Method of an uplink HARQ operation at an expiry of time alignment timer

Abstract

Disclosed is the radio (wireless) communication system providing a radio communication service and the terminal, and more particularly, to a method of an uplink HARQ (Hybrid Automatic Repeat reQuest) operation at an expiry of time alignment timer in an Evolved Universal Mobile Telecommunications System (E-UMTS) evolved from the Universal Mobile Telecommunications System (UMTS) or a Long Term Evolution (LTE) system.

The invention claimed is: 
     
       1. A method of processing data for a HARQ (hybrid automatic repeat request) operation in a wireless communication system, the method comprising:
 storing, by a user equipment (UE), a data unit into a corresponding HARQ buffer; and 
 flushing, by the UE, the stored data unit in the corresponding HARQ buffer and performing, by the UE, a release procedure for at least one of a physical uplink control channel (PUCCH) or sounding reference symbol (SRS) resource, when a timer expires, 
 wherein the timer is a time alignment timer (TAT) which is used to control how long a the UE (User Equipment) is considered to have has an uplink time that is aligned, 
 wherein the stored data unit in the corresponding HARQ buffer is flushed as a result of the expired time an expiration of the timer, wherein the timer is used to indicate a time duration for which the UE is considered to have has the uplink time that is aligned, 
 wherein the stored data unit is a Medium Access Control (MAC) Protocol Data Unit (PDU), and 
 wherein the TAT is started when a time advance command (TAC) is received from the network. 
 
     
     
       2. The method of  claim 1 , further comprising:
 receiving an uplink grant from a network; and generating a data unit based on the received uplink grant. 
 
     
     
       3. The method of  claim 2 , wherein the uplink grant is received on a PDCCH (Physical Downlink Control Channel). 
     
     
       4. The method of  claim 2 , wherein the uplink grant includes at least one of uplink scheduling information, a C-RNTI (Cell-Radio Network Temporary Identifier), and or a Semi-persistent Scheduling C-RNTI. 
     
     
       5. The method of  claim 2 , wherein any configured downlink assignments and the uplink grant are cleared when the timer expires. 
     
     
       6. The method of  claim 1 , wherein the corresponding HARQ buffer is one of all HARQ buffers. 
     
     
       7. The method of  claim 6 , wherein the all HARQ buffers are flushed when the timer expires. 
     
     
       8. The method of  claim 1 , wherein a PUCCH/SRS resources are released when the timer expires RRC (Radio Resource Control) layer is notified to release the at lease one of the PUCCH or SRS resource. 
     
     
       9. The method of  claim 7 , wherein a RRC (Radio Resource Control) layer is notified to release the PUCCH/SRS resources. 
     
     
       10. A user equipment (UE) using configured to use a HARQ (Hybrid Automatic Repeat reQuest) operation in a wireless communication system, the UE comprising:
 a controller configured to:
 store a data unit into a corresponding HARQ buffer; and 
 flush the stored data unit in the corresponding HARQ buffer and perform a release procedure for at least one of a physical uplink control channel (PUCCH) or sounding reference symbol (SRS) resource, when a timer expires, 
 wherein the timer is a time alignment timer (TAT) which is used to control how long the UE is considered to have has an uplink time that is aligned, 
 wherein the stored data unit in the corresponding HARQ buffer is flushed as a result of the expired time an expiration of the timer, wherein the timer is used to indicate a time duration for which the UE is considered to have the uplink time that is aligned, 
 wherein the stored data unit is a Medium Access Control (MAC) Protocol Data Unit (PDU), and 
 wherein the TAT is started when a time advance command (TAC) is received from the network. 
 
 
     
     
       11. The user equipment (UE) of  claim 10 , wherein the controller is further configured to: receive an uplink grant from a network, and generate a data unit based on the received uplink grant. 
     
     
       12. The user equipment (UE) of  claim 11 , wherein the uplink grant is received on a PDCCH (Physical Downlink Control Channel). 
     
     
       13. The user equipment (UE) of  claim 11 , wherein the uplink grant includes at least one of uplink scheduling information, a C-RNTI (Cell-Radio Network Temporary Identifier), and a Semi-persistent Scheduling C-RNTI. 
     
     
       14. The user equipment (UE) of  claim 11 , wherein any configured downlink assignments and the uplink grant are cleared when the timer expires. 
     
     
       15. The user equipment (UE) of  claim 10 , wherein the corresponding HARQ buffer is one of all HARQ buffers. 
     
     
       16. The user equipment (UE) of  claim 15 , wherein the all HARQ buffers are flushed when the timer expires. 
     
     
       17. The user equipment (UE) of  claim 10 , wherein a PUCCH/SRS resources are released when the timer expires RRC (Radio Resource Control) layer is notified to release the at least one of the PUCCH or SRS resource. 
     
     
       18. The user equipment (UE) of  claim 17 , wherein a RRC (Radio Resource Control) layer is notified to release the PUCCH/SRS resources. 
     
     
       19. The method of claim 1, wherein the data unit is used for a retransmission when the retransmission for the data unit is indicated to the UE.  
     
     
       20. The user equipment (UE) of claim 10, wherein the data unit is used for a retransmission when the retransmission for the data unit is indicated to the UE.