GPS ONE Xtra in SL8090

Legacy Legacy AirPrime modules
1

But i understand is GPS One Xtra is a server, which is used to store Almanac and Ephemeris data.
On giving position fix using at!gpstrack=2,240,100000,1000,3. Once position is fixed and get location using at!gpsloc?. Then it will store Almanac and Ephemeris data on Gps one xtra server. Then switched off the device, when it is switched on. i checked

at!gpsxtrastatus?
Xtra Time status = Invalid
Xtra Data status = Invalid
Validity Start = 1980 01 06 6 00:00:00
Validity End = 1980 01 06 6 00:00:00

OK

After giving at!gpsxtrainitdnld, it will still, shows Xtra Data status = Invalid. how will this gps one xtra work to reduce the ttff?

Best Regards
Sukhdeep

2

Hi,

Please find my understanding,

  • Module use the downloaded XTRA data for position fix only, it will not upload Almanac nor Ephemeris data back to Xtra server after getting fix

  • The Xtra data is valid normally for few days but it won’t be stored in internal memory so it become invalid in your test.
    We need to manually start the download, via AT!GPSXTRAINITDNLD, every time after power up or enable auto download feature with AT!GPSXTRADATAENABLE)

Thx

3

at!gpsxtradataenable?

XTRA Data Enabled: 1
XTRA Data Retry Number: 3
XTRA Data Retry Interval: 1
XTRA Data Autodownload Enabled: 1
XTRA Data Autodownload Interval: 1

OK

I have already enabled autodownload.

  1. Then why Xtra Data status = Invalid is shown in at!gpsxtrastatus?.
  2. Does it mean, that Xtra Data status indicate, whether module has downloaded the xtra data from server or not?
  1. what type of xtra data will be downloaded? From where that data comes to server?
4

Hi Sukhdeep

  1. If auto download enabled in GPSXTRADATAENABLE, it will download the XTRA data if user request GPS fix.
AT!GPSXTRASTATUS?
 Xtra Time status   = Unknown
 Xtra Data status   = Invalid
    Validity Start = 1980 01 06 6 00:00:00
    Validity End   = 1980 01 06 6 00:00:00


OK
AT!GPSXTRADATAENABLE?

XTRA Data Enabled: 1
XTRA Data Retry Number: 3
XTRA Data Retry Interval: 10
XTRA Data Autodownload Enabled: 1
XTRA Data Autodownload Interval: 1


OK
AT!GPSFIX=1,255,10000


OK
AT!GPSXTRASTATUS?
 Xtra Time status   = Valid
 Xtra Data status   = Valid
    Validity Start = 2013 10 22 1 05:00:00
    Validity End   = 2013 10 29 1 05:00:00


OK

  1. Yes, I think so.

  2. Almanac, Ephemeris for example, Xtra is Qualcomm proprietary, data is maintained by them.

Thx

5

I enabled xtra Autodownload, Does it mean, no need to pay attention to at!gpsxtrastatus? As it is showing,it has taken data from xtra server or not. Module itself, it will fix position on giving fix request.

whether need to give separately at!gpsxtrainitdnld also with autodownload enable or is it required only with disabled autodownload?

Thanks & Regards
Sukhdeep

6
  1. AT!GPSXTRASTATUS? tell us whether data is available
  2. AT!GPSXTRAINITDNLD to download XTRA manually

So, both is not needed after we enabled auto download, as module will handle and download XTRA data automatically.

But still, you can use them if you decided to disable auto download and for debug purpose.

Hope it helps.

7

I have one more doubt, if we enabled auto xtra data download.
Then why AT!GPSXTRASTATUS? does not show data is available or not?