Abstract: A serving cell change method and apparatus is provided for efficiently performing the serving cell change in a mobile communication system. The UE receives a cell change control information including an activation time from a serving cell, when a downlink channel status of the serving cell is inferior to a downlink channel status of a target cell, reports a measurement result to the serving cell while performing data communication with the serving cell, monitors receipt of a cell change indicator transmitted by the target cell before the expiration of the activation time while performing the data communication with the serving cell, and when the cell change indicator is received, communicates data with the target cell by sending an acknowledgement in response to the cell change indicator and switching to the target cell.

Abstract: A method is described for adapting the size of data for a future Transmission Time Interval (TTI) by a User Equipment (UE), wherein all the Media Access Control (MAC)-d flows are grouped and stored in different lists based on a type of grants associated with the MAC-d flows, ability of a MAC-d flow to be multiplexed with another MAC-d flow from a list, and data availability in a logical channel mapped onto a MAC-d flow in the current TTI. The E-TFC is then selected by the UE for the future TTI using the MAC-d flow having the highest power offset in a consolidated list including the grouped MAC-d flows. The size of the data is thereby adapted using the selected E-TFC. Further disclosed is a method for generating RLC PDUs by the UE for the future TTI using the variation in the scheduled grant for the UE and the size of the data adapted for the future TTI.

Abstract: A method for enhancing Layer 2 for High Speed Packet Access uplink. The method includes segmenting a Radio Link Control (RLC) Service Data Unit (SDU) into plurality of Medium Access Control (MAC) i/is Packet Data Units (PDUs), a size of which is limited to a Maximum RLC PDU Size (MRPS) and indicating RLC PDUs of the same size by a single Length (L) entry and indicating the RLC PDUs by a (size, number) pair in the L entry.