US 12,010,750 B2
Radio link maintenance involving multiple uplink carriers
Min Wang, Luleå (SE); and Jinhua Liu, Beijing (CN)
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), Stockholm (SE)
Appl. No. 16/959,270
Filed by Telefonaktiebolaget LM Ericsson (publ), Stockholm (SE)
PCT Filed Jan. 11, 2019, PCT No. PCT/EP2019/050716
§ 371(c)(1), (2) Date Jun. 30, 2020,
PCT Pub. No. WO2019/138087, PCT Pub. Date Jul. 18, 2019.
Claims priority of provisional application 62/616,194, filed on Jan. 11, 2018.
Prior Publication US 2020/0337102 A1, Oct. 22, 2020
Int. Cl. H04W 76/18 (2018.01); H04L 1/1867 (2023.01); H04W 24/08 (2009.01); H04W 36/00 (2009.01); H04W 36/08 (2009.01); H04W 36/30 (2009.01); H04W 74/0833 (2024.01); H04W 80/02 (2009.01)
CPC H04W 76/18 (2018.02) [H04L 1/189 (2013.01); H04W 24/08 (2013.01); H04W 36/0079 (2018.08); H04W 36/0085 (2018.08); H04W 36/08 (2013.01); H04W 36/305 (2018.08); H04W 74/0833 (2013.01); H04W 80/02 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A method in a user equipment (UE) in dual connectivity mode for handling radio link failures; wherein the UE is connected to a radio communication network by a plurality of uplink (UL) carriers; the method comprising:
performing retransmissions of a certain Radio Link Control (RLC) data packet on at least two of the plurality of UL carriers that are separate, wherein one link is a primary UL carrier and the other link is a supplementary UL (SUL) carrier;
monitoring retransmissions of a RLC data packet commonly for all of the at least two UL carriers using a single retransmission counter for both of the primary UL carrier and the SUL carrier in dual connectivity mode;
providing information indicative of a common Radio Link Failure (RLF) for the at least two UL carriers;
wherein the UE is configured to select a cell based on one or more of the following criteria:
select a cell out of one or a plurality of cells that support a SUL carrier;
select a cell based on measurements on both Downlink (DL) and UL radio link quality;
select a cell only based on measurements of the DL radio channel quality; and
select a cell based on a load measurement of the cell, and the load of each carrier belonging to the same cell; and
wherein, if a first cell is configured with a SUL carrier and the primary UL carrier, and a second cell is not configured with a SUL carrier, the UE performs:
measuring DL radio link quality and UL radio link quality;
determining if the DL radio link quality of both the first and second cells is above a certain minimum quality threshold and/or if the SUL carrier provides a larger path gain than that of the primary UL carrier; and
based on the determining be in the affirmative, selecting the first cell.