Abstract: When a mobile unit (21(p)) initiates a call for communication in a first cell of a first cell set identified in an overall service area of base stations or cell sites by a first area identifier and moves into a second cell of a second cell set identified by a second area identifier, the first area identifier is transferred (S3(n1)) from a first station (17(n1)) corresponding to the first cell to a second station (17(n2)) corresponding to the second cell. When the unit terminates the communication while present in the second cell, the second area identifier is transmitted (S3(n2)) to a central office (11) and to the unit if the second area identifier is judged (S2(n2)) different from the first area identifier. Each station therefore comprises a transferring and a transmitting arrangement. Preferably, a channel disconnection signal (43) carries such a second area identifier. The communication can be terminated at a counterpart unit.