Fast recovery from link failure in dual-connectivity systems

Patent metadata

Field	Value
Publication number	US-12520362-B2
Application number	US-201917287706-A
Country	US
Kind code	B2
Filing date	Dec 3, 2019
Priority date	Dec 3, 2018
Publication date	Jan 6, 2026
Grant date	Jan 6, 2026

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may detect a radio link failure between the UE and a master node of a dual-connectivity configuration. The UE may transmit, to a secondary node in the dual-connectivity configuration, an indication that the radio link failure has occurred. The secondary node may receive the indication of a radio link failure and transmit the indication of the radio link failure to the master node of the dual-connectivity configuration. The master node may identify a target node for the UE and perform a handover procedure of the UE from the master node to the target node.

First claim

What is claimed is:

1 . A user equipment (UE), comprising:
at least one processor; a transceiver; and memory comprising instructions executable by the at least one processor to cause the UE to:
detect a radio link failure between the UE and a master node, the UE and the master node being associated with a dual-connectivity configuration;
select a recovery procedure based at least in part on a layer at which the radio link failure had occurred; and
perform the selected recovery procedure, wherein instructions to perform the selected recovery procedure are executable by the at least one processor to cause the UE to:
transmit, via the transceiver and to the master node via a secondary node also being associated with the dual-connectivity configuration, a radio resource control master cell-group failure information message or a radio resource control reestablishment request for reestablishing a connection with the master node, wherein:
the selected recovery procedure is a fast recovery procedure based at least in part on the layer at which the radio link failure had occurred being a physical layer, media access control layer, or a radio link control layer; or
the selected recovery procedure is a radio resource control reestablishment procedure based at least in part on the layer at which the radio link failure had occurred being a packet data convergence protocol layer.

2 . The UE of claim 1 , wherein:
the radio link failure occurred at a radio resource control layer based at least in part on a failure to comply with a provided radio configuration in a radio resource control message, or the radio link failure is an integrity check failure based at least in part on reception of an integrity check failure indication from the packet data convergence protocol layer.

3 . The UE of claim 2 , wherein the instructions to perform the selected recovery procedure are executable by the at least one processor to cause the UE to:
receive, via the transceiver, a radio resource control reestablishment message after transmission of the radio resource control master cell-group failure information message or the radio resource control reestablishment request; and perform a reestablishment procedure after receiving the radio resource control reestablishment message.

4 . The UE of claim 3 , wherein the instructions are further executable by the at least one processor to cause the UE to:
detect, after transmitting the radio resource control master cell-group failure information message and before receiving a response message from a network, a second radio link failure between the UE and the secondary node associated with the dual-connectivity configuration; and perform the reestablishment procedure after detection of the second radio link failure between the UE and the secondary node.

5 . The UE of claim 3 , wherein the instructions are further executable by the at least one processor to cause the UE to:
transmit, via the transceiver, the radio resource control master cell-group failure information message over a split signaling radio bearer or a signaling radio bearer established between the UE and the secondary node only, or transmit, via the transceiver, the radio resource control reestablishment request over the split signaling radio bearer or the signaling radio bearer established between the UE and the secondary node only.

6 . The UE of claim 5 , wherein the split signaling radio bearer (SRB) comprises a SRB1 and the SRB established between the UE and the secondary node comprises a SRB3.

7 . The UE of claim 3 , wherein the radio resource control reestablishment request comprises a physical cell identifier of the master node, a cell radio network temporary identifier assigned by the master node, an indication of a cause of the reestablishment procedure, a measurement report, or a combination thereof.

8 . The UE of claim 5 , wherein the radio resource control reestablishment request comprises the radio resource control master cell-group failure information message.

9 . The UE of claim 2 , wherein the instructions to perform the selected recovery procedure are executable by the at least one processor to cause the UE to:
transmit, via the transceiver, a first random-access message to the master node; receive, via the transceiver, a second random-access message from the master node in response to the first random-access message, the second random-access message providing a grant for uplink resources for the UE to transmit the radio resource control reestablishment request; transmit, via the transceiver, the radio resource control reestablishment request on the uplink resources; receive, from the master node via the transceiver, a radio resource control reestablishment message after transmission of the radio resource control reestablishment request; and perform a reestablishment procedure after receiving the radio resource control reestablishment message.

10 . The UE of claim 9 , wherein the instructions to transmit the radio resource control reestablishment request are executable by the at least one processor to cause the UE to:
transmit the radio resource control reestablishment request over a signaling radio bearer.

11 . The UE of claim 9 , wherein the radio resource control reestablishment request comprises a physical cell identifier of the master node, a cell radio network temporary identifier assigned by the master node, an indication of a cause of the reestablishment procedure, or a combination thereof.

12 . The UE of claim 11 , wherein the cause of the reestablishment procedure comprises an integrity protection (IP) failure with a master cell group or a reconfiguration failure with the master cell group.

13 . The UE of claim 1 , wherein the instructions to perform the selected recovery procedure are executable by the at least one processor to cause the UE to:
transmit, to the secondary node via the transceiver, an indication that the radio link failure had occurred, wherein the indication comprises the radio resource control master cell-group failure information message that contains a master cell-group link failure cause and an available measurement report; and monitor for a response from the secondary node after transmission of the indication that the radio link failure had occurred.

14 . The UE of claim 13 , wherein the instructions are further executable by the at least one processor to cause the UE to:
receive, via the transceiver, a radio resource control reconfiguration message indicating that the UE is to perform a handover procedure from the master node to a target node; and initiate the handover procedure from the master node to the target node after reception of the radio resource control reconfiguration message.

15 . The UE of claim 13 , wherein the instructions are further executable by the at least one processor to cause the UE to:
receive, via the transceiver, a radio resource control release message indicating that the UE is to release a radio resource control connection with the master node and the secondary node; release the radio resource control connection with the master node and the secondary node after reception of the radio resource control release message; and perform a cell selection procedure followed by a radio resource control establishment procedure after releasing the radio resource control connection with the master node and the secondary node.

16 . A user equipment (UE), comprising:
at least one processor; a transceiver; and memory comprising instructions executable by the at least one processor to cause t

Assignees

• Qualcomm Inc
• Purkayastha Punyaslok
• Horn Gavin Bernard
• Ozturk Ozcan
• Cheng Peng
• Santhanam Arvind Vardarajan

Inventors

• Purkayastha Punyaslok
• Horn Gavin Bernard
• Ozturk Ozcan
• Cheng Peng
• Santhanam Arvind Vardarajan

Classifications

• H04W36/087

  between radio units of access points · CPC title

• H04W36/00692

  using simultaneous multiple data streams, e.g. cooperative multipoint [CoMP], carrier aggregation [CA] or multiple input multiple output [MIMO] (allocation of physical resources in CoMP or in CA H04L5/0035) · CPC title

• H04W24/08

  Testing, {supervising or monitoring} using real traffic · CPC title

• H04W76/18

  Management of setup rejection or failure · CPC title

• H04W36/305

  Handover due to radio link failure (control signalling for hand-off failure H04W36/0079) · CPC title