Method and apparatus of handling user equipment category in wireless communication system

• US 9,204,289 B2
• Filed: 02/13/2012
• Issued: 12/01/2015
• Est. Priority Date: 02/15/2011
• Status: Active Grant

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Jang, Jae Hyuk, Kim, Soeng Hun, Van Lieshout, Gert-Jan, Cho, Joon Young
• Primary Examiner(s): Oveissi, David
• Application Number:
  US13/371,901
• Publication Number:
  US 20120207130A1
• Time in Patent Office: 1,387 Days
• US Class Current: 1/1
• CPC Class Codes: H04W 76/27 Transitions between radio resource control [RRC] states
• CPC Class Codes: H04W 8/24 Transfer of terminal data

Abstract

A User Equipment (UE) category handling method and an apparatus for handling late version UE category attached to an early release version network in a Long Term Evolution (LTE) system are provided. A communication method includes transmitting a terminal capability report message including multiple terminal categories, receiving a Radio Resource Control (RRC) connection reconfiguration message including a terminal category to be used by the terminal according to serving base station of the terminal, and communicating with the network using the terminal category received from the network. The UE category handling method and apparatus of the present invention allows the UE to report a network-adaptive UE category, thereby avoiding soft buffer problem caused by version information mismatch and facilitating communication with the network without malfunctioning.

Claims

1. A transmission method of a terminal in a mobile communication system, the transmission method comprising:

transmitting a plurality of terminal categories, each of which corresponds to one of at least two category groups;

receiving transmission mode information corresponding to one of the plurality of terminal categories;

if the transmission mode information includes a first transmission mode, identifying a total number of soft channel bits as a first value based on the first transmission mode, else identifying the total number of soft channel bits as a second value; and

transmitting data based on the transmission mode information,

wherein the first value is greater than the second value,

wherein the plurality of terminal categories are transmitted through a terminal capability message, and

wherein the terminal capability message comprises a first terminal category field indicating a first terminal category and a second terminal category field indicating a second terminal category, each of the first and second terminal categories being selected from one of the at least two category groups.

2. The method of claim 1, wherein the transmission mode information includes transmission mode 9 as the first transmission mode if a serving base station of the terminal is an enhanced version network.

3. The method of claim 2, wherein the transmission mode 9 supports up to 8 layers for transmission, transmits a precoded modulation reference signal, and uses a new downlink control information format.

4. The method of claim 1, wherein the transmission mode information is received through a radio resource control (RRC) connection reconfiguration message.

5. The method of claim 1, wherein a soft buffer size NIR corresponding to the total number of soft channel bits is obtained using an equation:

6. The method of claim 1, further comprising receiving, when a handover is triggered, a handover command message from a target cell including information on the terminal category to be used in the target cell.

7. The method of claim 1, wherein the transmission mode information corresponds to a type of serving base station of the terminal.

8. A terminal for transmitting data to a network in a mobile communication system, the terminal comprising:

a transceiver configured to communicate signals with the network; and

a controller configured to control transmission of a plurality of terminal categories, each of which corresponds to one of at least two category groups, control reception of transmission mode information corresponding to one of the plurality of terminal categories, if the transmission information is a first transmission mode, identify a total number of soft channel bits as a first value based on the first transmission mode, else identify the total number of soft channel bits as a second value, and control transmission of data based on the transmission mode information,

wherein the first value is greater than the second value,

wherein the plurality of terminal categories are transmitted through a terminal capability message, and

wherein the terminal capability message comprises a first terminal category field indicating a first terminal category and a second terminal category field indicating a second terminal category, each of the first and second terminal categories being selected from one of the at least two category groups.

9. The terminal of claim 8, wherein the transmission mode information includes transmission mode 9 as the first transmission mode if a serving base station of the terminal is an enhanced version network.

10. The terminal of claim 9, wherein the transmission mode 9 supports up to 8 layers for transmission, transmits a precoded modulation reference signal, and uses a new downlink control information format.

11. The terminal of claim 8, wherein the transmission mode information is received through a radio resource control (RRC), connection reconfiguration message.

12. The terminal of claim 8, wherein a soft buffer size NIR corresponding to the total number of soft channel bits is obtained using an equation:

13. The terminal of claim 8, wherein the controller controls, if a handover is triggered, reception of a handover command message from a target cell including information on the terminal category to be used in the target cell.

14. The terminal of claim 8, wherein the transmission mode information corresponds to a type of serving base station of the terminal.