[Smwg] The latest definitive draft Functional Resource descriptions

John Pietras john.pietras at gst.com
Wed Oct 10 20:09:36 UTC 2018

CSSMWG colleagues ---
At next week's CCSDS Fall Workshop we will be discussing various topics regarding Functional Resources, including the status and contents of the Functional Resource Reference Model Tech Note. The latest full draft of that Tech Note was v0.14, which was posted to the CWE at the end of July at URL

However, I have just concluded a review of the definitions of the Functional Resources that are associated with Forward Frame CSTS, the results of which are documented in the Functional Resources for the Forward Frame CSTS White Paper, which has been posted at URL

The format of the White Paper is to document each FF-CSTS-related FR, using both the corresponding higher-level descriptive material from the FR RM Tech Note and tables of (a) the configuration parameters, (b) read-only parameters, (c) notification events, and (d) directives of each FR type. The core content of these tables is based on the current contents of the Candidate SANA FR Registry. PEDs that are acceptable as-is are labeled as "See the SANA FR Registry". PEDs that need adjustment of some sort are so annotated with the description of the needed adjustment(s), and new PEDS are annotated with "NEW PARAMETER (EVENT, DIRECTIVE)".

The functional resource types addressed by this White Paper are:

-         Antenna

-         Forward 401 Space Link Carrier Transmission

-         Forward TC PLOP, Synchronization and Channel Encoding

-         Forward AOS Synchronization, Channel Encoding and OID Generation

-         Forward TC MC Multiplexing

-         Forward TC VC Multiplexing

-         Forward AOS MC Multiplexing

-         Forward AOS VC Multiplexing

-         Forward USLP MC Multiplexing

-         Forward USLP VC Multiplexing

-         Forward Frame CSTS Provider

The White Paper also identifies the Forward 415 Space Link Carrier Transmission FR as an FR that is part of (will be part of) the possible production configurations for the Forward Frame service, but at this time there is only a placeholder for this FR type in the FR RM Tech Note and it is completely absent from the Candidate SANA FR Registry.

Note that the list includes Forward USLP VC Multiplexing and Forward USLP VC Multiplexing FR types. There has been some discussion as to whether the forthcoming Unified Space Data Link Protocol (USLP) should be represented by existing FR types (e.g., Forward TC, Forward  AOS, and Return TM AOS) or have its own set of FRs. Given that USLP combines subsets of capabilities of TC, TM, and AOS (as well as Prox-1, which we don't have to concern ourselves with since the FRs are currently confined to ESLTs) , I have come to the conclusion that it is easier/better overall to create separate USLP-specific FRs than to try to sprinkle "If the frames are USLP fixed/variable-length frame" kinds of statements throughout the definitions of the current TC, TM, and AOS SDLP FR types. So the White Paper contains new FR definitions for USLP. (There will also be several other Forward USLP FR types, but these deal with packet and COP-related functionality that the Forward Frame service bypasses, and so these other USLP FR types are not examined in the White Paper).

In addition to the new USLP-related FR types, the White Paper includes a substantial revision of the Forward AOS Synchronization, Channel Encoding and OID Generation FR type. This revision reflects comments provided by Ken Andrews of JPL, who is performing the analysis of the sync and channel coding that will be required for forward space links carrying AOS frames (and in the near future, fixed-length USLP frames).

For the time being, the White Paper sections for the aforementioned FR types take precedence over the corresponding sections of the FR RM Tech Note. My intention is to integrate the updated material from the White Paper back into the FR RM Tech Note over the next few months. As you may know, the FR RM Tech Note does not normally address the individual parameters, events, and directives of the FR types, deferring that level of information to the SANA FR Registry. So when the sections are migrated back to the FR RM Tech Note, the detailed PED tables will not be migrated and instead the updated sections will merely reference the appropriate subtrees of the SANA FR Registry.

Looking forward to discussing these topics with you next week.

Best regards,

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