RE: [10GBT-Cabling] [10GBASE-T] a channel capacity estimation program for your evaluation
This is not new to the cable people, that is the reason for Cat 7 cables
specifications (IEC 61156-6 Cat 7) and products. The individual shielded
pairs is the optimal solution.
Best Regards
Jacob Ben Ary
ben_ary@mail.aquanet.co.il
-----Original Message-----
From: owner-stds-802-3-10gbt-cabling@majordomo.ieee.org
[mailto:owner-stds-802-3-10gbt-cabling@majordomo.ieee.org] On Behalf Of
xichen@marvell.com
Sent: Thursday, February 20, 2003 12:13 AM
To: stds-802-3-10GBT-Cabling@ieee.org; stds-802-3-10GBT-Modeling@ieee.org;
stds-802-3-10gbt@ieee.org
Cc: William Jones
Subject: [10GBT-Cabling] [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
details.
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,
Xiaopeng
(See attached file: i3e.m)
"William Jones" <wjones@solarflare.com>@majordomo.ieee.org on 01/22/2003
11:18:48 PM
Sent by: owner-stds-802-3-10gbt@majordomo.ieee.org
To: <stds-802-3-10gbt@ieee.org>
cc:
Subject: RE: [10GBASE-T] channel model
Xiaopeng
How are the calculations coming? Are you using the models Chris sent out
last week?
regards
Bill
-----Original Message-----
From: William Jones
Sent: Wednesday, January 15, 2003 4:08 PM
To: stds-802-3-10gbt@ieee.org
Subject: [10GBASE-T] channel model(part 2)
Bill,
Sure. Once the common channel model (I only need the frequency domain
characteristics) is available, I can begin to work on it.
Regards,
Xiaopeng
----------
Xiaopeng
Would you be willing to sign up for technical feasibility based on an
optimal DFE calculation?
regards
Bill
-----------
Bill,
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.
Regards,
Xiaopeng
-------------
Xiaopeng
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.
regards
Bill