Research On Wireless Backhaul Constraint Topology Panning Based On Hierarchical Model

The relay wireless backhaul solution uses FDD LTE or TDD LTE standard bearer to transmit back to the site.Compared with microwave,it has stronger non-line-of-sight transmission capability.It can solve the problem of unreachable traditional transmission methods in urban,suburban and other scenarios.Therefore,it has become the mainstream solution for current wireless communication network deployment.According to the constraints of equipment selection,communication distance,site connection mode,site deployment location,and topology relationship between sites,it is the Relay wireless return to design a reasonable host station,sub-station deployment and connection plan to reduce base station deployment costs and reduce path propagation loss.Pass the core issue in the design of the scheme.Therefore,the paper proposes a wireless backhaul constraint topology planning method based on a hierarchical model,and on this basis,proposes a low-cost topology planning optimization method and an optimization method to replace the complete edge set to achieve a low-cost and low-loss wireless backhaul topology planning.The specific work of the thesis is as follows:(1)In order to effectively characterize the topology between satellites,host stations and substations,the hierarchical model is used to effectively express the hierarchical communication network structure,and the entire communication network is divided into local communication subnets,regional communication subnets and global communication networks.Among them,the host station and its connected substations constitute a local communication subnet;the communication between the host stations constitutes a regional communication subnet;the communication between the host station and the satellite constitutes a global communication network.The distance threshold is used to divide the candidate sites into several independent connected components.In order to construct the communication subnet according to the constraints,a 4-2 tree model is proposed to divide each connected component.On the basis of connected components,all host stations are divided into several regional communication subnets with the shortest communication path according to the distance threshold of 50 km and the minimum spanning tree model,and each regional communication subnet is regarded as a satellite.channel.Finally,in accordance with the requirements of up to 8 channels per satellite,a global communication network that satisfies the constraints is constructed.The experimental results show that the wireless backhaul topology structure constructed by the hierarchical tree model can better meet the constraints and maintain complete site information.(2)In order to design an overall low-cost topology planning solution,this paper proposes a low-cost topology planning optimization method based on the topology planning that satisfies the constraints.The optimization focus of the low-cost topology planning scheme is to reduce the number of host stations and the number of satellites in the communication network under the premise of satisfying the topological constraints.Therefore,in order to achieve the goal of the least number of host stations,this method is realized by selecting a local communication subnet with the smallest number of host stations in each connected component.The number of satellites is determined by the number of regional communication subnets of the host station,and the number of regional communication subnets depends on the distribution of host stations in the connected group.Therefore,this paper takes the Cartesian product combination of the local communication networking scheme with the smallest number of host stations for each connected component as the cost-optimized solution sets,and determines the low-cost topology planning scheme through the gradual optimization method.The experimental results show that the low-cost topology optimization method proposed in this paper reduces 1.65 million USD and 1.2 million USD,respectively,compared with the other two low-cost optimization methods under the constraints of topology planning,verifying the effectiveness of the proposed algorithm.(3)In order to design a topology planning scheme with low return path loss,based on the overall low-cost topology planning,this paper proposes a Delaunay triangulation method to construct a complete edge set to replace the edge set of the communication subnet to be optimized is proposed to seek low-loss return path.Since the path loss only occurs in the backhaul process of the substations,it can be simplified to be positively related to the backhaul distance.For this reason,the key task of designing low return path loss is to optimize each local communication subnet.The optimization criterion is that all the substations return.The sum of transmission distances is the smallest.Experiments show that under the premise of satisfying the constraints of topology planning and ensuring the priority of low-cost topology planning,the optimized return path loss is reduced by 0.68 compared with the original loss,which optimizes the network structure and verifies the effectiveness of the proposed algorithm.