Method and apparatus for improving carrier aggregation in next generation mobile communication system

Abstract

A method and apparatus for improving carrier aggregation in a next generation mobile communication system are disclosed. The present disclosure provides a method performed by a user equipment (UE) in a wireless communication system, the method comprising: receiving, from a base station, a radio resource control (RRC) message including configuration information of a secondary cell (SCell), the configuration information including semi-persistent scheduling information of the SCell; and clearing resources associated with semi-persistent scheduling information of the SCell for the SCell under the condition of meeting the condition of converting the SCell into a static state, and under the following condition, clearing the resources associated with the semi-persistent scheduling information of the SCell for the SCell. The condition is satisfied: information indicating a stationary state of the SCell is included in the configuration information, a Media Access Control (MAC) Control Unit (CE) for transitioning the SCell to a stationary state is received, and a sleep timer associated with the SCell expires.

Description

[0001] This application is a divisional application of an invention patent application with an application date of January 29, 2020, Chinese application number 202080011678.3, and invention name “Method and device for improving carrier aggregation in next-generation mobile communication systems”. Technical Field

[0002] The present disclosure relates to a method and apparatus for improving carrier aggregation in a next generation mobile communication system.

[0003] Furthermore, the present disclosure also relates to a method and apparatus for efficiently performing state transition in a next generation mobile communication system. Background Art

[0004] In order to meet the increased demand for wireless data services after the commercialization of 4G communication systems, efforts have been made to develop improved 5G communication systems or quasi-5G (pre-5G) communication systems. For this reason, 5G communication systems or quasi-5G communication systems are called super 4G network communication systems or post-LTE systems.

[0005] In order to achieve high data transmission rates, 5G communication systems are being considered for implementation in millimeter wave (mmWave) bands (e.g., 60 GHz bands). In 5G communication systems, technologies such as beamforming, massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, analog beamforming, and massive antennas are being discussed as means to mitigate propagation path losses in the millimeter wave bands and increase propagation transmission distances.

[0006] In addition, 5G communication systems have developed technologies to improve system networks, such as evolved small cells, advanced small cells, cloud radio access networks (RAN), ultra-dense networks, device-to-device communication (D2D), wireless backhaul, mobile networks, cooperative communications, cooperative multi-point (CoMP), and receive interference elimination. In addition, 5G systems have also developed advanced coding 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), and sparse code division multiple access (SCMA)).

[0007] Meanwhile, the Internet has evolved from a human-oriented connection network in which humans generate and consume information to an Internet of Things (IoT) network in which information is exchanged between distributed components such as objects. Internet of Everything (IoE) technology, in which big data processing technology connected to cloud servers and the like is combined with IoT technology, has emerged. In order to implement IoT, various technical elements (such as sensing technology, wired / wireless communication, network infrastructure, service interface technology, and security technology) are required, and technical research such as sensor networks, machine-to-machine (M2M) communication, machine-type communication (MTC), and similar technologies for connecting between objects have been conducted recently. In the IoT environment, by collecting and analyzing data generated in connected objects, intelligent Internet Technology (IT) services that create new value for people's lives can be provided. IoT can be applied to various fields such as smart homes, smart buildings, smart cities, smart cars, Internet of Vehicles, smart grids, health care, smart home appliances, or high-tech medical services through the integration of traditional information technology (IT) and various industries.

[0008] Therefore, various attempts have been made to apply 5G communication to IoT networks. For example, 5G communication technologies such as sensor networks, machine-to-machine (M2M) communication, and machine-type communication (MTC) have been implemented through technologies such as beamforming, MIMO, and array antennas. The application of cloud RAN as a big data processing technology can be an example of the fusion of 5G technology and IoT technology.

[0009] The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with respect to the present disclosure. Summary of the invention

[0010] Technical issues

[0011] In the next generation mobile communication system, carrier aggregation can be used to provide a service with a high data transmission rate and a low transmission delay to a terminal. However, there is a need for a method of preventing a processing delay that may be generated when carrier aggregation is configured in a terminal connected to a network and a carrier is activated or when carrier aggregation is used and then a carrier is deactivated.

[0012] Solution to the problem

[0013] According to one aspect of the present disclosure, a method for a user equipment (UE) in a wireless communication system is provided. The method includes: receiving a message including secondary cell (SCell) configuration information from a base station; identifying whether a condition for switching the SCell to a dormant state is met; and if the condition for switching the SCell to a dormant state is met, releasing periodic transmission resources for the SCell configured in the UE.

[0014] According to another aspect of the present disclosure, a user equipment (UE) in a wireless communication system is provided. The UE includes: a transceiver; and a controller configured to receive a message including secondary cell (SCell) configuration information through the transceiver, identify whether a condition for converting the SCell to a static state is met, and release periodic transmission resources for the SCell configured in the UE when the condition for converting the SCell to a static state is met.

[0015] According to one aspect of the present disclosure, a method performed by a user equipment UE in a wireless communication system is provided, the method comprising: receiving a radio resource control RRC message including configuration information of a secondary cell SCell from a base station, the configuration information including semi-persistent scheduling information of the SCell; and clearing resources associated with the semi-persistent scheduling information of the SCell for the SCell when a condition for transitioning the SCell to a dormant state is met, wherein the condition is met in the following cases: information indicating the dormant state of the SCell is included in the configuration information, a media access control MAC control unit CE for transitioning the SCell to a dormant state is received, and a sleep timer associated with the SCell expires.

[0016] According to one aspect of the present disclosure, a user equipment UE in a wireless communication system is provided, the UE comprising: a transceiver; and a controller coupled to the transceiver and configured to: receive a radio resource control RRC message including configuration information of a secondary cell SCell from a base station, the configuration information including semi-persistent scheduling information of the SCell, and clear resources associated with the semi-persistent scheduling information of the SCell for the SCell when a condition for converting the SCell to a dormant state is met, wherein the condition is met in the following cases: information indicating the dormant state of the SCell is included in the configuration information, a media access control MAC control unit CE for converting the SCell to a dormant state is received, and a sleep timer associated with the SCell expires.

[0017] Disclosure of beneficial effects

[0018] The present disclosure proposes a new stationary mode to allow a UE in an RRC connected mode connected to a network to quickly activate and deactivate carrier aggregation in a next generation mobile communication system. The present disclosure proposes a method for operating a new stationary mode in a cell unit (cell level) and a method for operating a stationary (or dormant) mode in a bandwidth portion unit (bandwidth portion level), thereby quickly activating carrier aggregation and saving the battery of the UE.

[0019] Before proceeding to the following detailed description, it may be helpful to set forth definitions of certain words and phrases used in this patent document: the terms "include" and "comprising" and their derivatives, mean including but not limited to; the term "or" is inclusive, meaning and / or; the phrases "associated with" and "associated with" and their derivatives may mean including, included within, interconnected with, containing, contained within, connected to or connected with, coupled to or coupled with, communicable with, cooperating with, interlaced with, juxtaposed with, proximate to, bound to or bound with, having, having properties of, etc.; and the term "controller" refers to any device, system, or portion thereof that controls at least one operation, such device may be implemented in hardware, firmware, or software, or some combination of at least two thereof. It should be noted that the functionality associated with any particular controller may be centralized or distributed, whether local or remote.

[0020] In addition, the various functions described below can be implemented or supported by one or more computer programs, each of which is formed by a computer-readable program code and embodied in a computer-readable medium. The terms "application" and "program" refer to one or more computer programs, software components, instruction sets, processes, functions, objects, classes, instances, related data, or a portion thereof suitable for implementation in a suitable computer-readable program. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium that can be accessed by a computer, such as a read-only memory (ROM), a random access memory (RAM), a hard drive, a compact disk (CD), a digital video disk (DVD), or any other type of memory. "Non-transitory" computer-readable media do not include wired, wireless, optical, or other communication links that transmit temporary electrical or other signals. Non-transitory computer-readable media include media that can permanently store data and media in which data can be stored and rewritten later, such as rewritable optical disks or erasable memory devices.

[0021] Definitions for certain words and phrases are provided within this patent document, those of ordinary skill in the art should understand that in many, if not most, instances, such definitions apply to prior, as well as future uses of such defined words and phrases. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] For a more complete understanding of the present disclosure and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, wherein like reference numerals represent like parts:

[0023] Figure 1A shows the structure of an LTE system to which the present disclosure can be applied;

[0024] Figure 1B Showing the structure of a wireless protocol in an LTE system to which the present disclosure can be applied;

[0025] Figure 1C Showing the structure of a next-generation mobile communication system to which the present disclosure can be applied;

[0026] Figure 1D To show the structure of a wireless protocol of a next-generation mobile communication system to which the present disclosure can be applied;

[0027] Figure 1E A procedure for serving UE by effectively using a very wide frequency bandwidth in a next generation mobile communication system according to the present disclosure is shown;

[0028] Figure 1F A process of switching a UE from an RRC idle mode to an RRC connected mode in a next generation mobile communication system is shown, which is a method of configuring multiple bandwidth parts (BWPs) and configuring a default BWP or a first active BWP;

[0029] Figure 1G The state transition process of the cell or BWP proposed in the present disclosure is shown;

[0030] Figure 1H The method proposed in the present disclosure for converting the state of a BWP by performing state conversion in units of Scells is shown;

[0031] Fig. 1I The MAC control information indicating the state transition to the active state, the dormant state or the inactive state proposed in the present disclosure is shown;

[0032] Figure 1J UE operations for performing state transition of a cell configured in the UE according to the present disclosure are shown;

[0033] Figure 1K The structure of a UE to which the embodiments of the present disclosure can be applied is shown;

[0034] Figure 1L A block diagram showing a TRP in a wireless communication system to which embodiments of the present disclosure may be applied;

[0035] Figure 2A shows the structure of an LTE system to which the present disclosure can be applied;

[0036] Figure 2B Showing the structure of a wireless protocol in an LTE system to which the present disclosure can be applied;

[0037] Figure 2C Showing the structure of a next-generation mobile communication system to which the present disclosure can be applied;

[0038] Figure 2D To illustrate a wireless protocol structure of a next generation mobile communication system to which the present disclosure can be applied;

[0039] Figure 2E A process of serving UE by effectively using frequency bandwidth in a next generation mobile communication system according to the present disclosure is shown;

[0040] Figure 2F A process of switching a UE from an RRC idle mode to an RRC connected mode in a next generation mobile communication system is shown, which is a method of configuring multiple bandwidth parts (BWPs) and configuring a default BWP or a first active BWP;

[0041] Figure 2G The state transition process of the cell or BWP proposed in the present disclosure is shown;

[0042] Figure 2H The method proposed in the present disclosure for converting the BWP state by performing state conversion in units of BWP is shown;

[0043] Fig.2I The MAC control information indicating the state transition to the active state, the dormant state or the inactive state proposed in the present disclosure is shown;

[0044] Figure 2J UE operations for performing state transition of a cell configured in the UE according to the present disclosure are shown;

[0045] Figure 2K shows the structure of a UE to which the embodiments of the present disclosure can be applied; and

[0046] Figure 2L A block diagram showing a TRP in a wireless communication system to which an embodiment of the present disclosure can be applied. DETAILED DESCRIPTION

[0047] Discussed below Figures 1A to 2L The various embodiments used to describe the principles of the present disclosure in this patent document are for illustration only and should not be construed in any way to limit the scope of the present disclosure. Those skilled in the art will appreciate that the principles of the present disclosure can be implemented in any suitably arranged system or device.

[0048] Hereinafter, the operating principle of the present disclosure will be described in detail with reference to the accompanying drawings. When describing the present disclosure below, when it is determined that its detailed description may unnecessarily confuse the subject matter of the present disclosure, the detailed description of the relevant known configuration or function incorporated herein will be omitted. The terms to be described below are defined in consideration of the functions in the present disclosure, and may vary depending on the user, the user's intention or habit. Therefore, the definition of the term should be based on the content of the entire specification.

[0049] When describing the present disclosure below, detailed description of related known configurations or functions incorporated herein will be omitted when it is determined that a detailed description thereof may unnecessarily obscure the subject matter of the present disclosure. Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings.

[0050] In the following description, for the convenience of description, terms used to identify access nodes, terms related to network entities, terms related to messages, terms related to interfaces between network entities, and terms related to various identification information are used. Therefore, the present disclosure is not limited to the following terms, and other terms with the same technical meaning may be used.

[0051] For convenience 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, and may be equally applied to a system according to another standard. In the present disclosure, for convenience of description, the term "eNB" may be interchangeable with "gNB". That is, a base station described as an eNB may indicate a gNB.

[0052] Figure 1A The structure of an LTE system to which the present disclosure is applicable is shown.

[0053] refer to Figure 1A The radio access network of the LTE system includes next-generation base stations (evolved node B) (hereinafter, referred to as ENB, Node B or base station) 1a-05, 1a-10, 1a-15 and 1a-20, mobility management entity (MME) 1a-25 and serving gateway (S-GW) 1a-30. User terminals (user equipment) (hereinafter, referred to as UE or terminal) 1a-35 access external networks through ENB 1a-05 to 1a-20 and S-GW 1a-30.

[0054] exist Figure 1AIn the LTE system, ENBs 1a-05 to 1a-20 correspond to existing Node Bs of the UMTS system. The ENB is connected to the UE 1a-35 through a radio channel, and plays a more complex role than a conventional Node B. In the LTE system, since all user traffic including real-time services such as Voice over IP (VoIP) via Internet Protocol is served through a shared channel, a means for collecting and scheduling status information about a buffer status, an available transmission power status, and a channel status of the UE is required, and the ENBs 1a-05 to 1a-20 serve as the means.

[0055] One ENB generally controls multiple cells. For example, in order to achieve a transmission rate of 100 Mbps, the LTE system uses Orthogonal Frequency Division Multiplexing (OFDM) as a wireless access technology at a 20 MHz bandwidth. In addition, according to the channel state of the UE, an Adaptive Modulation and Coding (AMC) scheme that determines the modulation scheme and channel coding rate is applied.

[0056] The S-GW 1a-30 is a device for providing a data bearer, and generates or removes a data bearer under the control of the MME 1a-25. The MME is a device for performing not only a function of managing the mobility of UE but also various control functions, and is connected to a plurality of ENBs.

[0057] Figure 1B A structure of a wireless protocol in an LTE system to which the present disclosure can be applied is shown.

[0058] refer to Figure 1B , UE and ENB each include packet data convergence protocol (PDCP) 1b-05 and 1b-40, radio link control (RLC) 1b-10 and 1b-35, and medium access control (MAC) 1b-15 and 1b-30 in the wireless protocol of the LTE system. Packet data convergence protocol (PDCP) 1b-05 and 1b-40 perform the operation of compressing / reconstructing the IP header. The main functions of PDCP are described as follows.

[0059] -Header compression and decompression function (Header compression and decompression: ROHC only)

[0060] -User data transmission function (user data transmission)

[0061] - In-sequence delivery function (deliver upper-layer PDUs in sequence during PDCP re-establishment procedure for RLC AM)

[0062] - Resequence function (for split bearers in DC (supports RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

[0063] - Duplicate detection function (duplicate detection of lower layer SDUs during PDCP re-establishment process for RLC AM)

[0064] - Retransmission functionality (retransmission of PDCP SDUs during handover for split bearers in DC and retransmission of PDCP PDUs during PDCP data recovery procedure for RLC AM)

[0065] -Encryption and decryption functions (encryption and decryption)

[0066] - Timer-based SDU removal functionality (timer-based SDU discard in uplink)

[0067] Radio Link Control (RLC) 1b-10 and 1b-35 reconfigures the PDCP packet data unit (PDU) to a suitable size and performs automatic repeat request (ARQ) operations. The main functions of RLC are described as follows.

[0068] -Data transmission function (transmission of upper layer PDU)

[0069] -ARQ function (error correction through ARQ (only for AM data transmission))

[0070] - Concatenation, segmentation and reassembly function (concatenation, segmentation and reassembly of RLC SDU (only for UM and AM data transmission))

[0071] - Re-segmentation function (resegment RLC data PDU (only for AM data transmission))

[0072] - Reordering function (reorder RLC data PDU (only for UM and AM data transmission)

[0073] - Duplicate detection function (Duplicate detection (only for UM and AM data transmission))

[0074] - Error detection function (protocol error detection (for AM data transmission only))

[0075] -RLC SDU deletion function (RLC SDU discard (only for UM and AM data transmission))

[0076] -RLC reestablishment function (RLC reestablishment)

[0077] MAC 1b-15 and 1b-30 are connected with various RLC layer devices included in one UE, and perform operations for multiplexing RLC PDUs to MAC PDUs and demultiplexing RLC PDUs from MAC PDUs. The main functions of MAC are described as follows.

[0078] - Mapping function (mapping between logical channels and transport channels)

[0079] - Multiplexing and demultiplexing functions (multiplexing / demultiplexing MAC SDUs belonging to one or more different logical channels to / from a transport block (TB) delivered to / from the physical layer on a transport channel)

[0080] -Scheduling information reporting function (Scheduling information reporting)

[0081] -HARQ function (error correction through HARQ)

[0082] -Logical channel priority control function (priority processing between logical channels of a UE)

[0083] -UE priority control function (prioritization between UEs with the help of dynamic scheduling)

[0084] -MBMS service identification function (MBMS service identification)

[0085] -Transmission format selection function (transmission format selection)

[0086] -Filling function (fill)

[0087] PHY layers 1b-20 and 1b-25 perform operations for: channel encoding and modulating higher layer data to generate OFDM symbols, and sending the OFDM symbols through a radio channel; or, demodulating and channel decoding OFDM symbols received through a radio channel, and transmitting the demodulated and channel-decoded OFDM symbols to a higher layer.

[0088] Figure 1C Shown is a structure of a next-generation mobile communication system to which the present disclosure can be applied.

[0089] refer to Figure 1C , the radio access network of the next generation mobile communication system (hereinafter referred to as NR or 5G) includes a next generation base station 1c-10 (new radio node B) (hereinafter referred to as NR gNB or NR base station) and a new radio core network (NR CN) 1c-05. The user terminal (new radio user equipment) (hereinafter referred to as NR UE or UE 1c-15) accesses the external network through the NR gNB 1c-10 and NR CN 1c-05.

[0090] exist Figure 1CIn the present invention, NR gNB 1c-10 corresponds to the evolved Node B (eNB) of the conventional LTE system. NR gNB can be connected to NR UE 1c-15 through a radio channel and can provide better service than the conventional Node B. Since all user services are served through shared channels in the next generation mobile communication system, a device for collecting and scheduling status information of the UE's buffer status, available transmission power status, and channel status is required, and the device corresponds to NR gNB1c-10. One NR gNB generally controls multiple cells. NR gNB can have a bandwidth wider than the conventional maximum bandwidth in order to implement ultra-high-speed data transmission compared to conventional LTE, orthogonal frequency division multiplexing (OFDM) can be applied through radio access technology, and beamforming technology can also be applied.

[0091] In addition, according to the channel state of the UE, an adaptive modulation and coding (AMC) scheme that determines the modulation scheme and channel coding rate is applied. NR CN 1c-05 performs functions of supporting mobility, configuring bearers, and configuring QoS. NR CN is a device for performing functions of managing the mobility of UE and various control functions, and is connected to multiple gNBs. In addition, the next-generation mobile communication system can be linked to the conventional LTE system, and NR CN is connected to MME 1c-25 through a network interface. MME is connected to eNB 1c-30, which is a conventional base station.

[0092] Figure 1D The structure of a wireless protocol of a next-generation mobile communication system to which the present disclosure can be applied is shown.

[0093] refer to Figure 1D The radio protocols of the next generation mobile communication system include NR SDAP 1d-01 and 1d-45, NR PDCP 1d-05 and 1d-40, NR RLC 1d-10 and 1d-35, and NR MAC 1d-15 and 1d-30 in UE and NR gNB.

[0094] The main functions of NR SDAP 1d-01 and 1d-45 may include some of the following functions.

[0095] -User data transmission function (user plane data transmission)

[0096] - Functionality to map QoS flows and data bearers for uplink and downlink (mapping between QoS flows and DRBs for both DL and UL)

[0097] - Function to mark QoS flow ID for uplink and downlink (mark QoS flow ID in both DL packet and UL packet)

[0098] - Functionality to map reflective QoS flows for uplink SDAP PDUs to data bearers (Reflective QoS flows to DRB mapping for UL SDAP PDUs)

[0099] For SDAP layer devices, the UE may receive configuration regarding whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, each bearer, or each logical channel through an RRC message. If the SDAP header is configured, the 1-bit indicator of NAS reflected QoS and the 1-bit indicator of AS reflected QoS may indicate to the UE to update or reconfigure information regarding the mapping of QoS flows and data bearers in the uplink and downlink. The SDAP header may include QoS flow ID information indicating QoS. QoS information may be used as data processing priority or scheduling information to support seamless services.

[0100] The main functions of NR PDCP 1d-05 or 1d-40 may include some of the following functions.

[0101] -Header compression and decompression function (Header compression and decompression: ROHC only)

[0102] -User data transmission function (user data transmission)

[0103] - Sequence delivery function (deliver upper layer PDUs in sequence)

[0104] - Out-of-order delivery function (deliver upper layer PDU out of order)

[0105] - Reordering function (PDCP PDU reordering for reception)

[0106] -Duplicate detection function (duplicate detection of lower layer SDU)

[0107] -Retransmission function (retransmit PDCP SDU)

[0108] -Encryption and decryption functions (encryption and decryption)

[0109] - Timer-based SDU removal functionality (timer-based SDU discard in uplink)

[0110] The reordering function of the NR PDCP device is a function of sequentially reordering the PDCP PDUs received by the lower layer based on the PDCP sequence number (SN), and may include a function of sequentially transmitting the reordered data to a higher layer, a function of directly transmitting the data regardless of the order, a function of recording the PDCP PDUs lost due to reordering, a function of reporting the status of the lost PDCP PDUs to the transmitting side, and a function of making a request for retransmitting the lost PDCP PDUs.

[0111] The main functions of NR RLC 1d-10 or 1d-35 may include some of the following functions.

[0112] -Data transmission function (upper layer PDU transmission)

[0113] - Sequence delivery function (deliver upper layer PDUs in sequence)

[0114] - Out-of-order delivery function (deliver upper layer PDU out of order)

[0115] -ARQ function (error correction through ARQ)

[0116] - Concatenation, segmentation and reassembly functions (concatenation, segmentation and reassembly of RLC SDUs)

[0117] - Re-segmentation function (resegmentation of RLC data PDU)

[0118] - Reordering function (reorder RLC data PDU)

[0119] -Duplicate detection function (duplicate detection)

[0120] -Error detection function (protocol error detection)

[0121] -RLC SDU deletion function (RLC SDU discard)

[0122] -RLC reestablishment function (RLC reestablishment)

[0123] The sequential delivery function (in-sequence delivery) of the NR RLC device is a function of sequentially delivering PDCP PDUs received from a lower layer to a higher layer, and may include a function of reassembling and delivering RLC SDUs (when one original RLC SDU is divided into multiple RLC SDUs and then received), a function of reordering received RLC PDUs based on an RLC sequence number (SN) or a PDCP SN, a function of recording RLC PDUs lost due to reordering, a function of reporting the status of lost RLC PDUs to a transmitting side, a function of making a request for retransmission of lost PDCP PDUs, a function of sequentially delivering only RLC SDUs before the lost RLC SDU if there is a lost RLC SDU, a function of sequentially delivering all RLC SDUs received before the timer is started and a predetermined timer expires when there is a lost RLC SDU, or a function of sequentially delivering all RLC SDUs received up to this point in time to a higher layer when a predetermined timer expires when there is a lost RLC SDU. In addition, the NR RLC device can process the RLC PDUs sequentially in the order in which the RLC PDUs are received (according to the arrival order regardless of the sequence number or order number), and can transmit the RLC PDUs to the PDCP device regardless of the order of the RLC PDUs (out-of-order delivery). In the case of segmentation, the NR RLC device can receive segments stored in the buffer or to be received in the future, reconfigure the segments into one RLC PDU, process the RLC PDU, and then send the RLC PDU to the PDCP device. The NR RLC layer may not include a cascading function, and the function may be performed by the NR MAC layer or may be replaced by a multiplexing function of the NR MAC layer.

[0124] The out-of-order function (out-of-order delivery) of the NR RLC device is a function of directly transmitting the RLC SDU received from the lower layer to the higher layer without considering the order of the RLC SDU, and may include a function of reassembling and transmitting the RLC PDU (when one original RLC SDU is divided into multiple RLC SDUs and then received) and a function of storing the RLC SN or PDCP SN of the received RLC PDU, reordering the RLC PDU, and recording the lost RLC PDU.

[0125] NR MAC 1d-15 and 1d-30 can be connected to multiple NR RLC layer devices configured in one UE, and the main functions of NR MAC may include some of the following functions.

[0126] - Mapping function (mapping between logical channels and transport channels)

[0127] -Multiplexing and demultiplexing functions (multiplexing / demultiplexing MAC SDU)

[0128] -Scheduling information reporting function (Scheduling information reporting)

[0129] -HARQ function (error correction through HARQ)

[0130] -Logical channel priority control function (priority processing between logical channels of a UE)

[0131] -UE priority control function (prioritization between UEs with the help of dynamic scheduling)

[0132] -MBMS service identification function (MBMS service identification)

[0133] -Transmission format selection function (transmission format selection)

[0134] -Filling function (fill)

[0135] PHY layers 1d-20 and 1d-25 perform operations for: channel coding and modulating data of a higher layer to generate OFDM symbols, and transmitting the OFDM symbols through a radio channel; or, demodulating and channel decoding OFDM symbols received through a radio channel, and transmitting the demodulated and channel-decoded OFDM symbols to a higher layer.

[0136] The present disclosure proposes a method for quickly activating carrier aggregation and saving UE battery in a next generation mobile communication system.

[0137] The network or gNB can configure Spcell (Pcell or PScell) and multiple Scells in the UE. When the UE communicates with one gNB, Spcell refers to Pcell; when the UE communicates with two gNBs (primary gNB and secondary gNB), Spcell refers to the Pcell of the primary gNB or the PScell ​​of the secondary gNB.

[0138] Pcell and Pscell are primary cells used by each MAC layer device for communication between UE and gNB, and correspond to cells used for synchronizing timing, performing random access, sending HARQ ACK / NACK feedback through PUCCH transmission resources, and exchanging most control signals. The technology in which gNB operates multiple Scells and Spcells to increase transmission resources for uplink or downlink is called carrier aggregation.

[0139] After receiving the configuration of the Spcell and multiple Scells, the UE may receive the configuration of the mode for each Scell. The mode of the Scell ​​may include an active mode and an inactive (deactivated mode).

[0140] In active mode, the UE can transmit uplink data to the gNB and receive downlink data from the gNB in ​​the Scell ​​in active mode (or the activated bandwidth part of the Scell). In addition, the UE can monitor the PDCCH for an indication of identifying the gNB, measure the downlink channel for the Scell ​​in active mode (or the activated bandwidth part of the Scell), periodically report the measurement information to the gNB, and periodically transmit a pilot signal (sounding reference signal: SRS) to the gNB so that the gNB can measure the uplink channel.

[0141] However, in inactive mode, the UE may not transmit data to or receive data from the gNB in ​​the Scell, not monitor the PDCCH for indication of identifying the gNB, not measure channels, not report measurements, and not transmit pilot signals.

[0142] Therefore, in order to activate Scell ​​in inactive mode, the gNB first configures measurement configuration information in the UE through an RRC message, and the UE measures the cell or frequency based on the measurement configuration information. In addition, after receiving the cell or frequency measurement report from the UE, the gNB can activate the deactivated Scell ​​based on the frequency / channel measurement information. Therefore, when the gNB activates carrier aggregation for the UE, much delay is generated.

[0143] The present disclosure proposes a dormant mode for Scell ​​(or bandwidth portion) to reduce delay and save UE battery.

[0144] In the stationary mode, the UE may not transmit or receive data to or from the gNB in ​​the stationary Scell ​​or stationary bandwidth part (BWP), may not monitor the PDCCH for indications identifying the gNB, and may not transmit pilot signals. However, the UE in the stationary mode may measure the channel and report the measurement results of the measured frequency / cell / channel periodically or when an event is generated according to the gNB configuration. Therefore, the UE neither monitors the PDCCH nor transmits pilot signals in the stationary Scell ​​or stationary BWP, thereby saving battery (compared to the active mode). Unlike in the inactive mode, the UE reports the channel measurements, so the gNB can quickly activate the stationary Scell ​​or stationary BWP based on the measurement report and use carrier aggregation.

[0145] Since frequencies of significantly high bands can be used in the next generation mobile communication system, the frequency bandwidth can also be very wide. However, in UE implementation, fully supporting very wide bandwidths requires high implementation complexity, which leads to high costs. Therefore, the next generation mobile communication system can introduce the concept of bandwidth part (BWP), so multiple BWPs can be configured in one cell (Spcell or Scell), and the UE and gNB can transmit and receive data in one or more BWPs according to the configuration of the gNB.

[0146] When introducing the stationary mode proposed in the present disclosure, the present disclosure considers Scell ​​and a plurality of bandwidth parts configured in the Scell, and proposes a state transition (or switching) method and its detailed operation. In addition, the present disclosure proposes a method for managing the stationary mode and the transition state in units of Scell ​​(Scell ​​level) and a method for managing the stationary mode and the transition state in units of bandwidth parts (BWP level), and proposes detailed operations according to the bandwidth parts of each mode (active, inactive or stationary mode).

[0147] In the present disclosure, BWP may be used without distinguishing between uplink and downlink, and the meaning of BWP may be uplink BWP or downlink BWP according to the context.

[0148] Figure 1E A process of serving UE by effectively using a frequency bandwidth in a next generation mobile communication system according to the present disclosure is shown.

[0149] exist Figure 1E In the present invention, a method for providing services to UEs with different capabilities or categories by efficiently using frequency bandwidth and saving battery in a next generation mobile communication system is described.

[0150] One cell provided by NR gNB can serve a very wide frequency bandwidth of 1e-05. However, in order to provide services to UEs with different capabilities, the wide frequency bandwidth can be divided into multiple bandwidth parts to manage one cell.

[0151] First, the turned-on UE may search the entire frequency band provided by the service provider (PLMN) in units of predetermined resource blocks (e.g., in units of 12 resource blocks (RBs)). That is, the UE may start to discover the primary synchronization sequence (PSS) / secondary synchronization sequence (SSS) in the entire system bandwidth in units of resource blocks, as shown in reference numeral 1e-10.

[0152] If the UE searches for PSS / SSS1e-01 or 1e-02 in units of resource blocks and then detects a signal, the UE can read the signal, analyze (decode) the signal, and identify the boundary between the subframe and the radio transmission resource frame (radio frame). Therefore, the UE can identify the subframe in units of 1ms and synchronize the downlink signal with the NR gNB. A resource block (RB) is the size of a predetermined frequency resource and a predetermined time resource and can be defined as a two-dimensional unit. For example, a time resource can be defined in units of 1ms, and a frequency resource can be defined as 12 subcarriers (1carrier x 15kHz = 180kHz).

[0153] When the UE completes synchronization, the UE can identify information about the control resource set (CORESET) by checking the master system information block (MIB) or the minimum system information (MSI), and identify the initial access bandwidth part (BWP) information, as shown in the figure marks 1e-15 and 1e-20.

[0154] The CORESET information refers to the resource through which the control signal is transmitted from the NR gNB, and may be, for example, the location of the resource through which the PDCCH channel is transmitted. That is, the CORESET information is information indicating the resource through which the first system information (system information block 1: SIB 1) is transmitted, and indicates the frequency / time resource through which the PDCCH is transmitted.

[0155] The UE may identify information about the initial bandwidth part (BWP) by reading the first system information. As described above, if the UE completes synchronization of the downlink signal with the NR gNB and is able to receive the control signal, the UE may perform a random access procedure in the initial bandwidth part (BWP) of the cell on which the UE resides, make a request for configuring an RRC connection, receive an RRC message, and perform RRC connection configuration.

[0156] In the RRC connection configuration, multiple bandwidth parts can be configured in each cell (Pcell, Pscell, Spcell or Scell). Multiple bandwidth parts can be configured in one cell for downlink, and separately, multiple bandwidth parts can be configured for uplink.

[0157] Multiple bandwidth portions may be indicated and configured by a BSP identifier to serve as an initial BWP, a default BWP, or a first active BWP.

[0158] The initial BWP may be used as a cell-specific BWP in which one exists per cell, and may be used as a BWP in which a UE initially accessing a cell may configure a connection in the cell through a random access procedure, or a UE configuring a connection may perform synchronization.

[0159] The NR gNB may configure, for each cell, an initial downlink BWP to be used in the downlink and an initial uplink BWP to be used in the uplink.

[0160] The configuration information of the initial BWP can be broadcast through the first system information (system information 1: SIB 1) indicated by CORESET, and can be configured again in the UE accessing the NR gNB through RRC messages.

[0161] The initial BWP may be used while being designated with BWP identifier number 0 in each of the uplink and downlink. That is, all UEs accessing the same cell may equally designate the same initial BWP as BWP identifier number 0. This provides an advantage of easily performing a contention-based random access procedure because the NR gNB may transmit a random access response (RAR) message in the initial BWP that all UEs may read during the random access procedure.

[0162] The first active BWP may be configured as UE-specific and may be assigned to and indicated by an identifier of a BWP among a plurality of BWPs. The first active BWP may be configured for each of a downlink and an uplink and may include a first active downlink BWP and a first active uplink BWP configured as respective BWP identifiers.

[0163] When multiple BWPs are configured in a cell, the first active BWP can be used to indicate which BWP is activated and used first. For example, when a Pcell or Pscell and multiple Scells are configured in the UE and multiple BWPs are configured in each Pcell or Pscell or each Scell, if the Pcell, Pscell or Scell ​​is activated, the UE can activate and use the first active BWP among the multiple BWPs configured in the Pcell, Pscell or Scell. That is, the first active downlink BWP can be activated and used for the downlink, and the first active uplink BWP can be activated and used for the uplink.

[0164] After receiving information indicating activation of the Scell ​​or BWP through an RRC message, MAC control information, or DCI, the UE may perform an operation of switching the downlink BWP of the Scell ​​to the BWP indicated by the RRC message (e.g., the first active downlink BWP) to activate the downlink BWP, and switching the uplink BWP to the BWP indicated by the RRC message (e.g., the first active uplink BWP) to activate the uplink BWP. Alternatively, the UE may perform the operation upon receiving an indication indicating that the Scell ​​or BWP transitions to a stationary state through an RRC message, MAC control information, or DCI. This is because when transmitting a channel measurement report in a stationary state, the NR gNB can effectively use carrier aggregation by measuring and reporting the frequency / channel used for the first active downlink / uplink BWP, because when activating the Scell ​​or BWP, the UE switches the downlink BWP to the first active downlink and activates the downlink BWP, and switches the uplink BWP to the first active uplink BWP and activates the uplink BWP.

[0165] The default BWP may be configured as UE-specific and may be assigned to and indicated by an identifier of a BWP among multiple BWPs. The default BWP may be configured for downlink only. The default BWP may be used as a BWP to which an activated BWP among multiple downlinks falls back after a predetermined time.

[0166] For example, a BWP inactivity timer may be configured through an RRC message for each cell or each BWP, and the timer may be started or restarted when data transmission / reception occurs in an activated BWP instead of a default BWP, or may be started or restarted when an activated BWP is switched to another BWP.

[0167] If the timer expires, the UE may roll back or switch the activated downlink BWP in the cell to the default BWP. The switch may be a process of deactivating the currently activated BWP and activating the BWP to be switched to, and may be triggered by an RRC message, MAC control information (MAC control element), or L1 signaling (downlink control information (DCI) of PDCCH). The switch may be triggered by an indication of the BWP to be activated or switched to, and the BWP may be indicated by a BWP identifier (e.g., 0, 1, 2, 3, or 4).

[0168] The reason why the default BWP is used only for downlink is to facilitate NR gNB scheduling, because the NR gNB allows the UE to receive the indication of the NR gNB (e.g., DCI of PDCCH) after a predetermined time by falling back to the default BWP for each cell. For example, if the NR gNB configures the default BWP of a UE accessing a cell as the initial BWP, the NR gNB can continuously transmit scheduling indications only in the initial BWP after a predetermined time. If the default BWP is not configured through the RRC message, the default BWP can fall back to the initial BWP by treating the initial BWP as the default BWP when the BWP inactivity timer expires.

[0169] In another method, in order to increase the implementation freedom of Nr gNB, a default BWP for uplink can be defined and configured, so the default BWP for uplink can be used like the default BWP for downlink.

[0170] Figure 1F The present invention shows a process of UE switching from RRC idle mode to RRC connected mode in a next generation mobile communication system, which is a method of configuring multiple bandwidth parts (BWPs) and configuring a default BWP or a first active BWP.

[0171] One cell to which the gNB provides services may serve a very wide frequency band. First, the UE may search the entire frequency band provided by the service provider (PLMN) in units of predetermined resource blocks (e.g., in units of 12 resource blocks (RBs)). That is, the UE may start to discover the primary synchronization sequence (PSS) / secondary synchronization sequence (SSS) in the entire system bandwidth in units of resource blocks.

[0172] If the UE searches for PSS / SSS in resource block units and then detects a signal, the UE can read the signal, analyze (decode) the signal, and identify the boundary between the subframe and the radio transmission resource frame (radio frame). If the UE completes synchronization, the UE can read the system information of the cell on which the UE currently resides. That is, the UE can identify information about the control resource set (CORESET) by checking the master system information block (MIB) or the minimum system information (MSI) in steps 1f-01 and 1f-05, and identify the initial access bandwidth part (BWP) information by reading the system information. The CORESET information refers to the location of the time / frequency transmission resource through which the control signal is transmitted from the gNB, and may be, for example, the location of the resource through which the PDCCH channel is transmitted.

[0173] As described above, if the UE completes synchronization of downlink signals with the gNB and is able to receive control signals, the UE can perform a random access procedure in the initial BWP in steps 1f-10, 1f-15, 1f-20, 1f-25, and 1f-30, receive a random access response, make a request to configure an RRC connection, receive an RRC message, and configure an RRC connection.

[0174] If the basic RRC connection is fully configured, the gNB may transmit an RRC message (UECapabilityEnquire) to query the UE capabilities to identify the UE capabilities in 1f-35. In another method, the gNB may inquire (or request) the MME or AMF for the UE capabilities to identify the UE capabilities. This is because if the MME or AMF accesses the UE, the MME or AMF may have the UE capability information. If the gNB does not have the requested UE capabilities, the gNB may request the UE capabilities from the UE. Alternatively, the gNB may store the UE capability information, in which case step 1f-35 may be omitted.

[0175] The reason why the gNB transmits an RRC message to the UE to identify the UE capabilities is to identify the UE capabilities, such as information indicating the frequency bands that the UE can read or the areas of the frequency bands that the UE can read. After identifying the UE capabilities, the gNB can configure an appropriate BWP in the UE.

[0176] If the UE receives an RRC message querying the UE capabilities, the UE may transmit information in step 1f-40, the information including information indicating the bandwidth range supported by the UE, information indicating an offset relative to a reference center frequency to indicate the bandwidth range supported in the current system bandwidth, information directly indicating the start and end points of the supported frequency bandwidth, or information indicating the center frequency and bandwidth.

[0177] The BWP can be configured through the RRCSetup message or RRCResume message of the RRC connection configuration in step 1f-25 or the RRCReconfiguration message in step 1f-45. The RRC message may include configuration information of a PCell, a Pscell or multiple Scells, and multiple BWPs may be configured for each cell (PCell, Pscell or Scell).

[0178] When multiple BWPs are configured for each cell, multiple BWPs to be used in the downlink of each cell can be configured. In the case of an FDD system, multiple BWPs to be used in the uplink of each cell can be configured to distinguish from the downlink BWP. In the case of a TDD system, multiple BWPs to be used in both the downlink and uplink of each cell can be configured.

[0179] The information used to configure the BWP of each cell (PCell, Pscell or Scell) may include at least one of the following information.

[0180] -Downlink BWP configuration information of the cell

[0181] ■ Initial downlink BWP configuration information

[0182] ■ Multiple BWP configuration information and BWP IDs corresponding to respective BWPs

[0183] ■ Indicates the BWP ID of the first active downlink BWP

[0184] ■Indicates the BWP ID of the default BWP

[0185] ■BWP inactivity timer configuration and timer value

[0186] - Uplink BWP configuration information of the cell

[0187] ■ Initial uplink BWP configuration information

[0188] ■ Multiple BWPS configuration information and BWP IDs corresponding to respective BWPs

[0189] ■ Indicates the BWP ID of the first active uplink BWP

[0190] The configured initial BWP, default BWP, or first active BWP may be used for the following purposes and may be operated to achieve the purposes.

[0191] The initial BWP may be used as a cell-specific BWP in which one exists per cell, and may be used as a BWP in which a UE initially accessing a cell may configure a connection in the cell through a random access procedure, or a UE configuring a connection may perform synchronization.

[0192] The NR gNB may configure, for each cell, an initial downlink BWP to be used in the downlink and an initial uplink BWP to be used in the uplink.

[0193] The configuration information of the initial BWP can be broadcast through the first system information (system information 1: SIB 1) indicated by CORESET, and can be configured again in the UE to which the NR gNB is connected through an RRC message.

[0194] The initial BWP can be used while being designated with BWP identifier number 0 in each of the uplink and downlink. That is, all UEs accessing the same cell can equally designate the initial BWP to the same BWP identifier number 0. This provides an advantage of easily performing a contention-based random access procedure because the NR gNB can transmit a random access response (RAR) message in the initial BWP that all UEs can read during the random access procedure.

[0195] The first active BWP may be configured as UE-specific and may be assigned to and indicated by an identifier of a BWP among a plurality of BWPs. The first active BWP may be configured for each of a downlink and an uplink, and the first active downlink BWP and the first active uplink BWP may be configured using respective BWP identifiers.

[0196] When multiple BWPs are configured in a cell, the first active BWP can be used to indicate which BWP is activated and used first. For example, when a Pcell or Pscell and multiple Scells are configured in the UE, and multiple BWPs are configured in each Pcell or Pscell or each Scell, if the Pcell, Pscell or Scell ​​is activated, the UE can activate and use the first active BWP among the multiple BWPs configured in the Pcell, Pscell or Scell. That is, the first active downlink BWP can be activated and used for the downlink, and the first active uplink BWP can be activated and used for the uplink.

[0197] After receiving information indicating activation of the Scell ​​or BWP through an RRC message, MAC control information, or DCI, the UE may perform an operation of switching the downlink BWP of the Scell ​​to the first active downlink BWP (configured or indicated by the RRC message) and activating the downlink BWP, and switching the uplink BWP to the first active uplink BWP and activating the uplink BWP. In addition, the UE may perform the operation upon receiving an indication indicating that the Scell ​​or BWP transitions to a stationary state through an RRC message, MAC control information, or DCI. This is because when transmitting a channel measurement report in the stationary state, the NR gNB can effectively use carrier aggregation by measuring and reporting the frequency / channel used for the first active downlink / uplink BWP, because when activating the Scell ​​or BWP, the UE switches the downlink BWP to the first active downlink BWP (configured or indicated by the RRC message) to activate the downlink BWP, and switches the uplink BWP to the first active uplink BWP to activate the uplink BWP.

[0198] The default BWP may be configured as UE-specific and may be assigned to and indicated by an identifier of a BWP among multiple BWPs. The default BWP may be configured for downlink only. The default BWP may be used as the BWP to which the activated BWP falls back after a predetermined time among multiple downlink BWPs.

[0199] For example, a BWP inactivity timer may be configured through an RRC message for each cell or each BWP, and the timer may be started or restarted when data transmission / reception occurs in an activated BWP instead of a default BWP, or may be started or restarted when an activated BWP is switched to another BWP.

[0200] If the timer expires, the UE may roll back or switch the activated downlink BWP in the cell to the default BWP. The switch may be a process of deactivating the currently activated BWP and activating the BWP to be switched to, and may be triggered by an RRC message, MAC control information (MAC control element), or L1 signaling (downlink control information (DCI) of PDCCH). The switch may be triggered by an indication of the BWP to be activated or switched to, and the BWP may be indicated by a BWP identifier (e.g., 0, 1, 2, 3, or 4).

[0201] The reason why the default BWP is used only for downlink is to facilitate NR gNB scheduling, because the NR gNB allows the UE to receive the indication of the NR gNB (e.g., DCI of PDCCH) after a predetermined time by falling back to the default BWP for each cell. For example, if the NR gNB configures the default BWP of a UE accessing a cell as the initial BWP, the NR gNB can continuously transmit scheduling indications only in the initial BWP after a predetermined time. If the default BWP is not configured through the RRC message, the default BWP can fall back to the initial BWP by treating the initial BWP as the default BWP when the BWP inactivity timer expires.

[0202] In another method, in order to increase the implementation freedom of Nr gNB, a default BWP for uplink can be defined and configured, so the default BWP for uplink can be used like the default BWP for downlink.

[0203] In addition, the UE can configure the state transition timer through the RRC establishment message of the RRC connection configuration, the RRCResume message of step 1f-25, or the RRCReconfiguration message of step 1f-45 to enable the UE to configure the state transition itself, even if the UE does not receive an indication from the NR gNB through RRC messages, MAC control information, or DCI of PDCCH.

[0204] For example, if a cell deactivation timer (ScellDeactivationTimer) is configured for each Scell ​​and the cell deactivation timer expires, the Scell ​​may transition to an inactive state.

[0205] If a cell hibernation timer (ScellHibernationTimer) is configured for each Scell ​​and the cell hibernation timer expires, the Scell ​​can be converted to the dormant state. When the cell hibernation timer expires, only the Scell ​​in the active state is converted to the dormant state, while the Scell ​​in the inactive state or the dormant state is not converted to the dormant state.

[0206] A stationary cell deactivation timer may be configured for each Scell, and a stationary Scell ​​may be switched to an inactive state. When the stationary cell deactivation timer expires, only the stationary Scell ​​is switched to an inactive state, while the active or inactive Scell ​​is not switched to an inactive state.

[0207] If the ScellDeactivationTimer and the ScellHibernationTimer are configured together, the ScellHibernationTimer is prioritized. That is, if the ScellHibernationTimer is configured, the corresponding Scell ​​is not deactivated even if the ScellDeactivationTimer expires. In other words, if the ScellHibernationTimer is configured, the Scell ​​is first converted from the active state to the static state due to the expiration of the ScellHibernationTimer, and the cell that has been converted to the static state is converted to the inactive state due to the expiration of the static state cell deactivation timer. Therefore, if the ScellHibernationTimer is configured, the Scell ​​deactivation timer does not affect the Scell ​​state conversion, and if the ScellHibernationTimer is configured, the Scell ​​will not be converted to the inactive state even if the ScellDeactivationTimer expires.

[0208] If the cell deactivation timer is not configured in the RRC message, the UE may consider setting the cell deactivation timer to an infinite value.

[0209] In addition, the NR gNB may configure frequency measurement configuration information and frequency measurement gap information through an RRC establishment message of an RRC connection configuration, an RRCResume message of step 1f-25, or an RRCReconfiguration message of step 1f-45, and the message may include information about a target (measurement object) for which the frequency is to be measured.

[0210] The measurement object may include information about a BWP in which a reference signal (RS) / synchronization signal (SS) for measurement is configured, and may also include a center frequency, a bandwidth corresponding to the BWP, and a time pattern that should be applied during measurement.

[0211] The measurement report gap information may include a measurement gap length corresponding to the time at which the measurement is performed, a measurement gap period, and measurement gap start time information. RS is a signal of an NR gNB having a partial time / frequency pattern in a transmission resource of a subframe in which a control signal or a data signal is transmitted, and may be used to determine the signal strength of a corresponding BWP or a corresponding cell. SS is a synchronization signal (such as a PSS or SSS) transmitted periodically, and may be used to determine the signal strength of a corresponding BWP or a corresponding cell.

[0212] As described above, when the RRC connection configuration is completed, the UE may configure multiple BWPs according to the instructions configured via the RRC message. In addition, to save battery, the UE may activate one or a small number of BWPs among the multiple configured BWPs. For example, the NRgNB may indicate a BWP to be activated.

[0213] The NR gNB may indicate activation of the BWP (e.g., whether activation or deactivation is performed) through an RRC message, MAC control information (MAC CE), or L1 signaling (PHY layer control signal, such as PDCCH) to indicate switching from the initial access BWP to a new BWP. Since there are many new accesses in the initial access BWP, it may be more advantageous to allocate a new BWP and manage the connected users separately. This is because the initial access BWP can be shared and used by all UEs in common, rather than configured in a UE-specific manner. In addition, the default BWP may be dynamically indicated through MAC control information, L1 signaling, or system information (in order to reduce signaling overhead).

[0214] Hereinafter, the present disclosure proposes a stationary state in a next generation mobile communication system, and proposes a method of supporting transitions among three states in units of cells.

[0215] Figure 1GThe state transition process of the cell or BWP proposed in the present disclosure is shown.

[0216] exist Figure 1G In the present invention, each cell or BWP of the UE may have an active state 1g-01, an inactive state 1g-03 or a dormant state 1g-02, and may perform state transition due to configuration information indication of an RRC message, MAC control information or DCI of a PDCCH.

[0217] The state transition operation (active, inactive or quiescent state) of the Scell ​​proposed in the present disclosure may be performed as follows.

[0218] -Configuring the Scell ​​state via RRC messages

[0219] - Receiving Scell ​​activation and deactivation MAC CE

[0220] - When receiving a Scell ​​static MAC CE

[0221] - The cell dormancy timer is not configured in the active Scell ​​and the configured cell deactivation timer expires

[0222] - When the cell dormancy timer configured in the active Scell ​​expires

[0223] - The dormant-state-Scell ​​deactivation timer configured in the dormant-state Scell ​​expires

[0224] In addition, the state transition operation proposed by the present disclosure may have the following characteristics.

[0225] -Spcell (Pcell or Pscell) cannot be switched to a dormant state and is always in an active state. Spcell performs synchronization with the UE for transmitting and receiving main control signals, and releases the connection with the NR gNB if the Spcell is dormant or inactive, so the Spcell should always remain in an active state.

[0226] - If PUCCH is configured, even the Scell ​​cannot transition to the dormant state. The Scell ​​should be in the active state because there may be another cell that should transmit HARQ ACK / NACK feedback via PUCCH.

[0227] - Due to such a feature, if the cell deactivation timer (ScellDeactivationTimer) is not applied to the Scell ​​or Spcell in which the PUCCH is configured, the cell deactivation timer may operate only for other Scells.

[0228] - The ScellHibernationTimer is given priority over the ScellDeactivationTimer. If a value is set as the timer value through an RRC message, the same value can be applied to all cells. In another method, the NR gNB can apply different timer values ​​for Scell ​​or BWP considering the characteristics of each Scell ​​or BWP.

[0229] - If there is no indication through the RRC message whether the Scell ​​is active or dormant, the Scell ​​may initially operate substantially in an inactive state.

[0230] The first embodiment of the present disclosure proposes a first embodiment corresponding to operations of each cell (Scell) and BWP according to each state when the active state, inactive state, or stationary state proposed by the present disclosure is applied to a next generation mobile communication system using BWP.

[0231] In the first embodiment of the present disclosure, an active state, an inactive state, or a static state is operated, and a state transition is performed in units of Scells. When a state transition is performed in units of Scells, one of a plurality of BWPs belonging to a Scell ​​(a predetermined BWP (e.g., a first active BWP), an already activated BWP, or a most recently used BWP) performs a state transition according to a state transition of the Scell.

[0232] For example, if the Scell ​​is switched from the active state to the static state, the first active uplink / downlink BWP among the multiple BWPs belonging to the Scell ​​may be switched to the static state. This is because the first active uplink / downlink BWP configured by RRC is activated when the BWP in the inactive state or the static state is switched to the active state, so it is effective to transmit the channel measurement report of the static state in the first active uplink / downlink BWP.

[0233] Figure 1H The method proposed in the present disclosure for converting the BWP state by performing state conversion in units of Scells is shown.

[0234] In the first embodiment of the present disclosure, the active state, the inactive state or the static state is operated in units of Scells, and as Figure 1H When state transition is performed in units of Scells, one of a plurality of BWPs belonging to the Scell ​​(a predetermined BWP (eg, a first active BWP), an already activated BWP, or a most recently used BWP) performs state transition according to the state transition of the Scell.

[0235] like Figure 1H As shown, Pcell 1h-10 can always maintain an active state to prevent the release of the wireless connection between the NR gNB and the UE. In the case of an FDD system, each cell (Pcell or each Scell) can distinguish between the frequencies used for downlink and uplink, and multiple BWPs can be configured for each of the downlink and uplink.

[0236] In the present disclosure, only one BWP may have an active state or a dormant state for each of the downlink and the uplink in each Scell, and the remaining BWPs may be in an inactive state. That is, even if the state transition is performed in units of Scells, only one BWP may perform state transition for each of the uplink and the downlink according to the state transition of the Scell ​​and perform a BWP operation corresponding thereto.

[0237] For example, Figure 1H As shown, the NR gNB can configure the first Scell ​​1h-20, the second Scell ​​1h-30 and the third Scell ​​1h-40 in the UE.

[0238] If the NR gNB converts the first Scell ​​1h-20 to a dormant state through an RRC message or MAC CE, the UE may convert one BWP 1h-21 (e.g., the first active downlink BWP) among the multiple BWPs configured for the downlink in the first Scell ​​to a dormant state, and may operate the remaining downlink BWPs in an inactive state. The UE may convert one BWP 1h-22 (e.g., the first active uplink BWP) among the multiple BWPs configured for the uplink in the first Scell ​​to a dormant state, and may operate the other uplink BWPs in an inactive state.

[0239] If the NR gNB converts the second Scell ​​1h-30 to an inactive state through an RRC message or MAC CE, the UE may convert one BWP 1h-31 (e.g., a BWP previously in an active state or a dormant state) among multiple BWPs configured for downlink in the second Scell ​​to an inactive state, and may operate other downlink BWPs in an inactive state. The UE may convert one BWP 1h-32 (e.g., a BWP previously in an active state or a dormant state) among multiple BWPs configured for uplink in the second Scell ​​to an inactive state, and may operate other uplink BWPs in an inactive state.

[0240] If the NR gNB converts the third Scell ​​1h-40 to an active state through an RRC message or a MAC CE, the UE may convert one BWP 1h-41 (e.g., the first active downlink BWP) among the multiple BWPs configured for downlink in the third Scell ​​to an active state, and may operate other downlink BWPs that are in an inactive state. The UE may convert one BWP 1h-42 (e.g., the first active uplink BWP) among the multiple BWPs configured for uplink in the third Scell ​​to an active state, and may operate other uplink BWPs that are in an inactive state.

[0241] In the following, the present disclosure proposes a state transition operation for Scell ​​and a state transition operation for a downlink or uplink BWP belonging to the Scell ​​when the NR gNB instructs the UE to perform a state transition in units of Scell.

[0242] - If (Scell ​​activation / BWP activation) the MAC layer device receives a MAC CE or RRC message indicating activation of any Scell, some or all of the following operations may be performed.

[0243] ■ Activate the Scell, and activate the downlink BWP and uplink BWP among the multiple BWPs of the Scell.

[0244] ■ Transmit a Sounding Reference Signal (SRS) to allow the NR gNB to measure the channel for uplink in the Scell ​​(or activated BWP). For example, the SRS may be transmitted periodically.

[0245] ■The UE can report channel measurement results (CSI, CQI, PMI, RI, PTI or CRI) for downlink in the Scell ​​(or activated BWP) according to the configuration of the NR gNB.

[0246] ■Monitor PDCCH to read the NR gNB indication in the Scell ​​(or activated BWP).

[0247] ■ Monitor PDCCH to read the cross scheduling for Scell ​​(or activated BWP).

[0248] ■ If PUCCH is configured in the Scell ​​(or activated BWP), PUCCH is transmitted.

[0249] ■If the Scell ​​is deactivated before the indication indicating activation of the Scell ​​(or if the Scell ​​is in a dormant state before the indication indicating activation of the Scell), the downlink (DL) BWP and uplink (UL) BWP of the Scell ​​are activated as the first active downlink BWP (indicated by firstActiveDownlinkBWP-Id) and the first active uplink BWP (indicated by firstActiveUplinkBWP-Id) indicated by the RRC message.

[0250] ■ A cell deactivation timer (sCellDeactivationTimer) is started or restarted for the Scell. In another method, the cell deactivation timer can be started or restarted only when the cell dormancy timer is not configured.

[0251] ■If there is a suspended type 1 configuration transmission resource, the resource can be initialized according to the type 1 transmission resource configuration, or the resource can be reinitialized and used. Type 1 configuration transmission resources are periodic transmission resources (uplink or downlink) pre-allocated by RRC messages that can be used after activation by RRC messages.

[0252] ■If the cell hibernation timer (sCellHibernationTimer) is configured in the cell, then

[0253] ◆The cell dormancy timer (sCellHibernationTimer) is started or restarted for Scell.

[0254] ■Trigger PHR for Scell.

[0255] - If (Scell ​​deactivation or BWP deactivation) the MAC layer device receives a deactivation MAC CE or RRC message indicating any Scell ​​deactivation,

[0256] - Or, if the cell deactivation timer for the Scell ​​expires and the cell dormancy timer is not configured. (If the cell dormancy timer is configured, the cell dormancy timer is given priority, so the expiration of the cell deactivation timer is ignored. That is, if the cell dormancy timer is configured, the cell state should first be transitioned from the active state to the dormant state, and then from the dormant state to the inactive state.)

[0257] The UE may then perform some or all of the following operations.

[0258] ■Deactivate the Scell ​​(or the BWP of the Scell).

[0259] ■Stop the cell deactivation timer configured in the Scell.

[0260] ■ Stop configuring the BWP deactivation timer for the Scell.

[0261] ■ If there is a configured and activated BWP in the Scell, deactivate the Scell.

[0262] ■ If there is a BWP configured and sleeping in the Scell, deactivate the Scell.

[0263] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​may be released (cleared).

[0264] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information about periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used. Periodic transmission resources may be referred to as type 2 configured transmission resources. In addition, the operation of releasing (clearing) periodic transmission resources can only be performed when the Scell ​​transitions from an active state to an inactive state. This is because a release (clearing) operation is not required when transitioning from a quiescent state to an inactive state because there are no periodic transmission resources in the quiescent state. In another method, periodic transmission resources may be released (cleared) only when periodic downlink transmission resources or periodic uplink transmission resources are configured or exist.

[0265] ■ If there are PUSCH transmission resources configured for the Scell ​​for periodic channel measurement information (semi-persistent CSI reporting), the periodic transmission resources are released (cleared).

[0266] ■Periodic uplink transmission resources configured in the Scell ​​(configured uplink grant type 1 configured via RRC) can be suspended. The term "suspend" means that the transmission resource configuration information configured via RRC message is stored in the UE but is no longer used. Periodic transmission resources can be referred to as type 1 configured transmission resources.

[0267] ■ Clear all HARQ buffers configured for the Scell.

[0268] - If the PDCCH indicates the presence of downlink data (downlink assignment) or allocation of uplink transmission resources (uplink grant) in any activated Scell,

[0269] - or, if the PDCCH indicates that there is downlink data for any activated Scell ​​in the serving cell (downlink allocation) for scheduling the activated Scell ​​or allocating uplink transmission resources (uplink grant),

[0270] - or, for an activated configured Scell, if any MAC PDU is transmitted over preconfigured downlink transmission resources (configured downlink allocation) or preconfigured uplink transmission resources (configured uplink grant), then

[0271] ■UE restarts the cell deactivation timer for the Scell. In another method, the cell deactivation timer may be restarted only when the cell is not configured to be dormant.

[0272] ■ If a cell dormancy timer is configured for Scell, then

[0273] ◆The cell sleep timer is restarted.

[0274] - If any Scell ​​or Scell's BWP is deactivated or inactive, then

[0275] ■ The UE does not transmit the SRS for the Scell ​​(or the BWP of the Scell).

[0276] ■ The UE neither measures (CSI, CQI, PMI, RI, PTI or CRI) nor reports the channels in the Scell ​​(or the BWP of the Scell) for downlink.

[0277] ■ Uplink data is not transmitted through the UL-SCH in the Scell ​​(or the BWP of the Scell).

[0278] ■ The random access procedure for the Scell ​​(or the BWP of the Scell) is not performed.

[0279] ■ The UE does not monitor the PDCCH in the Scell ​​(or the BWP of the Scell).

[0280] ■ UE does not monitor PDCCH for Scell ​​(or BWP of Scell). For example, in case of cross scheduling, PDCCH for Scell ​​is not monitored in the cell in which scheduling is performed.

[0281] ■ PUCCH or SPUCCH is not transmitted in the Scell.

[0282] - If there is a random access procedure being performed in the Scell ​​during the deactivation of the Scell, the random access procedure is canceled.

[0283] - The dormant state is not applicable to the Spcell or Scell ​​in which the PUCCH is configured.

[0284] The MAC layer device can operate two timers to effectively manage the static state of the Scell. The two timers are described in detail below.

[0285] -ScellHibernationTimer: operates in the Scell ​​configured in the UE, but does not operate in the Scell ​​in which the PUCCH is configured.

[0286] If the cell dormancy timer expires, the MAC layer device converts the Scell ​​in the active state to the dormant state. The cell dormancy timer can be applied only to the Scell ​​in the active state. A value configured by RRC can be equally applied to the cell dormancy timer of each Scell. The cell dormancy timer is given priority over the cell deactivation timer. That is, if the cell dormancy timer is configured and running, the Scell ​​does not convert to the inactive state, and the cell deactivation timer does not affect the Scell, regardless of whether the cell deactivation timer is running or expired.

[0287] - DormantScellDeactivationTimer: Operates in the Scell ​​configured in the UE, but not in the Scell ​​in which the PUCCH is configured. If the dormant cell deactivation timer expires, the MAC layer device converts the Scell ​​in the dormant state to an inactive state. One value configured by RRC can be equally applied to the dormant cell deactivation timer of each Scell. That is, the dormant cell deactivation timer is only applied to the Scell ​​in the dormant state.

[0288] - If the dormant state is indicated by an RRC message when configuring the Scell, the UE can switch the Scell ​​to the dormant state. If the dormant state is indicated in the Scell ​​state configuration of the RRC message even at the time of handover or SCG change, the UE can switch the Scell ​​to the dormant state.

[0289] - If the MAC layer device receives an indication of the quiescent state of the Scell ​​when configuring the Scell ​​through an RRC message, or receives a MAC CE indicating that the state of the Scell ​​is transitioned to the quiescent state, then

[0290] The UE may perform some or all of the following operations.

[0291] ■The Scell ​​(or the BWP of the Scell) switches to the quiescent state.

[0292] ■ Stop the cell deactivation timer configured or operated in the Scell ​​(or the BWP of the Scell).

[0293] ■ If the cell dormancy timer is configured in the Scell ​​(or the BWP of the Scell), stop the cell dormancy timer.

[0294] ■The stationary cell deactivation timer is started or restarted in the Scell ​​(or the BWP of the Scell).

[0295] ■ Stop the BWP deactivation timer configured for the Scell ​​(or the BWP of the Scell). This is to prevent unnecessary BWP switching procedures in the Scell.

[0296] ■ The downlink BWP of the Scell ​​can be put to sleep and the channel measurement results can be reported. In addition, the uplink BWP of the Scell ​​can be deactivated and not used. This is because the measurement channel is only used for the downlink BWP in the Scell ​​in the static state, and the measurement results are reported to the uplink BWP of the Spcell (Pcell or Pscell) or the Scell ​​in which the PUCCH exists.

[0297] ■ Make the downlink (DL) BWP and uplink (UL) BWP of the Scell ​​sleep or switch to the first active downlink BWP (indicated by firstActiveDownlinkBWP-Id) and the first active uplink BWP (indicated by firstActiveUplinkBWP-Id) indicated by the RRC message, because the state of the Scell ​​(or the BWP of the Scell) is indicated to be transitioned to the static state. This is because the first active uplink / downlink BWP configured by RRC is activated when the BWP in the inactive state or the static state transitions to the active state, so it is effective to transmit the channel measurement report of the static state in the first active uplink / downlink BWP.

[0298] In another method, during the transition to the dormant state, only the downlink BWP can be dormant and switched to the BWP indicated or configured by the RRC message (e.g., the first active downlink BWP). This is because the uplink BWP is also activated and switched to the BWP indicated or configured by the RRC message (e.g., the first active uplink BWP) when the Scell ​​is activated. If the BWP in the active state was originally the first active downlink or uplink BWP in the Scell ​​before the dormant state was indicated, the BWP can be dormant without performing a switching operation.

[0299] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared).

[0300] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0301] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because when the Scell ​​transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0302] In another method, the periodic transmission resources may be released (cleared) only when the periodic downlink transmission resources or the periodic uplink transmission resources are configured or when the periodic downlink transmission resources or the periodic uplink transmission resources exist.

[0303] ■ The periodic uplink transmission resources configured in the Scell ​​(or BWP of the SCell) (configured uplink grant type 1 configured via RRC) can be suspended. The term "suspend" means that the transmission resource configuration information configured via RRC messages is stored in the UE but is no longer used.

[0304] The proposed method (i.e., the operation of suspending the periodic uplink transmission resource (configuring uplink grant type 1)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because the periodic transmission resource is not used when the Scell ​​transitions from the inactive state to the dormant state. In another method, the periodic transmission resource can be released (cleared) only when the periodic downlink transmission resource or the periodic uplink transmission resource is configured or exists.

[0305] ■ Clear all HARQ buffers configured in the Scell.

[0306] - If the cell dormancy timer in the activated Scell ​​(or the BWP of the Scell) expires, then

[0307] ■The UE switches the Scell ​​(or the BWP of the Scell) to the dormant state.

[0308] ■The UE stops the cell deactivation timer configured or operated in the Scell ​​(or the BWP of the Scell).

[0309] ■The UE stops the cell dormancy timer configured or operated in the Scell ​​(or the BWP of the Scell).

[0310] ■The UE starts or restarts the dormant cell deactivation timer in the Scell ​​(or the BWP of the Scell).

[0311] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared).

[0312] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0313] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because when the Scell ​​transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0314] In another method, the periodic transmission resources may be released (cleared) only when the periodic downlink transmission resources or the periodic uplink transmission resources are configured or when the periodic downlink transmission resources or the periodic uplink transmission resources exist.

[0315] - If the stationary cell deactivation timer configured in the stationary Scell ​​expires,

[0316] ■The Scell ​​(or the Scell's BWP) transitions to the inactive state.

[0317] ■ Stop the dormant cell deactivation timer of the Scell ​​(or the BWP of the Scell).

[0318] - If the Scell ​​(or the BWP of the Scell) is in quiescent state, then

[0319] ■ The UE does not transmit the SRS for the Scell ​​(or the BWP of the Scell).

[0320] ■The UE may measure (CSI, CQI, PMI, RI, PTI or CRI) the channel used for the downlink according to the configuration of the NR gNB in ​​the Scell ​​(or the BWP of the Scell) and report the measurement. For example, the UE may report channel or frequency measurements periodically.

[0321] ■ Uplink data may not be transmitted through the UL-SCH in a Scell ​​(or a BWP of a Scell).

[0322] ■ The random access procedure for Scell ​​(or BWP of Scell) may not be performed.

[0323] ■ The UE may not monitor the PDCCH in the Scell ​​(or the BWP of the Scell).

[0324] ■ UE may not monitor PDCCH for Scell ​​(or BWP of Scell). For example, in case of cross scheduling, PDCCH for Scell ​​may not be monitored in the cell in which scheduling is performed.

[0325] ■ PUCCH or SPUCCH may not be transmitted in a Scell ​​(or a BWP of a Scell).

[0326] ■ The downlink BWP of the Scell ​​may be put to sleep and the channel measurement results may be reported. In addition, the uplink BWP of the Scell ​​may be deactivated and not used. This is because the channel is measured for the downlink BWP only in the Scell ​​in the static state, and the measurement results are reported to the uplink BWP of the Spcell (Pcell or Pscell) or the Scell ​​in which the PUCCH exists.

[0327] ■ Make the downlink (DL) BWP and uplink (UL) BWP of the Scell ​​sleep or switch to the downlink BWP (e.g., the first active downlink BWP (indicated by firstActiveDownlinkBWP-Id) indicated or configured by the RRC message and the uplink BWP (e.g., the first active uplink BWP (indicated by firstActiveUplinkBWP-id)) indicated or configured by the RRC message, because the Scell ​​(or the BWP of the Scell) is instructed to transition to the dormant state. This is because the first active uplink / downlink BWP configured by the RRC message is activated when the BWP in the inactive state or dormant state transitions to the active state, so it is effective to transmit the channel measurement report of the dormant state in the first active uplink / downlink BWP.

[0328] In another method, during the transition to the dormant state, only the downlink BWP can be switched and dormant to the downlink BWP indicated or configured by the RRC message (e.g., the first active downlink BWP). This is because the uplink BWP is also activated and switched to the first active uplink BWP when the Scell ​​is activated. If the BWP in the active state was originally the first active downlink or uplink BWP in the Scell ​​before the dormant state was indicated, the BWP can be put to sleep without performing a switching operation.

[0329] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared).

[0330] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0331] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because when the Scell ​​transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0332] ■ The periodic uplink transmission resources configured in the Scell ​​(configured uplink grant type 1 configured via RRC) can be suspended. The term "suspend" means that the transmission resource configuration information configured via RRC messages is stored in the UE but is no longer used.

[0333] The proposed method (i.e., suspending the operation of periodic uplink transmission resources (configuring uplink grant type 1)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because the periodic transmission resources are not used when the Scell ​​transitions from the inactive state to the dormant state.

[0334] - If there is a random access procedure being performed during the transition of the Scell ​​to the dormant state, the random access procedure may be canceled.

[0335] Hereinafter, the present disclosure proposes the operation of each cell (Scell) according to each state when the active state, inactive state or static state proposed by the present disclosure is applied to a system (e.g., a UMTS or LTE system) using a fixed frequency bandwidth in each frequency band without using BWP according to the second embodiment of the present disclosure.

[0336] - If the (Scell ​​activation) MAC layer device receives a MAC CE indicating activation of any Scell ​​or an RRC message indicating activation of the Scell, some or all of the following operations may be performed.

[0337] ■Scell ​​can be activated.

[0338] ■A sounding reference signal (SRS) may be transmitted to allow the NR gNB to measure the channel for the uplink in the Scell. For example, the SRS may be transmitted periodically.

[0339] ■The UE can report the channel measurement results (CSI, CQI, PMI, RI, PTI or CRI) for the downlink in the Scell ​​according to the configuration of the NR gNB.

[0340] ■PDCCH can be monitored in Scell ​​to read the indications from NR gNB.

[0341] ■ PDCCH can be monitored to read the cross scheduling for Scell.

[0342] ■ If PUCCH can be configured in the Scell, PUCCH is transmitted.

[0343] ■ A cell deactivation timer (sCellDeactivationTimer) may be started or restarted for the Scell ​​(in another method, the cell deactivation timer may be started or restarted only when the cell dormancy timer is not configured).

[0344] ■If the cell hibernation timer (sCellHibernationTimer) is configured in the cell, then

[0345] ◆The cell deactivation timer (sCellDeactivationTimer) is started or restarted for Scell.

[0346] ■ PHR can be triggered for Scell.

[0347] - If the (Scell ​​deactivation) MAC layer device receives a MAC CE indicating deactivation of any Scell ​​or an RRC message indicating deactivation of any Scell,

[0348] - or if the cell deactivation timer for the Scell ​​expires and the cell dormancy timer is not configured (if the cell dormancy timer is configured, the cell dormancy timer should be given priority, so the expiration of the cell deactivation timer can be ignored. That is, if the cell dormancy timer is configured, the cell state should first be transitioned from the active state to the dormant state, and then from the dormant state to the inactive state), then

[0349] -The UE may perform some or all of the following operations.

[0350] ■Scell ​​can be deactivated.

[0351] ■The cell deactivation timer configured in the Scell ​​can be stopped.

[0352] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared).

[0353] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0354] In addition, the operation of releasing (clearing) the periodic transmission resources can be performed only when the Scell ​​is converted from the active state to the inactive state. This is because the release (clearing) operation is not required when converting from the static state to the inactive state because there are no periodic transmission resources in the static state. In another method, the periodic transmission resources can be released (cleared) only when the periodic downlink transmission resources or the periodic uplink transmission resources are configured or exist.

[0355] ■ If there are PUSCH transmission resources configured for the Scell ​​for periodic channel measurement information (semi-persistent CSI reporting), the periodic transmission resources are released (cleared).

[0356] ■ Clear all HARQ buffers configured for the Scell.

[0357] - If any Scell ​​is deactivated or any Scell ​​is inactive, then

[0358] ■UE does not transmit SRS for Scell.

[0359] ■ The UE neither measures (CSI, CQI, PMI, RI, PTI or CRI) nor reports the channels for the downlink in the Scell.

[0360] ■ Uplink data is not transmitted via UL-SCH in the Scell.

[0361] ■ The random access procedure for Scell ​​is not performed.

[0362] ■UE does not monitor PDCCH in Scell.

[0363] ■ UE does not monitor PDCCH for Scell ​​For example, in case of cross scheduling, PDCCH for Scell ​​is not monitored in the cell in which scheduling is performed.

[0364] ■ PUCCH or SPUCCH is not transmitted in the Scell.

[0365] - If the PDCCH indicates the presence of downlink data (downlink allocation) or allocation of uplink transmission resources in any activated Scell,

[0366] - or, if the PDCCH indicates that there is downlink data for the activated Scell ​​in the serving cell (downlink allocation) for scheduling the activated Scell ​​or allocating uplink transmission resources (uplink grant),

[0367] - or, for an activated configured Scell, if any MAC PDU is transmitted over preconfigured downlink transmission resources (configured downlink allocation) or preconfigured uplink transmission resources (configured uplink grant), then

[0368] ■The UE may restart the cell deactivation timer for the Scell ​​(in another method, the cell deactivation timer may be restarted only when the cell is not configured to be dormant).

[0369] ■ If a cell dormancy timer is configured for Scell, then

[0370] ◆The cell sleep timer can be restarted.

[0371] - If there is a random access procedure being performed in the Scell ​​during the deactivation of the Scell, the random access procedure may be canceled.

[0372] The MAC layer device can operate two timers to effectively manage the static state of the Scell.

[0373] -ScellHibernationTimer: operates in the Scell ​​configured in the UE, but does not operate in the Scell ​​in which the PUCCH is configured.

[0374] If the cell dormancy timer expires, the MAC layer device converts the Scell ​​in the active state to the dormant state. That is, the cell dormancy timer can be applied only to the Scell ​​in the active state. A value configured by RRC can be equally applied to the cell dormancy timer of each Scell. The cell dormancy timer is given priority over the cell deactivation timer. That is, if the cell dormancy timer is configured and running, the Scell ​​does not convert to the inactive state regardless of whether the cell deactivation timer is running or expired, and the cell deactivation timer does not affect the Scell.

[0375] - DormantScellDeactivationTimer: Operates in the Scell ​​configured in the UE, but not in the Scell ​​in which the PUCCH is configured. If the dormant cell deactivation timer expires, the MAC layer device converts the Scell ​​in the dormant state to an inactive state. One value configured by RRC can be equally applied to the dormant cell deactivation timer of each Scell. That is, the dormant cell deactivation timer is only applied to the Scell ​​in the dormant state.

[0376] - If the dormant state is indicated by an RRC message when configuring the Scell, the UE may switch the Scell ​​to the dormant state. If the dormant state is indicated even in the Scell ​​state configuration of the RRC message for handover or SCG change, the UE may switch the Scell ​​to the dormant state.

[0377] - If the MAC layer device receives an indication of the quiescent state of the Scell ​​when configuring the Scell ​​through an RRC message, or receives a MAC CE indicating that the state of the Scell ​​is transitioned to the quiescent state, then

[0378] -The UE may perform some or all of the following operations.

[0379] ■Scell ​​can be switched to a quiescent state.

[0380] ■ A cell deactivation timer configured or operated in the Scell ​​may be stopped.

[0381] ■If a cell dormancy timer is configured in a cell, the cell dormancy timer can be stopped.

[0382] ■The stationary cell deactivation timer can be started or restarted in the Scell.

[0383] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared).

[0384] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0385] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because when the Scell ​​transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling. In another method, the periodic transmission resources can be released (cleared) only when the periodic downlink transmission resources or the periodic uplink transmission resources are configured or when the periodic downlink transmission resources or the periodic uplink transmission resources exist.

[0386] ■ Clear all HARQ buffers configured in the Scell.

[0387] - If the cell dormancy timer in the activated Scell ​​expires, then

[0388] ■UE switches the Scell ​​to dormant state.

[0389] ■The UE stops the cell deactivation timer configured or operated in the Scell.

[0390] ■The UE stops the cell dormancy timer configured or operated in the Scell.

[0391] ■UE starts or restarts the dormant cell deactivation timer in the Scell.

[0392] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared).

[0393] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0394] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because when the Scell ​​transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0395] In another method, the periodic transmission resources may be released (cleared) only when the periodic downlink transmission resources or the periodic uplink transmission resources are configured or when the periodic downlink transmission resources or the periodic uplink transmission resources exist.

[0396] - If the dormant cell deactivation timer configured in the dormant cell expires, then

[0397] ■Scell ​​switches to quiescent state.

[0398] ■The dormant cell deactivation timer of the Scell ​​can be stopped.

[0399] - If the Scell ​​is in quiescent state, then

[0400] ■UE does not transmit SRS for Scell.

[0401] ■The UE may measure the channel (CSI, CQI, PMI, RI, PTI or CRI) used for the downlink in the Scell ​​according to the configuration of the NR gNB and report the measurement. For example, the UE may periodically report channel or frequency measurements.

[0402] ■ Uplink data is not transmitted via UL-SCH in the Scell.

[0403] ■ The random access procedure for Scell ​​is not performed.

[0404] ■UE does not monitor the PDCCH in the Scell.

[0405] ■ UE does not monitor PDCCH for Scell ​​For example, in case of cross scheduling, PDCCH for Scell ​​may not be monitored in the cell in which scheduling is performed.

[0406] ■ PUCCH or SPUCCH is not transmitted in the Scell.

[0407] ■Periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the Scell ​​(or the BWP of the Scell) may be released (cleared). The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information about periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and is no longer used.

[0408] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can be performed only when the Scell ​​transitions from the active state to the dormant state. This is because when the Scell ​​transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0409] - If there is a random access procedure being performed during the transition of the Scell ​​to the dormant state, the random access procedure is canceled.

[0410] - The dormant state is not applicable to the Spcell or Scell ​​in which the PUCCH is configured.

[0411] Hereinafter, the present disclosure proposes state transition MAC control information (MAC Control Element: MAC CE) indicating an active state, a dormant state, or an inactive state of each Scell.

[0412] Fig. 1I The MAC control information indicating the state transition to the active state, the dormant state or the inactive state proposed in the present disclosure is shown.

[0413] The active and inactive MAC CEs proposed in the present disclosure are only embodiments and may have the following features: Fig. 1I The format shown in , and can be divided into MAC CE format 1i-05 with a size of 1 byte and supporting 7 Scells and MAC CE format 1i-10 with a size of 4 bytes and supporting 31 Scells. In addition, MAC CE has the following characteristics.

[0414] - In case no static MAC CE is received but only active and inactive MAC CEs are received, the UE operates as follows.

[0415] ■Each field in the active and inactive MAC CE indicates the corresponding Scell ​​identifier, and the value corresponding to each field can indicate whether the Scell ​​is activated or deactivated. If the value of the indicator for the Scell ​​indicated by the Scell ​​indicator is 1, the Scell ​​is activated only when the state of the Scell ​​is the inactive state. However, if the state of the Scell ​​is a state other than the inactive state, the indicator value can be ignored.

[0416] If the value of the indicator for the Scell ​​indicated by the Scell ​​indicator is 0, the Scell ​​may be deactivated. That is, if the value of the indicator for the Scell ​​is 0, the Scell ​​may be deactivated regardless of the state of the Scell.

[0417] The active and inactive MAC CEs proposed in the present disclosure are only embodiments and may have the following features: Fig. 1I The format shown can be divided into a MAC CE format 1i-05 with a size of 1 byte and supporting 7 Scells and a MAC CE format 1i-10 with a size of 4 bytes and supporting 31 Scells. In addition, MAC CE has the following features.

[0418] - In case no active and inactive MAC CEs are received but only static MAC CEs are received, the UE operates as follows.

[0419] ■ Each field of the static MAC CE indicates a corresponding Scell ​​identifier, and a value corresponding to each field may indicate whether the Scell ​​is activated or deactivated.

[0420] If the indicator value for the Scell ​​indicated by the Scell ​​indicator is 1, the Scell ​​may be put to sleep. That is, if the value of the indicator for the Scell ​​is 1, the Scell ​​may be put to sleep regardless of the state of the Scell.

[0421] If the value of the indicator for the Scell ​​indicated by the Scell ​​indicator is 0, the Scell ​​may be activated only when the state of the Scell ​​is the dormant state. However, if the state of the Scell ​​is a state other than the dormant state, the indicator value may be ignored.

[0422] - In the case where a MAC layer device receives active and inactive MAC CEs and static MAC CEs, the UE operates as described below.

[0423] ■ Each field of the Active and Inactive MAC CE and the Quiescent MAC CE indicates a corresponding Scell ​​identifier, and a combination of values ​​corresponding to these fields may indicate that the state of the Scell ​​transitions to an active state, a quiescent state, or an inactive state.

[0424] A MAC layer device can receive active and inactive MAC CEs and static MAC CEs together with a MAC CE of 1 byte or a MAC CE of 4 bytes. If two types of MAC CEs are received together, the state transition of each Scell ​​indicated by the MAC CE can be determined according to the combination of the indication values ​​of the MAC CE, as shown in the following table. However, the following table is only an embodiment of the present disclosure.

[0425]

[0426] Figure 1J UE operations for converting the state of a cell configured in the UE according to the present disclosure are illustrated.

[0427] exist Figure 1J In NR gNB, multiple Scells can be configured together with Spcells (Pcell or Pscell) in the UE.

[0428] If the cell configured in step 1j-05 is a Spcell, the UE can always maintain the Spcell in an active state according to the instruction of the NR gNB in ​​step 1j-10. If the cell configured in step 1j-05 is a Scell, the UE can change the state according to the instruction of the NRgNB or the expiration of the timer configured in the cell. For example, if the NR gNB indicates the state change of the Scell ​​through an RRC message or MACCE, or if the timer configured by the NR gNB expires and thus triggers the state change operation of the Scell, the UE can change the state of the Scell ​​to an active state, a static state, or an inactive state, and perform the operations proposed in the present disclosure in steps 1j-25, 1j-30 and 1j-35 that are suitable for the respective states. Since its detailed description is the same as above, the detailed description will be omitted.

[0429] Figure 1K The structure of a UE to which the embodiments of the present disclosure can be applied is shown.

[0430] refer to Figure 1K , the UE may include a radio frequency (RF) processor 1k-10, a baseband processor 1k-20, a memory 1k-30, and a controller 1k-40.

[0431] The RF processor 1k-10 performs functions for transmitting and receiving signals through a radio channel, such as frequency band conversion and amplification of signals. That is, the RF processor 1k-10 up-converts the baseband signal provided by the baseband processor 1k-20 into an RF band signal, transmits the RF band signal through an antenna, and then down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 1k-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and the like. Although Figure 1K Only one antenna is shown, but the UE may include multiple antennas. The RF processor 1k-10 may include multiple RF chains. In addition, the RF processor 1k-10 may perform beamforming. For beamforming, the RF processor 1k-10 may control the phase and size of each signal transmitted / received through multiple antennas or antenna elements. In addition, the RF processor may perform MIMO and may receive multiple layers during MIMO operation. The RF processor 1k-10 may perform receive beam scanning by appropriately configuring multiple antennas or antenna elements according to the control of the controller, or may adjust the receive beam direction and beam width so that the receive beam corresponds to the transmission beam.

[0432] The baseband processor 1k-20 performs functions for conversion between baseband signals and bit streams according to the physical layer standard of the system. For example, in data transmission, the baseband processor 1k-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, in data reception, the baseband processor 1k-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 1k-10. For example, in the orthogonal frequency division multiplexing (OFDM) scheme, when transmitting data, the baseband processor 1k-20 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols through IFFT (Inverse Fast Fourier Transform) operations and CP (Cyclic Prefix) insertion. In addition, in data reception, the baseband processor 1k-20 divides the baseband signal provided by the RF processor 1k-10 into units of OFDM symbols, reconstructs the signal mapped to the subcarrier through a Fast Fourier Transform (FFT) operation, and then reconstructs the received bit stream through demodulation and decoding.

[0433] The baseband processor 1k-20 and the RF processor 1k-10 can transmit and receive signals as described above. Therefore, each of the baseband processor 1k-20 and the RF processor 1k-10 can be referred to as a transmitter, a receiver, a transceiver, or a communication unit. In addition, at least one of the baseband processor 1k-20 and the RF processor 1k-10 may include a plurality of communication modules for supporting a plurality of different radio access technologies. At least one of the baseband processor 1k-20 and the RF processor 1k-10 may include different communication modules for processing signals in different frequency bands. For example, different radio access technologies may include an LTE network and an NR network. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.5 GHz and 5 GHz) bands and millimeter (mm) wave (e.g., 60-GHz) bands.

[0434] The memory 1k-30 stores data such as basic programs, applications, and configuration information for UE operation. The memory 1k-30 provides the stored data according to a request from the controller 1k-40.

[0435] The controller 1k-40 controls the overall operation of the UE. For example, the controller 1k-40 transmits and receives signals through the baseband processor 1k-20 and the RF processor 1k-10. The controller 1k-40 records data in the memory 1k-30 and reads data. To this end, the controller 1k-40 may include at least one processor. For example, the controller 1k-40 may include a CP (communication processor) that performs control for communication and an AP (application processor) that controls a higher layer such as an application layer.

[0436] Figure 1L A block diagram showing a TRP in a wireless communication system to which an embodiment of the present disclosure can be applied.

[0437] like Figure 1L As shown, the NR gNB includes an RF processor 1l-10, a baseband processor 1l-20, a backhaul communication unit 1l-30, a memory 1l-40 and a controller 1l-50.

[0438] The RF processor 11-10 performs functions for transmitting and receiving signals through a radio channel, such as frequency band conversion and amplification of signals. That is, the RF processor 11-10 up-converts the baseband signal provided from the baseband processor 11-20 into an RF band signal, then transmits the converted signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 11-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although Figure 1L Only one antenna is shown, but the first access node may include multiple antennas. The RF processor 11-10 may include multiple RF chains. In addition, the RF processor 11-10 may perform beamforming. For beamforming, the RF processor 11-10 may control the phase and size of each signal transmitted / received by multiple antennas or antenna elements. The RF processor may perform downlink MIMO operations by transmitting one or more layers.

[0439] The baseband processor 11-20 performs the function of performing conversion between the baseband signal and the bit stream according to the physical layer standard of the first radio access technology. For example, in data transmission, the baseband processor 11-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, in data reception, the baseband processor 11-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 11-10. For example, in the OFDM scheme, when transmitting data, the baseband processor 11-20 can generate complex symbols by encoding and modulating the transmission bit stream, map the complex symbols to subcarriers, and then configure the OFDM symbols by IFFT operation and CP insertion. In addition, in data reception, the baseband processor 11-20 divides the baseband signal provided by the RF processor 11-10 in units of OFDM symbols, recovers the signal mapped with subcarriers by FFT operation, and then recovers the received bit stream by demodulation and decoding. The baseband processor 11-20 and the RF processor 11-10 can transmit and receive signals as described above. Therefore, the baseband processor 1l-20 or the RF processor 1l-10 can be called a transmitter, a receiver, a transceiver, a communication unit or a wireless communication unit.

[0440] The communication unit 11-30 provides an interface for communicating with other nodes within the network.

[0441] The memory 11-40 stores data such as basic programs, applications, and configuration information for MeNB operation. Specifically, the memory 11-40 can store information about the bearer assigned to the accessed UE and the measurement results reported from the accessed UE. In addition, the memory 11-40 can store information as a reference for determining whether to provide multiple connections to the UE or to stop the connection. The memory 11-40 provides the stored data according to a request from the controller 11-50.

[0442] The controller 11-50 controls the overall operation of the MeNB. For example, the controller 11-50 transmits and receives signals through the baseband processor 11-20 and the RF processor 11-10 or through the backhaul communication unit 11-30. In addition, the controller 11-50 records data in the memory 11-40 and reads data. To this end, the controller 11-50 may include at least one processor.

[0443] Figure 2A The structure of an LTE system to which the present disclosure can be applied is shown.

[0444] refer to Figure 2A The radio access network of the LTE system includes next generation base stations (hereinafter referred to as evolved node B (ENB), Node B or base station) 2a-05, 2a-10, 2a-15 and 2a-20, mobility management entity (MME) 2a-25 and serving gateway (S-GW) 2a-30. User terminals (user equipment) (hereinafter referred to as UE or terminal) 2a-35 access external networks through ENB 2a-05 to 2a-20 and S-GW 2a-30.

[0445] exist Figure 2A In the LTE system, ENB 2a-05 to 2a-20 correspond to the existing Node B of the UMTS system. The ENB is connected to the UE 2a-35 through a radio channel, and plays a more complex role than a conventional Node B. In the LTE system, since all user services including real-time services such as Voice over IP (VoIP) through the Internet Protocol are served through a shared channel, a device for collecting and scheduling status information about the buffer status, available transmission power status, and channel status of the UE is required, and the ENB 2a-05 to 2a-20 can be used as the device.

[0446] Generally speaking, one ENB can control multiple cells. For example, in order to achieve a transmission rate of 100Mbps, the LTE system can use orthogonal frequency division multiplexing (OFDM) as a wireless access technology in a 20MHz bandwidth. In addition, according to the channel state of the UE, an adaptive modulation and coding (AMC) scheme that determines the modulation scheme and channel coding rate can be applied.

[0447] The S-GW 2a-30 is a device for providing a data bearer, and generates or removes a data bearer under the control of the MME 2a-25. The MME is a device for performing not only a function of managing the mobility of UE but also various control functions, and can be connected to a plurality of ENBs.

[0448] Figure 2B A structure of a wireless protocol in an LTE system to which the present disclosure can be applied is shown.

[0449] refer to Figure 2B In the wireless protocol of the LTE system, the UE and ENB each include a packet data convergence protocol (PDCP) 2b-05 and 2b-40, a radio link control (RLC) 2b-10 and 2b-35, and a medium access control (MAC) 2b-15 and 2b-30. The packet data convergence protocol (PDCP) 2b-05 and 2b-40 perform the operation of compressing / reconstructing the IP header. The main functions of PDCP are described as follows.

[0450] -Header compression and decompression function (Header compression and decompression: ROHC only)

[0451] -User data transmission function (user data transmission)

[0452] - In-sequence delivery function (in-sequence delivery of upper layer PDUs during PDCP re-establishment procedure for RLC AM)

[0453] - Resequence function (for split bearers in DC (supports RLC AM only): PDCP PDU routing for transmission and PDCP PDU reordering for reception)

[0454] - Duplicate detection function (duplicate detection of lower layer SDUs during PDCP re-establishment process for RLC AM)

[0455] - Retransmission functionality (retransmission of PDCP SDUs during handover for split bearers in DC and retransmission of PDCP PDUs during PDCP data recovery procedure for RLC AM)

[0456] -Encryption and decryption functions (encryption and decryption)

[0457] - Timer-based SDU removal functionality (timer-based SDU discard in uplink)

[0458] Radio Link Control (RLC) 2b-10 and 2b-35 reconfigures the PDCP Packet Data Unit (PDU) to an appropriate size and performs an Automatic Repeat Request (ARQ) operation. The main functions of RLC are described as follows.

[0459] -Data transmission function (upper layer PDU transmission)

[0460] -ARQ function (error correction through ARQ (only for AM data transmission))

[0461] - Concatenation, segmentation and reassembly function (concatenation, segmentation and reassembly of RLC SDU (only for UM and AM data transmission))

[0462] - Re-segmentation function (resegment RLC data PDU (only for AM data transmission))

[0463] - Reordering function (reorder RLC data PDU (only for UM and AM data transmission)

[0464] - Duplicate detection function (Duplicate detection (only for UM and AM data transmission))

[0465] - Error detection function (protocol error detection (for AM data transmission only))

[0466] -RLC SDU deletion function (RLC SDU discard (only for UM and AM data transmission))

[0467] -RLC reestablishment function (RLC reestablishment)

[0468] MAC 2b-15 and 2b-30 are connected with various RLC layer devices included in one UE, and perform operations of multiplexing RLC PDU to MAC PDU and demultiplexing RLC PDU from MAC PDU. The main functions of MAC are described as follows.

[0469] - Mapping function (mapping between logical channels and transport channels)

[0470] - Multiplexing and demultiplexing functions (multiplexing / demultiplexing MAC SDUs belonging to one or more different logical channels to / from a transport block (TB) delivered to the physical layer on a transport channel)

[0471] -Scheduling information reporting function (Scheduling information reporting)

[0472] -HARQ function (error correction through HARQ)

[0473] -Logical channel priority control function (priority processing between logical channels of a UE)

[0474] -UE priority control function (prioritization between UEs with the help of dynamic scheduling)

[0475] -MBMS service identification function (MBMS service identification)

[0476] -Transmission format selection function (transmission format selection)

[0477] -Filling function (fill)

[0478] The PHY layers 2b-20 and 2b-25 perform operations for: channel encoding and modulating higher layer data to generate OFDM symbols, and transmitting the OFDM symbols through a radio channel; or, demodulating and channel decoding OFDM symbols received through a radio channel, and transmitting the demodulated and channel-decoded OFDM symbols to a higher layer.

[0479] Figure 2C Shown is a structure of a next-generation mobile communication system to which the present disclosure can be applied.

[0480] refer to Figure 2C , the radio access network of the next generation mobile communication system (hereinafter referred to as NR or 5G) includes a next generation base station 2c-10 (hereinafter referred to as new radio node B, NR gNB or NR base station) and a new radio core network (NR CN) 2c-05. The user terminal 2c-15 (new radio user equipment) (hereinafter referred to as NR UE or UE) accesses the external network through the NR gNB 2c-10 and the NR CN 2c-05.

[0481] exist Figure 2CIn the present invention, NR gNB 2c-10 corresponds to the evolved Node B (eNB) of the conventional LTE system. NR gNB can be connected to NR UE 2c-15 through a radio channel and can provide better services than conventional Node B. Since all user services are served through shared channels in the next generation mobile communication system, a device for collecting and scheduling status information of the buffer status, available transmission power status and channel status of the UE is required, and the device corresponds to NR gNB2c-10. One NR gNB usually controls multiple cells. NR gNB can have a bandwidth wider than the traditional maximum bandwidth to implement ultra-high-speed data transmission (compared with conventional LTE), orthogonal frequency division multiplexing (OFDM) can be applied through radio access technology, and beamforming technology can also be applied.

[0482] In addition, according to the channel state of the UE, an adaptive modulation and coding (AMC) scheme that determines the modulation scheme and channel coding rate is applied. NR CN 2c-05 performs the functions of supporting mobility, configuring bearers, and configuring QoS. NR CN is a device for performing functions of managing the mobility of NR UE and various control functions, and is connected to multiple NR gNBs. In addition, the next-generation mobile communication system can be linked to the legacy LTE system, and the NR CN is connected to the MME 2c-25 through a network interface. The MME is connected to the eNB 2c-30, which is a legacy base station.

[0483] Figure 2D A wireless protocol structure of a next-generation mobile communication system to which the present disclosure can be applied is shown.

[0484] refer to Figure 2D The radio protocols of the next generation mobile communication system include NR SDAP 2d-01 and 2d-45, NR PDCP 2d-05 and 2d-40, NR RLC 2d-10 and 2d-35, and NR MAC 2d-15 and 2d-30 in UE and NR gNB.

[0485] The main functions of NR SDAP 2d-01 and 2d-45 may include some of the following functions.

[0486] -User data transmission function (user plane data transmission)

[0487] - Functionality for mapping QoS flows and data bearers for uplink and downlink (mapping between QoS flows and DRBs for both DL and UL)

[0488] - Function to mark QoS flow ID for uplink and downlink (mark QoS flow ID in both DL packet and UL packet)

[0489] - Functionality to map Reflective QoS flows for uplink SDAP PDUs to data bearers (Reflective QoS flows to DRB mapping for UL SDAP PDUs)

[0490] For SDAP layer devices, the UE may receive a configuration through an RRC message that involves whether to use the header of the SDAP layer device or the function of the SDAP layer device for each PDCP layer device, each bearer, or each logical channel. If the SDAP header is configured, the 1-bit indicator of NAS reflected QoS and the 1-bit indicator of AS reflected QoS of the SDAP header may indicate that the UE updates or reconfigures information about the mapping of QoS flows and data bearers in the uplink and downlink. The SDAP header may include QoS flow ID information indicating QoS. QoS information may be used as data processing priority or scheduling information to support seamless services.

[0491] The main functions of NR PDCP 2d-05 or 2d-40 may include some of the following functions.

[0492] -Header compression and decompression function (Header compression and decompression: ROHC only)

[0493] -User data transmission function (user data transmission)

[0494] - Sequence delivery function (deliver upper layer PDUs in sequence)

[0495] - Out-of-order delivery function (deliver upper layer PDU out of order)

[0496] - Reordering function (for reordering of received PDCP PDUs)

[0497] -Duplicate detection function (duplicate detection of lower layer SDU)

[0498] -Retransmission function (retransmit PDCP SDU)

[0499] -Encryption and decryption functions (encryption and decryption)

[0500] - Timer-based SDU removal functionality (timer-based SDU discard in uplink)

[0501] The reordering function of the NR PDCP device is a function of sequentially reordering the PDCP PDUs received by the lower layer based on the PDCP sequence number (SN), and may include a function of transmitting the reordered data to a higher layer in sequence, a function of directly transmitting the reordered data regardless of the sequence, a function of recording the PDCP PDUs lost due to reordering, a function of reporting the status of the lost PDCP PDUs to the transmitting side, and a function of making a request for retransmitting the lost PDCP PDUs.

[0502] The main functions of NR RLC 2d-10 or 2d-35 may include some of the following functions.

[0503] -Data transmission function (upper layer PDU transmission)

[0504] - Sequence delivery function (deliver upper layer PDUs in sequence)

[0505] - Out-of-order delivery function (deliver upper layer PDU out of order)

[0506] -ARQ function (error correction through ARQ)

[0507] - Concatenation, segmentation and reassembly functions (concatenation, segmentation and reassembly of RLC SDUs)

[0508] - Re-segmentation function (resegmentation of RLC data PDU)

[0509] - Reordering function (reorder RLC data PDU)

[0510] -Duplicate detection function (duplicate detection)

[0511] -Error detection function (protocol error detection)

[0512] -RLC SDU deletion function (RLC SDU discard)

[0513] -RLC reestablishment function (RLC reestablishment)

[0514] The sequential delivery function (in-sequence delivery) of the NR RLC device is a function of sequentially delivering RLC PDUs received from a lower layer to a higher layer, and may include a function of reassembling and delivering the RLC SDU (when one original RLC SDU is divided into a plurality of RLC SDUs and then received), a function of reordering the received RLC PDU based on the RLC sequence number (SN) or the PDCP SN, a function of recording the RLC PDU lost due to the reordering, a function of reporting the lost RLC PDU status to the transmitting side, a function of making a request for retransmitting the lost RLC PDU, a function of sequentially delivering only the RLC SDUs before the lost RLC SDU to a higher layer if there is a lost RLC SDU, a function of sequentially delivering all RLC SDUs received before the timer is started and a predetermined timer expires when there is a lost RLC SDU, or a function of sequentially delivering all RLC SDUs received up to this point in time and a predetermined timer expires when there is a lost RLC SDU. In addition, the NR RLC device can process the RLC PDUs sequentially in the order in which the RLC PDUs are received (according to the arrival order regardless of the sequence number or order number), and can transmit the RLC PDUs to the PDCP device regardless of the order of the RLC PDUs (out-of-order delivery). In the case of segmentation, the NR RLC device can receive segments stored in the buffer or to be received in the future, reconfigure the segments into one RLC PDU, process the RLC PDU, and then transmit the RLC PDU to the PDCP device. The NR RLC layer may not include a cascading function, and the function may be performed by the NR MAC layer or may be replaced by a multiplexing function of the NR MAC layer.

[0515] The out-of-order function (out-of-order delivery) of the NR RLC device is a function of directly transmitting the RLC SDU received from a lower layer to a higher layer without considering the order of the RLC SDU, and may include a function of reassembling and transmitting the RLC PDU (when one original RLC SDU is divided into multiple RLC SDUs and then received) and a function of storing the RLC SN or PDCP SN of the received RLC PDU, reordering the RLC PDU, and recording lost RLC PDUs.

[0516] NR MAC 2d-15 and 2d-30 can be connected to multiple NR RLC layer devices configured in one UE, and the main functions of NR MAC may include some of the following functions.

[0517] - Mapping function (mapping between logical channels and transport channels)

[0518] -Multiplexing and demultiplexing functions (multiplexing / demultiplexing MAC SDU)

[0519] -Scheduling information reporting function (Scheduling information reporting)

[0520] -HARQ function (error correction through HARQ)

[0521] -Logical channel priority control function (priority processing between logical channels of a UE)

[0522] -UE priority control function (prioritization between UEs with the help of dynamic scheduling)

[0523] -MBMS service identification function (MBMS service identification)

[0524] -Transmission format selection function (transmission format selection)

[0525] -Filling function (fill)

[0526] The PHY layers 2d-20 and 2d-25 perform operations for: channel coding and modulating data of a higher layer to generate OFDM symbols, and transmitting the OFDM symbols through a radio channel; or, demodulating and channel decoding OFDM symbols received through a radio channel, and transmitting the demodulated and channel-decoded OFDM symbols to a higher layer.

[0527] The present disclosure proposes a method for quickly activating carrier aggregation and saving UE battery in a next generation mobile communication system.

[0528] The network or base station can configure Spcell (Pcell or PScell) and multiple Scells in the UE. When the UE communicates with one base station, Spcell refers to Pcell; when the UE communicates with two base stations (primary base station and secondary base station), Spcell refers to Pcell of the primary base station or PScell ​​of the secondary base station.

[0529] Pcell and Pscell are primary cells used by each MAC layer device for communication between UE and base station, and correspond to cells that synchronize timing, perform random access, transmit HARQ ACK / NACK feedback through PUCCH transmission resources, and exchange most control signals. The technology in which NR gNB operates multiple Scells and Spcells to increase transmission resources for uplink and downlink is called carrier aggregation.

[0530] After receiving the configuration of the Spcell and multiple Scells, the UE may receive the configuration of the mode for each Scell. The mode of the Scell ​​may include an active mode and a deactivated mode.

[0531] In active mode, the UE can transmit uplink or downlink data to and receive uplink or downlink data from the NR gNB in ​​the active mode Scell ​​(or the activated BWP of the Scell). In addition, the UE can monitor the PDCCH to identify the indication of the NR gNB, measure the downlink channel of the active mode Scell ​​(or the activated BWP of the Scell), periodically report the measurement information to the NR gNB, and periodically transmit a pilot signal (sounding reference signal: SRS) to the NR gNB to allow the NR gNB to measure the uplink channel.

[0532] However, in inactive mode, the UE may not transmit data to or receive data from the NR gNB in ​​the Scell, may not monitor the PDCCH for an indication identifying the NR gNB, may not measure channels, may not report measurements, and may not transmit pilot signals.

[0533] Therefore, to activate Scell ​​in inactive mode, NR gNB first configures measurement configuration information in UE through RRC message, and UE measures the cell or frequency based on the measurement configuration information. After receiving the cell or frequency measurement report from UE, NR gNB can activate the deactivated Scell ​​based on the frequency / channel measurement information. Therefore, when NR gNB activates carrier aggregation for UE, much delay occurs.

[0534] The present disclosure proposes a dormant mode for Scell ​​(or BWP) to reduce delay and save UE battery.

[0535] In the stationary mode, the UE may not transmit data to or receive data from the NR gNB in ​​the stationary Scell ​​or stationary BWP, may not monitor the PDCCH for an indication identifying the NR gNB, and may not transmit pilot signals. However, the UE in the stationary mode may measure the channel and report the measurement results of the measured frequency / cell / channel periodically or when an event is generated according to the NR gNB configuration. Therefore, the UE neither monitors the PDCCH nor transmits pilot signals in the stationary Scell ​​or stationary BWP, thereby saving battery (compared to the active mode). Unlike in the inactive mode, channel measurement reports are transmitted, so the NR gNB can use carrier aggregation by quickly activating the stationary Scell ​​or stationary BWP based on the measurement report.

[0536] Since frequencies of significantly high bands can be used in the next-generation mobile communication system, the frequency bandwidth can also be very wide. However, in UE implementation, fully supporting very wide bandwidths requires high implementation complexity, which leads to high costs. Therefore, the next-generation mobile communication system can introduce the concept of bandwidth part (BWP), so multiple BWPs can be configured in one cell (Spcell or Scell), and the UE and NR gNB can transmit and receive data in one or more BWPs according to the configuration of the NR gNB.

[0537] When introducing the stationary mode proposed in the present disclosure, the present disclosure considers Scell ​​and multiple bandwidth parts configured in the Scell, and proposes a state transition method and its detailed operation. In addition, the present disclosure proposes a method for managing the stationary mode and the transition state in units of Scell ​​(Scell ​​level) and a method for managing the stationary mode and the transition state in units of bandwidth parts (BWP level), and proposes detailed operations of bandwidth parts according to each mode (active, inactive or stationary).

[0538] In addition, one or more BWPs can be configured as active or dormant in a cell (Spcell, Pcell, Pscell, or Scell) in the present disclosure. That is, by converting multiple BWPs to an active state for use in one cell, it is possible to increase the data transmission rate by a method similar to carrier aggregation. The UE can measure channels for multiple BWPs by converting multiple BWPs in one cell to a dormant state and report the channel measurement results. In addition, it is possible to save UE battery by converting multiple BWPs in one cell to an inactive state.

[0539] The indication of the state transition of the multiple BWPs for each cell may be configured through an RRC message, a MAC CE, or Downlink Control Information (DCI) of a PDCCH.

[0540] In the present disclosure, BWP may be used without distinguishing between uplink and downlink, and the meaning of BWP may be each of uplink BWP and downlink BWP according to context.

[0541] Figure 2E A process of serving UE by effectively using a frequency bandwidth in a next generation mobile communication system according to the present disclosure is shown.

[0542] exist Figure 2E In the present invention, a method for providing services to UEs with different capabilities or categories and saving battery by efficiently using frequency bandwidth in a next generation mobile communication system is described.

[0543] One cell that the NR gNB provides services to can serve a very wide frequency bandwidth of 2e-05. However, in order to provide services to UEs with different capabilities, the wide frequency bandwidth can be divided into multiple bandwidth parts to manage one cell.

[0544] First, when the UE is initially powered on, it may search the entire frequency band provided by the service provider (PLMN) in units of predetermined resource blocks (e.g., in units of 12 resource blocks (RBs)). That is, the UE may start to discover the primary synchronization sequence (PSS) / secondary synchronization sequence (SSS) in the entire system bandwidth in units of resource blocks, as shown in reference numeral 2e-10.

[0545] If the UE searches for PSS / SSS2e-01 or 2e-02 in units of resource blocks and then detects a signal, the UE can read the signal, analyze (decode) the signal, and identify the boundary between the subframe and the radio transmission resource frame (radio frame). Therefore, the UE can identify the subframe in units of 1ms and synchronize the downlink signal with the NR gNB. A resource block (RB) is the size of a predetermined frequency resource and a predetermined time resource and can be defined as a two-dimensional unit. For example, a time resource can be defined in units of 1ms, and a frequency resource can be defined as 12 subcarriers (1carrier x 15kHz = 180kHz).

[0546] If the UE completes synchronization, the UE can identify information about the control resource set (CORESET) by checking the master system information block (MIB) or the minimum system information (MSI), and identify the initial access bandwidth part (BWP) information, as shown in the figure numbers 2e-15 and 2e-20.

[0547] The CORESET information refers to the location of the time / frequency transmission resource through which the control signal is transmitted from the NR gNB, and may be, for example, the location of the resource through which the PDCCH channel is transmitted. That is, the CORESET information is information indicating the resource through which the first system information (system information block 1: SIB 1) is transmitted, and indicates the frequency / time resource through which the PDCCH is transmitted.

[0548] The UE can identify information about the initial BWP by reading the first system information. As described above, if the UE completes synchronization of the downlink signal with the NR gNB and is able to receive the control signal, the UE can perform a random access procedure in the initial BWP of the cell on which the UE resides, make a request for configuring an RRC connection, receive an RRC message, and perform RRC connection configuration.

[0549] In the RRC connection configuration, multiple BWPs can be configured in each cell (Pcell, Pscell, Spcell or Scell). Multiple BWPs can be configured in one cell for downlink, and separately, multiple BWPs can be configured for uplink.

[0550] Multiple BWPs may be indicated and configured by a BSP identifier to serve as an initial BWP, a default BWP, or a first active BWP.

[0551] The initial BWP may be used as a cell-specific BWP in which one exists per cell, and may be used as a BWP in which a UE initially accessing a cell may configure a connection in the cell through a random access procedure, or a UE configuring a connection may perform synchronization.

[0552] The NR gNB may configure, for each cell, an initial downlink BWP to be used in the downlink and an initial uplink BWP to be used in the uplink.

[0553] The configuration information of the initial BWP can be broadcast through the first system information (system information 1: SIB 1) indicated by CORESET, and can be configured again in the UE to which the NR gNB is connected through an RRC message.

[0554] The initial BWP can be used in a state where it is designated with a BWP identifier number 0 in each of the uplink and downlink. That is, all UEs accessing the same cell can equally designate the same initial BWP as the BWP identifier number 0. This provides an advantage of easily performing a contention-based random access procedure because the NR gNB can transmit a random access response (RAR) message in the initial BWP that all UEs can read during the random access procedure.

[0555] The first active BWP may be configured as UE-specific and may be specified and indicated by an identifier of a BWP among a plurality of BWPs.The first active BWP may be configured for each of a downlink and an uplink, and the first active downlink BWP and the first active uplink BWP may be configured using respective BWP identifiers.

[0556] When multiple BWPs are configured in a cell, the first active BWP can be used to indicate which BWP is activated and used first. For example, when a Pcell or Pscell and multiple Scells are configured in the UE, and multiple BWPs are configured in each Pcell or Pscell or each Scell, if the Pcell, Pscell or Scell ​​is activated, the UE can activate and use the first active BWP among the multiple BWPs configured in the Pcell, Pscell or Scell. That is, the first active downlink BWP can be activated and used for the downlink, and the first active uplink BWP can be activated and used for the uplink.

[0557] After receiving an indication indicating activation of a Scell ​​or BWP transitioning from an inactive state to an active state through an RRC message, MAC control information, or DCI, the UE may perform an operation of switching the downlink BWP of the Scell ​​to a downlink BWP (e.g., a first active downlink BWP) indicated or configured by the RRC message to activate the downlink BWP, and switching the uplink BWP to an uplink BWP (e.g., a first active uplink BWP) indicated or configured by the RRC message to activate the uplink BWP. In addition, upon receiving an indication indicating a transition of the Scell ​​or BWP to a stationary state through an RRC message, MAC control information, or DCI, the UE may perform the operation. This is because when transmitting a channel measurement report in a stationary state, the NR gNB can effectively use carrier aggregation by measuring and reporting the frequency / channel used for the first active downlink / uplink BWP, because when activating the Scell ​​or BWP, the UE switches the downlink BWP to the first active downlink BWP and activates the downlink BWP, and switches the uplink BWP to the first active uplink BWP and activates the uplink BWP.

[0558] The default BWP may be configured as UE-specific and may be assigned to and indicated by an identifier of a BWP among multiple BWPs. The default BWP may be configured for downlink only. The default BWP may be used as the BWP to which the activated BWP falls back after a predetermined time among multiple downlink BWPs.

[0559] For example, a BWP inactivity timer may be configured through an RRC message for each cell or each BWP, and the timer may be started or restarted when data transmission / reception occurs in an activated BWP instead of a default BWP, or may be started or restarted when an activated BWP is switched to another BWP.

[0560] If the timer expires, the UE may roll back or switch the activated downlink BWP in the cell to the default BWP. The switch may be a process of deactivating the currently activated BWP and activating the BWP to be switched to, and may be triggered by an RRC message, MAC control information (MAC control element), or L1 signaling (downlink control information (DCI) of PDCCH). The switch may be triggered by an indication of the BWP to be activated or switched to, and the BWP may be indicated by a BWP identifier (e.g., 0, 1, 2, 3, or 4).

[0561] The reason why the default BWP is used only for downlink is to facilitate NR gNB scheduling, because the NR gNB allows the UE to receive the indication of the NR gNB (e.g., DCI of PDCCH) after a predetermined time by falling back to the default BWP for each cell. For example, if the NR gNB configures the default BWP of a UE accessing a cell as the initial BWP, the NR gNB can continuously transmit scheduling indications only in the initial BWP after a predetermined time. If the default BWP is not configured through the RRC message, the default BWP can fall back to the initial BWP by treating the initial BWP as the default BWP when the BWP inactivity timer expires.

[0562] In another method, in order to increase the implementation freedom of Nr gNB, a default BWP for uplink can be defined and configured, so the default BWP for uplink can be used like the default BWP for downlink.

[0563] Figure 2F The present invention shows a process of UE switching from RRC idle mode to RRC connected mode in a next generation mobile communication system, which is a method of configuring multiple BWPs and configuring a default BWP or a first active BWP.

[0564] One cell to which the gNB provides services may serve a very wide frequency band. First, the UE may search the entire frequency band provided by the service provider (PLMN) in units of predetermined resource blocks (e.g., in units of 12 resource blocks (RBs)). That is, the UE may start to discover the primary synchronization sequence (PSS) / secondary synchronization sequence (SSS) in the entire system bandwidth in units of resource blocks.

[0565] If the UE searches for PSS / SSS in units of resource blocks and then detects a signal, the UE can read the signal, analyze (decode) the signal, and identify the boundary between the subframe and the radio transmission resource frame (radio frame). If the UE completes synchronization, the UE can read the system information of the cell on which the UE currently resides. That is, in steps 2f-01 and 2f-05, the UE can identify information about the control resource set (CORESET) by checking the master system information block (MIB) or the minimum system information (MSI), and identify the initial access bandwidth part (BWP) information by reading the system information. The CORESET information refers to the location of the time / frequency transmission resource through which the control signal is transmitted from the NR gNB, and may be, for example, the location of the resource through which the PDCCH channel is transmitted.

[0566] As described above, if the UE completes synchronization of downlink signals with the NR gNB and is able to receive control signals, the UE can perform a random access procedure in the initial BWP in steps 2f-10, 2f-15, 2f-20, 2f-25, and 2f-30, receive a random access response, make a request to configure an RRC connection, receive an RRC message, and configure an RRC connection.

[0567] When the basic RRC connection is fully configured, the NR gNB may transmit an RRC message (UECapabilityEnquire) to the UE to query the UE capabilities in order to identify the UE capabilities in 2f-35. In another method, the NR gNB may inquire (or request) the MME or AMF for the UE capabilities in order to identify the UE capabilities. This is because if the UE has previously accessed the MME or AMF, the MME or AMF may have the UE capability information. If the NR gNB does not have the requested UE capabilities, the NR gNB may request the UE capabilities from the UE. Alternatively, the NR gNB may store the UE capability information, in which case step 2f-35 may be omitted.

[0568] The reason why the NR gNB transmits an RRC message to the UE to identify the UE capabilities is to identify the UE capabilities, such as information indicating the frequency bands that the UE can read or the areas of the frequency bands that the UE can read. After identifying the UE capabilities, the NR gNB can configure an appropriate BWP in the UE.

[0569] If the UE receives an RRC message querying the UE capabilities, the UE may transmit information in step 2f-40, the information including information indicating the bandwidth range supported by the UE, information indicating an offset from a reference center frequency to indicate the bandwidth range supported in the current system bandwidth, information directly indicating the start and end points of the supported frequency bandwidth, or information indicating the center frequency and bandwidth.

[0570] The BWP can be configured through the RRCSetup message or RRCResume message of the RRC connection configuration in step 2f-25 or the RRCReconfiguration message in step 2f-45. The RRC message may include configuration information of a PCell, a Pscell or multiple Scells, and multiple BWPs can be configured for each cell (PCell, Pscell or Scell).

[0571] When multiple BWPs are configured for each cell, multiple BWPs to be used in the downlink of each cell can be configured. In the case of an FDD system, multiple BWPs to be used in the uplink of each cell can be configured to distinguish from the downlink BWP. In the case of a TDD system, multiple BWPs to be used in both the downlink and uplink of each cell can be configured.

[0572] The information for configuring the BWP of each cell (PCell, Pscell or Scell) may include at least one of the following information.

[0573] -Downlink BWP configuration information of the cell

[0574] ■ Initial downlink BWP configuration information

[0575] ■ Multiple BWP configuration information and BWP IDs corresponding to respective BWPs

[0576] ■ Initial state configuration information for each BWP of the plurality of BWPs (eg, active state, quiescent state, or inactive state)

[0577] ■ Indicates the BWP ID of the first active downlink BWP

[0578] ■Indicates the BWP ID of the default BWP

[0579] ■BWP inactivity timer configuration and timer value

[0580] - Uplink BWP configuration information of the cell

[0581] ■ Initial uplink BWP configuration information

[0582] ■ Multiple BWPS configuration information and BWP IDs corresponding to respective BWPs

[0583] ■ Initial state configuration information for each BWP of the plurality of BWPs (eg, active state, quiescent state, or inactive state)

[0584] ■ Indicates the BWP ID of the first active uplink BWP

[0585] The configured initial BWP, default BWP, or first active BWP may be used for the following purposes and may be operated to achieve the purposes.

[0586] The initial BWP may be used as a cell-specific BWP in which one exists per cell, and may be used as a BWP in which a UE initially accessing a cell may configure a connection in the cell through a random access procedure, or a UE configuring a connection may perform synchronization.

[0587] The NR gNB may configure, for each cell, an initial downlink BWP to be used in the downlink and an initial uplink BWP to be used in the uplink.

[0588] The configuration information of the initial BWP can be broadcast through the first system information (system information 1: SIB 1) indicated by CORESET, and can be configured again in the UE accessed by the NR gNB through RRC messages.

[0589] The initial BWP can be used while being designated as BWP identifier number 0 in each of the uplink and downlink. That is, all UEs accessing the same cell can equally designate the same initial BWP as BWP identifier number 0 to use the initial BWP. This provides an advantage of easily performing a contention-based random access procedure because the NRgNB can transmit a random access response (RAR) message in the initial BWP that all UEs can read during the random access procedure.

[0590] The first active BWP may be configured as UE-specific and may be specified and indicated by a BWP identifier among multiple BWPs. The first active BWP may be configured for each of the downlink and uplink, and the first active downlink BWP and the first active uplink BWP may be configured using respective BWP identifiers.

[0591] When multiple BWPs are configured in a cell, the first active BWP can be used to indicate which BWP is activated and used first. For example, when a Pcell or Pscell and multiple Scells are configured in the UE, and multiple BWPs are configured in each Pcell or Pscell or each Scell, if the Pcell, Pscell or Scell ​​is activated, the UE can activate and use the first active BWP among the multiple BWPs configured in the Pcell, Pscell or Scell. That is, the first active downlink BWP can be activated and used for the downlink, and the first active uplink BWP can be activated and used for the uplink.

[0592] Upon receiving an indication to activate the Scell ​​or BWP through an RRC message, MAC control information, or DCI, the UE may perform an operation of switching the downlink BWP of the Scell ​​to the downlink BWP (e.g., the first active downlink BWP) indicated or configured through the RRC message and activating the downlink BWP, and switching the uplink BWP to the uplink BWP (e.g., the first active uplink BWP) indicated or configured through the RRC message and activating the uplink BWP. In addition, upon receiving an indication to indicate that the Scell ​​or BWP transitions to a stationary state through an RRC message, MAC control information, or DCI, the UE may perform the operation. This is because when transmitting a channel measurement report in the stationary state, the NR gNB can effectively use carrier aggregation by measuring and reporting the frequency / channel used for the first active downlink / uplink BWP, because when activating the Scell ​​or BWP, the UE switches the downlink BWP to the first active downlink BWP to activate the downlink BWP, and switches the uplink BWP to the first active uplink BWP to activate the uplink BWP.

[0593] The default BWP may be configured as UE-specific and may be assigned to and indicated by an identifier of a BWP among multiple BWPs. The default BWP may be configured for downlink only. The default BWP may be used as the BWP to which the activated BWP falls back after a predetermined time among multiple downlink BWPs. For example, a BWP inactivity timer may be configured through an RRC message for each cell or each BWP, and the timer may be started or restarted when data transmission / reception occurs in an activated BWP instead of the default BWP, or may be started or restarted when the activated BWP switches to another BWP.

[0594] If the timer expires, the UE may roll back or switch the activated downlink BWP in the cell to the default BWP. The switch may be a process of deactivating the currently activated BWP and activating the BWP to be switched to, and may be triggered by an RRC message, MAC control information (MAC control element), or L1 signaling (downlink control information (DCI) of PDCCH). The switch may be triggered by an indication of the BWP to be activated or switched to, and the BWP may be indicated by a BWP identifier (e.g., 0, 1, 2, 3, or 4).

[0595] The reason why the default BWP is used only for downlink is to facilitate NR gNB scheduling, because the NR gNB allows the UE to receive the indication of the NR gNB (e.g., DCI of PDCCH) after a predetermined time by falling back to the default BWP for each cell. For example, if the NR gNB configures the default BWP of a UE accessing a cell as the initial BWP, the NR gNB can continuously transmit scheduling indications only in the initial BWP after a predetermined time. If the default BWP is not configured through the RRC message, the default BWP can fall back to the initial BWP by treating the initial BWP as the default BWP when the BWP inactivity timer expires.

[0596] In another method, in order to increase the implementation freedom of Nr gNB, a default BWP for uplink can be defined and configured, so the default BWP for uplink can be used like the default BWP for downlink.

[0597] In the RRC Setup message of the RRC Connection Configuration, the RRCResume message in step 2f-25, or the RRCReconfiguration message in step 2f-45, the UE may configure a state transition timer to enable the UE to transition states by itself, even if the UE does not receive an indication from the NR gNB through an RRC message, MAC control information, or DCI of the PDCCH. For example, if a cell deactivation timer (ScellDeactivationTimer) or a BWP deactivation timer (BwpDeactivationTimer) is configured for each Scell ​​or BWP and the cell deactivation timer or BWP deactivation timer expires, the Scell ​​or BWP may transition to the inactive state. If a cell hibernation timer (ScellHibernationTimer) or a BWP hibernation timer (BwpHibernationTimer) is configured for each Scell ​​or BWP and the cell hibernation timer or BWP hibernation timer expires, the Scell ​​or BWP may transition to the static state.

[0598] When the cell dormancy timer or BWP dormancy timer expires, only the Scell ​​or BWP in the active state is converted to the dormant state, while the Scell ​​or BWP in the inactive state or dormant state is not converted to the dormant state. In addition, by configuring a dormant state cell deactivation timer (dormantScellDeactivationTimer) or a dormant state BWP deactivation timer (dormantBwpDeactivationTimer) for each Scell ​​or BWP, the Scell ​​or BWP in the dormant state can be converted to the inactive state.

[0599] When the stationary state cell deactivation timer or the stationary state BWP deactivation timer expires, only the Scell ​​or BWP in the stationary state is converted to the inactive state, and the Scell ​​or BWP in the active state or the inactive state is not converted to the inactive state. If the cell deactivation timer (ScellDeactivationTimer) (or BWP deactivation timer) and the cell hibernation timer (ScellHibernationTimer) (or BWP hibernation timer) are configured together, the cell hibernation timer (ScellHibernationTimer) (or BWP hibernation timer) is given priority. That is, if the cell hibernation timer (ScellHibernationTimer) (or BWP hibernation timer) is configured, even if the cell deactivation timer (ScellDeactivationTimer) (or BWP deactivation timer) expires, the corresponding Scell ​​or BWP is not deactivated. In other words, if the cell hibernation timer (or BWP hibernation timer) is configured, the Scell ​​is first converted from the active state to the stationary state due to the expiration of the cell hibernation timer, and the cell that has been converted to the stationary state is converted to the inactive state due to the expiration of the stationary state cell deactivation timer. Therefore, if the cell dormancy timer is configured, the cell deactivation timer does not affect the state transition of the Scell ​​or BWP, and if the cell dormancy timer is configured, the Scell ​​does not transition to the inactive state even if the cell deactivation timer expires.

[0600] If the cell deactivation timer (or BWP deactivation timer) is not configured in the RRC message, the UE may consider setting the cell deactivation timer (or BWP deactivation timer) to an infinite value.

[0601] The NR gNB may configure frequency measurement configuration information and / or frequency measurement gap information through an RRC establishment message of an RRC connection configuration, an RRCResume message of step 2f-25, or an RRCReconfiguration message of step 2f-45, and the message may include frequency measurement target object information.

[0602] The frequency measurement object may include information about a BWP in which a reference signal (RS) / synchronization signal (SS) for measurement is configured, and may also include a center frequency, a bandwidth corresponding to the BWP, and a time pattern that should be applied during measurement.

[0603] The measurement report gap information may include at least one of a measurement gap length corresponding to the time when the measurement is performed, a measurement gap period, and a measurement gap start time information. RS is a signal of the NR gNB transmitted according to a partial time / frequency pattern in a transmission resource of a subframe in which a control signal or a data signal is transmitted, and may be used to determine the signal strength of the corresponding BWP or the corresponding cell. SS is a synchronization signal (such as PSS or SSS) transmitted periodically, and may be used to determine the signal strength of the corresponding BWP or the corresponding cell.

[0604] As described above, when the RRC connection configuration is completed, the UE may configure multiple BWPs according to the instructions configured via the RRC message. In addition, to save battery, the UE may activate one or a small number of BWPs among the multiple configured BWPs. For example, the NRgNB may indicate a BWP to be activated.

[0605] The NR gNB may indicate activation of the BWP (e.g., whether activation or deactivation is performed) through an RRC message, MAC control information (MAC CE), or L1 signaling (PHY layer control signal, such as PDCCH) to indicate switching from the initial access BWP to a new BWP. Since there are many new access users in the initial access BWP, it may be more advantageous for scheduling to allocate a new BWP and manage the connected users separately. This is because the initial access BWP can be shared and used by all UEs instead of being configured in a UE-specific manner. In addition, the default BWP may be dynamically indicated through MAC control information, L1 signaling, or system information (in order to reduce signaling overhead).

[0606] Hereinafter, the present disclosure proposes a stationary state in a next generation mobile communication system, and proposes a method of supporting transitions among three states in units of BWP.

[0607] Figure 2G The state transition process of the cell or BWP proposed in the present disclosure is shown.

[0608] exist Figure 2G In the present invention, each cell or BWP of the UE may have an active state 2g-01, an inactive state 2g-03 or a dormant state 2g-02, and may perform a state transition due to a configuration information indication of an RRC message, MAC control information or DCI of a PDCCH.

[0609] The state transition operation (active, inactive or quiescent state) of the Scell ​​or BWP proposed in the present disclosure may be performed as follows.

[0610] -Configuring Scell ​​state or BWP via RRC message

[0611] - Receiving Scell ​​activation and deactivation MAC CE

[0612] - Receiving BWP activation, deactivation and static MAC CE

[0613] - When receiving a Scell ​​static MAC CE

[0614] - The cell dormancy timer is not configured in the active Scell ​​and the configured cell deactivation timer expires

[0615] - The BWP dormancy timer is not configured in the active BWP and the configured BWP deactivation timer expires

[0616] - When the cell dormancy timer configured in the active Scell ​​expires

[0617] - When the BWP dormancy timer configured in the active BWP expires

[0618] - When the Scell ​​deactivation timer configured in the Scell ​​in the static state expires

[0619] - A case where the stationary state BWP deactivation timer configured in the stationary state BWP expires In addition, the state transition operation proposed in the present disclosure may have the following characteristics.

[0620] -Spcell (Pcell or Pscell) (or BWP of a cell) cannot be switched to a dormant state and is always in an active state. Spcell performs synchronization with the UE for transmitting and receiving main control signals, and releases the connection with the NR gNB if the Spcell is dormant or inactive, so the Spcell should always remain in an active state.

[0621] - If PUCCH is configured, even the Scell ​​cannot transition to the dormant state. The Scell ​​should be in the active state because there may be another cell that should transmit HARQ ACK / NACK feedback via PUCCH.

[0622] - Due to this feature, if the cell deactivation timer (ScellDeactivationTimer) is not applied to the Scell ​​or Spcell in which the PUCCH is configured, the cell deactivation timer may operate only for other Scells.

[0623] - The ScellHibernationTimer is given priority over the ScellDeactivationTimer. If a value is set as the timer value through an RRC message, the same value can be applied to all cells. In another method, the NR gNB can configure different timer values ​​for Scell ​​or BWP considering the characteristics of each Scell ​​or BWP.

[0624] - If there is no indication through the RRC message whether the Scell ​​is active or dormant, the Scell ​​may initially operate substantially in an inactive state.

[0625] The first embodiment of the present disclosure proposes a first embodiment corresponding to operations of each cell (Scell) and BWP according to each state when the active state, inactive state, or stationary state proposed by the present disclosure is applied to a next generation mobile communication system using BWP.

[0626] In the first embodiment of the present disclosure, an active state, an inactive state, or a static state is operated, and a state transition is performed in units of BWPs. When a state transition is performed in units of BWPs, a BWP that is instructed to perform a state transition performs a state transition according to the instruction of the state transition. For example, if a BWP is transitioned from an active state to a static state, the BWP may be transitioned to a static state.

[0627] Figure 2H The method proposed in the present disclosure for converting the BWP state by performing state conversion in units of BWP is shown.

[0628] In the first embodiment of the present disclosure, Figure 2H The operation shown is an active state, an inactive state or a dormant state, and the state transition is performed in units of BWPs. When the state transition is performed in units of BWPs, one BWP among a plurality of BWPs belonging to the Scell ​​is indicated, and the BWP performs the state transition.

[0629] like Figure 2H As shown, Pcell 2h-10 can always maintain an active state to prevent the release of the wireless connection between the NR gNB and the UE. In the case of an FDD system, each cell (Pcell or each Scell) can distinguish between the frequencies used for the downlink and uplink, and multiple BWPs can be configured for each of the downlink and uplink. In the case of a TDD system, the frequency between the downlink and uplink may not be distinguished, and multiple BWPs may be configured between the downlink and uplink without distinguishing.

[0630] In the present disclosure, a plurality of BWPs may have an active state or a static state for each of a downlink and an uplink in each Scell, and the remaining BWPs may be in an inactive state. That is, it is possible to increase the amount of data transmitted through carrier aggregation by increasing the number of transmission resources used to transmit data in a plurality of active BWPs, and it is possible to efficiently perform scheduling and reduce UE power consumption by receiving channel measurement reports about a plurality of BWPs using a plurality of static BWPs.

[0631] For example, Figure 2H As shown, the NR gNB can configure the first Scell ​​2h-20, the second Scell ​​2h-30 and the third Scell ​​2h-40 in the UE.

[0632] If the NR gNB converts any BWP of the first Scell ​​2h-20 to a quiescent state through an RRC message or MAC CE, the UE may convert the indicated BWP among the multiple BWPs configured in the first Scell ​​to a quiescent state.

[0633] If the NR gNB converts any BWP of the second Scell ​​2h-30 to an inactive state through an RRC message or MAC CE, the UE may convert the indicated BWP among the multiple BWPs configured in the second Scell ​​to an inactive state.

[0634] If the NR gNB converts any BWP of the third Scell ​​2h-40 to active state through an RRC message or MAC CE, the UE may convert the indicated BWP among the multiple BWPs configured in the third Scell ​​to active state.

[0635] In the following, as described above, the present disclosure proposes a state transition operation of BWP when the NR gNB instructs the UE to perform a state transition in units of BWP.

[0636] -If (BWP Activation) the MAC layer device receives a MAC CE or RRC message indicating activation of any BWP, some or all of the following operations may be performed.

[0637] ■Activate BWP.

[0638] ■ Transmit a Sounding Reference Signal (SRS) to allow the NR gNB to measure the channel for uplink in the activated BWP. For example, the SRS may be transmitted periodically.

[0639] ■The UE can report channel measurement results (CSI, CQI, PMI, RI, PTI or CRI) for the downlink in the activated BWP according to the configuration of the NR gNB.

[0640] ■Monitor PDCCH to read the indication of the NR gNB in ​​the activated BWP.

[0641] ■ Monitor PDCCH to read the cross scheduling in the activated BWP.

[0642] ■ If PUCCH is configured in the activated BWP, PUCCH is transmitted.

[0643] ■ The BWP deactivation timer can be started or restarted for BWP. In another approach, the BWP deactivation timer can be started or restarted only if the BWP sleep timer is not configured.

[0644] ■ If there is a pending type 1 configured transmission resource, the resource may be initialized according to the type 1 transmission resource configuration, or the resource may be initialized and used again. A type 1 configured transmission resource is a periodic (uplink or downlink) transmission resource pre-allocated by an RRC message, which can be used after being activated by an RRC message

[0645] ■If the BWP sleep timer is configured in the BWP, then

[0646] ◆BWP sleep timer can be started or restarted for BWP.

[0647] ■PHR for BWP can be triggered.

[0648] - If (BWP Deactivation) the MAC layer device receives a MAC CE indicating deactivation of any BWP or an RRC message indicating deactivation of any BWP,

[0649] - or if the BWP deactivation timer for the Scell ​​expires and the BWP dormancy timer is not configured (if the BWP dormancy timer is configured, the BWP dormancy timer should be given priority, so the expiration of the BWP deactivation timer can be ignored. That is, if the BWP dormancy timer is configured, the BWP state should first be transitioned from the active state to the dormant state, and then from the dormant state to the inactive state), then

[0650] -The UE may perform some or all of the following operations.

[0651] ■The BWP of the Scell ​​can be deactivated.

[0652] ■The BWP deactivation timer configured in BWP can be stopped.

[0653] ■ The BWP deactivation timer configured for the BWP may be stopped.

[0654] ■ Periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the BWP may be released (cleared).

[0655] The term "release (clear)" means that configuration information such as periodic information configured by RRC message is stored in the UE, but information about periodic transmission resources activated or indicated by L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used. Periodic transmission resources may be referred to as type 2 configured transmission resources.

[0656] ■ If there are PUSCH transmission resources configured for BWP for periodic channel measurement information (semi-persistent CSI reporting), the periodic transmission resources are released (cleared).

[0657] ■Periodic uplink transmission resources configured in the BWP (configured uplink grant type 1 configured via RRC) may be suspended. The term "suspend" means that the transmission resource configuration information configured via RRC messages is stored in the UE but is no longer used. Periodic transmission resources may be referred to as type 1 configured transmission resources.

[0658] ■Flush all HARQ buffers configured for BWP.

[0659] - If the PDCCH indicates the presence of downlink data (downlink allocation) or allocation of uplink transmission resources in any activated BWP,

[0660] - or, if the PDCCH indicates that there is downlink data for an activated BWP in the serving cell (downlink allocation) for scheduling any activated BWP or allocating uplink transmission resources (uplink grant),

[0661] - or, for an activated configured BWP, if any MAC PDU is transmitted over preconfigured downlink transmission resources (configured downlink allocation) or preconfigured uplink transmission resources (configured uplink grant), then

[0662] ■ The UE may restart the BWP deactivation timer for BWP. In another method, the BWP deactivation timer may be restarted only when BWP dormancy is not configured.

[0663] ■ If the BWP Sleep Timer is configured for use with the BWP, then

[0664] ◆BWP sleep timer can be restarted.

[0665] - If the BWP of the Scell ​​is deactivated or inactive, then

[0666] ■UE does not transmit SRS for BWP for Scell.

[0667] ■ The UE neither measures (CSI, CQI, PMI, RI, PTI or CRI) nor reports the channels in the BWP of the Scell ​​for downlink.

[0668] ■ Uplink data is not transmitted through the UL-SCH in the BWP of the Scell.

[0669] ■ The random access procedure of the BWP for the Scell ​​is not performed.

[0670] ■The UE does not monitor the PDCCH in the BWP of the Scell.

[0671] ■ UE does not monitor PDCCH in BWP of Scell ​​For example, in case of cross scheduling, PDCCH for Scell ​​is not monitored in the cell in which scheduling is performed.

[0672] ■ PUCCH or SPUCCH are not transmitted in the BWP.

[0673] - If there is a random access procedure being performed in the BWP during deactivation of the BWP, the random access procedure is canceled.

[0674] - The dormant state is not applicable to the Spcell or Scell ​​in which the PUCCH is configured.

[0675] The MAC layer device can operate two timers to effectively manage the static state of the Scell.

[0676] -BWP Hibernation Timer (BWPHibernationTimer): Operates in the BWP configured in the UE, but does not operate in the Scell ​​in which the PUCCH is configured. If the BWP hibernation timer expires, the MAC layer device transitions the BWP in the active state to the dormant state. That is, the cell hibernation timer can be applied only to the Scell ​​in the active state. A value configured by RRC can be equally applied to the cell hibernation timer of each Scell. The cell hibernation timer is given priority over the cell deactivation timer. That is, if the cell hibernation timer is configured and running, the cell hibernation timer does not transition to the inactive state regardless of whether the cell deactivation timer is running or expired, and the cell deactivation timer does not affect the Scell.

[0677] - DormantBWPDeactivationTimer: Operates in the Scell ​​configured in the UE, but does not operate in the Scell ​​in which the PUCCH is configured. If the dormant BWP deactivation timer expires, the MAC layer device converts the BWP in the dormant state to an inactive state. One value configured by RRC can be equally applied to the dormant cell deactivation timer of each BWP. That is, the dormant BWP deactivation timer is only applied to the BWP in the dormant state.

[0678] If the dormant state is indicated by the RRC message when configuring the BWP, the UE can switch the BWP to the dormant state. If the dormant state is indicated in the BWP state configuration of the RRC message even at the time of handover or SCG change, the UE can switch the BWP to the dormant state.

[0679] - If the MAC layer device receives an indication of a quiescent state when configuring the BWP via an RRC message, or receives a MAC CE indicating that the state of the BWP is transitioned to a quiescent state, then

[0680] ■The UE may perform some or all of the following operations

[0681] ■Scell's BWP can be switched to a static state.

[0682] ■ The cell deactivation timer configured or operated in the BWP of the Scell ​​may be stopped.

[0683] ■ If the BWP sleep timer is configured in the BWP of the Scell, the BWP sleep timer can be stopped.

[0684] ■The stationary state BWP deactivation timer can be started or restarted in the BWP of the Scell.

[0685] ■ The BWP deactivation timer of the BWP configured for the Scell ​​may be stopped. This is to prevent unnecessary BWP switching procedures in the Scell.

[0686] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the BWP of the Scell ​​may be released (cleared).

[0687] The term "release (clear)" means that configuration information such as periodic information configured by RRC message is stored in the UE, but information about periodic transmission resources activated or indicated by L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used. The proposed method (i.e., the operation of releasing (clearing) configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can only be performed when the BWP is transitioned from the active state to the dormant state. This is because when the BWP is transitioned from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0688] ■The periodic uplink transmission resources configured in the BWP of the SCell (configured uplink grant type 1 configured through RRC) can be suspended. The term "suspend" means that the transmission resource configuration information configured through the RRC message is stored in the UE but is no longer used. The proposed method (i.e., the operation of suspending periodic uplink transmission resources (configured uplink grant type 1)) can only be performed when the BWP transitions from the active state to the dormant state. This is because the periodic transmission resources are not used when the BWP transitions from the inactive state to the dormant state. ■Clear all HARQ buffers configured in the BWP.

[0689] - If the BWP dormancy timer in the activated BWP of the Scell ​​expires, then

[0690] ■UE can switch the BWP of the Scell ​​to the dormant state.

[0691] ■The UE may stop the BWP deactivation timer configured or operated in the BWP of the Scell.

[0692] ■The UE may stop the BWP dormancy timer configured or operated in the BWP of the Scell.

[0693] ■The UE starts or restarts the dormant BWP deactivation timer in the BWP of the Scell.

[0694] - If the stationary BWP deactivation timer configured in the stationary BWP expires, then

[0695] ■The BWP of the Scell ​​can be switched to an inactive state.

[0696] ■ The quiescent state BWP deactivation timer of the Scell's BWP may be stopped.

[0697] - If the Scell's BWP is in quiescent state, then

[0698] ■UE does not transmit SRS for BWP of Scell.

[0699] ■UE measures the channel (CSI, CQI, PMI, RI, PTI or CRI) for downlink in the BWP of Scell ​​according to the configuration of NR gNB and reports the measurement. For example, UE can report channel or frequency measurements periodically.

[0700] ■ Uplink data is not transmitted through the UL-SCH in the BWP of the Scell.

[0701] ■ The random access procedure of the BWP for the Scell ​​is not performed.

[0702] ■UE does not monitor the PDCCH in the BWP of the Scell.

[0703] ■ UE does not monitor PDCCH in BWP of Scell ​​For example, in case of cross scheduling, PDCCH for Scell ​​is not monitored in the cell in which scheduling is performed.

[0704] ■ PUCCH or SPUCCH is not transmitted in the BWP of the Scell.

[0705] ■ The downlink BWP can be put to sleep and the channel measurement results can be reported. In addition, the uplink BWP of the Scell ​​can be deactivated and not used. This is because the channel is measured for the downlink BWP only in the Scell ​​in the static state, and the measurement results are reported to the uplink BWP of the Scell ​​or Spcell (Pcell or Pscell) in which the PUCCH exists.

[0706] ■ Make the downlink (DL) BWP and uplink (UL) BWP of the Scell ​​sleep or switch to the downlink BWP (e.g., the first active downlink BWP (indicated by firstActiveDownlinkBWP-Id) and the uplink BWP (e.g., the first active uplink BWP (indicated by firstActiveUplinkBWP-id)) indicated or configured by the RRC message because the BWP of the Scell ​​is instructed to transition to the static state. This is because the first active uplink / downlink BWP configured by the RRC message is activated when the BWP in the inactive state or the static state transitions to the active state, so it is effective to transmit the channel measurement report of the static state in the first active uplink / downlink BWP.

[0707] In another method, during the transition to the dormant state, only the downlink BWP can be dormant and switched to the downlink BWP (e.g., the first active downlink BWP) indicated or configured by the RRC message. This is because the uplink BWP is also activated and switched to the first active uplink BWP when the BWP is activated. If the active BWP was originally the first active downlink or uplink BWP in the BWP before the dormant state was indicated, the BWP can be put to sleep without performing a switching operation.

[0708] ■ The periodic downlink transmission resources (DL SPS or configured downlink allocation) or periodic uplink transmission resources (UL SPS or configured uplink grant type 2) configured in the BWP of the Scell ​​may be released (cleared).

[0709] The term "release (clear)" means that configuration information such as periodic information configured through an RRC message is stored in the UE, but information on periodic transmission resources activated or indicated through L1 signaling (e.g., DCI) is removed (cleared or released) and no longer used.

[0710] The proposed method (i.e., the operation of releasing (clearing) the configured periodic downlink transmission resources (DL SPS or configured downlink allocation) or the configured periodic uplink transmission resources (UL SPS or configured uplink grant)) can only be performed when the BWP transitions from the active state to the dormant state. This is because when the BWP transitions from the inactive state to the dormant state, there is no information about the periodic transmission resources activated or indicated by L1 signaling.

[0711] ■ The periodic uplink transmission resources configured in the BWP of the Scell ​​(configured uplink grant type 1 configured via RRC) can be suspended. The term "suspend" means that the transmission resource configuration information configured via RRC message is stored in the UE but is no longer used.

[0712] The proposed method (i.e., the operation of suspending periodic uplink transmission resources (configuring uplink grant type 1)) can only be performed when the BWP transitions from the active state to the dormant state. This is because the periodic transmission resources are not used when the BWP transitions from the inactive state to the dormant state.

[0713] - If there is a random access procedure being performed during the transition of the BWP to the quiescent state, the random access procedure may be canceled.

[0714] Hereinafter, the present disclosure proposes state transition MAC control information (MAC Control Element: MAC CE) indicating an active state, a dormant state, or an inactive state of each BWP.

[0715] Fig.2I The MAC control information indicating the state transition to the active state, the dormant state or the inactive state proposed in the present disclosure is shown.

[0716] The active and inactive MAC CEs proposed in the present disclosure may have the following characteristics: Fig.2I The format shown in , and can be divided into MAC CE format 2i-05 supporting 7 Scells and MAC CE format 2i-10 supporting 31 Scells. In addition, MAC CE can have the following characteristics.

[0717] - In MAC CE format 2i-05 or 2i-10, a group of bits indicating each cell may be defined, the group may be defined as field Ci, and indicator i of field Ci may indicate a cell identifier. Field Ci corresponding to each Scell ​​may include an identifier indicating an uplink or a downlink, a BWP identifier, and an indicator indicating a BWP state (active state, static state, or inactive state). Therefore, in the MAC CE format, a specific cell may be indicated, a downlink or an uplink of the indicated cell may be indicated, a BWP of the indicated downlink or uplink of the indicated cell may be indicated, and a state transition of the BWP of the indicated downlink or uplink of the indicated cell may be indicated.

[0718] -MAC CE format 2i-15 may include an identifier corresponding to a cell, an indicator indicating uplink or downlink, a BWP identifier, and an indicator indicating the BWP state (active state, static state, or inactive state). Therefore, in the MAC CE format, a specific cell may be indicated, the downlink or uplink of the indicated cell may be indicated, the BWP of the downlink or uplink of the indicated cell may be indicated, and the state transition of the BWP of the downlink or uplink of the indicated cell may be indicated.

[0719] Various MAC CE formats based on the proposed features can be extended as embodiments, and the features proposed in the present disclosure correspond to indicating the state transition of the downlink or uplink BWP of each cell through MAC CE and switching the downlink or uplink BWP of each cell through MAC CE.

[0720] Figure 2J UE operations for converting the state of a cell configured in the UE according to the present disclosure are illustrated.

[0721] exist Figure 2J In NR gNB, multiple Scells in UE can be configured together with Spcells (Pcell or Pscell).

[0722] If the cell configured in step 2j-05 is a Spcell, the UE can always maintain the Spcell in an active state according to the instruction of the NR gNB in ​​step 2j-10. If the cell configured in step 2j-05 is a Scell, the UE can change the state according to the instruction of the NRgNB or the expiration of the timer configured in the cell. For example, if the NR gNB indicates the state change of the Scell ​​through an RRC message or MACCE, or if the timer configured by the NR gNB expires and thus triggers the state change operation of the BWP of the Scell, the UE can change the state of the BWP of the Scell ​​to an active state, a dormant state, or an inactive state, and perform the operations proposed in the present disclosure in steps 2j-25, 2j-30 and 2j-35 that are suitable for the respective states of the BWP. Since its detailed description is the same as above, the detailed description will be omitted.

[0723] Figure 2K The structure of a UE to which the embodiments of the present disclosure can be applied is shown.

[0724] refer to Figure 2K , the UE may include a radio frequency (RF) processor 2k-10, a baseband processor 2k-20, a memory 2k-30, and a controller 2k-40.

[0725] The RF processor 2k-10 performs functions for transmitting and receiving signals through a radio channel, such as frequency band conversion and amplification of signals. That is, the RF processor 2k-10 up-converts the baseband signal provided by the baseband processor 2k-20 into an RF band signal, transmits the RF band signal through an antenna, and then down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 2k-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), and the like. Although Figure 2K Only one antenna is shown, but the UE may include multiple antennas. In addition, the RF processor 2k-10 may include multiple RF chains. In addition, the RF processor 2k-10 can perform beamforming. For beamforming, the RF processor 2k-10 can control the phase and size of each signal transmitted / received through multiple antennas or antenna elements. The RF processor can perform MIMO and can receive multiple layers when performing MIMO operations. The RF processor 2k-10 can perform receive beam scanning by appropriately configuring multiple antennas or antenna elements according to the control of the controller, or can control the direction and beam width of the receive beam so that the receive beam and the transmit beam work together.

[0726] The baseband processor 2k-20 performs functions for conversion between baseband signals and bit streams according to the physical layer standard of the system. For example, in data transmission, the baseband processor 2k-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, in data reception, the baseband processor 2k-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 2k-10. For example, in the orthogonal frequency division multiplexing (OFDM) scheme, when transmitting data, the baseband processor 2k-20 generates complex symbols by encoding and modulating the transmission bit stream, maps the complex symbols to subcarriers, and then configures OFDM symbols by inverse fast Fourier transform (IFFT) operations and cyclic prefix (CP) insertion. In addition, in data reception, the baseband processor 2k-20 divides the baseband signal provided by the RF processor 2k-10 into units of OFDM symbols, reconstructs the signal mapped to the subcarriers by fast Fourier transform (FFT) operations, and then reconstructs the received bit stream by demodulation and decoding.

[0727] The baseband processor 2k-20 and the RF processor 2k-10 can transmit and receive signals as described above. Therefore, each of the baseband processor 2k-20 and the RF processor 2k-10 can be referred to as a transmitter, a receiver, a transceiver or a communication unit. In addition, at least one of the baseband processor 2k-20 and the RF processor 2k-10 may include a plurality of communication modules for supporting a plurality of different radio access technologies. In addition, at least one of the baseband processor 2k-20 and the RF processor 2k-10 may include different communication modules for supporting signals in different frequency bands. For example, different radio access technologies may include LTE networks and NR networks. In addition, different frequency bands may include ultra-high frequency (SHF) (e.g., 2.5 GHz and 5 GHz) bands and millimeter (mm) wave (e.g., 60-GHz) bands.

[0728] The memory 2k-30 stores data such as basic programs, applications, and setting information for UE operation. The memory 2k-30 provides the stored data according to a request from the controller 2k-40.

[0729] The controller 2k-40 controls the overall operation of the UE. For example, the controller 2k-40 transmits and receives signals through the baseband processor 2k-20 and the RF processor 2k-10. In addition, the controller 2k-40 records data in the memory 2k-30 and reads data. To this end, the controller 2k-40 may include at least one processor. For example, the controller 2k-40 may include a communication processor (CP) that performs control for communication and an application processor (AP) that controls a higher layer such as an application layer.

[0730] Figure 2L A block diagram showing a TRP in a wireless communication system to which an embodiment of the present disclosure can be applied.

[0731] like Figure 2L As shown, the NR gNB includes an RF processor 2l-10, a baseband processor 2l-20, a backhaul communication unit 2l-30, a memory 2l-40 and a controller 2l-50.

[0732] The RF processor 21-10 performs functions for transmitting and receiving signals through a radio channel, such as frequency band conversion and amplification of signals. That is, the RF processor 21-10 up-converts the baseband signal provided from the baseband processor 21-20 into an RF band signal, then transmits the converted signal through an antenna, and down-converts the RF band signal received through the antenna into a baseband signal. For example, the RF processor 21-10 may include a transmission filter, a reception filter, an amplifier, a mixer, an oscillator, a DAC, an ADC, etc. Although Figure 2L Only one antenna is shown, but the first access node may include multiple antennas. In addition, the RF processor 21-10 may include multiple RF chains. The RF processor 21-10 may perform beamforming. For beamforming, the RF processor 21-10 may control the phase and size of each signal transmitted / received by multiple antennas or antenna elements. The RF processor may perform downlink MIMO operations by transmitting one or more layers.

[0733] The baseband processor 21-20 performs the function of converting between the baseband signal and the bit stream according to the physical layer standard of the first radio access technology. For example, when transmitting data, the baseband processor 21-20 generates complex symbols by encoding and modulating the transmission bit stream. In addition, when receiving data, the baseband processor 21-20 reconstructs the received bit stream by demodulating and decoding the baseband signal provided from the RF processor 21-10. For example, in the OFDM scheme, when transmitting data, the baseband processor 21-20 can generate complex symbols by encoding and modulating the transmission bit stream, map the complex symbols to subcarriers, and then configure the OFDM symbols by IFFT operation and CP insertion. In addition, in data reception, the baseband processor 21-20 divides the baseband signal provided by the RF processor 21-10 in units of OFDM symbols, recovers the signal mapped with subcarriers by FFT operation, and then recovers the received bit stream by demodulation and decoding. The baseband processor 21-20 and the RF processor 21-10 transmit and receive signals as described above. Therefore, each of the baseband processor 2l-20 or the RF processor 2l-10 can be referred to as a transmitter, a receiver, a transceiver, a communication unit, or a wireless communication unit.

[0734] The communication units 21-30 provide an interface for communicating with other nodes within the network.

[0735] The memory 21-40 stores data such as basic programs, applications, and setting information for MeNB operation. Specifically, the memory 21-40 can store information about the bearer assigned to the accessed UE and the measurement results reported from the accessed UE. In addition, the memory 21-40 can store information as a reference for determining whether to provide multiple connections to the UE. The memory 21-40 provides the stored data in response to a request from the controller 21-50.

[0736] The controller 21-50 controls the overall operation of the MeNB. For example, the controller 21-50 transmits and receives signals through the baseband processor 21-20 and the RF processor 21-10 or through the backhaul communication unit 21-30. In addition, the controller 21-50 records data in the memory 21-40 and reads data. To this end, the controller 21-50 may include at least one processor.

[0737] In the above detailed embodiments of the present disclosure, the components included in the present disclosure are expressed in the singular or plural according to the detailed embodiments presented. However, the singular form or plural form is selected to facilitate the description suitable for the presented situation, and the various embodiments of the present disclosure are not limited to a single element or multiple elements of the component. In addition, multiple elements described in the specification can be configured as a single element, or a single element in the specification can be configured as multiple elements.

[0738] At the same time, the exemplary embodiments disclosed in the specification and the drawings are only used to easily describe the technical content of the present disclosure and help understand the present disclosure, and are not intended to limit the scope of the present disclosure. That is to say, it is obvious to those skilled in the art to which the present disclosure belongs that different modifications can be implemented based on the technical spirit of the present disclosure. In addition, if necessary, the above-mentioned various embodiments can be used in combination. For example, some of the embodiments proposed in the present disclosure can be combined to operate base stations and terminals. In addition, although the above embodiments have been presented with reference to 5G / NR systems, other modifications based on the technical ideas of the embodiments can also be implemented in combination with other systems (such as LTE, LTE-A, and LTE-A-Pro systems).

[0739] In the above detailed embodiments of the present disclosure, the components included in the present disclosure are expressed in the singular or plural according to the detailed embodiments presented. However, the singular form or plural form is selected to facilitate the description suitable for the presented situation, and the various embodiments of the present disclosure are not limited to a single element or multiple elements of the component. In addition, multiple elements described in the specification can be configured as a single element, or a single element in the specification can be configured as multiple elements.

[0740] Meanwhile, the description order shown in the drawings for the method does not necessarily correspond to the execution order, and the order relationship may be changed or the methods may be executed in parallel.

[0741] Furthermore, the drawings illustrating the method of the present disclosure may omit some elements, or may include only some elements, without departing from the scope of the present disclosure.

[0742] In the above detailed embodiments of the present disclosure, the components included in the present disclosure are expressed in the singular or plural according to the detailed embodiments presented. However, the singular form or plural form is selected to facilitate the description suitable for the presented situation, and the various embodiments of the present disclosure are not limited to single or multiple elements. The elements expressed in the plural form can be configured as singular, or the elements expressed in the singular form can be configured as plural.

[0743] Although the embodiments have been described in the detailed description of the present disclosure, the present disclosure may be modified in various forms without departing from the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the embodiments but should be defined by the appended claims and their equivalents.

[0744] Although the present disclosure has been described with various embodiments, various changes and modifications may occur to those skilled in the art. The present disclosure is intended to encompass such changes and modifications as fall within the scope of the appended claims.

Claims

1. A method performed by a user equipment UE in a wireless communication system, the method comprising: receiving a radio resource control (RRC) message including configuration information of a secondary cell (SCell) from a base station, wherein the configuration information includes semi-persistent scheduling information of the SCell; as well as When a condition for switching the SCell to a quiescent state is met, clearing resources associated with the semi-persistent scheduling information of the SCell for the SCell, The condition is satisfied when: information indicating the quiescent state of the SCell is included in the configuration information, a media access control MAC control element CE for switching the SCell to the quiescent state is received, and a sleep timer associated with the SCell expires.

2. The method according to claim 1, wherein: When a MAC CE for switching the SCell to the quiescent state is received, the SCell will be in the quiescent state.

3. The method according to claim 1, wherein: In case the dormancy timer associated with the SCell expires, the SCell will be in the dormant state, and The sleep timer associated with the SCell is configured by the RRC message.

4. The method according to claim 1, wherein: In case that information indicating the stationary state of the SCell is included in the configuration information, the SCell will be in the stationary state.

5. The method according to claim 1, further comprising: When an SCell deactivation timer is configured for the SCell, the SCell deactivation timer is stopped.

6. The method according to claim 1, further comprising: Starting a dormant state deactivation timer of the SCell; as well as When the dormant state deactivation timer expires, the SCell is deactivated.

7. The method according to claim 1, wherein: When the SCell is in a static state, the physical downlink control channel PDCCH of the SCell is not monitored, and data of the SCell is not sent or received. 8 . The method according to claim 1 , further comprising, when the SCell is in a static state, periodically reporting a channel measurement result of the SCell.

9. The method according to claim 8, wherein: The channel measurement result includes at least one of channel state information CSI, channel quality indicator CQI, precoding matrix indicator PMI, precoding type indicator PTI or CSI-RS resource indicator CRI.

10. The method according to claim 1, wherein: In the case where the SCell is a special cell SpCell, the dormant state is not applied.

11. A user equipment UE in a wireless communication system, the UE comprising: Transceiver; and A controller is coupled to the transceiver and is configured to: receiving a radio resource control (RRC) message including configuration information of a secondary cell (SCell) from a base station, wherein the configuration information includes semi-persistent scheduling information of the SCell, and When a condition for switching the SCell to a quiescent state is met, clearing resources associated with the semi-persistent scheduling information of the SCell for the SCell, The condition is satisfied when: information indicating the quiescent state of the SCell is included in the configuration information, a media access control MAC control element CE for switching the SCell to the quiescent state is received, and a sleep timer associated with the SCell expires.

12. The UE according to claim 11, wherein: When a MAC CE for switching the SCell to the quiescent state is received, the SCell will be in the quiescent state.

13. The UE according to claim 11, wherein: In case the dormancy timer associated with the SCell expires, the SCell will be in the dormant state, and The sleep timer associated with the SCell is configured by the RRC message.

14. The UE according to claim 11, wherein: In case that information indicating the stationary state of the SCell is included in the configuration information, the SCell will be in the stationary state.

15. The UE according to claim 11, wherein: In a case where an SCell deactivation timer is configured for the SCell, the controller is configured to stop the SCell deactivation timer.

16. The UE according to claim 11, wherein: The controller is also configured to: Starting a dormant state deactivation timer for the SCell, and When the dormant state deactivation timer expires, the SCell is deactivated.

17. The UE according to claim 11, wherein: When the SCell is in a static state, the physical downlink control channel PDCCH of the SCell is not monitored, and data of the SCell is not sent or received.

18. The UE according to claim 11, wherein: The controller is configured to periodically report a channel measurement result of the SCell when the SCell is in a static state.

19. The UE according to claim 18, wherein: The channel measurement result includes at least one of channel state information CSI, channel quality indicator CQI, precoding matrix indicator PMI, precoding type indicator PTI or CSI-RS resource indicator CRI.

20. The UE according to claim 11, wherein: In the case where the SCell is a special cell SpCell, the dormant state is not applied.

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