Research On Broadcasting Algorithm Of Cognitive Mobile Ad Hoc Network

Mobile ad hoc network has been rapidly developed and widely used in many civil and military fields,due to its advantages such as no center,fast self-organization,flexible and mobile equipment and no fixed infrastructure required.Broadcasting is an important part in the mobile ad hoc network,which has important civilian and military value.Therefore,the broadcasting algorithm in the mobile ad hoc network is studied in this paper.First,in the traditional mobile ad hoc network,in order to improve the broadcast coverage,reduce the forwarding probability and the broadcast collision,a dynamic space-covered broadcast algorithm based on neighbor-degree in mobile ad hoc wireless networks is proposed.Introduced the neighbor-degree,available-angle and available-distance.The neighbor-degree is used to generate the node initial forwarding probability.The node weight is proposed based on the available-angle and available-distance to calculate the node final forwarding probability,which can realize the dynamic selection of forwarding nodes and reflect the dynamic space-covered of nodes.The forwarding strategy is proposed to reduce broadcast collision.Simulation results show that compared with dynamic probability broadcast and node location based space-covered broadcast,the proposed broadcast algorithm reduces the broadcast collision,improves the broadcast coverage;when there are many nodes,the node forwarding probability is reduced.And the comprehensive performance of the proposed algorithm is better than the latter two algorithms.Secondly,in the mobile ad hoc network of cognitive radio,in order to solve the problems of the low broadcast success rate of the distributed broadcast algorithm and high broadcast conflict rate of low-latency broadcast algorithm based on selective broadcast channel set,a multi-hop CR Ad Hoc broadcast algorithm based on relay node selection is proposed.The relay node is selected according to the node's available channel set and the forwarding probability which is based on the neighbor-degree.And the corresponding relay node's available channel set is randomly shifted.On the premise of ensuring the broadcast success rate,broadcast delay and broadcast collision,the node forwarding probability is reduced.The comprehensive evaluation function is established to quantitatively analyze the comprehensive performance of the broadcast algorithm.And the derivation of broadcast collision probability is given.Simulation results show that compared with the distributed broadcast algorithm,the proposed broadcast algorithm improves the broadcast success rate and reduces the broadcast delay;compared with the low-latency broadcast algorithm,it reduces the node forwarding probability and the broadcast collision probability.And its comprehensive performance is better than the two comparison algorithms.Finally,in the mobile ad hoc networks of cognitive radio,in order to ensure broadcast and network performance when the node energy is limited,an active rendezvous broadcast algorithm based on channel weight is proposed.From the perspective of balanced utilization of high-quality channels,one-to-many node matching is performed.And the channel weight is calculated by channel utilization and effective channel capacity.In each time slot,the best channel is selected according to the channel weight and used as the rendezvous channel for broadcasting to realize active switching between channels.There is no need to exchange any control information between adjacent nodes.Simulation results show that compared with the comparison algorithms,the proposed algorithm reduces the broadcast delay,improves the broadcast success rate,average remaining energy of nodes and the number of remaining nodes.And its comprehensive performance is better.