From owner-stds-802-3-hssg@ieee.org Wed Mar 1 17:46 GMT 2000 Received: from gatekeeper.pdd.3com.com (gatekeeper [161.71.169.3]) by isolan.pdd.3com.com (8.9.1b+Sun/8.9.3) with ESMTP id RAA16484; Wed, 1 Mar 2000 17:46:34 GMT Received: from ruebert.ieee.org ([199.172.136.3]) by gatekeeper.pdd.3com.com (Netscape Messaging Server 3.6) with ESMTP id AAA2126; Wed, 1 Mar 2000 17:44:53 +0000 Received: by ruebert.ieee.org (8.9.3/8.9.3) id MAA15159; Wed, 1 Mar 2000 12:12:30 -0500 (EST) From: "Edward Chang" To: "Sean Leighton" , Subject: RE: PAM-5, what are your BERs ? Date: Wed, 1 Mar 2000 12:18:48 -0500 Message-ID: MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2910.0) In-Reply-To: <38BD340D.E908D3A@lucent.com> Importance: Normal X-MimeOLE: Produced By Microsoft MimeOLE V5.00.2314.1300 Sender: owner-stds-802-3-hssg@ieee.org Precedence: bulk X-Resent-To: Multiple Recipients X-Listname: stds-802-3-hssg X-Info: [Un]Subscribe requests to majordomo@majordomo.ieee.org X-Moderator-Address: stds-802-3-hssg-approval@majordomo.ieee.org X-Lines: 60 Status: RO Content-Type: text/plain; charset="us-ascii" Content-Length: 1608 Sean: Thanks for reminding us FEC. The BER defined in the standard is the actual error rate without any error correction. This establishes the fundamental reliability and quality criteria of components, systems, and technologies. The error correction techniques can be added as an option for applications which need better BER than what has been specified in the standard. However, this is outside of the standard. For cost-effectiveness, I believe users will request the specified BER in the standard should be sufficient without added error collection. As we discussed on the reflector several months ago, FEC is not free, which adds cost and overhead to the link. We may consider using FEC, if we really need it. Regards, Edward S. Chang NetWorth Technologies, Inc. EChang@NetWorthtech.com Tel: (610)292-2870 Fax: (610)292-2872 -----Original Message----- From: owner-stds-802-3-hssg@ieee.org [mailto:owner-stds-802-3-hssg@ieee.org]On Behalf Of Sean Leighton Sent: Wednesday, March 01, 2000 10:15 AM To: stds-802-3-hssg@ieee.org Subject: Re: PAM-5, what are your BERs ? Hello, With regards to the BER problem, are we open to the possible use of forward error correction to correct for bit errors in the transmission stream. Currently in T1X1.5, there is a submission for inband FEC based on a BCH-3 code that turns a 1x10**-7 BER into a corrected BER of 1x10**-17. Prehaps a BCH-1 code could be used? Using FEC would introduce the need for some additional bits within the frame format and it would probably introduce some latency, but it would introduce some coding gain. Cheers, Sean