Method and apparatus for driving a timer according to a BWP type in a wireless communication system

Abstract

The present disclosure provides a method for controlling activation of a secondary cell (Scell) performed by a terminal, the method including: receiving a radio resource control (RRC) message including information about a first timer for deactivation of the Scell ​​and information about a second timer for deactivation of a bandwidth part (BWP) of the Scell; receiving a medium access control (MAC) control element (CE) for changing a state of the SCell; and controlling the first timer or the second timer based on the MAC CE and the RRC message.

Description

Technical Field

[0001] The present disclosure relates to a method for performing operations differently according to the type of bandwidth part (BWP) when using carrier aggregation (CA) technology in a wireless communication system, more specifically in the 3rd Generation Partnership Project (3GPP) 5th Generation New Radio (5G NR) technology. Background Art

[0002] After the commercialization of the 4th generation (4G) communication system, efforts have been made to develop an improved 5th generation (5G) communication system or a quasi-5G communication system to adapt to the growing demand for wireless data services. For this reason, 5G or quasi-5G communication systems are referred to as super-4G network communication systems or post-long term evolution (LTE) systems. In order to obtain high data transfer rates, it is being considered to implement 5G communication systems in ultra-high frequency (millimeter wave (mmWave)) bands (such as the 60GHz band). In order to reduce the path loss of radio waves and increase the transmission distance of radio waves in the ultra-high frequency bands for 5G communication systems, various technologies are being studied and applied to NR systems, such as beamforming, large-capacity multiple input and multiple output (large-capacity MIMO), full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and large-scale antennas. In addition, in order to improve the system network for 5G communication systems, various technologies including evolved small cells, advanced small cells, cloud radio access networks (cloud RAN), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, mobile networks, cooperative communication, coordinated multi-point (CoMP), and reception interference cancellation have been developed. In addition, for 5G systems, advanced coding and modulation (ACM) schemes (such as hybrid FSK and QAM modulation (FQAM) and sliding window superposition coding (SWSC)) and advanced access technologies (such as filter bank multi-carrier (FBMC), non-orthogonal multiple access (NOMA), sparse code multiple access (SCMA)) are being developed.

[0003] Furthermore, the Internet has evolved from a human-centric connected network where humans create and consume information to the Internet of Things (IoT), in which decentralized components such as objects exchange information with each other to process it. The Internet of Everything (IoE) has emerged, combining IoT technology with technologies for processing big data, such as through connections to cloud servers. To realize the IoT, technologies such as sensing, wired / wireless communications and network infrastructure, service interface technology, and security are required. Consequently, recent research has focused on technologies such as sensor networks for interconnecting objects, machine-to-machine (M2M) communication, and machine-type communication (MTC). Within the IoT environment, intelligent internet technology services can be provided to create new value for human life by collecting and analyzing data obtained from interconnected objects. Through the convergence and integration of existing information technology (IT) with various industries, the IoT can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars or connected vehicles, smart grids, healthcare, smart appliances, and advanced medical services.

[0004] Therefore, various attempts are underway to apply 5G communication systems to IoT networks. For example, technologies such as sensor networks, machine-to-machine communication, and machine-to-communication (MTC) are implemented using 5G communication technologies such as beamforming, multiple-input multiple-output (MIMO), and array antennas. The application of cloud RAN as a big data processing technology is an example of the convergence of 5G and IoT technologies.

[0005] Specifically, with the development of wireless communication systems, a method for efficiently using a secondary cell (SCell) is needed. Summary of the Invention

[0006] Technical issues

[0007] The present disclosure relates to a method for preventing unnecessary cell state transitions in a wireless communication system, more particularly in 3rd Generation Partnership Project (3GPP) 5th Generation New Radio (5G NR) technology.

[0008] Solution to the problem

[0009] The present disclosure provides a method for efficiently using a secondary cell (SCell) as a wireless communication system develops.

[0010] Advantageous Effects of the Present Disclosure

[0011] The present disclosure provides an apparatus and method for efficiently providing a service in a wireless communication system.

[0012] According to an embodiment of the present disclosure, a method for controlling activation of a secondary cell (SCell) performed by a terminal includes: receiving a radio resource control (RRC) message, the RRC message including information related to a first timer for deactivation of the SCell and information related to a second timer for deactivation of a bandwidth part (BWP) of the SCell; receiving a media access control (MAC) control element (CE) for changing the state of the SCell; and controlling the first timer and the second timer based on the MAC CE and the RRC message.

[0013] The RRC message may include at least one of the state information of the SCell and the configuration information of the BWP of the SCell.

[0014] The RRC message may include information indicating a default BWP or an initial BWP of the SCell and information indicating a first active BWP that is activated for the first time.

[0015] One of the BWPs of the Scell ​​may include a dormant BWP.

[0016] The first timer may be an sCellDeactivationTimer, and the second timer may be a bwp-InactivityTimer, and the method may include performing an operation of transitioning the SCell to a deactivated state due to expiration of the first timer, and performing an operation of switching the active BWP of the SCell to a default BWP or an initial BWP due to expiration of the second timer.

[0017] The first timer may expire when data transmission and reception are not performed via the activated SCell within a specific time period, and the second timer may expire when data transmission and reception are not performed on the active BWP if the active BWP is not the default BWP.

[0018] Controlling the first timer and the second timer based on the MAC CE and the RRC message may include starting the first timer when the SCell is activated and the first active BWP is not a dormant BWP, and causing the second timer to not run when the first active BWP is a dormant BWP.

[0019] According to another embodiment of the present disclosure, a method for controlling the activation of an SCell performed by a base station includes: transmitting an RRC message including information related to a first timer for deactivation of the SCell and information related to a second timer for deactivation of the BWP of the SCell; transmitting a MAC CE for changing the state of the SCell; and transitioning the SCell to a deactivated state due to expiration of the first timer, and switching the active BWP of the SCell to a default BWP or an initial BWP due to expiration of the second timer.

[0020] The RRC message may include status information of the SCell, configuration information of the BWP of the SCell, information indicating a default BWP or an initial BWP of the SCell, and information indicating a first active BWP that is activated for the first time.

[0021] A BWP of an SCell may include a dormant BWP.

[0022] When the first active BWP of the SCell is not the dormant BWP, the first timer may be started, and when the first active BWP of the SCell is the dormant BWP, the second timer may not be started.

[0023] According to another embodiment of the present disclosure, a terminal for controlling the activation of an SCell includes: a transceiver; and a processor, which is combined with the transceiver and configured to: receive an RRC message, the RRC message including information related to a first timer for deactivation of the SCell and information related to a second timer for deactivation of the BWP of the SCell; receive a MAC CE for changing the state of the SCell; and control the first timer and the second timer based on the MAC CE and the RRC message.

[0024] The RRC message may include status information of the SCell, configuration information of the BWP of the SCell, information indicating a default BWP or an initial BWP of the SCell, and information indicating a first active BWP activated for the first time, and one BWP of the SCell may include a dormant BWP.

[0025] The first timer may be sCellDeactivationTimer, and the second timer may be bwp-InactivityTimer, and the processor may further be configured to perform an operation of transitioning the SCell to a deactivated state due to expiration of the first timer, and to perform an operation of switching the active BWP of the SCell to a default BWP or an initial BWP due to expiration of the second timer.

[0026] The processor may be further configured to start a first timer when the SCell is activated and the first active BWP is not a dormant BWP, and not start a second timer when the first active BWP is a dormant BWP.

[0027] According to another embodiment of the present disclosure, a base station for controlling the activation of an SCell includes: a transceiver; and a processor, which is combined with the transceiver and configured to: transmit an RRC message, the RRC message including information related to a first timer for deactivation of the SCell and information related to a second timer for deactivation of the BWP of the SCell; and transmit a MAC CE for changing the state of the SCell, wherein the SCell transitions to a deactivated state due to expiration of the first timer, and the active BWP of the SCell switches to a default BWP or an initial BWP due to expiration of the second timer. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1A is a diagram illustrating a structure of a New Radio (NR) system according to an embodiment of the present disclosure.

[0029] Figure 1B is a diagram illustrating a radio protocol architecture of Long Term Evolution (LTE) and NR systems according to an embodiment of the present disclosure.

[0030] Figure 1C is a diagram showing the structure of downlink and uplink channel frame structures when beam-based communication is performed on an NR system according to an embodiment of the present disclosure.

[0031] Figure 1D is a diagram for explaining a carrier aggregation (CA) technology according to an embodiment of the present disclosure.

[0032] Figure 1E is a diagram illustrating the concept of uplink residual power according to an embodiment of the present disclosure.

[0033] Figure 1F is a flowchart illustrating an operation sequence of a terminal when the terminal is configured with a secondary cell (SCell) and the SCell is activated according to an embodiment of the present disclosure.

[0034] Figure 1G is a block diagram of a configuration of a terminal in a wireless communication system according to an embodiment of the present disclosure.

[0035] Figure 1H is a block diagram of a configuration of a base station in a wireless communication system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0036] Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, when it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present disclosure, its description will be omitted. In addition, the terms to be described later are defined by considering the functions described in the present disclosure and may change according to the intention or habits of the user or operator. Therefore, the terms should be defined based on the overall description in this specification.

[0037] As used in the following description, for the convenience of description, terms identifying access nodes, terms indicating network entities, terms indicating messages, terms indicating interfaces between network entities, terms indicating various types of identification information, etc. are exemplified. Therefore, the present disclosure is not limited to the terms described below, and other terms representing objects having equivalent technical meanings may be used.

[0038] The advantages and features of the present disclosure and the methods for achieving these advantages and features will be more readily understood by reference to the following description of the embodiments and accompanying drawings. However, the present disclosure may be implemented in many different forms and should not be construed as limited to the disclosed embodiments set forth herein; rather, the embodiments are provided to make the present disclosure thorough and complete and to fully convey the concepts of the present disclosure to those skilled in the art, and the present disclosure is defined solely by the appended claims. Throughout this specification, like reference numerals refer to like elements.

[0039] It should be understood that each block of the flowchart in the figure and the combination of blocks of the flowchart can be executed by computer program instructions. These computer program instructions can be loaded into a processor of a general-purpose computer, a special-purpose computer, or another programmable data processing device, and thus the instructions executed by the processor of the computer or another programmable data processing device produce means for performing the functions detailed in one or more flowchart blocks. The computer program instructions can also be stored in a computer-executable or computer-readable memory that can instruct the computer or another programmable data processing device to implement functions in a specific manner, and thus the instructions stored in the computer-executable or computer-readable memory can produce an article of manufacture that includes instruction means for performing the functions described in the flowchart blocks. The computer program instructions can also be loaded into a computer or another programmable data processing device, and thus the instructions for operating the computer or another programmable data processing device by generating a computer-implemented process when a series of operations are performed in the computer or another programmable data processing device can provide operations for performing the functions described in the flowchart blocks.

[0040] In addition, each block may represent a module, segment, or portion of code that includes one or more executable instructions for performing a specified logical function. It should also be noted that in some alternative implementations, the functions mentioned in the blocks may occur out of order. For example, two consecutive blocks may also be executed simultaneously or in reverse order, depending on the functions they correspond to.

[0041] As used herein, the term "unit" refers to a software element or a hardware element, such as a field programmable gate array (FPGA) or an application specific integrated circuit (ASIC), and performs a certain function. However, the term "unit" is not limited to software or hardware. A "unit" can be configured as in an addressable storage medium or can be configured to operate one or more processors. Therefore, according to an embodiment, the term "unit" can include an element (for example, a software element, an object-oriented software element, a class element, and a task element), a process, a function, an attribute, a procedure, a subroutine, a program code segment, a driver, firmware, microcode, a circuit, data, a database, a data structure, a table, an array, or a variable. The function provided by an element and a "unit" can be combined with a smaller number of elements and "units", or can be divided into other elements and "units". In addition, an element and a "unit" can be implemented to reproduce one or more central processing units (CPUs) in a device or a secure multimedia card. In addition, according to some embodiments, a "unit" can include one or more processors.

[0042] In the following description of the present disclosure, when it is considered that related known functions or configurations will unnecessarily obscure the essence of the present disclosure, they are not described in detail. Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0043] As used in the following description, for the convenience of description, terms that identify access nodes, terms that indicate network entities, terms that indicate messages, terms that indicate interfaces between network entities, terms that indicate various types of identification information, etc. are exemplified. Therefore, the present disclosure is not limited to the terms described below, and other terms that represent objects with equivalent technical meanings may be used. For example, in the following description, a terminal may refer to a media access control (MAC) entity that exists in the terminal for a primary cell group (MCG) and a secondary cell group (SCG) as described below.

[0044] Hereinafter, for ease of description, the present disclosure uses terms and names defined in the 3rd Generation Partnership Project Long Term Evolution (3GPP LTE) standard. However, the present disclosure is not limited to the terms and names, but may also be applied to systems conforming to other standards.

[0045] Hereinafter, a base station (BS) is an entity that allocates resources to a terminal and may be at least one of a next-generation Node B (gNode B), an evolved Node B (eNB), a Node B, a BS, a radio access unit, a BS controller, or a network node. A terminal may include a user equipment (UE), a mobile station (MS), a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. However, the terminal is not limited to the above examples.

[0046] In particular, the present disclosure can be applied to the 3GPP New Radio (NR) standard (the fifth generation (5G) mobile communication standard). Furthermore, based on 5G communication technology and Internet of Things (IoT)-related technologies, the present disclosure can be applied to smart services (e.g., smart homes, smart buildings, smart cities, smart cars or connected vehicles, healthcare, digital education, retail services, security and safety-related services, etc.). In this disclosure, for ease of description, eNB and gNB are used interchangeably. In other words, a base station described as an eNB can represent a gNB. Furthermore, the term "terminal" can refer to mobile phones, narrowband IoT (NB-IoT) devices, sensors, and other wireless communication devices.

[0047] Wireless communication networks have evolved from providing initial voice-oriented services to broadband wireless communication systems that provide high-speed, high-quality packet data services based on communication standards such as 3GPP High Speed ​​Packet Access (HSPA), LTE or Evolved Universal Terrestrial Radio Access (E-UTRA), and LTE-Advanced (LTE-A), 3GPP2's High Rate Packet Data (HRPD), Ultra Mobile Broadband (UMB), and IEEE 802.16e.

[0048] As a representative example of a broadband wireless communication system, the LTE system adopts an orthogonal frequency division multiplexing (OFDM) scheme for the downlink (DL) and a single-carrier frequency division multiple access (SC-FDMA) scheme for the uplink (UL). The UL refers to the radio link through which a terminal (UE or MS) transmits data or control signals to a base station (or eNB), while the DL refers to the radio link through which a base station transmits data or control signals to a terminal. In the multiple access scheme described above, data or control information for each user can be identified by allocating and operating time-frequency resources carrying data or control information to each user to prevent overlap (i.e., achieving orthogonality between time-frequency resources).

[0049] Since post-LTE communication systems (i.e., 5G communication systems) need to be able to freely reflect the diverse requirements of users and service providers, 5G communication systems are required to support services that simultaneously meet various requirements. Services under consideration for 5G communication systems include enhanced mobile broadband (eMBB), massive machine-type communications (mMTC), and ultra-reliable low-latency communications (URLLC).

[0050] According to some embodiments, eMBB may be intended to provide a higher data transfer rate than the data transfer rate supported by existing LTE, LTE-A or LTE-Pro. For example, in a 5G communication system, from the perspective of the BS, eMBB should be able to deliver a peak data rate of 20 gigabits per second (Gbps) in the DL and a peak data rate of 10 Gbps in the UL. In addition, the 5G communication system should be able to provide a better user-perceived data rate while delivering the peak data rate. In order to meet such requirements, the 5G communication system may require improvements in various transmission and reception technologies, including further improved multiple-input multiple-output (MIMO) transmission technology. In addition, although the current LTE system transmits signals by using a maximum transmission bandwidth of 20 megahertz (MHz) in the 2 GHz band, the 5G communication system can meet the data transfer rate required by the 5G technology by using a frequency bandwidth wider than 20 MHz in the 3 GHz to 6 GHz band or a band higher than 6 GHz.

[0051] Meanwhile, in the 5G communication system, mMTC is considered to support application services such as IoT. In order to efficiently provide IoT, mMTC may require support for massive connections with terminals in a cell, enhanced terminal coverage, improved battery life, low terminal costs, etc. Since IoT is a system equipped with multiple sensors and various devices to provide communication functions, it must be able to support a large number of terminals in a cell (for example, 1000 terminals per square kilometer (km2)). 2 ) one million terminals). In addition, because terminals supporting mMTC are likely to be located in shadowed areas that are not covered by cells due to the nature of the service, such as basements of buildings, mMTC may require a wide coverage area compared to other services provided by 5G communication systems. Terminals supporting mMTC should be configured as low-cost terminals and require a very long battery life, such as 10 to 15 years, because terminal batteries are difficult to replace frequently.

[0052] Finally, URLLC is used for cellular-based wireless communication services for mission-critical applications, such as remote control of robots or machines, industrial automation, unmanned aerial vehicles (UAVs), remote healthcare, emergency warning services, etc. Therefore, URLLC communications should be able to provide very low latency (ultra-low latency) and very high reliability (ultra-high reliability). For example, a service supporting URLLC may have to meet an air interface latency of less than 0.5 milliseconds (ms) and at the same time have a reliability of equal to or less than 10 -5 Therefore, for services supporting URLLC, the 5G system needs to provide a shorter Transmission Time Interval (TTI) than other services and can also require the allocation of wideband resources to ensure high reliability of the communication link.

[0053] The above three services (i.e., eMBB, URLLC, and mMTC) considered in the 5G communication system can be multiplexed in one system for transmission. In this regard, different transmission and reception technologies and transmission and reception parameters can be used between services to meet the different requirements of the corresponding services. However, mMTC, URLLC, and eMBB are only examples of different service types, and the service types to which the present disclosure is applied are not limited to the above examples.

[0054] In the following, for ease of description, the present disclosure uses terms and names defined in the LTE and NR standards, which are the latest standards defined by the 3GPP organization among the existing communication standards. However, the present disclosure is not limited to the terms and names, but can also be applied to systems that comply with other standards. In particular, the present disclosure can be applied to the 3GPP NR standard (5G mobile communication standard). In addition, the embodiments of the present disclosure can be applied to other communication systems with similar technical backgrounds and channel configurations. Those skilled in the art should also understand that the embodiments of the present disclosure can be applied to other communication systems by modifications that do not depart from the scope of the present disclosure.

[0055] Hereinafter, the present disclosure provides a method for preventing unnecessary cell state transitions when the bandwidth part (BWP) in which a secondary cell (SCell) operates is a dormant BWP when using carrier aggregation (CA) technology in a wireless communication system, and more specifically in 3GPP 5G NR technology.

[0056] In addition, in the following disclosure, a method for performing operations differently according to the type of BWP when using the CA technology is described.

[0057] Through the embodiments of the present disclosure, the terminal can keep an unused SCell in a standby state so that the SCell can be used immediately when needed, thereby reducing delay.

[0058] Figure 1A is a diagram showing the architecture of an NR system according to an embodiment of the present disclosure. Figure 1A , a wireless communication system may include a plurality of BSs 1a-05, 1a-10, 1a-15, and 1a-20, an access and mobility management function (AMF) 1a-26, and a user plane function (UPF) 1a-30. UE (hereinafter referred to as UE or terminal) 1a-35 may be connected to an external network through the BSs 1a-05, 1a-10, 1a-15, and 1a-20 and the UPF 1a-30. However, the wireless communication system is not limited to Figure 1A Examples of Figure 1A More or fewer components as shown.

[0059] BSs 1a-05, 1a-10, 1a-15, and 1a-20, which are access nodes in a cellular network, can provide wireless connectivity for UEs accessing the network. In other words, in order to serve user traffic, BSs 1a-05, 1a-10, 1a-15, and 1a-20 can schedule UEs by collecting status information (such as the UE's buffer status, available transmit power status, and channel status), and thus support connectivity between each UE and a core network (CN; in particular, the NR CN is referred to as 5GC). In addition, a communication system including an NR system can be configured to process traffic by dividing traffic into a user plane (UP) related to actual user data transmission and a control plane (CP) such as connection management, and Figure 1A The gNBs 1a-05 and 1a-20 in the 5GC can use the UP and CP related techniques defined in NR technology, while the ng-eNBs 1a-10 and 1a-15 can be connected to the 5GC but use the UP and CP related techniques defined in LTE technology.

[0060] An AMF (or Session Management Function (SMF)) 1a-25 may be connected to a plurality of BSs as an entity responsible for various control functions including a mobility management function for UEs, and a UPF 1a-30 is a gateway device providing data transmission.

[0061] Figure 1B is a diagram illustrating a radio protocol architecture of Long Term Evolution (LTE) and NR systems according to an embodiment of the present disclosure.

[0062] refer to Figure 1B , the radio protocol stack of each of the UE and eNB in ​​the LTE system may include a packet data convergence protocol (PDCP) layer (or entity) 1b-05 or 1b-40, a radio link control (RLC) layer (or entity) 1b-10 or 1b-35, and a medium access control (MAC) layer (entity) 1b-15 or 1b-30.

[0063] The PDCP layer 1b-05 or 1b-40 may be responsible for performing compression / decompression of the IP header, and the RLC layer 1b-10 or 1b-35 may configure the PDCP packet data (PDU) to an appropriate size.

[0064] The MAC layer 1b-15 or 1b-30 may be connected with a plurality of RLC layers configured for the UE, and multiplex the RLC PDU into the MAC PDU and demultiplex the RLC PDU from the MAC PDU.

[0065] The physical (PHY) layer 1b-20 or 1b-25 can perform channel coding and modulation on the upper layer data to generate orthogonal frequency division multiplexing (OFDM) symbols and transmit the OFDM symbols via the radio channel, or perform demodulation and channel decoding on the OFDM symbols received via the radio channel and transmit the demodulated and channel-decoded OFDM symbols to the upper layer. In addition, hybrid automatic repeat request (HARQ) is used for additional error correction at the PHY layer, and the receiving end can transmit 1-bit information indicating whether the packet transmitted from the transmitting end has been received. This information is called HARQ acknowledgement (ACK) / negative acknowledgement (NACK) information.

[0066] In LTE, DL HARQ ACK / NACK information for UL data transmission can be transmitted via the Physical HARQ Indicator Channel (PHICH), and in NR, this information can be provided based on the scheduling information of the corresponding UE in the Physical DL Control Channel (PDCCH), which is a channel on which DL / UL resource allocation, etc., is transmitted. In other words, in NR, the BS or UE can determine whether UL data needs to be retransmitted and whether to perform a new transmission via the PDCCH. This is because asynchronous HARQ is used in NR. UL HARQ ACK / NACK information for DL ​​data transmission can be transmitted via the Physical UL Control Channel (PUCCH) or the Physical UL Shared Channel (PUSCH). Generally speaking, the PUCCH is transmitted in the UL of the primary cell (PCell), as described later, but when the UE supports it, the BS can additionally transmit the PUCCH to the UE in the SCell, as described later, and the SCell is called the PUCCH SCell.

[0067] although Figure 1B Although not shown in the figure, a radio resource control (RRC) layer may exist as an upper layer of the PDCP layer at each of the UE and the BS, and exchange connection and measurement configuration control information to control radio resources.

[0068] In addition, the PHY layer can be configured to use one or more frequencies / carriers, and the technology for configuring and using multiple frequencies simultaneously is called Carrier Attachment (CA). CA technology can significantly increase transmission capacity by the number of secondary carriers by using a primary carrier and one or more secondary carriers for communication between the UE and the base station (e.g., an eNB in ​​LTE or a gNB in ​​NR) instead of using only one carrier. In LTE, the cell in the base station using the primary carrier is called a PCell, and the cell using the secondary carrier is called an SCell. The technology that extends CA functionality to two base stations is called dual connectivity (DC). In DC technology, the UE can simultaneously connect to and use a primary base station (primary E-UTRAN NodeB (MeNB)) and a secondary base station (secondary E-UTRAN nodeB (SeNB)), and the cell belonging to the primary base station is called an MCG, and the cell belonging to the secondary base station is called an SCG. Each cell group has a representative cell, and the representative cell of the MSG is called a PCell, and the representative cell of the SCG is called a primary secondary cell (PSCell). When using the above-mentioned NR, the MCG can use LTE technology, while the SCG can use NR, so that the UE can use LTE and NR simultaneously. In NR, each cell group (i.e., MSG or SCG) can have a maximum of 16 serving cells (PCell and SCell in MCG, or PSCell and SCell in SCG).

[0069] Figure 1C is a diagram illustrating the structures of DL and UL channel frames when an NR system performs beam-based communication according to an embodiment of the present disclosure.

[0070] refer to Figure 1C , BS 1c-01 may transmit signals in the form of beams 1c-11, 1c-13, 1c-15, and 1c-17 to achieve wider coverage or transmission of stronger signals. Therefore, UE 1c-03 in the cell may have to use a specific beam ( Figure 1C Beam #1 1c-13) in 1c-13 is used to transmit or receive data.

[0071] In addition, the state of the UE can be divided into an idle mode (RRC_IDLE) state and a connected mode (RRC_CONNECTED) state according to whether the UE is connected to the BS. Therefore, in the RRC_IDLE state, the BS may not be able to recognize the location of the UE.

[0072] When a UE in the RRC_IDLE state attempts to transition to the RRC_CONNECTED state, the UE may receive synchronization signal blocks (SSBs) 1c-21, 1c-23, 1c-25, and 1c-27 transmitted by the BS. The SSBs are SSB signals periodically transmitted according to a period set by the BS, and each of the SSBs may include a primary synchronization signal (PSS) 1c-41, a secondary synchronization signal (SSS) 1c-43, and a physical broadcast channel (PBCH).

[0073] exist Figure 1C In the example, assume a scenario where SSB is transmitted for each beam. As an example, assume the following case: SSB#0 1c-21 is transmitted by using beam#0 1c-11, SSB#1 1c-23 is transmitted by using beam#11c-13, SSB#2 1c-25 is transmitted by using beam#2 1c-15, and SSB#3 1c-27 is transmitted by using beam#3 1c-17. In addition, although Figure 1C It is assumed that the UE in the RRC_IDLE state is located in beam #1. Even when the UE in the RRC_CONNECTED state performs random access, the UE selects the SSB received at the time point when it performs random access.

[0074] refer to Figure 1C , the UE can receive SSB#1 transmitted by using beam #1. After receiving SSB#1, the UE can obtain the physical cell identifier (PCI) of the BS through the PSS and SSS, and by receiving the PBCH, the UE can determine the identifier of the currently received SSB (i.e., #1) and which position in the 10ms frame is the location where the current SSB is received and which system frame number (SFN) within the SFN range with a periodicity of 10.24 seconds corresponds to the location where the current SSB is received. In addition, the master information block (MIB) may be included in the PBCH and include information about where the system information block type 1 (SIB1) for broadcasting more detailed cell configuration information will be received. After receiving SIB1, the UE can identify the total number of SSBs transmitted by the BS and recognize the position of the physical random access channel (PRACH) opportunity (in Figure 1C In the figure, it is assumed that a PRACH opportunity is allocated every 1 ms: PRACH opportunity 1c-30 to 1c-39), at which the UE can perform random access to transition to the RRC_CONNECTED state (more precisely, at this opportunity the UE is allowed to transmit a preamble, which is a physical signal specifically designed to achieve UL synchronization).

[0075] In addition, the UE can determine which PRACH opportunity among the PRACH opportunities is mapped to the SSB index based on the information of SIB1. Figure 1C In the figure, a scenario in which a PRACH opportunity is allocated every 1 ms is assumed, and a scenario in which 1 / 2 SSB is allocated per PRACH opportunity (i.e., two PRACH opportunities per SSB) is assumed. Therefore, the following scenario is shown: starting from the PRACH opportunity that starts according to the SFN value, two PRACH opportunities are allocated for each SSB. In other words, PRACH opportunities 1c-30 and 1c-31 can be allocated to SSB#0, and PRACH opportunities 1c-32 and 1c-33 can be allocated to SSB#1. After the PRACH opportunities are configured for all SSBs, PRACH opportunities (PRACH opportunities 1c-38 and 1c-39) can be allocated again for the first SSB.

[0076] Therefore, the UE recognizes the positions of PRACH opportunities 1c-32 and 1c-33 of SSB#1 and transmits a random access preamble at the earliest PRACH opportunity (e.g., PRACH opportunity 1c-32) at the current time point among PRACH opportunities 1c-32 and 1c-33 corresponding to SSB#1. Since the BS has already received the preamble at PRACH opportunity 1c-32, the BS can know that the UE has transmitted the preamble by selecting SSB#1 and can transmit and receive data using the beam corresponding to SSB#1 when performing subsequent random access.

[0077] Figure 1D is a diagram for explaining CA technology according to an embodiment of the present disclosure.

[0078] refer to Figure 1D Generally speaking, a base station can transmit and receive multiple carriers across several frequency bands. For example, when BS 1d-05 transmits carrier 1d-15 with center frequency f1 and carrier 1d-10 with center frequency f3, according to related art, the UE uses one of the two carriers to transmit and receive data. However, a CA-capable UE can simultaneously transmit and receive data across multiple carriers. BS 1d-05 can allocate more carriers to CA-capable UE 1d-30, depending on the situation, thereby increasing the transmission rate of UE 1d-30.

[0079] In the traditional sense, when one forward carrier and one reverse carrier transmitted and received from a base station form a cell, CA can be understood as a UE transmitting and receiving data simultaneously via multiple cells. In this way, the maximum transmission rate increases in proportion to the number of aggregated carriers.

[0080] In the following description of the present disclosure, when a UE receives data on a forward carrier or transmits data on a reverse carrier, this has the same meaning as transmitting or receiving data by using a control channel and a data channel provided by a cell corresponding to a center frequency and a frequency band representing a carrier. In addition, although the embodiments of the present disclosure will be described based on LTE and NR systems for ease of description, the present disclosure can be applied to various wireless communication systems that support carrier aggregation.

[0081] Even when CA is being performed or not, the reverse transmission power must be maintained at an appropriate level because the reverse transmission of another cell (i.e., transmission from the UE to the BS) causes interference in the reverse transmission of the other cell. To this end, when the UE performs reverse transmission, the UE can calculate the reverse transmission power by using a certain function and perform reverse transmission based on the calculated reverse transmission power. For example, the UE can calculate the required reverse transmission power by inputting input values ​​that can be used to estimate the channel state (such as scheduling information including the amount of allocated transmission resources, the modulation and coding scheme (MCS) level to be applied, the path loss value, etc.) into a certain function, and perform reverse transmission by applying the calculated required reverse transmission power value. The reverse transmission power applicable to the UE is limited by the UE's maximum transmission value, and when the calculated required transmission power value exceeds the UE's maximum transmission value, the UE can perform reverse transmission by applying the maximum transmission power. In this case, since sufficient reverse transmission power is not applied, the quality of the reverse transmission may be reduced. It may be desirable for the BS to perform scheduling so that the required transmission power does not exceed the maximum transmission power. However, since the BS cannot measure some parameters such as path loss, the UE transmits a power headroom report (PHR) when necessary to report the status of its available transmission power (power headroom (PH)) to the BS.

[0082] Factors that affect the available transmit power include 1) the amount of allocated transmit resources, 2) the MCS to be applied to reverse transmission, 3) the path loss of the associated forward carrier, 4) the cumulative value of the power control command, etc. The path loss (hereinafter referred to as PL) or the cumulative value of the power control command may be different for each reverse carrier, and therefore, when multiple reverse carriers are aggregated in one UE, it is desirable to configure whether to transmit PHR for each of the reverse carriers. However, for efficient transmission of PHR, the PH of all multiple reverse carriers may be reported on one reverse carrier. Depending on the operating policy, the PH of the carrier in which no actual PUSCH transmission occurs may be required. Therefore, in this case, a method of reporting the PH of multiple reverse carriers on one reverse carrier may be more efficient. For this purpose, it is necessary to extend the existing PHR. The multiple PHs to be included in one PHR can be configured according to a predetermined order.

[0083] The PHR is triggered when the PL of the typically connected forward carrier changes to a value greater than or equal to a certain reference value, when the PHR prohibit timer expires, or when a certain period of time has passed after the PHR was generated. Even when the PHR is triggered, the UE does not immediately transmit the PHR, but waits until reverse transmission is permitted, for example, when reverse transmission resources are allocated. This is because the PHR is not information that must be processed very quickly.

[0084] In addition, as described above, the cell to which the UE initially connects by performing random access may be referred to as a PCell, and the cell added to the PCell may be referred to as an SCell. SCells are added to or released from a UE using messages from the RRC layer, and when an SCell is added via RRC, the corresponding SCell is in a deactivated state. Thereafter, the configured cell may be activated (active) or deactivated (inactive) by receiving an SCell activation / deactivation MAC control element (CE) from the BS.

[0085] In addition, in the NR system, for each configured serving cell (PCell or SCell), the UE can be configured with up to four BWPs, and can actually operate on only one configured BWP in each serving cell. At this time, the BWP actually used can be called the active BWP. For example, for SCell 1 with a total bandwidth of 100 MHz, BWP#1 with a bandwidth of 20 MHz and BWP#2 with a bandwidth of 80 MHz can be assumed. In this example, when configuring each serving cell to thereby configure the BWP that performs operation for the first time when the corresponding SCell is activated, the BS can specify the first active BWP (the BWP activated for the first time), such as BWP#1. Therefore, when SCell 1 transitions from a deactivated state to an activated state, the active BWP can be BWP#1.

[0086] Furthermore, when a deactivated serving cell is activated, a delay may occur until it is actually activated. Even when the BS activates a serving cell so that it can actually be used, a delay may occur because the UE measures the channel state of the serving cell (its activated BWP) and reports it to the BS, and the BS then needs to determine which MCS to use for scheduling via the serving cell. In particular, in the aforementioned beam-based system, when the UE and BS communicate using multiple beams, a longer actual delay may be required due to the need to measure the channel state by changing beams.

[0087] For this problem, a method can be considered in which a "dormant BWP" among the BWPs configured by the BS in the serving cell is configured when the serving cell itself is activated (i.e., the corresponding SCell is in an activated state) and the active BWP is switched to the dormant BWP. For example, in order to configure the dormant BWP for the UE, the BS may not perform the PDCCH-related configuration in the configuration information of the corresponding BWP. Therefore, when changing to the dormant BWP, the UE performs operations such as measuring and reporting signals in the corresponding serving cell, but is not allowed to transmit and receive data through the PDCCH. However, when data transmission and reception are required in another activated serving cell (e.g., PCell), the BS can transmit a command via the PDCCH to change (or switch) the active BWP to another BWP of the serving cell in which the dormant BWP is the active BWP. In other words, since data transmission and reception are impossible in the dormant BWP, the BS can transmit a command for switching the active BWP of the corresponding serving cell to a BWP other than the dormant BWP to the UE on the PDCCH of another activated serving cell, so the UE can transmit and receive data in the corresponding serving cell by switching the active BWP of the corresponding serving cell from the dormant BWP to another BWP.

[0088] Figure 1E is a diagram illustrating the concept of UL remaining power according to an embodiment of the present disclosure.

[0089] exist Figure 1E , Example 1 schematically illustrates a scenario in which the UE is configured with two serving cells (i.e., PCell 1e-01 and SCell 1e-03) and then performs UL transmission according to the scheduling of the BS. In the scenario of Example 1, the UE cannot transmit PUCCH and PUSCH simultaneously in one serving cell due to restrictions on the transmission method and radio frequency (RF) structure. Therefore, the UE may transmit PUSCH (1e-05) in which PUCCH information is embedded. In this case, the PUCCH information may be transmitted on the PCell, or when the PUSCH is not transmitted on the PCell, the PUCCH information may be transmitted on the SCell with a low index among the SCells. The above-mentioned PHR message may be transmitted through a part of the PUSCH, and therefore, in the scenario of Example 1, the UE only needs to report the maximum transmission power P transmitted from each serving cell. CMAX,c The pH value is obtained by subtracting the transmit power consumed in PUSCH transmission 1e-05 and 1e-07. This can be called Type 1 pH.

[0090] Similarly, Example 2 schematically illustrates a scenario in which the UE is configured with two serving cells (i.e., PCell 1e-11 and SCell 1e-13) and then performs UL transmission according to the scheduling of the BS. In the scenario of Example 2, the UE may have the ability to transmit PUCCH and PUSCH simultaneously in one serving cell, or to transmit PUCCH and PUSCH separately using a UL transmission technology that allows simultaneous transmission. Here, in PCell 1e-11 (or when PUCCH can be transmitted on SCell, the same applies to SCell 1e-13), the UE needs to report the maximum transmission power P from PCell 1e-11 by taking into account the transmission power consumed by PUCCH transmission 1e-15 and PUSCH transmission 1e-17. CMAX,f,c The PH value obtained by subtracting both the PUSCH transmit power and the PUCCH transmit power. This can be called Type 2 PH.

[0091] Example 3 schematically illustrates a scenario in which the UE is configured with two serving cells (i.e., PCell1e-81 and SCell1e-83) and then performs UL transmission according to the scheduling of the BS. In the scenario of Example 3, the UE cannot transmit PUCCH and PUSCH simultaneously in one serving cell due to restrictions on the transmission method and RF structure. Therefore, the UE can transmit PUSCH (1e-85) in which PUCCH information is embedded. In this case, the PUCCH information can be transmitted on the PCell, or when the PUSCH is not transmitted on the PCell, the information can be transmitted on the SCell with a low index among the SCells. In addition, in the scenario of Example 3, on the Scell ​​1e-83, there is no PUSCH transmission, but only the sounding reference signal (SRS) is transmitted. This can happen in the following scenario: when SCell 1e-83 is a time division duplex (TDD) cell, UL data transmission is no longer performed on SCell 1e-83, but SRS is transmitted on UL as a reference signal for channel estimation for DL ​​data transmission and allows the BS to measure the UL channel and use the measurement results for DL. Therefore, the UE only needs to report the maximum transmit power P from each serving cell. CMAX,c The PH value is obtained by subtracting the transmission power consumed in PUSCH transmission 1e-85 and SRS transmission 1e-87. Here, the PH value is obtained by subtracting the transmission power consumed in PUSCH transmission 1e-85 and SRS transmission 1e-87 from the maximum transmission power P CMAX,c The remaining power obtained by subtracting the transmit power of PUSCH transmission 1e-85 is called type 1 PH and is obtained by subtracting the transmit power of PUSCH transmission 1e-85 from the maximum transmit power P CMAX,c The remaining power obtained by subtracting the transmission power consumed in SRS transmission 1e-87 is referred to as Type 3 PH.

[0092] When reporting Type 1 PH, Type 2 PH, or Type 3 PH, the UE may report such PH by using a MAC CE (which is a control message from the MAC layer), and more specifically, the UE may report the PH by using a single-entry PHR MAC CE format 1e-21 or a multi-entry PHR MAC CE format 1e-31. When only a single carrier is used, the UE may report using a single-entry PHR MAC CE format, and when DC is configured (or CA is configured), the UE may report using a multi-entry PHR MAC CE format.

[0093] When using the single-entry PHR MAC CE format, the UE transmits the corresponding serving cell's PH1e-23 and the serving cell's maximum transmit power P CMAX,f,c The value of PH is used to indicate one of the ranges from -32 dB to 38 dB, which may indicate the available transmit power of the UE.

[0094] The UE calculates the available transmit power by using the following equation or an equation corresponding thereto.

[0095]

[0096] In the above equation, when PUSCH transmission is performed in serving cell c (frequency f) at time point i, PH(i) can be based on the maximum reverse transmission power P CMAX,f,c (i) The number of resource blocks M PUSCH RB,b,f,c (i) Power offset Δ derived from MCS TF,c (i), PL PL c and the accumulated transmit power control (TPC) command f c (i) Perform calculations.

[0097] In the above equation, PL c This may be the PL of a cell configured to provide PL to the serving cell c. The PL used to determine the reverse transmit power of the serving cell may be the PL of the serving cell's forward channel or the PL of another cell's forward channel. The BS may select which of these PLs to use and notify the UE of the selected PL via a message from the RRC layer. If the UE uses multiple beams in a cell, the BS may notify the UE of which beam or reference signal to select for measurement and calculation.

[0098] In the above equation, f c (i) may be the accumulated value of TPC commands from serving cell c.

[0099] P O_PUSCH,CIt can be the sum of cell-specific and UE-specific values ​​as upper layer parameters. In general, PUSCH can be applied according to the type of PUSCH transmission (such as semi-persistent scheduling, dynamic scheduling and random access response). O_PUSCH,C different values ​​of .

[0100] α c It is a 3-bit cell-specific value provided via upper layers and represents the weight value applied to PL when calculating reverse transmit power (i.e., the larger the weight value, the greater the impact of PL on reverse transmit power), and the applicable weight value can be limited according to the type of PUSCH transmission.

[0101] The value of j is used to indicate the type of PUSCH. j=0 may indicate semi-persistent scheduling, j=1 may indicate dynamic scheduling, and j=2 may indicate random access response.

[0102] In the above equation, in the absence of PUSCH transmission on a specific serving cell, M PUSCH and Δ TF The above equation defined thereby will not apply.

[0103] In addition, P is the maximum transmit power of the UE serving cell c (at frequency f). CMAX,f,c It can be determined as shown in the following equation or by using the equation corresponding thereto. CMAX_L,f,c and P CMAX_H,f,c between.

[0104] P CMAX_L，f，c ≤P CMAX，f，c ≤P CMAX_H，f，c and

[0105] P CMAX_L，f，c =MIN{P EMAX，c -ΔT C，c ,(P PowcrClass -ΔP PowcrClass )-MAX(MAX(MPR c , A-MPR c )+ΔT (B，c +ΔT C，c +ΔT RxSRS , P-MPR c )}

[0106] P CMAX_H，f，c =MIN{P EMAX，c , P PowerClass -ΔP PowerClass}

[0107] In the above equation, as P CMAX，f，c The maximum value of P CMAX_H，f，c It can be determined that the P can be directly transmitted by the BSEMAX，c The value of and P determined for each frequency band PowerClass -ΔP PowerClass The minimum value among the values.

[0108] Furthermore, in the above equation, as P CMAX，f，c The minimum value of P CMAX_L，f，c It can be determined based on the value of each of the maximum values ​​reduced by additional factors. For example, P can be directly transmitted by the BS EMAX，c The value can be reduced by ΔT according to the specific requirements of the frequency band C，c =1.5dB, and the minimum value of the UE maximum transmit power may be reduced based on the larger value among the following values: by considering the maximum power reduction (MPR) determined according to the transmit modulation and transmit bandwidth of the UE c ) obtained, an additional maximum power reduction (A-MPR) determined according to signaling that the BS additionally transmits to the UE in order to reduce interference from adjacent frequency bands, etc. c ) value (or so-called Network Signaling (NS) value), and Power Management Maximum Power Reduction (P-MPR) for reducing the transmit power to meet the required value when the electromagnetic wave energy is absorbed into the human body c ) value. For example, in a system operating at a high frequency (such as an NR system), the UE may perform transmission at high power, but if transmission is performed at high power, such high power transmission may be harmful to the human body, and therefore, the maximum transmission value may be adjusted according to the value required for regulating high power transmission. By c The situation where the actual transmit power is controlled by reducing the minimum value of the maximum transmit power may be referred to as power backoff due to power management.

[0109] When using the multi-entry PHR MAC CE format, the UE may indicate the serving cell reporting PH via bitmap 1e-33 and report the PH of the serving cell indicated in bitmap 1e-33 and the serving cell reporting PH unconditionally, and when reporting is required, the UE may report the corresponding P together. CMAX，f，c In addition, when the UE reports PH, the UE can report PH by using a field with a length of 6 bits, such as Figure 1E As shown, in NR, depending on the frequency range in which the BS operates (e.g., the frequency ranges below and above 7.125 GHz are referred to as FR1 and FR2, respectively), the PH can have a range of -23 dB to 40 dB in FR2 and a range of -13 dB to 50 dB in FR1.

[0110] For a multi-entry PHR MAC CE, P bits 1e-35 and virtual (V) bits 1e-37 may be additionally included.

[0111] In the case of the P bit, when the maximum transmit power value of the corresponding serving cell is less than the original value by applying the power backoff caused by power management, the UE can report the PHR to the BS by setting the P bit to 1, thereby notifying the BS of the P reported by the UE for the corresponding serving cell. CMAX,f,c Values ​​have been adjusted for power backoff.

[0112] In the case of the V bit, at the time point when the UE reports the multi-entry PHR MAC CE, there will be a case where actual UL data transmission is performed or not performed on each serving cell according to the scheduling information, and for actual transmission, the V bit is set to 0, and the PH value is calculated and reported according to the actual transmission, and when the actual transmission is not performed, the V bit is set to 1 and the value calculated under the assumption that a predetermined virtual transmission has been performed is reported as the PH. Virtual transmission is called a PUSCH reference format or a virtual format.

[0113] Therefore, when the UE transmits the PHR of each cell configured and activated for the UE by the current BS, even if the same PH reporting field is used in a multi-entry PHR format according to the radio access technology (RAT) and the operating frequency of the corresponding serving cell, the UE can generate a value by using a table according to the type of the corresponding serving cell and report the value to the BS.

[0114] Conditions for when to transmit a PHR to the BS (i.e., whether a PHR is triggered) may be defined, and the following conditions may be defined and applied in LTE and NR systems:

[0115] - Condition 1: In the state where prohibitPHR-Timer has expired, the DL reception strength of the serving cell belonging to any MAC entity configured for the UE has changed by more than or equal to phr-Tx-PowerFactorChange dB.

[0116] --In other words, from the perspective of the MCG in the DC scenario, PHR is reported for the MCG even when a signal strength change occurs in one of the serving cells of the SCG.

[0117] Condition 2: The phr-PeriodicTimer used in any MAC entity expires.

[0118] Condition 3: Initially configure PHR.

[0119] Condition 4: The SCell including the UL belonging to any MAC entity is activated.

[0120] Condition 5: When using DC technology, the PSCell of the SCG is added or changed.

[0121] Condition 6: When there are resources for transmission via the UL of the serving cell belonging to any MAC entity configured for the UE in a state where the prohibitPHR-Timer has expired, the required amount by which the transmit power must be reduced according to the power backoff due to power management is greater than or equal to phr-Tx-PowerFactorChange dB compared to the previous value reported via the PHR MAC CE.

[0122] When a PHR triggering condition occurs in each BS, as defined in the above conditions, the UE may generate a PH and report the PH to the corresponding BS.

[0123] Figure 1F is a flowchart illustrating an operation sequence of a UE when the UE is configured with a secondary SCell and the SCell is activated according to an embodiment of the present disclosure.

[0124] exist Figure 1F In the RRC_IDLE state, the UE may be in a state after performing access to the BS and establishing a connection with the BS (1f-01). That is, due to reasons such as receiving a paging message from the BS or the presence of data to be transmitted in the UL, the UE may transition from the RRC_IDLE state to the RRC_CONNECTED state by performing a random access procedure with the BS.

[0125] When the UE initially accesses the network or when the AMF for managing the UE changes, the UE may transmit UE capability information to the BS at the request of the BS (1f-03). The UE capability information may include information about the functions supported by the UE, and the BS may configure the UE with the functions expected by the BS among the functions supported by the UE. Examples of UE capability information may include information about whether dormant BWP is supported. In addition, the UE capability information may include 1 bit for each of FR1 and FR2. However, the UE capability information is not limited to the above examples and may include all pieces of information about the capabilities of the UE.

[0126] Thereafter, the UE may receive various configuration information from the BS via an RRC layer message (1f-05). The RRC layer message may be, for example, an RRCReconfiguration message, and the configuration information received by the UE from the BS may include configurations for adding (or releasing) one or more SCells and the current PCell. In addition, when an SCell is added in the configuration information, detailed configuration of the BWP may be received for each SCell. In this case, one of the configured BWPs may be a dormant BWP. In addition, one of the configured BWPs may be a default BWP, or when a default BWP is not configured, an initial BWP (BWP#0). In addition, the UE may be configured with a first active BWP by the BS, which is a BWP that is activated for the first time when the corresponding SCell is activated, and the first active BWP may be a dormant BWP or a normal BWP on which data can be transmitted and received.

[0127] In addition, Timer 1 (sCellDeactivationTimer) and Timer 2 (bwp-InactivityTimer) can be configured for each SCell. Timer 1 can be a timer configured to transition the SCell to a deactivated state when Timer 1 expires and there is no data transmission / reception on the SCell. In other words, when Timer 1 expires, the UE deactivates the corresponding SCell. In addition, if the current active BWP in the SCell is not the default BWP, Timer 2 can be a timer used to switch the active BWP to the default BWP when there is no data transmission or reception on the current active BWP. Data transmission and reception refers to transmitting a PDCCH on the corresponding BWP, transmitting the PDCCH of the corresponding BWP, or performing data transmission in the configured UL or DL. When a default BWP is not configured, the UE switches the BWP to the initial BWP (BWP#0). In other words, when Timer 2 expires, the UE switches the active BWP for the corresponding SCell to the dormant BWP (or to the initial BWP if not configured).

[0128] In the RRCReconfiguration message, the BS may indicate to the UE whether the initial state of each SCell is an activated state or a deactivated state.

[0129] Thereafter, the UE may receive an SCell activation / deactivation MAC CE among MAC CEs as a control message from the MAC layer to change the state of the SCell controlled by the BS (1f-07). The SCell activation / deactivation MAC CE may include a bitmap indicating activation or deactivation of each SCell.

[0130] The UE may determine whether to activate the corresponding SCell (1f-09) via an RRC layer message or both an RRC layer message and an SCell activation / deactivation MAC CE. Based on this, the UE may perform the following operations related to activation (1f-11), and if deactivated, the UE may configure the SCell to be in a deactivated state (1f-13).

[0131] In the above operation, for an SCell whose initial state is configured as active via an RRC layer message, the UE determines whether the first active BWP of the corresponding SCell configured by the BS is a dormant BWP. When the first active BWP is not a dormant BWP, the UE may start Timer 1. In addition, Timer 2 may be started. However, when the first active BWP is a dormant BWP, the UE may not start Timer 1. In addition, the UE may not start Timer 2. This is because if Timer 1 and Timer 2 are started when the UE's active BWP is a dormant BWP, the SCell is unnecessarily deactivated or a handover to a normal BWP occurs, which defeats the purpose of a dormant BWP, namely, to remain in a dormant state for a long time and to switch only when necessary.

[0132] In addition, when the UE receives the SCell activation / deactivation MAC CE from the BS, the UE can activate the SCell if the bit corresponding to the SCell is set to 1, and deactivate the SCell if the bit is set to 0. In this case, for the SCell with the corresponding bit set to 1, the following operations are performed.

[0133] When an SCell is in a deactivated state before receiving an SCell activation / deactivation MAC CE message, the UE determines whether the first active BWP of the corresponding SCell is a dormant BWP. If the first active BWP is not a dormant BWP, the UE may start Timer 1. Additionally, the UE may start Timer 2. However, if the first active BWP is a dormant BWP, the UE may not start Timer 1. Additionally, the UE may not start Timer 2. This is because if Timers 1 and 2 are started when the UE's active BWP is a dormant BWP, the SCell may be unnecessarily deactivated or a switch to a normal BWP may occur. This defeats the purpose of a dormant BWP, which is to remain in a dormant state for extended periods and only switch to a non-dormant state when necessary. In other words, when the UE receives a command to activate a deactivated SCell, if the first active BWP is a dormant BWP, the UE may not start Timer 1 and Timer 2. However, if the first active BWP is not a dormant BWP, Timer 1 and Timer 2 are started. In addition, when the UE receives a command for reactivating an already activated SCell, if the first active BWP is a dormant BWP, the UE may not start timer 1 and timer 2, but if the first active BWP is not a dormant BWP, it starts timer 1 and timer 2.

[0134] In addition, when there is an SCell that is activated upon receiving the SCell activation / deactivation MAC CE message, PHR is also triggered as described above. In this case, the UE can determine the PH type (type 1 / 2 / 3) and PH value of each serving cell.

[0135] In the case of an activated SCell where PUSCH is not configured in all UL BWPs but only SRS is configured, the UE reports Type 3 PH for the corresponding SCell. For the remaining SCells excluding these SCells, when the corresponding SCell was previously deactivated, the UE determines whether there is an SCell with PUSCH configured in at least one UL BWP and the first active BWP is a dormant BWP. If an SCell that meets the above conditions exists, the UE reports Type 3 PH if SRS is configured in the SCell's dormant BWP, and Type 1 PH if SRS is not configured in the SCell's dormant BWP (in this case, the UE reports a dummy value; i.e., the V field is set to 1 for the SCell). Alternatively, as described above, when the (first) active BWP is a dormant BWP, the UE can always report Type 1 PH, regardless of whether SRS is configured. In this case, the UE reports a dummy value. In other words, for SCells whose active BWP is a dormant BWP when reporting a PHR, the UE always transmits Type 1 PH in a dummy format. In addition, for other activated SCells, the UE may include Type 1 PH, or report actual values ​​or virtual values ​​according to resource allocation when reporting PH.

[0136] In addition, for a SCELL that is activated but receives a deactivation command (i.e., a bit set to 0) via the SCell activation / deactivation MAC CE message, the UE can determine whether the current active BWP is a dormant BWP, and for the SCell whose current active BWP is not a dormant BWP, stop timer 1 and timer 2.

[0137] Figure 1G is a block diagram of a configuration of a UE in a wireless communication system according to an embodiment of the present disclosure.

[0138] refer to Figure 1G , the UE may include a radio frequency (RF) processor 1g-10, a baseband processor 1g-20, a storage device 1g-30, and a controller 1g-40. However, the UE is not limited to the above example, but may include more than Figure 1G Fewer or more components than those shown.

[0139] The RF processor 1g-10 can perform functions such as signal conversion and amplification between frequency bands to transmit and receive signals via a radio channel. Specifically, the RF processor 1g-10 up-converts the baseband signal from the baseband processor 1g-20 into an RF signal, and then transmits the RF signal via an antenna, and down-converts the RF signal received via the antenna into a baseband signal. For example, the RF processor 1g-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and the like. Although in Figure 1G Only one antenna is shown in the figure, but the UE may include multiple antennas. The RF processor 1g-10 may include multiple RF chains. In addition, the RF processor 1g-10 may perform beamforming. For beamforming, the RF processor 1g-10 may adjust the phase and amplitude of each signal transmitted and received through multiple antennas or antenna elements.

[0140] The baseband processor 1g-20 performs the function of converting between baseband signals and bit strings according to the physical layer standard of the system. For example, when transmitting data, the baseband processor 1g-20 generates complex symbols by encoding and modulating the transmitted bit string. In addition, when receiving data, the baseband processor 1g-20 reconstructs the received bit string by demodulating and decoding the baseband signal from the RF processor 1g-10. For example, according to the OFDM scheme, when transmitting data, the baseband processor 1g-20 generates complex symbols by encoding and modulating the transmitted bit string, maps the complex symbols to subcarriers, and then generates OFDM symbols through an inverse fast Fourier transform (IFFT) operation and cyclic prefix (CP) insertion. In addition, when receiving data, the baseband processor 1g-20 divides the baseband signal from the RF processor 1g-10 into OFDM symbol units, recovers the signals mapped to the subcarriers through an FFT operation, and then recovers the received bit string through demodulation and decoding.

[0141] The baseband processor 1g-20 and the RF processor 1g-10 each transmit or receive signals, as described above. Therefore, the baseband processor 1g-20 and the RF processor 1g-10 can be referred to as transmitters, receivers, transceivers, or communicators. Furthermore, at least one of the baseband processor 1g-20 and the RF processor 1g-10 can include multiple communication modules to support multiple different RATs. Furthermore, at least one of the baseband processor 1g-20 and the RF processor 1g-10 can include different communication modules to process signals of different frequency bands. For example, different RATs can include wireless local area network (WLAN) technologies (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802.11), cellular network technologies (e.g., LTE), and the like. Different frequency bands can include super high frequency (SHF) bands (e.g., 2.5 GHz or 5 GHz) and millimeter (mm) wave bands (e.g., 60 GHz). The UE can transmit and receive signals to and from the base station via the baseband processor 1g-20 and the RF processor 1g-10, and the signals can include control information and data.

[0142] The storage device 1g-30 stores basic programs, applications, and data for the operation of the UE, such as configuration information. In particular, the storage device 1g-30 can store information related to WLAN nodes for performing wireless communications using WLAN access technology. The storage device 1g-30 also provides the stored data at the request of the controller 1g-40. The storage device 1g-30 can be composed of a storage medium, such as a read-only memory (ROM), a random access memory (RAM), a hard disk, a compact disc (CD)-ROM, and a digital versatile disc (DVD), or a combination thereof. In addition, the storage device 1g-30 can include a plurality of memories. In an embodiment of the present disclosure, according to the present disclosure, the storage device 1g-30 can store a program for executing a method for determining whether to start a timer related to BWP switching and state transition according to the type of BWP activated in the SCell configured by the BS according to the instruction (sleeping BWP or normal BWP).

[0143] The controller 1g-40 controls all operations of the UE. For example, the controller 1g-40 transmits or receives signals via the baseband processor 1g-20 and the RF processor 1g-10. The controller 1g-40 also writes data to and reads data from the storage device 1g-40. To this end, the controller 1g-40 may include at least one processor. For example, the controller 1g-40 may include a communication processor (CP) for performing communication control and an application processor (AP) for controlling an upper layer such as an application. In addition, at least one component in the UE may be implemented as a single chip. In addition, according to an embodiment of the present disclosure, the controller 1g-40 may include a multi-connection processor 1g-42 that performs processing for operating in a multi-connection mode. For example, the controller 1g-40 may control the UE to perform Figure 1F The operation process of the UE is shown.

[0144] According to an embodiment of the present disclosure, the controller 1g-40 may determine whether to start a timer related to BWP switching and state transition according to the type of BWP activated in the SCell configured by the BS according to the instruction (sleeping BWP or normal BWP).

[0145] Figure 1H is a block diagram of a configuration of a BS in a wireless communication system according to an embodiment of the present disclosure.

[0146] refer to Figure 1H , the BS may include an RF processor 1h-10, a baseband processor 1h-20, a communicator 1h-30, a storage device 1h-40, and a controller 1h-50. However, the BS is not limited to the above example, but may include more than Figure 1H Fewer or more components than those shown.

[0147] The RF processor 1h-10 performs functions of transmitting and receiving signals via a radio channel, such as signal conversion and amplification between frequency bands. Specifically, the RF processor 1h-10 can up-convert the baseband signal from the baseband processor 1h-20 into an RF signal, and then transmit the RF signal via the antenna, and down-convert the RF signal received via the antenna into a baseband signal. For example, the RF processor 1h-10 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although in Figure 1H Although only one antenna is shown in the figure, the RF processor 1h-10 may include multiple antennas. For example, the RF processor 1h-10 may include multiple RF chains. In addition, the RF processor 1h-10 may perform beamforming. For beamforming, the RF processor 1h-10 may adjust the phase and amplitude of each signal transmitted and received via multiple antennas or antenna elements. In addition, the RF processor 1h-10 may perform DL MIMO operations by transmitting one or more layers.

[0148] The baseband processor 1h-20 can perform the function of converting between the baseband signal and the bit string according to the physical layer standard of the RAT. For example, when transmitting data, the baseband processor 1h-20 can generate complex symbols by encoding and modulating the transmitted bit string. In addition, when receiving data, the baseband processor 1h-20 can reconstruct the received bit string by demodulating and decoding the baseband signal from the RF processor 1h-10. For example, according to the OFDM scheme, when transmitting data, the baseband processor 1h-20 can generate complex symbols by encoding and modulating the transmitted bit string, mapping the complex symbols to subcarriers, and then generating OFDM symbols through IFFT operation and CP insertion. In addition, when receiving data, the baseband processor 1h-20 can divide the baseband signal from the RF processor 1h-10 into OFDM symbol units, recover the signal mapped to the subcarrier through FFT operation, and then recover the received bit string through demodulation and decoding. The baseband processor 1h-20 and the RF processor 1h-10 transmit and receive signals as described above. Therefore, the baseband processor 1h-20 and the RF processor 1h-10 can be called a transmitter, a receiver, a transceiver, a communicator, or a wireless communicator. The BS can transmit and receive signals to and from the UE via the baseband processor 1h-20 and the RF processor 1h-10, and the signals may include control information and data.

[0149] The communicator 1h-30 can provide an interface for communicating with other nodes in the network. For example, the communicator 1h-30 can convert a bit string to be transmitted from the primary BS to another node (such as a secondary BS and CN) into a physical signal, and can convert a physical signal received from another node into a bit string. The communicator 1h-30 can also be a backhaul communicator.

[0150] The storage device 1h-40 stores basic programs, applications and data for the operation of the BS, such as configuration information. The storage device 1h-40 can store information about the bearers allocated to the connected UEs, measurement results reported by the connected UEs, etc. In addition, the storage device 1h-40 can store information that is a standard for determining whether to provide or terminate multiple connections to and from the UE. The storage device 1h-40 also provides the stored data at the request of the controller 1h-50. The storage device 1h-40 can be composed of a storage medium such as a ROM, RAM, hard disk, CD-ROM and DVD or a combination thereof. In addition, the storage device 1h-40 can include multiple memories. According to some embodiments, the storage device 1h-40 can store programs for performing a two-step random access process and a method for configuring, generating and transmitting the MsgB format.

[0151] The controller 1h-50 controls all operations of the BS. For example, the controller 1h-50 transmits or receives signals through the baseband processor 1h-20 and the RF processor 1h-10 or through the communicator 1h-30. In addition, the controller 1h-50 writes data to the storage device 1h-40 and reads data from it. To this end, the controller 1h-50 may include at least one processor. According to an embodiment of the present disclosure, the controller 1h-50 includes a multi-connection processor 1h-52 that performs processing for operating in a multi-connection mode.

[0152] In addition, at least one component in the BS may be implemented as a single chip. Each component of the BS may perform operations according to the embodiments of the present disclosure.

[0153] The methods according to the embodiments of the present disclosure described in the accompanying claims or in its specification can be implemented by hardware, software, or a combination of hardware and software.

[0154] When the method is implemented using software, a computer-readable storage medium may be provided that stores at least one program (software module). The at least one program stored in the computer-readable storage medium is configured to be executed by at least one processor in an electronic device. The at least one program includes instructions that cause the electronic device to perform the method according to the embodiments of the present disclosure described in the claims or the specification thereof.

[0155] The program (software module or software) may be stored in RAM, non-volatile memory (including flash memory, ROM, EEPROM, magnetic disk storage, CD-ROM, DVD or other types of optical storage) and magnetic tape cartridges. Alternatively, the program may be stored in a memory configured as a combination of some or all of the aforementioned memories. A plurality of such memories may be included.

[0156] In addition, the program can be stored in an attachable storage device that can be accessed via a communication network such as the Internet, an intranet, a LAN, a wide LAN (WLAN), and a storage area network (SAN), or a combination thereof. The storage device can be connected to the device for performing the method according to the embodiment of the present disclosure via an external port. In addition, a separate storage device on the communication network can also be connected to the device for performing the method according to the embodiment of the present disclosure.

[0157] In certain embodiments of the present disclosure, components included in the present disclosure are expressed in either singular or plural form, depending on the specific embodiment being presented. However, the singular or plural expression is selected as appropriate for the circumstances presented for ease of description, and the present disclosure is not limited to elements in singular or plural form, i.e., an element expressed in plural form may be configured as a single element, or an element expressed in singular form may be configured as multiple elements.

[0158] In addition, although specific embodiments have been described in the detailed description of the present disclosure, various modifications may be made therein without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but is defined by the appended claims and their equivalents. It will be apparent to those skilled in the art that other modifications based on the technical spirit of the present disclosure may be implemented. The embodiments may be combined with each other for operation when necessary. For example, parts of the methods presented in the present disclosure may be combined with each other to operate a BS and a UE. Although embodiments are proposed based on a 5G or NR system, other modifications based on the technical spirit of the embodiments may be applicable to other systems, such as LTE, LTE-A, and LTE-A-Pro systems.

Claims

1. A method for controlling at least one secondary cell (SCell) performed by a terminal, the method comprising: receiving a radio resource control (RRC) message, the RRC message including first information about a first timer for deactivation of the SCell, second information about a second timer, state information of the SCell, third information for configuring a first active broadband part (BWP), and fourth information for configuring a dormant BWP; Determining, based on the RRC message, whether the SCell is activated; as well as determining, based on the third information and the fourth information, whether the first active BWP of the SCell is the dormant BWP; Wherein, when the first active BWP of the SCell is the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled not to run, Wherein, when the first active BWP of the SCell is not the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled to run, and The second timer is a timer used to switch to the default BWP.

2. The method according to claim 1, further comprising: receiving a medium access control MAC control element CE for changing a state of at least one of the SCells; as well as determining whether the SCell is activated based on the RRC message and the MAC CE, Wherein, in a case where the first active BWP of the SCell is the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled not to run, and Wherein, when the first active BWP of the SCell is not the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled to run.

3. The method according to claim 1, wherein the RRC message includes information indicating the default BWP or initial BWP of the SCell, in, The first active BWP is the BWP that is activated for the first time, and A BWP of the SCell includes the dormant BWP.

4. The method according to claim 1, wherein The first timer is sCellDeactivationTimer, and the second timer is bwp-InactivityTimer, and The method further comprises: An operation of transitioning the SCell to a deactivated state due to expiration of the first timer is performed, and an operation of switching the active BWP of the SCell to the default BWP or the initial BWP due to expiration of the second timer is performed.

5. The method according to claim 1, wherein When data transmission and reception are not performed via the SCell in the activated state within a specific time period, the first timer expires, and In a case where the active BWP is not the default BWP, the second timer expires when data transmission and reception are not performed on the active BWP.

6. The method according to claim 1, further comprising: When the SCell is activated and the first active BWP is not the dormant BWP, the first timer is started.

7. A method for controlling at least one secondary cell (SCell) performed by a base station, the method comprising: transmitting a radio resource control (RRC) message, the RRC message including first information about a first timer for deactivation of the SCell, second information about a second timer, state information of the SCell, third information for configuring a first active broadband part (BWP), and fourth information for configuring a dormant BWP, The RRC message is used to determine whether the SCell is activated; The third information and the fourth information are used to determine whether the first active BWP of the SCell is the dormant BWP. Wherein, when the first active BWP of the SCell is the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled not to run, Wherein, when the first active BWP of the SCell is not the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled to run, and The second timer is a timer used to switch to the default BWP.

8. The method according to claim 7, further comprising: transmitting a medium access control MAC control element CE for changing the state of at least one of the SCells, The MAC CE and the RRC message are used to determine whether the SCell is activated. Wherein, in a case where the first active BWP of the SCell is the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled not to run, and Wherein, when the first active BWP of the SCell is not the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled to run.

9. The method according to claim 7, wherein: When the first timer expires, the SCell is transitioned to a deactivated state, and when the second timer expires, the active BWP of the SCell is switched to the default BWP or the initial BWP.

10. The method according to claim 7, wherein The RRC message includes information indicating the default BWP or initial BWP of the SCell, in, The first active BWP is the BWP that is activated for the first time, and A BWP of the SCell includes the dormant BWP.

11. A terminal for controlling at least one secondary cell (SCell), the terminal comprising: transceiver; as well as a processor connected to the transceiver and configured to: receiving a radio resource control (RRC) message including first information about a first timer for deactivation of the SCell, second information about a second timer, state information of the SCell, third information for configuring a first active broadband part (BWP), and fourth information for configuring a dormant BWP, determining whether the SCell is activated based on the RRC message, determining, based on the third information and the fourth information, whether the first active BWP of the SCell is the dormant BWP; Wherein, when the first active BWP of the SCell is the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled not to run; Wherein, when the first active BWP of the SCell is not the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled to run, and The second timer is a timer used to switch to the default BWP. The terminal according to claim 11 , wherein: The processor is further configured to: receiving a medium access control MAC control element CE for changing the state of at least one of the SCells; and determining whether the SCell is activated based on the RRC message and the MAC CE, Wherein, in a case where the first active BWP of the SCell is the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled not to run, and Wherein, when the first active BWP of the SCell is not the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled to run. The terminal according to claim 11 , wherein The RRC message includes information indicating the default BWP or initial BWP of the SCell, in, The first active BWP is the BWP that is activated for the first time, and A BWP of the SCell includes the dormant BWP. The terminal according to claim 11 , wherein The first timer is sCellDeactivationTimer, and the second timer is bwp-InactivityTimer, and The processor is further configured to execute an operation of transitioning the SCell to a deactivated state due to expiration of the first timer, and to execute an operation of switching the active BWP of the SCell to the default BWP or the initial BWP due to expiration of the second timer.

15. The terminal according to claim 11, wherein the processor is further configured to: When the SCell is activated and the first active BWP is not the dormant BWP, the first timer is started.

16. A base station for controlling at least one secondary cell (SCell), the base station comprising: transceiver; as well as a processor connected to the transceiver and configured to: transmitting a radio resource control (RRC) message, the RRC message including first information about a first timer for deactivation of the SCell, second information about a second timer, state information of the SCell, third information for configuring a first active broadband part (BWP), and fourth information for configuring a dormant BWP, The RRC message is used to determine whether the SCell is activated. The third information and the fourth information are used to determine whether the first active BWP of the SCell is the dormant BWP. Wherein, when the first active BWP of the SCell is the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled not to run, Wherein, when the first active BWP of the SCell is not the dormant BWP and the state information of the SCell is set to be activated in the RRC message, the second timer is controlled to run, and The second timer is a timer used to switch to the default BWP.

17. The base station according to claim 16, wherein: The processor is further configured to: transmitting a medium access control MAC control element CE for changing the state of at least one of the SCells, The MAC CE and the RRC message are used to determine whether the SCell is activated. Wherein, in a case where the first active BWP of the SCell is the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled not to run, and Wherein, when the first active BWP of the SCell is not the dormant BWP and the SCell is deactivated before receiving the MAC CE for activating the SCell, the second timer is controlled to run.

18. The base station according to claim 16, wherein: When the first timer expires, the SCell is transitioned to a deactivated state, and when the second timer expires, the active BWP of the SCell is switched to the default BWP or the initial BWP. The RRC message includes information indicating the default BWP or initial BWP of the SCell, The first active BWP is the BWP that is activated for the first time, and A BWP of the SCell includes the dormant BWP.

Images