| 摘要 |
PURPOSE:To economically use a portable terminal in a public switching network even in a private branch switching network with respect to the portable terminal accommodation system to the public switching network and the private branch switching network. CONSTITUTION:In this communication system provided with a public switching network 100 provided with the position register function of portable terminals, a private branch switching network 200, and a portable terminal 300 which can communicate with any switching network, the private branch switching network 200 is provided with a public network position registration storage means 202 and a position registration request means 203. The state that the portable terminal 300 is accomodated in the public switching network 100 and the position registration is already requested to the network 100 through its own private branch switching network is stored in the means 202, and the means 203 requests the position registration to the private branch switching network 200 and the public switching network 100 if the portable terminal 300 requesting the position registration is stored in the public switching network 200 but is not stored in the means 202, and the means 203 requests the position registration to only the network 200 if this portable terminal 300 is stored in the network 100 and is already stored in the means 202. |
