DMX (serial first) over Xbee Pro Module with Arduino
If you really want to transmitting a full universe of DMX, I would not reinvent the wheel and use a ready made and proven solution, this is because DMX is not a rugged protocol and needs a  lot of bandwidth (for a serial protocol), there are number of solutions out there in varying levels of complexity including using ip over wifi as a transport.

If it is only a few channels you want to get across, how about just extracting the changes in those channels and transmit them and then create a new stream at the other end?