A proactive spectrum handoff scheme with efficient spectrum utilisation for cognitive radio ad hoc networks

This paper proposes a proactive spectrum handoff scheme for cognitive radio (CR) ad hoc networks by exploiting the efficient utilisation of the available wireless spectrum by CR. The novelty of this spectrum handoff scheme is that it is able to use the available free channels which are idle for one complete CR packet transmission as well as idle for less than one packet transmission. This has been done by channel scheduling and packet fragmentation to reduce unusable channels. In this scheme, spectrum sensing is done during packet transmission. The main contribution of the proposed spectrum handoff scheme is that it outperforms the existing proactive and reactive spectrum handoff schemes in terms of reduced CR average service time, improved throughput, and improved spectrum utilisation under the different primary user (PU) arrival rates. It is also analysed that the proposed spectrum handoff scheme is best suited scheme in heavy PU traffic arrival rates.