Cooperative sensing delay minimization in cloud-assisted DSA networks

Dynamic Spectrum Access (DSA) is considered as a promising solution to address the problem of spectrum scarcity in future wireless networks. However, the main challenges associated with this approach are to acquire accurate spectrum usage information in a timely manner and to deal with the dynamicity of channel occupancy. Although Cooperative Sensing (CS) can provide significant advantages over individual device-level sensing in terms of sensing efficiency and the achievable throughput, the acquired channel occupancy information may become outdated in dynamic channel conditions due to the involved latency. In this regard, we propose to utilize a collaborative cloud-edge processing framework to minimize the CS delay in DSA networks. In this framework, the cloud-center can estimate channel occupancy parameters such as duty cycle based on the available historical sensing data by using a suitable spectrum prediction technique, and subsequently this prior knowledge can be utilized to adapt the sensing mechanism employed at the edge-side of a DSA network. Motivated by this, we formulate and solve the problem of minimizing CS delay in cloud-assisted DSA networks. A two-stage bisection search method is employed to solve this CS delay minimization problem. Our results show that the proposed cloud-assisted CS scheme can significantly reduce the CS delay in DSA networks.