Design And Implementation Of Multipath Bandwidth Aggregate Transmission System In Dynamic Network

When the railway locomotive is running,it is necessary to monitor the driver and important equipment in real time to determine whether the locomotive is in good condition.The resulting amount of monitoring data is very large.Due to the mobility of locomotives,data cannot be directly transmitted to the monitoring center using a wired network,and the traditional single wireless transmission has a low throughput and cannot meet actual needs.Therefore,multi-path wireless transmission can be used to improve throughput.However,due to the small coverage area of the established wireless base station,the available connection time for wireless transmission is short,and the transmission quality of different paths also changes dynamically with the movement of the locomotive.In this environment,the multi-path transmission is affected by the Head-of-line Blocking(HOL),and the entire link resources cannot be effectively used.At the same time,the high bandwidth after aggregation needs to cooperate with the transmission management of the application layer to prevent the waste of bandwidth resources.In view of the above problems,this paper designs and implements a multi-path bandwidth aggregation transmission system suitable for dynamic networks by deeply studying the multi-path transmission mechanism and analyzing actual needs.The system is designed from the bandwidth aggregation of the transmission layer to the transmission management of the application layer,which is mainly divided into 4 modules:(1)Data information sensing and reporting at terminal,quickly sense the data that users need to transmit,use non-transmission time to preprocess data information,reduce transmission processing time,and improve transmission efficiency;(2)Multi-path bandwidth aggregation at the transport layer,which uses the multi-path transmission protocol Multipath TCP(MPTCP)to aggregate multiple wireless link resources.At the same time,in view of the decline of MPTCP in dynamic network transmission performance,the Evaluation Screening Scheduler(ESSched)algorithm is designed to improve the performance of multipath transmission;(3)Service management at central server,manage and control the terminal data to use the aggregated high bandwidth for transmission,avoid the waste of bandwidth resources,and handle the information receiving,status query and retransmission request of data,and realize the safe storage of data information;(4)System update at terminal,which realize the remote update of the terminal program of the transmission system to adapt to the transmission needs of different application scenarios.Finally,this paper tests and analyzes the designed transmission system from two aspects of function and performance.Through functional testing to confirm that each application module of the transmission system can run well.Through performance testing to compare the performance of the Evaluation Screening Scheduler algorithm designed in this paper with the Lowest-RTT-First scheduler(Low RTT),Round-robin scheduler(RR)and Redundant scheduler(RDDT).The results show that the Evaluation Screening Scheduler algorithm designed in this paper has better transmission performance.