US 12,381,619 B2
Efficient tracking area update in LEO-NTN
Abhishek Roy, San Jose, CA (US); Chia-Chun Hsu, Hsinchu (TW); Pradeep Jose, Cambridge (GB); and Mehmet Kunt, Cambridge (GB)
Assigned to MEDIATEK SINGAPORE PTE. LTD., Singapore (SG)
Appl. No. 17/996,443
Filed by MediaTek Singapore Pte. Ltd., Singapore (SG)
PCT Filed Apr. 21, 2021, PCT No. PCT/CN2021/088720
§ 371(c)(1), (2) Date Oct. 18, 2022,
PCT Pub. No. WO2021/213442, PCT Pub. Date Oct. 28, 2021.
Claims priority of provisional application 63/012,945, filed on Apr. 21, 2020.
Prior Publication US 2023/0208505 A1, Jun. 29, 2023
Int. Cl. H04B 7/185 (2006.01)
CPC H04B 7/18504 (2013.01) [H04B 7/18513 (2013.01)] 18 Claims
OG exemplary drawing
 
1. A method comprising:
performing cell selection by a user equipment (UE) in a new radio (NR) based Low Earth Orbit (LEO) Non-Terrestrial Network (NTN),
wherein the UE selects a first cell associated with a first tracking area code (TAC) list;
performing a registration procedure with a first TAC from the first TAC list;
performing cell reselection and selecting a second cell, wherein the second cell is associated with a second TAC list; and
determining whether the first TAC is included in the second TAC list,
wherein the UE initiates a TA update (TAU) procedure when the first TAC is not included in the second TAC list,
wherein the TAU procedure involves the UE sending a TAU Request message that comprises the second TAC list, and
wherein the UE receives a TAU Accept message and the UE is registered to a second TAC from the second TAC list.