nRF9160 and eDRX mode on LTE-M connection

[bjornolav]

We are using eDRX to save power, but it seems like eDRX is not active always. 

We currently use LTE_LC_EVT_EDRX_UPDATE callback to determine if eDRX is active. Is this a safe way to determine if the cell has eDRX activated? Quite often we do not receive the callback. Quite often we do not receive this callback when connecting. Does that indicate no eDRX?

nRF Connect SDK v2.3.0

Modem fw 1.3.4

Best regards

Bjørn Olav Steihaug

Datek Next

[Kazi Afroza Sultana]

Hello Bjørn,

Which samples you are following?

How have you configured the eDRX mode in config life? Could you please show how you handle this LTE_LC_EVT_EDRX_UPDATE event in the callback function?

Thanks.

BR

Kazi

[bjornolav]

Hi Kazi

We set eDRX parameter through AT commands:

 sprintf(atCmdEdrx,"AT+CEDRXS=%s,4,\"%s\"", mode, strEdrx);

    sprintf(atCmdPtw,"AT%%XPTW=4,\"%s\"", strPtw);

    nrf_modem_at_cmd(reply, 100, atCmdEdrx);

    nrf_modem_at_cmd(reply, 100, atCmdPtw);

This seems to work fine in most cases. We got some more information since I asked the question from the telecom provider. The sim cards we use gives us access to both Telia and Telenor networks. The profile on Telia did not have eDRX tuned on while Telenor had turned it on. 

My question is how we can detect missing eDRX in the future? Is using LTE_LC_EVT_EDRX_UPDATE event as safe method? When reading the documentation, I see other methods but the impression that they just return our settings and not what the telecom operator really offers.

Best regards

Bjørn