Design of a Medium Access Control Protocol for Dynamic Spectrum Access Networks

In this paper we present a design of a medium access control protocol that allows the utilization of unused licensed spectrum of deployed wireless cellular systems (Primary System) by an overlaid multi-hop ad hoc network (Secondary System). The basic design principle is that the secondary operates in a non-intrusive manner and does not interact with the primary. We address a number of architectural challenges pertinent to this networking environment, and evaluate the performance of the MAC. Our performance evaluation results show that, in a single-hop ad hoc network, the proposed MAC transparently utilizes 75% of the bandwidth left unused by the primary, while, in the multi-hop cases, due to spatial reuse, the bandwidth utilization can be significantly higher.