Wireless communication system, wireless communication apparatus, wireless communication method and computer program

• US 20050047383A1
• Filed: 07/21/2004
• Published: 03/03/2005
• Est. Priority Date: 07/24/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Yoshida, Hidemasa
• Granted Patent: US 7,813,372 B2
• Time in Patent Office: Days
• US Class Current: 370/338
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

In a self-organized distribution type wireless network without relationship between a controlling station and a controlled station, in order to execute a channel access by effectively utilizing a plurality of frequency channels, there is provided a communication system. In the system, a communication station determines a seed and generates a frequency channel switching pattern basing upon the seed. The seed is written in a beacon in each transmission frame to notify it to other stations. A new entry station scans all frequency channels, identifies a channel switching pattern of the frequency channels in accordance with the seed in the beacon received from another station, selects a candidate of a beacon transmission position and a transmission channel, and determines the beacon transmission position and transmission channel which are best for own station to transmit a beacon.

Claims

1. A wireless communication system for forming a network with a plurality of wireless communication apparatuses without relationship between a controlling station and a controlled station in a communication environment having a plurality of channels, wherein:

each of said wireless communication apparatuses;

notifies beacon information containing seed information corresponding uniquely to a beacon transmission timing and a transmission channel of its own station,

when one of said wireless communication apparatuses newly participates in the network, the new entry apparatus identifies a channel switching pattern for beacon transmission on each channel, in accordance with the seed information in the information of a beacon received from another station, selects one candidate of own station from candidates not in use of the beacon transmission timing and transmission channel, and transmits the beacon information.

2. The wireless communication system according to claim 1, wherein each of said wireless communication apparatuses determines the transmission channel of the beacon information from channels favorable to its own station.

3. The wireless communication system according to claim 1, wherein each of said wireless communication apparatuses determines the beacon transmission timing and the transmission channel from candidates from which a channel whose communication quality is not favorable to its own station is excluded at the time of new entry.

4. The wireless communication system according to claim 1, wherein each of said wireless communication apparatuses determines the beacon transmission timing in a distributed manner on a time basis with regard to other stations on the determined beacon transmission channel at the time of new entry.

5. The wireless communication system according to claim 1, wherein each of said wireless communication apparatuses determines the beacon transmission channel in a distributed manner on a frequency axis with regard to other stations at the time of new entry.

6. The wireless communication system according to claim 1, wherein, in a case where some of the frequency channels is degraded in communication quality in a steady state, each of said wireless communication apparatuses determines the beacon transmission timing and the transmission channel to switch a beacon transmission position and the transmission channel from candidates excluding the degraded channel.

7. A wireless communication apparatus operating in a wireless communication environment without relationship between a controlling station and a controlled station in which a plurality of channels are prepared, said wireless communication apparatus comprising:

communication means for transmitting and receiving wireless data;

control means for controlling a transmission/reception operation of the wireless data by said communication means;

beacon transmission position control means for determining a beacon transmission timing and a transmission channel of its own station;

seed information generation means for generating seed information uniquely corresponding to a channel switching pattern defining the determined beacon transmission timing and the transmission channel of the own station; and

beacon information notification means for notifying beacon information including the generated seed information every predetermined frame period within a communication range of said communication means.

8. The wireless communication apparatus according to claim 7, wherein said beacon transmission position control means determines the transmission channel of the beacon information from channels favorable to the own station.

9. The wireless communication apparatus according to claim 7, further comprising beacon analysis means for analyzing the beacon information received from another station, wherein said beacon transmission position control means refers to a channel switching pattern identified on the basis of the seed information taken out from the received beacon information to select the beacon transmission timing and the transmission timing to use from candidates not in use at the time of new entry.

10. The wireless communication apparatus according to claim 9, wherein said beacon transmission position control means determines the beacon transmission timing and the transmission channel from candidates from which a channel whose communication quality is not favorable to its own station is excluded at the time of new entry.

11. The wireless communication apparatus according to claim 9, wherein said beacon transmission position control means determines the beacon transmission timing in a distributed manner on a time basis with regard to other stations on the determined beacon transmission channel at the time of new entry.

12. The wireless communication apparatus according to claim 9, wherein said beacon transmission position control means determines the beacon transmission channel in a distributed manner on a frequency axis with regard to other stations at the time of new entry.

13. The wireless communication apparatus according to claim 9, wherein, in a case where some of the frequency channels is degraded in communication quality in a steady state, said beacon transmission position control means determines the beacon transmission timing and the transmission channel to switch a beacon transmission position and the transmission channel from candidates excluding the degraded channel.

14. A wireless communication method for operating in a wireless communication environment without relationship between a controlling station and a controlled station in which a plurality of channels are prepared, said wireless communication method comprising:

a beacon transmission position control step for determining a beacon transmission timing and a transmission channel of its own station;

a seed information generation step for generating seed information uniquely corresponding to a channel switching pattern defining the determined beacon transmission timing and the transmission channel of the own station; and

a beacon information notification step for notifying beacon information including the generated seed information every predetermined frame period within a communication range of said communication means.

15. The wireless communication method according to claim 14, wherein in said beacon transmission position control step, the transmission channel of the beacon information is determined from channels favorable to the own station.

16. The wireless communication method according to claim 14, further comprising a beacon analysis step for analyzing the beacon information received from another station, wherein, in said beacon transmission position control step, a channel switching pattern identified on the basis of the seed information taken out from the received beacon information is referred to select the beacon transmission timing and the transmission timing to use from candidates not in use at the time of new entry.

17. The wireless communication method according to claim 16, wherein, in said beacon transmission position control step, the beacon transmission timing and the transmission channel is determined from candidates from which a channel whose communication quality is not favorable to its own station is excluded at the time of new entry.

18. The wireless communication method according to claim 16, wherein, in said beacon transmission position control step, the beacon transmission timing is determined so as to be distributed on a time basis with regard to other stations on the determined beacon transmission channel at the time of new entry.

19. The wireless communication method according to claim 16, wherein, in said beacon transmission position control step, the beacon transmission channel is determined so as to be distributed on a frequency axis with regard to other stations at the time of new entry.

20. The wireless communication method according to claim 16, wherein, in a case where some of the frequency channels is degraded in communication quality in a steady state, in said beacon transmission position control step, the beacon transmission timing and the transmission channel are determined to switch a beacon transmission position and the transmission channel from candidates excluding the degraded channel.

21. A computer program described in a computer-readable format so as to execute, on a computer system, a process for operating in a wireless communication environment without relationship between a controlling station and a controlled station in which a plurality of channels are prepared, said computer program comprising:

a beacon transmission position control step for determining a beacon transmission timing and a transmission channel of its own station;

a seed information generation step for generating seed information uniquely corresponding to a channel switching pattern defining the determined beacon transmission timing and the transmission channel of the own station; and

a beacon information notification step for notifying beacon information including the generated seed information every predetermined frame period within a communication range of said communication means.