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Title:
METHODS FOR RAN-VISIBLE (LIGHTWEIGHT) QOE CONFIGURATION AND MEASUREMENT COORDINATION AMONG RAN NODES
Document Type and Number:
WIPO Patent Application WO/2022/164379
Kind Code:
A1
Abstract:
Methods for managing quality-of-experience, QoE, measurements by a user equipment, UE. A first example method, carried out by a first radio access network, RAN, node, comprises transmitting (1010), to a second node in the RAN, configuration information for one or more RAN-visible QoE measurements configured for the UE by the first node. The second node may be associated with the first node with respect to at least one of: changing a configuration for the UE for multi-connectivity; mobility for the UE; RRC resume or RRC reestablishment for the UE; and switching transfer of data for the service from a path going to the UE via the first RAN node to a path going to the UE via the second RAN node.(Fig. 10)

Inventors:
LUNARDI LUCA (IT)
RUNE JOHAN (SE)
BARAC FILIP (SE)
CENTONZA ANGELO (ES)
PARICHEHREHTEROUJENI ALI (SE)
EKLÖF CECILIA (SE)
Application Number:
PCT/SE2022/050096
Publication Date:
August 04, 2022
Filing Date:
January 31, 2022
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ERICSSON TELEFON AB L M (SE)
International Classes:
H04W24/08; H04W24/04
Foreign References:
US20200092762A12020-03-19
Other References:
HUAWEI: "Further discussions on the remaining open issues of QoE report visibility at RAN", vol. RAN WG3, no. E-meeting; 20210125 - 20210205, 15 January 2021 (2021-01-15), XP051969165, Retrieved from the Internet [retrieved on 20210115]
HUAWEI ET AL: "Discussions on potential RAN3 impacts about the QoE measurement configuration, reporting and releasing under SA, NSA and MR-DC operation", vol. RAN WG3, no. 20201102 - 20201112, 23 October 2020 (2020-10-23), XP051946081, Retrieved from the Internet [retrieved on 20201023]
QUALCOMM INCORPORATED: "Handling of NR QoE measurements", vol. RAN WG2, no. Electronic; 20210125 - 20210205, 15 January 2021 (2021-01-15), XP051974268, Retrieved from the Internet [retrieved on 20210115]
3GPP TS 36.331
3GPP TS 36.413
3GPP TS 28.405
3GPP TS 26.247
3GPP TS 23.501
3GPP TR 36.805
3GPP TS 38.331
3GPP TS 38.423
3GPP TS 38.413
3GPP TS 38.473
Attorney, Agent or Firm:
AYOUB, Nabil (SE)
Download PDF:
Claims:
CLAIMS

What is claimed is:

1. A method, for a first node in a radio access network, RAN, for managing quality-of- experience, QoE, measurements by a user equipment, UE, the method comprising: transmitting (1010), to a second node in the RAN, configuration information for one or more RAN-visible QoE measurements configured for the UE by the first node.

2. The method of claim 1, wherein the second node is associated with the first node with respect to at least one of: changing a configuration for the UE for multi -connectivity; mobility for the UE;

RRC resume or RRC reestablishment for the UE; and switching transfer of data for the service from a path going to the UE via the first RAN node to a path going to the UE via the second RAN node.

3. The method of claim 1 or 2, wherein the method comprises, prior to said transmitting, configuring the UE for the one or more RAN-visible QoE measurements.

4. The method of any one of claims 1-3, wherein the configuration information comprises one or more of any of the following: an indication of a service type for which the RAN-visible QoE is configured; an indication of whether a session pertained to an application from the service type for which the RAN-visible QoE configuration is configured is ongoing or not; an indication of a type of the QoE measurement; an indication of whether the first RAN node is interested to receive the RAN-visible QoE measurement results upon delivery of the RAN-visible QoE measurements from the wireless terminal to the second RAN node; an indication that a RAN-visible QoE report with information pertaining to the second RAN node has been received; an indication, signalled together with a RAN-visible QoE report, of whether the report has been already signalled to the TCE; and a RAN-visible QoE report received from a wireless terminal.

5. The method of any one of claims 1-4, wherein the status information is transmitted to the second node along with status information pertaining to one or more additional UEs.

6. The method of any one of claims 1-5, wherein the method further comprises sending (1020), to the second node, a request regarding the one or more RAN-visible QoE measurements, wherein the request comprises any one of: a request to send to the first RAN node the QoE reports received by the second RAN node; a request to support reception of RAN-visible QoE reporting; a request to suspend one or a list of the activated RAN-visible QoE measurements; a request to resume one or a list of the suspended RAN-visible QoE measurements; a request to release or to pause one or a list of the activated RAN-visible QoE measurements; and a request to configure the UE with a certain configuration of RAN-visible measurements or certain configuration of radio measurements linked to the QoE measurements.

7. The method of claim 6, wherein the request comprises additional conditions associated to the start and the stop of reporting, including at least one of any of: a reconfiguration of radio bearers at the UE which results in the switch of RAN node receiving the QoE reports; an overload indication sent from the first RAN node to the second RAN node; a period of time; until session end; until a subsequent mobility event is triggered; until further UE reconfiguration; a service type or service subtype; and a slice or list of slices.

8. The method of any of claims 6 or 7, wherein the method comprises receiving (1030), from the second node, a message acknowledging the request or indicating failure or inability to comply with the request.

9. The method of any one of claims 6-8, wherein the request pertains to multiple UEs.

10. A method, for a second node in a radio access network, RAN, for managing quality-of- experience, QoE, measurements by a user equipment, UE, the method comprising: receiving (1110), from a first node in the RAN, configuration information for one or more RAN-visible QoE measurements configured for the UE by the first node.

11. The method of claim 10, wherein the second node is associated with the first node with respect to at least one: changing a configuration for the UE for multi -connectivity; mobility for the UE;

RRC resume or RRC reestablishment for the UE; and switching transfer of data for the service from a path going to the UE via the first RAN node to a path going to the UE via the second RAN node.

12. The method of claim 10 or 11, wherein the configuration information comprises one or more of any of the following: an indication of a service type for which the RAN-visible QoE is configured; an indication of whether a session pertained to an application from the service type for which the RAN-visible QoE configuration is configured is ongoing or not; an indication of a type of the QoE measurement; an indication of whether the first RAN node is interested to receive the RAN-visible QoE measurement results upon delivery of the RAN-visible QoE measurements from the wireless terminal to the second RAN node; an indication that a RAN-visible QoE report with information pertaining to the second RAN node has been received; an indication, signalled together with a RAN-visible QoE report, of whether the report has been already signalled to the TCE; and a RAN-visible QoE report received from a wireless terminal.

13. The method of any one of claims 10-12, wherein the method comprises refraining from configuring or changing a configuration of QoE measurements by the UE, in response to the status information.

14. The method of any one of claims 10-13, wherein the method further comprises receiving (1120), from the first node, a request regarding the one or more RAN-visible QoE measurements, wherein the request comprises any one of: a request to send to the first RAN node the QoE reports received by the second RAN node; a request to support reception of RAN-visible QoE reporting; a request to suspend one or a list of the activated RAN-visible QoE measurements; a request to resume one or a list of the suspended RAN-visible QoE measurements; a request to release or to pause one or a list of the activated RAN-visible QoE measurements; and a request to configure the UE with a certain configuration of RAN-visible measurements or certain configuration of radio measurements linked to the QoE measurements.

15. The method of claim 14, wherein the request comprises additional conditions associated to the start and the stop of reporting, including at least one of any of: a reconfiguration of radio bearers at the UE which results in the switch of RAN node receiving the QoE reports; an overload indication sent from the first RAN node to the second RAN node; a period of time; until session end; until a subsequent mobility event is triggered; until further UE reconfiguration; a service type or service subtype; and a slice or list of slices.

16. The method of claim 14 or 15, the method further comprising responding with an indication of a status of execution of the request.

17. The method of claim 14 or 15, wherein the method comprises sending (1130) to the first node, in response to the request, a message acknowledging the request or indicating failure or inability to comply with the request.

18. The method of any one of claims 10-17, wherein the request pertains to multiple UEs.

19. A radio access network, RAN, node (1400) arranged to configure a user equipment, UE, to perform quality-of-experience, QoE, measurements, the RAN node (1400) comprising: communication interface circuitry (1440, 1450) configured to communicate with UEs and with a network node or function outside the RAN; and processing circuitry (1410, 1420, 1430) operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to carry out a method according to any of claims 1-18.

20. A radio access network, RAN, node (1400) arranged to configure user equipment (UEs) to perform quality-of-experience, QoE, measurements, the RAN node (1400) being further arranged to carry out a method according to any of claims 1-18.

21. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a radio access network, RAN, node arranged to configure user equipment (UEs) to perform quality-of-experience, QoE, measurements, configure the RAN node to carry out a method according to any of claims 1-18.

22. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a radio access network, RAN, node arranged to configure user equipment (UEs) to perform quality-of-experience, QoE, measurements, configure the RAN node to carry out a method according to any of claims 1-18.

23. A method for a user equipment, UE, for handling configurations of quality-of-experience, QoE, measurements in a radio access network, RAN, the method comprising: receiving (1210), from a RAN node, a RAN-visible QoE configuration; determining (1220) that the UE already has a RAN-visible QoE configuration for the same service type or application; and upon said determining, taking (1230) one or more of the following actions: discarding the new RAN-visible QoE configuration; releasing the old RAN-visible QoE configuration and configuring itself and the upper layers with the new RAN-visible QoE configuration; suspending the new configuration; suspending the old configuration and activating the new configuration; if the old configuration is already in a suspended state when the new configuration is received, keeping the new configuration active and either releasing the old configuration or keeping the old configuration suspended; if the type of the services/applications or a subtype of services is specified by the new RAN-visible QoE configuration, configuring itself and the upper layers of the targeted type or subtype of the services and/or targeted applications with the mentioned services and keeping the old RAN-visible QoE configuration for the rest of the applications; in a dual-connectivity scenario, if one of the RAN-visible QoE configurations was received from a master node while the other was received from a secondary node, releasing the RAN-visible QoE configuration received from the secondary node and keeping the RAN-visible QoE configuration received from the master node; in a dual -connectivity scenario, if one of the RAN-visible QoE configurations was received from a master node while the other was received from a secondary node, suspending the RAN-visible QoE configuration received from the secondary node and keeping the RAN-visible QoE configuration received from the master node active; if an ongoing application session of the type of service and/or subtype of service that the RAN-visible QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the old configuration was received, keeping the old configuration and either releasing or suspending the new configuration; and if an ongoing application session of the type of service and/or subtype of service that the RAN-visible QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the new configuration was received, keeping the new configuration and either releasing or suspending the old configuration. pment, UE, (1300) configured to perform quality-of-experience, QoE, measurements in a radio access network, RAN, the UE (1300) comprising: radio transceiver circuitry (1340) configured to communicate with at least one RAN node; and processing circuitry (1310, 1320, 1330) operatively coupled to the radio transceiver circuitry, whereby the processing circuitry and the radio transceiver circuitry are configured to carry out the method of claim 23.

25. A user equipment, UE, (1300) configured to perform quality-of-experience, QoE, measurements in a radio access network, RAN, the UE being further arranged to carry out the method of claim 23.

26. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment, UE, configured to perform quality-of-experience, QoE, measurements in a radio access network, RAN, configure the UE to carry out the method of claim 23.

27. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a user equipment, UE, configured to perform quality-of- experience, QoE, measurements in a radio access network, RAN, configure the UE to carry out the method of claim 23.

Description:
METHODS FOR RAN- VISIBLE (LIGHTWEIGHT) QOE CONFIGURATION AND MEASUREMENT COORDINATION AMONG RAN NODES

TECHNICAL FIELD

The present invention generally relates to wireless communication networks and particularly relates to efficient techniques for configuring, performing, and reporting various quality-of-experience (QoE) measurements by user equipment (UE) in a wireless network.

BACKGROUND

Long-Term Evolution (LTE) is an umbrella term for the so-called fourth-generation (4G) radio access technologies developed within the Third-Generation Partnership Project (3GPP) and initially standardized in Release 8 (Rel-8) and Release 9 (Rel-9) LTE, which is also known as Evolved UMTS Radio Access Network (E-UTRAN) is targeted at various licensed frequency bands and is accompanied by improvements to non-radio aspects commonly referred to as System Architecture Evolution (SAE), which includes the Evolved Packet Core (EPC) network. LTE continues to evolve through subsequent releases.

3 GPP LTE Release 10 (Rel-10) supports bandwidths larger than 20 MHz. One important Rel-10 requirement is backward compatibility with LTE Rel-8, including spectrum compatibility. Thus, a wideband LTE Rel-10 carrier (e.g., wider than 20 MHz) should appear as a plurality of carriers (“component carriers” or CCs) to an LTE Rel-8 (“legacy”) terminal. Legacy terminals can be scheduled in all parts of the wideband LTE Rel-10 carrier. One way to achieve this is by Carrier Aggregation (CA), whereby a Rel-10 terminal can receive multiple CCs, each preferably having the same structure as a Rel-8 carrier. Additionally, LTE Rel-12 introduced dual connectivity (DC) whereby a UE can be connected to two network nodes simultaneously, thereby improving connection robustness and/or capacity.

Currently the fifth generation (“5G”) of cellular systems, also referred to as New Radio (NR), is being standardized within the Third-Generation Partnership Project (3GPP). NR is developed for maximum flexibility to support multiple and substantially different use cases. These include enhanced mobile broadband (eMBB), machine type communications (MTC), ultra-reliable low latency communications (URLLC), side-link device-to-device (D2D), and several other use cases.

5G/NR technology shares many similarities with LTE. For example, NR uses CP- OFDM (Cyclic Prefix Orthogonal Frequency Division Multiplexing) in the downlink (DL, i.e., transmissions from the network) and both CP-OFDM and DFT-spread OFDM (DFT-S- OFDM) in the uplink (UL, i.e., transmissions to the network). As another example, in the time domain, NR DL and UL physical resources are organized into equal-sized 1-ms subframes. A subframe is further divided into multiple slots of equal duration, with each slot including multiple OFDM-based symbols.

However, time-frequency resources can be configured much more flexibly for an NR cell than for an LTE cell. Furthermore, In addition to providing coverage via cells as in LTE, NR networks also provide coverage via “beams.” In general, a DL “beam” is a coverage area of a network-transmitted reference signal (RS) that may be measured or monitored by a user equipment (UE, e.g., wireless communication device).

Quality of Experience (QoE) measurements have been specified for UEs operating in LTE networks and in earlier-generation UMTS networks. Measurements in both networks operate according to the same high-level principles. Their purpose is to measure the experience of end users when using certain applications over a network. For example, QoE measurements for streaming services and for MTSI (Mobility Telephony Service for IMS) are supported in LTE. QoE measurements will also be needed for UEs operating in NR networks, and thus QoE measurements are being specified for NR.

The solutions in LTE and UMTS are similar, with the overall principles as follows. Quality of Experience Measurement Collection (QMC) enables configuration of application layer measurements in the UE and transmission of QoE measurement results by means of Radio Resource Control (RRC) signalling. An application layer measurement configuration received from OAM or the core network (CN) is encapsulated in a transparent container, which is forwarded to the UE in a downlink RRC message. Application layer measurements received from the UE's higher layer are encapsulated in a transparent container and sent to the network in an uplink RRC message. The result container is forwarded to a Trace Collector Entity (TCE).

A new study item for “Study on NR QoE management and optimizations for diverse services” has been approved for NR Rel-17. The purpose is to study solutions for QoE measurements in NR, not only for streaming services as in LTE but also for other services such as augmented or virtual reality (AR/VR), URLLC, etc. Based on requirements of the various services, the NR study will also include more adaptive QoE management schemes that enable intelligent network optimization to satisfy user experience for diverse services.

Radio Resource Control (RRC) signaling is used to configure application layer measurements in UEs and to collect QoE measurement result files from the configured UEs. In particular, an application layer measurement configuration from a core network (e.g., EPC) or a network operations/administration/maintenance (OAM) function (also referred to as “network management system” or “NMS”) is encapsulated in a transparent container and sent to a UE’s serving RAN node, which forwards it to the UE in an RRC message. Application layer measurements made by the UE are encapsulated in a transparent container and sent in an RRC message to the serving RAN node, which forwards the container to a Trace Collector Entity (TCE) or a Measurement Collection Entity (MCE) associated with the core network.

The measurements may be initiated towards RAN in a management-based manner, i.e., from an O&M node, in a generic way, e.g., for a group of UEs, or they may also be initiated in a signaling-based manner, i.e., initiated from CN to RAN, e.g., for a single UE. The configuration of the measurement includes the measurement details, which is encapsulated in a container that is transparent to RAN.

When initiated via the core network, the measurement is started towards a specific UE. For the LTE case, the “TRACE START” S1AP message is used, which carries, among other things, details about the measurement configuration the application should collect (in the “Container for application layer measurement configuration” information element, transparent to the RAN) and the details to reach the trace collection entity to which the measurements should be sent.

The RAN is not aware of when the streaming session is ongoing in the UE Access Stratum and is also not aware of when the measurements are ongoing. It is an implementation decision when RAN stops the measurements. Typically, it is done when the UE has moved outside the measured area.

One opportunity provided by legacy solutions is also to be able to keep the QoE measurement for the whole session, even during handover situation. Further background of the LTE (E-UTRAN) solutions is provided below.

E-UTRAN - Application layer measurement capabilities

For E-UTRAN, the UE capability transfer is used to transfer UE radio access capability information from the UE to E-UTRAN. This is shown in Figure 1.

The UE-EUTRA-Capability information element (IE) is used to convey the E- UTRA UE Radio Access Capability Parameters and the Feature Group Indicators for mandatory features to the network.

In the response message “UECapabilitylnformation,” the UE can include the “UE- EUTRA-Capability” IE. The “UE-EUTRA-Capability” IE may include the UE-EUTRA- Capability -V1530-IE, which can be used by the UE to indicate whether the UE supports QoE Measurement Collection for streaming services and/or MTSI services, as detailed in the “MeasParameters-vl530” encoding below.

The contribution CR 4297 (R2-2004624) for 3GPP TS 36.331 vl6.0.0 at the 3GPP TSG RAN2 Meeting #110 proposed an extension of the “UE-EUTRA-Capability” IE that may include, within the “UE-EUTRA-Capability-vl6xy-IE,” a “measParameters-vl6xy” comprising the qoe-Extensions-rl6 IE. The qoe-Extensions-rl6 IE may be used to indicate whether the UE supports the Release 16 extensions for QoE Measurement Collection, i.e., whether the UE supports more than one QoE measurement type at a time and whether the UE supports the signaling of withinArea, sessionRecordinglndication, qoe-Reference, temporary StopQoE and restartQoE.

E-UTRAN - Application layer measurement reporting

The purpose of the “Application layer measurement reporting” procedure described in 3GPP TS 36.331 and shown in Figure 2 is to inform E-UTRAN about application layer measurement report.

A UE capable of application layer measurement reporting in RRC CONNECTED may initiate the procedure when configured with application layer measurement, i.e., when measConfigAppLayer has been configured by E-UTRAN.

Upon initiating the procedure, the UE shall: l>if configured with application layer measurement, and SRB4 is configured, and the UE has received application layer measurement report information from upper layers: 2> set the measReportAppLayerContainer in the MeasReportAppLayer message to the value of the application layer measurement report information;

2> set the serviceType in the MeasReportAppLayer message to the type of the application layer measurement report information;

2> submit the MeasReportAppLayer message to lower layers for transmission via SRB4.

E-UTRAN - QoE measurement configuration setup and release - RRC signaling

The RRCConnectionReconfiguration message is used to reconfigure the UE to setup or release the UE for Application Layer measurements. This is signaled in the measConfigAppLayer- 15 IE within the “OtherConfig” IE.

The setup includes the transparent container measConfigAppLayerContainer which specifies the QoE measurement configuration for the application of interest and the serviceType IE to indicate the application (or service) for which the QoE measurements are being configured. Supported services are streaming and MTSI.

The contribution CR 4297 (R2-2004624) for 3GPP TS 36.331 vl6.0.0 at the 3GPP TSG RAN2 Meeting #110 proposed to extend the QoE measurement configuration.

The measConfigAppLayerToAddModList-rl6 may be used to add or modify multiple QoE measurement configurations (up to maxQoE-Measurement-rl6). The measConfigAppLayerToReleaseList-rl6 IE may be used to remove multiple QoE measurement configuration (up to maxQoE-Measurement-rl6).

E-UTRAN - QoE measurement reporting - RRC signaling

As specified in 3GPP TS 36.331, the MeasReportAppLayer RRC message is used by the UE to send to the E-UTRAN node the QoE measurement results of an application (or service). The service for which the report is being sent is indicated in the “serviceType” IE.

The contribution CR 4297 (R2-2004624) for 3GPP TS 36.331 vl6.0.0 at the 3GPP TSG RAN2 Meeting #110 proposed to extend the MeasReportAppLayer IES introducing a QoE reference comprising the PLMN identity and the identifier of the QoE Measurement Collection.

For E-UTRAN, an example of desired UE behavior for application-layer measurement reporting is described in CR 4297 (R2-2004624).

UE Application layer measurement configuration

The “UE Application layer measurement configuration” IE is described in 3GPP TS 36.413 V16.3.0 and TS 36.423 vl6.3.0.

Area scope for QoE measurements

According to 3 GPP TS 28.405, the area scope parameter defines the area in terms of cells or Tracking Area/Routing Area/Location Area where the QoE Measurement Collection (QMC) shall take place. If the parameter is not present, the QMC shall be done throughout the PLMN specified in PLMN target.

The area scope parameter in UMTS is either:

- List of cells, identified by CGI. Maximum 32 CGI can be defined.

- List of Routing Area, identified by RAI. Maximum of 8 RAIs can be defined.

- List of Location Area, identified by LAI. Maximum of 8 LAIs can be defined. The area scope parameter in LTE is either:

- list of cells, identified by E-UTRAN-CGI. Maximum 32 CGI can be defined.

- List of Tracking Area, identified by TAC. Maximum of 8 TAC can be defined. The parameter is mandatory if area based QMC is requested.

SUMMARY

Embodiments of the techniques and apparatuses described herein enable a coordinated handling, between RAN nodes, of configurations for RAN visible (lightweight) QoE measurements.

Some embodiments of the present disclosure include exemplary methods (e.g., procedures) for managing quality-of-experience (QoE)measurements in a radio access network (RAN). These exemplary methods can be performed by a user equipment (UE, e.g., wireless device, loT device, modem, etc.) in communication with a radio access network (RAN) node (e.g., base station, eNB, gNB, ng-eNB, en-gNB, etc.).

An example method according to some of the embodiments described herein is carried out by a first node in a radio access network (RAN), for managing quality-of- experience (QoE) measurements by a user equipment (UE). This example method includes the step of transmitting, to a second node in the RAN, configuration information for one or more RAN visible (lightweight) QoE measurements configured for the UE by the first node.

A corresponding method according to some of the embodiments described herein is carried out by a second node in a radio access network (RAN), for managing quality-of- experience (QoE) measurements by a user equipment (UE). This example method includes the step of receiving, from a second node in the RAN, configuration information for one or more RAN visible (lightweight) QoE measurements configured for the UE by the first node.

Other embodiments include a method for a user equipment (UE) for handling configurations of quality-of-experience (QoE) measurements in a radio access network (RAN). This example method includes the steps of receiving, from a RAN node, a RAN visible (lightweight) QoE measurement configuration, and determining that the UE already has a QoE configuration for the same service type or application. The method further includes, upon said determining, taking one or more of the following actions: discarding the new RAN visible (lightweight) QoE configuration; releasing the old RAN visible (lightweight) QoE configuration and configuring itself and the upper layers with the new RAN visible (lightweight) QoE configuration; suspending the new configuration; suspending the old configuration and activating the new configuration; if the old configuration is already in a suspended state when the new configuration is received, keeping the new configuration active and either releasing the old configuration or keeping the old configuration suspended; if the type of the services/applications or a subtype of services is specified by the new RAN visible (lightweight) QoE configuration, configuring itself and the upper layers of the targeted type or subtype of the services and/or targeted applications with the mentioned services and keeping the old RAN visible (lightweight) QoE configuration for the rest of the applications; in a dual connectivity scenario, if one of the RAN visible (lightweight) QoE configurations was received from a master node while the other was received from a secondary node, releasing the RAN visible (lightweight) QoE configuration received from the secondary node and keeping the RAN visible (lightweight) QoE configuration received from the master node; in a dual connectivity scenario, if one of the RAN visible (lightweight) QoE configurations was received from a master node while the other was received from a secondary node, suspending the RAN visible (lightweight) QoE configuration received from the secondary node and keeping the RAN visible (lightweight) QoE configuration received from the master node active; if an ongoing application session of the type of service and/or subtype of service that the RAN visible (lightweight) QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the old configuration was received, keeping the old configuration and either releasing or suspending the new configuration; and if an ongoing application session of the type of service and/or subtype of service that the RAN visible (lightweight) QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the new configuration was received, keeping the new configuration and either releasing or suspending the old configuration.

Various embodiments of the solutions described herein enable mechanisms to transfer the RAN visible (lightweight) QoE measurement configuration and status information among the RAN nodes, enabling proper handling of the measurements by the node receiving the information, node sending the information and/or both. In addition, these mechanisms allow the gNB-CU to forward the RAN visible (lightweight) QoE report to the gNB-DU, hence the gNB-Du can use the RAN visible (lightweight) QoE measurements in its optimizations and algorithms. For example a gNB-DU can use the RAN visible QoE metric such as buffer level to tune its link adaptation and scheduling policies These and other objects, features, and advantages of embodiments of the present disclosure will become apparent upon reading the following Detailed Description in view of the Drawings briefly described below.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 illustrates UE capability transfer in LTE (E-UTRAN).

Figure 2 shows application layer measurement reporting in E-UTRAN.

Figure 3 is a high-level block diagram of an example architecture of the Long-Term Evolution (LTE) Evolved UTRAN (E-UTRAN) and Evolved Packet Core (EPC) network, as standardized by 3 GPP.

Figure 4 and Figure 5 illustrate two high-level views of an example 5G/NR network architecture.

Figure 6 shows an example configuration of NR user plane (UP) and control plane (CP) protocol stacks.

Figures 7A, 7B, 7C and 7D show various procedures between a UTRAN and a UE for quality-of-experience (QoE) measurements in a legacy UMTS network.

Figures 8A and 8B illustrate various aspects of QoE measurement configuration for a UE in an LTE network.

Figures 9A, 9B and 9C illustrate various aspects of QoE measurement collection for a UE in an LTE network.

Figure 10 is a flow diagram of an example method (e.g., procedure) for a first RAN node (RNN, e.g., eNB, gNB, ng-eNB, etc. or component(s) thereof), according to various example embodiments of the present disclosure.

Figure 11 is a flow diagram of an example method (e.g., procedure) for a second RAN node (RNN, e.g., eNB, gNB, ng-eNB, etc. or component(s) thereof), according to various example embodiments of the present disclosure.

Figure 12 is a flow diagram of an example method (e.g., procedure) for a user equipment (UE, e.g., wireless device, loT device, etc. or component s) thereof), according to various example embodiments of the present disclosure.

Figure 13 is a block diagram of an example wireless device or UE according to various example embodiments of the present disclosure.

Figure 14 is a block diagram of an example network node according to various example embodiments of the present disclosure. Figure 15 is a block diagram of an example network configured to provide over-the- top (OTT) data services between a host computer and a UE, according to various example embodiments of the present disclosure.

DETAILED DESCRIPTION

Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Other embodiments, however, are contained within the scope of the subject matter disclosed herein, and the disclosed subject matter should not be construed as limited to only the embodiments set forth herein; rather, these embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa.

Furthermore, the following terms are used throughout the description given below:

• Radio Node: As used herein, a “radio node” can be either a “radio access node” or a “wireless device.”

• Radio Access Node: As used herein, a “radio access node” (or equivalently “radio network node,” “radio access network node,” or “RAN node”) can be any node in a radio access network (RAN) of a cellular communications network that operates to wirelessly transmit and/or receive signals. Some examples of a radio access node include, but are not limited to, a base station (e.g., a New Radio (NR) base station (gNB/en-gNB) in a 3GPP Fifth Generation (5G) NR network or an enhanced or evolved Node B (eNB/ng-eNB) in a 3GPP LTE network), base station distributed components (e.g., CU and DU), base station control- and/or user-plane components (e.g., CU-CP, CU-UP), a high-power or macro base station, a low-power base station (e.g., micro, pico, femto, or home base station, or the like), an integrated access backhaul (IAB) node, a transmission point, a remote radio unit (RRU or RRH), and a relay node. Thus, the term “RAN node” may apply to any of, forexample: gNB, eNB, en-gNB, ng-eNB, gNB-CU, gNB-CU-CP, gNB-CU-UP, eNB-CU, eNB-CU-CP, eNB-CU-UP, lAB-node, lAB-donor DU, lAB-donor-CU, IAB-DU, IAB-MT, O-CU, O-CU-CP, O-CU-UP, O-DU, O-RU, O-eNB.

• Core Network Node: As used herein, a “core network node” is any type of node in a core network. Some examples of a core network node include, e.g., a Mobility Management Entity (MME), a serving gateway (SGW), a Packet Data Network Gateway (P-GW), an access and mobility management function (AMF), a session management function (AMF), a user plane function (UPF), a Service Capability Exposure Function (SCEF), or the like.

• Wireless Device: As used herein, a “wireless device” (or “WD” for short) is any type of device can obtain access to (i.e., to be served by) a cellular communications network by communicating wirelessly with network nodes and/or other wireless devices. Communicating wirelessly can involve transmitting and/or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and/or other types of signals suitable for conveying information through air. Some examples of a wireless device include, but are not limited to, smart phones, mobile phones, cell phones, voice over IP (VoIP) phones, wireless local loop phones, desktop computers, personal digital assistants (PDAs), wireless cameras, gaming consoles or devices, music storage devices, playback appliances, wearable devices, wireless endpoints, mobile stations, tablets, laptops, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), smart devices, wireless customer-premise equipment (CPE), mobile-type communication (MTC) devices, Internet-of-Things (loT) devices, vehicle-mounted wireless terminal devices, etc. Unless otherwise noted, the term “wireless device” is used interchangeably herein with the term “user equipment” (or “UE” for short).

• Network Node: As used herein, a “network node” is any node that is either part of the radio access network (e.g., a radio access node or equivalent name discussed above) or of the core network (e.g., a core network node discussed above) of a cellular communications network. Functionally, a network node is equipment capable, configured, arranged, and/or operable to communicate directly or indirectly with a wireless device and/or with other network nodes or equipment in the cellular communications network, to enable and/or provide wireless access to the wireless device, and/or to perform other functions (e.g., administration) in the cellular communications network.

• The terms “QoE measurement report”, “QoE report”, “measurement report” and “report” are used interchangeably.

• The terms “QoE measurement configuration”, “QoE measurement”, “QoE configuration” and “application layer measurement configuration” are used interchangeably.

• The terms “service” and “application” are used interchangeably.

• The terms “MCE” and “TCE” are used interchangeably.

Note that the description herein focuses on a 3 GPP cellular communications system and, thus 3GPP terminology or terminology similar to 3GPP terminology is oftentimes used. However, the concepts disclosed herein are not limited to a 3GPP system. Furthermore, although the term “cell” is used herein, it should be understood that (particularly with respect to 5G NR) beams may be used instead of cells and, accordingly, concepts described herein apply equally to both cells and beams.

As briefly summarized above, it has been agreed for 3GPP Rel-17 to provide RAN nodes visibility into QoE reports so that RAN nodes can adapt various aspects of their performance based on UE QoE measurements. However, there are various problems, issues, and/or difficulties in adapting conventional QoE measurements for use by RAN nodes in this manner. This is discussed in more detail below, after the following description of LTE and NR network architectures.

One approach to handling QoE measurements for a UE when setting up and operating in dual connectivity, with a first network node acting as MN and a second network node acting as SN, might comprise the following steps, as performed by a first RAN node:

Creating QoE configurations for the UE; and

Sending all or part of the QoE configuration to the UE;

Sending all or part of the QoE configurations to the second network node when setting up or reconfiguring the SN, wherein the SN related and MN related QoE configuration may be different;

- Possibly receiving QoE measurement result data from the second network node.

This approach might also fulfil the requirement that measurements should continue until the end of the session, even if the UE moves outside the area during the session - this can be done, for example, by having the network control the start and stop of the measurements due to area updates. In one approach, for example, the network might send the release command to release the QoE measurements. A session feedback indication may be used by the network as a help to know when to stop the measurements, for example. These approaches may be used, for example, if the UE performs handover or re-establishes its connection to a cell controlled by a node that is outside of the configured area.

Another technique for QoE measurement involves what might be referred to as “lightweight” QoE measurements, which are QoE related measurements complementary to the QoE metrics (also called “conventional QoE measurements” in the remainder of this document). According to this approach, a RAN node can configure a wireless terminal with Lightweight QoE measurements.

As used herein, the term “lightweight QoE measurement” (or “lightweight QoE metric”) refers to any measurement that is different from any of the legacy QoE measurements specified in 3GPP TS 26.247, 26.114, 26.118, and 26.346, at least in a manner that requires fewer information bits to transmit than a corresponding legacy QoE measurement. The term “RAN visible” is also used herein synonymously with “lightweight QoE measurement.” Likewise, the terms “condensed,” “compact,” “simplified,” and “more abstract” may be used synonymously with “lightweight” in the context of a format or representation for QoE measurements, metrics, or data. For example, a lightweight QoE measurement can be an encoded and/or compressed version of a legacy QoE measurement, such that the lightweight QoE measurement may not convey the same granularity of information as the legacy QoE measurement. As a more specific example, a lightweight QoE measurement can be an integer or a binary flag that represents a corresponding legacy QoE measurement that is a larger integer, a real value, an array of values, etc.

In some cases, the “encoding” mentioned above can be a mapping between actual measurements and binary, integer, or enumerated values. In other cases, a legacy QoE measurement can be input to an artificial intelligence (AI)/machine learning (ML) system, a neural network-based model, or other algorithm to produce a simplified metric (e.g., single- value quality rating/score/index) of QoE for a user for running a certain service. In some cases, a plurality of legacy QoE measurements (e.g., data throughput, latency jitter, etc.) can be input to such an algorithm to produce a single metric representative of all QoE aspects covered by the multiple legacy QoE measurements. In other cases, however, the single metric may only represent a subset of all QoE aspects covered by the legacy QoE measurements, such as those deemed most relevant based on some predetermined criteria. However, there are some problems unresolved. For example, a mechanism of coordination among RAN nodes for handling the lightweight QoE is not defined. In some scenarios, where a first RAN node and a second RAN node are both involved in connectivity procedures concerning a wireless terminal/UE (such as MR-DC, mobility, resume and re- establishment), and the first RAN node configured the UE for RAN visible (lightweight) QoE measurements beside the legacy QoE measurement or independent from the legacy QoE measurements, the second RAN node is unaware of: status information of the RAN visible (lightweight) QoE measurements configured for the wireless terminal, status of radio measurements (such as MDT) configured for the wireless terminal and associated to the RAN visible (lightweight) QoE measurements, actions to be performed concerning the QoE measurements configured for the wireless terminal: o e.g., request of the first RAN node to receive the RAN visible QoE measurement reports o e.g., the requirement to forward the RAN visible QoE measurement reports to the first RAN node and

- whether the RAN visible (lightweight) QoE measurements report has been signalled to the TCE.

Since the second RAN node is unaware of the status and actions described above, it may happen that the second node tampers with (e.g., overwrites) an ongoing QoE measurement configured for the UE. In addition, currently it is not possible for a distributed unit of a gNB e.g., a gNB-DU to read and use the content of a RAN visible (lightweight) QoE report.

In this document, solutions are introduced to enable a coordination among RAN nodes (directly via e.g., Xn or X2 interfaces, or indirectly via core network and NG or SI interface) and the wireless terminal via forwarding the configuration information and configuration status information for a configured RAN visible QoE. The solutions described herein are applicable to any scenario involving at least two RAN nodes such as mobility (Handover, Conditional Handover, DAPS Handover, etc.), Dual or Multi Connectivity, RRC Resume and RRC Reestablishment.

Embodiments of these solutions may comprise some or all of the following actions for the first RAN node, second RAN node and the wireless terminal: According to some methods proposed herein, the first RAN node sends the following information to the second RAN node concerning a wireless terminal in the mobility procedure (e.g., handover, conditional handover, DAPS handover, etc.) or a dual connectivity procedure or a RRC connection resume procedure or a RRC connection reestablishment procedure. The information includes at least one of the following RAN visible (lightweight) QoE measurement configuration information:

• An indication, indicating the service types for which the RAN visible (lightweight) QoE is configured;

• An indication, indicating whether a session pertained to an application from the service type for which the RAN visible (lightweight) QoE configuration is configured is ongoing or not;

• An indication, indicating the type of the QoE measurement such as management based, or a signaling based or a hybrid (combination of management based and signaling based QoE)

• An indication, indicating whether the first RAN node is interested to receive the RAN visible (lightweight) QoE measurement results (or a part of RAN visible QoE measurements) upon delivery of the QoE measurements from the wireless terminal to the second RAN node. In other words, if the indication indicates that the first RAN node is interested in receiving the RAN visible (lightweight) QoE measurement results, this indication indicates a request from the first RAN node to the second RAN node, requesting the RAN visible (14ightweight) QoE measurement reports to be shared with the first node when delivered to the second RAN node from the wireless terminal. The second RAN node may still send the regular QoE report, i.e. the non-RAN visible part, to the TCE/MCE without forwarding it to the first RAN node.

• An indication indicating that a RAN visible (lightweight) QoE report with information pertaining to the second RAN node has been received.

• An indication, signalled together with a RAN visible (lightweight) QoE report, stating whether the report has been already signalled to the TCE. o Such indication is signalled together with QoE measurement configuration information including the size of the report to be signalled to the TCE and optionally the frequency in time of signalling QoSE reports to the TCE. • A RAN visible (lightweight) QoE report received from a wireless terminal. Forwarding of this information may optionally be conditioned by: o that the RAN visible (lightweight) QoE report contains information pertaining to the second RAN node, and or o that the second RAN node has previously indicated that it wants RAN visible (lightweight) QoE reports from the wireless terminal to be forwarded to the second RAN node.

• Forwarding one or a list of RAN visible (lightweight) QoE reports or a part of the RAN visible (lightweight) QoE measurements of one or multiple UEs from the Central Unit (e.g., gNB-CU) to the distributed unit (e.g., gNB-DU), e.g., over 3GPP Fl interface. In other methods according to the techniques described herein, the second RAN node receiving the RAN visible (lightweight) QoE configuration and status information, may take at least one of the following actions:

• Receiving the RAN visible (lightweight) QoE measurement configuration from the first RAN node

• Configuring the required radio resources to receive the RAN visible (lightweight) QoE measurements from the UE. The radio resource may include any types of radio bearer such as SRB1, SRB2, SRB3, SRB4.

• Decision on reconfiguring the wireless terminal with the new RAN visible (lightweight) QoE configuration based on the received RAN visible (lightweight) QoE configuration status information o In one non-limiting example embodiment, the second RAN node shall not reconfigure the UE with existing/preconfigured signaling based lightweight QoE configuration,

• Preparing itself to receive the RAN visible (lightweight) QoE measurement report from the wireless terminal over the radio bearer such as SRB1, SRB2, SRB3, SRB4, etc.

• Receiving the RAN visible (lightweight) QoE measurement report from the wireless terminal

• Forwarding the RAN visible (lightweight) QoE measurement report or at least a part of the RAN visible (lightweight) QoE measurement report to the first RAN node. • Forwarding the RAN visible (lightweight) QoE measurement report to at least one of the RAN nodes that is responsible for at least one of the cells with the cell IDs indicated in the list of the cell IDs appended to the RAN visible QoE measurement report. o As a further option, there may be one or more wireless terminal context identifier(s), such one or more I-RNTI(s) appended to the RAN visible (lightweight) QoE report, where each such context identifier may optionally be associated with one of the appended cell ID(s). o As another option, the cell ID(s) appended to the RAN visible (lightweight) QoE report may be replaced by wireless terminal context identifier(s), such as I-RNTI(s). o Optionally, the RAN visible (lightweight) QoE report may be included in a message requesting a context retrieval (i.e. retrieval of information associated with the wireless terminal) in conjunction with an RRC connection re-establishment procedure or in conjunction with an RRC connection resume procedure.

• Forwarding one or a list of RAN visible (lightweight) QoE reports or a part of the RAN visible (lightweight) QoE measurements of one or multiple UEs from the Central Unit (e.g., gNB-CU) to the distributed unit (e.g., gNB-DU), e.g., over 3GPP Fl interface. Sending an indication to the first RAN node that a RAN visible (lightweight) QoE report has been received from the wireless terminal. This may be conditioned by that the RAN visible (lightweight) QoE report contains information pertaining to the first RAN node.

• Sending an indication to at least one of the RAN nodes that is responsible for at least one of the cells with the cell IDs indicated in the list of the cell IDs appended to the lightweight QoE measurement report, wherein the indication informs each of the other RAN node(s) (which receive(s) the indication) that a RAN visible (lightweight) QoE report with information pertaining to the RAN node has been received from the wireless terminal. The indication may comprise a wireless terminal context identifier, such as an I-RNTI, and/or a QoE reference ID. (A RAN node receiving such an indication may then choose to retrieve the RAN visible (lightweight) QoE report from the second RAN node, or more preferably, selectively retrieve only the parts of the RAN visible (lightweight) QoE report that pertains to (i.e., are relevant for) the retrieving RAN node.)

• If the second RAN node receives an indication of whether the RAN visible (lightweight) QoE report has been signalled to the TCE, together with QoE measurement configurations including report size and/or frequency of reporting to the TCE, the second RAN node should o Check whether the RAN visible (lightweight) QoE report received from the first RAN node has been signalled to the TCE, and if not o Continue to add to the QoE report new QoE measurements until the report reaches the report size configured as part of the QoE measurement configuration and/or o Continue to add to the QoE report new QoE measurements until the QoE reporting period (derived from the frequency at which the RAN should report QoE reports to the TCE) expires, after which the RAN should signal the report to the TCE o In case both a QoE report size and a reporting frequency for QoE Reports is configured as part of the QoE measurement configuration, the RAN should signal the QoE Report to the TCE when the first of these two conditions (report size or report period expiration) is fulfilled In other methods according to the techniques described herein, the wireless terminal receiving the RAN visible (lightweight) QoE configuration from the first RAN node, may take at least one of the following actions:

• Logging RAN visible (lightweight) QoE measurement report upon receiving it from the upper layers (e.g., application layer)

• Logging the serving cell measurements as part of a list beside the RAN visible QoE measurements. o Serving cell measurements can be logged periodically or based on configured events and threshold

• Logging the list of the serving cells related cell identifier such as global cell ID, physical cell ID, frequency of the cell, as well as configured and active BWP information as part of RAN visible QoE measurement.

• Logging the wireless terminal’ s context identifier associated with the serving cells. • Reporting the RAN visible (lightweight) QoE measurements including the above-mentioned information to at least one of the serving cells via configured radio bearers for the QoE measurement reporting. o As an option, the wireless terminal may append a list of cell IDs to the RAN visible (lightweight) QoE report, where the cell IDs represent the cells in which the content of the RAN visible (lightweight) QoE report has been collected or created. o As another option, the wireless terminal may append a list of wireless terminal context identifiers pertaining to the cells in which the content of the RAN visible (lightweight) QoE report has been collected or created.

In various embodiments or instances, the above-mentioned actions for the first and second RAN nodes can be executed in any mobility scenarios (such as Handover, Conditional Handover, DAPS Handover), or any Dual Connectivity scenarios such (such as LTE-DC, EN-DC, NE-DC, NR-DC) in which the first and second RAN nodes are serving the wireless terminal at the same time. The solutions are also applicable to the RRC resume and RRC Reestablishment procedures. Some actions may also be executed in conjunction with RRC connection resume procedures.

These solutions enable mechanisms to transfer the RAN visible (lightweight) QoE measurement configuration and status information among the RAN nodes, enabling proper handling of the measurements by the node receiving the information, node sending the information and/or both. In addition, this mechanism allows the gNB-CU to forward the RAN visible (lightweight) QoE report to the gNB-DU, hence the gNB-Du can use the RAN visible (lightweight) QoE measurements in its optimizations and algorithms. For example, a gNB-DU can use the RAN visible QoE metric such as buffer level to tune its link adaptation and scheduling policies

To help put these techniques in context, Figure 3 illustrates an overall example architecture of a network comprising LTE and SAE is shown in Figure 1. E-UTRAN 100 includes one or more evolved Node B’s (eNB), such as eNBs 105, 110, and 115, and one or more user equipment (UE), such as UE 120. As used within the 3 GPP standards, “user equipment” or “UE” means any wireless communication device (e.g., smartphone or computing device) that is capable of communicating with 3 GPP-standard-compliant network equipment, including E-UTRAN as well as UTRAN and/or GERAN, as the third-generation (“3G”) and second-generation (“2G”) 3GPP RANs are commonly known. As specified by 3GPP, E-UTRAN 100 is responsible for all radio-related functions in the network, including radio bearer control, radio admission control, radio mobility control, scheduling, and dynamic allocation of resources to UEs in uplink and downlink, as well as security of the communications with the UE. These functions reside in the eNBs, such as eNBs 105, 110, and 115. Each of the eNBs can serve a geographic coverage area including one more cells, including cells 106, 111, and 116 served by eNBs 105, 110, and 115, respectively.

The eNBs in the E-UTRAN communicate with each other via the X2 interface, as shown in Figure 1. The eNBs also are responsible for the E-UTRAN interface to the EPC 130, specifically the SI interface to the Mobility Management Entity (MME) and the Serving Gateway (SGW), shown collectively as MME/S-GWs 134 and 138 in Figure 1. In general, the MME/S-GW handles both the overall control of the UE and data flow between the UE and the rest of the EPC. More specifically, the MME processes the signaling (e.g., control plane) protocols between the UE and the EPC, which are known as the Non-Access Stratum (NAS) protocols. The S-GW handles all Internet Protocol (IP) data packets (e.g., data or user plane) between the UE and the EPC and serves as the local mobility anchor for the data bearers when the UE moves between eNBs, such as eNBs 105, 110, and 115.

EPC 130 can also include a Home Subscriber Server (HSS) 131, which manages user- and subscriber-related information. HSS 131 can also provide support functions in mobility management, call and session setup, user authentication and access authorization. The functions of HSS 131 can be related to the functions of legacy Home Location Register (HLR) and Authentication Centre (AuC) functions or operations. HSS 131 can also communicate with MMEs 134 and 138 via respective S6a interfaces.

In some embodiments, HSS 131 can communicate with a user data repository (UDR) - labelled EPC-UDR 135 in Figure 3 - via a Ud interface. EPC-UDR 135 can store user credentials after they have been encrypted by AuC algorithms. These algorithms are not standardized (i.e., vendor-specific), such that encrypted credentials stored in EPC-UDR 135 are inaccessible by any other vendor than the vendor of HSS 131.

The multiple access scheme for the LTE PHY is based on Orthogonal Frequency Division Multiplexing (OFDM) with a cyclic prefix (CP) in the downlink, and on Single- Carrier Frequency Division Multiple Access (SC-FDMA) with a cyclic prefix in the uplink. To support transmission in paired and unpaired spectrum, the LTE PHY supports both Frequency Division Duplexing (FDD) (including both full- and half-duplex operation) and Time Division Duplexing (TDD). The LTE FDD downlink (DL) radio frame has a fixed duration of 10 ms and consists of 20 slots, numbered 0 through 19, each with a fixed duration of 0.5 ms. A 1-ms subframe comprises two consecutive slots where subframe I consists of slots 2z and 2z+l.

As briefly mentioned above, a dual connectivity (DC) framework was introduced in LTE Rel-12. In LTE DC, a UE is configured with a Master Cell Group (MCG) associated with a master eNB (MeNB) and a Secondary Cell Group (SCG) associated with a Secondary eNB (SeNB). Each of the CGs includes a primary cell (PCell) and optionally one or more secondary cells (SCells). The term “Special Cell” (or “SpCell” for short) refers to the PCell of the MCG or the PSCell of the SCG depending on whether the UE’s medium access control (MAC) entity is associated with the MCG or the SCG, respectively. In non-DC operation (e.g., CA), SpCell refers to the PCell. An SpCell is always activated and supports physical uplink control channel (PUCCH) transmission and contention-based random access by UEs.

Figure 4 illustrates a high-level view of the 5G network architecture, consisting of a Next Generation RAN (NG-RAN) 299 and a 5G Core (5GC) 298. NG-RAN 299 can include a set of gNodeB’s (gNBs) connected to the 5GC via one or more NG interfaces, such as gNBs 200, 250 connected via interfaces 202, 252, respectively. In addition, the gNBs can be connected to each other via one or more Xn interfaces, such as Xn interface 240 between gNBs 200 and 220. With respect the NR interface to UEs, each of the gNBs can support frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof.

NG-RAN 299 is layered into a Radio Network Layer (RNL) and a Transport Network Layer (TNL). The NG-RAN architecture, i.e., the NG-RAN logical nodes and interfaces between them, is defined as part of the RNL. For each NG-RAN interface (NG, Xn, Fl) the related TNL protocol and the functionality are specified. The TNL provides services for user plane transport and signaling transport. In some example configurations, each gNB is connected to all 5GC nodes within an “AMF Region,” which is defined in 3GPP TS 23.501. If security protection for CP and UP data on TNL of NG-RAN interfaces is supported, NDS/IP shall be applied.

The NG RAN logical nodes shown in Figure 4 include a central (or centralized) unit (CU or gNB-CU) and one or more distributed (or decentralized) units (DU or gNB-DU). For example, gNB 200 includes gNB-CU 210 and gNB-DUs 220 and 230. CUs (e.g., gNB-CU 210) are logical nodes that host higher-layer protocols and perform various gNB functions such controlling the operation of DUs. Each DU is a logical node that hosts lower-layer protocols and can include, depending on the functional split, various subsets of the gNB functions. Each of the CUs and DUs can include various circuitry needed to perform their respective functions, including processing circuitry, transceiver circuitry (e.g., for communication), and power supply circuitry. Moreover, the terms “central unit” and “centralized unit” are used interchangeably herein, as are the terms “distributed unit” and “decentralized unit.”

A gNB-CU connects to gNB-DUs over respective Fl logical interfaces, such as interfaces 222 and 232 shown in Figure 4. The gNB-CU and connected gNB-DUs are only visible to other gNBs and the 5GC as a gNB. In other words, the Fl interface is not visible beyond gNB-CU. In the gNB split CU-DU architecture illustrated by Figure 4, DC can be achieved by allowing a UE to connect to multiple DUs served by the same CU or by allowing a UE to connect to multiple DUs served by different CUs.

Figure 5 shows another high-level view of an example 5G network architecture, including a Next Generation Radio Access Network (NG-RAN) 399 and a 5G Core (5GC) 398. As shown in the figure, NG-RAN 399 can include gNBs 310 (e.g., 310a, b) and ng- eNBs 320 (e.g., 320a, b) that are interconnected with each other via respective Xn interfaces. The gNBs and ng-eNBs are also connected via the NG interfaces to 5GC 398, more specifically to the AMF (Access and Mobility Management Function) 330 (e.g., AMFs 330a, b) via respective NG-C interfaces and to the UPF (User Plane Function) 340 (e.g., UPFs 340a, b) via respective NG-U interfaces. Moreover, the AMFs 330a, b can communicate with one or more policy control functions (PCFs, e.g., PCFs 350a, b) and network exposure functions (NEFs, e.g., NEFs 360a, b).

Each of the gNBs 310 can support the NR radio interface including frequency division duplexing (FDD), time division duplexing (TDD), or a combination thereof. Each of ng-eNBs 320 can support the LTE radio interface. Unlike conventional LTE eNBs, however, ng-eNBs 320 connect to the 5GC via the NG interface. Each of the gNBs and ng-eNBs can serve a geographic coverage area including one more cells, such as cells 31 la-b and 321a-b shown in Figure 3. Depending on the particular cell in which it is located, a UE 305 can communicate with the gNB or ng-eNB serving that particular cell via the NR or LTE radio interface, respectively. Although Figure 3 shows gNBs and ng-eNBs separately, it is also possible that a single NG-RAN node provides both types of functionality.

Figure 6 shows an exampleexample configuration of NR user plane (UP) and control plane (CP) protocol stacks between a UE, a gNB, and an AMF, such as those shown in Figure 4 and Figure 5. The Physical (PHY), Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP) layers between the UE and the gNB are common to UP and CP. The PDCP layer provides ciphering/deciphering, integrity protection, sequence numbering, reordering, and duplicate detection for both CP and UP. In addition, PDCP provides header compression and retransmission for UP data.

On the UP side, Internet protocol (IP) packets arrive to the PDCP layer as service data units (SDUs), and PDCP creates protocol data units (PDUs) to deliver to RLC. When each IP packet arrives, PDCP starts a discard timer. When this timer expires, PDCP discards the associated SDU and the corresponding PDU. If the PDU was delivered to RLC, PDCP also indicates the discard to RLC.

The RLC layer transfers PDCP PDUs to the MAC through logical channels (LCH). RLC provides error detection/correction, concatenation, segmentation/reassembly, sequence numbering, reordering of data transferred to/from the upper layers. If RLC receives a discard indication from associated with a PDCP PDU, it will discard the corresponding RLC SDU (or any segment thereof) if it has not been sent to lower layers.

The MAC layer provides mapping between LCHs and PHY transport channels, LCH prioritization, multiplexing into or demultiplexing from transport blocks (TBs), hybrid ARQ (HARQ) error correction, and dynamic scheduling (on gNB side). The PHY layer provides transport channel services to the MAC layer and handles transfer over the NR radio interface, e.g., via modulation, coding, antenna mapping, and beam forming.

On UP side, the Service Data Adaptation Protocol (SDAP) layer handles quality-of- service (QoS). This includes mapping between QoS flows and Data Radio Bearers (DRBs) and marking QoS flow identifiers (QFI) in UL and DL packets. On CP side, the non-access stratum (NAS) layer is between UE and AMF and handles UE/gNB authentication, mobility management, and security control.

The RRC layer sits below NAS in the UE, but terminates in the gNB rather than the AMF. RRC controls communications between UE and gNB at the radio interface as well as the mobility of a UE between cells in the NG-RAN. RRC also broadcasts system information (SI) and performs establishment, configuration, maintenance, and release of DRBs and Signaling Radio Bearers (SRBs) and used by UEs. Additionally, RRC controls addition, modification, and release of carrier aggregation (CA) and dual -connectivity (DC) configurations for UEs. RRC also performs various security functions such as key management.

After a UE is powered ON, it will be in the RRC__IDLE state until an RRC connection is established with the network, at which time the UE will transition to RRC CONNECTED state (e.g., where data transfer can occur). The UE returns to RRC_IDLE after the connection with the network is released. In RRC IDLE state, the UE’s radio is active on a discontinuous reception (DRX) schedule configured by upper layers. During DRX active periods (also referred to as "DRX On durations"), an RRC_IDLE UE receives SI broadcast in the cell where the UE is camping, performs measurements of neighbor cells to support cell reselection, and monitors a paging channel on PDCCH for pages from 5GC via gNB. An NR UE in RRC_IDLE state is not known to the gNB serving the cell where the UE is camping. However, NR RRC includes an RRC_INACTIVE state in which a UE is known (e.g., via UE context) by the serving gNB. RRC_INACTIVE has some properties similar to a “suspended” condition used in LTE.

As discussed above, QoE measurements have been specified for UEs operating in LTE networks and in earlier-generation UMTS networks. Measurements in both networks operate according to the same high-level principles. Their purpose is to measure the experience of end users when using certain applications over a network. For example, QoE measurements for streaming services and for MTSI (Mobility Telephony Service for IMS) are supported in LTE.

QoE measurements may be initiated towards the RAN from an OAM node generically for a group of UEs (e.g., all UEs meeting one or more criteria), or they may also be initiated from the CN to the RAN for a specific UE. The configuration of the measurement includes the measurement details, which is encapsulated in a container that is transparent to RAN.

A“"TRACE STAR”" S1AP message is used by the LTE EPC for initiating QoE measurements by a specific UE. This message carries details about the measurement configuration the application should collect in the “Container for application layer measurement configuration” IE, which transparent to the RAN. This message also includes details needed to reach the TCE to which the measurements should be sent.

Figures 7A-D show various procedures between a UMTS RAN (UTRAN) and a UE for QoE measurements in a legacy UMTS network. Thse are similar to those specified for LTE (E-UTRAN). As shown in Figure 7A, the UTRAN can send a UE Capability Enquiry message to request the UE to report its application layer measurement capabilities. As shown in Figure 7B, the UE can provide its application layer measurement capabilities to the UTRAN via a UE Capability Information message, particularly in a “Measurement Capability” IE that includes information related to UE capability to perform the QoE measurement collection for streaming services and/or MTSI services. Table 1 below shows example contents of this IE: Table 1

The UTRAN can respond with a UE Capability Information Confirm message.

Figure 5C shows that the UTRAN can send a Measurement Control message containing “Application layer measurement configuration” IE in order to configure QoE measurement in the UE. Table 2 below shows example contents of this IE:

Table 2

Figure 7D shows that the UE can send QoE measurement results via UTRAN to the TCE using a Measurement Report message that includes an “Application layer measurement reporting” IE. Table 3 below shows example contents of this IE:

Table 3

As was discussed above, Figures 1 and 2 illustrate procedures between an E-UTRAN and a UE for configuring QoE measurements in an LTE network. Figure 1 shows an example UE capability transfer procedure used to transfer UE radio access capability information from the UE to E-UTRAN. Initially, the E-UTRAN can send a UECapabilityEnquiry message, similar to the arrangement shown in Figure 7A. The UE can respond with a UECapabilitylnformation message that includes a “UE-EUTRA- Capability” IE.

This IE may further include a UE-EUTRA-Capability-vl530 IE, which can be used to indicate whether the UE supports QoE Measurement Collection for streaming services and/or MTSI services. In particular, the UE-EUTRA-Capability-v 1530 IE can include a measParameters-vl 530 IE containing the information about the UE’s measurement support. In some cases, the UE-EUTRA-Capability IE can also include a UE-EUTRA- Capability-vl6xy-IE”, which can include a qoe-Extensions-r16 field. Figure 8 A shows an example ASN. l data structure for these various IES, with the various fields defined in Table 4 below.

Table 4.

Figure 8B shows an example ASN. l data structure for the qoe-Reference parameter mentioned in Table 4 above.

Figures 9A-C illustrate various aspects of QoE measurement collection for a UE in an LTE network. In particular, Figure 9A shows an exampleexample signal flow diagram of a QoE measurement collection process for LTE. To initiate QoE measurements, the serving eNB sends to a UE in RRC CONNECTED state an RRCConnectionReconfiguration message that includes a QoE configuration file, e.g., a measConfigAppLayer IE within an OtherConfig IE. As discussed above, the QoE configuration file is an application-layer measurement configuration received by the eNB (e.g., from EPC) encapsulated in a transparent container, which is forwarded to UE in the RRC message. The UE responds with an RRCConnectionReconfigurationComplete message. Subsequently, the UE performs the configured QoE measurements and sends a MeasReportAppLayer RRC message to the eNB, including a QoE measurement result file. Although not shown, the eNB can forward this result file transparently (e.g., to EPC).

Figure 9B shows an exampleexample ASN.l data structure for a measConfigAppLayer IE. The setup includes the transparent container measConfigAppLayerContainer which specifies the QoE measurement configuration for the Application of interest. In the serviceType field, a value of “qoe” indicates Quality of Experience Measurement Collection for streaming services and a value of “qoemtsi” indicates Enhanced Quality of Experience Measurement Collection for MTSI. This field also includes various spare values.

Figure 9C shows an example ASN.l data structure for a measReportAppLayer IE, by which a UE can send to the E-UTRAN (e.g., via SRB4) the QoE measurement results of an application (or service). The service for which the report is being sent is indicated in the serviceType IE.

As specified in 3GPP TS 28.405, LTE RAN nodes (i.e., eNBs) are allowed to temporarily stop and restart QoE measurement reporting when an overload situation is observed. This behavior can be summarized as follows. In case of overload in RAN, an eNB may temporarily stop UE reporting by sending to relevant UEs an RRCConnectionReconfiguration message with a measConfigAppLayer IE (in otherConfig) set to temporarily stop application layer measurement reporting. The application stops the reporting and may stop recording further information. When the overload situation in RAN is ended, an eNB may restart UE reporting by sending to relevant UEs an RRCConnectionReconfiguration message with a measConfigAppLayer IE (in otherConfig) set to to restart application layer measurement reporting. The application restarts the reporting and recording if it was stopped.

In general, the RAN (e.g., E-UTRAN or NG-RAN) is not aware of an ongoing streaming session for a UE and nor of when QoE measurements are being performed by the UE. Even so, it is important for the client or management function analyzing the measurements that the entire streaming session is measured. It is beneficial, then, that the UE maintains QoE measurements for the entire session, even during handover situation. However, it is an implementation decision when RAN stops the QoE measurements. For example, it could be done when the UE has moved outside the measured area, e.g., due to a handover.

In addition to QoE measurements, a UE can be configured to perform and report measurements to support minimization of drive tests (MDT), which is intended to reduce and/or minimize the requirements for manual testing of actual network performance (i.e., by driving around the geographic coverage of the network). The MDT feature was first studied in LTE Rel-9 (e.g., 3GPP TR 36.805) and first standardized in Rel-10. MDT can address various network performance improvements such as coverage optimization, capacity optimization, mobility optimization, quality-of-service (QoS) verification, and parameterization for common channels (e.g., PDSCH).

A UE can be configured to perform logged and/or immediate MDT measurements. A UE in RRC IDLE state can be configured (e.g., via a LoggedMeasurementConfiguration RRC message from the network) to perform periodical MDT measurement logging. A received MDT configuration can include logginginterval and loggingduration. The UE starts a timer (T330) set to loggingduration (e.g., 10-120 min) upon receiving the configuration, and perform periodical MDT logging every logginginterval (1.28-61.44 s) within the loggingduration while the UE is in RRC_IDLE state. In particular, the UE collects DL reference signal received strength and quality (i.e., RSRP, RSRQ) based on existing measurements required for cell reselection purposes. The UE reports the collected/logged information to the network when the UE returns to RRC CONNECTED state. Figure 4 shows an example logged MDT procedure performed by a UE.

In contrast, a UE can be configured to perform and report immediate MDT measurements while in RRC CONNECTED state. Similar to logged MDT, immediate MDT measurements are based on existing UE and/or network measurements performed while a UE is in RRC CONNECTED, and can include any of the following measurement quantities:

• Ml : RSRP and RSRQ measurement by UE.

• M2: Power Headroom measurement by UE.

• M3 : Received Interference Power measurement by eNB.

• M4: Data Volume measurement separately for DL and UL, per QoS class indicator (QCI) per UE, by eNB.

• M5: Scheduled IP layer Throughput for MDT measurement separately for DL and UL, per RAB per UE and per UE for the DL, per UE for the UL, by eNB. • M6: Packet Delay measurement, separately for DL and UL, per QCI per UE, see UL PDCP Delay, by the UE, and Packet Delay in the DL per QCI, by the eNB.

• M7 : Packet Loss rate measurement, separately for DL and UL per QCI per UE, by the eNB.

• M8: received signal strength (RS SI) measurement by UE.

• M9: round trip time (RTT) measurement by UE.

For example, the reporting of Ml measurements can be event-triggered according to existing RRM configuration for any of events A1-A6 or B1-B2. In addition, Ml reporting can be periodic, A2 event-triggered, or A2 event-triggered periodic according to an MDT- specific measurement configuration. As another example, the reporting of M2 measurements can be based on reception of Power Headroom Report (PHR), while reporting for M3-M9 can be triggered by the expiration of a measurement collection period.

As was noted above, however, reconfiguration of a UE’s connections after a first RAN has configured the UE for lightweight QoE measurements may result in a second RAN unknowingly tampering with ongoing measurements, enable a coordination among RAN nodes (directly via e.g., Xn or X2 interfaces, or indirectly via core network and NG or SI interface) and the wireless terminal via forwarding the configuration information and configuration status information for a configured RAN visible QoE. The solutions described herein are applicable to any scenario involving at least two RAN nodes such as mobility (Handover, Conditional Handover, DAPS Handover, etc.), Dual or Multi Connectivity, RRC Resume and RRC Reestablishment.

These solutions may be first described by detailing techniques related to the first RAN node, i.e., the node, in the several scenarios briefly described above, that configures the UE with QoE measurements. According to various scenarios, this first RAN node is associated with a second RAN node due to operations or signaling procedures involving both the first RAN node and the second RAN node, such as, for example, dual connectivity, mobility, RRC resume, RRC reestablishment, switching the transfer of the data for the service from a path going to the UE via the first RAN node to a path going to the UE via the second RAN node (non-limiting examples). The first RAN node has configured a wireless terminal for RAN visible (lightweight) QoE measurements, or it has forwarded to the wireless terminal the RAN visible (lightweight) QoE configuration that it may have received from the OAM. Figure 10 is a process flow illustrating an example method according to the techniques detailed immediately and as described generally herein, for a first RAN node. In a first approach according to various of the presently disclosed techniques, the first RAN node transmits to the second RAN node, configuration information concerning the RAN visible (lightweight) QoE measurements associated to at least one of the RAN visible (lightweight) QoE measurement configuration(s) that the first RAN node configured a wireless terminal for QoE purposes. This is shown in Figure 10 at block 1010. The configuration information concerning the RAN visible (lightweight) QoE measurements may comprise any one or more of any of the following: information concerning the configured RAN visible (lightweight) QoE measurements o An indication of a wireless terminal which the first RAN node has configured for lightweight QoE measurement or a list of such wireless terminals. The indication may have the form of an identifier of the wireless terminal. o A configuration of RAN visible (lightweight) QoE measurements and/or QoE measurement reporting that the first RAN node has sent to a UE which is now (or will soon be) served by the second RAN node.

■ Optionally, together with such a configuration, the first RAN node may include an indication of whether an application session of a service type or service subtype the QoE measurement configuration targets is ongoing. o An indication or a list of indications indicating at least one of the lightweight QoE measurements configured for a wireless terminal

■ Optionally, together with such an indication, the first RAN node may include an indication of whether an application session of a service type or service subtype the QoE measurement configuration targets is ongoing. o A reference or a list of references, such as one or a list of QoE reference ID(s) associated to the configured lightweight QoE measurements

■ Optionally, together with such a reference, the first RAN node may include an indication of whether an application session of a service type or service subtype the QoE measurement configuration targets is ongoing. an indication indicating the type of the configured RAN visible (lightweight) QoE measurements, such as management-based QoE or signaling-based QoE or a hybrid/combined type of management based and signaling based. a list of indications indicating the service types or service subtypes for which the RAN visible lightweight QoE measurements are configured. per-service type or per-service subtype indication(s) or a per-service type or per-service subtype list of indications indicating if the respective RAN visible lightweight QoE measurements are configured but not activated, activated, suspended, or deactivated an indication that per-slice RAN visible (lightweight) QoE measurements has been enabled and a list of corresponding S-NSSAIs an indication or a list of indications concerning the MCEs associated to the configured RAN visible lightweight QoE measurements an indication that the second RAN node shall consider the configured RAN visible lightweight QoE measurements as valid for a certain period of time or until a given time of the day an indication of the time where the radio measurements, e.g. MDT measurements, linked to the QoE measurements were started. an indication of whether an application session for which the an indication that an application session has started in a wireless terminal, where the first RAN node previously has sent to the second RAN node a lightweight QoE measurement configuration targeting the service type or service subtype the application belongs to or an indication that such a lightweight QoE measurement configuration has been configured for the wireless terminal.

■ As an option, the lightweight QoE measurement configuration targeting the service type or service subtype the application belongs t, or the indication of that such a configuration has been sent to the wireless terminal, may be sent to the second RAN node in the same message as the indication of the start of the application session. an indication that an application session has stopped in a wireless terminal, where the first RAN node previously has sent to the second RAN node a lightweight QoE measurement configuration targeting the service type or service subtype the application belongs to or an indication that such a lightweight QoE measurement configuration has been configured for the wireless terminal and/or an indication that the concerned application session had started in the wireless terminal.

■ As an option, a RAN visible (lightweight) QoE report received from the wireless terminal may be sent to the second RAN node together with the indication that the application session has stopped in the wireless terminal.

■ As another option, an indication of existence of a RAN visible (lightweight) QoE report received from the wireless terminal may be sent to the second RAN node together with the indication that the application session has stopped in the wireless terminal. o an identifier or a list of identifiers (e.g., a QoE reference ID or a newly defined reference ID) coupling this lightweight QoE measurement (or a list of lightweight QoE measurements) to a legacy QoE measurement (or a list thereof) and/or an MDT measurement (or a list thereof) o information for what type of radio measurements, e.g., MDT measurements, that were performed in a coupling towards the QoE measurements. The MDT measurements may not continue at handover and this information gives the target the possibility to configure the same type of radio measurements in the target node. The information maybe in the form of a measConfig or a measID connected to a measConfig, for example. The information may also be any type of identification of the radio measurements.

In case a group of UEs is simultaneously undergoing one of the above described signaling procedures of interest (such as dual connectivity, mobility, RRC resume, RRC reestablishment), the actions described herein and the corresponding measurement status transfer signaling may carry the statuses pertaining to more than one UE (for example a list of measurements configured for all UEs currently undergoing a handover). Note that signalling procedures for mobility, RRC resume, and RRC reestablishment, for example, are typically executed for one UE at a time, so the status information transfer described above for a group of UEs may be carried in a newly defined procedure.

In a second technique according to various of the presently disclosed embodiments, the first RAN node sends to the second RAN node, requests concerning the lightweight QoE measurements associated to one (or a list of) RAN visible lightweight QoE measurements with which the first RAN node configured a wireless terminal for QoE measurements. An example is shown in Figure 10 at block 1020. These requests may comprise any one or more of the following: requests concerning the configured RAN visible lightweight QoE measurements o a request to send to the first RAN node (or to buffer and subsequently send to the first RAN node) the QoE reports received by the second RAN node, the request optionally comprising additional conditions associated to the start and the stop of such reporting, such as:

■ a reconfiguration of the (signaling) radio bearers at the UE which results in the switch of RAN node receiving the QoE reports, an overload indication sent from the first RAN node to the second RAN node, a period of time, until session end, until a subsequent mobility events is triggered, until further UE reconfiguration, service type or service subtype, slice or list of slices o a request to support reception of RAN visible lightweight QoE reporting o a request to suspend one or a list of the activated RAN visible lightweight QoE measurements o a request to resume one or a list of the suspended RAN visible lightweight QoE measurements o a request to release or to pause one or a list of the activated RAN visible lightweight QoE measurements

■ in a first example related to Inter-RAT mobility or inter-system mobility, the second RAN node belongs to a RAT or a system that does not support one or more of the service types or service subtypes associated to the ongoing RAN visible lightweight QoE measurements), meaning that the measurements pertaining to these service types and/or subtypes are hence to be released or paused.

■ another example is when a procedure (e.g. associated to dual connectivity operation) is about to be triggered and the first RAN node that configured the UE for QoE measurements received an indication (e.g. from OAM) that the full set or part of the ongoing QoE measurements shall be stopped or pause o a request to configure the UE with a certain configuration of RAN visible lightweight measurements or certain configuration of radio measurements linked to the QoE measurements.

An indication, signalled together with a RAN visible (lightweight) QoE report, stating whether the report has been already signalled to the TCE. o Such indication is signalled together with QoE measurement configuration information including the size of the report to be signalled to the TCE and optionally the frequency in time of signalling QoSE reports to the TCE.

In case the operations pertaining to the second embodiment need to be executed for a group of UEs, the requests pertaining to multiple UEs described may be carried in the same message (for example a list of measurements configured for all UEs currently undergoing a handover is carried in the same Xn/X2/NG/Sl message). Note that signalling procedures for e.g. mobility, RRC resume, RRC reestablishment are typically executed for one UE at a time, so the request described above for a group of UEs may be carried in a newly defined procedure. o In a sub-embodiment, the requests pertaining to multiple UEs may be of the same type for all UEs (in which case a single request type indication is needed for the whole list of UEs) or may be of different types for different UEs (wherein this includes that in a list of diverse request types for a group of multiple UEs, there may still be UEs for which the same request types are indicated).

In all of the above, more than one type of request pertaining to the same UE or the same QoE measurement configuration may be conveyed in the same message (i.e., multiple requests per UE or QoE measurement configuration may be included in the same message from the first RAN node to the second RAN node).

Other aspects of the presently disclosed techniques may be described with respect to the second RAN node discussed in the various scenarios mentioned above, i.e., the node that receives certain information from the first RAN node regarding a previous QoE measurement configuration for a UE. This second RAN node is associated with the first RAN node due to operations or signaling procedures involving both the first RAN node and the second RAN node, such as dual connectivity, mobility, resume, reestablishment, etc. Figure 11 is a process flow diagram illustrating an example method according to these techniques, for the second RAN node

In some embodiments, the second RAN node receives, from the first RAN node, configuration information concerning the RAN visible lightweight QoE measurements associated to one (or a list of) lightweight QoE measurements with which the first RAN node configured a wireless terminal for RAN visible (lightweight) QoE measurements. This is shown at block 1110 of Figure 11. This configuration information of the RAN visible lightweight QoE measurements may comprise the information detailed in the embodiments for the first RAN node, above.

In some of these and in other embodiments, the second RAN node receives, from the first RAN node, requests concerning the RAN visible lightweight QoE measurements associated to one (or a list of) lightweight QoE measurements with which the first RAN node configured a wireless terminal for QoE measurements. An example is shown at block 1120 of Figure 11. These requests may comprise any of the requests detailed in the embodiments for the first RAN node, above.

In response to the request for RAN visible lightweight QoE measurement results from the first RAN node, upon receiving the RAN visible lightweight QoE measurement results (e.g. in a QoE report or appended/associated to a QoE report) from the wireless terminal, the second RAN node forwards at least part of the RAN visible (lightweight) QoE measurement results to the first RAN node. Forwarding the RAN visible lightweight QoE measurement results can be done via one of the following approaches

• Over Xn interface, if there is a direct Xn interface between two RAN nodes; The information may be encapsulated in a container in the form of an inter-node RRC message within the XnAP message.

• Over X2 interface, if there is a direct x2 interface between two RAN nodes; The information may be encapsulated in a container in the form of an inter-node RRC message within the X2AP message.

• Over NG interface, if there is an NG interface between two Ran nodes connected via core network; The information may be encapsulated in a container in the form of an inter-node RRC message within the network messages.

• Over NG and SI interface, for inter-system mobility or multi -connectivity scenarios, in which two RAN nodes are connected via an NG and SI interfaces; The information may be encapsulated in a container in the form of an inter-node RRC message within the network messages.

• In another embodiment if the second RAN node receives an indication of whether the RAN visible (lightweight) QoE report has been signalled to the TCE, together with QoE measurement configurations including report size and/or frequency of reporting to the TCE, the second RAN node should: o Check whether the RAN visible (lightweight) QoE report received from the first RAN node has been signalled to the TCE, and if not

■ Continue to add to the QoE report new QoE measurement results until the report reaches the report size configured as part of the QoE measurement configuration and/or

■ Continue to add to the QoE report new QoE measurement results until the QoE reporting period (derived from the frequency at which the RAN should report QoE reports to the TCE) expires, after which the RAN should signal the report to the TCE

■ In case both a QoE report size and a reporting frequency for QoE Reports is configured as part of the QoE measurement configuration, the RAN should signal the QoE Report to the TCE when the first of these two conditions (report size or report period expiration) is fulfilled. As a further option, the RAN ndoe may signal the QoE report to the TCE if the UE leaves the current serving cell(s), at least if it thereby also leaves an area scope configured for the RAN visible (lightweight) QoE configuration).

• In response to a request of one of the previously indicated types from the first RAN node, the second RAN node may send an indication of the status of the execution of the request, wherein such a status indication may indicate one of “successful”, “rejected”, “pending”, “partially successful - partially rejected”, or “partially pending - partially rejected” (where other execution status indications are not precluded).

• In one embodiment, upon receiving from the first RAN node a QoE measurement configuration associated with a UE, or an indication of a QoE measurement configuration associated with a UE (where the UE is served by the second RAN node or will be served by the second RAN node after on ongoing or in the process of being prepared mobility or dual/multi -connectivity operation has been concluded), or at any later time while the UE is served by the second RAN node and the concerned QoE measurement configuration is still existing and valid, the second RAN node may send an MDT or RRM measurement configuration to the first RAN node to be forwarded to the UE, wherein this MDT or RRM measurement configuration optionally may be linked to the QoE measurement configuration, e.g., to enable synchronization and/or coordination of the QoE measurements and the MDT and/or RRM measurements.

• In another embodiment, upon receiving from the first RAN node a QoE measurement configuration associated with a UE, or an indication of a QoE measurement configuration associated with a UE (where the UE is served by the second RAN node or will be served by the second RAN node after on ongoing or in the process of being prepared mobility or dual/multi -connectivity operation has been concluded), or at any later time while the UE is served by the second RAN node and the concerned QoE measurement configuration is still existing and valid, the second RAN node may send to the first RAN node a request to configure the UE with MDT or RRM measurements to be linked to the concerned QoE measurement configuration, e.g. to enable synchronization and/or coordination of the QoE measurements and the MDT and/or RRM measurements.

In yet another embodiment, upon receiving from the first RAN node a QoE measurement configuration associated with a UE, or an indication of a QoE measurement configuration associated with a UE (where the UE is served by the second RAN node or will be served by the second RAN node after on ongoing or in the process of being prepared mobility or dual/multi -connectivity operation has been concluded), or at any later time while the UE is served by the second RAN node and the concerned QoE measurement configuration is still existing and valid, the second RAN node may send an MDT or RRM measurement configuration to the UE, wherein this MDT or RRM measurement configuration optionally may be linked to the QoE measurement configuration, e.g. to enable synchronization and/or coordination of the QoE measurements and the MDT and/or RRM measurements.

In the above, if more than one UE simultaneously undergoes the procedures triggering the above actions (status information sending or request sending) the corresponding network signaling (Xn/X2/NG/Sl) may carry, in the same message, status indications and/or requests pertaining to one or more of these UEs. Similarly, responses to such requests may also contain information pertaining to multiple UEs and/or multiple RAN visible (lightweight) QoE configurations. For instance, if the second RAN node receives from the first RAN node a message with multiple requests (of one or more of the previously described type(s) of request(s)), the second RAN node may respond with indications of the status of the execution of each of the first RAN node’s requests. The indications may be per UE or per RAN visible (lightweight) QoE measurement configuration and each indication may e.g. be one of “successful”, “rejected”, “pending”, “partially successful - partially rejected”, or “partially pending - partially rejected” (where other execution status indications are not precluded).

The techniques described herein may also be described with respect to the UE in the various scenarios discussed above.

Upon receiving the configuration of the RAN visible lightweight QoE configuration, the wireless terminal starts logging the serving cell link quality and append it to the RAN visible lightweight QoE measurements.

• In one embodiment, the measurement of the serving cell quality will be in the form of RSRP, RSRQ, SINR, etc. at cell level and/or at each beam e.g., SSB beams or CSI-RS beams, in which the measurements are associated to the beams, and/or the measurements may also comprise indications or snapshots of buffer content sizes of various buffers and/or application layer measures such as bitrates of downlink (or uplink) application media streams, selected media coding qualities/formats, playout rates, etc.

• In another embodiment, UE logs the serving cells measurement upon receiving an indication (e.g., session start indication) from the application layer

• In yet another embodiment, UE logs the serving cells measurement upon receiving an indication (e.g., session start indication) from the application layer indicating the start of the RAN visible lightweight QoE measurements

• In yet another embodiment, UE logs the serving cell measurements periodically while the sampling rate and periodicity is configured by RAN node as part of RAN visible lightweight QoE measurements.

• In yet another embodiment, UE logs the serving cell measurements based on events and certain thresholds configured by the RAN node as part of RAN visible lightweight QoE measurements.

• In yet another embodiment, if the UE has received configurations of MDT and/or RRM measurements linked with QoE measurements and/or reporting for RAN visible (lightweight) QoE measurement, e.g. to enable synchronized or coordinated QoE measurements and MDT and/or RRM measurements, the UE may log information indicating the linking or resulting from the linking, e.g. indications of measurement samples or measurement durations that are synchronized between the linked measurement types.

• In yet another embodiment, the serving cell measurement is a list comprising the measResultServingCell as part of 3GPP TS 38.331 :

MeasResultServingCellList : := SEQUENCE (SIZE

(L.maxMeasReport)) OF MeasResultNR

MeasResultNR ::= SEQUENCE { physCellld PhysCellld OPTIONAL, measResult SEQUENCE { cellResults SEQUENCE{ resultsSSB-Cell MeasQuantityResults

OPTIONAL, resultsCSI-RS-Cell MeasQuantityResults

OPTIONAL

}, rsIndexResults SEQUENCE{ results S SB -Indexes ResultsPer S SB -IndexList

OPTIONAL, resultsCSLRS -Indexes ResultsPerC SLRS -IndexList

OPTIONAL

}

OPTIONAL

},

... ,

} In order to resolve a situation that a UE RRC receives two RAN visible (lightweight) QoE configurations from two different RAN nodes but for the same service type (or applications), a UE RRC can take some actions, even without network involvement (i.e., without signaling of the QoE configuration status between first and second RAN nodes).

Figure 12 shows an example approach. As shown at block 1210, the UE receives, from a RAN node, a RAN visible (lightweight) QoE measurement configuration. Upon receiving this RAN visible (lightweight) QoE measurement configuration for a service type or application, the UE may check whether the RRC and upper layers are already configured with an existing RAN visible (lightweight) QoE configuration for the same service type or the same application, as shown at block 1220. As shown at block 1230, if there exists a RAN visible (lightweight) QoE configuration of the same service type, UE RRC may take one of the following actions: o Discard the new RAN visible (lightweight) QoE configuration or o Release the old RAN visible (lightweight) QoE configuration and configure itself and the upper layers with the new RAN visible (lightweight) QoE configuration o Suspend the new configuration or o Suspend the old configuration and activate the new configuration o If the type of the applications or a sub type of services is specified by the new RAN visible (lightweight) QoE configuration, configures itself and the upper layers of the targeted sub-type of the services and/or targeted applications with the mentioned new RAN visible (lightweight) QoE configuration and keeps the old RAN visible (lightweight) QoE configuration for the rest of the applications. o In a dual connectivity scenario, if one of the RAN visible (lightweight) QoE configurations was received from a master node while the other was received from a secondary node, release the RAN visible (lightweight) QoE configuration received from the secondary node and keep the RAN visible (lightweight) QoE configuration received from the master node. o In a dual connectivity scenario, if one of the RAN visible (lightweight) QoE configurations was received from a master node while the other was received from a secondary node, suspend the RAN visible (lightweight) QoE configuration received from the secondary node and keep the RAN visible (lightweight) QoE configuration received from the master node active. o If an ongoing application session of the type of service and/or subtype of service that the RAN visible (lightweight) QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the old configuration was received, keep the old configuration and either release or suspend the new configuration. o If an ongoing application session of the type of service and/or subtype of service that the RAN visible (lightweight) QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the new configuration was received, keep the new configuration and either release or suspend the old configuration.

As a non-limiting example of implementation of these techniques in specifications for NG-RAN, the RAN visible lightweight QoE measurement configuration information may be implemented as part of the UE Application Layer Measurement Configuration IE as part of 3GPP XnAP interface TS 38.423.

- begin proposed 3 GPP specification -

9.2.3.X UE Application layer measurement configuration

The IE defines configuration information for the QoE Measurement Collection (QMC) function.

- end proposed 3 GPP specification -

The new information elements can be passed as part of the Trace Activation IE as part of any inter-RAN node signaling concerning a mobility or a dual connectivity scenario as well as RRC Resume and Reestablishment procedures that requires Trace Activation IE concerning a QoE measurements. Some of the signals conveying Trace Activation IES can be as following

• HANDOVER REQUEST

• RETRIEVE UE CONTEXT RESPONSE • SGNB ADDITION REQUEST

• S-NODE ADDITION REQUEST

• TRACE START

Trace Activation IE is shown in the following example including the UE application layer measurement configuration IE comprising the RAN visible lightweight QoE measurements. - begin proposed 3GPP specification -

9.2.3. Y Trace A ctivation

This IE defines parameters related to a trace activation.

end proposed 3 GPP specification

The second RAN node upon receiving the RAN visible QoE measurements from the wireless terminal can send the lightweight QoE measurement to the first node. This can be implemented as part of inter-RAN node standard interfaces such as 3GPP TS 38.423 or 3GPP TS 38.413. In a non-limiting example, the solution is implemented as part of the Access And Mobility Indication signal as part of 38.423.

- begin proposed 3 GPP specification -

9.1.3.25 ACCESS AND MOBILITY INDICATION This message is sent by NG-RAN nodei to transfer access and mobility related information to NG-RAN node 2 .

Direction: NG-RAN node1 → NG-RAN node 2.

- end proposed 3 GPP specification - A RAN node receiving the RAN visible (lightweight) QoE measurement report can forward the report from the CU to the DU. A non-limiting example implementation of forwarding the RAN visible (lightweight) QoE measurement report is shown in the Access and Mobility Indication signal that is sent from the gNB-CU to the gNB-DU as part of 3GPP TS 38.473.

- begin proposed 3 GPP specification -

9.2.10.1 ACCESS AND MOBILITY INDICATION

This message is sent by gNB-CU to gNB-DU to provide access and mobility information to the gNB-DU.

Direction: gNB-CU gNB-DU.

- end proposed 3 GPP specification -

Although various embodiments are described above in terms of methods, techniques, and/or procedures, the person of ordinary skill will readily comprehend that such methods, techniques, and/or procedures can be embodied by various combinations of hardware and software in various systems, communication devices, computing devices, control devices, apparatuses, non-transitory computer-readable media, computer program products, etc.

Figure 13 shows a block diagram of an example wireless device or user equipment (UE) 1300 (hereinafter referred to as “UE 1300”) according to various embodiments of the present disclosure, including those described above with reference to other figures. For example, UE 1300 can be configured by execution of instructions, stored on a computer- readable medium, to perform operations corresponding to one or more of the example methods described herein.

UE 1300 can include a processor 1310 (also referred to as “processing circuitry”) that can be operably connected to a program memory 1320 and/or a data memory 1330 via a bus 1370 that can comprise parallel address and data buses, serial ports, or other methods and/or structures known to those of ordinary skill in the art. Program memory 1320 can store software code, programs, and/or instructions (collectively shown as computer program product 1321 in Figure 13) that, when executed by processor 1310, can configure and/or facilitate UE 1300 to perform various operations, including operations corresponding to various example methods described herein. As part of or in addition to such operations, execution of such instructions can configure and/or facilitate UE 1300 to communicate using one or more wired or wireless communication protocols, including one or more wireless communication protocols standardized by 3GPP, 3GPP2, or IEEE, such as those commonly known as 5G/NR, LTE, LTE-A, UMTS, HSPA, GSM, GPRS, EDGE, IxRTT, CDMA2000, 802.11 WiFi, HDMI, USB, Firewire, etc., or any other current or future protocols that can be utilized in conjunction with radio transceiver 1340, user interface 1350, and/or control interface 1360.

As another example, processor 1310 can execute program code stored in program memory 1320 that corresponds to MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP (e.g., for NR and/or LTE). As a further example, processor 1310 can execute program code stored in program memory 1320 that, together with radio transceiver 1340, implements corresponding PHY layer protocols, such as Orthogonal Frequency Division Multiplexing (OFDM), Orthogonal Frequency Division Multiple Access (OFDMA), and Single-Carrier Frequency Division Multiple Access (SC-FDMA). As another example, processor 1310 can execute program code stored in program memory 1320 that, together with radio transceiver 1340, implements device-to-device (D2D) communications with other compatible devices and/or UEs.

Program memory 1320 can also include software code executed by processor 1310 to control the functions of UE 1300, including configuring and controlling various components such as radio transceiver 1340, user interface 1350, and/or control interface 1360. Program memory 1320 can also comprise one or more application programs and/or modules comprising computer-executable instructions embodying any of the example methods described herein. Such software code can be specified or written using any known or future developed programming language, such as e.g., Java, C++, C, Objective C, HTML, XHTML, machine code, and Assembler, as long as the desired functionality, e.g., as defined by the implemented method steps, is preserved. In addition, or as an alternative, program memory 1320 can comprise an external storage arrangement (not shown) remote from UE 1300, from which the instructions can be downloaded into program memory 1320 located within or removably coupled to UE 1300, so as to enable execution of such instructions.

Data memory 1330 can include memory area for processor 1310 to store variables used in protocols, configuration, control, and other functions of UE 1300, including operations corresponding to, or comprising, any of the example methods described herein. Moreover, program memory 1320 and/or data memory 1330 can include non-volatile memory (e.g., flash memory), volatile memory (e.g., static or dynamic RAM), or a combination thereof. Furthermore, data memory 1330 can comprise a memory slot by which removable memory cards in one or more formats (e.g., SD Card, Memory Stick, Compact Flash, etc.) can be inserted and removed. Persons of ordinary skill will recognize that processor 1310 can include multiple individual processors (including, e.g., multi-core processors), each of which implements a portion of the functionality described above. In such cases, multiple individual processors can be commonly connected to program memory 1320 and data memory 1330 or individually connected to multiple individual program memories and or data memories. More generally, persons of ordinary skill in the art will recognize that various protocols and other functions of UE 1300 can be implemented in many different computer arrangements comprising different combinations of hardware and software including, but not limited to, application processors, signal processors, general-purpose processors, multi-core processors, ASICs, fixed and/or programmable digital circuitry, analog baseband circuitry, radio-frequency circuitry, software, firmware, and middleware.

Radio transceiver 1340 can include radio-frequency transmitter and/or receiver functionality that facilitates the UE 1300 to communicate with other equipment supporting like wireless communication standards and/or protocols. In some example embodiments, the radio transceiver 1340 includes one or more transmitters and one or more receivers that enable UE 1300 to communicate according to various protocols and/or methods proposed for standardization by 3GPP and/or other standards-setting organizations (SSOs). For example, such functionality can operate cooperatively with processor 1310 to implement a PHY layer based on OFDM, OFDMA, and/or SC-FDMA technologies, such as described herein with respect to other figures.

In some example embodiments, radio transceiver 1340 includes one or more transmitters and one or more receivers that can facilitate the UE 1300 to communicate with various LTE, LTE-Advanced (LTE-A), and/or NR networks according to standards promulgated by 3GPP. In some example embodiments of the present disclosure, the radio transceiver 1340 includes circuitry, firmware, etc. necessary for the UE 1300 to communicate with various NR, NR-U, LTE, LTE-A, LTE-LAA, UMTS, and/or GSM/EDGE networks, also according to 3GPP standards. In some embodiments, radio transceiver 1340 can include circuitry supporting D2D communications between UE 1300 and other compatible devices.

In some embodiments, radio transceiver 1340 includes circuitry, firmware, etc. necessary for the UE 1300 to communicate with various CDMA2000 networks, according to 3GPP2 standards. In some embodiments, the radio transceiver 1340 can be capable of communicating using radio technologies that operate in unlicensed frequency bands, such as IEEE 802.11 WiFi that operates using frequencies in the regions of 2.4, 5.6, and/or 60 GHz. In some embodiments, radio transceiver 1340 can include a transceiver that is capable of wired communication, such as by using IEEE 802.3 Ethernet technology. The functionality particular to each of these embodiments can be coupled with and/or controlled by other circuitry in the UE 1300, such as the processor 1310 executing program code stored in program memory 1320 in conjunction with, and/or supported by, data memory 1330.

User interface 1350 can take various forms depending on the particular embodiment of UE 1300, or can be absent from UE 1300 entirely. In some embodiments, user interface 1350 can comprise a microphone, a loudspeaker, slidable buttons, depressible buttons, a display, a touchscreen display, a mechanical or virtual keypad, a mechanical or virtual keyboard, and/or any other user-interface features commonly found on mobile phones. In other embodiments, the UE 1300 can comprise a tablet computing device including a larger touchscreen display. In such embodiments, one or more of the mechanical features of the user interface 1350 can be replaced by comparable or functionally equivalent virtual user interface features (e.g., virtual keypad, virtual buttons, etc.) implemented using the touchscreen display, as familiar to persons of ordinary skill in the art. In other embodiments, the UE 1300 can be a digital computing device, such as a laptop computer, desktop computer, workstation, etc. that comprises a mechanical keyboard that can be integrated, detached, or detachable depending on the particular embodiment. Such a digital computing device can also comprise a touch screen display. Many example embodiments of the UE 1300 having a touch screen display are capable of receiving user inputs, such as inputs related to example methods described herein or otherwise known to persons of ordinary skill.

In some embodiments, UE 1300 can include an orientation sensor, which can be used in various ways by features and functions of UE 1300. For example, the UE 1300 can use outputs of the orientation sensor to determine when a user has changed the physical orientation of the UE 1300’s touch screen display. An indication signal from the orientation sensor can be available to any application program executing on the UE 1300, such that an application program can change the orientation of a screen display (e.g., from portrait to landscape) automatically when the indication signal indicates an approximate 90-degree change in physical orientation of the device. In this example manner, the application program can maintain the screen display in a manner that is readable by the user, regardless of the physical orientation of the device. In addition, the output of the orientation sensor can be used in conjunction with various example embodiments of the present disclosure.

A control interface 1360 of the UE 1300 can take various forms depending on the particular example embodiment of UE 1300 and of the particular interface requirements of other devices that the UE 1300 is intended to communicate with and/or control. For example, the control interface 1360 can comprise an RS-232 interface, a USB interface, an HDMI interface, a Bluetooth interface, an IEEE (“Firewire”) interface, an I 2 C interface, a PCMCIA interface, or the like. In some example embodiments of the present disclosure, control interface 1360 can comprise an IEEE 802.3 Ethernet interface such as described above. In some example embodiments of the present disclosure, the control interface 1360 can comprise analog interface circuitry including, for example, one or more digital-to-analog converters (DACs) and/or analog-to-digital converters (ADCs).

Persons of ordinary skill in the art can recognize the above list of features, interfaces, and radio-frequency communication standards is merely exemplary, and not limiting to the scope of the present disclosure. In other words, the UE 1300 can comprise more functionality than is shown in Figure 13 including, for example, a video and/or still-image camera, microphone, media player and/or recorder, etc. Moreover, radio transceiver 1340 can include circuitry necessary to communicate using additional radio-frequency communication standards including Bluetooth, GPS, and/or others. Moreover, the processor 1310 can execute software code stored in the program memory 1320 to control such additional functionality. For example, directional velocity and/or position estimates output from a GPS receiver can be available to any application program executing on the UE 1300, including any program code corresponding to and/or embodying any example embodiments (e.g., of methods) described herein.

Figure 14 shows a block diagram of an example network node 1400 according to various embodiments of the present disclosure, including those described above with reference to other figures. For example, example network node 1400 can be configured by execution of instructions, stored on a computer-readable medium, to perform operations corresponding to one or more of the example methods described herein. In some example embodiments, network node 1400 can comprise a base station, eNB, gNB, or one or more components thereof. For example, network node 1400 can be configured as a central unit (CU) and one or more distributed units (DUs) according to NR gNB architectures specified by 3GPP. More generally, the functionally of network node 1400 can be distributed across various physical devices and/or functional units, modules, etc.

Network node 1400 can include processor 1410 (also referred to as “processing circuitry”) that is operably connected to program memory 1420 and data memory 1430 via bus 1470, which can include parallel address and data buses, serial ports, or other methods and/or structures known to those of ordinary skill in the art. Program memory 1420 can store software code, programs, and/or instructions (collectively shown as computer program product 1421 in Figure 14) that, when executed by processor 1410, can configure and/or facilitate network node 1400 to perform various operations, including operations corresponding to various example methods described herein. As part of and/or in addition to such operations, program memory 1420 can also include software code executed by processor 1410 that can configure and/or facilitate network node 1400 to communicate with one or more other UEs or network nodes using other protocols or protocol layers, such as one or more of the PHY, MAC, RLC, PDCP, and RRC layer protocols standardized by 3GPP for LTE, LTE-A, and/or NR, or any other higher-layer (e.g., NAS) protocols utilized in conjunction with radio network interface 1440 and/or core network interface 1450. By way of example, core network interface 1450 can comprise the SI or NG interface and radio network interface 1440 can comprise the Uu interface, as standardized by 3 GPP. Program memory 1420 can also comprise software code executed by processor 1410 to control the functions of network node 1400, including configuring and controlling various components such as radio network interface 1440 and core network interface 1450.

Data memory 1430 can comprise memory area for processor 1410 to store variables used in protocols, configuration, control, and other functions of network node 1400. Program memory 1420 and data memory 1430 can comprise non-volatile memory (e.g., flash memory, hard disk, etc.), volatile memory (e.g., static or dynamic RAM), network-based (e.g., “cloud”) storage, or a combination thereof. Persons of ordinary skill in the art will recognize that processor 1410 can include multiple individual processors (not shown), each of which implements a portion of the functionality described above. In such case, multiple individual processors may be commonly connected to program memory 1420 and data memory 1430 or individually connected to multiple individual program memories and/or data memories. More generally, persons of ordinary skill will recognize that various protocols and other functions of network node 1400 may be implemented in many different combinations of hardware and software including, but not limited to, application processors, signal processors, general-purpose processors, multi-core processors, ASICs, fixed digital circuitry, programmable digital circuitry, analog baseband circuitry, radio-frequency circuitry, software, firmware, and middleware.

Radio network interface 1440 can comprise transmitters, receivers, signal processors, ASICs, antennas, beamforming units, and other circuitry that enables network node 1400 to communicate with other equipment such as, in some embodiments, a plurality of compatible user equipment (UE). In some embodiments, interface 1440 can also enable network node 1400 to communicate with compatible satellites of a satellite communication network. In some example embodiments, radio network interface 1440 can comprise various protocols or protocol layers, such as the PHY, MAC, RLC, PDCP, and/or RRC layer protocols standardized by 3 GPP for LTE, LTE-A, LTE-LAA, NR, NR-U, etc.; improvements thereto such as described herein above; or any other higher-layer protocols utilized in conjunction with radio network interface 1440. According to further example embodiments of the present disclosure, the radio network interface 1440 can comprise a PHY layer based on OFDM, OFDMA, and/or SC-FDMA technologies. In some embodiments, the functionality of such a PHY layer can be provided cooperatively by radio network interface 1440 and processor 1410 (including program code in memory 1420).

Core network interface 1450 can comprise transmitters, receivers, and other circuitry that enables network node 1400 to communicate with other equipment in a core network such as, in some embodiments, circuit-switched (CS) and/or packet-switched Core (PS) networks. In some embodiments, core network interface 1450 can comprise the SI interface standardized by 3GPP. In some embodiments, core network interface 1450 can comprise the NG interface standardized by 3GPP. In some example embodiments, core network interface 1450 can comprise one or more interfaces to one or more AMFs, SMFs, SGWs, MMEs, SGSNs, GGSNs, and other physical devices that comprise functionality found in GERAN, UTRAN, EPC, 5GC, and CDMA2000 core networks that are known to persons of ordinary skill in the art. In some embodiments, these one or more interfaces may be multiplexed together on a single physical interface. In some embodiments, lower layers of core network interface 1450 can comprise one or more of asynchronous transfer mode (ATM), Internet Protocol (IP)-over-Ethemet, SDH over optical fiber, T1/E1/PDH over a copper wire, microwave radio, or other wired or wireless transmission technologies known to those of ordinary skill in the art.

In some embodiments, network node 1400 can include hardware and/or software that configures and/or facilitates network node 1400 to communicate with other network nodes in a RAN (also referred to as a “wireless network”), such as with other eNBs, gNBs, ng-eNBs, en-gNBs, IAB nodes, etc. Such hardware and/or software can be part of radio network interface 1440 and/or core network interface 1450, or it can be a separate functional unit (not shown). For example, such hardware and/or software can configure and/or facilitate network node 1400 to communicate with other RAN nodes via the X2 or Xn interfaces, as standardized by 3 GPP. OA&M interface 1460 can comprise transmitters, receivers, and other circuitry that enables network node 1400 to communicate with external networks, computers, databases, and the like for purposes of operations, administration, and maintenance of network node 1400 or other network equipment operably connected thereto. Lower layers of OA&M interface 1460 can comprise one or more of asynchronous transfer mode (ATM), Internet Protocol (IP)-over-Ethemet, SDH over optical fiber, T1ZE1/PDH over a copper wire, microwave radio, or other wired or wireless transmission technologies known to those of ordinary skill in the art. Moreover, in some embodiments, one or more of radio network interface 1440, core network interface 1450, and OA&M interface 1460 may be multiplexed together on a single physical interface, such as the examples listed above.

Figure 15 is a block diagram of an example communication network configured to provide over-the-top (OTT) data services between a host computer and a user equipment (UE), according to various example embodiments of the present disclosure. UE 1510 can communicate with radio access network (RAN, also referred to as “wireless network”) 1530 over radio interface 1520, which can be based on protocols described above including, e.g., LTE, LTE-A, and 5G/NR. For example, UE 1510 can be configured and/or arranged as shown in other figures discussed above.

RAN 1530 can include one or more terrestrial network nodes ( e.g., base stations, eNBs, gNBs, controllers, etc.) operable in licensed spectrum bands, as well one or more network nodes operable in unlicensed spectrum (using, e.g., LAA or NR-U technology), such as a 2.4-GHz band and/or a 5-GHz band. In such cases, the network nodes comprising RAN 1530 can cooperatively operate using licensed and unlicensed spectrum. In some embodiments, RAN 1530 can include, or be capable of communication with, one or more satellites comprising a satellite access network.

RAN 1530 can communicate with core network 1540 according to various protocols and interfaces described above. For example, one or more apparatus (e.g., base stations, eNBs, gNBs, etc.) comprising RAN 1530 can communicate to core network 1540 via core network interface 1550 described above. In some example embodiments, RAN 1530 and core network 1540 can be configured and/or arranged as shown in other figures discussed above. For example, eNBs comprising an E-UTRAN 1530 can communicate with an EPC core network 1540 via an SI interface. As another example, gNBs and ng-eNBs comprising an NG-RAN 1530 can communicate with a 5GC core network 1530 via an NG interface.

Core network 1540 can further communicate with an external packet data network, illustrated in Figure 15 as Internet 1550, according to various protocols and interfaces known to persons of ordinary skill in the art. Many other devices and/or networks can also connect to and communicate via Internet 1550, such as example host computer 1560. In some example embodiments, host computer 1560 can communicate with UE 1510 using Internet 1550, core network 1540, and RAN 1530 as intermediaries. Host computer 1560 can be a server (e.g, an application server) under ownership and/or control of a service provider. Host computer 1560 can be operated by the OTT service provider or by another entity on the service provider’s behalf.

For example, host computer 1560 can provide an over-the-top (OTT) packet data service to UE 1510 using facilities of core network 1540 and RAN 1530, which can be unaware of the routing of an outgoing/incoming communication to/from host computer 1560. Similarly, host computer 1560 can be unaware of routing of a transmission from the host computer to the UE, e.g, the routing of the transmission through RAN 1530. Various OTT services can be provided using the example configuration shown in Figure 15 including, e.g., streaming (unidirectional) audio and/or video from host computer to UE, interactive (bidirectional) audio and/or video between host computer and UE, interactive messaging or social communication, interactive virtual or augmented reality, etc.

The example network shown in Figure 15 can also include measurement procedures and/or sensors that monitor network performance metrics including data rate, latency and other factors that are improved by example embodiments disclosed herein. The example network can also include functionality for reconfiguring the link between the endpoints (e.g., host computer and UE) in response to variations in the measurement results. Such procedures and functionalities are known and practiced; if the network hides or abstracts the radio interface from the OTT service provider, measurements can be facilitated by proprietary signaling between the UE and the host computer.

The embodiments described herein provide novel techniques for configuring, performing, and reporting lightweight QoE metrics by UEs. Such techniques can facilitate better analysis and optimization decisions in the RAN, while avoiding unnecessary network traffic caused by conventional measurement reports that include large amounts of information, such as conventional QoE metrics. When used in NR UEs (e.g., UE 1510) and gNBs (e.g., gNBs comprising RAN 1530), embodiments described herein can provide various improvements, benefits, and/or advantages that can improve QoE determination and network optimization for OTT applications and/or services. As a consequence, this improves the performance of these services as experienced by OTT service providers and end-users, including more precise delivery of services with lower latency without excessive UE energy consumption or other reductions in user experience.

The foregoing merely illustrates the principles of the disclosure. Various modifications and alterations to the described embodiments will be apparent to those skilled in the art in view of the teachings herein. It will thus be appreciated that those skilled in the art will be able to devise numerous systems, arrangements, and procedures that, although not explicitly shown or described herein, embody the principles of the disclosure and can be thus within the spirit and scope of the disclosure. Various example embodiments can be used together with one another, as well as interchangeably therewith, as should be understood by those having ordinary skill in the art.

As described herein, device and/or apparatus can be represented by a semiconductor chip, a chipset, or a (hardware) module comprising such chip or chipset; this, however, does not exclude the possibility that a functionality of a device or apparatus, instead of being hardware implemented, be implemented as a software module such as a computer program or a computer program product comprising executable software code portions for execution or being run on a processor. Furthermore, functionality of a device or apparatus can be implemented by any combination of hardware and software. A device or apparatus can also be regarded as an assembly of multiple devices and/or apparatuses, whether functionally in cooperation with or independently of each other. Moreover, devices and apparatuses can be implemented in a distributed fashion throughout a system, so long as the functionality of the device or apparatus is preserved. Such and similar principles are considered as known to a skilled person.

Any appropriate steps, methods, features, functions, or benefits disclosed herein may be performed through one or more functional units or modules of one or more virtual apparatuses. Each virtual apparatus may comprise a number of these functional units. These functional units may be implemented via processing circuitry, which may include one or more microprocessor or microcontrollers, as well as other digital hardware, which may include Digital Signal Processor (DSPs), special-purpose digital logic, and the like. The processing circuitry may be configured to execute program code stored in memory, which may include one or several types of memory such as Read Only Memory (ROM), Random Access Memory (RAM), cache memory, flash memory devices, optical storage devices, etc. Program code stored in memory includes program instructions for executing one or more telecommunications and/or data communications protocols as well as instructions for carrying out one or more of the techniques described herein. In some implementations, the processing circuitry may be used to cause the respective functional unit to perform corresponding functions according one or more embodiments of the present disclosure.

Furthermore, functions described herein as being performed by a wireless device or a network node may be distributed over a plurality of wireless devices and/or network nodes. In other words, it is contemplated that the functions of the network node and wireless device described herein are not limited to performance by a single physical device and, in fact, can be distributed among several physical devices.

Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. It will be further understood that terms used herein should be interpreted as having a meaning that is consistent with their meaning in the context of this specification and the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

In addition, certain terms used in the present disclosure, including the specification, drawings and example embodiments thereof, can be used synonymously in certain instances, including, but not limited to, e.g., data and information. It should be understood that, although these words and/or other words that can be synonymous to one another, can be used synonymously herein, that there can be instances when such words can be intended to not be used synonymously. Further, to the extent that the prior art knowledge has not been explicitly incorporated by reference herein above, it is explicitly incorporated herein in its entirety. All publications referenced are incorporated herein by reference in their entireties.

As used herein unless expressly stated to the contrary, the phrases “at least one of’ and “one or more of,” followed by a conjunctive list of enumerated items (e.g., “A and B”, “A, B, and C”), are intended to mean “at least one item, with each item selected from the list consisting of’ the enumerated items. For example, “at least one of A and B” is intended to mean any of the following: A; B; A and B. Likewise, “one or more of A, B, and C” is intended to mean any of the following: A; B; C; A and B; B and C; A and C; A, B, and C.

As used herein unless expressly stated to the contrary, the phrase “a plurality of’ followed by a conjunctive list of enumerated items (e.g., “A and B”, “A, B, and C”) is intended to mean “multiple items, with each item selected from the list consisting of’ the enumerated items. For example, “a plurality of A and B” is intended to mean any of the following: more than one A; more than one B; or at least one A and at least one B.

Embodiments of the techniques and apparatus described herein also include, but are not limited to, the following enumerated examples: Al . A method for a user equipment (UE) for handling configurations of quality-of- experience (QoE) measurements in a radio access network (RAN), the method comprising: receiving, from a RAN node, a RAN visible lightweight QoE configuration; determining that the UE already has a RAN visible lightweight QoE configuration for the same service type or application; and upon said determining, taking one or more of the following actions: o discarding the new RAN visible (lightweight) QoE configuration; o releasing the old RAN visible (lightweight) QoE configuration and configuring itself and the upper layers with the new RAN visible (lightweight) QoE configuration; o suspending the new configuration; o suspending the old configuration and activating the new configuration; o if the old configuration is already in a suspended state when the new configuration is received, keeping the new configuration active and either releasing the old configuration or keeping the old configuration suspended; o if the type of the services/applications or a subtype of services is specified by the new RAN visible (lightweight) QoE configuration, configuring itself and the upper layers of the targeted type or subtype of the services and/or targeted applications with the mentioned services and keeping the old RAN visible (lightweight) QoE configuration for the rest of the applications; o in a dual connectivity scenario, if one of the RAN visible (lightweight) QoE configurations was received from a master node while the other was received from a secondary node, releasing the RAN visible (lightweight) QoE configuration received from the secondary node and keeping the RAN visible (lightweight) QoE configuration received from the master node; o in a dual connectivity scenario, if one of the RAN visible (lightweight) QoE configurations was received from a master node while the other was received from a secondary node, suspending the RAN visible (lightweight) QoE configuration received from the secondary node and keeping the RAN visible (lightweight) QoE configuration received from the master node active; o if an ongoing application session of the type of service and/or subtype of service that the RAN visible (lightweight) QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the old configuration was received, keeping the old configuration and either releasing or suspending the new configuration; and o if an ongoing application session of the type of service and/or subtype of service that the RAN visible (lightweight) QoE configurations target (or all such ongoing applications sessions in case more than one is ongoing) is currently using radio bearer(s) towards the RAN node from which the new configuration was received, keeping the new configuration and either releasing or suspending the old configuration.

Bl. A method, for a first node in a radio access network (RAN), for managing quality-of- experience (QoE) measurements by a user equipment (UE), the method comprising: transmitting, to a second node in the RAN, configuration information for one or more RAN visible (lightweight) QoE measurements configured for the UE by the first node.

B2. The method of embodiment Bl, wherein the second node is associated with the first node with respect to changing a configuration for the UE, e.g., for dual connectivity, mobility, RRC resume, RRC reestablishment, switching the transfer of the data for the service from a path going to the UE via the first RAN node to a path going to the UE via the second RAN node.

B3. The method of embodiment Bl or B2, wherein the method comprises, prior to said transmitting, configuring the UE for the one or more RAN visible (lightweight) QoE measurements.

B4. The method of any one of embodiments B1-B3, wherein the configuration information comprises one or more of any of the following:

- An indication, indicating the service types for which the RAN visible (lightweight) QoE is configured;

- An indication, indicating whether a session pertained to an application from the service type for which the RAN visible (lightweight) QoE configuration is configured is ongoing or not; - An indication, indicating the type of the QoE measurement such as management based, or a signaling based or a hybrid (combination of management based and signaling based QoE);

- An indication, indicating whether the first RAN node is interested to receive the RAN visible (lightweight) QoE measurement results (or a part of RAN visible lightweight QoE measurements) upon delivery of the QoE measurements from the wireless terminal to the second RAN node;

- An indication indicating that a RAN visible (lightweight) QoE report with information pertaining to the second RAN node has been received;

- An indication, signalled together with a RAN visible (lightweight) QoE report, stating whether the report has been already signalled to the TCE; and

- A RAN visible (lightweight) QoE report received from a wireless terminal.

B5. The method of any one of embodiments B1-B4, wherein the status information is transmitted to the second node along with status information pertaining to one or more additional UEs.

B6. The method of any one of embodiments B1-B5, wherein the method further comprises sending, to the second node, a request regarding the one or more RAN visible lightweight QoE measurements.

B7. The method of embodiment B6, wherein the request comprises any one of: o a request to send to the first RAN node (or to buffer and subsequently send to the first RAN node) the QoE reports received by the second RAN node, the request optionally comprising additional conditions associated to the start and the stop of such reporting, such as:

■ a reconfiguration of the (signaling) radio bearers at the UE which results in the switch of RAN node receiving the QoE reports, an overload indication sent from the first RAN node to the second RAN node, a period of time, until session end, until a subsequent mobility events is triggered, until further UE reconfiguration, service type or service subtype, slice or list of slices; o a request to support reception of RAN visible lightweight QoE reporting; o a request to suspend one or a list of the activated RAN visible lightweight QoE measurements; o a request to resume one or a list of the suspended RAN visible lightweight QoE measurements; o a request to release or to pause one or a list of the activated RAN visible lightweight QoE measurements; and o a request to configure the UE with a certain configuration of RAN visible lightweight measurements or certain configuration of radio measurements linked to the QoE measurements.

B8. The method of embodiment B6 or B7, wherein the method comprises receiving, from the second node, a message acknowledging the request or indicating failure or inability to comply with the request.

B9. The method of any one of embodiments B6-B8, wherein the request pertains to multiple UEs.

BIO. A method, for a second node in a radio access network (RAN), for managing quality - of-experience (QoE) measurements by a user equipment (UE), the method comprising: receiving, from a first node in the RAN, configuration information for one or more RAN visible (lightweight) QoE measurements configured for the UE by the first node.

Bl 1. The method of embodiment BIO, wherein the second node is associated with the first node with respect to changing a configuration for the UE, e.g., for dual connectivity, mobility, RRC resume, RRC reestablishment, switching the transfer of the data for the service from a path going to the UE via the first RAN node to a path going to the UE via the second RAN node.

B12. The method of any one of embodiments B10-B11, wherein the configuration information comprises one or more of any of the following:

- An indication, indicating the service types for which the RAN visible (lightweight) QoE is configured; - An indication, indicating whether a session pertained to an application from the service type for which the RAN visible (lightweight) QoE configuration is configured is ongoing or not;

- An indication, indicating the type of the QoE measurement such as management based, or a signaling based or a hybrid (combination of management based and signaling based QoE);

- An indication, indicating whether the first RAN node is interested to receive the RAN visible (lightweight) QoE measurement results (or a part of RAN visible lightweight QoE measurements) upon delivery of the QoE measurements from the wireless terminal to the second RAN node;

- An indication indicating that a RAN visible (lightweight) QoE report with information pertaining to the second RAN node has been received;

- An indication, signalled together with a RAN visible (lightweight) QoE report, stating whether the report has been already signalled to the TCE; and

- A RAN visible (lightweight) QoE report received from a wireless terminal.

B13. The method of any one of embodiments B10-B12, wherein the method comprises refraining from configuring or changing a configuration of QoE measurements by the UE, in response to the status information.

B14. The method of any one of embodiments B10-B13, wherein the method further comprises receiving, from the first node, a request regarding the one or more RAN visible lightweight QoE measurements.

B15. The method of embodiment B14, wherein the request comprises any one of: o a request to send to the first RAN node (or to buffer and subsequently send to the first RAN node) the QoE reports received by the second RAN node, the request optionally comprising additional conditions associated to the start and the stop of such reporting, such as:

■ a reconfiguration of the (signaling) radio bearers at the UE which results in the switch of RAN node receiving the QoE reports, an overload indication sent from the first RAN node to the second RAN node, a period of time, until session end, until a subsequent mobility events is triggered, until further UE reconfiguration, service type or service subtype, slice or list of slices; o a request to support reception of RAN visible lightweight QoE reporting; o a request to suspend one or a list of the activated RAN visible lightweight QoE measurements; o a request to resume one or a list of the suspended RAN visible lightweight QoE measurements; o a request to release or to pause one or a list of the activated RAN visible lightweight QoE measurements; and o a request to configure the UE with a certain configuration of RAN visible lightweight measurements or certain configuration of radio measurements linked to the QoE measurements.

B16. The method of embodiment B14 or B15, the method further comprising responding with an indication of a status of execution of the request.

B17. The method of embodiment B14 or B15, wherein the method comprises sending to the first node, in response to the request, a message acknowledging the request or indicating failure or inability to comply with the request.

B18. The method of any one of embodiments B10-B17, wherein the request pertains to multiple UEs.

C1. A user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), the UE comprising: radio transceiver circuitry configured to communicate with at least one RAN node; and processing circuitry operatively coupled to the radio transceiver circuitry, whereby the processing circuitry and the radio transceiver circuitry are configured to perform operations corresponding to the method of embodiment Al.

C2. A user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), the UE being further arranged to perform operations corresponding to the method of embodiment A1. C3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to perform quality-of-experience (QoE) measurements in a radio access network (RAN), configure the UE to perform operations corresponding to the method of embodiment Al.

C4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a user equipment (UE) configured to perform quality-of- experience (QoE) measurements in a radio access network (RAN), configure the UE to perform operations corresponding to the method of embodiment Al.

DI . A radio access network (RAN) node arranged to configure a user equipment (UE) to perform quality-of-experience (QoE) measurements, the RAN node comprising: communication interface circuitry configured to communicate with UEs and with a network node or function outside the RAN; and processing circuitry operatively coupled to the communication interface circuitry, whereby the processing circuitry and the communication interface circuitry are configured to perform operations corresponding to the methods of any of embodiments Bl -Bl 8.

D2. A radio access network (RAN) node arranged to configure user equipment (UEs) to perform quality-of-experience (QoE) measurements, the RAN node being further arranged to perform operations corresponding to the methods of any of embodiments Bl -Bl 8.

D3. A non-transitory, computer-readable medium storing computer-executable instructions that, when executed by processing circuitry of a radio access network (RAN) node arranged to configure user equipment (UEs) to perform quality-of-experience (QoE) measurements, configure the RAN node to perform operations corresponding to the methods of any of embodiments Bl -Bl 8.

D4. A computer program product comprising computer-executable instructions that, when executed by processing circuitry of a radio access network (RAN) node arranged to configure user equipment (UEs) to perform quality-of-experience (QoE) measurements, configure the RAN node to perform operations corresponding to the methods of any of embodiments Bl- B18.

ABBREVIATIONS

3GPP 3 rd Generation Partnership Project

5GCN 5G Core Network

5GS 5G System

AF Application Function

AMF Access and Mobility Management Function

AN Access Network

API Application Programming Interface

AGV Automated Guided Vehicle

BAP Backhaul Adaptation Protocol

CN Core Network

CP Control Plane

CU Central Unit

DC Dual Connectivity

DU Distributed Unit eNB E-UTRAN NodeB

EN-DC E-UTRA-NR Dual Connectivity

E-UTRA Evolved UTRA

E-UTRAN Evolved UTRAN gNB Radio base station in NR

IAB Integrated Access and Backhaul

ID Identifier/Identity

IE Information Element

LTE Long Term Evolution

MCE Measurement Collector Entity

MDT Minimization of Drive Testing

MME Mobility Management Entity

MN Master Node

MR-DC Multi-Radio Dual Connectivity

NE-DC NR-E-UTRA Dual Connectivity NG Next Generation

NGEN-DC NG-RAN E-UTRA-NR Dual Connectivity

NG-RAN NG Radio Access Network

NR New Radio

OAM/O&M Operation and Maintenance

PCF Policy Control Function

QCI QoS Class Identifier

QMC QoE Measurement Collection

QoE Quality of Experience

QoS Quality of Service

RAN Radio Access Network

RAT Radio Access Technology

RRC Radio Resource Control

SI The interface between the RAN and the CN in LTE.

S1AP SI Application Protocol

SMF Session Management Function

SMO Service Management and Orchestration

SN Secondary Node

S-NSSAI Single-Network Slice Selection Assistance Information

TCE Trace Collector Entity

UE User Equipment

UPF User Plane Function