Issue with SMS functionality on RM520N-GL module

IoT Modules 5G Module
1

Dear, @Niki.Liu-Q @vincent.ding-Q @herbert.pan-Q @silvia @staff

I am currently using the RM520N-GL module, and I am facing an issue where SMS functionality stops working after a few hours of activity. Here are the details:

  1. Upon starting or rebooting the router, both SMS and internet services work fine. During this time, if I call the module’s SIM from a mobile phone, I hear a “number busy” message.

  2. After a few hours, SMS functionality stops working while the internet continues to work. At this point, if I call the module’s SIM, I hear a “switched off” message.

If I reboot the router, SMS services resume but stop again after a few hours. I have also noticed that:

When I hear the “number busy” message, SMS works fine.

When I hear the “switched off” message, SMS stops working.

I have already activated IMS using the AT+QCFG=“ims”,1 command. also tired different firmwares but not solved.

  • The module is operating on the 5G SA n78 band only.

I would appreciate your guidance in resolving this issue.
Thank you,

2

What do these AT commands return when SMS is working, and again after it stops working?

AT+CGDCONT?
AT$QCPDPIMSCFGE?
3

Now SMS not working even reboot 3 times.
Currently SMS not working and listen switch off message if call on module sim.

command output :

+CGDCONT: 1,"IPV4V6","JioNet","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,,"",,,,0 
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,,"",,,,0 
+CGDCONT: 3,"IPV4V6","sos","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,1,,,,,,,,,,"",,,,0 
 
OK

$QCPDPIMSCFGE: 1,0,0,0 
$QCPDPIMSCFGE: 2,1,0,0 
$QCPDPIMSCFGE: 3,1,0,0
4

Those responses look correct. It’s unclear to me where the problem might be.

Hopefully one of your listed contacts will come into the conversation.

1 Like
5

ok, thank you. :heart:
i hope someone will help.

6

You could check whether the “ims” APN context has got an IP address, like so:

AT+CGDCONT?
+CGDCONT: 1,"IPV4V6","live.vodafone.com","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,1,0,,,,,,,,,"",,,,0
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 3,"IPV4V6","hos","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
+CGDCONT: 4,"IPV4V6","sos","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,1,,,,,,,,,"",,,,0
+CGDCONT: 5,"IPV4V6","web.vodafone.de","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,"",,,,0
OK
AT+CGPADDR
+CGPADDR: 1,"100.85.219.84"
+CGPADDR: 2,"36.5.110.0.3.91.247.33.78.160.120.170.185.171.234.89"
+CGPADDR: 3,""
+CGPADDR: 4,""
+CGPADDR: 5,""
OK
7 
+CGDCONT: 1,"IPV4V6","JioNet","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,,"",,,,0
+CGDCONT: 2,"IPV4V6","ims","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,0,,,,,,,,,,"",,,,0
+CGDCONT: 3,"IPV4V6","sos","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0",0,0,0,1,,,,,,,,,,"",,,,0

OK

+CGPADDR: 1,"36.9.64.193.0.8.46.162.128.0.0.0.0.0.0.0"

+CGPADDR: 2,"36.9.65.1.0.30.250.174.128.0.0.0.0.0.0.0"
+CGPADDR: 3,"0.0.0.0","0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0"

OK
8

Dear @mdpatel
Please share your current firmware.

9

my current firmware: RM520NGLAAR01A08M4G_01.205.01.205

10

Dear @mdpatel
Did you check the ims status when SMS stop working?

I will share another firmware to test again.

12

I had a similar issue, and it turned out to be a problem with how the SMS center number was set. I fixed it by double-checking the +CSCA value and reconfiguring it manually. Also, if you’re trying to send bulk messages or need a workaround while testing, I’ve used sms.to to send and receive messages through API when the module wasn’t cooperating. It helped isolate the problem faster.

13

I had a similar issue and it turned out the problem was linked to how the sip provider handles SMS over data. I had to check with them if SMS via LTE is even supported, since some only support SMS over IMS or require special settings. Once I clarified that with the sip provider and made sure VoLTE and IMS were properly enabled on the module, things started working fine.