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