초록 ▼

In a system and method for handoff using a hybrid network, a wireless local area network (WLAN) terminal determines its own position information through communication with a code division multiple access (CDMA) base station and a global positioning system (GPS) satellite, and a cell mapping server o

In a system and method for handoff using a hybrid network, a wireless local area network (WLAN) terminal determines its own position information through communication with a code division multiple access (CDMA) base station and a global positioning system (GPS) satellite, and a cell mapping server obtains information about a WLAN cell where the WLAN terminal is currently located from the WLAN terminal position information, determines information about a cell to which the terminal is expected to be handed off from the current position of the WLAN terminal, and provides the cell information to the WLAN terminal. This allows handoff to be performed without scanning a destination access point, thereby significantly reducing WLAN handoff time.

대표청구항 ▼

1. A system for handoff in a wireless local area network (WLAN) using code division multiple access (CDMA) information, the system comprising: a WLAN terminal which determines its own position information through communication with a CDMA base station and a global positioning system (GPS) satellite;

1. A system for handoff in a wireless local area network (WLAN) using code division multiple access (CDMA) information, the system comprising: a WLAN terminal which determines its own position information through communication with a CDMA base station and a global positioning system (GPS) satellite;a cell mapping server for obtaining information about a WLAN cell corresponding to an area where the WLAN terminal is located from the position information of the WLAN terminal, for determining cell information about a WLAN cell to which the WLAN terminal is expected to be handed off from the position information of the WLAN terminal, and for providing the cell information to the WLAN terminal; andan Access Point (AP) for executing handoff with the WLAN terminal without communicating with the WLAN terminal in a channel scanning process,wherein the position information comprises information about a CDMA base station corresponding to the area where the WLAN terminal is located; andwherein the WLAN terminal comprises: a CDMA module for receiving, from the CDMA base station, CDMA cell information about a CDMA cell accessed by the WLAN terminal; anda controller for transmitting the CDMA cell information to the cell mapping server. 2. The system according to claim 1, wherein the position information further comprises GPS coordinate information of the WLAN terminal. 3. The system according to claim 1, wherein the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off comprises information about an access point that serves the WLAN cell to which the WLAN terminal is expected to be handed off. 4. The system according to claim 1, wherein the WLAN terminal further comprises: a GPS receiving module for receiving coordinate information of the WLAN terminal from the GPS satellite; anda storage unit for storing the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off,wherein the controller transmits the coordinate information to the cell mapping server, receives, from the cell mapping server, the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off, and stores the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off, in the storage unit. 5. The system according to claim 4, wherein the WLAN terminal further comprises: a WLAN module for receiving, from the controller, the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off and for performing the handoff based on the cell information. 6. The system according to claim 1, wherein the cell mapping server comprises: a cell mapping database for storing information about CDMA cells and WLAN cells mapped to the CDMA cells and for storing the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off, the WLAN cell to which the WLAN terminal is to be handed off being mapped to a CDMA cell; anda cell mapping controller for determining the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off based on the position information of the WLAN terminal and the mapping information stored in the cell mapping database, and for providing the cell information to the WLAN terminal. 7. The system according to claim 6, wherein the cell mapping controller obtains information about a WLAN cell overlapping a CDMA cell corresponding to the area where the WLAN terminal is located, compares the WLAN cell information to GPS position information of the WLAN cell to determine information about a WLAN sub-cell corresponding to the area where the WLAN terminal is located, and determines the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off, which is associated with the WLAN sub-cell. 8. The system according to claim 6, wherein the cell mapping database stores at least one of information about an overall structure of CDMA cells, information about an overall structure of WLAN cells, and GPS coordinate information of the WLAN cells and sub-cells. 9. The system according to claim 6, wherein the cell mapping server further comprises a position information receiving module for receiving the position information from the WLAN terminal. 10. The system according to claim 1, wherein the WLAN terminal performs handoff based on the cell information about the WLAN cell to which the WLAN terminal is expected to be handed off, the cell information of the WLAN cell to which the WLAN terminal is to be handed off being received from the cell mapping server without scanning a destination access point. 11. The system according to claim 1, further comprising: a GPS satellite for transmitting GPS coordinate information to the WLAN terminal; anda CDMA base station system for transmitting CDMA cell information to the WLAN terminal. 12. A system for managing a code division multiple access (CDMA) network and a wireless local area network (WLAN), the system comprising: a cell mapping database for storing information about CDMA cells and WLAN cells, mapping information of the WLAN cells mapped to the CDMA cells, and cell information about a WLAN cell to which a terminal is expected to be handed off;a cell mapping controller for determining the cell information about the WLAN cell to which the terminal is expected to be handed off based on terminal position information comprising one of global positioning system (GPS) coordinate information of the terminal and information about a CDMA cell corresponding to an area where the terminal is located, and the mapping information stored in the cell mapping database, and for providing, to the terminal, the cell information about the WLAN cell to which the terminal is expected to be handed off; andan Access Point (AP) for executing handoff with the terminal without communicating with the terminal in a channel scanning process,wherein the cell information about the WLAN cell to which the terminal is expected to be handed off comprises information about an access point serving the WLAN cell to which the terminal is expected to be handed off, andwherein the terminal provides the position of the WLAN terminal within the CDMA cell and the coordinate information of the terminal to a cell mapping server. 13. The system according to claim 12, further comprising a position information receiving module for receiving, from the terminal, the one of the GPS coordinate information of the terminal and the information about the CDMA cell corresponding to the area where the terminal is located. 14. The system according to claim 12, wherein the cell mapping controller obtains information about a WLAN cell overlapping the CDMA cell corresponding to the area where the terminal is located, compares the WLAN cell information to GPS position information of the WLAN cell to determine information about a WLAN sub-cell corresponding to the area where the terminal is located, and determines the cell information about the WLAN cell to which the terminal is expected to be handed off, which is associated with the WLAN sub-cell. 15. The system according to claim 12, wherein the cell mapping database stores at least one of information about an overall structure of the CDMA cells, information about an overall structure of the WLAN cells, and GPS coordinate information of the WLAN cells and sub-cells. 16. A method for handoff in a wireless local area network (WLAN) using code division multiple access (CDMA) information, the method comprising: determining, by a WLAN terminal, a position of the WLAN terminal within a CDMA network cell through communication with a base station and a coordinate position of the WLAN terminal through communication with a global positioning system (GPS) satellite, the coordinate position of the WLAN terminal being indicated by coordinates;providing, by the WLAN terminal, the position of the WLAN terminal within the CDMA network cell and the coordinate position of the WLAN terminal to a cell mapping server;determining, by the cell mapping server, cell information about a WLAN cell to which the WLAN terminal is to be handed off based on the position of the WLAN terminal within the CDMA network cell, the coordinate position of the WLAN terminal, and a cell mapping database; andtransmitting, by the cell mapping server, the cell information to the WLAN terminal. 17. The method according to claim 16, further comprising: sending, by the WLAN terminal, a request for authentication to a first Access Point (AP);in response to the request, checking, by the first AP, whether the WLAN terminal has permission to access a network connected to the first AP, and transmitting an authentication response to the WLAN terminal;sending, by the WLAN terminal, a re-association request to the first AP;sending, by the first AP, a handoff request to a second AP;providing, by the second AP, a handoff response to the first AP in response to the handoff request; andsending, by the first AP, a re-association response to the WLAN terminal in response to the handoff response,wherein the handoff response comprises information related to the re-association, andwherein the first AP is a destination AP to be handed off and the second AP is an AP connected to the WLAN terminal. 18. The method according to claim 16, wherein the cell information about the WLAN cell to which the WLAN terminal is to be handed off comprises information about an access point serving the WLAN cell to which the WLAN terminal is expected to be handed off. 19. The method according to claim 16, further comprising: storing, by the cell mapping server, the cell information about the WLAN cell to which the WLAN terminal is to be handed off, the cell information being provided to the WLAN terminal; andperforming handoff based on the stored cell information without scanning a destination access point. 20. The method according to claim 16, wherein determining, by the cell mapping server, the cell information about the WLAN cell to which the WLAN terminal is to be handed off based on the position of the WLAN terminal within the CDMA network cell, the coordinate position of the WLAN terminal, and a cell mapping database further comprises: comparing the position of the WLAN terminal within the CDMA network cell to the coordinate position of the WLAN terminal. 21. The method according to claim 16, wherein determining, by the cell mapping server, the cell information about the WLAN cell to which the WLAN terminal is to be handed off based on the position of the WLAN terminal within the CDMA network cell, the coordinate position of the WLAN terminal, and a cell mapping database further comprises: retrieving information about a WLAN cell overlapping the CDMA cell corresponding to an area where the WLAN terminal is located;determining information about a WLAN sub-cell corresponding to the area where the WLAN terminal is located by comparing the retrieved WLAN cell information to the coordinate position of the WLAN terminal; anddetermining information about a neighboring cell matched to the retrieved WLAN sub-cell corresponding to the area where the WLAN terminal is located.