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Re: [802.3_MAINT] Follow up on proposed Comment to add distance specification for 10GBASE-S over OM4 media

Steve,
 
In bullet points #2 and 3, you list the worst case wavelength and OMA power. Can you also do the same for bullet point #1 for spectral width?
 
Thanks,
Brad

On Mon, Aug 15, 2011 at 10:23 AM, Swanson, Steven E <SwansonSE@xxxxxxxxxxx> wrote:
Matt,
 
I had an error in my calculation:
 
1. The average spectral width is 0.317

2. The average wavelength is 850.6; worst case 845.7

3. The average OMA power is -1.41; worst case -2.42

Using these numbers in the IEEE model yields 4.9 dB of margin at 400m.

Using these numbers in the IEEE model yields 2.6 dB of margin at 550m.

 

Steven E. Swanson
Corning Incorporated
800 17th Street NW, HI/ES
Hickory, NC 28603-0489

t       828-901-5328
f       828-901-5533
c       607-725-1129

swansonse@xxxxxxxxxxx

 

From: Swanson, Steven E [mailto:SwansonSE@xxxxxxxxxxx]
Sent: Monday, August 15, 2011 10:50 AM
To: STDS-802-3-MAINT@xxxxxxxxxxxxxxxxx
Subject: Re: [802.3_MAINT] Follow up on proposed Comment to add distance specification for 10GBASE-S over OM4 media

Matt etal,
 
I had our guys look at the VCSELs we have purchased on the open market used in our test facilities; there are 70 transceivers from 6 different manufacturers. 78% of the spectral widths are less than 0.35. The triple trade-off numbers are as follows:
 
1. The average spectral width is 0.286

2. The average wavelength is 849.4; worst case 845.7

3. The average OMA power is -1.24; worst case -2.42

Using these numbers in the IEEE model yields 5.2 dB of margin at 400m.

Using these numbers in the IEEE model yields 3.3 dB of margin at 550m.

The more I look at this, I think we are being REALLY, REALLY conservative in IEEE, maybe too much so; here is the distribution of spectral width:

 

Steven E. Swanson
Corning Incorporated
800 17th Street NW, HI/ES
Hickory, NC 28603-0489

t       828-901-5328
f       828-901-5533
c       607-725-1129

swansonse@xxxxxxxxxxx

 

From: Matt Traverso (mattrave) [mailto:mattrave@xxxxxxxxx]
Sent: Thursday, July 28, 2011 9:05 PM
To: STDS-802-3-MAINT@xxxxxxxxxxxxxxxxx
Subject: [802.3_MAINT] Follow up on proposed Comment to add distance specification for 10GBASE-S over OM4 media

Hello to the now very active IEEE Maintenance reflector!

 

As I mentioned during my presentation at the IEEE plenary in July I would like to schedule a few calls to follow up on the questions/comments raised during the meeting. (see http://www.ieee802.org/3/maint/public/traverso_1_0711.pdf)

 

My goal for these calls per the discussion on the floor is to try to build more confidence in the proposed reach value.  I believe that there was broad consensus at the meeting that (a) goal of specifying value is worthwhile,(b) theoretical analysis was sound.  I hope to confirm my perception at the first call & discuss further justification for 400m reach.

 

My intention is to submit a comment by the comment deadline of Aug 26th.

 

Call timing:

Wednesday Aug 10th, 10 – 11:30 am PT

Wednesday Aug 17th , 10 – 11:30 am PT

 

Meeting login details below

 

best regards

--matt traverso

 

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