<br><br><div><span class="gmail_quote">On 12/3/06, <b class="gmail_sendername">Sean Moss-Pultz</b> <<a href="mailto:sean_mosko@fic.com.tw">sean_mosko@fic.com.tw</a>> wrote:</span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Robert-<br><br>Sorry for the time it took me to get back to you on this one. Hopefully you<br>still remember your original question:<br><br>" Sean I just want you to ask your AGPS experts - when you have to ask<br>externaly
e.g. open local - you could wait a day for me doing a bit more<br>research:<br>"Would be a RTCM 2.3 Typ 17 stream enough for AGPS?"<br>"Would the binary from gobal locate allows to define an own routings to
<br>a server?"<br>"Would it be possible to run an own server (runnnig open software)?"<br><br>Here is your answer from a senior engineer at Global Locate:<br><br>---<br><br>There is an "open" GPS<br>
hw/fw solution out there, but it is open only because the fw side of it<br>went belly-up and the hw side decided to keep the silicon in their<br>catalog. But there's few PhDs in signal processing or navigation to<br>support it. PhDs have less time on their hands than GUI developers,
<br>evidently.<br><br>About the questions:<br><br>What is the context? AGPS protocol stack support on a handheld, or<br>The AGPS server on the network side?<br><br>I'll assume he's discussing the handset side.<br><br>First some background.
<br><br>MS-A AGPS<br> server sends minimum ephemeris to handset (age is about 2 hours<br>or less)<br> handset replies with measurements;<br> server computes (and "owns") the position<br> Data rates are moderate, but the same for each position
<br><br>MS-B AGPS<br> server sends ephemeris for local conditions (age is about 2<br>hours)<br> handset computes (and "owns") the position<br> data rates are about the same, but can be smaller for subsequent
<br>fixes.<br><br>LTO<br> LTO gets to handset via:<br> - GPRS<br> - WiFi<br> - Bluetooth<br> - USB<br> Only about 40KB needed every 2 days, although we prefer every 6<br>hours for safety<br>
if it is cheap enough.<br><br>The AGPS features currently only expect a NAL (network abstraction<br>layer) to reach the AGPS servers.<br>For the LTO, same thing.<br>Right now, our only NAL is for TCP/IP, as User-plane (SUPL) for OMA
<br>support is easiest.<br>In future, C-Plane may be offered by some GSM BBs and we can use that if<br>the network supports it.<br><br>"Would be a RTCM 2.3 Typ 17 stream enough for AGPS?"<br> If it has a TCP/IP portal on the network side to reach LTO or
<br>AGPS servers, and<br> would need a NAL on the handset side to connect to the GPS<br>control stack.<br><br>"Would the binary from gobal locate allows to define an own routings to<br>a server?"<br> Right now the NAL is built in and assumes TCP/IP.
<br> If you configured the AGPS NAL for a local proxy, then rerouted<br>to<br> whatever you choose, you're all set.<br><br>"Would it be possible to run an own server (runnning open software)?"<br> You would need to:
<br> - develop a SUPL protocol stack<br> - get an assistance data feed. Network operators pay big $$$<br>for this from<br> commercial providers. Developing your own is a major task.<br> - get authority from cell providers and network operators for
<br>AGPS to go through them<br> (Note the "own" position fix for MS-A above: you could get<br>between an operator<br> and $$, a dangerous place to be!)<br> - develop a database of {cell-tower ==> lat,long,alt}
<br> So it is a pretty big job with some major hurdles.<br><br>---<br><br>Hope that helps!<br><br>-Sean<br><br><br>_______________________________________________<br>OpenMoko community mailing list<br><a href="mailto:community@lists.openmoko.org">
community@lists.openmoko.org</a><br><a href="http://lists.openmoko.org/cgi-bin/mailman/listinfo/community">http://lists.openmoko.org/cgi-bin/mailman/listinfo/community</a><br></blockquote></div>pardon my ignorance, but can someone explain what LTO is? a quick google didn't help
<br><br clear="all"><br>-- <br>--Jeff<br>What DO you call whitewater when you live in the desert?