MARKOV MODEL OF WIRELESS SENSOR NETWORK AVAILABILITY

The use of wireless sensor networks (WSN) in industry and for forest fire detection has recently become increasingly popular. Assessment of the availability of such networks is an important task, since they perform essential functions in critical situations. Sensor networks can be used to prevent and detect forest fires, and they must meet high availability requirements. Various options for organizing the WSN system are considered - with and without recovery. For such systems, the paper evaluates the probability of no-failure operation, as well as the readiness function, taking into account the network coverage ratio. In the paper the Markov WSN model for evaluating its availability function is developed taking into account the network coverage area. The obtained graphical dependencies allow us to evaluate how a change in the failure rate of sensors or system equipment affects the availability function value. The goal of this paper is to obtain metrics to assess the availability of system for monitoring forest by WSN and the availability function of a network using the Markov models. A special metric, so-called coverage availability factor is suggested in this paper taking into account different combinations of sensor failures which influence on completeness of monitoring forest fires.