A method, system and transmitting side protocol entity is disclosed for sending packet data units for unacknowledged mode services in a mobile communication network. A retransmission parameter is set to a desired value in order to prevent retransmission of packet data units in a handover situation. The transmitting side acknowledged mode radio link control entity purges from the retransmission buffer based on status reports from a user equipment. The packet data units that have been acknowledged by user equipment. A status report includes the sequence number of the highest packet data unit expected by the user equipment, and therefore the status report indicates the sequence number of the radio link control packet data units that have been received at the user equipment (either correctly or incorrectly). All the remaining packet data units in the retransmission buffer are scheduled for transmission and transmitted to the new node.