Testing And Research Of LTE Voice Service

With the rapid development of mobile communication technology,mobile communication's broadband has become the main trend of future mobile communication system.As the main evolution direction of mobile communication system,LTE has the advantages of high speed and low delay which the previous generation technology can't match.These advantages make voice business possible to execute in PS domain.In recent years,the problem of how to develop the LTE voice service faster and better has been paid more and more attention by the major operators and equipment dealers.In the early stage of LTE network construction,when the terminal is connected to the LTE network,it is unable to collect and generate the CS service signal.In order to make the terminal can initiate voice service in LTE network access,and receive voice paging service,the industry produced two transitivity kinds of LTE voice solution which based on CS domain: dual standby terminal and CSFB.With the gradual improvement of the LTE network,most operators choose the Vo LTE voice scheme based on the PS domain to replace the first two schemes to complete the final transformation and upgrade.However,some operators continue to use the two schemes of dual standby terminals and CSFB providing voice services for the protection of CS domain investment in mature 2G/3G networks.The development of China's LTE is also very rapid,so whether the domestic operators choose and when to choose the promotion of VoLTE has also attracted more and more attention.First Based on the discussion of the LTE architecture,this paper focuses on the three key technologies of SC-FDMA,OFDM,MIMO and link adaptation in LTE that Vo LTE relies on,demonstrating the advantages of VoLTE voice program on speed,capacity and delay.Secondly,through the analysis of LTE voice service continuity,this paper analyzes and compares the dual standby terminal scheme,CSFB and VoLTE three voice schemes,meanwhile focus on the introduction of the characteristics of VoLTE,network architecture and key technologies.Theoretically demonstrates the advanced nature of VoLTE technology,and concludes that VoLTE is the final speech solution of LTE.Second the VoLTE voice call/traditional 2G/OTT's qualities are measured by using MOS instrument,and under the same background environment,the multi scheme crosswise comparison is used to verify the excellent performance of VoLTE from the practical point of view.It provides a reference for the operator to choose the LTE voice scheme in the long run.Third Although compared with other speech schemes,VoLTE has incomparable advantages,but the optimization problem of VoLTE is also the most difficult in other speech schemes.A poor Vo LTE network is even less useful than an ordinary 2G network.Therefore,in view of the uniqueness and complexity of VoLTE optimization,combined with the current actual situation of China's LTE development,the author compiled a set of innovative testing optimization standards in line with Vo LTE.At the same time,combined with China VoLTE experimental network,the author uses the compiled optimization standards to optimize the problems in the process of VoLTE testing,and summarizes the optimization results to form the optimization case.The test optimization standards and optimization cases proposed in this paper have certain reference value for the optimization of Vo LTE network in china.