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

Re: [802.3BA] Discussion on 40G for => 10 km SMF

Dear Atsushi and colleagues,
we've debated at length the issues of cost/crossovers/enabling
technologies/etc and yet it seems difficult to make progress towards 75%

A group of system vendors or "customers" of 40G components, got together
and with an open-minded unbiased attitude looked at all the arguments
mentioned above; we carefully reviewed the arguments on both sides and
came to the conclusion that CWDM is preferred to jumpstart the 40G SMF
After all as a product manager whose job is to steer product decisions
based on listening to what my customers want, I was hoping this was a
constructive approach to help move the work of the TF forward. 

My concern now shifts to how to resolve the impasse without impacting
the standard. 
I see three possible scenarios:
a) The serial camp who represented ~30% of the consensus comes up with a
plan to get the remaining 45%.
b) The CWDM camp supported by ~70% of the TF comes up with few extra
c) We give up the objective (I can't believe I am writing this:-)
because we can't get consensus. At that point I think the market will

In Motion #8 (see below) 31 TF members abstained, this is a good time to
*try* to make a decision one way or another. I hope the undecided will
use the reflector to solicit more information and help the TF reach a
decision in September.

We need to move the standard forward or else we end up impacting the
whole industry effort on HSE.


[...Move to adopt 4x10G CWDM as per "cole_03_0708.pdf" as the baseline
for the 40GE 10km SMF PMD objective.
Moved by: Chris Cole
Second by: Pete Anslow
Technical (>75%)
Task Force
Yes: 81
No: 38
Abstain: 3
802.3 voters:
Yes: 52
No: 22
Abstain: 8...]



	From: Atsushi Takai [mailto:atsushi.takai@xxxxxxxxxx] 
	Sent: Thursday, July 31, 2008 12:18 AM
	To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
	Subject: Re: [802.3BA] Discussion on 40G for => 10 km SMF
	I may understand.
	If you will find any violation below, please let me know.
	TF members
		I am supporting 40G serial.
	My view on 40G Serial and CWDM is as below.
	(1) COST
	We can achieve less than 4x10G cost using 40G serial
	while we need some breakthrough technology using 40G CWDM
	I agree 40G CWDM will be 4-8 times of 10G as written in
"cole_04_0708" page 8.
	And most likely 6 times.
	Using current technology, it is difficult to achieve less than 4
because we have to pay for wavelength control.
	In case of 40G serial, module structure is the same as X2.
	I believe we can achieve less than 4 times cost for each part in
the 40G module comparing 10G serial.
	We are waiting 3rd generation SERDES and 2nd generation of
driver and TIA IC to achieve low cost 40GbE serial. 
	I am sure that industry is working on these devices.
	(2) Time
	There exists plural 40G serial module vendors today using
1550-nm EA-DFB. 
	1310-nm EA-DFB is easier because we can neglect dispersion
	Thus 40GbE serial is possible.
	And cost reduction plan is visible.
	I also sure 40G CWDM will be available if market will accept
larger than 4 times cost.
	Cost reduction plan will follow the same as 10G and plan for
less than 4 times is invisible today.
	(3) Power consumption
	We need also breakthrough to achieve less than 4 time power
consumption using CWDM.
	Power consumption reduction plan is invisible
	We are sure we can achieve less than 4 time power consumption
using serial in future.
		(4) Size
	I am not sure it is too early to talk 40G electrical interface.
	But 40GbE serial has possibility for XFP or SFP+ size.
	I did not hear LX4 XFPor SFP+ due to pin constraint and power
	(5) Risk for wavelength failure
	WDM technology has always the risk for wavelength failure, while
serial does not have.
	We may resolve some way for 40G CWDM because of high reliability
of long wavelength optical devices.
	(6) Another aspect
		We made speed breakthrough every 4 or 5 years in the
	We started to deliver 10G modules in 1997.
	The 300-pin MSA started in 2000.
	10GbE was issued in 2002.
	40G is the next milestone for technology evolution and now is a
little bit behind the past trend.
	(We had unhappy period that every progress seemed to stop.)
	Today 40G is the technology to challenge and overcome for both
optical and electrical technology.
	I  think IEEE should not avoid such technology evolution.
	I believe IEEE should take 40GbE serial.
	Atsushi Takai
	Marketing Division, Opnext Japan, Inc

		----- Original Message ----- 
		From: John DAmbrosia <mailto:jdambrosia@xxxxxxxxxxxxxxx>

		To: Atsushi Takai <mailto:atsushi.takai@xxxxxxxxxx>  ;
		Sent: Wednesday, July 30, 2008 8:30 PM
		Subject: RE: [802.3BA] Discussion on 40G for => 10 km


		First, let me say that the email below is intended to
make sure that this group does not stray in a direction that would
ultimately lead to the violation of IEEE-SA Antitrust and Competition
Policy.  As chair, I am remaining neutral on the TF's technical


		Regardless of the decision that this body makes, the
market may demand that both solutions are developed anyway.  


		Please note in the following document from the IEEE,
"Promoting Competition and Innovation:

		What You Need to Know about the IEEE Standards
Association's Antitrust and Competition Policy," which may be found at   Please
note the following statement:


		"For example, selecting one technology for inclusion in
a standard is lawful, but an agreement to prohibit standards

		participants (or implementers) from implementing a
competing standard or rival technology would be unlawful - although as a
practical matter, a successful standard may lawfully achieve this result
through the workings of the market."


		As I have phrased it to the Task Force, the Task Force
makes decisions about what it is going to do, it does not make decisions
about what it is not going to do.


		Regardless of the decision that this Task Force makes,
it is very easy to envision both implementations getting developed in
the industry.  Given the need stated by CWDM supporters for a near term
solution, it is easy to envision an industry effort happening if the TF
goes serial.  It is just as easy to envision a new CFI happening for a
serial solution if the TF chooses to go CWDM.  


		Also, as a point of clarification, as I am currently
looking at the presentation for another discussion, you may wish to
refer to Flatman_01_0108
f), which is a survey of data centers that Alan Flatman did that shows
40G being deployed in access-to-distribution links in 2010.










				From: Atsushi Takai
		Sent: Wednesday, July 30, 2008 2:26 AM
		To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
		Subject: Re: [802.3BA] Discussion on 40G for => 10 km


		Hi Mark


		I agree that DC application is cost sensitive.

		As many people agreed in some presentations at meeting,
CWDM will be cheaper at near term and serial will became cheaper in
maybe 2011 or beyond.

		That means transceiver supplier have to develop CWDM in
2009 timeframe and serial in 2010 or 11.

		This development will cost much. And I do not think CWDM
cost in 2009 or 2010 will be cheaper than 4x10G. 

		Even more DC application users can choose 8x10G CWDM
that has more bandwidth.

		I do not think CWDM has superior merit for DC

		Also I think there was a presentation that said that DC
will start install 40G in 2015 or beyond.


		Atsushi Takai
		Marketing Division, Opnext Japan, Inc



			----- Original Message ----- 

			From: Mark Nowell (mnowell)

			To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx 

			Sent: Wednesday, July 30, 2008 4:08 AM

			Subject: Re: [802.3BA] Discussion on 40G for =>
10 km SMF




			I agree some reflector discussion would be
helpful on this topic.


			I characterize the discussion I heard around the
choice of PMD as really boiling down to a debate on the primary
applications and the drivers for those applications.


			The original justification for adding the 40G
SMF objective was primarily based on the application of Data Center
inter-switch links.  There was also other applications such as for use
in interconnecting to OTN equipment which is good for BMP.  In both
cases lower cost solutions are preferential.  The debate appears to
revolve around what other assumptions there are around market timing,
technology risks, cost projections and operational issues etc.


			To me the simple view is that to achieve low
cost, you need higher volume.  Higher volume is achieved by the having a
solution that addresses the largest primary application and as many
others as possible.  I am assuming that the primary application is still
the DC.


			Since DC applications are inherently much more
sensitive to cost, a near term low cost solution is needed or else the
application will likely not be adopted.  In this case, if 40G SMF PMD is
uneconomical in the near term then the DC users will likely stay with
nx10G as long as possible and then presumably assess the 40G/100G
economics at some later date.


			The argument for adopting serial technology now
is that the potential higher volume of the DC application will trigger
the necessary development investments now and drive the cost of that
technology down so we will ultimately get it to the low cost solutions
needed.  My concern is that the timing and cost windows needed for the
DC application do no fit with that model and we would end up with little
adoption in that market and end up with a lower volume, higher cost PMD
which is what we would all like to avoid.







John DAmbrosia [mailto:jdambrosia@xxxxxxxxxxxxxxx] 
				Sent: Monday, July 28, 2008 6:53 PM
				To: STDS-802-3-HSSG@xxxxxxxxxxxxxxxxx
				Subject: [802.3BA] Discussion on 40G for
=> 10 km SMF

				Dear Task Force Members,

				Per Motion #9 from July, the editorial
team is working on creating a "a draft based on adopted baseline
proposals for circulation prior to the September 2008 interim meeting

				."  Unfortunately, at the July meeting
the Task Force did not reach consensus on a baseline proposal to satisfy
the 40G over => 10km SMF objective.    Therefore, in September we need
to reach closure on this issue.  


				With that said, I would like to strongly
recommend that the TF make use of the reflector to discuss the various
issues of debate that have been going on, both during the meetings and
during offline discussions.  


				Let's use the next several weeks to have
meaningful debate so we can reach consensus at the September meeting.




				John D'Ambrosia

				Chair, IEEE P802.3ba Task Force