> on 01/22/2003
11:18:48 PM

Sent by:

To:    <>

Subject:    RE: [10GBASE-T] channel model


How are the calculations coming?  Are you using the models Chris sent out
last week?


-----Original Message-----
From: William Jones
Sent: Wednesday, January 15, 2003 4:08 PM
Subject: [10GBASE-T] channel model(part 2)


Sure.  Once the common channel model (I only need the frequency domain
characteristics) is available, I can begin to work on it.



Would you be willing to sign up for technical feasibility based on an
optimal DFE calculation?



I has no problem to use TIA or ISO based channel and noise model once it is
standardized.  My point is that even using the frequency-domain model we
can still give a quite good estimation of the practically achievable
distance at a throughtput of 10Gbps over CAT-5E or CAT-6 cables.




We believe, as George discussed in his part of the tutorial in Kauai, that
with an adequate amount of crosstalk cancellation, the throughput is
achievable.  The question then becomes can this level of cancellation be
practically achieved, hence, my interest in time domain models.

Until we get the models from the channel modeling Ad Hoc, we could argue
this point endlessly.  Until then, I still believe we should not use DSL
models, but, rather something from TIA 568b or ISO 11801.