RE: [10GBASE-T] RE: EMI Discussion
Dan,
I agree that the Study Group could use more breadth of data, considering
that both EMI measurements I found (jones_2_0103 and powell_1_0303) have
been based on unscreened Cat5e cabling. I also agree that the Study
Group should take EMI into consideration in selecting proposals to adopt
for a first draft.
The question I have is about the best approach. Personally, I believe
that creating an objective to "meet FCC Class A requirements" is what
the Study Group needs at this point in time. That would place a burden
on the Study Group to evaluate our cable type and reach objectives
relative to EMI compliance.
Do you agree with that approach?
Thanks,
Brad
-----Original Message-----
From: DOVE,DANIEL J (HP-Roseville,ex1) [mailto:dan.dove@hp.com]
Sent: Wednesday, August 13, 2003 6:22 PM
To: Booth, Bradley; stds-802-3-10gbt@ieee.org
Subject: RE: [10GBASE-T] RE: EMI Discussion
Hi Brad,
I think the point of "enough data" is subjective and up to the Study
group
to determine.
While I have reviewed a number of the presentations via the web, I have
not
given it nearly as much study as the members of this SG, so I don't
presume
to be as qualified to make that judgement as they are. I have seen some
data
indicating areas of concern <Cobb July03,Powell May03>, and I have
reviewed
the methods and data used to generate the CFI slide as discussed in my
earlier email, and from that I believe we need more breadth in the data
to
understand what percentage of CAT-5e and CAT-6 cables will be
supportable
for EMI compliance.
A lot of the data provided at the URL you reference is focused on signal
integrity, not EMI. This is fine because there are a lot of signal
integrity
challenges to deal with. I think the priority is OK, but am suggesting
broader EMI investigation for the UTP solutions.
I won't be at the September meeting, so I was providing my
recommendation to
the SG with the hope that some are inspired to present broader based
data,
and all will evaluate that data and apply their judgement to the issue.
Regards,
Dan
> -----Original Message-----
> From: Booth, Bradley [mailto:bradley.booth@intel.com]
> Sent: Wednesday, August 13, 2003 1:24 PM
> To: stds-802-3-10gbt@ieee.org
> Subject: RE: [10GBASE-T] RE: EMI Discussion
>
>
>
> 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:
> http://www.ieee802.org/3/10GBT/public/material/
>
> 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?
>
> Thanks,
> Brad
>
> -----Original Message-----
> From: DOVE,DANIEL J (HP-Roseville,ex1) [mailto:dan.dove@hp.com]
> Sent: Wednesday, August 13, 2003 2:02 PM
> To: 'Geoff Thompson'
> Cc: stds-802-3-10gbt@ieee.org
> 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
> done
> by Bob Conte et al. It was an impressive effort and I think we are
> looking
> at something similar here.
>
> Regards,
>
> Dan
>
> > -----Original Message-----
> > From: Geoff Thompson [mailto:gthompso@nortelnetworks.com]
> > Sent: Wednesday, August 13, 2003 10:49 AM
> > To: DOVE,DANIEL J (HP-Roseville,ex1)
> > Cc: stds-802-3-10gbt@ieee.org
> > 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
> >
>