Fast Active Scanning Wireless Network Apparatus and Method

• US 20090207758A1
• Filed: 04/15/2009
• Published: 08/20/2009
• Est. Priority Date: 04/29/2003
• Status: Active Grant

• Current Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Original Assignee: NTT Docomo Incorporated (Nippon Telegraph and Telephone Corporation)
• Inventors: Kawahara, Toshiro, Wantanabe, Fujio, Jeong, Moo Ryong
• Granted Patent: US 8,340,665 B2
• Time in Patent Office: Days
• US Class Current: 370/254
• CPC Class Codes: H04B 7/022 Site diversity; Macro-diversity using two or more spaced independent antennas H04B7/04
• CPC Class Codes: H04W 48/14 using user query or user detection
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 74/08 Non-scheduled access, e.g. ALOHA hybrid access H04W74/02
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

In a fast active scanning wireless network apparatus and method for quick determination of available access points, information about a candidate set of available access points is obtained, and a candidate access point is identified from the candidate set. A mobile station then queries the candidate access point with a probe request that designates the candidate access point as a sole responder. The probe request prevents other access points from contending for the medium of communication between the mobile station and the designated sole responder access point by excluding the attempt by other access points to transmit probe responses. The apparatus and method thus increases the probability of a fast and successful probe request from the mobile station and subsequent response from the designated access point. The designated access point may also respond with a probe response of high priority, preventing intervention of communication.

Claims

1. A method of enabling active channel scanning in a wireless network, said method comprising:

collecting candidate access point information that differentiates between candidate access points that are possibly available for association;

selecting a candidate access point from said candidate access points based on said candidate access point information; and

transmitting a probe request, said probe request including an address of said selected access point that is specified in a basic service set identification field.

2. The method of claim 1, wherein said selected candidate access point has been differentiated as most likely to provide communication.

3. The method of claim 1, wherein said probe request specifies a basic service set identification.

4. The method of claim 1, wherein said probe request comprises fields of information wherein a broadcast address is entered in a destination address field, and either of a service set identification for said selected candidate access point or a broadcast service set identification is entered in a service set identification field.

5. The method of claim 1, wherein said method complies with one of the IEEE 802.11, 802.15 and 802.16 wireless standards of interoperability.

6. A wireless station in a wireless communications network comprising:

a collector which collects candidate access point information that differentiates between candidate access points that are possibly available for association;

a selector that, based on the candidate access point information, selects a candidate access point from said candidate access points; and

a transmitter for transmitting a probe request, said probe request including an address of said selected candidate access point that is specified in a basic service set identification field.

7. The wireless station of claim 6, said selected candidate access point has been differentiated as most likely to provide communication.

8. The wireless station of claim 6, wherein said probe request specifies a basic service set identification.

9. The wireless station of claim 6, wherein said probe request comprises fields of information wherein a broadcast address is entered in a destination address field and either of a service set identification for said selected candidate access point or a broadcast service set identification-is entered in a service set identification field.

10. The wireless station of claim 6, wherein said wireless station complies with one of the IEEE 802.11, 802.15 and 802.16 wireless standards of interoperability.

11. A wireless access point among a plurality of access points in a telecommunications system that are possibly available for association, comprising:

A receiver that receives a probe request from a wireless station, said probe request including an address of said wireless access point that is specified in a basic service set identification field; and

a transmitter for transmitting a response to said probe request.

12. The wireless access point of claim 11, further comprising a collector that collects candidate access point information that differentiates between candidate access points, said transmitter transmitting said candidate access point information.

13. The wireless access point of claim 11, wherein said probe request specifies a basic service set identification.

14. The wireless access point of claim 11, wherein said probe request comprises fields of information wherein a broadcast address is entered in a destination address field, and either of a service set identification for said wireless access point or a broadcast service set identification is entered in a service set identification field.

15. The wireless access point of claim 11, wherein said access point complies with one of the IEEE 802.11, 802.15 and 802.16 wireless standards of interoperability.

16. In a wireless telecommunications system comprising

a plurality of access points, wherein at least one of the access points comprises a processor which processes candidate access point information that differentiates between candidate access points that are possibly available for association;

and

a wireless terminal which, based on said candidate access point information, selects one of said access points and transmits a probe request, said probe request including an address of said candidate access point that is specified in a basic service set identification field.

17. The system of claim 16, wherein said candidate access point has been differentiated as most likely to provide communication.

18. The system of claim 16, wherein said probe request specifies a basic service set identification.

19. The system of claim 16, wherein both said selected access point and said wireless station comply with one of the IEEE 802.11, 802.15 and 802.16 wireless standards of interoperability.

20. A wireless telecommunications system comprising:

a plurality of wireless stations, wherein at least one of the wireless stations comprises a processor which processes candidate access point information that differentiates between candidate access points that are possibly available for association; and

a wireless station that, based upon said candidate access point information, selects an access point and transmits a probe request, said probe request including an address of said selected access point that is specified in a basic service set identification field.

21. The system of claim 20, wherein said selected access point has been differentiated as most likely to provide communication.

22. The system of claim 20, wherein said probe request specifies a basic service set identification.

23. The system of claim 20, wherein said wireless station complies with one of the IEEE 802.11, 802.15 and 802.16 wireless standards of interoperability.

24. A method of enabling active channel scanning in a wireless network, said method comprising:

collecting candidate access point information that differentiates between candidate access points that are possibly available for association;

selecting a candidate access point from said candidate access points based on said candidate access point information; and

transmitting a probe request, said probe request including an address of said selected access point that is specified in a destination address field.

25. The method of claim 24, wherein said probe request comprises a basic service identification set field for a broadcast basic service set identification or an address of said selected access point, and a service set identification field for a broadcast service set identification or a service set identification of said selected access point.

26. A wireless station in a wireless communications network comprising:

a collector which collects candidate access point information that differentiates between candidate access points that are possibly available for association;

a selector that, based on the candidate access point information, selects a candidate access point from said candidate access points; and

a transmitter for transmitting a probe request, wherein said probe request specifies an address of said selected candidate access point in a destination address field.

27. The wireless station of claim 26, wherein said selected candidate access point responds to said probe request with an acknowledgement frame prior to any other type of frame being transmitted from said selected candidate access point.

28. The wireless station of claim 27, wherein said probe request comprises a basic service identification set field for a broadcast basic service set identification or an address of said selected access point, and a service set identification field for a broadcast service set identification or a service set identification of said selected access point.

29. A wireless access point among a plurality of access points in a telecommunications system that are possibly available for association, comprising:

A receiver that receives a probe request from a wireless station, wherein said probe request specifies a destination address of said access point; and

a transmitter for transmitting a response to said probe request.

30. The access point of claim 29, wherein an address of said selected access point is provided in a destination field of said probe request.

31. In a wireless telecommunications system comprising

a plurality of access points, wherein at least one of the access points comprises a processor which processes candidate access point information that differentiates between candidate access points that are possibly available for association;

and

a wireless terminal which, based on said candidate access point information, selects one of said access points and transmits a probe request, wherein said probe request specifies an address of said selected access point as a destination address.

32. The system of claim 31, wherein said selected access point responds to said probe request with an acknowledgement frame prior to any other type of frame being transmitted from said selected candidate access point.

33. The system of claim 32, wherein an address of said selected access point is provided in a destination address field of said probe request.

34. A wireless telecommunications system comprising:

a plurality of wireless stations, wherein at least one of the wireless stations comprises a processor which processes candidate access point information that differentiates between candidate access points that are possibly available for association; and

a wireless station that, based upon said candidate access point information, selects an access point and transmits a probe request, wherein said probe request specifies an address of said selected access point as a destination address.

35. The system of claim 34, wherein said selected access point responds to said probe request with an acknowledgement frame prior to any other type of frame being transmitted from said specified candidate access point.

36. The system of claim 35, wherein an address of said selected access point is provided in a destination address field of said probe request.