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

• US 20080100494A1
• Filed: 12/13/2007
• Published: 05/01/2008
• Est. Priority Date: 02/09/2004
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: YAMAURA, Tomoya
• Granted Patent: US 7,881,273 B2
• Time in Patent Office: Days
• US Class Current: 342/20
• 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: H04B 1/1027 assessing signal quality or detecting noise/interference for the received signal
• CPC Class Codes: H04B 1/401 for selecting or indicating operating mode
• CPC Class Codes: H04K 2203/18 for wireless local area networks or WLAN
• CPC Class Codes: H04K 3/226 Selection of non-jammed channel for communication spectrum sharing arrangements H04W16/14; selection of wireless resources by user or terminal H04W72/02
• CPC Class Codes: H04K 3/822 by detecting the presence of a surveillance, interception or detection
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• CPC Class Codes: H04W 16/16 for PBS [Private Base Station] arrangements
• CPC Class Codes: H04W 48/16 Discovering, processing access restriction or access information
• CPC Class Codes: H04W 52/0238 where the received signal is an unwanted signal, e.g. interference or idle signal
• CPC Class Codes: H04W 84/12 WLAN [Wireless Local Area Networks]
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks
• CPC Class Codes: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/021 adapted for Wireless Local Loop operation
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Disclosed is radar wave detection and DFS (dynamic frequency selection) with high efficiency while considering, for instance, the power consumption of each communication station within an autonomous distributed network. At least one communication station runs in an interference avoidance operation mode, operates a radar wave detection section, and fulfills the obligation to issue instructions for radar wave detection and DFS for an approximately predetermined period of time. After the lapse of the approximately predetermined period of time, another communication station switches to the interference avoidance operation mode and assumes the obligation to issue instructions for radar wave detection and DFS. In other words, two or more communication stations sequentially run in the interference avoidance operation mode in a time sharing manner. Therefore, the average power consumption of the communication stations decreases.

Claims

1. A wireless communication apparatus for transmitting/receiving a signal within a frequency band for which radar wave detection is required, the wireless communication apparatus comprising:

communication means for transmitting/receiving wireless data at a plurality of available carrier frequencies;

radar wave detection means for monitoring a radar wave at the currently used carrier frequency; and

communication control means for controlling the communication operation of said communication means either in an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection or in a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency,

wherein said communication control means retains a sequence table, which describes an operating sequence that is defined by communication stations operating in the same communication range, to determine the order in which the communication stations operate in the interference avoidance operation mode.

2. The wireless communication apparatus according to claim 1, wherein said communication control means stops the operation of said radar wave detection means in said normal operation mode.

3. The wireless communication apparatus according to claim 1, wherein said communication control means switches between the interference avoidance operation mode and normal operation mode in accordance with said sequence table.

4. The wireless communication apparatus claim 1, wherein said communication control means notifies, during an operation in the interference avoidance operation mode, a remote communication station operating in the normal operation mode that the remote communication station should subsequently operate in the interference avoidance operation mode, and switches from the interference avoidance operation mode to the normal operation mode upon receipt of an acknowledgement from the remote communication station.

5. The wireless communication apparatus according to claim 1, wherein said communication control means notifies, during an operation in the interference avoidance operation mode, a remote communication station operating in the normal operation mode that the remote communication station should subsequently operate in the interference avoidance operation mode, and switches from the interference avoidance operation mode to the normal operation mode upon receipt of a notification that the remote communication station has switched to the interference avoidance operation mode.

6. The wireless communication apparatus according to claim 4, wherein said communication control means retains a neighboring station list for neighboring station management, notes neighboring stations indicated in said neighboring station list, and selects, in a random manner but with a predetermined probability, the next communication station that should operate in the interference avoidance operation mode.

7. The wireless communication apparatus according to claim 6, wherein said neighboring station list indicates neighboring stations that are within the communication range of said first communication station.

8. The wireless communication apparatus according to claim 6, wherein said communication control means selects a communication station from neighboring stations indicated in said neighboring station list with virtually constant probability.

9. The wireless communication apparatus according to claim 6, wherein said communication control means selects a communication station with a probability that is weighted according to the power supply situation information about neighboring stations indicated in said neighboring station list.

10. The wireless communication apparatus according to claim 9, wherein said communication control means assigns a relatively heavy weight to an AC-powered communication station and a relatively light weight to a battery-powered communication station.

11. The wireless communication apparatus according to claim 1, wherein said sequence table contains the power supply situation information about each communication station and assigns the time of operating in the interference avoidance operation mode to each communication station in accordance with the power supply situation information.

12. The wireless communication apparatus according to claim 11, wherein said sequence table contains the information for determining whether each communication station is AC powered or battery powered, and allocates a longer time of operating in the interference avoidance operation mode to an AC-powered communication station than to a battery-powered communication station.

13. The wireless communication apparatus according to claim 1, wherein, where, for instance, a communication station operable in the interference avoidance operation mode newly participates in or leaves the system, thereby causing a change in the network configuration, said communication control means notifies remote stations of the change in the network configuration upon detection of the change in the network configuration during an operation in the normal operation mode or updates the contents of said sequence table upon detection of the change in the network configuration or upon receipt of a remote station'"'"'s report on the change in the network configuration during an operation in the interference avoidance operation mode.

14. The wireless communication apparatus according to claim 11, further comprising a battery, which serves as an apparatus drive power supply, and remaining battery power detection means for detecting the remaining power of said battery, wherein, where said remaining battery power detection means detects a change in the remaining battery power, said communication control means makes a report on the change in the remaining battery power, and wherein, where a remaining battery power change report is received from a remote station during an operation in the interference avoidance operation mode, said communication control means updates the contents of said sequence table.

15. The wireless communication apparatus according to claim 14, wherein said communication control means determines the time of operating in the interference avoidance operation mode in accordance with the remaining battery power detected by said remaining battery power detection means.

16. The wireless communication apparatus according to claim 1, wherein said sequence table describes each communication station'"'"'s time of operating in the interference avoidance operation mode.

17. The wireless communication apparatus according to claim 1, further comprising an AC power supply, which serves as the apparatus drive power supply, wherein said communication control means sets an indefinite duration of time of operating in the interference avoidance operation mode.

18. The wireless communication apparatus according to claim 1, wherein said communication control means autonomously determines the time of operating in the interference avoidance operation mode in accordance with the local station'"'"'s power supply situation.

21. A wireless communication system comprising two or more wireless communication apparatuses according to claim 1, for transmitting/receiving a signal within a frequency band for which radar wave detection is required.

22. The wireless communication system according to claim 21, wherein the two or more communication stations operate while switching between an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection and a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency.

23. The wireless communication system according to claim 22, wherein the two or more communication stations operate in the interference avoidance operation mode in a time sharing manner.

24. The wireless communication system according to claim 23, wherein the communication stations sequentially operate, one at a time, in a predetermined order in the interference avoidance operation mode.

25. The wireless communication system according to claim 24, wherein the communication stations operating in the interference avoidance operation mode in a time sharing manner retain a sequence table, which describes the order in which the communication stations operate in the interference avoidance operation mode;

and wherein at least one communication station always operates in the interference avoidance operation mode.

19. A wireless communication apparatus for transmitting/receiving a signal within a frequency band for which radar wave detection is required, the wireless communication apparatus comprising:

communication means for transmitting/receiving wireless data at a plurality of available carrier frequencies;

radar wave detection means for monitoring a radar wave at the currently used carrier frequency; and

communication control means for controlling the communication operation of said communication means either in an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection or in a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency,

wherein said communication control means retains a neighboring station list for neighboring station management, notes neighboring stations indicated in said neighboring station list, and selects, in a random manner but with a predetermined probability, the next communication station that should operate in the interference avoidance operation mode.

20. A wireless communication apparatus for transmitting/receiving a signal within a frequency band for which radar wave detection is required, the wireless communication apparatus comprising:

communication means for transmitting/receiving wireless data at a plurality of available carrier frequencies;

radar wave detection means for monitoring a radar wave at the currently used carrier frequency; and

communication control means for controlling the communication operation of said communication means either in an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection or in a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency,

wherein said communication control means retains a neighboring station list for neighboring station management, notes neighboring stations indicated in said neighboring station list, and selects a communication station with a probability that is weighted according to the power supply situation information about neighboring stations indicated in said neighboring station list.

26. A wireless communication method for transmitting/receiving a signal within a frequency band for which radar wave detection is required, wherein a plurality of carrier frequencies are available, the wireless communication method comprising:

a radar wave detection step for monitoring for a radar wave at a currently used carrier frequency; and

a communication control step for controlling a communication operation either in an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection or in a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency and wherein said communication control step comprises retaining a sequence table, which describes an operating sequence that is defined by communication stations operating in the same communication range to determine the order in which the communication stations operate in the interference avoidance operation mode.

27. A wireless communication method for transmitting/receiving a signal within a frequency band for which radar wave detection is required, wherein a plurality of carrier frequencies are available, the wireless communication method comprising:

a radar wave detection step for monitoring for a radar wave at a currently used carrier frequency; and

a communication control step for controlling a communication operation either in an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection or in a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency and wherein said communication control step comprises retaining a neighboring station list for neighboring station management, noting neighboring stations indicated in said neighboring station list, and selecting, in a random manner but with a predetermined probability, the next communication station that should operate in the interference avoidance operation mode.

28. A wireless communication method for transmitting/receiving a signal within a frequency band for which radar wave detection is required, wherein a plurality of carrier frequencies are available, the wireless communication method comprising:

a radar wave detection step for monitoring for a radar wave at a currently used carrier frequency; and

a communication control step for controlling a communication operation either in an interference avoidance operation mode for detecting a radar wave and instructing various stations to change the employed carrier frequency in accordance with a radar wave detection or in a normal operation mode for performing a communication operation while changing the employed carrier frequency in compliance with a remote station'"'"'s instruction for a change in the employed carrier frequency and wherein said communication control step comprises retaining a neighboring station list for neighboring station management, noting neighboring stations indicated in said neighboring station list, and selecting a communication station with a probability that is weighted according to the power supply situation information about neighboring stations indicated in said neighboring station list.