Experimental controller tuning and QoS optimization of a wireless transmission scheme for real-time remote control applications

In this paper an experimental optimization of a wireless (802.11b) transmission scheme, coupled to the tuning process of the controller parameters, for real-time control applications is presented. In congested wireless networked controlled systems (WNCS), there is considerable loss of data-packets in the transmission process between the client and server sides. Accordingly the quality of service (QoS) suffers and the system's performance deteriorates. An integrated framework is proposed, which monitors the QoS-factor, and (a) adjusts the data retransmission attempts, and (b) periodically tunes the controller's parameters. Experimental studies on a WNCS-prototype are used for the optimization procedure. These studies indicate the need for a compromise between the achieved QoS, the network's throughput, and the selected sampling period.