[Sois-tcoa] RE: SOIS Time Distribution Service

[Keith Scott]

Chris,

Works for me!  Figuring out how a time distribution service might be
provided in hardware will be interesting...

As for the Toulouse meeting, it's really not a problem people didn't show
up.  I had just gotten off the plane and only had the four slides I posted.
My only objective for Toulouse was gauging peoples' reactions to a re-synch,
so I'm thinking that email is probably a more efficient use of everyone's
time  :)

Best regards,

		--keith

>-----Original Message-----
>From: Chris Plummer [mailto:c.plummer at skynet.be] 
>Sent: Monday, November 29, 2004 6:28 PM
>To: 'Keith Scott'; 'Scott Burleigh'; Stuart.Fowell at scisys.co.uk
>Cc: 'Amalaye Oyake'; philippe.david at esa.int; 
>patrick.plancke at esa.int; Massimiliano.Ciccone at esa.int; 'Stuart 
>Fowell'; tyamada at pub.isas.ac.jp; Jane.K.Marquart at nasa.gov; 
>Rick.Schnurr at nasa.gov; 'Abhijit Sengupta'; 
>SCOTT.C.BURLEIGH at jpl.nasa.gov; Ashton.G.Vaughs at jpl.nasa.gov; 
>sois-tcoa at mailman.ccsds.org
>Subject: RE: SOIS Time Distribution Service
>
>Hi Keith,
>
>It gets my vote with a couple of provisos:
>
>Firstly, let's keep well away from the dreaded "API" 
>terminology. We are all
>grown ups here and can handle abstraction! (-Oh boy....am I 
>going to regret
>saying that). Instead let's stick with an abstract service interface
>definition in true ISO 7498 style.
>
>Secondly, I'm sure that an NTP-like protocol is the right way 
>to go and that
>we should concentrate our initial efforts in this direction, 
>but we must
>also bear in mind that this kind of service is often provided 
>in hardware.
>Therefore, we must be careful that we do not preclude the use 
>of different
>mechanisms to provide the service.
>
>I fully agree that a high accuracy time service is not part of 
>the charter.
>There will always be cases where one payload or system onboard the
>spacecraft needs a high accuracy time service, but these are 
>the minority.
>Most applications will want a modest accuracy, wall-clock type 
>time service,
>and these are the applications we, SOIS, should cater for.
>
>Finally, sincere apologies on the part of Patrick and myself 
>that no-one
>showed up for the time distribution session. We had had to dynamically
>re-shuffle the agenda to cater for some of the joint meetings 
>and could not
>get word of this to you. We will endeavour to do better next time!
>
>Cheers,
>       Chris.
>