[Ccsds-omg-liaison] Preliminary AB Review of the Space Telecommunication Interface (STI) RFP

Elisa Kendall ekendall at thematix.com
Tue Jun 11 16:30:31 UTC 2019

Hi Jeff and all,

Here is my preliminary review of the STI RFP (mars/19-05-12).  I noticed 
that Matthew already submitted something, but haven't reviewed his 
comments, so apologies for any duplication.

First, I'm a little surprised that this is coming out of MARS rather 
than the Space DTF.  I'm assuming there is a back-story there, such as 
some revision to IDL or CORBA planned?

Overall - this seems like a really early draft to me.  The language 
needs tightening up in lots of places, no timeline, etc., so I'll only 
mention a few highlights with respect to the language, which needs some 
careful review.  I will skip the overview as a result and dive into the 

1. The numbering of the requirements is off - this needs to be cleaned 
up and every paragraph properly numbered.  There were some duplicates 
and unclear requirements numbering, among other things.

2. Fix 'Section Error! Reference source not found.,' in 6.1, second 
paragraph, and the first part of that first sentence in that paragraph 
is duplicative.

3. The sentence under the set of bullets in 6.1 doesn't make sense - "We 
will describe problem each of these elements bring in the following" - 
copy and paste errors?

4. The language in the requirements doesn't really reflect requirements 
language at all for me.  For example, some of the bullets in 6.2 are a 
bit hand wavy, such as being adaptable and flexible enough to support 
missions starting 5 years ago and running 10 years into the future?

5. Paragraph beginning "Radiation Suitable Processing:" needs an editing 
pass - words missing here and there? e.g. "certain level immunity" --. 
"certain level of immunity"? "not as capable as commercial off the shelf 
electronics" - explain in what way they are not as capable, leading to 
requirements for this RFP? Similarly, the paragraph starting 
"Specialized Signal Processing Abstraction:", and paragraph starting 
"Static Deployment:" need a review pass for grammar, etc.

6. If the "PIM and PSM for SWRadio Components Final Adopted 
Specification [SWR]" is expected to be reused to the extent possible, it 
should be described in 6.3.1, not in a "related" section.  It is listed 
as mandatory in 6.3.

7. Should the QoS elements listed in 6.5.2 (should be 3?) Networking, 
under i, be more specific?  There is nothing quantitative here to say 
reliability or timeliness, would be measured, under what circumstances, 
to ensure that the goals of the RFP are met.

I asked a friend who actually works on software radios and has done for 
years for feedback, especially with respect to 6.5.2, and he said that 
the three things you need for distributed communication is a destination 
address, a transport, and a protocol, which corresponds to my 
recollection. I think you have the first two, but the the protocol piece 
needs more work.

The trouble with space communication is the large amount of time it 
takes for signals to reach a satellite. I seem to recall that it is in 
the 10's of minutes to reach the outer planets of our solar system. This 
issue is discussed in 6.5.2.f, but 6.5.2.b says "IP routing", so one 
presumes some type of IP protocol. TCP/IP won't work for these 
latencies, but perhaps UDP would be OK. Were you thinking that you 
really want UDP?  The software radio specification is built on CORBA, 
and he had seen examples of use of CORBA for UDP. Are you asking for 
CORBA? What about the Internet Inter-ORB Protocol (IIOP) for CORBA? What 

8. Also, you mention security in 6.5.3, but what standard protocol?  
Were you thinking about CORBA for this?

9. Then, after reading through this a couple of times - my 
understanding, and again after talking with colleagues, is that a lot of 
the software radio work was built on Software Communication Architecture 
(SCA) version 2.2.2. The RFP mentions the SCA a couple of times. It's 
now at version 4.1, and some of the new 4.1 features will address 
features you are asking for. Do you want to comply to the latest version 
of the SCA?  Shouldn't that be mandated?

That's it for me - I think this is still quite early, but look forward 
to seeing updates next week.

Best regards,


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