The Design And Realization Of Gprs Terminals With Mms Sending

With the rapid development of communication technology, Mobile World Wide Web is changing people's lives deeply, as a resource of sustainable use and development in plenty of fields. And at present, an embedded system is widely used in telecommunication, industrial control and other areas for its low power consumption, high performance characteristic and its portability. In this paper the GPRS terminal that can send the Multimedia Message Service (MMS) is designed and realized using the embedded system and the GPRS network. The microcontrol unit STC89LE516AD and embedded operation systemμC/OS-II are the basis of the terminal, which drive BENQ GPRS module M22 to Connect the MMS Gateway via GPRS wireless network, sequentially succeed in sending the MMS.Firstly, the GPRS principle is introduced in this paper, the function and application of the GPRS module M22 are elaborated then. In succession, a detailed description is carried out about the theory of WAP protocol and MMS. The system composed by STC89LE516AD and the embedded operation systemμC/OS-II is described and researched in detail. The GPRS terminal's design and realization of hardware and software follow finally. The design of the hardware mainly includes the choice of microprocessor chips, the design of the MCU's peripheral circuits, the design of the M22's peripheral circuits and the power circuit and so on. The design of the software mainly includes the transplant ofμC/OS-II on STC89LE516AD, the realization of TCP/IP including PPP, IP, UDP, the division of system task and the specific realization of each function module. The whole software framwork can be described as an embedded operating system + TCP/IP stack+application programme. The application programme is developped on the basis ofμC/OS-II and divided into severel tasks, which simplify the application system's software design and improve the system'sreliability.The GPRS terminal disigned in this topic, completes the successful sending of the simple MMS at the lowlevel microprocessor, which has prepared the theory and technology for the modification and production of the MMS terminal in the future...