nRF9160 DK + Asset Tracker v2, AWS A-GPS

[MostlyHardware]

Hello!

I am having some GPS problems with the Asset tracker v2 firmware. It can find satellites, but it doesn't track them nor do I get a GPS fix before the timeout occurs. I was thinking to enable A-GPS to speed up the fix, but since I am connecting it to my own AWS IoT instance it doesn't seem to download any A-GPS data. How can I modify the asset tracker firmware so that it downloads A-GPS properly?

Some other info:

• I have clear skies and open surroundings for the device
• If I run the GNSS firmware it gets a GPS fix within 30 seconds, so I am suspecting some kind of interference with the modem. iBasis supports PSM in my area but it doesn't seem to be activated if I read it out via modem commands.
• The original asset tracker firmware which connected to nRFcloud worked perfectly, so the device isn't faulty.

Thanks!

[MostlyHardware]

Håkon Alseth said:

Could you try to open the Trace Collector first, then issue all the AT commands?

Hi,

Sure, here it is:

trace-2022-10-10T17-27-42.632Z.bin

[Håkon Alseth]

Hi,

 

Thank you for the trace. It unfortunately shows that you are indeed requesting PSM, but not receiving it from the network.

Have you contacted Telenor support and asked about this?

Do you have a SIM with "iot capabilities" from Telenor? https://telenor.se/handla/mobilabonnemang/internet-of-things/

 

Kind regards,

Håkon

[MostlyHardware]

Hi again,

I've been trying to ask Telenor a couple of times now but it seems they don't really understand my request.

In the meantime I found this feature request in the github repo:
https://github.com/nrfconnect/sdk-nrf/pull/5097

It seems A-GPS / AWS IoT support was added roughly a year ago, so it should be supported. But in the end it doesn't really work for me. Would be really nice to go this route instead of trying out different sims.

Thanks!

[Håkon Alseth]

Hi,

  

You will need to enter power saving mode, either PSM or eDRX, in order to use the GPS while the LTE Link is active.

This is because the modem time-multiplexes it, meaning that you need to be in an idle state when starting the GPS.

 

If you are unable to enter an idle state on the LTE Link (which again is controlled by the network, ie. Telenor in this case), the gps cannot start.

 

Kind regards,

Håkon