Patent ID: 8254339

Claim:
A memory release method in a receiver apparatus of HSDPA (High Speed Downlink Packet Access) data transmission scheme, comprising: receiving a plurality of data units from a transmitter apparatus, wherein each of the plurality of data units include a sequence number; storing the received plurality of data units in each of a plurality of reordering buffers of the receiver apparatus; reordering, by each of the plurality of reordering buffers, each of the plurality of data units based on the sequence numbers included in each of the plurality of data units; ranking each of the plurality of reordering buffers on the basis of Quality of Service (QoS) information indicating a traffic class of the data units stored in the reordering buffers; judging that said reordering buffers need memory-release; determining a size of memory to be released in accordance with an operation mode of RLC (Radio Link Control) by determining to release a first size of memory when the operation mode of RLC is AM (Acknowledge Mode) and determining to release a second size of memory when the operation mode of RLC is UM (Unacknowledge Mode); and releasing the determined size of memory from a lowest ranked one of said ranked reordering buffers when it is judged that memory-release is necessary.