A base station (109) of a cellular communication system (100) comprises an RNC interface (301) which receives a radio link handover initiation message for a radio link from a radio network controller (113). A switch delay processor (309) determines a handover switch delay and a characteristics processor (311) sets a characteristic of a radio link handover acknowledge message in response to the handover switch delay. A message generator (313) generates a radio link handover acknowledge message and transmits this to the radio network controller (113). The radio network controller (113) comprises an RNC handover controller (125) which determines a radio link handover switch time in response to the characteristic. A better timing of the radio link handover may be achieved. The invention may e.g. be applicable to an HSDPA (High Speed Downlink Packet Access) service of a UMTS (Universal Mobile Telecommunication System) cellular communication system and may reduce the amount of data discarded from buffers during an HSDPA handover.