Re: [8023-10GEPON] Loss Budget compilation
Dear Dr. Effenberger,
I would like to show my appreciation for your effort clarifying
the each class power budget in simple and nice tables.
I believe the budget number mostly reflects Takizawa's presentations;
3av_0705_takizawa_1.pdf and 3av_0707_takizawa_1.pdf, and it seems
acceptable for most attendee.
I would like to put some miner comments to make my understanding
clearer, comparing to Takizawa's tables.
1.PR10-D :
It seems to me that it should not necessarily be the same OLT
output power level as that of PR30-D.
22dB power budget looks a little strange compared to the other classes,
which should be ChIL + 1dB power penalty. If the different optical
wavelengths will be applied for PR10-D and PR30-D, for example,
1590nm and 1577nm, there is no big meaning for commonality of PMDs.
Besides, 1dB lower output power specification can be safer at
1590nm wavelength, where EML power level may slightly be lower,
compared to C-band.
I am not sure about the possibility for PR10-D, but in case of uncooled
EMLs, the budget number should also be described a little differently.
2.PR10-U :
It seems reasonable to unify the 1G/10G ONU output power levels
considering the dual-mode receiver overload in OLT.
As for the actual OLT receiver, I believe 4-dB attenuator insertion,
instead of 6-dB, in front of the 10G APD receiver is feasible
for parallel-PMD configuration. And this also makes the 1G sensitivity
margin bigger. Please see the attached figure.
The only issue is that this rejects the possibility of PIN serial-PMD
option.
3.FEC :
There is no description in the tables, but I believe all the numbers
are settled including RS(255,223) FEC code. But I am still concerned
about the presentation by Dr. Jeff Mandin, who pointed out that
E-FEC doubles the circuit size and power dissipation of RS(255,239).
In case of S-FEC, all the power levels should be 1dB higher than
those in the tables now.
But E-FEC still seems unavoidable especially with crucial high-power
request for DML in 10G ONUs.
Best regards,
Hiroshi Hamano
%% Frank Effenberger <feffenberger@HUAWEI.COM>
%% [8023-10GEPON] Loss Budget compilation
%% Tue, 25 Sep 2007 12:31:16 -0400
>
>
>
> Dear All,
>
>
>
> Per request of the chairman, I have compiled the loss budgets as best I can
> assess them.
>
> In doing so, I have attempted to minimize the number of distinct component
> levels.
>
>
>
> Please take a look, and comment freely on the exploder.
>
>
>
> Sincerely,
>
> Dr. Frank J. Effenberger 献声針 娃繋鴬鯉
>
> Huawei Technologies USA
>
> 1700 Alma Drive, Plano TX 75075
>
> Office (732) 625 3002
>
> Cell (908) 670 3889
>
>
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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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DualmodeRX.pdf