[Css-csts] F-CLTU Pink Book - relationships among production status, PLOP CMMs, and link events

[John Pietras]

Wolfgang,
You have been keeping very busy cranking out these SLE Pink Sheets. I hope this next round will result in new Blue Books.

I have taken a quick look at the F-CLTU book this morning to see how you have covered the material in the production-status/PLOP CMM/link events (e.g., frequency sweep completed) table that we worked on two years ago, and see that you have covered part of the material as NOTEs in Annex B. However, as currently constructed, those NOTEs appear to only describe the effects on F-CLTU production status given that, for example, the PLOP is in CMM-XYZ. It does not appear to address how the CMM itself is affected by the link events. This is a topic of confusion and interest within parts of NASA that until now have simple offered a forward bitstream service and are just now being required to implement SLE and in particular the lowest  layers of the Telecommand stack needed for F-CLTU. It was the questions that I was getting about this larger set of relationships that I was trying to address and clarify when I developed the set of state tables that you and I subsequently refined in Cleveland and in the months following the Cleveland meeting. I was a bit disappointed that that larger set of relationships did not get covered in the F-CLTU Pink Book.

On the other hand, I realize that the relationship of CMM to link events is not really the purview of the F-CLTU and FSP books - it should be defined in the documents produced by the Space Link Service (SLS) Area. One option would be to follow-up with SLS to see if they would be willing to incorporate the material in their formal documentation. However, as this would be a new topic for them, I anticipate that it might take some time for them to consider the proposal and get it into their program of work. And SLS might even decline to specify a single definitive set of relationships among CMMs and link events. In the meantime, space data systems are being developed by people who lack the guidance as to how these various aspects are all supposed to work together.

I propose that the F-CLTU and FSP book contain an informative annex containing the "larger" state table, with the explanation that these are the state relationships that are assumed by the F-CLTU and FSP books. If and when SLS defines those relationships in normative documentation, future versions of the F-CLTU and FSP books can simply reference those specifications.

Finally, a small technical point on Annex B of the F-CLTU Pink Sheets. Annex B is a normative annex, but the relationships among production status and CMMs are described in Notes. By definition, Notes are informative - if the material that these Notes contain are supposed to be normative, then they must be documented as requirements and not Notes.

Best regards,
John

From: css-csts-bounces at mailman.ccsds.org [mailto:css-csts-bounces at mailman.ccsds.org] On Behalf Of Wolfgang Hell
Sent: Monday, September 29, 2014 4:58 AM
To: CCSDS_CSTSWG (css-csts at mailman.ccsds.org)
Subject: [Css-csts] F-CLTU Pink Book

Dear CSTS WG Members,

I have uploaded to the CWE ( Cross Support Services Area (CSS)<http://cwe.ccsds.org/css> > Documents<http://cwe.ccsds.org/css/docs/Forms/AllItems.aspx?View=%7B8045374D-F8E0-4356-83CA-993252A38FE8%7D> > CSS-CSTS<http://cwe.ccsds.org/css/docs/Forms/AllItems.aspx?RootFolder=%2Fcss%2Fdocs%2FCSS%2DCSTS&View=%7B8045374D-F8E0-4356-83CA-993252A38FE8%7D> > CWE Private<http://cwe.ccsds.org/css/docs/Forms/AllItems.aspx?RootFolder=%2Fcss%2Fdocs%2FCSS%2DCSTS%2FCWE%20Private&View=%7B8045374D-F8E0-4356-83CA-993252A38FE8%7D> > SLE Services) the document "Pink FCLTU 912x1b3ec1 20140925" for your review. I believe that this version is consistent with all changes the WG had agreed upon. The remaining SLE book (FSP) will follow soon. Please note that as work on the Pink Books progresses, further changes in the common ASN.1 modules will become necessary and therefore you should not regard in particular the first ASN.1 module in Pink Books  uploaded so far as final.

Best regards,
Wolfgang

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