Patent ID: 8111675

Claim:
A channel search method for a vertical handoff in a wireless network environment, the channel search method comprising: collecting channel information from a first terminal which is provided with a wireless local area network (WLAN) service via a channel connection with a WLAN node, the WLAN node providing a coverage area; determining a channel search order for a channel connection between a second terminal and the WLAN node by using the collected channel information; selecting a channel where a channel connection between the second terminal and the WLAN node is allowed, according to the determined channel search order; and providing the second terminal by the WLAN node with the WLAN service via the selected channel, when the second terminal enters a coverage area of the WLAN node, wherein the collecting comprises: collecting the channel information by performing an overhearing with respect to a communication interfacing area of the first terminal, wherein the collecting of the channel information by performing the overhearing comprises: performing the overhearing when the second terminal enters the communication interfacing area of the first terminal, before the second terminal enters the coverage area of the WLAN node; and wherein the providing comprises: transmitting a registration request message from the second terminal to the WLAN node via the selected channel; and setting the channel connection between the second terminal and the WLAN node in response to the transmitted registration request message.