Dynamic Spectrum Hole Management in Cognitive Radio

One of the major concerns of cognitive radio, is to be flexible and dynamic enough to, on one hand, minimize interferences with primary users, and on the other hand, guarantee the requested Quality of Service (QoS) level for cognitive transmissions. This paper addresses the problem of Spectrum Hole reassignment (SH reassignment) when the primary user reutilizes the frequency band. For that purpose, we propose a dynamic algorithm for SH reallocation to minimize cognitive transmissions interruption and to increase the number of served cognitive users (cognitive user with successful transmissions). The proposed algorithm is composed by 3 steps: Multi-Allocation spectrum hole procedure (MSHP), High Capabilities Spectrum Hole Reallocation Procedure (HCSHR) and Spectrum Hole Borrowing Procedure (SHB). We prove by analytic analysis and by simulations the good impact of the proposed algorithm on decreasing the interruption ratio for cognitive transmissions and on increasing the throughput of cognitive radio users.