Re: [10GBT] Channel models

[Valerie Rybinski <Valerie_Rybinski@SIEMON.COM>]

Sanjay:

FEXT measurements between two pairs are symmetrical regardless of which pair is the transmit (disturbing) pair and which pair is the receiving (disturbed) pair.  ELFEXT calculations can be slightly different due to attenuation/insertion loss variances between the cable or cabling pairs.

Hope this helps.  - Val

Sanjay Kasturia <SKasturia@TERANETICS.COM> Sent by: stds-802-3-10gbt@IEEE.ORG 05/12/2004 04:38 PM Please respond to "IEEE P802.3an"

To:        STDS-802-3-10GBT@listserv.ieee.org         cc:                 Subject:        Re: [10GBT] Channel models

Bryan,

Good question. I assumed that FEXT between pair i and j would be the
same as between j and i. Thinking about it some more, I am not sure if
that is correct. Can others let us know what measurements have revealed?


Chris DiMinico, can you answer this?


Sanjay

sanjay@teranetics.com
cell (650) 704-7686
office (408) 653-2235

-----Original Message-----
From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
Behalf Of Sparrowhawk, Bryan
Sent: Wednesday, May 12, 2004 4:19 PM
To: STDS-802-3-10GBT@listserv.ieee.org
Subject: Re: [10GBT] Channel models

Sanjay,
I have a question about your terminology regarding far end crosstalk in
"c)".
Could you have meant twelve pair combinations for FEXT instead of 6?
Or do you speak of "Far end crosstalk" as others speak of 'reverse
NEXT'?
Bryan S.

-----Original Message-----
From: Sanjay Kasturia [mailto:SKasturia@TERANETICS.COM]
Sent: Friday, April 09, 2004 3:36 PM
To: STDS-802-3-10GBT@listserv.ieee.org
Subject: [10GBT] Channel models

We have four channel models defined from the March 2004 plenary meeting.


For detailed PHY performance simulations, we will need sample channel
data that complies with these models.

We will greatly appreciate it if any task force participants can provide
full matrix (4x4) channel data. This would ideally include:
a) Insertion loss data on each of four pairs - real and imaginary
b) Near end crosstalk coupling (6 unique pair-combinations) - real and
imaginary
c) Far end crosstalk coupling (6 unique pair-combinations) - real and
imaginary
d) Four unique echo transfer functions (one for each pair) - real and
imaginary

This can be obtained by measurements on actual cable and then scaling to
meet the specified channel models.
Any cable companies volunteering to provide this data?

There is some data from the cabling Ad-hoc available on:
http://www.ieee802.org/3/an/public/material/index.html
This data has some of the items listed above but not all. It does,
however, provide enough to get some sense of performance.

Sanjay Kasturia

sanjay@teranetics.com
cell (650) 704-7686
office (408) 653-2235