Design And Implementation Of Server In Vehicle Monitoring System Based On GPS-GSM

Vehicle Monitoring System (VMS) is not only an important component ofIntelligent Transportation Systems (ITS), but also an integrative system whichmelts accurate position technology, mature mobile communication technology andcredible computer network technology in an integral whole. It is used forimproving the using efficiency of vehicles, making it convenient for directing,implementing monitor for security and assorting with management. At present, thedevelopment of economy has increased personal earning and brought great profit tothe manager of a car team, at the same time, it also brought some problems such ashow to regulate traffic jam, relieve congest, improve management efficiency androad security, settle the problem timely, prevent the cars raping and rending and soon, which need to be settled urgently. This paper relies on "D_Partner" VehicleMonitoring System in Changchun FAW Qiming Info.Tech.Co.,Ltd,, and is for theproblem above, after analysis the trait of the research object and some methods ofposition and wireless communication in detail, a method used to design andimplement the server in vehicle monitoring system based on GPS-GSM is broughtforward.Global Position System (GPS)GPS is an omni-directional, three-dimensional and real time satellitenavigation and position system which is brought forward and developed byAmerican Department of Defense (ADOD), and it can be used in the field ofnavigation, land and avigation. Because of its round-the-clock working, globality,continuity, better position precision and lower cost, make ADOD give up the SApolicy, which is used to reduce precision in order to prevent lawless user using GPSto initiate war. Presently, GPS has been applied in so many subjects widely andsuccessfully, such as Earth Measure and VMS and so on, besides, GPS has gonedeeply into the daily life.Global System for Mobile communications (GSM)GSM is an advanced mobile communication system using digitalcommunication technology and uniform network standard, which is broughtforward by European Committee for Standardization (ECS). It has highercommunication quality, better secrecy, larger network capability, stronger abilityfor resisting the interference and rambling worldwide automatically and canprovide many data services including Short Message Service (SMS). Furthermore,GSM has been the most mature, perfect and spacious mobile communicationnetwork in our country.In all of GSM data services, peer-to-peer SMS has been the best choice for thelarge-scale VMS, because of its relatively advantages such as lower cost, 140 bytesshort message capability, flexible Chinese and English coding modules and shortmessage store mechanism. The most important thing is that SMS doesn't need to beconnected through dialing, so it can work well while speaking.Vehicle Monitoring System based on GPS-GSMIn VMS based on GPS-GSM, the dynamic location, time and state informationof the monitored vehicles are sent to the Monitor&Control Center (MCC) by SMSthrough GSM communication link, and moving track is shown on digital mapwhich has powerful geography information inquiry function. In order to implementmonitor, manage, direct effectively, MCC can provide the inquiry function forsome vehicle parameters which are interesting for users, such as accurate location,speed, moving direction, state etc. VMS consists of vehicle terminal, server, MCCand data base. Thereinto, server takes charge of the data receiving, sending,processing and storing, so it is the kernel part of VMS.Design and Implementation of ServerThe communication form and protocol between server and other entities havebeen analyzed in detail and chosen in the end regarding the requirement of serverand the trait of the monitored objects, which are large coverage, scale and long time.At the same time, the application of memory management and data processingtechnology provides higher real time capability, credible and steady service. Inorder to be transplanted and extended easily, a detailed function instruction andclass design of each function module is given according the theory ofmodularization and object-oriented, moreover, some programming flow charts ofthe mainly function are given too. The corresponding methods to settle thedifficulties and problems that meet in the design and implementation process areintroduced after analysis. Finally, the threads and functions designed in server aredisposed in the whole.Test of ServerConsidering that real time capability and reliability of informationtransmission, ability of processing subsequent data are the mainly factors to beused for judging of the performance of server, so some actual tests on the shortmessage delay, ability of processing subsequent data and stability are carriedthrough in Automobile Electronic Department of Changchun FAW QimingInfo.Tech.Co.,Ltd, based on the test of basic communication function betweenserver and vehicle terminal, MCC and data base. Then, the actual test results areanalyzed and explained in this paper.ConclusionsIt can be seen from the actual test results that the server realizes the wholefunctions depicted in the requirement analyse. Furthermore, the transmission speedand delay of short message have been ameliorated, owing to the use of Digital DataNetwork (DDN) direct connection between server and Short Message ServiceCenter (SMSC). In addition, the application of some effective computer networkprocessing technologies such as thread synchronization, network fault-toleranceand memory management make server have better veracity and reliability on theside of subsequent data processing. The server designed in this paper has passed theSystem Testing (ST) in Nov.2005, during the actual test running period, thestability of server can exceed 95 percents, and can meet the actual need. In a word,the server in VMS based on GPS-GSM designed in this paper has better real timecapability, reliability, stability, and the advance aim of design has achievedsuccessfully.The author believes that the maturity and commercial application of the newgeneration mobile communication network such as GPRS and 3G, and thedevelopment of the satellite navigation and position system which has betterposition precision and self-determination knowledge property rights will open acapacious space for the application and development of VMS, create more societyand economy profits, and bring benefits to human being.