Analysis And Optimization Of LTE Voice Call Continuity

With the rapid development of mobile communication technology, Mobile Broadband Access had become the main tread of the mobile communication system. The major operators and equipment manufacturers are paying more and more attention to the LTE which had become the main evolution solutions of mobile communication system. So now, how to provide voice call business over LTE system and in the initial deployment of LTE and in the case of coexistence of multiple access network environment, how to perform the interoperability between LTE and 2G/3G system had become critical issues.Currently, international organization for standardization 3GPP had proposed a number of solutions for business continuity. Especially, to achieve Voice Call Continuity with LTE access,3GPP had proposed 3 solutions. After introducing the relevant background knowledge, this paper introduced two mainstream LTE Voice Call Continuity solutions (SRVCC,CSFB) of 3GPP including contents, network architectures and basic processes. By comparing two solutions, it was concluded that CS Fallback can be the provisional solution when begin to build the LTE system and SRVCC should be the final one. But the current versions of the 3GPP solutions were not perfect, and solutions were not carried out performance analysis, so unable to determine the performance of its handover can achieve the requirements of operators to deploy. This paper conducted performance analysis to each of the two solutions, derived parameters of the current solutions to handover time delay can not be met, especially the needs of operators, needed to conduct further research and optimizationBased on the results of performance analysis, this paper optimized the two solutions. The Optimization method of SRVCC was that made the SGW/PGW as a voice media stream anchor point, to avoid the handover time delay caused by the IMS remote media update, in this way made the handover time delay to the requirements of operators to deploy. On the other hand, the optimization method of CSFB was the introduction of Sv interface and SRVCC PS HO process, in this way not only shortened the latency access to CS domain, while ensuring a future solution of the smooth evolution to the final one. Finally, two optimization solutions was verified.