Re: [8023-10GEPON] [POWER-BUDGET] 10G PIN sensitivity at ONU
Dear Dr.Effenberger,
In the vender summary, I suppose, most venders here assume the receiver
sensitivity without FEC of
-16dBm for PIN equipments,
-23dBm for APD equipments.
The sensitivity difference is 7dB.
As indicated in the paper 3av_0703_takizawa_1.pdf, vendors are a little
pessimistic about XFP PIN sensitivity.
But I also have the same feeling that in the practical XFP production
APDs show slightly better performance than expected in comparison with PINs.
I asked my XFP colleagues why, but could not get a clear answer.
Maybe APDs are treated more sensitivity consciously than PINs.
I keep asking my colleagues.
Thank you for your comments.
Best regards,
Hiroshi Hamano
Fujitsu Labs. Ltd.
%% Frank Effenberger <feffenberger@HUAWEI.COM>
%% Re: [8023-10GEPON] [POWER-BUDGET] 10G PIN sensitivity at ONU
%% Mon, 14 May 2007 14:40:26 -0400
> Dear Hiroshi,
>
> I am left to wonder, then, why the APD sensitivity number is not similarly
> reduced? I think we both began with the specifications on practical XFP
> optics, which are -18 dBm for PINs and -24 dBm for APDs (that was my idea,
> at least).
> So, if PINs get degraded to -16 dbm, then shouldn't APDs get degraded to -22
> dBm?
>
> Put another way, if we use the numbers put forward from the Japanese
> sub-group, we see that the APD - PIN sensitivity difference is 8 dB. This
> seems to be a little on the high side. More nominal APD advantage is around
> 6 dB, especially when you factor in that the APD is probably less than
> optimized in the access device.
>
> Sincerely,
> Frank E.
>
>
>
>
> -----Original Message-----
> From: Hiroshi HAMANO [mailto:hamano.hiroshi@JP.FUJITSU.COM]
> Sent: Monday, May 14, 2007 7:10 AM
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: Re: [8023-10GEPON] [POWER-BUDGET] 10G PIN sensitivity at ONU
>
> Dear Dr. Lingle;
>
> Thank you for your E-mail.
>
> I have asked some colleagues, who are involved in XFP design and production,
>
> about its receiver sensitivity. They said that practical XFP receiver
> sensitivities are distributed between -18dBm and -19dBm, and they cause
> yield issues if you reject receivers with the sensitivity worse than -18dBm.
> As additional WDM filter losses and other penalties are significant and
> cannot be ignored, related items are listed in the table of 'Vender
> Summary',
> ONU sensitivity should be considered worse than that of PIN-RX.
> Some 1dB may be easily allocated for each WDM filter and penalty, but
> piling up those worst-case numbers is destructive in the 29dB CH IL B++
> case.
> Total loss coordination in the ONU transceiver was therefore admitted as
> the vendor's choice to make the sensitivity degradation together as small as
>
> possible (within 1-2dB, I suppose). I am not sure a detailed discussion
> about
> loss and penalty has been done in each vendor, but I believe, with FEC,
> '-19dBm'
> is the most likely and marginal number for ONU sensitivity at this moment,
> and most of the vendors here have suggested the same.
>
> I appreciate your further questions and comments.
>
> Best regards
> Hiroshi Hamano
> Fujitsu Labs. Ltd.
>
>
> %% "Lingle, Jr, Robert (Robert)" <rlingle@OFSOPTICS.COM>
> %% [8023-10GEPON] [POWER-BUDGET] 10G PIN sensitivity at ONU
> %% Fri, 11 May 2007 10:12:54 -0400
>
> > The effective PIN diode sensitivities assumed in the two draft Downstream
> > power budgets on the Reflector (Effenberger 4/18 and Takizawa 4/30) differ
> > by 2 dB, when FEC cosnsiderations are eliminated:
> >
> > Effenberger -22 dBm, including ~4dB of FEC gain, for effective Rx
> > sensitivity of -18 dBm.
> > Takizawa -19 dBm, including ~3 dB of FEC gain, for effective Rx
> sensitivity
> > of -16 dBm.
> >
> > Hamano-san told us that the Takizawa budget does not assume a cheaper PIN
> > than Effenberger, but he said that it rather includes penalties inside the
> > Rx which must be accounted for.
> >
> > I would appreciate it if Hamano-san (or some other person familiar with
> the
> > issue) to describe in some detail the estimates leading to the -16 dBm
> > number, so we can try to narrow the gap between these two drafts in this
> > area to a common number.
> >
> > Robert
> >
> > Robert Lingle, Jr.
> > Fiber Design and Transmission Simulation
> > OFS Corporate R&D, Atlanta
> > 404-886-3581 (cell)
> > 770-798-5015 (office)
> >
> >
>
>
---
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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
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