Multiple communication system, exchange, and terminal device

摘要

A multiple communication system is comprised of a plurality of communication networks including mobile communication networks. The plurality of communication networks are connected to each other by exchanges. Terminal devices including mobile terminal devices belong to respective communication networks and can communicate with each other via the exchange in the communication network in which the terminal device is accommodated. When a call is originated, the terminal device sends a designated call incoming code for specifying a destination mobile communication network for connection. The exchange connects to the mobile communication network corresponding to the designated incoming call code received from the terminal device.