[Sis-ams] Draft documents

[Scott Burleigh]

Hi.  I have posted to the sis-ams CWE (http://public.ccsds.org/sites/cwe/sis-ams/default.aspx) the Requirements list I sent out last week and also a draft Charter and Resource Plan.  We unfortunately don't have a lot of time to discuss these things by email between now and the April meeting, but I think we should still be able to come to some resolution on progressing to Working Group status by the end of the Athens session.  I've also posted to the CWE the Agenda for that meeting, which should additionally be available elsewhere on the CCSDS web site.

One other thing we should consider at the Athens meeting is the Real-Time Publish-Subscribe (RTPS) protocol standard that is now being advanced within OMG.  This is the only effort that I know of, besides AMS, to establish an open standard wire protocol for asynchronous message exchange.

RTPS is already an IEC standard, but unfortunately you have to pay money to read the specification: $217 at the ANSI Web Store (http://webstore.ansi.org/ansidocstore/product.asp?sku=IEC%2FPAS+62030+Ed%2E+1%2E0+en%3A2004) or 292 Swiss Francs at the IEC Web Store (http://domino.iec.ch/webstore/webstore.nsf/artnum/033452).  As near as I can tell without buying the book, RTPS is essentially a formal description of the NDDS commercial messaging product that has been marketed by Real-Time Innovations, Inc. (http://www.rti.com) for about ten years.

NDDS is designed for hard real-time industrial process control applications, and I have some doubts that it would satisfy the proposed Requirements for AMS: I don't think it's likely to be particularly delay- and disruption-tolerant, there isn't any obvious support for the email-like message staging that Roger talked about for MOIMS, I didn't see any easy way to partition the message exchange continuum, it seems pretty firmly tied to UDP/IP without any obvious way to run it over alternative transmission systems such as message queues or even TCP, etc.  All the same, we should give it a serious look.  I know that the NASA Constellation project, at least, is predisposed to going with standards coming out of the commercial world in preference to standards developed by national space agencies, so if RTPS can be stretched to address the requirements it will probably be warmly received.

Scott