US 12,095,498 B2
Method and apparatus for handling radio link failure on unlicensed frequency in a wireless communication system
Sangwon Kim, Seoul (KR); and Sunghoon Jung, Seoul (KR)
Assigned to LG ELECTRONICS INC., Seoul (KR)
Appl. No. 17/310,830
Filed by LG ELECTRONICS INC., Seoul (KR)
PCT Filed Mar. 19, 2020, PCT No. PCT/KR2020/003735
§ 371(c)(1), (2) Date Aug. 25, 2021,
PCT Pub. No. WO2020/197162, PCT Pub. Date Oct. 1, 2020.
Claims priority of application No. 10-2019-0032959 (KR), filed on Mar. 22, 2019; application No. 10-2019-0032961 (KR), filed on Mar. 22, 2019; and application No. 10-2019-0032977 (KR), filed on Mar. 22, 2019.
Prior Publication US 2022/0166460 A1, May 26, 2022
Int. Cl. H04B 1/74 (2006.01); H04W 48/06 (2009.01); H04W 76/18 (2018.01); H04W 48/02 (2009.01)
CPC H04B 1/74 (2013.01) [H04W 48/06 (2013.01); H04W 76/18 (2018.02); H04W 48/02 (2013.01)] 6 Claims
OG exemplary drawing
 
1. A method performed by a wireless device in a wireless communication system, the method comprising:
performing a Listen Before Talk (LBT) procedure on a serving Primary Cell (PCell) on a serving shared spectrum, wherein the wireless device is in an RRC_CONNECTED state;
detecting consecutive failures of the LBT procedure on the serving PCell;
declaring radio link failure (RLF) on the serving shared spectrum upon detecting the consecutive failures of the LBT procedure on the serving PCell;
considering all cells on multiple shared spectrums configured for the wireless device as barred for a certain period time, wherein the serving shared spectrum is included in the multiple shared spectrums;
disabling operations for the multiple shared spectrums during the certain period time, wherein the operations on the multiple shared spectrums include performing measurements for the serving shared spectrum;
initiating a radio resource control (RRC) connection re-establishment procedure upon the disabling operations for the multiple shared spectrums;
performing cell selection procedure only for cells on a licensed frequency, and not for cells on the multiple shared spectrums, during the certain period time;
selecting a cell on the licensed frequency from the cell selection procedure; and
establishing an RRC connection to the selected cell on the licensed frequency.