Wireless base station, network system, communication method, and base station control program

• US 20040266427A1
• Filed: 06/25/2004
• Published: 12/30/2004
• Est. Priority Date: 06/27/2003
• Status: Active Grant

• Current Assignee: NEC Infrontia Corporation (NEC Corporation)
• Original Assignee: NEC Corporation
• Inventors: Kurokawa, Hideki
• Granted Patent: US 7,310,524 B2
• Time in Patent Office: Days
• US Class Current: 455/426.2
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 88/08 Access point devices

Abstract

This invention provides a wireless network system including a logically or physically separated wired network, a wireless base station connected to the wired network, and a plurality of wireless mobile terminals which performs wireless communication with the wireless base station. The wireless base station used in this system includes a wired communication unit which is connected to a wired network, a wireless communication unit which performs wireless communication using one radio frequency, and a wired line/wireless channel bridging function. The wireless base station also includes a control unit which controls one wireless communication unit to send out packets storing pieces of information corresponding to a plurality of virtual wireless networks so as to form a plurality of virtual wireless networks.

Claims

1. A wireless base station including wired communication means which is connected to a wired network, wireless communication means for performing wireless communication by using one radio frequency, and a wired line/wireless channel bridging function, comprising

control means for controlling said one wireless communication means to send out packets storing pieces of information corresponding to a plurality of virtual wireless networks so as to form the plurality of virtual wireless networks.

2. A station according to claim 1, wherein said control means causes said one wireless communication means to send out, as packets storing pieces of information corresponding to a plurality of virtual wireless networks, notification information storing an information element which changes for said each virtual wireless network and a packet storing a basic service set identifier which changes for said each virtual wireless network.

3. A station according to claim 1, wherein

said station comprises a management table in which identifiers of logically or physically separated wired networks and basic service set identifiers of virtual wireless networks coupled to the networks are associated with each other, and

said control means converts on the basis of said management table header information of a packet which is received by said wired communication means and addressed to a wireless channel, sends out the information through said wireless communication means, converts on the basis of said management table header information of a packet which is received by said wireless communication means and addressed to a wired line, and sends out the information through said wired communication means.

4. A station according to claim 3, wherein in said management table, identifiers of the wired networks and extended service set identifiers of virtual wireless networks coupled to the networks are stored so as to be associated with each other.

5. A station according to claim 4, wherein said control means stores an extended service set identifier which changes for each virtual wireless network in a management frame to be returned in response to a request from a wireless mobile terminal on the basis of said management table, and returns the management frame to the wireless mobile terminal which has sent the request, together with a basic service set identifier of the virtual wireless network to which the extended service set identifier is assigned.

6. A station according to claim 3, wherein in said management table, identifiers of the wired networks and association counts of virtual wireless networks coupled to the networks are stored so as to be associated with each other.

7. A station according to claim 6, wherein said control means identifies a type of wireless mobile terminal associated with a virtual wireless network from an extended service set identifier of the virtual wireless network, and performs control to change the association count in said management table in accordance with a traffic amount for each type of wireless mobile terminal associated with the virtual wireless network having a basic service set identifier with which the association count is associated.

8. A station according to claim 3, wherein in said management table, identifiers of the wired networks and maximum retry counts of virtual wireless networks coupled to the networks are stored so as to be associated with each other.

9. A station according to claim 8, wherein the maximum retry counts in said management table can be set at not less than one level for each virtual wireless network, and said control means changes the maximum retry count to not less than one level in accordance with a characteristic of a received packet.

10. A station according to claim 9, wherein

the maximum retry counts in said management table are set at two levels on a side with a few broadcasts and a side with many broadcasts for each virtual wireless network,

the characteristic of the received packet indicates a real-time communication packet which is set in advance as a packet to be used for communication whose communication contents are reproduced in real time at a transmission destination and a control packet for the real-time communication packet, and

said control means performs control to set the maximum retry count on the side with a few broadcasts when the characteristic of the received packet indicates a real-time communication packet, and sets the maximum retry count on the side with many broadcasts when the characteristic of the received packet indicates a control packet.

11. A station according to claim 3, wherein in said management table, identifiers of the wired networks and authentication methods in virtual wireless networks coupled to the networks are stored so as to be associated with each other.

12. A station according to claim 3, wherein in said management table, identifiers of the wired networks and delivery traffic indication message notification information periods in virtual wireless networks coupled to the networks are stored so as to be associated with each other.

13. A wireless network system comprising a logically or physically separated wired network, a wireless base station connected to said wired network, and a plurality of wireless mobile terminals which perform wireless communication with said wireless base station,

said wireless base station including wired communication means which is connected to a wired network, wireless communication means for performing wireless communication with said wireless mobile terminals by using one radio frequency, and a wired line/wireless channel bridging function, and

control means for controlling said one wireless communication means to send out packets storing pieces of information corresponding to a plurality of virtual wireless networks so as to form the plurality of virtual wireless networks.

14. A system according to claim 13, wherein said control means causes said one wireless communication means to send out, as packets storing pieces of information corresponding to a plurality of virtual wireless networks, notification information storing an information element which changes for said each virtual wireless network and a packet storing a basic service set identifier which changes for said each virtual wireless network.

15. A system according to claim 13, wherein

said station comprises a management table in which identifiers of logically or physically separated wired networks and basic service set identifiers of virtual wireless networks coupled to the networks are associated with each other, and

said control means converts on the basis of said management table header information of a packet which is received by said wired communication means and addressed to a wireless channel, sends out the information through said wireless communication means, converts on the basis of said management table header information of a packet which is received by said wireless communication means and addressed to a wired line, and sends out the information through said wired communication means.

16. A system according to claim 15, wherein in said management table, identifiers of the wired networks and extended service set identifiers of virtual wireless networks coupled to the networks are stored so as to be associated with each other.

17. A system according to claim 16, wherein said control means stores an extended service set identifier which changes for each virtual wireless network in a management frame to be returned in response to a request from a wireless mobile terminal on the basis of said management table, and returns the management frame to the wireless mobile terminal which has sent the request, together with a basic service set identifier of the virtual wireless network to which the extended service set identifier is assigned.

18. A system according to claim 15, wherein in said management table, identifiers of the wired networks and association counts of virtual wireless networks coupled to the networks are stored so as to be associated with each other.

19. A system according to claim 18, wherein said control means identifies a type of wireless mobile terminal associated with a virtual wireless network from an extended service set identifier of the virtual wireless network, and performs control to change the association count in said management table in accordance with a traffic amount for each type of wireless mobile terminal associated with the virtual wireless network having a basic service set identifier with which the association count is associated.

20. A system according to claim 15, wherein in said management table, identifiers of the wired networks and maximum retry counts of virtual wireless networks coupled to the networks are stored so as to be associated with each other.

21. A system according to claim 20, wherein the maximum retry counts in said management table can be set at not less than one level for each virtual wireless network, and said control means changes the maximum retry count to not less than one level in accordance with a characteristic of a received packet.

22. A system according to claim 21, wherein

the maximum retry counts in said management table are set at two levels on a side with a few broadcasts and a side with many broadcasts for each virtual wireless network,

the characteristic of the received packet indicates a real-time communication packet which is set in advance as a packet to be used for communication whose communication contents are reproduced in real time at a transmission destination and a control packet for the real-time communication packet, and

said control means performs control to set the maximum retry count on the side with a few broadcasts when the characteristic of the received packet indicates a real-time communication packet, and sets the maximum retry count on the side with many broadcasts when the characteristic of the received packet indicates a control packet.

23. A system according to claim 15, wherein in said management table, identifiers of the wired networks and authentication methods in virtual wireless networks coupled to the networks are stored so as to be associated with each other.

24. A system according to claim 15, wherein in said management table, identifiers of the wired networks and delivery traffic indication message notification information periods in virtual wireless networks coupled to the networks are stored so as to be associated with each other.

25. A system according to claim 13, comprising a plurality of wireless base stations having identical settings, wherein control means of said plurality of wireless base stations perform control to continue communication without changing a network layer address of said wireless mobile terminal even when said wireless mobile terminal switches a wireless base station for wireless communication among said plurality of wireless base stations.

26. A wireless communication method in a wireless network system including a logically or physically separated wired network, a wireless base station connected to the wired network, and a plurality of wireless mobile terminals which performs wireless communication with the wireless base station, comprising

the sending step of sending out a converted packet after the conversion step of converting header information of a received packet on the basis of a management table including information for conversion of header information of a packet to be transferred, when the wireless base station receives a packet addressed to the wireless mobile terminal from the wired network and sends out the packet to the wireless mobile terminal or receives a packet addressed to a communication partner in the wired network from the wireless mobile terminal and sends out the packet to the communication partner.

27. A method according to claim 26, wherein the management table is formed such that identifiers of the respective wired networks and basic service set identifiers of virtual wireless networks coupled to the networks are associated with each other, and in the conversion step, the identifier of the wired network in header information of a packet to be transferred and the basic service set identifier of the virtual wireless network are converted.

28. A method according to claim 27, wherein the management table is formed such that identifiers of the respective wired networks and extended service set identifiers of virtual wireless networks coupled to the networks are associated with each other, and in the conversion step, the identifier of the wired network in header information of a packet to be transferred and the basic service set identifier and the extended service set identifier of the virtual wireless network are converted.

29. A control program for a wireless base station including wired communication means which is connected to a wired network, wireless communication means for performing wireless communication by using one radio frequency, and a wired line/wireless channel bridging function,

the control program causing the wireless base station to execute processing in the step defined in the wireless communication method defined in claim 26.