Apparatus and method for controlling multi-channel access

• US 20090154485A1
• Filed: 05/22/2008
• Published: 06/18/2009
• Est. Priority Date: 12/18/2007
• Status: Active Grant

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Lee, Jae Yong, Kim, Nae-Soo, Pyo, Cheol Sig, Kim, Se Han, Park, Tae Joon, Kim, Byung Chul
• Granted Patent: US 7,899,074 B2
• Time in Patent Office: Days
• US Class Current: 370/438
• CPC Class Codes: H04W 72/02 Selection of wireless resources by user or terminal
• CPC Class Codes: H04W 72/20 Control channels or signalling for resource management
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

Provided is an apparatus and method for controlling multi-channel access in USN-based MAC. The multi-channel access control apparatus includes a channel scanner, a control channel preoccupier, and an available channel exchanger. The channel scanner scans at least one or more available channels among the N data channels in a Tx sensor node. The control channel preoccupier preoccupies, in the Tx sensor node, the control channel through control channel sensing and back-off and broadcasts a preamble on the control channel periodically. The available channel exchanger detects, in an Rx sensor node, the available channels available to the Tx sensor node on the basis of the received preamble, selects a channel available to the Rx sensor node among the detected available channels, and transmits information about the selected channel to the Tx sensor node.

Claims

1. An apparatus for controlling access to multiple channels including a control channel and N data channels, the apparatus comprising:

a channel scanner scanning at least one or more available channels among the N data channels in a Tx sensor node;

a control channel preoccupier preoccupying, in the Tx sensor node, the control channel through control channel sensing and back-off and broadcasting a preamble on the control channel periodically; and

an available channel exchanger detecting, in an Rx sensor node, the available channels available to the Tx sensor node on the basis of the received preamble, selecting a channel available to the Rx sensor node among the detected available channels, and transmitting information about the selected channel to the Tx sensor node.

2. The apparatus of claim 1, further comprising a data transmitter transmitting data from the Tx sensor node to the Rx sensor node after changing the channel of the Tx sensor node into the channel selected by the Rx sensor node.

3. The apparatus of claim 1, wherein the preamble comprises information about the Rx sensor node to which the Tx sensor node is to transmit data, and information about the available channels scanned by the Tx sensor node.

4. The apparatus of claim 1, wherein the Tx sensor node and the Rx sensor node basically set the channel of a transceiver to the control channel, and set the channel of the transceiver to a specific channel only in a data Tx/Rx mode.

5. The apparatus of claim 1, wherein the Tx sensor node and the Rx sensor node have a periodic wake-up period and a sleep period, and sensor nodes except the Tx sensor node in a wireless sensor network listen the control channel in the wake-up period to receive the preamble periodically.

6. The apparatus of claim 1, wherein the time period (T_CtrlSense) for the control channel sensing is the sum of the time period (T_CCA) for determining whether there is non-noise data in a transceiver and the time period (T_WaitAck) for waiting to receive an Ack message indicating the receipt of the preamble from the Rx sensor node.

7. The apparatus of claim 1, wherein the time (T_ChSense) taken for the channel scanner to scan one data channel is the sum of the time (SIFS) taken for the Tx sensor node/the Rx sensor node to change the mode of its transceiver from an Rx/Tx mode into a Tx/RX mode and the time (T_CCA) taken to determine whether there is non-noise data in the transceiver.

8. The apparatus of claim 1, wherein the back-off is the back-off of IEEE 802.11 DCF.

9. A method of controlling access to multiple channels including a control channel and N data channels in a wireless sensor network system, the method comprising:

scanning at least one or more available channels among the N data channels, by a Tx sensor node;

preoccupying the control channel through control channel sensing and back-off and broadcasting a preamble on the control channel periodically, by the Tx sensor node; and

detecting the available channels available to the Tx sensor node on the basis of the received preamble, selecting a channel available to the Rx sensor node among the detected available channels, and transmitting information about the selected channel to the Tx sensor node, by an Rx sensor node.

10. The method of claim 9, further comprising transmitting data to the Rx sensor node after changing the channel of the Tx sensor node into the channel selected by the Rx sensor node, by the Tx sensor node.

11. The method of claim 9, wherein the preamble comprises information about the Rx sensor node to which the Tx sensor node is to transmit data, and information about the available channels scanned by the Tx sensor node.

12. The method of claim 9, wherein the Tx sensor node and the Rx sensor node basically set the channel of a transceiver to the control channel, and set the channel of the transceiver to a specific channel only in a data Tx/Rx mode.

13. The method of claim 9, wherein the Tx sensor node and the Rx sensor node have a periodic wake-up period and a sleep period, and sensor nodes except the Tx sensor node in a wireless sensor network listen the control channel in the wake-up period to receive the preamble periodically.

14. The method of claim 9, wherein the time period (T_CtrlSense) for the control channel sensing is the sum of the time period (T_CCA) for determining whether there is non-noise data in a transceiver and the time period (T_WaitAck) for waiting to receive an Ack message indicating the receipt of the preamble from the Rx sensor node.

15. The method of claim 9, wherein the time (T_ChSense) taken to scan one data channel is the sum of the time (SIFS) taken for the Tx sensor node/the Rx sensor node to change the mode of its transceiver from an Rx/Tx mode into a Tx/RX mode and the time (T_CCA) taken to determine whether there is non-noise data in the transceiver.

16. The method of claim 9, wherein the back-off is the back-off of IEEE 802.11 DCF.