Research On Channel Assignment Algorithm In Cognitive Radio Ad Hoc Network

With the improvement of the science and technology, the processing ability of mobileterminals are more and more powerful, and their cost are lower, which makes the networkconnecting anywhere and anytime comes true. The increasing of the wireless equipments thatcause the frequency resources so crowd in ISM network, however, some frequency band isnot effective, it is idle in most of the time, which is realized by many international group,research institutes and researchers who committed to new technologies and methods to solvethe deficiency of the spectrum utilization. Currently, cognitive radio is one of most effectivetechnology that can improve the spectrum utilization and network capacity. With thedevelopment of the cognitive radio, the cognitive Ad Hoc network is more and moreattractive.The channel assignment is one of the main tasks to design the MAC protocol incognitive Ad Hoc network, efficient and reasonable channel assignment algorithm canincrease the channel spatial reuse, improve the network performance. The channel assignmentalgorithm of the existing cognitive Ad Hoc network is analyzed and simulated in the paperwhich is focus on the deficiency of the channel assignment protocol based on the distancedepended MAC. Because of the discontinuous of the channel spectrum of the cognitive AdHoc network, the decline of the channel is also different. a channel selective algorithm isproposed in this paper, which depends on the distance of the senders and receivers, theneighbors update the channel state based on the interference range of the channel thatimproves the channel utilization. If the control channel transport too many controlinformation, the control channel will be saturated, it is the bottleneck of the network, thecontrol channel only needs to exchange the channel selective information in the scheme of thepaper that avoid the bottleneck problem of the control channel.The cognitive Ad Hoc network simulation model is constructed on the networksimulation tool NS-2, the channel assignment algorithm performance is researched throughthe simulation experiment. The results show that the proposed algorithm can increase thespatial reuse and the spectrum utilization of the channel, and the network performance isimproved.