WIRELESS APPARATUS, WIRELESS COMMUNICATION SYSTEM, CONTROL METHOD, AND CONTROL PROGRAM

• US 20090146866A1
• Filed: 12/10/2008
• Published: 06/11/2009
• Est. Priority Date: 12/10/2007
• Status: Active Grant

• Current Assignee: NEC Platforms, Ltd.
• Original Assignee: NEC Communication Systems Limited
• Inventors: Yokoyama, Naoki, Suzuki, Yoko, Shimomura, Akira, Someya, Dai, Matsumoto, Akira, Abe, Kenichi, Ito, Tetsuya, Ueno, Hiroaki
• Granted Patent: US 8,116,688 B2
• Time in Patent Office: Days
• US Class Current: 342/52
• CPC Class Codes: G01S 7/021 Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]

Abstract

A wireless apparatus which can realize a DFS function that avoidance of interference with radar is considered in an Ad-Hoc mode under a multihop circumstance is provided. A Beacon frame is transmitted at a shorter interval than a previously set interval when radar is detected by wireless apparatuses N1 to N6 which have a DFS function which perform avoidance of interference with radar.

Claims

1. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar,

wherein when radar is detected, a Beacon frame is transmitted at a shorter transmission interval than a previously set transmission interval.

12. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 1.

2. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar,

wherein when a CSA (Channel Switch Announcement) frame is received, a CSA frame including a CSA element included in the CSA frame is transmitted.

3. The wireless apparatus according to claim 2, wherein the CSA frame is transmitted after standby a random time.

27. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 2.

4. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar,

wherein the wireless apparatus manages a resumption time that becomes a DFS Owner or a resumption time that enters a DFS Owner Recovery mode to assume the role of DFS Owner, compares the managed time to a resumption time that another wireless apparatus becomes a DFS Owner, and controls for quitting a DFS Owner according to the comparison result.

5. The wireless apparatus according to claim 4, further comprising:

a unit which includes and transmits the resumption time in a Beacon frame; and

a control unit which, when a Beacon frame is received, compares a resumption time of another wireless apparatus included in the Beacon frame to the managed time and quits a DFS Owner according to the comparison result.

28. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 4.

6. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar,

wherein identification information for uniquely identifying each apparatus is included in a CSA (Channel Switch Announcement) frame, and when a plurality of CSA frames are received, a CSA frame to be adopted by the wireless apparatus among the plurality of CSA frames is determined according to identification information included in the CSA frame.

29. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 6.

7. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar; and

a unit for notifying a channel list which is an index for a channel switch to an adjacent wireless apparatus when detecting radar.

8. The wireless apparatus according to claim 7, further comprising:

a unit for measuring a received signal level for each radio channel and predicting an interference area of a radio channel that channel interference occurs for each radio channel, based on the received signal level of each radio channel; and

a unit for creating the channel list based on the interference area of the radio channel predicted for each radio channel.

30. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 7.

9. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar,

wherein when a Beacon frame is received, if a Quiet Count included in the Beacon frame is smaller in value than a Quiet Count of the wireless apparatus, the Quiet Count of the wireless apparatus is changed to the Quiet Count included in the Beacon frame, and if the Quiet Count included in the Beacon frame is larger in value than the Quiet Count of the wireless apparatus, the wireless apparatus controls for ignoring the Beacon frame.

31. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 9.

10. A wireless apparatus, comprising:

a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar;

a plurality of wireless interfaces;

a management unit for managing information of a channel when a first wireless interface detects radar; and

a control unit for by priority switching to a channel other than a channel managed by the management unit when switching a channel of a second wireless interface.

11. The wireless apparatus according to claim 10, further comprising, a notifying unit for notifying information of a channel managed by the management unit to another wireless apparatus which shares a channel with the second wireless interface.

32. A wireless communication system, comprising:

a plurality of wireless apparatuses according to claim 10.

13. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar, comprising a step of:

when radar is detected, transmitting a Beacon frame at a shorter transmission interval than a previously set transmission interval.

14. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar, comprising a step of:

when a CSA (Channel Switch Announcement) frame is received, transmitting a CSA frame including a CSA element included in the CSA frame.

15. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar, comprising a step of:

managing a resumption time that becomes a DFS Owner or a resumption time that enters a DFS Owner Recovery mode to assume the role of DFS Owner, comparing the managed time to a resumption time that another wireless apparatus becomes a DFS Owner, and controlling for quitting a DFS Owner according to the comparison result.

16. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar, comprising a step of:

when a plurality of CSA (Channel Switch Announcement) frames in which identification information for uniquely identifying each apparatus is included are received, determining a CSA frame to be adopted by the wireless apparatus among the plurality of CSA frames according to identification information included in the CSA frame.

17. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar, comprising a step of:

notifying a channel list which is an index for a channel switch to an adjacent wireless apparatus when detecting radar.

18. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar, comprising a step of:

when a Beacon frame is received, changing a Quiet Count of the wireless apparatus to a Quiet Count included in the Beacon frame if the Quiet Count included in the Beacon frame is smaller in value than the Quiet Count of the wireless apparatus, and controlling for ignoring the Beacon frame if the Quiet Count included in the Beacon frame is larger in value than the Quiet Count of the wireless apparatus.

19. A control method which is performed in a wireless apparatus which has DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar and a plurality of wireless interfaces, comprising steps of:

managing information of a channel when a first wireless interface detects radar; and

controlling by priority for switching to a channel other than a channel managed by the management steps when switching a channel of a second wireless interface.

20. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar to execute a processing of:

when radar is detected, transmitting a Beacon frame at a shorter transmission interval than a previously set transmission interval.

21. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar to execute a processing of:

when a CSA (Channel Switch Announcement) frame is received, transmitting a CSA frame including a CSA element included in the CSA frame.

22. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar to execute a processing of:

managing a resumption time that becomes a DFS Owner or a resumption time that enters a DFS Owner Recovery mode to assume the role of DFS Owner, comparing the managed time to a resumption time that another wireless apparatus becomes a DFS Owner, and controlling for quitting a DFS Owner according to the comparison result.

23. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar to execute a processing of:

when a plurality of CSA (Channel Switch Announcement) frames in which identification information for uniquely identifying each apparatus is included are received, determining a CSA frame to be adopted by the wireless apparatus among the plurality of CSA frames according to identification information included in the CSA frame.

24. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar to execute a processing of:

notifying a channel list which is an index for a channel switch to an adjacent wireless apparatus when detecting radar.

25. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar to execute a processing of:

when a Beacon frame is received, changing a Quiet Count of the wireless apparatus to a Quiet Count included in the Beacon frame if the Quiet Count included in the Beacon frame is smaller in value than the Quiet Count of the wireless apparatus, and for controlling for ignoring the Beacon frame if the Quiet Count included in the Beacon frame is larger in value than the Quiet Count of the wireless apparatus.

26. A computer-readable medium storing a control program which allows a wireless apparatus which has a DFS (Dynamic Frequency Selection) function which performs avoidance of interference with radar and has a plurality of wireless interfaces to execute a processing of:

managing information of a channel when a first wireless interface detects radar; and

switching by priority to a channel other than a channel managed by the management processing when switching a channel of a second wireless interface.