Design Of Parallel Transmission Mechanism For Heterogeneous Networks And Implementation On Domestic Platform

Nowadays,more and more application scenarios need to quickly upload massive amounts of important data generated by the terminal equipment to the data center through the wireless network link.Multilink parallel transmission technology can simultaneously use multiple wireless network links for data transmission,which not only retains the wireless network's support for mobility,but also theoretically achieves high-speed and stable transmission effects.However,the current multilink parallel transmission mechanism is not perfect,especially in a heterogeneous network environment.If the performance difference between links is large,the parallel transmission performance may be greatly reduced.Based on the above background,this thesis designs a parallel transmission mechanism for heterogeneous networks environment and implements it on a domestic platform,in order to provide high-speed,stable,autonomous and controllable transmission services for massive amounts of important data in different scenarios.The main work of the thesis is as follows:(1)In order to effectively deal with the problem of a large drop in parallel transmission performance caused by large differences in the performance of heterogeneous networks or obvious fluctuations in the degree of difference,this thesis proposes a parallel transmission mechanism for heterogeneous networks,based on the design idea of the dual-agent IP tunnel parallel transmission mechanism.Aiming at the two problems of low link resource utilization and mutual restriction of link performance,three modules of sending management,aggregation sorting,and high-priority retransmission are designed.(2)The sending management module is used to control data to be transmitted in parallel through multiple links.In this module,a dynamic adjustment scheme of send buffer capacity based on link capacity is designed.Combined with the existing scheduling strategy,this module can effectively improve resource utilization.The aggregation sorting module mainly sorts and aggregates the data transmitted by multiple links,then sends the ordered data to the destination host.In this module,an adaptive adjustment algorithm of passive waiting time threshold based on delay is designed to quickly sense the severe disorder and occasional packet loss in the multilink transmission process,in order to avoid long-time head-of-line blocking.The high-priority retransmission module is mainly used to achieve fast retransmission of necessary data.The retransmission data is provided by the agent's send buffer and the current optimal path is selected for transmission.Compared with ordinary retransmission,high-priority retransmission has the advantages of shorter retransmission path,better retransmission link performance and transparency of the retransmission process to terminal equipment.The combination of aggregation sorting and high-priority retransmission can effectively alleviate the problem of performance constraints between links.(3)The heterogeneous network parallel transmission mechanism designed in this thesis is deployed and implemented on a domestic platform composed of Feiteng CPU and Kylin operating system to improve the independent controllability of the overall heterogeneous network parallel transmission system.The tests and analyses are carried out from both functions and performance.First,it was confirmed through functional tests that the three functional modules were able to operate well and could exert the expected effects.After that,the heterogeneous network parallel transmission mechanism proposed in this thesis and the EDPF-based IP tunnel parallel transmission mechanism were tested in the simulation environment and the actual environment.The results show that the parallel transmission mechanism designed in this thesis is less affected by the performance difference between links in heterogeneous network environment,and the transmission is faster and more stable.