Evaluating a wireless real-time communication protocol on Windows NT and WaveLAN

One of the main reasons explaining the success of field busses in industrial automation was the drastic reduction of wiring, thus allowing for flexible reconfigurations at low cost. A possible next step, which allows even more flexibility, would be to abandon wires altogether and to rely on a wireless medium for communication. However, the question of the reliability and real time guarantees arises. The authors present and evaluate a reliable real time communication protocol that enhances the IEEE 802.11 standard. The reliability and real time properties of the protocol rely on determining parameters that model basic assumptions on the occurrences of message losses and bound of message delays. We determine realistic parameters by fine grained measurements of message delays and message losses and measure the protocol performance resulting from the so determined parameters.