[Css-csts] Production status for TD-CSTS in complete mode

[John Pietras]

CSTSWG colleagues ---
As part of the discussion of the TD-CSTS and its prototyping at the Cleveland meeting, we noted that the refinement for the production status of the TD service was confined to the status of the TDM Segment Generation function. This is relevant when the TD service is operating in real-time mode because the service is transferring radiometric data as it is being generated. But a question was raised about what the scope of production status should be when the service is operating in complete mode, in which case the TD service is only transferring data out of the TDM Recording Buffer and there may not even be a TDM Segment Generation function executing at the time. I took the action to explore the issue and to modify the TD-CSTS book accordingly.

Perhaps not too surprisingly, this issue did come up several years ago and we did come up with a resolution at the time. That resolution is essentially captured in the way that the TD book currently defines the production status.

At the Bordeaux meeting in 2013, I raised the issue of the role of Recording Buffer status in Production Status. In brief, the problem is this: in complete mode, the "production status" is just the status of the Recoding Buffer*. However, in complete mode, the production-status notifications are made available to the TD service *by being placed in that Recording Buffer*". Therefore, if the Recording Buffer is in any but the 'operational' state, it is impossible for the TD service to get the production status notifications out of the Recording Buffer. (It's kind of like trying to use email to tell your colleagues that your internet access is down).
[*We decided that even if the space link were active while the complete mode TD-CSTS is operating, the status of the other functions - including TDM Generation - was not of concern to the user of the TD-service instance. Besides, the production status of those respective FRs would be available to the MD service anyway.]

Following the Bordeaux meeting, I attempted to develop a way to by-pass the Recording Buffer in order to report what is in essence the Recording Buffer production status by introducing the Information Query and Notification procedures, for the primary purpose accessing the current production status and related event notifications (TD-CSTS v0.7).

However, at the Noordwijkerhout meeting the following spring (2014), the CSTSWG review of the expanded TD-CSTS resulted in the decision to remove the Notification procedure altogether and to restrict the Info Query procedure from accessing production status. The reason for both decisions was that having "real time" production status reported by the TD service in complete mode while the Recording Buffer is releasing data-synchronous production status notifications would be more confusing to the operator than the potential utility, especially in light of the fact that the MD service could be used to get this information.

So that is why the TD service today specifies production status only as it applies to the real-time mode and not to complete mode - the WG decided that the service *should not* report production status while in complete mode.

So, unless the CSTSWG now decides to reverse the decision made at the Noordwijkerhout meeting, there should not and will not be any changes to the TD service specification in this regard.

Best regards,
John
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