All,
The reflector appears
to be very quiet. I would really like to have this discussion so we can
try to move forward.
John
-----Original
Message-----
From:
owner-stds-802-3-blade@listserv.ieee.org
[mailto:owner-stds-802-3-blade@listserv.ieee.org] On Behalf Of DAmbrosia, John
F
Sent: Tuesday, October 05,
2004 10:39 AM
To:
STDS-802-3-BLADE@listserv.ieee.org
Subject: [BP] Question regarding
Channels
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