Research And Development Of On-Board Wireless Communication System Based On GSM

With the improvement of train speed and the quantity of passenger increasing,how to inform traffic departments parameters about train in good time and report vehicle-dispatching information to trainman so as to guarantee security of train's run and management of traffic department is still one of questions which are in dire need of solution.Based on this, utilizing GSM data service and GSM voice service and GSM short message service ,A On-board wireless communication system which uses GSM as transporting tool is explored and put forward in this paper.At first,the architecture of GSM system and GSM protocol architecture are introduced in the paper, and then discussing characteristics of the On-board wireless communication system in detail ,based on this,protocol architecture of the On-board wireless communication system is put forward.Secondly.according to the protocol architecture of the On-board wireless communication system and combined with its application environment ,the architecture of hardware and software for the On-board wireless communication system are bringed forward ,after discussing this ,the relations and the function of its each software module are made out.After, the technology of serial port communication and socket communication are studied deeply,and analyzing the feature of GSM Modem and AT Command for GSM Modem,based on this,software design concerning communication-interface module is accomplished.Following ,after dicussing and comparing adventage and disadvantage of flow control protocols concerning Data-Link-Layer, Go-back-N ARQ is presented and used as method of flow control concerning Data-Link-Layer.and then , the problems on time delay,frame length, window size ,frame format and so on are studied deeply. Next,synthesizing the features of wired and wireless LAN ,A network structure based on combination of wired and wireless network is presented as network structure of On-board wirless comminucation system,alone with a discussion of problems on store and forward switching ,enrolment of consumer,managementof route control.call control and problems of Network Layer.At one time ,design and realization of On-board wireless comminucation System are introduced combined with its feature.At last,after giving study of GSM short message service realization of Short message service for On-board wireless comminucation system is introduced,including short message transmission and reception,and management of short message,and problem on store and forward switching of short message,and how to realize short message sevice while executing data service or voice service.