Method and apparatus for self-optimization in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting a higher data transmission rate. Embodiments disclosed herein relate to methods (300 to 1300) and systems (100) for performing self-optimization in a wireless network. The method (300 to 1300) includes performing a self-organizing network (SON) / minimization of drive test (MDT) optimization. The method (700, 800) includes inter-radio access technology (inter-RAT) rewrite protection of a signaling-based MDT configured in an evolved terrestrial radio access (E-UTRA) through a management-based MDT configured in a new radio (NR). The method (300, 400) includes optimization of voice fallback from NR to Long Term Evolution (LTE) by handover. The method (900, 1000) includes processing random access channel (RACH) reports in the NR, including RACH reports with a network slice AS group (NSAG). The method (500, 600) includes processing a successful handover report (SHR) in the NR. The method (1100, 1200, 1300) includes self-optimization of an NR-U (NR in unlicensed spectrum), deployment and operation of the NR-U.

Description

Technical Field

[0001] Embodiments disclosed herein relate to wireless networks, and more particularly to methods and systems for performing self-optimization in wireless networks. Background Art

[0002] 5G mobile communication technology defines a wide frequency band, making high transmission rates and new services possible. And it can be realized not only in the "sub-6GHz" frequency band such as 3.5GHz, but also in the "above 6GHz" frequency band called millimeter wave including 28GHz and 39GHz. In addition, it has been considered to implement 6G mobile communication technology (called super 5G system) in the terahertz frequency band (for example, 95GHz to 3THz frequency band) in order to achieve a transmission rate fifty times faster than 5G mobile communication technology and an ultra-low latency of one tenth of 5G mobile communication technology.

[0003] At the beginning of the development of 5G mobile communication technology, in order to support services and meet performance requirements related to enhanced mobile broadband (eMBB), ultra-reliable low-latency communication (URLLC) and massive machine type communication (mMTC), standardization has been ongoing on the following items: beamforming and massive MIMO for mitigating radio wave path loss in millimeter waves and increasing radio wave transmission distance, parameter sets supporting efficient utilization of millimeter wave resources and dynamic operation of time slot formats (for example, operating multiple subcarrier spacings), initial access technology for supporting multi-beam transmission and broadband, definition and operation of BWP (bandwidth part), new channel coding methods such as LDPC (low-density parity check) codes for large-scale data transmission and polarization codes for highly reliable transmission of control information, L2 preprocessing, and network slicing for providing dedicated networks dedicated to specific services.

[0004] Currently, discussions on improvements and performance enhancements of initial 5G mobile communication technologies are underway, taking into account the services to be supported by 5G mobile communication technologies, and physical layer standardization on technologies such as V2X (Vehicle to Everything) for assisting driving determination of autonomous vehicles based on information about the position and status of vehicles sent by the vehicles and for enhancing user convenience, NR-U (New Radio Unlicensed) for system operation that is intended to comply with various rule-related requirements in unlicensed bands, NR UE power saving, non-terrestrial network (NTN) for UE-satellite direct communication that provides coverage in areas where communication with terrestrial networks is unavailable, and positioning are underway.

[0005] In addition, in the air interface architecture / protocol, standardization has been ongoing on technologies such as Industrial Internet of Things (IIoT) for supporting new services by interworking and converging with other industries, IAB (Integrated Access and Backhaul) for providing nodes for network service area expansion by supporting wireless backhaul links and access links in an integrated manner, mobility enhancement including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access for simplifying the random access procedure (2-step RACH for NR). In terms of system architecture / services, 5G baseline architecture (e.g., service-based architecture or service-based interface) is also being standardized to combine network function virtualization (NFV) and software-defined network (SDN) technologies, as well as mobile edge computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, the already exponentially growing number of connected devices will be connected to the communication network, and it is therefore expected that enhanced functions and performance of the 5G mobile communication system and integrated operation of connected devices will be necessary. To this end, new research is planned in the following areas: effective support for extended reality (XR) such as AR (augmented reality), VR (virtual reality), MR (mixed reality), etc.; improving 5G performance and reducing complexity using artificial intelligence (AI) and machine learning (ML); AI service support; metadata service support; and drone communication.

[0007] In addition, such developments in 5G mobile communication systems will serve not only as a basis for developing new waveforms for providing coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as full-dimensional MIMO (FD-MIMO), array antennas, and massive antennas, metamaterial-based lenses and antennas for improving coverage of terahertz band signals, high-dimensional spatial multiplexing technology using OAM (orbital angular momentum), and RIS (reconfigurable smart surface), but will also serve as a basis for developing full-duplex technology for improving the frequency efficiency of 6G mobile communication technology and improving system networks, AI-based communication technology for achieving system optimization by utilizing satellites and AI (artificial intelligence) from the design stage and internalizing end-to-end AI support functions, and next-generation distributed computing technology for implementing services at a level of complexity that exceeds the limits of UE operating capabilities by utilizing ultra-high performance communication and computing resources. Summary of the invention

[0008] Technical issues

[0009] The present invention is proposed to solve at least the above problems and / or disadvantages and to provide at least the advantages described below.Therefore, for a more enhanced communication system, there is a need for a method and apparatus for self-optimization in a wireless communication system.

[0010] Technical Solution

[0011] A primary object of the embodiments herein is to disclose a method and system for self-optimization in a wireless network.

[0012] Another object of embodiments herein is to disclose a method and system for performing Self-Organizing Network (SON) / Minimization of Drive Tests (MDT) optimization.

[0013] Another object of embodiments herein is to disclose a method and system for inter-radio access technology (inter-RAT) overwrite protection of signaling-based MDT configured in Evolved Universal Terrestrial Radio Access (E-UTRA) by management-based MDT configured in New Radio (NR).

[0014] It is another object of embodiments herein to disclose a method and system for providing optimization of voice fallback from NR to Long Term Evolution (LTE) through switching.

[0015] Another object of the embodiments herein is to disclose a method and system for handling random access channel (RACH) reports in NR, including RACH reports with network slice AS group (NSAG) support.

[0016] Another object of embodiments herein is to disclose a method and system for handling a successful handover report (SHR) in NR.

[0017] Another object of the embodiments herein is to disclose methods and systems for self-optimization, NR-U (NR in unlicensed spectrum), NR-U deployment, and operation.

[0018] Advantageous Effects of the Invention

[0019] Advantages and salient features of the present invention will become more apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the accompanying drawings, discloses exemplary embodiments of the present invention. According to the present invention, self-optimization can be effectively performed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Embodiments of the present invention are illustrated in the accompanying drawings, and the same reference numerals indicate corresponding parts in the various drawings throughout the drawings. Embodiments of the present invention will be better understood by reference to the following description of the accompanying drawings. Embodiments of the present invention are illustrated by way of example in the accompanying drawings, and wherein:

[0021] Figure 1 A system for performing self-optimization in a wireless network according to embodiments disclosed herein is shown.

[0022] Figure 2Several modules of a processor of a user equipment (UE) according to embodiments disclosed herein are shown.

[0023] Figure 3 A method for performing self-optimization in a wireless network to handle voice fallback during mobility of a UE according to embodiments disclosed herein is shown.

[0024] Figure 4 A flow chart for handling radio link failure (RLF) during voice fallback according to embodiments disclosed herein is shown.

[0025] Figure 5 A method for performing self-optimization of a successful handover report (SHR) in a wireless network according to embodiments disclosed herein is shown.

[0026] Figure 6 The embodiment disclosed herein is used to perform the following steps: Figure 5 The method for recording SHR upon successful switching is shown.

[0027] Figure 7 A method for supporting logging minimization of drive tests (MDT) override protection based on inter-radio access technology (RAT) signaling in a wireless network according to an embodiment disclosed herein is shown.

[0028] Figure 8 A method for MDT coverage protection based on logging of inter-radio access technology (RAT) signaling according to embodiments disclosed herein is shown.

[0029] Fig. 9 A method for performing self-optimization of processing of random access channel (RACH) reports in a wireless network according to embodiments disclosed herein is shown.

[0030] Fig.10 A method for storing feature-specific random access information for a network slice AS group (NSAG) in a UE according to an embodiment disclosed herein is shown.

[0031] Fig.11 A method for providing random access (RA) reporting for consecutive uplink (UL) Listen Before Talk (LBT) failures in a bandwidth part (BWP) in NR-U (NR in unlicensed spectrum) during a RA procedure according to an embodiment disclosed herein is shown.

[0032] Fig.12 A method for RA reporting for consecutive UL LBT failures in some BWPs during the RA procedure according to embodiments disclosed herein is shown.

[0033] Fig.13 A method for storing RA information about LBT failure according to an embodiment disclosed herein is shown.

[0034] Fig.14 The structure of a UE to which the embodiments of the present disclosure can be applied is shown.

[0035] Fig.15 The structure of a base station to which the embodiments of the present disclosure can be applied is shown.

[0036] It is noteworthy that, to the extent possible, the same reference numerals have been used to represent the same elements in the drawings. In addition, it will be understood by those of ordinary skill in the art that the elements in the drawings are illustrated for simplicity and may not necessarily be drawn to scale. For example, the sizes of some elements in the drawings may be exaggerated relative to other elements to help improve the understanding of aspects of the present invention. In addition, one or more elements may have been represented by conventional symbols in the drawings, and the drawings may only show specific details relevant to understanding embodiments of the present invention to avoid obscuring the details in the drawings, which are clear to those of ordinary skill in the art who also benefit from the description herein. DETAILED DESCRIPTION

[0037] Therefore, embodiments of the present invention provide a method for performing self-optimization in a wireless network. The method includes performing a handover procedure by a user equipment (UE) based on a mobility command received from a network. The mobility command includes a voice fallback indication. The method includes detecting a radio link failure (RLF) by the UE during the handover procedure. The method includes recording the detected RLF information in an RLF report by the UE. In addition, the method includes reporting the recorded RLF report to the network for one of self-organizing network (SON) or minimization of drive test (MDT) optimization.

[0038] Therefore, embodiments of the present invention provide a UE including a processor. The processor is configured to perform a handover procedure based on a mobility command received from a network. The mobility command includes a voice fallback indication. The processor is configured to detect RLF during the handover procedure. The processor is configured to record the detected RLF information in an RLF report. The processor is configured to report the recorded RLF report to the network for one of SON or MDT optimization.

[0039] Therefore, embodiments of the present invention provide a method for performing self-optimization in a wireless network. The method includes receiving a radio resource control (RRC) reconfiguration message with a handover command (or sometimes referred to as a handover request) from a network by a UE. The method includes receiving a configuration from the network by the UE to record a successful handover report (SHR) based on one or more conditions if the UE performs a successful handover from a cell or to a cell and satisfies one or more conditions. The configuration for recording the SHR can be received in an RRC reconfiguration message or any other RRC reconfiguration message containing a handover command. The method includes performing a handover from a cell or to a cell based on the received handover command by the UE. The method includes recording the SHR when a successful handover from a cell or to a cell and satisfying one or more conditions. In addition, the method includes reporting the recorded SHR by the UE.

[0040] Therefore, an embodiment of the present invention provides a UE including a processor. The processor is configured to receive an RRC reconfiguration message with a handover command from a network. If the UE performs a successful handover from a cell or to a cell and satisfies one or more conditions, the processor is configured to receive a configuration from the network to record an SHR based on one or more conditions. The processor is configured to perform a handover from a cell or to a cell based on the received handover command. The processor is configured to record the SHR when performing a successful handover from a cell or to a cell and satisfying one or more conditions. The processor is configured to report the recorded SHR.

[0041] Therefore, embodiments of the present invention provide a method for performing self-optimization in a wireless network. The method includes sending at least one UE capability information to a network by a UE to notify the UE that it can support logging minimization of drive tests (MDT) coverage protection based on inter-RAT signaling. The method includes receiving, by the UE based on the UE capability information, a logged MDT configuration and measurement type based on inter-RAT signaling from the network. The method includes storing, by the UE, the received logged MDT configuration and measurement type based on inter-RAT signaling in a report. The method includes notifying, by the UE during a handover process, the availability of the logged MDT configuration and measurement type based on inter-RAT signaling to the network.

[0042] Therefore, an embodiment of the present invention provides a UE including a processor. The processor is configured to send at least one UE capability information to a network to notify the UE that it can support the MDT coverage protection based on the record of inter-RAT signaling. The processor is configured to receive the MDT configuration and measurement type based on the record of inter-RAT signaling from the network based on the UE capability information. The processor is configured to store the received MDT configuration and measurement type based on the record of inter-RAT signaling in a report. The processor is configured to notify the network of the availability of the MDT configuration and measurement type based on the record of inter-RAT signaling during the handover process.

[0043] Therefore, an embodiment of the present invention provides a method for performing self-optimization in a wireless network. The method includes receiving a network slice AS group (NSAG) identifier and an NSAG priority of at least one NSAG from a core network by a UE, and receiving an NSAG identifier and a cell reselection priority from a radio access network (RAN). The NSAG is associated with one or more slices or a single network slice selection assistance information (S-NSSAI). The method includes performing a random access (RA) procedure by the UE. The method includes recording the NSAG identifier and NSAG priority of at least one NSAG from the core network, and the NSAG identifier and cell reselection priority from the RAN in a random access channel (RACH) report if RACH is triggered based on at least one slice of S-NSSAI when the UE performs the RA procedure. The method includes reporting a recorded RACH report by the UE. The method includes sending a RACH report by the UE to a base station of the network.

[0044] Therefore, an embodiment of the present invention provides a UE including a processor. The processor is configured to receive an NSAG identifier and an NSAG priority of at least one NSAG from a core network, and to receive an NSAG identifier and a cell reselection priority from a RAN. The NSAG is associated with one or more slices or S-NSSAI. The processor is configured to perform an RA process. The processor is configured to record the NSAG identifier and the NSAG priority of the NSAG from the core network, and the NSAG identifier and the cell reselection priority from the RAN in a RACH report if RACH has been triggered based on at least one slice of the S-NSSAI when the UE performs the RA process. The processor is configured to report the recorded RACH report. The processor is configured to send the RACH report to a base station of the network.

[0045] Therefore, embodiments of the present invention provide a method for performing self-optimization in a wireless network. The method includes performing at least one RA process by a UE in a bandwidth part (BWP) of a SpCell (special cell) of the network. The method includes switching to a standby BWP of the SpCell by the UE due to continuous uplink (UL) Listen Before Talk (LBT) failure detection during the RA process. The method includes recording, by the UE in at least one RA report, one or more parameters related to the RA process in which continuous UL LBT failures are detected. The method includes reporting a recorded RA report by the UE. The method includes sending a RA report by the UE to a base station of the network.

[0046] Therefore, an embodiment of the present invention provides a UE including a processor. The processor is configured to perform at least one RA process in a BWP of a SpCell of a network. The processor is configured to switch to a standby BWP of the SpCell due to continuous UL LBT failure detection during the RA process. The processor is configured to record one or more parameters related to the RA process in which continuous UL LBT failure is detected in at least one RA report. The processor is configured to report the recorded RA report. The processor is configured to send the RA report to a base station of the network.

[0047] These and other aspects of the example embodiments herein will be better appreciated and understood when considered in conjunction with the following description and accompanying drawings. However, it should be understood that the following description, while indicating the example embodiments and many of their specific details, is given by way of illustration and not limitation. Many changes and modifications may be made within the scope of the example embodiments herein without departing from the spirit thereof, and the example embodiments herein include all such modifications.

[0048] 5G NR (New Radio) Radio Access Network (RAN), also known as NG-RAN (Next Generation Radio Network) consists of multiple NR base stations called gNBs. NG-RAN can operate in both licensed and unlicensed spectrum. When operating in unlicensed spectrum (NR-U), NG-RAN implements the Listen Before Talk (LBT) function. A detailed description of such operations is present in 3gpp Layer1 / Layer2 / Layer3 specifications such as TS 38.331 / TS38.321 / TS38.300, etc. gNBs can be connected to each other through the Xn interface and can be connected to various core network elements such as AMF (Access and Mobility Management Function), UPF (User Plane Function), etc. In addition, gNB can also be divided into two physical entities named CU (Central Unit) and DU (Distributed Unit). CU provides support for the higher layers of the protocol stack such as SDAP (Session Data Application Protocol), PDCP (Packet Data Convergence Protocol), and RRC (Radio Resource Control). DU provides support for the lower layers of the protocol stack such as RLC (Radio Link Control), MAC (Media Access Control), and physical layer. Each gNB can have multiple cells serving multiple UEs (user equipment).

[0049] There are a large number of algorithms and configuration parameters used in NG-RAN. In particular, determining the optimal radio parameters is a very difficult task and operators usually resort to manual techniques such as drive tests to determine the best parameters. However, this manual parameter tuning is an expensive operation as it depends on many factors such as the number of users, number of neighbors, maximum cell throughput, average cell throughput, etc. Moreover, many of these manual operations need to be repeated every time a neighboring gNB is installed or a new service is introduced.

[0050] To solve this problem, 3GPP introduced self-organizing network (SON) technology in wireless technologies such as New Radio (NR). SON solutions can be divided into three categories such as self-configuration, self-optimization, and self-healing. SON architecture can be a centralized, distributed, or hybrid solution. Mobility Robust Optimization (MRO) is a SON technology used to optimize various parameters related to mobility.

[0051] According to 3GPP specifications, such as TS 38.300 V17.0.0, MRO is designed to detect and enable correction of the following issues:

[0052] -Connectivity failures due to intra-system or inter-system mobility;

[0053] - Inter-system or intra-system unnecessary handover (HO) (premature inter-system HO from NR to Evolved UMTS Terrestrial Radio Access Network (E-UTRAN) without radio link failure);

[0054] - HO ping-pong between systems or within a system.

[0055] MRO provides a means to distinguish the above problems from NR coverage related problems and other problems not related to mobility. To analyze the connection failure, the user equipment (UE) makes the radio link failure (RLF) report available to the network. The UE stores the latest RLF report, including both Long Term Evolution (LTE) and NR RLF reports, until the RLF report is acquired by the network or 48 hours after the connection failure is detected.

[0056] One of the features of mobility robustness optimization in NR R17 is to detect connection failures that occur due to early or late inter-system handovers. These problems are defined as follows:

[0057] a. Inter-system / late handover: RLF occurs after the UE stays in a cell belonging to a NG-RAN node for a long time; the UE attempts to reconnect to a cell belonging to an E-UTRAN node.

[0058] b. Inter-system / premature handover: RLF occurs shortly after a successful handover from a cell belonging to an E-UTRAN node to a target cell belonging to an NG-RAN node; the UE attempts to reconnect to the source cell or another cell belonging to an E-UTRAN node.

[0059] One of the objectives of inter-system mobility robustness optimization in NR R17 is to detect non-optimal use of network resources. In particular, in inter-system operation and when considering NR, determine the situation known as unnecessary HO to another system. The problem is defined as follows:

[0060] a. Even if the quality of NR coverage is sufficient for the service used by the UE, the UE is still handed over from NR to E-UTRAN. Therefore, the handover can be considered as an unnecessary HO (premature inter-system HO without connection failure) to another system (i.e. EPS).

[0061] In inter-system HO, if the serving cell threshold (NR cell) is set too high and a cell with good signal strength is available in the other system (i.e. EPS), a handover to the other system may be triggered unnecessarily, resulting in inefficient use of the network. With a lower threshold, the UE can continue in the source system (5GS).

[0062] One of the functions of mobility robustness optimization is to detect ping-pong occurring in an inter-system environment. The problem is defined as follows:

[0063] a. The UE is handed over from a cell in a source system (e.g., 5GS) to a cell in a target system (e.g., EPS) that is different from the source system, and then within a predefined limited time, the UE is handed over back to a cell in the source system while the coverage of the source system is sufficient for the service used by the UE. The event can occur more than once

[0064] Inter-radio access in NR RRC_CONNECTED state for voice fallback Technology (IRAT) Mobility:

[0065] If the inter-RAT handover from NR to LTE is due to voice fallback (UE falls back to LTE for voice services, perhaps because voice over NR is not supported), the network indicates the flag Voice Fallback Indication which shall be set to true as follows.

[0066] The 3GPP defined indication for voiceFallbackIndication for handover is as follows:

[0067] Voice fallback indication:

[0068] Indicates that the handover is triggered by EPS fallback for IMS voice as specified in TS 23.502.

[0069] When voice fallback is required but inter-RAT handover is not possible, the network can redirect the UE to the Evolved Packet System (EPS) (LTE). The RRC message and RRC release for redirection include setting the voice fallback indication to true. When handover is not possible, for example, because the interface with the LTE node (eNB) is unavailable, the network (gNodeB) can send an RRC release (Release). If the UE faces a radio link failure (RLF) in LTE after the voice fallback handover, the UE can attempt to select a cell in LTE. If the cell selection is successful, the UE attempts to establish a connection in LTE and perform a voice call. If the cell selection is unsuccessful, the UE moves back to the NR cell from where it was handed over to LTE.

[0070] Minimization of Drive Test (MDT) coverage protection recorded by Inter-Radio Access Technology (IRAT):

[0071] Two types of MDT are supported in NR and LTE management-based MDT and signaling-based MDT. It may happen that signaling-based MDT is overwritten by management-based MDT which may have a lower priority. Signaling-based MDT is used for a single UE, while management-based MDT may be used for a group of UEs. IRAT logged MDT coverage protection refers to support for signaling-based logged MDT coverage protection to address the scenario of configuring signaling-based MDT in E-UTRAN in the following cases:

[0072] The UE reselects to NR while collecting logged measurements

[0073] The UE reselects to the NR after collecting the logged measurements and before uploading the logged MDT report.

[0074] The relevant details are available in 3GPP work item description documents such as RP-221825. These solutions build on the existing NR intra-coverage protection schemes detailed in 3GPP specifications such as TS38.331 V17.1.0, TS37.320 V17.1.0, etc.

[0075] Random access enhancements in NR Release 17:

[0076] NR Release 17 further enhances the Random Access Channel (RACH) for various features such as slicing, small data transmission, reduced capability UEs, coverage enhancement (msg3 repetition), etc. Multiple preambles and multiple physical RACH (PRACH) opportunities (RO) from the available RACH preambles can be partitioned for various features. The gNB can also assign different available RACH opportunities to different functions indicated in the system information. For slicing, different slices or slice groups (NSAGs) can be assigned to different RACH resources. The UE receives the NSAG identifier and NSAG priority from the AMF (NAS) in a NAS message such as Registration Update.

[0077] An extract from 3GPP TS 38.331 v17 defining the feature groups and their characteristics is given below.

[0078] Feature combination:

[0079] The feature combination information element (IE) indicates the feature or feature combination to be associated with a set of random access resources (eg, an instance of a feature combination preamble). Table 1 below describes the feature combination indication field description.

[0080]

[0081] Table 1

[0082] Feature combination preamble:

[0083] IE Feature Combination Preamble associates a set of preambles with a feature combination. For the parameters that can be provided in this IE, the UE applies the field value when performing random access using the preamble in the feature combination preamble, otherwise the UE applies the corresponding value determined by the applicable requirement code, such as Need S. On a specific bandwidth part (BWP), each random access (RA) type (e.g., 4-step RACH or 2-step RACH) can have at most one set of preambles associated with a given feature combination.

[0084] The UE sends a RACH report to the network in an RRC message, e.g., UE Information Response. Upon receiving the RACH report, the gNB Central Unit (CU) may send it to the gNB Distributed Unit (DU) or Operation, Administration, and Maintenance (OAM) SON module, or may use it directly to optimize various parameters related to random access. For example, the number of preambles, configuration of Group A and Group B preambles, RACH priority information, contention resolution timer, number of RACH preambles for 2-step RACH, physical uplink shared channel (PUSCH) related parameters for 2-step RACH, etc.

[0085] Successful switch report:

[0086] 3GPP introduced successful handover reporting in NR Release 17. The gNB can configure the UE to report a successful handover report (SHR) based on certain thresholds. The thresholds for the T310 / T312 timers are determined by the source gNB, while the thresholds for the T304 timer are determined by the target gNB. A detailed description is available in Release 17.1.0 of the 3gpp NR specifications such as TS38.331 / TS 37.320 / TS38.300.

[0087] The UE may log various events and information and report them to the network to support optimization of Minimization of Drive Tests (MDT). Some of the information that may be logged are RA reports, RLF reports, and SHR. The message content compliant with Release 17 (V17.2.0) NR specification is given below.

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095] NR operation in unlicensed spectrum:

[0096] According to TS 38.300, RA operating with shared spectrum channel access can support the following deployment scenarios:

[0097] - Scenario A: Carrier aggregation between NR in licensed spectrum (SpCell) and NR in shared spectrum (SCell);

[0098] - Scenario A.1: SCell is not configured with uplink (downlink (DL) only);

[0099] - Scenario A.2: SCell is configured with uplink (DL+uplink (UL)).

[0100] - Scenario B: Dual connectivity between LTE in licensed spectrum and NR in shared spectrum (PSCell);

[0101] - Scenario C: NR in shared spectrum (PCell);

[0102] - Scenario D: NR cell in shared spectrum and uplink in licensed spectrum;

[0103] - Scenario E: Dual connectivity between NR in licensed spectrum (PCell) and NR in shared spectrum (PSCell).

[0104] Carrier aggregation of cells in shared spectrum is applicable to all deployment scenarios.

[0105] Before performing transmission on a cell configured with shared spectrum channel access, the gNB and UE apply Listen Before Talk (LBT). When LBT is applied, the transmitter listens / senses the channel to determine whether the channel is idle or busy, and performs transmission only when the channel is sensed to be idle. When consecutive uplink LBT failures are detected on the SpCell, the UE switches to another UL BWP with RACH resources configured on that cell, starts RACH, and reports the failure through the Media Access Control (MAC) Control Element (CE). For PSCell, if consecutive uplink LBT failures are detected on all UL BWPs with configured RACH resources, the UE declares a Secondary Cell Group (SCG) RLF and reports the failure to the Master Node (MN) through SCG Failure Information. For the Primary Cell (PCell), if uplink LBT failures are detected on all UL BWPs with configured RACH resources, the UE declares RLF. If the UE succeeds in the random access procedure in any BWP, the UE does not declare RLF.

[0106] For RACH, for on-demand system information (SI), the UE may not log random access (RA) reports on failed random access procedures. In existing methods, there is no method by which the network can know the random access in the BWP where the RA failed, and this lists further optimizations for NR-U (NR in unlicensed spectrum) RACH.

[0107] Existing methods include various problems when performing SON / MDT optimization. These problems include:

[0108] a) Inter-RAT rewrite protection of signalling based MDT configured in E-UTRA by management based MDT configured in NR.

[0109] b) Optimize voice fallback from NR to LTE through handover.

[0110] c) Processing of RACH reports in NR including RACH reports with NSAG support.

[0111] d) Handling SHR in NR for NR-U (NR operation in unlicensed spectrum)

[0112] e) Optimize NR-U operation

[0113] Therefore, there is a need in the art for a solution that overcomes the above-mentioned shortcomings.

[0114] The embodiments of this article and its various features and advantageous details are explained more fully with reference to the non-limiting embodiments shown in the drawings and described in detail in the following description. The description of well-known components and processing techniques is omitted so as not to unnecessarily obscure the embodiments of this article. The examples used herein are only intended to promote the understanding of the way in which the embodiments of this article can be practiced, and further enable those skilled in the art to practice the embodiments of this article. Therefore, the examples should not be interpreted as limiting the scope of the embodiments herein.

[0115] For the purpose of interpreting this specification, the definitions (as defined herein) will apply, and wherever appropriate, terms used in the singular will also include the plural, and vice versa. It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. Unless otherwise indicated, the terms "including," "having," and "comprising" should be interpreted as open-ended terms.

[0116] The words / phrases "exemplary," "example," "show," "in an instance," "etc," "etc," "and others," "for example," and "i.e." are used herein merely to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the subject matter described herein using the words / phrases "exemplary," "example," "show," "in an instance," "etc," "etc," "and others," "for example," and "i.e." are not necessarily to be construed as preferred or advantageous over other embodiments.

[0117] The embodiments herein can be described and illustrated according to the blocks that perform one or more functions described. These blocks (which may be referred to herein as managers, units, modules, hardware components, etc.) 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, hard-wired circuits, etc.), and can be optionally driven by firmware. The circuit can be, for example, embodied in one or more semiconductor chips, or embodied on substrate supports such as printed circuit boards. The circuits constituting the blocks can be implemented by dedicated hardware, or by a processor (for example, one or more programmed microprocessors and associated circuits), or by a combination of dedicated hardware that performs some functions of the block and a processor that performs other functions of the block. Without departing from the scope of the present disclosure, each block of the embodiment can be physically divided into two or more interactive and discrete blocks. Similarly, without departing from the scope of the present disclosure, the blocks of the embodiment can be physically combined into more complex blocks.

[0118] It should be noted that the elements in the drawings are shown for the purposes of this specification and for ease of understanding, and may not necessarily be drawn to scale. For example, a flow chart / sequence diagram illustrates the method in terms of the steps required to understand the various aspects of the embodiments as disclosed herein. In addition, with respect to the construction of the device, one or more components of the device may have been represented by conventional symbols in the drawings, and the drawings may only show those specific details relevant to understanding the present embodiment so as not to obscure the drawings, which details will be apparent to those of ordinary skill in the art having the benefit of the description herein. In addition, with respect to the system, one or more components / modules comprising the system may have been represented by conventional symbols in the drawings, and the drawings may only show those specific details relevant to understanding the present embodiment so as not to obscure the drawings, which details will be apparent to those of ordinary skill in the art having the benefit of the description herein.

[0119] The accompanying drawings are used to help easily understand the various technical features, and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. Therefore, the present disclosure should be interpreted as extending to any modifications, equivalents and replacements other than those specifically specified in the accompanying drawings and corresponding descriptions. The use of words such as first, second, third, etc. to describe components / elements / steps is for the purpose of this specification and should not be interpreted as sequential ordering / placement / occurrence unless otherwise specified.

[0120] Embodiments herein provide methods and systems for self-organizing network (SON) / minimization of drive tests (MDT) optimization in wireless networks. Referring now to the drawings, and more particularly to Figures 1 to 13 , wherein like reference characters denote corresponding features throughout the various figures, embodiments are shown.

[0121] Figure 1 A system 100 for performing self-optimization in a wireless network is shown. The system 100 includes a user equipment (UE) 102 for performing SON / MDT optimization, a network 104, and a core network 106. The UE 102 also includes a processor 108, a communication module 110, and a memory module 112.

[0122] In an embodiment of the present invention, the processor 108 is configured to detect a radio link failure (RLF) due to voice fallback during a handover process, and record the detected RLF for one of SON or MDT optimization. In an embodiment of the present invention, the processor 108 is configured to record a successful handover report (SHR) based on one or more conditions if the UE 102 performs a successful handover. In an embodiment of the present invention, the processor 108 is configured to notify the network 104 of the UE capability of supporting recorded MDT coverage protection based on inter-radio access technology (RAT) signaling during the handover process. In an embodiment of the present invention, the processor 108 is configured to report to the base station of the network 104 if the random access channel (RACH) is triggered by a single network slice selection auxiliary information (S-NSSAI) when the UE 102 performs a random access (RA) process. In an embodiment of the present invention, for NR-U (New Radio in Unlicensed Spectrum), the processor 108 is configured to log one or more parameters related to at least one RA procedure to a base station of the network 104 when the UE 102 switches to a spare bandwidth part (BWP) of a SpCell (special cell) of the network 104 due to continuous uplink (UL) listen-before-talk (LBT) failure detection. The processor 108 is configured to report the logged parameters.

[0123] The processor 108 further includes a switching module 202, a recording module 204, a configuration module 206, a radio resource control (RRC) module 208, and a RA module 210. Figure 2 As described in.

[0124] In an embodiment of the present invention, the handover module 202 may receive a mobility command from the network 104 and perform a handover procedure based on the mobility command. The mobility command may include a voice fallback indication. In an embodiment of the present invention, the handover module 202 may receive a handover command and perform a handover from or to a cell. In an embodiment of the present invention, the handover module 202 may detect one or more RLFs during the handover procedure.

[0125] In an embodiment of the present invention, the recording module 204 may record the detected RLF information from the handover module 202 in the RLF report. The recording module 204 may send or report the RLF report to the network 104 for one of SON or MDT optimization. In an embodiment of the present invention, the recording module 204 may record the cell global identifier (CGI) of the source cell of the mobility command as the reestablished cell in the RLF report. When the UE 102 attempts to select an evolved terrestrial radio access (E-UTRA) cell after the RLF occurs and the E-UTRA cell cannot be selected, the recording module 204 records the CGI of the source cell. If the UE 102 successfully selects the E-UTRA cell and successfully reconnects to the E-UTRA cell, the recording module 204 may set eutraReconnectCellId-r16 (according to the 3gpp NR RRC specification, TS 38.331) in the RLF report to the CGI of the E-UTRA cell to which the UE 102 is connected. In an embodiment of the present invention, the recording module 204 may record the SHR when performing a successful handover from or to a cell and if one or more conditions are met. The recording module 204 may report the recorded SHR. In an embodiment of the present invention, if the source cell of the network 104 in the NR-U provides a configuration (satisfying the conditions), the recording module 204 may record in the SHR report whether there is an indication of continuous UL LBT failure in the source cell, the number of LBT failures in the source cell, the value of the LBT_COUNTER of the source cell, and at least one of one or more received signal strength indicator (RSSI) measurements and one or more channel occupancy measurements of the source cell and the neighboring cells. As is usually done, the recorded indication of whether there is a continuous UL LBT failure in the source cell, the number of LBT failures in the source cell, the value of the LBT_COUNTER of the source cell, and one or more received signal strength indicator (RSSI) measurements and one or more channel occupancy measurements in the source cell and the neighboring cells represent those values ​​at the time of recording (i.e., at the time of successful handover that meets the threshold). In the embodiment of the present invention, if the target cell of the network 104 provides a configuration (satisfactory condition), the recording module 204 may record in the SHR report an indication of whether there are consecutive UL LBT failures in the target cell, the number of LBT failures in the target cell, the value of the LBT_COUNTER of the target cell, and at least one of one or more RSSI measurements and one or more channel occupancy measurements of the target cell and the neighboring cells. In the embodiment of the present invention, the recording module 204 may store the recorded MDT configuration and measurement type based on inter-RAT signaling in the report received from the network 104.In an embodiment of the present invention, the recording module 204 may record the network slice AS group (NSAG) identifier and NSAG priority of the NSAG received from the core network 106 (e.g., access and mobility management function (AMF)) and the NSAG identifier and cell reselection priority received from the radio access network (RAN) in the RACH report. The recording module 204 may report the recorded RACH report. If at least one slice based on the S-NSSAI triggers the RACH when the UE 102 performs the RA process, the recording module 204 may record the NSAG identifier, the NSAG priority, and the cell reselection priority. In the RACH report, the NSAG identifiers of one or more NSAGs are listed in the order of NSAG priorities provided by one or more non-access layers (NAS). The recording module 204 may report the recorded RACH report. The recording module 204 may send the RACH report to the base station of the network 104. In an embodiment of the present invention, the recording module 204 may record one or more parameters related to at least one RA process in at least one RA report in which consecutive UL LBT failures are detected. The recording module 204 may report the recorded RA report. When the RA process is successful in the standby BWP, the logging module 204 can log parameters related to the RA process. The logging module 204 can send an RA report to a base station of the network 104.

[0126] In an embodiment of the present invention, the configuration module 206 may apply the source cell configuration using the recorded CGI of the source cell obtained from the recording module 204. In an embodiment of the present invention, the configuration module 206 may receive a configuration from the network 104 to record the SHR based on one or more conditions such as a threshold percentage of a T310 or T312 or T304 timer. If the UE 102 performs a successful handover from or to the cell and the conditions are met, the UE records the SHR. The configuration provided by the source cell may include, but is not limited to, thresholdpercentageT310 and thresholdpercentageT312 in the source cell. The configuration provided by the target cell includes thresholdpercentageT304 in the target cell. In an embodiment of the present invention, the configuration module 206 may send at least one UE capability information to the network 104 to notify the UE 102 that it can support the recorded MDT coverage protection based on the inter-RAT signaling. The configuration module 206 may receive the recorded MDT configuration and measurement type based on the inter-RAT signaling from the network 104 based on the UE capability information. The configuration module 206 may set the availability of the logged MDT configuration and measurement type based on inter-RAT signaling to true when the configured timer runs.

[0127] In an embodiment of the present invention, the RRC module 208 may send an RRC reestablishment to a base station of the network 104 using the source cell configuration from the configuration module 206. In an embodiment of the present invention, the RRC module 208 may receive an RRC reconfiguration message with a handover command from the network 104. The RRC module 208 may receive an RRC reconfiguration message from the network. The RRC module 202 may verify whether the UE 102 has logged measurements of the network and whether the registered public land mobile network (RPLMN) is stored in the report of the logging module 204. If the UE 102 has logged measurements and stored the RPLMN, the RRC module 208 may notify the network of the availability of the logged MDT configuration and measurement type based on inter-radio access technology (RAT) signaling during the handover process. The RRC module 208 may notify the network 104 of the availability of the logged MDT configuration and measurement type based on inter-RAT signaling through an RRC reconfiguration complete message. The RRC module 208 may inform the network of the availability of the recorded MDT configuration and measurement type based on the inter-RAT signaling through an RRC SetupComplete message, an RRC ResumeComplete message, or an RRC ReestablishmentComplete message.

[0128] In an embodiment of the present invention, the RA module 210 may receive an NSAG identifier and an NSAG priority of at least one NSAG from the core network 106. The RA module 210 may receive an NSAG identifier and a cell reselection priority from the RAN. The NSAG is associated with one or more slices or S-NSSAI. The RA module 210 may receive an NSAG identifier and an NSAG priority of the NSAG through one or more NAS messages from the core network 106 (e.g., from a core network function such as AMF). The RA module 210 may perform a RA procedure. If at least one slice of the S-NSSAI triggers a RACH when the UE 102 performs a RA procedure, the NSAG-identifier and NSAG-priority of the NSAG from the core network 106, as well as the NSAG identifier and the cell reselection priority from the RAN may be recorded and reported in a RACH report. In an embodiment of the present invention, the RA module 210 may perform at least one RA procedure in the BWP of the SpCell of the network 104. The RA module 210 may detect one or more consecutive UL LBT failures during the RA procedure in the NR-U. The RA module 210 may switch to the standby BWP of the SpCell due to continuous UL LBT failure detection during the RA process. If continuous UL LBT failure is detected, parameters related to the RA process may be recorded and reported. When the RA process is successful in the standby BWP, parameters related to the RA process may be recorded and reported. Parameters related to the RA process may be, but are not limited to, the location and bandwidth information of the BWP, the subcarrier spacing information of the BWP, and the absolute frequency point information of the BWP.

[0129] In an embodiment of the present invention, the processor 108 can process and execute data of multiple modules of the UE 102 respectively. The processor 108 can be configured to execute instructions stored in the memory module 112. The processor 108 may include one or more of a microprocessor, a circuit, and other hardware configured for processing. The processor 108 may be at least one of a single processor, multiple processors, multiple homogeneous or heterogeneous cores, multiple different types of central processing units (CPUs), microcontrollers, special media, and other accelerators. The processor 108 may be an application processor (AP), a pure graphics processing unit (e.g., a graphics processing unit, GPU), a visual processing unit (VPU)), and / or an artificial intelligence (AI) dedicated processor (e.g., a neural processing unit (NPU)).

[0130] In the embodiments of the present invention, multiple modules of the processor 108 of the UE 102 can communicate with the network 104 and the core network 106 through the communication module 110. The communication module 110 can be in the form of a wired network or a wireless communication network module. The wireless communication network may include, but is not limited to, a global positioning system (GPS), a global system for mobile communications (GSM), Wi-Fi, Bluetooth low energy, near field communication (NFC), etc. Depending on the use environment, wireless communication may also include Bluetooth, ZigBee, short-range wireless communication (such as ultra-wideband (UWB)) and medium-range wireless communication, such as Wi-Fi) or long-range wireless communication (such as 3G / 4G / 5G / 6G and non-3GPP technology or WiMAX) One or more.

[0131] In the embodiments of the present invention, the memory module 112 may include one or more volatile and non-volatile memory components capable of storing data and instructions of the modules of the UE 102 to be executed. Examples of the memory module 112 may be, but are not limited to, NAND, embedded multimedia card (eMMC), secure digital (SD) card, universal serial bus (USB), serial advanced technology attachment (SATA), solid state drive (SSD), etc. The memory module 112 may also include one or more computer-readable storage media. Examples of non-volatile storage elements may include magnetic hard disks, optical disks, floppy disks, flash memory, or electrically programmable memory (EPROM) or electrically erasable and programmable (EEPROM) memory. In addition, in some examples, the memory module 112 may be considered a non-transitory storage medium. The term "non-transitory" may indicate that the storage medium is not embodied in a carrier or propagation signal. However, the term "non-transitory" should not be interpreted as meaning that the memory module 112 is non-removable. In some examples, a non-transitory storage medium may store data that may change over time (e.g., in a random access memory (RAM) or cache).

[0132] Figure 1 The example modules of UE 102 are shown separately, but it should be understood that other embodiments are not limited thereto. In other embodiments, UE 102 may include fewer or more modules. In addition, the labels or names of the modules are only for illustrative purposes and do not limit the scope of the present invention. One or more modules can be combined together to perform the same or substantially similar functions in UE 102.

[0133] Figure 3A method 300 for performing self-optimization in a wireless network is shown for handling voice fallback during mobility of a UE 102 from a network 104. The method 300 includes receiving, by a processor 108 of the UE 102, a mobility command from the network 104, as shown in step 302. The mobility command includes a voice fallback indication. The method 300 includes performing, by the processor 108, a handover procedure based on the mobility command, as shown in step 304. The method 300 includes detecting, by the processor 108, a RLF during the handover procedure, as shown in step 306. The method 300 includes recording, by the processor 108, the detected RLF information in an RLF report, as shown in step 308. Thereafter, the method 300 includes reporting, by the processor 108, the RLF report to the network 104 for one of SON or MDT optimization, as shown in step 310.

[0134] The various actions in method 300 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Figure 3 Some of the actions listed in .

[0135] Figure 4 A flow chart 400 is shown for handling RLF during voice fallback. As shown in step 402, the UE 102 receives a mobility command from NR (e.g., NR mobilityFromNRCommand) including a field with a voice fallback indication (e.g., NRVoiceFallback indication IE) set to true. As shown in step 404, the UE 102 detects RLF during mobility from NR. The UE 102 records and stores the last handover type (NR RRC IE lastHO-type-r17) in the RLF report as voice fallback (e.g., an indication that the handover type is an inter-radio access technology (RAT) handover for voice fallback), as shown in step 406.

[0136] As described in step 408, UE 102 verifies whether an E-UTRA cell has been selected after the RLF occurs. The RLF detected during the mobilityFromNR procedure may be an RLF in LTE. If UE 102 attempts to select an E-UTRA cell after the RLF occurs and cannot select an E-UTRA cell, UE 102 records the CGI of the source cell of the mobility command as the reestablished cell in the RLF report, as shown in step 410. UE 102 applies the source cell configuration using the recorded CGI of the source cell. UE 102 sends an RRC reestablishment to the base station of network 104 using the source cell configuration. UE 102 sets NR RRCIEreestablishmentCellId-r16 in the RLF report to the CGI of the cell that sent the RRC reestablishment (RRCRestablishmentRequest).

[0137] As shown in step 412, if the UE 102 is able to select an E-UTRA cell after the RLF has occurred, the UE 102 verifies the connection establishment. If the UE 102 has successfully selected an E-UTRA cell and has successfully reconnected to the E-UTRA cell, the UE 102 sets the NR RRC IE eutraReconnectCellId-r16 in the RLF report to the CGI of the E-UTRA cell to which the UE 102 has been connected, as shown in step 414. If the UE 102 is able to select an E-UTRA cell after the RLF has occurred, and the connection establishment is unsuccessful, the UE 102 includes the identity of the E-UTRA cell to which it has been connected in the RLF report, for example in the reestablishmentcellId or in a new field, as described in step 416. A network node such as an NR gNB retrieves the RLF report and identifies various information, such as the cell where the UE 102 performed re-establishment after the voice fallback handover, and also identifies that there is no suitable E-UTRA cell at the point where the inter-RAT handover occurred, or if there is a cell where the RRC connection is successful after the RLF, identifies the identity of the E-UTRA cell, and optimizes inter-RAT mobility.

[0138] Figure 5A method 500 for performing self-optimization of successful handover reporting (SHR) in a wireless network is shown. The method 500 includes receiving, by a processor 108 of a UE 102, an RRC reconfiguration message with a handover command from a network 104, as shown in step 502. The method 500 includes if the UE 102 performs a successful handover from or to a cell and one or more conditions are met, the processor 108 receiving a configuration from the network 104 to record the SHR based on one or more conditions, as described in step 504. The configuration of the conditions may occur in an RRC message before receiving the handover command, or may occur in an RRC message carrying the handover command. The method 500 includes performing, by the processor 108, a handover from or to a cell based on the received handover command, as described in step 506. The method 500 includes recording, by the processor 108, the SHR when a successful handover from or to a cell is performed and one or more conditions are met, as described in step 508. The method 500 includes reporting, by the processor 108, the recorded SHR, as described in step 510.

[0139] The various actions in method 500 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Figure 5 Some of the actions listed in .

[0140] Figure 6 shows the method for executing Figure 5The method 600 for recording SHR upon successful handover shown in FIG. 600 includes verifying, by the processor 108 of the UE 102, whether the configuration of the satisfied condition is provided by the source cell of the network 104, as shown in step 602. If the configuration is provided by the source cell, the UE 102 records in the SHR report an indication of whether there are consecutive UL LBT failures in the source cell, the number of LBT failures in the source cell, the value of the LBT_COUNTER of the source cell, and at least one of one or more RSSI measurements and one or more channel occupancy measurements of the source cell and the neighboring cells, as described in step 604. An indication of whether there are consecutive UL LBT failures in the source cell, the number of LBT failures in the source cell, the value of the LBT_COUNTER of the source cell, and one or more RSSI measurements and one or more channel occupancy measurements of the source cell and the neighboring cells are identified when recording these values. The configuration provided by the source cell may be, but is not limited to, thresholdpercentageT310, thresholdpercentageT312, etc. If the configuration is provided by the target cell, UE 102 records in the SHR report an indication of whether there are consecutive UL LBT failures in the target cell, the number of LBT failures in the target cell, the value of LBT_COUNTER of the target cell, and at least one of one or more RSSI measurements and one or more channel occupancy measurements of the target cell and the neighboring cells, as shown in step 606. The configuration provided by the target cell may be, but is not limited to, thresholdpercentageT304, thresholdpercentageT310, thresholdpercentageT312, thresholdpercentageT304, etc., which are defined in 3gpp specifications such as TS 38.331.

[0141] The various actions in method 600 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Figure 6 Some of the actions listed in .

[0142] In embodiments herein, if the UE 102 performs a successful handover from or to a NR-U cell, and if it is configured to record the SHR based on certain conditions, and if these conditions are met, the UE 102 also records in the SHR the time when the handover occurred.

[0143] In an embodiment of the present invention, UE 102 records the time of handover completion (e.g., random access completed in the target cell) in a successful handover report. In an embodiment of the present invention, UE 102 records the time of starting handover (e.g., receiving an RRC reconfiguration message for handover) in an SHR.

[0144] In the embodiments herein, if the target cell provides a (satisfactory) configuration, the UE 102 records the time of completing the handover in the SHR, and if the source cell provides a (satisfactory) configuration, the UE 102 records the time of starting the handover.

[0145] In an embodiment of the present invention, UE 102 includes whether there are consecutive UL LBT failures in both the source cell and the target cell, the number of LBT failures in both the source cell and the target cell, and the value of LBT_COUNTER (a variable defined in TS 38.321) in both the source cell and the target cell, and RSSI measurements and channel occupancy measurements of the source cell, target cell, and neighboring cells in the SHR whenever these values ​​are available. In an embodiment of the present invention, UE 102 includes information in the SHR regardless of whether the threshold condition is met.

[0146] Figure 7 A method 700 for supporting inter-RAT signaling-based logged MDT coverage protection in a wireless network is shown. The method 700 includes sending, by the processor 108 of the UE 102, at least one UE capability information to the network 104 to inform the UE 102 that the signaling (inter-RAT)-based logged MDT coverage protection can be supported, as shown in step 702. The method 700 includes receiving, by the processor 108, from the network 104, an inter-RAT signaling-based logged MDT configuration and measurement type based on the UE capability information, as described in step 704. The method 700 includes storing, by the processor 108, the received inter-RAT signaling-based logged MDT configuration and measurement type in a report, as described in step 706. The method 700 includes receiving, by the processor 108, an RRC reconfiguration message from the network, as shown in step 708. The method 700 includes verifying, by the processor 108, whether the UE 102 has logged measurements of the network and whether a registered public land mobile network (RPLMN) is stored in the report, as described in step 710. The method 700 includes, during the handover process, if the UE 102 logs the measurement and stores the RPLMN, then the processor 108 notifies the network of the availability of the MDT configuration and measurement type logged based on the inter-RAT signaling through the RRC reconfiguration complete message, as shown in step 712. When the configured timer is running, the UE 102 sets the availability of the MDT configuration and measurement type logged based on the inter-RAT signaling to true.

[0147] The various actions in method 700 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Figure 7 Some of the actions listed in .

[0148] In an embodiment of the present invention, a UE 102 that supports logged MDT coverage protection based on inter-RAT (Inter-RAT) signaling can use E-UTRA capability signaling to notify the eNB (evolved Node B or eNodeB) about its ability to support logged MDT coverage protection based on inter-RAT (Inter-RAT) signaling. This capability indicates to the eNB that the UE 102 can handle the E-UTRA LoggedMDT configuration including the MDT type. E-UTRA notifies the MDT type (whether it is signaling MDT) based on the capability received from the UE 102. The eNB uses the received capability to provide the relevant configuration to the UE. When connected to a gNB (next generation Node B or gNodeB), the UE 102 can notify the gNB of the same capability through NR-UE capability signaling. In an embodiment of the present invention, if the UE 102 is capable of performing logged MDT coverage protection based on inter-RAT (Inter-RAT) signaling, the UE 102 is also capable of performing logged MDT coverage protection based on NR signaling. The UE 102 receives the measurement type of the logged MDT signaling, such as sigLoggedMeasType, in the E-UTRA logged MDT configuration and stores it in VarLogMeasReport.

[0149] In an embodiment of the present invention, if UE 102 receives RRC reconfiguration during mobility to NR (e.g., NR RRC reconfiguration message from gNB via eNB), and if UE 102 has signaling-based logged measurements available for E-UTRA, and if the RPMN is included in the plmn-IdentityList stored in VarLogMeasReport, UE 102 notifies the gNB through NR RRC reconfiguration completion whether signaling-based logged measurements or signaling-based logged measurement configuration is available, as shown below.

[0150]

[0151] In an embodiment of the present invention, if UE 102 notifies about the logged measurement configuration for E-UTRA while T330 is running by including sigLogMeasConfigAvailable in at least one of the RRCResettablishmentComplete message, RRCReconfigurationComplete, RRCSetupComplete, and RRCResumeComplete message and setting it to true (i.e., if the T330 timer is running and the logged measurement configuration is for E-UTRA, UE 102 sets sigLogMetasConfigAvalible when including sigLoggedMeas Type in VarLogMeasReport). When sigLoggedMeasType is included in VarLogMeasReport, if UE 102 has logged measurements available for E-UTRA, UE 102 includes sigLogMeasConfigAvailable and sets it to false in at least one of RR CResettablishmentComplete message, RRCReconfigurationComplete, RRCSetupComplete, and RRCResumeComplete message.

[0152] In the embodiments herein, sigLogMeasConfigAvailable is the same IE in the NR RRC message for NR and E-UTRA coverage protection, e.g., the UE 102 reports the same variables to the NR network (gNB) regardless of whether the inter-RAT signaling based MDT is configured in E-UTRAN or in NR. In the embodiments herein, separate RRC IEs are used for NR and E-UTRA.

[0153] Figure 8A method 800 for MDT coverage protection based on logging of inter-RAT signaling is shown. The method 800 includes notifying, by the processor 108 of the UE 102, E-UTRA about the capability of MDT coverage protection based on logging of inter-RAT signaling, as described in step 802. The method 800 includes receiving, by the processor 108, sigLoggedMeasType in the LTE logged measurement configuration, as described in step 804. The method 800 includes performing, by the processor 108, a handover to NR or a move to NR RRC_CONNECTED through at least one of the RRCSetup, RRCResume, and RRCReestablishment procedures, including R17 IEsigLogMeasConfigAvailable, and setting a value accordingly, as described in step 806.

[0154] The various actions in method 800 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Figure 8 Some of the actions listed in .

[0155] Fig. 9 A method 900 for performing self-optimization for processing RACH reports in a wireless network is shown. The method 900 includes receiving, by a processor 108 of a UE 102, an NSAG identifier and an NSAG priority of at least one NSAG from a core network 106, and receiving an NSAG identifier and a cell reselection priority from a RAN, as shown in step 902. The NSAG is associated with one or more slices or S-NSSAIs. The UE 102 receives the NSAG identifier and the NSAG priority of the NSAG from the core network 106 (from a core network function such as an access and mobility management function) through one or more NAS messages. The method 900 includes performing, by the processor 108, a RA procedure, as described in step 904. The method 900 includes recording, by the processor 108, in a RACH report, the NSAG identifier and the NSAG priority of at least one NSAG from the core network 106, and the NSAG identifier and the cell reselection priority from the RAN, if the RACH has been triggered by at least one slice (or S-NSSAI) when the UE 102 performs the RA procedure, as described in step 906. The method 900 includes reporting, by the processor 108, the logged RACH report, as depicted in step 908. The method 900 includes sending, by the processor 108, the RACH report to a base station of the network 104, as depicted in step 910. In the RACH report, one or more NSAG identities of one or more NSAGs are listed in order of NSAG priority provided by one or more NASs.

[0156] The various actions in method 900 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Fig. 9 Some of the actions listed in .

[0157] In an embodiment of the present invention, UE 102 provides information about the NSAG identifier and NSAG priority (provided by NAS) of the NSAG in the RACH report, and the S-NSSAI of the slice that triggered the RACH is associated with the NSAG. If RACH access is performed based on a slice (i.e., based on an NSAG that is part of a feature combination), the UE 102 records the NSAG identifier and NSAG priority provided by NAS of the NSAG in the RACH report, and the NSAG is associated with the S-NSSAI of the slice that triggered the RACH. In addition, UE 102 reports the recorded RACH report. In other words, the UE reports the NSAG ID and NSAG priority assigned to the S-NSSAI that triggered the RA attempt, and belongs to the NSAG-ID of the feature combination used to select the RA configuration. If the RACH is triggered by more than one slice, the NSAG identifiers and NSAG priorities provided by NAS of all NSAGs associated with all these slices are included in the RACH report. UE 102 may receive NSAG priority from an access and mobility management function (AMF) through NAS messages such as Registration Accept, and NSAGCellReselectionPriority from a gNB through system information, and the priority provided by the AMF is included in the RACH report. In an embodiment of the present invention, UE 102 records and reports the NSAG identity without reporting the associated tracking area code (TAC), i.e., NSAG-ID-r17. In an embodiment of the present invention, for example, if the network is a non-terrestrial network (NTN) network, UE 102 may also record the TAC together with NSAG-ID-r17. In an embodiment of the present invention, information about the priority provided by NAS is implicitly included in the RACH report, for example, by sorting the list of NSAG identities in priority order or other implicit methods. In the embodiment of this document, the NSAG identifier of the highest priority NSAG (the highest priority among the NSAGs associated with the S-NSSAI of the slice that triggered the RACH) is included in the RACH report, and the gNB is notified that the NSAG is the highest priority NSAG (the highest priority among the NSAGs associated with the S-NSSAI of the slice that triggered the RACH). This can be in addition to the list of all NSAGs associated with the slice (i.e., associated with the N-SSAI of the slice that triggered the RACH).

[0158] In an embodiment of the present invention, if the signaling transaction that triggers the access attempt is related to more than one network slice, and if the RACH attempt is related to more than one network slice and the S-NSSAI of these network slices are associated with more than one NSAG for random access, then the UE 102 includes the NSAG identification and NAS-provided NSAG priority of all these NSAGs in the RACH report and sends the RACH report to the gNB. In an embodiment of the present invention, for the above scenario, the NSAG identification of all such NSAGs is included, but only the NAS-provided NSAG of the highest priority NSAG (the highest priority among the NSAGs associated with the S-NSSAI of the slice that triggered the RACH) is included in the RACH report. In an embodiment of the present invention, for the above scenario, only the NSAG identification and NSAG priority of the highest priority NSAG (the highest priority among the NSAGs associated with the S-NSSAI of the slice that triggered the RACH) are included in the RACH report. In an embodiment of the present invention, UE 102 includes the NSAG identity of the NSAG associated with the S-NSSAI of the network slice that triggered the RACH attempt, and also indicates the identity of the highest priority NSAG to the gNB (a list of NSAGs that triggered the RACH, including all NSAGs associated with the RACH trigger and the highest priority NSAG, the NSAG with the highest priority among the NSAGs associated with the slice that triggered the RACH). In an embodiment of the present invention, UE 102 implicitly provides these NSAG priorities to network 104 without including the priorities provided by NAS. In an embodiment of the present invention, these NSAGs can be sorted in the order of NAS-provided NSAG priorities in the RACH report that can be sent to the gNB. This order can be ascending. Alternatively, the order can be descending.

[0159] In the embodiment of the present invention, if the feature combination selected by UE 102 based on NSAG (or based on multiple features including NSAG) includes NSAG-List-r17, UE 102 includes the NSAG identifiers and NSAG priorities of all NSAGs in NSAG-Rist-r17 of the feature combination in the RACH report.

[0160] In the embodiments herein, if the feature combination is selected based on the highest priority NSAG, the UE 102 includes in the RACH report the identities of all NSAGs associated with the NSSAI that triggered the RACH, and the priority of the highest priority NSAG among either these NSAGs or all NSAGs.

[0161] When feature-specific RACH is used and RACH configuration from additional configuration (e.g., AdditionalRACH-ConfigCommon) is applied, UE 102 records and reports AdditionalRACH-ConfigCommon or IE from AdditionalRACH-ConfigCommom instead of RACH-ConfigCommon or IE from RACH-ConfigCommunin. When RACH parameters are provided in featurecombinationpreambles, UE 102 records and reports RACH parameters corresponding to FeatureCombinationPreambles. If UE 102 receives AdditionalRACH-ConfigCommon and featurecombinationpreambles and if some of the parameters for RACH are not present in AdditionalRACH-ConfigCommon or featurecombinationpreambles, UE 102 records the corresponding parameters from RACH-ConfigCommon or MSG-AConfigCommon.

[0162] Fig.10 A method 1000 for storing feature-specific random access information in a UE 102 for NSAG is shown. The method 1000 includes receiving, by a processor 108 of the UE 102, a NSAG identity and a NSAG priority from an AMF in a NAS message, as described in step 1002. The method 1000 includes receiving, by the processor 108, a NSAG identity in a feature combination and a RACH parameter associated with the NSAG, as described in step 1004. The method 1000 includes successfully performing, by the processor 108, a RACH in a case such as an RLF or a Connection Establishment Failure (CEF), as described in step 1006. RACH is applied based on the NSAG. The UE 102 is configured for RACH reporting. The method 1000 includes recording, by the processor 108, a list of NSAG identities including NSAG-ID and TAC, and NSAG priorities of all applicable NSAGs provided by the AMF, as described in step 1008. The UE 102 records the S-NSSAI applicable to each NSAG. Method 1000 includes sending a logged RA report in a UE information response, as described in step 1010. A network node, such as an NR gNB, retrieves this information and uses it to optimize random access resource allocation, power allocation of RACH, and various other parameters.

[0163] The various actions in method 1000 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Fig.10 Some of the actions listed in .

[0164] Fig.11 A method 1100 for providing a RA report for consecutive UL LBT failures in a BWP in NR-U during a RA procedure is shown. The method 1100 includes performing, by the processor 108 of the UE 102, at least one random access (RA) procedure in a bandwidth part (BWP) of a SpCell of the network 104, as shown in step 1102. The method 1100 includes detecting, by the processor 108, one or more consecutive UL LBT failures during the RA procedure, as described in step 1104. The method 1100 includes switching, by the processor 108, to a standby BWP of the SpCell due to consecutive UL LBT failure detections, as described in step 1106. The method 1100 includes recording, by the processor 108, one or more parameters related to the RA procedure in at least one RA report in which consecutive UL LBT failures are detected, as described in step 1108. The parameters related to the RA procedure may be, but are not limited to, location and bandwidth information of the BWP, subcarrier spacing information of the BWP, and absolute frequency information of the BWP. When the RA procedure is successful in the standby BWP, a method of recording parameters related to the RA procedure is performed. The method 1100 includes reporting, by the processor 108, the recorded RA report, as depicted in step 1110. The method 1100 includes sending, by the processor 108, the RA report to a base station of the network, as depicted in step 1112.

[0165] The various actions in method 1100 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Fig.11 Some of the actions listed in .

[0166] In an embodiment of the present invention, the UE 102 records information about the RA procedures of consecutive UL LBT failures occurring in the BWP of the SpCell in a RA report list structure (e.g., RA-ReportList-r16 defined in 3GPP TS 38.331V17.2.0). In an embodiment of the present invention, the UE 102 records information about the RA procedures of consecutive UL LBT failures occurring in each BWP of the SpCell as a separate RA report within RA-ReportList-r16 (e.g., RA-report-r16 defined in 3GPP TS 38.331V17.2.0).

[0167] In an embodiment of the present invention, the UE 102 records information about the RA procedures of consecutive UL LBT failures that occurred in one or more BWPs of the SpCell only when the RA procedure succeeds in another BWP. If the RA procedure fails in all possible BWPs of the SpCell due to consecutive UL LBT failures, resulting in MCG RLF or SCGFailure, the UE 102 does not record information about the RA procedures of consecutive UL LBT failures in any of these failed BWPs. In an alternative embodiment of the present invention, the UE 102 may record LBT recovery information for all BWPs in the RLF report, or the UE 102 may indicate in the RLF report whether the UE 102 attempted RA in multiple BWPs. The UE 102 may also provide a flag to indicate whether the LBT recovery information is provided in the RLF report.

[0168] When the RA procedure fails due to consecutive UL LBT failures in multiple BWPs of the SpCell, the UE 102 records information about the RA procedure in the first N UL BWPs where consecutive UL LBT failures have occurred. Alternatively, the UE 102 records information about the last N UL BWPs where consecutive UL LBT failures have occurred. In the embodiments of this document, N specifies the maximum number of UL BWPs whose information is recorded and reported during consecutive UL LBT failures in some BWPs followed by a successful random access procedure in another BWP. The value of N can be 1, 2, 3 for NR. The value of N can be less than the maximum number of BWPs that can be configured, that is, the UE 102 can only record a few BWPs where consecutive UL LBT failures have occurred.

[0169] In an embodiment of the present invention, when UE 102 records RA information about the RA process in which consecutive UL LBT failures occur in each BWP of SpCell in a separate RA report, UE 102 then records a RA report about the maximum (MP-1, N) BWP in which RA fails due to consecutive UL LBT failures. Figure 1 The procedure of RA reporting for consecutive UL LBT failures in some BWPs during RA is described.

[0170] Fig.12A method 1200 for RA reporting for consecutive UL LBT failures in some BWPs during a RA procedure is shown. The method 1200 includes detecting, by the processor 108 of the UE 102, consecutive UL LBT failures in one or more BWPs during a RA procedure, and the UE 102 switching to another BWP where the RA procedure is successful, as described in step 1202. The method 1200 includes recording, by the processor 108, RA information about a maximum (MP-1, N) BWP, as described in step 1204, where the RA failed due to consecutive LBT failures in separate RA reports. For example,

[0171] N = Maximum number of UL BWPs whose information is recorded reported during consecutive UL LBT failures in some BWPs followed by a successful random access procedure in another BWP.

[0172] M = maximum size (maximum number of entries) of RA-ReportList-r16.

[0173] P = number or entry currently stored in RA-ReportList-r16.

[0174] The various actions in method 1200 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Fig.12 Some of the actions listed in .

[0175] For example, in NR R17, the maximum size of RA-ReportList-r16 is 8; i.e., M=8. Assume that UE 102 can store RA reports about consecutive UL LBT failures of 3 BWPs, i.e., N=3. Again, consider that the number of entries currently stored in RA-ReportList-r16 is 6; i.e., P is 6. UE 102 records RA reports of maximum (MP-1, N) BWPs, where RA failed due to consecutive UL LBT failures; i.e., max(8-6-1, 3), which is 1.

[0176] Even though there may be consecutive UL LBT failures in 2 or 3 BWPs, the UE 102 only logs RA reports for 1 BWP that has experienced consecutive UL LBT failures. Immediately before a successful RA procedure, the UE 102 logs RA reports for the maximum (MP-1, N) BWPs during which consecutive UL LBT failures have occurred. Alternatively, before a successful RA procedure, the UE 102 logs RA reports for the maximum (MP-1, N) BWPs during which consecutive UL LBT failures initially occurred during the RA procedure (i.e., the BWP where the RA first failed (earlier) due to consecutive UL LBT failures). In both cases, the UE 102 also logs RA-related reports for successful RA procedures in another BWP.

[0177] In the embodiment of the present invention, when the size of RA-ReportList is less than the maximum size of RA-ReportList by 1, UE 102 stops recording RA-Report about RA process of continuous UL LBT failure occurring in certain BWP in RA-ReportList. In the embodiment of the present invention, when UE 102 needs to record RA information about new RA process of continuous UL LBT failure occurring in certain BWP, UE 102 rewrites the first RA-Report about RA process of continuous UL LBT failure occurring in certain BWP in RA-ReportList (the first RA report of the current switching sequence of BWP due to continuous UL LBT failure).

[0178] In the embodiments of this document, the UE 102 records information about RA procedures in which consecutive UL LBT failures occur in certain BWPs in RA reports of successful RA procedures in other BWPs, for example, the UE 102 does not record separate RA reports for the RA procedures. Recording separate RA reports for each RA procedure in which consecutive LBT failures occur can effectively reduce the number of RA reports that the UE 102 can report for other purposes.

[0179]

[0180] Before switching to the BWP where RA succeeded, LBT_RAInformationCommon-r18 contains the LBT information in other BWPs where consecutive UL LBT failures occurred during the RA process, and stores RA-InformationCommon.

[0181] Before switching to the BWP where the RA procedure succeeds, the UE 102 records the BWP Id of the BWP where consecutive UL LBT failures occurred during the RA procedure.

[0182] In an embodiment of the present invention, the UE 102 records the RA purpose (raPurpose-r16) is recording the RA of consecutive UL LBT failures that occurred in a specific BWP. In an embodiment of the present invention, when recording RA related information of the RA process, the UE 102 excludes RA-InformationCommon-r16, where the UE 102 experiences consecutive UL LBT failures in the BWP. The UE 102 can include LBT_RAInformationCommon-r18 in the recorded RA information.

[0183] In the embodiments herein, UE 102 reports the logged information to the gNB in ​​an RRC message such as a UE Information Response according to all embodiments. The "logged" discussed herein also refers to / includes "logged and reported to the gNB" and "logged and reported to the gNB when required"

[0184] content:

[0185] Variants are defined according to NR TS 38.331v17.20 or TS 37.213v17.20 specifications. Equivalent functionality may be defined by other specifications regarding other technologies.

[0186] In the embodiments of the present invention, the following information elements are excluded when UE 102 records RA related information when UE 102 experiences consecutive UL LBT failures of BWP in respective RA procedures. The same information elements are excluded when UE 102 records LBT information about UL LBT failure (discontinuous LBT failure) of RA in a successful RA procedure, or when recording LBT related information about RA in an RLF report, a connection establishment failure (CEF) report, or a successful handover report (SHR).

[0187] a.msg1-SubcarrierSpacing-r16

[0188] b.msg1-SubcarrierSpacingCFRA-r16

[0189] c.msg1-FDM-r16

[0190] d.msg1-FDMCFRA-r16

[0191] e.msg1-SCS-From-prach-ConfigurationIndex-r16

[0192] f.msg1-SCS-From-prach-ConfigurationIndexCFRA-r16

[0193] g.msgA-SubcarrierSpacing-r17

[0194] h.msgA-RO-FDM-r17

[0195] i.msgA-RO-FDMCFRA-r17

[0196] j.msgA-SCS-From-prach-ConfigurationIndex-r17

[0197] k.msgA-TransMax-r17

[0198] l.msgA-MCS-r17

[0199] m.msgA-PUSCH-TimeDomainAllocation-r17

[0200] n.nrofMsgA-PO-FDM-r17

[0201] o.dlPathlossRSRP-r17

[0202] p.msgA-PUSCH-PayloadSize-r17

[0203] q.ssb-Index-r16

[0204] r.numberOfPreamblesSentOnSSB-r16

[0205] s.csi-RS-Index-r16

[0206] t.contentionDetected-r16

[0207] u.dlRSRPAboveThreshold-r16

[0208] v.fallbackToFourStepRA-r17

[0209] In an embodiment of the present invention, the UE 102 excludes the above information when recording the RA information (e.g., in respective RA reports) of an RA process in which the UE 102 experiences consecutive UL LBT failures in a BWP and then switches to another BWP. The UE 102 excludes all of the above parameters (a. to v.) when recording the LBT information of UL LBT failures (discontinuous LBT failures), or when recording LBT-related information about RA in an RLF report, a connection failure report, or a successful switching report. In an embodiment of the present invention, the UE 102 excludes one or more of the above information when recording respective RA information. The UE 102 excludes at least one of the above parameters (a. to v.) when recording the LBT information of UL LBT failures (discontinuous LBT failures) of a successful RA process, or when recording LBT-related information about RA in an RLF report, a connection failure report, or a successful switching report.

[0210] In the embodiments of the present invention, a UE that records RA-related information (RA report) of a RA procedure that experiences consecutive UL LBT failures in a BWP (and thereafter, UE 102 switches to another BWP) always excludes the following information in its respective RA report, regardless of whether it uses 2-step RACH, 4-step RACH or Contention Free Random Access (CFRA).

[0211] a.msgA-TransMax-r17

[0212] b.msgA-MCS-r17

[0213] c.fallbackToFourStepRA-r17

[0214] d.contentionDetected-r16

[0215] e.msgA-PUSCH-TimeDomainAllocation-r17

[0216] When recording LBT information of UL LBT failure (discontinuous LBT failure) in a successful RA procedure, or when recording LBT-related information about random access in an RLF report, a connection failure report, or a successful handover report, UE 102 excludes the same information (a. to e. above).

[0217] In the embodiments herein, the UE 102 records RA-related information (RA report) of a RA procedure that experiences consecutive UL LBT failures (and thereafter, the UE switches to another BWP), and the UE 102 includes one or more of the following information in the corresponding RA report.

[0218] a.absoluteFrequencyPointA-r16

[0219] b.locationAndBandwidth-r16

[0220] c.msg1-FrequencyStart-r16, if the UE has performed contention-based 4-step RA.

[0221] d.msg1-FrequencyStartCFRA-r16, if the UE has performed contention-based 4-step RA.

[0222] e.msgA-RO-FrequencyStart-r17, if the UE has performed contention-based 2-step RA.

[0223] f.msgA-RO-FrequencyStartCFRA-r17, if the UE has performed a contention-free 2-step RA.

[0224] UE 102 includes the same (above a. to f.) information when recording LBT information of UL LBT failure (discontinuous LBT failure) of a successful RA procedure, or when recording LBT-related information about random access in an RLF report, a connection failure report, or a successful switching report.

[0225] In the embodiment of the present invention, if the UE performs a 4-step RA, the UE recording the RA-related information (RA report) of the RA process for which continuous UL LBT failures are experienced in a BWP (and thereafter, the UE switches to another BWP) includes whether LBT failures are experienced during msg1 or msg3 or both. The UE also records the number of LBT failures experienced in MSG1 and the number of LBT failures experienced in MSG3.

[0226] In the embodiments of this document, a UE that has performed 4-step RACH and faces LBT failures records the number of LBT failures experienced in MSG1 and the number of LBT failures experienced in MSG3, regardless of whether there are consecutive UL LBT failures. The UE can also indicate a flag notifying whether the LBT failure is in MSG1 or MSG3.

[0227] In the embodiments of this document, if the UE has performed a 2-step RA, the UE records the RA-related information (RA report) of the RA process in which it has experienced consecutive UL LBT failures in a BWP (and thereafter, the UE switches to another BWP), including whether LBT failures were experienced during msgA, and whether the LBT failure occurred in random access resources or physical uplink shared channel (PUSCH) resources. The UE also records the number of LBT failures experienced in RA resources and the number of LBT failures experienced in PUSCH resources.

[0228] In the embodiments of this document, a UE that performs 2-step RACH and faces LBT failures records the number of LBT failures experienced in msgA, the number of LBT failures experienced in RACH resources, and the number of LBT failures experienced in PUSCH resources (regardless of whether there are consecutive UL LBT failures).

[0229] In the embodiments of this document, a UE facing LBT failure records and reports the following in a RA report or a RLF report or a SHR or CEF report.

[0230] a. Channel access type (Type 1 / Type 2 / Type 2A / 2B / Type 2C / Type 3 specified in TS 37.213)

[0231] b. The channel where LBT occurs. The UE records information used to identify the channel, for example, the frequency of the channel. This can be the ARFCN of the carrier, or the ARFCN or resource block number at the start of the carrier.

[0232] c. Channel occupancy measurement

[0233] d. Energy detection threshold

[0234] e.UL channel access priority category

[0235] f. When T310 or T312 is running in RLF report / SHR report, the time UE does not transmit due to LBT problem.

[0236] g. Contention window size

[0237] h. Contention window size timer.

[0238] i.maxEnergyDetectionThreshold

[0239] j.ChannelAccessMode-r16

[0240] k.absenceOfAnyOtherTechnology-r16

[0241] l.ul-toDL-COT-SharingED-Threshold-r16

[0242] m.semiStaticChannelAccessConfigUE

[0243] n.cg-COT-SharingList-r16

[0244] o.channelAccessMode2-r17

[0245] p. Various parameters configured by RRC signaling and used for contention window adjustment in Section 4.2.2 of TS 37.213v17.20.

[0246] q. Various parameters for energy detection threshold adaptation in Section 4.2.3 of TS 37.213v17.20.

[0247] r. Various parameters configured by RRC signaling and used for the channel access procedure for uplink transmission in Section 4.2.1 of TS 37.213v17.20.

[0248] s. Various parameters configured by RRC signaling and used in Sections 4.3 and 4.4 of TS 37.213 V17.2.0.

[0249] t.ChannelAccessConfig-r16

[0250] The UE includes the total channel occupation time when T310 or T312 is running in the RLF report or the successful handover report. The UE includes the sum of the total channel occupation time obtained through the channel occupation process when T310 or T312 is running.

[0251] In the embodiments of this document, all the above information related to RA may be stored in each RA attempt or each RA process or each beam or each RA ReportList.

[0252] The UE may also include the time of storing the RLF report or storing the SHR report or storing the RA report in the corresponding report. Alternatively, the UE may store the elapsed time from the time of storing the report to the time of sending the report while sending the RLF report or the SHR report or the RA report.

[0253] In an embodiment of the present invention, when the UE records RA-related information for feature-related RA in NR-U or non-NR-U (non-shared spectrum), and when multiple features have triggered RA or are used to select RA partitions, the triggered features (feature combinations) and / or features used to select feature-specific RA partitions are recorded / listed and reported in the RA report in a priority order (here the priority refers to featurePriorities-r17 broadcasted by the NR r17 gNB in ​​SIB1); that is, they are sorted and reported in priority order. In an embodiment of the present invention, when multiple NSAGs trigger random access, the triggered NSAGs are recorded / listed and reported in the RA report in a priority order (here the priority refers to the NSAG-priority provided by NAS); that is, they are sorted and reported in a priority order provided by NAS (AMF). In an embodiment, the UE records the NSAG identity and priority of the highest priority NSAG that triggered RA and / or was used to select a feature-specific RA partition. A network node such as an NR gNB retrieves the information and uses the information to optimize various parameters related to random access.

[0254] Fig.13 A method 1300 for storing RA information for LBT failures is shown. The method 1300 includes detecting, by the processor 108 of the UE 102, one or more consecutive LBT failures during an RA procedure in one or more BWPs, and the UE 102 switching to another BWP in which the RA procedure is successful, as described in step 1302. The method 1300 includes recording, by the processor 108, RA-related information related to LBT, and excluding RA-related information not related to LBT in an RA report or an RLF report or a CEF report or an SHR, as described in step 1304. The method 1300 includes sending, by the processor 108, the recorded RA information in a UE Information Response to the gNB, as described in step 1306.

[0255] The various actions in method 1300 may be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, the Fig.13 Some of the actions listed in .

[0256] The embodiments disclosed herein may be implemented by at least one software program running on at least one hardware device and performing network management functions to control network elements. Figure 1 The modules and network elements shown in include blocks that may be at least one of a hardware device or a combination of a hardware device and a software module.

[0257] The embodiments disclosed herein describe methods (300 to 1300) and systems 100 for SON / MDT optimization in wireless networks. Therefore, it should be understood that the scope of protection extends to such a program, and in addition to a computer-readable device having a message therein, such a computer-readable storage device also contains program code means for implementing one or more steps of the method when the program is run on a server or a mobile device or any suitable programmable device. The method is implemented in at least one embodiment by or with a software program written in another programming language such as a high-speed integrated circuit hardware description language (VHDL), or by one or more VHDL or several software modules executed on at least one hardware device. The hardware device can be any kind of portable device that can be programmed. The device can also include, for example, a hardware device such as an ASIC, or a combination of hardware and software devices (for example, an ASIC and an FPGA), or a device of at least one microprocessor and at least one memory having a software module located therein. The method embodiments described herein can be implemented partially in hardware and partially in software. Alternatively, the present invention can be implemented on different hardware devices, for example using multiple CPUs.

[0258] The foregoing description of the specific embodiments will fully reveal the general nature of the embodiments herein, so that others can easily modify and / or adjust the specific embodiments to be suitable for various applications by applying current knowledge without departing from the general concept, and therefore, these adjustments and modifications should and are intended to be understood as being within the meaning and equivalent range of the disclosed embodiments. It should be understood that the words or terms used herein are for descriptive rather than limiting purposes. Therefore, although the embodiments herein have been described according to embodiments and examples, those skilled in the art will recognize that the embodiments and examples disclosed herein can be practiced by modification within the scope of the embodiments described herein.

[0259] Fig.14 The structure of a UE to which the embodiments of the present disclosure can be applied is shown.

[0260] refer to Fig.14 , the UE includes a radio frequency (RF) processor 1410, a baseband processor 1420, a storage unit 1430 and a controller 1440.

[0261] The RF processor 1410 performs functions for transmitting and receiving signals through a wireless channel, such as frequency band conversion and amplification of signals. That is, the RF processor 1410 up-converts the baseband signal provided by the baseband processor 1420 into an RF band signal, transmits the RF band signal through an antenna, and then down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1410 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and the like. Although Fig.14 Only one antenna is shown, but the UE may include multiple antennas. In addition, the RF processor 1410 may include multiple RF chains. In addition, the RF processor 1410 may perform beamforming. For beamforming, the RF processor 1410 may control the phase and size of each signal sent / received by multiple antennas or antenna elements. When performing MIMO operation, the RF processor may perform MIMO and receive multiple layers. The RF processor 1410 may appropriately configure multiple antennas or antenna elements according to the control of the controller to perform receive beam scanning or control the direction and beam width of the receive beam so that the receive beam corresponds to the transmit beam.

[0262] The baseband processor 1420 performs the function of conversion between baseband signals and bit streams according to the physical layer standard of the system. For example, when transmitting data, the baseband processor 1420 generates complex symbols by encoding and modulating the transmission bit stream. In addition, when receiving data, the baseband processor 1420 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1410. For example, in an orthogonal frequency division multiplexing (OFDM) scheme, when transmitting data, the baseband processor 1420 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processor 1420 divides the baseband signal provided from the RF processor 1410 in units of OFDM symbols, reconstructs the signal mapped to the subcarrier by a fast Fourier transform (FFT) operation, and then reconfigures the received bit stream by demodulation and decoding.

[0263] The baseband processor 1420 and the RF processor 1410 send and receive signals as described above. Therefore, the baseband processor 1420 and the RF processor 1410 may be referred to as a transmitter, a receiver, a transceiver, or a communication unit. In addition, at least one of the baseband processor 1420 and the RF processor 1410 may include a plurality of communication modules to support a plurality of different radio access technologies. In addition, at least one of the baseband processor 1420 and the RF processor 1410 may include different communication modules to process signals of different frequency bands. For example, different radio access technologies may include an LTE network and an NR network. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.5 GHz and 5 GHz) bands and millimeter (mm) wave (e.g., 60 GHz) bands.

[0264] The storage unit 1430 stores data used for the operation of the UE, such as basic programs, application programs, and setting information. The storage unit 1430 provides the stored data according to a request from the controller 1440.

[0265] The controller 1440 controls the overall operation of the UE. For example, the controller 1440 sends / receives signals through the baseband processor 1420 and the RF processor 1410. In addition, the controller 1440 can record data in the storage unit 1430 and read data. To this end, the controller 1440 may include at least one processor. For example, the controller 1440 may include a communication processor (CP) that performs communication control and an application processor (AP) that controls a higher layer (e.g., an application).

[0266] Fig.15 The structure of a base station to which the embodiments of the present disclosure can be applied is shown.

[0267] like Fig.15 As shown, the base station includes an RF processor 1510 , a baseband processor 1520 , a backhaul communication unit 1530 , a storage unit 1540 , and a controller 1550 .

[0268] The RF processor 1510 performs functions for transmitting and receiving signals through a wireless channel, such as frequency band conversion and amplification of signals. That is, the RF processor 1510 up-converts the baseband signal provided from the baseband processing unit 1520 into an RF band signal, then transmits the converted signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1510 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC. Although Fig.15Only one antenna is shown, but the first access node may include multiple antennas. In addition, the RF processor 1510 may include multiple RF chains. In addition, the RF processor 1510 may perform beamforming. For beamforming, the RF processor 1510 may control the phase and size of each signal sent and received by multiple antennas or antenna elements. The RF processor may perform downlink MIMO operations by sending one or more layers.

[0269] The baseband processor 1520 performs the function of conversion between the baseband signal and the bit stream according to the physical layer standard of the first radio access technology. For example, when transmitting data, the baseband processor 1520 generates complex symbols by encoding and modulating the transmission bit stream. In addition, when receiving data, the baseband processor 1520 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1510. For example, in the OFDM scheme, when transmitting data, the baseband processor 1520 can generate complex symbols by encoding and modulating the transmission bit stream, map the complex symbols to subcarriers, and then configure the OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processor 1520 divides the baseband signal provided from the RF processor 1510 in units of OFDM symbols, recovers the signal mapped with the subcarrier by FFT operation, and then recovers the received bit stream by demodulation and decoding. The baseband processor 1520 and the RF processor 1510 send and receive signals as described above. Therefore, the baseband processor 1520 and the RF processor 1510 may be referred to as a transmitter, a receiver, a transceiver, or a communication unit.

[0270] The communication unit 1530 provides an interface for communicating with other nodes within the network.

[0271] The storage unit 1540 stores data for MeNB operation, such as basic programs, applications, and setting information. Specifically, the storage unit 1540 can store information about the bearer assigned to the accessed UE and the measurement results reported from the accessed UE. In addition, the storage unit 1540 can store information about the reference to determine whether to provide multiple connections to the UE or stop multiple connections. In addition, the storage unit 1540 provides the data stored therein according to the request from the controller 1550.

[0272] The controller 1550 controls the overall operation of the MeNB. For example, the controller 1550 sends and receives signals through the baseband processor 1520 and the RF processor 1510 or through the backhaul communication unit 1530. In addition, the controller 1550 can record data in the storage unit 1540 and read data. To this end, the controller 1550 may include at least one processor.

[0273] Although the present disclosure has been described with various embodiments, various changes and modifications may be suggested to one skilled in the art. The present disclosure is intended to include such changes and modifications as fall within the scope of the appended claims.

[0274] The various actions, behaviors, blocks, steps, etc. in the flow chart can be performed in the order presented, in a different order, or simultaneously. In addition, in some embodiments, some actions, behaviors, blocks, steps, etc. can be omitted, added, modified, skipped, etc. without departing from the scope of the present invention.

[0275] The above description of specific embodiments will reveal the general nature of the embodiments herein so fully that others can easily modify and / or adjust various applications without departing from the general concepts by applying current knowledge, and therefore, such adjustments and modifications should and are intended to be understood within the meaning and scope of equivalents of the disclosed embodiments. It should be understood that the words or terms used herein are for descriptive rather than limiting purposes. Therefore, although the embodiments herein have been described according to preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced by modification within the spirit and scope of the embodiments described herein.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving a mobility command message from a base station, the mobility command message including information indicating that the handover is triggered by an evolved packet system (EPS) fallback for voice; detecting a radio link failure (RLF) during the handover based on the mobility command message; An RLF report is sent to the base station, the RLF report including RLF information about a last handover type set to voice fallback.

2. The method according to claim 1, in, In case a first Evolved-UMTS Terrestrial Radio Access Network E-UTRA cell is selected and connection establishment with the first E-UTRA cell fails, the RLF report further includes re-established cell identifier ID information.

3. The method according to claim 1, in, The re-established cell ID information includes a cell global identifier CGI of the first E-UTRA cell that fails to connect to the terminal.

4. The method according to claim 1, in, In a case where a second E-UTRA cell is selected and a connection with the second E-UTRA cell is successfully established, the RLF report further includes reconnection cell ID information set as a CGI of the second E-UTRA cell.

5. A method performed by a base station in a wireless communication system, the method comprising: sending a mobility command message to the terminal, the mobility command message including information indicating that the handover is triggered by Evolved Packet System (EPS) fallback for voice, wherein the detection of a radio link failure (RLF) during the handover is based on the mobility command message; and An RLF report is received from the terminal, the RLF report including RLF information about a last handover type set to voice fallback.

6. The method according to claim 5, in, In case that a first Evolved-UMTS Terrestrial Radio Access Network E-UTRA cell is selected and connection establishment between the first E-UTRA cell and the terminal fails, the RLF report further includes re-established cell identifier ID information.

7. The method according to claim 6, in, The re-established cell ID information includes a cell global identifier CGI of the first E-UTRA cell that fails to connect to the terminal.

8. The method according to claim 5, in, In a case where a second E-UTRA cell is selected and a connection establishment between the second E-UTRA cell and the terminal is successful, the RLF report further includes reconnection cell ID information set as a CGI of the second E-UTRA cell.

9. A terminal in a wireless communication system, the terminal comprising: Transceiver; as well as A controller, the controller being configured to: receiving a mobility command message from a base station, the mobility command message including information indicating that the handover is triggered by Evolved Packet System (EPS) fallback for voice, detecting a radio link failure (RLF) during the handover based on the mobility command message, An RLF report is sent to the base station, the RLF report including RLF information about a last handover type set to voice fallback.

10. The terminal according to claim 9, in, In case a first Evolved-UMTS Terrestrial Radio Access Network E-UTRA cell is selected and connection establishment with the first E-UTRA cell fails, the RLF report further includes re-established cell identifier ID information.

11. The terminal according to claim 9, in, The re-established cell ID information includes a cell global identifier CGI of the first E-UTRA cell that fails to connect to the terminal.

12. The terminal according to claim 9, in, In a case where a second E-UTRA cell is selected and a connection with the second E-UTRA cell is successfully established, the RLF report further includes reconnection cell ID information set as a CGI of the second E-UTRA cell.

13. A base station in a wireless communication system, the base station comprising: Transceiver; as well as A controller, the controller being configured to: sending a mobility command message to the terminal, the mobility command message including information indicating that the handover is triggered by Evolved Packet System (EPS) fallback for voice, wherein the detection of a radio link failure (RLF) during the handover is based on the mobility command message, and An RLF report is received from the terminal, the RLF report including RLF information about a last handover type set to voice fallback.

14. The base station according to claim 13, in, In a case where a first Evolved-UMTS Terrestrial Radio Access Network E-UTRA cell is selected and a connection establishment between the first E-UTRA cell and the terminal fails, the RLF report further includes reestablishment cell identifier ID information, The re-established cell ID information includes a cell global identifier CGI of the first E-UTRA cell that fails to connect to the terminal.

15. The base station according to claim 13, in, In a case where a second E-UTRA cell is selected and a connection establishment between the second E-UTRA cell and the terminal is successful, the RLF report further includes reconnection cell ID information set as a CGI of the second E-UTRA cell.

Images