Look into the Maxstream data radio modems (http://www.maxstream.net/) for direct serial transmission. Use the 900 mHz as it cuts through better(they also have high power ant packages). The Maxstreams are super handy and very, very easy to use. I don't know if AUS lets you run 900's or you have to use 2.4. TCP/IP Wireless can be a problem over that distance unless it is a permanent solution(Do you have wireless you can tap into through your cellphone?). The beauty of the Maxstream solution is the simplicity and the bulletproof nature of the device. You can set them up in repeater mode and blast away for even longer throws. Transmitting impluses over the link still requires you to have a backup timer at the split location so why not use something you can get error checking on and have the facility to get a re-transmit to boot. They are a pretty good value for the money. I have used the TED's from Alge, Cellular and the Maxstream as solutions on data transmissions and the Maxstream works the best(Sorry Fred and Ted). The bidirectional characteristic and the price point will make your mouth water. Once you start goofing with them you can think of tons of other applications. Check it out and good luck.