| The committee looking at this is named TP-PMD. There is at this time NO
recommendation for a standard. The committee decided at the October
meeting that it did not want to do a standard specifically for 150 ohm STP,
and so it voted to aim in the direction of a standard that would be
usable for 150 ohm STP, and 100 ohm CATEGORY 5 UTP. It was also decided
that an attempt should be made to try to include category 3 and 4
cables if possible. If it is not possible to get category 3 and 4 to
work with the category 5 scheme, then a separate approach for the lower
grade cables has not been ruled out. Also, cables other than category 3
and 4 have been discussed.
At the December meeting there was a proposal put forward to use one
coding scheme, with scrambling, for STP/cat5, and another DSP based
scheme for the category 3 cables. Other proposals also exist, but the
one mentioned crystalizes the debate. The topics will be debated at the next
meeting, and possibly the meeting after that. The committee needs to
decide whether it will do one or two standards, and then choose the
best coding schemes for each (by balancing complexity vs time vs
probability of success, etc). Don't expect any details for at least 4
months.
The targets at this time for any standard(s) are Class B EMC performance,
100 meters on STP/cat5, as much distance as possible on cat3/cat4,
error rates which are functionally as good as the error rates for the
fiber systems (i.e. > 1E-12 bit error rate), and compatibility with the
existing chipsets.
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