Research And Realization Of CS Fallback Technology On LTE Dual Mode Terminal Conformance Test Set

With the gradually extending commercialization of LTE networks, using multi-mode terminals are becoming increasingly common that requires a multi-mode terminal to switch flexibly in different network, and gracefully deal with voice and data services. In this case, the terminal test set ensuring the multi-mode terminal to have the characteristics referred above plays a very important role.Before entering the real network and ultimately delivered to users mobile terminals must pass protocol conformance test. Such test is done by the terminal test set. Operators generally accomplish early deployment using CS Fallback(CSFB) to support for voice services over LTE. This technique has many advantages including, but not limited to high feasibility, low cost,2G/3G network reusability. Based on LTE/GSM dual-mode terminal test set referred as Comprehensive Test Set(CTS), two different types that are LTE to GSM CSFB redirection and LTE to GSM CSFB CCO with NACC specified to GSM network realization are given.In the first chapter, the background of the paper, the content of LTE and GSM related with CSFB, the dual mode terminal test set are introduced. In the second chapter, the basic theory, functionality, hardware and software architecture of CTS are introduced; In the third chapter, this article gives the analysis of the technical feasibility and performance of CSFB, discussion of CSFB under different network scenario, the realization for CTS in terms of the best CSFB, the implementation of CS Fallback technology-related modules and scripts and system interfaces, the details of overall design and implementation of CTS. Chapter IV is to verify by logs collected by the measurement process for the entire CSFB technology on CTS; Finally, Chapter VI concludes the paper and proposes future research work.