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Re: [10GBT] Standards Procedure

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While we don’t need to work the details of PMA specs & waveforem templates to select a proposal, but can work some before and some after,  I strongly suggest that we not select proposals piecemeal.


In these complex signal processing systems, most phy vendors know that the complexity is a strong function of many, finely-balanced interacting specifications.  As was pointed out in the study group, the specifications for a 10GBASE-T device push state-of-the-art in many respects – DSP complexity, canceller length & linearity, front-end sensitivity, low-power analog design, parallel digital design, magnetics bandwidth and  EMI balance, to name a few.   We rightfully had more than a year of strong debate on technical and economic feasibility of 10GBASE-T, and, for good reason – these things are hard!  As such, the economic feasibility and the market potential needs to be determined on the basis of a more complete proposal, not piecemeal, since these will be dictated by the timeframe not for the standard, but for reasonable complexity standards-compliant devices.


Specifically, proposing line coding or FEC in absence of baud rate and equalization, and, in the absence of relatively complete complexity estimates will lead us away from the 5 criteria which were our goal.  Nailing down a piece at a time is like building a 747 without a blueprint, and, worse yet, with congress delegated to make several independent design choices.   AND, we don’t have to go down that path.  If we get proposals out on the table, and fill them out, we can converge.  To give a specific example, I currently see 3 proposals in Sanjay’s spreadsheet which have the level of detail necessary to consider complexity and feasibility –  unfortunately, it’s not all 6 submittals.  However, each of these 3 does have enough detail that we can begin the work of validating the estimates, of checking for coding performance, and of making the complexity/performance tradeoffs necessary to bring successful 10GBASE-T standard products to market in a reasonable timeframe. 


If we were to mix & match and make separate, incremental decisions on these major architectural parameters, or, if we don’t have enough open review for the wider audience to consider the options on the table, we’ll end up with a relatively poor standard, one which will NOT pass muster as an economically feasible solution for a number of years.


-George Zimmerman

-----Original Message-----
From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf Of Sanjay Kasturia
Wednesday, June 16, 2004 10:05 AM
Subject: Re: [10GBT] Standards Procedure


I strongly recommend that we quickly zero in on one proposal even if we have to keep some parameters open for fine tuning based on more detailed investigation. I feel this will lead to a better standard in the end.


Carrying multiple proposals forward, specially if they are radically different, is going to be quite impractical and will also mean that the task force resources continue to be divided.


The sooner we converge on one proposal, the more time we will have to develop and test things like PMA specs, waveform templates, startup, autonegotiation, the protocol conformance stuff and a whole load of other items that have to be covered.


To give a specific example, if we to carry PAM and OFDM together in parallel, it will imply differences on almost every front and the Task Force attention and scrutiny will be divided.


On the other hand, given where we are today, it is impractical to nail everything down, so if we decide to continue, for example, with a THP based transmitter, we could put a range for the number of THP taps and take another meeting to narrow it down to a specific number.


If we make a decision now on a forward error correction technique we will have the Task Force's full attention on verifying it and are more likely to find problems (if they exist) and fixes to the problems.





Sanjay Kasturia

Editor-in-chief, 802.3an

cell (650) 704-7686

office (408) 653-2235



From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf Of Booth, Bradley
Sent: Tuesday, June 15, 2004 10:12 PM
Subject: Re: [10GBT] Standards Procedure

Just a clarification of the timeline that George alluded to, and so that the Task Force members understand.  As per the current schedule, the Task Force will ask the 802.3 Working Group to permit us to go the Working Group ballot after the March 2005 meeting.  To be able to make this request, the Task Force should have a technical complete draft to present to the Working Group at the March 2005 meeting.  The Task Force can make some minor technical changes at the March meeting, but it will be up to the Working Group to decide if the Task Force is ready to go to Working Group ballot.


A method to do this is to have a set of baseline proposals that the Task Force adopts as the formation a D1.0.  If the Task Force cannot select one proposal, then the Task Force should eliminate those with the least support.  The remaining proposals would need to continue to be developed and weened as the Task Force moves forward.  For example, if there are 3 coding proposals in July, the Task Force could document these 3 proposals.  At each successive meeting, the Task Force would work to adopt only one proposal.  Exiting the January 2005 meeting, the Task Force should only have one proposal in the specification.  I would like to warn the Task Force that carrying multiple proposals for various portions of the draft specification as the Task Force moves forward will create a tremendous burden on the editorial staff.  The faster the Task Force can move to the selection of one proposal, the easier it will be for the editorial staff and for the Task Force to focus on creating a draft that is ready for Working Group ballot.


If anyone has any questions on this, please feel free to ask them on the reflector.  It is important that as a Task Force that we all understand the timeline required for us to meet the goals of this project.


Thank you,



Brad Booth

Chair, IEEE P802.3an Task Force


-----Original Message-----
From: stds-802-3-10gbt@IEEE.ORG [mailto:stds-802-3-10gbt@IEEE.ORG] On Behalf Of George Eisler
Sent: Tuesday, June 15, 2004 11:34 PM
Subject: [10GBT] Standards Procedure

Thanks to Sanjay for the wrap up and to Jeff for high-lighting the roadblocks to our current efforts to agree to a proposed draft 1.0 at the close of July.


I would however like to point out that our schedule calls for presenting 1.0 to the Working Group in March 2005. To meet this schedule requires Task Force agreement to a technically complete document at the latest at our likely January 2005 interim. A minimum of four meetings are available to accomplish  this; it does not mean that we have to have a technically complete document in July. There is therefore time to establish a sequence for openly arriving at a technical solution that we can all be proud of. Rushing to votes on full or partial proposals that have barely seen the light of day is not the way to achieve this.


I have observed that at our last two meetings technical proposals were presented that were published on the web only a couple of days (at best) before the deadline and less than one week before presentation to the Task Force. It was then followed by a vote a day or two later. I personally feel relieved that most of these failed to clear the hurdle.


The level of signal processing technology that must be used in a 10G PHY that meets our objectives is at the leading edge; it far exceeds that which was required in 1000BASE-T. Most of the key parameters require extensive computer simulations for verification and for the assessment of other attributes such as complexity, gate count, latency, EMI performance, etc. While soliciting support, holding private discussions and forming alliances has its obvious benefits, it is just that – private. Time must be allowed for technical analysis by all qualified participants and for open debate on the pros and cons of various solutions. Only then should binding votes be taken. The holes in the present spread sheet point to the immaturity of most proposals, most especially in the areas of complexity and performance comparisons. Error correcting codes must also be subjected to long simulation runs to verify the absence of error floors in the region of interest. In a word, we are not there yet.  


The openness of the process serves a dual purpose. First, it obviously broadens the base of ideas and helps to highlight benefits and shortcomings of various proposals. Second, it allows many Task Force voters who are not PHY vendors to form a basis on which to make decisions even if they lack their own means of full technical verification.


I also wish to point out that many standards bodies apply the general rule that at least one meeting cycle must intervene between the presentation of a significant technical proposal and its adoption, eliminating the element of surprise from affecting the outcome. It is a wise rule that our Task Force should adopt and I plan to make such a motion at the July meeting.  


As Jeff suggests, it would be beneficial to set up a sequence for making the crucial choices, while still planning to stay within the stated time line. One way would be to limit major system proposals to July, (with Task Force agreement), down-select in September, with last technical features added in November and TF approval in January. There could be an extra meeting in Dec/Feb if necessary. Technical ad-hoc meetings can be carried on in between


George Eisler