How to receive SMS message in standby mode in nRF9160?

[Yusuke]

I want to wake up nRF9160 by SMS.

What I want to do:

The nRF9160 usually sleeps to reduce power consumption, and only when it receives SMS it wakes up and send some data by UDP or so.

I succeeded in implementing MQTT(+TLS), but have no experience to implement SMS function.

Any advice?

[Yusuke]

I've already checked the link below, but I don't really get what each line means.
devzone.nordicsemi.com/.../sending-sms-using-at_client-example

This is my understanding.

----------------
AT+CFUN=1
=> Turn on the modem. The modem can receive SMS at any time.

AT+CPIN="1234"
=> Set Pin number, which is a password of SIM.

AT+CNMI=3,2,0,1
=> Configure the process of receving SMS.
----------------

After this setting, MCU can go to sleep to wait until SMS is received. When SMS is received, MCU wakes up.

Is this correct? I'm not familiar with SMS function. Sorry for poor skill.

[Håkon Alseth]

The sample you link to is for sending sms. For receiving sms, you need to poll the AT socket. Try to use at_client, and see if you are able to get a sms successfully received. Note that you need a SIM card which has a phone number in order to send/receive sms.

 

Kind regards,

Håkon

[Yusuke]

Hi, Hakon.

I can't receive SMS in eDRX. 

When I set 82 sec interval, I hope nRF9160 check if it receives SMS in that interval, but it doesn't work.

Does this mean SMS can't be received when you use eDRX?

[Håkon Alseth]

Hi,

 

Are you able to receive SMS successfully in other operating modes?

Is it just eDRX that is the problem?

 

Kind regards,

Håkon

[Yusuke]

Yea, I can receive SMS in normal mode without PSM or eDRX.
I use at_client program and hologram SIM. The SIM allows you to send SMS.

[Yusuke]

Could u tell me how to set up eDRX on LTE link monitor? I want to know the at commands for it.

[Håkon Alseth]

SMS reception should work in eDRX and PSM, but the SMS itself will be delayed by one period, so if the eDRX or PSM timeout is set to 1 hour, you might have to wait 1 hour to read the received SMS.

Which operator network are you connected to?

Is it NB1 or LTE M1? 

Yusuke said:

Could u tell me how to set up eDRX on LTE link monitor?

To request eDRX: eDRX setting +CEDRXS

To check if the settings were applied: Read EDRX dynamic parameters +CEDRXRDP

Kind regards,

Håkon

[Yusuke]

Hi, Hakon. Thank you for your advice. Very helpful.

>Is it NB1 or LTE M1? 
LTE-M1, hologram SIM

>SMS reception should work in eDRX and PSM
I see. So it's worth to try to find a way of using SMS and eDRX at the same time in nRF9160.

If SMS and eDRX integrated sample program is provided, it's very helpful. I think the best way to send messages in some interval while checking an incoming message is to use eDRX and SMS. 

[Yusuke]

AT+CEDRXRDP=4,"0110","0110","0000"
+CEDRXRDP: 0
OK

When I run the above AT command with at_client program, I received "+CEDRXRDP: 0."

But, studying the current consumption(floor: 40uA) and receiving interval, eDRX seems to be working in mqtt_simple + edrx, not at_client.

I guess something is missing.

What should I add? Any help?