Apparatus and method for supporting ultra-wide bandwidth in 5th generation new radio

Abstract

Methods and systems for communication technology in which a fifth generation (5G) communication system supporting a higher data transfer rate after a fourth generation (4G) system is converged with Internet of Things (IoT) technology are provided. A method performed by a terminal in a wireless communication system includes receiving, from a base station, a radio resource control (RRC) message including a configuration of at least one frequency band and a configuration of a primary frequency band for the terminal, wherein the configuration of the at least one frequency band includes at least one of a subcarrier spacing, a cyclic prefix, and information on a frequency domain location and a bandwidth of the at least one frequency band; monitoring a control channel on the primary frequency band from the base station; and receiving, from the base station, a downlink control information indicating an active frequency band among the at least one frequency band based on the control channel.

Description

[0001] This application is a divisional application of the invention patent application filed on October 31, 2017, with application number 201780067861.3 and entitled "Apparatus and method for supporting ultra-wide bandwidth in fifth-generation (5G) new radio". Technical Field

[0002] This disclosure relates to the physical layer (PHY) / media access control (MAC) layer operation of terminals and base stations in mobile communication systems. More specifically, this disclosure relates to methods and apparatus capable of efficiently utilizing bandwidth and flexibly and dynamically supporting bandwidth changes, because when a base station attempts to transmit / receive ultra-wideband signals to / from a single carrier, signal transmission / reception can only be achieved within a limited bandwidth due to the terminal's limited operating bandwidth and power consumption. Background Technology

[0003] To meet the rising demand for radio data traffic since the commercialization of fourth-generation (4G) communication systems, efforts have been made to develop and improve fifth-generation (5G) communication systems, or pre-5G communication systems. For this purpose, 5G communication systems or pre-5G communication systems are referred to as super-4G network communication systems or post-Long Term Evolution (LTE) systems. To achieve high data transmission rates, 5G communication systems are considered to be implemented in very high frequency (millimeter wave (mmWave)) bands (e.g., the 60 GHz band). To mitigate path loss and increase transmission distance of radio waves in very high frequency bands, beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive MIMO technologies have been discussed in 5G communication systems. In addition, to improve the network of the system, technologies such as Evolved Small Cell, Advanced Small Cell, Cloud Radio Access Network (Cloud RAN), Ultra-Dense Network, Device-to-Device Communication (D2D), Wireless Backhaul, Mobile Network, Cooperative Communication, Coordinated Multipoint (CoMP), and Receiver Interference Cancellation have been developed in 5G communication systems. Furthermore, hybrid FSK and QAM modulation (FQAM) and Sliding Window Overlay Coding (SWSC) have been developed as Advanced Coding and Modulation (ACM) schemes, while Filter Bank Multicarrier (FBMC), Non-Orthogonal Multiple Access (NOMA), and Sparse Coded Multiple Access (SCMA) have been developed as advanced access technologies.

[0004] Meanwhile, the Internet evolved from a human-centric connectivity network through which humans generate and consume information in the Internet of Things (IoT) network. The IoT network transmits / receives and processes information between distributed components such as things. The Internet of Everything (IoE) technology has also emerged, combining big data processing technologies with IoT technologies through connections to cloud servers and other technologies. To implement IoT, technological elements such as sensing technologies, wired and wireless communication and network infrastructure, service interface technologies, and security technologies are required. Recently, technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) for connecting things have been researched. In the IoT environment, intelligent Internet technology (IT) services can be provided, creating new value in human life by collecting and analyzing data generated in connected things. IoT can be applied to fields such as smart homes, smart buildings, smart cities, smart cars or connected cars, smart grids, healthcare, smart appliances, and advanced healthcare services by integrating and combining existing information technology (IT) with various industries.

[0005] Therefore, various attempts have been made to apply 5G communication systems to IoT networks. For example, 5G communication technologies such as sensor networks, M2M, and MTC have been implemented using techniques such as beamforming, MIMO, and array antennas. As an example of the integration of 5G communication technology with IoT technology, the application of cloud radio access networks (cloud RAN) as a big data processing technology can also be considered.

[0006] Existing LTE systems already employ multi-carrier schemes, where multiple component carriers (CCs) such as carrier aggregation (CA) and dual connectivity (DC) are bundled and operated to support broadband. Aggregating up to 32 CCs can support a bandwidth of 640MHz on a 20MHz CC basis. However, if schemes such as LTE CA are applied to support ultra-wide bandwidth, such as 1GHz in 5G New Radio (NR) systems, the number of CC combinations that the terminal must use increases exponentially, the size of the UE capability report increases, and 5G NR systems can only operate within a limited number of CC combinations. Furthermore, as the number of CCs in a CA increases, the reception complexity of the terminal and the control complexity of the base station both increase. However, despite these problems with CA / DC, CA / DC exhibits greater flexibility in resource utilization than single-carrier systems. This is because the extended bandwidth can be changed by adding / releasing secondary cells (SCells), and resources can be scheduled for transmission / reception to another CC through cross-carrier scheduling.

[0007] The above information is provided for background purposes only to aid in understanding this disclosure. No decision is made and no assertion is made as to whether any of the above content can be used as prior art with respect to this disclosure. Summary of the Invention

[0008] Technical issues

[0009] The aspects of this disclosure are intended to address at least the problems and / or disadvantages mentioned above, and to provide at least the following advantages. Thus, one aspect of this disclosure provides a limited signal transmission / reception process for a base station and a terminal based on the power consumption of the terminal in a single carrier, and a control method capable of dynamically and flexibly utilizing the entire bandwidth of the system.

[0010] Other aspects of this disclosure are not limited to those mentioned above. For example, those skilled in the art to which this disclosure pertains will readily understand from the following description other objectives not mentioned.

[0011] Solution to the problem

[0012] According to one aspect of this disclosure, a communication method for a terminal is provided. The method includes: receiving from a base station a first message including configuration information of at least one frequency band; receiving from the base station a second message for activating a frequency band among the at least one frequency band; and activating the frequency band according to the second message, wherein the configuration information includes an indication of the at least one frequency band, and wherein each of the at least one frequency band is a portion of a bandwidth.

[0013] In this method, the configuration information includes at least one of the following: digital information, frequency location information of the at least one frequency band, and the number of resource blocks of the at least one frequency band.

[0014] In this method, the second message includes at least one of downlink control information (DCI).

[0015] In this method, the configuration information of the at least one frequency band includes at least one of the configuration information of at least one downlink frequency band and at least one uplink frequency band.

[0016] In this method, the configuration information of the at least one downlink frequency band includes at least one of resource information of at least one control area having a search space specific to a user equipment (UE) and resource information of a control area having a common search space.

[0017] In this method, the configuration information of the at least one uplink frequency band includes resource information specific to the control area of ​​the UE.

[0018] In this method, activation includes: receiving control information in the frequency band from the base station; and receiving downlink signals in the frequency band from the base station no later than a predetermined time after receiving the control information.

[0019] According to another aspect of this disclosure, a communication method for a base station is provided. The method includes: transmitting to a terminal a first message containing configuration information including at least one frequency band; and transmitting to the terminal a second message for activating a frequency band among the at least one frequency band, wherein the configuration information includes an indication of the at least one frequency band, and wherein each of the at least one frequency band is a portion of a bandwidth.

[0020] In this method, the configuration information includes at least one of the following: digital information, frequency location information of the at least one frequency band, and the number of resource blocks of the at least one frequency band.

[0021] In this method, the second message includes at least one of the DCIs.

[0022] In this method, the configuration information of the at least one frequency band includes at least one of the configuration information of at least one downlink frequency band and at least one uplink frequency band.

[0023] In this method, the configuration information of the at least one downlink frequency band includes at least one of resource information of at least one control region having a UE-specific search space and resource information of a control region having a common search space.

[0024] In this method, the configuration information of the at least one uplink frequency band includes resource information specific to the control area of ​​the UE.

[0025] The method further includes: transmitting control information in the frequency band to the terminal; and transmitting downlink signals in the frequency band to the terminal no later than a predetermined time after transmitting the control information.

[0026] According to another aspect of this disclosure, a terminal is provided. The terminal includes: a transceiver configured to transmit and receive signals; and a controller configured to receive from a base station a first message including configuration information comprising at least one frequency band, receive from the base station a second message for activating a frequency band among the at least one frequency band, and activate the frequency band according to the second message, wherein the configuration information includes an indication of the at least one frequency band, and wherein each of the at least one frequency band is a portion of a bandwidth.

[0027] According to another aspect of this disclosure, a base station is provided. The base station includes: a transceiver configured to transmit and receive signals; and a controller configured to transmit a first message to a terminal including configuration information of at least one frequency band, and to transmit a second message to the terminal for activating a frequency band among the at least one frequency band, wherein the configuration information includes an indication of the at least one frequency band, and wherein each of the at least one frequency band is a portion of a bandwidth.

[0028] Beneficial effects of the invention

[0029] According to embodiments of this disclosure, multiple terminals with various frequency band sizes can be controlled to utilize resources equally within the system's operating bandwidth. Furthermore, the terminals can perform scheduling, modulation and coding scheme (MCS), channel state indication (CSI) reporting, measurements, etc., within their configured portion of the frequency band, minimizing the degradation in scheduling and handover performance across the entire bandwidth. Additionally, if a terminal causes connectivity problems within its configured portion of the frequency band, it is possible to restore the connection within a short delay.

[0030] The effects achievable through the embodiments of this disclosure are not limited to the objectives mentioned above. For example, other effects not mentioned will become apparent to those skilled in the art from the following description.

[0031] Other aspects, advantages, and distinctive features of this disclosure will become apparent to those skilled in the art from the following detailed description of various embodiments disclosed in conjunction with the accompanying drawings. Attached Figure Description

[0032] The above and other aspects, features, and advantages of certain embodiments of this disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings, in which:

[0033] Figure 1 This is a diagram illustrating a Scalable Bandwidth (BW) system for Long Term Evolution (LTE) according to various embodiments of the present disclosure;

[0034] Figure 2 This is a diagram illustrating various frequency band partitioning schemes according to various embodiments of the present disclosure;

[0035] Figure 3 This is a diagram of the frequency band division structure according to an embodiment of the present disclosure;

[0036] Figure 4a This is a diagram illustrating the operation of downlink data transmission / reception scheduling and uplink data transmission / reception scheduling according to embodiments of the present disclosure;

[0037] Figure 4b This is a diagram illustrating a downlink data scheduling scheme according to an embodiment of the present disclosure;

[0038] Figure 5 This is a diagram illustrating the relationship between Hybrid Automatic Repeat Request (HARQ) and frequency bands according to embodiments of the present disclosure;

[0039] Figure 6 This is a diagram illustrating a first operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure;

[0040] Figure 7 This is a diagram illustrating a second operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure;

[0041] Figure 8 This is a diagram illustrating a third operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure;

[0042] Figure 9 This is a diagram illustrating a fourth operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure;

[0043] Figure 10 This is a diagram illustrating the control sub-band structure according to an embodiment of the present disclosure;

[0044] Figure 11 This is a diagram illustrating the frequency band recovery process according to an embodiment of the present disclosure;

[0045] Figure 12 This is a diagram illustrating the frequency band recovery process according to an embodiment of the present disclosure;

[0046] Figure 13 This is a diagram illustrating the frequency band recovery process according to an embodiment of the present disclosure;

[0047] Figure 14 This is a diagram illustrating the frequency band recovery process according to an embodiment of the present disclosure;

[0048] Figure 15 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of the present disclosure;

[0049] Figure 16 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of the present disclosure;

[0050] Figure 17 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of the present disclosure;

[0051] Figure 18 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of the present disclosure;

[0052] Figure 19This is a diagram illustrating a desired flexible bandwidth (BW) system in a fifth-generation (5G) communication system according to an embodiment of the present disclosure;

[0053] Figure 20 This is a diagram illustrating the configuration of a terminal according to an embodiment of the present disclosure;

[0054] Figure 21 This is a diagram illustrating the configuration of a base station according to an embodiment of the present disclosure.

[0055] Throughout the accompanying drawings, it should be noted that the same reference numerals are used to depict the same or similar elements, features, and structures. Detailed Implementation

[0056] The following description is provided with reference to the accompanying drawings to aid in a full 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 should be considered merely exemplary. Therefore, those skilled 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. Furthermore, for clarity and brevity, descriptions of well-known functions and constructions may be omitted.

[0057] The terms and words used in the following description and claims are not limited to their literal meaning, but are used by the inventors only to enable a clear and consistent understanding of this disclosure. Therefore, it will be apparent to those skilled in the art that the following description providing various embodiments of this disclosure is for illustrative purposes only and is not intended to limit the disclosure as defined by the appended claims and their equivalents.

[0058] It should be understood that, unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” include plural indicators. Thus, for example, a reference to “part surface” includes a reference to one or more such surfaces.

[0059] The term “substantially” means that the feature, parameter, or value does not need to be precisely achieved, but rather deviations or variations (including, for example, tolerances, measurement errors, measurement accuracy limitations, and other factors known to those skilled in the art) may occur in a quantity that does not preclude the effect that the feature is intended to provide.

[0060] It should be understood that when a component is referred to as "connected to" or "coupled to" another component in this specification, it can mean that a component is directly connected to or directly coupled to another component, or electrically connected to or coupled to another component in the presence of other components. Additionally, in this specification, "including" a specific configuration is to be understood as additional configurations that may also be included within the scope of the embodiments or technical concepts disclosed herein.

[0061] Furthermore, the constituent parts shown in the embodiments of this disclosure are illustrated independently to represent different functional characteristics. Therefore, it is not implied that each constituent part is constructed as a separate hardware or software unit. For example, for ease of description, corresponding constituent parts are included by being arranged as each constituent part, and at least two constituent parts in a corresponding constituent part may form a single constituent part, or a constituent part may be divided into multiple constituent parts to perform functions. Integrated and separate embodiments of corresponding components are also included within the scope of this disclosure unless departing from its spirit.

[0062] Furthermore, some elements may not be essential for performing the basic functions of this disclosure, but rather optional elements that only improve its performance. This disclosure can be implemented by including only the essential elements necessary for carrying out the essence of this disclosure, in addition to the elements used to improve performance. A structure that includes only the essential elements, in addition to the optional elements used only to improve performance, is also included within the scope of this disclosure.

[0063] Various advantages and features of this disclosure, as well as methods for achieving these advantages and features, will become apparent from the following detailed description of embodiments with reference to the accompanying drawings. However, this disclosure is not limited to the embodiments disclosed herein, but will be practiced in various forms. The embodiments have been provided to complete the disclosure and to enable those skilled in the art to readily understand the scope of this disclosure. Therefore, this disclosure will be defined by the scope of the appended claims. The same reference numerals denote the same elements throughout the specification.

[0064] In this context, it is understood that each block of the flowchart and combinations thereof can be executed by computer program instructions. Since these computer program instructions can be mounted on a processor for a general-purpose computer, special-purpose computer, or other programmable data processing apparatus, the processor creates components by which these instructions, executed by the computer or other programmable data processing apparatus, perform the functions described in the blocks of the flowchart. Since these computer program instructions can also be stored in a computer-usable or computer-readable storage device of the computer or other programmable data processing apparatus to implement the functions in a specific manner, the computer program instructions stored in the computer-usable or computer-readable storage device can also produce articles of manufacture, including instruction components that perform the functions described in the blocks of the flowchart. Since the computer program instructions can also be mounted on a computer or other programmable data processing apparatus, performing a series of operations on the computer or other programmable data processing apparatus to create a process executed by the computer, thereby executing the instructions of the computer or other programmable data processing apparatus, can also provide operations for performing the functions described in the blocks of the flowchart.

[0065] Here, the term "-unit" as used in this embodiment means a software or hardware component, such as a field-programmable gate array (FPGA) and an application-specific integrated circuit (ASIC), and a "-unit" performs any role. However, the meaning of "-unit" is not limited to software or hardware. A "-unit" can be configured in an addressable storage medium and can also be configured to reproduce one or more processors. Thus, for example, a "-unit" includes components such as software components, object-oriented software components, class components, and task components and processors, functions, attributes, procedures, subroutines, program code segments, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functionality provided in components and "-units" can be combined with a smaller number of components and "-units," or can be further separated into additional components and "-units." Furthermore, components and "-units" can also be implemented as one or more central processing units (CPUs) within a reproduction device or secure multimedia card.

[0066] This disclosure proposes a control and configuration method for ultra-wideband transmission / reception in a fifth-generation (5G) mobile communication system. Specifically, methods for scheduling, handover, and radio link failure (RLF) recovery in ultra-wideband can be considered. In a 5G mobile communication system, it is anticipated that various services (or slices) will be supported, such as enhanced mobile broadband (eMBB), ultra-reliable and low latency communication (URLLC), and enhanced machine-type communication (eMTC). This can be understood in the same context as supporting Voice over Internet Protocol (VoIP), best-effort (BE) services, etc., in the Long Term Evolution (LTE) system as a 4G mobile communication system. Furthermore, it is anticipated that various digitizations will be supported in a 5G mobile communication system. This may specifically include subcarrier spacing, which can directly affect the transmission time interval (TTI). This is one of the characteristics of a 5G mobile communication system, which is very different from the characteristics of the current standardized LTE, which only supports one TTI (e.g., 1 ms). If a 5G mobile communication system supports a TTI much shorter than LTE's 1ms TTI (e.g., 0.1ms, etc.), it is expected to be very helpful in supporting URLLC, which requires short latency. In embodiments of this disclosure, numeric terms can be used to refer to subcarrier spacing, subframe length, symbol / sequence length, cyclic prefix, etc. Furthermore, numeric terms can be the reason why terminals have different bandwidths (BW). Base stations can be represented by various abbreviations, such as next-generation (gNB), evolved Node B (eNB), Node B (NB), and base station (BS). Terminals can be represented by various abbreviations, such as UE, MS, STA, etc.

[0067] Figure 1This is a diagram illustrating an LTE Scalable Bandwidth (BW) system according to various embodiments of the present disclosure.

[0068] refer to Figure 1 The LTE system introduces the concept of scalable BW to support various BWs and can support terminals with various BWs (e.g., 5 / 10 / 20MHz, etc.) that have the same center frequency.

[0069] For example, if UE 1 is a 5MHz-enabled terminal and UE 2 is a 10MHz-enabled terminal, the LTE base station can appropriately configure the control channel and transmit control signals so that both UE 1 and UE 2 can receive the control signals. However, when the base station's entire available bandwidth is very large—that is, in ultra-wide bandwidth—this approach limits the resources available to support terminals with relatively small bandwidths. For example, if UE 3 operates at the edge of the bandwidth used by the base station, then UE 3 may not be able to receive the base station's control signals independently.

[0070] Therefore, in 5G NR (New Radio) communication systems, terminals must be able to transmit and receive critical control signals to maintain connectivity with the base station even within bandwidths not supported by existing scalable BW systems. For example, in LTE, critical control signals can be transmitted via the Signaling Radio Bearer (SRB) through the primary cell (PCell). Furthermore, within the PCell, control signals for scheduling and Hybrid Automatic Repeat Request (HARQ) procedures in both the PCell itself and secondary cells (SCells) can be transmitted / received. Both the PCell and SCell in LTE can be considered independent cells. Additionally, each cell requires a separate Medium Access Control (MAC) entity and, depending on its link adaptation and HARQ entities. However, in 5G NR single-carrier communication systems, the entire bandwidth effectively corresponds to a single cell. Furthermore, the PCell should essentially provide functionality for the terminal's connection / connection establishment / maintenance and data transmission / reception.

[0071] Figure 2 This is a diagram illustrating various frequency band division schemes according to various embodiments of the present disclosure.

[0072] Meanwhile, even when the base station operates in ultra-wide bandwidth, due to limited implementation and complexity, the terminal only enables transmission / reception immediately within a portion of the entire bandwidth. To enable the terminal to operate in a bandwidth larger than its maximum available bandwidth (BW), the terminal can only operate by dividing the bandwidth into time-based segments. To facilitate ultra-wide bandwidth management, the base station can configure the entire bandwidth by dividing it into several frequency bands of appropriate size and instructing the terminal to perform various MAC functions (e.g., scheduling, measurement, link adaptation, modulation and coding (MCS) schemes, HARQ, etc.) within specific frequency bands. Furthermore, based on the frequency bands, the terminal can determine and receive the structure of the control channel and reference signal (RS).

[0073] refer to Figure 2 Scenario A illustrates a static partitioning. Under Scenario A, the base station can divide the entire bandwidth into multiple frequency bands of equal size. For example, the entire bandwidth can be divided into four frequency bands of equal size. Terminal 1 (UE 1) can support bandwidth greater than frequency band 1. In this case, because the base station configures the frequency bands to a fixed size, terminal 1 can operate with base station 1 even in some parts of the entire available bandwidth, rather than in the entire available bandwidth. For example, although terminal 1 can operate with the base station in frequency band 1, because the remaining bandwidth in terminal 1's available bandwidth that is greater than the bandwidth of frequency band 1 is less than the bandwidth of frequency band 2, terminal 1 cannot operate with the base station in the remaining bandwidth.

[0074] Scenario B illustrates flexible partitioning. According to Scenario B, the base station can divide the entire bandwidth into multiple frequency bands of various sizes. In this case, if the available bandwidth of terminal 1 is equal to the bandwidth of frequency band 1, then terminal 1 can operate with the base station across the entire available bandwidth. However, in the case of terminal 2 (UE 2), if the maximum available bandwidth is less than the bandwidth of frequency band 4 configured by the base station, then operation of terminal 2 cannot be supported.

[0075] Therefore, as in case C, methods such as static partitioning with fine granularity can be considered. According to case B, the base station can partition the entire bandwidth by minimizing the unit of frequency band. In this case, since the bandwidth to be used by the terminal can be represented by a small band, terminals with bandwidths of various sizes can be supported. For example, terminal 1 can operate with the base station through a band of frequency bands 1 to 6, and terminal 2 can communicate with the base station through a band of frequency bands 13 to 16.

[0076] On the other hand, in case C, too many frequency bands would increase the workload during management. Therefore, as in case D, a method of freely configuring the frequency band size (with fine-grained flexible partitioning) can be useful. This method involves dividing the frequency band into smaller units while changing its size. In this case, terminal 2 cannot be supported in case B, but in case D, terminal 2 can operate with the base station through a bundle of frequency bands 6 and 7.

[0077] In embodiments of this disclosure, to address the problem of how a base station divides the entire bandwidth into frequency bands and configures these bands in terminals from cases A to D, the base station configures a frequency band of different sizes for each terminal. Hereinafter, from a system perspective, a method will be described for representing the frequency bands configured in a terminal by combining sub-bands of the same size. Furthermore, from a system perspective, independent scheduling, link adaptation, MCS, HARQ procedures, etc., are not performed within the divided sub-bands as in existing CA methods; however, from a terminal perspective, a method for performing a scheduling, link adaptation, MCS, HARQ procedure, etc., within the configured frequency band will be described.

[0078] Figure 3 This is a diagram of the frequency band division structure according to an embodiment of the present disclosure.

[0079] refer to Figure 3 The structure of the physical layer control channel should be designed to be scalable across one or more subbands within a frequency band. This means that terminals with a frequency band can be supported, where the frequency band can be represented by at least a plurality of subbands within that frequency band. However, terminals with frequency bands larger than the configured frequency band need not be supported within the frequency band. The size of a frequency band as a subband can be determined by at least one of the following: channel characteristics, digitization, control subband size, and minimum packet size between the terminal and the base station. The terminal can perform a set of MAC functions (e.g., scheduling, MCS, HARQ, etc.) for a service. A frequency band can mean a portion of the total bandwidth, which may be referred to as a bandwidth portion (BWP), a portion of the bandwidth, etc.

[0080] Methods for configuring frequency bands or subbands

[0081] A base station can configure subbands in a terminal using a method such as System Information (SI) or Radio Resource Control (RRC) connection establishment process. For example, subband configuration can be represented by resource elements (REs) (i.e., a resource unit consisting of subcarrier spacing and symbols, the time of the RE, and the number of frequency domains). The time domain can be represented by symbol numbers, and the frequency domain can be represented by subcarrier spacing numbers. REs can vary depending on the type of digitization. If the base station divides resources into multiple different digitization regions, the length of the symbols and the subcarrier spacing of the REs configured in each region can be changed. Therefore, if multiple digitization regions are supported, the base station needs to set multiple RE types in the terminal. Simultaneously, a subband can be represented by k REs. The value k can be a value that is (pre-)set to a value, independent of the digitization region. Alternatively, if needed, the base station can set a value for each digitization region in the terminal via additional SI or RRC messages. According to embodiments of this disclosure, subband configuration can be represented by the number and frequency location of physical resource blocks (PRBs) (e.g., the location of the center frequency).

[0082] For terminals where subband information is configured, the base station can configure the terminal's operating bandwidth, i.e., the frequency band of the subbands based on the IDLE (idle) mode terminal or the connected mode terminal. For example, the frequency band can be configured in the terminal via a subband index and the number of subbands. In this case, although the subbands have the same size, the frequency band can have different sizes depending on the configuration. The frequency band can be configured in the terminal along with the subband configuration via SI or RRC messages, or it can be configured separately in the UE via SI or RRC messages. Therefore, according to embodiments of this disclosure, the subband can be configured by SI, and the frequency band can be configured by RRC messages. On the other hand, since the frequency band is represented as the basic unit of the subband, the network can notify the terminal of the digital information to configure the frequency band via SI or RRC messages. The terminal can accurately identify the structure of a frequency band by combining the digital information set for each frequency band with the subband information used for each digital band. If only one of the frequency band and subband is configured, then in order to obtain information about the other, the terminal can obtain information from the information about the configured frequency band or subband according to predetermined rules.

[0083] On the other hand, each subband is a network-distinguished unit, but a frequency band can be configured for each terminal, and the areas can overlap in terms of the network. Additionally, the location and number of control subbands can be set within the configured frequency band. Control subbands can be referred to as control resource sets, control sub-resources, control channel resources, etc. Control subbands indicate resources used for receiving DCI in the control channel monitored by the terminal. According to embodiments of this disclosure, at least one common control subband and control subbands for each terminal can be configured for a frequency band. DL downlink (DL) assignment messages and / or UL (uplink) permission messages for general scheduling of each terminal can be indicated as control subbands for each terminal. If no other frequency band is indicated in the DL assignment message and / or UL permission message, then the terminal can accept the DL assignment message and / or UL permission message indicated by the control subbands for each terminal as a transmission / reception indication for the frequency band in which the control subbands for each terminal are configured. For example, a one-to-one relationship can exist between control subbands and frequency bands for each terminal.

[0084] Resource information used for data transmission is indicated by resource block (RB) units. In this case, the start (or end) point of the first RB matches the start (or end) point of the frequency band, or it can be a position that can be directly calculated from the frequency band and sub-band configuration information. When instructions are given for data transmission / reception resources within the same frequency band, the base station can notify the terminal of the resources allocated to the start point and the number of RBs. When instructions are given for data transmission / reception resources within different frequency bands, in addition to RB information, the base station also needs to notify the terminal of the frequency band index information (frequency band index, frequency band ID, etc.) indicating the frequency band. Therefore, the base station can transmit configuration information to the terminal, including the index information for each beam, to configure one or more frequency bands in the terminal. Simultaneously, RB information is logically partitioned, and real physical resources can be mapped to continuous or discontinuous resource REs. Frequency band index information can be assigned individually to DL (deep) or UL (lower) frequency bands, and can also be assigned jointly regardless of the DL / UL frequency bands.

[0085] As can be seen from the above description, the base station can include digitization information in the frequency band setting information to instruct the terminal to configure the frequency band. The terminal can calculate the RE structure based on the digitization information and identify control sub-bands and resource information for data transmission based on the calculated RE structure. Furthermore, since the location and size of each frequency band are represented by sub-bands, the base station can use SI or RRC messages to individually set the digitization applied to the RE structure used to construct sub-bands in the terminal. The RE structure used to configure sub-bands and the RE structure used to configure frequency bands can be different. In addition, DL bands and UL bands can have different configuration information (such as frequency location and digitization) and are linked to the terminal's DL and UL operations respectively, allowing DL and UL bands to be configured independently. The terminal can perform operations for DL ​​control and data reception based on the information of the frequency bands configured in the DL bands, and can perform operations for UL control and data transmission based on the information of the frequency bands configured in the UL bands.

[0086] During the transition from idle mode to connected mode, the base station can configure the common / control subbands for the terminal from the base station. During the random access procedure, the base station can configure the frequency band information or the control subbands of the frequency band connected to the terminal via the Random Access Response (RAR) or Message 4 (Msg4) (e.g., RRC connection complete). If no separate configuration is available, the terminal can determine the location of the subbands and frequency bands used in connected mode based on at least one of the synchronization signal (SS) bandwidth, idle mode bandwidth, and physical random access channel (PRACH) bandwidth, according to predetermined rules. To configure the frequency band and subband configuration and digitization information required for operation, the terminal can transmit UE capability information to the network during the connection process (e.g., random access or RRC (re)configuration). UE capability information may include at least one of the following: the number of radio frequencies (RFs), the maximum operating bandwidth of one RF, the maximum operating bandwidth of the terminal, the RF retuning wait time for the terminal with the center frequency maintained, the RF retuning wait time for the terminal with the center frequency switched, the type of operable digitization, etc.

[0087] The functionalities that can be provided in the system architecture proposed in this disclosure can be considered as follows.

[0088] - Configuration of control / RS / CSI reporting / HARQ feedback per frequency band

[0089] -Self-band / Cross-band scheduling

[0090] -Band aggregation for transmitting a single transport block

[0091] - Cross-band HARQ retransmission

[0092] -Public Signaling

[0093] -Band recovery

[0094] -RRM (Radio Resource Management) Measurement

[0095] Configuration of per-band control / RS / CSI reporting / HARQ

[0096] When setting a frequency band, the base station can notify the terminal of the band's location and extent (e.g., start, size, or center frequency and bandwidth) through multiple basic units (e.g., RBs or sub-bands). The location and extent of the frequency band is part of a carrier in which the network system operates, and therefore, according to embodiments, can be set by the frequency offset and bandwidth of the frequency band relative to the center frequency of the entire carrier bandwidth. Alternatively, according to embodiments, the location and extent of the frequency band can be set by the frequency offset and bandwidth of the frequency band relative to the center frequency of the synchronization signal detected by the terminal.

[0097] On the other hand, the center frequency of the carrier bandwidth understood by the terminal can be the center frequency of the synchronization signal detected by the terminal, or it can be the same as the center frequency information of the carrier indicated by the SI connected to the synchronization signal detected by the terminal, or the center frequency information of the carrier indicated to the terminal by the base station during the RRC connection establishment process.

[0098] The terminal can understand the frequency band range as the system bandwidth. Therefore, even if frequency bands in different ranges are allocated, the terminal and base station should be designed to receive signals according to the same reception rules. For example, it should be able to transmit and receive reference signals (RS) or the location of control channels transmitted by the base station based on the start and size of the frequency band configured in the terminal. Furthermore, it should also be able to transmit and receive CSI reports or HARQ feedback transmitted by the terminal based on the start and size of the frequency band configured in the terminal. Additionally, when multiple frequency bands are configured in the terminal, the base station can be additionally configured in the terminal to either share HARQ processing across the multiple frequency bands or to separate HARQ processing for each frequency band.

[0099] The frequency band monitored by the terminal is generally referred to as the primary frequency band (p-band). Monitoring may not be performed in resource areas other than the p-band until separate control / configuration is performed in the p-band. Auxiliary frequency bands (s-bands) are selectively operated according to the configuration via the p-band, and according to embodiments, the p-band and s-band may be referred to as the first RF band and the second RF band. Furthermore, the p-band can be activated to an active state via an RRC message or MAC CE among at least one configured frequency band candidate. Similarly, the s-band can be activated to an active state via an RRC message, MAC CE, or DCI among at least one configured frequency band candidate. Likewise, the base station can deactivate one or more frequency bands from an active state to an inactive state by transmitting a deactivation signal / message to the terminal via an RRC message, MAC CE, or DCI. In embodiments of this disclosure, the active frequency band and p-band can be used interchangeably with similar meanings. However, according to embodiments of this disclosure, the active frequency band and p-band may be different. For example, when configuring a p-band, the DL band and UL band can be combined with each other. Furthermore, the p-band is the basic active band in a cell, but not all active bands are p-bands. Additionally, the p-band may not be deactivated except during a separate band handover process. In the case of TDD, the frequency positions of the DL band and UL band can be the same, allowing them to be configured as a bundle. A p-band configuration can include at least one DL band and at least one UL band, enabling the base station to instruct the terminal. If the terminal reports a UE capability report including RF information to the base station, the base station can set a p-band for each different RF of the terminal.

[0100] In the p-band or active DL band, the following operations may also be considered.

[0101] a) Monitor UE public information (for UEs using RRC connections)

[0102] b) Monitor common beam information in systems above 6 GHz.

[0103] c) Monitor the dedicated search space specific to the UE configuration and obtain the configuration for the second RF BW (if needed).

[0104] d) Support for RRM measurement (this is required if the RRM BW is inside the first RF BW)

[0105] The differences in configuration and operation between the p-band and the active band will be described. The base station can additionally set the p-band state along with one or more band configurations via RRC messages. For a band configured by the p-band, the terminal can be configured to receive at least one of the following only in the p-band: 1) RRC messages, 2) MAC CE, 3) L2 common signaling, 4) L1 common signaling, and 5) UE-specific signaling. Furthermore, the terminal can be configured to operate at least one other function only in the p-band, such as 1) Radio Link Monitoring (RLM), 2) Discontinuous Reception (DRX), 3) Measurement, 4) Synchronization, 5) Paging, and 6) Random Access. According to embodiments of this disclosure, the base station can configure RLM, measurement, and DRX functions in the terminal, enabling the terminal to operate not only in the p-band but also in the s-band.

[0106] If a terminal can operate on an active frequency band in only one band at a time, then when the terminal instructs a band switch or cross-band scheduling from a p-band (e.g., band #0) to another s-band (e.g., band #1), the terminal needs to deactivate the p-band (band #0) for a period of time and activate the other s-band (band #1). In this case, the terminal's operation in the switched s-band (band #1) can be restricted according to the configuration of each of the aforementioned messages or functions. In this respect, both the p-band and s-band can be active frequency bands, but the terminal's operation for each band can be different. For example, the terminal's operation can differ when the RLM and RLF functions are applied only to the p-band, and when they are applied to both the p-band and s-band. If the RLM / RLF is applied only to the p-band, then if no signal is received from the base station when the terminal is operated by activating the s-band, the terminal may not perform RLM, or even if it does, the RLF event may not be triggered. In this case, this can be replaced by a process of falling back from the s-band to the p-band, which will be described below. If RLM / RLF is applied to both the p-band and s-band, the terminal can trigger RLM and RLF events for the active band among all bands configured for RLM / RLF. The RLM results in the s-band can be preset or reflected in the RLM / RLF event determination for the serving cell, depending on the base station settings.

[0107] As described above, if the base station does not configure RLM / RLF in the S-band of the terminal, then backoff to the P-band can be additionally supported. The terminal can start a separately configured backoff timer if a reception error of the base station signal is determined due to channel quality degradation in the S-band. If the conditions for receiving the base station signal again are met, the terminal can stop, reset, or restart the backoff timer. If the base station signal reception error conditions continue to be met and the backoff timer expires, the terminal can switch the RF to the P-band. After switching to the P-band, the terminal can monitor the effective control channel based on the P-band or a commonly configured control channel location and DRX settings. If the conditions for successfully receiving the terminal's feedback or UL signal in the S-band are not met within a predetermined time or until the timer expires, the base station can operate the terminal's control signals in the effective control channel based on the DRX settings and the location of the control channel configured in the terminal in the P-band.

[0108] Meanwhile, base stations and terminals can perform p-band recovery operations because the terminal's performance is degraded in the p-band. The p-band recovery and rollback operations can be categorized as shown in Table 1 below.

[0109] Table 1

[0110]

[0111] On the other hand, a process for activating and deactivating a frequency band can be as follows. According to embodiments of this disclosure, activating / deactivating a MAC control element (CE) can be a new MAC CE for the frequency band. Alternatively, according to embodiments of this disclosure, activating / deactivating a MAC CE can reuse an existing SCell.

[0112] If a MAC entity is configured with one or more SBands, then the network can activate and deactivate the configured SBands.

[0113] The network activates and deactivates (one or more) SBands in the following ways:

[0114] - Send activation / deactivation MAC CE;

[0115] - Configure an sBandDeactivationTimer for each configured SBand (except for SBands configured with PUCCH, if any): The associated SBand is deactivated when it expires.

[0116] The MAC entity should be for each NR-UNIT and each configured SBand:

[0117] 1> If an activation / deactivation MAC CE is received in this NR-UNIT, then activate SBand:

[0118] 2> Activate SBand:

[0119] 2> Start or restart the SBandDeactivationTimer associated with SBand.

[0120] 1> Otherwise, if an activation / deactivation MAC CE is received in this NR-UNIT, then deactivate SBand; or

[0121] 1> If the SBandDeactivationTimer associated with the activated SBand expires in this NR-UNIT:

[0122] 2> Deactivate SBand;

[0123] 2> Stop the sBandDeactivationTimer associated with SBand;

[0124] 2> Refresh all HARQ buffers associated with SBand.

[0125] 1> If the NR-PDCCH on the activated SBand indicates uplink permission or downlink assignment; or

[0126] 1> If the NR-PDCCH on the serving cell of the SBand activated by the scheduling indicates uplink permission or downlink assignment for the activated SBand:

[0127] - Restart the sBandDeactivationTimer associated with SBand;

[0128] Next, we will describe the associated operations with band switching / activation indications in single or multiple active band operations.

[0129] A terminal can monitor at least one of one or more configured frequency bands based on RF conditions, and can view one or more of them. Therefore, it is advantageous in terms of scalability that the base station's frequency band indication is typically applied to terminals under different RF conditions. However, the base station should be aware of the terminal's other RF conditions in advance through the terminal's capability reports. Otherwise, if the base station issues an activation indication for frequency band #2 to any terminal in frequency band #1, and the base station cannot know whether frequency band #1 has been deactivated due to the terminal's RF limitations, a failure is possible.

[0130] If a terminal operating in a single active frequency band receives a frequency band activation instruction from the base station, it will deactivate the previous frequency band while switching to the indicated frequency band (i.e., activating the indicated frequency band). Furthermore, if a terminal operating in multiple active frequency bands receives a frequency band activation instruction from the base station, it can activate the indicated frequency band and maintain the frequency band that was previously activated.

[0131] In this way, the estimation scheme based on the terminal's capability report is simple, but it may still be prone to failure. For clear procedures and operations, the base station should be able to set the maximum number of active frequency bands for the terminal and clearly indicate the deactivation of frequency bands.

[0132] The terminal can be pre-configured to operate on the active frequency band according to either of the following two methods, or configured by the base station / network. Furthermore, this operation can also be applied in the following situations: in addition to combining a separate frequency band activation indication from the base station, frequency band switching / activation can be performed in conjunction with a cross-frequency band scheduling indication.

[0133] a) Configure multiple active frequency bands, but each active frequency band can switch to only one of the deactivated frequency bands. Therefore, the number of active frequency bands can be changed only via RRC messages (according to embodiments, the number of active frequency bands can be changed via SI, DCI, MAC CE, etc.).

[0134] b) Configure multiple active frequency bands, and the base station can provide the terminal with activation / deactivation instructions for each frequency band. Since the number of active frequency bands can be changed, the network can be manipulated such that the number of active frequency bands does not exceed the terminal's maximum number of active frequency bands, or all frequency bands are deactivated. If the base station indicates that the number of active frequency bands exceeds the terminal's maximum number of active frequency bands, the terminal can operate by at least one of the following: 1) deactivate the first activated frequency band, 2) deactivate the last activated frequency band, 3) deactivate the lowest frequency band according to the frequency band index sequence, 4) deactivate the frequency band with the lowest priority among the frequency bands set by the base station, and 5) deactivate a frequency band arbitrarily determined by the terminal from the previously active frequency bands. The frequency band to be deactivated can be determined to exclude the p-band.

[0135] The process for determining the movement time (including the readjustment wait time when activating the band with DCI or MAC CE) will be described.

[0136] The terminal can adjust the RF readjustment time based on the relationship between the active band switching conditions and the switching band. The base station can set the time required to switch to another band relative to one band (e.g., the p-band) in the terminal based on capability reports via RRC messages. If the terminal does not meet the settings, it can perform a per-band rejection.

[0137] When the base station instructs the terminal to perform band activation via DCI, the terminal 1) can monitor the fastest effective control channel in the band activated after the handover time axis included in the DCI, based on the handover waiting time from the DCI reception time (e.g., subframe / time slot / hour slot, etc.) preset by the RRC message to the handover completion; or 2) can monitor the fastest effective control channel after the time determined by the value of k by specifying the handover waiting time k from the DCI reception time (e.g., subframe / time slot / hour slot, etc.) to the handover completion and the band ID in the DCI.

[0138] When a base station instructs a terminal to perform band activation via MAC CE, the terminal can operate by at least one of the following: 1) monitoring the fastest effective control channel in the band activated after the handover wait time from the successful HARQ acknowledgment (ACK) received for MAC CE (e.g., subframe / timeslot, hourly slot, etc.) to the handover completion, based on the band ID included in the MAC CE and the handover wait time preset by the RRC message; 2) analyzing the MAC CE based on the band ID included in the MAC CE and the handover wait time preset by the RRC message, and allowing the MAC to determine the band switch, monitoring the fastest effective control channel in the band activated after the handover wait time from the time indicating the PHY is reached again (e.g., subframe / timeslot / hourly slot, etc.); 3) specifying the handover wait time k from the successful MAC CE reception time (e.g., subframe / timeslot / hourly slot, etc.) to the handover completion and the band ID in the MAC CE. The fastest effective control channel in the frequency band activated after the handover wait time from the successful CE reception time (e.g., subframe / time slot / hour slot, etc.) to the handover completion; and 4) by specifying in the MAC CE the handover wait time k from the successful HARQ ACK transmission time (e.g., subframe / time slot / hour slot, etc.) for successful MAC CE reception to the handover completion, and the frequency band ID, to monitor the fastest effective control channel in the frequency band activated after the handover wait time from the successful HARQ ACK transmission time (e.g., subframe / time slot / hour slot, etc.) for successful MAC CE reception to the handover completion.

[0139] The base station can individually instruct the terminal to perform frequency band configuration and CSI-RS configuration. To control CSI-RS measurements and reporting for each frequency band of the UE, the base station can instruct the terminal to report measurement results according to at least one of the following methods: The terminal can measure the CSI-RS indicated by the base station and report the results according to CSI-RS reporting settings interlocked with CSI-RS resources.

[0140] 1) If mapping information between frequency bands and CSI-RS resources is configured:

[0141] The base station can set the mapping information between frequency bands and CSI-RS resources in the terminal via RRC messages. The mapping information may include information about frequency band configuration or CSI-RS resource (measurement / reporting) configuration. The base station can transmit a frequency band index to the terminal to indicate frequency band switching, and the terminal can perform measurements and reports on the CSI-RS determined based on the frequency band index and mapping information.

[0142] 2) If the mapping information between frequency bands and CSI-RS resources is not set:

[0143] a) The base station can transmit the frequency band index and CSI-RS resource index to the terminal to indicate frequency band switching, and the terminal can perform measurements and reports on the indicated CSI-RS.

[0144] (b) The base station can transmit a frequency band index to the terminal to indicate a frequency band switch. The terminal can use this implementation to identify CSI-RS resources included in the active frequency band and report the identified CSI-RS to the base station, including an index of the CSI-RS resources identified after measurement of the identified CSI-RS.

[0145] The base station can individually instruct the terminal to perform frequency band configuration and CSI-RS configuration. To set up a common CSI-RS for multiple frequency bands for the terminal and control measurement and reporting, the base station can instruct the terminal to report measurement results according to at least one of the following methods: 1) The terminal can measure the CSI-RS indicated by the base station and report the results to the base station according to CSI-RS reporting settings interlocked with CSI-RS resources. 2) The base station transmits a frequency band index to the terminal to indicate frequency band switching, and the terminal can report to the base station after measuring the CSI-RS currently included in the active frequency band.

[0146] Self-band / Cross-band Scheduling

[0147] Figure 4a This is a diagram illustrating the operation of downlink data transmission / reception scheduling and uplink data transmission / reception scheduling according to embodiments of the present disclosure, and Figure 4b This is a diagram illustrating a downlink data scheduling scheme according to an embodiment of the present disclosure.

[0148] refer to Figure 4a and 4bThe base station can control the transmission / reception of the terminal's control channel or data channel through the control sub-band (c sub-band) configured in the p-band in each terminal. The base station can instruct the terminal to transmit or receive DL (downlink) or uplink (UL) data transmission / reception areas through self-band data scheduling or cross-band data scheduling. Furthermore, the base station can instruct the terminal to change the position / size of the control sub-band within the same frequency band through self-band control scheduling. Additionally, the base station can instruct the terminal to change the position / size of an additional control sub-band in another frequency band through cross-band control scheduling. When instructing the position of the control sub-band within the same or another frequency band, the position of time resources (e.g., subframes, time slots, hour slots, symbols, etc.) and the position of frequency resources can also be indicated.

[0149] In the case of uplink scheduling, a preset waiting time value (e.g., 4 ms) or a separate waiting time value can be indicated to the UE via the control subband. The Physical Downlink Shared Channel (PDSCH) and the PDSCH used for data transmission / reception in the same subframe can be indicated. In the system considered in the embodiments of this disclosure, in cases of cross-band scheduling where bandwidth needs to be changed even in downlink scheduling, it may be necessary to separately indicate specific subframes (or time slots, symbols, etc.) (subframes used for downlink data transmission). This is because when the location of a frequency band to be used is changed, processing time for radio frequency and readjustment of baseband (BB) circuitry may be required. Therefore, by considering the available frequency band information carried on the terminal's capability report and the degree of change in the terminal's used bandwidth by the base station's control operations, the base station can transmit control signals and then indicate (with permission for delay) the transmission / reception of downlink resources after a preset waiting time. For example, if the transmission of PDSCH begins within a predetermined time (e.g., k symbols) after the transmission of control signals on the PDCCH, then the PDCCH and PDSCH can exist in the same frequency band. However, if the transmission of PDSCH begins after a predetermined time (e.g., k symbols) following the transmission of control signals on PDCCH, then PDCCH and PDSCH can exist in different frequency bands.

[0150] refer to Figure 4aThis diagram illustrates the operations of performing self-band and cross-band scheduling for data transmission and reception, as well as self-band and cross-band scheduling for uplink data transmission and reception. Latency can be included in each control signal (e.g., DCI, MAC CE, etc.), or at least one latency value can be pre-set in the terminal for each S-band during the terminal's capability negotiation and connection establishment / reconfiguration process. Since the delay is greater when the terminal's bandwidth completely changes than when the terminal's bandwidth partially overlaps but only changes, the base station can transmit latency to the terminal via each control signal based on this scenario, or transmit an index of two or more latency values ​​to the terminal via control signals, thus appropriately delaying the terminal before performing downlink reception. If the latency value is set to 0 or not set, the terminal can perform downlink data reception within the same TTI (or Transmission Time Unit (TTU)).

[0151] When a band switching event, which depends on a waiting time value, is predicted to fail, the terminal can discard downlink data reception from the base station. Depending on the base station configuration, the terminal can use feedback information about the HARQ processing ID to report to the base station the data transmission block (TB) that was discarded or information about the terminal's discard (reception failure).

[0152] In band switching operations, the latency value can vary depending on whether the center frequency of the actual RF band of the terminal is being switched. For example, in the case of a TDD terminal, a delay does not always occur when switching between the DL band and the UL band; rather, a delay only occurs when the center frequencies of the DL band and the UL band are being switched.

[0153] like Figure 4a As shown, the location of another frequency band or the location of a control sub-band within another frequency band can be informed by a control sub-band within a frequency band. The terminal can switch RF according to network instructions to receive the control sub-band of another frequency band (e.g., frequency band 2) within one frequency band (e.g., frequency band 1), and receive data reception or transmission information for downlink or uplink data in the control sub-band of frequency band 2. Furthermore, a control sub-band within a frequency band can inform the terminal of the location of the frequency band including the control sub-band, and / or the data area of ​​another frequency band that does not include the control sub-band.

[0154] Figure 4bThe diagram illustrates three types of frequency band scheduling schemes in the downlink scenario. The terminal can configure the first frequency band (band #1) and the second frequency band (band #2) based on the RRC connection establishment or RRC reconfiguration process. Here, it is assumed that the size of the first frequency band is smaller than the size of the second frequency band, and the size of the second frequency band is equal to the terminal's maximum operating bandwidth. For example, the size of the first frequency band could be four sub-bands (sub-bands 7-10), the size of the second frequency band could be six sub-bands (sub-bands 1-6), and the terminal's maximum operating frequency band could be equal to the size of six sub-bands. Furthermore, the terminal can monitor control signals in the smaller first frequency band to reduce power consumption.

[0155] First, an operation known as self-band scheduling will be described. A terminal can receive a DL control signal from a base station in the nth time slot via a first frequency band, and, according to the indication of the control signal, receive a downlink control signal transmitted by the base station in the same first frequency band as the control signal. The time resource location of the data channel (e.g., start position and interval) can be statically set for each terminal, or the time resource location can be dynamically indicated by the downlink control signal using an index in the time slot or symbol unit. The scheme for indicating self-band scheduling can inform the frequency band index in the downlink control signal, the format of the specific control signal (e.g., when the waiting time or resource start position information considering the waiting time is not included in the control signal, etc.), etc.

[0156] Next, an operation known as self-band scheduling will be described. A terminal can receive downlink control signals from a base station in the (n+1)th time slot of a first frequency band and data transmitted from the base station in the (n+2)th time slot of a second frequency band. The time resource location (e.g., start position and interval) of the data channel can be statically set for each terminal, or the time resource location can be dynamically indicated by the downlink control signals using an index in the time slot or symbol unit. The length of the time slot or symbol can be recalculated based on the digital information configured in the dedicated frequency band. If the terminal is instructed to receive data after receiving the control signal at an interval shorter than the RF redial waiting time previously reported by the base station, then the terminal 1) can notify the base station of the cause information (such as information about a problem in cross-band scheduling or information about an RF redial information error) by transmitting an RRC connection reconfiguration request, or 2) can perform a p-band or active band switching / setting request to the base station via an RRC message or MAC CE.

[0157] Next, the operation of implementing operations such as cross-band scheduling and self-band scheduling via frequency band indication will be described. The terminal can receive downlink control signals from the base station via a first frequency band in the (n+3)th time slot, and receive downlink control signals of a second frequency band according to the indication of the downlink control signals. Specifically, based on at least one piece of information, including the frequency band index and the downlink control channel resource location included in the downlink control signals, the terminal can monitor the downlink control channel of the second frequency band by switching frequency bands. If there is no separate indication of the downlink control channel resource location, the terminal can monitor the downlink control channel at the earliest point after RF retuning is completed, based on the downlink control channel and its resource information configured for each frequency band by the RRC message. To know when the terminal monitors the downlink control channel, the base station can determine the time when the base station transmits control signals to the terminal and the location of the downlink control signals that the terminal wants to monitor, based on the RF retuning wait time value for each terminal determined according to information related to the RF retuning wait time reported to the UE.

[0158] On the other hand, instructions for self-band scheduling operations and cross-band scheduling operations or band indication operations can simultaneously reach the terminal in the downlink control channel. If self-band scheduling operations and cross-band scheduling operations conflict with each other, for example, when RF retuning cannot be performed while data is being received, the terminal 1) can always prioritize self-band scheduling operations, or 2) prioritize data transmission / reception operations determined to be of higher priority based on priority (e.g., based on at least one of digitization, control signal format, traffic volume, service, band, PDU size, and delay requirements). If both self-band scheduling and band indication operations are indicated simultaneously, the terminal can monitor the downlink control channel at the earliest time after the RF retuning waiting time after the data transmission / reception according to the self-band scheduling instruction is completed.

[0159] According to embodiments of this disclosure, base stations are not allowed to indicate scheduling operations that are not feasible during the terminal's rescheduling waiting time.

[0160] Simultaneously, a base station can configure asymmetric p-bands with different frequency bands (e.g., location, size, etc.) for the downlink and uplink of a single terminal. However, the p-band needs to support both the downlink and uplink to smoothly operate the main control functions. Therefore, even with different frequency bands allocated, the terminal can be understood as a single p-band.

[0161] As described above, cross-band scheduling can be indicated by 1) a single DCI / MAC CE signal for cross-band scheduling, or 2) two signals for band switching / activation indication (e.g., DCI / MAC CE) and self-band scheduling. Generally, the p-band is not changed by cross-band scheduling; however, transmitting p-band functionality can be useful if it is necessary to maintain functionality in the p-band during band switching. In 1), if the indication is made by a single signal, the base station should pre-configure whether to switch the p-band in the terminal in the RRC message, or include whether to switch the p-band in the DCI / MAC CE. In 2), if the indication is made by two signals, the base station should pre-configure whether to switch the p-band associated with the band switching / activation indication in the terminal in the RRC message, or include whether to switch the p-band in the DCI / MAC CE.

[0162] On the other hand, such as Figure 4a As shown, the area to which the control signals of each frequency band are transmitted can be designated as a specific sub-band. For example, a control area can be assigned to a specific frequency region of the frequency band. For example, in the case of frequency band 1, sub-band 1 could be the area where control signals are transmitted. Alternatively, as... Figure 4b As shown, the area where control signals for each frequency band are transmitted is not located in a specific sub-band, but can be located across the bandwidth of that frequency band. For example, the resource area to which control signals are transmitted can be allocated not only to a specific frequency region, but can also be located across the entire bandwidth of that frequency band for a specific time.

[0163] According to embodiments of this disclosure, a base station may configure a terminal or define an operation according to a standard, such that after a frequency band switch of the terminal and DL / UL data transmission / reception according to cross-frequency band scheduling, the operation is performed by at least one of the following: 1) monitoring control signals by returning the terminal to a frequency band that receives DL assignment or UL permission (i.e., scheduling indication); 2) monitoring control signals by positioning the terminal in a frequency band that is the target of the scheduling indication; or 3) monitoring control signals by switching the terminal to a frequency band configured by the base station.

[0164] Furthermore, the time for monitoring the bandwidth according to the scheduling application can be immediately after transmitting or receiving a DL / UL data transmission block in the indicated frequency band, or after the terminal determines that the conditions set by the base station are met. The conditions set by the base station can be at least one of the following: a) the number of scheduling indications for the frequency band, b) the complete time including HARQ retransmissions up to the Nth transmission / reception block, c) the time spent in the current monitoring bandwidth after the first cross-band scheduling indication (or the corresponding timer, etc.), d) the time during which scheduling indications for the corresponding frequency band are received on successive PDCCHs (or the corresponding timer, etc.), e) the number of PDCCHs for which scheduling indications for the current monitoring bandwidth are not received, and f) the continuous time (or the corresponding timer, etc.) of the PDCCH intervals for which scheduling indications for the current monitoring bandwidth are not received.

[0165] Band aggregation to transmit a single transport block

[0166] According to embodiments of this disclosure, to reduce power consumption, the base station configures a frequency band smaller than the available frequency band of the terminal in the terminal as a p-band, and when a large amount of data needs to be transmitted and received, it can instruct cross-band scheduling to transmit and receive signals in resources set up in the auxiliary frequency band (s-band) for the larger frequency band. In this case, if the p-band and s-band are completely separate frequency bands, the terminal can only buffer signals for the corresponding frequency band after a delay (e.g., on the order of hundreds of microseconds). Therefore, it may be difficult to transmit and receive signals to the control channel and data channel simultaneously in the same subframe. However, if the p-band is included in the s-band as a frequency resource, the delay for RF / BB retuning is small (e.g., on the order of a few microseconds), allowing the control channel and data channel to transmit / receive simultaneously in the same subframe. In this case, if different transport blocks are transmitted in the physical resource block (PRB) of the p-band and the PRB of the s-band, additional resource allocation (e.g., in DCI) and HARQ processing are inevitably required. Therefore, a method can be considered to transmit a transport block by bundling different PRBs in the p-band and s-band. Even if different digitization is applied in each band, this method should still be able to bundle and transmit a transport block. The base station can use at least one of the following methods to instruct the terminal to perform band aggregation.

[0167] 1) The base station can assign a new frequency band ID by setting the aggregated frequency band (frequency band 1 + frequency band 2) as an additional frequency band 3, and issue an instruction to perform aggregation on frequency band 1 and frequency band 2 in the DL control indicator (DCI) transmitted through the DL control channel by using the frequency band ID of frequency band 3.

[0168] 2) The base station can use the frequency band ID to indicate the frequency band 2 to be aggregated in the terminal via the DCI transmitted through the DL control channel of frequency band p (frequency band 1). The DCI for frequency band 2 can be transmitted in either frequency band p or frequency band 2. The terminal can perform aggregation on frequency band p (frequency band 1) and frequency band 2 based on the frequency band ID information.

[0169] Cross-band HARQ retransmission

[0170] Figure 5 This is a diagram illustrating the relationship between HARQ and frequency bands according to embodiments of the present disclosure. According to embodiments of the present disclosure, a terminal and / or base station can perform retransmissions in another frequency band for transport blocks that failed to be transmitted in one frequency band.

[0171] refer to Figure 5 HARQs used for transmission failures in one frequency band can be retransmitted in another frequency band. For example, if a downlink transmission failure occurs in frequency band 1 when frequency bands 1 through 3 are configured in the terminal, the base station can perform downlink data retransmission in frequency band 2. Scheduling and prioritization can be performed for this. Multiplexing can be performed when the data to be transmitted exists in the frequency band used for transmitting retransmitted data.

[0172] In the downlink case, the base station can perform retransmissions in different frequency bands based on the implementation of self-band / cross-band scheduling. This operation can be performed based on the base station's determination in the downlink, but it is helpful for the base station to determine which frequency band is suitable for retransmission based on the terminal's uplink signal. For example, the base station can periodically or dynamically allocate uplink resources for signal transmission to the terminal's S-band. When the terminal determines that the quality of the base station signal received in the P-band, or the quality / error of the received data channel, is greater than a certain level, the terminal can transmit uplink signals in the allocated S-band transmission resources. The base station can indicate the operation of retransmitting downlink data in the S-band based on the quality of the terminal's uplink signal. According to another embodiment of this disclosure, the band ID of the candidate S-bands that can be used for retransmission is transmitted to the base station along with the UE's HARQ feedback signal, allowing the base station to determine the retransmission operation based on the terminal's candidate band report.

[0173] On the other hand, while a similar downlink approach can even be applied to the uplink, there is a significant delay in the base station re-performing uplink resource allocation (UL grant) after the terminal receives the base station's reference or feedback signal and informs the base station of its response. This is because there is a certain delay after the base station instructs the terminal to transmit uplink signals. Therefore, in the uplink, the terminal first transmits UL signals (e.g., PRACH, SRS, etc.) using UL resources allocated across multiple frequency bands, and the base station receives the UL signals and then determines the frequency bands that indicate UL grant.

[0174] During HARQ processing, base stations and terminals can explicitly reference the HARQ processing ID in a specific frequency band when using a band ID in addition to the HARQ processing ID to transmit control signals in DCI or UCI and HARQ feedback messages. If no band ID is specified, it becomes necessary to allocate a large number of HARQ processing IDs proportionally to the number of frequency bands, or to restrict the use of the same HARQ processing ID across frequency bands. However, considering operations such as cross-band HARQ retransmissions, restricting HARQ processing IDs across frequency bands makes it difficult to obtain additional performance.

[0175] The Physical Uplink Control Channel (PUCCH) for UCI transmission of HARQ feedback for the terminal can be allocated as an RRC message via the p-band. According to embodiments of this disclosure, at least one of the following can be operated: 1) dynamically allocating the PUCCH to the s-band via a control sub-band of the p-band; or b) configuring a control sub-band belonging to the p-band according to the base station configuration and allocating the PUCCH to the same s-band via the control sub-band. When resources are allocated to the PUCCH in the s-band, the terminal can piggyback and transmit the UCI.

[0176] To support cross-band HARQ retransmission, even if a frequency band is deactivated, the terminal can continuously store the HARQ buffer stored for retransmission without refreshing it. The terminal can refresh the HARQ buffer only when releasing or deactivating a cell.

[0177] In HARQ operations based on frequency band switching, each frequency band can be configured with different HARQ control variables (e.g., HARQ ACK / NACK timing, round-trip time, HARQ retransmission timer, etc.). The terminal can change the HARQ operation based on the HARQ control variables associated with the corresponding frequency band used for the HARQ operation indication, which includes a frequency band index.

[0178] Public Signaling

[0179] Figure 6This is a diagram illustrating a first operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure. Figure 7 This is a diagram illustrating a second operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure. Figure 8 This is a diagram illustrating a third operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure. Figure 9 This is a diagram illustrating a fourth operation of transmitting a common signal from a higher layer to a terminal according to an embodiment of the present disclosure, and Figure 10 This is a diagram illustrating the control sub-band structure according to an embodiment of the present disclosure.

[0180] The base station can be operated by setting the SRB in the terminal to be transmitted to the main control subband (PCS) in the p-band or by setting data resources through the PCS. The base station and / or the terminal can transmit and receive RRC messages or Non-Access Stratum (NAS) messages via the SRB. For example, paging messages can be transmitted from the Mobility Management Entity (MME) to the terminal via NAS messages. The base station can also be operated by setting the data radio bearer (DRB) in the terminal to be transmitted to the secondary control subband (SCS) in the p-band or by setting data resources through the SCS. The PCS or p-band can be operated such that the terminal has the same control resources or bandwidth (i.e., access bandwidth) that operate concurrently during the initial access procedure. For example, in the case of paging messages, the operational scenario can vary depending on the terminal's state. In the case of an idle-mode UE, paging messages can be received from a resource obtainable from the synchronization signal and the Physical Layer (PHY) Broadcast Channel (PBCH), or from paging resources received from the SI. In the case of an inactive UE (where some connected operations are omitted and the RAN maintains the UE context state for power conservation in the connected state), the paging reception process can be performed based on the paging operation and the paging resources set by the RRC message in the connected state. Furthermore, the paging resources set in the connected state can differ from the access bandwidth.

[0181] Simultaneously, in the case of a connected UE, the operation of receiving SI or paging messages received on the downlink shared channel in the p band should be considered. If a connected UE receives a paging message, the paging message may correspond to another service / slice. Since a terminal can only see a portion of the frequency band corresponding to the configured frequency band of the entire system frequency band, the base station may have the burden of separately transmitting common signals dropped from higher layers (e.g., for viewing SI messages for different terminals in different frequency bands).

[0182] refer to Figure 6The base station can duplicate the SI information (common signal) 610 into three copies and transmit each of the three duplicated signals 620, 623, and 625 to three terminals (UE 1 / UE 2 / UE 3) via separate control channels (e.g., C subband 1, C subband 5, and C subband 12). If the common signal 610 is a paging message, the base station interprets the paging message and requests efforts to generate paging messages for each of the frequency bands 630, 633, and 635 of terminals UE 1, UE 2, and UE 3, and transmits the paging messages to terminals UE 1, UE 2, and UE 3.

[0183] Based on the paging configuration, paging opportunities can be determined using the System Frame Number (SNF) and subframe index. In idle mode, the UE sets paging opportunities from the MME and monitors the downlink control channel (PDCCH) in the frames and subframes corresponding to the set paging opportunities, even through several base stations, to receive paging messages as resources identified by the Paging Radio Network Temporary Identifier (P-RNTI). More specifically, the terminal can set a number of frames (paging frames) and their corresponding subframes (paging opportunities) as the first paging opportunity based on System Frame 0, and configure the paging opportunities to repeat for each DRX cycle represented in frames. The paging frame number and paging timing in the paging configuration can be set in the terminal by allowing the base station to directly transmit the values ​​to the terminal. However, in the case of the paging frame number, the terminal can perform calculations based on other parameters (e.g., DRX period, number of paging frames in the DRX period, number of paging timings in the DRX period, terminal ID, etc.). Alternatively, in the case of the paging timing, the terminal can perform calculations based on other variables (e.g., number of paging frames in the DRX period, number of paging timings in the DRX period, terminal ID, number of subframes in the paging frame, etc.).

[0184] On the other hand, detailed equations for paging configuration can be found in a portion of the instruction manual document below.

[0185] A paging frame (PF) is a radio frame that may contain one or more paging opportunities. When using DRX, the UE only needs to monitor one PF per DRX cycle.

[0186] A paging narrowband (PNB) is a narrowband on which the UE performs paging message reception.

[0187] PF, PO, and PNB are determined using the DRX parameter provided in SI through the following equation:

[0188] PF is given by the following equation:

[0189] SFN mod T=(T div N)*(UE_ID mod N)

[0190] The index i_s pointing to the PO from the subframe mode defined in 7.2 will be derived from the following calculation:

[0191] i_s = floor(UE_ID / N) mod Ns

[0192] If P-RNTI is monitored on MPDCCH, then PNB is determined by the following equation:

[0193] PNB=floor(UE_ID / (N*Ns))mod Nn

[0194] Whenever the DRX parameter value changes in the SI, the SI DRX parameter stored in the UE will be updated locally in the UE. If the UE does not have an IMSI, for example, when making an emergency call without a USIM, the UE will use UE_ID=0 as the default identifier in the PF, i_s, and PNB equations above.

[0195] The following parameters are used to calculate PF, i_s, and PNB:

[0196] -T: UE's DRX period. Except for NB-IoT, if a UE-specific extended DRX value of 512 radio frames is configured by a higher layer according to 7.3, then T = 512. Otherwise, T is determined by the shortest of the UE-specific DRX values ​​(if assigned by a higher layer), and a default DRX value is broadcast in the SI. If a UE-specific DRX is not configured by the higher layer, the default value is applied. UE-specific DRX does not apply to NB-IoT.

[0197] -nB: 4T, 2T, T, T / 2, T / 4, T / 8, T / 16, T / 32, T / 64, T / 128 and T / 256, and for NB-IoT there are also T / 512 and T / 1024.

[0198] -N: min(T, nB)

[0199] -Ns: max(1, nB / T)

[0200] -Nn: The number of paging narrowbands provided in SI

[0201] -UE_ID:

[0202] If P-RNTI is monitored on PDCCH, then IMSI mod 1024.

[0203] If P-RNTI is monitored on NPDCCH, then IMSI mod 4096.

[0204] If P-RNTI is monitored on MPDCCH, then IMSI mod 16384.

[0205] The DRX cycle includes a value set by the NAS for each terminal and a common setting value for the base station. If both are set, the smaller of the value and the common setting value can be used. However, in embodiments of this disclosure, multiple common signaling resources can be set in a subframe (or time slot). Therefore, if the MME's paging configuration method can identify common signaling resources while taking them into account, waste caused by copying common signaling resources to multiple common signaling resources can be prevented. According to embodiments of this disclosure, if only one common signaling resource exists in a frequency band, the frequency band index and the common signaling resource index can be used equally. According to embodiments of this disclosure, if multiple common signaling resources are allocated in a frequency band, the common signaling resource index is used. To this end, an additional common signaling resource index can be configured when a common signaling resource is allocated to a specific frequency band via an RRC message.

[0206] According to a first method for reducing waste of public signaling messages, the public band index can be calculated based on at least one of existing system frame numbers, subframes, DRX cycle information, or other information used to obtain such information in the paging configuration. For example, the terminal ID can be moduloed using the number (Ncs) of public signaling resources that the base station has already set as SI to specify one of the public signaling resources. The terminal ID can be any value derived from the International Mobile Subscriber Identity (IMSI) or the IMSI. According to another example, the band / public signaling resource index can be calculated based on the output value of a function that uses at least one of the following as input: DRX cycle, the number of paging frames in the DRX cycle, the number of paging opportunities in the DRX cycle, the terminal ID, the number of subframes in the paging frame, and the number of public bands / public signaling resources.

[0207] According to the second method for reducing the waste of public signaling messages, the equation for i_s in the two variables Ns and i_s required for the existing index pointing equation is as follows: i_s = floor(UE_ID / N) mod Ns i_s = (floor(UE_ID / N) mod Ns) mod Ncs, or i_s = floor(UE_ID / (N*Ns)) mod Ncs. The equation can be used by changing i_s = floor(UE_ID / N) mod Ns.

[0208] For example, the base station and the terminal can use the following [Table 2] to calculate the paging timing (PO). If Ns is 1 and i_s is 0, then PO is 9, so paging can be received in the 9th subframe.

[0209] Table 2

[0210] Ns PO when i_s = 0 PO when i_s = 1 PO when i_s = 2 PO when i_s = 3 1 9 N / A N / A N / A 2 4 9 N / A N / A 4 0 4 5 9

[0211] According to the third method for reducing the waste of public signaling messages, the terminal can receive public frequency bands or public signaling resources from the base station via RRC messages in RRC connected state. An idle mode UE that does not receive public frequency bands or public signaling resources from a newly camped base station can first perform a random access procedure to receive public signaling resources from the base station via RRC messages.

[0212] According to a fourth method for reducing waste of public signaling messages, the paging configuration of the MME is the same as in the prior art, and only frequency bands or public signaling resources monitored by the terminal can be allocated among multiple resources in a specific time period within a base station. When the base station receives a paging message from the MME, the base station can calculate the maximum value Np of the paging resources (e.g., the number of frames × the number of public signaling resources in the subframe) within a time period set based on information of the terminal receiving the paging (e.g., at least one of UE ID, IMSI, etc.). The base station can determine the index for a resource according to the equation (UE ID) mod Np. The base station / terminal can determine the resources to receive paging in the set time period in such a way that the public signaling resources in the subframe are counted using the index of the determined resources.

[0213] The above methods can be roughly classified into the following three types: 1) a method that determines the paging timing for each terminal using an equation for time axis information (e.g., paging frames and paging subframes) and then determines the resources for each terminal using another equation for frequency axis information (e.g., frequency band index or common signaling resource index); 2) a method that aligns paging resources one-dimensionally on the time and frequency axes and then determines the paging resources for each terminal using an equation; and 3) a method that selects a portion of the paging resources using an equation for the time and frequency axes, aligns the selected paging resources one-dimensionally, and then determines the paging resources for each terminal using another equation.

[0214] Even when the terminal is in an inactive mode other than IDLE, the paging operation described above can be performed in a similar manner.

[0215] The aforementioned paging resources can be configured as multiple paging resource areas identified for service / digital / slice support. When operating a terminal through a specific service / digital / slice, paging reception can be performed in the corresponding paging resource area. When operating a terminal for multiple services / digital / slices, 1) the base station transmits paging signals for each of the multiple paging resource areas to the terminal in an overlapping manner, or 2) the base station transmits a paging signal for only one paging resource area to the terminal while simultaneously monitoring the paging timing of multiple paging resource areas, or 3) the base station can transmit a paging signal to the terminal in a paging resource area corresponding to a service / digital / slice selected according to a set priority, and the terminal can also monitor the paging timing of the paging resource area. To support this operation, the base station can notify the terminal of the relationship between each paging resource area and the service / digital / slice through the SI.

[0216] refer to Figure 7 A common frequency band 730 is set up so that all terminals can receive a common signal as in existing LTE, and the base station can pre-configure the settings in the terminal when the terminal receives the common frequency band 730 via RRC messages. For example, the base station can be configured to operate the terminal according to at least one of the following: a) allow the terminal to receive the common frequency band 730 at a specific time; or b) give the terminal only the opportunity to receive the common frequency band 730 at a specific time, and determine whether the terminal receives the common frequency band 730 based on the state of the frequency band the terminal is operating; or c) give the terminal only the opportunity to receive the common frequency band 730 at a specific time, and allow the terminal to receive the common frequency band 730 only if there is no indication of operation in the frequency band the terminal is operating. In embodiments of this disclosure, at least two of methods a), b), and c) can be set individually.

[0217] To mitigate the drawback of having multiple signals 720 and 725 copied / divided for separate transmission across multiple frequency bands 730, 733, and 735, as shown in Figure 6, a structure is proposed where one control sub-band is shared by multiple frequency bands 730, 733, and 735. For example, sub-band 4 can be shared by frequency band 1 (730) and frequency band 2 (733), and sub-band 10 can be shared by frequency band 2 (733) and frequency band 3 (735). Therefore, the common signals to be copied / divided can be reduced to two signals 720 and 725. This scheme is less efficient than... Figure 7 The example is efficient, but the sharing of control subbands between bands can be dynamically controlled to minimize inefficiency.

[0218] refer to Figure 8The base station can duplicate the SI information (common signal) 810 into three copies and transmit each of the two duplicated signals 820 and 825 to the three terminals (UE 1 / UE 2 / UE 3) via separate control channels (e.g., C subband 1, C subband 5, and C subband 12). If the common signal 810 is a paging message, the base station interprets the paging message and needs to make an effort to generate a paging message for each of the frequency bands 830, 833, and 835 of terminals UE 1, UE 2, and UE 3, which are included in frequency bands 830, 833, and 835, and transmit the paging message to terminals UE 1, UE 2, and UE 3.

[0219] refer to Figure 9 Whether to receive depends on the RRC message and specific conditions. Figure 7 The method for using the common frequency band shown differs. The base station can indicate to the terminal whether to dynamically receive the common frequency band 930 via frequency bands (band 1, band 3) 940 and 945 configured in each terminal (e.g., UE 1 and UE 3). However, to simplify L1 signaling, the base station can pre-set the position / size of the common frequency band 930 and its control subbands (e.g., c subbands 8, 9) in the terminal via RRC messages. To return the terminal to the dedicated frequency band, the base station may be operated according to at least one of the following: a) a method for transmitting a return (or handover) instruction from the base station to the terminal in the common frequency band 930; b) a method for setting the terminal to return to the dedicated frequency band after a preset timer expires, or a method for setting the terminal to return to the dedicated frequency band by the base station; c) a method for pre-setting the terminal to return to the dedicated frequency band after performing a target operation (e.g., receiving SI or paging) in the common frequency band 930, or a method for setting the terminal to return to the dedicated frequency band by the base station; or d) a method for receiving a p-band change control signal in the common frequency band 930, setting the dedicated frequency band to the p-band, and moving the dedicated frequency band.

[0220] To operate the various methods mentioned above, it can support, for example... Figure 10 The various frequency band and control subband allocation schemes shown are illustrated.

[0221] refer to Figure 10For example, each frequency band can have a separate control sub-band. For instance, control sub-band 1 can be assigned to frequency band 1 1010, control sub-band 5 can be assigned to frequency band 2 1013, and control sub-band 13 can be assigned to frequency band 3 1015. According to embodiments of this disclosure, sub-bands used for data transmission other than the control sub-bands can be shared by multiple frequency bands. For example, frequency band 1 1010 and frequency band 2 1013 can share sub-bands 3 and 4 as sub-bands for data transmission. As another example, control frequency bands can be jointly assigned to multiple frequency bands (sharing control sub-bands between frequency bands). For example, frequency band 1 1020 and frequency band 2 1023 can be shared by control sub-band 3. Frequency band 2 1023 and frequency band 3 1025 can share control sub-band 11. As another example, a common control frequency band can be configured so that all terminals can receive a common signal. For example, a common frequency band 1030, including control subbands 8 and 9, can be configured for all terminals.

[0222] Band recovery

[0223] Simultaneously, the terminal can perform a handover or band recovery process based on the degradation of the base station's signal strength / quality. Handover is a process used to reconfigure the RRC connection to the target cell based on the determination of the serving base station in response to a degradation of the serving cell's signal strength / quality. On the other hand, the band recovery proposed in the embodiments of this disclosure is a process for resetting the p-band while maintaining the connection between the serving base station and the terminal.

[0224] The terminal can be operated via handover or band recovery, depending on the timers, parameters, and weights set to different values ​​for each process. For example, handover may be important in a licensed 6 GHz subband, while band recovery may be important in bands above 6 GHz. Furthermore, band recovery may be important in unlicensed bands where the LBT (Listen-Before-Speak) criterion is applied. According to embodiments of this disclosure, the terminal can also change the weights based on the operating frequency, rather than through base station configuration.

[0225] The following describes the analysis of applying existing RLF conditions to the frequency band.

[0226] Conditions for RLF detection in related technologies

[0227] Out of step (T310 expires when N310 consecutive OOC (out of coverage) indications from L1 are received)

[0228] Except in cases where the p-band overlaps with a common frequency band, this does not apply to frequency bands.

[0229] RA (Random Access) failure (RA problem indication when running T300 / 301 / 304 / 311)

[0230] If RACH (Random Access Channel) is configured via the p-band, then it is applicable.

[0231] RLC (Radio Link Control) indication (maximum # reached for UL retransmission)

[0232] Not applicable to frequency bands, but applicable to cells.

[0233] HO (Handover) failed (target cell indication, incomplete HO, HO timer expired).

[0234] Not directly related to frequency band

[0235] Note: If any of the four conditions are met, then an RLF will be triggered.

[0236] Table 3

[0237]

[0238]

[0239] Table 4

[0240]

[0241]

[0242] Table 5

[0243]

[0244] Based on the above analysis, conditions other than RLC indication (e.g., OOC, RA failure, HO failure) are unlikely to be used when applied to frequency bands. Under the RLC indication condition, since the terminal and serving base station remain connected even if SRB control is impossible due to deterioration in p-band connectivity, the RLF for the serving base station can be determined based on whether the sum of the aggregated RLC packet retransmission frequencies before the expiration of the recovery timer for p-band exceeds the maximum retransmission frequency.

[0245] Simultaneously, after a fault in the p-band is determined, a p-band recovery timer is activated. If p-band recovery is not completed before the timer expires, the terminal can determine an RLF (Recovery Level Fault) for the serving base station. Band recovery processing is primarily applied to the p-band, but according to embodiments, it can also be applied to the common band or the S-band. The following four band recovery processes are possible.

[0246] Case 1: Triggered by gNB

[0247] Scenario 2: Triggered by UE

[0248] Scenario 3: gNB / UE triggered & UL-based recovery

[0249] Scenario 4: gNB / UE triggered & DL-based recovery

[0250] Figure 11 This diagram illustrates a frequency band recovery process according to an embodiment of the present disclosure. Figure 12 This diagram illustrates a frequency band recovery process according to an embodiment of the present disclosure. Figure 13 This is a diagram illustrating a frequency band recovery process according to an embodiment of the present disclosure, and Figure 14 This is a diagram illustrating a frequency band recovery process according to an embodiment of the present disclosure.

[0251] Figure 11 The diagram illustrates the operation of a base station (first node) and a terminal (second node) according to a method for triggering frequency band recovery processing based on a base station. The base station can reconfigure another frequency band as the P-band based on a measurement report.

[0252] refer to Figure 11 In operation 1110, the base station can configure a first frequency band to the terminal as the primary frequency band for serving cell measurements, and in operation 1120, configure a second frequency band that was not configured as the primary frequency band for serving cell measurements. In operation 1130, the base station can receive measurement reports from the terminal for the first and / or second frequency bands. In operation 1140, the base station can determine whether to change the primary frequency band using the second frequency band based on the measurement reports received from the terminal in operation 1130. Furthermore, in operation 1150, the base station can perform configuration on the terminal based on the determination in operation 1140 to change the primary frequency band to the second frequency band as the new primary frequency band.

[0253] Simultaneously, in operation 1160, the terminal can receive configuration from the base station for a first frequency band used as the primary frequency band for serving cell measurements, and in operation 1170, it can receive configuration for a second frequency band not configured for serving cell measurements. In operation 1180, the terminal can transmit measurement reports for the first and / or second frequency bands to the base station. Furthermore, in operation 1190, based on the base station determination in operation 1140, the terminal can receive configuration from the base station to change the primary frequency band to a second frequency band used as a new primary frequency band. The terminal changes the primary frequency band according to the base station's configuration for the second frequency band used as the new primary frequency band, and can apply attributes and measurement operations applied to the previous primary frequency band to the new primary frequency band.

[0254] Figure 12 The illustration shows a flowchart of the operation of a base station (first node) and a terminal (second node) according to an embodiment of the present disclosure of a method for triggering frequency band recovery processing according to a terminal.

[0255] A terminal detecting low signal quality at a base station can notify the base station of a candidate frequency band it will move to. In this case, the terminal can transmit information about the candidate frequency band to which it will move using pre-allocated UL resources. Additionally, the base station can reconfigure the P-band based on information received from the terminal.

[0256] refer to Figure 12 In operation 1210, the base station can configure a first frequency band as the main frequency band to the terminal for the purpose of serving cell measurements. Additionally, in operation 1215, the base station can set the UL resources used for reporting problems with the main frequency band to a second frequency band that is not configured as the main frequency band. The terminal can determine whether the validity conditions of the channel state based on the main frequency band (first frequency band) are met, and whether a main frequency band failure has occurred. If the channel of the main frequency band does not meet the validity conditions, the terminal can transmit a problem report to the base station, and the base station can receive the report message in operation 1220. At this time, in addition to the report about the main frequency band, the base station can also receive a report about the second frequency band from the terminal. If the base station receives a problem report about the main frequency band in operation 1220, the base station can determine in operation 1225 whether to change the main frequency band to the second frequency band as the new main frequency band. At this time, the base station can determine whether to designate the second frequency band as the new main frequency band by referring to at least one of the measurement results of the second frequency band and the signal quality of the first frequency band where the problem occurred. Additionally, in operation 1230, the base station can perform configuration on the terminal based on the determination in operation 1225 to change the main frequency band to a second frequency band used as the new main frequency band.

[0257] Simultaneously, in operation 1240, the terminal can receive the configuration of a first frequency band as the main frequency band from the base station for the purpose of serving cell measurement. Additionally, in operation 1245, the terminal can receive UL resources from the base station for reporting problems with the main frequency band to the settings of a second frequency band not configured as the main frequency band. In operation 1250, the terminal can determine whether the validity conditions of the channel state based on the main frequency band (first frequency band) are met, and determine whether a main frequency band failure has occurred. Furthermore, if the channel of the main frequency band does not meet the validity conditions, the terminal can transmit a problem report about the main frequency band to the base station via the second frequency band in operation 1255. In operation 1260, based on the base station determination in operation 1225, the terminal can receive the configuration from the base station to change the main frequency band to a second frequency band used as a new main frequency band. The terminal changes the main frequency band according to the base station's configuration for the second frequency band used as the new main frequency band, and can apply the attributes and measurement operations applied to the previous main frequency band to the new main frequency band.

[0258] refer to Figure 13According to embodiments of this disclosure, a base station / terminal triggers a frequency band recovery process, and a flowchart illustrating the operation of a base station (first node) and a terminal (second node) according to the UL-based frequency band recovery process is shown. Both the base station and the terminal detect low signal quality; therefore, the base station can reconfigure the new frequency band to the P-band based on the base station's probe signal transmission and the terminal's response signal transmission before a certain timer expires.

[0259] In operation 1310, for the purpose of serving cell measurement, the base station can configure a first frequency band as the main frequency band to the terminal. Additionally, in operation 1315, the base station can allocate SRS resources to second and third frequency bands that are not configured as the main frequency band. Furthermore, the base station can allocate resources for transmitting probe signals from the base station in the main frequency band (first frequency band). At this time, considering the base station, the second frequency band can be one or more frequency bands, and the third frequency band can be at least one of multiple second frequency bands determined by the terminal. The terminal can determine whether the validity conditions of the channel state based on the main frequency band (first frequency band) are met, and whether a main frequency band failure has occurred. In operation 1320, the base station can determine whether the validity conditions of the channel state based on the first frequency band are met based on the terminal's SRS signal, and determine whether a main frequency band failure has occurred. Furthermore, if the channel of the main frequency band does not meet the validity conditions, then in operation 1325, the base station starts a first timer and can transmit probe signals to the terminal via the second frequency band until the first timer expires. When a probe signal is transmitted, the base station starts a second timer, and in operation 1330, the base station can wait to receive a response signal until the second timer expires. In operation 1335, the base station can determine, based on the terminal's response signal to the probe signal transmitted via the second frequency band, whether to change the main frequency band to a third frequency band as the new main frequency band. The response signal can be received via the third frequency band. Additionally, the base station can perform configuration on the terminal based on the determination in operation 1335 to change the main frequency band to a third frequency band as the new main frequency band.

[0260] Meanwhile, in operation 1340, for the purpose of serving cell measurement, the terminal can receive the configuration of the first frequency band as the main frequency band from the base station. Additionally, in operation 1345, the terminal can receive the settings for SRS resources for the terminal to the second and third frequency bands not configured as the main frequency band from the base station. Furthermore, the terminal can receive the settings for resources for transmitting probe signals from the base station for the main frequency band (first frequency band). In operation 1350, the terminal can determine whether the validity conditions based on the channel state of the main frequency band (first frequency band) are met, and determine whether a main frequency band failure has occurred. If a main frequency band failure occurs, the terminal can transmit an SRS signal to the base station. If the channel of the main frequency band does not meet the validity conditions, the terminal starts a third timer and can wait to receive probe signals from the base station via all configured second frequency bands until the third timer expires. The third timer can be the same as the first timer. When the terminal receives a probe signal in operation 1355, the terminal starts a fourth timer for it, and in operation 1360, the terminal can transmit a response signal to the base station via the third frequency band. The fourth timer can be the same as the second timer. In operation 1365, based on the determination of the base station in operation 1335, the terminal can receive configuration from the base station to change the main frequency band to a third frequency band used as the new main frequency band. The terminal changes the main frequency band to the third frequency band used as the new main frequency band according to the configuration of the base station, and can apply the attributes and measurement operations applied to the previous main frequency band to the new main frequency band.

[0261] refer to Figure 14 According to embodiments of this disclosure, a base station / terminal triggers a frequency band recovery process, and a flowchart illustrating the operation of a base station (first node) and a terminal (second node) according to a UL-based recovery method is shown. Both the base station and the terminal detect low signal quality; therefore, the base station can reconfigure the new frequency band to the P-band based on the terminal's measurement report before a certain timer expires.

[0262] In operation 1410, for the purpose of serving cell measurements, the base station can configure a first frequency band as the primary frequency band to the terminal. Additionally, in operation 1415, the base station can set its RS resources to a second and third frequency band that are not configured as the primary frequency band, and can set a timer-based measurement report for the set RS resources to the terminal. At this time, considering the base station, the second frequency band can be one or more frequency bands, and the third frequency band can be at least one of multiple second frequency bands determined by the terminal. The terminal can determine whether the validity conditions of the channel state based on the primary frequency band (first frequency band) are met, and whether a primary frequency band failure has occurred. Furthermore, in operation 1420, the base station can determine whether the validity conditions of the channel state based on the first frequency band are met based on the terminal's measurement report, and determine whether a primary frequency band failure has occurred. If the channel of the primary frequency band does not meet the validity conditions, then in operation 1425, the base station starts a first timer and a second timer, and can transmit a reference signal (RS) to the terminal via the second frequency band until the first timer expires. In operation 1430, the base station can wait to receive measurement reports until the second timer expires. Measurement reports can be received via the third frequency band. In operation 1435, the base station can determine whether to change the main frequency band to the third frequency band as the new main frequency band based on the measurement reports of the terminal for RS transmitted via the second frequency band. In addition, the base station can perform configuration on the terminal according to the determination in operation 1435 to change the main frequency band to the third frequency band as the new main frequency band.

[0263] Meanwhile, in operation 1440, for the purpose of serving cell measurement, the terminal can receive the configuration of the first frequency band as the main frequency band from the base station. Additionally, in operation 1445, the terminal can receive the base station's RS resources configured for the second and third frequency bands not configured as main frequency bands, and can receive timer-based measurement reports for the configured RS resources. In operation 1450, the terminal can determine whether the validity conditions of the channel state based on the main frequency band (first frequency band) are met, and determine whether a main frequency band failure has occurred. Furthermore, if the channel of the main frequency band does not meet the validity conditions, the terminal can start a third timer and a fourth timer. The third timer is the same as the first timer, and the fourth timer can be the same as the second timer. In operation 1455, the terminal can receive the base station's RS via all configured second frequency bands until the third timer expires. When receiving RS, the terminal can transmit a measurement report about the RS to the base station via the third frequency band in operation 1460 until the third timer expires. In operation 1465, based on the determination in operation 1435, the terminal can receive a configuration from the base station to change the main frequency band to a third frequency band used as the new main frequency band. The terminal changes the main frequency band according to the base station's configuration, and can apply the attributes and measurement operations applied to the previous main frequency band to the new main frequency band. Simultaneously, when determining the signal quality in a specific frequency band, the following four options can be considered.

[0264] Option 1: P-band

[0265] Option 2: P-band and common band for initial access

[0266] Option 3: P-band and (one or more) S-bands

[0267] Option 4: P-band, (one or more) S-bands, and common bands for initial access

[0268] Band recovery operation is essentially a process of measuring channel quality for multiple frequency bands and switching band P with other frequency bands based on the measurement results. In this process, the channel quality measurement operation for each frequency band can be separated from the band switching process, and the band switching process can be performed using one of the following methods.

[0269] a) The base station can configure multiple frequency bands and their indices to the terminal via RRC messages, and then indicate frequency band activation or deactivation via MAC CE or L1 signals including the frequency band index. The terminal can switch the frequency band indicated by the frequency band index to an active or deactivated state according to the frequency band activation or deactivation indication.

[0270] (b) The base station can configure multiple frequency bands and their indices to the terminal via RRC messages, and then indicate frequency band switching via a MAC CE or L1 signal including two frequency band indices for the current frequency band and the subject frequency band. The terminal can, based on the frequency band switching indication, switch the frequency band indicated by the current frequency band index to a deactivated state and switch the frequency band indicated by the subject frequency band index to a activated state.

[0271] c) The base station can configure two frequency bands and their indices to the terminal via RRC messages, including the index used for this configuration, and then indicate frequency band switching via MAC CE or L1 signals and the configured indexes. The terminal can, based on the frequency band switching indication, switch the currently active frequency band to a deactivated state and vice versa, within the two frequency bands specified in the configuration.

[0272] d) The base station can configure m frequency bands and their indices to the terminal via RRC messages, and then indicate frequency band switching via a MAC CE or L1 signal including the current frequency band index. The terminal can switch the frequency band indicated by the current frequency band index to the deactivated state according to the frequency band switching indication, and switch the frequency band indicated by the next frequency band index to the active state according to the index order.

[0273] e) The base station can configure m frequency bands and their indices to the terminal via RRC messages, including indices used for this configuration. It then indicates band switching via a MAC CE or L1 signal that includes the configuration index and the current frequency band index. The terminal can, based on the band switching indication, switch the frequency band indicated by the current frequency band index to a deactivated state and, according to the index order, switch the frequency band indicated by the next frequency band index to a activated state.

[0274] f) The base station can configure m frequency bands and their indices to the terminal via RRC messages, set the frequency band priorities, and indicate frequency band switching via a MAC CE or L1 signal including the current frequency band index. The terminal can, according to the frequency band switching indication, switch the frequency band indicated by the current frequency band index to a deactivated state and switch the frequency band indicated by the next frequency band index to an active state according to priority order.

[0275] (g) The base station can configure m frequency bands and their indices to the terminal via RRC messages, and set the frequency band priorities. The base station also includes indices used for this configuration. It then indicates frequency band switching via a MAC CE or L1 signal that includes the configuration index and the current frequency band index. The terminal can, based on the frequency band switching indication, switch the frequency band indicated by the current frequency band index to a deactivated state and switch the frequency band indicated by the next frequency band index to a activated state according to priority order.

[0276] In the frequency band handover process from a) to g), the hold-up time for the switched frequency band can be valid if one of the following conditions is met: 1) until the next handover instruction is issued; 2) after a predetermined time k (e.g., symbol, time slot, subframe, frame, etc.); and 3) after a predetermined time k (e.g., symbol, time slot, subframe, frame, etc.) set by the base station via an RRC message. If the hold-up time expires, the terminal can return to the frequency band state before the handover.

[0277] In the band switching processes a) through g), deactivation can be performed by a timer without separate instruction. For example, when a terminal monitors the downlink control channel of a specific band, if a signal from the base station is not received by the terminal via the band until a certain timer expires, the terminal can deactivate that band.

[0278] RRM measurement

[0279] Figure 15 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of this disclosure. Figure 16 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of this disclosure. Figure 17 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of the present disclosure. Figure 18 This is a diagram illustrating the monitoring bandwidth of a terminal for serving a base station and neighboring base stations according to an embodiment of the present disclosure.

[0280] Even when receiving small-capacity data services, the terminal needs to constantly monitor the DL control channel. Therefore, if the monitoring bandwidth is large, power consumption may be high even with small-capacity data services. To reduce power consumption, the terminal may receive a configuration with small-sized monitoring resources from the serving base station and receive the DL control channel through these resources. In embodiments of this disclosure, band scheduling methods for operations such as operation are described. However, even when the terminal performs an operation receiving data from the serving base station via a limited band (BW), in the case of a connected mode terminal, it may be necessary to monitor the entire band to perform neighboring cell radio resource management (RRM) measurement operations. Simultaneously, measurements of the serving base station can be performed using at least one of the following methods.

[0281] Option A (L1):

[0282] Option A-1: ​​Control the sub-band embedding RS position

[0283] Option A-2: Control subband indicates another control subband in the same or upcoming subframe.

[0284] Option A-3: Control sub-band indication of additional RS position in the same or upcoming subframe.

[0285] Option B (RRC):

[0286] Option B-1: Control sub-band and RS position are indicated separately in the RRC message.

[0287] Option B-2: Control sub-band and RS position are indicated together in the RRC message.

[0288] refer to Figure 15 Terminal 1510 can receive control channels from serving base station (gNB1) 1520 via a portion of the frequency band 1530. Additionally, terminal 1510 can be configured to monitor a wideband 1540 used for RRM measurements of neighboring base station (gNB2) 1525, i.e., to receive synchronization signals (PBCH) 1555 and reference signals (RS) 1550. This can result in high power consumption for terminal 1510.

[0289] refer to Figure 16 When the same frequency bands 1610 and 1620 are allocated to terminal 1510 for control channel monitoring from serving base station 1520 and RRM measurement 1630 from neighboring base station 1525, a handover delay of a few µs may occur. For this operation, serving base station 1520 can configure terminal 1510 with a dedicated RRM frequency band 1620 for RRM measurements performed by neighboring base station 1525. The active frequency band 1610 operating in serving base station 1520 may include the dedicated RRM frequency band 1620. Additionally, without changing the center frequency, terminal 1510 can perform RRM measurements without adhering to the measurement interval configuration.

[0290] refer to Figure 17 When the non-overlapping frequency bands 1710 and 1720 are allocated to terminal 1510 for control channel monitoring from serving base station 1520 and RRM measurement 1730 from neighboring base station 1525, a handover delay of several hundred µs may occur. This indicates that subframes operating in 1 ms increments in this process need to account for a 1 ms delay. For this operation, serving base station 1520 can configure a dedicated RRM frequency band 1720 for terminal 1510 to perform RRM measurements for neighboring base station 1525. If the active frequency band operating in serving base station 1520 may not include the dedicated RRM frequency band 1720, then the terminal can perform measurements according to the measurement interval configuration.

[0291] refer to Figure 18When partially overlapping frequency bands 1810 and 1820 are each allocated to terminal 1510 for control channel monitoring from serving base station 1520 and RRM measurements 1830 and 1835 from neighboring base station 1525, a handover delay of several to tens of microseconds may occur. For this operation, serving base station 1520 can configure terminal 1510 with a dedicated RRM frequency band for performing RRM measurements from neighboring base station 1525 and a reference frequency band 1820 for synchronization. Terminal 1510 may include the reference frequency band 1820 within the active frequency band 1810 operating in serving base station 1520; however, if a change in center frequency is required, synchronization can first be performed for neighboring base station 1525 according to the measurement gap configuration. Terminal 1510 may include the dedicated frequency band 1820 within the active frequency band 1810 operating in serving base station 1520; however, if the center frequency remains unchanged, the RS of neighboring base stations in the currently active frequency band can be measured, regardless of the measurement gap configuration.

[0292] According to embodiments of this disclosure, a base station can configure a separate frequency band for RRM measurements of neighboring base stations to a terminal. The terminal can receive the frequency band configuration for measurement from the serving base station or a neighboring base station according to at least one of the following methods.

[0293] Option A: The serving base station can configure the frequency band for measurement for terminals connected to it based on information received from neighboring base stations. The serving base station can notify the terminal of the measurement object's ID (e.g., cell ID, TRP (TxRxPoint) ID, etc.) and information about the location / size of the frequency band used for measurement. The sub-band and frequency band configuration of the serving base station can differ from that of neighboring base stations, but the serving base station can control the terminal to enter areas where it can receive signals from neighboring base stations as far as possible. Upon successful reception of the synchronization signal and PBCH from neighboring base stations, or the RRC message from the serving base station, the terminal obtains the digital information used by the neighboring base stations and recalculates the accurate RS position of the neighboring base stations based on the obtained digital information. The terminal can then perform measurements at the checked RS position.

[0294] Option B: The terminal successfully receives the synchronization signal and PBCH from the neighboring base station to determine the RS location based on the terminal's BW capability included in the SI, and performs measurements at the corresponding RS location.

[0295] Option C: The terminal performs initial access processing to the neighboring base station, reports the terminal's capability information to the neighboring base station, and receives a response message from the neighboring base station to perform a measurement at the RS location included in the message.

[0296] According to embodiments of this disclosure, a base station can configure a frequency band for a terminal by communicating with the frequency band used for RRM measurements of neighboring base stations. The base station can notify the terminal of a frequency band index and resource settings for one or more CSI-RS in the RRM measurement configuration. 1) The frequency band index also has digital information, therefore the digital information used for CSI-RS resources can also follow the digital information communicated with the indicated frequency band. Alternatively, 2) when digital information is included in the CSI-RS resource settings, and the digital information included in the CSI-RS resource settings conflicts with the digital information of the frequency band index, the terminal can follow the digital information included in the CSI-RS resource settings used for RRM measurements.

[0297] Simultaneously, the serving base station can individually or collectively allocate resource areas to the terminal for receiving the control channel of the serving base station and the RS of neighboring base stations. When resource areas are consolidated and set as a single resource area, the terminal can independently perform control channel reception operations and neighboring base station measurement operations using either a Time Division Multiplexing (TDM) or Frequency Division Multiplexing (FDM) scheme. In the TDM case, the serving base station can allocate measurement gaps to the terminal. The base station can be operated according to at least one of the following: a) performing a configuration such that the terminal is guaranteed to receive signals from neighboring base stations at a specific time; b) performing a configuration such that the terminal only has the opportunity to receive signals from neighboring base stations at a specific time, and determines whether to receive signals from neighboring base stations based on the operating conditions of the serving base station for the terminal; and c) performing a configuration such that the terminal only has the opportunity to receive signals from neighboring base stations at a specific time, and only receives signals from neighboring base stations when no operation is indicated for the serving base station.

[0298] When performing L3 filtering, the terminal can reflect only the measurement results in the RRM BW as the input values ​​for the L3 filter. Alternatively, when measurements are performed in both the RRM BW and the active band BW, the terminal can separate each measurement result for each BW. Furthermore, if the RRM BW is reset, or if the average value of the RRM BW is not received from L1 within a predetermined time, the terminal can abandon the existing L3 filtering and begin a new one.

[0299] As an RRM BW, one or more BWs can be configured to the terminal based on the base station's determination. If multiple RRM BWs are configured, the terminal can be operated by selecting the RRM BW with the shortest readjustment time based on its relationship to the currently operating frequency band. Alternatively, the terminal can be operated by prioritizing the RRM BW that includes the SS among multiple RRM BWs. Alternatively, the terminal can be operated by selecting an RRM BW based on the priority and readjustment time constraints set by the base station for multiple RRM BWs. For example, the terminal can select the RRM BW with the highest priority among the RRM BWs, where the readjustment time is shorter than the time k (e.g., symbol, time slot, subframe, frame, etc.) used to switch to the RRM BW in the active or primary frequency band.

[0300] The measurement gap configuration and measurement operation during RRM BW setup, as well as the portion of the BW used for connection mode, are the same. Operation at time

[0301] The base station can allocate frequency resources to the terminal for performing RRM measurements, and this will be referred to as RRMBW below. Additionally, the base station can configure one or more frequency bands to the terminal for scheduling, etc. If the RRM BW and BW allocated to a frequency band can switch between each other without RF retuning, then the terminal can perform RRM measurements during signal transmission and reception with the base station. However, if the terminal can switch the RRM BW and BW of the frequency band only during RF retuning, then RRM measurements can be performed according to the base station's measurement interval configuration. The latency caused by retuning can be determined by various factors, such as whether the center frequency of the operating RF band changes, whether the digits need to be changed for measurement, etc.

[0302] Simultaneously, since the terminal can receive configurations for one or more frequency bands, the application of a measurement gap can be optionally determined based on the relationship between the RRM BW used for the current P-band, the active frequency band, or the frequency band being used for data transmission and reception. For example, if RF retuning for switching to the RRM BW is performed for one or more frequency bands currently operated by the terminal among multiple frequency bands, or if the RF retuning wait time is longer than a predetermined wait time, the configured measurement gap can be activated. For example, if RF retuning for switching to the RRM BW is performed for one or more frequency bands that are active or in use before time k (e.g., time slot, symbol, subframe, etc.) at the gap start point, according to the measurement gap configuration, the terminal can prepare for RRM measurements during the measurement gap. During the measurement gap, the terminal can pre-complete RF retuning to perform measurements against the measurement resources set in the RRM BW. For example, if an RF retuning for switching to the RRM BW is performed according to the measurement gap configuration for one or more frequency bands that are activated or in use at the gap start point, and it is determined that the measurement gap does not reach its end time within the timeframe that is the combination of the RF retuning wait time and the minimum measurement time, then the terminal can perform RRM measurements within the measurement gap. During the measurement gap, the terminal can pre-complete the RF retuning to perform measurements for the measurement resources set in the RRM BW. If RF retuning is performed and it is determined that the measurement gap reaches its end time within the timeframe that is the combination of the RF wait time and the minimum measurement time, then the terminal does not perform RRM measurements during the measurement gap.

[0303] If a measurement report is not executed within the set time period, the base station can inquire about the reason, and the terminal can respond to the base station's request by reporting an index value including information about the reason. Alternatively, the terminal can transmit a measurement gap reconfiguration request to the base station, and the base station can determine, based on the reason for the measurement gap reconfiguration request transmitted from the terminal and the terminal's capability information, how to reconfigure the measurement gap.

[0304] Additionally, depending on the relationship between the monitoring bandwidth s and the serving base station and neighboring base stations, the following can also be considered.

[0305] Scenario A: Cross-cell targeting

[0306] No measurement gap configured within the carrier.

[0307] Includes the minimum BW for synchronization / PBCH / (paging).

[0308] Scenario B: No cross-cell alignment (configured for in-carrier measurement gaps)

[0309] Option 1: Maintain a portion of the public BW across cells

[0310] Option 2: Flexible configuration for some BW (Browser Warp) configurations

[0311] Case C: Partial overlap across cells

[0312] Configure measurement gaps for specific targets

[0313] Figure 19 This is a diagram illustrating a desired flexible BW system in a 5G communication system according to an embodiment of the present disclosure.

[0314] refer to Figure 19 The flexible BW system consists of three BWs (including an access BW, an idle mode BW, and a connected mode BW) and the switching configuration between them.

[0315] Access BW refers to the minimum BW used by the terminal to perform initial access processing (such as cell selection, SI acquisition, random access, etc.). Essentially, the access BW can be predetermined based on the carrier frequency. However, in scenarios where access is achieved through a different Radio Access Technology (RAT) controlled by an anchor base station or another base station within the same RAT, the terminal can receive access BW information or information for acquiring the access BW through the anchor base station. The access BW is configured by the sub-bands and frequency bands exemplified in the embodiments of this disclosure, and the base station can configure the access BW to the terminal via SI or RRC messages. The position of the basic downlink control channel can be set by controlling the number of sub-bands and symbols. Additionally, the position of the basic downlink data channel can be set by the frequency band corresponding to the control sub-band. As the basic downlink data channel, the basic DL-SCH (Downlink Shared Channel) of Layer 2 can be set. Furthermore, the base station can jointly set the reference frequency position (e.g., carrier center frequency, etc.) for calculating BW information to the terminal.

[0316] Idle mode BW refers to a BW configured for use by the terminal to perform processes such as additional SI acquisition, paging, and random access. As suggested in embodiments of this disclosure, the idle mode BW can be the same as the access BW, but a BW different from the access BE can be configured as the idle mode BW to maximize bandwidth utilization. As a configuration method, SI is generally used, but in some cases, RRC messages can be used for configuration. For example, the terminal can receive the idle mode BW configuration in advance from the base station while connected, or it can obtain information for determining the idle mode BW (e.g., the number of base station frequency bands, frequency band / subband configuration, amount of common signaling resources, etc.).

[0317] Connected mode BW refers to the BW configured for control / data channels set for the terminal. Control subband and frequency band information can be set via RRC messages. In addition to the basic downlink control / data channels and basic DL-SCH determined by the access BW, additional downlink control / data channels and DL-SCH can be set. When receiving a paging indication or generating UL data, the terminal can receive the settings for connected mode BW through random access processing. The terminal can be operated according to the control / data channels set in the connected mode BW by switching to connected mode.

[0318] Simultaneously, synchronization signals (SS) and CSI-RS can be considered for RRM measurements. Synchronization signals are transmitted and received in the access BW, and if cell-specific, CSI-RS can be transmitted and received in either idle mode or connected mode BW; if UE-specific, CSI-RS can be transmitted in connected mode BW. The base station can operate the BW according to various scenarios for each terminal.

[0319] For example, according to scenario 1, the terminal can perform measurements by setting the synchronization signal in the access BW as a reference signal for RRM measurements. Alternatively, if there is no separate setting for the idle mode BW, the terminal can be operated by assuming the idle mode BW is the same as the access BW. For example, idle mode operations such as cell (re)selection can be performed based on the results of measurements for the SS.

[0320] According to scenario 2, the terminal can receive settings from the base station via SI, including the access BW and an idle mode BW greater than the access BW. Additionally, the terminal can receive cell-specific CSI-RS settings for the idle mode BW. The terminal can perform measurements on the cell-specific CSI-RS according to the measurement configuration and perform idle mode operations such as cell (re)selection based on the results. The terminal measures the SS for base stations that do not use cell-specific CSI-RS, and therefore can operate by reflecting offset values ​​used to correct errors between performance metrics. Depending on some measurement configurations, the terminal can operate based on representative values ​​of the SS and cell-specific CSI-RS measurement results.

[0321] According to scenario 3, the terminal can receive settings for the idle mode BW (excluding the access BW) from the base station via SI. Additionally, the terminal can receive settings for cell-specific CSI-RS for the idle mode BW. The terminal can perform measurements for the cell-specific CSI-RS according to the measurement configuration and perform idle mode operations such as cell (re)selection based on the results. When the terminal measures SS for base stations that do not use cell-specific CSI-RS, it can operate by reflecting offset values ​​used to correct errors between performance metrics. In this case, neighboring base stations transmit SS in the access BW, and the terminal monitors an idle mode BW different from the access BW set by the serving base station. Therefore, the serving base station can configure measurement gaps or set measurement resources to monitor the access BW of neighboring base stations by RF retuning to the terminal. The terminal can measure the SS of neighboring base stations in the configured measurement gaps or set measurement resources and reflect offset values ​​used for error correction, thereby performing idle mode operations such as cell (re)selection.

[0322] According to scenario 4, the terminal can receive settings from the base station via RRC messages, including the access BW or idle mode BW, and the connection mode BW being the same as or larger than the access BW or idle mode BW. Additionally, the terminal can receive cell / UE-specific CSI-RS settings for the connection mode BW. The terminal can perform measurements for the cell / UE-specific CSI-RS according to the measurement configuration, and perform connection mode operations such as RRM measurements and reporting based on the results. The terminal can perform measurements in priority order (i.e., in the order of UE-specific CSI-RS, cell-specific CSI-RS, and SS). The terminal can report the measurement results of the RS for each measurement to the base station.

[0323] According to scenario 5, the terminal can receive settings for a connection mode BW that does not include the access BW or idle mode BW, or partially overlaps with the access BW or idle mode BW, from the base station via RRC messages. Additionally, the terminal can receive cell / UE-specific CSI-RS settings for the connection mode BW. The terminal can perform measurements for the cell / UE-specific CSI-RS according to the measurement configuration and perform connection mode operations such as RRM measurement and reporting based on the results. The terminal can report the measurement results of the RS for each measurement to the base station. For base stations that do not use cell / UE-specific CSI-RS, the terminal measures SS, and therefore can operate by reflecting offset values ​​used to correct errors between performance metrics. In this case, neighboring base stations transmit SS in the access BW, and the terminal monitors a connection mode BW different from the access / idle BW set by the serving base station. Therefore, the serving base station can configure measurement gaps or set measurement resources to monitor the access / idle BW of neighboring base stations by RF retuning to the terminal. The terminal can measure the SS of adjacent base stations in the configured measurement gap or the set measurement resources, and reflect the offset value for error correction, thereby performing connection mode operations such as RRM measurement and reporting.

[0324] Figure 20 This is a diagram illustrating the configuration of a terminal according to an embodiment of the present disclosure.

[0325] refer to Figure 20 The terminal may include: a transceiver 2010, which performs signal transmission and reception with network entities such as other terminals and base stations; and a controller 2020, which controls all operations of the terminal. In embodiments of this disclosure, all operations supporting the above synchronization can be understood as being performed by the controller 2020. However, the controller 2020 and the transceiver 2010 need not be implemented as separate devices, but can be implemented as a single component, such as a single chip. Furthermore, the controller 2020 and the transceiver 2010 can be electrically connected to each other. The transceiver 2010 may include a transmitter 2013 and a receiver 2015. Additionally, the terminal may also include a memory 2030.

[0326] The terminal's controller 2020 controls the terminal to perform any of the operations described in the above embodiments. For example, the terminal's controller 2020 may receive a first message from the base station that includes configuration information of at least one frequency band, receive a second message from the base station for activating a frequency band in the at least one frequency band, and activate the frequency band according to the second message.

[0327] The controller 2020 may include a system decision unit 2023, a bandwidth controller 2025, and a measurement unit 2027. The system decision unit 2023 can control the operation of the terminal according to the configuration of the base station, and the bandwidth controller 2025 can determine and control the operating bandwidth of the terminal. The measurement unit 2027 can measure the reference signal from the base station and store the measurement results in the memory 2030. Furthermore, the system decision unit 2023, the bandwidth controller 2025, and the measurement unit 2027 do not necessarily need to be implemented as separate modules, but can be implemented as a single component, such as a single chip.

[0328] In addition, the terminal transceiver 2010 can transmit and receive signals according to any of the operations described in the above embodiments.

[0329] Additionally, the controller 2020 can be, for example, a circuit, a dedicated circuit, or at least one processor. Furthermore, terminal operation can be implemented by providing a memory device (memory 2030) storing the corresponding program code in any component of the base station. For example, the controller 2020 can perform the above operations by having a processor, central processing unit (CPU), or the like read and execute the program code stored in the memory device.

[0330] It should be noted that, Figure 20 The terminal configuration diagrams, illustrated control / data signal transmission method diagrams, illustrated terminal operation processing diagrams, and terminal device configuration diagrams shown are not intended to limit the scope of this disclosure. For example, Figure 20 All components, entities, or operations shown in this disclosure should not be interpreted as fundamental elements for implementing this disclosure, and may be implemented without departing from the spirit of this disclosure.

[0331] Figure 21 This is a diagram illustrating the configuration of a base station according to an embodiment of the present disclosure.

[0332] refer to Figure 21 The base station may include: a transceiver 2110, which performs signal transmission and reception with other network entities such as terminals and MMEs; and a controller 2120, which controls all operations of the base station. In embodiments of this disclosure, all operations supporting the above synchronization can be understood as being performed by the controller 2120. However, the controller 2120 and the transceiver 2110 are not necessarily implemented as separate devices, but can be implemented as a single component, such as a single chip. Furthermore, the controller 2120 and the transceiver 2110 can be electrically connected to each other. The transceiver 2110 may include a transmitter 2113 and a receiver 2115. Additionally, the base station may also include a memory 2130.

[0333] The base station controller 2120 controls the base station to perform any of the operations described in the above embodiments. For example, the base station controller 2120 may transmit a first message to the terminal including configuration information of at least one frequency band, and a second message to the terminal for activating a frequency band in the at least one frequency band.

[0334] In addition, the base station transceiver 2110 can transmit and receive signals according to any of the operations described in the above embodiments.

[0335] Additionally, the controller 2110 can be, for example, a circuit, a dedicated circuit, or at least one processor. Furthermore, the operation of the base station can be implemented by providing a memory device (memory 2130) storing the corresponding program code in any component of the base station. For example, the controller 2110 can perform the above operations by having a processor, CPU, or the like read and execute the program code stored in the memory device.

[0336] Alternatively, the operation of the base station or terminal can be implemented by providing a memory device (memory 2130) that stores the corresponding program code in any component of the base station or terminal equipment. For example, the controller 2020 or 2120 of the base station or terminal can perform the above operations by having a processor or CPU read and execute the program code stored in the memory device 2030 or 2130.

[0337] The various components, modules, etc., of the entities, base stations, or terminal devices described in this specification can be operated using hardware circuitry (e.g., logic circuitry based on complementary metal-oxide-semiconductor), firmware, software, and / or hardware, or a combination of firmware and / or software inserted into a machine-readable medium. As an example, various electrical structures and methods can be implemented using transistors, logic gates, and circuits (such as application-specific integrated circuits (ASICs)).

[0338] Although this disclosure has been described in conjunction with detailed embodiments, various modifications can be made without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be construed as limited to the described embodiments, but rather as defined by the appended claims and their equivalents.

[0339] The embodiments of this disclosure disclosed in this specification and accompanying drawings are provided by way of specific examples only to aid in understanding the description and not to limit the scope of this disclosure. It will be apparent to those skilled in the art to which this disclosure pertains that various modifications may be made in addition to the embodiments disclosed herein without departing from the scope of this disclosure.

[0340] Embodiments have been described in detail and with accompanying drawings. While specific terminology has been used herein, it is for the purpose of readily describing this disclosure and is not intended to limit its scope. It will be apparent to those skilled in the art to which this disclosure pertains that various modifications may be made in addition to the embodiments disclosed herein without departing from the scope of this disclosure.

[0341] While this disclosure has been shown and described with reference to various embodiments thereof, those skilled in the art will understand that various changes in form and detail may be made therein without departing from the spirit and scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. A method performed by a terminal in a wireless communication system, the method comprising: The terminal receives a Radio Resource Control (RRC) message from a base station. The RRC message includes a configuration of at least one frequency band and a configuration of a main frequency band for the terminal. The configuration of the at least one frequency band includes at least one of subcarrier spacing, cyclic prefix, and information about the frequency domain location and bandwidth of the at least one frequency band. Monitor the control channel on the main frequency band from the base station; as well as Based on the control channel, downlink control information indicating the active frequency band in at least one frequency band is received from the base station.

2. The method according to claim 1, wherein, Receiving downlink control information includes: Identify the main frequency band based on the configuration of the main frequency band; Receive downlink control information from the base station indicating the active frequency band in at least one frequency band; and Switching from the primary frequency band to the active frequency band based on downlink control information.

3. The method according to claim 1, further comprising: If the scheduled timer expires, switch from the active frequency band to the recovery frequency band.

4. The method according to claim 1, further comprising: Communication is performed with the base station based on the active frequency band, and The configuration of the at least one frequency band further includes at least one frequency band identifier corresponding to the at least one frequency band, and The at least one frequency band includes at least one downlink frequency band or at least one uplink frequency band.

5. A method performed by a base station in a wireless communication system, the method comprising: Send a Radio Resource Control (RRC) message to the terminal. The RRC message includes the configuration of at least one frequency band and the configuration of the main frequency band for the terminal. The configuration of the at least one frequency band includes at least one of subcarrier spacing, cyclic prefix, and information about the frequency domain location and bandwidth of the at least one frequency band. as well as Based on the control channel on the main frequency band, downlink control information indicating the active frequency band in at least one frequency band is sent to the terminal.

6. The method according to claim 5, wherein, When the scheduled timer expires, the active frequency band is switched to the recovery frequency band.

7. The method according to claim 5, wherein, The main frequency band is identified based on the main frequency band configuration; and Based on downlink control information, the primary frequency band is switched to the active frequency band.

8. The method according to claim 5, further comprising: Communication is performed between the active frequency band and the terminal, and The configuration of the at least one frequency band further includes at least one frequency band identifier corresponding to the at least one frequency band, and The at least one frequency band includes at least one downlink frequency band or at least one uplink frequency band.

9. A terminal in a wireless communication system, the terminal comprising: transceiver; as well as The controller, coupled to the transceiver, is configured as follows: The terminal receives a Radio Resource Control (RRC) message from a base station. The RRC message includes a configuration of at least one frequency band and a configuration of a main frequency band for the terminal. The configuration of the at least one frequency band includes at least one of subcarrier spacing, cyclic prefix, and information about the frequency domain location and bandwidth of the at least one frequency band. Monitor the control channel on the main frequency band from the base station; as well as Based on the control channel, downlink control information indicating the active frequency band in at least one frequency band is received from the base station.

10. The terminal according to claim 9, wherein, The controller is also configured to: Identify the main frequency band based on the configuration of the main frequency band; Receive downlink control information from the base station indicating the active frequency band in at least one frequency band; as well as Switching from the primary frequency band to the active frequency band based on downlink control information.

11. The terminal according to claim 9, wherein, The controller is also configured to: If the scheduled timer expires, switch from the active frequency band to the recovery frequency band.

12. The terminal according to claim 9, wherein, The controller is also configured to: Communication is performed with the base station based on the active frequency band, and The configuration of the at least one frequency band further includes at least one frequency band identifier corresponding to the at least one frequency band, and The at least one frequency band includes at least one downlink frequency band or at least one uplink frequency band.

13. A base station in a wireless communication system, the base station comprising: transceiver; as well as The controller, coupled to the transceiver, is configured as follows: Send a Radio Resource Control (RRC) message to the terminal. The RRC message includes the configuration of at least one frequency band and the configuration of the main frequency band for the terminal. The configuration of the at least one frequency band includes at least one of subcarrier spacing, cyclic prefix, and information about the frequency domain location and bandwidth of the at least one frequency band. as well as Based on the control channel on the main frequency band, downlink control information indicating the active frequency band in at least one frequency band is sent to the terminal.

14. The base station according to claim 13, wherein, If the scheduled timer expires, the active frequency band is switched to the recovery frequency band; as well as Among them, the main frequency band is identified based on the configuration of the main frequency band; And based on downlink control information, the primary frequency band is switched to the active frequency band.

15. The base station according to claim 13, wherein, The controller is also configured to: Communication is performed between the active frequency band and the terminal, and The configuration of the at least one frequency band further includes at least one frequency band identifier corresponding to the at least one frequency band, and The at least one frequency band includes at least one downlink frequency band or at least one uplink frequency band.

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