CN115314916A - Method performed by user equipment and user equipment - Google Patents

Abstract

The invention provides a method executed by User Equipment (UE), which comprises the following steps: when a PC5-RRC connection, namely a PC5 interface radio resource control connection, is established between the UE serving as a remote UE and a relay UE, the UE receives a sidelink communication reference signal received power SL-RSRP measurement configuration parameter configured by the relay UE; and after receiving the SL-RSRP measurement configuration parameters configured by the relay UE, the UE performs SL-RSRP measurement according to the received SL-RSRP measurement configuration parameters, filters the SL-RSRP measurement, and performs relay selection or reselection according to the filtering result.

Description

Method performed by user equipment and user equipment

technical field

The present invention relates to the technical field of wireless communication, and more specifically, the present invention relates to a method for performing sidelink communication relay selection or reselection by user equipment and the corresponding user equipment.

Background technique

In June 2018, at the 3rd Generation Partnership Project (3rd Generation Partnership Project: 3GPP) RAN#80 plenary session, version 16 was based on the V2X feasibility study topic of 5G NR network technology (see non-patent literature: RP-181480, New SID Proposal: Study on NR V2X) was approved. The main functions included in version 16 of NR V2X are to support unicast, multicast and broadcast in scenarios without and with network coverage.

In December 2019, at the RAN#86 plenary session, a research project on NR sidelink relaying (sidelink communication relay) for version 17 was proposed (see non-patent literature: RP-193253 New Study Item on NR Sidelink Relaying), and won the approve. The latest version of this research project can be found in the non-patent literature: RP-201474 reivsed SID NRsidelink relay. This research project focuses on UE (User Equipment) to network and UE to UE relay solutions for extending the coverage based on sidelink communication. One of the goals of this research project is to support the selection and reselection of sidewalk communication relays.

In March 2020, at the RAN#91st plenary meeting, a work item for NR sidelink relaying (sideline communication relay) of version 17 was proposed (see non-patent literature: RP-210904 New Study Item on NR SidelinkRelaying), and was awarded approve. One of the goals of this work item is to standardize the selection and reselection of sideline communication relays.

In order to perform sidelink communication with the base station or another remote UE, the remote UE may need to select a relay UE to provide it with a relay service. When the remote UE selects a relay UE to serve itself, it may perform relay reselection due to various situations.

This disclosure discusses the handling of remote UEs and relay UEs in selection and reselection scenarios.

Contents of the invention

In order to solve at least part of the above problems, the present invention provides a method performed by user equipment and the user equipment, which can effectively trigger the selection or reselection of the relay by the remote UE.

According to the present invention, a method performed by a user equipment UE is proposed, including: when a PC5-RRC connection, that is, a PC5 interface radio resource control connection, is established between the UE as a remote UE and a relay UE, the UE receiving the sidelink communication reference signal received power SL-RSRP measurement configuration parameter configured by the relay UE; and after the UE receives the SL-RSRP measurement configuration parameter configured by the relay UE, according to the received The SL-RSRP measurement configuration parameter performs SL-RSRP measurement and filters the SL-RSRP measurement, and performs relay selection or reselection according to the filtering result.

Preferably, the relay UE determines that the PC5-RRC connection established with the remote UE is a connection for a relay service.

Preferably, if the remote UE does not receive the SL-RSRP measurement configuration parameter configured by the relay UE, the remote UE measures the sidelink communication discovery reference signal received power SD-RSRP and performs the SD-RSRP RSRP performs filtering, and performs relay selection or reselection according to the filtered result.

In addition, according to the present invention, a method performed by the user equipment UE is proposed, including: when a PC5-RRC connection, that is, a PC5 interface radio resource control connection, is established between the UE as the relay UE and the remote UE, the The UE always configures sidelink communication reference signal received power SL-RSRP measurement configuration parameters for the remote UE.

Preferably, the relay UE configures the SL-RSRP measurement configuration parameters for the remote UE in the first PC5-RRC message after establishing the PC5-RRC connection with the remote UE.

In addition, according to the present invention, a method performed by a user equipment UE is proposed, including: the UE as a remote UE receives the sidelink communication reference signal received power SL-RSRP measurement configuration parameter configured by the base station; and the UE according to Perform SL-RSRP measurement on the received SL-RSRP measurement configuration parameters.

Preferably, the remote UE receives the SL-RSRP measurement configuration parameters configured by the base station through a system message or through radio resource control RRC dedicated signaling.

Preferably, the SL-RSRP measurement configuration parameters configured by the base station received by the remote UE include: at least one of an SL-RSRP measurement object, a measurement frequency point, and a measurement period that the remote UE needs to measure.

Preferably, the UE performing the SL-RSRP measurement according to the received SL-RSRP measurement configuration parameters includes at least one of the following situations:

When the remote UE does not receive the SL-RSRP measurement configuration parameters configured for it by the relay UE, the remote UE uses the SL-RSRP measurement configuration parameters configured by the base station, further, if the If the remote UE is out of coverage, the remote UE adopts the pre-configured SL-RSRP measurement configuration parameters;

The remote UE uses the SL-RSRP measurement configuration parameters configured by the base station. Further, if the remote UE is out of coverage, the remote UE uses the preconfigured SL-RSRP measurement configuration parameters. When After the remote UE receives the SL-RSRP measurement configuration parameters configured by the relay UE, it uses the SL-RSRP measurement configuration parameters configured by the relay UE instead to perform the SL-RSRP measurement; as well as

The remote UE uses the SL-RSRP measurement configuration parameters configured by the base station. Further, if the remote UE is out of coverage, the remote UE uses the preconfigured SL-RSRP measurement configuration parameters. When After the remote UE receives the SL-RSRP measurement configuration parameters configured by the relay UE, it adds, deletes, or modifies the saved measurements according to the received SL-RSRP measurement configuration parameters, and according to the Perform the SL-RSRP measurement on the SL-RSRP measurement configuration parameters obtained as a result of the operation, and when the SL-RSRP measurement configuration parameters configured by the base station are received again, according to the received SL-RSRP measurement configuration Add, delete or modify the saved measurement, and perform the SL-RSRP measurement according to the SL-RSRP measurement configuration parameters obtained as the operation result.

In addition, according to the present invention, a user equipment is proposed, including: a processor; and a memory storing instructions; wherein the instructions execute the above method when executed by the processor.

According to the present invention, the selection or reselection of the relay by the remote UE can be effectively triggered.

Description of drawings

FIG. 1 is a diagram schematically showing a scenario of UE-to-Network relay.

FIG. 2 is a diagram schematically illustrating UE-to-UE relay.

Fig. 3 is a flowchart illustrating a method performed by a user equipment according to Embodiment 1 of the present invention.

Fig. 4 is a flowchart illustrating a method performed by a user equipment according to Embodiment 2 of the present invention.

FIG. 5 is a block diagram showing a user equipment UE according to the present invention.

Detailed ways

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the present invention should not be limited to the specific embodiments described below. In addition, for the sake of brevity, detailed descriptions of known technologies that are not directly related to the present invention are omitted to prevent confusion to the understanding of the present invention.

Some terms involved in the present invention are described below, and the specific meanings of the terms can be found in the latest 3GPP standard specifications, such as TS38.300, TS38.331, TS36.300, TS36.331, etc. Unless otherwise indicated, the terms involved in the present invention have the following meanings.

UE: User Equipment User Equipment

NR: New Radio, a new generation of wireless technology

RRC: Radio Resource Control radio resource control

RRC_CONNECTED: RRC connected state

RRC_INACTIVE: RRC inactive state

RRC_IDLE: RRC idle state

RAN: Radio Access Network, wireless access layer

Sidelink: side travel communication

SDAP: Service Data Adaptation Protocol, Service Data Adaptation Protocol

SCI: Sidelink Control Information, sidelink communication control information

RSRP: Reference Signal Receiving Power, reference signal receiving power

PSCCH: Physical Sidelink Control Channel, physical sidelink communication control channel

PSSCH: Physical Sidelink Shared Channel, physical sidelink communication shared channel

AS: Access Stratum, access layer

DL: Downlink, downlink

IE: Information Element, Information Element

CE: Control Element, control element

MIB: Master Information Block, master information block

NR: New Radio, new radio

SIB: System Information Block, system information block

DMRS: Dedicated demodulation reference signal, dedicated demodulation reference signal

SD-RSRP: Sidelink Discovery Reference Signal Received Power, sidelink communication discovery reference signal received power

SL-RSRP: Sidelink RSRP, sidelink communication reference signal received power

NG-RAN: NG Radio Access Network, a new generation of radio access network

5GC: 5G Core Network, 5G core network

PDU: Protocol Data Unit, protocol data unit

SDU: Service Data Unit, Service Data Unit

Remote UE: remote UE

Relay UE: Relay UE

In the present invention, network, base station and RAN can be used interchangeably, and the network can be a long-term evolution LTE network, a new radio access technology (New RAT, NR) network, an enhanced long-term evolution eLTE network, or a subsequent evolution version of 3GPP Other networks defined in .

In the present invention, the user equipment UE may refer to the NR equipment supporting the NR Sidelink relay function described in the background art, or may refer to other types of NR equipment or LTE equipment.

Hereinafter, a description will be given of related art of the present invention.

The PC5 interface is an interface for Sidelink communication between the UE and the UE on the control plane and the user plane. For Sidelink unicast, the PC5-RRC connection is an AS layer logical connection between a pair of source layer 2 IDs and target layer 2 IDs. The establishment of a PC5 unicast link corresponds to the establishment of a PC5-RRC connection.

UE-to-Network relay is shown in Figure 1. In scenarios 1 and 2, the remote UE is on the left, the relay UE is in the middle, and the network is on the right; in scenario 3, the networks are on both sides, and the middle is from left to On the right are remote UE and relay UE respectively. The remote UE is connected to the relay UE through the PC5 interface, and the relay UE is connected to the network through the Uu interface. Since the remote UE is far away from the network or the communication environment is not good, the relay UE needs to relay and forward the signaling and data between the two.

Scenarios for UE-to-Network relay include:

1) The remote UE is outside the coverage area, and the relay UE is within the coverage area;

2) Both the remote UE and the relay UE are within the coverage and are in the same cell;

3) Both the remote UE and the relay UE are within coverage, but in different cells.

UE-to-UE relay is shown in Figure 2, the left and right sides are remote UEs, and the middle is a relay UE. The remote UE and the relay UE are respectively connected through the PC5 interface. Since two remote UEs are far away or the communication environment is not good, it is necessary for the relay UE to relay and forward the signaling and data between the two remote UEs.

Scenarios for UE-to-UE relay include:

1) Within the coverage: two remote UEs (ie, the source UE and the target UE) and the relay UE are within the coverage;

2) Out of coverage: two remote UEs (i.e. source side UE and target side UE) and relay UE are both out of coverage;

3) Partial coverage: among the two remote UEs and the relay UE, at least one UE is within the coverage area, and at least one UE is outside the coverage area.

Wherein, the coverage refers to the coverage of the base station.

In the SL relay architecture, after the remote UE selects a relay UE to provide relay service for itself, it will establish a PC5-RRC connection with the relay UE, so as to communicate with the base station or another remote UE through the relay UE.

The sidelink communication measurement results of the unicast link, for example, sidelink RSRP (Sidelink Reference Signal Receiving Power, SL-RSRP for short, reference signal received power) may be used to trigger selection or reselection of sidelink communication relays. In the prior art, SL-RSRP measurement parameters, such as frequency points for measurement, measurement periods, and filter parameters for measurement, are configured by the relay UE to the remote UE. After receiving the measurement parameters configured by the relay UE, the remote UE needs to perform corresponding measurement configuration and report a measurement report to the relay UE. The relay UE may choose to configure measurement parameters or not configure measurement parameters according to its own needs.

When the relay UE does not perform SL-RSRP measurement configuration, the remote UE cannot effectively perform SL-RSRP measurement, and trigger selection or reselection of the relay UE according to the SL-RSRP measurement result.

Through the present invention, it can be ensured that the remote UE obtains the measurement configuration of SL-RSRP to the greatest extent, and SL-RSRP measurement is performed according to the measurement configuration, so that when the PC5 link between the remote UE and the relay UE is in poor condition, The selection or reselection of the relay UE is triggered in time.

Hereinafter, several embodiments of the present invention for the above-mentioned problems are described in detail.

Example 1

Fig. 3 is a flowchart illustrating a method performed by a user equipment according to Embodiment 1 of the present invention.

As shown in FIG. 3 , this embodiment includes steps 301 and 303 .

In step 301, when a PC5-RRC connection (or unicast link) is established between the remote UE and the relay UE, the remote UE receives the SL-RSRP measurement configuration parameters configured by the relay UE.

Here, optionally, when a PC5-RRC connection (or unicast link) is established between the remote UE and the relay UE, the relay UE always configures SL-RSRP measurement configuration parameters for the remote UE.

Wherein, the relay UE may be a UE that has been determined to provide a relay service for a remote UE, and may also refer to a UE with a relay capability, or a UE that performs a relay service according to an upper layer instruction.

Optionally, the relay UE needs to determine that the unicast link established with the remote UE is for the relay service.

Optionally, another expression is: the information element sl-MeasConfig in the RRCReconfigurationSidelink always carries or is always configured when the UE is a relay UE.

Optionally, the relay UE configures the SL-RSRP measurement configuration parameters for the remote UE, which is configured in the first PC-RRC message (such as a reconfiguration message) after the PC5-RRC connection is established between the relay UE and the remote UE. Wherein, optionally, the establishment of the connection may be indicated by an upper layer.

In step 303, after receiving the SL-RSRP measurement configuration parameters configured by the relay UE, the remote UE performs SL-RSRP measurement according to the configuration, performs layer-3 filtering on the SL-RSRP measurement, and selects a relay according to the filtering result Or re-election.

Wherein, the relay selection may refer to before the remote UE has selected a relay UE, and the relay reselection may refer to after the remote UE has selected a relay UE.

Optionally, when the relay UE establishes a PC5-RRC connection with the remote UE, the remote UE is not provided with a relay service, that is, the PC5-RRC connection established between the two UEs is only for ordinary sidelink communication, The relay UE also always configures SL-RSRP measurement configuration parameters for the remote UE, which is used for the remote UE to perform relay selection or reselection.

Example 2

Fig. 4 is a flowchart illustrating a method performed by a user equipment according to Embodiment 2 of the present invention.

As shown in FIG. 4 , this embodiment includes steps 401 and 403 .

In step 401, the remote UE receives SL-RSRP measurement configuration parameters configured by the base station.

Wherein, the remote UE may receive the configuration of the base station through a system message, or through RRC dedicated signaling, or through relay UE forwarding (the relay UE may forward through unicast, multicast or broadcast).

Optionally, the SL-RSRP measurement configuration parameter may be used for remote UE to perform unicast link SL-RSRP measurement, or for remote UE to perform SL-RSRP measurement for relay selection or reselection, or It is used to configure the unicast link SL-RSRP measurement for the peer UE of the remote UE, or it is added in the measurement configuration for the air interface to indicate that a certain measurement parameter can be the same as the remote UE's relay reselection or Selected SL-RSRP measurement (such as but not limited to: frequency point, filter parameters, measurement period, reference signal, etc.). When the SL-RSRP measurement configuration parameter is used to configure the unicast link SL-RSRP measurement for the peer UE of the remote UE, the remote UE can directly use it for its own relay selection or reselection SL-RSRP measurement .

Wherein, the relay selection may refer to before the remote UE has selected a relay UE, and the relay reselection may refer to after the remote UE has selected a relay UE.

The SL-RSRP measurement configuration parameters configured by the base station received by the remote UE include but are not limited to: the SL-RSRP measurement object that the remote UE needs to measure, the measurement frequency point, and the measurement period.

In step 403, the remote UE performs SL-RSRP measurement according to the SL-RSRP measurement configuration.

The SL-RSRP measurement configuration adopted by the remote UE includes but is not limited to the following possibilities:

1) When the remote UE does not receive the SL-RSRP measurement configuration parameters configured by the relay UE, the remote UE uses the SL-RSRP measurement configuration parameters configured by the base station. Further, if the remote UE is out of coverage, the remote UE uses pre-configured SL-RSRP measurement configuration parameters.

2) The remote UE uses the SL-RSRP configured by the base station to measure configuration parameters. Further, if the remote UE is out of coverage, the remote UE uses pre-configured SL-RSRP measurement configuration parameters. After the remote UE receives the SL-RSRP measurement configuration parameters configured by the relay UE, it changes to use the SL-RSRP measurement configuration parameters configured by the relay UE to perform SL-RSRP measurement.

3) The remote UE uses the SL-RSRP configured by the base station to measure configuration parameters. Further, if the remote UE is out of coverage, the remote UE uses pre-configured SL-RSRP measurement configuration parameters. When the remote UE receives the SL-RSRP measurement configuration parameters configured by the relay UE, it adds, deletes or modifies the saved measurements according to the specific measurement parameters, and performs SL based on the SL-RSRP measurement configuration parameters obtained from the operation results. - RSRP measurement. When receiving the SL-RSRP measurement configuration parameters configured by the base station again, add, delete or modify the saved measurements according to the specific measurement parameters, and perform SL-RSRP measurement according to the SL-RSRP measurement configuration parameters obtained from the operation results.

Wherein, optionally, whether the remote UE has received the SL-RSRP measurement configuration parameters configured by the relay UE can be determined by judging whether the information element sl-MeasConfig in the RRCReconfigurationSidelink sent by the relay UE to the remote UE carries or is valid.

Example 3

If the remote UE receives the SL-RSRP measurement configuration parameters configured by the relay UE, the remote UE measures the SL-RSRP, performs Layer 3 filtering on the SL-RSRP, and performs relay selection or reselection according to the filtered result.

If the remote UE does not receive the SL-RSRP measurement configuration parameters configured by the relay UE, the remote UE measures SD-RSRP, performs Layer 3 filtering on SD-RSRP, and performs relay selection or reselection according to the filtered result.

Wherein, optionally, whether the remote UE has received the SL-RSRP measurement configuration parameters configured by the relay UE can be determined by judging whether the information element sl-MeasConfig in the RRCReconfigurationSidelink sent by the relay UE to the remote UE carries or is valid.

Wherein, the relay selection may refer to before the remote UE has selected a relay UE, and the relay reselection may refer to after the remote UE has selected a relay UE.

Fig. 5 is a brief structural block diagram of the user equipment UE involved in the present invention. As shown in FIG. 5 , the user equipment UE50 includes a processor 501 and a memory 502 . The processor 501 may include, for example, a microprocessor, a microcontroller, an embedded processor, and the like. The memory 502 may include, for example, a volatile memory (such as a random access memory RAM), a hard disk drive (HDD), a nonvolatile memory (such as a flash memory), or other memories. Memory 502 has program instructions stored thereon. When the instructions are executed by the processor 501, the above method described in detail in the present invention and executed by the user equipment may be executed.

The program running on the device according to the present invention may be a program that causes a computer to realize the functions of the embodiments of the present invention by controlling a central processing unit (CPU). The program or information processed by the program may be temporarily stored in volatile memory (such as random access memory RAM), hard disk drive (HDD), non-volatile memory (such as flash memory), or other memory systems.

A program for realizing the functions of the various embodiments of the present invention can be recorded on a computer-readable recording medium. The corresponding functions can be realized by causing a computer system to read programs recorded on the recording medium and execute the programs. The so-called "computer system" here may be a computer system embedded in the device, which may include an operating system or hardware (such as peripheral devices). The "computer-readable recording medium" may be a semiconductor recording medium, an optical recording medium, a magnetic recording medium, a recording medium in which a short-term dynamic storage program is stored, or any other recording medium readable by a computer.

Various features or functional modules of the devices used in the above-mentioned embodiments may be implemented or executed by circuits (for example, single-chip or multi-chip integrated circuits). Circuits designed to perform the functions described in this specification may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination of the above. A general-purpose processor can be a microprocessor, or it can be any existing processor, controller, microcontroller, or state machine. The above-mentioned circuits may be digital circuits or analog circuits. Where advances in semiconductor technology have resulted in new integrated circuit technologies that replace existing integrated circuits, one or more embodiments of the invention may also be implemented using these new integrated circuit technologies.

In addition, the present invention is not limited to the above-described embodiments. Although various examples of the embodiments have been described, the present invention is not limited thereto. Fixed or non-mobile electronic equipment installed indoors or outdoors can be used as terminal equipment or communication equipment, such as AV equipment, kitchen equipment, cleaning equipment, air conditioners, office equipment, vending machines, and other household appliances.

As above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific structure is not limited to the above embodiments, and the present invention also includes any design changes that do not deviate from the gist of the present invention. In addition, various changes can be made to the present invention within the scope of the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments are also included in the technical scope of the present invention. In addition, components having the same effect described in the above embodiments can be substituted for each other.

Claims (10)

1. A method performed by a User Equipment (UE), comprising:

when a PC5-RRC connection, namely a PC5 interface radio resource control connection, is established between the UE serving as a remote UE and a relay UE, the UE receives a sidelink communication reference signal received power SL-RSRP measurement configuration parameter configured by the relay UE; and

and after receiving the SL-RSRP measurement configuration parameters configured by the relay UE, the UE performs SL-RSRP measurement according to the received SL-RSRP measurement configuration parameters, filters the SL-RSRP measurement, and performs relay selection or reselection according to a filtering result.

2. The method of claim 1, wherein,

the relay UE determines that the PC5-RRC connection established with the remote UE is a connection for relay service.

3. The method of claim 1, wherein,

and if the remote UE does not receive the SL-RSRP measurement configuration parameters configured by the relay UE, the remote UE measures and filters the SD-RSRP according to the side line communication discovery reference signal received power SD-RSRP, and performs relay selection or reselection according to the filtered result.

4. A method performed by a User Equipment (UE), comprising:

when a PC5-RRC connection, namely a PC5 interface Radio Resource Control (RRC) connection is established between the UE serving as the relay UE and the remote UE, the UE always configures a sidelink communication reference signal received power (SL-RSRP) measurement configuration parameter for the remote UE.

5. The method of claim 4, wherein,

and the relay UE configures the SL-RSRP measurement configuration parameters for the remote UE in a first PC5-RRC message after the PC5-RRC connection is established between the relay UE and the remote UE.

6. A method performed by a User Equipment (UE), comprising:

the UE serving as a remote UE receives a sidelink communication reference signal received power (SL-RSRP) measurement configuration parameter configured by a base station; and

and the UE carries out SL-RSRP measurement according to the received SL-RSRP measurement configuration parameters.

7. The method of claim 6, wherein,

the remote UE receives the SL-RSRP measurement configuration parameters configured by the base station through system messages or through Radio Resource Control (RRC) dedicated signaling.

8. The method of claim 6, wherein,

the SL-RSRP measurement configuration parameters configured by the base station received by the remote UE comprise: and the remote UE needs at least one of a measurement object, a measurement frequency point and a measurement period of the measured SL-RSRP.

9. The method of claim 6, wherein,

the UE performing the SL-RSRP measurement according to the received SL-RSRP measurement configuration parameters comprises at least one of the following situations:

when the remote UE does not receive the SL-RSRP measurement configuration parameters configured for the relay UE, the remote UE uses the SL-RSRP measurement configuration parameters configured by the base station, and further, if the remote UE is out of coverage, the remote UE adopts the preconfigured SL-RSRP measurement configuration parameters;

the remote UE uses the SL-RSRP measurement configuration parameters configured by the base station, further, if the remote UE is out of the coverage area, the remote UE adopts the pre-configured SL-RSRP measurement configuration parameters, and after receiving the SL-RSRP measurement configuration parameters configured by the relay UE, the remote UE changes to adopt the SL-RSRP measurement configuration parameters configured by the relay UE to carry out SL-RSRP measurement; and

the remote UE uses the SL-RSRP measurement configuration parameter configured by the base station, further, if the remote UE is out of coverage, the remote UE uses the preconfigured SL-RSRP measurement configuration parameter, when the remote UE receives the SL-RSRP measurement configuration parameter configured by the relay UE, the remote UE performs an operation of adding, deleting, or modifying a stored measurement according to the received SL-RSRP measurement configuration parameter, performs the SL-RSRP measurement according to the SL-RSRP measurement configuration parameter obtained as an operation result, when the SL-RSRP measurement configuration parameter configured by the base station is received again, performs an operation of adding, deleting, or modifying a stored measurement according to the received SL-RSRP measurement configuration parameter, and performs the SL-RSRP measurement according to the SL-RSRP measurement configuration parameter obtained as an operation result.

10. A user equipment, comprising:

a processor; and

a memory storing instructions;

wherein the instructions, when executed by the processor, perform the method of any of claims 1 to 9.

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