[CESG] Magenta Book issue: "Profiles"

[Hooke, Adrian J (9000)]

Area Directors: as you will have observed in recent days, we are having some problems deciding whether documents should be categorized as Blue or Magenta. The latest problems have surfaced with several documents that point to external specifications in a normative way (e.g., SOIS-MTS, SIS-LTP, SLS-DVBS) rather than containing their own normative specifications. This is sometimes done for reasons of copyright, i.e., we can't simply cut-and-paste the text of another standard and make it our own. However, in all of these cases one thing is clear: we are pointing to another normative specification and adopting all of it, or a precise subset/superset of it, as our own normative technical standard. So is it a Blue Book or a Magenta Book?

Some have argued that we are essentially creating an "Application Profile" and as such the document should be Magenta. However, in the current governing documents <http://public.ccsds.org/publications/YellowBooks.aspx>  http://public.ccsds.org/publications/YellowBooks.aspx  (the "Procedures Manual for the Consultative Committee for Space Data Systems" and the "Restructured Organization and Processes for the Consultative Committee for Space Data Systems") there is no such formal document category as an "Application Profile Magenta Book". The Procedures Manual refers - once - to "application profiles for CCSDS specifications recommended for use in particular mission support configurations". The restructuring book notes - once - that "a Recommended Practice might specify some specific "Application Profiles" of multiple CCSDS Standards that are recommended for use in particular mission support configurations". In the still-draft new document "ORGANIZATION AND PROCESSES FOR THE CONSULTATIVE COMMITTEE FOR SPACE DATA SYSTEMS" there is a bit more proposed text about "Application Profiles", but we haven't agreed on that yet.

Clearly, we need some better guidance to help distinguish between a Recommended Standard and a Recommended Practice in the cases where we are adopting a normative "profile" of another standard. So it may be helpful to invent language to distinguish between:


a)      a profile that specifies how to accomplish a new general function by normative reference to specific normative text in some other specification(s) [e.g., LTP, MTS or DVB-S] and;

b)      a profile that specifies how to support a particular mission class by recommended reference to how some other specification(s) may be used or stacked together [e.g., IP-over-CCSDS].

We could call the former an "Adaptation Profile" that would live in a Blue Book and the latter a "Utilization Profile" that would live in a Magenta Book.

As an interesting aside, it looks like we in fact already have got internationally standardized "Adaptation Profiles" that have been certified Blue: the four Service Classes in section 7 of the CFDP Blue Book are exactly and precisely Adaptation Profiles.  We just happen to have packed them into 727.0-B-4 along with everything else related to file transfer, instead of publishing each one in its own (thin) Blue Book.  And it appears that we're doing the very same thing with Conformance Classes in the AMS book.

What's important here is that by formally recognizing these Adaptation Profiles as legitimate independent Recommended Standards we would make it possible to do flexible things (like incrementally adding more Conformance Classes to AMS or more Service Classes to CFDP)  by publishing thin, easily reviewed new Blue Books as the demands of flight mission operations evolve, without ever having to go back and hack/reissue the original protocol specs.

There are other issues to resolve with Magenta Books (concerning interoperability testing), but for now could you please comment on the above proposal?

///adrian

Adrian J. Hooke
Chairman, CCSDS Engineering Steering Group (CESG)
Space Communications and Navigation Office (SCaN)
Space Operations Mission Directorate
NASA Headquarters
Washington DC  20024-3210

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