[Sis-csi] TDRSS scheduling

[Keith Hogie]

All,

   Here is a very brief version of TDRSS scheduling processes.
I didn't get to the Ground Network scheduling process yet.  Also,
I won't be at the telecon on Thur 6/2 since I need to go to
my daughters 8th grade awards ceremony and embarrass her by taking
pictures of her getting lots of awards.


High level version of TDRSS scheduling process

3 weeks prior to event - requests submitted, submitting too far
     in advance of 3 weeks not useful

2 weeks prior to event - conflict resolution goes on based on
     priorities, and lots of other magic.

1 week prior to event - final schedule comes out, events are pretty
     much locked in but users can try to make use of any idle time
     slots

just prior or possibly during event - some parameters like data
     rate may be changed on the fly.


   Of course this process goes on continually.  It involves mission
schedulers initiating requests, TDRSS folks coordinating and
resolving conflicts, mission schedulers dealing with conflicts,
mission schedulers looking for last minute slots.

   There are TDRSS Demand Access Services (DAS) coming available
that change this picture a bit.  With DAS, users can submit long
term requests far in advance and then send data whenever they
like.  However, this is only an augmentation of standard TDRSS
services and not an automated replacement.  With DAS there are
limitations of 150 Kbps and it only supports one-way data flows
from space to ground.

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   Keith Hogie                   e-mail: hogie at ipinspace.gsfc.nasa.gov
   Computer Sciences Corp.       office: 301-794-2999  fax: 301-794-9480
   7700 Hubble Dr.
   Lanham-Seabrook, MD 20706  USA        301-286-3203 @ NASA/Goddard
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