How to use PSM and eDRX mode in custom code?

[shital]

Hi,

We are using nRF9160 and want to use PSM & eDRX mode in one of our project.
We referred 'Asset tracker Application' & found that lte_lc_psm_req() and lte_lc_edrx_req() are APIs to activate/deactivate corresponding modes.
Please correct me if I am wrong here.

Using above mentioned 2 APIs require changes in prj.conf & Kconfig.
But, as we are customisig our code from the scratch, we dont have Kconfig file.

Can you please tell us how to prepare these files & how to add them in a project ?

Thank You,
shital

[Håkon Alseth]

Hi,

 

These settings can be found in the lte_lc module, and here's the setting for requesting edrx:

https://github.com/NordicPlayground/fw-nrfconnect-nrf/blob/master/drivers/lte_link_control/Kconfig#L70

 

If you want this specific setting in your project, you add "CONFIG_<name of the entry>=y" to your prj.conf.

For instance:

CONFIG_LTE_EDRX_REQ=y

 

Similar for PSM, where you can choose to enable this in the background at bootup, via lte_lc driver, or you can call it from the application via "lte_lc_psm_req()".

Here's an example that does that: https://github.com/Rallare/fw-nrfconnect-nrf/blob/nrf9160_samples/samples/nrf9160/udp_with_psm/src/main.c#L112

Where the PSM timing parameters are set in the prj.conf: https://github.com/Rallare/fw-nrfconnect-nrf/blob/nrf9160_samples/samples/nrf9160/udp_with_psm/prj.conf#L25

 

Kind regards,

Håkon

[shital]

Hi,

Thanks for contributing with solution.

We tried PSM and eDRX APIs in our customized code (from the scratch) by modifing prj.conf file, as suggested by you. It compiles good without warning and error.

Now I am curios to test the PSM / eDRX modes, but my city doesn't have LTE Cat-M1 / NB-IoT network.

- Is it possible to test PSM / eDRX mode without the network ?
Please suggest me a way, if it is possible.

- If the network is available, please suggest me a way/setup to cross check that the device is in PSM/eDRX mode?

Thank You,
Shital

[Håkon Alseth]

shital said:

- Is it possible to test PSM / eDRX mode without the network ?

 You will need to have M1 or NB-IoT coverage to run tests.

shital said:

- If the network is available, please suggest me a way/setup to cross check that the device is in PSM/eDRX mode?

If a network is available, you can test PSM by requesting this in AT command CPSMS, and then reading the parameters for the link by entering "AT+CEREG=5" and "AT+CEREG?" to read the parameters that the network has set.

 

For eDRX, you set via this AT command:

https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/nw_service/cedrxs_set.html?cp=2_1_6_2_0

 

And read the parameters that the network set via:

https://infocenter.nordicsemi.com/topic/ref_at_commands/REF/at_commands/nw_service/cedrxrdp_set.html?cp=2_1_6_3_0

 

AT commands can be issued and read when you run the sample "at_client" in NCS.

 

Kind regards,

Håkon