The Design And Implementation Of USSD Gateway

This document introduces the analysis,designing and implementation of a new access method to the Internet, especially from a wireless handset.The fundamental network of data service mobile system has been quickly developed in China nowadays. As the quick development of mobile communication technology, to utilize the resource both of the wirless communication network and the Internet to develop value-added data services has been paid much attention on. USSD gateway comes into being in this background. USSD gateway has successfully combined the wirless mobile network with the Internet seamlessly. And user can access the imformation of the Internet through a handset.In this paper, the design and implementation of USSD gateway has been discussed. The Main Contribution includes:Firstly from the user demand: After carefully studying and analyzing the USSD service specification, we forms the USSD service data flow. And we decide use USSD gateway to implement the USSD service logic.And we also study the many China mobile application protocols such as SMPP, EMPP. After that we decide to use SMPP protocol as the application layer protocol between the USSD gateway and mobile PLMN, while, EMPP protocol as the application layer protocol between USSD gateway and the SCP.Secondly, from the system design:after gather all the demand of the user, we complete the logic data flow design of the whole USSD gateway. The USSD gateway has been branched out into many modules according to its function. Thesemodules can be grouped in three big parts. They are: kernel part, functional part and communication part. Further small parts are gained by the division of the three big parts. These smaller modules include route module, portal module, fee module and connection management module,etc. We also define the interface of these modules.Finally, the system is implemented with C language on RedHat Linux 7.2. The details of the implementation are illustrated in this paper. All modules are based on the message management platform which mainly contains all the data messages that goes in two opposite directions; The main0 function of USSD gateway firstly get message from the message management platform and further process will be take on according to the type of every message. Possible process may be : routing, navigating, recording fee information,etc. After processing, USSD gateway need to send these message to their destination which connection modules take in charge of. Additionally, we also design log modules and safe modules for the management purpose.USSD gateway has combined the mobile PLMN and the Internet perfectly. In the mean while, we propose a new way of accessing to the Internet for wirless handset users. And this way has been proved to be feasible because this system-USSD gateway version 1.0 has run stablely in Chongqing China Mobile for business purpose.