Performance Evaluation of IEEE 802.11 Wireless Networks for Real-time Networked Control Systems
Li Gui, Yu‐Chu Tian, Colin Fidge · QUT ePrints (Queensland University of Technology) · 2007
In real-time networked control systems (NCSs), a controller interacts with sensors and actuators via a communications network. Wireless networks are being increasingly proposed as a basis for NCS implementation, but they introduce unpredictable transmission latencies and potential packet dropouts. This paper aims to evaluate the performance of wireless transmissions for real-time applications using the IEEE 802.11b protocol and to propose strategies for reduction of communication time delays. For sensors with the same data rate, our results show that careful choice of transmission intervals and avoiding putting all sensors in one physical layer can improve transmission performance. If sensors have different data rates our investigation shows that putting the slowest sensors farthest from the controller will minimize the transmission delays and jitter, especially when there is a large number of sensors.