PURPOSE: To relieve the load of position registration processing with respect to an exchange by stopping the processing of position registration during other optional setting then it is discriminated that a mobile set is moving at a high speed thereby reducing the traffic.

CONSTITUTION: This exchange is provided with a mobile terminal equipment 1 and radio base stations 2a-2d form speech zones 3a-3d respectively. Then each of the radio base stations 2a-2d sends intermittently a position registration start signal including a zone ID allocated specifically to the mobile terminal equipment. Then an exchange 4 accommodates the radio base stations 2a-2d to control the radio base stations 2-2d and the mobile terminal equipment 1. When the terminal equipment detects high speed moving, the terminal equipment stops the usual position registration request and does not send the position registration request signal to the exchange till no high speed moving is detected. In the case of exchange for an incoming call, a registration part of a table corresponding to each terminal equipment for high speed moving is referenced and when high speed moving is registered, it is informed to a caller.