Wireless communication networks and process control applications: Studying the influence of MAC protocols

The performances of the process control applications, which are implemented through networks, depend greatly on the scheduling of the messages. Furthermore, in the context of the wireless networks, because of the unreliable medium, it is difficult to meet the timing requirements imposed by the applications dynamics. The objective of this paper is, by considering a Wireless Local Area Network (WLAN) and a process control application, to compare the performances of this application by using MAC protocols of the type CSMA (which manage the messages scheduling): two protocols with collision avoidance (CA), provided by manufacturers (IEEE 802.11 - WiFi, IEEE 802.15.4 - ZigBee) which do not prevent the occurrence of collisions; a proposed free-collision protocol which is based on priorities specified by means of BlackBurst messages.