[802.3ae_Serial] Summary of my 3-12-02 Presentation in St. Louis
Hi Jeff,
Here is the ~ 200 word summary of my presentation last week for inclusion in
the minutes:
The TDP measurement method and results of the 10 Gb/s Optical Test-Fest held
in Santa Rosa
Stretch Camnitz
Agilent Test and Measurement
Late last year, it was discovered that intrinsic jitter in the existing BER
test equipment was making it very difficult for known "good" 10 Gb TX DUTs
to pass the bathtub jitter requirement. An alternative approach for
screening jitter was proposed at the January Raleigh meeting, based on the
increase in power (sensitivity penalty) required to achieve the 1E-12 BER in
a reference receiver. This technique, known as Transmitter and Dispersion
Penalty (TDP), conventionally tests for vertical (or amplitude) eye closure
in the transmitter signal. In order to screen for jitter, the BER value is
measured at two sampling points: +- 0.1 UI from the eye center. The
relationship of this measurement to the jitter bathtub curve can be
conceptually understood be noting that the penalty rises dramatically if the
sampling point approaches the sloping wall of the bathtub curve.
Another proposal made in Raleigh was a "simplified" stressed eye generator
which replaced the random jitter component with an additive amplitude
interference stress. This substitution makes the level of stress easier to
optimize, and reduces "sigma" ("RJ") jitter, more closely reflecting the
jitter observed in direct modulated laser devices.
A "contract" between the transmitters and receivers in the system, formerly
defined by the jitter bathtub curves, can now be defined by the sensitivity
penalty.
A testfest was held at the February Santa Rosa meeting. Agilent T&M set up a
test system with the stressed eye, bathtub, and TDP measurements. Section 52
participants brought devices for testing. The testing showed that the TDP
measurement and the stressed eye methodology are workable, though the level
of stress and precise measurement parameters were in need of adjustment.
-----Original Message-----
From: Jeffrey Warren [mailto:jwarren@extremenetworks.com]
Sent: Tuesday, March 12, 2002 1:01 PM
To: 'stretch_camnitz@agilent.com'
Subject: Summary of your 3-12-02 Presentation
Stretch,
In the past (last 2+ years) I've made this request to approx six (6)
presentors. Since this subject of "New Optical Test Methods" is so important
and is very complex to those of us that are not optical experts I have the
following request. Please summarize your presentation for direct inclusion
into the IEEE802.3ae March 2002 plenary meeting minutes. This summary should
be 200 words or less, capturing the main discussion points and proposed
modifications to Clasue 52, etc. Please reply back with this summary text
prior to end of next week (or sooner if possible), this is when I plan to
post the 10GE minutes to the IEEE 802.3ae Web Site.
- Jeff IEEE802.3ae Secretary