Re: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN vs. APD
Dear Dr. Effenberger,
I cannot understand why you say that there exists unfairness between PIN
and APD sensitivities. I believe both the RX sensitivities are quite
fair enough with regard to production feasibility.
No such arguments arise among vendors here, because they always think
about both receiver types seriously and check both budget tables.
If the RX-type will be once decided, all the vendors have to put the one
in production anyway, even though their RX preference is the other.
If you think that PIN-RX sensitivity in our vendor summary looks conservative,
same as Dr. Frank Chang thought that APD-RX looks so --- he pointed that out
at the last Geneva meeting ---, I understand somewhat both of your feelings,
considering such a tight Class B++ power budget.
But please understand the 10G transceiver production facts, for instance, XFPs.
It is not the laboratory experiments or single ROSA performance.
Vendors also have to spend a lot care for product deviations, especially
for ONU, to avoid yield which makes its cost jump up.
Besides, as it is the specification of ONU sensitivity, additional unknown
WDM filter loss onto the bare transceiver cannot be ignored, which Takizawa
always comments on his power budget presentation.
I once suggested that a slight change (0.5dB) for RX sensitivity, and got
a strong booing from all the vendors.
So, the vendors cannot change their RX sensitivities of both PINs and APDs
at moment.
Best regards,
Hiroshi Hamano
%% Frank Effenberger <feffenberger@HUAWEI.COM>
%% Re: [8023-10GEPON] [POWER BUDGET] resolving differences over PIN vs. APD
%% Sat, 7 Jul 2007 15:58:30 -0400
> 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)
>
>