The Research And Development Of Trunked Dispatching System Based On IP

Recent years, with the rapid development of trunked system, there are more and more needs for communication and dispatching in cities, and also for its great advantages of the convenience,rapidness,flexibility,sharing channel resource. However, there are some faults in the analogue trunked system which are mainly in technique outdated,single function,difficulty in hookup and encryption,low-allowance and the low utilization and so on, but the digital trunked system's compatibility,open,the high utilization and strong security function has become the inexorable trend for the development of communication.MPT1327 is a classical signalling standard of analog systems, as a new generation of digital trunked system, TETRA digital trunked communication system's open standards and multiple services has made it more popular. At present it is a transitional stage from analog trunked system to digital trunked system, the analog trunked system will exist for a long time due to its technology maturity,wide application and relative low price, to research and realise the terminal device of making the analog trunked system and the digital trunked system coexist has realistic and academic value.Based on collecting the MPT1327 and digital trunked technology standards of TETRA, this paper analyzed the net arithmetics and interface of TETRA trunked system as well as MPT1327 signalling; adopting embedded technology and IP technology we designed the hardware platform, which was mainly constructed by ARM+DSP, including voice sampling,encoding/decoding,NET and E1 transceiver chip and so on, adopted in-system programming chip to simplify the hardware design and facilitate system maintainence and upgrades; finished the transplantation of U-Boot and Linux which base on S3C2410; completed the voice processing and net module's driver coding; designed the sotfswitch control protocol of dispatcing system, at the same time, adopted Socket NET programming to realize the softswitch protocol, and used IP Multicast technology to solve the multi-session problem of dispatching system; designed a configuration server with VC++, in order to config parameter intently. At last, made a test to the voive processing,NET,integrated performance and system configuration, the result indicated the constructed platform is feasible for dispatching system, and it would have a good application and prospects in TETRA digital trunked system.