A cellular mobile radio network includes base stations, a packet control unit capable of communicating with a radio terminal via two or more base stations, and routing means for routing data between a remote unit and the packet control unit. The data transmitted by the remote unit to the terminal are stored temporarily in the packet control unit. The remote unit is adapted to receive from the terminal acknowledgments relating to transmitted data segments and to retransmit data segments that have not been acknowledged on the expiry of a retransmission time depending on the received acknowledgments. Data segments are transmitted from the remote unit to the terminal via a first base station connected to the packet control unit. In response to a request for communication transfer to a second base station connected to the packet control unit, only a portion of the data stored temporarily in the packet control unit is retransmitted to the terminal via the second base station.