To surely continue/disconnect a call in the terminal equipment of a biderectional communication system for which a frame to which an error detection code is added and the frame to which it is not added coexist in reception data.

A counter N is provided. By the counter N, the number of the frames at the time of successively receiving the frames to which the error detection code is not added is counted (step 632). When the counted value becomes a prescribed value, the transmission of the frame to which the error detection code is added is requested to a base station (step 635). When the frame to which the error detection code is added can not be received even by the request, the call is disconnected (step 641).