A method of HARQ process configuration in a mobile communication system, wherein a plurality of HARQ processes are transmitted from a transmitter to a receiver comprising the step of configuring a plurality of HARQ processes of unrestricted use for data flows having different priorities and the step of pre-configuring at least one reserved HARQ process for specific data flows of high priority. According to another embodiment, instead of a reserved HARQ process, an additional HARQ process is pre-configured.