Re: [8023-10GEPON] [POWER_BUDGET] Report of local discussion
Dear Frank,
Unfortunately, you are mistaken:
The current 1G EPON does NOT use PX-10 or PX-20 optics.
NTT has been telling us that for about a year now.
Regards,
Frank E.
-----Original Message-----
From: Frank Chang [mailto:ychang@VITESSE.COM]
Sent: Thursday, February 22, 2007 12:58 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [POWER_BUDGET] Report of local discussion
Frank et al.
I have asked the group similar questions before but in different way. My
interpretation is that we maynot have to do 1/10 coexistence for 29dB
budget. If current 1G use PX-10 and PX-20 optics specified at 20dB and 24dB,
then assuming 10G optics going to share the same fiber installment, so it
doesnot make any sense to me we have to specify 10G budget as 29dB for the
same ODN. I donot think the extra loss form connector hold true here.
My understanding 1/10 coexistence is only for 20dB and 24dB budgets, 29dB
budget will be a standalone case for 10G, addressing the apps similar to
gpon B+ case, unless the current 1G deployment use aggressive budgets other
than spec'd.
Regards
Frank C.
-----Original Message-----
From: Frank Effenberger [mailto:feffenberger@huawei.com]
Sent: Thursday, February 22, 2007 9:03 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [POWER_BUDGET] Report of local discussion
Dear All,
I have an observation to make... It seems that the current standard
specifies loss budgets for PX-10 and PX-20 optics at 20dB and 24dB.
However, it should be clear by now that the actual fielded optics are in
most cases producing an Insertion Loss budget of 29dB. I think we are
missing a standard specification for this.
If that was all, then IEEE could decide to revise clause 60 (or whatever
editorial method you want to do), or decide not to (and leave the market to
its own devices: pun intended). However, our task force has embarked on the
standardization of 10/1 optics, and it seems that many folks want to
consider the 29dB budget, and compatibility with 1/1G EPON is also desired.
So, I don't think we have a choice - we need to define what the 29 dB power
budget is for 1G EPON. (And note: by power budget, I mean the specification
of the transmitter and receiver power ranges, any penalties that come to
bear - in short, everything you find in clause 60.)
If we don't specify the budget of the practical 1G EPON optics, then we
cannot do a proper job of considering compatibility, shared use of the
1310nm channel, and so forth. It is critical.
So, since we seem to have a gathering of the Japanese companies that are
deeply involved in the 1G EPON deployments, it is a good time to ask them to
please present, to our task force, what is their version of clause 60 for
the "29dB" 1G EPON systems, in the field today.
Sincerely,
Frank Effenberger
-----Original Message-----
From: Motoyuki TAKIZAWA [mailto:mtaki@ACCESS.FUJITSU.COM]
Sent: Thursday, February 22, 2007 2:47 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