[Sls-slp] Fwd: Re: Pink Sheet Request for Prox-1 Data Link

Greg Kazz greg.j.kazz at jpl.nasa.gov
Wed Aug 31 23:10:13 UTC 2005


SLS-SLPers,

Attached are the proposed pink sheets in response to RIDs received against 
1) Space Link Identifiers Blue Book and 2) Proximity-1 Space Data Link 
Protocol Blue book. The response to these RIDs are as follows:

1) Space Link Identifiers

Additional Note 3 added to p 7-5. If the Encapsulation Packet header is 
changed as proposed in the Encapsulation Service Pink Sheets, then 
this  note points out not to use the original definition of the 
encapsulation packet as defined in the soon to become historical link layer 
specifications.

2) Proximity-1 Data Link Layer

a) Update to the ordering of frames in the frame sublayer. NASA/JPL MRO 
spacecraft in test discovered that the forward link can be starved when 
there is a large asymmetry in data rates (128:1 and beyond) between the 
forward and return link. To prevent this, frame ordering now includes a 
check to see if any data frames need to be transmitted. If so , those 
frames are shared with PLCW traffic, thus preventing data frame starvation.

b) Minor change: PLCW_Repeat MIB parameter is now, PLCW_Repeat_Interval. 
Which clarifies the functionality

c) Event E8 in full duplex session establishment now includes a note that 
if Carrier_only was received  but no data was sent then this event shall be 
a required notification in the protocol and reported to the vehicle 
controller subsystem. Same is true for Event E36 in Half-duplex.   This 
situation was discovered in NASA/JPL MRO system test.

Please let me know if you have any questions or comments.
We will discuss these proposals at the SLS-SLP meeting in Atlanta.

best regards,

Greg Kazz
Chairman CCSDS SLS-SLP WG

>Date: Wed, 31 Aug 2005 18:46:41 -0400
>From: Thomas Gannett <tgannett at us.net>
>Subject: Re: Pink Sheet Request for Prox-1 Data Link
>X-Sender: tgannett at mail.us.net
>To: Greg Kazz <Greg.J.Kazz at jpl.nasa.gov>
>Cc: ed Greenberg <egreenbe at jpl.nasa.gov>
>X-Mailer: QUALCOMM Windows Eudora Version 5.1.1
>X-Source-IP: rwcrmhc13.comcast.net [204.127.198.39]
>X-Source-Sender: tgannett at us.net
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>
>Greg:
>
>Attached are proposed change pages for both Space Link Identifiers and 
>Proximity-1.  Since the covers of both books will be changed with the next 
>issue, I have replaced the covers with a status cover sheet.
>
>TG
>
>
>
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