Re: [10GBT-Modeling] RE: [10GBT-Cabling] [10GBASE-T] a channel capacity estim...
Albert's observation that the NEXT limit does not fit the envelope of the
measurement data must be
addressed. We need to establish limit(s) > 250 MHz . The measurement data
test plan request I sent
to the cabling ad hoc reflector was designed to solicit measurement data to
use as the basis of establishing
the worst case limits > 250 MHz.
Selection of the "best fit" measurement data for modeling will fall-out of
the measurement data used to
establish the limits.
In a message dated 2/21/03 10:59:17 PM Eastern Standard Time,
As, I did not participate in the process, I can only offer my
My understanding of Chris's mail is that the ref. channel for
1000BASE-T was selected out of measured data such, that it would
result in a best "parallel" fit wrt imposed by the std limit. Then,
it was scaled down to represent the WC. (We can always ask Chris
for more clarification.)
The situation with NEXT and FEXT is much different because of the
comb like nature. The envelop has to be drawn with a considerable
margin to guarantee the spec "pass" in the frequency domain. Again,
we can ask our cable group for clarification.