The invention relates to a method for transmitting data packets between an eNodeB and a mobile node (MN) when simultaneously using the HARQ protocol with soft-combining for unicast and multicast transmissions. Unicast transmissions are assigned to HARQ processes by the eNB, whereas multicast transmissions need to be assigned to a HARQ process by the MN. According to a first aspect, the soft-buffer memory is strictly separated into a unicast and multicast section, and HARQ protocol operations for unicast and multicast are independent. Due to the separation, the eNB can still correctly assign the unicast transmissions to a HARQ process. According to a second aspect, the soft-buffer is not separated but commonly used for unicast and multicast. However, in order for the eNB to still be able to correctly assign the unicast transmissions to a free HARQ process, the MN assigns the multicast transmission depending on a rule, known also to the eNB.