Thread Links Date Links
Thread Prev Thread Next Thread Index Date Prev Date Next Date Index

Re: [8023-10GEPON] power budget ad hoc teleconference



I believe that a SOA-PIN combination receiver may have better
sensitivity by several dB over an APD receiver for the upstream for the
B++ situation with 1G/10G coexistence.

At Robert's request, here is a summary of what I stated on tonight's
call with some additional backup information.  In this note, I will make
use of "back of the envelope" calculations.  However, I have also made
more detailed models, and we have experiments under way to verify
predictions.  Also I assume no FEC in any of the following.

In addition, to reducing the power requirements on the ONU transmitter,
such a receiver would be RIN-noise limited, and not suffer from the
"dual rate problem" (see for example 3av_0703_effenberger_4.pdf) - and
the "smart TIA" would not need to be invented.

The SOA had been previously discounted as a potential upstream receiver
since a "noise blocking filter" for the 10G upstream signal (e.g. at
1310 +/- 6 nm) would potentially block the legacy GE-PON upstream
signals (1260 - 1360 nm).

10 Gb/s data presented at the November meeting (3av_0611_spiekman_1.pdf;
page 19), show that at SOA with no optical filter between the SOA and
the PIN; can improve the sensitivity of a "bare" by 7 dB.  (These
results were by no means remarkable (e.g. 8 dB SOA noise figure) and
similar results can be found in the literature.

Roughly speaking a 1.25 Gb/s PIN would see a similar improvement with an
unfiltered SOA as a pre-amplifier.   

Now plug in whatever numbers you want for 10 and 1.25 Gb/s PIN
sensitivities - I'll use -18 dBm (10G) and -25 dBm (1.25 Gb/s) - The
result is a receiver with -32 dBm sensitivity at 1.25 Gb/s and -25 dBm
at 10 Gb/s.  This by itself is a slight improvement over an APD at 10
Gb/s (Frank used -24 dBm in his presentation.)  At 1.25 Gb/s sensitivity
this is > 2 dB better than the critical 29.7 dBm requirement for the
legacy GE-PON.

These results can be improved upon by inserting a "noise blocking
filter".  The filter certainly cannot completely block the 1260-1360 nm
legacy GE-PON signal, but since there is some 1.25 Gb/s sensitivity
margin to spare, one can attenuate some of the 1.25 Gb/s signal that
lies outside of the wavelength spec of the 10 Gb/s signal.

As a result sensitivities of -30 dBm at 1.25 Gb/s and -28 dBm at 10 Gb/s
should be possible using a SOA-PIN combination, appropriate optical
filter, and a shared TIA, optimized for 10 Gb/s operation.  Even better
performance is possible with a more tightly wavelength controlled 10
Gb/s transmitter.

The 100 nm operating bandwidth, should also not be a problem, see for
example:

In-service upgrade of an amplified 130-km metro CWDM transmission system
using a single LOA with 140-nm bandwidth
Iannone, P.; Reichmann, K.; Spiekman, L.
Optical Fiber Communications Conference, 2003. OFC 2003
Volume , Issue , 23-28 March 2003 Page(s): 548 - 550 vol.2
Digital Object Identifier   10.1109/OFC.2003.1248402
Summary: We demonstrate a 130-km metro CWDM transmission system using a
single LOA with 140-nm bandwidth. An in-service upgrade, for which one
of the eight 2.5-Gb/s CWDM channels is replaced with 8/spl
times/2.5-Gb/s DWDM channels, results in negligible performance
degradation.

As indicated above, more sophisticated models exist, and we are
experimenting with this idea.

I would appreciate any feedback or critisism.  We hope to share
additional data with this forum.





David Piehler
Alphion

-----Original Message-----
From: Lingle, Jr, Robert (Robert) [mailto:rlingle@OFSOPTICS.COM]
Sent: Tuesday, April 10, 2007 12:09 AM
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON] power budget ad hoc teleconference


All,

The next call(s) will occur on Tuesday April 10 at 7PM EST and Wednesday
April 11 at 9AM EST.

(Because of the US time change in March, I believe that 7PM EST Tuesday
is
now 8AM Japan time on Wednesday.)

Toll-free in US	866-263-8899
Outside US 	816-249-6061
Conf. Code	7707985015

The following Orlando presentations, among others, may be relevant to
the
discussions:

3av_0703_effenberger_1
3av_0703_takizawa_1
3av_0703_jiang_1
3av_0703_stefanov_2

In the call, I would like to address the following items. Please address
them on the Reflector prior to the call.

1. Much attention has been focused on the class B++ CH IL case.  The
only
proposed power budgets for PX10 and PX20 are those in
3av_0703_effenberger_1, slides 6 and 7. Are Frank's numbers for PX10 and
PX20 met with components available today? Or would these also require
development as in the case of B++? Does anyone recommend any changes to
these? If not, should we plan to adopt them at the May meeting?

2. In analyzing the power budgets from effenberger and takizawa for
class
B++, it seems clear (at least to me) that the following components must
be
developed to meet the power budgets:

-- US 1300nm requires the development of a NEW DML, perhaps cooled, that
can
output 3-4 dBm minimum at 1300nm, compared to a more typical 0 to 1 dBm
at
present.
-- DS w/ APD requires a NEW EML with +3 dBm minimum output power,
compared
to a -1 to 0 dBm typical minimum output power at present.
-- DS w/ PIN can be done with existing EML+EDFA; it MIGHT be done with
existing SOA with Psat(1dB)=10dBm, but might require development of an
SOA
with higher Psat(1dB)=12 dBm.

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)