Methodology of cooperative spectrum sensing and dynamic access to the channels in WSN

Cognition into wireless sensors is a current paradigm to improve the performance of wireless sensor networks (WSN) and the efficient use of the radio frequency spectrum. The classic static allocation of the radio frequency bands causes coexistence problems or underutilization of resources. This issue could be addressed using cognitive sensors with dynamic spectrum allocation. Therefore, a novel methodology for cooperative spectrum sensing and dynamic access to the channels (MSDAC) for a cluster of a WSN is proposed in this article. The MSDAC proposal aims the asynchronous coordination and communication between the cluster sensors in a simple way based on reinforcement-learning for home automation applications. Additionally, a set of experiments are formulated to evaluate and to compare the proposal. The experiments are based on a case study with a wireless local area network acting as primary user and a secondary network with burst traffic formed by IEEE 802.15.4 devices performing the MSDAC. The results show an improvement in the message delivery ratio and in the coexistence capability when MSDAC is used. In addition, the lowest amount of message retransmissions causes a reduction in the sensor active time when compared with other approaches, which is beneficial for energy saving.