Re: [8023-10GEPON] Power Budget report
Dear Takizawa-san,
Thank You for the report. I have just a few minor comments about formalism, which is my piece of cake in the scope of PMD clause.
I agree with the suggestion that several parameters will be left out blank in the D1.0 version of the standard - it only makes sense not to include anything if we do not know what to put. I am also concerned slightly about the measurement techniques, which are discussed in detail in clause 60 for 1 G systems and which were not discussed at all up to now. I am planning on leaving this sections blank as well for the moment since the group has not discussed anything in this matter.
As far as the PIN / APD based receiver issue is concerned - it is my personal opinion that we should try to specify ONU receiver sensitivity parameters more aggressively and not look only at what is currently at the market. The current discussion on this topic indicates that indeed we can go 2 dB lower with (probably) minor yield hit on PINs, which is substantiated by the product sheets available online. It is true that they represent high ER devices, but we must remember one thing - we are not drafting a solution which is to be ready next month. We are trying to forecast what will be the viable technology in 2-3 years and it is ,I think, not only my belief that until then, the PIN production technology will move forward, even if 10G EPONs are the only driver for it.
Thus I would question betting only on the specs of currently available devices and would urge both groups to consider reaching a compromise and present the Task Force with a power budget which may be aggressive for PINs at the moment (easily acceptable for APDs) but is within the expected PIN sensitivity evolution curve we all were told about already so many times. Please note that the longer we argue about PIN / APD issues, the longer it takes to fill up the tables and move on with other, not less important topics of discussion.
Thank You for Your attention
Marek Hajduczenia (141238)
NOKIA SIEMENS Networks S.A., Portugal - R
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-----Original Message-----
From: Motoyuki TAKIZAWA [mailto:mtaki@ACCESS.FUJITSU.COM]
Sent: quarta-feira, 29 de Agosto de 2007 9:50
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: [8023-10GEPON] Power Budget report
Dear Robert and all,
This is a discussion report about 10GEPON power budget recently held
among Japanese people.
1. FEC Algorism
Many people (5 vendors out of 6) support E-FEC to alleviate the
requirement for transmitter's launch power.
Algorism experts suggest RS(255,223) as an E-FEC.
Several individuals (1 vendor) support Standard-FEC with following
reasons.
- Additional gain by RS(255,223) is small even as compared to RS(255,239)
(0.6dB with PIN-RX, 0.9dB with APD-RX)
- 10G burst-mode CDR operation stability at high-error region is still
unknown
- Optics should have potential to achieve the target power budget
without E-FEC
2. IEEE Formalism
Half of the people (3 vendors out of 6) there turned to support the
idea of "3av_0707_hamano_1.pdf".
TDP numbers in there are confirmed by their own 10G-Ether transceiver
data.
But some people (1 vendor) worry about insufficiency of data and
investigations to fulfill all the numbers in the IEEE spec. list.
And they suggest to leave most of the specs., including TDP and S(OMA),
blank or TBD at Draft.1, and to fill only the numbers, Launch(OMA) and
SRS(OMA), instead.
3. Receiver Type in 10GEPON ONU
No approaches for compromise were seen in the discussions between the
two groups of PIN and APD.
They are asking for potential supporters and I think we'll see
discussions again on the reflector or in the next Seoul meeting.
Best regards,
--
Motoyuki Takizawa
Fujitsu Access Ltd. R&D Center