Re: [8023-10GEPON] [POWER_BUDGET] Report of local discussion
Motoyuki-san,
I think for 29dB CHIL we have to use APD at the ONU Receiver, APD cost is a temporary issue, its matter of quantities. Even for today APD cost decrease quite fast. Aside the high sensitivity we can achieve by using APD (more than 6dB!), FEC coding gain will be more effective (more than 4dB).
Haim.
-----Original Message-----
From: Motoyuki TAKIZAWA [mailto:mtaki@ACCESS.FUJITSU.COM]
Sent: Thursday, February 22, 2007 9:47 AM
To: STDS-802-3-10GEPON@LISTSERV.IEEE.ORG
Subject: [8023-10GEPON] [POWER_BUDGET] Report of local discussion
All,
As I was assigned in the last telecon to form a group to work
on a Tx and Rx characteristic table for the 29dB CHIL especially
from the view point of system vendors, we had a discussion on it
among some Japanese members.
I don't submit the draft table to here now. We did have draft
characteristic tables from some vendors but we ended up modifying
them again considering the issues we came up with in the call.
This is an intermediate report of our talk.
<Date>
Feb 20, 1:00PM-3:00PM JST
<Participants>
Tsutomu Tatsuta NTT
Akihiro Otaka NTT
Ken-ichi Suzuki NTT
Tomoaki Masuta NEC
Akio Tajima NEC
Toshiaki Mukojima Oki
Shinji Tsuji Sumitomo
Hiroki Ikeda Hitachi
Satoshi Shirai Mitsubishi
Naoki Suzuki Mitsubishi
Hiroshi Hamano Fujitsu Laboratory
Tetsuya Yokomoto Fujitsu Access
Motoyuki Takizawa Fujitsu Access
<Assumption>
The assumption of wavelengths were 1.31um for US and 1.57um for DS,
following the solution 3 in the presentation below.
http://www.ieee802.org/3/av/public/2007_01/3av_0701_tatsuta_1.pdf
<Downstream>
The main point was wheather applying PIN-PD or APD in the ONU.
Needless to say, PIN should be better for the cost reason, however
we need to take a risk applying 'high power' SOA at the OLT that
has less maturity (reliability).
One idea of judging this is if the ONUs should have the same
architecture for each class(PX10, PX20, ClassB++) as same as 802.3ah
standard. It will have an influence on cost and selection for pieces
of components both on the OLT/ONU.
<Upstream>
"PD + Preamp -------- DFB(EML)" would be a preferable solution
for many of us. But we need a narrow band filter between
Preamp(SOA) and PD and it doesn't seem we can have 1G/10G
coexistence at the moment for this reason because 1GEPON needs
100nm band around 1310nm.
Possible solutions are:
- Seeking possibility of increasing LD(DFB/EML) power
- Considering another appropriate wavelength for US
Another topic was the availability of uncooled laser @10G
with broad range of temperature(-40 to +85 degrees C), which
will be expected to use for PX10/PX20.
<Action Item>
- Revise the draft charasteristic table
DS: PD vs APD, considering if all ONUs should have the
same arthitecture for each class.
US: Study two solutions in detail.
- Study availability of uncooled 10G laser with broad temperature
range(-40 to +85 degrees C).
Next discussion will be held on 2/23 JST.
[Clarification]
This local talk is actually not a closed one but I think it is
important to make a draft ASAP and that it is good to have a
local discussion among Japanese System Vendors first like I
was asked to in the last telecon, maybe for the reason of
timezone, language, etc...
I think I'll report back to the ad hoc here and we'll have a
fruitful discussion.
Best Regards,
--
Motoyuki Takizawa
Fujitsu Access Ltd. R&D Center