Re: [BP] Question regarding Channels
Howard,
I sent out the email on Friday stating that Tyoo would remove the
restriction of only giving the data out under NDA and the data would be
uploaded early this week. (I have to remove all of the confidentiality
statements in all of the files.) The plots of the data are available in
dambrosia_01_0904.
John
-----Original Message-----
From: Howard A. Baumer [mailto:hbaumer@broadcom.com]
Sent: Tuesday, October 05, 2004 11:28 AM
To: DAmbrosia, John F
Cc: STDS-802-3-BLADE@listserv.ieee.org
Subject: Re: [BP] Question regarding Channels
John,
Is your channel data available for download from the 802.3sp web site?
Howard
DAmbrosia, John F wrote:
> All,
>
> Since time did not allow the conversation last week, I would like to
> talk further on the reflector to understand the opposition to the
> different channels that were proposed.
>
> I will point to my test cases as a starting point, but the
> conversation really applies to all of the channels.
>
> As I see it, we have the following types of impairments in the total
> system-
>
> 1. Loss dominated
> 2. Significant stub effects that cause deep nulls
> 3. Ripple in the channel
> 4. NEXT
> 5. FEXT
> 6. Return Loss
>
> I believe most of the opposition arose from 1, 2, 3 and 6, but would
> like to have this conversation now.
>
> The comments that I heard regarding my channels were the following -
>
> * The data is not freely available. - This is no longer true,
> as I indicated last week.
> * The data violates the informative channel model. I believe
> there were different cases where this happened.
> o Case 1 had minor ripple below the mask.
> o Cases 2 and 3 were margin cases that the Signaling Ad Hoc had
> requested.
> o Case 6 came from a 22" link with top layer backplane
> connections. This channel was justified for its potential appearance
> in systems where all cost was being minimized, so counterboring was
> not assumed.
>
> o Case 7 had a resonance ripple at approximately -55dB at 11
> GHz. Once again this was a test case asked for by the Signal Ad Hoc
> to examine channel ripple. Otherwise up to 11 Ghz it is 5 to 15 dB
> above the informative mask
>
> * Return loss is too high. In my opinion, this is a
> contradictory statement. The mask that I proposed that fit my data
> was not as aggressive as Joel's channels (#1,2,3,6,7,8,14,17,18).
> All of these models violated the proposed SDD11 mask in the lower
> frequency region, which I proposed.
>
> * The data hadn't been seen. This is a partially true
> statement. Tyco has been diligent in presenting the data as quickly
> as gathered and processed. The SDD21 channel data for Cases 2, 4,5,6,
> and 7 was posted to the Signaling Ad Hoc reflector for the Sept 9 meeting.
>
> So I reviewed Joel's data that was proposed
>
> Case #1 - 4_3_4 (4000-13) Total 11"
>
> Case #2 - 7_3_7 (4000-13) Total 17" has xtalk
>
> Case #3 - 10_3_10 (4000-13) Total 23"
>
> Case #6 - 4_10_4 (4000-13) Total 18"
>
> Case #7 - 7_10_7 (4000-13) Total 24" has xtalk
>
> Case #8 - 10_10_10 (4000-13) Total 30"
>
> Case #14 - 3_3_15_7 (4000-13) Total 29"
>
> Case #17 - 7_20_7 (4000-13) Total 34" has xtalk
>
> Case #18 - 10_20_10 (4000-13) Total 40"
>
> All of these test channels are well above the channel model. We will
> still need a test case that falls very closely on the informative
> channel model, which is where the Tyco channels 1 - 3 are falling
> (with included margin cases). From both IBM and LSI's analysis these
> channels were solvable. The StatEye analysis results were much more
> pessimistic (which is an on-going problem with StatEye that is being
> investigated) than the analysis of these companies and the crosstalk
> was not applied properly.
>
> So to me it looks like overall loss isn't necessarily the big
> problem. Loss can be very advantageous, as was demonstrated at last
> week's meetings, as to how it can actually help reduce xtalk and
> return loss. Ripple and nulls on the other hand appear to be the
> bigger problem.
>
> So I would like to open up discussion as to which Tyco channels people
> were most concerned about. Also, I do not know what to propose for a
> "weighting" scheme, so any suggestions on this would be of extreme use
> in helping us to reach consensus and move forward.
>
> Cheers!
>
> John D'Ambrosia
>
> Manager, Semiconductor Relations
>
> Global CC&CE
>
> Tel 717.986.5692
>
> Fax 717.592.2470
>
> Cell 717.979.9679
>