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Re: Distance Objectives !!!!!


Your are correct, what I am proposing is what should go into a standard. However, the methodology we seem to be using is to pick a signaling proposal, such as WWDM, and then setting as objectives the distances which can be achieved with that signaling proposal. I'm opting for a far more impartial scheme, one of specification of installed and new fiber performance characteristics, and later adding distances based on one or more accepted signaling proposals.

If distances must be specified, I'd start with premises wiring standards: 100m, 550m and 2-3km, as we did for GbE.


BRIAN_LEMOFF@xxxxxxxxxxxxxxxxxxxxxxxxxx wrote:

     Your suggestion sounds more like language that would be included in a  
     specification within a standard, and less like an objective, whose purpose  
     is to define the mission of and set the goals for the group. Once we have  
     evaluated all of the available PMDs and how they perform over all of the  
     available fibers, we will be in a position to make a table like the one you  
     have included here.  The question we need to ask ourselves is "What should  
     we set as the minimum we are willing to settle for in terms of distance and  
     fiber type".  I feel that excluding support for the installed base of MMF  
     from the objectives will allow us to settle for a standard that falls short  
     of what our customers may be expecting.  I have no objection to adding  
     additional distances and fiber types into the objectives, as long as we are  
     confident that we will be able to support them.  Here is an example that  
     includes some of Ed Cornejo's suggestions:
     To define physical solutions to support distances of:  
                At least 100 m on multimode fiber            
                At least 250 m on multimode fiber, including the installed base  
                At least 2 km on single mode fiber            
                At least 10 km on single mode fiber  
                At least 50km on single mode fiber  
     I personally don't feel that all of these are needed in the objectives  
     (particularly since the WWDM transceiver that we have been working on  
     should support the first four cases in a cost-effective manner), however if  
     this makes the objective more palatable to 75% of the committee, I have no  
     problem with it at all. I do feel strongly that support for installed MMF  
     should be included in the objective.
     -Brian Lemoff
      HP Labs--

Best Regards,

Richard Taborek Sr.    Tel: 650 210 8800 x101 or 408 370 9233
Principal Architect         Fax: 650 940 1898 or 408 374 3645
Transcendata, Inc.           Email: rtaborek@xxxxxxxxxxxxxxxx
1029 Corporation Way    
Palo Alto, CA 94303-4305    Alt email: rtaborek@xxxxxxxxxxxxx