METHOD FOR VERTICAL HANDOFF BETWEEN HETRO SYSTEMS, AND METHOD FOR TRANSMITTING/RECEIVING DATA FILE USING IT

摘要

A VHO(Vertical Handoff) method between heterogeneous systems and a method for transmitting and receiving data files using the same are provided to minimize the power consumption of a mobile terminal, increase the utilization of networks, and achieve load balancing by using an energy-effective IEEE 802.11 search algorithm when VHO is executed between an IEEE 802.16e network and an IEEE 802.11 network. If the control part of a mobile terminal acquires the present speed of the mobile terminal(400), the control part compares the acquired value with "vmax"(401). In case the acquired value is larger than vmax, the control part confirms whether the mobile terminal is under communication with an IEEE 802.11 system(405). If so, the control part waits until the communication state ends. Then, if the communication state is completed, the control part turns off an IEEE 802.11 interface module(406). However, if the present speed of the mobile terminal is larger than vmax, the control part receives a MOB_NBR-ADV message broadcasted from an IEEE 802.16e system, extracts IEEE 802.11 WLAN AP installation density information from the received message, and compares it with a reference value(403). If the extracted value is smaller than or equal to the reference value, the control part turns off the IEEE 802.11 interface module(406). If the extracted value is larger than the reference value, the control part turns on the IEEE 802.11 interface module for vertical handoff to an IEEE 802.11 WLAN and searches for a WLAN AP(404).