Asset Tracker V2 does not get GPS Fix when A-GPS is disabled

[mniestroj]

When default configuration is used (so A-GPS is enabled, nRF Cloud is used) with asset_tracker_v2 (https://github.com/nrfconnect/sdk-nrf/tree/master/applications/asset_tracker_v2), then getting GPS gets fix after 1 to maybe 20 minutes (it is random). When A-GPS is disabled (all CONFIG.*AGPS.* are set to 'n'), then GPS never gets fix. The default GPS timeout is quite short (60s), so it was extended to 300s. Unfortunately, this change didn't help.

When GPS sample (https://github.com/nrfconnect/sdk-nrf/tree/master/samples/nrf9160/gps) is used with default configuration (which is without A-GPS), then GPS gets fix within 15-60s after reboot and this is reproducible. I would expect the same (or slightly worse, but at least reproducible/deterministic) behavior with asset_tracker_v2 application and disabled A-GPS.

[mniestroj]

Håkon Alseth said:

Could you share the output of AT command XMONITOR? 

XMONITOR: %XMONITOR: 5,"Orange","Orange","26003","D1F5",7,20,"0219BA11",484,6200,43,30,"","11100000","11100000","01011110"

Håkon Alseth said:

This is not a power-optimized solution.

If your provided network does not allow the UE to enter eDRX or PSM, you should consider disabling the LTE to use the GNSS.

Not doing anything about disabled PSM breaks main application functionality and consumes even more power, as GNSS reaches a timeout trying to obtain fix, resulting in maximum time spent in "GNSS listen" mode.

Håkon Alseth said:

Roaming SIMs can have issues obtaining PSM/eDRX in certain networks, it highly depends on what agreement the roaming SIM has with the networks available in your area.

A home registered SIM, provided that LTE M1 support is available, usually has PSM capabilities atleast. I would recommend that you reach out to the LTE network providers in your area and ask.

Thanks for clarification.

[Håkon Alseth]

Hi,

 

Have you checked with the SIM vendor if they have a roaming agreement in place with Orange in your country? If yes, also ask about power saving features like PSM / eDRX.

 

Kind regards,

Håkon