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<p class="MsoNormal">Dear SLP WG,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Sharing some feedback from Amanuel Geda from DLR below:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">So far the trend is clear, we encourage projects to use USLP, since it encorporates all the features of AOS into USLP, when fixed transfer frames are used.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Regards,<o:p></o:p></p>
<p class="MsoNormal">Greg<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="color:black;mso-ligatures:none">From: </span>
</b><span style="color:black;mso-ligatures:none">"Amanuel.Geda@dlr.de" <Amanuel.Geda@dlr.de><br>
<b>Date: </b>Wednesday, May 24, 2023 at 12:03 AM<br>
<b>To: </b>"Marco.Rovatti@esa.int" <Marco.Rovatti@esa.int>, "Kazz, Greg (US 312B)" <greg.j.kazz@jpl.nasa.gov><br>
<b>Subject: </b>[EXTERNAL] RE: A Mission Proposal - AOS Transfer Frames over Proximity-1 Session Control<o:p></o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none"><o:p> </o:p></span></p>
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<p class="MsoNormal"><span style="font-size:11.0pt">Hi Greg and Marco,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">I think Marco raised a good point: the WG should encourage projects to use USLP.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">If the project wants fixed frame, still USLP can also be used as fixed frame.<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Is there any service that AOS can deliver which can not be done by USLP?<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">It is probably good to remind the project to consider USLP. It will be a good feedback for the WG if the project describes the rational for AOS instead of USLP.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Cheers,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt">Amanuel<o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;mso-ligatures:none">From:</span></b><span style="font-size:11.0pt;mso-ligatures:none"> SLS-SLP <sls-slp-bounces@mailman.ccsds.org>
<b>On Behalf Of </b>Marco Rovatti via SLS-SLP<br>
<b>Sent:</b> Dienstag, 23. Mai 2023 15:53<br>
<b>To:</b> Kazz, Greg(US 312B) <greg.j.kazz@jpl.nasa.gov>; Kazz, Greg (US 312B) via SLS-SLP <sls-slp@mailman.ccsds.org><br>
<b>Subject:</b> Re: [Sls-slp] A Mission Proposal - AOS Transfer Frames over Proximity-1 Session Control<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Hi Greg, <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">I haven’t spoken with Moonlight people yet and I had not attended the meeting mentioned by Ignacio held a couple of days ago as I was not involved, therefore I’m only speculating here. I will
coordinate internally with Moonlight and Ignacio to get a better picture. <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">In any case, I still don’t get what kind of problem Moonlight project is trying to solve by using AOS over Prox-1.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">At a first glance it seems that they will get into more troubles than those they want to fix, but, again, pending listening to Moonlight opinions.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">In fact, AOS is fixed length frames and does not support COP.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">In the end, it might work with workarounds, however I would not recommend it.
<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"> <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Preferred options:<o:p></o:p></span></p>
<ol style="margin-top:0in" start="1" type="1">
<li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo3"><span lang="EN-GB" style="font-size:11.0pt">Use prox-1 frames OR<o:p></o:p></span></li><li class="MsoListParagraph" style="margin-left:0in;mso-list:l0 level1 lfo3"><span lang="EN-GB" style="font-size:11.0pt">Use USLP
<o:p></o:p></span></li></ol>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Cheers<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt">Marco <o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span style="font-size:11.0pt;mso-ligatures:none">From:</span></b><span style="font-size:11.0pt;mso-ligatures:none"> SLS-SLP <<a href="mailto:sls-slp-bounces@mailman.ccsds.org">sls-slp-bounces@mailman.ccsds.org</a>>
<b>On Behalf Of </b>Kazz, Greg (US 312B) via SLS-SLP<br>
<b>Sent:</b> 22 May 2023 19:42<br>
<b>To:</b> Kazz, Greg (US 312B) via SLS-SLP <<a href="mailto:sls-slp@mailman.ccsds.org">sls-slp@mailman.ccsds.org</a>><br>
<b>Subject:</b> [Sls-slp] A Mission Proposal - AOS Transfer Frames over Proximity-1 Session Control<o:p></o:p></span></p>
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<p class="MsoNormal"><span lang="EN-GB"><o:p> </o:p></span></p>
<p class="MsoNormal">Dear SLP WG,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">A question has come to me via the ESA Moonlight mission regarding the feasibility of using the AOS Space Data Link Protocol over the Proximity-1 session control (state tables that control link establishment, data exchange, and link termination).
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">I would like to know your opinion on this question: <span style="background:yellow;mso-highlight:yellow">
What does the SLP WG think about the possibility of using the AOS transfer frame format with Prox-1 session control ?</span><o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Here are my thoughts below:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Pro:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">As you may know from our last meeting, the WG is attempting to split the Prox-1 SDLP book into a separate session control book, separate COP-P book, and a separate transfer frame PDU book, that one similar to the existing TC, TM, AOS books.
If we succeed in that endeavor, it would be much easier for a mission to swap in different CCSDS data link layer protocols below the Prox-1 session control sublayer.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Con:<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">However, all the fine details to ensure dividing up the Prox-1 books has not yet been worked out by the SLP WG. This really has only been done for USLP and Prox-1. Nor has any interoperability testing been accomplished as well to clearly
demonstrate interoperability. Therefore, it would be the responsibility of each and every mission to take on that additional risk, if they were to use AOS for example with Prox-1 session control. Lastly, CCSDS created USLP in order to do just that – replace
AOS, TM, TC, Prox-1 with one link layer PDU useable in all venues. USLP has been interoperability tested by CCSDS.
<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">We have a <span style="background:yellow;mso-highlight:yellow">
short fuse of two weeks</span> to gather our inputs to this question, so I appreciate a quick response back from you all.<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Best regards,<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal">Greg – Chairman CCSDS SLP WG<o:p></o:p></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">Greg Kazz<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">Principal Engineer<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">Technical Group Supervisor,<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">312B Project Protection, Project Software, and End to End Information System Engineering<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">Jet Propulsion Laboratory<o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">4800 Oak Grove Dr., M/S 301-490<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="ES-MX" style="font-size:11.0pt;mso-ligatures:none">Pasadena, CA 91109</span><span style="font-size:11.0pt;mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="ES-MX" style="font-size:11.0pt;mso-ligatures:none">1+(818)393 6529(voice)</span><span style="font-size:11.0pt;mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-ligatures:none">1</span><span lang="ES-MX" style="font-size:11.0pt;mso-ligatures:none">+(818)393 6871(fax)</span><span style="font-size:11.0pt;mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="ES-MX" style="font-size:11.0pt;mso-ligatures:none">email:
<a href="mailto:greg.j.kazz@jpl.nasa.gov">greg.j.kazz@jpl.nasa.gov</a> </span><span style="font-size:11.0pt;mso-ligatures:none"><o:p></o:p></span></p>
<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-GB" style="font-size:11.0pt;mso-ligatures:none">This message is intended only for the recipient(s) named above. It may contain proprietary information and/or protected content. Any unauthorised disclosure, use, retention
or dissemination is prohibited. If you have received this e-mail in error, please notify the sender immediately. ESA applies appropriate organisational measures to protect personal data, in case of data privacy queries, please contact the ESA Data Protection
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