Just a few comments –
(1) I would not be so quick to dismiss XPM. XPM gets stronger as delta
lambda gets small, and at higher RF frequencies. It’s not well known but most
video signals have or less discrete, high modulation index, phase and/or intensity
tones in the 2 – 10 GHz range. These are used for SBS suppression, and they vary
significantly among vendors. I have not done any calculations, but there was a
paper at ECOC this year from KDDI that showed that cross-talk from RF carriers
could add a penalty – aside from power loss.
(2) Is there any need to define the acceptable degradation on the video
signal? This is perhaps the most significant issue with the B/GPON RF video
overlay. I am not concerned with power loss (or gain) but rather the effective
increase in RIN (mediated by either XPM or SRS), or by discrete RF interference
from idle fames again mediated by XPM and/or SRS. (Incidentally would these
idle frames be in phase if you had several 10G DWDM signals originating from
the same switch/router?
I am not trying to open a big can of worms
here, and my feeling is that these effects are probably negligible, although measurable.
David Piehler
Alphion
mobile: +1 732 692 4581
From: Hajduczenia,
Marek [mailto:marek.hajduczenia@SIEMENS.COM]
Sent: Tuesday, January 09, 2007
3:56 AM
To:
STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON]
[Channel link model ad-hoc]
Dear Tatsuta-san,
Thank You very much for Your contribution.
I found it useful and if there is no problem with it, I would like to reuse
part of Your conclusions in the introductory section of the presentation on the
ad-hoc activities.
I agree with Your conclusions and I
believe that the updated Excel spreadsheet will contain SBS and SRS power
penalties - SRS is completed while SBS is still under examination to achieve 0
- order approximation with reasonable quality.
The presentation will be distributed today
and I will ask for the potential supporters of the conclusions and
implementation.
The updated Excel spreadsheet will also be
distributed in due time on the reflector ...
Best wishes
From: TATSUTA
[mailto:tatsuta@ansl.ntt.co.jp]
Sent: terça-feira, 9 de Janeiro de
2007 6:32
To: Hajduczenia, Marek;
STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON]
[Channel link model ad-hoc]
Dear Marek and all,
I summarized the influence of RF signal as attached.
My conclusion is following;
1. SRS and SBS should be studied.
2. XPM does not need to be considered, if a wavelength of 10G-EPON downstream
is separated in 5nm or more from RF signal wavelength.
3. The other items do not need to be considered, unless S/X value of ONU input
point is specified in the standard body (I do not think we specify it.). I
think S/X is implementation issue.
Sincerely yours,
Tsutomu TATSUTA
At 21:41 07/01/04, Hajduczenia, Marek wrote:
Dear
Sergey,
I would appreciate any help You can provide me with. I have some formulas to
estimate the impact of the video channel overlay on the downstream and upstream
channels but I have a very hard time trying to figure out how to calculate /
estimate the values of individual parameters.
Do You have any idea how to apply the formulas with the set of parameters that
we have in the Excel spreadsheet?
Best wishes
Marek Hajduczenia (141238)
SIEMENS Networks S.A. - IC COM D1
R
Rua Irm縊s
Siemens, 1
Ed. 1, Piso 1
Alfragide
2720-093 Amadora
Portugal
* Marek.Hajduczenia@siemens.com
http://marekhaj.easyisp.pl/index.php
(+351.21.416.7472 4+351.21.424.2082<?xml:namespace prefix = o ns =
"urn:schemas-microsoft-com:office:office" />
From: Ten, Sergey Y [mailto:TenS@CORNING.COM]
Sent: quarta-feira, 3 de Janeiro
de 2007 19:32
To: STDS-802-3-10GEPON@listserv.ieee.org
Subject: Re: [8023-10GEPON]
[Channel link model ad-hoc]
Marek,
The impact of the RF overlay may be modeled (in zero
approxiamtion) as increased loss at data signal wavelength since Raman
scattering will transfer energy from digital signal to video signal.
In the next order approximation one has to take into account
transfer of the modulation.
I can help you with taking into account zero approximation.
SergeyFax +1 607 974 4354
-----Original
Message-----
From: Hajduczenia, Marek [mailto:marek.hajduczenia@SIEMENS.COM]
Sent: Wednesday, January 03, 2007
11:14 AM
To:
STDS-802-3-10GEPON@listserv.ieee.org
Subject: [8023-10GEPON] [Channel
link model ad-hoc]
Dear all,
since there was no
activity in the said ad-hoc for some time, I decided to run the first update of
the channel link model spreadsheet (please find it attached in a zipped form -
10GEPON-D.0.0.zip). The main changes included in this release are as follows:
- the examined target range is always limited
from L_start to Target reach, with the granularity depending on the Target
reach value. The formula used to calculate the individual steps in column
[A18:A34] is defined as follows: =(($L$3-$L$4)/16*(ROW($A18)-ROW($A$18))+$L$4)
- the resulting chart for power penalties versus
distance has now the auto ranges for X and Y /top value/ enabled - this
way the chart auto adjusts to the selected range
- L_step was removed since the granularity is
auto adjusted ...
- the "Add Ins Loss" parameter is now
calculated based on the split count for the PSC module used in the EPON
system. Cell L5 contains the split count (Split_count parameter). The cell
L8 value is calculated using the following formula: =10*LOG(L5)+$AM$121*LN($L$5)+$AN$121,
where the theoretical loss for N way splitter are summed with the
approximated excess loss, based on the approximation curves estimated for
typical, commercially available splitters (Cell range [Y69:AL130]). The
curve coefficients for average expected splitter parameters are as
follows: $AM$121 (A=0.5636) and $AN$121 (B=0.3979) with the approximation
curve of logarithmatic type: A*ln(N)+B
To be added,
if required: changing the average splitter type into worst/best case scenario
values - preferably with the switch variables defined in the spreadsheet (may
be tough to find some space for that though :-9)
As for the other
parameters in the spreadsheet: as Dawe suggested previously, we should probably
examine the "TP4 offset cell" (T8) which currently follows "Tx
mask top" (G14) in similar style to 10GEPBud3_1_16a.xls. Dawe thinks that
this cell needs a thorough review and we should adjust its value in such a way
that it compensates for the upstream channel burst mode transmission.
Additionally, we should
try to numerate the impact of the optional video overlay channel on the overall
power budget. Is anyone willing to help me with that ?
Thank You for Your time
and attention
Best wishes
Marek Hajduczenia (141238)
SIEMENS
Networks S.A. - IC COM D1 R
Rua
Irm縊s Siemens, 1
Ed. 1, Piso 1
Alfragide
2720-093 Amadora
Portugal
* Marek.Hajduczenia@siemens.com
http://marekhaj.easyisp.pl/index.php
(+351.21.416.7472 4+351.21.424.2082