[Sis-mia] Questions on Video Streaming Green Book

Scott, Keith L. kscott at mitre.org
Tue Dec 13 13:07:37 UTC 2016


So I would say ‘multiplexing’ for what you’re describing in 5.2.2?

The question of 5.4 has to do with tree formation in the presence of simplex links, probably better to just leave it.

Cool, thx!

                                --keith

From: "Jeremy.Mayer at dlr.de" <Jeremy.Mayer at dlr.de>
Date: Tuesday, December 13, 2016 at 6:44 AM
To: Keith Scott <kscott at mitre.org>, "rodney.grubbs at nasa.gov" <rodney.grubbs at nasa.gov>
Cc: "sis-mia at mailman.ccsds.org" <sis-mia at mailman.ccsds.org>
Subject: RE: Questions on Video Streaming Green Book

Hey Keith,
I can answer some of these:
5.2: The DLR transparent gateway – encapsulates UDP datagrams and is otherwise agnostic to the video protocol running over UDP, yes? – Yes, I touch upon that is section 5.2.1. Should I explain more in 5.2?
5.2.1: the comment in the second paragraph – is the addition correct or is it the gateway timestamp that’s being used (or something else)?  - Edited.
5.2.2: where you say that MPEG-TS and BP are doing some of the same things (robustness for error-recovery and interleaving) – can you say a bit more on the implications of that? – Edited.
5.2.2: BP does interleaving?  I’m thinking ‘traditional’ interleaving where data items are assigned to a matrix row-by-row and read out column-by-column once the matrix is full.  I think you’re thinking of something else – can you tell me what it is you mean? – In the sense of sequentially interspersing different channels on the wire, I would say that BP does perform that task, albeit not in a consistent (row in, column out) fashion. I would be happy to rephrase, but am drawing a blank as to a better choice of words ☺
5.4: probably a question for later. – All of that section?
6.1: 10% BER w/ what I assume is LTP red – how does that EVER succeed?  Chances of getting 100 Bytes through correctly at 10% BER are really low. If the buffer is longer than 2x OWLT, it’s possible. We also used short GOP structures for some testing.There was an error in this section, which has been corrected. Thanks for the eyes.

A new copy is included.

Thanks,
Jeremy

From: Scott, Keith L. [mailto:kscott at mitre.org]
Sent: Montag, 12. Dezember 2016 18:49
To: Grubbs, Rodney P. (MSFC-EO50); Mayer, Jeremy
Cc: sis-mia at mailman.ccsds.org
Subject: Questions on Video Streaming Green Book

Hey,

Attached are some light edits and some questions about the Bundle Streaming Requirements Green Book (the comments in the markup).  Since CESG review is the only thing the Green Book goes through, can I get your feedback on the commented items before I submit to CESG?

Summary of questions:
5.2: The DLR transparent gateway – encapsulates UDP datagrams and is otherwise agnostic to the video protocol running over UDP, yes?
5.2.1: the comment in the second paragraph – is the addition correct or is it the gateway timestamp that’s being used (or something else)?
5.2.2: where you say that MPEG-TS and BP are doing some of the same things (robustness for error-recovery and interleaving) – can you say a bit more on the implications of that?
5.2.2: BP does interleaving?  I’m thinking ‘traditional’ interleaving where data items are assigned to a matrix row-by-row and read out column-by-column once the matrix is full.  I think you’re thinking of something else – can you tell me what it is you mean?
5.4: probably a question for later.
6.1: 10% BER w/ what I assume is LTP red – how does that EVER succeed?  Chances of getting 100 Bytes through correctly at 10% BER are really low.


                                --keith

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