Research On Energy-optimized Routing Protocols In Cognitive Ad Hoc Networks

In recent years, the idea of cognitive radio has been applied in many fields of wirelesscommunication, Ad Hoc network is a novel network types, it not only can be used asan independent network, can also be used as the supplementary form to the currentfixed infrastructure network. Cognitive radio has been considered as the technology to free usespectrum resources, which is very appropriate in the Ad Hoc network, especially suitable for theAd Hoc cognitive radio emergency network.According to the Ad Hoc network simulation platform has not considered the demand ofchannel allocation, this paper proposes a cross layer design of cognitive Ad Hoc networksimulation platform with the MCU (Multi-channel Control Unit) module and PCU (Power ControlUnit) module, which select channel for data stream transmission and dynamic adjusttransmitting power can effectively reduce the energy consumption. We modify the AODV (Ad hocOn-demand Distance Vector routing) routing protocol to the CAODV (Cognitive Ad hocOn-demand Distance Vector routing) routing protocol in accordance withcognitive Ad Hoc network characteristics, and simulate CAODV in the proposed cognitiveAd Hoc network simulation platform from the time delay, throughput and energy consumption,and compare the simulation results with single channel simulation platform, the simulation resultsshow that, the proposed cognitive Ad Hoc network simulation platform can improve networkperformance due to the more effective use of multi channel technology, meet the needs of channelassignment, and because of the use of power control module can effectively reducethe node energy consumption.According to the mobile nodes in the cognitive Ad Hoc network is a small batteryfor power supply, put forward a kind of power control algorithm NPCA (Neighbour-PowerControl Algorithm), which dynamically adjust transmit power based on the neighbor nodeset, effectively reduce the power consumption of the nodes. We raise ORT-AODV (OverridRouting Table-Ad hoc On-demand Distance Vector routing) that solve problems likecognitive nodes switch to the frequency band used before and the intermediatenode switching frequency problems, and then put forward PCORT-AODV (Power ControlOverrid Routing Table-Ad hoc On-demand Distance Vector routing) by adding the power controlalgorithm NPCA to the ORT-AODV routing protocol, simulate ORT-AODV and PCORT-AODVin cognitive Ad Hocnetwork simulation platform. Simulation results show that theORT-AODV due to consider the cognitive nodes switch to the available frequency band usedbefore and the intermediate node switching frequency, can effectively improve thenetwork performance in delay and throughput than CAODV, the energy consumption ofPCORT-AODV due to the use of power control algorithm is better than ORT-AODV.Finally we construct CR-SPT (Cognitive Radio-Shortest Path Tree) shortest path tree algorithm for cognitive Ad Hoc network based on SPT (Shortest Path Tree) by dynamicallyconsidering nodes left or join to the multicast tree, and proposes an energy function, using theenergy function as the weight to construct ESPT (Energy Shortest Path Tree) multicast routingalgorithm, then simulate CR-SPT in the cognitive Ad Hoc network simulation platform andcompare with SPTA and Dijkstra algorithm in updating times and updating time when deletingnodes, the simulation results show that the update times and update time of CR-SPT are less thanSPTA (Shortest Path Tree Algorithm) and Dijkstra, ESPT can largely reduce the energyconsumption due to the use of energy function as the weight to construct multicast tree.