Mobile radio communication system capable of preventing interference between time slots when propagation delay exists

A mobile radio communication system comprising a base station having a communication area, first through N-th mobile stations being capable of communicating with said base station through a radio channel carrying a communication signal when said first through N-th mobile stations are located in said communication area, where N represents a positive integer which is greater than one, and a main station connected to said base station through a communication path having a path propagation delay time, said main station communicating with said first through said N-th mobile stations by said communication signal through said base station, wherein:

• said communication signal comprises a plurality of transmission frames and a plurality of reception frames, one of said transmission frames being followed by one of said reception frames that is, in turn, followed by an additional one of said transmission frames with a predetermined period interposed between the one of said reception frames and the additional one of said transmission frame, each of said transmission frames having first primary through N-th primary time slots which are arranged in a sequential order, each of said reception frames having first subsidiary through N-th subsidiary time slots which are arranged in a sequential order;
• said main station comprising:
• detecting means for detecting whether said path propagation delay time is longer than a predetermined delay time to produce a detection signal when said path propagation delay time is longer than said predetermined delay time;
• and
• inhibiting means for inhibiting said first through said N-th mobile stations from using either one of said first primary and said N-th subsidiary time slots in said communication signal in response to said detection signal.