GPS XTRA data not updating on SL808xT

Legacy Legacy AirPrime modules
1

The GPS on my Sl808xT is taking a long time (>5 minutes) to acquire a lock. I’ve enabled the features for GPS XTRA DATA but it’s failing to update the location assistance data.

Download is enabled:

at!gpsxtradataenable?

XTRA Data Enabled: 1
XTRA Data Retry Number: 2
XTRA Data Retry Interval: 1
XTRA Data Autodownload Enabled: 1
XTRA Data Autodownload Interval: 24

Current XTRADATA is out of date:

AT!GPSXTRASTATUS?

 Xtra Time status   = Unknown
 Xtra Data status   = Valid
    Validity Start = 2014 08 07 3 11:00:00
    Validity End   = 2014 08 14 3 11:00:00

Manually initiate a download:

AT!GPSXTRAINITDNLD
 Xtra command sent successfully
OK

XTRADATA remains out of date:

AT!GPSXTRASTATUS?

 Xtra Time status   = Unknown
 Xtra Data status   = Valid
    Validity Start = 2014 08 07 3 11:00:00
    Validity End   = 2014 08 14 3 11:00:00

When I run the download command I have a working 3G connection established. If I run a packet capture on the module I don’t see any XTRADATA download requests being sent.

Is there something else I should be doing to download the XTRADATA? Is there any way of debugging why this fails?

Appreciate any help.

2

Does anyone have any suggestions as to why the GPS XTRA data isn’t updating?

The 3G data connection is established and passing traffic when I run the update command, so I don’t understand why apparently there is no request being sent to the GPS XTRA data servers.

3

Perhaps it’s not working because I’ve not explicitly set an APN for the embedded XTRADATA client to use.

However the command to this this fails on my SL808xT module:

22:28:13:868 - 
AT!GPSXTRAAPN?
22:28:13:885 - ERROR
22:28:27:836 - 
AT!GPSXTRAAPN=1,0x19,IPV4,"publicapn"
22:28:27:849 - ERROR

Am I supposed to be setting the APN in a different way on the SL808xT module? I’ve already got an APN set with +CGDCONT and the data connection is working.