Is the functionality for fragmentation and reassembling concatenated SMS messages built in for the sendsendDataMessage() and the sendTextMessage() ?
In other words; If I put a arraybyte over 200 bytes as input to the sendDataMessage, will it be fragmented and reassembled automatically, so the getUserData() will give the same 200 bytes?
No, it couldn't. The maximum SMS message size is 140 bytes, even if when you use SmsManager.sendDataMessage().
So you need to set a loop to handle your multipart sms. Maybe you also need SmsManager.divideMessage(String text) to do several fragments.
Please refer to this problem: http://www.anddev.org/networking-database-problems-f29/npe-from-smsmanager-senddatamessage-t49916.html
BTW, so I think just for this reason, Google choose to open this API: SmsManager.sendMultipartTextMessage()