Wireless transmission device and transmission channel setting method thereof, wireless transmission / reception system including the wireless transmission device, and transmission / reception channel setting method thereof

摘要

PPROBLEM TO BE SOLVED: To provide a radio transmitter and method for setting its transmitting channel and a radio transmission and reception system and method for setting its transmitting and receiving channels which can quickly return to a communicating state when the power is supplied or at the time of returning from interference radio waves of other stations and noise or the like and from a power saving mode, or the like. PSOLUTION: A communication unit performs carrier sensing of a full frequency channel when the power is supplied and finds the current clear channel fc by a clear channel calculating means 32. When a frequency channel is set, a frequency channel used in the preceding communication is stored as a frequency channel fa of a first candidate and a clear channel fc found in the preceding communication is stored as a frequency channel fb of a second candidate. When connection is attempted by the frequency channel fa to fail in communication establishment, the second candidate (fb) is advanced to the first candidate (fa) to set the current clear channel as a next candidate. When communication is restarted, a clear channel fc is newly found, always updating a clear channel. PCOPYRIGHT: (C)2006,JPO&NCIPI