HANDOVER METHOD AND MOBILE COMMUNICATION SYSTEM

• US 20090180441A1
• Filed: 03/11/2009
• Published: 07/16/2009
• Est. Priority Date: 10/17/2003
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Corporation of America (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Corporation (Panasonic Holdings Corporation)
• Inventors: Ikeda, Shinkichi
• Granted Patent: US 8,169,970 B2
• Time in Patent Office: Days
• US Class Current: 370/331
• CPC Class Codes: H04W 36/0019 adapted for mobile IP [MIP]
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 88/005 Data network PoA devices

Abstract

In a mobile communication system utilizing Mobile IP, information on the access network is exchanged between access routers. And when a mobile terminal performs a handover, the previously exchanged information on the neighbor access routers and the access network information are provided to the mobile terminal. By so doing, the mobile terminal can determine a destination access router in advance, enabling to realize an efficient handover processing.

Claims

1. A handover method comprising:

prior to a handover;

multicast-sending, by at least one first wireless base station on an access network, access network interface information at a specific radio frequency toward a wired backbone network, the access network interface information including respective location information for the at least one first wireless base station;

determining, by a second wireless base station, a value for a distance from the at least one first wireless base station to a second wireless base station, using the respective location information included in the access network interface information received via the backbone network; and

generating, by the second wireless base station, neighbor access network information according to the respective determined value for the distance from the at least one first wireless base station to the second wireless base station;

when the wireless base station decides to perform handover for a mobile terminal;

notifying, by the second wireless base station, a handover notification containing at least a part of the neighbor access network information, and

selecting, by the mobile terminal, a destination wireless base station based on the handover notification and communication quality;

wherein the determining, by the second wireless base station, includes determining whether the respective determined value for the distance of each of the at least one first wireless base station to the second wireless base station is within a range of a predetermined distance on the basis of the respective location information, to handle one or more of the corresponding access network interface information of the at least one first wireless base station within the range of the predetermined distance as the respective neighbor access network information; and

wherein the selecting, by the mobile terminal, includes selecting an wireless base station having a shortest respective determined distance and better communication quality as the destination wireless base station on the basis of the handover notification.

2. The handover method according to claim 1, further comprising:

deleting from neighbor access network information in the generating step, by the second wireless base station, the first wireless base station not receiving the access network interface information at estimated receiving time of the access network interface information received by the first wireless base station, or the first wireless base station having sent a deleting request signal.

3. The handover method according to claim 1,

further storing, by the second wireless base station, the access network interface information as the respective neighbor access network information in an order of increasing respective distance.

4. The handover method according to claim 1,

wherein the notifying, by the second wireless base station, includes notifying the handover notification included in the respective neighbor access network information, as a candidate destination router information, after arranging the access network interface information in an order of increasing respective determined distance.

5. The handover method according to claim 1,

wherein the access network interface information includes a network identifier for identifying the access network, and

the selecting, by the mobile terminal, includes selecting the destination wireless base station out of the at least first wireless base station with a connectable network identifier on the basis of the handover notification.

6. A wireless base station comprising:

an access network information receiving section operable to receive, from at least one other wireless base station via a backbone network, respective access network interface information of the at least one other wireless base station, the respective access network interface information including respective location information for the at least one other wireless base station;

a neighbor access network information processor operable to determine a value for a distance from the at least one other wireless base station to the wireless base station, using the respective location information included in the received access network interface information;

a handover notification determining section operable to determine a handover notification based on the value for the distance from the at least one other wireless base station to the wireless base station;

a transmitter operable to send to a mobile terminal the handover notification when deciding to perform handover for a mobile terminal; and

a location information controller operable to detect a self-location of the wireless base station;

wherein the neighbor access network information processor adds the self-location as corresponding location information to the access network interface information for transmission;

wherein the neighbor access network information processor is operable to determine whether the respective determined value for the distance of each of the other wireless base stations to the wireless base station is within a predetermined distance on the basis of the received respective location information and the self-location obtained from the location information controller, to store the corresponding access network interface information of the other wireless base stations within the predetermined distance as the respective neighbor access network information in an order of increasing respective determined distance; and

wherein the access network interface information includes at least, radio frequency information for communication with the access network, and a respective network identifier for identifying the access network.

7. The wireless base station according to claim 6, wherein the wireless base station, at the neighbor access network information processor, deletes another wireless base station not receiving the access network interface information at estimated receiving time of the access network interface information received by the another wireless base station, or the another wireless base station having sent a deleting request signal, from neighbor access network information.

8. The wireless base station according to claim 6, wherein the handover notification determining section is operable to extract the corresponding access network information of the other wireless base stations having the respective determined value of the distance or communication quality within a range of the predetermined distance or the communication quality from the neighbor access network information processor, arrange the extracted access network interface information in an order of increasing respective determined distance or the communication quality as a candidate destination wireless base station information, and notify the handover notification.