Low Overhead Spectrum Allocation and Secondary Access in Cognitive Radio Networks

Cognitive radio networks spectrum access, which allows secondary users opportunistically access unused licensed channels to exploit instantaneous spectrum availability, is a promising approach to achieve efficient spectrum utilization and mitigate spectrum scarcity. In order to reduce spectrum handoff overhead, this paper propose two heuristic spectrum allocation and reallocation methods based on graph coloring method. For a given network topology, the proposed spectrum allocation method first generates an interference graph based on the network topology and interference constraints. Then for secondary access on a graph coloring algorithm is cooperative spectrum reallocation among secondary users to minimize spectrum handoffs. Obtained results demonstrate that graph coloring method and algorithms are a promising concept that can enhance the performance of secondary spectrum usage. KeywordsGraph coloring problem; Cognitive radio network; Spectrum allocation