The Application And Optimization Research Of VoLTE Based On 4GLTE Core Network

To Compare the traditional communication technologies of 2G/3G,the 4G LTE(Long Term Evolution)only keeps PS domain,all the data and voices are managed by PS domain.VoLTE(Voice over LTE)is an end-to-end voice solution via all IP,which is based upon the 4G network.VoLTE not only significantly reduces the time of call connection,but also integrates HD voice services and IMS(IP multimedia subsystem)network with other multimedia business and Internet business,providing more rich services than narrowband voice services.VoLTE will be used as the main application,and gradually replaces the traditional CS.At the first stage,this paper will introduce the basic principle of VoLTE briefly,including the architectures of LTE,EPC and IMS,and the principles of their network elements.Secondly,we would discuss the accesses of VoLTE(including EPC beares and attachments,How does UE access to the IMS via IP),and how does equipment switch from non-IMS coverd area to 2G/3G in order to complete the uninterrupted voice calls.And also introduce three techniques of fallback in the network of IMS:CSFB?SRVCC and SvLTE.Last but most important,it would introduce the network configuration,key parameters,and some network problems in VoLTE network testing and validation process,a case study about iphone abnormal ringing,Samsung S6 dropping call,and abnormal ringin in the process of waiting for connection in VoLTE network,respectively starting from the perspective of business test,theoretical analysis,network configuration,network optimization,in order to optimize VoLTE network further.