GSM通訊協定及測試環境之建構

Abstract

GSM泛歐式數位行動電話是由歐洲電信標準協會(ETSI, European Telecommunications Standards Institute)所制訂的標準規格，其用戶數量居目前全世界無限通訊系統之冠。然而發展通訊軟體除了要熟悉通訊協定、並以程式語言來描述以外，更要有能力驗證所開發之通訊軟體是否與規格相符，因此測試的實行(Test Realization)[11]在發展通訊軟體的過程中佔有相當重要的角色。 我們從研究GSM通訊協定標準規格開始，以Telelogic@ Tau為開發工具，進行通訊協定行為描述、模擬驗證成功之後，接著便著手建立實體測試環境，讓待測程式與GSM標準測試個案透過TCP/IP網路進行一致性測試。而獲得的結果與測試個案的要求完全符合。值得一提的是，此一測試環境建立的經驗，可以應用於往後其他通訊軟體之開發上。例如第三代通訊協定(3GPP, Third Generation Partnership Project)。

GSM protocol, which is specified by ETSI, has the most number of subscribers among all mobile communication protocols. To realize a communication system, we have to first understand the protocol. After that, the protocol is described by a suitable programming language. Finally, the developed protocol must be tested whether it is consistent with the protocol’s specification. Therefore, “Test Realization” plays an important role for the development of a communication system. We use the Telelogic@ Tau as our development tool for the description and validation of protocol’s behavior. Then the testing environment, which is constructed on TCP/IP network, is developed for physical testing. With our testing environment, the developed system can communicate with test cases for conformance test. We show that our developed protocol is compatible with the test cases. Moreover, the experience of the testing environment’s construction can be applied in the development of other communication protocols, such as 3GPP.