Research And Realization Of Reliable Communications Based On GPRS

With the popularization of distributed system such as ITS (intelligent transport system) and SCADA (supervisory control and data acquisition), there're more and more demands of reliable communications in this kind of system.Because most members of distributed system are mobile or separate, it's important to select an appropriate method to transfer message. In physical layer, clients select GPRS (general packet radio service) to access Internet after comparing and analyzing. TCP/IP protocols are used in upper layer and interlaced hamming code satisfies application-layer's demand of reliable communications.Client is composed of MCU and GSM/GPRS chip which can access Internet wireless. It can also transfer audio and short message. MCU packets the data then send them by GSM/GPRS chip. The MCU controls the chip with AT commands. We can implement the protocols such as TCP, UDP and IP by hardware or software. In application layer, a simple protocol was designed and a program was developed by C/C++ to implements interlaced hamming coding. This paper first details the design of client, discusses how to choose GSM/GPRS chip and relevant component. From the point of view of message transmission, we analyzed the protocols mentioned in the whole system. Then, the principle of interlaced hamming code was introduced. In the holistic communications software's design pattern, the technology such as multi-thread, thread-pool and I/O completion port used in server was emphasized. At last, the contribution and innovation in the paper are collected, and some remain problems are pointed out with the direction of next research steps.