A two-stage power and QoS aware dynamic spectrum assignment scheme for cognitive wireless sensor networks

Novel applications running on top of wireless sensor networks set new QoS requirements, demand devices´ seamless connectivity, and call for new communication paradigms such as opportunistic spectrum access. However, realization of opportunistic spectrum access without causing interference to primary users poses significant challenges that are further exacerbated by the power constrained nature of wireless sensors and the QoS requirements of the supported applications. In this work we consider the problem of dynamic spectrum assignment in opportunistic access spectrum bands in the context of cognitive wireless sensor networks. We propose a dynamic spectrum assignment scheme that establishes a virtual link, between wireless sensors, which exhibits minimal power consumption and deterministic capacity. The virtual link is created on top of opportunistic and free access bands and to this end we utilize cognitive radio technology. The proposed DSA scheme is based on a two-stage stochastic integer program with non-fixed recourse. Numerical results verify the effectiveness of the proposed dynamic spectrum assignment scheme.