A mobile VoIP architecture over LTE & WLAN networks

Mobile VoIP based on IP Multimedia Subsystem (IMS) is one of the most issues according to introducing UTRAN long term evolution (LTE) networks. In addition to, there are many hot spot such as WLAN of free worldwide directory. In order to provide a mobile VoIP service over various networks, it is important to define VoIP architecture and provide interconnection at the service & media layer between heterogeneous networks. In this paper, we suggest a VoIP architecture over LTE & WLAN and extend existing technologies about Mobile VoIP solutions to operating in a variety of access networks, including basic call flow and handover scenario.