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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 is 
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 the 
original version of TIA 568.

100BASE-TX ran on a an installed base of CAT5 (per 568 spec) that was put 
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 Mb/s 
Manchester encoded data over twisted pair that had been designed only for 
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 amount 
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 with
>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 an
>objective to meet specific FCC compliance requirements?
>-----Original Message-----
>From: DOVE,DANIEL J (HP-Roseville,ex1) []
>Sent: Wednesday, August 13, 2003 2:02 PM
>To: 'Geoff Thompson'
>Subject: RE: [10GBASE-T] RE: EMI Discussion
>Hi Geoff,
>Good point of clarification.
>I was not directly involved in that effort. At the time I was working on
>802.4 (rf modems,CATV,etc) but I know a number of the folks who worked
>on it
>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 []
> > Sent: Wednesday, August 13, 2003 10:49 AM
> > To: DOVE,DANIEL J (HP-Roseville,ex1)
> > Cc:
> > 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 worse).
> > We considered DIW as the baseline.
> > The TIA CAT3 spec was not approved until after the approval
> > of 10BASE-T.
> >
> > Geoff
> >