From owner-stds-802-3-hssg@ieee.org Wed Mar 1 18:13 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 SAA17078; Wed, 1 Mar 2000 18:13:13 GMT Received: from ruebert.ieee.org ([199.172.136.3]) by gatekeeper.pdd.3com.com (Netscape Messaging Server 3.6) with ESMTP id AAA2178; Wed, 1 Mar 2000 18:11:33 +0000 Received: by ruebert.ieee.org (8.9.3/8.9.3) id MAA23328; Wed, 1 Mar 2000 12:39:00 -0500 (EST) Message-Id: <4.2.0.58.20000301103618.00aa7100@192.168.2.12> X-Sender: mwincn@192.168.2.12 X-Mailer: QUALCOMM Windows Eudora Pro Version 4.2.0.58 Date: Wed, 01 Mar 2000 10:39:30 -0700 To: Ed Grivna , stds-802-3-hssg@ieee.org From: "Mike Wincn" Subject: Re: PAM-5, what are your BERs ? In-Reply-To: <200003011542.JAA03765@geronimo.bip.cypress.com> Mime-Version: 1.0 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: 26 Status: RO Content-Type: text/plain; charset="us-ascii" Content-Length: 758 Ed: At 09:42 AM 01-03-2000 -0600, Ed Grivna wrote: >Hi Sean, > >unfortuantely, FEC has additional drawbacks beyond just latency. the >primary concern here would be that you need to ratchet-up the signaling >rate even faster to include the overhead of sending the FEC bits. >Depending on the amount of redundancy in the FEC information, >you may need to increase the signalling rate as much as 5-to-10%. this condition was allowed, in one or more very early 5-PAM MAS proposals, and was one of the strongest reasons for choosing 5 levels rather than 4 or something less. regards, -- J M Wincn, Staff Engineer Cielo Communications, Inc. 325 Interlocken Pkwy, Bldg A Broomfield, CO 80021-3497 Voice: 303-464-2264 Cell: 408-394-5283 Fax: 303-460-6348