Method and apparatus for optimizations during intra-system and inter-system mobility in a wireless communication system

Abstract

[0001] The disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments of the disclosure relate to a method and system for optimizing mobility in a wireless network. The method involves a User Equipment (UE) performing a full configuration procedure, during which the UE retains the configuration of a Successful Handover Report (SHR) and a Successful PSCell Addition / Change Report (SPR). Upon completion of the full configuration procedure, the UE utilizes the retained SHR and SPR configurations to perform subsequent operations. This approach enhances the efficiency and reliability of mobility management within the wireless network, ensuring seamless connectivity and improved user experience.

Description

METHOD AND APPARATUS FOR OPTIMIZATIONS DURING INTRA-SYSTEM AND INTER-SYSTEM MOBILITY IN A WIRELESS COMMUNICATION SYSTEM

[0001] The disclosure relates to a method and an apparatus for performing optimizations during mobility in a wireless communication system

[0002] Considering the development of wireless communication from generation to generation, the technologies have been developed mainly for services targeting humans, such as voice calls, multimedia services, and data services. Following the commercialization of 5G (5th generation) communication systems, it is expected that the number of connected devices will exponentially grow. Increasingly, these will be connected to communication networks. Examples of connected things may include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machines, and factory equipment. Mobile devices are expected to evolve in various form-factors, such as augmented reality glasses, virtual reality headsets, and hologram devices. In order to provide various services by connecting hundreds of billions of devices and things in the 6G (6th generation) era, there have been ongoing efforts to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as beyond-5G systems.

[0003] 6G communication systems, which are expected to be commercialized around 2030, will have a peak data rate of tera (1,000 giga)-level bit per second (bps) and a radio latency less than 100μsec, and thus will be 50 times as fast as 5G communication systems and have the 1 / 10 radio latency thereof.

[0004] In order to accomplish such a high data rate and an ultra-low latency, it has been considered to implement 6G communication systems in a terahertz (THz) band (for example, 95 gigahertz (GHz) to 3THz bands). It is expected that, due to severer path loss and atmospheric absorption in the terahertz bands than those in mmWave bands introduced in 5G, technologies capable of securing the signal transmission distance (that is, coverage) will become more crucial. It is necessary to develop, as major technologies for securing the coverage, Radio Frequency (RF) elements, antennas, novel waveforms having a better coverage than Orthogonal Frequency Division Multiplexing (OFDM), beamforming and massive Multiple-input Multiple-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antennas, and multiantenna transmission technologies such as large-scale antennas. In addition, there has been ongoing discussion on new technologies for improving the coverage of terahertz-band signals, such as metamaterial-based lenses and antennas, Orbital Angular Momentum (OAM), and Reconfigurable Intelligent Surface (RIS).

[0005] Moreover, in order to improve the spectral efficiency and the overall network performances, the following technologies have been developed for 6G communication systems: a full-duplex technology for enabling an uplink transmission and a downlink transmission to simultaneously use the same frequency resource at the same time; a network technology for utilizing satellites, High-Altitude Platform Stations (HAPS), and the like in an integrated manner; an improved network structure for supporting mobile base stations and the like and enabling network operation optimization and automation and the like; a dynamic spectrum sharing technology via collision avoidance based on a prediction of spectrum usage; an use of Artificial Intelligence (AI) in wireless communication for improvement of overall network operation by utilizing AI from a designing phase for developing 6G and internalizing end-to-end AI support functions; and a next-generation distributed computing technology for overcoming the limit of UE computing ability through reachable super-high-performance communication and computing resources (such as Mobile Edge Computing (MEC), clouds, and the like) over the network. In addition, through designing new protocols to be used in 6G communication systems, developing mechanisms for implementing a hardware-based security environment and safe use of data, and developing technologies for maintaining privacy, attempts to strengthen the connectivity between devices, optimize the network, promote softwarization of network entities, and increase the openness of wireless communications are continuing.

[0006] It is expected that research and development of 6G communication systems in hyper-connectivity, including person to machine (P2M) as well as machine to machine (M2M), will allow the next hyper-connected experience. Particularly, it is expected that services such as truly immersive eXtended Reality (XR), high-fidelity mobile hologram, and digital replica could be provided through 6G communication systems. In addition, services such as remote surgery for security and reliability enhancement, industrial automation, and emergency response will be provided through the 6G communication system such that the technologies could be applied in various fields such as industry, medical care, automobiles, and home appliances.

[0007] Wireless communication technologies have seen rapid advancements, with 5G New Radio (NR) being a prominent example that promises enhanced performance and capabilities. One of the critical aspects of wireless networks like 5G NR is mobility, which allows user equipment (UE) to move seamlessly across different cells. Mobility in 5G NR is managed through various procedures depending on the state of the UE.

[0008] When the UE is in RRC_IDLE mode, mobility is handled through cell reselection. In contrast, for UEs in RRC_CONNECTED mode, mobility is managed via a procedure called handover. Network-controlled mobility, which applies to UEs in RRC_CONNECTED mode, requires explicit Radio Resource Control (RRC) signaling to be triggered by the gNodeB (gNB) in the NR.

[0009] The handover process in the NR typically consists of three main steps: handover preparation, handover execution, and handover completion. During handover preparation, the gNB may configure the UE to report measurements. Based on these measurements or its understanding of the network topology, the gNB sends an RRC Reconfiguration message to instruct the UE to handover to a target cell from the source cell. The UE then accesses the target cell and sends an RRC Reconfiguration complete message.

[0010] An alternative method introduced in 3GPP NR release 16 allows the gNB to configure the UE with execution conditions for triggering handover. Once these conditions are met, the UE moves to the target cell and sends the RRC Reconfiguration complete message. Both methods involve the UE performing handover by sending layer 3 (RRC) messages, which can result in considerable signaling overhead and latency issues.

[0011] In the context of dual connectivity, the UE may perform PSCellChange or Conditional PSCellChange, which can also be categorized as layer 3 mobility. Specifically, PSCellChange or Conditional PSCellChange can be referred to as SCG layer 3 mobility, while handover and Conditional Handover (CHO) can be referred to as MCG layer 3 mobility.

[0012] Current systems face significant issues during the handling of the Successful Handover Report (SHR) and Successful PSCell Addition / Change Report (SPR) configuration by the UE during the full configuration procedure. For inter-system mobility, the UE releases the radio configurations and performs SHR determination, which may lead to the UE not having the necessary configuration when it determines SHR.

[0013] Thus, it is desired to address the above-mentioned disadvantages, issues or other shortcomings or at least provide a useful alternative.

[0014] The principal object of the embodiments herein is to provide a system and a method for performing optimizations during mobility in a wireless network.

[0015] Another object of the embodiments herein is to avoid deletion of the SHR configuration and the SPR configuration upon successful full configuration.

[0016] Yet another object of the embodiments herein is to perform SHR determination and SPR determination before the release of the radio resources, Radio Link Control (RLC) entity, and Medium Access Control (MAC) configuration.

[0017] In an aspect, the objects are achieved by providing a method for optimizing the mobility in a wireless network. The method comprises performing by a UE a full configuration procedure. Further, the UE retains Successful Handover Report (SHR) configuration and a Successful PSCell Addition / Change Report (SPR) configuration upon performing the full configuration. The UE further performs an operation using a retained configuration.

[0018] In another aspect, the objects are achieved by providing a User Equipment (UE) for optimizing mobility in the wireless network. The UE includes a memory, a processor, and an intra-inter mobility controller. The intra-inter mobility controller performs a full configuration procedure and retains the SHR configuration and the SPR configuration upon performing the full configuration. Further, the UE performs the operation using the retained configuration.

[0019] These and other aspects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It is understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

[0020] Aspects of the disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide efficient communication methods in a wireless communication system.

[0021] These and other features, aspects, and advantages of the present embodiments are illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which:

[0022] Fig. 1 is a block diagram that illustrates hardware components associated with the UE according to the embodiments as disclosed herein.

[0023] Fig. 2 is a flow diagram that illustrates a scenario of full configuration for handover execution at the UE where the SHR configuration is not released upon the full configuration according to the embodiments as disclosed herein.

[0024] Fig. 3 is a flow diagram that illustrates the scenario of the UE releasing the dedicated configuration except SPR configuration upon full configuration execution according to the embodiments as disclosed herein.

[0025] Fig. 4 is a flow diagram that illustrates the scenario of successful execution of Inter-Radio Access Technology (RAT) handover according to embodiments as disclosed herein.

[0026] Fig. 5 is a flow diagram that illustrates the method of optimizing the mobility in a wireless network according to the embodiments as disclosed herein.

[0027] Fig. 6 is a flow diagram that illustrates the method of determining SHR, according to the embodiments as disclosed herein.

[0028] Fig. 7 is a block diagram that illustrates hardware components associated with a UE according to the embodiments as disclosed herein.

[0029] Fig. 8 is a block diagram that illustrates hardware components associated with a base station according to the embodiments as disclosed herein.

[0030] Fig. 9 is a block diagram that illustrates hardware components associated with a network entity according to the embodiments as disclosed herein.

[0031] Aspects of the disclosure are to address at least the above-mentioned problems and / or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the disclosure is to provide a terminal and a communication method thereof in a wireless communication system.

[0032] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and details in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. Also, the various embodiments described herein are not necessarily mutually exclusive, as some embodiments can be combined with one or more other embodiments to form new embodiments. The term "or" as used herein, refers to a non-exclusive or, unless otherwise indicated. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein can be practiced and to further enable those skilled in the art to practice the embodiments herein. Accordingly, the examples are not be construed as limiting the scope of the embodiments herein.

[0033] As is traditional in the field, embodiments are described and illustrated in terms of blocks that carry out a described function or functions.　These blocks, which referred to herein as managers, units, modules, hardware components or the like, are physically implemented by analog and / or digital circuits such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hardwired circuits and the like, and optionally be driven by firmware and software. The circuits, for example, be embodied in one or more semiconductor chips, or on substrate supports such as printed circuit boards and the like.　The circuits constituting a block be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware to perform some functions of the block and a processor to perform other functions of the block. Each block of the embodiments be physically separated into two or more interacting and discrete blocks without departing from the scope of the proposed method.　Likewise, the blocks of the embodiments be physically combined into more complex blocks without departing from the scope of the proposed method.

[0034] The accompanying drawings are used to help easily understand various technical features and it is understood that the embodiments presented herein are not limited by the accompanying drawings. As such, the proposed method is construed to extend to any alterations, equivalents and substitutes in addition to those which are particularly set out in the accompanying drawings. Although the terms first, second, etc. used herein to describe various elements, these elements are not be limited by these terms. These terms are generally used to distinguish one element from another.

[0035] The UE may be configured with full configuration or delta configuration for mobility.

[0036] Steps for performing the full configuration is given in 3gpp specifications like TS 38.331, excerpts are given below.

[0037] 2> if the RRCReconfiguration includes the fullConfig:

[0038] 3> perform the full configuration procedure;

[0039] Fullconfiguration:

[0040] The UE shall:

[0041] 1> release / clear all current dedicated radio configurations except for the following:

[0042] - the MCG C-RNTI;

[0043] - the AS security configurations associated with the master key;

[0044] - the SRB1 / SRB2 configurations and DRB / multicast MRB configurations as configured by radioBearerConfigorradioBearerConfig2.

[0045] NOTE 1: Radio configuration is not just the resource configuration but includes other configurations likeMeasConfig. Radio configuration also includes the RLC bearer configurations as configured byRLC-BearerConfig, PC5 Relay RLC channel as configured bySL-RLC-ChannelConfig, and Uu Relay RLC channel as configured byUu-RelayRLC-ChannelConfig. In case NR-DC or NE-DC is configured, this also includes the entire NR or E-UTRA SCG configuration which are released according to the MR-DC release procedure as specified in 5.3.5.10.

[0046] NOTE 1a: For NR sidelink communication / discovery, the radio configuration includes the sidelink RRC configuration received from the network, but does not include the sidelink RRC reconfiguration and sidelink UE capability received from other UEs via PC5-RRC. In addition, the UE considers the new NR sidelink configurations as full configuration, in case of state transition and change of system information used for NR sidelink communication / discovery.

[0047] NOTE 1b: To establish the RLC bearer of SRB(s) after release due tofullConfig, the network can include thesrb-Identitywithinsrb-ToAddModList(i.e. the UE applies RLC default configuration) and / or providerlc-BearerToAddModListof concerned SRB(s) explicitly.

[0048] - the logged measurement configuration;

[0049] 1> if thespCellConfigin themasterCellGroupincludes thereconfigurationWithSync:

[0050] 2> release / clear all current common radio configurations;

[0051] 2> ifsl-PathSwitchConfigwas included inreconfigurationWithSync:

[0052] 3> use the default values specified in 9.2.3 for timer T311;

[0053] 2> else:

[0054] 3> use the default values specified in 9.2.3 for timers T310, T311 and constants N310, N311;

[0055] 1> else (full configuration after re-establishment or during RRC resume):

[0056] 2> if the UE is acting as L2 U2N Remote UE:

[0057] 3> use value for timer T311, as included inue-TimersAndConstantsreceived inSIB1

[0058] 2> else:

[0059] 3> use values for timers T301, T310, T311 and constants N310, N311, as included inue-TimersAndConstantsreceived inSIB1;

[0060] Mobility may be inter-system mobility, for e.g. Inter-RAT mobility from NR to LTE. Upon successful completion of the mobility from NR, UE performs the following steps:

[0061] Successful completion of the mobility from NR

[0062] Upon successfully completing the handover, at the source side the UE shall:

[0063] 1> reset MAC;

[0064] 1> stop all timers that are running except T325, T330 and T400;

[0065] 1> release ran-NotificationAreaInfo, if stored;

[0066] 1> release the AS security context including the KRRCenckey, the KRRCintkey, the KUPintkey and the KUPenckey, if stored;

[0067] 1> release all radio resources, including release of the RLC entity and the MAC configuration;

[0068] 1> release the associated PDCP entity and SDAP entity for all established RBs;

[0069] NOTE : PDCP and SDAP configured by the source RAT prior to the handover that are reconfigured and re-used by target RAT when delta signalling (i.e., during inter-RAT intra-system handover whenfullConfigis not present) is used, are not released as part of this procedure.

[0070] 1> if the UE was configured withsuccessHO-Configwhen connected to the source PCell and thetargetRAT-Typeis set toeutra:

[0071] 2> perform the actions for the successful handover report determination for inter-RAT handover as specified in clause 5.7.10.6.

[0072] 1> if thetargetRAT-Typeis set toeutraand thenas-SecurityParamFromNRis included: or

[0073] 1> if thetargetRAT-Typeis set toutra-fdd:

[0074] 2> indicate the release of the RRC connection to upper layers together with the release cause 'other'.

[0075] For the purpose of the invention, the 3gpp specifications such as TS 38.300, TS 38.331, TS 38.321 v18.0.0 is considered as relevant background.

[0076] According to the background TS 38.300 and TS 38.331 v18.0.0, the UE uses SHR configuration such as thresholdPercentageT310 or thresholdPercentageT312 from source cell of a handover to determine the SHR. Based on these specifications in the background, if the UE is configured with the thresholds, UE determines and logs SHR.

[0077] Similarly, according the background TS 38.300 and TS 38.331 v18.0.0, the UE uses SPR configuration such as thresholdPercentageT310-SCG or thresholdPercentageT312-SCG from source cell of a PSCellChange to determine the SPR. Based on these specifications in the background, if the UE is configured with the thresholds, UE determines and logs SPR.

[0078] The 3GPP Release 18 is considering Lower Layers (L1 / L2 layers) Triggered Mobility, also known as LTM, to solve the problem of latency and overhead associated with layer 3 mobility. The goal of LTM, as per 3GPP, is to enable a serving cell change via L1 / L2 signaling in order to reduce the latency overhead and interruption time. The network (gNB) may configure the UE with multiple candidate cells to allow fast application of configurations for candidate cells. Additionally, the network may send MAC CE or L1 signaling (using a cell switch command) to dynamically switch the UE from a source cell to one of the configured candidate cells. LTM can further be triggered based on L1 measurements rather than L3 measurements. The UE may receive LTM measurement configuration from the gNB, which includes L1 measurement configuration that specifies what to measure, how to report, and what to report.

[0079] A 5G New Radio (NR) radio access network, also known as Next Generation Radio Network (NG-RAN), includes a number of NR base stations known as gNBs. These gNBs can be connected to each other through the Xn interface and are connected to various core network elements such as Access and Mobility Management Function (AMF) and User Plane Function (UPF). Further, gNBs can be divided into two physical entities named Centralized Unit (CU) and Distributed Unit (DU). The CU provides support for the higher layers of the protocol stack, such as Session Data Application Protocol (SDAP), Packet Data Convergence Protocol (PDCP), and Radio Resource Control (RRC), while the DU provides support for the lower layers of the protocol stack, such as Radio Link Control (RLC), Medium Access Control (MAC), and the Physical layer. Each gNB can have multiple cells serving many UEs.

[0080] A large number of algorithms and configuration parameters are used in NG-RAN. Identifying the most optimal radio parameters is a very difficult task, and operators used to resort to manual techniques like drive tests to identify the optimal parameters. However, such manual parameter tuning is a costly operation since it depends on many factors, such as the number of users, number of neighbors, maximum throughput in the cell, average throughput in the cell, etc. Further, whenever a neighbor gNB is installed or a new service is introduced, many of these manual operations need to be repeated.

[0081] To resolve this problem, 3GPP introduced Self-Organizing Networks (SON) techniques in wireless technologies like NR. SON was first introduced in 3GPP Release 9 in LTE. The SON solutions can be divided into three categories: Self-Configuration, Self-Optimization, and Self-Healing. The SON architecture can be a centralized, distributed, or hybrid solution. Mobility Robustness Optimization (MRO) is a SON technique used to optimize various parameters related to mobility.

[0082] According to 3gpp specifications, Mobility Robustness Optimization aims at detecting and enabling correction of following problems:

[0083] - Connection failure due to intra-system or inter-system mobility;

[0084] - Inter-system Unnecessary HO (too early inter-system HO from NR to E-UTRAN with no radio link failure); and

[0085] - Inter-system HO ping-pong.

[0086] The MRO provides means to distinguish the above problems from NR coverage related problems and other problems, not related to mobility.

[0087] One of the functions of Mobility Robustness Optimization is to detect a sub-optimal successful handover event. The aim is to identify underlying conditions during successful ordinary handovers, successful DAPS handovers, or successful Conditional handovers. For analysis of successful handover, the UE supports Successful Handover Report based on configuration by network (for e.g. through IEsuccessHO-Configas defined in 3gpp Technical Specification TS 38.331 in the NR), if received, and makes the Successful Handover Report available to the network. Upon retrieval of a Successful Handover Report, the receiving node may analyse whether its mobility configuration needs adjustment.

[0088] Network configures the UE for successful handover reporting. In the NR, gNB configures the UE for successful handover reporting through OtherConfig in RRCReconfiguration.

[0089]

[0090] SuccessHO-Config includes some thresholds and may also include some conditions which the UE evaluates at the time of handover. Based on the evaluation, the UE logs Successful Handover report.

[0091] In the NR, SuccessHO-Config is defined as follows:

[0092]

[0093] Some of the thresholds include, but not limited to thresholdPercentageT304, thresholdPercentageT310 and thresholdPercentageT312. The details on the timers are:

[0094]

[0095] In the NR, R18, the configuration of successful handover involves the following steps (based on TS 38.331 V18.0.0):

[0096] Other configuration:

[0097] The UE shall:

[0098] 1> if successHO-Config is set to setup:

[0099] 2> consider itself to be configured to provide the successful handover information in accordance with 5.7.10.6;

[0100] else:

[0101] 2> consider itself not to be configured to provide the successful handover information.

[0102] In the NR, the evaluation of successful handover is performed according to the below:

[0103] For Intra-NR mobility:

[0104] 1> set the content of the RRCReconfigurationComplete message as follows:

[0105] 2> if the RRCReconfiguration includes the reconfigurationWithSync in spCellConfig of an MCG:

[0106] 3> if the UE was configured with successHO-Config when connected to the source PCell:

[0107] 4> if the applied RRCReconfiguration is not due to a conditional reconfiguration execution upon cell selection performed while timer T311 was running, as defined in 5.3.7.3; or

[0108] 4> if the applied RRCReconfiguration is not received when T316 was running:

[0109] 5> perform the actions for the successful handover report determination as specified in clause 5.7.10.6, upon successfully completing the Random Access procedure triggered for the reconfigurationWithSync in spCellConfig of the MCG;

[0110] For Inter-NR mobility

[0111] For the inter-system mobility, in the current specifications, UE releases the radio configurations and performs SHR determination.

[0112] Successful completion of the mobility from NR:

[0113] Upon successfully completing the handover, at the source side the UE shall:

[0114] 1> reset MAC;

[0115] 1> stop all timers that are running except T325, T330 and T400;

[0116] 1> release ran-NotificationAreaInfo, if stored;

[0117] 1> release the AS security context including the KRRCenc key, the KRRCint key, the KUPint key and the KUPenc key, if stored;

[0118] 1> release all radio resources, including release of the RLC entity and the MAC configuration;

[0119] 1> release the associated PDCP entity and SDAP entity for all established RBs;

[0120] NOTE : PDCP and SDAP configured by the source RAT prior to the handover that are reconfigured and re-used by target RAT when delta signalling (i.e., during inter-RAT intra-system handover when fullConfig is not present) is used, are not released as part of this procedure.

[0121] 1> if T316 was not running at the time of receiving MobilityFromNRCommand and if the UE was configured with successHO-Config when connected to the source PCell and the targetRAT-Type is set to eutra:

[0122] 2> perform the actions for the successful handover report determination for inter-RAT handover as specified in clause 5.7.10.6.

[0123] 1> if the targetRAT-Type is set to eutra and the nas-SecurityParamFromNR is included: or

[0124] 1> if the targetRAT-Type is set to utra-fdd:

[0125] 2> indicate the release of the RRC connection to upper layers together with the release cause 'other'.

[0126] If the conditions for successful handover configuration are satisfied, UE logs successful handover report (SHR). Logging of SHR is done in the background based on the SHR configuration, as below.

[0127] 5.7.10.6 Actions for the successful handover report determination

[0128] The UE shall for the PCell:

[0129] 1> if the procedure is triggered due to successful completion of reconfiguration with sync, and if the ratio between the value of the elapsed time of the timer T304 and the configured value of the timer T304, included in the last appliedRRCReconfigurationmessage including thereconfigurationWithSync, is greater thanthresholdPercentageT304if included in thesuccessHO-Configreceived before executing the last reconfiguration with sync; or

[0130] 1> if the procedure is triggered due to successful completion of reconfiguration with sync, and if the ratio between the value of the elapsed time of the timer T310 and the configured value of the timer T310, configured while the UE was connected to the source PCell before executing the last reconfiguration with sync, is greater thanthresholdPercentageT310included in thesuccessHO-Configif configured by the source PCell before executing the last reconfiguration with sync; or

[0131] 1> if the procedure is triggered due to successful completion of reconfiguration with sync, and if the T312 associated to the measurement identity of the target cell was running at the time of initiating the execution of the reconfiguration with sync procedure and if the ratio between the value of the elapsed time of the timer T312 and the configured value of the timer T312, configured while the UE was connected to the source PCell before executing the last reconfiguration with sync, is greater thanthresholdPercentageT312included in the successHO-Configif configured by the source PCell before executing the last reconfiguration with sync; or

[0132] 1> if the procedure is triggered due to successful completion of reconfiguration with sync, and ifsourceDAPS-FailureReporting is included in thesuccessHO-Configbefore executing the last reconfiguration with sync and is set totrueand if the last executed handover was a DAPS handover and if an RLF occurred at the source PCell during the DAPS handover while T304 was running; or:

[0133] 1> if the procedure is triggered due to successful completion of Mobility from NR to E-UTRA,and if the ratio between the value of the elapsed time of the timer T310 and the configured value of the timer T310, configured while the UE was connected to the source PCell before executing the last Mobility from NR to E-UTRA, is greater thanthresholdPercentageT310included in thesuccessHO-Configif configured by the source PCell before executing the last Mobility from NR to E-UTRA; or

[0134] 1> if the procedure is triggered due to successful completion of Mobility from NR to E-UTRA, and if the T312 associated to the measurement identity of the target cell was running at the time of initiating the execution of the Mobility from NR to E-UTRA and if the ratio between the value of the elapsed time of the timer T312 and the configured value of the timer T312, configured while the UE was connected to the source PCell before executing the last Mobility from NR to E-UTRA, is greater thanthresholdPercentageT312included in the successHO-Configif configured by the source PCell before executing the last Mobility from NR to E-UTRA:

[0135] 2> store the successful handover information inVarSuccessHO-Reportand determine the content in VarSuccessHO-Reportas specified in TS 38.331

[0136] In the NR, the SHR is defined as follows:

[0137]

[0138]

[0139] The UE indicates the availability of SHR in RRC complete messages. In the NR, the messages can be RRCSetupComplete, RRCResumeComplete and RRCReconfigurationComplete. Further UE may receive a request to send SHR and report the SHR to the network.

[0140] In the NR, the request to include SHR is sent in UEInformationRequest message and the UE sends the SHR to gNB through UEInformationResponse message.

[0141] The UE may be configured for, reporting information related to successful PSCell Addition and Successful PSCell Change. This information could be configured to be stored and reported in a report called Successful PSCell Addition / Change Report (SPR as defined below).

[0142]

[0143] Network configures the UE for reporting SPR using successPSCell-Config in OtherConfig as given below using RRC messages such as RRCReconfiguration in the NR.

[0144]

[0145] UE operations using the successPSCell-Config is described in specifications such as section 5.7.10.7 TS 38.331

[0146] 5.7.10.7 Actions for the successful PSCell change or addition report determination

[0147] The UE shall for the PSCell:

[0148] 1> if the ratio between the value of the elapsed time of the timer T304 and the configured value of the timer T304, included in the last appliedRRCReconfigurationmessage for the SCG including the reconfigurationWithSync, is greater thanthresholdPercentageT304-SCGif included in thesuccessPSCell-Configreceived before executing the last reconfiguration with sync for the SCG; or

[0149] 1> ifsn-InitiatedPSCellChangeassociated to the last appliedRRCReconfigurationwithreconfigurationWithSyncfor the SCG is configured and if the ratio between the value of the elapsed time of the timer T310 and the configured value of the timer T310, configured while the UE was connected to the source PSCell before executing the last reconfiguration with sync for the SCG, is greater thanthresholdPercentageT310-SCGincluded in thesuccessPSCell-Configif configured by the source PSCell before executing the last reconfiguration with sync for the SCG; or

[0150] 1> ifsn-InitiatedPSCellChangeassociated to the last appliedRRCReconfigurationwithreconfigurationWithSyncfor the SCG is configured and if the T312 associated to the measurement identity of the target PSCell was running at the time of initiating the execution of the reconfiguration with sync procedure for the SCG and if the ratio between the value of the elapsed time of the timer T312 and the configured value of the timer T312, configured while the UE was connected to the source PSCell before executing the last reconfiguration with sync, is greater thanthresholdPercentageT312-SCGincluded in the successPSCell-Configif configured by the source PSCell before executing the last reconfiguration with sync for the SCG:

[0151] 1> ifsn-InitiatedPSCellChangeassociated to the last appliedRRCReconfigurationwithreconfigurationWithSyncfor the SCG is not configured and if the ratio between the value of the elapsed time of the timer T310 and the configured value of the timer T310, configured while the UE was connected to the source PSCell before executing the last reconfiguration with sync for the SCG, is greater thanthresholdPercentageT310-SCGincluded in thesuccessPSCell-Configif configured by the PCell before executing the last reconfiguration with sync for the SCG; or

[0152] 1> ifsn-InitiatedPSCellChangeassociated to the last appliedRRCReconfigurationwithreconfigurationWithSyncfor the SCG is not configured and if the T312 associated to the measurement identity of the target PSCell was running at the time of initiating the execution of the reconfiguration with sync procedure for the SCG and if the ratio between the value of the elapsed time of the timer T312 and the configured value of the timer T312, configured while the UE was connected to the source PSCell before executing the last reconfiguration with sync, is greater thanthresholdPercentageT312-SCGincluded in the successPSCell-Configif configured by the PCell before executing the last reconfiguration with sync for the SCG:

[0153] 2> clear the information included inVarSuccessPSCell-Report, if any;

[0154] 2> store the successful PSCell change or addition information inVarSuccessPSCell-Reportand determine the content inVarSuccessPSCell-Reportas described in TS 38.331:

[0155] During full configuration, target cell releases the entire dedicated configuration and applies its own configuration. This helps the target cell to configure the UE even when it doesn't understand or doesn't want to consider the configurations from the source cell, there by simplifying the handover implementation at the target cell. However, current methods do not describe a method on how the UE handles the SHR configuration during full configuration. Also, there is no system that describes the SPR configuration during full configuration. This will result in UE not logging the essential information for optimizing handover or PSCellChange, as it is clear from the above descriptions that the operations require the usage of SHR configuration or SPR configuration.

[0156] Further, for the inter-system mobility, in the current specifications, the UE releases the radio configurations and thereafter performs SHR determination. This may result in UE not having the configuration when it determines SHR.

[0157] In contrast to the existing system, the embodiments herein describe a method and a system where the UE avoids releasing SHR configuration information and SPR configuration information upon performing full configuration. Embodiments disclosed herein provides a method for performing optimisations during intra-system and inter-system mobility. In an embodiment, the UE avoids releasing SHR configuration upon performing full configuration. The UE releases all the dedicated configuration except specific configurations such as SHR configuration upon performing full configuration. The UE avoids releasing SHR configuration configured by the source PCell upon performing full configuration. The UE releases all the dedicated configuration except specific configurations such as SHR configuration configured by the source PCell upon performing full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0158] In an embodiment, the terms source network apparatus and source cell, are used interchangeably. Similarly, the terms target network apparatus, and target cell are used interchangeably.

[0159] Referring now to the drawings and more particularly to FIGS. 1 through 5, where similar reference characters denote corresponding features consistently throughout the figure, these are shown preferred embodiments.

[0160] Fig. 1 is a block diagram that illustrates the hardware features of the UE (100) according to the embodiments as disclosed herein.

[0161] Examples of the UE (100) can include, but are not limited to, Consumer Electronics (such as Mobile Phones and Smartphones), Tablets, Wearable Devices, Computing Devices (such as Laptops, Notebooks, Desktops, Workstations, etc.), IoT Devices, Automotive Systems (such as connected cars, Autonomous Vehicles, Vehicle-to-Everything (V2X) communication devices, etc.), Enterprise Devices such as robotics, Specialized Equipment (such as Medical Devices, Public Safety Devices, etc.), Media Devices (such as Gaming Consoles, Streaming Devices, etc.).

[0162] Examples of the wireless network include, but are not limited to, Cellular Networks (such as 2G, 3G, 4G, 5G, Beyond 5G (B5G) / 6G, or advanced cellular networks), Local Area Networks (LANs) (such as Wi-Fi, Li-Fi, etc.), Personal Area Networks (PANs) (such as Bluetooth, Zigbee, Z-Wave, etc.), Wide Area Networks (WANs) (such as Satellite Communication Networks, Long Range Wide Area Network, Narrowband IoT, Low-bandwidth communication for IoT, etc.), Metropolitan Area Networks (MANs), Machine-to-Machine (M2M), Ad Hoc and Mesh Networks, Emerging and Advanced Networks.

[0163] The source network apparatus (200) and the target network apparatus (300) can encompass a diverse range of devices including but not limited to gNodeB, Access and Mobility Management Function (AMF), Session Management Function (SMF), User Plane Function (UPF), Unified Data Management (UDM) and others.

[0164] In an embodiment, the UE (100) communicates with the network and the UE (100) includes a memory (101), a processor (102), an intra-inter mobility controller (103) and an I / O interface (104).

[0165] The memory (101) stores instructions to be executed by the processor (102). The memory (101) can include non-volatile storage elements. Examples of such non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memories, or forms of electrically programmable memories (EPROM) or electrically erasable and programmable (EEPROM) memories. In addition, the memory (101) may in some examples be considered a non-transitory storage medium. The term non-transitory may indicate that the storage medium is not embodied in a carrier wave or a propagated signal. However, the term non-transitory should not be interpreted that the memory (101) is non-movable. In some examples, the memory (101) stores larger amounts of information. In certain examples, a non-transitory storage medium may store data that can over time change (e.g., in Random Access Memory (RAM) or cache). The memory (101) stores the capability of the UE, AS security configurations, SRB1 and SRB2 configurations, logged measurement configurations, QoS parameters, handover control message, session information, location information, SHR configuration, SPR configuration, MAC configuration and others.

[0166] The processor (102) may include one or a plurality of processors. The one or the plurality of processors may be a general-purpose processor such as a central processing unit (CPU), an application processor (AP), or the like, a graphics-only processing unit such as a graphics processing unit (GPU), a visual processing unit (VPU), and / or an AI-dedicated processor such as a neural processing unit (NPU). The processor (102) may include multiple cores and is configured to execute the instructions stored in the memory (101). The processor (102) fetches the SHR configuration, the SPR configuration, MAC configuration among others. Further, the processor (102) retrieves instructions and executes them.

[0167] The I / O interface (104) transmits the information between the memory (204) and external peripheral devices. The peripheral devices are the input-output devices associated with the source network apparatus (200) and the target network apparatus (300). The I / O interface (104) receives several pieces of information from a plurality of UEs, network devices, servers, and the like. The I / O interface (104) ensures that the operating speed of the processor is synchronized with respect to the input and output devices. The I / O interface (104) establishes a connection between different peripheral devices like memory, and others to perform the optimisations during mobility in wireless network.

[0168] In an embodiment, the intra-inter mobility controller (103) of the UE (100) communicates with the processor (102), I / O interface (104), and memory (101) to manage optimizations during mobility in the wireless network. The intra-inter mobility controller (103) performs the full configuration procedure. Additionally, the UE (100) retains the SHR configuration and the SPR configuration during full configuration. The intra-inter mobility controller (103) determines whether an inter-RAT handover is completed and performs actions for SHR determination for the inter-RAT handover before releasing the radio resources, RLC entity, and the MAC configuration at the source side, upon successfully completing the inter-RAT handover. Furthermore, the intra-inter mobility controller (103) determines the SHR based on the SHR configuration.

[0169] In an embodiment, the operation includes determining at least one of the Successful PSCell Addition / Change Report (SPR)and a successful handover report (SHR). The intra-inter mobility controller (103) determines a Successful PSCell Addition / Change Report (SPR)when the retained configuration is the SPR configuration, whereas the intra-inter mobility controller (103) determines the successful handover report (SHR) when the retained configuration is the SHR configuration.

[0170] At least one component of the intra-inter mobility controller (103) may use an AI / ML model. Functions associated with the AI model are executed through the memory (101) and processor (102). The processors manage input data processing based on predefined operating rules or AI / ML models stored in volatile and non-volatile memory. These models are created through training or learning processes.

[0171] Learning involves applying a learning process to multiple data sets to develop a desired operating rule or AI / ML model. This can occur within the device or via a separate server / system. The AI / ML model may include multiple neural network layers, each with weight values and layer operations. Examples of neural networks include CNN, DNN, RNN, RBM, DBN, BRDNN, GAN, and deep Q-networks.

[0172] The learning process trains a target device (e.g., a robot) using various data to enable it to make decisions or predictions. Learning methods include supervised, unsupervised, semi-supervised, and reinforcement learning.

[0173] While Fig. 1 illustrates the hardware components of the UE (100), alternative embodiments may include different or additional components. The labels or names of these elements are illustrative and do not limit the invention's scope. Components may also be combined to perform similar functions.

[0174] Fig. 2 is a flow diagram that illustrates a scenario of full configuration for handover execution at the UE where the SHR configuration is not released upon the full configuration according to the embodiments as disclosed herein.

[0175] In an embodiment, the UE receives RRC reconfiguration message including full configuration (S201), and the UE releases the dedicated configuration excluding SHR configuration (S202).

[0176] In an embodiment, the UE (100) avoids releasing SHR configuration upon performing full configuration. The UE releases all the dedicated configuration except specific configurations such as SHR configuration upon performing full configuration.

[0177] In an embodiment, the UE avoids releasing SHR configuration upon performing full configuration if the full configuration is for the handover (such as ReconfigurationWithSync). The UE releases all the dedicated configuration except specific configurations such as SHR configuration upon performing full configuration for the handover (such as ReconfigurationWithSync).

[0178] Full configuration:

[0179] The UE shall:

[0180] 1> release / clear all current dedicated radio configurations except for the following:

[0181] - the MCG C-RNTI;

[0182] - the AS security configurations associated with the master key;

[0183] - the SRB1 / SRB2 configurations and DRB / multicast MRB configurations as configured by radioBearerConfig or radioBearerConfig2;

[0184] - the successHO-Config.

[0185] NOTE 1: Radio configuration is not just the resource configuration but includes other configurations likeMeasConfig. Radio configuration also includes the RLC bearer configurations as configured byRLC-BearerConfig, PC5 Relay RLC channel as configured bySL-RLC-ChannelConfig, and Uu Relay RLC channel as configured byUu-RelayRLC-ChannelConfig. In case NR-DC or NE-DC is configured, this also includes the entire NR or E-UTRA SCG configuration which are released according to the MR-DC release procedure as specified in 5.3.5.10.

[0186] NOTE 1a: For NR sidelink communication / discovery, the radio configuration includes the sidelink RRC configuration received from the network, but does not include the sidelink RRC reconfiguration and sidelink UE capability received from other UEs via PC5-RRC. In addition, the UE considers the new NR sidelink configurations as full configuration, in case of state transition and change of system information used for NR sidelink communication / discovery.

[0187] NOTE 1b: To establish the RLC bearer of SRB(s) after release due tofullConfig, the network can include thesrb-Identitywithinsrb-ToAddModList(i.e. the UE applies RLC default configuration) and / or providerlc-BearerToAddModListof concerned SRB(s) explicitly.

[0188] - the logged measurement configuration;

[0189] 1> if the spCellConfig in themasterCellGroupincludes thereconfigurationWithSync:

[0190] 2> release / clear all current common radio configurations;

[0191] As illustrated, the UE (100) releases all the configurations except the MCG Cell Radio Network Temporary Identifier (C-RNTI), the AS security configurations associated with the master key, the SRB1 / SRB2 configurations and DRB / multicast MRB configurations as configured by RadioBearerConfig or radioBearerConfig2 and the SHR configuration. This helps that the target cell can configure its own configuration without considering the previous configuration except for the specific configurations such as SHR configurations where the operations using the retained configuration is important.

[0192] In an embodiment, the UE avoids releasing SHR configuration configured by the source PCell upon performing full configuration. The UE releases all the dedicated configuration except specific configurations such as SHR configuration configured by the source PCell upon performing full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0193] In an embodiment, the UE avoids releasing T310 and T312 thresholds (such as thresholdPercentageT310, thresholdPercentageT312 in the NR) in the SHR configuration upon performing full configuration. The UE releases all the dedicated configuration except specific configurations such as T310 and T312 thresholds (such as thresholdPercentageT310, thresholdPercentageT312 in the NR) in the SHR configuration upon performing full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0194] Fig. 3 is a flow diagram that illustrates the scenario of the UE releasing the dedicated configuration except SPR configuration upon full configuration execution according to the embodiments as disclosed herein. In an embodiment, UE avoids releasing SPR configuration upon performing full configuration. UE releases all the dedicated configuration except specific configurations such as SPR configuration upon performing full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR). This helps that the target cell can configure its own configuration without considering the previous configuration except for the specific configurations such as SPR configurations where the operations using the retained configuration is important.

[0195] In an embodiment, the UE receives RRC reconfiguration message including full configuration (S301), and the UE releases the dedicated configuration excluding SPR configuration (S302).

[0196] In an embodiment, the UE (100) avoids releasing SPR configuration upon performing SN only full configuration. The UE (100) releases all the dedicated configuration except specific configurations such as SPR configuration upon performing SN only full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0197] In an embodiment, the UE (100) avoids releasing SPR configuration configured by the PCell upon performing full configuration. UE releases all the dedicated configuration except specific configurations such as SPR configuration configured by the PCell upon performing full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0198] In an embodiment, the UE (100) avoids releasing SPR configuration configured by the PCell (200) upon performing SN only full configuration. The UE (100) releases all the dedicated configuration except specific configurations such as SPR configuration configured by the PCell upon performing SN only full configuration. In an embodiment, the above is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0199] In an embodiment, according to TS 38.331:

[0200] Fullconfiguration

[0201] The UE shall:

[0202] 1> release / clear all current dedicated radio configurations except for the following:

[0203] - the MCG C-RNTI;

[0204] - the AS security configurations associated with the master key;

[0205] - the SRB1 / SRB2 configurations and DRB / multicast MRB configurations as configured by radioBearerConfig or radioBearerConfig2;

[0206] - the successHO-Config.

[0207] NOTE 1: Radio configuration is not just the resource configuration but includes other configurations likeMeasConfig. Radio configuration also includes the RLC bearer configurations as configured byRLC-BearerConfig, PC5 Relay RLC channel as configured bySL-RLC-ChannelConfig, and Uu Relay RLC channel as configured byUu-RelayRLC-ChannelConfig. In case NR-DC or NE-DC is configured, this also includes the entire NR or E-UTRA SCG configuration which are released according to the MR-DC release procedure as specified in 5.3.5.10.

[0208] NOTE 1a: For NR sidelink communication / discovery, the radio configuration includes the sidelink RRC configuration received from the network, but does not include the sidelink RRC reconfiguration and sidelink UE capability received from other UEs via PC5-RRC. In addition, the UE considers the new NR sidelink configurations as full configuration, in case of state transition and change of system information used for NR sidelink communication / discovery.

[0209] NOTE 1b: To establish the RLC bearer of SRB(s) after release due tofullConfig, the network can include thesrb-Identitywithinsrb-ToAddModList(i.e. the UE applies RLC default configuration) and / or providerlc-BearerToAddModListof concerned SRB(s) explicitly.

[0210] - the logged measurement configuration;

[0211] - thesuccessPSCell-Config

[0212] 1> if thespCellConfigin themasterCellGroupincludes thereconfigurationWithSync:

[0213] 2> release / clear all current common radio configurations;

[0214] In an embodiment, the UE (100) avoids releasing the SPR configuration configured by the source PSCell upon performing a full configuration. The UE (100) releases all dedicated configurations except specific configurations such as the SPR configuration configured by the source PSCell upon performing a full configuration. This embodiment is applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0215] In an embodiment, the UE avoids releasing the SPR configuration configured by the source PSCell upon performing an SN-only full configuration. The UE releases all dedicated configurations except specific configurations such as the SPR configuration configured by the source PSCell upon performing an SN-only full configuration. This embodiment is also applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0216] In an embodiment, the UE avoids releasing T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) in the SPR configuration upon performing a full configuration. The UE releases all dedicated configurations except specific configurations such as T310 and T312 thresholds in the SPR configuration upon performing a full configuration. This embodiment is applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0217] In an embodiment, the UE (100) avoids releasing T310 and T312 thresholds in the SPR configuration upon performing an SN-only full configuration. The UE (100) releases all dedicated configurations except specific configurations such as T310 and T312 thresholds in the SPR configuration upon performing an SN-only full configuration. This embodiment is applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0218] In an embodiment, the UE (100) avoids releasing the SPR configuration configured by the PCell upon performing a full configuration. The UE (100) releases all dedicated configurations except specific configurations such as the SPR configuration configured by the PCell upon performing a full configuration. This embodiment is applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0219] In an embodiment, the UE (100) avoids releasing T310 and T312 thresholds configured by the PCell in the SPR configuration upon performing a full configuration. The UE (100) releases all dedicated configurations except specific configurations such as T310 and T312 thresholds configured by the PCell in the SPR configuration upon performing a full configuration. This embodiment is applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0220] In an embodiment, the UE (100) avoids releasing the SPR configuration configured by the PCell upon performing an SN-only full configuration. The UE (100) releases all dedicated configurations except specific configurations such as the SPR configuration configured by the PCell upon performing an SN-only full configuration. This embodiment is applied when the full configuration is for handover, such as reconfigurationWithSync in the NR.

[0221] In an embodiment, the UE (100) avoids releasing T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) configured by the PCell in the SPR configuration upon performing SN only full configuration. All the dedicated configurations are released by the UE (100) except for specific configurations such as T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) configured by the PCell in the SPR configuration upon performing SN only full configuration. This embodiment is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0222] In an embodiment, the UE (100) avoids releasing T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) configured by the source PSCell in the SPR configuration upon performing full configuration. The UE (100) releases all the dedicated configurations except for specific configurations such as T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) configured by the source PSCell in the - configuration upon performing full configuration. This embodiment is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0223] In an embodiment, the UE (100) avoids releasing T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) configured by the source PSCell in the SPR configuration upon performing SN only full configuration. The UE releases all the dedicated configurations except for specific configurations such as T310 and T312 thresholds (such as thresholdPercentageT310 and thresholdPercentageT312 in the NR) configured by the source PSCell in the SPR configuration upon performing SN only full configuration. This embodiment is applied when the full configuration is for handover (such as reconfigurationWithSync in the NR).

[0224] Fig. 4 is a flow diagram illustrating the scenario of successful execution of Inter-Radio Access Technology (RAT) handover according to embodiments disclosed herein. In one embodiment, upon successfully completing the Inter-RAT handover, the UE (100) performs actions for the successful handover report (SHR) determination for inter-RAT handover before releasing the radio resources, including the release of the RLC entity and the MAC configuration at the source side. SHR determination may be further decided based on whether timer T316 is running. This ensures that the UE (100) has SHR configuration while it performs SHR determination.

[0225] In another embodiment, upon successfully completing the Inter-RAT handover, the UE (100) releases the radio resources, including the release of the RLC entity and the MAC configuration at the source side, except for the SHR configuration configured by the source PCell. SHR determination may be further decided based on whether timer T316 is running. This ensures that the UE (100) has SHR configuration while it performs SHR determination. The UE (100) further releases the SHR configuration after determining SHR. Additionally, the UE (100) releases the SHR configuration if T316 was running when the UE (100) received the Inter-RAT handover command.

[0226] For Inter-NRmobility

[0227] Successful completion of the mobility from NR

[0228] Upon successfully completing the handover, at the source side the UE shall:

[0229] 1> reset MAC;

[0230] 1> stop all timers that are running except T325, T330 and T400;

[0231] 1> release ran-NotificationAreaInfo, if stored;

[0232] release the AS security context including the KRRCenc key, the KRRCint key, the KUPint key and the KUPenc key, if stored;

[0233] 1> if T316 was not running at the time of receiving MobilityFromNRCommand and if the UE was configured with successHO-Config when connected to the source PCell and the targetRAT-Type is set to eutra:

[0234] 2> perform the actions for the successful handover report determination for inter-RAT handover as specified in clause 5.7.10.6.

[0235] 1> release all radio resources, including release of the RLC entity and the MAC configuration;

[0236] 1> release the associated PDCP entity and SDAP entity for all established RBs;

[0237] NOTE : PDCP and SDAP configured by the source RAT prior to the handover that are reconfigured and re-used by target RAT when delta signalling (i.e., during inter-RAT intra-system handover whenfullConfigis not present) is used, are not released as part of this procedure.

[0238] 1> if thetargetRAT-Type is set toeutraand thenas-SecurityParamFromNRis included: or

[0239] 1> if thetargetRAT-Type is set toutra-fdd:

[0240] 2> indicate the release of the RRC connection to upper layers together with the release cause 'other'.

[0241] Alternatively, Successful completion of the mobility from NR

[0242] Upon successfully completing the handover, at the source side the UE shall:

[0243] 1> reset MAC;

[0244] 1> stop all timers that are running except T325, T330 and T400;

[0245] 1> release ran-NotificationAreaInfo, if stored;

[0246] 1> release the AS security context including the KRRCenc key, the KRRCint key, the KUPint key and the KUPenc key, if stored;

[0247] 1> release all radio resources, including release of the RLC entity and the MAC configuration except the SHR configuration;

[0248] 1> release the associated PDCP entity and SDAP entity for all established RBs;

[0249] NOTE : PDCP and SDAP configured by the source RAT prior to the handover that are reconfigured and re-used by target RAT when delta signalling (i.e., during inter-RAT intra-system handover whenfullConfigis not present) is used, are not released as part of this procedure.

[0250] 1> if T316 was not running at the time of receiving MobilityFromNRCommand and if the UE was configured with successHO-Config when connected to the source PCell and the targetRAT-Type is set to eutra:

[0251] perform the actions for the successful handover report determination for inter-RAT handover as specified in clause 5.7.10.6.

[0252] 1>else

[0253] 2>release the SHR configuration if available.

[0254] 1> if the targetRAT-Type is set to eutra and the nas-SecurityParamFromNR is included: or

[0255] 1> if the targetRAT-Type is set to utra-fdd:

[0256] 2> indicate the release of the RRC connection to upper layers together with the release cause 'other'.

[0257] The method of optimizing mobility in a wireless network is illustrated in Fig. 5, which is a flow diagram according to the disclosed embodiments. Constant transitions or handovers of the UE (100) occur between the source network apparatus (200) and the target network apparatus (300). The SHR report is used for validating and reporting the information for successful handover. It includes important information on network performance monitoring and optimization, radio measurements, cause of the logging the information, location measurements, random access measurements and so on.

[0258] Additionally, the SPR is used to report the success of PSCell (Primary Secondary Cell Group Cell) changes. The SPR provides feedback to the network on the success of these PSCell addition or PSCell changes, allowing for optimization of PSCell addition and PSCell Change. The figure illustrates the method of determining the SHR and the SPR using the retained SHR configuration and the SPR configuration upon performing the full configuration.

[0259] At step S501, the UE (100) performs the full configuration procedure. Target gNB performs full configuration when it can not understand some of the parameters in the UE configuration or when it chooses full configuration as an easy implementation option.

[0260] After successfully performing the full configuration, the UE (100) retains the SHR configuration and the SPR configuration for determining the SHR and the SPR, respectively, as illustrated at step S502. The UE (100) also retains information on the MCG C-RNTI, the AS security configurations associated with the master key, and the SRB1 / SRB2 configurations and DRB / multicast MRB configurations as configured by radioBearerConfig or radioBearerConfig2. At step S503, the UE (100) performs the operation using the SHR configuration and the SPR configuration.

[0261] Fig. 6 is a flow diagram that illustrates the method of determining SHR, according to the embodiments as disclosed herein.

[0262] At step S601, the UE (100) determines whether the inter-RAT handover is successfully completed. Upon successful completion of the inter-RAT handover, the UE (100) performs actions for the SHR determination for inter-RAT handover before releasing at least one of the radio resources, RLC entity, and MAC configuration at the source side as illustrated at step S602. The UE (100) verifies whether the timer T316 is not running at the time of receiving MobilityFromNRCommand and if the UE (100) was configured with successHO-Config when connected to the source PCell and the targetRAT-Type is set to E-UTRA for SHR determination. The UE (100) then resets the MAC configuration, stops all timers except T325, T330, and T400, and releases ran-NotificationAreaInfo if stored. Additionally, the UE (100) releases the AS security context, including the KRRCenc key, the KRRCint key, the KUPint key, and the KUPenc key if stored, and releases all radio resources, including the RLC entity, MAC configuration, and associated PDCP entity and SDAP entity for all established RBs.

[0263] In an embodiment, the UE determines the successful PSCell change or an addition report, when the retained configuration is the SPR configuration and the UE (100) determines the successful handover report, when the retained configuration is the SHR configuration.

[0264] In an embodiment, the full configuration is performed upon reception of an enumerated fullconfig in RRCReconfiguration message.

[0265] In an embodiment, the full configuration is performed during the handover.

[0266] Fig. 7 is a block diagram that illustrates hardware components associated with a UE according to the embodiments as disclosed herein.

[0267] The terminal is an electronic device capable of wireless communication, may include a User Equipment (UE), a portable phone, a smartphone, a tablet, an Internet of things (IoT) device, etc., having various form factors, and may perform wireless communication with a base station (BS) through a wireless channel.

[0268] Referring to FIG. 7, the UE 700 may include at least one transceiver (hereinafter, referred to as simply "transceiver") 701, at least one processor (hereinafter, referred to as simply "processor") 702, and at least one memory (hereinafter, referred to as simply "memory") 703. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 701, the processor 702, and the memory 703 of the UE 700 may operate. However, components of the UE 700 are not limited to the exemplary components illustrated in FIG. 7. In another embodiment, the UE 700 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 701, the processor 702, or the memory 703 may be integrated in the form of one component.

[0269] The transceiver 701 may be a communication circuit or communication circuitry that enables the UE 700 to perform wireless communication with a node or an entity of a network. For example, the transceiver 701 may enable the UE 700 to transmit or receive a signal to or from a BS through cellular communication, or to transmit or receive a signal to or from another UE through cellular communication. For example, the transceiver 701 may support at least one of various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (701) may include all subsequent generations of evolved wireless communications.

[0270] According to an embodiment, the UE 700 may include a plurality of transceivers. For example, in the case of supporting evolved-universal terrestrial radio access-new radio (E-UTRA-NR) sual connectivity (EN-DC), the UE 700 may include a first transceiver supporting the 4G LTE wireless communication and a second transceiver supporting the 5G NR wireless communication. According to another embodiment, in the case of supporting NR-dual connectivity (NR-DC), the UE 700 may include a plurality of transceivers supporting the 5G NR wireless communication. According to still another embodiment, in the case of supporting near field wireless communication, the UE 700 may separately include a transceiver supporting at least one standard in the group of wireless communication protocol standards as defined in the protocol standards for Bluetooth®, wireless local area network (WLAN) network (including institute of electrical and electronics engineers (IEEE) 802.11-2016 standard or its amendments, e.g., 802.11ah, 802.11ad, 802.11ay, 802.11ax, 802.11az, 802.11ba, and 802.11be, without being limited thereto).

[0271] According to an embodiment, the transceiver 701 may include various circuit structures used to transmit or receive signals to or from a BS through a wireless channel. The signals may include control information and data. For example, the transceiver 701 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 701 may output a signal received through a wireless channel to the processor 702 and may transmit, through a wireless channel, a signal output from the processor 702.

[0272] The processor 702 may control general operations of the UE 700 according to embodiments of the disclosure. The processor 702 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 702 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 703, individually, collectively or in any combination thereof. Further, the processor 702 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0273] The processor 702 may be electrically, operatively, or communicatively coupled to the transceiver 701 to control the transceiver 701.

[0274] The processor 702 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. For example, the processor 702 may include a communication processor (CP) configured to control communication operations and an application processor (AP) configured to control execution of an upper layer (for example, an application layer). In a specific embodiment, at least a part of the processor 702 may be included in one chip and the other part of the processor 702 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 701 or the memory 703.

[0275] The processor 702 may perform or control or cause an operation of the UE 700 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 702 may control operations of the UE 700 for processing a downlink signal received from a BS or generating and transmitting an uplink signal to a BS. To this end, the processor 702 may execute a computer program, codes, or instructions stored in the memory 703, so as to control other components of the UE 700 to enable execution of various operations.

[0276] The memory 703 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 703 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0277] The memory 703 may be electrically, operatively, or communicatively coupled to the processor 702 and may be accessed by the processor 702.

[0278] The memory 703 may store a computer program, codes, or instructions executable by the processor 702. According to an embodiment, a computer program, codes, or instructions executable by the processor 702 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 703, the processor 702 may perform various functions according to an embodiment of the disclosure.

[0279] According to an embodiment of the disclosure, operations of the UE 700 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 703 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0280] Fig. 8 is a block diagram that illustrates hardware components associated with a base station according to the embodiments as disclosed herein.

[0281] FIG. 8 is a block diagram of a base station (BS) 800 according to an embodiment of the disclosure.

[0282] The BS 800 may perform wireless communication with at least one user equipment (UE) located within the area of the BS 800 through a wireless channel.

[0283] Referring to FIG. 8, the BS 800 may include at least one transceiver (hereinafter, referred to as simply "transceiver") 801, at least one processor (hereinafter, referred to as simply "processor") 802, and at least one memory (hereinafter, referred to as simply "memory") 803. According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the transceiver 801, the processor 802, and the memory 803 of the BS 800 may operate. However, components of the BS 800 are not limited to the exemplary components illustrated in FIG. 8. In another embodiment, the BS 800 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in some embodiments, any combination of the transceiver 801, the processor 802, or the memory 803 may be integrated in the form of one component.

[0284] The transceiver 801 may be a communication circuit or communication circuitry that enables the BS 800 to perform wireless communication with a node or an entity of a network. For example, the transceiver 801 may enable the BS 800 to transmit or receive a signal to or from the UE 700 through cellular communication, or to transmit or receive a signal to or from another network entity through wireless communication. For example, the transceiver 801 may support various cellular communication technologies including 3rd generation (3G), 4th generation (4G), long term evolution (LTE), 5th generation (5G) NR, 6th generation (6G), and various cellular wireless communication technologies supported by the transceiver (801) may include all subsequent generations of evolved wireless communications. According to an embodiment, the transceiver 801 may include various circuit structures used to transmit or receive signals to or from a UE through a wireless channel. The signals may include control information and data. For example, the transceiver 801 may include a radio frequency (RF) transmitter for up-converting and amplifying the frequency of a transmitted signal and an RF receiver for low-noise-amplifying a received signal and down-converting the frequency thereof. The transceiver 801 may output a signal received through a wireless channel to the processor 802 and may transmit, through a wireless channel, a signal output from the processor 802.

[0285] Meanwhile, according to an embodiment of the present disclosure, the BS 800 may perform communication with a node or an entity of a network through wired or wireless communication. For example, the BS 800 may perform wired or wireless communication with an adjacent BS, or a node or an entity of a core network through a backhaul network. Although not illustrated in FIG. 8, when the BS 800 performs wired communication, the BS 800 may further include a separate network interface for wired communication in addition to the transceiver 801. The network interface may be referred to as network interface circuitry or communication interface circuitry.

[0286] The processor 802 may control general operations of the BS 800 according to embodiments of the disclosure. The processor 802 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 802 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 803, individually, collectively or in any combination thereof. Further, the processor 802 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme.

[0287] The processor 802 may be electrically, operatively, or communicatively coupled to the transceiver 801 to control the transceiver 801.

[0288] The processor 802 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 802 may be included in one chip and the other part of the processor 802 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the transceiver 801 or the memory 803.

[0289] The processor 802 may perform or control or cause an operation of the BS 800 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 802 may control operations of the BS 800 for generating and transmitting a downlink signal to a UE or processing an uplink signal received from a UE. Otherwise, the BS 800 may transmit or receive a signal to or from a neighboring BS, transfer a signal received from a UE to an upper node of the network, or transmit a signal transferred from an upper node of the network to a UE. To this end, the processor 802 may execute a computer program, codes, or instructions stored in the memory 803, so as to control other components of the BS 800 to enable execution of various operations.

[0290] The memory 803 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 803 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0291] The memory 803 may be electrically, operatively, or communicatively coupled to the processor 802 and may be accessed by the processor 802.

[0292] The memory 803 may store a computer program, codes, or instructions executable by the processor 802. According to an embodiment, a computer program, codes, or instructions executable by the processor 802 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 803, the processor 802 may perform various functions according to an embodiment of the disclosure.

[0293] According to an embodiment of the disclosure, operations of the BS 800 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 803 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0294] Fig. 9 is a block diagram that illustrates hardware components associated with a network entity according to the embodiments as disclosed herein.

[0295] The UE or the base station may perform various communication procedures related to the control plane or the user plane by cooperating with one or more network entities based on wireless communication. For example, the UE may communicate with network entity such as an Access and Mobility Management Function (AMF) or a Session Management Function (SMF) via the base station, or the base station may perform at least one communication procedure by directly transmitting and receiving signals to / from, or relaying signals between, the network entities.

[0296] The structure of the above-described network entity will be described in more detail with reference to the drawings.

[0297] FIG. 9 is a block diagram of a network entity 900 according to an embodiment of the disclosure.

[0298] The network entity 900 may include an entity (apparatus, device, or server, etc.) that performs one or more network functions (NFs) or a part of a network function constituting a core network (e.g., a 5th generation (5G) core (5GC)) in a communication system. In this case, multiple NFs may be implemented within a single network entity, or a single NF may be distributed and implemented across a plurality of network entities. In addition, when an NF is implemented within the network entity, the NF may be implemented in the form of software, and in such a case, a program for operating the NF may be stored in memory of the network entity 900.

[0299] A single NF may be implemented by one or more instances, which may be deployed on the same network entity or distributed across multiple network entities to operate. The instance may be a software unit that logically executes a specific network function, and may be implemented in a form that is decoupled from physical hardware resources. Further, one or more NFs may be implemented in the form of one network slice to operate to satisfy specifications required by a particular service.

[0300] The NF may include at least one of an access and mobility management function (AMF), a session management function (SMF), a local session management function (L-SMF), a user plane function (UPF), a local user plane function (L-UPF), a policy control function (PCF), a unified data management (UDM), a unified data repository (UDR), a network exposure function (NEF), a network repository function (NRF), an application function (AF), a network slice selection function (NSSF), a network data analytics function (NWDAF), a network slice admission control function (NSACF), an authentication server function (AUSF), or a data network (DN).

[0301] Referring to FIG. 9, the network entity 900 may include at least one network interface 901, at least one processor 902 (hereinafter, "processor"), and at least one memory 903 (hereinafter, "memory"). As described above, a NF may be implemented in the form of a physical device such as the network entity 900, or may be virtualized and executed in the form of an instance. When implemented as an instance, the NF need not necessarily include physical components as illustrated in FIG. 9. In such a case, the instance may be logically represented as comprising one or more logical functional elements.

[0302] According to at least one or a combination of methods corresponding to the embodiments described in the present disclosure, the network interface 901, the processor 902, and the memory 903 of the network entity 900 may operate. However, components of the network entity 900 are not limited to the exemplary components illustrated in FIG. 9. In another embodiment, the network entity 900 may further include additional components in addition to the above-mentioned components, or some components may be omitted. Further, in an embodiment, the network interface 901, the processor 902, or the memory 903 may be integrated in the form of one component.

[0303] The network interface 901 is a collective term for a transmitter part of the network entity 900 and a receiver part of the network entity 900, and may be a communication circuit for transmitting or receiving a signal to or from a user equipment (UE), a base station (BS), or another network entity. Here, the communication circuit may include both a communication circuit for wireless communication and a communication circuit for a wired communication. For example, the network interface 901 may include a circuit, logic, hardware, etc., configured to exchange a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless communication or wired communication. The network interface 901 may operate using various protocols (e.g., non-access stratum (NAS) protocol). The network interface 901 may also be referred to, for convenience of description or depending on implementation, as communication circuitry, network interface circuitry, or a communication interface circuitry.

[0304] The processor 902 may control general operations of the network entity 900 according to embodiments of the disclosure. The processor 902 may be implemented by one or more integrated circuit (or circuitry) (IC) chips and may execute various data processings. The processor 902 may include at least one electric circuit, and may execute instructions (or a program, codes, data, etc.) stored in the memory 903, individually, collectively or in any combination thereof. Further, the processor 902 may include a single-core processor or multi-core processor, and may include a processor assembly including a plurality of processing circuits (circuitry) according to a specific implementation scheme. Further, it should be noted that, according to another embodiment, in a case where NF is implemented in the form of an instance, the network function may be not necessarily configured by physical hardware.

[0305] According to an embodiment, the processor 902 may be electrically, operatively, or communicatively coupled to the network interface 901 to control the network interface 901.

[0306] The processor 902 may include at least one processor (or processing circuitry), and the at least one processor may perform the following operations individually, collectively or in any combination thereof. In a specific embodiment, at least a part of the processor 902 may be included in one chip and the other part of the processor 902 may be included in another chip. Otherwise, at least one processor may be included in another component, for example, the network interface 901 or the memory 903.

[0307] The processor 902 may perform or control or cause an operation of the network entity 900 for executing at least one or a combination of methods according to embodiments of the disclosure. For example, the processor 902 may control operations of the network entity 900 for exchanging a control plane message or a user plane message with a UE, a BS, or other core network entities through wireless or wired communication, using various protocols (e.g., NAS protocol). To this end, the processor 902 may execute a computer program, codes, or instructions stored in the memory 903, so as to control other components of the network entity 900 to enable execution of various operations.

[0308] The memory 903 corresponds to a hardware storage device capable of temporarily or permanently storing information and may include one or more storage media. For example, the memory 903 may include a memory assembly including one or more storage media. For example, the one or more storage media may include permanent memory, such as a hard drive, flash memory, or read-only memory (ROM), semipermanent memory, such as random access memory (RAM), cache memory, or a combination thereof.

[0309] The memory 903 may be electrically, operatively, or communicatively coupled to the processor 902 and may be accessed by the processor 902.

[0310] The memory 903 may store a computer program, codes, or instructions executable by the processor 902. According to an embodiment, a computer program, codes, or instructions executable by the processor 902 may be either stored in a single memory device or separated and distributedly stored in two or more memory devices. By executing the instructions stored in the memory 903, the processor 902 may perform various functions according to an embodiment of the disclosure.

[0311] According to an embodiment of the disclosure, operations of the network entity 900 may be caused to be performed based on execution of instructions (or a computer program or codes) stored in the memory 903 by at least one processor (or processing circuitry) configured to execute the same individually, collectively, or in any combination thereof, based on processing circuitry that is not configured to execute instructions, and / or based on components of processing circuitry that is not configured to execute instructions.

[0312] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the scope of the embodiments as described herein.

[0313] Meanwhile, although specific embodiments of the present disclosure have been described in detail, various modifications may be made without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be defined by the claims and equivalents thereof.

Claims

1.A method performed by a user equipment (UE) in a wireless communication system, the method comprising:receiving, from a base station, a radio resource control (RRC) message for an inter-radio access technology (RAT) mobility; andin case that a T316 timer is not running at a time of the receiving of the RRC message, determining a successful handover report upon successful completion of the inter-RAT mobility.2.The method of claim 1,wherein, in case that a type of target RAT associated with the RRC message is set to an evolved universal terrestrial radio access (E-UTRA), the determining of the successful handover report is performed.3.The method of claim 1, further comprising:releasing a current dedicated radio configuration except for at least one configuration including a first configuration for the successful handover report.4.The method of claim 3,wherein the at least one configuration further includes a second configuration for a successful primary secondary cell group (SCG) cell (PSCell) change or addition report.5.The method of claim 4, further comprises:determining the successful PSCell change or addition report based on the second configuration.6.The method of claim 3,wherein the RRC message includes information indicating a full configuration, andwherein the releasing of the current dedicated radio configuration is performed based on the information.7.The method of claim 1,wherein the inter-RAT mobility includes a mobility from a new radio (NR) to an E-UTRA.8.A user equipment (UE) comprising:at least one transceiver;at least one processor communicatively coupled to the at least one transceiver; andat least one memory, communicatively coupled to the at least one processor, storing instructions executable by the at least one processor individually or in any combination to cause the UE to:receive, from a base station, a radio resource control (RRC) message for an inter-radio access technology (RAT) mobility, andin case that a T316 timer is not running at a time of the receiving of the RRC message, determine a successful handover report upon successful completion of the inter-RAT mobility.9.The UE of claim 8,wherein, in case that a type of target RAT associated with the RRC message is set to an evolved universal terrestrial radio access (E-UTRA), the determining of the successful handover report is performed.10.The UE of claim 8, wherein the instructions further cause the UE to:release a current dedicated radio configuration except for at least one configuration including a first configuration for the successful handover report.11.The UE of claim 10,wherein the at least one configuration further includes a second configuration for a successful primary secondary cell group (SCG) cell (PSCell) change or addition report.12.The UE of claim 11, wherein the instructions further cause the UE to:determine the successful PSCell change or addition report based on the second configuration.13.The UE of claim 10,wherein the RRC message includes information indicating a full configuration, andwherein the releasing of the current dedicated radio resource configuration is performed based on the information.14.The UE of claim 8,wherein the inter-RAT mobility includes a mobility from a new radio (NR) to an E-UTRA.15.One or more non-transitory computer-readable storage media storing computer-executable instructions that, when executed by at least one processor of a user equipment (UE) individually or collectively, cause the UE to perform operations, the operations comprising:receiving, from a base station, a radio resource control (RRC) message for an inter-radio access technology (RAT) mobility; andin case that a T316 timer is not running at a time of the receiving of the RRC message, determining a successful handover report upon successful completion of the inter-RAT mobility.

Images