Managing quality of experience measurements with DC

Abstract

A user equipment (UE) communicates in dual connectivity (DC) with a primary node (MN) via a primary node (MN) link and with a secondary node (SN) via a secondary node (SN) link. The UE reporting a Quality of Experience (QoE) measurement to the SN via the SN link; and in response to detecting a radio link failure (RLF) on the SN link, the UE suspends reporting of the QoE measurements via the SN link.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of the filing date of Provisional U.S. Patent Application No. 63 / 485,529, entitled “Managing Quality of Experience Measurement in DC,” filed on February 16, 2023. The entire contents of that provisional application are hereby expressly incorporated herein by reference. Technical Field

[0003] The present disclosure relates to wireless communication systems, and more particularly, to wireless communication systems that manage quality of experience measurement collection and reporting during mobility and / or state transitions. Background Art

[0004] In a wireless communication system, a base station supporting a specific radio access technology (RAT) communicates with a user equipment (UE) using a protocol for controlling radio resources corresponding to the RAT, as well as other protocols. The protocol for controlling radio resources may be, for example, a radio resource control (RRC) protocol utilized by 4G, 5G, 6G, or later generation wireless communication systems. After establishing a radio connection via a base station, the UE operates in a connected state of the protocol for controlling radio resources, which may be RAT-specific (e.g., EUTRA-RRC CONNECTED, NR-RRC CONNECTED).

[0005] Mobile networks are evolving to improve the user experience. Therefore, an assessment of the user experience at the UE end is useful for network operators. In particular, such an assessment is useful when operators provide real-time services that require, for example, high data rates and low latency, where even intermittent quality degradation may degrade the user experience. Such real-time services include streaming services (typically video services), Multimedia Telephony Service (MTSI) of the Internet Multimedia Subsystem (IMS), Multicast and / or Broadcast Service (MBS) and / or Extended Reality (XR) services. Many of these services are part of the commercial traffic growth rate and are therefore of concern to the end user experience.

[0006] In general, Quality of Experience (QoE) Measurement Collection (QMC) provides detailed information to the UE at the call (also known as "application session") level. These measurements can provide information that network operators cannot derive from RAN or CN measurements. The UE can collect QoE information and provide it to management systems for analysis and / or key performance indicator (KPI) calculations.

[0007] In LTE systems, the QMC function enables the collection of application layer measurements from UEs. Supported service types can include streaming services and MTSI services. The trace function from the Minimization of Drive Test (MDT) framework activates QMC. LTE supports both signaling-based and management-based initiation cases. For the signaling-based case, the application layer measurement collection is initiated from a CN node to a specific UE using the MDT mechanism. For the management-based case, the application layer measurement collection is initiated by an Operation, Administration and Maintenance (OAM) node targeting a certain area (not a specific UE).

[0008] As described in 3GPP specifications 28.405 v16.0.0, 36.300 v16.6.0, and 36.331 v16.5.0, a transparent container encapsulates the application layer measurement configuration received from the OAM node or CN, which is forwarded by the Radio Access Network (RAN) to the UE in a downlink RRC message. The RAN encapsulates the application layer measurements received from the UE’s higher layers in a transparent container and sends the measurements to the network in an uplink RRC message. Application layer measurement configuration and measurement reporting are only supported in the RRC CONNECTED state. The E-UTRAN can release the application layer measurement configuration to the UE at any time.

[0009] However, it is unclear how the UE and / or the network should support QoE measurements and reporting in certain mobility scenarios or failure scenarios, such as radio link failure, especially when the UE is operating in dual connectivity. SUMMARY

[0010] An example embodiment of the techniques of this disclosure is a method implemented in a user equipment (UE). The method includes communicating in dual connectivity (DC) with a master node (MN) via a MN link and with a secondary node (SN) via a SN link, reporting quality of experience (QoE) measurements to the SN via the SN link, and in response to detecting a radio link failure (RLF) on the SN link, suspending reporting of the QoE measurements via the SN link.

[0011] Another example embodiment of the techniques is a method implemented in a first radio access network (RAN) node. The method includes providing a master node (MN) link to a user equipment (UE) that communicates in dual connectivity with the first RAN node operating as a MN and a second RAN node operating as a secondary node (SN) and providing a SN link, the UE reporting quality of experience (QoE) measurements to the SN via the SN link, receiving an indication from the UE of a failure of the SN link, and sending an indication to the UE of whether the UE is to switch reporting of the QoE measurements to the MN link.

[0012] Another example embodiment of the techniques is a device comprising a transceiver and processing hardware, wherein the device is configured to implement one of the methods described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1A is a block diagram of an example system in which a base station and / or user equipment (UE) may implement the presently disclosed techniques for managing quality of experience (QoE) measurement collection and reporting in the UE;

[0014] FIG. 1B Yes, you can FIG. 1A A block diagram of an example base station including a central unit (CU) and a distributed unit (DU) operating in a system;

[0015] FIG. 2A is a block diagram of the example protocol stack, FIGS. 1A-1B The UE can communicate with the base station according to the example protocol stack;

[0016] FIG. 2B is a block diagram of the example protocol stack, FIGS. 1A-1B The UE may communicate with one or more base stations using a distributed architecture according to the example protocol stack;

[0017] FIG. 3A An example scenario is shown in which the network configures Quality of Experience (QoE) reporting for a SN when the UE is in Dual Connectivity (DC) mode;

[0018] FIG. 3B Shown with FIG. 3A A scenario similar to the one described above, but in which the UE receives the QoE configuration from the MN or SN;

[0019] FIG. 3C An example scenario is shown in which the network configures QoE reporting for the SN when the UE is in DC and the SN determines to configure SN QoE for the UE via MN connection;

[0020] FIG. 3D Shown with FIG. 3C A scenario similar to the scenario of , but wherein the SN determines to configure SNQoE for the UE via the SN connection;

[0021] FIG. 3E shows an example scenario in which the network configures QoE reporting for the SN when the UE is in standalone (SA) mode and the UE reports to the SN after receiving the QoE configuration from the MN;

[0022] FIG. 4AAn example scenario is shown in which the UE detects RLF on the SN link and switches reporting to the MCG leg and switches back to the SCG leg after recovering the SN connection;

[0023] FIG. 4B An example scenario is shown that is similar to the scenario of FIG. 4A but in which the UE is unable to recover the SN connection and reconfigures QoE reporting via the MCG leg;

[0024] FIG. 4B An example scenario is shown that is similar to the scenario of FIG. 4A but in which the UE is unable to recover the SN connection and reconfigures QoE reporting via the MCG leg;

[0025] FIG. 4C An example scenario is shown that is similar to the scenario of FIG. 4A but in which the UE recovers the SN connection and resumes QoE collection and reporting;

[0026] FIG. 4D An example scenario is shown that is similar to the scenario of FIG. 4A but in which the network releases the SN link;

[0027] FIG. 5A An example scenario is shown in which the UE detects RLF on the MN link, performs fast MCG recovery, and recovers SRB5;

[0028] FIG. 5B An example scenario is shown that is similar to the scenario of FIG. 5A but in which the UE suspends split SRB4 but does not suspend SRB3;

[0029] FIGS. 6A-6C An example scenario is shown in which the UE performs QoE measurement and reporting after SN connection release or secondary node change;

[0030] FIG. 7A is a flowchart of an example method in which a UE receives QoE configuration for a SN via an MN link;

[0031] FIG. 7B is a flowchart of an example method in which a UE receives QoE configuration for a SN via an SN link;

[0032] FIG. 8A is a flowchart of an example method in which an MN receives QoE configuration for a SN and sends the QoE configuration to a UE;

[0033] FIG. 8B is a flowchart of an example method in which an MN receives QoE configuration for a SN and sends the QoE configuration to a SN;

[0034] FIG. 8C is a flowchart of an example method in which the MN receives a QoE measurement report for the SN;

[0035] FIG. 8D is a flowchart of an example method in which the MN receives a QoE configuration for the SN when the UE is in standalone mode;

[0036] FIG. 8E is a flowchart of an example method in which the SN receives a QoE configuration for the SN and sends the QoE configuration to the MN;

[0037] FIG. 8F is a flowchart of an example method in which the SN receives a QoE configuration for the SN and sends the QoE configuration to the UE;

[0038] FIG. 8G is a flowchart of an example method in which the SN receives a QoE measurement report for the SN;

[0039] FIG. 8H is a flowchart of an example method in which the MN sends a UE connection mode indication (DC or SA) to the CN or OAM;

[0040] FIG. 8I is a flowchart of an example method in which the CN / OAM receives a UE connection mode indication (DC) from the MN;

[0041] FIG. 8J is a flowchart of an example method in which the CN / OAM receives a UE connection mode indication (SA) from the MN;

[0042] FIG. 9A is a flowchart of an example method in which the UE detects an RLF on the SN and switches QoE measurements for the SN from a SCG leg to a MCG leg;

[0043] FIG. 9B is a flowchart of an example method in which the UE detects an RLF on the SN link and suspends QoE measurements for the SN;

[0044] FIG. 9C is a flowchart of an example method in which the UE detects an RLF on the SN link and decides to suspend QoE measurements for the SN and SRB4 is not configured;

[0045] FIG. 9D is a flowchart of an example method in which the UE detects an RLF on the SN and determines to suspend QoE measurements for the SN when the network does not allow QoE measurement reports to be reported to the SN via a MCG leg;

[0046] FIG. 9Eis a flowchart of an example method in which the MN or SN indicates that QoE measurement reporting for the SN is allowed via the MCG leg;

[0047] FIG. 10 is a flowchart of an example method in which the UE suspends split SRB4 or SRB5 for QoE measurement reporting when performing a fast MCG link recovery procedure;

[0048] FIG. 11A is a flowchart of an example method in which the UE receives an SCG release message and reconfigures QoE measurement configuration for the SN from the SN to the MN;

[0049] FIG. 11B is a flowchart of an example method in which the MN determines to release the SN and reconfigures QoE measurement configuration for the SN from the SN to the MN;

[0050] FIG. 11C is a flowchart of an example method in which the MN determines to release the SN and retains QoE measurement configuration for the SN by the SN;

[0051] FIG. 11D is a flowchart of an example method in which the UE receives one or more messages from the MN to release the SCG and maintain QoE measurement reporting for the SN; and

[0052] FIG. 11E is a flowchart of an example method in which the MN changes a secondary node of the UE and (re)configures QoE configuration for the SN from the SN to the MN. DETAILED DESCRIPTION

[0053] A UE, a source node in a RAN, a target node in a RAN, a core network, and / or an operations, administration, and maintenance (OAM) node implement techniques of the present disclosure to manage QoE measurement and reporting during mobility and / or when a radio link failure occurs. As discussed in greater detail below, a UE can receive a command to suspend and / or resume QoE reporting during a handover procedure. Alternatively, the UE can autonomously determine to suspend and / or resume QoE reporting during a handover procedure. Further, the UE can receive multiple QoE configurations and operate QoE reporting accordingly. Still further, when the UE encounters a radio link failure, the UE can suspend measurement and reporting, continue measurement or suspend reporting, attempt to switch to another radio bearer, etc., in various implementations.

[0054] More specifically, the network node implements QMC and supports configuration and reporting of multiple simultaneous QoE measurements for the same or different service types of a UE. To identify the measurements and support activation, modification, and release functions, the RAN node uses a mapping between a reference ID and a QoE configuration. In addition, in some cases, the RAN can initiate suspension and resumption for one or more QoE configurations. More specifically, the RAN can suspend and resume functions in a handover scenario. During the handover scenario, the RAN can also support suspension and resumption initiated by a QoE node such as OAM.

[0055] Referring first to FIG. 1A , an example wireless communication system 100 includes a UE 102, a source base station (S-BS) 104, a target base station (T-BS) 106, and a core network (CN) 110. The base stations 104 and 106 can operate in a RAN 105 connected to a core network (CN) 110. The CN 110 can be implemented as, for example, an evolved packet core (EPC) 111 or a fifth generation (5G) core (5GC) 160. In another example, the CN 110 can also be implemented as a sixth generation (6G) core.

[0056] The source base station 104 covers a cell 124, and the target base station 106 covers a cell 126. If the source base station 104 is a gNB, the cell 124 is a NR cell. If the base station 124 is an ng-eNB, the cell 124 is an evolved universal terrestrial radio access (E-UTRA) cell. Similarly, if the target base station 106 is a gNB, the cell 126 is a NR cell, and if the base station 126 is an ng-eNB, the cell 126 is an E-UTRA cell. The cells 124 and 126 can be located in the same radio access network notification area (RNA) or different RNAs. In general, the RAN 105 can include any number of base stations, and each of the base stations can cover one, two, three, or any other suitable number of cells. The UE 102 can support at least a 5G NR (or simply “NR”) or E-UTRA air interface to communicate to the base stations 104 and 106. Each of the base stations 104, 106 can be connected to the CN 110 via an interface (e.g., an SI or NG interface). The base stations 104 and 106 can also interconnect via an interface for interconnecting NG RAN nodes (e.g., an X2 or Xn interface).

[0057] Among other components, the EPC 111 may also include a serving gateway (SGW) 112, a mobility management entity (MME) 114, and a packet data network gateway (PGW) 116. Generally speaking, the SGW 112 is configured to transmit user plane packets related to audio calls, video calls, Internet traffic, etc., and the MME 114 is configured to manage authentication, registration, paging, and other related functions. The PGW 116 provides connectivity from the UE 102 to one or more external packet data networks (e.g., an Internet network and / or an Internet Protocol (IP) Multimedia Subsystem (IMS) network). The 5GC 160 includes a user plane function (UPF) 162, an access and mobility management function (AMF) 164, and / or a session management function (SMF) 166. In general, UPF 162 is configured to transport user plane packets associated with audio calls, video calls, Internet traffic, etc.; AMF 164 is configured to manage authentication, registration, paging, and other related functions; and SMF 166 is configured to manage PDU sessions.

[0058] like FIG. 1A As shown, source base station 104 supports cell 124, and target base station 106 supports cell 126. Cells 124 and 126 may partially overlap, such that UE 102 may select, reselect, or handover from one of cells 124 and 126 to the other. To exchange messages or information directly, source base station 104 and target base station 106 may support an X2 or Xn interface. In general, CN 110 may be connected to any suitable number of base stations supporting NR cells and / or EUTRA cells.

[0059] The source base station 104 and the UE 102 establish a connection, over which the UE 102 and the source base station 104 transmit data payloads, for example, wirelessly. After the connection is established via the source base station 104, the UE 102 is in a connected state (e.g., EUTRA-RRC CONNECTED, NR-RRC CONNECTED) of a RAT protocol for controlling radio resources. The source base station 104 maintains a context for the UE 102, wherein the context for the UE 102 includes configurations and other information associated with the connection between the UE 102 and the source base station 104. The context for the UE 102 may include configurations for SRB1, SRB2, SRB4, DRBs, and / or other configurations associated with the connection between the UE 102 and the source base station 104 (e.g., security configurations).

[0060] At some point in time, the UE 102 establishes, resumes, or re-establishes a radio connection with the target base station 106 for service. This can occur in various scenarios. In one scenario (a "handover scenario"), the source base station 104 can determine that the UE 102 is to be handed over to the target base station 106. In another scenario (a "reestablishment scenario"), the UE 102 can detect a radio link failure (RLF) on a connection established with the source base station 104 or detect an integrity check failure on SRB1, SRB2, or SRB4, and subsequently select the target base station 106 for service. In yet another scenario (a "reselection scenario"), the source base station 104 can detect that below-threshold or no data activity of the UE 102 has occurred over a certain time interval on an established connection. Upon this detection, the source base station 104 instructs the UE 102 to enter an inactive state of a RAT protocol (e.g., EUTRA-RRC INACTIVE, NR-RRC INACTIVE). At some point in time thereafter, such as when the UE 102 has moved to a different coverage area and has payload data to transmit to the system, the UE 102 (in the inactive state) selects or reselects the target base station 106 for service.

[0061] The source base station 104 is equipped with processing hardware 130, which can include one or more general-purpose processors (e.g., CPUs) and non-transitory computer-readable memory storing instructions for execution by the one or more general-purpose processors. Additionally or alternatively, the processing hardware 130 can include special-purpose processing units. In an example implementation, the processing hardware 130 includes an RRC controller 132 for implementing procedures and messaging at the RRC sublayer of a protocol communication stack. The processing hardware 130 can also include a QMC controller 134 configured to manage QoE configuration and QoE reporting for one or more UEs. The target base station 106 can include substantially similar components. Specifically, components 142 and 144 can be similar to components 132 and 134, respectively.

[0062] The UE 102 is equipped with processing hardware 150, which can include one or more general-purpose processors such as CPUs and non-transitory computer-readable memory storing machine-readable instructions executable on the one or more general-purpose processors, and / or special-purpose processing units. In an example implementation, the processing hardware 150 includes an RRC controller 152 for implementing procedures and messaging at the RRC sublayer of a protocol communication stack. The processing hardware 150 can also include a QMC controller 154 configured to manage QoE configuration, QMC, and reporting.

[0063] FIG. 1BAn example distributed or disaggregated implementation of any one or more of the base stations 104, 106 is depicted. In this implementation, a source base station 104A, 104B, 106A, or 106B includes a central unit (CU) 172 and one or more DUs 174. The CU 172 includes processing hardware, such as one or more general- purpose processors (e.g., CPUs) and computer-readable memory storing machine-readable instructions executable on the general-purpose processor(s), and / or special-purpose processing units. For example, the CU 172 can include a PDCP controller, an RRC controller, and / or a paging controller, such as the PDCP controllers 134, 144, the RRC controllers 136, 146, and / or the paging controllers 138, 148. In some implementations, the CU 172 can include a radio link control (RLC) controller configured to manage or control one or more RLC operations or processes. In other implementations, the CU 172 does not include an RLC controller.

[0064] Each of the DUs 174 also includes processing hardware, which can include one or more general-purpose processors (e.g., CPUs) and computer-readable memory storing machine-readable instructions executable on the general-purpose processor(s), and / or special-purpose processing units. For example, the processing hardware can include a MAC controller (e.g., the MAC controllers 132, 142) configured to manage or control one or more MAC operations or processes (e.g., random access procedures), and / or an RLC controller configured to manage or control one or more RLC operations or processes. The processing hardware can also include a physical layer controller configured to manage or control one or more physical layer operations or processes.

[0065] In some implementations, the CU 172 can include a logical node CU-CP 172A that hosts the control plane portion of the PDCP protocol of the CU 172. The CU 172 can also include a logical node CU-UP 172B that hosts the user plane portion of the PDCP protocol and / or a service data adaptation protocol (SDAP) protocol of the CU 172. The CU-CP 172A can transmit control information (e.g., RRC messages, Fl application protocol messages), and the CU-UP 172B can transmit data packets (e.g., SDAP PDUs or Internet Protocol packets).

[0066] The CU-CP 172A can be connected to multiple CU-UPs 172B over an El interface. The CU-CP 172A selects an appropriate CU-UP 172B for a requested service of the UE 102. In some implementations, a single CU-UP 172B can be connected to multiple CU-CPs 172A over an El interface. If the CU-CP and the DU belong to a gNB, the CU-CP 172A can be connected to one or more DUs 174 over an Fl-C interface and / or an Fl-U interface. If the CU-CP and the DU belong to an ng-eNB, the CU-CP 172A can be connected to one or more DUs 174 over a Wl-C interface and / or a Wl-U interface. In some implementations, one DU 174 can be connected to multiple CU-UPs 172B under control of the same CU-CP 172A. In such implementations, the CU-CP 172A uses a bearer context management function to establish connections between the CU-UP 172B and the DU 174.

[0067] FIG. 2A An example protocol stack 200 is shown in simplified form, which a UE 102 can use to communicate with an eNB / ng-eNB or gNB (e.g., one or more of the base stations 104, 106).

[0068] In the example stack 200, a physical layer (PHY) 202A for EUTRA provides transport channels to a MAC sublayer 204A for EUTRA, which in turn provides logical channels to a RLC sublayer 206A for EUTRA. The RLC sublayer 206A for EUTRA in turn provides RLC channels to a PDCP sublayer 208 for EUTRA and, in some cases, to a PDCP sublayer 210 for NR. Similarly, a PHY 202B for NR provides transport channels to a MAC sublayer 204B for NR, which in turn provides logical channels to a RLC sublayer 206B for NR. The RLC sublayer 206B for NR in turn provides data transfer services to the PDCP sublayer 210 for NR. The PDCP sublayer 210 for NR in turn can provide data transfer services to a service data adaptation protocol (SDAP) 212 or a radio resource control (RRC) sublayer (not shown) in NR. In some implementations, the UE 102 supports both the EUTRA and NR stacks, as shown in FIG. 2A FIG. 2A EUTRA and NR interfaces. Further, as shown in FIG. 2A the UE 102 can support layering of NR PDCP 210 over EUTRA RLC 206A, and layering of the SDAP sublayer 212 over the NR PDCP sublayer 210.​

[0069] The EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 receive packets, which may be referred to as service data units (SDUs) (e.g., from an Internet Protocol (IP) layer layered directly or indirectly above the PDCP layer 208 or 210) and output packets, which may be referred to as protocol data units (PDUs) (e.g., to the RLC layer 206A or 206B). For simplicity, this disclosure refers to both SDUs and PDUs as "packets," except where the difference between SDUs and PDUs is relevant.

[0070] On the control plane, the EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 may provide a signaling radio bearer (SRB) or an RRC sublayer (not shown in FIG. 2 ) to exchange, for example, RRC messages or non-access stratum (NAS) messages. On the user plane, the EUTRA PDCP sublayer 208 and the NR PDCP sublayer 210 may provide a data radio bearer (DRB) to support data exchange. The data exchanged on the NR PDCP sublayer 210 may be SDAP PDUs, Internet Protocol (IP) packets, or Ethernet packets.

[0071] Therefore, it is possible to functionally split the radio protocol stack, e.g. FIG. 2B 204B, and NR PHY 202B) are delegated to the DU 174. To support connectivity to the 5GC, the NR PDCP 210 provides SRBs to the RRC 214, and the NR PDCP 210 provides DRBs to the SDAP 212 and SRBs to the RRC 214.

[0072] FIGS. 3A-3E This is a message sequence for an example scenario of SN Quality of Experience (QoE) Measurement Collection (QMC) and Reporting for a UE in DC. In general, FIGS. 3A-3E Equivalent events in the are marked with similar reference numerals (e.g. FIG. 3A Event 306 in is similar to FIGS. 3B-3E 306 in FIG), with differences discussed below where appropriate. In addition to the differences shown in the figures and discussed below, any of the alternative implementations discussed with respect to a particular event (e.g., for message delivery and processing) may apply to similarly numbered events in other figures, and may also apply to both integrated and distributed base stations.

[0073] First referenceFIG. 3A In scenario 300A, the UE initially operates 302 in dual connectivity mode with a master base station 104 of the RAN 105 and a secondary base station 106 of the RAN 105. When the UE is in or enters the DC mode, the MN 102 communicates with the CN 110 / OAM 180 and sends 304 a UE connection mode indication indicating that the UE is in the DC mode. The CN 110 / OAM 180 then determines 306 to configure a QoE configuration for the SN 106 for the UE 102. The CN 110 / OAM 180 sends 308 a command to the master base station 104 to activate QMC and reporting for the UE 102. Depending on the implementation, the QMC activation command can also include a specific reference identifier identifying the QoE configuration, such as a reference ID. In implementations in which the QMC does not include a specific reference ID, a Trace ID can be used to identify the QoE configuration. In other implementations, the CN 110 / OAM 180 sends one or more QoE configurations and / or any other information elements described above to the master base station 104 when communicating 308 with the master base station 104 and the UE 102.

[0074] In some implementations, the QMC activation is a Trace Start message (e.g., as defined in TS 32.421). In further implementations, the QMC activation command is included in an OAM-to-BS message or a CN-to-BS message, such as a Next Generation Application Protocol (NGAP) message. The CN 110 / OAM 180 can send 308 the CN-to-BS message or the OAM-to-BS message including the QMC activation command to the master base station 104, respectively. Depending on the implementation, the activation command includes one or more QoE configurations, a configuration identifier (i.e., configuration ID), a reference identifier (i.e., reference ID), a Trace ID, Interfaces to Trace IE, Trace Depth IE, TCE IP address (i.e., qoEReference), UE address (i.e., qoECollectionEntityAddress), an indication of the QMC activation and / or suspension status, and / or a TCE URI as interface IEs in the activation command (e.g., as defined in TS 32.421). Depending on the implementation, variables and functions with similar features can be named differently. In some implementations, the activation command includes an IE describing the scope information (i.e., areaScope). In implementations in which the QMC activation command includes more than one QoE configuration, the CN 110 or OAM 180 includes a specific reference ID for the QoE configuration in the QMC activation command. Depending on the implementation, the reference IDs can have the same or different values.

[0075] In some implementations, one or more QoE configurations are associated with a first Trace ID. In other implementations, CN 110 or OAM 180 includes additional Trace IDs for additional QoE configurations beyond the first QoE configuration in the QMC activation command. Depending on the implementation, each of the additional QoE configurations can have an additional Trace ID, or multiple QoE configurations can be associated with a single Trace ID. CN 110 or OAM 180 can generate different values ​​for each Trace ID.

[0076] The master base station 104 then sends 310 a message to the UE 102 reconfiguring radio resources for the UE 102, such as an RRC reconfiguration message. The UE 102 can send a "complete" message to the master base station 104 in response to the message 310, such as an RRC reconfiguration complete message (not shown). In some implementations, the master base station 104 generates a QoE configuration identifier, such as a QoE configuration ID, associated with the first QoE configuration and / or the first reference ID. The master base station 104 can also generate a specific QoE configuration ID for each of the QoE configurations and / or reference IDs. In further implementations, the master base station 104 includes the one or more QoE configurations in the reconfiguration message. In other implementations, the master base station 104 can send the one or more QoE configurations to the UE 102 in communications 306 with the UE 102, the secondary base station 106, and the CN 110. In response to receiving 310 the reconfiguration message, the UE 102 starts 318 QMC (QoE measurement collection) and reporting. Depending on the implementation, the UE 102 can start sending 320 uplink (UL) messages to the master base station 104 containing one or more QoE reports. In some implementations, the uplink message is an UL RRC message. The master base station 104 can then send 322 the one or more QoE reports to a trace collection entity (TCE) and / or a multi-cell / multicast coordination entity (MCE) 190. Depending on the implementation, the QoE reports can be encapsulated in a transparent container that the master base station 104 receives 320 from the UE 102 and forwards to the CN 110 or the OAM 180. In further implementations, the UE 102 sends 320 the QoE reports periodically. In other implementations, the UE 102 sends 320 the QoE reports in response to specific and / or pre-defined triggering events. The master base station 104 can immediately send 322 any received 320 QoE reports to the CN 110 or the OAM 180. In other implementations, the master base station 104 aggregates the QoE reports before sending a message including the QoE reports to the CN 110 or the OAM 180. In yet other implementations, the master base station 104 aggregates the QoE reports with QoE reports from other UEs before sending a message including the QoE reports to the CN 110 or the OAM 180.

[0077] In one implementation, the CN 110 or the OAM node 180 sends 312 a command to the secondary base station 106 to activate QMC and reporting for the UE 102, instead of sending 308 the command to the primary base station. The secondary base station 106 then sends 314 a message to the primary base station 104 to reconfigure radio resources for the UE 102. The primary base station 104 sends 316 a message to the UE 102 to reconfigure radio resources for the UE 102, such as an RRC reconfiguration message. In response to receiving 314 the reconfiguration message, the UE 102 starts 318 QMC and reporting. Depending on the implementation, the UE 102 can start sending 324 an uplink (UL) message to the primary base station 104, and the message can contain one or more QoE reports. In some implementations, the uplink message is an UL RRC message. The primary base station 104 can then send 326 the one or more QoE reports to the secondary base station 106. In one implementation, the UE 102 encapsulates the UL RRC message (e.g., QoE reports) for the SN in an UL RRC message to the MN. Thereafter, the secondary base station 106 then sends 328 the one or more QoE reports to a trace collection entity (TCE) and / or a multi-cell / multicast coordination entity (MCE) 190.

[0078] In one implementation, the CN 110 or the OAM node 180 sends 308 a command to the primary base station and sends 312 a command to the secondary base station 106 to activate QMC and reporting for the UE 102. In one implementation, the CN 110 or the OAM node 180 sends 312 to the secondary base station 106, and the QoE configuration is for the SN only. In another implementation, the CN 110 or the OAM node 180 sends 308 to the primary base station 104, and the QoE configuration is for both the MN and the SN.

[0079] In one implementation, the QoE configuration for the MN is for a first application service (e.g., a VR service), and the QoE configuration for the SN is for a second application service (e.g., MBS).

[0080] Events 324, 326, and 328 can be collectively referred to as the SN QoE reporting procedure 392. Events 302, 304, 306, 308, 310, 312, 314, 316, 318, 320, 322, 324, 326, and 328 can be collectively referred to as the SN QoE measurement configuration procedure 390.

[0081] Reference is now made to FIG. 3BScenario 300B is similar to 300A and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for the SN. However, here, the secondary base station 106 can send the QoE configuration directly to the UE 102 and can also receive the QoE measurement reports directly from the UE 102.

[0082] After determining to configure the UE with the QoE configuration 106, the CN 110 or OAM 180 sends 312 a QMC activation message to the secondary base station 106. The CN 110 or OAM 180 includes in the QMC activation message a command to modify one or more QoE configurations. The secondary base station 106 sends 315 a radio resource reconfiguration message (e.g., an RRC reconfiguration message) to the UE 102, which includes the command to modify one or more QoE configurations. In one implementation, the message includes radio bearer configuration for QoE reporting (e.g., SRB5 for QoE measurement report transmissions). Upon receiving 315 the radio resource reconfiguration message, the UE 102 starts 318 QMC and reporting. Depending on the implementation, the UE 102 can start sending 325 uplink (UL) messages to the secondary base station 106 containing one or more QoE reports. In some implementations, the uplink message is an UL RRC message. The secondary base station 106 then sends 329 the one or more QoE reports to a trace collection entity (TCE) and / or a multi-cell / multicast coordination entity (MCE) 190. Events 325 and 327 are collectively referred to as the SN QoE reporting procedure 393. Events 320 and 322 are collectively referred to as the SN QoE reporting procedure 394 in FIG. 3B . Events 302, 304, 306, 308, 310, 312, 315, 318, 320, 322, 325, and 327 are collectively referred to as the SN QoE measurement configuration procedure 390 in FIG. 3B .

[0083] Referring now to FIG. 3C , scenario 300C is similar to 300A and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for the SN. However, unlike scenario 300A, the primary base station 104 can send an SN interface message to the secondary base station 106 indicating the current QoE configuration.

[0084] After deciding to configure the QoE configuration 106 for the UE, CN 110 or OAM 180 sends 308 a QMC activation message to primary base station 104. CN 110 or OAM 180 includes a command to modify one or more QoE configurations in the QMC activation message. Primary base station 104 then sends 313 an SN interface including the QoE configuration to secondary base station 106. In response, secondary base station 106 may send 314 an RRC reconfiguration message to primary base station 104. Primary base station 104 then sends 316 a message, such as an RRC reconfiguration message, to UE 102 to reconfigure radio resources for UE 102. Depending on the implementation, the primary base station may send 316 the QoE configuration message to UE 102 regardless of receipt of response message 314.

[0085] UE 102, master base station 104, secondary base station 106 and TCE / MCE 190 perform SN QoE reporting process 392 or 393 or 394. Events 302, 304, 306, 308, 313, 314, 316 and 318 are FIG. 3C The above steps are collectively referred to as SN QoE measurement configuration process 390.

[0086] Now refer to FIG. 3D Scenario 300D is similar to 300C and similarly involves CN 110 / OAM 180, master base station 104, secondary base station 106, and UE 102 activating QMC and reporting for SN. However, unlike scenario 300C, secondary base station 106 sends QoE configuration for UE 102 over the SN link.

[0087] After deciding to configure QoE configuration 106 for the UE, CN 110 or OAM 180 sends 308 a QMC activation message to primary base station 104. CN 110 or OAM 180 includes a command to modify one or more QoE configurations in the QMC activation message. Primary base station 104 then sends 313 an SN interface including the QoE configuration to secondary base station 106. In response, secondary base station 106 then sends 315 a message to UE 102, such as an RRC reconfiguration message, to reconfigure radio resources for UE 102.

[0088] UE 102, master base station 104, secondary base station 106 and TCE / MCE 190 perform SN QoE reporting process 392 or 393. Events 302, 304, 306, 308, 313, 315 and 318 are FIG. 3D The above steps are collectively referred to as SN QoE measurement configuration process 390.

[0089] Now refer to FIG. 3EScenario 300E is similar to 300A and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for SNs. However, unlike scenario 300A, the secondary base station 106 sends the QoE configuration for the UE 102 over the SN link.

[0090] Reference is first made to FIG. 3E In scenario 300E, the UE initially operates 303 in SA (standalone) mode with the primary base station 104 of the RAN. When the UE is in or enters SA mode, the MN 102 communicates with the CN 110 / OAM 180 and sends 305 a UE connection mode indication indicating that the UE is in SA mode. The CN 110 / OAM 180 then decides 306 to configure the UE with a QoE configuration for SNs. The CN 110 / OAM 180 then sends 308 a command to the primary base station 104 to activate QMC and reporting for the UE 102. Depending on implementation, the QMC activation command can also include a specific reference identifier identifying the QoE configuration, such as a reference ID. In implementations in which the QMC does not include a specific reference ID, the Trace ID can be used to identify the QoE configuration. In other implementations, the CN 110 / OAM 180 sends one or more QoE configurations and / or any other information elements described above to the primary base station 104 when communicating 308 with the primary base station 104 and the UE 102.

[0091] In some implementations, the QMC activation is a Trace Start message (e.g., as defined in TS 32.421). In further implementations, the QMC activation command is included in an OAM-to-BS message or a CN-to-BS message such as a Next Generation Application Protocol (NGAP) message. The CN 110 / OAM 180 can send 308 a CN-to-BS message or an OAM-to-BS message including the QMC activation command to the master base station 104, respectively. Depending on the implementation, the activation command includes one or more QoE configurations, a configuration identifier (i.e., configuration ID), a reference identifier (i.e., reference ID), a Trace ID, Interfaces to Trace IE, TraceDepth IE, TCE IP address (i.e., qoEReference), UE address (i.e., qoECollectionEntityAddress), an indication of the QMC activation and / or suspension status, and / or TCE URI as interface IEs in the activation command (e.g., as defined in TS 32.421). Depending on the implementation, variables and functions with similar features can be named differently. In some implementations, the activation command includes an IE describing the area information (i.e., areaScope). In implementations where the QMC activation command includes more than one QoE configuration, the CN 110 or OAM 180 includes a specific reference ID for the QoE configuration in the QMC activation command. Depending on the implementation, the reference IDs can have the same or different values.

[0092] In some implementations, the one or more QoE configurations are associated with a first Trace ID. In other implementations, the CN 110 or OAM 180 includes an additional Trace ID for an additional QoE configuration beyond the first QoE configuration in the QMC activation command. Depending on the implementation, each of the additional QoE configurations can have an additional Trace ID, or multiple QoE configurations can be associated with a single Trace ID. The CN 110 or OAM 180 can generate different values for each Trace ID.

[0093] The master base station 104 then sends 330 a SgNB Addition Request to the secondary base station 106. In response, the base station 106 sends 332 a SgNB Addition Request Ack to the master base station 104. The master base station then sends 317 an RRC Reconfiguration message including the SCG configuration and the QoE configuration for the SN to the UE 102. In some implementations, the master base station 104 can send multiple RRC Reconfiguration messages to the UE 102 configuring the SCG configuration and the QoE configuration.

[0094] The UE 102 can send a "complete" message, such as an RRC Reconfiguration Complete message (not shown), to the master base station 104 in response to the message 317. In some implementations, the master base station 104 generates a QoE configuration identifier, such as a QoE configuration ID, associated with the first QoE configuration and / or the first reference ID. The master base station 104 can also generate a specific QoE configuration ID for each of the QoE configurations and / or reference IDs. In further implementations, the master base station 104 includes the one or more QoE configurations in the reconfiguration message. In other implementations, the master base station 104 can send the one or more QoE configurations to the UE 102 when communicating 306 with the UE 102, the secondary base station 106, and the CN 110. In response to receiving 317 the reconfiguration message, the UE 102 starts 318 QMC (QoE Measurement Collection) and reporting, and enters 302 the DC mode with the master base station 104 and the secondary base station 106. In response to the UE being in the DC mode, the MN 102 communicates with the CN 110 / OAM 180 and sends 304 a UE connection mode indication indicating that the UE is in the DC mode. The UE 102, the master base station 104, the secondary base station 106, and the TCE / MCE 190 then perform the SN QoE reporting procedure 392 or 393.

[0095] Next. FIGS. 4A-4D is a message sequence of an example scenario in which a UE detects radio link failure on a SN when SN Quality of Experience (QoE) Measurement Collection (QMC) and reporting is performed for a UE in DC. Generally, FIGS. 4A-4D equivalent events in FIG. 4A event 432 in FIGS. 4B-4D event 432 in, discussed below as appropriate. Except for the differences shown in the figures and discussed below, any of the alternative implementations discussed with respect to a particular event (e.g., for messaging and processing) can apply to events labeled with similar reference numbers in other figures, and can also apply to both integrated and distributed base stations.

[0096] Referring first to FIG. 4A In the scenario 400A, the UE initially performs 490 a SN QoE measurement reporting configuration procedure, which is similar to FIGS. 3A-3Dthe SN QoE measurement reporting configuration procedure. The UE 102 then detects 432 an RLF between the UE and the SN. In response to the RLF, the UE 102 sends 434 a SCGFailurelnformation message to the MN 104 and switches 436 the QoE measurement collection / reporting for the SN from the SCG leg to the MCG leg. The UE then performs 492 the SN QoE reporting procedure. In one implementation, the QoE reporting for the SN is switched from SRB5 to SRB4. In another implementation, the QoE reporting for the SN is switched from SN split SRB4 to MN split SRB4. In some implementations, the UE includes the current QoE configuration or QoE reporting or QoE reporting available indication in the SCGFailurelnformation message.

[0097] In response to the SCGFailurelnformation, the MN decides 438 to keep the SN and sends 442 a RRCReconfiguration message to the UE 102 including at least an SCG configuration (e.g., a ReconfigurationWithSync field or a secondaryCellGroup field of the SCG) to restore the SN link. The UE 102 then 444 applies the SCG configuration and restores the SN connection (e.g., applies the rach configuration from the SCG configuration and performs a rach procedure to again synchronize the SN). In response to the SN connection restoration, the UE 102 switches 448 the QoE measurement collection / reporting for the SN from the MCG leg to the SCG leg. The UE then performs 493 the SN QoE reporting procedure.

[0098] In one implementation, the MN 104 can decide to keep the SN connection but not to switch the QoE reporting from the MCG leg to the SCG leg. In response to this decision, the MN then includes a specific field (e.g., release SRB5 or release SCG split SRB4) in the 442 RRCReconfiguration message to request this.

[0099] Reference is now made to FIG. 4B Scenario 400B is similar to 400A and similarly involves the CN 110 / OAM 180, the master base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for the SN. However, unlike scenario 400A, the MN 104 decides to release the SN after the SN link failure.

[0100] After receiving 434 the SCGFailurelnformation from the UE 102, the MN 104 decides 439 to release the SN connection between the UE 102 and the SN 106. In response to the decision, the MN 104 sends 460 a SgNB Release Request message to the SN 106. The SN 106 then sends 462 a SgNB Release Request Ack message to the MN 104. In response to the SN release, the MN then sends 443 an RRCReconfiguration message including a SCG release field to the UE 102 and / or sends 405 a UE connected mode indication with a SA field to the CN 110 or OAM 180. In response to the RRCReconfiguration message, the UE 102 releases 445 the SN connection and keeps 449 QoE measurement collection / reporting for the SCG via the MCG leg. In one implementation, the CN 110 or OAM 180 sends 408 a QMC activation message to the MN 104 in response to the UE connected mode indication. The MN 104 then sends 444 an RRCReconfigugraiton including a QoE configuration to the UE 102. The UE 102 then (re)configures 449 QoE measurement collection / reporting for the SN via the MCG leg. The UE then performs 494 a SN QoE reporting procedure.

[0101] In one implementation, the SN 106 sends 464 a SN Status Transfer or 466 a DATA Forwarding or 468 a Secondary RAT Data Usage Report to the MN 104 in response to the SN release. The MN 104 or the SN 106 or the CN 110 or the OAM 180 then performs 470 a Path Update Procedure to update the SCG path to a MCG path in response to the SN release. After the path update, the MN 104 sends 472 a UE Context Release message to the SN 106.

[0102] In some implementations, the UE 102 includes a specific field in the SCGFailurelnformation indicating that it prefers to report QoE via the MCG leg. In response to the preference, the MN 104 decides to release the SN. In another implementation, the MN 104 decides to release the SN because the MN 104 is unable to recover the SN link (e.g., the SN is overloaded or the MN loses connection with the SN).

[0103] Events 439, 460, 462, 443, 405, 408, 444, 464, 466, 468, 470, 472, and 449 are collectively referred to as MN-initiated SN release and reconfiguration QoE procedure 480 in FIG. 4B

[0104] Reference is now made to FIG. 4C Scenario 400C is similar to 400A and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for the SN. However, unlike scenario 400A, the UE 102 suspends QoE measurement collection / reporting for the SN after an RLF on the SN.

[0105] In response to the RLF on the SN, the UE 102 suspends 437 QoE measurement collection / reporting for the SN. In one implementation, the UE 102 suspends QoE measurement reporting for the SN, but not QoE measurement collection for the SN. The MN then decides 438 to keep the SN and sends 442 the UE 102 an RRCReconfiguration message including at least an SCG configuration to restore the SN link. The UE 102 then 444 applies the SCG configuration and restores the SN connection. In response to the SN connection restoration, the UE 102 resumes 450 QoE measurement collection / reporting for the SN. The UE then performs 492 or 493 the SN QoE reporting procedure.

[0106] In one implementation, the UE 102 decides to suspend QoE measurement collection / reporting for the SN when the UE is not configured with QoE configuration for the MN (e.g., not configured with SRB4 for sending QoE measurement reports to the MN). In another implementation, the UE 102 decides to switch QoE measurements from the SCG leg to the MCG leg when the UE 102 is configured with QoE configuration for the MN.

[0107] Reference is now made to FIG. 4D Scenario 400D is similar to 400C and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for the SN. However, unlike scenario 400C, the MN 104 decides to release the SN after the SN link failure.

[0108] After the SN radio link failure, the UE 102, MN 104, SN 106, CN 110, or OAM 180 performs 480 the MN-initiated SN release and reconfiguration QoE procedure to (re)configure QoE measurement collection / reporting for the MN. The UE 102 then performs 494 the SN QoE reporting procedure. ​

[0109] Reference is now made to FIG. 5A In scenario 500A, the UE initially performs 590 a SN QoE measurement reporting configuration procedure, which is similar to the 390 SN QoE measurement reporting configuration procedure in FIGS. 3A-3D In scenario 500A, the UE initially performs 590 a SN QoE measurement reporting configuration procedure, which is similar to the 390 SN QoE measurement reporting configuration procedure in

[0110] Reference is now made to FIG. 5B Scenario 500B is similar to 500A and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, and the UE 102 activating QMC and reporting for the SN. However, unlike scenario 500A, after an RLF on the SN, the UE suspends the split SRB4 for QoE reporting for the SN and resumes the split SRB4 for QoE reporting for the SN after radio link recovery on the SN.

[0111] The UE 102 sends 434 a SCGFailureInformation message to the MN 104 and switches 436 QoE measurement collection / reporting for the SN from the SCG leg to the MCG leg. The UE then performs 492 a SN QoE reporting procedure. In one implementation, QoE reporting for the SN is switched from SRB5 to SRB4. In another implementation, QoE reporting for the SN is switched from SN split SRB4 to MN split SRB4. In some implementations, the UE includes the current QoE configuration or QoE reporting or QoE reporting available indication in the SCGFailureInformation message.

[0112] Reference is now made to FIG. 6A In scenario 600A, the UE initially performs 690 a SN QoE measurement reporting configuration procedure, which is similar to the 390 SN QoE measurement reporting configuration procedure in FIGS. 3A-3D390 SN QoE Measurement Report Configuration Procedure in SN 106. SN 106 decides 641 to release the SN connection between SN 106 and UE 102. In response to the decision, SN 106 sends 661 SgNB Release Request to MN 104. MN 104 then sends 663 SgNB Release Request Acknowledge to SN 106. UE 102, MN 104, SN 106, CN 110, and OAM 180 then perform events 642, 605, 608, 645, 644, 664, 666, 668, 670, 672, and 649, which are similar to FIG. 4B 442, 405, 408, 445, 444, 464, 466, 468, 470, 472, and 449 in FIG. UE 102 then performs a MN QoE reporting procedure 694, which is similar to the SN QoE reporting procedure 394. In some implementations, the SN connection release is determined by MN 104, not by SN 106.

[0113] Events 641, 661, 663, 642, 605, 608, 645, 644, 664, 666, 668, 670, 672, and 649 FIG. 6A It is collectively referred to as the SN-initiated SN release and QoE reconfiguration process.

[0114] Now refer to FIG. 6B In scenario 600B, the UE initially performs 690 the SN QoE measurement report configuration procedure, which is similar to FIGS. 3A-3D 390 SN QoE Measurement Report Configuration Procedure in

[0065] MN 104 decides 640 to change the UE's secondary node from SN 106 to T-SN 106B. In response to this decision, MN 104 sends 646 an SgNB Add Request message to T-SN 106B. T-SN 106B then sends 648 an SgNB Add Request Confirm message to MN 104. After receiving the confirmation from T-SN 106B, MN 104 sends 652 an SgNB Release Request message to SN 106 and sends 654 an RRC Reconfiguration message including the SCG configuration to UE 102. SN 106 then sends 652 an SgNB Release Request Confirm message to MN 104 in response to the SgNB Release Request message. In one implementation, the change of the secondary node may be decided by SN 106. SN 106 then sends an SgNB Change Required message to MN 104. In response to the SgNB Change Required message, the MN 104 may send 646 an SfNB Add Request message to the T-SN 106B.

[0115] In response to the message 654, the UE 102 then sends 676 an RRC reconfiguration complete message to the MN 104. The UE 102 then continues 662 to collect QoE data for the SN and suspends QoE reporting for the SN. In one implementation, the MN 104 can request the UE 102 to release the QoE configuration for the SN through the 654 RRC reconfiguration message (e.g., including a SCG QoE release field). In another implementation, the MN 104 can request the UE 102 to continue to collect QoE data for the SN and suspend QoE reporting for the SN through the 654 RRC reconfiguration message.

[0116] After receiving the RRC reconfiguration complete message, the MN 104 sends 656 an SgNB reconfiguration complete message to the SN 106 and sends 604 a UE connected mode indication message to the CN 110 or OAM 180 indicating that the UE 102 is in DC with the T-SN. In response to the UE connected mode indication, the CN 110 or OAM 180 can decide 606 to configure a QoE configuration. The CN 110 or OAM 180 then sends 609 a QMC activation including the QoE configuration to the T-SN 106B. The T-SN 106B then sends an RRC reconfiguration message to the UE 102 configuring the QoE configuration for the T-SN. After receiving the 655 RRC reconfiguration message from the MN 104, the UE 102 stops 674 QoE data collection for the SN and / or discards QoE reports for the SN. The UE 102 then applies 664 the new QoE configuration and starts QoE measurement collection / reporting for the T-SN. In one implementation, the UE 102 sends the QoE report for the SN to the MN 104 or the T-SN 106B (e.g., through the RRC reconfiguration complete message, or through a measurement report message on SRB4 or SRB5) before it discards the report. The UE then performs 692 or 693 the SN QoE reporting procedure, which is similar to 392 or 393.

[0117] In one implementation, the T-SN 106B can send the QoE configuration to the MN 104 after it receives the QoE configuration from the QMC activation, which is similar to 314. In another implementation, the CN 110 or OAM 180 can send the QMC activation including the QoE configuration to the MN 104 instead of sending it to the T-SN 106B, which is similar to 308. After receiving the QoE configuration from the T-SN 106B or the CN 110 or OAM 180, the MN 104 sends an RRC reconfiguration message to the UE 102 configuring the QoE configuration, which is similar to 310 or 316.

[0118] In some implementations, the UE 102 switches from SCG leg to MCG leg for QoE measurement collection / reporting for the SN after it receives 654 the RRC reconfiguration message from the MN 104, instead of performing event 662.

[0119] Reference is next made to FIG. 6C Scenario 600C is similar to 600B and similarly involves the CN 110 / OAM 180, the primary base station 104, the secondary base station 106, the target secondary base station 106B, and the UE 102 activating QMC for the SN and reporting. However, unlike scenario 600B, the CN 110 or OAM 180 decides to (re)configure the QoE measurement from the SN to the MN after the PSCell change.

[0120] After the PSCell change from the SN 106 to the T-SN 106B, the CN 110 or OAM decides 606 to configure the QoE configuration. In response to the decision, the CN 110 or OAM 180 sends 608 a QMC activation including the QoE configuration to the MN 104. The MN 104A then sends 655 an RRC reconfiguration message including the QoE configuration for the MN to the UE 102. After receiving 655 the RRC reconfiguration message from the MN 104, the UE 102 stops 674 QoE data collection for the SN and / or discards the QoE report for the SN. The UE 102 then applies 665 the new QoE configuration and starts QoE measurement collection / reporting for the MN. In one implementation, the UE 102 sends the QoE report for the SN to the MN 104 (e.g., through an RRC reconfiguration complete message, or through a measurement report message on SRB4 or SRB5) before it discards the report. The UE 102 then performs MN QoE reporting procedure 694, which is similar to SN QoE reporting procedure 394.

[0121] Reference is now made to FIG. 7A Method 700A can be implemented in a suitable UE and, in general, involves receiving a command to collect QoE data and then reporting the QoE data to the SN. For clarity, method 700A is discussed with reference to RAN 105 and UE 102.

[0122] At block 702, the UE 102 communicates with the RAN 105 and receives a QoE configuration for the SN from the MN (e.g., event 310 or 316 of FIG. 3). At block 704, the UE 102 starts QoE measurement collection and reporting for the SN (e.g., event 312 or 318 of FIG. 3). FIGS. 3A-3C 、 FIG. 3E At block 706, the UE 102 receives a command to stop QoE data collection for the SN (e.g., event 314 or 320 of FIG. 3). At block 708, the UE 102 stops QoE data collection for the SN (e.g., event 316 or 322 of FIG. 3). FIGS. 3A-3C 、 FIG. 3Eevent 320 or 324 of FIG. 7). Then, at block 706, the UE 102 sends the QoE measurement report for the SN to the MN (e.g., event 318 of FIG. 7). Then, at block 708, the UE 102 sends the QoE measurement report for the SN to the SN (e.g., event 325 of FIG. 7). FIGS. 3A-3C , FIG. 3E event 320 or 324 of FIG. 7). Then, at block 706, the UE 102 sends the QoE measurement report for the SN to the MN (e.g., event 318 of FIG. 7). Then, at block 708, the UE 102 sends the QoE measurement report for the SN to the SN (e.g., event 325 of FIG. 7).

[0123] Referring now to FIG. 7B , the method 700B is generally similar to the method 700A, but here the UE 102 receives the QoE configuration from the SN and reports the QoE report to the SN. More specifically, the differences between the methods are discussed below. FIG. 7A and FIG. 7B Referring now to

[0124] At block 703, the UE 102 communicates with the RAN 105 and receives the QoE configuration for the SN from the SN (e.g., event 315 of FIG. 7). At block 704, the UE 102 starts QoE measurement collection and reporting for the SN (e.g., event 318 of FIG. 7). Then, at block 707, the UE 102 sends the QoE measurement report for the SN to the SN (e.g., event 325 of FIG. 7). FIG. 3D FIG. 3D FIG. 3D

[0125] For clarity, the methods 800A-800J are discussed with specific reference to the RAN 105, the base station 104 as the primary base station, the base station 106 as the secondary base station, the CN 110 or OAM 180 as the QoE node (e.g., network node), and the UE 102.

[0126] Referring now to FIG. 8A , the method 800A can be implemented in a primary base station node of a suitable RAN and includes receiving one or more QoE configurations, reference identifiers, configuration identifiers, and information about associations between the reference identifiers and the configuration identifiers for secondary nodes. At block 808, the MN 104 communicates with the RAN 105 and receives the QoE configuration for the SN from the SN 106 or the CN 110 or OAM 180 (e.g., event 308 or 314 of FIG. 8). At block 810, the MN 104 determines to configure the QoE configuration for the SN via the MN link. Then, at block 812, the MN 104 sends the QoE configuration to the UE 102 (e.g., event 310 or 316 of FIG. 8). In one implementation, this flow omits block 810 and the MN 104 sends the received QoE configuration to the UE 102. FIGS. 3A-3C , FIG. 3E FIGS. 3A-3C FIG. 3E

[0127] Referring now to FIG. 8B ​​​​​​, method 800B is generally similar to method 800A, but here the MN 104 sends the QoE configuration to the SN 106, and the QoE configuration is SN-related. More specifically, the differences between the methods discussed below in FIG. 8A and FIG. 8B . At block 808, the MN 104 communicates with the RAN 105 and receives the QoE configuration for the SN from the CN 110 or OAM 180 (e.g., event 308 of FIG. 3C , FIG. 3D ). Then, at block 813, the MN 104 sends the QoE configuration to the UE 102 (e.g., event 313 of FIG. 3C , FIG. 3D ).

[0128] Referring now to FIG. 8C , method 800C can be implemented in a primary base station node of a suitable RAN and includes receiving one or more QoE measurement reports for a secondary base station. At block 814, the MN 104 communicates with the RAN 105 and receives the QoE measurement reports for the SN (e.g., events 320, 324 of FIGS. 3A-3E ). Then, at block 816, the MN 104 sends the QoE configuration to the SN 106 or TCE / MCE 190 (e.g., events 322 or 326 of FIGS. 3A-3E ).

[0129] Referring now to FIG. 8D , method 800D can be implemented in a primary base station node of a suitable RAN and includes receiving one or more QoE measurement reports for a secondary base station in standalone mode. At block 818, the MN 104 communicates with the RAN 105 and receives the QoE measurement configuration for the SN (e.g., event 308 of FIG. 3E ). At block 820, the MN 104 determines to configure the QoE configuration for the SN for the UE 102 and the SN connection between the UE 102 and the SN 106. Then, at block 822, the MN 104 sends the QoE configuration and the SCG configuration to the UE 102 (e.g., event 317 of FIG. 3E ).

[0130] Referring now to FIG. 8E , method 800E can be implemented in a secondary base station node of a suitable RAN and includes receiving one or more QoE measurement reports for a secondary base station. At block 824, the SN 106 communicates with the RAN 105 and receives the QoE measurement configuration for the SN (e.g., events 312 or 313 of FIG. 3A , FIG. 3C ). Then, at block 826, the SN 106 sends the QoE configuration to the MN 104 (e.g., events 314 or 315 of FIG. 3A ,FIG. 3C event 314).

[0131] Referring now to FIG. 8F , method 800F is generally similar to method 800E, but here the SN 106 sends the QoE configuration to the UE 102. More specifically, at block 824, the SN 106 communicates with the RAN 105 and receives a QoE measurement configuration for the SN (e.g., event 312 or 313 of FIG. 8B). Then, at block 827, the SN 106 sends the QoE configuration to the UE 102 (e.g., event 315 of FIG. 8B). FIG. 3B 、 FIG. 3D FIG. 3B 、 FIG. 3D

[0132] Referring now to FIG. 8G , method 800G can be implemented in a secondary base station node of a suitable RAN and includes receiving one or more QoE measurement reports for the secondary base station. At block 828, the SN 106 communicates with the RAN 105 and receives a QoE measurement report for the SN (e.g., events 325, 326 of FIG. 8B). Then, at block 830, the SN 106 sends the QoE configuration to the TCE / MCE 190 (e.g., event 327 or 328 of FIG. 8B). FIGS. 3A-3E 、 FIGS. 3A-3E

[0133] Referring now to FIG. 8H , method 800H can be implemented in a master base station node of a suitable RAN and includes detecting whether the UE is switched to DC mode or SA mode and indicating the change to the CN 110 or OAM 180. At block 832, the MN 104 communicates with the RAN 105 and detects whether the UE 102 has switched to DC or SA mode. Then, at block 834, the MN 104 sends an indication to the CN 110 or OAM 180 indicating that the UE connection mode is now DC or SA (e.g., events 304 or 305 of FIG. 8A). In one implementation, the MN indicates the UE connection mode to the CN 110 or OAM 180 after a PCell change or a PSCell change. FIGS. 3A-3E 、

[0134] Referring now to FIG. 8I , method 800K can be implemented in the CN 110 or OAM 180 and includes receiving an indication that the UE 102 is now operating in DC. At block 836, the CN 110 or OAM 180 receives an indication from the MN 104 that the UE is now in DC (e.g., event 304 of FIG. 8A). At block 838, the CN 110 or OAM 180 determines to configure a QoE configuration for the UE 102 (e.g., event 305 of FIG. 8A). FIGS. 3A-3D 、 FIGS. 3A-3D ​​​event 306). Then, at block 840, the MN 104 sends a QMC activation message to the MN 104 or the SN 106 (e.g., FIGS. 3A-3D event 308 or 312).

[0135] Referring now to FIG. 8J Method 800J is generally similar to method 800K, but here the CN 110 or OAM 180 receives an indication that the UE is now in SA mode. More specifically, at block 837, the CN 110 or OAM 180 receives an indication from the MN 104 that the UE 192 is in SA (e.g., FIG. 3E event 305). At block 838, the CN 110 or OAM 180 determines to configure QoE configuration for the UE 102 (e.g., FIG. 3E event 306). Then, at block 841, the MN 104 sends a QMC activation message to the MN 104 (e.g., FIG. 3E event 308).

[0136] Referring now to FIG. 9A Method 900A can be implemented in a suitable UE and includes performing QoE measurement collection and reporting for a secondary node, and subsequently detecting a radio link failure on the secondary node. For clarity, method 900A is discussed with reference to RAN 105 and UE 102.

[0137] At block 902, the UE 102 communicates with the RAN 105 and detects a radio link failure on the SN 104 (e.g., FIG. 4A , 4B event 432). At block 904, the UE 102 sends a SCGFailurelnformation message to the MN 104 (e.g., FIG. 4A , FIG. 4B event 434). At block 906, the UE 102 switches QoE measurement collection / reporting from the SCG leg to the MCG leg (e.g., FIG. 4A , FIG. 4B event 436). At block 908, the UE 102 successfully recovers the connection between the UE 102 and the SN 106 (e.g., FIG. 4A event 442). Then, at block 910, the UE 102 switches QoE measurement collection / reporting from the MCG leg to the SCG leg (e.g., FIG. 4A event 448). At block 912, the UE 102 determines that it cannot recover the connection between the UE 102 and the SN 106 (e.g., FIG. 4B event 443). Then, at block 914, the UE 102 retains QoE measurement collection / reporting via the MCG leg (e.g.,FIG. 4B Event 449).

[0138] Now refer to FIG. 9B , method 900B is generally similar to method 900A, but here UE 102 suspends QoE measurement collection / reporting for SN 106. More specifically, at block 902, UE 102 communicates with RAN 105 and detects a radio link failure on SN 106 (e.g., FIG. 4C 、 FIG. 4D At block 904, UE 102 sends a SCGFailureInformation message to MN 104 (e.g., FIG. 4C 、 FIG. 4D At block 907, UE 102 suspends QoE measurement collection / reporting for SN 104 (e.g., FIG. 4C 、 FIG. 4D At block 908, UE 102 successfully restores the connection between UE 102 and SN 106 (e.g., FIG. 4C Then, at block 911, UE 102 resumes QoE measurement collection / reporting (e.g., FIG. 4C At block 912, UE 102 determines that it cannot restore the connection between UE 102 and SN 106 (e.g., FIG. 4B Then, at block 914, UE 102 reconfigures QoE measurement collection / reporting via the MCG branch (e.g., FIG. 4B Event 449).

[0139] Now refer to FIG. 9C , method 900C is generally similar to method 900B, but here UE 102 determines whether to suspend QoE measurement collection / reporting for SN 106 in view of SRB4 configuration.

[0140] At block 902, UE 102 communicates with RAN 105 and detects a radio link failure on SN 104 (e.g., FIGS. 4A-4D At block 916, UE 102 determines whether UE 102 is configured with SRB4 (i.e., SRB for QoE reporting for MN). If so, flow proceeds to block 906, where UE 102 switches QoE measurement collection / reporting from the SCG leg to the MCG leg (e.g., FIG. 4A 、 FIG. 4B Otherwise, the process proceeds to block 907, where the UE suspends QoE measurement collection / reporting for SN 104 (e.g., FIG. 4C 、 FIG. 4Devent 437).

[0141] Referring now to FIG. 9D , method 900D is generally similar to method 900C, but here the UE 102 determines whether to suspend QoE measurement collection / reporting for the SN 106 in view of network configuration. More specifically, at block 917, the UE 102 determines whether SN QoE reporting via SRB4 is allowed. If so, flow proceeds to block 906, where the UE 102 switches QoE measurement collection / reporting from the SCG leg to the MCG leg (e.g., as event 436). FIG. 4A 、 FIG. 4B event 437). Otherwise, flow proceeds to block 907, where the UE 102 suspends QoE measurement collection / reporting for the SN 104 (e.g., as event 436). FIG. 4C 、 FIG. 4D event 437).

[0142] In some implementations, the UE 102 switches QoE measurement collection / reporting for the SN from the SCG leg to the MCG leg while the UE 102 is allowed to report SN QoE measurements via SRB4 and is configured with SRB4.

[0143] Referring now to FIG. 9E , method 900E can be implemented in a primary base station of a suitable RAN or a secondary base station node of a suitable RAN and includes receiving one or more QoE measurement reports for a secondary base station. For clarity, method 900E is discussed with specific reference to RAN 105, base station 104 as a primary base station, base station 106 as a secondary base station, CN 110 or OAM 180 as a QoE node (e.g., network node), and UE 102.

[0144] At block 918, the MN 104 or SN 106 communicates with the RAN 105 and determines to allow the UE to perform QoE measurement collection / reporting for the SN when the SN experiences RLF. Then, at block 920, the MN 104 or SN 106 includes an indication in a QoE configuration message (e.g., RRCReconfiguration message for configuring QoE) or configures the UE with a split SRB4. In one implementation, the MN 104 includes an indication of the configuration in system information.

[0145] Referring now to FIG. 10 , method 1000 can be implemented in a suitable UE and includes performing QoE measurement collection reporting for a secondary node and subsequently detecting a radio link failure associated with a primary node. For clarity, method 1000 is discussed with specific reference to RAN 105 and UE 102.

[0146] At block 1002, the UE 102 communicates with the RAN 105 and detects a radio link failure (e.g., event 532 of FIG. 5A , 5B event 534 of FIG. 5A or event 535 of FIG. 5B ) on the link to the MN 104. At block 1004, the UE 102 suspends the SRB5 or split SRB4 for QoE report transmission (e.g., event 536 of FIG. 5A , 5B event 538 of FIG. 5A ). Then, at block 1008, the UE 102 resumes the SRB5 or split SRB4 for QoE report transmission (e.g., event 540 of FIG. 5B or event 541 of .

[0147] Referring now to FIG. 11A , the method 1100A can be implemented in a suitable UE and includes receiving a SCG release message from a master base station and subsequently reconfiguring QoE measurement collection / reporting for a secondary node to a master node. For clarity, the method 1100A is discussed with specific reference to the RAN 105 and the UE 102.

[0148] At block 1102, the UE 102 communicates with the RAN 105 and receives a SCG release message from the MN 104 (e.g., RRCReconfiguration message includes SCG release field) (e.g., event 642 of FIG. 6A ). At block 1104, the UE 102 receives a QoE configuration from the MN 104 (e.g., event 644 of FIG. 6A ). Then, at block 1106, the UE 102 reconfigures QoE measurement collection / reporting for a secondary node to the master node 104 (e.g., event 649 of FIG. 6A ). In one implementation, the UE 102 reconfigures QoE measurement collection / reporting for a secondary node to the master node immediately after receiving the SN release request from the MN 104, and thus block 1104 is an optional block 1104.

[0149] Referring now to FIG. 11B, method 1100B can be implemented in a master base station node of a suitable RAN and includes determining to release the SN connection of the UE 102. For clarity, method 1100B is discussed with reference to RAN 105, base station 104 as a master base station, base station 106 as a secondary base station, CN 110 or OAM 180 as a QoE node (e.g., network node), and UE 102.

[0150] At block 1108, the MN 104 communicates with the RAN 105 and determines to release the SN connection of the UE 102 or receives an SgNB Release Request from the SN 104 (e.g., event 641 of FIG. 6A At block 1110, the MN 104 then sends SCG release information and QoE configuration information to the UE 102 (e.g., event 642 or 644 of FIG. 6A The MN 104 can include the SCG release information and QoE configuration information in one or more messages (e.g., in one or more RRCReconfiguration messages).

[0151] Reference is now made to FIG. 11C Method 1100C is generally similar to method 1100B, but here the MN 102 determines to keep (preserve) QoE report transmission via the SCG SRB.

[0152] At block 1108, the MN 104 communicates with the RAN 105 and determines to release the SN connection of the UE 102 or receives an SgNB Release Request from the SN 104. At block 1112, the MN 104 determines to keep QoE report transmission for the SN via the SCG SRB (e.g., SRB5 or split SRB4). At block 1114, the MN 104 then sends SCG release information and QoE configuration information to the UE 102 in one or more RRC messages. The UE 102 is connected to the SN 106 using only split SRB4 or SRB5 (i.e., no SRB3).

[0153] Reference is now made to FIG. 11D Method 1100D can be implemented in a suitable UE and includes receiving a SCG release message from a master base station at block 1116 and (re)configuring QoE measurement collection / reporting for a secondary node at block 1118.

[0154] Finally, FIG. 11E An example method in a MN (e.g., MN 104) is shown. At block 1120, the MN 104 determines to change a secondary node of the UE or receives an SgNB Change Required message from the SN 106 (e.g., event 650 of FIG. 6B , FIG. 6Cevent 640). At block 1122, the MN 104 sends an SgNB Addition Request message (e.g., FIG. 6B , 6C event 646). At block 1124, the MN 104 sends an SgNB Release Request message (e.g., FIG. 6B , 6C event 650). At block 1126, the MN 104 sends an indication to the CN 110 or OAM 180 that the UE is in DC and changes the secondary node to the T-SN 106B (e.g., FIG. 6B , 6C event 604). At block 1128, the MN 104 receives a QoE Activation message from the CN 110 or OAM 180 (e.g., FIG. 6C event 608). Then, at block 1130, the MN 104 sends a QoE configuration to the UE 102 (e.g., FIG. 6C event 655).

[0155] The present disclosure encompasses at least the following examples.

[0156] A method for managing quality of experience (QoE) reporting is implemented in a radio access network (RAN). The method includes facilitating, by processing hardware, reporting of QoE measurements for a user equipment (UE) to a QoE node; determining, by the processing hardware, to perform a handover of the UE from a source node in the RAN to a target node; and after the determining, sending a suspension status of the reporting.

[0157] A method for managing QoE reporting is implemented in a source node in a RAN. The method includes facilitating, by processing hardware, reporting of QoE measurements for a UE to a QoE node according to a plurality of QoE configurations; determining, by the processing hardware, to perform a handover of the UE from the source node in the RAN to a target node; and providing, by the processing hardware, identification information to the target node identifying a QoE configuration within the plurality of QoE configurations in response to the determining.

[0158] A method for managing QoE reporting is implemented in a target node in a RAN. The method includes receiving, by processing hardware, a plurality of QoE configurations associated with reporting of QoE measurements from a UE to a QoE node; facilitating, by the processing hardware, a handover of the UE from a source node in the RAN to the target node according to the plurality of QoE configurations; and receiving, by the processing hardware, identification information at the target node identifying a QoE configuration within the plurality of QoE configurations in response to the handover.

[0159] A method for managing QoE reporting is implemented in a UE. The method includes: reporting, by processing hardware, QoE measurements to a QoE node via a RAN; receiving, by the processing hardware, a command to perform a handover from a source cell in the RAN to a target cell in the RAN; and determining, by the processing hardware, whether to suspend reporting during the handover based on an indication received from the RAN.

[0160] A method for managing QoE reporting is implemented in a QoE node operating in or in communication with a core network (CN). The method includes: receiving, by processing hardware, QoE measurements from a UE via a source node in a RAN; sending, by the processing hardware, a command to change a pause state of reporting of the QoE measurements to the UE via the RAN; receiving, by the processing hardware, an indication from the RAN that the pause state has not been changed; and, in response to determining that the UE has completed handover from the source cell to the target cell, resending the command to change the pause state.

[0161] The following description can be applied to the above description.

[0162] Generally, the description for one of the above figures can apply to another of the above figures. The above examples, implementations and methods can be combined if not contradictory. The above events or blocks can be optional or can be omitted. For example, events or blocks in dashed lines in the figures can be optional. In some implementations, “message” is used and can be replaced with “information element (IE)” and vice versa. In some implementations, “IE” is used and can be replaced with “field” and vice versa. In some implementations, “configuration” can be replaced with “configurations” or “configuration parameters” and vice versa. In some implementations, “LTM command” can be replaced with “serving cell change command,” “layer 1 / layer 2 handover command,” “lower layer handover command,” or “lower layer serving cell change command.” In some implementations, “some” means “one or more.” In some implementations, “at least one” means “one or more.” In some implementations, “DU configuration” can be replaced with “cell group configuration.” In some implementations, “cell index” can be replaced with “candidate cell index,” “serving cell index,” “LTM cell index,” “special cell (SpCell) index,” “PCell index,” or “PSCell index.” In some implementations, “cell ID” can be replaced with a name such as “candidate cell ID,” “serving cell ID,” “SpCell ID,” “LTM cell ID,” “pCell ID,” or “PSCell ID.” In some implementations, “cell ID” and “cell ID” in CU-to-DU messages can be replaced with different names listed above.

[0163] A user device (e.g., UE 102) in which techniques of the present disclosure can be implemented can be any suitable device capable of wireless communication, such as a smartphone, a tablet computer, a laptop computer, a mobile gaming console, a point-of-sale (POS) terminal, a health monitoring device, a drone, a camera, a media streaming dongle or another personal media device, a wearable device such as a smartwatch, a wireless hotspot, a femtocell, or a broadband router. Further, in some cases, a user device can be embedded in a host unit such as a vehicle or an electronic system of an advanced driver-assistance system (ADAS). Still further, a user device can operate as an Internet of Things (IoT) device or a mobile internet device (MID). Depending on the type, a user device can include one or more general-purpose processors, computer-readable memory, a user interface, one or more network interfaces, one or more sensors, and the like.

[0164] Certain embodiments are described in this disclosure as including logic or a number of components or modules. Modules can be software modules (e.g., code, or machine readable instructions stored on non-transitory machine-readable medium) or hardware modules. A hardware module is a tangible unit capable of performing certain operations and can be configured or arranged in a certain manner. A hardware module can include dedicated circuitry or logic that is permanently configured to perform certain operations, such as a special-purpose processor, such as a field programmable gate array (FPGA) or application-specific integrated circuit (ASIC), a digital signal processor (DSP), etc. A hardware module can also include programmable logic or circuitry that is temporarily configured by software to perform certain operations, such as a general-purpose processor, or other programmable processor. The decision to implement a hardware module in dedicated and permanently configured circuitry, or in temporarily configured circuitry (such as by being implemented with software), can be driven by cost and time considerations.

[0165] When implemented in software, the techniques can be provided as part of an operating system, a library used by multiple applications, a particular software application, etc. The software can be executed by one or more general-purpose processors or one or more special-purpose processors.

[0166] As used herein, the term "or" shall be interpreted as inclusive or, meaning and / or, unless explicitly indicated otherwise or indicated otherwise by context. Therefore, in this document, expressions such as "A or B" mean "A, B, or both A and B."

[0167] In reading this disclosure, those skilled in the art will understand that there are yet additional and alternative structural and functional designs for handling mobility between base stations by the principles disclosed herein. Accordingly, although specific embodiments and applications have been illustrated and described, it is understood that the disclosed embodiments are not limited to the precise construction and compositions disclosed herein. Various modifications, changes, and variations apparent to those skilled in the art can be made in the arrangement, operation, and details of the methods and devices disclosed herein without departing from the scope defined in the claims.

Claims

1. A method implemented in a user equipment (UE), the method comprising: Communicate with MN via the master node MN link and with SN via the slave node SN link in dual connectivity DC; reporting Quality of Experience (QoE) measurements to the SN via the SN link; as well as In response to detecting a radio link failure (RLF) on the SN link, suspending the reporting of the QoE measurement via the SN link.

2. The method of claim 1 , further comprising, in response to detecting the RLF on the SN link: Continue collecting the QoE measurements.

3. The method of claim 1 or 2, further comprising, in response to detecting the RLF on the SN link: The reporting of the QoE measurements is switched from the SN link to the MN link.

4. The method according to claim 3, wherein: The switching includes: Switch from signalling radio bearer 5 SRB5 dedicated to reporting of the QoE measurements to SRB4.

5. The method according to claim 3, wherein: The switching includes: Switch from SN split SRB4 to MN split SRB4.

6. The method of claim 1 or 2, further comprising: It is determined that the UE is not configured to report the QoE measurement to the MN via the MN link.

7. The method according to any one of the preceding claims, further comprising: In response to detecting the RLF: Send an SCG fault information message to the MN.

8. The method of claim 7, wherein: The SCG fault information message includes one or more of the following: (i) Current QoE configuration, (ii) QoE reporting, or (iii) QoE reporting available indication.

9. The method according to any one of the preceding claims, further comprising: After the RLF failure is detected, a secondary cell group (SCG) recovery is performed on the SN link.

10. The method of claim 9, further comprising: In response to detecting the SCG recovery of the SN link, resuming the reporting of the QoE measurements via the SN link.

11. The method of any one of claims 1 to 8, further comprising: In response to detecting release of the SN link after detecting the RLF failure, reconfiguring QoE procedures associated with reporting to the SN via the SN link to configure subsequent reporting of the QoE measurements to the MN via the MN link.

12. The method of claim 11, wherein: Detecting the release of the SN link includes: An SCG release indication is received from the MN.

13. A method implemented in a first Radio Access Network (RAN) node, the method comprising: providing a primary node (MN) link to a user equipment (UE), wherein the user equipment communicates with the first RAN node operating as the MN and the second RAN node operating as the secondary node (SN) and providing an SN link in dual connectivity, and the UE reports quality of experience (QoE) measurements to the SN via the SN link; receiving an indication of a failure of the SN link from the UE; as well as An indication is sent to the UE indicating whether the UE is to switch the reporting of the QoE measurement to the MN link.

14. The method of claim 13, wherein: The indication instructs the UE to release SRB5 or split SRB4.

15. A device comprising a transceiver and processing hardware, the UE being configured to implement the method as claimed in any one of the preceding claims.

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