Abstract: A mobile communication system comprises a switching station, base stations to constitute respective zones, and mobile stations moving in a service zone formed by the communication zones. Plural base stations exist in one communication zone, and one specific channel among control communication channels is allocated to one of the base stations. The mobile station transmits general communication request using one specific channel during request of the general communication. Or the control communication channel is allocated only to one station among the base stations. The mobile station has a circuit for measuring the signal-to-noise ratio, and if the signal-to-noise ratio is deteriorated, a signal indicating this state is transmitted to the switching station.