Multipart SMS over IMS with LE910R1-EA

Cellular Modules
1

Hi there. We have experience with several LE910C1-EU modems and are introducing products using the LE910R1-EA modem. We encounter issues when sending sms messages in text mode of over 160 characters (from the Telit AT Controller application as well as our full application):

  • Modem silently restarts (seems to crash) and nothing is sent.
  • Modem silently restarts and a corrupted message is received at the recipient phone.
  • Modem sends message successfully, but following (short) sms messages now appear corrupted until a modem restart.

We see this occurring on sim cards where CIREG shows that SMS over IMS is available. We do not see it on cards which do not support IMS.

Is this a known issue? We are running the latest software available on the download zone (.xx6). I wanted to try if disabling IMS makes any difference, but there does not seem to be a command for this (such as AT#ISMSCFG on other models).

I have yet to try whether using PDU mode makes any difference, since this requires the implementation of encoding the message ourselves.

2

Hello,

Indeed I can’t see AT#ISMSCFG command for LE910R1-EA. There is only AT+CGSMS command, which in fact is also present on LE910C1-EU. I think you cold register to 2G and 3G with AT+COPS command for test also.
Anyway, from what you described it seems like there may be a potential problem here. So, I would recommend you to contact the support for your region - you can find the contact email in the AT spec for instance. They will analyze and give you further guidelines.

BTW if you need to send a text SMS longer than 160 characters, you should send more than one, the module does not do it automatically.