Wireless base station, communication system, belonging information management method and storage medium for storing program

• US 8,385,260 B2
• Filed: 12/08/2008
• Issued: 02/26/2013
• Est. Priority Date: 12/06/2007
• Status: Active Grant

• Current Assignee: NEC Communication Systems Limited (NEC Corporation)
• Original Assignee: NEC Communication Systems Limited (NEC Corporation)
• Inventors: Takakura, Yoshiaki, Abe, Kenichi, Ito, Tetsuya, Matsumoto, Akira, Iizuka, Hiroyuki, Ezure, Yuichiro
• Primary Examiner(s): Moore, Ian N
• Assistant Examiner(s): Nguyen, Thai
• Application Number:
  US12/329,731
• Publication Number:
  US 20090149222A1
• Time in Patent Office: 1,541 Days
• Field of Search: 370/445, 370/447, 370/328, 370/338, 370/350
• US Class Current: 370/328
• CPC Class Codes: H04W 8/02 Processing of mobility data, e.g. registration information at HLR [Home Location Register] or VLR [Visitor Location Register]; Transfer of mobility data, e.g. between HLR, VLR or external networks
• CPC Class Codes: H04W 8/08 Mobility data transfer
• CPC Class Codes: H04W 92/20 between access points

Abstract

The present invention is to allow prompt and reliable synchronization of belonging information management table even in environments where there is a possibility of receiving update notification information from a plurality of wireless base stations, without needing unnecessarily large traffic for synchronization of belonging information management table. Wireless base station stores belonging information management table, to which belonging information of a terminal belonging to the base station is associated with, to new/old judgment information for judgment of new/old of update. Belonging information update unit performs update of belonging information including the new/old judgment information thereof. Further, upon receiving update notification information from other wireless base station, the belonging information update unit updates the belonging information management table based on the update notification information. The update notification information includes at least updated portion in the belonging information and new/old judgment information.

Claims

1. A wireless base station of a wireless meshed network in which a plurality of terminals arbitrarily move between wireless base stations, said wireless base station comprising:

a terminal interface function unit which communicates with the plurality of terminals belonging to a corresponding one wireless base station in the wireless meshed network comprised of said one wireless base station and a number of other wireless base stations, the plural terminals arbitrarily moving between the wireless base stations;

a wireless base station interface function unit which communicates with the other wireless base stations composing the wireless meshed network;

a management table storage unit which stores a belonging information management table which includes belonging information of a terminal in each of the wireless base stations with an update number, which update number is incremented by one (1) whenever the terminal is added or deleted in the belonging information, for judgment of new or old of an update state of the belonging information; and

a belonging information update unit which updates the belonging information of said one wireless base station when a change in a belonging status of the terminal due to addition or deletion has been detected by corresponding information received through the terminal interface function unit;

a first notification information transmission unit which transmits, when the belonging information is updated, first notification information including an updated portion in the belonging information together with the incremented update number to all other wireless base stations through the wireless base station interface function unit,

wherein the belonging information update unit updates, when the first notification information is received from other wireless base station, the belonging information management table stored in said one base station based on the first notification information;

a periodical information transmission unit which transmits periodical transmission information including the number of wireless base stations included in the belonging information management table of said one wireless base station together with respective incremented update numbers corresponding to each wireless base station to adjoining wireless base stations through the wireless base station interface function unit; and

a second notification information transmission unit which transmits second notification information, which includes the number of wireless base stations included in the belonging information management table of said one wireless base station together with the respective incremented update numbers and the number of belonging terminals corresponding to each wireless base station, to all the other wireless base stations through the wireless base station interface function unit, when finding an old update status of the belonging information management table in other wireless base stations indicated by the periodical transmission information,

wherein the belonging information update unit updates, when the second notification information is received from other wireless base station, the belonging information management table stored in said one wireless base stations based on the second notification information.

2. The wireless base station according to claim 1, wherein the second notification information transmission unit calculates a waiting time for transmitting the second notification information by a predetermined calculation method, and transmits the second notification information after elapsed the waiting time without receiving the second notification information from the other wireless base station, when finding the old update status of the belonging information management table of other wireless base station indicated by the periodical transmission information.

3. The wireless base station according to claim 1, wherein, the belonging information update unit updates the belonging information of said one wireless base station when a change in the belonging status of the terminal being moved from other wireless base station has been detected by corresponding information received through the terminal interface function unit, and further comprising:

a third notification information transmission unit which transmits third notification information, which includes the updated portion in the belonging information due to movement of the terminal together with information about the moved terminal and the wireless base station to which the terminal belonged before movement, to all other wireless base stations through the wireless base station interface function unit, when the belonging information of said one wireless base station is updated due to movement of the terminal,

wherein when receiving the third notification information from other wireless base station and finding that said one wireless base station is the wireless base station to which the moved terminal belonged before movement, the belonging information update unit updates the belonging information by deleting the terminal notified by the third notification information and transmits the first notification information including the updated portion in the belonging information to all other wireless base stations through the wireless base station interface function unit.

4. The wireless base station according to claim 1, wherein, when a data is not received from the terminal belonging to said one wireless base station in a predetermined time, the belonging information update unit deletes the belonging information corresponding to the terminal.

5. The wireless base station according to claim 1, further comprising a synchronization unit which confirms, when the update numbers in the belonging information management table are initialized, each update number based on the information received from other wireless base station in a predetermined time.

6. The wireless base station according to claim 1, further comprising:

a search request unit which transmits search request information including information on a destination terminal for performing search request to all other wireless base stations through the wireless base station interface function unit, when a parent wireless base station of the destination terminal for communication is unknown, and

a fourth notification information transmission unit which transmits, when receiving the search request information and finding the destination terminal belongs to said one wireless base station, the first notification information including the belonging information about the destination terminal to all other wireless base stations through the wireless base station interface function unit.

7. The wireless base station according to claim 1, wherein the terminal belonging to the wireless base station is connected to the terminal interface function unit in wired or wireless fashion.

8. A communication system of a wireless meshed network comprising:

a plurality of wireless base stations composing the wireless meshed network by communicating each other in a wireless fashion; and

a plurality of terminals which arbitrarily move and belong to the wireless base stations, and

wherein each of the wireless base stations comprises;

i) a belonging information management table which stores belonging information of the terminal in each of the wireless base stations with an update number, which update number is incremented by one (1) whenever the belonging information is updated, for judgment of new or old of an update state of the belonging information,

ii) a belonging information update unit which updates the belonging information of said one wireless base station when a change in a belonging status of the terminal has been detected,

iii) a first notification information transmission unit which transmits, when the belonging information is updated, notification information for notifying update including an updated portion in the belonging information together with the incremented update number to all other wireless base stations,

iv) a periodical information transmission unit which transmits periodical transmission information including a number of wireless base stations included in the belonging information management table of said one wireless base station together with respective incremented update numbers corresponding to each wireless base station to adjoining wireless base stations, and

v) a second notification information transmission unit which transmits second notification information, which includes the number of wireless base stations included in the belonging information management table of said one wireless base station together with the respective incremented update numbers and a number of belonging terminals corresponding to each wireless base station, to all other wireless base stations, when finding old update status of the belonging information management table in other wireless base stations indicated by the periodical transmission information,

wherein the belonging information update unit updates, when the first notification information or the second notification information is received from other wireless base station, the belonging information management table stored in said one wireless base stations based on the first notification information or the second notification information.

9. A belonging information management method in a wireless meshed network in which a terminal arbitrarily belongs to a wireless base station which composes the wireless meshed network, comprising:

a management table storing step for storing a belonging information management table which includes belonging information of the terminal in each of the wireless base station with an update number, which update number is incremented by one (1) whenever the terminal is added or deleted in the belonging information, for judgment of new or old of an update state of the belonging information;

a first belonging information updating step for updating the belonging information of said one wireless base station when a change in a belonging status of the terminal due to addition or deletion has been detected by corresponding information received from the terminal;

a first notification information transmitting step for transmitting, when the belonging information is updated, first notification information including an updated portion in the belonging information together with the incremented update number to all other wireless base stations;

a second belonging information updating step for updating, when the first notification information is received from other wireless base station, the belonging information management table stored in said one base station based on the first notification information;

a periodical information transmitting step for transmitting periodical transmission information including a number of wireless base stations included in the belonging information management table of said one wireless base station together with respective incremented update numbers corresponding to each wireless base station to adjoining wireless base stations;

a second notification information transmitting step for transmitting second notification information, which includes the number of wireless base stations included in the belonging information management table of said one wireless base station together with the respective incremented update numbers and a number of belonging terminals corresponding to each wireless base station, to all other wireless base stations, when finding old update status of the belonging information management table in other wireless base stations indicated by the periodical transmission information; and

a third belonging information updating step for updating, when the second notification information is received from other wireless base station, the belonging information management table stored in said one wireless base stations based on the second notification information.

10. The belonging information management method according to claim 9, wherein the second notification information transmitting step includes:

calculating a waiting time for transmitting the second notification information by a predetermined calculation method, and

transmitting the second notification information after elapsed the waiting time without receiving the second notification information from the other wireless base station, when finding old update status of the belonging information management table of other wireless base station indicated by the periodical transmission information.

11. The belonging information management method according to claim 9, wherein the first belonging information updating step includes, updating the belonging information of said one wireless base station when a change in the belonging status of the terminal being moved from other wireless base station has been detected by corresponding information received from the terminal, and further comprising:

a third notification information transmitting step for transmitting third notification information, which includes the updated portion in the belonging information due to movement of the terminal together with information about the moved terminal and the wireless base station to which the terminal belonged before movement, to all other wireless base stations, when the belonging information of said one wireless base station is updated due to movement of the terminal; and

a fourth belonging information updating step for updating, when receiving the third notification information from other wireless base station and finding that said one wireless base station is the wireless base station to which the moved terminal belonged before movement, the belonging information by deleting the terminal notified by the third notification information and transmitting the first notification information including the updated portion in the belonging information to all other wireless base stations.

12. The belonging information management method according to claim 9, wherein, when a data is not received from the terminal belonging to said one wireless base station in a predetermined time, the further step of deleting the belonging information corresponding to the terminal.

13. The belonging information management method according to claim 9, further comprising:

a synchronizing step for confirming, when the update numbers in the belonging information management table are initialized, each update number based on the information received from other wireless base station in a predetermined time.

14. The belonging information management method according to claim 9, further comprising:

a search requesting step for transmitting search request information including information on a destination terminal for performing search request to all other wireless base stations, when a parent wireless base station of the destination terminal for communication is unknown; and

a fourth notification information transmitting step for transmitting, when receiving the search request information and finding the destination terminal belongs to said one wireless base station, the first notification information including the belonging information about the destination terminal to all other wireless base stations.

15. A non-transitory computer-readable recording medium having embodied thereon a computer program, for a wireless base station composing a wireless meshed network in which a terminal arbitrarily moves, which causes a computer to execute belonging information management processing of a belonging information management table which includes belonging information of the terminal in each of the wireless base stations in the wireless meshed network with an update number, which is incremented by one (1) whenever the terminal is added or deleted in the belonging information, for judgment of new or old of an update state of the belonging information, comprising:

a first belonging information updating processing for updating the belonging information of a corresponding one wireless base station when a change in a belonging status of the terminal due to addition or deletion has been detected;

a first notification information transmitting processing for transmitting, when the belonging information is updated, first notification information including an updated portion in the belonging information together with the incremented update number to all other wireless base stations;

a second belonging information updating processing for updating, when the first notification information is received from other wireless base station, the belonging information management table stored in said one base station based on the first notification information;

a periodical information transmitting processing for transmitting periodical transmission information including a number of wireless base stations included in the belonging information management table of said one wireless base station together with respective incremented update numbers corresponding to each wireless base station to adjoining wireless base stations;

a second notification information transmitting processing for transmitting second notification information, which includes the number of wireless base stations included in the belonging information management table of said one wireless base station together with the respective incremented update numbers and a number of belonging terminals corresponding to each wireless base station, to all other wireless base stations, when finding old update status of the belonging information management table in other wireless base stations indicated by the periodical transmission information; and

a third belonging information updating processing for updating, when the second notification information is received from other wireless base station, the belonging information management table stored in said one wireless base stations based on the second notification information.

16. The non-transitory computer-readable recording medium according to claim 15, wherein the second notification information transmitting processing includes,

a processing of calculating a waiting time for transmitting the second notification information by a predetermined calculation method, and

a processing of transmitting the second notification information after elapsed the waiting time without receiving the second notification information from the other wireless base station, when finding old update status of the belonging information management table of other wireless base station indicated by the periodical transmission information.

17. The non-transitory computer-readable recording medium according to claim 15, wherein the first belonging information updating processing includes, a processing of updating the belonging information of said one wireless base station when a change in the belonging status of the terminal being moved from other wireless base station has been detected by corresponding information received from the terminal, and further comprising:

a third notification information transmitting processing for transmitting third notification information, which includes the updated portion in the belonging information due to movement of the terminal together with information about the moved terminal and the wireless base station to which the terminal belonged before movement, to all other wireless base stations, when the belonging information of said one wireless base station is updated due to movement of the terminal; and

a fourth belonging information updating processing for updating, when receiving the third notification information from other wireless base station and finding that said one wireless base station is the wireless base station to which the moved terminal belonged before movement, the belonging information by deleting the terminal notified by the third notification information and transmitting the first notification information including the updated portion in the belonging information to all other wireless base stations.

18. The non-transitory computer-readable recording medium according to claim 15, wherein, when a data is not received from the terminal belonging to said one wireless base station in a predetermined time, deleting the belonging information corresponding to the terminal.

19. The non-transitory computer-readable recording medium according to claim 15, further comprising:

a synchronizing processing for confirming, when the update numbers in the belonging information management table are initialized, each update number based on the information received from other wireless base station in a predetermined time.

20. The non-transitory computer-readable recording medium according to claim 15, further comprising:

a search requesting processing for transmitting search request information including information on a destination terminal for performing search request to all other wireless base stations, when a parent wireless base station of the destination terminal for communication is unknown, and

a fourth notification information transmitting processing for transmitting, when receiving the search request information and finding the destination terminal belongs to said one wireless base station, the first notification information including the belonging information about the destination terminal to all other wireless base stations.

21. A wireless base station composing a wireless meshed network in which a plurality of terminals arbitrarily move between a number of wireless base stations, said wireless base station comprising:

a terminal interface function means for communicating with the terminal belonging to said one wireless base station;

a wireless base station interface function means for communicating with other wireless base stations composing the wireless meshed network;

a management table storage means for storing a belonging information management table which includes belonging information of a terminal in each of the wireless base stations with an update number, which is incremented by one (1) whenever the terminal is added or deleted in the belonging information, for judgment of new or old of an update state of the belonging information;

a belonging information update means for updating the belonging information of said one wireless base station when a change in a belonging status of the terminal due to addition or deletion has been detected by corresponding information received through the terminal interface function means;

a first notification information transmission means for transmitting, when the belonging information is updated, first notification information including an updated portion in the belonging information together with the incremented update number to all other wireless base stations through the wireless base station interface function means, wherein

the belonging information update means updates, when the first notification information is received from other wireless base station, the belonging information management table stored in said one base station based on the first notification information;

a periodical information transmission means for transmitting periodical transmission information including the number of wireless base stations included in the belonging information management table of said one wireless base station together with respective update numbers corresponding to each wireless base station to adjoining wireless base stations through the wireless base station interface function means; and

a second notification information transmission means for transmitting second notification information, which includes the number of wireless base stations included in the belonging information management table of said one wireless base station together with the respective update numbers and the number of belonging terminals corresponding to each wireless base station, to all the other wireless base stations through the wireless base station interface function means, when finding an old update status of the belonging information management table in other wireless base stations indicated by the periodical transmission information,

wherein the belonging information update means updates, when the second notification information is received from other wireless base station, the belonging information management table stored in said one wireless base stations based on the second notification information.