nrf9160 behavior if reconnect fails after getting into PSM

[DevinCallahan]

I'm curious what the modem does if, upon waking up to service the PSM interval, it fails to connect?  Does it go back to "idle" and try again on the next PSM interval or does it do something else?

Also is there a good resource for learning about more these kinds of esoteric behaviors?  The 3GPP docs themselves are very challenging to read and understand in my opinion.

Thank you!

[Håkon Alseth]

Hi,

 

I'm curious what the modem does if, upon waking up to service the PSM interval, it fails to connect?  Does it go back to "idle" and try again on the next PSM interval or does it do something else?

it will not "skip the current window" if noone acknowledges the communication.

PSM is a time-wise scheduled connect. If the UE cannot find the eNB, it first starts retransmitting, and ultimately if there's no one on the other end; it starts searching for nearby towers to connect to.

This will be reflected in the modem state, for instance via. CEREG notifications.

 

Also is there a good resource for learning about more these kinds of esoteric behaviors?  The 3GPP docs themselves are very challenging to read and understand in my opinion.

Test the scenarios you want to learn more about.

Its important to see how your application behaves as well, during scenarios like "out-of-coverage".

This can be done by placing your device in a shielded box for instance.

 

Kind regards,

Håkon