A robust cooperative spectrum sensing method against faulty nodes in CWSNs

Cognitive wireless sensor networks (CWSNs) become promising infrastructures, which can improve spectrum utilization of traditional wireless sensor networks (WSNs). For cognition in WSNs, spectrum sensing is one of the most crucial function to prevent hazardous interferences with the licensed users and to identify available spectrum for improving the spectrum utilization. In this paper, we propose a robust cooperative spectrum sensing method based on Dempster-Shafer (D-S) theory. Firstly, taking into account the increase of transmitted data with the rise of the number of sensor nodes and the power limitation of nodes, we propose to adapt the D-S theory to the binary hypothesis test at the local sensing sensor node, in order to reduce the amount of control data to be transmitted. Secondly, we consider that some cognitive nodes may not work as expected. Hence, facing this problem of faulty nodes in CWSNs, we propose an evaluation method which considers simultaneously the sensor node reliability and the mutually supportive degree among different sensor nodes to support adapted decision. Simulation results show that the proposed method allows to improve significantly the detection performance compared to other techniques, even in presence of faulty nodes.