METHOD, DEVICE AND SYSTEM FOR SWITCHING VOICE CALL SERVICES

A method, device and system for automatically switching voice call services are described which are capable of intelligently determining IP network service authority states and data connection states of a current calling party and a called party through the cooperation of a terminal and an IP network service server when a user initiates a voice call based on a PLMN network and automatically switching the voice call of the PLMN network to a voice call service of an IP network when the states of the calling party and the called party both meet a set switching condition. By bearing the current call with the IP network instead of the PLMN network, the method, the device and the system disclosed herein achieve the purposes of improving call quality and saving call fee.