Abstract: A transmission part transmits a packet by radio. A power detection part performs, at a given cycle, sampling of power of a spatial radio signal in a packet transmission period during which the transmission part transmits the packet. A collision detection part calculates, as an index value, at least one of the average value and the degree of variation of power of the spatial radio signal in the packet transmission period on the basis of sampled data obtained in the sampling by the power detection part. The collision detection part also determines a reference value on the basis of transmission power of the packet. The collision detection part detects whether or not collision of the packet is present by comparing the index value with the reference value.

Abstract: A transmission part transmits a packet by radio. A power detection part performs, at a given cycle, sampling of power of a spatial radio signal in a packet transmission period during which the transmission part transmits the packet. A collision detection part calculates, as an index value, at least one of the average value and the degree of variation of power of the spatial radio signal in the packet transmission period on the basis of sampled data obtained in the sampling by the power detection part. The collision detection part also determines a reference value on the basis of transmission power of the packet. Then, the collision detection part detects whether or not collision of the packet is present by comparing the index value with the reference value.