Performability analysis for fault-tolerant WiFi communication system

In this paper, a performability model is developed to analyze the effect of Access Point failures on the performance of a WiFi communication system. The system consists of seven Access Points in which mobile nodes (vehicles) travel at speeds up to 60 Km/hr. Traffic information is continuously sent by the infrastructure to the vehicles (I2V) in the form of bursts of identical packets to decrease packet loss. The model is based on a continuous time Markov chain used to obtain the steady state probabilities of each state. A penalty is then calculated for each state. This penalty takes into account the number of bursts lost, the number of consecutive bursts lost, vehicle speed and the specific location within the network where these losses occur.