RE: Nrf9160 DK does not send periodic TAU when no tx is due

lorv — Thu, 10 Oct 2019 09:12:14 GMT

Thanks for your Answer that clarifies things.

If you set T3324 to 0 the UE goes directly to PSM after TAU and skpis the eDRX. This works well, I have tested it.

GNotman — Thu, 10 Oct 2019 09:01:57 GMT

The UE can request certain PSM timers however, the network must agree to the requested timers.

The network may agree the requested timers, override the request with their own values, or simply not allow PSM.

A 1 minute T3412 timer is very short, I would be surprised if the network would allow it.

Also I believe your T3324 (Requested RAT) value is invalid. You are you requesting 1m. x 0.

You can request both the T3324 and T3412 to be the same duration.

This works, however, the UE will remain active throughout the PSM cycle.

After the PSM request has been sent you can view the actually in use timers with either:

AT+CPSMS?

AT%XMONITOR

Note: You may need to wait a few seconds after the initial request is sent.