| With the development and application of Ericsson mobile switch technology, customers' requirements for large capacity and high performance of switch center have been more and more urgent. In order to satisfy the market requirements, Eircsson develops blade cluster mobile switch center, which has high performance and is easy to increase capacity and maintain. Test system needs improvements to adapt the new mobile switch center software. The test for traditional mobile switch center is always completed in Simulator Environment Architecture (SEA). All kinds of components running on SEA include mobile switch center, base station, media gateway, mobile telephone, and so on. Tester can use these components to do function test. In blade cluster environment, Ericsson brings the Testing and Test Control Notation (TTCN) and test tool TITAN, and integrates SEA and TTCN to do function test.The traditional test creates corresponding test environment for each test case. To execute some abnormal test cases, tester can only do it by loading patch in mobile switch center software. TTCN is typical used to test telecommunication system and protocol. There are several advantages when combining SEA and TTCN. Firstly, messages can be easily sent and received between SEA and TTCN. Secondly, TTCN test cases can be reused in next project by modifying a little, which avoids setting up the test environment and reduces a lot of workload. Thirdly, TTCN can be used to simulate the outside of tested module or system, thus it can send all kinds of signals with different data to realize the abnormal test cases, which avoids the error caused by tester and simplifies the testing method. Integration of SEA and TTCN is a new research area full of challenges. In test system, several aspects need to be considered, such as how to let SEA and TTCN communicate, how to configure and use TTCN, how to use TTCN to simulate outside of tested system, and so on.Research and realization of blade cluster mobile switch center test system is the focus in this dissertation. Firstly, the target software TCS is introduced, as well as the traditional testing for it. Then the impacts to TCS caused by blade cluster structure are analyzed. And the signal mechanism in the blade cluster software system is investigated, including monitoring and tracking method for signals. Applying TTCN, which is a recently introduced testing language, is the most important for test system. All test cases should use it. So the grammar and semanteme of TTCN which will be used in our test system are investigated. Then the communication port configuration between SEA and TTCN is figured out, and independent signal port and user-machine command port are designed for both blades. By selecting a suitable method to allocate buffer and using TTCN variables to transfer the blade data, the requirement of sharing communication buffer between blades is also fullfilled. Besides, TTCN is used to simulate the external service SCCOSE and CSSE which are necessary to test TCS, and signal flow chart is shown to explain how test cases invoke these two services by sending special signals. Finally, four typical call flow test cases are provided and run in order to verify the test system. The test result shows that the integration of SEA and TTCN is well applicable in the function test for blade cluster mobile switch server software system. |
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