Handling user equipment performance measurement reports for handover evaluation

Abstract

Example embodiments of the present disclosure relate to methods, devices, apparatuses and computer readable storage medium for handling user equipment (UE) performance measurement reports for handover evaluation. The method comprises: monitoring an evolution of a performance measurement precision of one or more quality of service (QoS) metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; determining, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and transmitting, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or evaluating a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

Description

HANDLING USER EQUIPMENT PERFORMANCE MEASUREMENT REPORTS FOR HANDOVER EVALUATIONFIELDS

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for handling user equipment (UE) performance measurement reports for handover evaluation.BACKGROUND

[0002] A discussion of Artificial Intelligence (AI) / Machine Learning (ML) for load balancing and mobility optimization use cases in next generation radio access network (NG-RAN) is now ongoing in the 3rd Generation Partnership Project (3GPP), which were introduced by a study on enhancement for data collection for New Radio (NR) and EUTRA-NR Dual Connection (EN-DC).SUMMARY

[0003] In a first aspect of the present disclosure, there is provided an apparatus. The apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: monitor an evolution of a performance measurement precision of one or more quality of service (QoS) metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; determine, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and transmit, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or evaluate a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

[0004] In a second aspect of the present disclosure, there is provided an apparatus. The apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration; and receive, from the source network node, an indication for a termination of a performance reporting of the terminal device.

[0005] In a third aspect of the present disclosure, there is provided a method. The method comprises: monitoring an evolution of a performance measurement precision of one or more QoS metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; determining, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and transmitting, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or evaluating a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

[0006] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration; and receiving, from the source network node, an indication for a termination of a performance reporting of the terminal device.

[0007] In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for monitoring an evolution of a performance measurement precision of one or more QoS metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; means for determining, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and means for transmitting, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or means for evaluating a decision of the apparatus to handover the terminal device to the target network node by associatinga weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

[0008] In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration; and means for receiving, from the source network node, an indication for a termination of a performance reporting of the terminal device.

[0009] In a seventh aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the third aspect.

[0010] In an eighth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fourth aspect.

[0011] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0013] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0014] FIG. 2 illustrates a signaling chart for handling UE performance measurement reports for handover evaluation according to some example embodiments of the present disclosure;

[0015] FIG. 3 illustrates an example process for handling UE performance measurement reports for handover evaluation according to some example embodiments of the present disclosure;

[0016] FIG. 4 illustrates an example process for handling UE performance measurement reports for handover evaluation according to some example embodiments of the present disclosure;

[0017] FIG. 5 illustrates a flowchart of a method implemented at an apparatus according to some example embodiments of the present disclosure;

[0018] FIG. 6 illustrates a flowchart of a method implemented at an apparatus according to some example embodiments of the present disclosure;

[0019] FIG. 7 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0020] FIG. 8 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0021] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0022] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0023] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0024] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it issubmitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0025] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0026] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0027] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0028] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0029] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) withsoftware / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0030] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0031] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0032] As used herein, the terms “network node”, “radio network node” and / or “radio access network node” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a nonterrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, an RAN split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU).

[0033] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0034] As used herein, the term “resource,” “transmission resource,” “resource block,”“physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0035] As described above, AI / ML for load balancing and mobility optimization use cases in NG-RAN was discussed. Taking the load balancing use case as our example, the objective of load balancing is to distribute load evenly among cells and among areas of cells, or to transfer part of the traffic from congested cells or from congested areas of cells, or to offload users from one cell, cell area, carrier, or Radio Access Technology (RAT) to improve network performance. This can be done by means of optimization of handover parameters and handover actions. The automation of such optimization can provide high quality user experience, while simultaneously improving the system capacity and to minimize human intervention in the network management and optimization tasks.

[0036] However, UE load balancing is not an easy task to address with classical optimization tools, as traffic load and network resource status may change in a very dynamic fashion, therefore, it is hard to determine whether UE service performance meets the desired targets after an offloading action is taken.

[0037] To alleviate this issue and to automate such load balancing optimization that ensures user experience of high quality with only minimal human intervention to network management tasks, the usage of AI / ML-based solutions can be proven useful. More specifically, based on collection of various measurements and feedback from UEs and network nodes, historical data, etc. AI / ML model-based solutions and predicted load could improve load balancing performance, to provide higher quality user experience and to improve the system capacity.

[0038] Feedback from an actor (e.g., an NG-RAN node taking a UE load balancing action) toward a data collection entity may be defined as information that may be neededto derive training data, inference data or to monitor the performance of the AI / ML model and its impact to the network through updating of key performance indicators (KPIs) and performance counters.

[0039] Until now, it is not clear how can a source network node in a handover of UE monitor the evolution of the precision of the UE QoS metrics (i.e., UL / DL throughput, packet error rate, end-to-end radio delay) during the dispatching of UE performance measurement reports by the target node.

[0040] In the present disclosure, a solution for handling UE performance measurement reports for handover evaluation is provided. In this solution, a source network node of a handover of a terminal device monitors an evolution of a performance measurement precision of one or more QoS metrics of the terminal device for one or more performance measurement reports issued to the source network node by a target network node upon handover the terminal device to the target network node. The source network node determines, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level. If the measurement precision level is reached within a reporting duration, the source network node transmits, to the target network node an indication for a termination of a performance reporting of the terminal device. If the measurement precision level is not reached within the reporting duration, the source network node evaluates a decision of the source network node to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports.

[0041] In this way, a solution and a messaging framework via the Xn or the X2 interface enabling a source network node (or an “Actor” gNB) to monitor the evolution of the precision of requested UE QoS metrics during the periodic reception of UE performance measurement reports is achieved.

[0042] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0043] FIG. 1 shows an example communication network 100 in which embodiments of the present disclosure may be implemented. As shown in FIG. 1, the communication network 100 may include a terminal device 110. Hereinafter the terminal device 110 may also be referred to as a UE.

[0044] The communication network 100 may further include network nodes 120-1 and 120-2. Hereinafter the network node 120 may also be referred to as a base station, a gNB or an eNB, respectively. As an example, the terminal device 110 may communicate with the network node 120-1 within a coverage of a cell 102 managed by the network node 120-1. If the radio link between the terminal device 110 and the network node 120-1 is getting worse, for example, due to the movement of the terminal device, a handover procedure may occur. After the handover successfully completes, the terminal device 110 may communicate with the network node 120-2 within a coverage of a cell 104 managed by the network node 120-2. In this handover procedure, the network node 120-1 may also be referred to as a source network node 120-1 and the network node 120-2 may also be referred to as a target network node 120-2.

[0045] It is to be understood that the number of network nodes and terminal devices shown in FIG. 1 is given for the purpose of illustration without suggesting any limitations. The communication network 100 may include any suitable number of network nodes and terminal devices.

[0046] In some example embodiments, links from the network nodes 120-1 or 120-2 to the terminal device 110 may be referred to as a downlink (DL), while links from the terminal device 110 to the network nodes 120-1 or 120-2 may be referred to as an uplink (UL). In DL, the network nodes 120-1 or 120-2 is a transmitting (TX) device (or a transmitter) and the terminal device 110 is a receiving (RX) device (or receiver). In UL, the terminal device 110 is a TX device (or transmitter) and the network nodes 120-1 or 120-2 is a RX device (or a receiver).

[0047] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO),Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0048] Upon handover the terminal device 110 to the target network node 120-2, the target network node 120-2 may collect data from the terminal device 110 and issue one or more UE performance measurement reports associated with one or more UE QoS metrics to the source network node 120-1 within a predetermined reporting duration. With reference to embodiments of the present disclosure and FIGS. 2-4, the solution for how to handle the received UE performance measurement report(s) by the source network node 120-1 for monitoring the evolution of the precision of the UE QoS metrics will be discussed in detail as below.

[0049] In some example embodiments of the present disclosure, it is to be understood that the term “a model” used hereinafter may be referred to an AI / ML based model. A model may be used to achieve a functionality to be required by a device at which the model is deployed, for example, positioning, beam prediction, CSI prediction, and specific load balancing and mobility optimization use cases, etc. The model descried hereinafter may also be considered as a logical model. It is to be understood that the model may be deployed at the source network node 120-1 in some example embodiments of the present disclosure.

[0050] Reference is now made to FIG. 2, which shows a signaling chart for handling UE performance measurement reports for handover evaluation according to some example embodiments of the present disclosure. As shown in FIG. 2, the signaling chart 200 involves a terminal device 110 and a source network node 120-1 and a target network node 120-2. For the purpose of discussion, reference is made to FIG. 1 to describe the signaling chart 200. It would be appreciated that the target network node 120-2 may also act as a source network node in some cases and perform similar operations as described with respect to the source network node 120-1 below.

[0051] The source network node 120-1 may describe the specifics (205) of a UE data collection from the target network node 120-2 by a data collection request message via an Xn interface or an X2 interface between the source network node 120-1 and the target network node 120-2. For example, the data collection request may indicate one or more QoS metrics required by the source network node 120-1 for monitoring the UEperformance and / or a predetermined reporting duration for the target network node 120-2 to report the corresponding UE performance measurement report(s).

[0052] After the handover of the terminal device 110 from the source network node 120-1 to the target network node 120-2 has been completed successfully, the target network node 120-2 may start (210) the data collection from the terminal device 110 and perform corresponding measurement(s) and generate one or more UE performance measurement report(s). The one or more UE performance measurement report(s) may indicate one or more UE QoS metrics required by the source network node 120-1 for monitoring the UE performance. The target network node 120-2 may provide (215) the one or more UE performance measurement report(s) to the source network node 120-1 within the predetermined reporting duration.

[0053] For example, the UE QoS metric may refer to an average packet loss rate and more specifically, to an average UL packet loss rate and an average DL packet loss rate.

[0054] In some example embodiments, the average UL packet loss rate may be referred to as UL Packet Data Convergence Protocol (PDCP) Service Data Unit (SDU) loss rate. The measurement of UL PDCP SDU loss rate is defined as 1000000* number of missing UL PDCP sequence numbers, representing packets that are not delivered to higher layers, of a data radio bearer, divided by total number of UL PDCP sequence numbers (also including missing sequence numbers).

[0055] In some example embodiments, the average UL packet loss rate may be referred to as DL Fl-U packet loss rate. The measurement of DL Fl-U packet loss rate is defined as 1000000* number of missing DL General Packet Radio Service (GPRS) Tunneling Protocol (GTP) sequence numbers, representing packets that are not delivered to lower layers, of a data radio bearer, divided by total number of UL GTP sequence numbers (also including missing sequence numbers).

[0056] As another example, the UE QoS metric may refer to an average UE throughput, which may comprise an average UL UE throughput and / or an average DL UE throughput.

[0057] In some example embodiments, the measurement of DL UE throughput may be defined as a ratio of a DL throughput volume hpVolDTpa. DL throughput time (ThpTimeDI). "ThpTimeDI" represents the time to transmit a data burst excluding the data transmitted in the slot when the buffer is emptied. A sample of " ThpTimeDI" for eachtime the DL buffer for one Data Radio Bearer (DRB) is emptied. “ThpVolDF represents The Radio Link Control (RLC) level volume of a data burst, excluding the data transmitted in the slot when the buffer is emptied. A sample for “ThpVolDF is the data volume, counted on RLC SDU level, in kbit successfully transmitted (acknowledged by UE) in DL for one DRB during a sample o “ThpTimeDF .

[0058] Furthermore, the average DL UE throughput may also be referred to as “Average DL UE buffered Throughput”.

[0059] The measurement of average UL UE throughput is defined as a ratio of a UL throughput volume (ThpVol I)la UL throughput time (ThpTimeUl). “ThpTimeU represents the time to transmit a data burst excluding the data transmitted in the slot when the buffer is emptied. A sample oi^ThpTimeUF for each time the UL buffer for one DRB is emptied. “ThpVolUF represents the RLC level volume of a data burst, excluding the data transmitted in the slot when the buffer is emptied. A sample for “ThpVolUF is the data volume counted on RLC SDU level in kbit received in UL for one DRB during a sample o “ThpTimeUF .

[0060] As another example, the UE QoS metric may refer to an end-to-end UE delay, which may comprise the DL delay between NG-RAN (target network node 120-2) and UE and / or UL delay between NG-RAN (target network node 120-2) and UE. The measurement of DL delay between NG-RAN and UE is defined as ratio of the sum of delay of each DL PDCP SDU packet successfully delivered to UE over total number of packets, where the delay of each DL PDCP SDU packet is the delay incurred in NG-RAN (including the delay at gNB-CU user plane (UP), on Fl-U and on gNB-DU) and the delay over Uu interface. The measurement of UL delay between NG-RAN and UE is defined as ratio of the sum of delay of each UL PDCP SDU packet successfully delivered to UE over total number of packets, where the delay of each UL PDCP SDU packet is the delay occurred in NG-RAN (including the delay at gNB-CU-UP, on Fl-U and on gNB-DU) and the delay over Uu interface.

[0061] All the UE QoS metrics associated with the one or more performance measurement reports are expressed in the ratio form as numerator / denominator. That is, the one or more QoS metrics may be represented as one or more ratios.

[0062] A denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device 110. This set ofmeasured packets were not considered by the target network node 120-2 to issue a previous performance measurement report.

[0063] The target network node 120-2 may provide (215) the one or more UE performance measurement report(s) to the source network node 120-1 within the predetermined reporting duration, for example, by a data collection response / update message via an Xn interface or an X2 interface between the source network node 120-1 and the target network node 120-2.

[0064] For example, the respective denominators and respective numerators of the one or more ratios associated with UE QoS metric(s) included in the UE performance measurement reports may be indicated by separate information elements (IES), e.g., in a data collection response / update message. An example of UE performance measurements metrics is listed as below. It is to be understood that the example listed as below cannot limit the scope of the present disclosure. The IEs of the respective denominators and respective numerators of the one or more ratios may also be configured with any other format.Table 1

[0065] As shown in Table 1, the IEs for respective denominators and respective numerators of the one or more ratios such as “Average UE Throughput DL Numerator”, “Average UE Throughput DL Denominator”, “Average UE Throughput UL Numerator”, “Average UE Throughput UL Denominator”, “Average Packet Delay Numerator”, “Average Packet Delay Denominator”, “Average Packet Loss Numerator” and “AveragePacket Loss Denominator” are included.

[0066] Based on the received one or more UE performance measurement reports, the source network node 120-1 may monitor an evolution of a performance measurement precision of one or more UE QoS metrics and determine (220) whether the one or more QoS metrics reach a predetermined precision level.

[0067] As an example, FIG. 3 illustrates an example process 300 for handling UE performance measurement reports for handover evaluation according to some example embodiments of the present disclosure. The process 300 involves the source network node 120-1 and the target network node 120-2.

[0068] Upon handover the terminal device 110 to the target network node 120-2 (e.g., at time to), the target network node 120-2 may start the data collection from the terminal device 110 and provide corresponding UE performance measurement reports to the source network node 120-1 within the reporting duration T (e.g., from to to to+NmaxP). For example, the reporting duration T is pre-configured. Within the reporting duration T, the target network node 120-2 may report each UE performance measurement report with a preconfigured reporting periodicity P.

[0069] For example, the target network node 120-2 report, to the source network node 120-1, the 1stUE performance measurement report at time point to+P, the 2ndUE performance measurement report at time point to+2P, ..., and the N’thUE performance measurement report at time point to+N’P.

[0070] Based on the received UE performance measurement reports, the source network node 120-1 may monitor the evolution of the precision of one or more UE QoS metrics obtained from the received UE performance measurement reports.

[0071] For example, the source network node 120-1 may determine whether a first set of UE QoS metrics obtained from the 1stUE performance measurement report reach a predetermine precision level. If not, the source network node 120-1 may wait for a subsequent UE performance measurement report. After receiving the 2ndUE performance measurement report, the source network node 120-1 may aggregate the first set of UE QoS metrics and a second set of UE QoS metrics obtained from the 2ndUE performance measurement report and determine whether the aggregated sets of UE QoS metrics reach the predetermined precision level.

[0072] If the predetermined precision level is still not reached, the source network node 120-1 may further wait for subsequent UE performance measurement report(s). If the source network node 120-1 determines, e.g., after receiving the N’thUE performance measurement report within the reporting duration and before an activation of at least one measurement termination condition at the target network node 120-2, the received UE QoS metrics reach the predetermined precision level, the source network node 120-1 may determine that the performance reporting of the terminal device 110 is to be terminated.

[0073] More specifically, by taking the example of packet loss rate indicator, the monitoring for the precision of packet loss rate by the source target node 120-1 is explained as below.

[0074] For instance, in case of packet loss rate measurements, the maximum tolerable error in measurement (precision error) is 0.1 % may be considered. This measurement precision tolerance requires that the number of transmitted packets - what appears in the denominator of the ratio - is at least equal to 1000. For the first three UE performance measurement reports sent from the target network node 120-2 to the source target node 120-1, the measured packet counts may be considered as:1stDenominator (Packet Loss rate) = 300,2ndDenominator (Packet Loss rate) = 400 and3rdDenominator (Packet Loss rate) = 300.

[0075] The reference time window for packet counting can be either: i) for packets transmitted during the time interval between two consecutive UE performance measurement reports or, ii) assuming that the UE performance measurement collection period for a monitored UE should be generally shorter than the UE performance reporting period (and these time intervals are generally non-synchronized) referring to a UE performance measurement collection period.

[0076] The source network node 120-1 may identify that the Packet Loss Rate based on the 1stUE performance measurement report cannot be provided with the requested precision. The source network node 120-1 may then wait for the 2ndUE performance measurement report and identify that even aggregating the results from 1stand 2ndUE performance measurement reports is still not sufficient for the requested precision, as the sum of the two denominators of the ratios is still less than 1000. Finally, after the targetnetwork node 120-2 delivering a subsequent UE performance measurement report (e.g., the N’thUE performance measurement report) to the source target node 120-1, the source target node 120-1 may identify that, by aggregating the 1st, 2ndand N’thUE performance measurement reports, a reliable (as measurement reliability can be tailored to measurement precision) packet loss rate can be provided. The source network node 120- 1 internally reports the packet loss rate given as:[1stNumerator (Packet Loss Rate) + 2ndNumerator (Packet Loss Rate) + 3rdNumerator (Packet Loss Rate)] / [1st(Denominator (Packet Loss Rate) + 2ndDenominator (Packet Loss Rate) +3rdDenominator (Packet Loss Rate)]

[0077] As described above, if the source network node 120-1 determines that the one or more UE QoS metrics obtained from the received one or more performance measurement reports reach the predetermined precision level within the reporting duration and before an activation of at least one measurement termination condition at the target network node 120-2, the source network node 120-1, as shown in FIG. 2, transmits (225) an indication to the target network node 120-2 for terminating the performance reporting of the terminal device 110.

[0078] As an example, the source network node 120-1 may inform the target network node 120-2, by the indication, to either fully (i.e., for all UE QoS metrics) or partly (i.e., only discontinue the UE performance measurement reporting procedure for the requested UE QoS metrics satisfying their precision requirements).

[0079] For example, the indication for the termination of the performance reporting of the terminal device 110 may be indicated by a new introduced IE, which may be called as “UE Associated Info Termination Item”. The IE “UE Associated Info Termination Item”, containing the list of UE identifiers representing the UEs for which termination of the UE performance feedback is requested by the source network node may be added into a data collection request message.

[0080] An example of IES contained in the data collection request message is listed as below. In this example, this message is sent by source network node 120-1 to target network node 120-2 to initiate or continue the requested information reporting according to the parameters given in the message. It is to be understood that the example listed as below cannot limit the scope of the present disclosure. The IEs containing in the data collection request message may also be configured with any other format.Table 2

[0081] Furthermore, the “Measurement Collection Duration” IE as a part of the “UE Performance Configuration” IE of data collection request message may be internally tuned by the source network node 120-1 based on the number of UE performance feedback measurement samples needed to fulfill the reporting criteria (i.e., the minimum tolerable UE performance measurement precision) for the given target cell of the target network node 120-2.

[0082] As another example, FIG. 4 illustrates an example process 400 for handling UE performance measurement reports for handover evaluation according to some example embodiments of the present disclosure. The process 300 involves the source network node 120-1 and the target network node 120-2.

[0083] Upon handover the terminal device 110 to the target network node 120-2 (e.g., at to), the target network node 120-2 may start the data collection from the terminal device 110 and provide corresponding UE performance measurement reports to the source network node 120-1 within the reporting duration T (e.g., from to to to+NmaxP). For example, the reporting duration T is pre-configured. Within the reporting duration T, the target network node 120-2 may report each UE performance measurement report with a preconfigured reporting periodicity P.

[0084] For example, the target network node 120-2 reports, to the source network node 120-1, the 1stUE performance measurement report at time point to+P, the 2ndUE performance measurement report at time point to+2P, ..., and the N111UE performance measurement report at time point to+NP.

[0085] Based on the received UE performance measurement reports, the source network node 120-1 may monitor the evolution of the precision of one or more UE QoS metrics obtained from the received UE performance measurement reports.

[0086] For example, the source network node 120-1 may determine whether a first set of UE QoS metrics obtained from the 1stUE performance measurement report reach a predetermined precision level. If not, the source network node 120-1 may wait for a subsequent UE performance measurement report. After receiving the 2ndUE performance measurement report, the source network node 120-1 may aggregate the first set of UE QoS metrics and a second set of UE QoS metrics obtained from the 2ndUE performance measurement report and determine whether the aggregated sets of UE QoS metrics reach the predetermined precision level.

[0087] If the predetermined precision level is still not reached, the source network node 120-1 may further wait for subsequent UE performance measurement report(s). It is possible that e.g., after receiving the N111UE performance measurement report, the source network node 120-1 determines that the received UE QoS metrics still do not reach the predetermine precision level and the reporting duration has been expired and / or at least one measurement termination condition has been activated at the target network node 120- 2.

[0088] In this case, as a number of UE performance measurement reports has been already received by the source network node 120-1, in order to maximize the utilization of these reports (and not discard them completely), the source network node 120-1 maystill consider them to evaluate the inference performance of the AI / ML model that has recommended or assisted with taking a UE handover action, albeit with lower importance (or priority). Such UE performance measurement report importance / priority may be indicated by means of the source network node 120-1 assigning a weighting factor to the received UE performance measurement reports. This weighting factor may range between e.g., a small value when the count of measured UE packets is below a (non-zero) threshold to e.g., the value of 1 when the required precision level is reached.

[0089] As shown in FIG. 2, for example, in a case where at least one measurement termination condition has been activated (230) at the target network node 120-2 and / or the one or more UE QoS metrics associated with the received UE performance measurement reports do not reach the predetermine precision level until an expiration of the reporting duration, the source network node 120-1 may assign (235) a weighting factor to the received UE performance measurement reports and evaluate a decision of the source network node 120-1 to handover the terminal device 110 to the target network node 120- 2. This weighting factor may indicate to which extent these received UE performance measurement reports should be considered for AI / ML model inference accuracy evaluation.

[0090] In some example embodiments, a measurement termination condition activated at the target network node 120-2 may comprise an expiration of a reporting duration for the performance reporting of the terminal device. Furthermore, in a case where the terminal device moves to an idle or inactive mode and / or the target network node or a target cell of the terminal device has been changed may also cause the measurement termination condition to be activated. In addition, the measurement termination condition may also refer to an indicator indicated in a request message that the performance report of the terminal device 110 is stopped if the predetermined precision level precision is not met.

[0091] In this way, a solution and a messaging framework via the Xn or the X2 interface enabling a source network node (or an “Actor” gNB) to monitor the evolution of the precision of requested UE QoS metrics during the periodic reception of UE performance measurement reports is achieved.

[0092] FIG. 5 shows a flowchart of an example method 500 implemented at an apparatus in accordance with some example embodiments of the present disclosure. Forthe purpose of discussion, the method 500 will be described from the perspective of the source network node 120-1 in FIG. 1.

[0093] At block 510, the source network node 120-1 monitors an evolution of a performance measurement precision of one or more QoS metrics of a terminal device for one or more performance measurement reports issued to the source network node by a target network node upon handover the terminal device to a target network node.

[0094] At block 520, the source network node 120-1 determines, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level.

[0095] If the measurement precision level is reached within a reporting duration, at block 530, the source network node 120-1 transmits, to the target network node an indication for a termination of a performance reporting of the terminal device.

[0096] If the measurement precision level is not reached within the reporting duration, at block 540, the source network node 120-1 evaluates a decision of the source network node to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports.

[0097] In some example embodiments, the method 500 further comprises: receiving the one or more performance measurement reports after the terminal device has been handed over to the target network node successfully and within the reporting duration.

[0098] In some example embodiments, the one or more QoS metrics comprises at least one of the following: an average uplink throughput of the terminal device, an average downlink throughput of the terminal device, an average uplink packet loss rate, an average downlink packet loss rate, or an end-to-end delay of the terminal device.

[0099] In some example embodiments, the one or more QoS metrics are represented as one or more ratios, and wherein a denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device, and wherein the set of measured packets were not considered by the target network node to issue a previous performance measurement report.

[0100] In some example embodiments, respective denominators and respective numerators of the one or more ratios are indicated in separate IES included in the received one or more performance measurement reports.

[0101] In some example embodiments, the separate IES are exchanged between the source network node and the target network node by a data collection request and / or response and / or update message via a Xn interface or a X2 interface.

[0102] In some example embodiments, the method 500 further comprises: in accordance with a determination that the one or more QoS metrics reach the predetermined precision level within the reporting duration and before an activation of at least one measurement termination condition at the target network node, transmitting, to the target network node, an indication for the termination of the performance reporting of the terminal device.

[0103] In some example embodiments, the indication to the target network node for the termination of the performance reporting is indicated by an information element, IE, of associated information termination item of the terminal device.

[0104] In some example embodiments, the IE of the associated information termination item indicates an identifier of the terminal device for which the performance reporting is to be terminated.

[0105] In some example embodiments, the indication indicates the termination of the performance reporting of the terminal device whose QoS metrics reach and / or do not reach the predetermined precision level.

[0106] In some example embodiments, the method 500 further comprises: in accordance with a determination that the one or more QoS metrics do not reach the predetermined precision level within the reporting duration or until at least one measurement termination condition is met at the target network node before the reporting duration expires, assigning the weight factor for the received one or more performance measurement reports.

[0107] In some example embodiments, the method 500 further comprises: determining whether performance measurements for a first set of QoS metrics associated with a first performance measurement report reach the predetermined precision level; in accordance with a determination that the first set of performance measurements for the first set of QoS metrics do not reach the predetermined precision level, monitoring a second set of QoS metrics associated with a second performance measurement report; determining whether the predetermined precision level is reached by aggregating the first set of QoS metrics and the second set of QoS metrics; and in accordance with a determination that the predetermined precision level is reached, determine that the performance reporting ofthe terminal device is to be terminated.

[0108] In some example embodiments, the method 500 further comprises: in accordance with a determination that the predetermined precision level is not reached and the reporting duration is expired or at least one measurement termination condition is met at the target network node, assigning the weight factor for the received one or more performance measurement reports.

[0109] In some example embodiments, the weight factor indicates respective impacts of the received one or more performance measurement reports for a handover action accuracy evaluation of the source network node.

[0110] In some example embodiments, the accuracy evaluation of the source network node for the terminal handover decision is translated to the accuracy of the output of a machine learning model deployed at the source network node.

[0111] In some example embodiments, the at least one measurement termination condition comprises at least one of the following: an expiration of a reporting duration for the performance reporting of the terminal device; the terminal device moves to an idle or inactive mode; a change of the target network node or a target cell of the terminal device; an indicator indicated in a request message that the performance report of the terminal device is stopped if the predetermined precision level precision is not met.

[0112] FIG. 6 shows a flowchart of an example method 600 implemented at an apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 600 will be described from the perspective of the target network node 120-2 in FIG. 1.

[0113] At block 610, the target network node 120-2 transmits, to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration.

[0114] At block 620, the target network node 120-2 receives, from the source network node, an indication for a termination of a performance reporting of the terminal device.

[0115] In some example embodiments, the one or more QoS metrics comprises at least one of the following: an average uplink throughput of the terminal device, an average downlink throughput of the terminal device, an average uplink packet loss rate, an average downlink packet loss rate, or an end-to-end delay of the terminal device.

[0116] In some example embodiments, the one or more QoS metrics are represented as one or more ratios, and wherein a denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device, and wherein the set of measured packets were not considered by the target network node to issue a previous performance measurement report.

[0117] In some example embodiments, respective denominators and respective numerators of the one or more ratios are indicated in separate IES included in the received one or more performance measurement reports.

[0118] In some example embodiments, the separate IEs are exchanged between the source network node and the target network node by a data collection request and / or response and / or update message via a Xn interface or a X2 interface.

[0119] In some example embodiments, the indication for the termination of the performance reporting is indicated by an information element, IE, of associated information termination item of the terminal device.

[0120] In some example embodiments, the IE of the associated information termination item indicates an identifier of the terminal device for which the performance reporting is to be terminated.

[0121] In some example embodiments, the indication indicates the termination of the performance reporting of the terminal device whose QoS metrics reach and / or do not reach the predetermined precision level.

[0122] In some example embodiments, the method 600 further comprises: transmitting, to the source network node, the one or more performance measurement reports after the terminal device has been handed over to the target network node successfully and within the reporting duration.

[0123] In some example embodiments, an apparatus capable of performing any of the method 500 (for example, the source network node 120-1 in FIG. 1) may comprise means for performing the respective operations of the method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the source network node 120-1 in FIG. 1.

[0124] In some example embodiments, the apparatus comprises means for monitoringan evolution of a performance measurement precision of one or more QoS metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; means for determining, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and means for transmitting, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or means for evaluating a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

[0125] In some example embodiments, the apparatus further comprises: means for receiving the one or more performance measurement reports after the terminal device has been handed over to the target network node successfully and within the reporting duration.

[0126] In some example embodiments, the one or more QoS metrics comprises at least one of the following: an average uplink throughput of the terminal device, an average downlink throughput of the terminal device, an average uplink packet loss rate, an average downlink packet loss rate, or an end-to-end delay of the terminal device.

[0127] In some example embodiments, the one or more QoS metrics are represented as one or more ratios, and wherein a denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device, and wherein the set of measured packets were not considered by the target network node to issue a previous performance measurement report.

[0128] In some example embodiments, respective denominators and respective numerators of the one or more ratios are indicated in separate IES included in the received one or more performance measurement reports.

[0129] In some example embodiments, the separate IEs are exchanged between the apparatus and the target network node by a data collection request and / or response and / or update message via a Xn interface or a X2 interface.

[0130] In some example embodiments, the apparatus further comprises: means for in accordance with a determination that the one or more QoS metrics reach the predeterminedprecision level within the reporting duration and before an activation of at least one measurement termination condition at the target network node, transmitting, to the target network node, an indication for the termination of the performance reporting of the terminal device.

[0131] In some example embodiments, the indication to the target network node for the termination of the performance reporting is indicated by an information element, IE, of associated information termination item of the terminal device.

[0132] In some example embodiments, the IE of the associated information termination item indicates an identifier of the terminal device for which the performance reporting is to be terminated.

[0133] In some example embodiments, the indication indicates the termination of the performance reporting of the terminal device whose QoS metrics reach and / or do not reach the predetermined precision level.

[0134] In some example embodiments, the apparatus further comprises: means for in accordance with a determination that the one or more QoS metrics do not reach the predetermined precision level within the reporting duration or until at least one measurement termination condition is met at the target network node before the reporting duration expires, assigning the weight factor for the received one or more performance measurement reports.

[0135] In some example embodiments, the apparatus further comprises: means for determining whether performance measurements for a first set of QoS metrics associated with a first performance measurement report reach the predetermined precision level; means for in accordance with a determination that performance measurements for the first set of QoS metrics do not reach the predetermined precision level, monitoring a second set of QoS metrics associated with a second performance measurement report; means for determining whether the predetermined precision level is reached by aggregating the first set of QoS metrics and the second set of QoS metrics; and means for in accordance with a determination that the predetermined precision level is reached, determine that the performance reporting of the terminal device is to be terminated.

[0136] In some example embodiments, the apparatus further comprises: means for in accordance with a determination that the predetermined precision level is not reached andthe reporting duration is expired or at least one measurement termination condition is met at the target network node, assigning the weight factor for the received one or more performance measurement reports.

[0137] In some example embodiments, the weight factor indicates respective impacts of the received one or more performance measurement reports for a handover action accuracy evaluation of the apparatus.

[0138] In some example embodiments, the accuracy evaluation of the apparatus for the terminal handover decision is translated to the accuracy of the output of a machine learning model deployed at the apparatus.

[0139] In some example embodiments, the at least one measurement termination condition comprises at least one of the following: an expiration of a reporting duration for the performance reporting of the terminal device; the terminal device moves to an idle or inactive mode; a change of the target network node or a target cell of the terminal device; an indicator indicated in a request message that the performance report of the terminal device is stopped if the predetermined precision level precision is not met.

[0140] In some example embodiments, the apparatus further comprises means for performing other operations in some example embodiments of the method 500 or the source network node 120-1. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus.

[0141] In some example embodiments, an apparatus capable of performing any of the method 600 (for example, the target network node 120-2 in FIG. 1) may comprise means for performing the respective operations of the method 600. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The apparatus may be implemented as or included in the target network node 120-2 in FIG. 1.

[0142] In some example embodiments, the apparatus comprises means for transmitting, to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration; and means for receiving, from the source network node, an indication for a termination of a performance reporting of the terminal device.

[0143] In some example embodiments, the one or more QoS metrics comprises at least one of the following: an average uplink throughput of the terminal device, an average downlink throughput of the terminal device, an average uplink packet loss rate, an average downlink packet loss rate, or an end-to-end delay of the terminal device.

[0144] In some example embodiments, the one or more QoS metrics are represented as one or more ratios, and wherein a denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device, and wherein the set of measured packets were not considered by the target network node to issue a previous performance measurement report.

[0145] In some example embodiments, respective denominators and respective numerators of the one or more ratios are indicated in separate IES included in the received one or more performance measurement reports.

[0146] In some example embodiments, the separate IEs are exchanged between the apparatus and the source network node by a data collection request and / or response and / or update message via a Xn interface or a X2 interface.

[0147] In some example embodiments, the indication for the termination of the performance reporting is indicated by an information element, IE, of associated information termination item of the terminal device.

[0148] In some example embodiments, the IE of the associated information termination item indicates an identifier of the terminal device for which the performance reporting is to be terminated.

[0149] In some example embodiments, the indication indicates the termination of the performance reporting of the terminal device whose QoS metrics reach and / or do not reach the predetermined precision level.

[0150] In some example embodiments, the apparatus further comprises: means for transmitting, to the source network node, the one or more performance measurement reports after the terminal device has been handed over to the apparatus successfully and within the reporting duration.

[0151] In some example embodiments, the apparatus further comprises means for performing other operations in some example embodiments of the method 600 or the target network node 120-2. In some example embodiments, the means comprises at leastone processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the apparatus.

[0152] FIG. 7 is a simplified block diagram of a device 700 that is suitable for implementing example embodiments of the present disclosure. The device 700 may be provided to implement a communication device, for example, the source network node 120-1 or the target network node 120-2 as shown in FIG. 1. As shown, the device 700 includes one or more processors 710, one or more memories 720 coupled to the processor 710, and one or more communication modules 740 coupled to the processor 710.

[0153] The communication module 740 is for bidirectional communications. The communication module 740 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 740 may include at least one antenna.

[0154] The processor 710 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 700 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0155] The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 724, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 722 and other volatile memories that will not last in the power-down duration.

[0156] A computer program 730 includes computer executable instructions that are executed by the associated processor 710. The instructions of the program 730 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 730 may be stored in the memory, e.g., the ROM 724.The processor 710 may perform any suitable actions and processing by loading the program 730 into the RAM 722.

[0157] The example embodiments of the present disclosure may be implemented by means of the program 730 so that the device 700 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 6. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0158] In some example embodiments, the program 730 may be tangibly contained in a computer readable medium which may be included in the device 700 (such as in the memory 720) or other storage devices that are accessible by the device 700. The device 700 may load the program 730 from the computer readable medium to the RAM 722 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0159] FIG. 8 shows an example of the computer readable medium 800 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 800 has the program 730 stored thereon.

[0160] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0161] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non- transitory computer readable medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0162] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0163] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0164] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0165] Further, although operations are depicted in a particular order, this should notbe understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0166] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WHAT IS CLAIMED IS:

1. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: monitor an evolution of a performance measurement precision of one or more quality of service, QoS, metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; determine, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and transmit, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or evaluate a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

2. The apparatus of claim 1, wherein the apparatus is caused to: receive the one or more performance measurement reports after the terminal device has been handed over to the target network node successfully and within the reporting duration.

3. The apparatus of claim 1 or 2, wherein the one or more QoS metrics comprises at least one of the following: an average uplink throughput of the terminal device, an average downlink throughput of the terminal device,an average uplink packet loss rate, an average downlink packet loss rate, or an end-to-end delay of the terminal device.

4. The apparatus of any of claims 1-3, wherein the one or more QoS metrics are represented as one or more ratios, and wherein a denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device, and wherein the set of measured packets were not considered by the target network node to issue a previous performance measurement report.

5. The apparatus of claim 4, wherein respective denominators and respective numerators of the one or more ratios are indicated in separate information elements, IES, included in the received one or more performance measurement reports.

6. The apparatus of claim 5, wherein the separate IEs are exchanged between the apparatus and the target network node by a data collection request and / or response and / or update message via a Xn interface or a X2 interface.

7. The apparatus of any of claims 1-6, wherein the apparatus is caused to: in accordance with a determination that the one or more QoS metrics reach the predetermined precision level within the reporting duration and before an activation of at least one measurement termination condition at the target network node, transmit, to the target network node, an indication for the termination of the performance reporting of the terminal device.

8. The apparatus of claim 7, wherein the indication to the target network node for the termination of the performance reporting is indicated by an information element, IE, of associated information termination item of the terminal device.

9. The apparatus of claim 8, wherein the IE of the associated information termination item indicates an identifier of the terminal device for which the performance reporting is to be terminated.

10. The apparatus of claim 8 or 9, wherein the indication indicates the termination of the performance reporting of the terminal device whose QoS metrics reach and / or do not reach the predetermined precision level.

11. The apparatus of any of claims 1-6, wherein the apparatus is caused to: in accordance with a determination that the one or more QoS metrics do not reach the predetermined precision level within the reporting duration or until at least one measurement termination condition is met at the target network node before the reporting duration expires, assign the weight factor for the received one or more performance measurement reports.

12. The apparatus of claim 7 or 10, wherein the apparatus is caused to: determine whether performance measurements for a first set of QoS metrics associated with a first performance measurement report reach the predetermined precision level; in accordance with a determination that performance measurements for the first set of QoS metrics do not reach the predetermined precision level, monitor a second set of QoS metrics associated with a second performance measurement report; determine whether the predetermined precision level is reached by aggregating the first set of QoS metrics and the second set of QoS metrics; and in accordance with a determination that the predetermined precision level is reached, determine that the performance reporting of the terminal device is to be terminated.

13. The apparatus of claim 12, wherein the apparatus is caused to: in accordance with a determination that the predetermined precision level is notreached and the reporting duration is expired or at least one measurement termination condition is met at the target network node, assign the weight factor for the received one or more performance measurement reports.

14. The apparatus of claim 11, wherein the weight factor indicates respective impacts of the received one or more performance measurement reports for a handover action accuracy evaluation of the apparatus.

15. The apparatus of claim 11, wherein the accuracy evaluation of the apparatus for the terminal handover decision is translated to the accuracy of the output of a machine learning model deployed at the apparatus.

16. The apparatus of any of claims 7-15, wherein the at least one measurement termination condition comprises at least one of the following: an expiration of a reporting duration for the performance reporting of the terminal device; the terminal device moves to an idle or inactive mode; a change of the target network node or a target cell of the terminal device; an indicator indicated in a request message that the performance report of the terminal device is stopped if the predetermined precision level precision is not met.

17. The apparatus of any of claims 1-16, wherein the apparatus comprises a source network node of the handover.

18. An apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the apparatus at least to: transmit, to a source network node of a handover of a terminal device, one or moreperformance measurement reports of the terminal device during a reporting duration; and receive, from the source network node, an indication for a termination of a performance reporting of the terminal device.

19. The apparatus of claim 18, wherein the one or more QoS metrics comprises at least one of the following: an average uplink throughput of the terminal device, an average downlink throughput of the terminal device, an average uplink packet loss rate, an average downlink packet loss rate, or an end-to-end delay of the terminal device.

20. The apparatus of claim 18 or 19, wherein the one or more QoS metrics are represented as one or more ratios, and wherein a denominator of a QoS metric reported in each performance measurement report is a count of a set of measured packets of the terminal device, and wherein the set of measured packets were not considered by the target network node to issue a previous performance measurement report.

21. The apparatus of claim 20, wherein respective denominators and respective numerators of the one or more ratios are indicated in separate information elements, IES, included in the received one or more performance measurement reports.

22. The apparatus of claim 21, wherein the separate IEs are exchanged between the apparatus and the source network node by a data collection request and / or response and / or update message via a Xn interface or a X2 interface.

23. The apparatus of any of claims 18-22, wherein the indication for the termination of the performance reporting is indicated by an information element, IE, of associated information termination item of the terminal device.

24. The apparatus of claim 23, wherein the IE of the associated information termination item indicates an identifier of the terminal device for which the performance reporting is to be terminated.

25. The apparatus of claim 23 or 24, wherein the indication indicates the termination of the performance reporting of the terminal device whose QoS metrics reach and / or do not reach the predetermined precision level.

26. The apparatus of claim any of claims 18-25, wherein the apparatus is caused to: transmit, to the source network node, the one or more performance measurement reports after the terminal device has been handed over to the apparatus successfully and within the reporting duration.

27. The apparatus of claim any of claims 18-26, wherein the apparatus comprises a target network node of the handover.

28. A method comprising: monitoring, at a source network node, an evolution of a performance measurement precision of one or more quality of service, QoS, metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; determining, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and transmitting, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or evaluating a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performancemeasurement reports if the measurement precision level is not reached within the reporting duration.

29. A method comprising: transmitting, from a target network node to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration; and receiving, from the source network node, an indication for a termination of a performance reporting of the terminal device.

30. An apparatus comprising: means for monitoring an evolution of a performance measurement precision of one or more quality of service, QoS, metrics of a terminal device for one or more performance measurement reports issued to the apparatus by a target network node upon handover the terminal device to a target network node; means for determining, based on the monitoring, whether the one or more QoS metrics reach a predetermined precision level; and means for transmitting, to the target network node an indication for a termination of a performance reporting of the terminal device if the measurement precision level is reached within a reporting duration; or means for evaluating a decision of the apparatus to handover the terminal device to the target network node by associating a weight factor to the received one or more performance measurement reports if the measurement precision level is not reached within the reporting duration.

31. An apparatus comprising: means for transmitting, to a source network node of a handover of a terminal device, one or more performance measurement reports of the terminal device during a reporting duration; andmeans for receiving, from the source network node, an indication for a termination of a performance reporting of the terminal device.

32. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 28 or the method of claim 29.

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