Re: [802.3_B400G] March Plenary

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

Thread Links

Date Links

Thread Prev

To: STDS-802-3-B400G@xxxxxxxxxxxxxxxxx

Subject: Re: [802.3_B400G] March Plenary

From: Chris Cole <chris@xxxxxxxxxxxxxxx>

Date: Wed, 15 Mar 2023 13:39:54 -0700

Arc-authentication-results: i=1; mx.google.com; dkim=pass header.i=@quintessent.com header.s=google header.b=UAifFmSn; spf=pass (google.com: domain of chris@xxxxxxxxxxxxxxx designates 209.85.210.48 as permitted sender) smtp.mailfrom=chris@xxxxxxxxxxxxxxx

Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=to:subject:message-id:date:from:in-reply-to:references:mime-version :dkim-signature; bh=7jro5p7j84KPK+EvYFE18WYz1dHRpDw6DwOBpnmvrtM=; b=r5LY7WNvDi1gAW/5Rp+oYshACisM14YI8L4zeiyMNk+d0UY4z/c1rFd0CvvKYoAqz3 qaDxp7Gj1sU2Gzx77gLn7Y7B4GuLrVb1e2+cMF/WEEJN32qzBUuWEiEw85LDYCjfMXci kphv7omCWkjqH6508cOp5eoIzmkyII7l2FRpMWMr1je/l5EmXU3/XTKWkQdbRVgx7PpM ewNZcmN+9opfHC1eUOhu9xhXBODBC5xm7U26h86rREIE8SRAnlYxdjBHm7/GfsbFAdUd HfG/EevlXy8lBSEp4jrQY//rYrm37o8V0YCtXYovmwkg4BBIhUL+mYfOrCBpJTMJ7RFd /ucQ==

Arc-seal: i=1; a=rsa-sha256; t=1678912810; cv=none; d=google.com; s=arc-20160816; b=L/wkgXcdAnKoimI9/7DqYRA69sQRsRSemxkLN0i/HQ6cN5wuUwKWv+ZtQbfGp85iw8 IwBmNWMum7TfBzi5uSNqLJ7MkvrJUiK0jn6G3sCas2Omg77jAnOBdAoslneYKjsc3dw+ O6KMOC2Orc8RywyKePzK1hgiNN2tcpApA9Ap+rbD8CjL2Ct4Zo0XKaDPeBxpkWEM3l/U ijJsq+qvsatq0dsgfBqgs7YcR8xSTWaxek5OALVQ92HXHkB3qE1vfnrV4wiYUJE+n8/o 0OgCjL6glJsnt5Ri5DsVtF+zvFF5ZTd/pwLjI0iu51luYoE+0NHDiD02kzw6JK9OqlSI HjWw==

Delivered-to: mhonarc@xxxxxxxxxxxxxxxx

Delivered-to: STDS-802-3-B400G@xxxxxxxxxxxxxxxxx

In-reply-to: <074e01d956db$c7b49ef0$571ddcd0$@gmail.com>

List-help: <https://listserv.ieee.org/cgi-bin/wa?LIST=STDS-802-3-B400G>, <mailto:LISTSERV@LISTSERV.IEEE.ORG?body=INFO%20STDS-802-3-B400G>

List-owner: <mailto:STDS-802-3-B400G-request@LISTSERV.IEEE.ORG>

List-subscribe: <mailto:STDS-802-3-B400G-subscribe-request@LISTSERV.IEEE.ORG>

List-unsubscribe: <mailto:STDS-802-3-B400G-unsubscribe-request@LISTSERV.IEEE.ORG>

References: <074e01d956db$c7b49ef0$571ddcd0$@gmail.com>

Reply-to: Chris Cole <chris@xxxxxxxxxxxxxxx>

During today's meeting, the basis for distinct use-cases for 800G IMDD and Coherent was presented as low cost and high performance, respectively.

One of the several high performance advantages of Coherent is Spectral Efficiency (SE), which traditionally benefited DWDM, however also benefits Gray links. Pierce and Eric challenged SE as irrelevant to Gray links.

A quick web search gives the following definition:

Spectral efficiency refers to the amount of data that can be transmitted over a specific bandwidth. You can use it to compare how efficiently two different systems utilize the same frequency.

A more comprehensive discussion can be found on Wiki at: https://en.wikipedia.org/wiki/Spectral_efficiency. Nowhere in the definitions is there any mention of Transport System minutia like tributaries.

The importance of SE to Gray links was nicely shown in a timely manner in Eric's presentation describing how to increase data rate through multiple coherent wavelengths., in direct contradiction to the earlier assertion.

Therefore, SE is an important Coherent high performance advantage that leads to distinct use-cases for some Ethernet applications, obviously to be traded-off against the low cost advantage of IMDD solutions.

Chris

To unsubscribe from the STDS-802-3-B400G list, click the following link: https://listserv.ieee.org/cgi-bin/wa?SUBED1=STDS-802-3-B400G&A=1