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



Dear Dr. Parruck and Dr. Hajduczenia,

Thank you for your discussions for solving the PIN/APD issue.
Perhaps I am not an appropriate person to discuss, because 
some PIN group member should be responsible.  But I try some, 
because my explanation, in my former E-mail, was perhaps 
not good and misunderstood.

There is 8dB sensitivity difference between 10G PIN and APD, 
including about 1-1.5dB E-FEC gain difference.  It is the 10G 
optics background and the main reason for the long PIN/APD battle.  
Your discussions are ignoring this background and only driving 
the PIN sensitivity close to APD, but I am afraid this approach 
is not fruitful.
As for the power budget spec. lists, all the vendors carefully 
investigated the tight B++ requirement and decided the spec. numbers 
with their optics experts, who have huge production experience of 
XFPs and other 10G transceivers.  I believe they started their 
assumption with the typical PIN-ROSA alone sensitivity of around 
-21dBm@10-12, same as that Dr. Parruck has indicated in his E-mail, 
and they decided, in the end, the ONU sensitivity spec. -20dBm with E-FEC.  
They have no room to improve as long as they assume current PIN-ROSA 
performance.

The following shows the PIN receiver sensitivity experimental results 
on the page 7 of 3av_0611_Chang_1.pdf.
3	10Gb/s	-19dBm		PIN-HBT		1998
4	10Gb/s	-20.4dBm	PIN-HBT		1995
5	10Gb/s	-22.4dBm	PIN-HEMT	1996
6	10Gb/s	-23.5dBm	PIN-HEMT	1995
I do not know other reports so far breaking this record -23.5dBm, 
and that means there were no big improvements for more than 10 years.  
And also future 10G PIN-ROSA sensitivity improvement seems limited 
unless there comes a drastic breakthrough.

Your discussions, requesting the PIN-ONU sensitivity lower, seem to me 
that you are indirectly persuading the PIN group to give up PIN and 
to choose APD, but I do not think it is acceptable for them.

This shows only my personal understanding, please ask some PIN group 
member for clear answer.

Best regards,
Hiroshi Hamano

%% "Hajduczenia, Marek" <marek.hajduczenia@SIEMENS.COM>
%% Re: [8023-10GEPON] PIN-PD Power Budget
%% Fri, 31 Aug 2007 10:36:22 +0100

>  
> Dear Bidyut, 
> That would be splendid since it would allow us to end the PIN/APD wars with a single neat aggressive power budget which would satisfy everyone. 
> The problem is that we seem to get not much closer to consensus than we were during the last two meetings. I am not a PIN / APD expert but isn't it possible to create a single proposal which could satisfy both camps and allow the rest of the group to back up the proposal ? 
> Forgive my ignorance if such a solution is impossible due to some obvious reasons I am not aware of
> 
> Marek Hajduczenia (141238)
> NOKIA SIEMENS Networks S.A., Portugal - R
> Rua Irm竢s Siemens, 1
> Ed. 1, Piso 1
> Alfragide
> 2720-093 Amadora
> Portugal
> * Marek.Hajduczenia@siemens.com
> http://www.marekhajduczenia.info/index.php
> (+351.21.416.7472  4+351.21.424.2082
> "C makes it easy to shoot yourself in the foot; C++ makes it harder, but when you do, it blows away your whole leg." - Bjarne Stroustrup 
> 
> -----Original Message-----
> From: Bidyut Parruck [mailto:Bidyut@CORTINA-SYSTEMS.COM] 
> Sent: quinta-feira, 30 de Agosto de 2007 19:17
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: Re: [8023-10GEPON] PIN-PD Power Budget
> 
> Hi Hamano-san,
> 
> My apologies - I didn't look for the PIN-PD receivers in July. However
> in light of where we are with respect to power budget, the discussion is
> relevant and worth revisiting.
> 
> Some of the same PIN-PD vendors, who claim RX sensitivity of -20 dBm for
> BER of 1x10E-3, publish datasheets showing -25 dBm for BER of 1x10E-3.
> If PIN-PD vendors could agree to a better sensitivity, we could all
> agree to one power budget. Could we hear from some of them if they are
> willing to move from -20 dBm?
> 
> Bidyut
> 
> -----Original Message-----
> From: Hiroshi HAMANO [mailto:hamano.hiroshi@JP.FUJITSU.COM] 
> Sent: Wednesday, August 29, 2007 8:20 PM
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: Re: [8023-10GEPON] PIN-PD Power Budget
> 
> Dear Sirs,
> 
> Thank you for discussing the power budget table in
> 3av_0705_takizawa_1.pdf.
> 
> For your interest, I copied again the E-mail discussion with
> Dr.Effenberger
> below.
> You can also find it in the E-mail reflector archive.
> 
> http://www.ieee802.org/3/10GEPON_study/email/msg00644.html
> 
> Best regards,
> Hiroshi Hamano
> 
> ------- Forwarded Message
> %% Hiroshi HAMANO <hamano.hiroshi@JP.FUJITSU.COM>
> %% Re: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN vs.
> APD
> %% Tue, 10 Jul 2007 20:48:35 +0900
> 
> Dear Dr. Effenberger,
> 
> I cannot understand why you say that there exists unfairness between PIN
> 
> and APD sensitivities.  I believe both the RX sensitivities are quite 
> fair enough with regard to production feasibility.
> No such arguments arise among vendors here, because they always think 
> about both receiver types seriously and check both budget tables.  
> If the RX-type will be once decided, all the vendors have to put the one
> 
> in production anyway, even though their RX preference is the other.
> 
> If you think that PIN-RX sensitivity in our vendor summary looks
> conservative, 
> same as Dr. Frank Chang thought that APD-RX looks so --- he pointed that
> out 
> at the last Geneva meeting ---, I understand somewhat both of your
> feelings, 
> considering such a tight Class B++ power budget.
> But please understand the 10G transceiver production facts, for
> instance, XFPs.  
> It is not the laboratory experiments or single ROSA performance.  
> Vendors also have to spend a lot care for product deviations, especially
> 
> for ONU, to avoid yield which makes its cost jump up.
> Besides, as it is the specification of ONU sensitivity, additional
> unknown 
> WDM filter loss onto the bare transceiver cannot be ignored, which
> Takizawa 
> always comments on his power budget presentation.
> I once suggested that a slight change (0.5dB) for RX sensitivity, and
> got 
> a strong booing from all the vendors.
> So, the vendors cannot change their RX sensitivities of both PINs and
> APDs 
> at moment.
> 
> Best regards,
> Hiroshi Hamano
> 
> ---------------------
> 
> %% Bidyut Parruck <Bidyut@CORTINA-SYSTEMS.COM>
> %% Re: [8023-10GEPON] PIN-PD Power Budget
> %% Wed, 29 Aug 2007 16:59:41 -0700
> 
> > 
> > 
> > 
> > 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:
> > 
> > 
> 
> 
> 
> 
> ---
> ---------------------------------------------
> HIROSHI HAMANO         Network Systems Labs.
> FUJITSU Labs. Ltd., Kawasaki, 211-8588 JAPAN
> TEL: +81-44-754-2641  FAX: +81-44-754-2640
> E-mail: hhlsi@flab.fujitsu.co.jp
> ---------------------------------------------
> 
> 




---
---------------------------------------------
HIROSHI HAMANO         Network Systems Labs.
FUJITSU Labs. Ltd., Kawasaki, 211-8588 JAPAN
TEL: +81-44-754-2641  FAX: +81-44-754-2640
E-mail: hhlsi@flab.fujitsu.co.jp
---------------------------------------------