RE: From serial PMD call 5 June
The minutes below represent the ideas very clearly, and I agree with the
differences in probability distribution. For DDJ, this is especially
true for the randomized data that results from scrambling. So, I agree
that testing with SJ will enforce some margin.
In FC, SJ above the corner frequency was intended to represent "other"
jitter that may occur in a real system that would not be seen in a
compliance test. So, what quantity of other jitter we expect to occur?
I'm not quite ready to think this is 0.
These 2 points tend to contradict. Do they perfectly offset (per
Anthony's proposal)? Obviously a supplier would rather not have to test
with "other" jitter, but a system customer may be glad to have it there.
Tom
-----Original Message-----
From: DAWE,PIERS (A-England,ex1) [mailto:piers_dawe@xxxxxxxxxxx]
Sent: Friday, June 08, 2001 6:02 AM
To: '802.3ae Serial'
Subject: From serial PMD call 5 June
Jitter spec numbers
-------------------
Opinion on the call was that:
0.35 UI of DJ was too much; nearer 0.3 UI would be fairer
0.015 UI of sigma_RJ was too little; 0.016 suggested
The extra 0.05 UI of sinusoidal jitter in the stressed sensitivity test
was
a significant burden.
Some believed that our draft jitter requirements are more demanding than
SONET.
Anthony Sanders suggested that the stressed eye should contain the
sinusoidal jitter as a component of the deterministic jitter, rather
than in
addition to it. SJ is more stressful than "regular" DJ as its
probability
distribution is concentrated towards the extremes. As these minutes may
not
represent the ideas correctly, Anthony would put some slides on the
reflector for discussion. Also Ali Ghiasi may be able to offer some
information on CDR requirements (how many UI of eye opening needed).
Next Draft
----------
Is expected 11 June.
Piers