Hello 10 G'ers,
The pdf file I was referring to is already at the web site:
Many thanks of appreciation to David Law's support.
Jaime Kardontchik wrote:
> I apologize if you will receive this email twice: I sent
> it several hours ago and I did not receive it back from the
> Reflector. May be it got lost because it had a pdf file
> attached to it. I deleted this pdf from the present email.
> Hello 10 G'ers,
> I have talked to a pair of companies, that are
> on the optical side of the equation, regarding
> my original PAM-5 4-WDM at 1.25 Gbaud proposal
> that I presented in Kauai, Nov 99, and in Dallas,
> Jan 2000 (see presentations in the web site).
> They suggested that if I modify my original
> proposal and use short wavelength VCSEL lasers
> instead of 1300 nm lasers, this modified proposal
> would become very attractive to them. They feel that
> important key optical (mux/demux) and electrical
> analog front end blocks are well within their
> capabilities to manufacture them and that it
> could meet the tight schedule of the Task Force
> because it uses mainstream available technologies
> and an already existing and standardized PCS
> (except for linearity issues, specially of the
> lasers, that will have to be addressed before
> the July 2000 meeting).
> Essentially, using short wavelength lasers this
> proposal will have the following advantages:
> 1) It will be the cheapest 10 GbE system that
> supports the installed multimode fiber.
> It will use cheap active optics at 1.25 Gbaud
> (VCSELs and Silicon photodiodes) and cheap
> optical mux/demuxes.
> 2) It will support up to 160 meters of the
> installed MMF (160 MHz*km fiber), meeting
> easily the minimum HSSG objective (100 m).
> At 160 meters the optical eye is wide open:
> there is no need for equalizers.
> 3) It will support much longer link lengths at a
> much lower cost that any serial 10 Gbaud
> approach using the installed MMF (the latter
> supports a bare 25 meter using 850 nm
> lasers and 85 meters using 1300 nm lasers;
> see Dallas spreadsheet).
> 4) It uses 1.25 Gbaud on 4 Copper traces.
> It allows the use of standard layout
> practices and cheap FR4-based PCBs and
> 5) It uses mainstream CMOS technology,
> reducing packaging costs and allowing
> larger integration (for example, on chip
> CMOS transimpedance amplifiers)
> 6) It reuses the 1000BASE-T PCS, another
> Ethernet standard, saving considerable
> development time.
> a) this proposal will support officially
> only link lengths that assure a nice
> opening of the optical eye pattern at
> the receiver. Hence, there is no need
> for any equalizer. However, after the
> Standards are completed, individual
> companies could come to the market
> offering their proprietary solutions
> (that could include Decision Feedback
> Equalizers) to support link lengths
> well above 160 meters.
> b) The decision of whether to use the
> 6-dB coding gain option of the PCS
> (Viterbi decoding) or the 3-dB option
> (standard symbol-by-symbol decoding)
> will be reached by the July 2000
> meeting after consulting with the
> interested parties.
> c) copy of this proposal was presented to
> Broadcom on Feb 2, urging it to consider
> it as a common PAM-5 proposal to be
> presented in the March 2000 meeting.
> If the proponents of PAM-5 solutions cannot
> agree to a common supported approach in the
> March 2000 meeting, I consider the odds of
> joining the standardization track very slim
> if not zero, in light of the existent Task
> Force schedule that includes an initial Draft
> in July 2000 and a demonstration of working
> prototypes by July 2001.
> Jaime E. Kardontchik
> Micro Linear
> San Jose, CA 95131
> email: kardontchik.jaime@xxxxxxxxxxx