Can we inject LBS Latitude and longitude to GPS to reduce the fix time?

[Balamurugan]

Hi,

we are developing NB-IOT based GPS tracker based on nRF9160.

we have implemented the A-GPS based on SUPL. After using A-GPS there is a minor improvement in the overall fix time. But still GPS fix time more compare to other GPS(different make) devices under same environment condition.

Also we have implemented the LBS based positioning in nRF9160 based on cell information(mcc,mnc,lac and cid) using third party API(unwiredlabs.com).

Even though  accuracy is not great(~1KM) its able to get cell latitude and longitude.

So my questions are

1.Can we inject LBS Latitude and longitude to GPS to reduce the fix time and get accurate location? similar to SUPL data injection.

2.Does nrf9160 has AT command/options to get nearby cell ids with RSSI value to try triangulation?, right now we are using MONITOR AT command to get the registered cell id.

3. Is there any other option to reduce the fix time/improve the GPS performance?

Thanks,

Bala

[Øyvind]

Hello, 

I don't have the answers and will need to forward it to our R&D team. Can you please provide what modem FW version you are running and what NCS version?

Thanks!

KInd regards,
Øyvind

[Balamurugan]

Modem FW version: 1.1.1 nRF91 firmware binaries

NCS Version:1.2

[Øyvind]

Hello, 

Here are the answers I got.

1. Normally LBS position (or some other coarse current position) should be part of the AGPS information, but if AGPS does not provide it, it can be injected separately to GPS over LPC API. I do not know how it is done in the application interface, e.g. what AT command to use (and in what order with respect to the other AGPS information).
2. This is something we currently don't have support for. For GPS, there is no benefit whatsoever to attempt to inject a position with better resolution than serving cell location.
3. Sorry, we don't have any answers to this.