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Re: [10GBT-Modeling] RE: [10GBT-Cabling] [10GBASE-T] a channel capacity esti...

I've asked Brad to post a paper I presented at the International Wire and 
Cable Symposium in regards to the
development of equal level far-end crosstalk (ELFEXT) and return loss 
specifications for Gigabit Ethernet 
operation on category 5 copper. It will address some of the background 
questions and provide 
some insight into the development of the cabling parameters and limits 
specified in 1000BASE-T.  

As I mentioned earlier, the measured cabling models were generated by Bob 
Cambell and I. They are illustrated in the 
1000BASE-T tutorial presentation (3/97) titled Category 5 Cabling Models For 
Line Code Simulations. 

A significant amount of effort went into the evaluation and specification of 
cabling for 1000BASE-T 
operation. It is true that many of the individuals involved with the line 
code development did not participate
in the cabling specification development.  


Chris DiMinico
MC Communications

In a message dated 2/27/03 4:59:51 PM Eastern Standard Time, writes:

<< Vivek,
 I believe the 100MHz came from the TIA  specifications. In fact, in the 
early days I remember checking the channel capacity over the 100MHz Bandwidth 
(for sanity check) on my own and realized that there is a nice healthy 
capacity margin above 1Gbps, therefore no need to even bring up the issue.
      Vivek Telang wrote:
 > Bill,
 > Sreen is right. The simulations for 1000BASE-T all used Cat5 modeling 
data. The only exception was that for FEXT, we used models provided by Chris, 
and the other cable guys. These FEXT specs were later ratified in the Cat5e 
spec. Also, the simulations used data that was specified out to 100MHz. I 
don't quite remember if the "official" Cat5 standard supported this, or 
whether the 100MHz data also came from Chris et al.
 > Vivek >>