Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [10GBT] Question about previous analysis of codes and undetected errors.



George,

I'm traveling a lot and will have limited access to e-mail and voicemail for
the next two weeks as well. I did get a very garbled voice mail on my cell
last week, but I thought it sounded like someone who wanted a job...

George, not only did 1000BASE-T use extremely robust SSD/ESD and control
coding, it also had 100+ detectable, illegal codes out of the 625 4D codes
during data mode. In any case, I would need to rework the 1000BASE-T
analysis from the 100BASE-T2 presentation (does anyone have a copy?), if you
think that's educational.

I'd also be happy to analyze the 12D PAM12 proposal on the table for the
undetected frame error rate requirement and make a presentation at the
November plenary, as there appears to be sufficient interest.

Regards,
Sailesh.
srao@phyten.com

>From: George Zimmerman <gzimmerman@SOLARFLARE.COM>
>Reply-To: George Zimmerman <gzimmerman@SOLARFLARE.COM>
>To: STDS-802-3-10GBT@LISTSERV.IEEE.ORG
>Subject: Re: [10GBT] Question about previous analysis of codes and
>undetected errors.
>Date: Tue, 12 Oct 2004 11:47:43 -0700
>
>Sailesh -
>Can you summarize the analysis that led you to determine that the
>undetected frame error rate for 1000BASE-T would be so much better than
>T2?  How did you account for the multiple errors coming out of the
>Viterbi decoder.
>
>A major component of most undetected error analyses referenced to date
>relies on looking at the independent error probabilities of individual
>bits and therefore taking the 4th power of the BER to get beyond the CRC
>distance for data bits.  While 1000BASE-T takes extra pains to protect
>the control symbols, data symbols would appear to be governed by the BER
>and independence mathematics.  With coded systems, such as 1000BASE-T,
>as you know, we get error bursts, so multiple bit errors in a frame are
>not independent.  As such, at a first level, it is difficult to see how
>the coded 1000BASE-T would have to be "several orders of magnitude"
>better than a similar uncoded system with essentially the same line
>coding for undetected error rates.
>
>This is of course very important to us in 10GBASE-T, because we are
>using a very powerful code, and there are no good references (that I've
>been able to find) for predicting the undetected error rate of these
>codes.  Simulation is impractical, and even very small undetected error
>rates (well beyond what is simulatable) would swamp anything from the
>constellation or mapping.
>
>This is the issue I'd left you a voicemail on a few days ago to discuss.
>
>-george
>
>-----Original Message-----
>From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
>Behalf Of Pat Thaler
>Sent: Tuesday, October 12, 2004 10:06 AM
>To: STDS-802-3-10GBT@listserv.ieee.org
>Subject: Re: [10GBT] Question about previous analysis of codes and
>undetected errors.
>
>Does anyone have this presentation? The 100BASE-T work falls before the
>archives on the IEEE 802.3 site.
>
>-----Original Message-----
>From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG]On
>Behalf Of sailesh rao
>Sent: Tuesday, 12 October, 2004 7:18 AM
>To: STDS-802-3-10GBT@listserv.ieee.org
>Subject: Re: [10GBT] Question about previous analysis of codes and
>undetected errors.
>
>
>Pat,
>
>The 1000BASE-T signaling was essentially derived from 100BASE-T2. In
>802.3ab, a group of us got together and determined that the undetected
>frame
>error rate for 1000BASE-T was orders of magnitude lower than that for
>100BASE-T2, and thus met the requirement for Ethernet.
>
>The undetected frame error rate analysis for 100BASE-T2 was presented to
>802.3y by John Creigh, then of IBM.
>
>Regards,
>Sailesh.
>srao@phyten.com
>
> >From: Pat Thaler <pat_thaler@AGILENT.COM>
> >Reply-To: pat_thaler@AGILENT.COM
> >To: STDS-802-3-10GBT@listserv.ieee.org
> >Subject: Re: [10GBT] Question about previous analysis of codes and
> >undetected errors.
> >Date: Mon, 11 Oct 2004 10:36:18 -0600
> >
> >I believe that there was, but I didn't follow 1000BASE-T as closely so
>it
> >would take time for me to find the relevant presentations. For 802.3ae,
>I
> >recalled who the presenter and I knew approximately which meeting
>archives
> >to look at which speeded the search a lot. It would be helpful if
>someone
> >else can provide the references to the 1000BASE-T error analysis.
> >
> >Regards,
> >Pat
> >
> >-----Original Message-----
> >From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG]On
>Behalf
> >Of Jose Tellado
> >Sent: Thursday, 07 October, 2004 3:40 PM
> >To: STDS-802-3-10GBT@listserv.ieee.org
> >Subject: Re: [10GBT] Question about previous analysis of codes and
> >undetected errors.
> >
> >
> >Thanks Pat,
> >
> >This material is very relevant for understanding undetected error rate
>for
> >802.3ae and will aid in our 802.3an analysis.
> >Is there a similar analysis for the 1000Base-T project?
> >
> >Regards,
> >Jose
> >
> >   _____
> >
> >From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On
> >Behalf Of Pat Thaler
> >Sent: Thursday, September 30, 2004 8:33 AM
> >To: STDS-802-3-10GBT@listserv.ieee.org
> >Subject: [10GBT] Question about previous analysis of codes and
>undetected
> >errors.
> >
> >
> >Hugh and I were asked for references showing how undetected error rate
>was
> >analyzed in previous 802.3 projects. Here is some of the material for
>the
> >64b/66b code in IEEE p802.3ae.
> >
> >For 64b/66b, one analysis of the scrambler non-effect on CRC error
> >detection can be found in:
> >http://ieee802.org/3/10G_study/public/jan00/walker_1_0100.pdf
> >
> >This presentation estimates mean time to false packet acceptance:
> >http://ieee802.org/3/ae/public/mar00/walker_1_0300.pdf
> >
> >This presentation discusses how the sync state and BER monitor machines
> >react to drop sync when BER is high:
> >http://ieee802.org/3/ae/public/jul00/walker_1_0700.pdf
> >
> >Regards,
> >Pat  <http://ieee802.org/3/ae/public/may00/walker_1_0500.pdf>
> >
>
>_________________________________________________________________
>Don't just search. Find. Check out the new MSN Search!
>http://search.msn.click-url.com/go/onm00200636ave/direct/01/

_________________________________________________________________
FREE pop-up blocking with the new MSN Toolbar  get it now!
http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/