Performing a random access procedure in a carrier aggregation with at least one SCell operating in an unlicensed spectrum

• US 10,455,622 B2
• Filed: 04/06/2016
• Issued: 10/22/2019
• Est. Priority Date: 04/10/2015
• Status: Active Grant

• Current Assignee: LG Electronics, Inc. (LG Corporation)
• Original Assignee: LG Electronics, Inc. (LG Corporation)
• Inventors: Lee, Sunyoung, Yi, Seungjune
• Primary Examiner(s): Moore, Ian N
• Assistant Examiner(s): Le, Brian T
• Application Number:
  US15/555,475
• Publication Number:
  US 20180049243A1
• Time in Patent Office: 1,294 Days
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 5/001 the frequencies being arranged in component carriers
• CPC Class Codes: H04W 16/14 Spectrum sharing arrangements between different networks
• 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: H04W 88/02 Terminal devices
• CPC Class Codes: H04W 88/16 Gateway arrangements

Abstract

A method and a device for performing a random access procedure in a carrier aggregation with at least one SCell operating in an unlicensed spectrum are disclosed. The method includes: configuring a timer; starting the timer when the UE initiates a Random Access Preamble (RAP) transmission procedure on a first cell; and stopping the RAP transmission procedure on the first cell if a Random Access Response (RAR) for the RAP transmission procedure on the first cell is not received until the timer expires.

Claims

1. A method for a User Equipment (UE) operating in a wireless communication system, the method comprising:

initiating a Random Access Preamble (RAP) transmission procedure on an unlicensed Secondary Cell (SCell), wherein a timer is started when the UE initiates the RAP transmission procedure on the unlicensed SCell;

stopping the RAP transmission procedure on the unlicensed SCell when a certain condition is met, wherein the certain condition is met when the RAP has not been transmitted within a predefined number of subframes from a subframe where the timer expires, even when a number of the RAP transmissions is less than a threshold value; and

transmitting, to a Base Station (BS), information on the UE stopping the RAP transmission procedure on the unlicensed SCell through a cell configured for the UE when the RAP transmission procedure on the unlicensed SCell is stopped.

2. The method according to claim 1, wherein the cell configured for the UE is a or Primary Cell (PCell), a Primary Secondary Cell (PSCell), any cell among serving cells belonging to the BS on a licensed spectrum, or any cell among cells on an unlicensed spectrum and not occupied by other transmitters.

3. The method according to claim 1, wherein the information is transmitted via Physical layer (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), or Radio Resource Control (RRC) signal.

4. The method according to claim 1, wherein the information includes an identification of the unlicensed SCell on which the RAP transmission procedure is stopped, or an identification of the RAP of which the transmission on the unlicensed SCell is stopped.

5. The method according to claim 1, wherein the UE initiates the RAP transmission procedure on the unlicensed SCell when a Physical Downlink Control Channel (PDCCH) order is received from the BS.

6. A User Equipment (UE) operating in a wireless communication system, the UE comprising:

a Radio Frequency (RF) module; and

a processor operably coupled with the RF module and configured to;

initiate a Random Access Preamble (RAP) transmission procedure on an unlicensed Secondary Cell (SCell), wherein a timer is started when the processor initiates the RAP transmission procedure on the unlicensed SCell;

stop the RAP transmission procedure on the unlicensed SCell when a certain condition is met, wherein the certain condition is met when the RAP has not been transmitted within a predefined number of subframes from a subframe where the timer expires, even when a number of the RAP transmissions is less than a threshold value; and

transmit, to a base station (BS), information on the processor stopping the RAP transmission procedure on the unlicensed SCell through a cell configured for the UE when the RAP transmission procedure on the unlicensed SCell is stopped.

7. The UE according to claim 6, wherein the second cell configured for the UE is a Primary Cell (PCell), a Primary Secondary Cell (PSCell), any cell among serving cells belonging to the BS on a licensed spectrum, or any cell among cells on an unlicensed spectrum and not occupied by other transmitters.

8. The UE according to claim 6, wherein the information includes an identification of the unlicensed SCell on which the RAP transmission procedure is stopped, or an identification of the RAP of which the transmission on the unlicensed SCell is stopped.

9. The UE according to claim 6, wherein the UE initiates the RAP transmission procedure on the unlicensed SCell when a Physical Downlink Control Channel (PDCCH) order is received from the BS.

10. The UE according to claim 6, wherein the information is transmitted via Physical layer (PHY), Medium Access Control (MAC), Radio Link Control (RLC), Packet Data Convergence Protocol (PDCP), or Radio Resource Control (RRC) signal.