With IP Multimedia Subsystem server, R&S CMW500 wideband radio communication tester supports end-to-end voice and video calls and can test interaction between two mobile devices. Users can configure and save virtual subscribers with varying usage profiles, and all IMS server's functionalities can be fully automated. Together with R&S CMW500 IP analysis function, it is possible to analyze transmitted data and media information for VoLTE, such as whether mobile phone uses correct Codec.