DEVICES FOR MULTI-CELL COMMUNICATIONS

• US 20130028198A1
• Filed: 07/27/2011
• Published: 01/31/2013
• Est. Priority Date: 07/27/2011
• Status: Active Grant

• Current Assignee: Sharp Kabushiki Kaisha (Hon Hai Precision Industry Co., Ltd.)
• Original Assignee: Sharp Laboratories of America Incorporated (Hon Hai Precision Industry Co., Ltd.)
• Inventors: Yamada, Shohei
• Granted Patent: US 9,949,221 B2
• Time in Patent Office: Days
• US Class Current: 370/329
• CPC Class Codes: H04W 48/20 Selecting an access point
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks

Abstract

A User Equipment (UE) configured for multi-cell communications is disclosed. The UE includes a processor and instructions stored in memory that is in electronic communication with the processor. The UE determines a primary cell (PCell) with a corresponding PCell time alignment timer. The UE also determines a secondary cell (SCell) with a corresponding SCell time alignment timer. The UE further determines whether the PCell time alignment timer is expired. The UE additionally sets the SCell time alignment timer as expired if the PCell time alignment timer is expired.

Claims

1. A User Equipment (UE) configured for multi-cell communications, comprising:

a processor;

memory in electronic communication with the processor;

instructions stored in the memory, the instructions being executable to;

determine a primary cell (PCell) with a corresponding PCell time alignment timer;

determine a secondary cell (SCell) with a corresponding SCell time alignment timer;

determine whether the PCell time alignment timer is expired; and

set the SCell time alignment timer as expired if the PCell time alignment timer is expired.

2. The UE of claim 1, wherein the SCell time alignment timer has an expiry value of infinity.

3. The UE of claim 1, wherein the instructions are further executable to determine whether the PCell time alignment timer is stopped due to an unsuccessful random access procedure.

4. The UE of claim 3, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the instructions are further executable to maintain the SCell time alignment timer.

5. The UE of claim 3, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the instructions are further executable to stop the SCell time alignment timer.

6. The UE of claim 3, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the instructions are further executable to:

stop the SCell time alignment timer, wherein the SCell is a designated SCell;

flush a hybrid automatic repeat request (HARQ) buffer for any other SCell that shares uplink transmission timing with the designated SCell;

avoid notifying radio resource control (RRC) to release a physical uplink shared channel (PUCCH) or sounding reference signal (SRS); and

clear any configured downlink assignment and any uplink grant for any other SCell that shares uplink transmission timing with the designated SCell.

7. The UE of claim 3, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the instructions are further executable to:

set as expired the SCell time alignment timer, wherein the SCell is a designated SCell;

flush a hybrid automatic repeat request (HARQ) buffer for any other SCell that shares uplink transmission timing with the designated SCell;

avoid notifying radio resource control (RRC) to release a physical uplink shared channel (PUCCH) or sounding reference signal (SRS); and

clear any configured downlink assignment and any uplink grant for any other SCell that shares uplink transmission timing with the designated SCell.

8. The UE of claim 1, wherein an Msg3 buffer does not include a media access control (MAC) service data unit (SDU) in a MAC protocol data unit (PDU) for transmission in the SCell.

9. A method for enabling multi-cell communications on a user equipment (UE), comprising:

determining a primary cell (PCell) with a corresponding PCell time alignment timer;

determining a secondary cell (SCell) with a corresponding SCell time alignment timer;

determining whether the PCell time alignment timer is expired; and

setting the SCell time alignment timer as expired if the PCell time alignment timer is expired.

10. The method of claim 9, wherein the SCell time alignment timer has an expiry value of infinity.

11. The method of claim 9, further comprising determining whether the PCell time alignment timer is stopped due to an unsuccessful random access procedure.

12. The method of claim 11, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the method further comprises maintaining the SCell time alignment timer.

13. The method of claim 11, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the method further comprises stopping the SCell time alignment timer.

14. The method of claim 11, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the method further comprises:

stopping the SCell time alignment timer, wherein the SCell is a designated SCell;

flushing a hybrid automatic repeat request (HARQ) buffer for any other SCell that shares uplink transmission timing with the designated SCell;

avoiding notifying radio resource control (RRC) to release a physical uplink shared channel (PUCCH) or sounding reference signal (SRS); and

clearing any configured downlink assignment and any uplink grant for any other SCell that shares uplink transmission timing with the designated SCell.

15. The method of claim 11, wherein if the PCell time alignment timer is stopped due to an unsuccessful random access procedure, the method further comprises:

setting as expired the SCell time alignment timer, wherein the SCell is a designated SCell;

flushing a hybrid automatic repeat request (HARQ) buffer for any other SCell that shares uplink transmission timing with the designated SCell;

avoiding notifying radio resource control (RRC) to release a physical uplink shared channel (PUCCH) or sounding reference signal (SRS); and

clearing any configured downlink assignment and any uplink grant for any other SCell that shares uplink transmission timing with the designated SCell.

16. The method of claim 9, wherein an Msg3 buffer does not include a media access control (MAC) service data unit (SDU) in a MAC protocol data unit (PDU) for transmission in the SCell.

17. A non-transitory, tangible computer-readable medium for enabling multi-cell communications, comprising executable instructions for:

determining a primary cell (PCell) with a corresponding PCell time alignment timer;

determining a secondary cell (SCell) with a corresponding SCell time alignment timer;

determining whether the PCell time alignment timer is expired; and

setting the SCell time alignment timer as expired if the PCell time alignment timer is expired.

18. The computer-readable medium of claim 17, wherein the SCell time alignment timer has an expiry value of infinity.

19. The computer-readable medium of claim 17, further comprising executable instructions for determining whether the PCell time alignment timer is stopped due to an unsuccessful random access procedure.

20. The computer-readable medium of claim 17, wherein an Msg3 buffer does not include a media access control (MAC) service data unit (SDU) in a MAC protocol data unit (PDU) for transmission in the SCell.