Network Selection And Optimization For Subway Passenger Information System

The passenger information system of urban rail transit(hereinafter referred to as PIS system)is mainly composed of central level station level wired network and train ground wireless communication network.Through the display terminals set in the station hall,platform,entrance and exit,and electric passenger compartment of urban rail transit station,the passengers or the public can understand the operation information and public of the train in a timely and accurate manner Shared media information.With the rapid development of urban subway in China,the data application and resource development of PIS system are increasingly intensified.The information transmission efficiency and broadcast effect that some subway Pls systems can carry in the earlier construction years are not ideal,and the network load pressure is increasing day by day,and a series of problems appear.These problems include:the stability,delay rate,definition and other indicators of the cable network can not meet the needs of users;wireless network coverage in the electric bus,Pls display terminal configuration in the car,anti-interference ability,fluency and other factors can not meet the stable live broadcast conditions of media advertisers and TV stations.This paper mainly studies from two aspects of urban rail transit mainstream PIS system cable backbone network and vehicle ground communication wireless network.Through literature review,on-site ride experience,system background data sorting,customer interviews,consulting industry experts and other forms,combined with the modern computer network and software engineering courses in graduate students' stage study network topology model,802.11n/ac spatial communication Model and other relevant knowledge and on-the-job work experience,for the existing metro line PIS system network selection and optimizationThe optimization of cable network specifically includes the comparison of MSTP embedded RPR network with RPR and RRPP backbone network,the analysis and evaluation of ring network topology,feasibility,problem-solving ability,cost,reliability and other aspects,and the final selection of a cable network optimization scheme more in line with the existing line road(MSTP embedded RPR)PIS system transformation conditions,to solve the station live recording Broadcast and vehicle video cannot be uploaded normally.The optimization of wireless network includes the comparison and selection of train ground wireless communication system based on 5GHz WLAN and TD-LTE network,the analysis of signal attenuation,propagation rate and other factors,and the idea of AP layout optimization,frequency planning,channel optimization,multicast implementation,Mesh establishment,link switching optimization and other ideas are proposed for simulation test.It is important to solve the problem that the average transmission rate of existing wireless communication system is too low to meet the PIS multimedia service,which has some reference and practical significance for the subsequent construction of new lines and the upgrading and maintenance of old lines.