[time-nuts] Re: World's most accurate PC clock!
cfmd at bredband.net
Mon Jul 4 13:19:34 EDT 2005
From: Bill Janssen <billj at ieee.org>
Subject: Re: [time-nuts] Re: World's most accurate PC clock!
Date: Mon, 04 Jul 2005 09:11:41 -0700
Message-ID: <42C95FBD.4080504 at ieee.org>
> Magnus Danielson wrote:
> >Much important stuff clipped
> >1,544 MHz, 2,048 MHz, 19,44 MHz, 51,84 MHz and 155,52 MHz is standard telecom
> >frequencies. The two first ones are the traditional PDH rates (and thus
> >synchronisation frequencies), the third is the normal SDH/SONET reference
> >oscillator frequency, but 51,84 MHz and 155,52 MHz is more commonly used for
> >bit-clock reference.
> Off topic I guess but wondering if you are involved with the T1X1 standards
> and if so what is happening with the synchronization group
No, I am not involved in the T1X1 standards. However, I would say that the
pace of work in both T1X1 and ETSI on SONET/SDH synchronisation has lowered
significantly to the best of my knowledge. Not that there isn't problems to be
solved, more that other things seems to be more important these days. It has
now been revamped to the ATIS OPTXS. Last published document is from 2003.
I saw what happend to ETSI TM1. The last thing they got out was a really good
tutorial on synchronisation, but the infrastructure fell apart as members where
cutting costs and moving their attention to other places. I had to move my
workitems to another part of ETSI since TM1 was basically closing shop and I
was the last one out. They staid in a slumber and there seems to be a very
minimal level of activity now.
Any particular issue you are wondering about or just in general?
Magnus - didn't fiddle all that much with the SDH sync back then
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