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 |
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.
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