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

• US 9,425,926 B2
• Filed: 04/22/2015
• Issued: 08/23/2016
• Est. Priority Date: 02/01/2008
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Chun, Sung Duck, Yi, Seung June, Park, Sung Jun, Lee, Young Dae
• Primary Examiner(s): Mehrmanesh, Elmira
• Application Number:
  US14/693,549
• Publication Number:
  US 20150229449A1
• Time in Patent Office: 489 Days
• Field of Search: 714/748, 714/749
• US Class Current: 1/1
• CPC Class Codes: H04L 1/1822 involving configuration of automatic repeat request [ARQ] with parallel processes
• CPC Class Codes: H04L 1/1835 Buffer management
• CPC Class Codes: H04L 1/1861 Physical mapping arrangements for ACK signaling see also H04L5/0053
• CPC Class Codes: H04L 1/1864 ARQ related signaling H04L1/1607 takes precedence
• CPC Class Codes: H04L 1/1874 Buffer management
• CPC Class Codes: H04L 1/1896 ARQ related signaling
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04W 28/04 Error control
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal

Abstract

A method of performing a Hybrid Automatic Repeat reQuest (HARQ) operation in a wireless communication system. The method according to one embodiment includes storing a data unit into at least one of a HARQ buffer among all HARQ buffers; and flushing all HARQ buffers when a timer expires. The timer is a time alignment timer (TAT) which is used to control how long a User Equipment (UE) is considered to have an uplink time that is aligned. The stored data unit is a Medium Access Control (MAC) Protocol Data Unit (PDU). The TAT is started when a time advance command (TAC) is received from a network.

Claims

1. A method of performing a Hybrid Automatic Repeat reQuest (HARQ) operation in a wireless communication system, the method comprising:

storing a data unit into at least one of a HARQ buffer among all HARQ buffers; and

flushing all HARQ buffers when a timer expires,

wherein the timer is a time alignment timer (TAT) which is used to control how long a User Equipment (UE) is considered to have an 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 a network.

2. The method of claim 1, further comprising:

receiving one or more uplink grants from the network.

3. The method of claim 2, wherein the one or more uplink grants are used for transmitting the data unit to the network.

4. The method of claim 2, wherein the one or more uplink grants are received on a Physical Downlink Control Channel (PDCCH).

5. The method of claim 2, wherein the one or more uplink grants include at least one of uplink scheduling information, a Cell-Radio Network Temporary Identifier (C-RNTI), and a Semi-persistent Scheduling C-RNTI.

6. The method of claim 1, wherein all HARQ buffers are flushed when the UE receives a new TAC while the TAT is not running.

7. The method of claim 1, wherein all HARQ buffers are flushed when the TAT is not running regardless of the reception of the TAC by the UE.

8. The method of claim 1, wherein all HARQ buffers are flushed when the TAT is expired regardless of the reception of the TAC by the UE.

9. The method of claim 1, wherein any configured downlink assignments within all HARQ buffers are also flushed when the TAT is expired.

10. The method of claim 1, wherein a Radio Resource Control (RRC) layer entity is notified to release Physical Uplink Control Channel/Sounding Reference Symbol (PUCCH/SRS) resources when the TAT is expired.

11. A user equipment (UE) using a Hybrid Automatic Repeat reQuest (HARQ) operation in a wireless communication system, the UE comprising:

a controller configured to;

store a data unit into at least one of a HARQ buffer among all HARQ buffers, and

flush all HARQ buffers 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 an 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 a network.

12. The UE of claim 11, wherein the controller is further configured to receive one or more uplink grants from the network.

13. The UE of claim 12, wherein the one or more uplink grants are used for transmitting the data unit to the network.

14. The UE of claim 12, wherein the one or more uplink grants are received on a Physical Downlink Control Channel (PDCCH).

15. The UE of claim 12, wherein the one or more uplink grants include at least one of uplink scheduling information, a Cell-Radio Network Temporary Identifier (C-RNTI), and a Semi-persistent Scheduling C-RNTI.

16. The UE of claim 11, wherein all HARQ buffers are flushed when the UE receives a new TAC while the TAT is not running.

17. The UE of claim 11, wherein all HARQ buffers are flushed when the TAT is not running regardless of the reception of the TAC.

18. The UE of claim 11, wherein all HARQ buffers are flushed when the TAT is expired regardless of the reception of the TAC.

19. The UE of claim 11, wherein any configured downlink assignments within all HARQ buffers are also flushed when the TAT is expired.

20. The UE of claim 11, wherein a Radio Resource Control (RRC) layer entity is notified to release Physical Uplink Control Channel/Sounding Reference Symbol (PUCCH/SRS) resources when the TAT is expired.