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[EFM] Re: [EFM-Copper] Copper questions for EFM


I decided to take a crack at this difficult problem just for the purpose of
identifying a path and not necessarily a solution.

There are two groups that they have solutions ,basically DMT and QAM camp,
that could have addressed the 10 Mbps symmetric objective. A third group may
join the fray after 10MDSL work being followed thru at T1E1.

One possible option is allow more time for real installation in the course
of the next 6 months or so. There are a lot of work that we left untouched:
i.e. noise model and disturber models for in-building network(public or
private). I think we can make progress on those issues while allowing the
temperature to cool down in the copper track.

One option is for example to request for another very high symmetrical data
rate for shorter loops for in-building applications, i.e. 25 Mbps symmetric.
(this is out of shdsl domain) I know some of you liked the idea. I arrange a
conference call and let everybody know

Another option as you said in your e-mail to spin off copper track into
another new group


----- Original Message -----
From: "Hugh Barrass" <hbarrass@xxxxxxxxx>
To: <>; <>
Sent: Sunday, March 24, 2002 10:18 AM
Subject: [EFM-Copper] Copper questions for EFM

> Fellow EFM'ers,
> Following the St. Louis meeting, we (the whole EFM TF) have some serious
questions to
> consider regarding the copper effort. Those of you who were at the meeting
will remember
> that there was much confusion over copper baselines and proposals. A
> summary:
> 1. The Raleigh compromise
> After much debate & discussion regarding seemingly incompatible goals and
objectives, we
> reached a compromise which seemed acceptable to both the "DSL-types" and
> "Ethernet-old-guard."
> 802.3ah would define a single PHY, aimed at short reach, high bandwidth
> This definition would be based on VDSL and would preserve the interface
definitions from
> T1E1.4 (alpha/beta) and ITU-T SG15/Q4 (gamma) which would enable other
standards to be
> defined in a compatible manner. These would include (but not be limited
> and the to-be-developed 10MDSL.
> As a result, we passed the copper objectives unanimously in the Task
> 2. St. Louis copper sub task force
> We spent a lot of time in the copper STF discussing what would happen
after we choose a
> baseline - particularly the choosing of a line code. As a result, there
was a lot of
> division and (though I hate to say it) ill-feeling. Despite all this, we
passed the
> baseline proposal by >80%. The rival baseline proposal was rejected by
> 3. St. Louis surprise motion
> A motion was introduced in the closing Task Force session which was not on
the agenda.
> This motion said, in essence, that we should reject the copper objectives
and baselines
> and replace them with new versions proposed. This motion got >60% support
but failed to
> win the 75% it needed to be binding.
> The fact that it got a majority (albeit slim) is a major problem for the
copper STF as
> it shows that the consensus reached in 1 & 2 above is completely invalid.
> 4. St. Louis baseline vote
> When the copper STF presented their baseline adoption to the main Task
Force the
> proposal got a majority but failed to reach the 75% needed for adoption.
This may be
> largely due to the discussion and ensuing confusion following the surprise
> The net effect is that the copper STF is without a baseline.
> ====================================================================
> So this leaves us with some questions which need to be addressed by the
Task Force to
> resolve the copper problems:
> A. What do you want the copper STF to do?
> This is the big question - do you want the copper STF to disband (meaning
that we
> resubmit the PAR for 802.3ah without a copper track)? do you want to
restate the copper
> objectives (also meaning a resubmission of the PAR to 802.3)? do you want
the copper STF
> to choose a different baseline (or to choose in a different manner) which
meets the
> agreed objectives?
> B. How can we maintain consensus from one meeting to the next?
> If we can swing from unanimous support to 60% opposition in 2 months - on
the basis of a
> surprise motion, how can we continue with any degree of confidence?
> C. When and how must these questions be answered?
> Do we need a "final resolution" in May? Can we make such a resolution in
an interim and
> expect it to hold for the Plenary?
> I look forward to any input on this subject. Feel free to send responses
to the
> reflector or to myself privately as appropriate.
> Hugh.