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Richard, I really like your idea of showing the percentage of material that is used according to time. Then we can produce the optimal solution Gert, I think we should discuss the materials in terms of loss or other relevant parameters instead of actual material. We could say which materials fall within the range of losses though. Following is an example of how we could show which materials are expected to be used where. Reader beware, I just made up these numbers and do not have access to the real numbers. I hope we can come to a general consensus on where the percentages are within +/-10%.
We should consult some backplane producers, end users or even industry analysts to get a good estimate. Cheers, Scott From: Mellitz, Richard [mailto:richard.mellitz@xxxxxxxxx] How about dielectric material that is projected to be used in X percent of the market in 201#? That plays to broad market potential. Silicon technology is expected to still have exponential growth. Changing “backplane/line card” board technology on the other hand is like turning a battle ship. Given that, we should at least evaluate how much of legacy product present in 201# we can cover given the disparity of the silicon vs. board technology pace. Simply put, coverage could be one of the metric to compare proposals. Unfortunately it’s still crystal ball. … Rich From: Havermann, Gert [mailto:Gert.Havermann@xxxxxxxxxxx] All, besides the grammar I would like to have some kind of reference to the "enhanced FR-4 Material". There are so many different anhanced materials available (low loss, ultra low loss, low dk glass...) all having a different influence on the length factor we are trying to fix (not to mention the cost differenve between materials). Regards Gert Havermann Absender ist HARTING Electronics GmbH & Co. KG; Sitz der Gesellschaft: Espelkamp; Registergericht: Bad Oeynhausen; Register-Nr.: HRA 5596; persönlich haftende Gesellschafterin: HARTING Electronics Management GmbH; Sitz der Komplementär-GmbH: Espelkamp; Registergericht der Komplementär-GmbH: Bad Oeynhausen; Register-Nr. der Komplementär-GmbH: HRB 8808; Geschäftsführer: Edgar-Peter Duening, Torsten Ratzmann, Dr. Alexander Rost Von: John D'Ambrosia [mailto:jdambrosia@xxxxxxxxxxxxxxx] All, Not sure this message got forwarded to the reflector, so forwarding. Regards, John From: Kolesar, Paul [mailto:PKOLESAR@xxxxxxxxxxxx] John and group, The objectives are on the right track, but there are a few grammatical and clarity issues. The first is an issue with the wording at the end of each. The phrase “up to at least” is illogical and confusing because it combines words that specify maxima (i.e. up to) with words that specify minima (i.e. at least). While this phraseology may be following some precedent of former objectives, it only serves to cloud the real intent. In the past these objectives have always been interpreted as the requirements for minimum reach. Therefore I propose that they each simply state it as such by replacing “lengths up to at least” with “lengths of at least”. Further, I do not know what is intended by the phrase “for links consistent with lengths”. Why use the word “consistent”? Is there a perception of some increased flexibility or some other advantage? Please explain. If the advantage is ambiguity, I would prefer stating objectives more crisply. Unless your rationale for this word choice is compelling, I propose combining these two issues into the following new phrase: “for link lengths of at least”. Lastly, it would be simpler and clearer to place all the adjectives describing “traces” before the noun rather than some before and some after. Rearranging these yields ”over improved FR-4 copper traces”. With all three of these changes, the two draft objectives become: · Define a 4-lane 100 Gb/s PHY for operation over improved FR-4 copper traces for links lengths of at least “X” m. · Define a 4-lane 100 Gb/s PHY for operation over copper twin-axial cables for links lengths of at least “Y” m. Of course all these grammatical improvements do not address the main issues which are the values of X and Y. But that is what study groups are for. Regards, Paul Kolesar From: John D'Ambrosia [mailto:jdambrosia@xxxxxxxxxxxxxxx] All, I wanted to try and foster some discussion on the reflector regarding objectives for the project to help all focus their planning of presentations for March. So what do we appear to have consensus on so far? a) We are in a study group looking at 100GbE over backplane and copper twin-ax b) Legacy support indicates broad market potential would be aided by 4 lane solutions What appears to need further consensus building? Well the big ones would seem to be reach for both backplane and cu cabling objectives. So if we can combine where we appear to have consensus with what we need to resolve, the following two statements could be used as strawmans for objectives for the group to work towards (leaving the reach #’s as variables for now): · Define a 4-lane 100 Gb/s PHY for operation over copper traces on improved FR-4 for links consistent with lengths up to at least “X” m. · Define a 4-lane 100 Gb/s PHY for operation over copper twin-axial cables for links consistent with lengths up to at least “Y” m. Feedback? John |