Enabling eDRX or PSM Mode with iot.1nce.net sim

[Adeel]

Hi Dev Team,

I have an iot.1nce.net sim that I am using in Germany.

+CGDCONT: 0,"IP","iot.1nce.net","10.205.84.3",0,0

I was trying the eDRX configuration using a basic mqtt_simple example with the thingy91 board.

My COPS Value returns this: 

+COPS: 0,2,"26201",7

I was trying to enable eDRX but I got issues in enabling eDRX. 

+CEDRXRDP: 4,"1001","",""

The network does not provide Network eDRX and the PTW.

My question was is eDRX and PSM supported for this Sim ?
If not , what could be the alternate.

Regards,
Adeel.

[Håkon Alseth]

Hi Adeel,

 

As you mention, it might be that the network doesn't allow roaming sim cards to enter eDRX/PSM modes.

You could try contacting Telekom and ask if they plan to open these features for roaming SIMs.

 

Have you checked if you get PSM?

 

Kind regards,

Håkon

[Adeel]

Hi Hakon,

I tried the PSM config by adding:

CONFIG_LTE_PSM_REQ_RPTAU="10101010"  // 10 mins
CONFIG_LTE_PSM_REQ_RAT="00100001"       // 1 min

in the prj.conf file. 

In the link monitor, I set AT+CEREG=5 and then AT+CEREG? to view the parameters provided by the network.

It is not the same as I had configured in the config file. 

Does it mean that PSM is not supported (or) does the network not support the values provided by me.

I am basically trying to have a PSM mode of 10 mins and an active window of 1 minute.

Regards,

Adeel.

[Håkon Alseth]

Hi,

 

Adeel said:

In the link monitor, I set AT+CEREG=5 and then AT+CEREG? to view the parameters provided by the network.

It is not the same as I had configured in the config file. 

You are allowed to enter PSM, and you are getting these back:

Active time: 00011110 (GPRS Timer 2: 000 = 2 sec, 11110 = 30, 2 * 30 = 60 sec)

Periodic TAU: 00000110 (GPRS Timer 3: 000 = 10 minutes, 00110 = 6, 10 min * 6 = 1 hour)

 

You can see the specific bitmasks for the two timers shown here:

https://devzone.nordicsemi.com/f/nordic-q-a/54538/turn-off-active-time-and-go-directly-to-power-save-mode/220898#220898

 

Note that you can ask for a specific interval, but the actual PSM intervals are ultimately determined by the network.

 

Kind regards,

Håkon

[Adeel]

Hi Hakon,

Thanks for the explanation. So I am a bit network dependent here to obtain my exact values.

Regards,

Adeel.

[Håkon Alseth]

Hi Adeel,

 

PSM usually has a lower limit, and in your network it seems to be 60 minutes.

If you're using mqtt, you can set the CONFIG_MQTT_KEEPALIVE equal to your polling interval if you want to poll more often.

 

This will then make the nRF go out of PSM before the TAU has expired, and automatically re-negotiate PSM afterwards.

 

Kind regards,

Håkon