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Re: [8023-10GEPON] PIN-PD Power Budget



Hi Frank,

 

Thanks for clearly stating the issue. The datasheets I’m “casually looking on the web” are from “major” vendors.

 

Both examples I showed had a sensitivity of -21 dBm for BER of 1x10E-12. I can understand 2-3 dB of margin – our current equations are using 5 dB. I do understand, initially, this could increase the cost of PIN-PD. But in the long run the same companies will innovate and bring the cost down. I think we should revisit this subject.

 

Regards,

 

Bidyut

 

From: Frank Effenberger [mailto:feffenberger@HUAWEI.COM]
Sent: Wednesday, August 29, 2007 4:16 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] PIN-PD Power Budget

 

All,

 

The 1e-12 BER PIN sensitivity that is being used in the slide below is -16 dBm.  

The slide says that the 1e-4 BER sensitivity is -19 dBm.  

The slide says that the 1e-3 BER sensitivity is -20 dBm.  

 

What Bidyut is noticing is that many receivers he is casually looking at on the web seem to have a much better sensitivity curve than what this slide says.  The typical sensitivity numbers are -20dBm, and I’d believe that the ‘hard spec’ would be about -18 dBm.  I’ve been saying the same thing for many months.  But “team PIN” seems convinced on -16 dBm, for reasons of economy and yield, I’ve been told.  But that is a matter of how aggressive you want to be with the specification…. 

 

Sincerely,

Frank E. 

 

 

 


From: Bidyut Parruck [mailto:Bidyut@CORTINA-SYSTEMS.COM]
Sent: Wednesday, August 29, 2007 6:05 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] PIN-PD Power Budget

 

Hi Ryan,

 

I’m not sure where the FEC numbers are baked in. Here’s the slide 8 from 3av_0705_takizawa_1.pdf.

 

Bidyut

 

 

From: Ryan Hirth [mailto:ryan.hirth@TEKNOVUS.COM]
Sent: Wednesday, August 29, 2007 2:10 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] PIN-PD Power Budget

 

Bidyut,

The additional gain from operating at BER 10E-12 to 10E-3 in your example is the FEC optical gain.  You cannot increase the receiver sensitivity and add gain for FEC since this would be adding in the same gain factor twice.

Regards,

 

Ryan Hirth

Director of ASIC Engineering

Teknovus Inc.

 


From: Bidyut Parruck [mailto:Bidyut@CORTINA-SYSTEMS.COM]
Sent: Wednesday, August 29, 2007 1:31 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: [8023-10GEPON] PIN-PD Power Budget

 

I have been looking at publicly available 10Gbps PON photodiode datasheets from major suppliers. For the receiver sensitivity, they all claim -21 dBm for BER of 1x10E-12. The typical characteristics curve suggests a BER of 1x10E-3 for input power level of -25 dBm.

 

With input BER of 1x10E-3, we can find FEC algorithms which would provide output BER of 1x10E-12 or better. Excuse my ignorance of the subject, but why can't we use -24 dBm as the receiver sensitivity for PIN-PD receivers? That will give us an additional 4 dB.

 

Here are some examples: