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Re: [8023-10GEPON] Comment #44


Thank you for your response.
Now, we got a common understanding about this issue as below:
"We disagree with removal of the "p-p" from the units for any elements of jitter".


Tibi Galambos さんは書きました:
Dear Kozaki-san and Hamano-san

Sorry for the possible misunderstanding. As long as the BER is specified, I do agree that the units can in a certain sense be UIp-p, and if that is the customary I have no objection at it. As long as we all agree that the mathematical model (for Rj and Tj) behind it is an unbounded distribution and the "p-p" value is defined by the probability (BER).

What I certainly can not agree is the removal of the "p-p" from the units for Dj.
So whether the "p-p" is left in or not for Rj and Tj it is fine with me.

Thanks for your attention,

-----Original Message-----
From: Seiji Kozaki [mailto:Kozaki.Seiji@xxxxxxxxxxxxxxxxxxxxxxxxxxx]
Sent: Sun 6/7/2009 6:29 PM
To: STDS-802-3-10GEPON@xxxxxxxxxxxxxxxxx
Subject: Re: [8023-10GEPON] Comment #44
Tibi-san, and all

I agree with Hamano-san's opinion.
In the meeting of Sept/2008, TF defined Rj value in UIp-p,
which is calculated by using RMS value.
Thus, the unit of specifications for Tj and Rj are should be UIp-p.

Seiji Kozaki

Hiroshi Hamano ????????:
Dear Dr. Galambos,

As indicated in 3av_0809_kozaki_2.pdf, RJ numbers in the Tables are not rms, but DJ aligned value to calculate TJ. Even though RJ does not have the peak-jitter nature, I still think DJ, RJ, and TJ numbers should all be described in UIp-p.

Best regards,
Hiroshi Hamano
Fujitsu Labs. Ltd.

%% Tibi Galambos <Tibi_Galambos@xxxxxxxxxxxxxx>
%% [8023-10GEPON] Comment #44
%% Sun, 7 Jun 2009 09:49:52 +0300

	The proposal for comment #44 is to remove "p-p" from the headers
of tables 75C-1 and 75C-2 altogether. This is not correct.

	The "p-p" attribute has to be removed from the TJ and RJ columns
only. The headers of both tables have to look as follows:
Reference point	DJ (UI p-p)	RJ (UI )	TJ (UI )	


	The jitter budget is built upon the following assumptions:
a.	Jitter is represented assuming the DJ to have an equi-probable
bimodal distribution and RJ to be Gausian.
b.	All sources of random jitter are assumed independent therefore
RJ rms values can be added by squares.
c.	All sources of DJ are assumed to be correlated (this is a worst
case assumption, meaning that all DJ components will be either together
at max value or together at min value, with equal probability for the
min and the max to occur)
	Under these assumptions, RJ and TJ are defined @ BER while DJ is
defined by it's peak to peak value and then the following calculation
			TJ (@ BER) = DJ p-p + RJ (@ BER)

Tibi Galambos Principal Engineer AFE (Analog Front-End)
Tel: +972-9-9628000 Ext. 473
Email: tibi_galambos@xxxxxxxxxxxxxx
Hiroshi Hamano
Network Systems Labs., Fujitsu Labs. Ltd.
Phone:+81-44-754-2641 Fax.+81-44-754-2640