Research Of Communication Server For Traffic Signal Control Based On IOCP

Urban traffic signal control system(UTCS) is an important subsystem of intelligenttransport system(ITS),which can regulate the signal timing plan of controlled region,balance the traffic flow running of road network, minimize the vehicles' parking numbers,delay time and environmental pollution, make the most advantage of road system, therebyguaranteeing the urban traffic main road and even the whole road network could run in anexpedite, safety and highly efficient mode. Communication server is an important part ofUTCS, which is responsible for communication with traffic signal controller, usermonitoring terminal and traffic optimize and control software. The communication servershould provide service for amount of traffic signal controllers and user terminal softwarefor a long time.This paper studies and analysis the application function of UTCS communicationserver, in response to the features that there are great amount of clients connection and datafrequent communication of UTCS,design method based on IOCP mechanism to realize theserver with Visual C++6.0is proposed in this paper. Firstly, the main modules andstructure of UTCS are presented, clarifies the key function of communication server inUTCS. Then introduces the IOCP model and multithreading technology, and discusses theperformance advantage of IOCP model when processing amounts of concurrency socketsI/O request. Beginning from the requirement analysis, describes the design plan ofcommunication server based on IOCP, including general frame, communication protocol, and main data tables. Lastly, realizes the communication server based on the design plan,the server's implementation process and results are described. And the solutions to somecrucial problems are discussed.For solving the problem that there are not amount of real traffic signal controllers tobe used during the test of communication server, the paper designs a traffic signal controlsimulator to test the performance of communication server. then tests the clientsconcurrency value, client response and resource consumption through building simulationplatform. The procedures not only reduce development costs and are simple, effective. Theexperimental result testified that the system implements various functions and propertyindex efficiently, achieves the anticipated goal.The achievement and significance of this research is that the server based on IOCPmechanism can manage and control thousands of traffic signal controllers, fully meets thedesign requirements of UTCS, which has stable and highly efficient performance. Thecommunication server has been applied in Wuxi, Kunshan, Wujiang and so on many cities,has got a good application effect.