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RE: [10GMMF] Re: Impulse Responses for "Worst Case" MMF

a few questions come to mind.

1. Do the 207 profiles represent 50 um, 62.5 um, or both? 
2. What is meant by the term "profiles"?  Does it refer to index profile or to the ensemble of impulse and frequency response data? I assume the latter, which leads to the third question.

3. If 81 fibers were generated, why are only 69 x 3 offsets to be made available?  Are the others disqualified?

4. What is the utility of examining three offsets? How do these offsets relate to 50 and 62.5 mode conditioning cord specifications?

Paul Kolesar

-----Original Message-----
[]On Behalf Of Ian
Sent: Tuesday, February 24, 2004 11:43 AM
Cc: 'Richard Penty';;;
'Bruce Tolley'
Subject: [10GMMF] Re: Impulse Responses for "Worst Case" MMF

Dear SG Colleagues,

At the meeting in Vancouver, several participants requested to be given 
the fibre responses generated by the "81 fibre" statistical model. 
Having discussed internally how best we might respond to these requests, 
we have consulted with Bruce Tolley. He has suggested that we make 
available at the next meeting a full set of responses, posted on the SG 
web site. These would be provided in a sufficiently detailed manner so 
that worst case fibre responses can be generated for arbitrary launch 
conditions. David Cunningham has kindly agreed to make a short 
presentation at the meeting to explain how the data can be used.

We are aware however that some colleagues would prefer responses being 
made available beforehand, and hence with immediate effect, we will make 
available the frequency and impulse responses of worst case fibres 
under offset launch conditions at a wavelength of 1.3 microns. The data 
has been generated using the approach in Webster et al., A statistical 
analysis of conditioned launch for Gigabit Ethernet links using 
multimode fiber, Journal of Lightwave Technology, vol. 17, no. 9, pp. 
1532-1541, September 1999. Responses for three values of offset will be 
provided, resulting in 207 profiles being made available. We hope that 
this will meet the majority of needs from the group. The data will be 
posted on a web site, but if it is required urgently, please send an 
email directly to me at, and the data will be sent 
directly to you.

May we make clear that whilst we understand that the data will be used 
for commercial purposes, it is made available on the basis that the it 
will not be sold to third parties, either directly or within software 
tools. We can of course not accept any liability for the results made 

I hope that this proves to be helpful to the workings of the group.

Yours sincerely,

Ian White and Richard Penty