Method and apparatus for maintaining timing advance in wireless communication system

Abstract

The UE includes a transceiver. The transceiver is configured to: transmit a UE capability information message, the UE capability information message comprising an indication that the UE supports multiple TAs per serving cell for multi-TRP operation; and receiving an RRC reconfiguration message, the RRC reconfiguration message including a plurality of TAG IDs for the serving cell, and a mapping between the plurality of TCI states and the plurality of TAG IDs for the serving cell. The UE also includes a processor operably coupled to the transceiver. The processor is configured to determine a TAG ID corresponding to at least one TCI state of the plurality of TCI states from the plurality of TAG IDs based on the mapping. The mapping is signaled according to the BWP of the serving cell. The transceiver is further configured to transmit the RA preamble to the serving cell to obtain a TA for the TAG of the serving cell.

Description

Technical Field

[0001] The present disclosure relates generally to wireless networks and, more particularly, to apparatus and methods for maintaining multiple timing advances in a serving cell. Background Art

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

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

[0004] Currently, with respect to services supported by 5G mobile communication technology, discussions on improvements and performance enhancements to initial 5G mobile communication technology are ongoing, and physical layer standardization has been completed for technologies such as V2X (Vehicle-to-Everything) for assisting autonomous vehicles in making driving decisions based on information transmitted by vehicles regarding their location and status and for improving user convenience, NR-U (New Radio Unlicensed) for system operation in compliance with various regulatory requirements in unlicensed frequency bands, NR UE energy saving, non-terrestrial network (NTN) for direct UE satellite communication for securing coverage in areas where communication with terrestrial networks is not possible, and positioning.

[0005] In addition, the standardization of air interface architecture / protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through interoperability and integration with other industries, IAB (Integrated Access and Backhaul) to provide nodes for network service area expansion by integrating wireless backhaul and access links, mobility enhancements including conditional handover and DAPS (Dual Active Protocol Stack) handover, and two-step random access (2-step RACH for NR) to simplify the random access procedure. Furthermore, the standardization of system architecture / services for technologies such as the 5G baseline architecture (e.g., service-based architecture or service-based interface) for combining network function virtualization (NFV) and software-defined networking (SDN) technologies, and mobile edge computing (MEC) for receiving services based on UE location, is also progressing.

[0006] With the commercialization of 5G mobile communication systems, the exponentially growing number of connected devices will be connected to the communication network, and as a result, enhanced functionality and performance of 5G mobile communication systems and the integrated operation of connected devices are expected to be required. To this end, new research is being put on the agenda regarding 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 use of artificial intelligence (AI) and machine learning (ML); support for AI services, support for metaverse services, and drone communications.

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

[0008] Technical issues

[0009] The demand for wireless data services is rapidly increasing due to the growing popularity of smartphones and other mobile data devices (e.g., tablet computers, "notebook" computers, netbooks, e-book readers, and machine-type devices) among consumers and enterprises. To meet this high growth in mobile data services and support new applications and deployments, improvements in radio interface efficiency and coverage are crucial.

[0010] Fifth-generation (5G) or New Radio (NR) mobile communications have been gaining momentum recently, with industry and academia worldwide conducting activities on various candidate technologies. Candidate driving technologies for 5G / NR mobile communications include: massive antenna technology from traditional cellular frequency bands to high frequencies to provide beamforming gain and support increased capacity; new waveforms (e.g., new radio access technologies (RATs)) to flexibly accommodate various services / applications with different requirements; new multiple access schemes to support large-scale connections, etc.

[0011] Solution to the problem

[0012] The present disclosure provides apparatus and methods for maintaining multiple timing advances in a serving cell.

[0013] In one embodiment, a user equipment (UE) is provided. The UE includes a transceiver. The transceiver is configured to: transmit a UE capability information message including an indication that the UE supports multiple timing advances (TAs) per serving cell for multiple transmit-receive point (TRP) operation; and receive a radio resource control (RRC) reconfiguration message including multiple timing advance group (TAG) identifiers (IDs) for a serving cell and a mapping between multiple TCI states for the serving cell and multiple timing TAG IDs. The UE also includes a processor operably coupled to the transceiver. The processor is configured to: determine, from the multiple TAG IDs, a TAG ID corresponding to at least one of the multiple TCI states based on the mapping. The mapping is signaled according to a bandwidth part (BWP) of the serving cell. The transceiver is further configured to: transmit a random access (RA) preamble to the serving cell to obtain the TA for the TAG of the serving cell.

[0014] In another embodiment, a base station (BS) is provided. The BS includes a processor and a transceiver operably connected to the processor. The transceiver is configured to receive a UE capability information message from a UE, the UE capability information message including an indication that the UE supports multiple TAs per serving cell for multi-TRP operation. The transceiver is further configured to send an RRC reconfiguration message including a plurality of timing advance group (TAG) identifiers (IDs) for the serving cell and a mapping between a plurality of TCI states and a plurality of TAG IDs for the serving cell. The mapping is signaled according to a BWP of the serving cell. The transceiver is further configured to receive an RA preamble.

[0015] In yet another embodiment, a method of operating a UE is provided. The method includes: sending a UE capability information message including an indication that the UE supports multiple TAs per serving cell for multiple transmit-receive point (TRP) operation; and receiving an RRC reconfiguration message including a plurality of timing advance group (TAG) identifiers (IDs) for the serving cell and a mapping between a plurality of TCI states for the serving cell and the plurality of TAG IDs. The method also includes: determining, from the plurality of TAG IDs, a TAG ID corresponding to each of the plurality of TCI states based on the mapping. The mapping is signaled according to a base position width (BWP) of the serving cell. The method also includes: sending an RA preamble to the serving cell to obtain a TA for the TAG of the serving cell.

[0016] According to an embodiment of the present disclosure, a method performed by a terminal is provided. The method includes: receiving configuration information for a serving cell from a base station, the configuration information including a first timing advance group (TAG) identifier for a first TAG associated with the serving cell and a second TAG identifier for a second TAG associated with the serving cell; receiving a timing advance command and a bit from the base station, the bit indicating a TAG to which the timing advance command applies, of two TAGs including the first TAG and the second TAG; and applying the timing advance command to the TAG indicated by the bit.

[0017] According to another embodiment of the present disclosure, a terminal is provided. The terminal includes: a transceiver; and a controller coupled to the transceiver and configured to: receive configuration information for a serving cell from a base station, the configuration information including a first timing advance group (TAG) identifier for a first TAG associated with the serving cell and a second TAG identifier for a second TAG associated with the serving cell; receive a timing advance command and a bit indicating a TAG to which the timing advance command applies from the base station, the bit indicating a TAG including the first TAG and the second TAG; and apply the timing advance command to the TAG indicated by the bit.

[0018] Beneficial effects of the present invention

[0019] According to various embodiments of the present disclosure, multiple TAs of multiple TAGs for a cell can be efficiently managed in a wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which: Figure 1 illustrates an example wireless network according to an embodiment of the present disclosure; Figure 2A illustrates example wireless transmit and receive paths according to the present disclosure; Figure 2B illustrates example wireless transmit and receive paths according to the present disclosure; Figure 3A An example UE according to an embodiment of the present disclosure is shown; Figure 3B An example gNB according to an embodiment of the present disclosure is shown; Figure 4 A method for maintaining multiple timing advances in a serving cell according to an embodiment of the present disclosure is shown; Figure 5 shows an example RRCReconfiguration message according to an embodiment of the present disclosure; Figure 6 shows an example RRCReconfiguration message according to an embodiment of the present disclosure; Figure 7 shows an example RRCReconfiguration message according to an embodiment of the present disclosure; Figure 8 A method for PDCCH-initiated random access according to an embodiment of the present disclosure is shown; Figure 9 A method for random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown; Figure 10 A method for random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown; Figure 11 A method for random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown; Figure 12 A method for random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown; Figure 13A method for random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown; Figure 14 A method for random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown; Figure 15 A method for maintaining multiple timing advances in a serving cell according to an embodiment of the present disclosure is shown; Figure 16 is a block diagram illustrating a structure of a terminal according to an embodiment of the present disclosure; and Figure 17 is a block diagram showing the structure of a base station according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0021] The embodiments herein and their various features and advantageous details will be more fully explained with reference to the non-limiting embodiments shown in the accompanying drawings and described in detail in the following description. Descriptions of well-known components and processing techniques are omitted so as not to unnecessarily obscure the embodiments herein. The examples used herein are intended only to aid in understanding how the embodiments herein may be implemented and to further enable those skilled in the art to implement the embodiments herein. Therefore, the examples should not be interpreted as limiting the scope of the embodiments herein.

[0022] For purposes of interpreting this specification, the definitions (as defined herein) shall apply, and where appropriate, terms used in the singular shall include the plural, and vice versa. It should be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The terms "including," "having," and "comprising" are to be construed as open-ended terms unless otherwise indicated.

[0023] The words / phrases "exemplary," "example," "illustrative," "in an instance," "such as," "etc.," "etc.," "for example," and "i.e." are used herein merely to mean "serving as an example, instance, or illustration." Any embodiment or implementation of the subject matter described herein using the words / phrases "exemplary," "example," "illustrative," "in an instance," "such as," "etc.," "etc.," "etc.," "for example," and "i.e." are not necessarily to be construed as preferred or advantageous over other embodiments.

[0024] The embodiments herein may be described and illustrated in terms of blocks that perform one or more of the described functions. These blocks, which may be referred to herein as managers, units, modules, hardware components, etc., are physically implemented by analog and / or digital circuitry, such as logic gates, integrated circuits, microprocessors, microcontrollers, memory circuits, passive electronic components, active electronic components, optical components, hard-wired circuitry, etc., and may optionally be driven by firmware. For example, the circuitry may be implemented in one or more semiconductor chips, or on a substrate support such as a printed circuit board. The circuitry comprising a block may be implemented by dedicated hardware, or by a processor (e.g., one or more programmed microprocessors and associated circuitry), or by a combination of dedicated hardware that performs some of the block's functions and a processor that performs other functions of the block. Each block of the embodiments may be physically separated into two or more interacting and discrete blocks without departing from the scope of this disclosure. Similarly, the blocks of the embodiments may be physically combined into more complex blocks without departing from the scope of this disclosure.

[0025] It should be noted that, for purposes of description and ease of understanding, the elements shown in the accompanying drawings may not necessarily be drawn to scale. For example, a flow chart / sequence diagram illustrates a method of steps required to understand aspects of the embodiments disclosed herein. Furthermore, with respect to device structures, one or more components of the device may be represented in the accompanying drawings by conventional symbols, and the accompanying drawings may only illustrate specific details relevant to understanding the embodiments, so as not to obscure the drawings by those details that would become apparent to those of ordinary skill in the art having the benefit of the description herein. Furthermore, with respect to systems, one or more components / modules comprising the system may be represented in the accompanying drawings by conventional symbols, and the accompanying drawings may only illustrate specific details relevant to understanding the embodiments, so as not to obscure the drawings by those details that would become apparent to those of ordinary skill in the art having the benefit of the description herein.

[0026] The accompanying drawings are used to facilitate easy understanding of various technical features, and it should be understood that the embodiments presented herein are not limited by the accompanying drawings. Therefore, the present disclosure should be interpreted as extending to any modifications, equivalents, and alternatives in addition to those specifically set forth in the accompanying drawings and corresponding descriptions. The use of terms such as first, second, and third to describe components / elements / steps is for descriptive purposes and should not be interpreted as sequential ordering / placement / appearance unless otherwise specified.

[0027] The various embodiments discussed below in the patent document to illustrate the principles of the present disclosure are for illustrative purposes only and should not be construed as limiting the scope of the present disclosure in any way. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any appropriately arranged wireless communication system. For example, although the detailed description of the embodiments of the present disclosure below will be directed to LTE and / or 5G communication systems, those skilled in the art will appreciate that, without departing from the scope of the present disclosure, the key points of the present disclosure can also be applied to other communication systems with similar technical backgrounds and channel formats after slight modifications. The technical solutions of the embodiments of the present application can be applied to various communication systems, for example, communication systems may include Global System for Mobile Communications (GSM), Code Division Multiple Access (CDMA) systems, Wideband Code Division Multiple Access (WCDMA) systems, General Packet Radio Service (GPRS) systems, Long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD) systems, Universal Mobile Telecommunications System (UMTS), Worldwide Interoperability for Microwave Access (WiMAX) communication systems, fifth generation (5G) systems, or new radio (NR) systems. Furthermore, the technical solutions of the embodiments of the present application can be applied to future-oriented communication technologies. Furthermore, the technical solutions of the embodiments of the present application can be applied to future-oriented communication technologies.

[0028] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. It should be noted that the same reference numerals in different drawings will be used to represent the same elements that have been described.

[0029] Other technical features will be apparent to those skilled in the art from the following drawings, description, and claims.

[0030] Before proceeding with the following detailed description, it may be beneficial to set forth the definitions of specific words and phrases used throughout this patent document. The term "connect" and its derivatives refer to any direct or indirect communication between two or more elements, regardless of whether those elements are in physical contact with each other. The terms "send," "receive," and "communicate," and their derivatives, include direct and indirect communication. The terms "include," "comprise," and their derivatives, are intended to include without limitation. The term "or" is inclusive, meaning and / or. The phrase "associated with..." and its derivatives, mean to include, be included within, be interconnected with, contain, be contained within, be connected to or with, be connected to or with, be communicable with, collaborate with, be interlaced, juxtaposed, adjacent, be bound to or with, have, have the property of, have a relationship with, or have a relationship with, etc. The term "controller" means any device, system, or portion thereof that controls at least one operation. Such a controller may be implemented using hardware or a combination of hardware and software and / or firmware. The functionality associated with any particular controller may be centralized or distributed, whether local or remote. The phrase "at least one," when used with a list of items, 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, B, and C.

[0031] In addition, the various functions described below may be implemented or supported by one or more computer programs, each of which is formed from computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data, or portions thereof suitable for implementation in appropriate 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 that can be accessed by a computer, such as read-only memory (ROM), random-access memory (RAM), hard drives, compact disks (CDs), digital video disks (DVDs), or any other type of memory. "Non-transitory" computer-readable media does not include wired, wireless, optical, or other communication links that transmit transient electrical or other signals. Non-transitory computer-readable media includes media in which data can be permanently stored, as well as media in which data can be stored and subsequently overwritten, such as rewritable optical disks or erasable storage devices.

[0032] Definitions for certain words and phrases are provided throughout this patent document, those of ordinary skill in the art should understand that in many, if not most instances, such definitions apply to prior, as well as future uses of such defined words and phrases.

[0033] Discussed below Figures 1 to 17 The various embodiments used to describe the principles of the present disclosure in this patent document are merely exemplary and should not be interpreted in any way as limiting the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any suitably arranged wireless communication system.

[0034] To meet the increased demand for wireless data services since the deployment of 4G communication systems, and to enable a variety of vertical applications, 5G / NR communication systems have been developed and are currently being deployed. 5G / NR communication systems are considered to be implemented in higher frequency (millimeter wave) 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 stable coverage and mobility support. To reduce radio wave propagation losses and increase transmission distances, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies are being discussed in 5G / NR communication systems.

[0035] Furthermore, in 5G / NR communication systems, development is underway for system network improvements based on advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device (D2D) communications, wireless backhaul, mobile networks, cooperative communications, coordinated multi-point (CoMP), and receiver-side interference cancellation.

[0036] The discussion of 5G systems and their associated frequency bands is provided for reference, as certain embodiments of the present disclosure may be implemented in 5G systems. However, the present disclosure is not limited to 5G systems or their associated frequency bands, and embodiments of the present disclosure may be used in conjunction with any frequency band. For example, aspects of the present disclosure may also be applied to the deployment of 5G communication systems, 6G, or even later versions that may utilize terahertz (THz) frequency bands.

[0037] The following Figures 1-3B Various embodiments are described for implementation using Orthogonal Frequency Division Multiplexing (OFDM) or Orthogonal Frequency Division Multiple Access (OFDMA) communication technology in a wireless communication system. Figures 1-3B The description is not intended to imply physical or architectural limitations to the manner in which different embodiments may be implemented. Different embodiments of the present disclosure may be implemented in any suitably arranged communications system.

[0038] Figure 1An example wireless network according to an embodiment of the present disclosure is shown. Figure 1 The embodiment of the wireless network shown is for illustration only. Other embodiments of the wireless network 100 may be used without departing from the scope of the present disclosure.

[0039] like Figure 1 As shown, the wireless network includes gNB 101 (e.g., 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.

[0040] gNB 102 provides wireless broadband access to network 130 for a plurality of first user equipment (UEs) within gNB 102's coverage area 120. The plurality of first UEs include 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, a wireless laptop, a wireless PDA, etc. gNB 103 provides wireless broadband access to network 130 for a plurality of second UEs within gNB 103's coverage area 125. The plurality of second UEs include 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), Long Term Evolution Advanced (LTE-A), WiMAX, WiFi, or other wireless communication technologies.

[0041] Depending on the network type, the term "base station" or "BS" can refer to any component (or collection of components) configured to provide wireless access to a network, such as a transmission point (TP), a transmission-reception point (TRP), an enhanced base station (eNodeB or eNB), a 5G / NR base station (gNB), a macrocell, a femtocell, a WiFi access point (AP), or other wireless-enabled device. A base station can provide wireless access according to one or more wireless communication protocols, such as 5G / NR Third 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, and others. For convenience, the terms "BS" and "TRP" are used interchangeably in this patent document to refer to a network infrastructure component that provides wireless access to remote terminals. Additionally, 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," "reception 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 a BS, whether the UE is a mobile device (e.g., a mobile phone or smartphone) or a device generally considered to be stationary (e.g., a desktop computer or vending machine).

[0042] The dashed lines illustrate the approximate extents of coverage areas 120 and 125, which are shown as approximately circular for purposes of illustration and explanation only. It should be clearly understood that coverage areas associated with gNBs, such as coverage areas 120 and 125, 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.

[0043] As described in more detail below, one or more of UEs 111-116 include circuitry, programming, or a combination thereof for maintaining multiple timing advances in a serving cell of a wireless communication system. In certain embodiments, one or more of gNBs 101-103 include circuitry, programming, or a combination thereof to support maintaining multiple timing advances in a serving cell of a wireless communication system.

[0044] although Figure 1 An example of a wireless network is shown, but Figure 1Various changes may be made. For example, the wireless network may include any number of gNBs and any number of UEs. Furthermore, gNB 101 may communicate directly with any number of UEs and provide those UEs with wireless broadband access to network 130. Similarly, each of gNBs 102-103 may communicate directly with network 130 and provide UEs with direct wireless broadband access to network 130. Furthermore, gNB 101, gNB 102, and / or gNB 103 may provide access to other or additional external networks, such as an external telephone network or other types of data networks.

[0045] Figure 2A and Figure 2B Example wireless transmit and receive paths according to the present disclosure are shown. In the following description, transmit path 200 may be described as being implemented in a gNB (e.g., gNB 102), and receive path 250 may be described as being implemented in a UE (e.g., UE 116). However, it should be understood that receive path 250 may be implemented in a gNB and transmit path 200 may be implemented in a UE. In some embodiments, receive path 250 is configured to support codebook design and structure for systems with 2D antenna arrays as described in embodiments of the present disclosure.

[0046] The transmit path 200 includes a channel coding and modulation block 205, a serial-to-parallel (S-to-P) block 210, an inverse fast Fourier transform (IFFT) block of size N 215, a parallel-to-serial (P-to-S) block 220, an add cyclic prefix block 225, and an upconverter (UC) 230. The receive path 250 includes a downconverter (DC) 255, a remove cyclic prefix block 260, a serial-to-parallel (S-to-P) block 265, a fast Fourier transform (FFT) block of size N 270, a parallel-to-serial (P-to-S) block 275, and a channel decoding and demodulation block 280.

[0047] In the transmit path 200, the channel coding and modulation block 205 receives a set of information bits, applies coding (e.g., low-density parity check (LDPC) coding), and modulates the input bits (e.g., using quadrature phase-shift keying (QPSK) or quadrature amplitude modulation (QAM)) to generate a sequence of frequency-domain modulation symbols. The serial-to-parallel conversion block 210 converts (e.g., demultiplexes) the serial modulation symbols into parallel data to generate N parallel symbol streams, where N is the IFFT / FFT size used in the gNB 102 and UE 116. The size-N IFFT block 215 performs an IFFT operation on the N parallel symbol streams to generate a time-domain output signal. The parallel-to-serial conversion block 220 converts (e.g., multiplexes) the parallel time-domain output symbols from the size-N IFFT block 215 to generate a serial time-domain signal. The add cyclic prefix block 225 inserts a cyclic prefix into the time-domain signal. Upconverter 230 modulates (eg, upconverts) the output of add cyclic prefix block 225 to RF frequency for transmission via a wireless channel. The signal may also be filtered at baseband before conversion to RF frequency.

[0048] The transmitted RF signal from gNB 102 arrives at UE 116 after traversing the wireless channel. UE 116 performs operations that are the inverse of those performed at gNB 102. Downconverter 255 downconverts the received signal to 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 parallel time-domain signals. Size-N 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 sequence of modulated data symbols. Channel decoding and demodulation block 280 demodulates and decodes the modulated symbols to recover the original input data stream.

[0049] Each of gNBs 101-103 may implement a transmit path similar to 200 for transmitting in the downlink to UEs 111-116 and may implement a receive path similar to 250 for receiving in the uplink from UEs 111-116. Similarly, each of UEs 111-116 may implement a transmit path 200 for transmitting in the uplink to gNBs 101-gNB103 and may implement a receive path 250 for receiving in the downlink from gNBs 101-gNB103.

[0050] Figure 2A and Figure 2B Each of the components in can be implemented using hardware alone, or a combination of hardware and software / firmware. As a specific example, Figure 2A and Figure 2BAt least some of the components in can be implemented in software, and other components can be implemented by configurable hardware, or a mixture 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 according to the implementation.

[0051] Furthermore, although described as using FFT and IFFT, this is exemplary only and should not be construed as limiting the scope of the present disclosure. Other types of transforms, such as discrete Fourier transform (DFT) and inverse discrete Fourier transform (IDFT) functions, may be used. It should be understood that for DFT and IDFT functions, the value of the variable N may be any integer (e.g., 1, 2, 3, 4, etc.), while for FFT and IFFT functions, the value of the variable N may be any integer that is a power of 2 (e.g., 1, 2, 4, 8, 16, etc.).

[0052] although Figure 2A and Figure 2B Examples of wireless transmit and receive paths are shown, but Figure 2A and Figure 2B Make various changes. For example, Figure 2A and Figure 2B The various components in may be combined, further subdivided, or omitted, and additional components may be added according to specific needs. Figure 2A and Figure 2B It is intended to illustrate examples of the types of transmit and receive paths that may be used in a wireless network.Any other suitable architecture may be used to support wireless communications in a wireless network.

[0053] Figure 3A An example UE 116 is shown in accordance with an embodiment of the present disclosure. Figure 3A The embodiment of UE 116 shown is for illustration only, and Figure 1 UE 111-UE 115 may have the same or similar configuration. However, UE has a variety of configurations, and Figure 3A The scope of this disclosure is not limited to any particular implementation of a UE.

[0054] like Figure 3A As shown, UE 116 includes antenna 305, transceiver 310, and microphone 320. UE 116 also includes speaker 330, processor 340, input / output (I / O) interface (IF) 345, input 350, display 355, and memory 360. Memory 360 includes operating system (OS) 361 and one or more applications 362.

[0055] Transceiver 310 receives an incoming RF signal from antenna 305, transmitted by a gNB in ​​network 100. Transceiver 310 downconverts the incoming RF signal to produce an intermediate frequency (IF) or baseband signal. The IF or baseband signal is processed by RX processing circuitry within transceiver 310 and / or processor 340, which filters, decodes, and / or digitizes the baseband or IF signal to produce a processed baseband signal. The RX processing circuitry then transmits the processed baseband signal to speaker 330 (e.g., for voice data) or to processor 340 (e.g., for web browsing data).

[0056] The TX processing circuitry in the transceiver 310 and / or processor 340 receives analog or digital voice data from the microphone 320 or other outgoing baseband data (e.g., web page data, email, or interactive video game data) from the processor 340. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to generate a processed baseband or IF signal. The transceiver 310 up-converts the baseband or IF signal into an RF signal that is transmitted via the antenna 305.

[0057] The processor 340 may include one or more processors or other processing devices and execute an OS 361 stored in the memory 360 to control the overall operation of the UE 116. For example, the processor 340 may control the transceiver 31 to receive downlink channel signals and transmit uplink channel signals according to well-known principles. In some embodiments, the processor 340 includes at least one microprocessor or microcontroller.

[0058] Processor 340 is also capable of executing other processes and programs residing in memory 360, such as, for example, a process for maintaining multiple timing advances in a serving cell, as discussed in more detail below. Processor 340 can move data into or out of memory 360 as needed for the executed processes. In some embodiments, processor 340 is configured to execute application 362 based on OS 361 or in response to signals received from a 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.

[0059] The processor 340 is also coupled to an input 350, including, for example, a touch screen, a keypad, etc., and a display 355. An operator of the UE 116 can use the input 350 to enter data into the UE 116. The display 355 can be a liquid crystal display, a light emitting diode display, or other display capable of presenting text and / or at least limited graphics, such as from a website.

[0060] Memory 360 is coupled to processor 340. A portion of memory 360 may include random access memory (RAM), and another portion of memory 360 may include flash memory or other read-only memory (ROM).

[0061] although Figure 3A An example of UE 116 is shown, but the Figure 3A Make various changes. For example, Figure 3A Various components in the 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. In addition, although Figure 3A The UE 116 is shown configured as a mobile phone or smartphone, but the UE may be configured to operate as other types of mobile or stationary devices.

[0062] Figure 3B An example gNB 102 is shown in accordance with an embodiment of the present disclosure. Figure 3B The embodiment of gNB 102 shown is for illustration only. Figure 1 gNB 101 and gNB 103 may have the same or similar configurations. However, gNBs have various configurations, and Figure 3B The scope of this disclosure is not limited to any particular implementation of a gNB.

[0063] like Figure 3B As shown, gNB 102 includes multiple antennas 370a-370n, multiple transceivers 372a-372n, a controller / processor 378, memory 380, and a backhaul or network interface 382.

[0064] Transceivers 372a-372n receive incoming RF signals from antennas 370a-370n, such as signals transmitted by UEs in network 100. Transceivers 372a-372n downconvert the incoming RF signals to generate IF or baseband signals. The IF or baseband signals are processed by receive (RX) processing circuitry within transceivers 372a-372n and / or controller / processor 378, which filters, decodes, and / or digitizes the baseband or IF signals to generate processed baseband signals. Controller / processor 378 may further process the baseband signals.

[0065] Transmit (TX) processing circuitry within transceivers 372a-372n and / or controller / processor 378 receives analog or digital data (e.g., voice data, web page data, email, or interactive video game data) from controller / processor 378. The TX processing circuitry encodes, multiplexes, and / or digitizes the outgoing baseband data to produce processed baseband or IF signals. Transceivers 372a-372n upconvert the baseband or IF signals into RF signals that are transmitted via antennas 370a-370n.

[0066] The controller / processor 378 may include one or more processors or other processing devices that control 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 well-known principles. The controller / processor 378 may also support additional functionality, such as more advanced wireless communication functions. For example, the controller / processor 378 may support beamforming or directional routing operations, in which the output / input signals from / to the multiple antennas 370a-370n are weighted differently to effectively steer the output signals in a desired direction. The controller / processor 378 may also support any of a variety of other functions within the gNB 102.

[0067] The controller / processor 378 is also capable of executing programs and other processes residing in the memory 380, such as the OS, and processes that support maintaining multiple timing advances in the serving cell, as discussed in more detail below. The controller / processor 378 can move data into or out of the memory 380 as required by the executing processes.

[0068] 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. The interface 382 can support communication over 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), the 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, the interface 382 can allow the gNB 102 to communicate over a wired or wireless local area network (LAN) or with a larger network (e.g., the Internet) via a wired or wireless connection. The interface 382 includes any suitable structure that supports communication over a wired or wireless connection (e.g., Ethernet or a transceiver).

[0069] Memory 380 is coupled to controller / processor 378. A portion of memory 380 may include RAM, while another portion of memory 380 may include flash memory or other ROM.

[0070] although Figure 3B An example of gNB 102 is shown, but the Figure 3B For example, gNB 102 may include any number of Figure 3B Each component shown. In addition, Figure 3B The various components in the diagram may be combined, further subdivided, or omitted, and additional components may be added according to specific needs.

[0071] Fifth-generation wireless communication systems support not only lower frequency bands but also higher frequency (millimeter wave) bands, such as the 10 GHz to 100 GHz band, to achieve higher data rates. To mitigate radio wave propagation losses and increase transmission range, fifth-generation wireless communication system designs incorporate beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technologies. Furthermore, fifth-generation wireless communication systems are expected to address diverse use cases with distinct requirements for data rates, latency, reliability, mobility, and other aspects. However, the air interface design of fifth-generation wireless communication systems is expected to be flexible enough to accommodate UEs with vastly different capabilities, depending on the end-customer service use case and market segment they address. Examples of use cases expected to be addressed by fifth-generation wireless communication systems include enhanced mobile broadband (eMBB), massive machine-type communications (m-MTC), and ultra-reliable low-latency communications (URLL). eMBB requirements, such as data rates of tens of Gbps, low latency, and high mobility, address the market segment representing traditional wireless broadband users who require internet connectivity anytime, anywhere, and while on the move. m-MTC requirements, such as ultra-high connection density, infrequent data transmission, ultra-long battery life, and low mobility, address the market segment representing the Internet of Things (IoT) / Internet of Everything (IoE), which envisions connecting billions of devices. URLL requirements, such as ultra-low latency, ultra-high reliability, and variable mobility, address the market segment representing vehicle-to-vehicle and vehicle-to-infrastructure communications, which represent industrial automation applications and are considered one of the drivers of autonomous vehicles.

[0072] In fifth-generation wireless communication systems operating in higher-frequency (millimeter wave) bands, UEs and gNBs communicate with each other using beamforming. Beamforming technology is used to mitigate propagation path loss and increase the propagation range for communications in higher frequency bands. Beamforming enhances transmission and reception performance using high-gain antennas. Beamforming can be categorized as transmit (TX) beamforming, performed on the transmitter side, and receive (RX) beamforming, performed on the receiver side. Generally, TX beamforming increases directivity by using multiple antennas densely positioned in a specific direction to cover the area of ​​propagation reach. In this context, a collection of multiple antennas can be referred to as an antenna array, and each antenna in the array can be referred to as an array element. Antenna arrays can be configured in various forms, such as linear arrays and planar arrays. The use of TX beamforming increases signal directivity, thereby increasing propagation range. Furthermore, since the signal is rarely transmitted in directions other than the directional direction, signal interference on other receivers is significantly reduced. Receivers can perform beamforming on RX signals using RX antenna arrays. RX beamforming increases the strength of RX signals transmitted in a specific direction by concentrating propagation in that direction. It also excludes signals transmitted in directions other than the specific direction from the RX signal, effectively blocking interfering signals. Using beamforming, a transmitter can generate multiple transmit beam patterns in different directions. Each of these transmit beam patterns is also 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, as each narrow TX beam provides coverage for a portion of the cell. The narrower the TX beam, the higher the antenna gain, thus increasing the propagation distance of signals transmitted using beamforming. A receiver can also generate multiple receive (RX) beam patterns in different directions. Each of these receive patterns is also referred to as a receive (RX) beam.

[0073] Fifth-generation wireless communication systems support standalone operation as well as dual connectivity (DC). In DC, multiple UEs (receiving and transmitting terminals) can be configured to utilize resources provided by two different nodes (or NBs) connected via a non-ideal backhaul. One node acts as a master node (MN), while the other acts as a secondary node (SN). The MN and SN are connected via a network interface, with at least the MN connected to the core network. NR also supports multi-RAT dual connectivity (MR-DC), whereby a UE in the RRC connected (RRC_CONNECTED) state is configured to utilize radio resources provided by two different schedulers located in two different nodes connected via a non-ideal backhaul, providing either 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 an RRC connected UE without Carrier Access Control (CA) / DC configured, there is only one serving cell, which consists of the primary cell. For an RRC connected UE with Carrier Access Control (CA) / DC configured, the term "serving cell" is used to refer to the set of cells that includes the specific cell and all secondary cells. In NR, the term "Master Cell Group" (MCG) refers to the set of serving cells associated with a master node, including the PCell and, optionally, one or more SCells. In NR, the term "Secondary Cell Group" (SCG) refers to the set of serving cells associated with a secondary node, including the PSCell and, optionally, one or more SCells. In NR, the PCell (primary cell) refers to the serving cell operating on the primary frequency in the MCG, where the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure. In NR, for UEs configured with carrier aggregation (CA), the SCell is the 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 with synchronization procedures. For dual connectivity operation, the term "SpCell" (i.e., special cell) refers to the PCell of the MCG or the PSCell of the SCG; otherwise, the term "special cell" refers to the PCell.

[0074] In fifth-generation wireless communication systems, the Node B (gNB) or base station broadcasts the primary and secondary synchronization signals (PSS, SSS) and system information in the cell-broadcast synchronization signal and PBCH block (SSB). This system information includes common parameters required for communication within the cell. In fifth-generation wireless communication systems (also known as Next Generation Radio (NR),) system information (SI) is divided into the MIB and multiple SIBs. The MIB is consistently transmitted on the BCH with an 80ms period and repeats every 80ms. It includes the parameters required to retrieve the SIB1 from the cell. The SIB1 is transmitted on the DL-SCH with a 160ms period and a variable repetition period. The default repetition period for SIB1 is 20ms, but the actual repetition period depends on the network implementation. For SSB and CORESET reuse mode 1, the SIB1 repetition period is 20ms. For SSB and CORESET reuse modes 2 / 3, the SIB1 repetition period is the same as the SSB period. SIB1 includes information about the availability and scheduling of other SIBs (e.g., SIB-to-SI message mapping, periodicity, and SI window size). It also includes an indication of whether one or more SIBs are provided only on demand. In this case, SIB1 includes the configuration necessary for the UE to fulfill its SI request. SIB1 is a cell-specific SIB; SIBs other than SIB1 and PosSIB are carried in system information (SI) messages, which are transmitted on the DL-SCH. Only SIBs or PosSIBs with the same periodicity can be mapped to the same SI message. SIBs and posSIBs are mapped to different SI messages. Each SI message is transmitted within a periodic time window (called an SI window, with the same SI window length for all SI messages). Each SI message is associated with an SI window, and the SI windows of different SI messages do not overlap. That is, a corresponding SI message is transmitted only within a single SI window. An SI message can be transmitted multiple times within an SI window. Using indications in SIB1, any SIB or posSIB other than SIB1 can be configured as cell-specific or region-specific. Cell-specific SIBs apply only to the cell where the SIB is provided, whereas area-specific SIBs apply to an area called an SI area, which includes one or more cells and is defined by systemInformationAreaID Identify; schedulingInfoList Configure the mapping of SIB to SI messages in pos-schedulingInfoList Each SIB is included in only one SI message, and each SIB and posSIB is included in the SI message at most once; for UEs in RRC connected state, the network can use RRCReconfigurationSystem information is provided by dedicated signaling of the message (for example, if the UE has an active BWP and the active BWP is not configured to monitor the common search space for system information and paging), or by request from the UE. In the RRC connected state, the UE obtains the required SIBs only from the PCell. For PSCell and SCell, the network provides system information through dedicated signaling (i.e., in RRCReconfiguration The required SI is provided within the UE's MIB (within the UE's MIB message). However, the UE will retrieve the PSCell's MIB to obtain the SFN timing of the SCG (which may be different from the MCG). When changing the SI associated with an SCell, the network releases and adds the associated SCell. For a PSCell, the required SI can only be changed through reconfiguration with synchronization.

[0075] In 5G wireless communication systems, random access (RA) is supported. Random access (RA) is used to achieve uplink (UL) time synchronization. RA is used during initial access, handover, radio resource control (RRC) connection reestablishment procedures, scheduling request transmission, secondary cell group (SCG) addition / modification, beam failure recovery, and data or control information transmission in the UL by an unsynchronized UE in the RRC connected state. Several types of random access procedures are supported, such as contention-based random access and contention-free random access, and each of these can be either a two-step or a four-step random access.

[0076] In fifth-generation wireless communication systems, the Physical Downlink Control Channel (PDCCH) is used to schedule DL transmissions on the PDSCH and UL transmissions on the PUSCH. The Downlink Control Information (DCI) on the PDCCH includes: downlink assignments, which contain at least the modulation and coding format, resource allocation, and hybrid ARQ information related to the DL-SCH; and uplink scheduling grants, which contain at least the modulation and coding format, resource allocation, and hybrid ARQ information related to the UL-SCH. In addition to scheduling, the PDCCH can also be used to: activate and deactivate configured PUSCH transmissions with configured grants; activate and deactivate PDSCH semi-persistent transmissions; notify one or more UEs of the timeslot format; notify one or more UEs of the PRB and OFDM symbols, where a UE can assume that there is no transmission for that UE; transmit TPC commands for the Physical Uplink Control Channel (PUCCH) and PUSCH; transmit one or more TPC commands for SRS transmission by one or more UEs; switch the active bandwidth portion of a UE; and initiate a random access procedure. Based on the corresponding search space configuration, the UE monitors a set of PDCCH candidates in configured monitoring opportunities in one or more configured control resource sets (CORESETs). A CORESET consists of a set of PRBs with a duration of one to three OFDM symbols. Resource elements (REGs) and control channel elements (CCEs) are defined within a CORESET, with each CCE comprising a set of REGs. The control channel is formed by aggregating CCEs. Different code rates for the control channel are achieved by aggregating different numbers of CCEs. Both interleaved and non-interleaved CCE-to-REG mapping are supported within a CORESET. Polar coding is used for PDCCHs. Each resource element group carrying a PDCCH carries its own DMRS. QPSK modulation is used for PDCCHs.

[0077] In fifth-generation wireless communication systems, the gNB signals a list of search space configurations for each configured BWP of a serving cell, where each search configuration is uniquely identified by a search space identifier. The search space identifier is unique within the BWP of a serving cell. The gNB explicitly signals the identifier of a search space configuration for a specific purpose (e.g., paging reception, SI reception, and random access response reception) for each configured BWP. In NR, the search space configuration includes the parameters Monitoring-periodic-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot, and duration. The UE uses the parameters PDCCH monitoring period (Monitoring-periodicity-PDCCH-slot), PDCCH monitoring offset (Monitoring-offset-PDCCH-slot), and PDCCH monitoring pattern (Monitoring-symbols-PDCCH-within-slot) to determine the PDCCH monitoring opportunity within the time slot. The PDCCH monitoring opportunity exists in time slots "x" to "x+duration", where the time slot numbered "x" in the radio frame numbered "y" satisfies the following equation 1:

[0078] [Equation 1]

[0079] (y (number of slots in a radio frame) + x - Monitoring-offset-PDCCH-slot) mod (Monitoring-periodicity-PDCCH-slot) = 0; The starting symbol of a 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 symbols) is given in the CORESET associated with the search space. The search space configuration includes the identifier of the CORESET configuration associated with it. The gNB signals a list of CORESET configurations for each configured BWP of the serving cell, 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. A radio frame is identified by a radio frame number or system frame number. Each radio frame consists of several slots, where the number and duration of slots in a radio frame depend on the subcarrier spacing. In NR, the number and duration of slots in a radio frame are predefined for each supported SCS. Each CORESET configuration is associated with a list of Transmission Configuration Indicator (TCI) states. Each TCI state is configured with a DL RS ID (SSB or CSI RS). The TCI state list corresponding to the CORESET configuration is signaled by the gNB via RRC signaling. One of the TCI states in the TCI state list is activated and indicated by the gNB to the UE. The TCI state indicates the DL TX beam used by the gNB for PDCCH transmission in the PDCCH for monitoring search space opportunities (the DL TX beam is quasi-co-located with the SSB / CSI RS of the TCI state).

[0080] Fifth-generation wireless communication systems support bandwidth adaptation (BA). With BA, the UE's receive and transmit bandwidth need not be as large as the cell's bandwidth and can be adjusted accordingly. Bandwidth can be commanded to change (for example, shrinking during periods of low activity to save power); bandwidth location can be shifted in the frequency domain (for example, to increase scheduling flexibility); and subcarrier spacing can be commanded to change (for example, to allow for different services). A subset of a cell's total cell bandwidth is called a bandwidth part (BWP). BA is implemented by configuring a BWP for an RRC-connected UE and informing the UE which of the configured BWPs is currently active. When BA is configured, the UE only needs to monitor the PDCCH on one active BWP; it does not need to monitor the PDCCH across the entire DL frequency range of the serving cell. In the RRC-connected state, a UE is configured with one or more DL and UL BWPs for each configured serving cell (i.e., PCell or SCell). For an activated serving cell, there is always one active UL and DL BWP at any given time. BWP switching for a serving cell is performed to activate an inactive BWP and deactivate an active BWP. BWP switching is controlled by the PDCCH indicating a downlink assignment or uplink grant, the bwp-InactivityTimer, RRC signaling, or the media access control (MAC) entity itself at the start of the random access procedure. When adding an SpCell or activating an SCell, the DL BWP and UL BWP, indicated by the firstActiveDownlinkBWP-Id (first active downlink BWP indicator) and firstActiveUplinkBWP-Id (first active uplink BWP indicator), respectively, are active unless a PDCCH indicating a downlink assignment or uplink grant is received. The active BWP for the serving cell is indicated by RRC or PDCCH. For unpaired spectrum, the DL BWP is paired with the UL BWP, and BWP switching is common for both UL and DL. Upon expiration of the BWP inactivity timer, the UE switches the active DL BWP to the default DL BWP or the initial DL BWP (if no default DL BWP is configured).

[0081] In existing systems, a UE may be configured with one or more serving cells. Each serving cell is associated with a timing advance group (TAG), where the UE maintains a timing advance (or TA) value for each TAG, which is used to adjust the UL timing of the serving cell associated with the TAG. Recently, multiple TRP (transmit receive point) communications have been enabled in 5G systems, where a serving cell may have multiple TRPs and the UE may communicate with each TRP of a serving cell to enhance throughput and reliability. DCI may be transmitted independently from each of these TRPs, and the UL may be transmitted independently to each of these TRPs using corresponding UL timing. To achieve this functionality, the UE maintains multiple TAs for each serving cell, unlike existing systems where only one TA is maintained for each serving cell.

[0082] In one example, the UE is in RRC_IDLE / RRC_INACTIVE state and camps on a cell (e.g., "cell A"). The UE performs a random access (RA) procedure in the cell and obtains a timing advance TA (e.g., "TA 1") during connection establishment / recovery. The UE starts TimingAlignmentTimer(Timing Alignment Timer). When the UE is in the RRC Connected (RRC_CONNECTED) state, it receives an RRC configuration message from the gNB indicating support for multiple TAs in serving cell A (e.g., by mapping TCI states to TAGs). Subsequently, an additional TA (e.g., "TA2") is obtained based on a random access procedure. To support multiple TAs per serving cell, several issues need to be addressed, such as whether the UE initiates another random access procedure to obtain a second TA, and if so, when the UE triggers this random access procedure and which RA resources are used. Furthermore, the network must determine which TAG of the serving cell the UE-initiated random access procedure for the serving cell is for. The network can initiate a random access procedure for an additional TA of the serving cell. In this case, the UE must know whether the RA is for the first or second TAG of serving cell A. During the random access procedure, the UE receives the TA. The TA can be received in a Random Access Response (RAR), a Fallback RAR, or an Absolute Timing Command (MAC) CE. The Absolute Timing Command (MAC) CE is distinct from the Timing Command (MAC) CE. The Absolute Timing Command MAC CE includes the absolute or complete TA, while the Timing Command MAC CE includes the difference between the old TA (last notified to the UE by the gNB) and the new TA. A mechanism is required to associate the received TA with one of the TAGs of the serving cell. Furthermore, the UE must determine whether a single TAT or separate TATs exist for each of the two TAGs of the serving cell. If separate TATs exist, which TAT of the serving cell should be started when a TA is received during the RA procedure? If one or both of the Timing Advance Timers (TATs) associated with the serving cell expire (TATs are associated with TAGs), the UE must determine the appropriate behavior. Therefore, this disclosure describes enhanced methods for signaling and maintaining multiple TAs in a serving cell.

[0083] Figure 4 A method 400 for maintaining multiple timing advances in a serving cell according to an embodiment of the present disclosure is shown. Figure 4 The embodiments of the methods shown in FIG. 5 are for illustration only. Figure 4 One or more components shown may be implemented in dedicated circuits configured to perform the functions described, or one or more components may be implemented by one or more processors executing instructions to perform the functions described. Other implementations for maintaining multiple timing advances in a serving cell may be used without departing from the scope of this disclosure.

[0084] like Figure 4 As shown, method 400 begins at step 402. At step 402, such as Figure 1 The UE 116 is in an RRC connected state. The UE is configured with one or more serving cells, which are provided by a gNB (e.g., Figure 1 The gNB 103 may signal the configuration of one or more serving cells to the UE using a signaling message (e.g., an RRC message such as an RRCReconfiguration message). Each of the one or more configured serving cells belongs to a primary cell group or a secondary cell group.

[0085] A serving cell can be associated with one or more PCIs (Physical Cell Identifiers). If a serving cell is associated with multiple PCIs, the TA can be different for different PCIs, and one or more PCIs associated with a serving cell can also have the same TA. For example, if a serving cell has 4 PCIs, PCI 1 to PCI 4, PCI 1 and PCI 2 can have the same TA, while PCI 3 and PCI 4 can have different TAs, depending on the coverage. In another example, if a serving cell has 3 PCIs, PCI 1 to PCI 3, they can all have different TAs. If a serving cell is associated with one or more PCIs, the TA can be different between TCI states, for example, the TCI state of one TRP can have a different TA from the TCI state of another TRP.

[0086] In step 404, when the UE is in the RRC connected state, the UE indicates to the gNB using a UE capability information message that it supports multiple timing advances (TAs) per serving cell (or that the UE supports multi-TRP operation with two TA enhancement based on multiple DCI or multi-TRP operation with two or more TAs). This capability may be per-UE (meaning that the UE supports or does not support multiple TAs regardless of any frequency band) or per-frequency band (either per FR1 (frequency range 1, i.e., 400 MHz to 7.125 GHz) / FR2 (frequency range 2, i.e., 24.25 GHz to 52.6 GHz), etc.), where the UE may support multiple TAs for some frequency bands / frequency ranges, all of them, or none of them.

[0087] In step 406, if the UE supports multiple TAs per serving cell, the UE receives an RRCReconfiguration message from the gNB, where one or more serving cells are configured with / associated with multiple timing advance groups (TAGs). The RRCReconfiguration message sent by the gNB to the UE includes a mapping between the TCI state (uplink / joint TCI state) and the TAG ID for the serving cell. The mapping between the TCI state (uplink / joint TCI state) and the TAG ID can be signaled per serving cell or per BWP for the serving cell.

[0088] In one embodiment, at step 408, the UE Figure 5 The signaling shown associates multiple TAs with the TCI status of the serving cell.

[0089] Figure 5 An example RRCReconfiguration message 500 is shown according to an embodiment of the present disclosure. Figure 5 The implementation of the RRCReconfiguration message in FIG is for illustration only. Other implementations of the RRCReconfiguration message 500 may be used without departing from the scope of the present disclosure.

[0090] exist Figure 5In the example of FIG, the RRCReconfiguration message includes a ServingCellConfig IE. The RRCReconfiguration message includes a CellGroupConfig IE. The CellGroupConfig IE includes a TAG list. The ServingCellConfig IE includes a tag-id field. The tag-id field is set to one of the TAG IDs in the TAG list in the CellGroupConfig IE. The BWP configuration of the serving cell includes an uplink / joint TCI state list. The tag-id field indicating the TAG ID of each of one or more uplink / joint TCI states is optionally signaled. The value of the tag-id field in the TCI state is set to one of the TAG IDs in the TAG list in the CellGroupConfig IE. If no TAG ID is signaled for a TCI state (uplink / joint TCI state) (i.e., the tag-Id field is absent), the UE considers the TAG ID for that TCI state (uplink / joint TCI state) to be the TAG ID of the corresponding serving cell, i.e., the TAG ID in the ServingCellConfig information element (IE) of the serving cell included in the RRCReconfiguration message (or it may be a default TAG ID, where the default TAG ID is predefined or signaled by the gNB in ​​the RRCReconfiguration message). If a TAG ID is signaled for a TCI state (uplink / joint TCI state), the UE considers the TAG ID for that TCI state (uplink / joint TCI state) to be the signaled TAG ID. The TAG ID signaled in the ServingCellConfig IE for that TCI state or for the serving cell is the identifier of one of the TAGs included in the TAG-Config (tag-ToAddModList) received in the RRC message for the cell group of the serving cell. TAG-Config tag-ToAddModList includes { timeAlignmentTimer , TAG IDs}. The TAG ID used for the TCI state of a serving cell can be the same as the TAG ID used for the TCI state of another serving cell, or can be the same as the TAG used for the TCI state of another serving cell. For example, a PCell can be associated with two TAGs (TAG 1 and TAG 2). SCells in the same cell group can be associated with TAG 2.

[0091] although Figure 5An example RRCReconfiguration message 500 is shown, but may be Figure 5 Various changes can be made. For example, the number of TAG IDs can be changed, the setting value of TAG ID can be changed, etc. according to specific needs.

[0092] In one embodiment, at step 408, the UE Figure 6 The signaling shown associates multiple TAs with the TCI status of the serving cell.

[0093] Figure 6 An example RRCReconfiguration message 600 is shown according to an embodiment of the present disclosure. Figure 6 The implementation of the RRCReconfiguration message in FIG is for illustration only. Other implementations of the RRCReconfiguration message 600 may be used without departing from the scope of the present disclosure.

[0094] exist Figure 6 In the example, the CellGroupConfig IE in the RRCReconfiguration message includes { timeAlignmentTimer , TAG ID}. The ServingCellConfig IE in the RRCReconfiguration message includes a first tag-Id and a second tag-Id. The value of tag-Id is set to one of the TAG IDs in the TAG list in the CellGroupConfig IE of the serving cell in the RRCReconfiguration message. The BWP configuration of the serving cell includes an uplink / joint TCI state list. Whether the TCI state belongs to the first TAG or the second TAG is indicated by the tag-idx field, where tag-idx is signaled for each TCI state. The first tag refers to tag-id1 in the ServingCellConfig IE, and the second tag refers to tag-id2 in the ServingCellConfig IE. Tag-idx set to 0 (first) or 1 (second) indicates whether the TCI state belongs to the first tag or the second tag, respectively.

[0095] although Figure 6 An example RRCReconfiguration message 600 is shown, but may be Figure 6 Various changes can be made. For example, the number of TAG IDs can be changed, the setting value of TAG ID can be changed, etc. according to specific needs.

[0096] In one embodiment, at step 408, the UE Figure 7The signaling shown associates multiple TAs with the TCI status of the serving cell.

[0097] Figure 7 An example RRCReconfiguration message 700 is shown according to an embodiment of the present disclosure. Figure 7 The implementation of the RRCReconfiguration message in FIG is for illustration only. Other implementations of the RRCReconfiguration message 700 may be used without departing from the scope of the present disclosure.

[0098] exist Figure 7 In the example, the CellGroupConfig IE in the RRCReconfiguration message includes { timeAlignmentTimer , TAG ID}. The ServingCellConfig IE in the RRCReconfiguration message includes a first tag-Id and a second tag-Id. The value of the tag-Id is set to one of the TAG IDs in the TAG list in the CellGroupConfig IE of the serving cell in the RRCReconfiguration message. The BWP configuration of the serving cell includes an uplink / joint TCI state list. By default, the TCI state is mapped to tag-id1 in the ServingCellConfig IE. Whether the TCI state belongs to tag-id2 is explicitly indicated (for example, the OtherTagInd field or the SecondTagInd field of each TCI state can be set to 1 or TRUE, or can exist to indicate whether the corresponding TCI state belongs to the second tag).

[0099] although Figure 7 An example RRCReconfiguration message 700 is shown, but may be Figure 7 Various changes can be made. For example, the number of TAG IDs can be changed, the setting value of TAG ID can be changed, etc. according to specific needs.

[0100] In one embodiment, at step 410, upon receiving an RRCReconfiguration message including multiple TAGs for a serving cell (e.g., at least two TAG IDs associated with the TCI state of the serving cell, note: the TCI state of the serving cell may be for the same PCI and / or different PCIs of the serving cell), if the UE does not have valid TA values ​​for all TAGs of the serving cell (e.g., timingAlignmentTimeris not running), the UE initiates a random access procedure. For example, if the serving cell is associated with TAG 1 and TAG 2, and the UE has a valid TA only for TAG 1 but not for TAG 2, the UE initiates a random access procedure to obtain a TA for TAG 2. If timingAlignmentTimer If the UE is operating for TAG 1 but not for TAG 2, the UE initiates a random access procedure to obtain the TA for TAG 2.

[0101] In one embodiment, at step 410, for an active BWP, upon receiving an RRCReconfiguration message including multiple TAGs for a serving cell (e.g., at least two TAG IDs associated with the TCI state of the serving cell, note: the TCI state of the serving cell may be for the same PCI and / or different PCIs of the serving cell), if the UE does not have valid TA values ​​for all TAGs of the serving cell (e.g., TimingAlignmentTimer is not running), the UE initiates a random access procedure. For example, if the active BWP of the serving cell is associated with TAG 1 and TAG 2, and the UE has a valid TA only for TAG 1 but not for TAG 2, the UE initiates a random access procedure to obtain a TA for TAG 2. If timingAlignmentTimer If the UE is operating for TAG 1 but not for TAG 2, the UE initiates a random access procedure to obtain the TA for TAG 2.

[0102] In one embodiment, at step 412, when activating the TCI state of the serving cell, if the serving cell is associated with multiple TAGs (e.g., at least two TAG IDs are associated with the TCI state of the serving cell, note: the TCI state of the serving cell may be for the same PCI and / or different PCIs of the serving cell), and the TA for the TAG corresponding to the activated TCI state is invalid (e.g., for the TAG, TimingAlignmentTimer (not running), the UE initiates a random access procedure to obtain a TA for that TAG. For example, if the serving cell is associated with TAG 1 and TAG 2, TCI state 1 is associated with TAG 1, and TCI state 2 is associated with TAG 2, the UE has a valid TA only for TAG 1 but not for TAG 2, and when TCI state 2 is activated, the UE initiates a random access procedure to obtain a TA for TAG 2.

[0103] In one embodiment, at step 412, when activating the TCI state of the serving cell, if the active BWP of the serving cell is associated with multiple TAGs (e.g., at least two TAG IDs are associated with the TCI state of the active BWP of the serving cell, note: the TCI state of the serving cell may be for the same PCI and / or different PCIs of the serving cell), and the TA for the TAG corresponding to the activated TCI state is invalid (e.g., for the TAG, TimingAlignmentTimer Not running). The UE initiates a random access procedure to obtain a TA for that TAG. For example, if the serving cell is associated with TAG 1 and TAG 2, TCI state 1 is associated with TAG 1, and TCI state 2 is associated with TAG 2, the UE has a valid TA only for TAG 1 but not for TAG 2, and when TCI state 2 is activated, the UE initiates a random access procedure to obtain a TA for TAG 2.

[0104] In one embodiment, at step 414, different RA resources (preambles and / or PRACH opportunities) may be configured in the serving cell for different TAGs associated with the serving cell. These different RA resources may be configured for each BWP used in the serving cell. The UE selects the RA resources corresponding to the TAG for which RA is initiated. For example, if the serving cell is associated with TAG 1 and TAG 2, RA resources may be configured for each BWP separately for TAG 1 and TAG 2. If RA is initiated for TAG 2, the UE uses the RA resources corresponding to that TAG to transmit the PRACH preamble.

[0105] In another embodiment, at step 416, if the serving cell is associated with multiple TAGs, each TAG may be associated with a subset of SSBs (either explicitly signaled by the gNB in ​​an RRC message for each BWP of the serving cell, or common to all BWPs of the serving cell, or implicitly). In the implicit approach, all SSBs corresponding to the TCI state associated with the same TAG are the SSBs associated with that TAG. When the UE initiates an RA for the serving cell of a TAG, it selects an SSB from the SSBs associated with that TAG (or, in other words, the SSBs associated with the TCI state of that TAG). The UE then selects the RA preamble and RACH opportunity corresponding to that SSB and transmits the RA preamble in the selected RO.

[0106] In one embodiment, upon receiving an RRCReconfiguration message including multiple TAGs for a serving cell (e.g., at least two TAG IDs are associated with the TCI state of the serving cell, note: the TCI state of the serving cell may be for the same PCI and / or different PCIs of the serving cell), if the UE receives a command (e.g., a PDCCH instruction) from the network instructing the UE to initiate a RACH (or random access procedure) for the serving cell, the UE initiates a random access procedure. In this embodiment: - The serving cell for which the RACH will be initiated is indicated by the PDCCH order.

[0107] - The serving cell is associated with at most two TAGs. In the case where the serving cell is associated with two TAGs, a bit indication is included in the PDCCH instruction, indicating whether the PDCCH instruction is for the first or second TAG of the serving cell. The first TAG may correspond to the TAG ID included in the ServingCellConfig IE, and the second TAG may correspond to the TAG ID indicated for the TCI state of the serving cell. The first TAG may correspond to the TAG ID with the lower value of the two TAG IDs of the serving cell.

[0108] - A one-bit indication may be included in a random access response message or an absolute timing advance command media access control (MAC) control element (CE), which is sent by the network during the random access procedure. In the case where the serving cell is associated with two TAGs, one bit indicates whether the TA is the first TAG or the second TAG for the serving cell. The first TAG may correspond to the TAG ID included in the serving cell configuration IE, and the second TAG may correspond to the TAG ID indicated for the TCI state of the serving cell. The first TAG may correspond to the TAG ID with the lower value of the two TAG IDs of the serving cell.

[0109] In one embodiment, the UE checks the SSB index included in the PDCCH order. The UE identifies whether the TCI state of the serving cell (for which the gNB sent the PDCCH order) exists in the active BWP associated with the SSB index, and the UE considers that the random access to be initiated is for the TAG associated with that TCI state. The TA received during the RA procedure (i.e., in the Random Access Response message or the Absolute Timing Advance Command Media Access Control (MAC) Control Element (CE)) applies to this TAG.

[0110] In one embodiment, at step 418, when initiating the RA process to obtain the TA for the TAG of the serving cell, the UE may select 4-step RA. The UE uses contention-based RA resources for RA preamble transmission. When sending the RA preamble, ra- ResponseWindow While the Random Access Response Window is running, the UE monitors the SpCell's PDCCH for a random access response identified by the RA-RNTI. If a valid downlink assignment is received on the PDCCH for the RA-RNTI, the received transport block (TB) is successfully decoded, and if the random access response contains a MAC sub-protocol data unit (sub-PDU) with a random access preamble identifier corresponding to the transmitted preamble, then the random access response is successfully received. The UE applies the received timing advance command for the indicated TAG in the MAC sub-PDU with the random access preamble identifier and starts the corresponding timing alignment timer. The UE processes the received UL grant for UL transmission (Msg3) to the TRP of the serving cell associated with the TAG for which the RA was initiated. The UE sends a C-RNTI MAC CE in Msg3, starts the contention resolution timer upon Msg3 transmission, and awaits a contention resolution message from the gNB. If a PDCCH addressed to the C-RNTI is received from the SpCell, then contention resolution is successful, and the random access procedure is complete. In case the contention resolution timer expires, the UE stops the timing alignment timer that was started when the RAR was received. In case the same timing alignment timer is used for multiple TAs of the serving cell, in case the contention resolution timer expires, the UE restores the timing alignment timer to the value that existed when the RAR restart timer was received.

[0111] In one embodiment, at step 418, when initiating the RA process to obtain the TA for the TAG of the serving cell, the UE may select 4-step RA. The UE uses the contention-free RA resources for RA preamble transmission. When sending the RA preamble, ra- ResponseWindowWhile the (Random Access Response Window) is running, the UE monitors the PDCCH of the SpCell for the random access response identified by the RA-RNTI. If a valid downlink assignment is received on the PDCCH for the RA-RNTI and the received TB is successfully decoded, and if the random access response contains a MAC sub-PDU with a random access preamble identifier corresponding to the transmitted preamble, then the random access response reception is successful. The UE applies the received timing advance command for the indicated TAG in the MAC sub-PDU with the random access preamble identifier. The RA is completed when the RAR is received, and the UE may ignore the received UL grant, or the UE processes the received UL grant for UL transmission to the TRP of the serving cell associated with the TAG for which the RA was initiated.

[0112] In one embodiment, at step 418, when initiating the RA process to obtain the TA for the TAG of the serving cell, the UE may select 4-step RA. The UE uses the contention-free RA resources for RA preamble transmission. When sending the RA preamble, ra- ResponseWindow While the (Random Access Response Window) is running, the UE monitors the SpCell's PDCCH for a random access response identified by the RA-RNTI. If a valid downlink assignment is received on the PDCCH for the C-RNTI and the received TB is successfully decoded, and if the TB includes an Absolute Timing Advance Command MAC CE, where the MAC CE includes the TA for the TAG for which the RA was initiated, then the random access response is successfully received. The UE applies the received Timing Advance Command for the indicated TAG, and the RA is completed.

[0113] In one embodiment, at step 418, when initiating the RA procedure to obtain the TA for the TAG of the serving cell, the UE may select 2-step RA. msgB-ResponseWindowWhile the (msgB response window) is running, the UE monitors the SpCell's PDCCH for the random access response identified by the RA-RNTI. The UE also monitors the SpCell's PDCCH for the C-RNTI. If a valid downlink assignment is received on the PDCCH for the C-RNTI and the received TB is successfully decoded, and if the TB includes an Absolute Timing Advance Command MAC CE, where the MAC CE includes the TA for the TAG for which the RA is initiated, then random access response reception is successful. The UE applies the received timing advance command for the indicated TAG, and the RA is completed. If a valid downlink assignment is received on the PDCCH for the MsgB-RNTI and the received TB is successfully decoded, and if the MsgB contains a successful RAR MAC sub-PDU with a random access preamble identifier corresponding to the transmitted preamble, then random access response reception is successful. The UE applies the received timing advance command for the indicated TAG in the successful RAR MAC sub-PDU with the random access preamble identifier. The RA is completed upon receiving the RAR and the UE may ignore the received UL grant or the UE processes the received UL grant for UL transmission to the TRP of the serving cell associated with the TAG for which the RA was initiated.

[0114] although Figure 4 An example of a method 400 for maintaining multiple timing advances in a serving cell is shown, but may be used for Figure 4 For example, although shown as a series of steps, Figure 4 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0115] Figure 8 A method 800 for PDCCH initiated random access according to an embodiment of the present disclosure is shown. Figure 8 The embodiments of the methods shown in FIG. 5 are for illustration only. Figure 8 One or more components shown may be implemented in dedicated circuits configured to perform the functions described, or one or more components may be implemented by one or more processors executing instructions to perform the functions described. Other implementations of PDCCH-initiated random access may be used without departing from the scope of this disclosure.

[0116] like Figure 8 As shown, method 800 begins at step 802. At step 802, such as Figure 1 The UE 116 of the UE from such as Figure 1The gNB of gNB 103 receives the PDCCH instruction. The PDCCH instruction instructs the UE to initiate a RACH for serving cell A. In step 804, the UE selects 4-step RA and sends an RA preamble to cell A. In step 806, the UE determines whether cell A is configured with multiple TAGs. If so, the method proceeds to step 808. Otherwise, the method proceeds to step 812. In step 808, after sending the RA preamble, the UE monitors for a PDCCH addressed to the C-RNTI (of the SpCell). In step 810, random access is completed when the UE receives a PDCCH addressed to the C-RNTI. The PDCCH addressed to the C-RNTI schedules a DL TB (with the TAG for which RA was initiated) that includes an absolute timing advance command (MAC CE) and includes the TA. In step 812, after sending the RA preamble, the UE monitors for a PDCCH addressed to the RA-RNTI (of the SpCell). At step 814 , random access is completed when the UE receives a PDCCH addressed to the RA-RNTI and schedules a TB containing a MAC sub-PDU having a random access preamble identifier corresponding to the transmitted preamble index (PREAMBLE_INDEX).

[0117] although Figure 8 An example of a method 800 for PDCCH initiated random access is shown, but may be used for Figure 8 For example, although shown as a series of steps, Figure 8 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0118] Figure 9 A method 900 for a random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown. Figure 9 The embodiments of the methods shown are for illustration only. Figure 9 One or more components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other implementations of random access operations for a serving cell configured with two TAGs may be used without departing from the scope of the present disclosure.

[0119] exist Figure 9 In the example, the serving cell is configured with two TAGs (TAG 1 and TAG 2). Figure 9 As shown, method 900 begins at step 902. At step 902, such as Figure 1 The UE 116 of the UE from such as Figure 1The gNB 103 receives the RRCReconfiguration message. The configuration of the serving cell (e.g., SpCell) includes / indicates multiple TAs / TAGs (e.g., TAG 1, TAG 2). At step 904, the UE initiates a random access procedure (e.g., if a scheduling request is triggered and the UE does not have PUCCH resources to send a scheduling request, the UE initiates a random access procedure. Similarly, for LBT failure recovery, beam failure recovery, etc., the UE can initiate a random access procedure in the RRC connected state).

[0120] In step 906, if TAT is currently running for both TAs / TAGs of the serving cell (e.g., SpCell), the UE selects a predefined TAG from among the multiple TAGs of the serving cell (e.g., SpCell). The predefined TAG may be TAG 1 or TAG 2. In step 908, if TAT is not currently running for both TAs / TAGs of the serving cell (e.g., SpCell), the UE selects a predefined TAG from among the multiple TAGs of the serving cell (e.g., SpCell). The predefined TAG may be TAG 1 or TAG 2. In step 910, if TAT is currently running for one of the multiple TAs / TAGs of the serving cell (e.g., SpCell), the UE selects a TAG for which TAT is not currently running / has expired (or the UE selects a TAG for which TAT is currently running).

[0121] In step 912, the UE selects an SSB from the SSBs transmitted by the serving cell (e.g., SpCell) (or, the UE selects an SSB from the SSBs associated with the selected TAG of the serving cell (e.g., SpCell)). The UE selects the RO corresponding to the selected SSB. In step 914, the UE transmits Msg1 (PRACH preamble in the selected RO) or MsgA (PRACH preamble, MsgA MACPDU in the selected RO) to the serving cell (e.g., SpCell) using contention-based random access resources. For Msg1 / PRACH preamble transmission timing, the UE applies the adjustment value N TA = 0 and N TA,offset , which corresponds to the selected TAG of the serving cell (eg, SpCell). At step 916, the UE receives a random access response (MAC RAR in Msg2 or Fallback RAR or Absolute Timing Command MAC CE in MsgB) including the TA.

[0122] In step 920, if the TAT for the selected TAG is running, the UE ignores the TA received in the random access response. If the TAT for the selected TAG is not running, the UE processes and applies the received TA for the selected TAG. The UE starts the TAT for the selected TAG. Subsequently, if contention resolution fails during the random access procedure, the UE stops the TAT for the selected TAG.

[0123] although Figure 9 An example of a method 900 for random access operation of a serving cell configured with two TAGs is shown, but the random access operation may be performed on the serving cell configured with two TAGs. Figure 9 For example, although shown as a series of steps, Figure 9 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0124] Figure 10 A method 1000 for a random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown. Figure 10 The embodiments of the methods shown in FIG. 5 are for illustration only. Figure 10 One or more components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other embodiments of random access operations for a serving cell configured with two TAG cells may be used without departing from the scope of the present disclosure.

[0125] exist Figure 10 In the example, the serving cell is configured with two TAGs (TAG 1 and TAG 2). Figure 10 As shown, method 1000 begins at step 1002. At step 1002, such as Figure 1 The UE 116 of the UE from such as Figure 1 The gNB 103 receives the RRCReconfiguration message. The configuration of the serving cell (e.g., SpCell) includes / indicates multiple TAs / TAGs (e.g., TAG 1, TAG 2). At step 1004, the UE initiates a random access procedure (e.g., if a scheduling request is triggered and the UE does not have PUCCH resources to send a scheduling request, the UE initiates a random access procedure. Similarly, for LBT failure recovery, beam failure recovery, etc., the UE can initiate a random access procedure in the RRC connected state).

[0126] In step 1006, the UE selects a predefined TAG from among a plurality of TAGs of the serving cell (e.g., SpCell). The predefined TAG may be TAG 1 or TAG 2. In step 1008, the UE selects an SSB from among the SSBs transmitted by the serving cell (e.g., SpCell) (or, the UE selects an SSB from among the SSBs associated with the selected TAG of the serving cell (e.g., SpCell)). The UE selects an RO corresponding to the selected SSB. In step 1010, the UE transmits Msg1 (PRACH preamble in the selected RO) or MsgA (PRACH preamble, MsgA MAC PDU in the selected RO) to the serving cell (e.g., SpCell) using contention-based random access resources. For Msg1 / PRACH preamble transmission timing, the UE applies N TA = 0 and N TA,offset , which corresponds to the selected TAG of the serving cell (eg, SpCell).

[0127] In step 1012, the UE receives a random access response including a TA (MAC RAR in Msg2 (if Msg1 is sent) or Fallback RAR or Absolute Timing Command MAC CE in MsgB (if MsgA is sent)). In step 1014, if the TAT for the selected TAG is running, the UE ignores the TA received in the random access response. In step 1016, if the TAT for the selected TAG is not running, the UE processes and applies the received TA for the selected TAG, starts the TAT for the selected TAG, and then stops the TAT for the selected TAG if contention resolution fails during the random access procedure.

[0128] although Figure 10 An example of a method 1000 for a random access operation of a serving cell configured with two TAGs is shown, but the random access operation may be performed on a serving cell configured with two TAGs. Figure 10 For example, although shown as a series of steps, Figure 10 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0129] Figure 11 A method 1100 for a random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown. Figure 11 The embodiments of the methods shown are for illustration only. Figure 11One or more components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other embodiments for random access operations for a serving cell configured with two TAGs may be used without departing from the scope of the present disclosure.

[0130] exist Figure 11 In the example, the serving cell is configured with two TAGs (TAG 1 and TAG 2). Figure 11 As shown, method 1100 begins at step 1102. At step 1102, such as Figure 1 The UE 116 of the UE from such as Figure 1 The gNB 103 receives the RRCReconfiguration message. The configuration of the serving cell (e.g., SpCell) includes / indicates multiple TAs / TAGs (e.g., TAG 1, TAG 2). At step 1104, the UE initiates a random access procedure (e.g., if a scheduling request is triggered and the UE does not have PUCCH resources to send the scheduling request, the UE initiates a random access procedure).

[0131] In step 1106, the UE selects an SSB from the SSBs transmitted by the serving cell (e.g., SpCell). The UE selects the RO corresponding to the selected SSB. In step 1108, the UE transmits Msg1 (PRACH preamble in the selected RO) or MsgA (PRACH preamble, MsgA MAC PDU in the selected RO) to the serving cell (e.g., SpCell) using contention-based random access resources. For Msg1 / PRACH preamble transmission timing, the UE applies the N of the TAG corresponding to the selected SSB of the serving cell (e.g., SpCell). TA = 0 and N TA,offset Each SSB transmitted by the serving cell (e.g., SpCell) is mapped to TAG 1 or TAG 2, and this mapping is signaled to the UE by the gNB (e.g., in the RRCReconfiguration message).

[0132] In step 1110, the UE receives a random access response including a TA (MAC RAR in Msg2 (in the case of transmitting Msg1) or Fallback RAR or Absolute Timing Command MAC CE in MsgB (in the case of transmitting MsgA)). In step 1112, if the TAT for the TAG corresponding to the selected SSB is running, the UE ignores the TA received in the random access response. Each SSB transmitted by the serving cell (e.g., SpCell) is mapped to TAG 1 or TAG 2. In step 1114, if the TAT for the TAG corresponding to the selected SSB is not running, the UE processes and applies the received TAT for the TAG corresponding to the selected SSB, the UE starts the TAT for the TAG corresponding to the selected SSB, and then if contention resolution fails during the random access procedure, the UE stops the TAT for the TAG corresponding to the selected SSB.

[0133] although Figure 11 An example of a method 1100 for a random access operation of a serving cell configured with two TAGs is shown, but the random access operation may be performed on the serving cell. Figure 11 For example, although shown as a series of steps, Figure 11 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0134] Figure 12 A method 1200 for a random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown. Figure 12 The embodiments of the methods shown are for illustration only. Figure 12 One or more components described in the embodiment may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other implementations of random access operations for a serving cell configured with two TAGs may be used without departing from the scope of the present disclosure.

[0135] exist Figure 12 In the example, the serving cell is configured with two TAGs (TAG 1 and TAG 2). Figure 12 As shown, method 1200 begins at step 1202. At step 1202, such as Figure 1 The UE 116 of the UE from such as Figure 1The gNB of gNB 103 receives the RRCReconfiguration message. The configuration of the serving cell (e.g., SpCell) includes / indicates multiple TAs / TAGs (e.g., TAG 1, TAG 2). At step 1204, the UE initiates a random access procedure (e.g., if a scheduling request is triggered and the UE does not have PUCCH resources for sending a scheduling request, the UE initiates a random access procedure. Similarly, for LBT failure recovery, beam failure recovery, etc. as defined in TS 38.321, the UE can initiate a random access procedure in the RRC connected state).

[0136] In step 1206, the UE selects an SSB from the SSBs sent by the serving cell (e.g., SpCell). The UE selects the RO corresponding to the selected SSB. In step 1208, the UE sends Msg1 (PRACH preamble in the selected RO) or MsgA (PRACH preamble, MsgA MAC PDU in the selected RO) to the serving cell (e.g., SpCell) using contention-based random access resources. For Msg1 / PRACH preamble transmission timing, the UE applies N TA = 0 and the default N TA,offset . Or, instead of the default N TA,offset , using N for TAG 1 TA,offset , or N for TAG 2 TA,offset . N for TAG 1 TA,offset and N for TAG 2 TA,offset Signaled by the gNB (e.g. in the RRCReconfiguration message). In one embodiment, N for TAG 1 may be used. TA,offset and N for TAG 2 TA,offset The maximum value of , or N for TAG 1 TA,offset and N for TAG 2 TA,offset The minimum value in .

[0137] In step 1210, the UE receives a random access response (MAC RAR in Msg2 (in the case of sending Msg1) or Fallback RAR or Absolute Timing Command MAC CE in MsgB (in the case of sending MsgA)) including a TA. The random access response indicates the TAG of the included TA. For example, a bit field in the random access response may indicate the first TAG or the second TAG of the serving cell. In step 1212, if the TAT for the TAG indicated in the random access response is running, the UE ignores the TA received in the random access response. In step 1214, if the TAT for the TAG indicated in the random access response is not running, the UE processes and applies the received TA for the indicated TAG, the UE starts the TAT for the indicated TAG, and then stops the TAT for the indicated TAG if contention resolution fails during the random access procedure.

[0138] although Figure 12 An example of a method 1200 for a random access operation of a serving cell configured with two TAGs is shown, but the random access operation may be performed on a serving cell configured with two TAGs. Figure 12 For example, although shown as a series of steps, Figure 12 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0139] Figure 13 A method 1300 for a random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown. Figure 13 The embodiments of the methods shown are for illustration only. Figure 13 One or more components shown may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other implementations of random access operations for a serving cell configured with two TAGs may be used without departing from the scope of the present disclosure.

[0140] exist Figure 13 In the example, the serving cell is configured with two TAGs (TAG 1 and TAG 2). Figure 13 As shown, method 1300 begins at step 1302. At step 1302, such as Figure 1 The UE 116 of the UE from such as Figure 1The gNB 103 receives the RRCReconfiguration message. The configuration of the serving cell (e.g., SpCell) includes / indicates multiple TAs / TAGs (e.g., TAG 1, TAG 2). At step 1304, the UE receives a PDCCH command for initiating a random access procedure for the serving cell (e.g., SpCell).

[0141] In step 1306, the UE selects the SSB indicated in the PDCCH instruction (if any). Otherwise, the UE selects an SSB among the SSBs sent by the serving cell (e.g., SpCell). The UE selects the RO corresponding to the selected SSB. In step 1308, the UE sends Msg1 (PRACH preamble in the selected RO) or MsgA (PRACH preamble, MsgA MAC PDU in the selected RO) to the serving cell (e.g., SpCell) using contention-based random access resources. For Msg1 / PRACH preamble transmission timing, the UE applies N TA = 0 and the default N TA,offset . Or, instead of the default N TA,offset , using N for TAG 1 TA,offset , or N for TAG 2 TA,offset . N for TAG 1 TA,offset and N for TAG 2 TA,offset Signaled by the gNB (e.g. in the RRCReconfiguration message). In one embodiment, N for TAG 1 may be used. TA,offset and N for TAG 2 TA,offset The maximum value of , or N for TAG 1 TA,offset and N for TAG 2 TA,offset The minimum value in .

[0142] In step 1310, the UE receives a random access response (MAC RAR in Msg2 (in the case of sending Msg1) or Fallback RAR or Absolute Timing Command MAC CE in MsgB (in the case of sending MsgA)) including a TA. The random access response indicates the TAG of the included TA. For example, a bit field in the random access response may indicate the first TAG or the second TAG of the serving cell. In step 1312, if the TAT for the TAG indicated in the random access response is running, the UE ignores the TA received in the random access response. In step 1314, if the TAT for the TAG indicated in the random access response is not running, the UE processes and applies the received TA for the indicated TAG, the UE starts the TAT for the indicated TAG, and then stops the TAT for the indicated TAG if contention resolution fails during the random access procedure.

[0143] although Figure 13 An example of a method 1300 for a random access operation of a serving cell configured with two TAGs is shown, but the random access operation may be performed on the serving cell. Figure 13 For example, although shown as a series of steps, Figure 13 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0144] Figure 14 A method 1400 for a random access operation of a serving cell configured with two TAGs according to an embodiment of the present disclosure is shown. Figure 14 The embodiments of the methods shown are for illustration only. Figure 14 One or more components described in the embodiment may be implemented in a dedicated circuit configured to perform the functions, or one or more components may be implemented by one or more processors executing instructions to perform the functions. Other implementations of random access operations for a serving cell configured with two TAGs may be used without departing from the scope of the present disclosure.

[0145] exist Figure 14 In the example, the serving cell is configured with two TAGs (TAG 1 and TAG 2). Figure 14 As shown, method 1400 begins at step 1402. At step 1402, such as Figure 1 The UE 116 of the UE from such as Figure 1The gNB 103 receives the RRCReconfiguration message. The configuration of the serving cell (e.g., SpCell) includes / indicates multiple TAs / TAGs (e.g., TAG 1, TAG 2). At step 1404, the UE receives a PDCCH command for initiating a random access procedure for the serving cell (e.g., SpCell).

[0146] At step 1406, the UE selects the SSB indicated in the PDCCH instruction (if any). Otherwise, the UE selects an SSB among the SSBs sent by the serving cell (e.g., SpCell). The UE selects the RO corresponding to the selected SSB. At step 1408, the UE sends Msg1 (PRACH preamble in the selected RO) or MsgA (PRACH preamble in the selected RO, MsgA MAC PDU) to the SpCell using contention-based random access resources. For Msg1 / PRACH preamble transmission timing, the UE applies the N of the TAG corresponding to the selected SSB of the SpCell. TA = 0 and N TA,offset Each SSB transmitted by the SpCell is mapped to TAG 1 or TAG 2, and this mapping is signaled to the UE by the gNB (e.g., in the RRCReconfiguration message).

[0147] In step 1410, the UE receives a random access response including a TA (MAC RAR in Msg2 (in the case of transmitting Msg1) or Back-off RAR or Absolute Timing Command MAC CE in MsgB (in the case of transmitting MsgA)). In step 1412, if the TAT for the TAG corresponding to the selected SSB is running, the UE ignores the TA received in the random access response. Each SSB transmitted by the SpCell is mapped to TAG 1 or TAG 2. In step 1414, if the TAT for the TAG corresponding to the selected SSB is not running, the UE processes and applies the received TA for the TAG corresponding to the selected SSB, the UE starts the TAT for the TAG corresponding to the selected SSB, and then if contention resolution fails during the random access procedure, the UE stops the TAT for the TAG corresponding to the selected SSB.

[0148] although Figure 14 An example of a method 1400 for random access operation of a serving cell configured with two TAGs is shown, but the method may be used for Figure 14 For example, although shown as a series of steps, Figure 14The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0149] In one embodiment, the uplink frame number used to send from the UE i Should start before the start of the corresponding downlink frame at the UE ,in, -N TA and N TA,offset Given by clause 4.2 of [5, TS 38.213], except that N TA = 0, msgA transmission on PUSCH; - given by clause 4.2 of [5, TS 38.213] From high-level parameters TACommon 、 TACommonDrift and TACommonDriftVariation Export (if configured), otherwise ; - given by clause 4.2 of [5, TS 38.213] Calculated by the UE based on the UE position and higher-layer parameters related to the serving satellite ephemeris (if configured), otherwise .

[0150] In one embodiment, upon obtaining the TA for the TAG of the serving cell, the UE (re)starts the TimingAlignmentTimer In this case, the value of the timer is obtained from TAG-Config (tag-ToAddModList), where the value is determined by the TAG ID corresponding to the TAG for which the TA was obtained. timeAlignmentTimer Field given.

[0151] In an embodiment, when timeAlignmentTimer Upon expiration, the MAC entity in the UE will do the following: - if timeAlignmentTimer Associated with a SpCell and no other associated with this SpCell timeAlignmentTimer is running (for example, if the SpCell is associated with two TAGs and the timeAlignmentTimer maturity): Clear all Hybrid Automatic Repeat Request (HARQ) buffers for all serving cells of the SpCell cell group; Notify RRC to release PUCCH for all serving cells c, if configured; Notify RRC to release SRS for all serving cells in the SpCell cell group, if configured; clearing any configured downlink allocations and configured uplink grants; Clear any PUSCH resources for semi-persistent channel state information (CSI) reporting; Will run all timeAlignmentTimer deemed to be due; Maintain N of all tags TA , where N TA is the timing adjustment value.

[0152] - if timeAlignmentTimer is associated with SpCell, and there is another cell associated with SpCell timeAlignmentTimer Running (e.g., for different tags of SpCell) Suspended and expired timeAlignmentTimer The UL transmission corresponding to the TCI state associated with the TAG - if timeAlignmentTimer Associated with STAG: If there is at least one activated SCell belonging to the STAG, the TAG associated with the SCell timeAlignmentTimer There are no running: Clear all HARQ buffers; Notify RRC to release PUCCH, if configured; Notify RRC to release SRS, if configured; clearing any configured downlink allocations and configured uplink grants; Clear any PUSCH resources for semi-persistent CSI reporting; Maintain the N of this TAG TA (defined in TS 38.211 [8]), where N TA is the timing adjustment value.

[0153] otherwise Suspended and expired timeAlignmentTimeUL transmission corresponding to the TCI state associated with the TAG.

[0154] In one embodiment, when an absolute timing advance command is received in response to a PDCCH order for a TAG of a serving cell, the MAC entity in the UE applies the timing advance command for the TAG indicated in the absolute timing advance command or the PDCCH order.

[0155] In one embodiment, TimingAlignmentTimer It may be common to all TAGs of the serving cell and the UE (re)starts the TA whenever it receives a TA for any TAG of the serving cell from the gNB. TimingAlignmentTimer In this case, the timer value is obtained from the TAG-Config (tag-ToAddModList) corresponding to the TAG ID signaled in the ServingCell Config IE of the serving cell. timeAlignmentTimer Field given.

[0156] In an embodiment, when the UE receives a TA for a TAG in a random access response message for a serving cell from the gNB, the MAC entity in the UE performs the following operations: 1 > If the MAC entity does not select a random access preamble from the contention-based random access preamble: 2 > Apply the timing advance command for the tag; 2 > If multiple TAGs are associated with the serving cell (i.e., the serving cell that receives the random access response message), 3 > Start the associated with the TAG timeAlignmentTimer (or start the TAG associated with the serving cell that received the random access response timeAlignmentTimer ); 2 > Otherwise 3 > Start or restart the timeAlignmentTimer .

[0157] 1 > Otherwise, if multiple TAGs are associated with the serving cell (i.e., the serving cell that received the Random Access Response message), 2 > Apply the timing advance command for the tag; 2 > Start the associated with the TAG timeAlignmentTimer (or start the TAG associated with the serving cell that received the random access response timeAlignmentTimer ); 2 > When the contention resolution is deemed unsuccessful during the RA process: 3 > N TAThe value (e.g., adjustment value) is set to the value before the received timing advance command is applied, 2 > Otherwise, if the tag is associated with timeAlignmentTimer Not running: 3 > Apply the timing advance command for the tag; 3 > Start the associated with the TAG timeAlignmentTimer ; 3 > when competitive resolution is deemed unsuccessful as described in clause 5.1.5; or 3 > When contention resolution is considered successful for an SI request as described in clause 5.1.5, after sending the HARQ feedback for the MAC PDU including the UE contention resolution identifier MAC CE: 4 > Stop associating with this tag timeAlignmentTimer .

[0158] If the SpCell is configured with multiple TAGs and RA is initiated for reasons other than the TA of the SpCell's TAG (e.g., RACH initiated for SR, BFR, or LBT failure, etc.), then during the random access procedure, for PRACH transmission, for Msg3 transmission, and for HARQ feedback transmission for Msg4, the UE applies N based on the TA of the following TAGs of the SpCell: TA :

[0159] - First TAG, - The TAG of the two TAGs to be applied in this case is signaled by the gNB in ​​the RRC message.

[0160] - Second TAG, - TAG indicated in the RAR during the RA procedure (this is only for Msg4 and HARQ feedback).

[0161] Figure 15 A method 1500 for maintaining multiple timing advances in a serving cell according to an embodiment of the present disclosure is shown. Figure 15 The embodiments of the methods shown are for illustration only. Figure 15 One or more components shown may be implemented in dedicated circuits configured to perform the functions described, or one or more components may be implemented by one or more processors executing instructions to perform the functions described. Other implementations for maintaining multiple timing advances in a serving cell may be used without departing from the scope of this disclosure.

[0162] like Figure 15 As shown, method 1500 begins at step 1502. At step 1502, such as Figure 1The UE 116 sends a capability information message including an indication that the UE supports multiple TAs per serving cell. In step 1504, the UE receives a signal from the BS (e.g., Figure 1 The gNB 103 receives an RRCReconfiguration message signaling that the serving cell is associated with multiple TAGs. The RRC includes a mapping between multiple TCI states and multiple TAG IDs for the serving cell. At step 1506, the UE determines the TAG ID corresponding to each TCI state from the multiple TCI states based on the mapping. Finally, at step 1508, the UE transmits an RA preamble.

[0163] although Figure 15 An example of a method 1500 for maintaining multiple timing advances in a serving cell is shown, but may be used for Figure 15 For example, although shown as a series of steps, Figure 15 The various steps in the process may overlap, occur in parallel, occur in a different order, occur any number of times, be omitted, or be replaced with other steps.

[0164] Figure 16 A block diagram of a terminal (or user equipment (UE)) according to an embodiment of the present disclosure is shown.

[0165] like Figure 16 As shown, the terminal according to the embodiment may include a transceiver 1610, a memory 1620 and a processor (or controller) 1630. The transceiver 1610, the memory 1620 and the processor (or controller) 1630 of the terminal may operate according to the communication method of the above-mentioned terminal. However, the components of the terminal are not limited thereto. For example, the terminal may include Figure 16 16. In addition, the processor (or controller) 1630, the transceiver 1610, and the memory 1620 may be implemented as a single chip. In addition, the processor (or controller) 1630 may include at least one processor.

[0166] Transceiver 1610 refers to a terminal station receiver and a terminal transmitter, and can send and receive signals to / from a base station or another terminal. The signals sent to or received from the terminal may include control information and data. Transceiver 1610 may include an RF transmitter for up-converting and amplifying the frequency of the transmitted signal, and an RF receiver for low-noise amplification and down-converting the frequency of the received signal. However, this is only an example of transceiver 1610, and the components of transceiver 1610 are not limited to RF transmitters and RF receivers.

[0167] In addition, the transceiver 1610 may receive and output signals to the processor (or controller) 1630 through a wireless channel, and transmit signals output from the processor (or controller) 1630 through a wireless channel.

[0168] The memory 1620 may store programs and data required for the terminal to operate. In addition, the memory 1620 may store control information or data included in signals obtained by the terminal. The memory 1620 may be a storage medium such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0169] The processor (or controller) 1630 may control a series of processes so that the terminal operates as described above. For example, the processor (or controller) 1630 may receive data signals and / or control signals, and the processor (or controller) 1630 may determine the result of receiving signals sent by a base station and / or other terminals.

[0170] Figure 17 A block diagram of a base station according to an embodiment of the present disclosure is shown.

[0171] like Figure 17 As shown, the base station of the present disclosure may include a transceiver 1710, a memory 1720, and a processor (or controller) 1730. The transceiver 1710, the memory 1720, and the processor (or controller) 1730 of the base station may operate according to the communication method of the above-mentioned base station. However, the components of the base station are not limited thereto. For example, the base station may include Figure 17 17. In addition, the processor (or controller) 1730, the transceiver 1710, and the memory 1720 may be implemented as a single chip. In addition, the processor (or controller) 1730 may include at least one processor.

[0172] The transceiver 1710 collectively refers to a base station receiver and a base station transmitter, and can send and receive signals to and from a terminal, other base stations, and / or core network functions (or entities). Signals sent to or received from a base station may include control information and data. The transceiver 1710 may include an RF transmitter for up-converting and amplifying the frequency of transmitted signals, and an RF receiver for low-noise amplification and down-converting the frequency of received signals. However, this is merely an example of the transceiver 1710, and the components of the transceiver 1710 are not limited to RF transmitters and RF receivers.

[0173] In addition, the transceiver 1710 may receive and output signals to the processor (or controller) 1730 through a wireless channel, and transmit signals output from the processor (or controller) 1730 through a wireless channel.

[0174] The memory 1720 may store programs and data required for base station operation. In addition, the memory 1720 may store control information or data included in signals obtained by the base station. The memory 1720 may be a storage medium such as ROM, RAM, a hard disk, a CD-ROM, and a DVD, or a combination of storage media.

[0175] The processor (or controller) 1730 may control a series of processes so that the base station operates as described above. For example, the processor (or controller) 1730 may receive a data signal and / or a control signal, and the processor (or controller) 1730 may determine the result of receiving a signal sent by a terminal and / or a core network function.

[0176] When the electrical structures and methods are implemented in software, a computer-readable recording medium containing one or more programs (software modules) may be provided. The one or more programs recorded on the computer-readable recording medium are configured to be executed by one or more processors in an electronic device. The one or more programs include instructions for executing the methods according to the embodiments described in the claims or detailed description of this disclosure.

[0177] It will be appreciated by those skilled in the art that the above-described illustrative embodiments are described herein and are not intended to be limiting. It will be understood that any two or more embodiments disclosed herein may be combined in any combination. In addition, other embodiments may be utilized, and other changes may be made, without departing from the spirit and scope of the subject matter presented herein. It will be readily understood that the various aspects of the present invention as generally described herein and illustrated in the accompanying drawings may be arranged, replaced, combined, separated, and designed in a variety of different configurations, all of which are contemplated herein.

[0178] It will be appreciated by those skilled in the art that the various illustrative logic blocks, modules, circuits, and steps described herein may be implemented as hardware, software, or a combination thereof. In order to clearly illustrate this interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in the form of their functional sets. Whether these functional sets are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. Technicians may implement the described functional sets in different ways for each specific application, but such design decisions should not be interpreted as causing deviations from the scope of the present application.

[0179] The various illustrative logical blocks, modules, and circuits described in this application may be implemented or executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to implement the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, a combination of multiple microprocessors, a combination of one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0180] The steps of the methods or algorithms described in this application may be directly embodied in hardware, software modules executed by a processor, or a combination thereof. The software modules may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, a hard disk, a removable disk, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor to enable the processor to read information from and write information to the storage medium. Alternatively, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. Alternatively, the processor and storage medium may reside in a user terminal as discrete components.

[0181] In one or more exemplary designs, the functions may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, each function may be stored on or transmitted via a computer-readable medium as one or more instructions or code. Computer-readable media include computer storage media and communication media, including any medium that facilitates the transfer of a computer program from one location to another. Storage media can be any available medium that can be accessed by a general-purpose or special-purpose computer.

[0182] Any of the above-mentioned variant embodiments can be used independently or in combination with at least one other variant embodiment. The above flowcharts illustrate example methods that can be implemented according to the principles of the present 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.

[0183] Although the present disclosure has been described using exemplary embodiments, various changes and modifications may be devised by those skilled in the art. It is intended that the present disclosure encompass such changes and modifications as fall within the scope of the appended claims. Nothing in this application should be construed as implying that any particular element, step, or function is essential to the scope of the claims. The scope of the patented subject matter is defined by the claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: receiving, from a base station, configuration information for a serving cell, the configuration information including a first TAG identifier for a first timing advance group TAG associated with the serving cell and a second TAG identifier for a second TAG associated with the serving cell; receiving a timing advance command and a bit from the base station, where the bit indicates a TAG to which the timing advance command applies, from two TAGs including the first TAG and the second TAG; as well as Apply the timing advance command to the TAG indicated by the bit.

2. The method according to claim 1, wherein The timing advance command and the bit are included in a random access response message or an absolute timing advance command medium access control MAC control element CE.

3. The method according to claim 1, further comprising: Start or restart the time alignment timer associated with the TAG indicated by the bit.

4. The method according to claim 3, further comprising: When the contention resolution timer expires, the time alignment timer associated with the TAG is stopped.

5. The method according to claim 3, wherein In a case where the time alignment timer associated with the TAG of a specific cell SpCell expires and the time alignment timer associated with the other TAG of the two TAGs of the SpCell is not running, the method further includes at least one of the following: Clear all hybrid automatic repeat request HARQ buffers for all serving cells; Notify the radio resource control (RRC) to release the physical uplink control channel (PUCCH) for all serving cells; Notifying the RRC to release the sounding reference signal SRS for all serving cells; clearing any configured downlink allocations and configured uplink grants; Clear any physical uplink shared channel (PUSCH) resources used for semi-persistent channel state information (CSI) reporting; Consider all running time alignment timers to have expired; or Maintain the N_TA value of all tags.

6. The method according to claim 1, further comprising: Information indicating an association between a transmission configuration indication (TCI) state and a TAG in the two TAGs is received from the base station.

7. The method according to claim 1, further comprising: The capability information of multiple transmission and reception points (TRPs) with two timing advances for each serving cell based on multiple downlink control information (DCI) is sent to the base station.

8. A terminal in a wireless communication system, the terminal comprising: transceiver; as well as A controller is coupled to the transceiver and configured to: receiving configuration information for a serving cell from a base station, the configuration information including a first TAG identifier for a first timing advance group TAG associated with the serving cell and a second TAG identifier for a second TAG associated with the serving cell, receiving a timing advance command and a bit from the base station, the bit indicating a TAG to which the timing advance command is applied, from two TAGs including the first TAG and the second TAG; and Apply the timing advance command to the TAG indicated by the bit.

9. The terminal according to claim 8, wherein: The timing advance command and the bit are included in a random access response message.

10. The terminal according to claim 8, wherein: The timing advance command and the bit are included in an absolute timing advance command medium access control MAC control element CE. The terminal according to claim 8 , wherein: The controller is further configured to: Start or restart the time alignment timer associated with the TAG indicated by the bit.

12. The terminal according to claim 11, wherein: The controller is further configured to: When the contention resolution timer expires, the time alignment timer associated with the TAG is stopped. The terminal according to claim 11 , wherein: When the time alignment timer associated with the TAG of a specific cell SpCell expires and the time alignment timer associated with the other TAG of the two TAGs of the SpCell is not running, the controller is further configured to perform at least one of the following: Clear all HARQ buffers for all serving cells, Notify the Radio Resource Control (RRC) to release the Physical Uplink Control Channel (PUCCH) for all serving cells. Notify the RRC to release the sounding reference signal SRS for all serving cells, clears any configured downlink allocations and configured uplink grants, Clear any Physical Uplink Shared Channel (PUSCH) resources used for semi-persistent Channel State Information (CSI) reporting. Consider all running time alignment timers to have expired; or Maintain the N_TA value of all tags. The terminal according to claim 8 , wherein: The controller is further configured to: Information indicating an association between a transmission configuration indication (TCI) state and a TAG in the two TAGs is received from the base station. The terminal according to claim 8 , wherein: The controller is further configured to: The capability information of multiple transmission and reception points (TRPs) with two timing advances for each serving cell based on multiple downlink control information (DCI) is sent to the base station.

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