Patent ID: 7899074

Claim:
An apparatus for controlling access to multiple channels including a control channel and N data channels, the apparatus comprising: 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, and wherein the time period (T.sub.CtrlSense) for the control channel sensing is the sum of the time period (T.sub.CCA) for determining whether there is non-noise data in a transceiver and the time period (T.sub.WaitAck) for waiting to receive an Ack message indicating the receipt of the preamble from the Rx sensor node.