Abstract: If the location cell of a calling subscriber or a called subscriber belongs to a set of special cells at the beginning of a call, a cheaper tariff is applied. According to the invention, the charging criterion is updated in the beginning and during the call. If a subscriber roams from the area of a public network cell to the set of special cells, the cell information propagates to the MSC of the called subscriber. The MSC and/or service control point compares this cell information with the set of special cells and determines that the new cell of the called subscriber belongs to the special cells, due to which the tariff can be changed. Information on the called subscriber's changed cell type is transmitted to the mobile switching centre of the calling subscriber.

Abstract: Charging criteria in a mobile telephone network may be improved by choosing one cell or a group of several cells of the mobile telephone network as a group of special cells. The cells of the group may be located in the areas of different MSC's. When a call is being established, a service control point SCP located in an intelligent network analyses whether the location cell of a calling subscriber and that of a called subscriber belong to the group of special cells. Subscriber numbers of the subscribers may also be taken into account. The service control point SCP then applies a special charging criterion determined for the group.

Abstract: The charging criteria for determining the price for a call between two subscribers in a cellular mobile telephone network, is improved. One cell, or a group consisting of several cells, is chosen as a group of special cells. Upon establishing a call, a mobile switching center of a calling subscriber analyzes whether the location cell of the calling subscriber and/or that of the called subscriber are members of a group of special cells. If this is the case, the charging criteria determined for the group will be applied. Additionally, private branch exchanges may also be connected to the mobile switching center.