Re: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN vs. APD
Frank C.,
I was never thinking of using an EDFA booster. Nor do I think that anybody
really holds much hope for an EDFA on each PON port of an OLT. Ugly!
Besides, the wavelength is all wrong.
Rather, the 'booster' that is commonly thought about is an SOA type. In its
eventual format, the SOA might be monolithically integrated with the EAM and
the laser. (Such integration also helps with the polarization and
wavelength matching of all the components, by the way, so much less
pump-power would be needed in this situation). It has the potential to be a
small packaged device, and is much more suitable for mass OLT use. But, the
issue raised on SOA's was the maximum power you can get out of it, and that
was what I was talking about.
Regards,
Frank E.
-----Original Message-----
From: Frank Chang [mailto:ychang@VITESSE.COM]
Sent: Monday, July 09, 2007 1:50 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN
vs. APD
Frank;
I feel there exist one confusion here. If transmit EDFA booster is used,
over +10dBm output is sth. easy to have, from budget perspective, donot have
to specify the "normal" PIN sens in order to meet the budget. Also its
better to fully use this very high-cost EDFA power, but this probably donot
help much the PIN cost taking into account manufacturing yield from over
100% to over 95%.
However, if you try to cut down the transmit power to e.g. +8dBm, you may
have to add extra cost to implement VOA etc, so there is actually the extra
cost to consider.
To me, introducing edfa booster at the first place is much bigger decision
to make. This probably the reason why both current GPON and EPON initiated
specs with APD.
Regards
Frank C.
-----Original Message-----
From: Frank Effenberger [mailto:feffenberger@huawei.com]
Sent: Saturday, July 07, 2007 12:59 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [POWER BUDGET] resolving differences over
PIN vs. APD
All,
I would like to add, though, that the PIN sensitivity was degraded by 2dB
off of its 'normal value', while the APD was not. If we degrade the APD by
the same factor, then we need +5dBm EML, which now puts you definitely out
of the game.
Just to be clear, I don't recommend the degradation. I think that our
device specifications need to be moderately forward-looking.
So, I recommend that we get rid of the 2dB hit on the PIN sensitivity, and
the number be placed at -18dBm (@1e-12 BER). In this case, the OLT
transmitter is only needed to be +8 dBm, which is comfortable for a boosted
transmitter.
Just trying to be fair...
I think people are going to try to estimate relative costs of APDs, PINs,
SOAs, and EMLs. Before we jump into that, we have to agree on the "level of
difficulty" for each of those parts. From my point of view, the APD camp
has been under-estimating the difficulty of its transmitter (evidently it is
at the edge of the technology today), and over-estimating the difficulty of
the competing transmitter (by pushing the budget up enough to make people
uncomfortable.) A more balanced view would lead to a better comparison.
Sincerely,
Frank Eff.
-----Original Message-----
From: Frank Chang [mailto:ychang@VITESSE.COM]
Sent: Saturday, July 07, 2007 3:28 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN
vs. APD
Robert;
I was out of office thur-fri, lets connect monday and sort this out.
Actually during break last meeting, there already some discussion with
several experts. There exist multi high output TOSA vendors for either
1.55um EML or 1.3um DML. And even we use some such +2dBm and +4dBm part in
the lab., which shipping primarily for telecom market.
Frank
-----Original Message-----
From: Lingle, Jr, Robert (Robert) [mailto:rlingle@ofsoptics.com]
Sent: Friday, July 06, 2007 7:22 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] [POWER BUDGET] resolving differences over
PIN vs. APD
Frank Chang,
I think it was you and I who disagreed over whether +3dBM average output
power EMLs were commercially available, which is item #3 below.
Why don't we try to sort this out by Monday with examples of highest power
commercial EMLs available.
Robert
-----Original Message-----
From: Lingle, Jr, Robert (Robert) [mailto:rlingle@OFSOPTICS.COM]
Sent: Thursday, June 14, 2007 12:13 PM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN
vs. APD
All,
As chair noted in his email of 6/12, please recall the discussion we had on
Monday evening in Geneva about pros and cons of PIN vs. APD in ONU.
Attached are the straw polls and points of argument.
I have identified three items in red to focus on initially.
<<APD vs PIN pro-n-con.pdf>>
1. An objection was raised to having an amplified EML at OLT due to
non-linear interactions between D/S and analog video overlay. David Piehler
supplied a response that will be posted separately to start a thread.
In two cases we had task force members stating directly contradictory
opinions:
2. one stated that PIN ONU leads to lowest fully subscribed cost, while
another stated that PIN ONU leads to highest fully subscribed cost.
3. one stated that high power EMLs (+2 to +3 dBm minimum output power) for
use with APD at ONU are commercially available today, while another stated
that such high power EMLs are not available today.
I would like to ask for volunteers who hold opinions on point #2 and point
#3 to volunteer to defend these those positions on the Reflector, with
back-up information.
Warmest Regards,
Robert
Robert Lingle, Jr.
Fiber Design and Transmission Simulation
OFS Corporate R&D, Atlanta
404-886-3581 (cell)
770-798-5015 (office)