Re: [802.3BA] 5 Criteria mod to support 40 G on SMF

[Matt Traverso <matt.traverso@xxxxxxxxx>]

Hong,

<Rant on 10km distance objective for 100G added as postscript>

An SMF PMD objective at 40G has yet to be written so there is still time to change it.  I'd be very much interested in hearing from end users what distances are required.  If you can produce some data to justify your comment please forward it to the reflector or join the next ad hoc discussion.

To a large extent, optical component manufacturers are at the mercy of the end users in this exercise -- we heard 10km in barbieri_01_0108, and thus 3 different technical feasibility presentations were uploaded.  If a different distance is justified, I have very high confidence that similar contributions of technical feasibility would be submitted.

Please point us toward some data -- we look forward to reviewing it.

Thanks
--matt

PS: I am biased on the issue of SMF distance as I believe (and have repeatedly presented) that 10km is not a cost minimized distance at 100Gbit/s and also now at 40Gbit/s (http://www.ieee802.org/3/ba/public/AdHoc/40GSMF/traverso_40_01_0208.pdf).  

Relaxing the distance offers optical transceiver vendors a number of avenues to minimize costs.  At the 100G rate, competitors to my company have presented that the cost deltas are less than the cost deltas that I and my company see.  The objective at 100G is at least 10km -- as was pointed out to me by the chair, there does not seem to be momentum to shift this distance.  Thus we are focused on 10km.

On Feb 7, 2008 3:53 PM, Hong Liu <hongliu@google.com> wrote:

Before we dive into the power budget and spreadsheet, we should probably
investigate the best balance of reach and cost for 40Gb/s SMF for server
market and computing applications.

Economically, it probably doesn't make sense to do 40Gb/s SMF at 10km for
server and computing.  1km~2km should be more than sufficient.


Hong Liu
Google Inc.

-----Original Message-----
From: Howard Frazier [mailto:hfrazier@BROADCOM.COM]
Sent: Thursday, February 07, 2008 3:21 PM
To: STDS-802-3-HSSG@LISTSERV.IEEE.ORG
Subject: [802.3BA] 5 Criteria mod to support 40 G on SMF

Dear members of the IEEE 802.3ba Task Force,

I have reviewed our approved set of 5 Criteria responses

http://www.ieee802.org/3/ba/PAR/HSSG_5C_0707.pdf

looking for any material that will need to be changed in the event we adopt
an objective to support 40 Gb/s operation on 10 km of single mode fiber. In
my opinion, the responses will remain valid and complete, with one
exception.

On page 6 of the above referenced file, in our response to the Economic
Feasibility criterion, we state:

 Presentations indicate that for the server market and
 computing applications the optimized rate to provide
 the best balance of performance and cost is 40 Gb/s.
 For the network aggregation market and core networking
 applications, the optimized rate offering the best
 balance of performance and cost is 100 Gb/s.

If we adopt a 40 Gb/s SMF objective, then this response should be modified
along the lines of:

 Presentations indicate that for the server market,
 computing applications and some cost-sensitive
 aggregation applications, the optimized rate to provide
 the best balance of performance and cost is 40 Gb/s.
 For the network aggregation market and core networking
 applications, the optimized rate offering the best
 balance of performance and cost is 100 Gb/s.

The change being the insertion of the words "some cost-sensitive aggregation
applications" in the first sentence.

I think that our previously approved responses for Broad Market Potential,
Compatibility, Distinct Identity, and Technical Feasibility will not require
any change in the event that we adopt an objective for 40 Gb/s operation on
SMF. I think that the proponents of the new objective will be able to
readily demonstrate this.

If you think I have over looked something else that might need to be
changed, please speak up, and please provide a proposed change.

Howard Frazier
Broadcom Corporation