Method and Apparatus of Delivering Protocol Data Units for a User Equipment in a Wireless Communications System

A communications device used in a wireless communications system for delivering protocol data units, named PDUs hereinafter, the communications device comprising:

• a control circuit for realizing functions of the communications device;
• a central processing unit coupled to the control circuit for executing a program code to operate the control circuit;
• and
• a memory coupled to the central processing unit for storing the program code;
• wherein the program code comprises:
• receiving a reordering PDU from a protocol entity, wherein the reordering PDU comprises a PDU sequence, a first PDU of the PDU sequence is a front-end segmented PDU, and a last PDU of the PDU sequence is a complete PDU;
• concatenating the first PDU with a previously stored PDU segment to form a complete PDU for delivering to an upper layer protocol entity of the protocol entity when the reordering PDU and the previously stored PDU segment are consecutive;
• and
• delivering all PDUs other than the first PDU in the reordering PDU to the upper layer protocol entity.