Semi-soft handoff

PURPOSE: A semi-soft handoff method using multiple common frequencies is provided to prevent a common frequency from being overloaded and ensure the safety of an initial channel, in the case of executing an inter-FA hard handoff in a cell, by operating many common frequencies. CONSTITUTION: Managing the frequency allocation status of all neighboring cells, a system sets up common frequencies for all the cells. The system reallocates a mobile station of a standby state in a common frequency to a paging channel to a standby state in a non-common frequency band or allocates a traffic to the mobile station through a traffic channel in a non-common frequency. The system confirms whether all the common frequencies have been overloaded. In this case, the system hands off the traffics in the common frequencies to a non-common frequency. If it is confirmed that the traffic in the common frequencies is smooth, the system receives a handoff request message and checks a common frequency having the least load. The system allocates traffic to this common frequency through an inter-FA hard handoff in a cell. Then the system executes an inter-cell inter-FA handoff by executing a soft handoff to a destination cell using the common frequency.