PURPOSE: To contrive to reduce data collection time by forming a period of a transmission standby between a receptible state of a radio equipment and a transmittable state and switching the frequency of the oscillator during the period from the transmission frequency from the reception local state in a polling system using the synthesizer radio equipment.

CONSTITUTION: When a radio equipment 20 of a slave station receives a data from a base station at a reception section 25 through a transmission/reception common antenna 23 and a transmission/reception changeover switch 24, the reception data is fetched in a MPU 11 and when a polling signal is detected, the frequency switching request is given at first and the MPU 21 changes the voltage given to a VCO 26 to change the oscillating frequency from the recep tion local to the transmission frequency. Then the MPU 11 decides it as the data sending timing based on the reception point of time of the polling signal as the reference, then a transmission request is given, the MPU 21 supplies power to the transmission section 27 to switch the switch 24 to the position of the sender side at the same time.