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

Re: [8023-10GEPON] Comment #44

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 )	
>> 	Justification:
>> 	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
>> holds:
>> 			TJ (@ BER) = DJ p-p + RJ (@ BER)
>> Tibi Galambos 
>> Principal Engineer AFE (Analog Front-End)
>> PMC-Sierra
>> Tel: +972-9-9628000 Ext. 473
>> Email: tibi_galambos@xxxxxxxxxxxxxx
>> <mailto:itibi_galambos@xxxxxxxxxxxxxx>
> ---
> -----------------------------------------
> Hiroshi Hamano
> Network Systems Labs., Fujitsu Labs. Ltd.
> Phone:+81-44-754-2641 Fax.+81-44-754-2640
> E-mail:hamano.hiroshi@xxxxxxxxxxxxxx
> -----------------------------------------