| 摘要 |
PURPOSE:To prevent ineffective retention of a radio channel by allowing a base station to inform a busy signal during the use of channel and a collision signal at collision, to a radio equipment. CONSTITUTION:When a mobile set 21 starts communication, a communication request signal with a preamble at the head is transmitted to a base station 1. When the base station 1 detects the preamble, the station uses an outgoing channel and transmits a busy signal to all mobile sets 21, 22. In receiving the busy signal, the mobile set 21 during communication continues the communication and the other mobile set 22 transmitting communication request from now withdraws the transmission. When plural mobile sets 21, 22 transmit the communication request at the same time, the base station 1 detecting it by means of pattern deformation of the preamble or the like transmits the collision signal to the outgoing channel. The mobile sets 21, 22 receiving the collision signal stop immediately transmission, and send out the communication request signal again after back-off is executed. |
