A radio access system connects a public switched telephone network and a subscriber unit. The subscriber unit includes a first detection part detecting a telematique signal; and a first control part transmitting a detection signal of the telematique signal on a control channel and transmitting the telematique signal on a traffic channel while bypassing a first speech coding-and-decoding part. The radio access system includes a second control part, provided between a radio base station and the public switched telephone network, transmitting the telematique signal on the traffic channel toward the public switched telephone network while bypassing a second speech coding-and-decoding part when the detection signal of the telematique signal is transmitted on the control channel.