[Css-csts] Re: An update to the ROCF SLE recommendation that can be done by the scretariat

Thu May 21 16:47:49 UTC 2015

Hi Wolfgang,

It does sound like we are on the same page.   And I think you are probably the right guy to provide those intro sentences (or paragraphs), if you have the time to devote.  I do not think it is a large task and I would be willing to help you craft them if the WG agrees.

Any other approach that solved the fundamental problem would also be completely acceptable as well.

Best regards, Peter

From: Wolfgang Hell <Wolfgang_._Hell at t-online.de<mailto:Wolfgang_._Hell at t-online.de>>
Date: Thursday, May 21, 2015 at 9:28 AM
To: Peter Shames <peter.m.shames at jpl.nasa.gov<mailto:peter.m.shames at jpl.nasa.gov>>, "Margherita.di.Giulio at esa.int<mailto:Margherita.di.Giulio at esa.int>" <Margherita.di.Giulio at esa.int<mailto:Margherita.di.Giulio at esa.int>>, Erik Barkley <Erik.J.Barkley at jpl.nasa.gov<mailto:Erik.J.Barkley at jpl.nasa.gov>>
Cc: CSTS-WG <css-csts at mailman.ccsds.org<mailto:css-csts at mailman.ccsds.org>>, "Holger.Dreihahn at esa.int<mailto:Holger.Dreihahn at esa.int>" <Holger.Dreihahn at esa.int<mailto:Holger.Dreihahn at esa.int>>, "John Pietras (pietras at gst.com<mailto:pietras at gst.com>)" <pietras at gst.com<mailto:pietras at gst.com>>, Tom Gannett <thomas.gannett at tgannett.net<mailto:thomas.gannett at tgannett.net>>
Subject: Re: An update to the ROCF SLE recommendation that can be done by the scretariat

Peter,

thanks for your prompt reply. in general terms we are on the same page and I was just trying to backup your position. In more specific terms I wanted to convey the message that imho just adding the sentence

"TC defines and uses the CLCW, which is carried in the TM (or AOS) OCF field for use in COP re-transmission operations.  The ROCF service is used to provide this CLCW to the user so that these re-transmission operations may be implemented in the user MOC."

won't cure the problem. As I tried to explain in my previous email, talking of the CLCW as the only OCF use case might be very confusing to the reader the latest when he/she gets to all the ROCF-START options. My second concern is that without addressing the potential terrestrial comms bandwidth limitations and the potential operational low latency requirements for the OCF delivery it is difficult to understand why ROCF is needed on top of RAF and RCF. All I'm suggesting is that these aspects are taken into account when we create the modest introductory material. This should put the reader on the right track from the beginning.

Best regards,
Wolfgang

Am 21.05.2015 um 16:46 schrieb Shames, Peter M (312B):
Thanks Wolfgang.  I was not in any way suggesting that we add voluminous Green Book materials, nor that we slight any of the key features, such as those you mentioned in the OCF section.

What I was doing was proposing that we add a modest paragraph or two (or even three) to the introductory sections of these documents.  In many cases, as in OCF, that sort of simple "here is what this does and why it is important" intro was missing.  Right now the ROCF devotes page after page of introductory "Green Book material" to definitions of the service itself, to the SLE reference model, service management, return frame and OCF production and provisioning, scheduling, underlying services, buffering, security aspects, etc, etc.  These introductory materials are the first 47 pages of the spec.

I think we can do beter by our users, without being unnecessarily duplicative by including too much Green Book material in a Blue Book.

Best regards, Peter

From: Wolfgang Hell <Wolfgang_._Hell at t-online.de<mailto:Wolfgang_._Hell at t-online.de>>
Date: Thursday, May 21, 2015 at 3:21 AM
To: "Margherita.di.Giulio at esa.int<mailto:Margherita.di.Giulio at esa.int>" <Margherita.di.Giulio at esa.int<mailto:Margherita.di.Giulio at esa.int>>, Erik Barkley <Erik.J.Barkley at jpl.nasa.gov<mailto:Erik.J.Barkley at jpl.nasa.gov>>
Cc: CSTS-WG <css-csts at mailman.ccsds.org<mailto:css-csts at mailman.ccsds.org>>, "Holger.Dreihahn at esa.int<mailto:Holger.Dreihahn at esa.int>" <Holger.Dreihahn at esa.int<mailto:Holger.Dreihahn at esa.int>>, Peter Shames <peter.m.shames at jpl.nasa.gov<mailto:peter.m.shames at jpl.nasa.gov>>, "John Pietras (pietras at gst.com<mailto:pietras at gst.com>)" <pietras at gst.com<mailto:pietras at gst.com>>, Tom Gannett <thomas.gannett at tgannett.net<mailto:thomas.gannett at tgannett.net>>
Subject: Re: An update to the ROCF SLE recommendation that can be done by the scretariat

Dear All,

I'm in favor of promoting whenever possible the use of CCSDS standards and if we can do something that helps the reader and therefore potential "customer" to digest the sometimes fairly complex material, I won't object. However, given that the SLE services extend the space link by providing a standard mechanism to access space link data, in my mind it is implied that understanding SLE services requires familiarity with the space link protocols which define the data that SLE services deal with. In fact, all SLE books have been written with that understanding in mind. I completely agree with Peter's analysis that the ROCF book contains all relevant references to the space link protocols and as such is complete. I also completely agree that in CCSDS we deal with other relevant standards by reference rather than inclusion. I'm sure we all agree that SLE books are not the right place to present Green Book type material related to space link protocols.

In the spirit of helping the reader I do not mind adding a sentence or two regarding why the ROCF service got "invented". However, my concern regarding the sentence proposed by Peter is that it might create the impression that the only purpose of the OCF is carrying the CLCW. While undoubtedly in most cases this is what the OCF is used for, other OCF types exist as well and are covered in detail in the ROCF-START operation. Therefore, if we add any material explaining what the OCF is, we shall not limit it to the CLCW case. Even if we add some explanation of what the OCF is, the reader may still fail to grasp why we cared to "invent" the ROCF service, given that via RAF and/or RCF we can get the frames that contain the OCFs of interest as well. We should add a few words regarding the potential need for low-latency delivery of the OCFs also in cases where the total space link data rate (significantly) exceeds the terrestrial communications bandwidth.

Best regards,
Wolfgang

Am 20.05.2015 um 12:18 schrieb Margherita.di.Giulio at esa.int<mailto:Margherita.di.Giulio at esa.int>:
Dear Erik and All,
I managed to read the sequence of e-mails on this subject  only today, as I am on mission for the whole week, I have no problem with instructing Secretariat about the introduction of the suggested sentence. However, one should first look into the R-OCF Recommendation and think of the appropriate place where to put it. Also, one may want to check if analogous sentences need to be introduced in  other SLE Recommendations.
I will have time to look into this only next week ( and I will coordinate with Wolfgang).
I do not know how far  the editor is with the Pink Books ( may be Tom can tell us), If there is still a chance  to introduce this change, say by the end of next week, then it is all right. Otherwise, we can keep this change in mind as a RID to be issued during the agency Review, as somebody suggested in one of the pervious e-mails.
Kind regards,
Margherita

-------------------------------------------------------------
Margherita di Giulio
Ground Station Back-end Section (HSO-GIB)
European Space Agency ESA/ESOC
Robert-Bosch-Str. 5
D-64293 Darmstadt - Germany
Tel: +49-6151-902779
e-mail: Margherita.di.Giulio at esa.int<mailto:Margherita.di.Giulio at esa.int>

From:        "Barkley, Erik J (3970)" <erik.j.barkley at jpl.nasa.gov><mailto:erik.j.barkley at jpl.nasa.gov>
To:        "Margherita.di.Giulio at esa.int"<mailto:Margherita.di.Giulio at esa.int><Margherita.di.Giulio at esa.int><mailto:Margherita.di.Giulio at esa.int>, "Wolfgang_._Hell at t-online.de"<mailto:Wolfgang_._Hell at t-online.de><Wolfgang_._Hell at t-online.de><mailto:Wolfgang_._Hell at t-online.de>, "Holger.Dreihahn at esa.int"<mailto:Holger.Dreihahn at esa.int><Holger.Dreihahn at esa.int><mailto:Holger.Dreihahn at esa.int>,
Cc:        "Shames, Peter M (312B)" <peter.m.shames at jpl.nasa.gov><mailto:peter.m.shames at jpl.nasa.gov>, "CCSDS Secretariat (thomas.gannett at tgannett.net<mailto:thomas.gannett at tgannett.net>)" <thomas.gannett at tgannett.net><mailto:thomas.gannett at tgannett.net>, "John Pietras (pietras at gst.com<mailto:pietras at gst.com>)" <pietras at gst.com><mailto:pietras at gst.com>, "css-csts at mailman.ccsds.org"<mailto:css-csts at mailman.ccsds.org><css-csts at mailman.ccsds.org><mailto:css-csts at mailman.ccsds.org>
Date:        13/05/2015 21:03
Subject:        An update to the ROCF SLE recommendation that can be done by the scretariat
________________________________

Margherita, Wolfgang, Holger,

With regard to the SLE books about to have pink sheet reviews, a question (please see previous email today) arose about adding an editorial sentence to the SLE blue books.  Peter has suggested the following addition to the ROCF blue book:

"TC defines and uses the CLCW, which is carried in the TM (or AOS) OCF field for use in COP re-transmission operations.  The ROCF service is used to provide this CLCW to the user so that these re-transmission operations may be implemented in the user MOC."

We can issue specific instructions to the secretariat as to exactly where to add this type of sentence.  It seems reasonable to me.  I would appreciate your comments on doing this, and if you concur I see no reason why this could not be included as part of the pink sheets going out for agency review.

Best regards,

-Erik

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