Decentralized wireless communication system, apparatus, and associated methodology

• US 8,078,112 B2
• Filed: 07/02/2010
• Issued: 12/13/2011
• Est. Priority Date: 07/29/2003
• Status: Active Grant

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Morioka, Yuichi
• Primary Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US12/829,660
• Publication Number:
  US 20100290421A1
• Time in Patent Office: 529 Days
• Field of Search: 455/1, 455/11.1, 455/41.2, 455/62, 455/63.1, 455/67.11, 455/67.13, 455 68- 70, 455/73, 455/403, 455/418, 455/434, 4554521-4522, 455/453, 455/455, 455/464, 455/466, 455500-502, 455/509, 455/513, 455/517, 455/550.1, 455/556.2, 455/561, 455/63.3, 455/423, 455/425, 455450-451, 455/515, 370328-330, 370/338, 370/341, 370/346, 370348-350, 370/313
• US Class Current: 455/63.1
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/541 using the level of interference
• CPC Class Codes: H04W 84/18 Self-organising networks, e.g. ad-hoc networks or sensor networks

Abstract

Communication stations select the channel which as many communication stations as possible can receive as a beacon sending channel based on interference information of each channel specified in a beacon signal. When there is a communication station which cannot receive a beacon, the beacon sending channel is changed. The communication stations can receive a beacon from all other communication stations by performing beacon receiving operation over a particular channel, avoiding the deadlock state.

Claims

1. A wireless communication apparatus which operates under a wireless communication environment in which multiple channels are prepared, said wireless communication apparatus comprising:

a transmitting unit configured to transmit wireless data over each channel of the multiple channels;

a receiving unit configured to receive the wireless data over each channel of the multiple channels;

a channel setting unit configured to set a data sending/receiving channel in the transmitting and receiving units;

a communication control unit configured to control transmission and reception of the wireless data via the transmitting unit and the receiving unit;

a beacon generating unit configured to generate a beacon signal including control information concerning the data sending/receiving channel, the transmitting unit sending the beacon over a beacon sending channel;

a beacon analyzing unit configured to analyze a beacon signal received from another wireless communication apparatus;

wherein said channel setting unit sets the data sending/receiving channel to another channel of the multiple channels based on the beacon signal received from the other wireless communication apparatus.

2. The wireless communication apparatus according to claim 1, wherein said channel setting unit sets a channel having a lowest interference level for the wireless communication apparatus to the beacon sending channel, when the beacon signal of the other wireless communication apparatus is not detected over any channel.

3. The wireless communication apparatus according to claim 1, wherein said channel setting unit extracts a most frequently used channel on which each of a majority of wireless communication stations transmits its own beacon and sets the most frequently used channel to the beacon sending channel of the wireless communication apparatus when no wireless communication apparatus receives great interference over the most frequently used channel.

4. The wireless communication apparatus according to claim 3, wherein said channel setting unit sets a channel having an average interference level lower than interference in the beacon sending channel of the wireless communication apparatus when a wireless communication apparatus receives great interference over the most frequently used channel.

5. The wireless communication apparatus according to claim 1, wherein said channel setting unit sets a channel not frequently used by other wireless communication apparatuses and having a low interference level with respect to the wireless communication apparatus to the beacon sending channel of the wireless communication apparatus when the wireless communication apparatus requires wideband communication capacity.

6. The wireless communication apparatus according to claim 1, wherein said communication control unit transmits a request to send packet (RTS) over a channel having a low interference level at another wireless communication apparatus that serves a data sending destination, and starts data transmission in response to receiving a clear to send packet (CTS) from the other wireless communication apparatus that serves as the data sending destination.

7. The wireless communication apparatus according to claim 1, wherein said beacon generating unit generates a beacon including an information of a channel through which data communication is performed.

8. The wireless communication apparatus according to claim 1, wherein said communication control unit returns a clear to send packet (CTS) in response to receiving a request to send packet (RTS) addressed to the wireless communication apparatus or a beacon including information of a channel being used to perform data communication.

9. The wireless communication apparatus according to claim 1, wherein said communication control unit withholds transmission of data over the data sending/receiving channel for a certain period in response to receiving a request to send packet (RTS) addressed to the other wireless communication apparatus, a beacon in which the request to send packet (RTS) addressed to the other wireless communication apparatus is superimposed, or a beacon including information of another data sending/receiving channel.

10. A wireless communication apparatus which operates in a wireless communication environment including multiple channels, said wireless communication apparatus comprising:

a transmitting unit configured to send wireless data over each channel of the multiple channels;

a receiving unit configured to receive the wireless data over each channel of the multiple channels;

a channel setting unit configured to set a data sending/receiving channel in the transmitting and receiving units;

a communication control unit configured to control transmission and reception of the wireless data via the transmitting unit and the receiving unit, the communication control unit being configured to control communication operation over the multiple channels;

a beacon analyzing unit configured to analyze a beacon signal received from a peripheral wireless communication apparatus,

wherein when said communication control unit determines that a beacon sending timing of the peripheral wireless communication apparatus approaches, said communication control unit determines whether or not said communication control unit is to perform communication with the peripheral wireless communication apparatus that sent the beacon, the communication control unit omitting beacon receiving operation when beacon reception is not required, the data sending/receiving channel used by the wireless communication apparatus being changed to a different one of the multiple channels in response to analysis of the beacon signal received from the peripheral wireless communication apparatus.

11. The wireless communication apparatus according to claim 10, wherein in said wireless communication environment, a request-to-send (RTS)/clear-to-send (CTS) protocol is employed for a wireless communication apparatus serving as a data sending source by transmitting the request to send packet (RTS), and also starting data transmission in response to receiving the clear to send packet (CTS) from a wireless communication apparatus serving as a destination of data to be sent;

and wherein said communication control unit, when omitting receiving operation of the beacon from the wireless communication apparatus serving as the destination, estimates a sending timing of the RTS and CTS signals based on beacon sending timing, and performs a receiving operation in the data sending/receiving channel currently used by the wireless communication apparatus only for estimating the sending timing.

12. A wireless communication method for causing a wireless communication apparatus to operate in a wireless communication environment including multiple channels, said method comprising:

setting, in a wireless transmitting unit and in a wireless receiving unit of the wireless communication apparatus, a data sending/receiving channel of the multiple channels;

controlling transmission and reception of data via the wireless transmitting unit and the wireless receiving unit of the wireless communication apparatus;

generating, in a beacon generating unit of the wireless communication apparatus, a beacon signal including a control information concerning the data sending/receiving channel; and

analyzing, in a beacon analyzing unit of the wireless communication apparatus, a beacon signal received from a peripheral wireless communication apparatus;

wherein the data sending/receiving channel is set to another channel of the multiple channels based on the beacon signal received from the peripheral wireless communication apparatus.

13. A wireless communication method for causing a wireless communication apparatus to operate in a wireless communication environment including multiple channels, said method comprising:

setting, in a wireless transmitting unit of the wireless communication apparatus, a beacon sending channel of the wireless communication apparatus;

sending, by the wireless transmitting unit of the wireless communication apparatus, a beacon through the beacon sending channel;

controlling the beacon receiving operation, in a wireless receiving unit of the wireless communication apparatus, to receive a beacon from a peripheral wireless communication apparatus;

analyzing, in a beacon analyzing unit of the wireless communication apparatus, the beacon signal received from the peripheral wireless communication apparatus; and

setting, at the wireless transmitting unit of the wireless communication apparatus, a data communication channel;

controlling data communication, the data communication being performed via the data communication channel;

wherein the controlling beacon receiving operation includes;

comprehending that a beacon sending timing of the peripheral wireless communication apparatus approaches;

determining whether or not data communication is to be performed with the peripheral wireless communication apparatus sending the beacon; and

omitting receiving operation of the beacon when beacon reception is not to be performed, a data communication channel currently used by the wireless communication apparatus being different from the beacon sending channel.