基于TD-LTE/GSM终端综测仪的CS Fallback技术研究与实现

With the commercialization of 4G network continues to mature, the use of multi-mode terminals is increasingly common. As its own characteristics of LTE network and the reality of widespead of GSM network, switch seamlessly in various communication networks for multimode terminals is becoming increasingly important for the user experience during voice services. CS Fallback as a transitional standard proposed by 3GPP solves the problem of voice calls for multi-mode terminals in 4G networks , and its importance has played a very important role in the TD-LTE network construction. This paper proposes a realization of CS Fallback based on hardware RF structure, which plays in an important role in protocol conformance test cases, significantly improving testing efficiency for multi-mode terminals, reducing the development cost terminal tester, completing protocol conformance test cases in terminal testers.