SIP client device with adaptive codec conversion method and adaptive codec conversion function in handover between heterogeneous networks

摘要

PURPOSE: An adaptive codec switching method for vertical handover and a sip client apparatus having an adaptive codec switching function are provided to supply high quality VoIP service for handover between heterogeneous networks by adaptively converting voice codec to a new network. CONSTITUTION: An apparatus measures a state value of a VoIP(Voice over Internet Protocol) session of a mobile terminal(S110), and calculates VoIP service quality based on the state value of the VoIP session(S120). The apparatus selects the codec of the most excellent VoIP service quality as the optimized codec in a codec group which calculates the VoIP service quality(S130). The apparatus converts the codec through a renegotiation process with the other terminals through the mobile terminal and a network(S140).