Virtual backbone construction for cognitive radio networks without common control channel

The advantages of virtual backbones have been proven in wireless networks. In cognitive radio networks (CRNs), virtual backbones can also play a critical role in both routing and data transport. However, the virtual backbone construction for CRNs is more challenging than for traditional wireless networks because of the opportunistic spectrum access. Moreover, when no common control channel is available to exchange the control information, this problem is even more difficult. In this paper, we propose a novel approach for constructing virtual backbones in CRNs, without relying on a common control channel. Our approach first utilizes the geographical information to let the nodes of a CRN self-organize into cells. Next, the nodes in each cell form into clusters, and a virtual backbone is established over the cluster heads. The virtual backbone is then applied to carry out the end-to-end data transmission. The proposed virtual backbone construction approach requires only limited exchange of control messages. It is efficient and highly adaptable under the opportunistic spectrum access. We evaluate our approach through extensive simulations.