Research On The Construction And Key Technology Of Public Wireless Network System For China Railway High Speed Train

Based on "train public wireless network" and "basic travel service" and "special carriage service ",this paper constructs intelligent travel extension service for high-speed train of China Railway to provide intelligent,diversified and individualized high-quality travel service experience for passengers in high-speed mobile scene.Based on the current operating environment of China's high-speed railway and network coverage along the line,three kinds of vehicle-based communication schemes based on operator's public network,satellite communication and ultra-wideband wireless LAN(EUHT-Enhanced Ultra High Throughput)are selected to build high-speed train public wireless network.The input cost and support performance of the three options are compared and analyzed respectively,and the qualitative and quantitative comprehensive evaluation methods are used to evaluate the emergence stage of building the vehicle-ground communication by the operator's public network.Based on the operator's public network communication,the public wireless network architecture of high-speed train is designed without affecting the electromagnetic interference and security of EMU.In order to further improve the operation and maintenance control,intelligent extension service,network service performance and system security of high-speed train public wireless network,the transportation management platform for the complex equipment of EMU public wireless network,the intelligent dispatching of high-speed train CDN(Content Delivery Network)streaming media,the receiving beamforming technology analysis based on train position and the network security protection design are deeply studied,Finally,it provides customized extension services such as travel selection for mobile travel scene,entertainment service in transit,high-speed rail order,shuttle station and so on.5G the commercial era,in order to further enhance the passenger travel service experience,take the 5G application in the vertical industry as an opportunity to create a 5G and high-speed rail public wireless network integration network,innovative high-speed train public wireless network operation model,The specific work of this paper is as follows:(1)Deeply analyze the service demand of passengers under the current high-speed mobile travel scene and the problems faced under the present conditions,investigate the public wireless network service mode and management status in the field of public transportation at home and abroad,and put forward a scheme design to realize the public wireless network service of high-speed train and promote the diversified,intelligent and individualized development of railway passenger travel service.(2)Study and propose an integrated weighting method based on OWA(Ordered Weighted Averaging)operator and difference drive,using the combination weighting based on OWA and difference drive to determine the evaluation index weight,and calculate the gray correlation coefficient of each scheme by grey comprehensive evaluation method.The rationality of the three options is ranked,and the communication scheme based on operator public network is determined.(3)Based on the safety requirements of EMU on-board equipment,the general structure,logic architecture and network architecture of high-speed train public wireless network are designed.According to the interconnection conditions between EMU carriages,the LAN solutions of EMU with wired network and wireless network are designed respectively.(4)Based on the spring boot foundation development framework,the jekins is used as the system construction tool to design the cloud tube platform micro-service architecture for the high-speed train public wireless network.By using high availability components and commercial Saa S(Software-as-a-service)basic services,the scalability,high availability and high performance of the cloud are guaranteed,and the remote configuration and management of the train public wireless network are solved.(5)Based on the traditional CDN principle and the characteristics of the linear network physical link at the end of the high-speed train,this paper puts forward the CDN concept based on the high-speed train set,referred to as "high-speed CDN".",which is based on the traditional The two-level cache scheme of high-speed rail CDN provided by the central server is designed.The content of each secondary cache is a redundancy of the first-level cache,which further improves the experience of passengers using public wireless network.At the same time,it provides smooth video entertainment and Internet experience.(6)Effect of Doppler effect compensation based on position information on improving the quality of received signal is analyzed based on the special operation scene of train.The variation of network rate LTE(Long Term Evolution)each slot by receiving beamforming technology is simulated experimentally.The Doppler effect compensation technology based on position information speed moving scene is proposed to verify the effectiveness of Doppler compensation technology based on position information and receiving beamforming technology in high-speed.(7)For the high-speed train network environment,according to the 802.11 series of related protocols Beacon packets will carry AP(Access Point)network related attributes to broadcast this feature,using the protocol standard undefined 224 fields for unique identity encryption,Unique identity encryption algorithm is updated periodically by RC4?the combination of device MAC address and random code.The system uses AP intermittent scanning form to detect,adjust the virtual interface to filter mode,continuously rotate all channels,and realize the detection and blocking of vehicle illegal AP.(8)Based on the wireless public network of train,the 8.has created the integrated,full-trip and chain extension service ecology,realized the integration of passenger flow,traffic flow and logistics,and greatly improved the passenger travel service experience.(9)Aiming at 5G application scenarios and business requirements,based on the existing high-speed train public wireless network operation service system,through the reuse of its infrastructure,A 5G room division technology is used to design the train public wireless network and 5G fusion network scheme.Through the innovative construction mode,the vehicle compartment sub-equipment is introduced,and the wireless tuning scheme is designed with 5G of large bandwidth,low delay,multi-connection and so on.The dual coverage of 5G signal and Wi-Fi signal in the carriage is realized.