METHOD FOR CALLBACK ON BUSY AND CALL PROCESSING METHOD, APPARATUS AND SYSTEM

摘要

The embodiments of the present invention relate to communications technology field, and disclose a method, apparatus and system for callback on busy. The method includes that a call forwarded by a called Mobile Switch Center (MSC) is received, and the call is forwarded when a calling user calls a called user through the called MSC and under the condition that the called MSC judges the called user is busy and the called user enables a forward on busy function; whether the called user is idle is detected by an Any Time Interrogation (ATI) signaling after that the calling user enables a callback on busy service is judged, and if the called user is idle, the calling user and the called user are connected to communicate with each other. The embodiments of the present invention use the ATI signaling to detect the status of the called user without using a call directly to detect whether the called user is idle, and further reduce the waste of relay links, and will not disturb the called user by using the ATI signaling to detect the status of the called user.