Trying to understand basic packet forwarder on Kerlink Gateway

Oh yes, it is sending AA

String message= "AA";
int messageLength = message.length();
Serial1.write("mac tx uncnf 1 ");
for (int i = 0; i < messageLength; i++)
{
Serial1.print(message.charAt(i), HEX);
Serial1.write("\r\n");
}