Method and apparatus for applying a time alignment timer in a wireless communication system using a carrier aggregation technique

• US 9,681,406 B2
• Filed: 09/21/2015
• Issued: 06/13/2017
• Est. Priority Date: 05/10/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Kim, Soeng Hun, Jeong, Kyeong In, Ng, Boon Loong, Jang, Jae Hyuk, Van Lieshout, Gert-Jan
• Primary Examiner(s): Javaid, Jamal
• Assistant Examiner(s): Soe, Kyaw Z
• Application Number:
  US14/860,068
• Publication Number:
  US 20160021628A1
• Time in Patent Office: 631 Days
• Field of Search: 370328
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04L 5/0098 Signalling of the activation or deactivation of component carriers, subcarriers or frequency bands
• CPC Class Codes: H04W 36/04 Reselecting a cell layer in multi-layered cells
• CPC Class Codes: H04W 48/12 using downlink control channel
• CPC Class Codes: H04W 56/0005 synchronizing of arrival of multiple uplinks
• CPC Class Codes: H04W 56/001 Synchronization between nodes
• CPC Class Codes: H04W 56/0045 compensating for timing error by altering transmission time
• CPC Class Codes: H04W 64/00 Locating users or terminals or network equipment for network management purposes, e.g. mobility management
• CPC Class Codes: H04W 72/0446 Resources in time domain, e.g. slots or frames
• CPC Class Codes: H04W 72/23 in the downlink direction of a wireless link, i.e. towards a terminal
• CPC Class Codes: H04W 74/0833 Random access procedures, e.g. with 4-step access
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

The present invention involves defining the operation of a terminal for determining which time alignment timer is to be applied to a certain condition when specific time alignment timers operate for each carrier-wave group in the event a wireless communication system uses a carrier aggregation technique. According to the present invention, a terminal may perform communication without malfunctions using a time alignment timer suitable for a certain condition. In detail, a method for a terminal to operate a time alignment timer according to the present invention comprises the steps of: receiving, from a base station, a message including a timing advance command and an index on a timing advance group (TAG); and operating the time alignment timer for the TAG, wherein the index has a value of 00 when the TAG includes a first cell. In the meantime, a method for a terminal to operate a time alignment timer according to the present invention comprises the steps of: operating a first time alignment timer for a first timing advance group (TAG) including a first cell; operating a second time alignment timer upon receipt of a timing advance command for a second TAG that does not include the first cell; and, if the first time alignment timer has expired, deeming the second time alignment timer to also be expired. In addition, a method for a base station to control a time alignment timer according to the present invention comprises the steps of: determining whether or not an uplink timing of a terminal needs correction; and transmitting a message including a timing advance command and an index on a timing advance group (TAG), wherein the index has a value of 00 when the TAG includes a first cell.

Claims

1. A method by a base station in a wireless communication system, the method comprising:

transmitting a system information block including a first timing alignment timer (TAT) which is applicable to a plurality of terminals included in a primary cell;

transmitting a radio resource control (RRC) message including a second TAT for the primary cell of a terminal included in a primary timing advance group (PTAG) and a third TAT for a secondary cell of the terminal included in a secondary TAG (STAG) with an identity of the STAG to the terminal;

receiving a random access preamble from the terminal; and

transmitting a message including a timing advance command (TAC) and an identity of a TAG to the terminal,

wherein the identity of the TAG is set to 00 when the TAG includes the primary cell.

2. The method of claim 1, wherein the message is one of a medium access control (MAC) control element (CE) message and a radio resource control message.

3. The method of claim 1,

wherein the second TAT is applied instead of the first TAT by the terminal.

7. The method of claim 1,

wherein each TAT is used to control how long the terminal considers uplink timing of at least one cell belonging to the each TAG is aligned.

8. The method of claim 1,

wherein the second TAT for the PTAG is transmitted without an identity of the PTAG.

4. A base station in a wireless communication system, the base station comprising:

a transceiver configured to transmit and receive a signal; and

a controller configured to;

transmit a system information block including a first timing alignment timer (TAT) which is applicable to a plurality of terminals included in a primary cell,

transmit a radio resource control (RRC) message including a second TAT for the primary cell of the terminal included in a primary timing advance group (PTAG) and a third TAT for a secondary cell of the terminal included in a secondary TAG (STAG) with an identity of the STAG to the terminal,

receive the random access preamble from the terminal,

transmit a message including a timing advance command (TAC) and an identity of a TAG to the terminal,

wherein the identity of the TAG is set to 00 when the TAG includes the primary cell.

5. The base station of claim 4, wherein the message is one of a medium access control (MAC) control element (CE) message and a radio resource control message.

6. The base station of claim 4,

wherein the second TAT is applied instead of the first TAT by the terminal.

9. The base station of claim 4,

wherein each TAT is used to control how long the terminal considers uplink timing of at least one cell belonging to the each TAG is aligned.

10. The base station of claim 4,

wherein the second TAT for the PTAG is transmitted without an identity of the PTAG.