Terminal, target special cell and method thereof in wireless communication system

Abstract

The present disclosure relates to a communication method and system for converging a 5th-Generation (5G) communication system for supporting higher data rates beyond a 4th-Generation (4G) system and an Internet of Things (IoT) technology. The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and security services. The present disclosure provides a method and apparatus for managing system information in a wireless communication system.

Description

[0001] This application is a divisional application of the invention patent application with the application date of December 14, 2020, application number 202080088223.1, and invention title "Method and apparatus for processing system information requests in a wireless communication system". Technical Field

[0002] The present disclosure relates to a wireless communication system. Specifically, the present disclosure relates to an apparatus, method, and system for managing system information in a radio resource control (RRC) connected state in a wireless communication system. Background Art

[0003] In order to meet the increasing demand for wireless data traffic since the deployment of 4G communication systems, efforts have been made to develop improved 5G or pre-5G communication systems. Therefore, 5G or pre-5G communication systems are also referred to as "beyond 4G networks" or "post-LTE systems". The 5G communication system is considered to be implemented in a higher frequency (millimeter wave) band (e.g., 60 GHz band) in order to achieve higher data rates. In order to reduce the propagation loss of radio waves and increase the transmission distance, beamforming, massive multiple-input multiple-output (MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antenna technology have been discussed in the 5G communication system. In addition, in the 5G communication system, system network improvement is being developed based on advanced small cells, cloud radio access network (RAN), ultra-dense network, device-to-device (D2D) communication, wireless backhaul, mobile network, cooperative communication, coordinated multi-point (CoMP), receiver interference cancellation, etc. In the 5G system, hybrid FSK and QAM modulation (FQAM) and sliding window superimposed coding (SWSC) as advanced coding modulation (ACM), and filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as advanced access technologies have been developed.

[0004] The Internet, as a human - centered connection network in which humans generate and consume information, is now evolving towards the Internet of Things (IoT) where distributed entities such as things exchange and process information without human intervention. The Internet of Everything (IoE) has emerged as a combination of IoT technologies and big data processing technologies through connection to cloud servers. As IoT implementation requires technical elements such as "sensing technology", "wired / wireless communication and network infrastructure", "service interface technology", and "security technology", sensor networks, machine - to - machine (M2M) communication, machine - type communication (MTC), etc. have been studied recently. Such an IoT environment can provide intelligent Internet technology services, which create new value for human life by collecting and analyzing data generated between interconnected things. Through the integration and combination of existing information technology (IT) and various industrial applications, IoT can be applied to various fields, including smart home, smart building, smart city, smart car or connected car, smart grid, healthcare, smart appliances, and advanced medical services.

[0005] In line with this, various attempts have been made to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine - type communication (MTC), and machine - to - machine (M2M) communication can be implemented through beamforming, MIMO, and array antennas. Cloud radio access network (RAN), as an application of the above - mentioned big data processing technology, can also be regarded as an example of the convergence between 5G technology and IoT technology.

[0006] Recently, there has been a need to enhance the current process for managing system information in the next - generation wireless communication system. SUMMARY OF THE INVENTION

[0007] TECHNICAL PROBLEM

[0008] Aspects of the present disclosure at least solve the above problems and / or disadvantages and at least provide the following advantages. Accordingly, one aspect of the present disclosure is to provide a communication method and system for fusing a fifth - generation (5G) communication system for supporting higher data rates beyond the fourth - generation (4G).

[0009] SOLUTION TO THE PROBLEM

[0010] According to one aspect of the present disclosure, a method executed by a terminal is provided. The method includes: when the terminal is in a Radio Resource Control (RRC) connected state, receiving an RRC message including System Information Block 1 (SIB1) and information associated with synchronous reconfiguration of a target Special Cell (SpCell); identifying, based on SIB1, that the terminal does not store a valid version of at least one required SIB; and after the random access procedure for the target SpCell is completed, sending a dedicated SIB request message for at least one required SIB to the target SpCell.

[0011] According to one aspect of the present disclosure, a method executed by a target SpCell is provided. The method includes: performing a random access procedure with a terminal in a Radio Resource Control (RRC) connected state with a source SpCell; and in a case where the terminal does not store a valid version of at least one required SIB, after the random access procedure is completed, receiving a dedicated System Information Block (SIB) request message for at least one required SIB from the terminal, where the random access procedure is performed in a case where the terminal has received an RRC message including SIB1 and information associated with synchronous reconfiguration of the target SpCell from the source SpCell.

[0012] According to one aspect of the present disclosure, a terminal is provided. The terminal includes: a transceiver configured to send and receive signals; and a controller configured to: when the terminal is in a Radio Resource Control (RRC) connected state, receive an RRC message including System Information Block 1 (SIB1) and information associated with synchronous reconfiguration of a target Special Cell (SpCell), identify, based on SIB1, that the terminal does not store a valid version of at least one required SIB, and after the random access procedure for the target SpCell is completed, send a dedicated SIB request message for at least one required SIB to the target SpCell.

[0013] According to one aspect of the present disclosure, a target SpCell is provided. The target SpCell includes: a transceiver configured to send and receive signals; and a controller configured to: perform a random access procedure with a terminal in a Radio Resource Control (RRC) connected state with a source SpCell, and in a case where the terminal does not store a valid version of at least one required SIB, after the random access procedure is completed, receive a dedicated System Information Block (SIB) request message for at least one required SIB from the terminal, where the random access procedure is performed in a case where the terminal has received an RRC message including SIB1 and information associated with synchronous reconfiguration of the target SpCell from the source SpCell.

[0014] According to one aspect of the present disclosure, there is provided a method performed by a terminal in a wireless communication system, the method comprising: receiving, in a radio resource control (RRC) connected state, an RRC reconfiguration message including a system information block type 1 (SIB1); determining that the terminal does not have a stored valid version of the SIB; and in the case where the RRC reconfiguration message is associated with a master cell group (MCG) and includes SIB1 and information associated with a synchronous reconfiguration of a special cell (SpCell) configuration of the MCG, after completion of a random access procedure for the target SpCell, sending a dedicated SIB request message for the SIB to the target SpCell, wherein, for dual connectivity operation, the SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of a secondary cell group (SCG), otherwise, the SpCell refers to the Pcell.

[0015] According to one aspect of the present disclosure, there is provided a method performed by a target special cell (SpCell) in a wireless communication system, the method comprising: performing a random access procedure with a terminal that is in a radio resource control (RRC) connected state with a source SpCell; and receiving, based on the terminal not having a stored valid version of a system information block (SIB), a dedicated SIB request message for the SIB from the terminal, wherein, in the case where an RRC reconfiguration message sent from the source SpCell to the terminal is associated with a master cell group (MCG) and includes SIB1 and information associated with a synchronous reconfiguration of a special cell (SpCell) configuration of the MCG, after completion of the random access procedure, the dedicated SIB request message for the SIB is received, wherein, for dual connectivity operation, the SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of a secondary cell group (SCG), otherwise, the SpCell refers to the Pcell.

[0016] According to one aspect of the present disclosure, there is provided a terminal in a wireless communication system, the terminal comprising: a transceiver configured to transmit and receive signals; and a controller coupled to the transceiver and configured to: in a radio resource control (RRC) connected state, receive an RRC reconfiguration message including system information block type 1 (SIB1); determine that the terminal does not have a stored valid version of the SIB; and in the case where the RRC reconfiguration message is associated with a master cell group (MCG) and includes SIB1 and information associated with a synchronous reconfiguration of a special cell (SpCell) configuration of the MCG, after completion of a random access procedure for the target SpCell, send a dedicated SIB request message for the SIB to the target SpCell, wherein, for dual connectivity operation, SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of a secondary cell group (SCG), otherwise, SpCell refers to the Pcell.

[0017] According to one aspect of the present disclosure, there is provided a target special cell (SpCell) in a wireless communication system, the target SpCell comprising: a transceiver configured to transmit and receive signals; and a controller coupled to the transceiver and configured to: perform a random access procedure with a terminal that is in a radio resource control (RRC) connected state with a source SpCell; and based on the terminal not having a stored valid version of a system information block (SIB), receive a dedicated SIB request message for the SIB from the terminal, wherein, in the case where an RRC reconfiguration message sent from the source SpCell to the terminal is associated with a master cell group (MCG) and includes SIB1 and information associated with a synchronous reconfiguration of a special cell (SpCell) configuration of the MCG, after completion of the random access procedure, the dedicated SIB request message for the SIB is received, wherein, for dual connectivity operation, SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of a secondary cell group (SCG), otherwise, SpCell refers to the Pcell.

[0018] Advantages of the Invention

[0019] Therefore, one aspect of the present disclosure provides more and better applications and services in a wireless communication system by effectively managing system information in the wireless communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] From the following description in conjunction with the drawings, the above and other aspects, features and advantages of specific embodiments of the present disclosure will become more apparent, in which:

[0021] Figure 1 A flowchart showing the processing of SIB1 during a handover procedure according to an embodiment of the present disclosure is shown.

[0022] Figure 2 FIG. 2 shows a flowchart of processing of SIB1 received in the RRC connected state according to an embodiment of the present disclosure.

[0023] Figure 3 FIG. 3 shows a flowchart of processing of SIB1 received in the RRC connected state according to another embodiment of the present disclosure.

[0024] Figure 4 is a block diagram of a terminal according to an embodiment of the present disclosure.

[0025] Figure 5 is a block diagram of a base station according to an embodiment of the present disclosure.

[0026] In all the figures, like reference numerals will be understood to refer to like parts, components, and structures. DETAILED DESCRIPTION

[0027] Before proceeding with the following detailed description, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document: The terms “include” and “comprise,” and derivatives thereof, mean inclusion without limitation; the term “or” is inclusive, meaning and / or; the phrases “associated with” and “associated therewith,” and derivatives thereof, may mean include, be included within, interconnect with, contain, be contained within, connect to or be connected with, couple to or be coupled with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or be bound with, have, have the property of, etc.; the term “controller” means any device, system, or part thereof that controls at least one operation, such a device may be implemented in hardware, firmware, software, or some combination of at least two of them. It should be noted that the functions associated with any particular controller may be centralized or distributed, whether local or remote.

[0028] In addition, the various functions described below can be implemented or supported by one or more computer programs, each 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, procedures, 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 disk drive, compact disc (CD), digital video disc (DVD), or any other type of memory. A "non-transitory" computer-readable medium does not include wired, wireless, optical, or other communication links that transmit transitory electrical or other signals. Non-transitory computer-readable media include media that can permanently store data and media that can store data and be rewritten later, such as rewritable compact discs or erasable memory devices.

[0029] Definitions for particular words and phrases are provided in this patent document, and one of ordinary skill in the art should understand that, in many instances if not most, such definitions apply to both the prior and future use of such defined words and phrases.

[0030] The following discussion of Figures 1 to 5 and the various embodiments used to describe the principles of the present disclosure in this patent document are merely exemplary and should not be construed in any way as limiting the scope of the present disclosure. Those skilled in the art will understand that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0031] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of the various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to aid understanding, but these are to be considered merely exemplary. Thus, one of ordinary skill in the art will recognize that various changes and modifications can be made to the various embodiments described herein without departing from the scope and spirit of the present disclosure. In addition, descriptions of well-known functions and structures may be omitted for clarity and conciseness.

[0032] The terms and words used in the following description and claims are not limited to bibliographical meanings, but are merely used by the inventors to enable a clear and consistent understanding of the present disclosure. Thus, it will be apparent to those skilled in the art that the following description of the various embodiments of the present disclosure is provided for illustrative purposes only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.

[0033] It should be understood that the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more such surfaces.

[0034] The term "substantially" means that the recited characteristics, parameters, or values need not be precisely achieved, but that deviations or variations including, for example, tolerances, measurement errors, measurement precision limitations, and other factors known to those of skill in the art may occur in amounts that do not preclude the effect the characteristic is intended to provide.

[0035] Those of skill in the art will appreciate that the blocks of a flowchart (or sequence diagram) and combinations of flowchart blocks can be represented and executed by computer program instructions. These computer program instructions can be loaded onto the processor of a general purpose computer, special purpose computer, or programmable data processing apparatus. When the loaded program instructions are executed by the processor, they create means for performing the functions described in the flowchart. Since the computer program instructions can be stored in a computer-readable memory available to a special purpose computer or programmable data processing apparatus, an article of manufacture capable of performing the functions described in the flowchart can also be created. Since the computer program instructions can be loaded onto a computer or programmable data processing apparatus, when executed as a process, they can perform the operations of the functions described in the flowchart.

[0036] The blocks of a flowchart can correspond to modules, segments, or code that contain one or more executable instructions for implementing one or more logical functions, or can correspond to a portion thereof. In some cases, the functions described by the blocks can be executed in an order different from that listed. For example, two blocks listed in sequence can be executed simultaneously or in reverse order.

[0037] In this specification, words such as "unit", "module", etc. can refer to software components or hardware components, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC) capable of performing functions or operations. However, "unit", etc. is not limited to hardware or software. A unit, etc. can be configured to reside in an addressable storage medium or drive one or more processors. A unit, etc. can refer to a software component, an object-oriented software component, a class component, a task component, a process, a function, an attribute, a procedure, a subroutine, a program code segment, a driver, firmware, microcode, a circuit, data, a database, a data structure, a table, an array, or a variable. The functions provided by components and units can be combinations of smaller components and units and can be combined with other components and units to form larger components and units. Components and units can be configured to drive a device in a secure multimedia card or one or more processors.

[0038] Before the detailed description, terms or definitions necessary for understanding the present disclosure are described. However, these terms should be interpreted in a non-limiting manner.

[0039] A "Base Station (BS)" is an entity that communicates with a User Equipment (UE) and can be referred to as a BS, Base Transceiver Station (BTS), Node B (NB), evolved NB (eNB), Access Point (AP), 5G NB (5GNB), or gNB (next-generation Node B).

[0040] A "UE" is an entity that communicates with a BS and can be referred to as a UE, device, Mobile Station (MS), Mobile Equipment (ME), or terminal.

[0041] In recent years, several broadband wireless technologies have been developed to meet the increasing number of broadband subscribers and provide more and better applications and services. The second-generation wireless communication systems have been developed to provide voice services while ensuring user mobility. The third-generation wireless communication systems support not only voice services but also data services. In recent years, the fourth wireless communication systems have been developed to provide high-speed data services. However, currently, the fourth-generation wireless communication systems lack resources to meet the growing demand for high-speed data services. Therefore, the fifth-generation wireless communication systems (also known as next-generation radio or NR) are being developed to meet the growing demand for high-speed data services and support ultra-reliability and low-latency applications.

[0042] The fifth-generation wireless communication systems support not only low-frequency bands but also higher-frequency (millimeter-wave) bands, such as the 10 GHz to 100 GHz bands, in order to achieve higher data rates. In order to mitigate the propagation loss of radio waves and increase the transmission distance, beamforming, massive MIMO, FD-MIMO, array antennas, analog beamforming, and massive antenna technologies are being considered in the design of the fifth-generation wireless communication systems. In addition, it is expected that the fifth-generation wireless communication systems will address different usage scenarios with completely different requirements in terms of data rate, latency, reliability, mobility, etc.

[0043] However, it is expected that the design of the air interface of the fifth-generation wireless communication system will be flexible enough to serve UEs with completely different capabilities, depending on the usage scenarios and market segments in which the UEs serve end customers. Several exemplary usage scenarios that the fifth-generation wireless communication system wireless system expects to address are enhanced mobile broadband (eMBB), massive machine type communication (m-MTC), ultra-reliable low latency communication (URLL), etc. eMBB requirements such as data rates in the tens of Gbps, low latency, high mobility, etc. are required to address the market segment of traditional wireless broadband subscribers who need Internet connectivity anytime, anywhere. m-MTC requirements such as very high connection density, infrequent data transmission, very long battery life, low mobility addresses, etc. are required to address the market segment of the Internet of Things (IoT) / Internet of Everything (IoE) that envisions the connection of billions of devices. URLL requirements such as very low latency, very high reliability, and variable mobility, etc. are required to address the market segment of industrial automation applications, vehicle-to-vehicle / vehicle-to-infrastructure communication, which is regarded as one of the enablers of autonomous vehicles.

[0044] In a fifth-generation wireless communication system operating in a higher frequency (e.g., millimeter wave) band, the UE and the gNB communicate with each other using beamforming. Beamforming techniques are used to mitigate propagation path loss and increase the propagation distance of higher-band communication. Beamforming uses high-gain antennas to enhance transmission and reception performance. Beamforming can be classified into transmit (TX) beamforming performed at the transmit end and receive (RX) beamforming performed at the receive end. Generally, TX beamforming increases directivity by allowing the area where the propagation arrives to be densely located in a specific direction using multiple antennas. In this case, the aggregation of multiple antennas can be referred to as an antenna array, and each antenna included in the array can be referred to as an array element. The antenna array can be configured in various forms, such as a linear array, a planar array, etc. The use of TX beamforming results in an increase in signal directivity, thereby increasing the propagation distance. In addition, since the signal is hardly transmitted in directions other than the direction of directivity, the signal interference acting on another receiving end is significantly reduced.

[0045] The receiving end can perform beamforming on the RX signal by using the RX antenna array. RX beamforming increases the intensity of the RX signal transmitted in a specific direction by allowing the propagation to be concentrated in a specific direction, and excludes the signals transmitted in directions other than the specific direction from the RX signal, thereby providing the effect of blocking interference signals. By using beamforming techniques, the transmitter can generate multiple transmission beam patterns in different directions. Each of these transmission beam patterns can also be referred to as a TX beam. A wireless communication system operating at high frequencies uses multiple narrow TX beams to transmit signals in a cell because each narrow TX beam provides coverage for a part of the cell. The narrower the TX beam, the higher the antenna gain, and thus the greater the propagation distance of the signal transmitted using beamforming. The receiver can also generate multiple receive (RX) beam patterns in different directions. Each of these receive patterns can also be referred to as a receive (RX) beam.

[0046] The fifth-generation wireless communication system supports stand-alone operation mode as well as dual connectivity (DC). In DC, multiple Rx / Tx UEs can be configured to utilize resources provided by two different nodes (or NBs) connected via a non-ideal backhaul. One node acts as the master node (MN), and the other acts as the secondary node (SN). The MN and the SN are connected via a network interface, and at least the MN is connected to the core network. NR also supports multi-RAT dual connectivity (MR-DC) operation, whereby a UE under radio resource control connection (RRC_CONNECTED) is configured to utilize radio resources provided by two different schedulers, where the two different schedulers are located in two different nodes connected via a non-ideal backhaul and providing evolved universal mobile telecommunications system (UMTS) terrestrial radio access (E-UTRA (i.e., if the node is an ng-eNB)) or NR access (i.e., if the node is a gNB). In NR, for a UE under RRC_CONNECTED that is not configured with carrier aggregation (CA) / DC, there is only one serving cell that includes the primary cell. For a UE under RRC_CONNECTED that is configured with CA / DC, the term "serving cell" is used to denote the set of cells that includes the (multiple) special cells and all secondary cells. In NR, the term master cell group (MCG) refers to the set of serving cells associated with the master node, including the primary cell (PCell) and optionally one or more secondary cells (SCells). In NR, the term secondary cell group (SCG) refers to the set of serving cells associated with the secondary node, including the primary SCG cell (PSCell) and optionally one or more SCells. In NR, the PCell refers to the serving cell operating on the primary frequency in the MCG, where the UE either performs the initial connection establishment process or initiates the connection re-establishment process. In NR, for a UE configured with CA, the SCell is the cell that provides additional radio resources on top of the special cell. The PSCell refers to the serving cell in the SCG where the UE performs random access when executing the synchronization reconfiguration process. 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.

[0047] In the fifth-generation wireless communication system, the physical downlink control channel (PDCCH) is used to schedule downlink (DL) transmissions on the physical downlink shared channel (PDSCH) and uplink (UL) transmissions on the physical uplink shared channel (PUSCH). The downlink control information (DCI) on the PDCCH includes: a downlink allocation that at least includes modulation and coding format, resource allocation, and hybrid automatic repeat request (ARQ) information related to the DL-SCH; an uplink scheduling grant that at least includes modulation and coding format, resource allocation, and hybrid ARQ information related to the UL-SCH. In addition to scheduling, the PDCCH can be used for: activating and deactivating configured PUSCH transmissions with configured grants; activating and deactivating semi-persistent PDSCH transmissions; notifying one or more UEs of the slot format; notifying one or more UEs of (multiple) physical resource blocks (PRBs) and (multiple) orthogonal frequency division multiplexing (OFDM) symbols, where a UE can assume that there is no transmission for that UE; transmitting transmission power control (TPC) commands for the physical uplink control channel (PUCCH) and PUSCH; transmitting one or more TPC commands for the sounding reference signal (SRS) transmission of one or more UEs; switching the active bandwidth part of a UE; initiating a random access process. A UE monitors a set of PDCCH candidates in a configured monitoring occasion in one or more configured control resource sets (CORESETs) according to the corresponding search space configuration. A CORESET consists of a set of PRBs with a duration of 1 to 3 OFDM symbols. Resource element groups (REGs) and control channel elements (CCEs) are defined in the CORESET, where each CCE includes a set of REGs. The control channel is formed by the aggregation of CCEs. Different code rates of the control channel are achieved by aggregating different numbers of CCEs. Interleaved and non-interleaved CCE-to-REG mappings are supported in the CORESET. Polar codes are used for the PDCCH. Each resource element group carrying the PDCCH carries its own DMRS. Quadrature phase shift keying (QPSK) modulation is used for the PDCCH.

[0048] In the fifth-generation wireless communication system, the gNB signals a search space configuration list for each configured BWP signaling, where each search configuration is uniquely identified by an identifier. The identifier of the search space configuration to be used for a specific purpose (such as paging reception, SI reception, random access response reception) is signaled explicitly by the gNB. In NR, the search space configuration includes the parameters Monitoring-periodicity-PDCCH-slot, Monitoring-offset-PDCCH-slot, Monitoring-symbols-PDCCH-within-slot, and duration. The UE uses the parameters 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 (multiple) PDCCH monitoring occasions within a time slot. The PDCCH monitoring occasion 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:

[0049] [Equation 1]

[0050] (y * (number of time slots in the radio frame) + x - Monitoring-offset-PDCCH-slot) mod (Monitoring-periodicity-PDCCH-slot) = 0;

[0051] The starting symbol of the PDCCH monitoring occasion in each time slot having a PDCCH monitoring occasion is given by Monitoring-symbols-PDCCH-within-slot. The length (in symbols) of the PDCCH monitoring occasion is given in the CORESET associated with the search space. The search space configuration includes an identifier of the CORESET configuration associated therewith. The gNB signals a list of CORESET configurations for each configured BWP, where each CORESET configuration is uniquely identified by an identifier. Note that the duration of each radio frame is 10 ms. The radio frame is identified by a radio frame number or a system frame number. Each radio frame includes several time slots, where the number of time slots in the radio frame and the duration of the time slots depend on the subcarrier spacing. In NR, the number of time slots in the radio frame and the duration of the time slots depending on the radio frame are predefined for each supported subcarrier spacing (SCS). Each CORESET configuration is associated with a list of TCI (transmission configuration indicator) states. Each TCI state configures a DL reference signal (RS) ID (SSB or channel state information RS (CSI-RS)). The list of TCI states corresponding to the CORESET configuration is signaled by the gNB via RRC signaling. One TCI state in the TCI state list is activated by the gNB and indicated to the UE. The TCI state indication is used by the gNB for the DL TX beam for transmitting the PDCCH in the PDCCH monitoring occasion of the search space (the DL TX beam is quasi-co-located (QCLed) with the SSB / CSI-RS of the TCI state).

[0052] In the fifth-generation wireless communication system, bandwidth adaptation (BA) is supported. With BA, the receive and transmit bandwidths of the UE do not need to be as large as the bandwidth of the cell and can be adjusted: the width can be commanded to change (e.g., shrink during low-activity periods to save power); the position can be moved in the frequency domain (e.g., to increase scheduling flexibility); and the subcarrier spacing can be commanded to change (e.g., to allow for different services). A subset of the total cell bandwidth of the cell is called a bandwidth part (BWP). BA is achieved by configuring the UE in the RRC connection with (a) BWP(s) and telling the UE which configured BWP is the current active BWP. When BA is configured, the UE only needs to monitor the PDCCH on one active BWP, i.e., it does not need to monitor the PDCCH on the entire DL frequency of the serving cell. In the RRC connected state, for each configured serving cell (i.e., PCell or SCell), the UE is configured with one or more DL and UL BWPs. For an active serving cell, there is always one active UL and DL BWP at any point in time. BWP switching for a serving cell is used to activate an inactive BWP and deactivate the active BWP at a time. BWP switching is controlled by the PDCCH indicating a downlink allocation or an uplink grant, by the bwp-InactivityTimer, by RRC signaling, or by the media access control (MAC) entity itself when initiating a random access procedure. When adding an SpCell or activating an SCell, in the absence of receiving a PDCCH indicating a downlink allocation or an uplink grant, the DL BWP and UL BWP indicated by firstActiveDownlinkBWP-Id and firstActiveUplinkBWP-Id, respectively, are active. The active BWP of a serving cell is indicated by the RRC or the PDCCH. For unpaired spectrum, the DL BWP is paired with the UL BWP, and BWP switching is common for both UL and DL. When the BWP inactivity timer expires, the UE switches to the active DL BWP, to the default DL BWP, or to the initial DL BWP (if the default DL BWP is not configured).

[0053] In the 5G wireless communication system, random access (RA) is supported. Random access (RA) is used to achieve UL time synchronization. RA is used by an asynchronous UE in the UL during initial access, handover, RRC connection reestablishment procedure, scheduling request transmission, SCG addition / modification, beam failure recovery, and data or control information transmission in the RRC CONNECTED state. Several types of random access procedures are supported.

[0054] Contention-based Random Access (CBRA): This is also known as 4-step CBRA. In this type of random access, the UE first sends a random access preamble (also known as Msg1), and then waits for a random access response (RAR) in the RAR window. The RAR is also known as Msg2. The next-generation Node B (gNB) sends the RAR on the PDSCH. The PDCCH scheduling the PDSCH carrying the RAR is addressed to the RA-Radio Network Temporary Identifier (RA-RNTI). The RA-RNTI identifies the time-frequency resource (also known as the Physical RA Channel (PRACH) occasion or PRACH Transmission (TX) occasion or RA Channel (RACH) occasion) in which the gNB detected the RA preamble. The RA-RNTI is calculated as follows: RA-RNTI = 1 + s_id + 14*t_id + 14*80*f_id + 14*80*8*ul_carrier_id, where s_id is the index of the first OFDM symbol of the PRACH occasion in which the UE sent Msg1 (i.e., the RA preamble); 0 s_id < 14; t_id is the index of the first slot of the PRACH occasion (0 t_id < 80); f_id is the index of the PRACH occasion within the slot in the frequency domain (0 f_id < 8), and ul_carrier_id is the carrier used for Msg1 transmission (0 for the normal UL (NUL) carrier and 1 for the supplementary UL (SUL) carrier). The gNB can multiplex several RARs of the individual random access preambles detected by the gNB into the same RAR MAC protocol data unit (PDU). If the RAR includes the RA preamble identifier (RAPID) of the RA preamble sent by the UE, the RAR in the MAC PDU corresponds to the UE's RA preamble transmission. If no RAR corresponding to its RA preamble transmission is received during the RAR window and the UE has not sent the RA preamble up to a configurable number (configured by the gNB in the RACH configuration), the UE returns to the first step, i.e., selects a random access resource (preamble / RACH occasion) and sends the RA preamble. A backoff period can be applied before returning to the first step.

[0055] If the UE receives a RAR corresponding to its RA preamble transmission, the UE sends Message 3 (Msg3) in the UL grant received in the RAR. Msg3 includes messages such as RRC connection request, RRC connection reestablishment request, RRC handover confirmation, scheduling request, SI request, etc. It may include a UE identifier (i.e., cell radio network temporary identifier (C-RNTI) or system architecture evolution (SAE)-temporary mobile subscriber identity (S-TMSI) or random number). After sending Msg3, the UE starts a contention resolution timer. While the contention resolution timer is running, if the UE receives a PDCCH addressed to the C-RNTI included in Msg3, the contention resolution is considered successful, the contention resolution timer stops, and the RA procedure is completed. While the contention resolution timer is running, if the UE receives a contention resolution MAC control element (CE) including the UE's contention resolution identity (the first X bits of the common control channel (CCCH) service data unit (SDU) sent in Msg3), the contention resolution is considered successful, the contention resolution timer stops, and the RA procedure is completed. If the contention resolution timer expires and the UE has not sent the RA preamble a configurable number of times, the UE returns to the first step, i.e., selects a random access resource (preamble / RACH occasion) and sends the RA preamble. A backoff period may be applied before returning to the first step.

[0056] Contention-free random access (CFRA): This is also referred to as legacy CFRA or 4-step CFRA. The CFRA procedure is used in scenarios such as handovers that require low latency, timing advance establishment for Scells, etc. The evolved Node B (or gNB) allocates a dedicated random access preamble to the UE. The UE sends the dedicated RA preamble. The ENB (or gNB) sends the RAR on the PDSCH addressed to the RA-RNTI. The RAR conveys the RA preamble identifier and timing alignment information. The RAR may also include a UL grant. Similar to the CBRA procedure, the RAR is sent within the RAR window. After receiving the RAR including the RAPID of the RA preamble sent by the UE, the CFRA is considered successfully completed. In the case where RA is initiated for beam failure recovery, if a PDCCH addressed to the C-RNTI is received in the search space for beam failure recovery, the CFRA is considered successfully completed. If the RAR window expires and the RA is not successfully completed and the UE has not sent the RA preamble a configurable (configured by the gNB in the RACH configuration) number of times, the UE retransmits the RA preamble.

[0057] For specific events, such as handover and beam failure recovery, if dedicated preambles are allocated to the UE, during the first step of random access, i.e., during the random access resource selection for Msg1 transmission, the UE determines whether to send a dedicated preamble or a non-dedicated preamble. Dedicated preambles are typically provided for a subset of SSB / CSI-RS. If among the SSB / CSI-RS for which the gNB provides contention-free random access resources (i.e., dedicated preambles / ROs), there is no SSB / CSI RS with a DL reference signal received power (RSRP) higher than a threshold, the UE selects a non-dedicated preamble. Otherwise, the UE selects a dedicated preamble. Thus, during the RA procedure, one random access attempt can be a CFRA, while another random access attempt can be a CBRA.

[0058] Two-step contention-based random access (2-step CBRA): In the first step, the UE sends a random access preamble on the PRACH and a payload (i.e., MAC PDU) on the PUSCH. The random access preamble and payload transmission are also referred to as MsgA. In the second step, after the MsgA transmission, the UE monitors for a response from the network (i.e., gNB) within a configured window. This response is also referred to as MsgB. If a CCCH SDU is transmitted in the MsgA payload, the UE uses the contention resolution information in MsgB to perform contention resolution. If the contention resolution identity received in MsgB matches the first 48 bits of the CCCH SDU transmitted in MsgA, the contention resolution is successful. If a C-RNTI is transmitted in the MsgA payload, the contention resolution is successful if the UE receives a PDCCH addressed to the C-RNTI. If the contention resolution is successful, the random access procedure is considered to be successfully completed. Instead of the contention resolution information corresponding to the sent MsgA, MsgB can include fallback information corresponding to the random access preamble sent in MsgA. If the fallback information is received, the UE sends Msg3 and performs contention resolution using Msg4, as in the CBRA procedure. If the contention resolution is successful, the random access procedure is considered to be successfully completed. If the contention resolution fails during fallback (i.e., when sending Msg3), the UE retransmits MsgA. If the configured window within which the UE monitors for a network response after sending MsgA expires and the UE does not receive MsgB containing contention resolution information or fallback information as above, the UE retransmits MsgA. If the random access procedure does not successfully complete even after the configurable number of times of sending msgA, the UE falls back to a 4-step RACH procedure, i.e., the UE only sends a PRACH preamble.

[0059] The MsgA payload may include one or more of a CCCH SDU, a dedicated control channel (DCCH) SDU, a dedicated traffic channel (DTCH) SDU, a buffer status report (BSR) MAC CE, a power headroom report (PHR) MAC CE, SSB information, a C-RNTI MAC CE, or padding. MsgA may include a UE ID (e.g., a random ID, S-TMSI, C-RNTI, recovery ID, etc.) and a preamble in the first step. The UE ID may be included in the MAC PDU of MsgA. A UE ID such as C-RNTI may be carried in a MAC CE, where the MAC CE is included in the MAC PDU. Other UE IDs (such as random ID, S-TMSI, C-RNTI, recovery ID, etc.) may be carried in the CCCH SDU. The UE ID may be one of a random ID, S-TMSI, C-RNTI, recovery ID, IMSI, idle mode ID, inactive mode ID, etc. In different scenarios where the UE performs the RA process, the UE ID may be different. When the UE performs RA after power-on (before it attaches to the network), the UE ID is a random ID. When the UE performs RA in the IDLE state after it attaches to the network, the UE ID is S-TMSI. If the UE has an assigned C-RNTI (e.g., is in the connected state), the UE ID is C-RNTI. In the case where the UE is in the INACTIVE state, the UE ID is the recovery ID. In addition to the UE ID, some additional control information may be sent in MsgA. The control information may be included in the MAC PDU of MsgA. The control information may include one or more of a connection request indication, a connection recovery request indication, an SI request indication, a buffer status indication, beam information (e.g., one or more DL TX beam IDs or SSB IDs), a beam failure recovery indication / information, a data indicator, a cell / BS / transmission reception point (TRP) handover indication, a connection reestablishment indication, a reconfiguration complete or handover complete message, etc.

[0060] 2-Step Contention-Free Random Access (2-Step CFRA): In this case, the gNB allocates (a) dedicated random access preamble(s) and (a) PUSCH resource(s) for MsgA transmission to the UE. The (a) RO(s) to be used for preamble transmission may also be indicated. In the first step, the UE sends a random access preamble on the PRACH using contention-free random access resources (i.e., dedicated preamble / PUSCH resource / RO), and the payload on the PUSCH. In the second step, after MsgA transmission, the UE monitors for a response from the network (i.e., gNB) within a configured window. If the UE receives a PDCCH addressed to the C-RNTI, the random access procedure is considered successfully completed. If the UE receives fallback information corresponding to the preamble it sent, the random access procedure is considered successfully completed.

[0061] For specific events such as handover and beam failure recovery, if (a) dedicated preamble(s) and (a) PUSCH resource(s) are allocated to the UE, during the first step of random access, i.e., during the random access resource selection for MsgA transmission, the UE determines whether to send a dedicated preamble or a non-dedicated preamble. Dedicated preambles are typically provided for a subset of SSB / CSI-RS. If among the SSB / CSI RS for which the gNB provides contention-free random access resources (i.e., dedicated preamble / RO / PUSCH resource), there is no SSB / CSI-RS with a DL RSRP higher than a threshold, the UE selects a non-dedicated preamble. Otherwise, the UE selects a dedicated preamble. Thus, during the RA procedure, one random access attempt may be 2-Step CFRA while other random access attempts may be 2-Step CBRA.

[0062] When initiating a random access procedure, the UE first selects a carrier (SUL or NUL). If the carrier for the random access procedure is explicitly signaled by the gNB, the UE selects the signaled carrier to perform the random access procedure. If the gNB does not explicitly signal the carrier for the random access procedure; and if the serving cell for the random access procedure is configured with supplementary uplink, and if the RSRP of the downlink path loss reference is less than rsrp-ThresholdSSB-SUL: the UE selects the SUL carrier to perform the random access procedure. Otherwise, the UE selects the NUL carrier to perform the random access procedure. Once the UL carrier is selected, the UE determines the UL and DL BWP for the random access procedure as specified in Section 5.15 of TS 38.321. Then, the UE determines whether to perform a 2-step or 4-step RACH for this random access procedure.

[0063] - If the random access procedure is initiated by a PDCCH command and if the ra-PreambleIndex explicitly provided by the PDCCH is not 0b000000, the UE selects a 4-step RACH.

[0064] - Otherwise, if the gNB signals 2-step contention-free random access resources for the random access procedure, the UE selects a 2-step RACH.

[0065] - Otherwise, if the gNB signals 4-step contention-free random access resources for the random access procedure, the UE selects a 4-step RACH.

[0066] - Otherwise, if the UL BWP selected for the random access procedure is only configured with 2-step RACH resources, the UE selects a 2-step RACH.

[0067] - Otherwise, if the UL BWP selected for the random access procedure is only configured with 4-step RACH resources, the UE selects a 4-step RACH.

[0068] - Otherwise, if the UL BWP selected for the random access procedure is configured with both 2-step and 4-step RACH resources,

[0069] - * If the RSRP of the downlink path loss reference is lower than the configured threshold, the UE selects a 4-step RACH. Otherwise, the UE selects a 2-step RACH.

[0070] In the fifth-generation wireless communication system, a Node B (or gNB) or a base station in a cell broadcasts a synchronization signal and a physical broadcast channel (PBCH) block (i.e., SSB), where the SSB consists of a primary synchronization signal and a secondary synchronization signal (PSS, SSS) and system information. The system information includes common parameters required for communication in the cell. In the fifth-generation wireless communication system (also known as next-generation radio or NR), the system information (SI) is divided into a master information block (MIB) and multiple system information blocks (SIBs), where:

[0071] - The MIB is always transmitted on the BCH with a period of 80 milliseconds (ms) and repeated within 80 ms, and it includes the parameters required to obtain SIB1 from the cell.

[0072] - SIB1 is transmitted on the downlink shared channel (DL-SCH) with a period of 160 ms and variable transmission repetitions. The default transmission repetition period of SIB1 is 20 ms, but the actual transmission repetition period depends on the network implementation. The scheduling information in SIB1 includes the mapping between SIBs and SI messages, the period of each SI message, and the SI window length. The scheduling information in SIB1 includes an indicator for each SI message, which indicates whether the associated SI message is being broadcast. If at least one SI message is not being broadcast, SIB1 may include random access resources (multiple PRACH preambles and multiple PRACH resources) for requesting the gNB to broadcast one or more SI messages.

[0073] - SIBs other than SIB1 are carried in system information (SI) messages, which are transmitted on the DL-SCH. Only SIBs with the same period can be mapped to the same SI message. Each SI message is transmitted within a periodically occurring time-domain window, called an SI window, which has the same length for all SI messages. Each SI message is associated with an SI window, and the SI windows of different SI messages do not overlap. That is, within an SI window, only the corresponding SI message is transmitted. Using the indication in SIB1, any SIB other than SIB1 can be configured as cell-specific or area-specific. Cell-specific SIBs are only applicable within the cell that provides the SIB, while area-specific SIBs are applicable within an area called an SI area, which consists of one or several cells and is identified by the systemInformationAreaID.

[0074] The UE obtains SIB1 from the resident or serving cell. The UE checks the BroadcastStatus bit in SIB1 for the SI messages that the UE needs to obtain. The gNB uses the IE si-RequestConfigSUL in SIB1 to signal the SI request configuration for the SUL. If the IE si-RequestConfigSUL does not exist in SIB1, the UE considers that the gNB has not signaled the SI request configuration for the SUL. The gNB uses the IE si-RequestConfig in SIB1 to signal the SI request configuration for the NUL. If the IE si-RequestConfig does not exist in SIB1, the UE considers that the gNB has not signaled the SI request configuration for the NUL. If the SI message that the UE needs to obtain is not being broadcast (i.e., the BroadcastStatus bit is set to zero), the UE initiates the transmission of an SI request. The process of SI request transmission is as follows:

[0075] If the gNB has signaled an SI request configuration for SUL signaling and the criteria for selecting SUL are met (i.e., RSRP derived from SSB measurements of the resident or serving cell < rsrp-ThresholdSSB-SUL, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in broadcast signaling such as SIB1)): The UE initiates the transmission of an SI request based on a Msg1-based SI request on SUL. In other words, the UE uses the (multiple) PRACH preambles and (multiple) PRACH resources in the SI request configuration of SUL to initiate a random access procedure. The UE sends Msg1 (i.e., the random access preamble) and waits for an acknowledgment of the SI request. The random access resources (the (multiple) PRACH preambles and (multiple) PRACH occasions) indicated in the SI request configuration of SUL are used for Msg1. Msg1 is transmitted on SUL. If an acknowledgment of the SI request is received, the UE monitors the SI window for the requested SI message during one or more SI periods of that SI message.

[0076] Otherwise, if the gNB has signaled an SI request configuration for NUL signaling and the criteria for selecting NUL are met (i.e., NUL is selected if SUL is supported in the resident or serving cell and RSRP derived from SSB measurements of the resident or serving cell >= rsrp-ThresholdSSB-SUL; or NUL is selected if SUL is not supported in the serving cell): The UE initiates the transmission of an SI request based on a Msg1-based SI request on NUL. In other words, the UE uses the (multiple) PRACH preambles and (multiple) PRACH resources in the SI request configuration of NUL to initiate a random access procedure. The UE sends Msg1 (i.e., the random access preamble) and waits for an acknowledgment of the SI request. The random access resources (the (multiple) PRACH preambles and (multiple) PRACH occasions) indicated in the SI request configuration of NUL are used for Msg1. Msg1 is transmitted on NUL. If an acknowledgment of the SI request is received, the UE monitors the SI window for the requested SI message during one or more SI periods of that SI message.

[0077] Otherwise, the UE initiates the transmission of the SI request based on the SI request based on Msg3. In other words, the UE initiates the transmission of the RRCSystemInfoRequest message. The UE sends Msg1 (i.e., the random access preamble) and waits for the random access response. The common random access resources ((multiple) PRACH preambles and (multiple) PRACH occasions) are used for Msg1. In the UL grant received in the random access response, the UE sends the RRCSystemInfoRequest message and waits for the confirmation of the SI request (i.e., the RRCSystemInfoRequest message). If the confirmation of the SI request (i.e., the RRCSystemInfoRequest message) is received, the UE monitors the SI window of the requested SI message in one or more SI periods of this SI message. Note that if SUL is configured, the UL carrier used for Msg1 transmission will be selected by the UE in a manner similar to that selected by the UE for the SI request based on Msg1. If the RSRP derived from the SSB measurement of the resident or serving cell < rsrp-ThresholdSSB-SUL, the SUL is the selected UL carrier, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in broadcast signaling such as SIB1). If the RSRP derived from the SSB measurement of the resident or serving cell >= rsrp-ThresholdSSB-SUL, the NUL is the selected UL carrier, where rsrp-ThresholdSSB-SUL is signaled by the gNB (e.g., in broadcast signaling such as SIB1).

[0078] However, there are some problems in the current SI request process.

[0079] - Problem 1: Delay in the completion of handover when dedicated SIB1 is configured

[0080] The SI request mechanism is being enhanced to enable the UE to request SI in the RRC connected state. According to the existing procedure, the UE can receive a handover command (i.e., an RRC reconfiguration message including a synchronization reconfiguration) from the source SpCell. If the handover command includes the dedicatedSIB1-Delivery IE, the RRC in the UE performs actions when receiving SIB1 as specified in TS 38.331 before triggering the RRCReconfigurationComplete message. The dedicatedSIB1-Delivery IE provides SIB1 of the target cell. As part of the SIB 1 processing triggered by receiving the dedicatedSIB1-Delivery IE, if the UE needs (multiple) SIBs other than SIB1 in the RRC connected state and these SIBs are not broadcast in the target cell according to the received SIB1, a DedicatedSIBRequest is triggered. As a result, the DedicatedSIBRequest will be queued before RRCReconfigurationComplete, which delays the transmission of RRCReconfigurationComplete and thus delays the handover completion.

[0081] - Problem 2: Unable to obtain SIB in RRC state

[0082] The UE is in the RRC connected state. The UE wants to receive SIBs (e.g., V2X is activated and the UE needs V2X SIBs). The UE first needs to obtain SIB 1.

[0083] If the si-BroadcastStatus of the required SIB in SIB1 is set to notBroadcasting, the UE triggers a DedicatedSIBRequest. Otherwise, the UE obtains the SI message of the required SIB from the broadcast. In the RRC connected state, if there is no common search space configured in the active DL BWP, the UE cannot obtain SIB1. As a result, the UE cannot obtain the required SIB.

[0084] This disclosure provides methods and apparatuses for handling the above problems. Hereinafter, those skilled in the art can freely combine or reconfigure the embodiments disclosed in this disclosure. For example, each part of the embodiments can be combined with each other to form an embodiment.

[0085] Embodiment 1 - SI Request When Receiving SIB1 During Handover

[0086] [Embodiment 1-1]

[0087] In a method of the present disclosure, the processing of SIB1 is divided into two parts:

[0088] - The first part includes the processing of si-SchedulingInfo;

[0089] - The second part includes the processing of content (parameters / IEs) other than si-SchedulingInfo.

[0090] Figure 1 The flowchart shows the processing of SIB1 during the handover process according to an embodiment of the present disclosure.

[0091] In step 101, the UE receives an RRC reconfiguration message from the network (i.e., the base station), which includes a reconfigurationWithSync IE (in the SpCellConfig of the MCG) and a dedicatedSIB1-Delivery IE.

[0092] In step 102, the RRC layer in the UE processes the synchronization reconfiguration:

[0093] * 1 > Start the timer T304 for the corresponding SpCell, and set the timer value to t304, which is included in reconfigurationWithSync

[0094] * 1 > If frequencyInfoDL is included:

[0095] ** 2 > Consider the target SpCell as the one on the SSB frequency indicated by frequencyInfoDL, which has the physical cell identity indicated by physCellId;

[0096] * 1 > Otherwise:

[0097] ** 2 > Consider the target SpCell as the one on the SSB frequency of the source SpCell, which has the physical cell identity indicated by physCellId;

[0098] * 1 > Start synchronizing to the DL of the target SpCell;

[0099] * 1 > Apply the predefined BCCH configuration;

[0100] * 1 > If necessary, obtain the MIB

[0101] * 1 > Reset the MAC entity of this cell group;

[0102] * 1 > Consider the (multiple) SCell(s) of this cell group (if configured) as being in the deactivated state.

[0103] * 1> Use the value of newUE-Identity as the C-RNTI of this cell group;

[0104] In step 103, the RRC layer in the UE processes the dedicatedSIB1-Delivery IE and applies the content in the second part of SIB1:

[0105] * 1> If cellAccessRelatedInfo contains an entry with the PLMN identity of the selected PLMN:

[0106] ** 2> In the remaining process, use the plmn-IdentityList, trackingAreaCode, and cellIdentity of the cell received in the corresponding PLMN-IdentityInfo containing the selected PLMN;

[0107] * 1> When in RRC_CONNECTED, ignore the frequencyBandList (if received);

[0108] * 1> Forward the cellIdentity to the upper layer;

[0109] * 1> Forward the trackingAreaCode to the upper layer;

[0110] * 1> Apply the configuration included in servingCellConfigCommon;

[0111] In step 104, the RRC layer initiates the transmission of an RRC reconfiguration complete message, and this triggers a random access procedure to the target SpCell.

[0112] In step 105, when the random access procedure is completed, the RRC layer in the UE processes the dedicatedSIB1-Delivery IE and applies the content in the first part of SIB1, as follows:

[0113] * - If the UE has a valid version of the SIBs stored that are required for the UE to operate in the cell:

[0114] ** - Use the stored version of the required SIBs;

[0115] * - If the UE does not have a valid version of the SIBs stored in one or more of the required SIBs:

[0116] ** - For (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to broadcasting: Obtain the (multiple) SI messages from the broadcast;

[0117] ** - For (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting: Trigger DedicatedSIBRequest to obtain the (multiple) required SIBs.

[0118] Alternatively, in step 105, when the random access procedure is completed, the RRC layer in the UE processes the dedicatedSIB1-Delivery IE and applies the content in the first part of SIB1 as follows:

[0119] * - If the UE has a valid stored version of the SIBs required for the UE to operate in the cell:

[0120] ** - Use the stored version of the required SIBs;

[0121] * - If the UE does not have a valid stored version of the SIBs in one or several of the required SIBs:

[0122] ** - If a common search space is configured in the active DL BWP:

[0123] *** For (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to broadcasting: Obtain the (multiple) SI messages from the broadcast;

[0124] *** For (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting: Trigger DedicatedSIBRequest to obtain the (multiple) required SIBs.

[0125] ** - Otherwise

[0126] *** Trigger DedicatedSIBRequest to obtain the (multiple) required SIBs.

[0127] According to another embodiment of the present disclosure, in step 105, when the random access procedure is completed, the RRC layer in the UE processes the dedicatedSIB1-Delivery IE and applies the content in the first part of SIB1 as follows:

[0128] * - If the UE has a valid version of the SIBs stored that are required for the UE to operate in the cell:

[0129] ** - Use the stored version of the required SIBs;

[0130] * - If the UE does not have a valid version of the SIBs stored in one or several of the required SIBs:

[0131] ** - Trigger DedicatedSIBRequest to obtain the required SIB(s).

[0132] [Embodiment 1-2]

[0133] Figure 2 The flowchart shows the processing of SIB1 received in the RRC connected state according to an embodiment of the present disclosure.

[0134] In step 201, the UE receives SIB 1 in the RRC connected state. SIB 1 can be received in the RRC reconfiguration message or obtained by the UE from the broadcast.

[0135] The UE processes SIB 1 as follows:

[0136] * - If cellAccessRelatedInfo contains an entry with the PLMN identity of the selected PLMN:

[0137] ** - In the remaining process, use the plmn-IdentityList, trackingAreaCode, and cellIdentity of the cell received in the corresponding PLMN-IdentityInfo containing the selected PLMN;

[0138] * - When in RRC_CONNECTED, ignore the frequencyBandList (if received);

[0139] * - Forward the cellIdentity to the upper layer;

[0140] * - Forward the trackingAreaCode to the upper layer;

[0141] * - Apply the configuration (202) included in servingCellConfigCommon;

[0142] * - If the UE has a valid version of the SIBs stored that are required for the UE to operate in the cell:

[0143] ** - Use the stored version of the required SIBs;

[0144] * - If the UE does not have a valid version of the SIBs in one or several of the required SIBs stored (203):

[0145] ** - For the (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to broadcasting: Obtain the (multiple) SI messages from the broadcast;

[0146] ** - For the (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting (204):

[0147] *** If this SIB1 is received in an RRCReconfiguration that includes reconfigurationWithSync in the spCellConfig of the MCG (205):

[0148] **** When the MAC of the MCG completes the random access procedure for the target SpCell, the UE triggers a DedicatedSIBRequest (206)

[0149] *** Otherwise:

[0150] **** Trigger a DedicatedSIBRequest to obtain the (multiple) required SIBs (207).

[0151] Alternatively, in step 203, if the UE does not have a valid version of the SIBs in one or several of the required SIBs stored:

[0152] ** - For the (multiple) SI messages that contain at least one required SIB according to si-SchedulingInfo, whose si-BroadcastStatus is set to broadcasting, and for which a common search space is configured in the active DL BWP: Obtain the (multiple) SI messages from the broadcast;

[0153] ** - For (a) SI message(s) that contains at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting or for which no common search space is configured in the active DL BWP:

[0154] *** If this SIB1 is received in an RRCReconfiguration that includes reconfigurationWithSync in the spCellConfig of the MCG:

[0155] **** When the MAC of the MCG completes the random access procedure for the target SpCell, the UE triggers a DedicatedSIBRequest

[0156] *** Otherwise:

[0157] **** Trigger a DedicatedSIBRequest to obtain the required SIB(s) (207).

[0158] According to another embodiment of the present disclosure, in step 203, if the UE does not store a valid version of the SIB in one or several required SIBs:

[0159] ** - If this SIB1 is received in an RRCReconfiguration that includes reconfigurationWithSync in the spCellConfig of the MCG:

[0160] *** When the MAC of the MCG completes the random access procedure for the target SpCell, the UE triggers a DedicatedSIBRequest

[0161] ** - Otherwise, if this SIB1 is received in an RRCReconfiguration

[0162] *** Trigger a DedicatedSIBRequest to obtain the required SIB(s).

[0163] ** - Otherwise

[0164] *** For (a) SI message(s) that contains at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to broadcasting: Obtain the SI message(s) from the broadcast;

[0165] ***For (a) SI message(s) that contains at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting:

[0166] ****Trigger DedicatedSIBRequest to obtain the required SIB(s).

[0167] [Embodiments 1 - 3]

[0168] Figure 3 FIG. 10 shows a flowchart of the processing of SIB1 received in the RRC connected state according to another embodiment of the present disclosure.

[0169] In step 301, the UE receives SIB 1 in the RRC connected state. SIB 1 may be received in an RRC reconfiguration message or obtained by the UE from a broadcast.

[0170] The UE processes SIB 1 as follows:

[0171] * - If cellAccessRelatedInfo contains an entry with a PLMN identity of the selected PLMN:

[0172] ** - During the remaining process, use the plmn-IdentityList, trackingAreaCode, and cellIdentity of the cell received in the corresponding PLMN-IdentityInfo that contains the selected PLMN;

[0173] * - When in RRC_CONNECTED, ignore the frequencyBandList (if received);

[0174] * - Forward the cellIdentity to the upper layer;

[0175] * - Forward the trackingAreaCode to the upper layer;

[0176] * - Apply the configuration included in servingCellConfigCommon (302);

[0177] * - If the UE has a valid version of the required SIB(s) stored for operation in the cell:

[0178] ** - Use the stored version of the required SIB;

[0179] * - If the UE does not have a valid version of the SIB(s) stored for one or several of the required SIBs (303):

[0180] ** - For (a) SI message(s) that contain(s) at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to broadcasting: Obtain the SI message(s) from the broadcast;

[0181] ** - For (a) SI message(s) (304) that contain(s) at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting:

[0182] *** If the SIB1 (305) is received in an RRCReconfiguration message (i.e., in the dedicatedSIB1-Delivery IE):

[0183] **** The UE triggers a DedicatedSIBRequest (306) after submitting an RRCReconfigurationComplete message for transmission via SRB1 to the lower layer

[0184] *** Otherwise:

[0185] **** Trigger a DedicatedSIBRequest to obtain the required SIB(s). (307)

[0186] Alternatively, in step 303, if the UE does not store a valid version of the SIB in one or several required SIBs:

[0187] ** - For (a) SI message(s) that contain(s) at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to broadcasting and for which a common search space is configured in the active DL BWP: Obtain the SI message(s) from the broadcast;

[0188] ** - For (a) SI message(s) that contain(s) at least one required SIB according to si-SchedulingInfo and whose si-BroadcastStatus is set to notBroadcasting or for which no common search space is configured in the active DL BWP:

[0189] *** If the SIB1 is received in an RRCReconfiguration message (i.e., in the dedicatedSIB1-Delivery IE):

[0190] **** After the UE submits the RRCReconfigurationComplete message to the lower layer via SRB1 for transmission, it triggers DedicatedSIBRequest

[0191] *** Otherwise:

[0192] **** Trigger DedicatedSIBRequest to obtain the required SIB(s).

[0193] According to another embodiment of the present disclosure, in step 303, if the UE does not store a valid version of the SIB in one or several required SIBs:

[0194] ** - If this SIB1 is received in the RRCReconfiguration message:

[0195] **** After the UE submits the RRCReconfigurationComplete message to the lower layer via SRB1 for transmission, it triggers DedicatedSIBRequest

[0196] ** - Otherwise

[0197] *** For the SI message(s) that contain at least one required SIB according to si - SchedulingInfo and whose si - BroadcastStatus is set to broadcasting: Obtain the SI message(s) from the broadcast;

[0198] *** For the SI message(s) that contain at least one required SIB according to si - SchedulingInfo and whose si - BroadcastStatus is set to notBroadcasting:

[0199] **** Trigger DedicatedSIBRequest to obtain the required SIB(s).

[0200] Embodiment 2 - Triggering the transmission of DedicatedSIBRequest

[0201] When the UE is in the RRC connected state and the UE wants to receive SIBs (for example, V2X is activated and the UE needs V2X SIBs), and if the UE does not have a stored valid version of the SIBs required for UE operation in the cell, the UE obtains the required SIBs as follows:

[0202] * - If the UE is in the RRC idle / INACTIVE state:

[0203] ** - The UE first obtains SIB1. In an embodiment, if the UE already has the obtained SIB1 in the current modification period and the si-BroadcastStatus for the required SIB in SIB1 is set to Broadcasting, the UE does not need to obtain SIB1 (i.e., the UE does not obtain SIB1 in this step).

[0204] ** - If the si-BroadcastStatus for the required SIB in the obtained SIB1 is set to notBroadcasting, the UE triggers a SI request based on Msg1 or Msg3. Which one of Msg1 or Msg3 to trigger has been explained previously in this disclosure.

[0205] ** - Otherwise, the UE obtains the SI message of the required SIB from the broadcast

[0206] * - Otherwise (i.e., the UE is in the RRC connected state):

[0207] ** - If there is a common search space in the active DL BWP:

[0208] *** - The UE first obtains SIB1. In an embodiment, if the UE already has the obtained SIB1 in the current modification period and the si-BroadcastStatus for the required SIB in SIB1 is set to Broadcasting, the UE does not need to obtain SIB1 (i.e., the UE does not obtain SIB1 in this step).

[0209] *** - If the si-BroadcastStatus in the obtained SIB1 is set to notBroadcasting:

[0210] **** The UE triggers DedicatedSIBRequest

[0211] *** Otherwise, the UE obtains the SI message of the required SIB from the broadcast

[0212] ** - Otherwise:

[0213] *** The UE triggers DedicatedSIBRequest

[0214] The DedicatedSIBRequest message includes requestedSIB-List-r16. The requestedSIB-List-r16 includes a list of required SIBs. In an embodiment, the requestedSIB-List-r16 is a bitmap, where each bit corresponds to a different SIB. SIBs 1 to 9 are defined in Release 15 (R15) of the 3GPP standard. New SIBs will be further added in Release 16 (R16). The question is which SIBs can be requested via requestedSIB-List-r16 and how the bits in requestedSIB-List-r16 are mapped to SIBs.

[0215] [Embodiment 2-1]

[0216] Only R16 SIBs can be requested via DedicatedSIBRequest.

[0217] The first bit in requestedSIB-List-r16 corresponds to SIB 10, the second bit corresponds to SIB 11, and so on.

[0218] Alternatively, the first bit in requestedSIB-List-r16 corresponds to SIB 2, the second bit corresponds to SIB 3, and so on. The bits corresponding to SIBs 2 to 9 are always set to zero.

[0219] [Embodiment 2-2]

[0220] Both R16 SIBs and R15 SIBs can be requested via DedicatedSIBRequest.

[0221] The first bit in requestedSIB-List-r16 corresponds to SIB 2, the second bit corresponds to SIB 3, and so on.

[0222] [Embodiment 2-3]

[0223] Only the SIBs required under RRC connection can be requested via DedicatedSIBRequest.

[0224] The SIBs required under RRC connection are pre-specified.

[0225] The bits in requestedSIB-List-r16 are mapped to the SIBs required under the connection in ascending order of SIB# starting from the first bit.

[0226] - Example

[0227] SIB 12, SIB 14, and SIB 16 are required under RRC connection

[0228] The first bit in requestedSIB-List-r16 corresponds to SIB 12, the second bit corresponds to SIB 14, and the third bit corresponds to SIB 16.

[0229] [Embodiment 2-4]

[0230] R16 SIB and SIB 6, 7, and 8 can be requested via DedicatedSIBRequest.

[0231] The first bit in requestedSIB-List-r16 corresponds to SIB 6, the second bit corresponds to SIB 7, and so on.

[0232] Embodiment 3 - Setting of si-BroadcastStatus bit in SIB1

[0233] All content in SIB1 is cell-specific. Thus, the content of SIB1 transmitted on one or more DL BWPs of the serving cell is the same. However, it is inefficient to set the value of the parameter si-BroadcastStatus corresponding to the SI message to be the same in all DL BWPs. SIB1 can be delivered to the UE on a DL BWP using dedicated signaling, and the (multiple) SI messages may not be broadcast on this DL BWP because there is no common search space configured on this DL BWP. However, in other DL BWPs, a common search can be configured and the (multiple) SI messages can be broadcast.

[0234] In one embodiment, if SIB1 is delivered or sent by the gNB on a DL BWP (such as BWP ID X), then if the SI message is not broadcast in DL BWP X, the si-BroadcastStatus corresponding to the SI message in SIB1 is set to not broadcast. If SIB1 is delivered or sent by the gNB on a DL BWP (such as BWP ID X), then if the SI message is broadcast in DL BWP X, the si-BroadcastStatus corresponding to the SI message in SIB1 is set to broadcast.

[0235] In another embodiment, if SIB1 is transmitted by the gNB using the dedicatedSIB1-Delivery IE, the si-BroadcastStatus corresponding to the SI message in SIB1 is set to not broadcast. If SIB1 is not transmitted by the gNB using the dedicatedSIB1-Delivery IE (i.e., SIB1 is broadcast by the GNB), then if the SI message is not broadcast in the DL BWP that transmits SIB1, the si-BroadcastStatus corresponding to the SI message in SIB1 is set to not broadcast. If SIB1 is not transmitted by the gNB using the dedicatedSIB1-Delivery IE (i.e., SIB1 is broadcast by the GNB), then if the SI message is broadcast in the DL BWP that transmits SIB1, the si-BroadcastStatus corresponding to the SI message in SIB1 is set to broadcast.

[0236] Figure 4 is a block diagram of a terminal according to an embodiment of the present disclosure.

[0237] Reference Figure 4 , the terminal includes a transceiver 410, a controller 420, and a memory 430. The controller 420 may refer to circuitry, an application specific integrated circuit (ASIC), or at least one processor. The transceiver 410, the controller 420, and the memory 430 are configured to perform the operations of the UE shown in the drawings (e.g., Figures 1 to 3 ). Although the transceiver 410, the controller 420, and the memory 430 are shown as separate entities, they may be implemented as a single entity, such as a single chip. Alternatively, the transceiver 410, the controller 420, and the memory 430 may be electrically connected or coupled to each other.

[0238] The transceiver 410 may send signals to other network entities (e.g., base stations) and receive signals from other network entities.

[0239] The controller 420 may control the terminal to perform functions according to one of the above embodiments. For example, the controller 420 controls the transceiver 410 and / or the memory 430 to perform operations related to the random access procedure according to various embodiments of the present disclosure.

[0240] In an embodiment, the operations of the terminal may be implemented using the memory 430 that stores the corresponding program code. Specifically, the terminal may be equipped with the memory 430 to store the program code for implementing the desired operations. To perform the desired operations, the controller 420 may read and execute the program code stored in the memory 430 by using at least one processor or central processing unit (CPU).

[0241] Figure 5 It is a block diagram of a base station according to an embodiment of the present disclosure.

[0242] Reference Figure 5 , the base station includes a transceiver 510, a controller 520, and a memory 530. The controller 520 may refer to a circuit system, an application specific integrated circuit (ASIC), or at least one processor. The transceiver 510, the controller 520, and the memory 530 are configured to perform the operations of the UE shown in the accompanying drawings (e.g., Figures 1 to 3 ). Although the transceiver 510, the controller 520, and the memory 530 are shown as separate entities, they may be implemented as a single entity, such as a single chip. Alternatively, the transceiver 510, the controller 520, and the memory 530 may be electrically connected or coupled to each other.

[0243] The transceiver 510 may send signals to other network entities (e.g., terminals) and receive signals from other network entities.

[0244] The controller 520 may control the UE to perform functions according to one of the above embodiments. For example, the controller 520 controls the transceiver 510 and / or the memory 530 to perform operations related to the random access process according to various embodiments of the present disclosure.

[0245] In an embodiment, the operations of the base station may be implemented using the memory 530 that stores corresponding program codes. Specifically, the base station may be equipped with the memory 530 to store program codes for implementing desired operations. To execute the desired operations, the controller 520 may read and execute the program codes stored in the memory 530 by using at least one processor or a central processing unit (CPU).

[0246] Although the present disclosure has been shown and described with reference to various embodiments of the present disclosure, those skilled in the art will understand that various changes may be made in form and detail without departing from the spirit and scope of the present disclosure defined by the appended claims and their equivalents.

[0247] As described above, the embodiments disclosed in the specification and the drawings are only used to present specific examples to easily explain the content of the present disclosure and help understanding, and are not intended to limit the scope of the present disclosure. Therefore, in addition to the embodiments disclosed herein, the scope of the present disclosure should be analyzed to include all changes or modifications derived from the technical concept of the present disclosure.

[0248] Although the present disclosure has been described with various embodiments, those skilled in the art can conceive of various changes and modifications. The present disclosure is intended to cover such changes and modifications that fall within the scope of the appended claims.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprises: In a radio resource control (RRC) connected state, receiving an RRC reconfiguration message including system information block type 1 (SIB1); Determining that the terminal does not have a stored valid version of the SIB; And In the case where the RRC reconfiguration message is associated with the master cell group (MCG) and includes SIB1 and information associated with a synchronous reconfiguration of the special cell (SpCell) configuration of the MCG, after the random access procedure for the target SpCell is completed, sending a dedicated SIB request message for the SIB to the target SpCell, Wherein, for dual connectivity operation, SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of the secondary cell group (SCG), otherwise, SpCell refers to the Pcell.

2. The method according to claim 1, wherein, The information associated with the synchronous reconfiguration includes information about a timer for the corresponding SpCell.

3. The method according to claim 1, further comprises: Determining that there is no common search space configured in the active bandwidth part (BWP), Wherein, in the case where there is no common search space configured in the active BWP and the terminal does not have a stored valid version of the SIB, sending the dedicated SIB request message.

4. The method according to claim 3, further comprises: Determining that there is a common search space configured in the active bandwidth part (BWP); And Based on the scheduling information included in the SIB1, identifying that the system information broadcast status is set to not broadcast, Wherein, in the case where there is a common search space configured in the active BWP and the system information broadcast status is set to not broadcast, sending the dedicated SIB request message.

5. A method performed by a target special cell (SpCell) in a wireless communication system, the method comprises: Performing a random access procedure with a terminal that is in a radio resource control (RRC) connected state with a source SpCell; And Based on the terminal not having a stored valid version of the system information block (SIB), receiving a dedicated SIB request message for the SIB from the terminal, Wherein, in the case where the RRC reconfiguration message sent from the source SpCell to the terminal is associated with the master cell group (MCG) and includes SIB1 and information associated with a synchronous reconfiguration of the special cell (SpCell) configuration of the MCG, after the random access procedure is completed, the dedicated SIB request message for the SIB is received, Wherein, for dual connectivity operation, SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of the secondary cell group (SCG), otherwise, SpCell refers to the Pcell.

6. The method according to claim 5, wherein, The information associated with the synchronous reconfiguration includes information about a timer for the corresponding SpCell.

7. The method according to claim 5, wherein, Receive the dedicated SIB request message when there is no common search space configured in the active bandwidth part (BWP), or when there is a common search space configured in the active BWP and the system information broadcast status included in the SIB1 is set to not broadcast.

8. A terminal in a wireless communication system, the terminal comprising: a transceiver (410) configured to transmit and receive signals; and a controller (420) coupled to the transceiver and configured to: in a radio resource control (RRC) connected state, receive an RRC reconfiguration message including system information block 1 (SIB1); determine that the terminal does not have a stored valid version of the SIB; and when the RRC reconfiguration message is associated with a master cell group (MCG) and includes SIB1 and information associated with a synchronization reconfiguration of a special cell (SpCell) configuration of the MCG, after completion of a random access procedure for the target SpCell, send a dedicated SIB request message for the SIB to the target SpCell, wherein, for dual connectivity operation, SpCell refers to the primary cell (PCell) of the MCG or the primary SCG cell (PSCell) of a secondary cell group (SCG), otherwise, SpCell refers to the Pcell.

9. The terminal according to claim 8, wherein, the information associated with the synchronization reconfiguration includes information about a timer for the corresponding SpCell.

10. The terminal according to claim 8, wherein, the controller is further configured to determine that there is no common search space configured in the active bandwidth part (BWP), and wherein, when there is no common search space configured in the active BWP and the terminal does not have a stored valid version of the SIB, send the dedicated SIB request message.

11. The terminal according to claim 10, wherein, the controller is further configured to: determine that there is a common search space configured in the active bandwidth part (BWP); and based on the scheduling information included in the SIB1, identify that the system information broadcast status is set to not broadcast, wherein, when there is a common search space configured in the active BWP and the system information broadcast status is set to not broadcast, send the dedicated SIB request message.

12. A target special cell (SpCell) in a wireless communication system, the target SpCell comprising: a transceiver (510) configured to transmit and receive signals; and a controller (520) coupled to the transceiver and configured to: perform a random access procedure with a terminal that is in a radio resource control (RRC) connected state with a source SpCell; and based on the terminal not having a stored valid version of a system information block (SIB), receive a dedicated SIB request message for the SIB from the terminal, Wherein, in a case where an RRC reconfiguration message sent from the source SpCell to the terminal is associated with a master cell group MCG and includes SIB1 and information associated with a synchronization reconfiguration of a special cell SpCell configuration of the MCG, after the random access procedure is completed, a dedicated SIB request message for the SIB is received, Wherein, for dual connectivity operation, SpCell refers to a primary cell PCell of the MCG or a primary SCG cell PSCell of a secondary cell group SCG; otherwise, SpCell refers to a Pcell.

13. The target SpCell according to claim 12, Wherein, the information associated with the synchronization reconfiguration includes information about a timer for a corresponding SpCell.

14. The target SpCell according to claim 12, Wherein, the dedicated SIB request message is received in a case where a common search space is not configured in an active bandwidth part BWP and the terminal does not have a valid version of the SIB stored.

15. The target SpCell according to claim 12, Wherein, the dedicated SIB request message is received in a case where a common search space is configured in an active bandwidth part BWP and a system information broadcast status included in the SIB1 is set to not broadcast.

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