Beam failure detection and recovery for deactivated secondary cell group (SCG)

Patent metadata

Field	Value
Publication number	US-12556262-B2
Application number	US-202218703744-A
Country	US
Kind code	B2
Filing date	Oct 7, 2022
Priority date	Nov 2, 2021
Publication date	Feb 17, 2026
Grant date	Feb 17, 2026

Abstract

Embodiments include methods for a user equipment (UE) configured to communicate with a radio access network (RAN) via a master cell group (MCG) and a secondary cell group (SCG). Such methods include, while the SCG is deactivated, performing beam failure detection (BFD) for at least one cell in the SCG, according to a first BFD configuration. Such methods include, in response to detecting an initial beam failure in the deactivated SCG, transmitting a first message indicating the initial beam failure to a RAN node configured to provide the MCG; and in response to detecting one or more subsequent beam failures in the deactivated SCG, refraining from transmitting to the RAN any messages indicating the one or more subsequent beam failures (e.g., until receiving another BFD configuration). Other embodiments include complementary methods for a RAN node, as well as UEs and RAN nodes configured to perform such methods.

First claim

The invention claimed is:

1 . A method performed by a user equipment (UE) configured to communicate with a radio access network (RAN) via a master cell group (MCG) and a secondary cell group (SCG), the method comprising:
while the SCG is deactivated, performing beam failure detection (BFD) for at least one cell in the SCG, according to a first BFD configuration; in response to detecting an initial beam failure in the deactivated SCG, transmitting a first message indicating the initial beam failure to a RAN node configured to provide the MCG; and in response to detecting one or more subsequent beam failures in the deactivated SCG after the initial beam failure, refraining from transmitting to the RAN any messages indicating the one or more subsequent beam failures until receiving another BFD configuration from the RAN node configured to provide the MCG.

2 . The method of claim 1 , further comprising:
after detecting the one or more subsequent beam failures, receiving a second BFD configuration from the RAN node configured to provide the MCG; detecting a further beam failure in the deactivated SCG based on performing BFD according to the second BFD configuration; and transmitting a second message indicating the further beam failure to the RAN node configured to provide the MCG.

3 . The method of claim 2 , wherein the second BFD configuration is received from the RAN node in response to transmitting the first message to the RAN node.

4 . The method of claim 2 , wherein each of the first and second messages is an SCGFailureInformation message including a failure type field that indicates beam failure for deactivated SCG.

5 . The method of claim 2 , wherein each of the first and second messages includes measurements results for one or more beams, including a beam for which failure was detected.

6 . The method of claim 2 , wherein each of the first and second BFD configurations includes one or more of the following settings or parameters:
an indication of whether the UE should perform BFD on at least one cell in the SCG while the SCG is deactivated; an indication of whether the UE should send a message in the MCG upon detecting beam failure for at least one cell in the SCG; an indication for the UE to start or stop BFD for the SCG; and an indication of which measurement results the UE should include in a message indicating at least one beam failure detected in the SCG.

7 . The method of claim 2 , wherein the second BFD configuration includes one or more settings or parameters that differ from corresponding settings or parameters of the first BFD configuration.

8 . The method of claim 1 , further comprising receiving an indication that the SCG is deactivated from the RAN node configured to provide the MCG, wherein performing the BFD is responsive to the indication from the RAN node.

9 . A user equipment (UE) configured to communicate with a radio access network (RAN) via a master cell group (MCG) and a secondary cell group (SCG), the UE comprising:
communication interface circuitry configured to communicate with the RAN via the SCG and the MCG; and processing circuitry operatively coupled to the communication interface circuitry, wherein the processing circuitry and the communication interface circuitry are configured to:
while the SCG is deactivated, perform beam failure detection (BFD) for at least one cell in the SCG, according to a first BFD configuration;
in response to detecting an initial beam failure in the deactivated SCG, transmit a first message indicating the initial beam failure to a RAN node configured to provide the MCG; and
in response to detecting one or more subsequent beam failures in the deactivated SCG after the initial beam failure, refrain from transmitting to the RAN any messages indicating the one or more subsequent beam failures until receiving another BFD configuration from the RAN node configured to provide the MCG.

10 . The UE of claim 9 , wherein the processing circuitry and the communication interface circuitry are further configured to:
after detecting the one or more subsequent beam failures, receive a second BFD configuration from the RAN node configured to provide the MCG; detect a further beam failure in the deactivated SCG based on performing BFD according to the second BFD configuration; and transmit a second message indicating the further beam failure to the RAN node configured to provide the MCG.

11 . The UE of claim 10 , wherein the processing circuitry and the communication interface circuitry are further configured to receive the second BFD configuration from the RAN node in response to transmitting the first message to the RAN node.

12 . The UE of claim 10 , wherein each of the first and second messages is an SCGFailureInformation message including a failure type field that indicates beam failure for deactivated SCG.

13 . The UE of claim 10 , wherein each of the first and second messages includes measurements results for one or more beams, including a beam for which failure was detected.

14 . The UE of claim 10 , wherein each of the first and second BFD configurations includes one or more of the following settings or parameters:
an indication of whether the UE should perform BFD on at least one cell in the SCG while the SCG is deactivated; an indication of whether the UE should send a message in the MCG upon detecting beam failure for at least one cell in the SCG; an indication for the UE to start or stop BFD for the SCG; and an indication of which measurement results the UE should include in a message indicating at least one beam failure detected in the SCG.

15 . The UE of claim 10 , wherein the second BFD configuration includes one or more settings or parameters that differ from corresponding settings or parameters of the first BFD configuration.

16 . The UE of claim 9 , wherein the processing circuitry and the communication interface circuitry are further configured to:
receive an indication that the SCG is deactivated from the RAN node configured to provide the MCG; and perform the BFD responsive to the indication received from the RAN node.

17 . A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to communicate with a radio access network (RAN) via a master cell group (MCG) and a secondary cell group (SCG), configure the UE to:
while the SCG is deactivated, perform beam failure detection (BFD) for at least one cell in the SCG, according to a first BFD configuration; in response to detecting an initial beam failure in the deactivated SCG, transmit a first message indicating the initial beam failure to a RAN node configured to provide the MCG; and in response to detecting one or more subsequent beam failures in the deactivated SCG after the initial beam failure, refrain from transmitting to the RAN any messages indicating the one or more subsequent beam failures until receiving another BFD configuration from the RAN node configured to provide the MCG.

18 . The non-transitory, computer-readable medium of claim 17 , further comprising instructions that, when executed by the processing circuitry, configure the UE to:
after detecting the one or more subsequent beam failures, receive a second BFD configuration from the RAN node configured to provide the MCG; detect a further beam failure in the deactivated SCG based on performing BFD according to the second BFD configuration; and transmit a second message indicating the further beam failure

Assignees

• Ericsson Telefon Ab L M

Inventors

• Wallentin Pontus
• Zou Zhenhua
• Wager Stefan

Classifications

• H04B7/088

  using beam selection · CPC title

• H04W76/18

  Management of setup rejection or failure · CPC title

• H04B7/06964 Primary

  Re-selection of one or more beams after beam failure · CPC title

• Y02D30/70

  in wireless communication networks · CPC title

• H04W76/27

  Transitions between radio resource control [RRC] states · CPC title