Performability Modelling and Analysis of Clustered Wireless Sensor Networks with Limited Storage CapacitiesInternet and Distributed Computing Systems

Wireless Sensor Network (WSN) technology has seen an increasing demand for use in various application areas including multimedia sensor networks, smart agriculture and industrial automation. The applications demand for optimum results are dictated by the complexity of their deployment environment, hence the need for improved performance, availability and reliability. Packet loss due to limited memory capacity has become a major drawback in some areas of WSN applications like Multimedia Wireless Sensor Networks (WMSN). Most of the existing studies consider performance and availability evaluation separately. Considering systems for pure performance evaluation may cause overestimation of systems ability to perform. On the other hand focussing only on the availability may be too conservative since various levels of performance are not considered. In this paper, we propose an analytical modelling approach for bounded WSN queues where cluster-tree architecture is considered and integrated performance and availability measures analysed in the presence of failures, repairs/replacement and restoration. Open queuing network is used to model the behaviour of the cluster head as an M/M/1/L queuing system and using spectral expansion method, the system is solved and validated against simulation results. Both analytical and simulation results presented are in good agreement and are further used to analyse the trade-off between the arrival rate and buffer size for optimum performance and availability