Radio link failure report for low layer triggered mobility

Abstract

This disclosure relates to 5G or 6G communication systems for supporting higher data transmission rates. A user equipment includes a transceiver and a processor operatively coupled to the transceiver. The transceiver is configured to receive from a source cell a conditional LTM configuration for at least one conditional lower-layer triggered mobility (LTM) candidate cell. The processor is configured to initiate a conditional LTM cell handover to a target cell among the at least one conditional LTM candidate cell; determine that the conditional LTM cell handover to the target cell has failed; and, in response to determining that the conditional LTM cell handover to the target cell has failed, generate a radio link failure (RLF) report.

Description

Technical Field

[0001] This disclosure generally relates to wireless networks. More specifically, this disclosure relates to radio link failure (RLF) reporting for Layer 1 / Layer 2 triggered mobility (LTM). Background Technology

[0002] 5G mobile communication technology defines a wide frequency band, enabling high transmission rates and new services. It can be implemented not only in "sub-6GHz" bands such as 3.5GHz, but also in "above 6GHz" bands, including 28GHz and 39GHz, known as millimeter waves (mmWave). Furthermore, 6G mobile communication technology (referred to as "super 5G systems") is being considered for implementation in terahertz bands (e.g., the 95GHz to 3THz band) to achieve transmission rates 50 times faster than 5G and ultra-low latency one-tenth that of 5G.

[0003] In the early stages of 5G mobile communication technology development, 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 for the following technologies: beamforming and massive MIMO for reducing radio wave path loss and increasing radio wave transmission distance in millimeter waves; support parameter sets for dynamic operation (e.g., operating multiple subcarrier spacings) for efficient utilization of millimeter wave resources and time slot formats; initial access technologies for supporting multi-beam transmission and broadband; definition and operation of BWP (bandwidth portion); new channel coding methods such as LDPC (low-density parity-check) codes for large-volume data transmission and polar codes for highly reliable transmission of control information; L2 preprocessing; and network slicing for providing dedicated networks for specific services.

[0004] Currently, regarding the services supported by 5G mobile communication technology, discussions are underway regarding improvements and performance enhancements to the initial 5G mobile communication technology. Physical layer standardization has been completed for technologies such as: V2X (vehicle-to-everything) for assisting autonomous vehicle driving decisions based on information transmitted by the vehicle regarding its location and status, and for improving user convenience; NR-U (New Radio Unlicensed) designed to comply with various regulatory requirements for system operation in unlicensed frequency bands; NR UE power saving; non-terrestrial networks (NTNs) for direct satellite communication between UEs to provide coverage in areas where communication with terrestrial networks is not possible; and positioning.

[0005] Furthermore, standardization of air interface architectures / protocols for technologies such as: Industrial Internet of Things (IIoT) for supporting new services through interoperability and integration with other industries; IAB (Integrated Access and Backhaul) for providing nodes for network service area extension by supporting wireless backhaul and access links in an integrated manner; mobility enhancements including conditional handover and DAPS (Dual Active Stack) handover; and two-step random access (two-step RACH for NR) for simplifying the random access process. Standardization of system architectures / services for technologies such as: 5G baseline architectures (e.g., service-based architectures or service-based interfaces) for combining Virtual Network Functions (NFV) and Software-Defined Networking (SDN) technologies; and mobile edge computing (MEC) for receiving services based on UE location.

[0006] With the commercialization of 5G mobile communication systems, an exponential increase in connected devices will be applied to communication networks, thus necessitating enhanced functionality and performance of 5G mobile communication systems as well as integrated operation of connected devices. To this end, new research is planned related to the following technologies: Extended Reality (XR) for efficient support of AR (Augmented Reality), VR (Virtual Reality), MR (Mixed Reality), etc.; 5G performance improvements and complexity reduction through the utilization of Artificial Intelligence (AI) and Machine Learning (ML); AI service support; Metaverse service support; and drone communication.

[0007] Furthermore, this development of 5G mobile communication systems will not only lay the foundation for the development of technologies such as: 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 MIMO; metamaterial-based lenses and antennas for improving coverage of terahertz band signals; high-dimensional spatial multiplexing technologies using OAM (orbital angular momentum); and RIS (reconfigurable smart surfaces), but will also lay the foundation for the development of technologies such as: full-duplex technologies for improving the frequency efficiency of 6G mobile communication technology and improving system networks; AI-based communication technologies for achieving system optimization by leveraging satellites and AI (artificial intelligence) from the design stage and internalizing end-to-end AI support functions; and next-generation distributed computing technologies for achieving services with a level of complexity exceeding the operational capabilities of UEs by utilizing ultra-high-performance communication and computing resources.

[0008] The demand for wireless data services is rapidly increasing due to the growing popularity of smartphones and other mobile data devices (such as tablets, notebook computers, netbooks, e-book readers, and machine-type devices) among consumers and businesses. To meet this high growth in mobile data services and support new applications and deployments, improving the efficiency and coverage of wireless interfaces is crucial.

[0009] To meet the increased demand for wireless data services since the deployment of 4G communication systems and to enable various vertical applications, 5G communication systems have been developed and are currently being deployed. Enabling technologies for 5G / NR mobile communications include: massive MIMO technology from traditional cellular bands to high frequencies to provide beamforming gain and support increased capacity; new waveforms for flexible adaptation to various services / applications with different requirements (e.g., new radio access technologies [RAT]); and new multiple access schemes to support massive connectivity. Summary of the Invention

[0010] [Technical Issues]

[0011] In next-generation wireless communication systems (e.g., 5G, 5G+, 6G), the UE prepares a radio link failure report in case of handover failure, conditional handover failure, DAPS handover failure, or radio link failure (RLF). The received RLF report helps the network optimize the configuration for handover failure, conditional handover failure, DAPS handover failure, or RLF. However, in the case of UE-initiated L1 / L2-triggered mobility / cell handover failure, no report is sent to the network.

[0012] This disclosure relates to apparatus and methods for reporting RLF for LTM.

[0013] [Solution to the problem]

[0014] In one embodiment, a user equipment (UE) is provided. The UE includes a transceiver and a processor operatively coupled to the transceiver. The transceiver is configured to receive conditional LTM configuration from a source cell for at least one conditional lower layer triggered mobility (LTM) candidate cell. The processor is configured to initiate a conditional LTM cell handover to a target cell among the at least one conditional LTM candidate cell; determine that the conditional LTM cell handover to the target cell has failed; and generate a radio link failure (RLF) report in response to determining that the conditional LTM cell handover to the target cell has failed.

[0015] In another embodiment, a method for operating a UE is provided. The method includes: receiving a conditional LTM configuration from a source cell for at least one conditional LTM candidate cell; and initiating a conditional LTM cell handover to a target cell among the at least one conditional LTM candidate cell. The method further includes: determining that the conditional LTM cell handover to the target cell has failed; and generating an RLF report in response to determining that the conditional LTM cell handover to the target cell has failed.

[0016] Other technical features will be apparent to those skilled in the art from the following figures, description and claims.

[0017] Before proceeding with the following detailed description, it may be advantageous to define certain words and phrases used throughout this patent document. The term “coupled” and its derivatives refer to any direct or indirect communication between two or more elements, regardless of whether these elements are physically in contact with each other. The terms “transmit,” “receive,” and “communicate,” and their derivatives include both direct and indirect communication. The terms “comprise” and “include,” and their derivatives mean non-restrictive inclusion. The term “or” is inclusive, meaning and / or. The phrase “associated with,” and its derivatives mean including, being included within, interconnected with, containing, being contained within, connected to or connected with, coupled to or coupled with, capable of communicating with, cooperating with, intertwined, juxtaposed, proximate, bound to or bound with, having, possessing the attributes of, related to, or similar meanings. The term “controller” means any device, system, or part thereof that controls at least one operation. Such a controller may be implemented in hardware or in a combination of hardware and software and / or firmware. The functionality associated with any particular controller can be centralized or distributed, local or remote. When the phrase "at least one" is used with a list of items, it means that different combinations of one or more of the listed items can be used, and only one item in the list may be required. For example, "at least one of the following: A, B, and C" includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

[0018] Furthermore, the various functions described below can be implemented or supported by one or more computer programs, each computer program being formed by computer-readable program code and contained in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, flows, functions, objects, classes, instances, associated data, or portions thereof suitable for implementation in suitable computer-readable program code. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, optical disc (CD), digital video disc (DVD), or any other type of storage. "Non-transitory" computer-readable media excludes wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media that can permanently store data, as well as media that can store data and subsequently rewrite it (such as rewritable optical discs or erasable storage devices).

[0019] Definitions of certain other words and phrases are provided throughout this patent document. Those skilled in the art will understand that, in many (if not all) instances, such definitions apply to the prior and future use of these defined words and phrases.

[0020] [Beneficial effects of the invention]

[0021] This disclosure provides a method and apparatus for reporting Radio Link Failure (RLF) failures in LTM / cell handover. Therefore, embodiments of this disclosure enhance radio link failure reporting for LTM / cell handover failures. Attached Figure Description

[0022] To gain a more complete understanding of this disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein: Figure 1 An example of a wireless network according to an embodiment of this disclosure is shown; Figure 2A illustrates an example of a wireless transmission path according to an embodiment of the present disclosure; Figure 2B illustrates an example of a wireless reception path according to an embodiment of the present disclosure; Figure 3A illustrates an example of a UE according to an embodiment of the present disclosure; Figure 3B illustrates an example of a gNB according to an embodiment of the present disclosure; Figure 4 An example of a signaling procedure for inter-gNB handover according to an embodiment of this disclosure is shown; Figure 5 An example of a process for LTM according to an embodiment of this disclosure is shown; Figure 6 An example of a process for RLF reporting according to an embodiment of this disclosure is shown; Figure 7 Another example of a process for RLF reporting according to embodiments of this disclosure is shown; Figure 8 Another example of a process for RLF reporting according to embodiments of this disclosure is shown; and Figure 9 An example of a method for LTM RLF reporting according to an embodiment of this disclosure is shown. Detailed Implementation

[0023] The following discussion Figures 1 to 9 The various embodiments described in this patent document to illustrate the principles of this disclosure are for illustrative purposes only and should not be construed as limiting the scope of this disclosure in any way. Those skilled in the art will understand that the principles of this disclosure can be implemented in any suitably arranged wireless communication system.

[0024] To meet the increased demand for wireless data services since the deployment of 4G communication systems and to enable various vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are envisioned to be implemented in higher frequency (mmWave) bands (e.g., 28 GHz or 60 GHz bands) to achieve higher data rates, or in lower frequency bands (e.g., 6 GHz) to achieve robust coverage and mobility support. To reduce radio wave propagation loss and increase transmission distance, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies are discussed in 5G / NR communication systems.

[0025] In addition, in 5G / NR communication systems, system network improvements are being developed based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multipoint (CoMP), and receiver interference cancellation.

[0026] The discussion of 5G systems and their associated frequency bands is for reference only, as some embodiments of this disclosure can be implemented in 5G systems. However, this disclosure is not limited to 5G systems or their associated frequency bands, and embodiments of this disclosure can be used in conjunction with any frequency band. For example, aspects of this disclosure can also be applied to the deployment of 5G communication systems, 6G, or even subsequent versions that may use terahertz (THz) frequency bands.

[0027] the following Figure 1 Figures 3B to 3B illustrate various embodiments of communication technologies implemented using Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) in wireless communication systems. Figure 1 The description up to Figure 3B does not imply any physical or architectural limitation on the implementation of the different embodiments. The different embodiments of this disclosure can be implemented in any suitably arranged communication system.

[0028] Figure 1 An example wireless network 100 according to an embodiment of this disclosure is shown. Figure 1 The illustrated embodiment of the wireless network is for illustrative purposes only. Other embodiments of the wireless network 100 may be used without departing from the scope of this disclosure.

[0029] like Figure 1 As shown, the wireless network includes gNB 101 (e.g., a base station BS), gNB 102, and gNB 103. gNB 101 communicates with gNB 102 and gNB 103. gNB 101 also communicates with at least one network 130 (such as the Internet, a proprietary Internet Protocol (IP) network, or other data network).

[0030] gNB 102 provides wireless broadband access to network 130 to a plurality of first user equipments (UEs) within its coverage area 120. The plurality of first UEs includes: UE 111, which may be located in a small business; UE 112, which may be located in an enterprise; UE 113, which may be a WiFi hotspot; UE 114, which may be located in a first residence; UE 115, which may be located in a second residence; and UE 116, which may be a mobile device such as a cellular phone, wireless laptop, wireless PDA, or similar device. gNB 103 provides wireless broadband access to network 130 to a plurality of second UEs within its coverage area 125. The plurality of second UEs includes UE 115 and UE 116. In some embodiments, one or more of gNBs 101-103 may communicate with each other and with UEs 111-116 using 5G / NR, Long Term Evolution (LTE), LTE-A Advanced, WiMAX, WiFi, or other wireless communication technologies.

[0031] Depending on the network type, the term "base station" or "BS" can refer to any component (or set of components) configured to provide wireless access to a network, such as a transmitting point (TP), a transmitting-receiving point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macro cell, a femtocell, a WiFi access point (AP), or other wireless enabling devices. A base station can provide wireless access according to one or more wireless communication protocols, such as 5G / NR 3rd Generation Partnership Project (3GPP) NR, Long Term Evolution (LTE), LTE-Advanced (LTE-A), High-Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac, etc. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to network infrastructure components that provide wireless access to remote terminals. Furthermore, depending on the network type, the term "user equipment" or "UE" can refer to any component such as a "mobile station," "subscriber station," "remote terminal," "wireless terminal," "receiving point," or "user device." For convenience, the terms “user equipment” and “UE” are used in this patent document to refer to a remote wireless device that wirelessly accesses the BS, whether the UE is a mobile device (such as a mobile phone or smartphone) or is generally considered a fixed device (such as a desktop computer or vending machine).

[0032] The dashed lines indicate the approximate extent of coverage areas 120 and 125, which are shown as approximately circular for illustrative and explanatory purposes only. It should be clearly understood that coverage areas (such as coverage areas 120 and 125) associated with the BS may have other shapes (including irregular shapes) depending on the configuration of the gNB and variations in the radio environment associated with natural and man-made obstacles.

[0033] As described in more detail below, one or more of UEs 111-116 include circuitry, programming, or a combination thereof for LTM RLF reporting. In some embodiments, one or more of gNBs 101-103 include circuitry, programming, or a combination thereof to support LTM RLF reporting in a wireless communication system.

[0034] although Figure 1 An example of a wireless network is shown, but more can be found on... Figure 1 Various modifications can be made. For example, the wireless network can include any number of gNBs and any number of UEs. Furthermore, gNB 101 can communicate directly with any number of UEs and provide these UEs with wireless broadband access to network 130. Similarly, each gNB 102-103 can communicate directly with network 130 and provide the UEs with direct wireless broadband access to network 130. Additionally, gNBs 101, 102, and / or 103 can provide access to other or additional external networks, such as external telephone networks or other types of data networks.

[0035] Figures 2A and 2B illustrate example wireless transmit and receive paths according to embodiments of the present disclosure. In the following description, transmit path 200 may be described as being implemented in a gNB (such as gNB 102), while receive path 250 may be described as being implemented in a UE (such as UE 116). However, it will be understood that receive path 250 may be implemented in the gNB, and transmit path 200 may be implemented in the UE. In some embodiments, transmit path 200 and / or receive path 250 are configured to implement and / or support RLF reporting for LTM as described in embodiments of the present disclosure.

[0036] Transmit path 200 includes channel coding and modulation block 205, serial-to-parallel (S-to-P) block 210, inverse fast Fourier transform (IFFT) block of size N 215, parallel-to-serial (P-to-S) block 220, cyclic prefix addition block 225, and upconverter (UC) 230. Receive path 250 includes downconverter (DC) 255, cyclic prefix removal block 260, serial-to-parallel (S-to-P) block 265, fast Fourier transform (FFT) block of size N 270, parallel-to-serial (P-to-S) block 275, and channel decoding and demodulation block 280.

[0037] In transmit path 200, channel coding and modulation block 205 receives a set of information bits, applies coding (such as low-density parity-check (LDPC) coding), and modulates the input bits (such as with quadrature phase shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a frequency-domain modulated symbol sequence. Serial-to-parallel block 210 converts the serial data through modulated symbols (such as demultiplexing) into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in gNB 102 and UE 116. IFFT block 215 of size N performs an IFFT operation on the N parallel symbol streams to generate a time-domain output signal. Parallel-to-serial block 220 converts (such as multiplexing) the parallel time-domain output symbols from IFFT block 215 of size N to generate a serial time-domain signal. Cyclic prefix addition block 225 inserts a cyclic prefix into the time-domain signal. Upconverter 230 modulates (such as upconverts) the output of cyclic prefix block 225 to an RF frequency for transmission via a wireless channel. The signal can also be filtered at baseband before conversion to the RF frequency.

[0038] The transmitted RF signal from gNB 102 reaches UE 116 after passing through the wireless channel, and performs the opposite operations to those at gNB 102. Downconverter 255 downconverts the received signal to the baseband frequency, and cyclic prefix removal block 260 removes the cyclic prefix to generate a serial time-domain baseband signal. Serial-to-parallel block 265 converts the time-domain baseband signal into a parallel time-domain signal. An N-sized FFT block 270 performs an FFT algorithm to generate N parallel frequency-domain signals. Parallel-to-serial block 275 converts the parallel frequency-domain signals into a modulated data symbol sequence. Channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0039] Each of gNBs 101-103 can implement a transmit path 200 similar to that used for sending to UEs 111-116 in the downlink, and a receive path 250 similar to that used for receiving from UEs 111-116 in the uplink. Similarly, each of UEs 111-116 can implement a transmit path 200 for sending to gNBs 101-103 in the uplink, and a receive path 250 for receiving from gNBs 101-103 in the downlink.

[0040] Each component in Figures 2A and 2B can be implemented using only hardware or a combination of hardware and software / firmware. As a specific example, at least some components in Figures 2A and 2B can be implemented using software, while others can be implemented using configurable hardware or a hybrid of software and configurable hardware. For example, FFT block 270 and IFFT block 215 can be implemented as configurable software algorithms, where the value of size N can be modified depending on the implementation.

[0041] Furthermore, although described as using FFT and IFFT, this is merely an example and should not be construed as limiting the scope of this disclosure. Other types of transforms, such as the Discrete Fourier Transform (DFT) and Inverse Discrete Fourier Transform (IDFT) functions, can be used. It will be understood that for the DFT and IDFT functions, the value of the variable N can be any integer (such as 1, 2, 3, 4, etc.), while for the FFT and IFFT functions, the value of the variable N can be any integer that is a power of 2 (such as 1, 2, 4, 8, 16, etc.).

[0042] Although Figures 2A and 2B illustrate examples of wireless transmit and receive paths, various modifications can be made to them. For example, the various components in Figures 2A and 2B can be combined, further subdivided, or omitted, and additional components can be added as needed. Furthermore, Figures 2A and 2B are intended to illustrate examples of transmit and receive path types that can be used in wireless networks. Any other suitable architecture can be used to support wireless communication in a wireless network.

[0043] Figure 3A illustrates an example UE 116 according to an embodiment of this disclosure. The embodiment of UE 116 shown in Figure 3A is for illustrative purposes only, and Figure 1 UEs 111-115 may have the same or similar configurations. However, UEs have a variety of configurations, and Figure 3A does not limit the scope of this disclosure to any particular implementation of the UE.

[0044] As shown in Figure 3A, UE 116 includes an antenna 305, a transceiver 310, and a microphone 320. UE 116 also includes a speaker 330, a processor 340, an input / output (I / O) interface (IF) 345, an input 350, a display 355, and a memory 360. The memory 360 includes an operating system (OS) 361 and one or more applications 362.

[0045] Transceiver 310 receives an input RF signal transmitted by a gNB of network 100 from antenna 305. Transceiver 310 down-converts the input RF signal to generate an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry in transceiver 310 and / or processor 340, which generates a processed baseband signal by filtering, decoding, and / or digitizing the baseband or IF signal. The RX processing circuitry sends the processed baseband signal to speaker 330 (e.g., for voice data) or to processor 340 (e.g., for web browsing data).

[0046] The TX processing circuitry in transceiver 310 and / or processor 340 receives analog or digital voice data from microphone 320 or other output baseband data (such as network data, email, or interactive video game data) from processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. Transceiver 310 up-converts the baseband or IF signal into an RF signal transmitted via antenna 305.

[0047] Processor 340 may include one or more processors or other processing devices and executes OS 361 stored in memory 360 to control the overall operation of UE 116. For example, processor 340 may control transceiver 310 to receive DL channel signals and transmit UL channel signals according to known principles. In some embodiments, processor 340 includes at least one microprocessor or microcontroller.

[0048] Processor 340 is also capable of executing other processes and programs residing in memory 360, such as the process for LTM RLF reporting, which is discussed in more detail below. Processor 340 can move data into or out of memory 360 as needed for the executing process. In some embodiments, processor 340 is configured to execute application 362 based on OS 361 or in response to signals received from gNB or operator. Processor 340 is also coupled to I / O interface 345, which provides UE 116 with the ability to connect to other devices such as laptops and handheld computers. I / O interface 345 is the communication path between these accessories and processor 340.

[0049] The processor 340 is also coupled to input 350 and display 355. Input 350 includes, for example, a touchscreen, a keypad, etc. The operator of UE 116 can use input 350 to input data into UE 116. Display 355 may be a liquid crystal display, a light-emitting diode display, or other display capable of displaying text and / or at least limited graphics (such as from a website).

[0050] The memory 360 is coupled to the processor 340. A portion of the memory 360 may include random access memory (RAM), and another portion of the memory 360 may include flash memory or other read-only memory (ROM).

[0051] Although Figure 3A shows an example of UE 116, various changes can be made to Figure 3A. For example, the various components in Figure 3A can be combined, further subdivided, or omitted, and additional components can be added as needed. As a specific example, processor 340 can be divided into multiple processors, such as one or more central processing units (CPUs) and one or more graphics processing units (GPUs). In another example, transceiver 310 can include any number of transceivers and signal processing chains and can be connected to any number of antennas. Furthermore, although Figure 3A shows UE 116 configured as a mobile phone or smartphone, the UE can be configured to operate as other types of mobile or fixed devices.

[0052] Figure 3B illustrates an exemplary gNB 102 according to an embodiment of this disclosure. The embodiment of gNB 102 shown in Figure 3B is for illustrative purposes only, and Figure 1 gNBs 101 and 103 may have the same or similar configurations. However, gNBs have multiple configurations, and Figure 3B does not limit the scope of this disclosure to any particular implementation of the gNB.

[0053] As shown in Figure 3B, the gNB 102 includes multiple antennas 370a-370n, multiple transceivers 372a-372n, a controller / processor 378, a memory 380, and a backhaul or network interface 382.

[0054] Transceivers 372a-372n receive input RF signals from antennas 370a-370n, such as signals transmitted by a UE in network 100. Transceivers 372a-372n down-convert the input RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuitry in transceivers 372a-372n and / or controller / processor 378, which generates processed baseband signals by filtering, decoding, and / or digitizing the baseband or IF signals. Controller / processor 378 can further process the baseband signals.

[0055] The transmit (TX) processing circuitry in transceivers 372a-372n and / or controller / processor 378 receives analog or digital data (such as voice data, network data, email, or interactive video game data) from controller / processor 378. The TX processing circuitry encodes, multiplexes, and / or digitizes the output baseband data to generate a processed baseband or IF signal. Transceivers 372a-372n up-convert the baseband or IF signal into an RF signal transmitted via antennas 370a-370n.

[0056] The controller / processor 378 may include one or more processors or other processing devices for controlling the overall operation of the gNB 102. For example, the controller / processor 378 may control the transceivers 372a-372n to receive uplink (UL) channel signals and transmit downlink (DL) channel signals according to known principles. The controller / processor 378 may also support additional functions, such as more advanced wireless communication functions. For example, the controller / processor 378 may support beamforming or directional routing operations, wherein the output / input signals from / to multiple antennas 370a-370n are weighted differently to efficiently guide the output signals in the desired direction. The controller / processor 378 may support any of a variety of other functions in the gNB 102.

[0057] The controller / processor 378 is also capable of executing programs and other processes residing in memory 380, such as the OS, and processes supporting RLF reporting for LTM, as discussed in more detail below. The controller / processor 378 can move data into or out of memory 380 as needed by the executing processes.

[0058] The controller / processor 378 is also coupled to a backhaul or network interface 382. The backhaul or network interface 382 allows the gNB 102 to communicate with other devices or systems via a backhaul connection or over a network. Interface 382 can support communication via any suitable wired or wireless connection. For example, when the gNB 102 is implemented as part of a cellular communication system (e.g., a system supporting 5G / NR, LTE, or LTE-A), interface 382 can allow the gNB 102 to communicate with other gNBs via a wired or wireless backhaul connection. When the gNB 102 is implemented as an access point, interface 382 can allow the gNB 102 to communicate with a larger network (such as the Internet) via a wired or wireless local area network or via a wired or wireless connection. Interface 382 includes any suitable architecture that supports communication via wired or wireless connections (such as Ethernet or transceivers).

[0059] The memory 380 is coupled to the controller / processor 378. A portion of the memory 380 may include RAM, and another portion of the memory 380 may include flash memory or other ROM.

[0060] Although Figure 3B shows an example of gNB 102, various changes can be made to Figure 3B. For example, gNB 102 may include any number of each component shown in Figure 3B. Furthermore, the individual components in Figure 3B may be combined, further subdivided, or omitted, and additional components may be added as needed.

[0061] In next-generation wireless communication systems operating in higher frequency (mmWave) bands (e.g., 5G, 5G+, 6G), UEs and gNBs use beamforming to communicate with each other. Beamforming technology is used to mitigate propagation path loss and increase propagation distance when communicating in higher frequency bands. Beamforming enhances the transmit and receive performance using high-gain antennas. Beamforming can be classified into transmit (TX) beamforming performed at the transmitter and receive (RX) beamforming performed at the receiver. Typically, TX beamforming increases directivity by densely positioning multiple antennas in a specific direction to allow propagation to reach an area. In this case, the aggregation of multiple antennas can be called an antenna array, and each antenna included in the array can be called an array element. Antenna arrays can be configured in various forms, such as linear arrays, planar arrays, etc. The use of TX beamforming results in increased signal directivity, thereby increasing propagation distance. Furthermore, since the signal propagates almost entirely outside the directional direction, signal interference acting on the other receiver is significantly reduced. The receiver can perform beamforming on the RX signal by using an RX antenna array. RX beamforming increases the strength of the RX signal received from a specific direction by allowing propagation to be concentrated in that direction, and excludes signals transmitted in directions other than that specific direction from the RX signal, thus providing a blocking effect against interfering signals. By using beamforming technology, a transmitter can generate multiple transmit beam patterns in different directions. Each of these transmit beam patterns can also be referred to as a transmit (TX) beam. Wireless communication systems operating at high frequencies use multiple narrow TX beams to transmit signals within a cell because each narrow TX beam provides coverage to a portion of the cell. The narrower the TX beam, the higher the antenna gain, and therefore the greater the propagation distance of the signal transmitted using beamforming. Receivers can also generate multiple receive (RX) beam patterns in different directions. Each of these receive patterns can also be referred to as a receive (RX) beam.

[0062] Next-generation wireless communication systems (e.g., 5G, 5G+, 6G) support standalone operation mode and dual connectivity (DC). In DC, multiple Rx / Tx UEs can be configured to utilize resources provided by two different nodes (or NBs) via a non-ideal backhaul connection. One node acts as the primary node (MN), and the other acts as the secondary node (SN). The MN and SN are connected via a network interface, and at least the MN is connected to the core network. NR also supports multi-RAT dual connectivity (MR-DC) operation, whereby a UE in RRC_CONNECTED state is configured to utilize radio resources provided by two different schedulers located in two different nodes via a non-ideal backhaul connection and providing E-UTRA (i.e., if the node is an ng-eNB) or NR access (i.e., if the node is a gNB). In NR, for a UE in RRC_CONNECTED state without carrier aggregation (CA) / DC configured, there is only one serving cell including the primary cell. For a UE configured with CA / DC in the RRC_CONNECTED state, the term "serving cell" refers to the set of cells including the special cell and all secondary cells. In NR, the term Primary Cell Group (MCG) refers to a group of serving cells associated with the primary node, including the primary cell (PCell) and one or more optional SCells. In NR, the term Secondary Cell Group (SCG) refers to a group of serving cells associated with the secondary node, including the PSCell and one or more optional secondary cells (SCells). In NR, a PCell refers to the serving cell in the MCG operating on the primary frequency, where the UE performs an initial connection establishment procedure or initiates a connection re-establishment procedure. In NR, for a UE configured with CA, an Scell ​​refers to a cell that provides additional radio resources on top of the special cell. The primary SCG cell (PSCell) refers to the serving cell in the SCG, where the UE performs random access when performing a reconfiguration procedure with synchronization. For dual connectivity operation, the term SpCell (i.e., special cell) refers to either the PCell of the MCG or the PSCell of the SCG. Otherwise, the term special cell refers to the PCell.

[0063] In next-generation wireless communication systems (e.g., 5G, 5G+, 6G), the node B (gNB) or base station in a cell broadcasts synchronization signals and PBCH blocks (SSBs), which include primary synchronization signals and secondary synchronization signals (PSS, SSS) as well as system information. System information includes common parameters required for communication within the cell. In fifth-generation wireless communication systems (also known as next-generation radio or NR), system information (SI) is divided into a main information block (MIB) and multiple system information blocks (SIBs). The MIB can be transmitted on the broadcast channel (BCH) at a period of 80ms and repeated within 80ms. The MIB includes the parameters required to obtain SIB1 from the cell. SIB1 is transmitted on the downlink shared channel (DL-SCH) at a period of 160ms with variable transmission repetition. The default transmission repetition period for SIB1 is 20ms, but the actual transmission repetition period depends on the network implementation. For SSB and Control Resource Set (CORESET) multiplexing mode 1, SIB1 The retransmission period is 20ms. For SSB and CORESET multiplexing modes 2 / 3, SIB1 The transmission repetition period is the same as the SSB period. SIB1 This includes information about the availability and scheduling of other SIBs (e.g., SIB-to-SI message mapping, period, SI window size), an indication of whether only one or more SIBs are provided on demand, and the configuration required for the UE to execute an SI request in the on-demand provision scenario. SIB1 is a cell-specific SIB; in addition to SIB1 SIBs other than posSIB SystemInformation (SI) messages are carried within the SI message set and transmitted on the DL-SCH. Only SIBs or posSIBs with the same period can be mapped to the same SI message. SIBs and posSIBs are mapped to different SI messages. Each SI message is transmitted within a periodically occurring time-domain window (called an SI window, which has the same length for all SI messages). Each SI message is associated with an SI window, and the SI windows for different SI messages do not overlap. That is, only the corresponding SI message is transmitted within an SI window. SI messages can be transmitted multiple times within an SI window. SIB1 The instructions in the document, except SIB1 Any SIB or posSIB other than the one provided can be configured as cell-specific or region-specific. Cell-specific SIBs are only applicable within the cell providing the SIB, while region-specific SIBs are applicable within a region called an SI region, which consists of one or more cells and is defined by s systemInformationAreaID To identify; the mapping of SIB to SI messages in schedulingInfoList The configuration is in the middle, and the mapping of posSIB to SI messages is in pos-SchedulingInfoListThe configuration is as follows: Each SIB is included in a single SI message, and each SIB and posSIB is included at most once in that SI message. For UEs in the RRC_CONNECTED state, the network can use... RRCReconfiguration System information is provided via dedicated signaling (e.g., if the UE has an active BWP that does not have a common search space configured to monitor system information), paging, or upon request from the UE. In the RRC_CONNECTED state, the UE obtains the required SIB from the PCell. For PSCell and SCell, the network provides system information via dedicated signaling (i.e., in...). RRCReconfiguration (The message contains) the required SI. Nevertheless, the UE should obtain the PSCell. MIB To obtain the SFN timing of the SCG (which may differ from the MCG). When the associated SI of an SCell changes, the network releases and adds the associated SCell. For PSCells, the required SI is changed through a reconfiguration with synchronization.

[0064] In next-generation wireless communication systems (e.g., 5G, 5G+, 6G), the Physical Downlink Control Channel (PDCCH) is used to schedule DL transmissions on the Physical Downlink Shared Channel (PDSCH) and UL transmissions on the Physical Uplink Shared Channel (PUSCH). The downlink control information (DCI) on the PDCCH includes: downlink allocation containing at least modulation and coding formats, resource allocation, and hybrid ARQ information related to the DL-SCH; and uplink scheduling authorization containing at least modulation and coding formats, resource allocation, and hybrid ARQ information related to the Uplink Shared Channel (UL-SCH). In addition to scheduling, PDCCH can also be used for: activating and deactivating configured PUSCH transmissions with configuration authorization; activating and deactivating PDSCH semi-persistent transmissions; notifying one or more UEs of slot formats; notifying one or more UEs of PRBs and OFDM symbols on which the UE can assume there are no transmissions for that UE; sending transmit power control (TPC) commands for PUCCH and PUSCH; sending one or more TPC commands for sounding reference signal (SRS) transmissions by one or more UEs; switching the active bandwidth portion of a UE; and initiating random access procedures. The UE monitors a set of PDCCH candidates in one or more configured control resource sets (CORESETs) according to the corresponding search space configuration. A CORESET includes a set of PRBs with a duration of 1 to 3 OFDM symbols. Resource element groups (REGs) and control channel elements (CCEs) are defined within a CORESET, with each CCE including a set of REGs. Control channels are formed by the aggregation of CCEs. Different code rates for control channels are achieved by aggregating different numbers of CCEs. CORESET supports interleaved and non-interleaved CCE-to-REG mapping. Polar coding is used for PDCCH. Each resource element group carrying PDCCH carries its own demodulation reference signal (DMRS). QPSK modulation is used for PDCCH.

[0065] In next-generation wireless communication systems (e.g., 5G, 5G+, 6G), for each BWP configuration of the serving cell, the gNB signals a list of search space configurations, where each search configuration is uniquely identified by a search space identifier. The search space identifier is unique within the serving cell's BWP. For each BWP configuration, the gNB explicitly signals the identifier of the search space configuration used for a specific purpose (such as paging reception, SI reception, and random access response reception). In NR, the search space configuration includes the parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot, and duration. The UE uses the parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, and Monitoring-symbols-PDCCH-within-slot to determine the timing of PDCCH monitoring within a time slot. PDCCH monitoring occurs between time slot "x" and "x + duration", where time slot "x" in a radio frame with number "y" satisfies the following equation: (Y) (Number of time slots in the wireless frame) + x - Monitoring-offset-PDCCH-slot) mod (Monitoring-periodicity-PDCCH-slot) = 0; The start symbol of the PDCCH monitoring opportunity in each slot with a PDCCH monitoring opportunity is given by Monitoring-symbols-PDCCH-within-slot. The length of the PDCCH monitoring opportunity (in symbolic form) is given in the CORESET associated with the search space. The search space configuration includes an identifier for the CORESET configuration associated with the search space. For each configuration of the BWP of the serving cell, the gNB signals a list of CORESET configurations, where each CORESET configuration is uniquely identified by a CORESET identifier. The CORESET identifier is unique within the BWP of the serving cell. Note that each radio frame has a duration of 10 ms. Each radio frame is identified by a radio frame number or a system frame number. Each radio frame includes several slots, where the number of slots and the slot duration in the radio frame depend on the subcarrier spacing. In NR, the number of slots and the slot duration in the radio frame are predefined for each supported SCS. Each CORESET configuration is associated with a list of Transport Configuration Indicator (TCI) states. Each TCI state configures a DL RS ID (SSB or CSI RS). The TCI status list corresponding to the CORESET configuration is signaled by the gNB via RRC signaling. One of the TCI statuses in the TCI status list is activated by the gNB and indicated to the UE. The TCI status indicates the DL TX beam used by the gNB to transmit the PDCCH during the PDCCH monitoring time in the search space (the DL TX beam and the SSB / CSI RS of the TCI status are quasi-co-located (QCLed)).

[0066] In next-generation wireless communication systems (e.g., 5G, beyond 5G, 6G), bandwidth adaptation (BA) is supported. Using BA, the UE's receive and transmit bandwidth does not need to be as large as the cell's bandwidth and can be adjusted: the bandwidth can be commanded to change (e.g., shrinking during low-activity periods to save power); the location can be moved in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be commanded to change (e.g., to allow different services). A subset of the cell's total cell bandwidth is called the bandwidth portion (BWP). BA is implemented by configuring BWPs for RRC-connected UEs and informing the UE which of the configured BWPs is currently active. When BA is configured, the UE monitors the PDCCH on an active BWP; that is, the UE does not need to monitor the PDCCH on the entire DL frequency of the serving cell. In RRC connected state, the UE has one or more DL and UL BWPs configured for each configured serving cell (i.e., PCell or SCell). For an active serving cell, there is always one active UL and DL BWP at any given time. Serving cell BWP handover is used to activate an inactive BWP and deactivate the active BWP at a given time. BWP handover is controlled via the PDCCH indicating downlink allocation or uplink grant, via the bwp-InactivityTimer, via RRC signaling, or via the MAC entity itself during the initiation of the random access procedure. When adding a SpCell or activating an SCell, the DL BWP and UL BWP, indicated by firstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id respectively, are active without receiving the PDCCH indicating downlink allocation or uplink grant. The active BWP for the serving cell is indicated via RRC or PDCCH. For unpaired spectrum, the DL BWP is paired with the UL BWP, and BWP handover is common to both UL and DL. When the BWP inactivity timer expires, the UE switches the active DL BWP to the default DL BWP or the initial DL BWP (if the default DL BWP is not configured).

[0067] In next-generation wireless communication systems (e.g., 5G, 5G+, 6G), there are two types of mobility: cell-level mobility and beam-level mobility. Cell-level mobility is triggered (i.e., handover) using explicit RRC signaling. For inter-gNB handover, the signaling process includes at least the following: Figure 4 The components shown.

[0068] Figure 4 An example signaling procedure 400 for inter-gNB handover according to an embodiment of this disclosure is shown. Figure 4 The illustrated examples of signaling procedures are for illustrative purposes only. Figure 4One or more of the components shown may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function. Other embodiments of the signaling procedure for inter-gNB handover may be used without departing from the scope of this disclosure.

[0069] exist Figure 4 In the example, source gNB 404 initiates a handover and sends a handover request 410 to target gNB 406 via the Xn interface. In step 415, the target gNB performs admission control and provides a new RRC configuration as part of the handover request confirmation 420. Source gNB 404 forwards the RRC reconfiguration received in the handover request confirmation 420. RRCReconfiguration Message 430 is sent to provide RRC configuration to UE 402. RRCReconfiguration Message 430 includes at least the cell ID and all the information required to access the target cell, so that UE 402 can access the target cell without reading system information. In some cases, information required for contention-based and contention-free random access may be included. RRCReconfiguration In message 430, the access information for the target cell may include beam-specific information (if present). In step 435, UE 402 moves the RRC connection to the target gNB 406 and completes the RRC reconfiguration. RRCReconfigurationComplete Respond to message 440. Figure 4 Examples of this can be referred to as a network-controlled or network-initiated handover process.

[0070] although Figure 4 An example of a signaling procedure 400 for inter-gNB handover is shown, but it is possible to modify it further. Figure 4 Make various changes. For example, although it is shown as a series of steps, Figure 4 The steps in the process can overlap, occur in parallel, occur in different orders, be repeated any number of times, be omitted, or be replaced by other steps.

[0071] In addition to network-controlled / network-initiated handover, next-generation wireless communication systems (e.g., 5G, 5G+, 6G) also support conditional handover and Dual Active Protocol Stack (DAPS) handover. In conditional handover, the network can configure one or more candidate cells and one or more L3-based measurement events for the handover, based on which the UE determines to execute the handover procedure. In DAPS handover, the UE continuously receives downlink user data from the source gNB until the source cell is released, and continuously transmits uplink user data to the source gNB until the random access procedure to the target gNB is successful.

[0072] Layer 1 (L1) / Layer 2 (L2) triggered mobility, also referred to herein as low-layer triggered mobility (LTM), is a process in which the gNB receives an L1 measurement report from the UE and, based on the L1 measurement report, changes the UE's serving cell via a cell handover command signaled via the MAC CE. The cell handover command indicates the LTM candidate cell configuration previously prepared by the gNB and provided to the UE via RRC signaling. The UE then hands over to the target cell according to the cell handover command. The LTM procedure can be used to reduce mobility latency. The network can request the UE to perform early TA acquisition of the candidate cell before cell handover. Early TA acquisition is triggered by a PDCCH command or by UE-based TA measurements.

[0073] The network indicates in the cell handover command whether the UE should use the Random Access (RA) procedure to access the target cell (if no TA value is provided), or use the indicated TA value to access the target cell via PUSCH transmission. For LTM without RACH, the UE accesses the target cell via the configuration grant provided in the RRC signaling and selects the configuration grant timing associated with the beam indicated in the cell handover command. The UE can monitor the PDCCH from the target cell for dynamic scheduling during LTM cell handover.

[0074] Figure 5 An example process 500 for LTM according to an embodiment of this disclosure is shown. Figure 5 The embodiments of the methods shown are for illustrative purposes only. Figure 5 One or more of the components shown may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function. Other embodiments of the process for LTM may be used without departing from the scope of this disclosure.

[0075] exist Figure 5 In the example, process 500 begins in step 1. In step 1, UE 502, in RRC connected state, sends a measurement report to gNB 504. Measurement Report The message indicates that gNB 504 has been configured with LTM and initiated candidate cell preparation.

[0076] In step 2, gNB 504 sends an RRC reconfiguration to UE 502, including the LTM candidate cell configuration of one or more candidate cells. RRCReconfiguration )information.

[0077] In step 3, UE 502 stores the LTM candidate cell configuration and sends an RRC reconfiguration completion message to gNB 504. RRCReconfigurationComplete )information.

[0078] In step 4a, UE 502 can perform DL synchronization with the candidate cell before receiving the cell handover command.

[0079] In step 4b, if requested by the network, UE 502 performs an early TA acquisition with the candidate cell before receiving the cell handover command. This is accomplished via contention-free random access (CFRA) triggered by a PDCCH command from the source cell, after which UE 502 sends a preamble to the indicated candidate cell. To minimize data interruption in the source cell due to CFRA to the candidate cell, UE 502 does not receive a RAR for TA value acquisition, and the TA value of the candidate cell is indicated in the cell handover command. UE 502 does not maintain a TA timer for the candidate cell and relies on the network implementation to guarantee the validity of the TA.

[0080] In step 5, UE 502 performs L1 measurement on the configured candidate cells and sends an L1 measurement report to gNB.

[0081] In step 6, gNB 504 determines to perform a cell handover to the target cell and sends a MACCE that triggers the handover, including a candidate configuration index for the target cell. UE 502 switches to the target cell and applies the configuration indicated by the candidate configuration index.

[0082] In step 7, if the UE does not have a valid TA for the target cell, the UE 502 performs a random access procedure to the target cell.

[0083] In step 8, UE 502 sends a message to the target cell. RRCReconfigurationComplete The LTM cell handover process is completed using a message. If UE 502 has already performed the RA procedure in step 7, then UE 502 considers the LTM execution to be successfully completed when the random access procedure is successfully completed. For LTM without RACH, UE 502 considers the LTM execution to be successfully completed when the UE determines that the network has successfully received its first UL data. UE 502 determines the successful reception of its first UL data by receiving a PDCCH in the target cell that addresses UE 502's C-RNTI. This PDCCH schedules new transmissions following the first UL data.

[0084] For LTM, the network can indicate one or more events based on L1 measurements. Based on these events, the UE 502 can initiate LTM execution on candidate LTM cells without receiving cell handover commands from the gNB 504. This process can be referred to as conditional LTM or UE-initiated LTM. The list of one or more candidate LTM cells for conditional LTM or UE-initiated LTM can be provided by the gNB 504. RRCReconfigurationSend a signal notification in the message (step 2).

[0085] although Figure 5 An example procedure 500 for LTM is shown, but it is possible to modify it. Figure 5 Make various changes. For example, although it is shown as a series of steps, Figure 5 The steps in the process can overlap, occur in parallel, occur in different orders, be repeated any number of times, be omitted, or be replaced by other steps.

[0086] In next-generation wireless communication systems (e.g., 5G, 5G+, 6G), the UE prepares a radio link failure report in the event of handover failure, conditional handover failure, DAPS handover failure, or radio link failure (RLF). The UE indicates the availability of the RLF report in the resumeComplete (during the RRC connection recovery process), setupComplete (during the RRC connection establishment process), and ReconfigurationComplete (during the RRC reconfiguration process) messages. The gNB can use the UE information request ( UEInformationRequest ) message rlf-ReportReq The UE requests an RLF report. The UE responds with the UE information ( UEInformationResponse The requested report is sent to the gNB in ​​the message.

[0087] Received RLF reports help the network optimize the configuration for handover failures, conditional handover failures, and DAPS handover failures or radio link failures (RLFs). Currently, no information is reported to the network in the case of UE-initiated L1 / L2-triggered mobility / cell handover failures. Therefore, enhancements to radio link failure reporting for L1 / L2-triggered mobility / cell handover failures are desired.

[0088] Various embodiments of this disclosure provide enhanced RLF reporting for reporting L1 / L2-triggered mobility / cell handover failures.

[0089] In some embodiments, the new switch type "CLTM" can be used in fields of the RLF report. lastHO-Type .

[0090] In some embodiments, the RLF report may include new fields. timeSinceLTM-Reconfig In the event of a conditional LTM failure, this field can be used to indicate the time elapsed between initiating the last conditional LTM execution towards the target cell and receiving the latest conditional LTM reconfiguration. In the event of a radio link failure, this field can be used to indicate the time elapsed between radio link failure and receiving the latest conditional LTM reconfiguration when connecting to the source PCell.

[0091] In some embodiments, the RLF report may include new fields. condltmCandidateCellList This field can be used to indicate whether to include [something] in the event of a connection failure. condltm-Config The list of candidate target cells for conditional LTM. In some embodiments, this field does not include... measResulNeighCells The candidate target cells included in the list.

[0092] In some embodiments, the RLF report may include new fields. CondltmCellId This field can be used to indicate whether something is included. Condltm-Config The candidate target cell selected by the UE for conditional LTM-based recovery during timer T311.

[0093] This disclosure provides various embodiments of a process for setting / reporting the aforementioned new parameters and / or new fields.

[0094] In some embodiments, the UE (such as, Figure 1 UE 116 can determine the content of the RLF report according to the following procedure: if connectionFailureType yes rlf and rlf-Cause Set as randomAccessProblem or beamFailureRecoveryFailure , or if connectionFailureType yes hof And if the failed handover is an intra-RAT handover, then the UE will ra-InformationCommon Configure to include random access information. If available, configure the UE settings. locationInfo .

[0095] If a failure is detected due to a reconfiguration failure with synchronization, the UE will VarRLF-report The fields are set as follows: -UE will connectionFailureType Set as hof .

[0096] - If the UE supports RLF reporting for DAPS handover, and if any DAPS bearer is configured during T304 operation: a) The UE will lastHO-Type Set as daps and b) If a radio link failure is detected in the source PCell, the UE will timeConnSourceDAPS-Failure Set to the time between initiating DAPS handover execution when timer T304 runs and detecting a wireless link failure in the source PCell, and set rlf-Cause Set as the trigger reason when a source wireless link failure is detected.

[0097] - If the UE supports RLF reporting for conditional handover, and if the conditional handover configuration is in the MCG in case of handover failure. VarConditionalReconfig Available in China: If the UE performs a conditional handover to the target PCell based on the target PCell's condRRCReconfig, then the UE will timeSinceCHO-Reconfig Configured to execute the target PCell, including switching for failure conditions. reconfigurationWithSync The last time RRCReconfiguration The message received in the source PCell includes the target PCell's failure condition switch. condRRCReconfig The last time conditionalReconfiguration The time elapsed between these points. Otherwise, the UE will... timeSinceCHO-Reconfig Configured to execute target PCell including failover. reconfigurationWithSync The last time RRCReconfiguration The message received in the source PCell includes condRRCReconfig The last time conditionalReconfiguration The time elapsed between them.

[0098] ○UE will collect choCandidateCellList Configure to include the global cell identifier (if available), otherwise include it in the MCG upon handover failure. VarConditionalReconfig within condRRCReconfig The physical cell identifier and carrier frequency of each of the candidate target cells included for conditional handover are excluded. measResulNeighCells The candidate target cells included in the list.

[0099] - If the UE supports RLF reporting for conditional LTM, and if the conditional LTM configuration fails in the MCG during handover failure (i.e., reconfiguration failure with synchronization). VarCondLTM-UE-Config Available in China: If the UE performs conditional LTM on the target PCell according to the target PCell's conditional LTM configuration, then the UE will timeSinceCondLTM-Reconfig Configured to execute the target PCell, including LTM for failure conditions. reconfigurationWithSync The last time RRCReconfiguration The message is the last time the target PCell's condition LTM configuration, including the failure condition LTM, is received in the source PCell. Condltm-Config The time elapsed between these points. Otherwise, the UE will... timeSinceCondLTM-Reconfig Configured to execute target PCells including those for failed LTM (or failure switchover). reconfigurationWithSync The last time RRCReconfiguration The message received in the source PCell includes the last conditional LTM configuration. Condltm-Config The time elapsed between them.

[0100] ○UE will condltmCandidateCellList Configure to include the global cell identifier (if available), otherwise include it in the MCG upon handover failure. VarCondLTM-UE-Config within ue-CondLTM-Config The physical cell identifier and carrier frequency of each of the candidate target cells used for LTM are included, but exclude... measResulNeighCells The candidate target cells included in the list.

[0101] - If the UE supports RLF reporting for LTM, and if the last executed RRCReconfiguration message including reconfigurationWithSync is related to conditional LTM, then the UE will lastHO- Type Set as cltm .

[0102] -UE will failedPCellId In nrFailedPCellId Set to the global cell identifier and tracking area code (if available), otherwise set to the physical cell identifier and carrier frequency of the target PCell in the failed handover.

[0103] -UE in previousPCellId Including nrPreviousCell And set them to receive including reconfigurationWithSync The last time RRCReconfiguration The message contains the global cell identifier and tracking area code of the PCell.

[0104] -UE will timeConnFailure Set to self-executable reconfigurationWithSync The last time RRCReconfiguration The time elapsed since the news was received.

[0105] Otherwise, if a failure is detected due to a radio link failure, the UE will VarRLF-report The field settings are as follows: -UE will connectionFailureType Set as rlf .

[0106] -UE will rlf-Cause Set as the trigger reason when a wireless link failure is detected.

[0107] -UE will failedPCellId In nrFailedPCellId Set to the global cell identifier and tracking area code (if available), otherwise set to the physical cell identifier and carrier frequency of the PCell that detected the radio link failure.

[0108] -If received before connection failure, including reconfigurationWithSync of RRCReconfiguration information: ○If the final successful execution includes reconfigurationWithSync of RRCReconfiguration The message pertains to intra-NR handover, and is received upon connection to the previous PCell (where the previous PCell is the PCell the UE connected to before the PCell where the radio link failure was detected), and if timer T311 did not run before entering the PCell where the radio link failure was detected, then: a) the UE in previousPCellId Including nrPreviousCell And set it to receive the last executed, including reconfigurationWithSync of RRCReconfiguration The message's PCell global cell identifier and tracking area code. b) If the last executed message includes... reconfigurationWithSync of RRCReconfiguration If the message involves DAPS handover, the UE will lastHO-Type Set as daps c) Otherwise, if the last execution includes reconfigurationWithSync of RRCReconfiguration If the message involves condition switching, the UE will lastHO-Type Set as cho d) Otherwise, if the last execution includes reconfigurationWithSync of RRCReconfiguration If the message involves conditional LTM, then the UE will lastHO-Type Set as cltm e) Finally, the UE will timeConnFailure Set to self-executable reconfigurationWithSync The last time RRCReconfiguration The time elapsed since the news was received.

[0109] Otherwise, if included reconfigurationWithSync The last time RRCReconfiguration The message pertains to the handover from E-UTRA to NR, and if the UE supports radio link failure reporting for inter-RAT MRO EUTRA, then the UE... previousPCellId Including eutraPreviousCell And set it to receive messages embedded in E-UTRARRC. MobilityFromEUTRACommand The message includes reconfigurationWithSync The last time RRCReconfiguration The message contains the global cell identifier and tracking area code of the PCell. Then, the UE will... timeConnFailure Configured to receive embedded E-UTRA RRC messages MobilityFromEUTRACommand The message includes reconfigurationWithSync The last time RRCReconfiguration The time elapsed since the news was received.

[0110] - If the conditional switching configuration is in MCG at the moment the wireless link failure is declared. VarConditionalReconfig If it is available in the middle, then the UE will timeSinceCHO-ReconfigConfigured to detect wireless link failure and receive data in the source PCell including condRRCReconfig The last message conditionalReconfiguration The time elapsed between then and then. Then, the UE will... choCandidateCellList Configure to include the global cell identifier (if available), otherwise include the MCG in case of radio link failure. VarConditionalReconfig within condRRCReconfig The data includes the physical cell identifier and carrier frequency of each of all candidate target cells used for conditional handover, but excludes... measResulNeighCells The candidate target cells included in the list.

[0111] - If the conditional LTM configuration is in the MCG at the moment the radio link failure is declared. VarCondLTM-UE-Config If it is available in the middle, then the UE will timeSinceCondLTM-Reconfig Configured to detect wireless link failure and receive the last one in the source PCell. Condltm-Config The time elapsed between then and then. Then, the UE will... condltmCandidateCellList Configure to include the global cell identifier (if available), otherwise include the MCG in case of radio link failure. VarCondLTM-UE- Config within ue-CondLTM-Config The physical cell identifier and carrier frequency of each of the candidate target cells used for conditional LTM are included, but exclude... measResulNeighCells The candidate target cells included in the list.

[0112] Figure 6 An example process 600 for RLF reporting according to an embodiment of this disclosure is shown. Figure 6 The embodiments of the methods shown are for illustrative purposes only. Figure 6 One or more of the components shown may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function. Other embodiments of the process for RLF reporting may be used without departing from the scope of this disclosure.

[0113] exist Figure 6In the example, process 600 begins at step 610. At step 610, UE 602 receives an RRC Reconfiguration message from source serving cell 604 (or from the gNB of source serving cell 604, which may be a PCell), and confirms receipt at step 615 by sending an RRC Reconfiguration Complete message to serving cell 604 (or to the gNB of source serving cell 604). The RRC Reconfiguration message may include conditional LTM configuration for one or more candidate LTM cells. The conditional LTM configuration may include an RRC Reconfiguration message for each of the candidate LTM cells, wherein the RRC Reconfiguration message includes a Reconfigurationwithsync information element (IE). The conditional LTM configuration may include one or more L1 measurement events / quantities, based on which UE 602 determines to perform conditional LTM on one of the candidate LTM cells.

[0114] In step 620, when the criteria for performing a conditional LTM cell handover to the target PCell are met, UE 602 initiates a conditional LTM cell handover to the target PCell (i.e., a candidate cell from the conditional LTM candidate cells). As part of the execution, UE 602 applies an RRCReconfiguration message including a Reconfigurationwithsync IE for the target PCell. UE 602 may start a timer when initiating the conditional LTM cell handover to the target PCell. This timer (e.g., timer "X") stops when the execution of the conditional LTM cell handover to the target PCell is successfully completed (e.g., when the RA procedure to the target PCell is successfully completed or when the UE receives a PDCCH addressed to the C-RNTI from the target PCell).

[0115] In step 625, the conditional LTM cell handover to the target PCell may fail (e.g., when timer "X" expires). If the conditional LTM cell handover to the target PCell fails, UE 602 generates an RLF report in response to the failed LTM cell handover, as follows: In step 630, UE 602 includes the time "T1" in the RLF report (i.e., UE 602 sets the timeSinceCondLTM-Reconfig in the RLF report to T1, or...). timeSinceCondLTM-Reconfig Configured to perform target PCell handover including LTM cell handover for failure conditions. reconfigurationWithSyncThe last time RRCReconfiguration The message is the last time the target PCell's condition LTM configuration, including the failure condition LTM, is received in the source PCell. Condltm-Config (The time elapsed between).

[0116] In step 635, UE 602 indicates in the RLF report that the last handover type was conditional LTM (i.e., UE 602 sets lastHO-Type to cltm in the RLF report).

[0117] In step 640, UE 602 indicates a list of one or more candidate conditional LTM cells in the RLF report (i.e., UE 602 will...). condltmCandidateCellList Configure to include the global cell identifier (if available), otherwise include the MCG in case of radio link failure. VarCondLTM-UE-Config within ue-CondLTM-Config The physical cell identifier and carrier frequency of each of the candidate target cells used for conditional LTM are included, but exclude... measResulNeighCells (Includes candidate target cells).

[0118] In step 645, UE 602 includes information about the target PCell for the failure condition LTM cell handover in the RLF report (this information may be the global cell identifier and tracking area code (if available), or the physical cell identifier and carrier frequency otherwise).

[0119] In step 650, UE 602 includes information about the source PCell in the RLF report (this information may be received from the PCell). reconfigurationWithSync The last time RRCReconfiguration The message's PCell global cell identifier and tracking area code.

[0120] In step 655, UE 602 includes the time "T2" in the RLF report (i.e., UE 602 will include the time "T2" in the RLF report). timeConnFailure Set to T2).

[0121] In some embodiments, UE 602 includes location information in the RLF report.

[0122] In step 660, UE 602 sends an RLF report to gNB (i.e., VarRLF-Report (For example, when a request is received from gNB).

[0123] although Figure 6 A sample procedure 600 for RLF reporting is shown, but it is possible to modify it for other purposes. Figure 6 Make various changes. For example, although it is shown as a series of steps, Figure 6The steps in the process can overlap, occur in parallel, occur in different orders, be repeated any number of times, be omitted, or be replaced by other steps.

[0124] Although Figure 6 The operations during the process are described as being performed for conditional LTM cell handover, but in some embodiments... Figure 6 Any operation during the process can be applied during network-initiated LTM cell handover, and the phrase "condition" can be omitted in operations applied to network-initiated LTM cell handover.

[0125] Figure 7 Another example process 700 for RLF reporting according to an embodiment of this disclosure is shown. Figure 7 The embodiments of the methods shown are for illustrative purposes only. Figure 7 One or more of the components shown may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function. Other embodiments of the process for RLF reporting may be used without departing from the scope of this disclosure.

[0126] exist Figure 7 In the example, process 700 begins at step 710. At step 710, UE 702 receives an RRC Reconfiguration message from source serving cell 704 (or from the gNB of source serving cell 704, which may be a PCell), and confirms receipt at step 715 by sending an RRC Reconfiguration Complete message to serving cell 704 (or to the gNB of source serving cell 704). The RRC Reconfiguration message may include conditional LTM configuration for one or more candidate LTM cells. The conditional LTM configuration may include an RRC Reconfiguration message for each of the candidate LTM cells, wherein the RRC Reconfiguration message includes a Reconfigurationwithsync IE. The conditional LTM configuration may include one or more L1 measurement events / quantities, based on which UE 702 determines to perform conditional LTM on one of the candidate LTM cells.

[0127] In step 720, UE 702 receives a command from the network to switch to the target PCell. This command may be an RRCReconfiguration message, including a Reconfigurationwithsync IE for the target PCell.

[0128] In step 725, UE 702 initiates a handover to the target PCell. As part of the execution, UE 702 applies an RRCReconfiguration message including a Reconfigurationwithsync IE for the target PCell. UE 702 may start a timer when initiating the handover to the target PCell. This timer (e.g., timer "X") stops when the handover to the target PCell is successfully completed (e.g., when the RA procedure to the target PCell is successfully completed or when UE 702 receives a PDCCH addressed to the C-RNTI from the target PCell).

[0129] In step 730, the handover to the target PCell may fail (e.g., when timer "X" expires). If the handover to the target PCell fails, UE 702 generates an RLF report as follows: In step 735, UE 702 includes the time "T1" in the RLF report (i.e., UE 702 sets the timeSinceCondLTM-Reconfig in the RLF report to T1, or...). timeSinceCondLTM-Reconfig Configured to execute target PCell including failover. reconfigurationWithSync The last time RRCReconfiguration The message is the last one received in the source PCell with the conditional LTM configuration for the target PCell, including the failed handover. Condltm-Config (The time elapsed between).

[0130] In step 740, UE 702 indicates a list of one or more candidate conditional LTM cells in the RLF report (i.e., UE 702 will...). condltmCandidateCellList Configure to include the global cell identifier (if available), otherwise include the MCG in case of radio link failure. VarCondLTM-UE-Config within ue-CondLTM-Config The physical cell identifier and carrier frequency of each of the candidate target cells used for conditional LTM are included, but exclude... measResulNeighCells (Includes candidate target cells).

[0131] In step 745, UE 702 includes information about the target PCell of the failed handover in the RLF report (this information may be the global cell identifier and tracking area code (if available), or the physical cell identifier and carrier frequency otherwise).

[0132] In step 750, UE 702 includes information about the source PCell in the RLF report (this information may be received from the PCell). reconfigurationWithSync The last time RRCReconfigurationThe message's PCell global cell identifier and tracking area code.

[0133] In step 755, UE 702 includes the time "T2" in the RLF report (i.e., UE 702 will include the time "T2" in the RLF report). timeConnFailure Set to T2).

[0134] In some embodiments, UE 702 includes location information in the RLF report.

[0135] In step 760, UE 702 sends an RLF report to gNB (i.e., VarRLF-Report (For example, when a request is received from gNB).

[0136] although Figure 7 A sample procedure 700 for RLF reporting is shown, but it is possible to modify it further. Figure 7 Make various changes. For example, although it is shown as a series of steps, Figure 7 The steps in the process can overlap, occur in parallel, occur in different orders, be repeated any number of times, be omitted, or be replaced by other steps.

[0137] Figure 8 Another example process 800 for RLF reporting according to an embodiment of this disclosure is shown. Figure 8 The embodiments of the methods shown are for illustrative purposes only. Figure 8 One or more of the components shown may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function. Other embodiments of the process for RLF reporting may be used without departing from the scope of this disclosure.

[0138] exist Figure 8In the example, process 800 begins at step 810. At step 810, UE 802 receives an RRC Reconfiguration message from source serving cell 804 (or from the gNB of source serving cell 804, which may be a PCell), and confirms receipt at step 815 by sending an RRC Reconfiguration Complete message to serving cell 804 (or to the gNB of source serving cell 804). The RRC Reconfiguration message may include conditional LTM configuration for one or more candidate LTM cells. The conditional LTM configuration may include an RRC Reconfiguration message for each of the candidate LTM cells, wherein the RRC Reconfiguration message includes a Reconfigurationwithsync IE. The conditional LTM configuration may include one or more L1 measurement events / quantities, based on which UE 802 determines to perform conditional LTM on one of the candidate LTM cells.

[0139] In step 820, a radio link failure may be detected in the source PCell. If a radio link failure is detected in the source PCell, UE 802 generates an RLF report as follows: In step 825, UE 802 includes the time "T1" in the RLF report (i.e., UE 802 sets the timeSinceCondLTM-Reconfig in the RLF report to T1, or...). timeSinceCondLTM-Reconfig Configured to detect wireless link failure and receive the last one in the source PCell. Condltm-Config (The time elapsed between).

[0140] In step 830, UE 802 indicates a list of one or more candidate conditional LTM cells in the RLF report (i.e., UE 802 sets...). condltmCandidateCellList Includes the global cell identifier (if available), otherwise includes the MCG in case of radio link failure. VarCondLTM-UE-Config within ue-CondLTM-Config The physical cell identifier and carrier frequency of each of the candidate target cells used for conditional LTM are included, but exclude... measResulNeighCells (Includes candidate target cells).

[0141] In some embodiments, UE 802 will connectionFailureType Set as rlf .

[0142] In some embodiments, UE 802 includes location information in the RLF report.

[0143] In step 835, UE 802 reports the RLF (i.e., VarRLF-Report ) is sent to the gNB (for example, when a request is received from the gNB).

[0144] although Figure 8 A sample procedure 800 for RLF reporting is shown, but it is possible to modify it further. Figure 8 Make various changes. For example, although it is shown as a series of steps, Figure 8 The steps in the process can overlap, occur in parallel, occur in different orders, be repeated any number of times, be omitted, or be replaced by other steps.

[0145] In some embodiments, the UE can initiate a rebuilding process to recover from a handover failure / radio link failure. In some embodiments, when initiating the rebuilding process, the UE starts timer T311 and performs cell selection. When T311 runs, during cell selection, the UE performs the following operations: If cell selection is triggered by detecting a radio link failure of the MCG, a reconfiguration failure of the MCG with synchronization, or a mobility failure from the NR, and if configured... attemptCondReconfig And if the selected community is not equipped with CondEventT1 Or the selected community has CondEventT1 And the departure conditions have not yet been met, and if the selected cell is one of the candidate cells, for these candidate cells, reconfigurationWithSync Included in MCG VarConditionalReconfig In masterCellGroup middle: -If the UE supports RLF reporting for conditional handover, then the UE will VarRLF-Report In choCellId Set to the global cell identifier (if available). Otherwise, the UE sets it to the physical cell identifier and carrier frequency of the selected cell.

[0146] -The stored data associated with the selected cell by the UE application. condRRCReconfig And perform the predetermined actions.

[0147] If cell selection is triggered by detecting a radio link failure of the MCG, a reconfiguration failure of the MCG with synchronization, or a mobility failure from the NR, and if configured... attemptCondLTM-Switch ( attemptCondLTM-Switch It can be included in the conditional LTM configuration (which can be received in the RRCReconfiguration message), and if the selected cell is VarCondLTM-UE-Config within ue-CondLTM-Config One of the LTM candidate cells ( VarCondLTM-UE-Config(Conditional LTM configuration received in the RRCReconfiguration message) -If the UE supports RLF reporting for conditional LTM, then the UE will VarRLF-Report In CondltmCellId Set to the global cell identifier (if available). Otherwise, the UE sets it to the physical cell identifier and carrier frequency of the selected cell.

[0148] - The UE performs a conditional LTM cell handover procedure for the selected LTM candidate cell.

[0149] If the LTM cell handover process fails under this condition, the UE can send an RRCReestablishmentRequest message to the gNB. In response, the UE can receive an RRCSetup message from the gNB.

[0150] In some embodiments, if the UE receives an RRCSetup message from the gNB, the UE performs the following operations: If UE is VarRLF-Report It contains available wireless link failure or handover failure information, and if RPLMN is included VarRLF-Report Stored in plmn-IdentityList If no settings are configured after a rebuild fails... VarRLF-Report In reconnectCellId And if this is the first one the UE receives after declaring failure. RRCSetup : - If the UE supports RLF reporting for conditional handover, and if it is set VarRLF-Report In choCellId Then the UE will VarRLF-Report In timeUntilReconnection Set to self-store VarRLF- Report In failedPCellId The time elapsed since the radio link failure or handover failure. Otherwise, if the UE supports RLF reporting for conditional LTM, and if it is set... VarRLF-Report In CondltmCellId (in the RLF report) CondltmCellId Used to instruct the UE to select for condition-based LTM recovery during T311 operation, including... Condltm-Config If the candidate target cell is used for conditional LTM, then the UE will VarRLF-Report In timeUntilReconnection Set to self-store VarRLF-Report In failedPCellId The time elapsed since the wireless link failed or the handover failed.

[0151] Otherwise, the UE willVarRLF-Report In timeUntilReconnection Set to the time elapsed since the last wireless link failure or handover failure.

[0152] -UE will VarRLF-Report In reconnectCellId In nrReconnectCellId Set the global cell identifier and tracking area code for PCell.

[0153] RLF Report ( VarRLF-Report (e.g., when a request is received from the gNB).

[0154] Figure 9 An example method 900 for RLF reporting for LTM according to an embodiment of this disclosure is shown. Figure 9 The embodiments of the methods shown are for illustrative purposes only. Figure 9 One or more of the components shown may be implemented in a dedicated circuit configured to perform the function, or one or more of the components may be implemented by one or more processors that execute instructions to perform the function. Other embodiments of the method for RLF reporting for LTM may be used without departing from the scope of this disclosure.

[0155] exist Figure 9 In the example, method 900 begins at step 910. In step 910, the UE (such as...) Figure 1 116) from the source cell (e.g., from Figure 1 BS 102) receives conditional LTM configuration for at least one conditional LTM candidate cell.

[0156] In step 920, the UE initiates a conditional LTM cell handover to a target cell among at least one conditional LTM candidate cells.

[0157] In step 930, the UE determines that the conditional LTM cell handover to the target cell has failed.

[0158] Finally, in step 940, in response to determining that the conditional LTM cell handover to the target cell has failed, the UE generates an RLF report.

[0159] In some embodiments, method 900 further includes receiving a request for an RLF report from the BS, and in response to receiving the request, sending an RLF report to the BS.

[0160] In some embodiments, method 900 further includes detecting an RLF in the source cell and generating an RLF report in response to detecting an RLF in the source cell. In these embodiments, the RLF report may include at least one of the following: the time elapsed between receiving a conditional LTM configuration and detecting an RLF in the source cell, and the conditional LTM configuration may be the most recently received conditional LTM configuration from the source cell.

[0161] In some embodiments, method 900 further includes: receiving a handover command; initiating a handover to the cell indicated by the handover command; determining that the handover has failed; and generating an RLF report in response to determining that the handover has failed. In these embodiments, the RLF report may include at least one of the following: the time elapsed between receiving the conditional LTM configuration and initiating the handover, the global cell identifier of the cell indicated by the handover command, the tracking area code of the cell indicated by the handover command, the physical cell identifier of the cell indicated by the handover command, the frequency of the cell indicated by the handover command, and the time elapsed since the handover was initiated.

[0162] In some embodiments, the RLF report includes the time elapsed between receiving the conditional LTM configuration and performing a conditional LTM cell handover to the target cell, and the conditional LTM configuration is the conditional LTM configuration of the most recently received failed target cell.

[0163] In some embodiments, the RLF report includes the time elapsed since the execution of a conditional LTM cell handover.

[0164] In some embodiments, the RLF report includes an indication that the RLF report corresponds to a failure condition LTM cell handover.

[0165] In some embodiments, the RLF report includes at least one of the following: a global cell identifier of at least one conditional LTM candidate cell, a physical cell identifier of at least one conditional LTM candidate cell, and a frequency of at least one conditional LTM candidate cell.

[0166] In some embodiments, the RLF report includes at least one of the following: the global cell identifier of the target cell corresponding to the failure condition LTM cell handover, the tracking area code of the target cell corresponding to the failure condition LTM cell handover, the physical cell identifier of the target cell corresponding to the failure condition LTM cell handover, and the frequency of the target cell corresponding to the failure condition LTM cell handover.

[0167] In some embodiments, the RLF report includes at least one of the following: the global cell identifier of the source cell, the tracking area code of the source cell, the physical cell identifier of the source cell, and the frequency of the source cell.

[0168] although Figure 9An example method 900 for RLF reporting for LTM is shown, but it is possible to modify it for other purposes. Figure 9 Make various changes. For example, although it is shown as a series of steps, Figure 9 The steps in the process can overlap, occur in parallel, occur in different orders, be repeated any number of times, be omitted, or be replaced by other steps.

[0169] Any of the above variations can be used independently or in combination with at least one other variation. The flowcharts above illustrate example methods that can be implemented according to the principles of this disclosure, and various changes can be made to the methods shown in the flowcharts herein. For example, although shown as a series of steps, the individual steps in each figure can overlap, occur in parallel, occur in different orders, or occur multiple times. In another example, a step can be omitted or replaced with another step.

[0170] Although this disclosure has been described with reference to exemplary embodiments, various changes and modifications can be made by those skilled in the art. This disclosure is intended to include such changes and modifications that fall within the scope of the appended claims. Nothing described in this application should be construed as implying that any particular element, step, or function is an essential element that must be included within the scope of the claims. The scope of the patent subject matter is defined by the claims.

Claims

1. A user equipment (UE) in a wireless communication system, the UE comprising: transceiver; as well as The processor is configured as follows: The transceiver is controlled to receive Radio Resource Control (RRC) messages from the source cell of the base station. These RRC messages include information related to conditional LTM configuration for at least one Layer 1 / Layer 2 triggered mobility LTM candidate cell. If the criteria for conditional LTM cell handover are met, a conditional LTM cell handover is initiated from the source cell to the target cell among the at least one conditional LTM candidate cells based on the RRC message. Upon detecting a handover failure in the conditional LTM cell, a Radio Link Failure (RLF) report associated with the failure is generated, and Control the transceiver to send the RLF report to the base station.

2. The UE according to claim 1, in, The processor is further configured to control the transceiver to receive requests for the RLF report from the base station. The RLF report is sent based on the request, and The RLF report includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the conditional LTM cell handover; information related to a second elapsed time between initiating the conditional LTM cell handover and the failure of the conditional LTM cell handover; information related to the handover type set for the conditional LTM cell handover; information related to the cell identifier of the at least one LTM candidate cell; or information related to the cell identifier of the target cell.

3. The UE according to claim 1, wherein, upon detecting the source cell, in, The processor is further configured to generate an RLF report associated with the RLF, and The RLF report associated with the RLF includes information related to the time elapsed between receiving the RRC message and detecting the RLF of the source cell.

4. The UE according to claim 1, wherein upon receiving a handover command for the target cell from the base station, in, The processor is further configured to initiate a handover from the source cell to the target cell, and, in the event of a handover failure, generate an RLF report associated with the handover failure. The RLF report associated with the handover failure includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the handover, information related to a second elapsed time between initiating the handover and the handover failure, or information related to the cell identifier of the target cell.

5. A method performed by a user equipment (UE), the method comprising: Receive a Radio Resource Control (RRC) message from the source cell of the base station, the RRC message including information related to the conditional LTM configuration for at least one Layer 1 / Layer 2 triggered Mobility LTM candidate cell; If the criteria for conditional LTM cell handover are met, a conditional LTM cell handover from the source cell to the target cell among the at least one conditional LTM candidate cells is initiated based on the RRC message. If the conditional LTM cell handover failure is detected, a radio link failure (RLF) report associated with the failure is generated. as well as Send the RLF report to the base station.

6. The method of claim 5, further comprising: Receive a request for the RLF report from the base station. The RLF report is sent based on the request, and The RLF report includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the conditional LTM cell handover; information related to a second elapsed time between initiating the conditional LTM cell handover and the conditional LTM cell handover failure; information related to the handover type set for the conditional LTM cell handover; information related to the cell identifier of the at least one LTM candidate cell; or information related to the cell identifier of the target cell.

7. The method of claim 5, further comprising: If an RLF (Recurrent Leakage Fault) is detected in the source cell, an RLF report associated with the RLF is generated. The RLF report associated with the RLF includes information related to the time elapsed between receiving the RRC message and detecting the RLF of the source cell.

8. The method of claim 5, further comprising: In the event that a handover command is received from the base station Initiate a handover from the source cell to the target cell; as well as If a handover failure is detected, an RLF report associated with the handover failure is generated. The RLF report associated with the handover failure includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the handover, information related to a second elapsed time between initiating the handover and the handover failure, or information related to the cell identifier of the target cell.

9. A base station in a wireless communication system, the base station comprising: transceiver; as well as The processor is configured as follows: The transceiver is controlled to send a Radio Resource Control (RRC) message to the User Equipment (UE). The RRC message includes information related to the conditional LTM configuration for at least one Layer 1 / Layer 2 triggered Mobility LTM candidate cell. The transceiver is controlled to send a request for a Radio Link Failure (RLF) report to the UE, and The transceiver is controlled to report the RLF from the UE receiver. The RLF report is associated with a failure of a conditional LTM cell handover from the source cell of the base station to the target cell among the at least one LTM candidate cells.

10. The base station according to claim 9, in, The RLF report includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the conditional LTM cell handover based on the RRC message; information related to a second elapsed time between initiating the conditional LTM cell handover and the conditional LTM cell handover failure; information related to the handover type set for the conditional LTM cell handover; information related to the cell identifier of the at least one LTM candidate cell; or information related to the cell identifier of the target cell.

11. The base station according to claim 9, in, The processor is further configured to control the transceiver to receive from the UE an RLF report associated with the source cell's RLF, and The RLF report associated with the RLF includes information related to the time elapsed between receiving the RRC message and detecting the RLF of the source cell.

12. The base station according to claim 9, in, The processor is further configured to control the transceiver to send a handover command from the source cell to the target cell to the UE, and to control the transceiver to receive an RLF report associated with a handover failure from the UE. The RLF report associated with the handover failure includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the handover, information related to a second elapsed time between initiating the handover and the handover failure, or information related to the cell identifier of the target cell.

13. A method performed by a base station in a wireless communication system, the method comprising: Send a Radio Resource Control (RRC) message to the User Equipment (UE), the RRC message including information related to the conditional LTM configuration for at least one Layer 1 / Layer 2 triggered Mobility LTM candidate cell; Send a request for a Radio Link Failure (RLF) report to the UE; as well as Receive the RLF report from the UE. The RLF report is associated with a failure of a conditional LTM cell handover from the source cell of the base station to the target cell among the at least one LTM candidate cells.

14. The method according to claim 13, in, The RLF report includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating the conditional LTM cell handover based on the RRC message; information related to a second elapsed time between initiating the conditional LTM cell handover and the conditional LTM cell handover failure; information related to the handover type set for the conditional LTM cell handover; information related to the cell identifier of the at least one LTM candidate cell; or information related to the cell identifier of the target cell.

15. The method of claim 13, further comprising: The UE receives an RLF report associated with the source cell's RLF or an RLF report associated with a handover failure. The RLF report associated with the RLF includes information related to the time elapsed between receiving the RRC message and detecting the RLF of the source cell, and The RLF report associated with the handover failure includes at least one of the following: information related to a first elapsed time between receiving the RRC message and initiating a handover from the source cell to the target cell, information related to a second elapsed time between initiating the handover and the handover failure, or information related to the cell identifier of the target cell.

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