Re: [8023-10GEPON] power budget ad hoc teleconference
Dear Frank.E and Power Budget Ad hoc members,
It seems Robert's e-mail and this mail have crossed in the post.
Now we have two power budget proposals, one of which is estimated
from 1G/10G differences and posted by you and the other one is
estimated from the opinions of Japanese vendors experts and posted
by me. I think it's time to discuss these two proposals and we might
as well merge them into the draft proposals.
Please feel free to ask about our proposals or make comments on it.
If we can have a consensus of opinions, I would like you to put them
into your table.
Firstly, the followings are the comments on your proposals I discussed
with some optics experts.
1. FEC gain
In the last teleconference on April 10, it was already pointed out that
3-dB FEC gain is theoretically the maximum number for PIN receiver.
RS(255,239) FEC coding gain is described as 5.9dB at BER of 10-12
in terms of OSNR, optical-signal to optical-noise ratio, in several
technical literatures(e.g. ITU-T G.series Supplement 39).
As a PIN photodiode is an optical-power to electrical-current converter,
electric signal power reflects the square of optical power, or twice in dB.
PIN receiver sensitivity is determined by electric SNR, electric-signal-power
to electric-circuit-noise ratio, and therefore the FEC coding gain in
terms of optical input power will be halved to 3dB.
---10G D/S (p.8); PX20 and B++(1)
2. DFB DM optical source penalty
It was also pointed out that 10G DFB DM optical source can be utilized
at the extinction ratio ER up to 6 dB, instead of 9 dB, avoiding its deep
ON/OFF switching to achieve 10G speed. Besides, it suffers serious
waveform distortion from its own resonance frequency. As a result, the
receiver sensitivity with the DFB transmitter is at least 2 dB worse
than that with EML. (Regarding this 2 dB sensitivity difference, Hamano
and Yokomoto suggested EML@ONU to relax the ONU optical source power
requirement in the presentation I posted on 4/17.)
FEC may somewhat relax the degradation not only by noise but by distortions
and interference, but it is dangerous to count it now in the specs.
---10G U/S (p.7); PX10, PX20, B++(a), and B++(b)
3. APD receiver overload
Around -5 dBm would be the maximum number for 10G APD receiver overload.
Some vender here criticized that it may even lower.
In APD receiver at its proper multiplication factor(M) setting,
amplified signal current flows into TIA, and therefore better sensitivity can
be achieved than that of PIN receiver.
According to 10G transceiver experts, PIN receiver overload seems to
be up to around 0dBm. But this APD-amplified signal current easily
saturates the receiver circuit, and significantly decrease the overload.
---10G U/S (p.7); PX10, PX20, and B++(a)
---10G D/S (p.8); B++(2)
Please find attached notes about the summary of Japanese discussions
so far.
Best regards,
Motoyuki Takizawa
On Wed, 18 Apr 2007 22:14:48 -0400
Frank Effenberger <feffenberger@HUAWEI.COM> wrote:
> Everybody,
> Please find attached a new version of my power budgets, which is based on
> the new ideas put forward in the call last week.
>
> I would like to point out that this work is based on certain system
> engineering themes to develop the three power budget classes, all of which
> have the goal of reducing the number of unique optics types to a minimum.
>
> The component engineers may gasp at some of the numbers that this approach
> generates, but at least it sets some targets. We can then see how close we
> can shoot.
>
> Next on my 'to-do' list is to transform these numbers into OMA formalism,
> etc., for better plugging into the spreadsheet. I think that this will help
> dispel some of the concern regarding optical path penalty.
>
> Regards,
> Frank E.
>
>
> -----Original Message-----
> From: Lingle, Jr, Robert (Robert) [mailto:rlingle@OFSOPTICS.COM]
> Sent: Wednesday, April 18, 2007 4:49 PM
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: Re: [8023-10GEPON] power budget ad hoc teleconference
>
> Please find attached notes from last week's call
>
> Robert
>
> -----Original Message-----
> From: Lingle, Jr, Robert (Robert) [mailto:rlingle@OFSOPTICS.COM]
> Sent: Tuesday, April 03, 2007 10:07 AM
> To: STDS-802-3-10GEPON@listserv.ieee.org
> Subject: [8023-10GEPON] power budget ad hoc teleconference
>
>
> All,
>
> The next Power Budget Ad Hoc teleconference will occur on Tuesday April 10
> at 7PM EST and Wednesday April 1 tentatively at 9AM EST. I may have to
> travel Wednesday and ask your flexibility if I need to push this time to
> 8:30AM or 9:30AM to accomodate.
>
> The topics will be a review of power budgets presented at the March Plenary
> by Frank Effenberger and Wenbin Jiang, as well as implications of the
> presentation by Stefanov on SOA output power issues.
>
> More details will follow.
>
> Robert
>
> Robert Lingle, Jr.
> Fiber Design and Transmission Simulation
> OFS Corporate R&D, Atlanta
> 404-886-3581 (cell)
> 770-798-5015 (office)
>
--
Motoyuki Takizawa
Fujitsu Access Ltd. R&D Center
PowerBudgetVendorSummary.pdf