Even if the number of subscribers increases, such increased number of the subscribers can be handled by a mobile communication system without increasing the equipment of the system, so that the assignment of the radio resources should not be constrained due to excessive location registration. A MSC of a mobile communication system determines a location registration period for each of mobile terminals according to subscriber information retained by HLR or VLR. In this case, a relatively long location registration period is set for the mobile terminal incorporated into a vending machine and having a weak mobility, as compared to the mobile terminal that frequently moves. This eliminates the wasteful operation of performing the location registration in a uniform period with the mobile terminal that frequently moves, so as to avoid the situation in which the assignment of the radio resources are constrained.