Is it possible to read and / or change the SMS header on Android?

Question

I am developing an Android application 1.6 and above that sends and receives SMS messages through a port. To send an SMS, I use the method:

SmsManager.sendDataMessage (String destinationAddress, String scAddress, short destinationPort, byte [] data, PendingIntent sentIntent, PendingIntent deliveryIntent)

but found that the byte [] data should contain only the message body. There seems to be no way to send multi-part data messages and not change the text of the SMS header (UDH) to indicate that the messages are, say, 1 out of 3.

I have a similar problem on the receiving side when trying to extract information about the number of messages from SMS received by me through the specified port. I use SMSMessage.getPdu () to retrieve a byte [] containing the message header and message body, but not a way to extract specific information from the header data. Does anyone know the format used by the Android platform for SMS headers?

Any help would be greatly appreciated.

Answer 1

You will need to check the 3GPP SMS specification. For me, I received destination port information from the 30th and 31st bytes.