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<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Dear Greg, all, <o:p>
</o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">First of all, my apologies for not having been able to join the Fall Meeting, unfortunately I am in Bremen working for Copernicus Expansion missions.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Perhaps the way I see this is a bit naïve, however, the need for using a longer FHP is driven by the selected C&S standard.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">New missions planning to use AOS 4.1 over DVB-2 or ACM and wanting to benefit from legacy HW/SW would need to restrain the max length of Transfer Frame to 2048 bytes at mission level.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">In this way, the legacy unit’s “non-compliance” would have no practical consequences. Even an AOS4.1 compliant transmitter would never generate a FHP “longer than 11 bit”, meaning the most significant
bits of the FHP will be set to zeroes as a consequence of the shorter Transfer Frame length.
<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Maybe, instead of keeping the old text, either as an optional requirement or as a note, we can just put a note in the blue book to highlight this constraint in case a mix of legacy equipment and
new standards are used. <o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">What do you think? <o:p>
</o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Best regards<o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US">Marco <o:p></o:p></span></p>
<p class="MsoNormal"><span style="mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<p class="MsoNormal"><b><span lang="EN-US" style="mso-ligatures:none">From:</span></b><span lang="EN-US" style="mso-ligatures:none"> SLS-SLP <sls-slp-bounces@mailman.ccsds.org>
<b>On Behalf Of </b>Kazz, Greg (US 312B) via SLS-SLP<br>
<b>Sent:</b> Tuesday, November 7, 2023 10:37 AM<br>
<b>To:</b> sls-slp@mailman.ccsds.org<br>
<b>Subject:</b> [Sls-slp] RID resolution to AOS Space Data Link Protocol (SDLP) 732.0-B<o:p></o:p></span></p>
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<p class="MsoNormal"><o:p> </o:p></p>
<p class="MsoNormal"><span lang="EN-US">Dear SLP WG,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I believe I sent out this provisional RID disposition to the SLP WG already, but since it the AOS SDLP pink sheet review is not over until Dec 11, I would like to see if we can come to consensus on the RID disposition
at this Fall meeting.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">I had planned to walk through it yesterday, but it seems to have fallen off the agenda.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Nevertheless, I do believe the solution is rather straightforward.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">The RID comes from ESA (Andrea Modenini).<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">The subject is the expansion of the First Header Pointer in AOS SDLP from 11 bits to 16 bits, using the current 5 spare bits in the M_PDU header so that AOS can accommodate up to the maximum size transfer frames as USLP
does, i.e., 64K frames.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">The RID focuses on how CCSDS should reconcile legacy missions use with new mission use of this expanded field.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Attached as word document (which I have placed into the CWE) is my provisional response to Andrea subject to your comments. Andrea has written me back and agrees that a NOTE is better than changing the normative text.<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="background:yellow;mso-highlight:yellow">Please let me know if you have any concerns or issue with this resolution. Depending upon your replies, we will carry on by email. By 12/11/2023, we will see if any additional
RIDs arrive and then we will need to disposition them by email as well.</span><span lang="EN-US"><o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Best regards,<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US">Greg<o:p></o:p></span></p>
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