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RE: [10GBASE-T] Technical feasibility: power

The current estimation should take into account the lower-power technology that could be potentially developed and used in 5 years.  Also we may find out that the "higer power" could be too high to be used anywhere in 5 years.


"Clint M Early" <>

07/31/2003 02:11 PM

        Subject:        RE: [10GBASE-T] Technical feasibility: power

So we should go ahead with higher power models and then hope that the
industry will get on board and start developing lower power technology,

Clint Early, Jr.

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                     owner-stds-802-3-10gbt@majordo        cc:       (bcc: Clint M Early/EHS/IPAPER)                                              
                                      Subject:  RE: [10GBASE-T] Technical feasibility: power                                  
                     07/31/2003 03:52 PM                                                                                                          


That is what I called painful lessons.  The customers always want parts
that have high performance margin and low power.  I believe that has become
the rule for our designers unless you really want something that can also
fry eggs.  In order to give a reasonable estimation of the power
comsuption, we should defintely take into account all possible technology
and design tricks that we know and we can use in 5 years.  Of course, we
cannot predict any magic stuff that can save the world will come out soon,
but we can wait.

A well-estimated number will save a lot words.


  Bruce Tolley                                                          
  <>                To:,      
                             Bruce Tolley <>            
  07/31/2003 12:56 PM                Subject:        RE: [10GBASE-T]    
                             Technical feasibility: power                

Thanks for the response

The first 1000BASE-T parts were much more than a few watts. Also the power
numbers on the roadmaps of the various vendors started dropping as soon one
of the competitors achieved lower power numbers. All the sudden, the
impossible became possible.

And yes we need data to be presented in September.


At 11:10 AM 7/31/2003 -0700, wrote:


I believe that everyone of us has painfully learned a lot from the history
of 1000BASE-T.  We have observed the power of a single 1000BASE-T dropped
from a few watts to sub-watt level today.   And we can pretty confidently
assess the impact of the technology that we are gonna use in 5 years and we
definitely should take that into account NOW.

Many circuit design experts will tell you that the power of digital circuit
part can be scaled down while the semiconductor technology got significant
improvement in the following years (how about using 65nm when 10GB-T reach

the market), but the analog circuit part won't get too much benefit from
that and its performance (for example, the ADC resolution) will be limited
by some fundamental physical rule.  Due to the complexity increase of the
DSP part and the analog part, even using 65nm technology for digital
circuit and using SiGe technology for analog circuit, to reach 100m on
CAT-7, the estimated power of the transceiver (assume it is practically
feasible) will be a number that can surprise you.  I believe more and more
data will be given in the following meeting to show you the reality.


Bruce Tolley <>
Sent by:

07/31/2003 10:12 AM

      Subject:        RE: [10GBASE-T] September interim meeting


Thanks for providing detail on data centers. I would argue that in terms of
broad market potential, 10GBASE-T would pass muster even if the only market
application was data centers.

On the power issue, the first 1000BASE-T implementations did not appear
until well after the standard was done, some 5 years after the High Speed
Study Group got its PAR, and consumed an obscene about of power. We might
have never achieved the  low power 1000BASE-T PHYs we have today if we had
tried to agree on exact numbers in 1996.


At 11:00 AM 7/31/2003 -0600, wrote:

CX4 is useful especially when we have in rack connections to make or ones
going to the next rack. However, the distance is too short for many other
data center connects. Also, the cable for the long distance is relatively
bulky which may be a problem for some uses. We will be glad to get it, but
it only solves a corner of the problem space.

Something for the longer distances in data centers that is lower cost than
fiber would be useful. For that environment, it doesn't necessarily have to
rely on already installed wiring. Running on existing wiring is nice, but
not essential.

My view of the important items for the data center environment:

It must perform solidly on the media we choose for it - data integrity
factors such as BER must be met.
It must be able to live on "standard" server bus adapter formats with a
TOE: e.g. PCI Express and Infiniband
 which means power is a concern
It must be transparent to existing MACs - that is, the MAC must see the
same behavior it sees with 10 Gig fiber.
100 m would be desireable (partly to enable future horizontal usage) but
the data center could live with shaving something off that. (100 m is nice
from a standards development standpoint as it saves us from arguing about
what lower number is enough.)
The media it runs over should not be so stiff or bulky that it is a problem
to accomodate with normal rack and data center cable management.
Of couse it must also meet EMI requirements

-----Original Message-----
From: Nariman Yousefi []
Sent: Wednesday, July 30, 2003 8:10 PM
Subject: RE: [10GBASE-T] September interim meeting


I agree that the issues you raised must be addressed by November. One of
the biggest challenges for this group is to establish reality on technical
feasibility on Cat7, Cat6 and Cat5e channels.  Different vendors have
different conclusion on Technical feasibility. That is due to assumptions
on alien cross talk mitigation techniques, impact on implementation
impairments on SNR, channel model, coding gain, and analysis on chip
complexity in a given process. Assumptions must be stated clearly by
vendors that present technical feasibility. In this case, technical
feasibility drives the broad market potential.  Technical feasibility must
be addressed at least based on the following criteria:

1. Achievable distance on Class D channel with and without installation
mitigation techniques.
2. Achievable distance on Class E channel with and without installation
mitigation techniques.
3. Transceiver complexity in terms of estimated power dissipation and
realistic targets for building blocks like ADC, PLL and etc 2-3 years from

We reached a conclusion that cat7 cable or class F channel has high enough
capacity for 10Gbps operation.  But, can a transceiver be built with
reasonable power dissipation and cost say in 90nm process or finer
geometries to achieve broad market potential?

We need to keep in mind that customers have fiber and CX4 as alternatives.


At 01:08 PM 7/30/2003 -0600, wrote:

Generally, when the group can agree on clear objectives, then they can
finish the rest of the work. Fuzzy objectives often indicate a lack of real

In November, I will also be expecting arguments that support the 5 criteria
based on the objectives -
Broad market potential - evidence that there will be a broad market the
minimum requirements of the objectives are met.

Technical feasibility - is it feasible to meet those minimum requirements

Economic feasibility - when you have met the minimum requirements will cost
be suitable to make it a viable product in the markets?

In the discussions at the plenary, a power consumption issue was raised by
some of the speakers.
If the broad market potential is based in part on use in devices such as
end nodes (including servers in data centers), then an objective for power
consumption such that this can reside in server card formats would be
important. Can it fit within the power constraints of a PCI Express board
and an Infiniband board (remembering that one has to allow some power for
the MAC and probably TOE/RDMAP engine)?

Looking at the objectifves in agenda_1_07_03, I don't see any that address
power consumption or the abilitiy to live on server card formats. In a
quick search, I also didn't find any material on power consumption in the
presentations that have been made to the study group. I hope that in
September the group will address the issue of power.

-----Original Message-----
From: Bruce Tolley []
Sent: Monday, July 28, 2003 1:22 PM
To: Booth, Bradley;
Subject: Re: [10GBASE-T] September interim meeting


Thanks for the follow up.

I am confident that if we can agree on crisp, clear objectives for 10 Gbps
reach and media supported in September that we can get our PAR approved and
move into Task Force mode, which is where the real work begins.


At 06:35 PM 7/24/2003 -0700, Booth, Bradley wrote:

Study Group Members,

Just to let others that were not at the meeting know the outcome of the
802.3 Working Group meeting, the Study Group will have to complete its PAR,
5 Criteria and Objectives in November.  This gives the Study Group the task
of completing the PAR, 5 Criteria and Objectives in 4 months.  This will
make our September Interim meeting extremely important.  We will need to
complete the effort as much as possible to pre-submit to the 802.3 Working
Group prior to the November Plenary.  November will permit us the ability
to modify the PAR, 5 Criteria and Objectives prior to asking 802.3 to put
the PAR on the NesCom agenda.  The September Interim meeting will focus on
the completion of our PAR, 5 Criteria and Objectives.

Chair, 10GBASE-T Study Group

Bruce Tolley
Senior Manager, Emerging Technologies
Gigabit Systems Business Unit
Cisco Systems
170 West Tasman Drive
San Jose, CA 95134-1706
ip phone: 408-526-4534
"Don't put your hiking boots in the oven unless you plan on eating them."

Colin Fletcher, The Complete Walker

Nariman Yousefi
Vice President Networking Engineering

PH  (949) 585 5450
FAX (949) 453 1848
e-mail :

Bruce Tolley Senior Manager, Emerging Technologies Gigabit Systems Business
Unit Cisco Systems 170 West Tasman Drive MS SJ B2 San Jose, CA 95134-1706
internet: ip phone: 408-526-4534
"Don't put your hiking boots in the oven unless you plan on eating them."
Colin Fletcher, The Complete Walker

Bruce Tolley Senior Manager, Emerging Technologies Gigabit Systems Business
Unit Cisco Systems 170 West Tasman Drive MS SJ B2 San Jose, CA 95134-1706
internet: ip phone: 408-526-4534
"Don't put your hiking boots in the oven unless you plan on eating them."
Colin Fletcher, The Complete Walker