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:
