Re: 1000BASE-T PCS question
- To: David Martin <dwmartin@xxxxxxxxxxxxxxxxxx>
- Subject: Re: 1000BASE-T PCS question
- From: Rich Taborek <rtaborek@xxxxxxxxxxxxxxxx>
- Date: Thu, 27 May 1999 15:23:20 -0700
- CC: HSSG_reflector <stds-802-3-hssg@xxxxxxxx>, "Sachs,Marty" <sachs@xxxxxxxxxxxxxx>, "Widmer,Albert_X" <"widmer@xxxxxxxxxx widmer@xxxxxxxxxx widmer"@us.ibm.com>
- Organization: Transcendata, Inc.
- References: <C7919D8389D9D111A3930000F80824AE0231F9DD@xxxxxxxxxxxxxxxxxxxxxx>
- Reply-To: rtaborek@xxxxxxxxxxxxxxxx
- Sender: owner-stds-802-3-hssg@xxxxxxxxxxxxxxxxxx
Do you know of any research or other proofs in this area? You say that
lower speed SONET links regularly achieves BERs of < 10 E-15. I have
substantial experience with mainframe serial links such as ESCON(tm)
where the effective system BERs are in the same ballpark. SONET uses
scrambling with long term DC balance and ESCON uses 8B/10B with short
term DC balance. The following questions come to mind:
- How important is DC balance?
- How does this importance scale in going to 10 Gbps?
I'll see if I can get some 8B/10B experts to chime in here if you can
get scrambling experts to bear down on the same problem.
>The point here is that the SONET scrambler is not the limiting issue in
>achieving low error rates. The issue is having enough photons/bit, or
>optical SNR (eye-Q) to accurately recover the data.
>David W. Martin
>+1 613 765-2901
>+1 613 763-2388 (fax)