The Design And Optimization Of USSD Service Based On SMPP Protocol

In recent years, digital mobile communication develops rapidly in China and the competition in communication market gets intense day by day. The focus of the competition in mobile communication domain has shifted from network-cover scope to operations and services. To attract more customers, every telecommunication operator is devoted to develop their particular multiplex data operations and multiplex services. In this case, a short message platform becomes a key profit growth spot and many short message supplementary services have emerged. As one kind of the newly emerged short message supplementary services, USSD calls the attention of telecommunication operators both at home and abroad.The thesis first introduces the features, the functions, and the transacting processes of USSD. It views SMPP protocol as the connection protocol between USSD gateways and Internet service providers, and conducts a thorough review on the key concepts, the functions, and the dialogue process of the SMPP protocol as well as the PDU definition of the protocol. Utilizing SMPP protocol and according to Huawei USSD Protocol, the thesis designs a basic USSD session flow which contains both mobile initiated dialog and network initiated dialog.Based on the session flow, the thesis programes the USSD API function in programming language C and deals with the function with pack processes and unpack processes.The author integrates the Socket network programming technology and client-server thought into the project ,and realizes USSD communication process in the object-oriented programming language C++. Then, the author seals it with Socket class. At the same time, the processing program of client is also realized by using the MFC of Visual C + +. What's more, the ADO technology and the multi-thread technology are utilized respectively to realize the database connection and to process the concurrent of communication network.Finally, the thesis, borrowing insights from Queue Theory, constructs a practical model for USSD application platform. By analyzing and comparing some running parameters including call loss percentage, the utilization ratio of system, and the length of queue, an optimal number of processor for a practical system is figured out. And thus, an optimized scheme is put forward.