Research And Implementation Of The Multi-channel Protocol And Protocol Test System

This thesis analyzes and studies the multi-channel protocol of the Internet of vehicles,which is the 1609.4 protocol(multi-channel communication)in the Wireless Access in Vehicle Environment and completes the mechanism implementation of this protocol--wireless network driver at the same time.It also designed and implemented a multi-channel protocol conformance testing system for protocol test.At present,most researches on the Internet of vehicles in China are only concerned with entertainment problems,and the research on the Internet protocol of vehicles is mainly based on theoretical research and simulation analysis,which rarely involves actual protocol implementation.In addition,this study not only completes the implementation of this protocol,but also designs the protocol testing system for the protocol,which is used to verify whether the protocol implementation matches the protocol specifications.These studies are of great help to the research and development of the Internet of vehicles and protocol.This paper focuses on the analysis and discussion of several mechanisms in the multi-channel protocol in WAVE protocol stack.Then,the protocol implementation was completed according to the protocol design,and some of the mechanism problems were improved.Next is the design implementation part of the protocol conformance test system based on the Linux operating system.Finally,the protocol test is completed.Through the above four steps,we can understand and study the multi-channel protocol part of the Internet of vehicles.The main research contents of this paper are as follows:(1)Research on protocol content.This paper mainly discusses and analyzes the WAVE protocol stack,and focuses on the IEEE 1609.4 multi-channel protocol,which includes channel coordination,multi-channel synchronization,channel routing,channel access and other mechanisms for in-depth analysis and discussion.It also analyzes that data transmission of guard interval in channel coordination and the problem of CCH and SCH interval and puts forward the problems existing in the concrete implementation channel access mode switching.(2)Research on protocol implementation.It designs and realizes that wireless network drive of the protocol base on the multi-channel protocol design.first it designs and implements the module loading in the wireless network drive,the interaction with the upper lower layer and the basic function of the data transceiver,as the precondition of realizing the multi-channel protocol mechanism,and then it analyzes and improves the specific implementation of the channel route,channel coordination,channel route and channel access.This paper studies and improves the existing negotiation channel reservation mechanism,improves the system throughput and reduces the packet loss rate.(3)Research on protocol test system.For the design and implementation of the protocol conformance test system,this paper uses a variety of mutex and synchronization mechanism control the thread scheduling and congestion,and developments in the form of multithreading.What's more it adopted the modular,so the application can be divided into the WAVE short message module,control module,the system being tested the IP message module,the log module four parts to design and implement.At the same time the system has been designed to achieve good optimization efficiency and accuracy.In the end,the static and dynamic test is carried out for the multi-channel protocol of the vehicle connected with the design and implementation,and the performance are also tested.The results of the system test show that the implementation of this protocol can pass the test easily and the improved access method has a significant improvement over the previous throughput and packet loss rate.