APPARATUS AND METHOD FOR DECIDING ON EXECUTION OF VERTICAL HANDOFF IN WIRELESS COMMUNICATION SYSTEM

摘要

An apparatus and a method for determining performing of handoff between different networks in a wireless communication system are provided to prevent unnecessary handoff between different networks by determining whether to perform handoff with reference to a service capability of a system and QoS request information of a user. A terminal checks an adjacent system having an RSSI(Received Signal Strength Indication) higher than a threshold value(301). The terminal checks service capability information of a serving system and the adjacent system(303). The terminal calculates a satisfaction value of each system(305). The terminal compares the satisfaction values of the systems(307). If the satisfaction value of the adjacent system is higher than that of the serving system, the terminal determines the adjacent system as a target system for performing handoff(309). The terminal calculates a usability value of the serving system and the target system(311). The terminal checks whether the usability value of the target system is higher than that of the serving system(313). If the usability value of the target system is high during more than a certain time, the terminal checks whether the difference between the usability value of the target system and that of the serving system is greater than a hysteresis. If the difference is greater than the hysteresis, the terminal performs handoff to the target system.