RE: AGPS and PSM

Tron — Fri, 15 May 2020 06:02:12 GMT

Thank you, precise and to the point.

RE: AGPS and PSM

Didrik Rokhaug — Wed, 13 May 2020 14:55:27 GMT

Hi.

The gps sample was originally created with only GPS in mind. It was later expanded when we added A-GPS support.

That is why the sample only uses GPS, and not LTE (more than necessary for A-GPS). Another consideration to factor in is that the sample is not guaranteed to be granted PSM, and can therefore not rely on PSM to get enough run-time for the GPS.

That is no longer necessary, with the improvements to the modem, but the sample is still meant to be as basic as possible.

[quote user=""]Do you recommend NOT using PSM when using AGPS?[/quote]

I would probably enable PSM after downloading the A-GPS data, but there should not be a problem using PSM with A-GPS.

However, we have found that the SUPL library is more stable if the GPS is turned off before the SUPL session is started.

This would make the following order of events: Start GPS -> Get A-GPS data request -> Stop GPS (using socket interface) -> Start SUPL session -> SUPL session ends -> Enable PSM -> Start GPS

But, things could be done in other orders as well.

Best regards,

Didrik