<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:x="urn:schemas-microsoft-com:office:excel" xmlns:p="urn:schemas-microsoft-com:office:powerpoint" xmlns:a="urn:schemas-microsoft-com:office:access" xmlns:dt="uuid:C2F41010-65B3-11d1-A29F-00AA00C14882" xmlns:s="uuid:BDC6E3F0-6DA3-11d1-A2A3-00AA00C14882" xmlns:rs="urn:schemas-microsoft-com:rowset" xmlns:z="#RowsetSchema" xmlns:b="urn:schemas-microsoft-com:office:publisher" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:odc="urn:schemas-microsoft-com:office:odc" xmlns:oa="urn:schemas-microsoft-com:office:activation" xmlns:html="http://www.w3.org/TR/REC-html40" xmlns:q="http://schemas.xmlsoap.org/soap/envelope/" xmlns:rtc="http://microsoft.com/officenet/conferencing" xmlns:D="DAV:" xmlns:Repl="http://schemas.microsoft.com/repl/" xmlns:mt="http://schemas.microsoft.com/sharepoint/soap/meetings/" xmlns:x2="http://schemas.microsoft.com/office/excel/2003/xml" xmlns:ppda="http://www.passport.com/NameSpace.xsd" xmlns:ois="http://schemas.microsoft.com/sharepoint/soap/ois/" xmlns:dir="http://schemas.microsoft.com/sharepoint/soap/directory/" xmlns:ds="http://www.w3.org/2000/09/xmldsig#" xmlns:dsp="http://schemas.microsoft.com/sharepoint/dsp" xmlns:udc="http://schemas.microsoft.com/data/udc" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:sub="http://schemas.microsoft.com/sharepoint/soap/2002/1/alerts/" xmlns:ec="http://www.w3.org/2001/04/xmlenc#" xmlns:sp="http://schemas.microsoft.com/sharepoint/" xmlns:sps="http://schemas.microsoft.com/sharepoint/soap/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:udcs="http://schemas.microsoft.com/data/udc/soap" xmlns:udcxf="http://schemas.microsoft.com/data/udc/xmlfile" xmlns:udcp2p="http://schemas.microsoft.com/data/udc/parttopart" xmlns:wf="http://schemas.microsoft.com/sharepoint/soap/workflow/" xmlns:dsss="http://schemas.microsoft.com/office/2006/digsig-setup" xmlns:dssi="http://schemas.microsoft.com/office/2006/digsig" xmlns:mdssi="http://schemas.openxmlformats.org/package/2006/digital-signature" xmlns:mver="http://schemas.openxmlformats.org/markup-compatibility/2006" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns:mrels="http://schemas.openxmlformats.org/package/2006/relationships" xmlns:spwp="http://microsoft.com/sharepoint/webpartpages" xmlns:ex12t="http://schemas.microsoft.com/exchange/services/2006/types" xmlns:ex12m="http://schemas.microsoft.com/exchange/services/2006/messages" xmlns:pptsl="http://schemas.microsoft.com/sharepoint/soap/SlideLibrary/" xmlns:spsl="http://microsoft.com/webservices/SharePointPortalServer/PublishedLinksService" xmlns:Z="urn:schemas-microsoft-com:" xmlns:st="" xmlns="http://www.w3.org/TR/REC-html40">
<head>
<meta http-equiv=Content-Type content="text/html; charset=iso-8859-1">
<meta name=Generator content="Microsoft Word 12 (filtered medium)">
<!--[if !mso]>
<style>
v\:* {behavior:url(#default#VML);}
o\:* {behavior:url(#default#VML);}
w\:* {behavior:url(#default#VML);}
.shape {behavior:url(#default#VML);}
</style>
<![endif]-->
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Calibri;
panose-1:2 15 5 2 2 2 4 3 2 4;}
@font-face
{font-family:Tahoma;
panose-1:2 11 6 4 3 5 4 4 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
a:link, span.MsoHyperlink
{mso-style-priority:99;
color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{mso-style-priority:99;
color:purple;
text-decoration:underline;}
p
{mso-style-priority:99;
mso-margin-top-alt:auto;
margin-right:0in;
mso-margin-bottom-alt:auto;
margin-left:0in;
font-size:12.0pt;
font-family:"Times New Roman","serif";}
p.MsoListParagraph, li.MsoListParagraph, div.MsoListParagraph
{mso-style-priority:34;
margin-top:0in;
margin-right:0in;
margin-bottom:0in;
margin-left:.5in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:"Calibri","sans-serif";}
span.EmailStyle18
{mso-style-type:personal;
font-family:"Calibri","sans-serif";
color:windowtext;}
span.EmailStyle20
{mso-style-type:personal-reply;
font-family:"Calibri","sans-serif";
color:#1F497D;}
.MsoChpDefault
{mso-style-type:export-only;
font-size:10.0pt;}
@page WordSection1
{size:8.5in 11.0in;
margin:1.0in 1.0in 1.0in 1.0in;}
div.WordSection1
{page:WordSection1;}
-->
</style>
<!--[if gte mso 9]><xml>
<o:shapedefaults v:ext="edit" spidmax="1026" />
</xml><![endif]--><!--[if gte mso 9]><xml>
<o:shapelayout v:ext="edit">
<o:idmap v:ext="edit" data="1" />
</o:shapelayout></xml><![endif]-->
</head>
<body lang=EN-US link=blue vlink=purple>
<div class=WordSection1>
<p class=MsoNormal><span style='color:#1F497D'>Gilles,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>D’accord. In particular
your last suggestion. <o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>I am working with Aaron Kiely to
examine how we can move this forward before the London meeting.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>By the way, I can provide a
representative flight software load binary file from the MSL mission for
evaluation.<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Can you provide some
representative uplink data sets from CNES for this evaluation?<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Thanks,<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'>Greg<o:p></o:p></span></p>
<p class=MsoNormal><span style='color:#1F497D'><o:p> </o:p></span></p>
<div>
<div style='border:none;border-top:solid #B5C4DF 1.0pt;padding:3.0pt 0in 0in 0in'>
<p class=MsoNormal><b><span style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>From:</span></b><span
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> Moury Gilles [mailto:gilles.moury@cnes.fr]
<br>
<b>Sent:</b> Wednesday, June 30, 2010 9:33 AM<br>
<b>To:</b> Kazz, Greg J (313B); sls-ngu@mailman.ccsds.org;
sls-hru@mailman.ccsds.org<br>
<b>Cc:</b> Gian.Paolo.Calzolari@esa.int; jean-luc.gerner@esa.int<br>
<b>Subject:</b> RE: [Sls-ngu] Consideration of data compression as a topic for
discussion in NGU meeting<o:p></o:p></span></p>
</div>
</div>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Greg,</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Indeed compression is being used on the uplink when data rate /
pass duration are not sufficient to upload a work plan (for example). On our
LEO earth observation spacecrafts, we often use what we call
"macrocommands" to actually encode the daily work plan so that it can
be uploaded in one single pass at 2 or 4 kbps. This macrocommand syntax is a
way of compressing work plans or sequences of commands by encoding with one
single macrocommand a complete Operational Control Procedure. This type of
compression is of course highly mission dependent and cannot be subject to
standardization. Nevertheless, it is very efficient.</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>On the contrary, a generic standard lossless compression for S/C
uploads could be envisaged derived from a mainstream universal lossless
compression algorithm like LZ (deflate RFC). This approach is interesting
if a single algorithm (with reasonable decoding complexity) provides
significant and consistent performances (2:1 compression ratio on average
at least) for a wide range of uploads types (work plans, software uploads, FPGA
configuration uploads, parameter tables uploads (e.g. star catalogues), ...).</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>The first step would be to assemble a set of representative uploads
covering the whole range of type of traffic on TC links, and then perform
performance test with LZ. This initial step is necessary to decide on agency
interest for such a TC compression CCSDS standard.</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Discussion with MHDC WG before next meeting could be beneficial to
assess their capability to support this first step, and to gather their
technical opinion on the opportunity/feasibility of such a standardization.</span><span
style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Best regards,</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
<p class=MsoNormal><span style='font-size:10.0pt;font-family:"Arial","sans-serif";
color:blue'>Gilles</span><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<p><span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif"'>Gilles
MOURY</span> <br>
<span lang=FR style='font-size:10.0pt;font-family:"Arial","sans-serif"'>CNES
Toulouse</span><span lang=FR> </span><o:p></o:p></p>
<div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'> <o:p></o:p></span></p>
</div>
<p class=MsoNormal><span style='font-size:12.0pt;font-family:"Times New Roman","serif"'><o:p> </o:p></span></p>
<div class=MsoNormal align=center style='text-align:center'><span lang=FR
style='font-size:12.0pt;font-family:"Times New Roman","serif"'>
<hr size=2 width="100%" align=center>
</span></div>
<p class=MsoNormal style='margin-bottom:12.0pt'><b><span lang=FR
style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'>De :</span></b><span
lang=FR style='font-size:10.0pt;font-family:"Tahoma","sans-serif"'> sls-ngu-bounces@mailman.ccsds.org
[mailto:sls-ngu-bounces@mailman.ccsds.org] <b>De la part de</b> Kazz, Greg J
(313B)<br>
<b>Envoyé :</b> mardi 29 juin 2010 00:57<br>
<b>À :</b> sls-ngu@mailman.ccsds.org; sls-hru@mailman.ccsds.org<br>
<b>Cc :</b> Gian.Paolo.Calzolari@esa.int<br>
<b>Objet :</b> [Sls-ngu] Consideration of data compression as a topic for
discussion in NGU meeting</span><span lang=FR style='font-size:12.0pt;
font-family:"Times New Roman","serif"'><o:p></o:p></span></p>
<p class=MsoNormal>All,<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Please let me know if you would be interested in having a
discussion on the use of data compression as a technique towards conserving
bandwidth on the uplink.<o:p></o:p></p>
<p class=MsoNormal>In other words, do you think compression is likely to be a
big payoff and manageable, and worthy of inclusion in a CCSDS NGU standard,
etc. ?<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>A current example of using compression on the uplink is the
NASA Mars Science Laboratory Project which is tentatively planning to use one
of the Lempel Ziv (LZ) encoders for compressing flight software loads. <o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Data compression could be another technique that the NGU WG
should consider for standardization for NGU applications. Considering that the
CCSDS Convolutional Code can approximately provide about a 5 db gain, and the
LDPC about 7 db. if we can get 3+ db from compression it might be a
worthwhile contender for consideration.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>So this additional work could manifest itself by involving agency
collaboration on studying the various compression candidates for use on the
uplink. If that is the case, then NGU would need support from the MHDC WG in
supporting such a study.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>Some of the question we could consider asking ourselves are:<o:p></o:p></p>
<p class=MsoNormal> <o:p></o:p></p>
<p class=MsoNormal>(1) Can we come up with uplink data sets that are good
examples of the type of uplink data that requires compression and that
compresses well?<o:p></o:p></p>
<p class=MsoNormal>(2) How much improvement might we get from different
variations of compression algorithms on the data types that are worth studying
?<o:p></o:p></p>
<p class=MsoNormal>(3) Have we convinced ourselves that the NGU data volume
problem is significant enough in the first place to warrant compression ?<o:p></o:p></p>
<p class=MsoNormal>(4) Is 2:1 lossless compression our goal ?<o:p></o:p></p>
<p class=MsoNormal>(5) What are the candidate compression algorithms and what
are the metrics to judge them by ?<o:p></o:p></p>
<p class=MsoNormal>(6) I don't know how much interest there is from other CCSDS
member agencies on this topic <span style='font-family:"Times New Roman","serif"'>–</span>
please let me know.<o:p></o:p></p>
<p class=MsoNormal><o:p> </o:p></p>
<p class=MsoNormal>If I get positive feedback from member agencies on this
survey, then I will pass this along to the MHDC WG to see if we can start up an
email dialog with them before the London meeting and also schedule some time in
London if necessary to meet with them.<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 Kazz<o:p></o:p></p>
<p class=MsoNormal>Chairman CCSDS NGU WG <o:p></o:p></p>
</div>
</body>
</html>