摘要 |
A method of measuring a state of a plurality of channels is provided. The method includes transmitting to a second device test signal information needed to transmit/receive a test signal for measuring the state of the plurality of channels; receiving an information received response from the second device, indicating that the second device has received the test signal; if the information received response is received, transmitting the test signal to the second device, using the test signal information, via the plurality of channels; and receiving from the second device the state information regarding the plurality of channels which has been measured by using the test signal. |