MAC protocol design and resource management for distributed cognitive radio networks

Cognitive radio (CR) has drawn extensive attention as a promising technique to enable dynamic spectrum allocation in wireless networks in order to increase spectrum utilization. Since coordination and communication over wireless medium is mainly performed at medium access control (MAC) layer, design of a smart MAC is vital for successful deployment of distributed CR network (DCRN). In this thesis, we first investigate research challenges specific to DCRN MAC design and present an overview of current state-of-the-art DCRN MAC protocols. We then propose a MAC protocol called OMC-MAC to address major research issues in DCRN. The distributed architecture and uncertainty in resource availability make QoS provisioning a challenging problem in such networks. Therefore, we incorporate a QoS support module in OMC-MAC in order to provide QoS guarantee to delay sensitive applications. We also investigate adaptive admission control mechanism to limit QoS users in DCRN. Next, we propose resource allocation schemes based on cross-layer interaction between MAC and network layers to minimize network wide resource wastage in multi-hop DCRN. In multi-hop DCRN, loss of a packet after traveling some hops results in wasting all resources allocated to it in previous hops. We propose schemes to allocate transmit power favoring packets which have traveled more hops before reaching resource allocating node. Similar resource allocation schemes are also investigated for multi-hop distributed orthogonal frequency division multiple access network. Finally, we explore research challenges and potential solution approaches in achieving virtualized future generation cellular networks. Network virtualization (NV) has been envisioned as a promising approach to reshape future generation wireless networks by enabling coexistence of several heterogeneous virtual networks to efficiently share the same physical resources and infrastructure. Successful implementation of NV in cellular systems largely depends on virtualization of their radio access part. Therefore, we investigate research issues in virtualizing radio access of cellular systems. We also discuss the potential of MAC mechanism and resource management developed in this thesis in enabling NV.Applied Science, Faculty ofElectrical and Computer Engineering, Department ofGraduat