Send SMS-COMMAND PDU possible using AT command?

IoT Modules LTE Standard Module
1

Hi,

Anyone manage to send a SMS-COMMAND PDU using AT command?

AT+CMGS in PDU mode seems to only support SMS-SUBMIT PDU.

Any sample AT sequence to send SMS-COMMAND would be appreciated.

I have tried the following sequence and it ends with error.

AT+CMGS=14

>
0022000000E50B910621561626F100→

+CMS ERROR: 350

Thanks.

3

From what I can see, +CMS ERROR: 350 is likely to mean the SMS command is being rejected by the message centre, and not by the modem.

4

I am not sure who rejects it.

What we intend to do is to send a SMS-COMMAND out to query the status of a submitted short message (using SMS-SUBMIT PDU) which was not delivered yet to phone by SMSC. In the SMS-SUBMIT PDU the delivery report flag has been set.

Or perhaps there is a better way to query SMSC on undelivered short message?

5

Tried out with AT+CMGC, it ends with ERROR also.

6

That’s a good point, AT+CMGC seems to be the correct AT command for this.

According to 3GPP 23.040, section 9.2.2:

SMS-SUBMIT, conveying a short message from the MS to the SC

SMS-COMMAND, conveying a command from the MS to the SC

Not all SMSCs support delivery reports (the TP-SRI bit is ignored). They may not support SMS commands of any TP-CT value.

Do delivery reports normally work with the network you’re using?

7

If TP-SRR is set in SMS-SUBMIT, a delivery report will be received when SMS is delivered to final destination.