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

Abstract

A method of delivering protocol data units (PDUs) for a user equipment in a wireless communications system includes receiving a reordering PDU from a protocol entity. The reordering PDU has a PDU sequence. A first PDU of the PDU sequence is a segment of a PDU having a segmented side at the front, and a last PDU of the PDU sequence is a segment of a PDU having a segmented side at the end. The first PDU and a previously stored PDU segment are discarded when the reordering PDU and the previously stored PDU segment are not consecutive. All PDUs other than the first PDU and the last PDU in the reordering PDU are delivered to an upper layer entity of the protocol entity and the last PDU is stored.

1 . A method for delivering protocol data units, named PDUs hereinafter, in a user equipment of a wireless communications system, the method comprising:
 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 back-end segmented PDU;   discarding the first PDU and a previously stored PDU segment when the reordering PDU and the previously stored PDU segment are not consecutive; and   delivering all PDUs other than the first PDU and the last PDU in the reordering PDU to an upper layer protocol entity of the protocol entity and storing the last PDU.   
   
   
       2 . The method of  claim 1 , wherein discarding the first PDU and the previously stored PDU segment when the reordering PDU and the previously stored PDU segment are not consecutive comprises discarding the first PDU when no PDU segment is previously stored. 
   
   
       3 . The method of  claim 1 , wherein the previously stored PDU segment is a back-end segmented PDU. 
   
   
       4 . The method of  claim 1  further comprising:
 determining whether the first PDU and the last PDU in the reordering PDU are segmented and segmentation types thereof according to a segmentation indication header field corresponding to the reordering PDU.   
   
   
       5 . The method of  claim 1 , wherein the reordering PDU is carried in a MAC-ehs PDU. 
   
   
       6 . The method of  claim 1  further comprising:
 determining whether the reordering PDU is consecutive with the previously stored PDU segment according to a transmission sequence number header field or a segmentation indication header field corresponding to the reordering PDU.   
   
   
       7 . The method of  claim 1 , wherein the PDU sequence comprises a plurality of consecutive PDUs, and the plurality of consecutive PDUs are MAC-ehs serving data units, named MAC-ehs SDUs, comprising MAC-d PDUs or MAC-c PDUs. 
   
   
       8 . The method of  claim 1 , wherein the wireless communications system is an Evolved High Speed Packet Access system. 
   
   
       9 . 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 back-end segmented PDU; 
 discarding the first PDU and a previously stored PDU segment when the reordering PDU and the previously stored PDU segment are not consecutive; and 
 delivering all PDUs other than the first PDU and the last PDU in the reordering PDU to an upper layer protocol entity of the protocol entity and storing the last PDU. 
   
   
   
       10 . The communications device of  claim 9 , wherein discarding the first PDU and the previously stored PDU segment when the reordering PDU and the previously stored PDU segment are not consecutive comprises discarding the first PDU when no PDU segment is previously stored. 
   
   
       11 . The communications device of  claim 9 , wherein the previously stored PDU segment is a back-end segmented PDU. 
   
   
       12 . The communications device of  claim 9 , wherein the program code further comprises:
 determining whether the first PDU and the last PDU in the reordering PDU are segmented and segmentation types thereof according to a segmentation indication header field corresponding to the reordering PDU.   
   
   
       13 . The communications device of  claim 9 , wherein the reordering PDU is carried in a MAC-ehs PDU. 
   
   
       14 . The communications device of  claim 8 , wherein the program code further comprises:
 determining whether the reordering PDU is consecutive with the previously stored PDU segment according to a transmission sequence number header field or a segmentation indication header field corresponding to the reordering PDU.   
   
   
       15 . The communications device of  claim 9 , wherein the PDU sequence comprises a plurality of consecutive PDUs, wherein the plurality of consecutive PDUs are MAC-ehs serving data units, named MAC-ehs SDUs, comprising MAC-d PDUs or MAC-c PDUs. 
   
   
       16 . The communications device of  claim 9 , wherein the wireless communications system is an Evolved High Speed Packet Access system.