The role of medium access control protocols in SCADA systems

This paper deals with the influence of the medium access control (MAC) protocol in the performance of the coriiriiunication channels used in the SCADA system (Supervisory Control And Data Acquisition). Three types of MAC protocols are presented and analyzed: Polling, CSMAXD (Carrier Sense Multiple Access with Collision Detection), and Token Bus. The simulation of each one of these protocols allows us to quantify its performance and establish cerbin criteria in order to be able to coinpare them. As a result of the analysis, the use of a MAC protocol is proposed for SCADA systems.