Efficient paging control is achieved in a communication system that selectively provides one of communication services implemented by integrating a plurality of communication systems. Before transmitting a downlink signal to a terminal, a gateway requests each of the communication systems to transmit a paging signal to the terminal. Receiving the paging signals transmitted from the communication systems, the terminal selects a communication system A with the lowest communication cost in accordance with communication cost information contained in the paging signal. The terminal sends a request for connection to the selected communication system A. As a result, the communication system A transmits the downlink signal to the terminal.