RE: [10GBASE-T] RE: EMI Discussion
The 10GBASE-T Study Group could build to Class F, but given the limited
deployment of Class F, the Study Group is evaluating Class D and Class E
cabling. Unlike in the 10BASE-T days, 802.3 has preferred minor
tweaking of the cabling specs instead of specifying cable. I know that
this information is not new to you, and the Study Group is trying to
work within the 802.3's preferred approach to cabling specifications
while having the cabling standards committees contribute to our effort.
I think the Study Group has evaluated a few areas where tweaks could be
made to Class D and Class E cabling to enhance the broad market
potential. Of course, none of that effort can occur until the PAR is
While 10BASE-T had a demand pull from the desktop market, 10GBASE-T is
not going to see that the demand pull from that market. 10GBASE-T's
primary market is the data center. There have been presentations from
various vendors as to the demand they have for this technology. The
Study Group is not trying to target the desktop market, yet it is trying
to make use of the same installation practices applied to 100BASE-TX and
From: Geoff Thompson [mailto:firstname.lastname@example.org]
Sent: Wednesday, August 13, 2003 7:11 PM
To: Booth, Bradley
Subject: RE: [10GBASE-T] RE: EMI Discussion
The point here is that since 10BASE-T we (802.3) have been dealing with
PHYs to utilize existing cabling specs. While this is not 100% true, it
largely true. There has been very little tweaking of the cabling to meet
our needs. 11801 was based largely on the technical foundation laid by
original version of TIA 568.
100BASE-TX ran on a an installed base of CAT5 (per 568 spec) that was
in place in anticipation of the broad deployment of FDDI TP-PMD.
This time we have talked about going wildly outside the bounds of the
specified behavior of the existing cabling. This is something that we
haven't done since the days of 1BASE5 & 10BASE-T when we were trying to
determine the technical feasibility of systematically running 1 & 10
Manchester encoded data over twisted pair that had been designed only
voice or, at best, ISDN.
It turned out to be 'mostly' adequate and the cabling industry had CAT3
available for new installs so that we really moved forward rather than
looked back for 10BASE-T. It should be noted that there was a huge
of demand pull for 10BASE-T from the desktop market while this was going
on. I don't see the equivalent here.
At 01:24 PM 8/13/2003 -0700, Booth, Bradley wrote:
>I know I don't have the depth of experience that Dan and Geoff have
>802, but I thought it is of interest that ISO/IEC 11801 1st edition was
>published in 1995, which was the same year as 100BASE-TX was published
>as a standard. While I agree that there is a lot of data to be
>collected, I believe that a large volume of data has been collected and
>placed on the following web site:
>What I'd like to find out from you (Dan and Geoff) is if you believe
>that all that more data needs to be gathered before the Study Group
>moves to Task Force or can this be covered if the Study Group creates
>objective to meet specific FCC compliance requirements?
>From: DOVE,DANIEL J (HP-Roseville,ex1) [mailto:email@example.com]
>Sent: Wednesday, August 13, 2003 2:02 PM
>To: 'Geoff Thompson'
>Subject: RE: [10GBASE-T] RE: EMI Discussion
>Good point of clarification.
>I was not directly involved in that effort. At the time I was working
>802.4 (rf modems,CATV,etc) but I know a number of the folks who worked
>and actually have an original copy of the massive binder full of work
>by Bob Conte et al. It was an impressive effort and I think we are
>at something similar here.
> > -----Original Message-----
> > From: Geoff Thompson [mailto:firstname.lastname@example.org]
> > Sent: Wednesday, August 13, 2003 10:49 AM
> > To: DOVE,DANIEL J (HP-Roseville,ex1)
> > Cc: email@example.com
> > Subject: RE: [10GBASE-T] RE: EMI Discussion
> > Dan-
> > At 12:03 PM 8/13/2003 -0400, DOVE,DANIEL J (HP-Roseville,ex1) wrote:
> > >In the case of 10BASE-T, where we were
> > >applying high speed (10MHz?) signals to CAT3 wiring which
> > had been installed
> > >for phone support, a *huge* quantity of testing was done to
> > verify signal
> > >integrity, EMI compatibility, and noise immunity.
> > Actually it was not CAT3, The installed base was AT&T DIW (or
> > We considered DIW as the baseline.
> > The TIA CAT3 spec was not approved until after the approval
> > of 10BASE-T.
> > Geoff