A method for transmitting radio link control, RLC, data blocks performed by an RLC entity in a wireless communication apparatus comprising a protocol stack comprising a logical link control, LLC, layer and an RLC layer comprising the RLC entity, the method comprising: a) receiving at the RLC entity a first LLC protocol data unit, PDU, formed by the LLC layer and corresponding to a first Packet Flow Context, PFC, and forming a first set of RLC data blocks corresponding to the first LLC PDU; b) transmitting a subset of the first set of RLC data blocks formed by the RLC entity, wherein each transmitted RLC data block comprises at least a portion of the first LLC PDU, which portion has not previously been transmitted in an RLC data block; c) after step a), receiving at the RLC entity a second LLC PDU formed by the LLC layer and corresponding to a second PFC and forming a second set of RLC data blocks corresponding to the second LLC PDU; d) after step b), transmitting all of the second set of RLC data blocks formed by the RLC entity, wherein each transmitted RLC data block comprises at least a portion of the second LLC PDU, which portion has not previously been transmitted in an RLC data block; and e) after step d), transmitting the remainder of the first set of RLC data blocks formed by the RLC entity but not transmitted in step b), wherein each transmitted RLC data block comprises at least a portion of the first LLC PDU, which portion has not previously been transmitted in an RLC data block, further comprising: f) before step d), determining relative priorities of the first and second PFCs, wherein step d) occurs in response to determining that the second PFC has a higher priority than the first PFC, and the number of RLC data blocks in the subset transmitted in step b) is based upon a time interval between the beginning of step b) and the point at which the second PFC is determined to have a higher priority than the first PFC, wherein each RLC data block includes a temporary flow identity, TFI, field, the TFI field of each RLC data block that contains a portion of the first LLC PDU contains a value indicating a first TFI associated with the first PFC, the TFI field of each RLC data block that contains a portion of the second LLC PDU contains a value indicating a second TFI associated with the second PFC, and the first TFI does not equal the second TFI. a) receiving at the RLC entity a first LLC protocol data unit, PDU, formed by the LLC layer and corresponding to a first Packet Flow Context, PFC, and forming a first set of RLC data blocks corresponding to the first LLC PDU; b) transmitting a subset of the first set of RLC data blocks formed by the RLC entity, wherein each transmitted RLC data block comprises at least a portion of the first LLC PDU, which portion has not previously been transmitted in an RLC data block; c) after step a), receiving at the RLC entity a second LLC PDU formed by the LLC layer and corresponding to a second PFC and forming a second set of RLC data blocks corresponding to the second LLC PDU; d) after step b), transmitting all of the second set of RLC data blocks formed by the RLC entity, wherein each transmitted RLC data block comprises at least a portion of the second LLC PDU, which portion has not previously been transmitted in an RLC data block; and e) after step d), transmitting the remainder of the first set of RLC data blocks formed by the RLC entity but not transmitted in step b), wherein each transmitted RLC data block comprises at least a portion of the first LLC PDU, which portion has not previously been transmitted in an RLC data block, further comprising: f) before step d), determining relative priorities of the first and second PFCs, wherein step d) occurs in response to determining that the second PFC has a higher priority than the first PFC, and the number of RLC data blocks in the subset transmitted in step b) is based upon a time interval between the beginning of step b) and the point at which the second PFC is determined to have a higher priority than the first PFC, wherein each RLC data block includes a temporary flow identity, TFI, field, the TFI field of each RLC data block that contains a portion of the first LLC PDU contains a value indicating a first TFI associated with the first PFC, the TFI field of each RLC data block that contains a portion of the second LLC PDU contains a value indicating a second TFI associated with the second PFC, and the first TFI does not equal the second TFI.