Two Layered Hierarchical Model for Cognitive Wireless Sensor Networks

Abstract

In recent years, we have seen tremendous growth in the applications of wireless sensor networks (WSNs) operating in unlicensed spectrum bands. However, there is evidence that existing unlicensed spectrum is becoming overcrowded. On the other hand, with recent advancements in Cognitive Radio technology, it is possible to apply the Dynamic Spectrum Access model in WSNs to get access to less congested spectrum, with better propagation characteristics. One of the predominant problems in Cognitive aided Sensor Networks is spectrum management. In this paper we propose an effective way of Co-operative spectrum management in a large environment. The key idea is to localize the sensor field by forming clusters such that each cluster in a way is independent of another. Intra-cluster communication takes place within the locally detected spectrum holes and inter-cluster communication takes place between cluster heads in a common spectrum hole. Thus forming a two-layered Cognitive aided Sensor Networks.