25.8. Syntax of the +CMSS AT Command in SMS Text Mode and PDU Mode

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Unlike +CMGS, the syntax of the +CMSS AT command is the same in both SMS text mode and PDU mode. Below shows the syntax of the +CMSS AT command: (Optional parameters are enclosed in square brackets.)

+CMSS=index[,address[,address_type]]

Before we discuss each of the parameters, let's see an example that gives you some idea of how an actual command line should look like:

AT+CMSS=5,"+85291234567",145

The index Parameter

The first parameter of the +CMSS AT command, index, specifies the location of the SMS message in the message storage area.

The address Parameter

The second parameter of the +CMSS AT command, address, specifies the destination address to send the SMS message to. Usually it is a mobile number formatted using the typical ISDN / telephony numbering plan (ITU E.164/E.163). For example, "+85291234567", "91234567", etc. Note that the value passed to the address parameter should be a string, i.e. it should be enclosed in double quotes.

The address parameter is optional and it can be omitted. If you do so, the +CMSS AT command will use the address stored in the SMS message header as the destination address.

The address_type Parameter

The third parameter of the +CMSS AT command, address_type, specifies the type of the address assigned to the address parameter. Two values are commonly used. They are 129 and 145:

• 129. It means the value of address is formatted using the typical ISDN / telephony numbering plan (ITU E.164/E.163) but it is not sure whether the value of address is an international number, a national number or a number of other types. Example addresses: "85291234567", "91234567".

• 145. It means the value of address is formatted using the typical ISDN / telephony numbering plan (ITU E.164/E.163) and it is an international number. Example address: "+85291234567".

As address_type is an optional parameter, it can be omitted. If you do so, the GSM/GPRS modem or mobile phone will use the default value of the address_type parameter, which is:

• 129 if the value of address does not start with a "+" character. For example, "85291234567".

• 145 if the value of address starts with a "+" character. For example, "+85291234567".

25.9. Format of the Information Response of the +CMSS AT Command in SMS Text Mode and PDU Mode

If the GSM/GPRS modem or mobile phone sends the SMS message successfully, it will return an information response to the computer / PC. The format of the +CMSS information response in SMS text mode and that in SMS PDU mode differ by a single parameter.

In SMS text mode, the information response of the +CMSS AT command has the following format: (Optional fields are enclosed in square brackets.)

+CMSS: message_reference[,service_center_time_stamp]

Here is an example that gives you some idea of how an actual information response should look like:

+CMSS: 5,"07/02/05,08:30:45+32"

In SMS PDU mode, the information response of the +CMSS AT command has the following format: (Optional fields are enclosed in square brackets.)

+CMSS: message_reference[,SMS-SUBMIT-REPORT_TPDU]

The message_reference Field

The first field of the information response of the +CMSS AT command, message_reference, contains an integer in the range from 0 to 255. It is a reference number allocated by the GSM/GPRS modem or mobile phone to the SMS message sent.

The service_center_time_stamp Field

In SMS text mode, the second field of the information response of the +CMSS AT command is service_center_time_stamp. It contains a string that indicates the time and date at which the SMS message arrived at the service center (i.e. SMSC). The time stamp format is "yy/MM/dd,hh:mm:ss±zz", where yy = year, MM = month, dd = day, hh = hour, mm = minute, ss = second, zz = time zone. Note: the unit of time zone is a quarter of an hour.

For example, "07/02/05,08:30:45+32" represents 5 February 2007, 8:30:45 GMT+8 hours. "+32" means GMT+8 hours, since 32 quarters of an hour = 8 hours.

Note that service_center_time_stamp is an optional field. A GSM/GPRS modem or mobile phone includes this field in the information response only if the messaging service value set by the AT command +CSMS (command name in text: Select Message Service) is 1 and the mobile network supports the use of this messaging service value. By default the messaging service value is 0. Usually this is the value to be used and the service_center_time_stamp field is not shown.

The SMS-SUBMIT-REPORT_TPDU Field

In SMS PDU mode, the second field of the information response of the +CMSS AT command is SMS-SUBMIT-REPORT_TPDU. It contains a TPDU of the type SMS-SUBMIT-REPORT in hexadecimal format. It carries a positive submission report returned from the SMSC. It acknowledges the GSM/GPRS modem or mobile phone that the submission of the SMS message to the SMSC was successful. The value of the SMS-SUBMIT-REPORT_TPDU field is a string and so it is always enclosed in quotes.

Note that SMS-SUBMIT-REPORT_TPDU is an optional field. A GSM/GPRS modem or mobile phone includes this field in the information response only if the messaging service value set by the AT command +CSMS (command name in text: Select Message Service) is 1 and the mobile network supports the use of this messaging service value. By default the messaging service value is 0. Usually this is the value to be used and the SMS-SUBMIT-REPORT_TPDU field is not shown.

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