Sending A Flash SMS Message (Complete Guide)

sending a flash sms

So far I’ve show how to send a text message in PDU mode. There is nothing special about this. There are a number of things you can do in PDU mode, that you can’t do in text mode.

A first example is a flash SMS message.

A flash SMS message is an SMS message that, instead of being stored in the SIM or memory of the receiving phone, pops-up on the receiving phone’s screen, without the user taking any action. When dismissed the message is usually gone.

Here is an example AT command to send a flash SMS message in PDU mode:

> 0001010B915121551532F40010104190991D9EA341EDF27C1E3E9743<Ctrl-Z>
Here is what the individual octets represent:
Size Value Description
1 octet 00 We don’t supply a SMSC number.
1 octet 01 PDU type and options. This is a plain SUBMIT-PDU.
1 octet 01 Our message reference.
1 octet 0B Size of the destination telephone number (in digits)
1 octet 91 International numbering plan.
6 octets 5121551532f4 This represents the destination and it translates to 1 512 555 1234
1 octet 00 Protocol identifier.
1 octet 10 Data Coding Scheme. This is the value that causes the message to be a flash message as opposed to a standard SMS.
1 octet 10 User Data Length or payload size (in characters).
16 septets 4190991D9E
The payload, also known as User Data. In this case, it is just GSM encoded text.
This particular string represents “A flash message!””

A more elaborate explanation of the GSM encoding and other fields is giving in a previous post in this series.

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