I was thinking this:
If the data is : <data_high2>---<data_high1>---<data_low2>---<data_low1>
Receiver waits for '' (or any such unique character).
Transmitter sends '' is followed by data_high2.
Receiver sends '#' and waits for '' again.
Transmitter sends '' followed by data_high1
Receiver sends '#' and waits for '' again.
Transmitter sends '' followed by data_low2
Receiver sends '#' and waits for '' again.
Transmitter sends '' followed by data_low1
Receiver sends '@' and waits for new data starting with '*' again. This repeats. Sound okay?