Research And Realization Of Analysis And Comparison Software For Police Digital Trunking Air Interface Protocol

Compared with analog communication system,the police digital trunking(PDT)communication system has advantages of vast coverage area,encrypted with own algorithm,simple technology and less cost,and it has been used extensively in municipal police system.In order to guarantee the interconnection of different manufacturers' equipments,PDT air interface protocol needs to be tested consistently.PDT air interface protocol can be monitored,analysed and tested by the PDT air interface protocol analysis and comparison software.Therefore,the PDT air interface protocol analysis and comparison software become a desiderating research topic.On the basis of summarizing the domestic and foreign studied status of air interface protocol analysis,the analysis and comparison software for PDT air interface protocol is studied and realized,the main works are as follows:1.Based on PDT air interface protocol stack structure,the burst structure and the frame structure are analyzed,the signaling of control channel,business channel,and packet data channel in call control layer are elaborated,voice business and data business process are described;2.The solution of analysis and comparison for PDT air interface protocol is proposed,the datagram format between the software and monitor is given,and the process of parsing short data,drawing MSC,drawing RSSI map and monitoring voice are described;3.Based on MFC application framework,the software is developed using the function in wireshark source code library.Based on wireshark plugin development technology,the PDT air interface protocol plugin is developed.Based on Baidu map API,the RSSI map is developed using JavaScript language.Based on PDT decoder,the PDT voice monitor is developed using C++ language.Protocol analysis,template comparison,RSSI map drawing,voice monitoring function and so on are realized;4.Protocol analysis,template comparison,RSSI map drawing,MSC drawing function and so on are tested.The test results show that the PDT air interface protocol analysis and comparison software can finish the analysis of PDT air interface data and the comparison of coincident testing data template.The software can meet the testing requirement of PDT communication system.