A METHOD AND SYSTEM FOR ESTABLISHING AN INITIAL CALL IN THE SERVICE OF THE VOICE SERVICE CONTINUITY

摘要

A method and system for establishing an initial call in the service of the voice service continuity comprises: the user terminal notifies its register state in the CS domain to the application server, the application server determines the mode of the call originated by the user terminal according to the information of the route controlling mode supported by the CS domain network which is currently registered by the user terminal, and notifies it to the user terminal; thereafter, when the user terminal originates a call of the CS domain, it can originate a call according to the mode of the notified originated call. Therefore, the present invention can use maximumly the CAMEL of the calling side CS domain to have an establishment of the initial call and anchor the call to AS with the DTF function. It not only ensures the maturity that the calling side CS domain implements the static anchoring to the call based on the CAMEL scheme, but also uses the USSD/SIP Notify/Prefix scheme as the supplement of the CAMEL scheme, so as to avoid the failure of the calling static grappling resulting from the CAMEL ability lack of the calling side CS domain.