Method for transmitting and receiving a downlink control channel and device for the same

Abstract

The present disclosure discloses a method for a terminal to receive a Physical Downlink Control Channel (PDCCH) in a wireless communication system. In particular, the method comprises receiving parameters related to PDCCH monitoring adaptation through a higher layer, receiving information instructing an operation related to PDCCH monitoring adaptation based on the parameters, and receiving the PDCCH based on the information. Receiving the PDCCH is characterized by including monitoring the PDCCH through a Common Search Space (CSS) set based on an RNTI different from a Radio Network Temporary Identifier (C-RNTI) during a time interval associated with the information.

Description

Technology Field

[0001] The present disclosure relates to a method for transmitting and receiving a downlink control channel and an apparatus for the same, and more specifically, to a method for monitoring a PDCCH based on a PDCCH monitoring adaptation for a Type0 / 0A / 1 / 2-PDCCH (Physical Downlink Control Channel) CSS (Common Search Space) set and an apparatus for the same. Background Technology

[0002] As the times change and more communication devices demand larger communication traffic, there is a demand for next-generation 5G systems, which are wireless broadband communication systems that are improved over existing LTE systems. In these next-generation 5G systems, referred to as NewRAT, communication scenarios are classified into Enhanced Mobile BroadBand (eMBB), Ultra-reliability and low-latency communication (URLLC), and Massive Machine-Type Communications (mMTC).

[0003] Here, eMBB is a next-generation mobile communication scenario characterized by High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate; URLLC is a next-generation mobile communication scenario characterized by Ultra Reliable, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, Remote Control); and mMTC is a next-generation mobile communication scenario characterized by Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT). The problem to be solved

[0004] The present disclosure aims to provide a method for transmitting and receiving a downlink control channel and an apparatus for the same.

[0005] The technical problems to be solved in this disclosure are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which this disclosure belongs from the description below. means of solving the problem

[0006] In a wireless communication system according to one embodiment of the present disclosure, a method for a terminal to receive a PDCCH (Physical Downlink Control Channel) comprises receiving parameters related to PDCCH monitoring adaptation through a higher layer, receiving information instructing an operation related to the PDCCH monitoring adaptation based on the parameters, and receiving the PDCCH based on the information, wherein receiving the PDCCH may include monitoring the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Radio Network Temporary Identifier) ​​during a time interval associated with the information.

[0007] At this time, based on receiving the PDCCH through the CSS Set based on the RNTI, it may include monitoring the PDCCH through the CSS Set based on the C-RNTI.

[0008] Additionally, it may further include receiving information related to time for monitoring the PDCCH based on the above C-RNTI, and monitoring the PDCCH based on the above C-RNTI through the above CSS Set based on the information related to time.

[0009] In addition, the above PDCCH monitoring adaptation may further include monitoring the PDCCH based on the C-RNTI for the type of CSS Set included in the specific SS Set, based on SS Set switching that directs switching to a specific SS Set.

[0010] In addition, the above CSS set may be a CSS Set having a type different from type 2.

[0011] In addition, during the above time interval, PDCCH can be monitored with priority given to USS (UE-Specific Search Space) over CSS.

[0012] In addition, the above CSS set may be a CSS set having a type different from type 3.

[0013] In a wireless communication system according to an embodiment of the present disclosure, a terminal for receiving a Physical Downlink Control Channel (PDCCH) comprises: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor so as to be operable and storing instructions that, when executed, cause the at least one processor to perform an operation, wherein the operation comprises: receiving parameters related to a PDCCH monitoring adaptation through the at least one transceiver, through a higher layer, receiving information instructing an operation related to the PDCCH monitoring adaptation based on the parameters through the at least one transceiver, and receiving the PDCCH based on the information through the at least one transceiver, wherein receiving the PDCCH may include monitoring the PDCCH through a Common Search Space (CSS) set based on a Radio Network Temporary Identifier (C-RNTI) and a different RNTI during a time interval associated with the information.

[0014] At this time, based on receiving the PDCCH through the CSS Set based on the RNTI, it may include monitoring the PDCCH through the CSS Set based on the C-RNTI.

[0015] Additionally, it may further include receiving information related to time for monitoring the PDCCH based on the above C-RNTI, and monitoring the PDCCH based on the above C-RNTI through the above CSS Set based on the information related to time.

[0016] In addition, the above PDCCH monitoring adaptation may further include monitoring the PDCCH based on the C-RNTI for the type of CSS Set included in the specific SS Set, based on SS Set switching that directs switching to a specific SS Set.

[0017] In addition, the above CSS set may be a CSS set having a type different from type 2.

[0018] In addition, during the above time interval, PDCCH can be monitored with priority given to USS (UE-Specific Search Space) over CSS.

[0019] In addition, the above CSS set may be a CSS set having a type different from type 3.

[0020] In a wireless communication system according to one embodiment of the present disclosure, an apparatus for receiving a Physical Downlink Control Channel (PDCCH) comprises: at least one processor; and at least one memory connected to the at least one processor so as to be operable and storing instructions that, when executed, cause the at least one processor to perform an operation, wherein the operation comprises: receiving parameters related to a PDCCH monitoring adaptation through a higher layer, receiving information directing an operation related to the PDCCH monitoring adaptation based on the parameters, and receiving the PDCCH based on the information, wherein receiving the PDCCH can monitor the PDCCH through a Common Search Space (CSS) set based on an RNTI different from a Radio Network Temporary Identifier (C-RNTI) during a time interval associated with the information.

[0021] A computer-readable storage medium comprising at least one computer program that causes at least one processor according to one embodiment of the present disclosure to perform an operation, wherein the operation comprises: receiving parameters related to a PDCCH monitoring adaptation through a higher layer, receiving information directing an operation related to the PDCCH monitoring adaptation based on the parameters, and receiving the PDCCH based on the information, wherein receiving the PDCCH may include monitoring the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Radio Network Temporary Identifier) ​​during a time interval associated with the information.

[0022] In a wireless communication system according to one embodiment of the present disclosure, a method for a base station to transmit a PDCCH (Physical Downlink Control Channel) may include transmitting parameters related to PDCCH monitoring adaptation through a higher layer, transmitting information instructing an operation related to the PDCCH monitoring adaptation based on the parameters, and transmitting the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Radio Network Temporary Identifier) ​​during a time interval associated with the information.

[0023] In a wireless communication system according to one embodiment of the present disclosure, a base station for transmitting a Physical Downlink Control Channel (PDCCH) comprises: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor so as to be operable and storing instructions that cause the at least one processor to perform an operation when executed, wherein the operation may include: transmitting parameters related to a PDCCH monitoring adaptation through the at least one transceiver, through a higher layer, and transmitting information instructing an operation related to the PDCCH monitoring adaptation through the at least one transceiver based on the parameters, and transmitting the PDCCH through a Common Search Space (CSS) set based on a Radio Network Temporary Identifier (C-RNTI) and a different RNTI through the at least one transceiver during a time interval associated with the information. Effects of the invention

[0024] According to the present disclosure, when a terminal monitors a PDCCH (Physical Downlink Control Channel), it can have the effect of reducing power consumption.

[0025] In particular, according to [Method #1] and / or [Method #2] of the present disclosure, power consumption can be reduced by performing PDCCH monitoring adaptation even when performing PDCCH monitoring for a Type0 / 0A / 1 / 2-PDCCH (Physical Downlink Control Channel) CSS (Common Search Space) set.

[0026] In addition, according to [Method #3] of the present disclosure, due to the limited number of PDCCH monitoring cycles, it is possible to monitor only the CSS Set and prevent the omission of monitoring of the USS (UE-Specific Search Space) set.

[0027] The effects obtainable from the present disclosure are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present disclosure pertains from the description below. Brief explanation of the drawing

[0028] FIGS. 1 and 2 are drawings for explaining the Idle Mode DRX (Discontinuous Reception) operation. FIGS. 3 to 5 are diagrams illustrating the operation of DRX in RRC (Radio Resource Control) connected mode. Figure 6 is a diagram illustrating a method for monitoring DCI format 2_6. FIGS. 7 to 9 are intended to explain the overall operation process of a terminal and a base station according to an embodiment of the present disclosure. FIG. 10 illustrates a communication system to which the present disclosure applies. FIG. 11 illustrates a wireless device that can be applied to the present disclosure. FIG. 12 illustrates a vehicle or autonomous vehicle that can be applied to the present disclosure. FIG. 13 illustrates an XR (eXtended Reality) device that can be applied to the present disclosure. Specific details for implementing the invention

[0029] The following technologies can be used in various wireless access systems such as CDMA (code division multiple access), FDMA (frequency division multiple access), TDMA (time division multiple access), OFDMA (orthogonal frequency division multiple access), and SC-FDMA (single carrier frequency division multiple access). CDMA can be implemented using radio technologies such as UTRA (Universal Terrestrial Radio Access) or CDMA2000. TDMA can be implemented using radio technologies such as GSM (Global System for Mobile Communications), GPRS (General Packet Radio Service), and EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, and E-UTRA (Evolved UTRA). UTRA is part of the UMTS (Universal Mobile Telecommunications System). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) using E-UTRA, and LTE-A (Advanced) is an evolved version of 3GPP LTE. 3GPP NR (New Radio or New Radio Access Technology) is an evolved version of 3GPP LTE / LTE-A.

[0030] For clarity of explanation, the description is based on 3GPP communication systems (e.g., NR), but the technical scope of the present disclosure is not limited thereto. Regarding background technology, terms, abbreviations, etc. used in the description of the present disclosure, reference may be made to matters described in standard documents published prior to the present disclosure (e.g., 38.211, 38.212, 38.213, 38.214, 38.300, 38.331, etc.).

[0031] Now, let's take a look at 5G communication, including NR systems.

[0032] The three major requirement areas of 5G include (1) the Enhanced Mobile Broadband (eMBB) area, (2) the Massive Machine Type Communication (mMTC) area, and (3) the Ultra-reliable and Low Latency Communications (URLC) area.

[0033] Some use cases may require multiple domains for optimization, while others may focus on only a single Key Performance Indicator (KPI). 5G supports these diverse use cases in a flexible and reliable way.

[0034] eMBB goes far beyond basic mobile internet access, covering media and entertainment applications in rich interactive tasks, the cloud, or augmented reality. Data is one of the core drivers of 5G, and dedicated voice services may not be seen for the first time in the 5G era. In 5G, voice is expected to be processed simply as an application using the data connection provided by the communication system. The main causes for the increased traffic volume are the increase in content size and the growing number of applications requiring high data transfer rates. Streaming services (audio and video), interactive video, and mobile internet connectivity will become more widely used as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are growing rapidly on mobile communication platforms, and this can be applied to both work and entertainment. Furthermore, cloud storage is a specific use case driving the growth of uplink data transfer rates. 5G is also used for remote work in the cloud, requiring much lower end-to-end latency to maintain an excellent user experience when haptic interfaces are used. Entertainment, for example, cloud gaming and video streaming, is another key factor increasing the demand for mobile broadband capabilities. Entertainment is essential on smartphones and tablets anywhere, including in highly mobile environments such as trains, cars, and airplanes. Other use cases include augmented reality for entertainment and information retrieval. Here, augmented reality requires very low latency and instantaneous data volumes.

[0035] Furthermore, one of the most anticipated use cases for 5G concerns mMTC, the ability to seamlessly connect embedded sensors across all fields. The number of potential IoT devices is projected to reach 20.4 billion by 2020. Industrial IoT is one of the areas where 5G plays a key role in enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure.

[0036] URLLC includes new services that will transform industries through ultra-reliable / available low-latency links, such as remote control of critical infrastructure and self-driving vehicles. Levels of reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0037] Next, we will look more specifically at several use cases in 5G communication systems, including NR systems.

[0038] 5G can complement FTTH (fiber-to-the-home) and cable-based broadband (or DOCSIS) as a means of providing streams rated at hundreds of megabits per second to gigabits per second. These high speeds are required for virtual and augmented reality, as well as for delivering TV at resolutions of 4K and above (6K, 8K, and higher). VR (Virtual Reality) and AR ( Augmented Reality) applications include near-immersive sports matches. Certain applications may require special network configurations. For example, in the case of VR games, game companies may need to integrate core servers with the network operator's edge network servers to minimize latency.

[0039] The automotive sector is expected to become a significant new driving force for 5G, with numerous use cases for mobile communications within vehicles. For instance, passenger entertainment requires high-capacity and high-mobility mobile broadband. This is because future users expect high-quality connectivity regardless of their location or speed. Another application in the automotive sector is the augmented reality dashboard. This displays information overlaid onto what the driver is seeing through the windshield, allowing them to identify objects in the dark and providing the driver with information about the objects' distances and movements. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure, and information exchange between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems will allow drivers to drive more safely by guiding them to alternative courses of action, thereby reducing the risk of accidents. The next step will be remotely controlled or self-driven vehicles. This requires highly reliable and very fast communication between different self-driven vehicles and between vehicles and infrastructure. In the future, self-driving vehicles will perform all driving activities, allowing drivers to focus solely on traffic anomalies that the vehicle itself cannot identify. The technical requirements for self-driving vehicles demand ultra-low latency and ultra-high reliability to increase traffic safety to a level unattainable by humans.

[0040] Smart cities and smart homes, referred to as a smart society, will be embedded with high-density wireless sensor networks. Distributed networks of intelligent sensors will identify conditions for maintaining the cost-effective and energy-efficient maintenance of the city or home. A similar setup can be implemented for each household. Temperature sensors, window and heating controllers, burglar alarms, and home appliances are all wirelessly connected. Many of these sensors typically feature low data transfer rates, low power consumption, and low cost. However, for example, real-time HD video may be required for certain types of devices for surveillance.

[0041] The consumption and distribution of energy, including heat or gas, are becoming highly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect these sensors using digital information and communication technologies to collect information and act accordingly. Since this information may include the behavior of suppliers and consumers, smart grids can improve efficiency, reliability, economic viability, production sustainability, and the automated distribution of fuels such as electricity. A smart grid can also be viewed as another sensor network with low latency.

[0042] The health sector possesses numerous applications that can benefit from mobile communications. Communication systems can support telemedicine, providing clinical care from remote locations. This helps reduce distance barriers and improves access to medical services that are not consistently available in remote rural areas. It is also used to save lives during critical medical care and emergencies. Mobile communication-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0043] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity in many industries. However, achieving this requires wireless connections to operate with latency, reliability, and capacity comparable to cables, while also simplifying their management. Low latency and a very low probability of error are new requirements that 5G needs to meet.

[0044] Logistics and freight tracking are important use cases for mobile communications that use location-based information systems to enable the tracking of inventory and packages anywhere. Use cases for logistics and freight tracking typically require low data rates but necessitate wide coverage and reliable location information.

[0045] 하향링크 채널 구조

[0046] The base station transmits a relevant signal to the terminal through the downlink channel described below, and the terminal receives the relevant signal from the base station through the downlink channel described below.

[0047] (1) 물리 하향링크 공유 채널(PDSCH)

[0048] PDSCH carries downlink data (e.g., DL-SCH transport block, DL-SCH TB), and modulation methods such as QPSK (Quadrature Phase Shift Keying), 16 QAM (Quadrature Amplitude Modulation), 64 QAM, and 256 QAM are applied. A codeword is generated by encoding the TB. PDSCH can carry up to two codewords. Scrambling and modulation mapping are performed for each codeword, and the modulation symbols generated from each codeword can be mapped to one or more layers. Each layer is mapped to a resource along with the DMRS (Demodulation Reference Signal) to generate an OFDM symbol signal, which is then transmitted through the corresponding antenna port.

[0049] (2) 물리 하향링크 제어 채널 (PDCCH)

[0050] The PDCCH carries Downlink Control Information (DCI). For example, the PCCCH (i.e., DCI) carries the transmission format and resource allocation for the DL-SCH (downlink shared channel), resource allocation information for the UL-SCH (uplink shared channel), paging information for the PCH (paging channel), system information on the DL-SCH, resource allocation information for higher-layer control messages such as random connection acknowledgments transmitted over the PDSCH, transmission power control commands, and the activation / deactivation of the CS (Configured Scheduling). The DCI includes a Cyclic Redundancy Check (CRC), which is masked or scrambled with various identifiers (e.g., Radio Network Temporary Identifier, RNTI) depending on the owner or use of the PDCCH. For example, if the PDCCH is for a specific terminal, the CRC is masked with the terminal identifier (e.g., Cell-RNTI, C-RNTI). If PDCCH is related to paging, the CRC is masked by P-RNTI (Paging-RNTI). If PDCCH is related to system information (e.g., System Information Block, SIB), the CRC is masked by SI-RNTI (System Information RNTI). If PDCCH is related to a random access response, the CRC is masked by RA-RNTI (Random Access-RNTI).

[0051] The modulation scheme of the PDCCH is fixed (e.g., Quadrature Phase Shift Keying, QPSK), and a single PDCCH consists of 1, 2, 4, 8, or 16 Control Channel Elements (CCEs) depending on the Aggregation Level (AL). A single CCE consists of 6 Resource Element Groups (REGs). A single REG is defined by one OFDMA symbol and one (P)RB.

[0052] To receive a PDCCH, the terminal may monitor a set of PDCCH candidates in a CORESET (e.g., blind decoding). A PDCCH candidate represents a CCE(s) that the terminal monitors for receiving / detecting a PDCCH. PDCCH monitoring may be performed on one or more CORESETs on active DL BWPs on each active cell where PDCCH monitoring is configured. The set of PDCCH candidates monitored by the terminal is defined as a set of PDCCH Search Spaces (SS). The SS set may be a set of Common Search Spaces (CSS) or a set of UE-specific Search Spaces (USS).

[0053] Table 1 shows an example of a PDCCH search space.

[0054] Type Search Space RNTI Use Case Type0-PDCCH Common SI-RNTI on a primary cell SIB Decoding Type0A-PDCCH Common SI-RNTI on a primary cell SIB Decoding Type1-PDCCH Common RA-RNTI or TC-RNTI on a primary cell Msg2, Msg4 decoding in RACH Type2-PDCCH Common P-RNTI on a primary cell Paging Decoding Type3-PDCCH Common INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, C-RNTI, MCS-C-RNTI, or CS-RNTI(s) UE Specific UE Specific C-RNTI, or MCS-C-RNTI, or CS-RNTI(s) User specific PDSCH decoding

[0055] SS sets can be configured via system information (e.g., MIB) or terminal-specific (UE-specific) upper layer (e.g., RRC) signaling. Each DL BWP in a serving cell may have up to S (e.g., 10) SS sets configured. For example, the following parameters / information may be provided for each SS set. Each SS set is associated with one CORESET, and each CORESET configuration may be associated with one or more SS sets. - searchSpaceId: Represents the ID of the SS set.

[0056] - controlResourceSetId: Represents the CORESET associated with the SS set.

[0057] - monitoringSlotPeriodicityAndOffset: Represents the PDCCH monitoring period interval (in slots) and the PDCCH monitoring interval offset (in slots).

[0058] - monitoringSymbolsWithinSlot: Represents the first OFDMA symbol(s) for PDCCH monitoring within the slot where PDCCH monitoring is configured. It is indicated by a bitmap, where each bit corresponds to each OFDMA symbol within the slot. The MSB of the bitmap corresponds to the first OFDMA symbol within the slot. The OFDMA symbol(s) corresponding to bit(s) with a bit value of 1 correspond to the first symbol(s) of the CORESET within the slot.

[0059] - nrofCandidates: AL={1, 2, 4, 8, 16} represents the number of star PDCCH candidates (e.g., one of 0, 1, 2, 3, 4, 5, 6, 8).

[0060] - searchSpaceType: Indicates whether the SS type is CSS or USS.

[0061] - DCI Format: Indicates the DCI format of the PDCCH candidate.

[0062] Based on the CORESET / SS set configuration, the terminal can monitor PDCCH candidates from one or more SS sets within the slot. An occasion (e.g., time / frequency resources) when PDCCH candidates must be monitored is defined as a PDCCH (monitoring) opportunity. One or more PDCCH (monitoring) opportunities may be configured within the slot.

[0063] Table 2 shows examples of DCI formats transmitted via PDCCH.

[0064] DCI format Usage 0_0 Scheduling of PUSCH in one cell 0_1 Scheduling of PUSCH in one cell 1_0 Scheduling of PDSCH in one cell 1_1 Scheduling of PDSCH in one cell 2_0 Notifying a group of UEs of the slot format 2_1 Notifying a group of UEs of the PRB(s) and OFDM symbol(s) where UE may assume no transmission is intended for the UE 2_2 Transmission of TPC commands for PUCCH and PUSCH 2_3 Transmission of a group of TPC commands for SRS transmissions by one or more UEs

[0065] DCI format 0_0 is used to schedule TB-based (or TB-level) PUSCH, and DCI format 0_1 ​​may be used to schedule TB-based (or TB-level) PUSCH or CBG (Code Block Group)-based (or CBG-level) PUSCH. DCI format 1_0 is used to schedule TB-based (or TB-level) PDSCH, and DCI format 1_1 may be used to schedule TB-based (or TB-level) PDSCH or CBG-based (or CBG-level) PDSCH (DL grant DCI). DCI format 0_0 / 0_1 is referred to as UL grant DCI or UL scheduling information, and DCI format 1_0 / 1_1 may be referred to as DL grant DCI or UL scheduling information. DCI Format 2_0 is used to transmit dynamic slot format information (e.g., dynamic SFI) to terminals, and DCI Format 2_1 is used to transmit downlink pre-emption information to terminals. DCI Format 2_0 and / or DCI Format 2_1 may be transmitted to terminals within a group via a Group Common PDCCH, which is a PDCCH transmitted to terminals defined as a group. DCI Format 0_0 and DCI Format 1_0 are referred to as fallback DCI formats, and DCI Format 0_1 ​​and DCI Format 1_1 may be referred to as non-fallback DCI formats. The DCI size / field configuration of the fallback DCI format remains the same regardless of terminal configuration. On the other hand, the DCI size / field configuration of the non-fallback DCI format varies depending on the terminal configuration.

[0066] DRX (Discontinuous Reception) 동작

[0067] The UE uses DRX (Discontinuous Reception) in the RRC_IDLE and RRC_INACTIVE states to reduce power consumption. When DRX is configured, the UE performs DRX operations according to the DRX configuration information.

[0068] A UE operating based on DRX repeatedly turns ON / OFF for receiving operations. For example, when DRX is configured, the terminal attempts to receive / detect PDCCH (e.g., PDCCH monitoring) only during a predetermined time interval (e.g., ON), and does not attempt to receive PDCCH during the remaining time (e.g., OFF / Sleep).

[0069] At this time, the time during which the terminal attempts to receive PDCCH is called On-duration, and On-duration is defined once per DRX cycle. The UE receives DRX configuration information from the base station (e.g., gNB) through RRC signaling and can perform DRX operations by receiving (Long) DRX command MAC CE.

[0070] Meanwhile, DRX configuration information can be included in MAC-CellGroupConfig. IE MAC-CellGroupConfig is used to configure MAC parameters for a cell group containing DRX.

[0071] DRX (Discontinuous Reception) refers to an operational mode that allows a User Equipment (UE) to reduce battery consumption by discontinuously receiving and monitoring downlink channels. In other words, a UE with DRX enabled can reduce power consumption by receiving downlink signals discontinuously. DRX operation is performed during a DRX cycle, which represents a time interval during which the On Duration is repeated periodically. DRX includes On Duration and Sleep Duration (or Opportunity for DRX). On Duration represents the time interval during which the terminal monitors the PDCCH to receive it. DRX can be performed in the RRC (Radio Resource Control)_IDLE State (or mode), RRC_INACTIVE State (or mode), or RRC_CONNECTED State (or mode). In the RRC_IDLE State and RRC_INACTIVE State, DRX is used to discontinuously receive paging signals.

[0072] - RRC_Idle State: A state where a wireless connection (RRC connection) is not established between the base station and the terminal.

[0073] - RRC Inactive State: A state where a wireless connection (RRC connection) has been established between the base station and the terminal, but the wireless connection is disabled.

[0074] - RRC_Connected state: A state in which a wireless connection (RRC connection) is established between the base station and the terminal.

[0075] DRX is basically divided into Idle mode DRX, Connected DRX (C-DRX), and Extended DRX. The DRX applied in the RRC IDLE state is called IDLE mode DRX, and the DRX applied in the RRC CONNECTED state is called Connected mode DRX (C-DRX).

[0076] eDRX (Extended / enhanced DRX) is a mechanism that can extend the cycle of IDLE mode DRX and C-DRX. Whether eDRX is allowed in IDLE mode DRX can be configured based on system information (e.g., SIB1).

[0077] SIB1 may include the eDRX-Allowed parameter. The eDRX-Allowed parameter is a parameter indicating whether IDLE mode extended DRX is allowed.

[0078] (1) IDLE mode DRX

[0079] In IDLE mode, the UE can use DRX to reduce power consumption. A single Paging Opportunity (PO) can be a time interval (e.g., a slot or subframe) during which a Paging-Radio Network Temporary Identifier (P-RNTI) based Physical Downlink Control Channel (PDCCH) can be transmitted. A P-RNTI based PDCCH can address and schedule paging messages. For P-RNTI based PDCCH transmissions, the PO can indicate the start subframe for the PDCCH iteration.

[0080] A paging frame (PF) is a single wireless frame that may contain one or more paging opportunities. When DRX is used, the UE may be configured to monitor only one PO per DRX cycle. The PF and / or PO may be determined based on DRX parameters provided through network signaling (e.g., system information).

[0081] Hereinafter, 'PDCCH' may refer to MPDCCH, NPDCCH, and / or general PDCCH. Hereinafter, 'UE' may refer to MTC UE, BL (Bandwidth Reduced Low Complexity) / CE (Coverage Enhanced) UE, NB-IoT UE, RedCap UE, general UE, and / or IAB-MT (Mobile Termination).

[0082] Figure 1 is a flowchart illustrating an example of how to perform IDLE mode DRX operations.

[0083] The UE receives IDLE mode DRX setting information from the base station through upper layer signaling (e.g., system information) (S110).

[0084] Additionally, the UE determines a Paging Frame (PF) and a Paging Occasion (PO) for monitoring the PDCCH in the paging DRX cycle based on the IDLE mode DRX setting information (S120). In this case, the DRX cycle includes an On Duration and a Sleep Duration (or an Opportunity for DRX).

[0085] Additionally, the UE monitors the PDCCH at the PO of the determined PF (S130). Meanwhile, the UE monitors only one time interval (PO) per paging DRX cycle. For example, the time interval can be a slot or a subframe.

[0086] Additionally, if the UE receives a scrambled PDCCH (more precisely, the CRC of the PDCCH) by the P-RNTI during the On Duration (i.e., when paging is detected), the UE can transition to connection mode and transmit and receive data with the base station.

[0087] Figure 2 is a diagram showing an example of IDLE mode DRX operation.

[0088] Referring to Fig. 2, when there is traffic (data) directed toward a UE in the RRC_Idle state (hereinafter referred to as 'Idle state'), paging is performed toward that UE.

[0089] Therefore, the UE wakes up every (paging) DRX cycle and monitors the PDCCH.

[0090] If Paging is present, the UE transitions to the Connected state and receives data. Otherwise, the UE can re-enter sleep mode.

[0091] (2) Connected Mode DRX (C-DRX)

[0092] C-DRX is a DRX applied in the RRC Connected State. The DRX cycle of C-DRX can be composed of a short DRX cycle and / or a long DRX cycle. The short DRX cycle is optional.

[0093] If C-DRX is configured, the UE performs PDCCH monitoring during the On Duration. If a PDCCH is successfully detected during monitoring, the UE activates the Inactive Timer and maintains the Awake State. Conversely, if no PDCCH is successfully detected during monitoring, the UE enters the Sleep State after the On Duration ends.

[0094] When C-DRX is configured, PDCCH reception occasions (e.g., slots with PDCCH search spaces / candidates) can be configured discontinuously based on the C-DRX configuration. On the other hand, when C-DRX is not configured, PDCCH reception occasions (e.g., slots with PDCCH search spaces / candidates) can be configured continuously according to the PDCCH Search Space Configuration. Meanwhile, PDCCH monitoring can be limited to a time interval set as the Measurement Gap regardless of the C-DRX configuration.

[0095] Figure 3 is a flowchart illustrating an example of how to perform a C-DRX operation.

[0096] The UE receives RRC signaling (e.g., MAC-MainConfig IE) containing DRX configuration information from the base station (S310). The DRX configuration information may include the following information.

[0097] - on-duration: The period (Duration) during which the UE waits to receive the PDCCH after waking up. Once the UE successfully decodes the PDCCH, it is awake and starts the drx-inactivity timer.

[0098] - onDurationTimer: The interval where the DRX Cycle starts (Duration); for example, it can refer to the time interval that needs to be continuously monitored at the beginning of the DRX cycle, and can be expressed in milliseconds.

[0099] - drx-InactivityTimer: Duration after the PDCCH Occasion corresponding to the PDCCH that directs a new UL or DL ​​transmission for the MAC entity; for example, it may be a time interval in milliseconds after the UE decodes a PDCCH containing scheduling information. That is, the duration during which the UE waits to successfully decode another PDCCH after decoding the last PDCCH. If no other PDCCH is detected within that interval, the UE transitions to Sleep mode.

[0100] The UE restarts the drx-inactivity timer after the successful decoding of the PDCCH for the initial transmission only, not the retransmission.

[0101] - drx-RetransmissionTimer: For DL, the maximum duration until a DL retransmission is received; for UL, the maximum duration until an acknowledgment for a UL retransmission is received. For example, for UL, this is the number of slots in the Bandwidth Part (BWP) to which the retransmission target TB (Transport Block) was sent; for DL, this is the number of slots in the Bandwidth Part (BWP) to which the retransmission target TB (Transport Block) was received.

[0102] - longDRX-Cycle: On Duration Occurrence Period

[0103] - drxStartOffset: The subframe number where the DRX cycle starts

[0104] - drxShortCycleTimer: The period (Duration) during which the UE must follow a short DRX cycle;

[0105] - shortDRX-Cycle: A DRX Cycle that runs for the number of drxShortCycleTimer values ​​when Drx-InactivityTimer ends.

[0106] - drx-SlotOffset: delay time before drx-onDurationTimer starts; for example, it can be expressed in ms and as a multiple of 1 / 32ms.

[0107] - Active Time: The total duration during which the UE monitors the PDCCH, including (a) the "On-duration" of the DRX cycle, (b) the time during which the UE performs continuous reception while the drx-inactivity timer has not expired, and (c) the time during which the UE performs continuous reception while waiting for a retransmission opportunity.

[0108] More specifically, when the DRX Cycle is configured, the Active Time for the serving cell of the DRX group includes the following times.

[0109] - (a) drx-onDurationTimer or (b) drx-InactivityTimer configured for the DRX group. Or

[0110] - (c) drx-RetransmissionTimerDL or drx-RetransmissionTimerUL for all serving cells in the DRX group. Or

[0111] - (d) ra-ContentionResolutionTimer or msgB-ResponseWindow. or

[0112] - (e) The period during which a Scheduling Request is transmitted via PUCCH and is pending, or

[0113] - (f) If, after successfully receiving a RAR (Random Access Response) for a random access preamble that the MAC entity did not select during contention-based random access, a PDCCH directing a new transmission addressed to the MAC entity's C-RNTI is not received.

[0114] Additionally, when DRX 'ON' is set through the DRX command of the MAC CE (command element) (S320), the UE monitors the PDCCH during the ON Duration of the DRX cycle based on the DRX setting (S330).

[0115] Figure 4 is a diagram showing an example of C-DRX operation.

[0116] Referring to FIG. 4, when the UE receives scheduling information (e.g., DL Assignment or UL Grant) in the RRC_Connected State (hereinafter referred to as the Connected State), the UE executes the DRX Inactivity Timer and the RRC Inactivity Timer.

[0117] DRX mode starts after the DRX Inactivity Timer expires. The UE wakes up from the DRX Cycle and monitors the PDCCH for a predetermined time (on duration timer).

[0118] In this case, when Short DRX is configured, when the UE starts DRX mode, the UE first starts a short DRX cycle, and after the short DRX cycle ends, starts a long DRX cycle. At this time, the long DRX cycle is a multiple of the short DRX cycle. That is, the UE wakes up more frequently during the short DRX cycle. After the RRC Inactivity Timer expires, the UE transitions to the Idle state and performs Idle mode DRX operations.

[0119] Figure 5 illustrates a DRX Cycle. C-DRX operation was introduced to save power in the UE. If a PDCCH is not received within the defined duration for each DRX cycle, the UE enters sleep mode and does not perform transmission / reception until the next DRX cycle.

[0120] On the other hand, when the UE receives a PDCCH during the on-duration, the Active time may be sustained (or increased) based on operations such as an inactivity timer and a retransmission timer. If no additional data is received within the Active time, the UE may perform a sleep operation until the next DRX operation.

[0121] In NR, a wake-up signal (WUS) was introduced to obtain additional power saving gains to the existing C-DRX operation. The WUS may be intended to indicate whether the UE needs to perform PDCCH monitoring during the on-duration of each DRX cycle (or multiple DRX cycles). If the UE does not detect the WUS at a defined or indicated WUS occasion, it may maintain a sleep operation without performing PDCCH monitoring during one or more DRX cycles associated with that WUS.

[0122] (3) Wake Up Signal (DCI Format 2_6)

[0123] In the power saving technology of the Rel-16 NR system, when a DRX operation is performed, the terminal can be notified of whether each DRX cycle is woke up through DCI format 2_6.

[0124] Referring to Fig. 6, the monitoring occasion for DCI format 2_6 is directed by the network ps-Offset It can be determined by the Time Gap reported by the terminal. In this case, the Time Gap reported by the terminal can be interpreted as the preparation period required for the operation after the terminal wakes up.

[0125] Referring to FIG. 6, the network can instruct the terminal to configure a search space (SS) set that can monitor DCI format 2_6. In the SS set configuration, the terminal can be instructed to monitor DCI format 2_6 through consecutive slots of a duration length at monitoring periodicity intervals.

[0126] In the DRX configuration, the start time of the DRX cycle (e.g., the point where the on-duration timer starts) and the network configured ps-Offset A monitoring window for monitoring DCI format 2_6 is determined by this. Additionally, PDCCH monitoring may not be required during the Time Gap interval reported by the terminal. Finally, the SS Set monitoring occasion for the terminal to perform actual monitoring can be determined as the first Full Duration within the monitoring window (i.e., Actual Monitoring Occasions in FIG. 6).

[0127] By detecting DCI format 2_6 in a monitoring window configured based on ps-Offset, the terminal can be instructed by the base station whether to wake up or not in a subsequent DRX cycle.

[0128] Search Space Set (SS Set) Group Switching

[0129] In the current NR standard, SS Set switching is defined as a method to reduce the power consumption of the terminal. This SS Set Group Switching allows the terminal to set two SS Set Groups and instructs the terminal to monitor one of the two SS Set Groups. Additionally, the terminal monitors the SS Sets included in the corresponding SS Set Group according to the instruction, and may skip monitoring the SS Sets not included in the corresponding SS Set Group.

[0130] For example, a terminal may be provided with a list of SS Set Groups consisting of a Type 3-PDCCH CSS (Common Search Space) set and / or a USS (User Specific Search Space) set. Additionally, if a list of SS Set Groups is provided, the terminal can monitor the SS Sets corresponding to group index #0.

[0131] Meanwhile, the terminal can perform SS Set Group Switching operations depending on whether SearchSpaceSwitchTrigger is set.

[0132] If SearchSpaceSwitchTrigger is set for the terminal, the terminal can switch the SS Set Group according to the instructions of DCI Format 2_0.

[0133] For example, if the value of the SS Set Group Switching Flag field in DCI Format 2_0 is 0, the terminal can start monitoring SS Set Group #0 and stop monitoring SS Set Group #1 after a certain period of time from the time it receives DCI Format 2_0.

[0134] Additionally, if the value of the SS Set Group Switching Flag field in DCI Format 2_0 is 1, the terminal may start monitoring SS Set Group #1 and stop monitoring SS Set Group #0 after a certain period of time from the time it receives DCI Format 2_0. If the terminal starts monitoring SS Set Group #1, the terminal may start counting the timer set by SearchSpaceSwitchTimer. If the timer expires, the terminal may start monitoring SS Set Group #0 and stop monitoring SS Set Group #1 after a certain period of time from the time the timer expires.

[0135] If SearchSpaceSwitchTrigger is not configured for the terminal, the terminal may change the SS Set Group upon receiving a DCI. For example, if the terminal receives a DCI while monitoring SS Set Group #0 (or SS Set Group #1), the terminal may start monitoring SS Set Group #1 (or SS Set Group #0) and stop monitoring SS Set Group #0 (or SS Set Group #1) after a certain period of time from the moment the DCI was received. At this time, the terminal may start counting the timer set by SearchSpaceSwitchTimer. If the timer expires, the terminal may start monitoring SS Set Group #0 (or SS Set Group #1) and stop monitoring SS Set Group #1 (or SS Set Group #0) after a certain period of time from the moment the timer expired.

[0136] Meanwhile, the embodiments described below can be applied to, for example, XR. XR (Extended Reality) is a concept that encompasses AR (Augmented Reality), VR (Virtual Reality), and MR (Mixed Reality). A characteristic of XR is that the time at which traffic can be expected to be received is fixed by fps (frames per second), and due to the influence of jitter, it may be received later or earlier than the expected time. This jitter of XR traffic is represented by a truncated Gaussian probability distribution. Therefore, power saving effects can be achieved by periodically setting DRX in accordance with fps. In addition, even without setting DRX, power saving effects can be expected by setting PDCCH monitoring adaptation alone. Of course, power saving effects can also be expected by setting both DRX and PDCCH monitoring adaptation.

[0137] The expected time of traffic reception and the expected time of reception due to the influence of jitter can be expressed as probabilities, and the embodiments described below can be applied to expect power saving effects in an XR environment as described above.

[0138] For example, at a time point relatively far from the expected time of traffic reception, the probability of jitter is low and the probability of reception is low; therefore, the terminal can save power by monitoring the PDCCH sparsely. Conversely, at a time point close to the expected time of traffic reception, the probability of jitter is high and the probability of reception is high; therefore, power consumption can be adjusted according to the probability of reception by monitoring the PDCCH densely. To this end, SS set group #0 can be configured as an SS set group containing an SS set for dense PDCCH monitoring, and SS set group #1 can be configured as an SS set group containing an SS set for sparse PDCCH monitoring. In other words, the SS Set Switching operation can be configured in the XR considering jitter.

[0139] As another example, the terminal can perform PDCCH monitoring during short intervals when the probability of traffic reception is high due to a high probability of jitter, and then repeat the micro-sleep operation. Through this, if traffic is not received normally, it can quickly micro-sleep to expect power savings, and then resume PDCCH monitoring to receive incoming traffic, thereby increasing the efficiency of PDCCH monitoring. In other words, PDCCH monitoring skipping behavior can be configured in the XR considering jitter.

[0140] In this disclosure, operation through DCI reception within DRX Active Time was proposed as an example, but the same method of operation can be applied to terminals where DRX is not configured.

[0141] The present disclosure proposes methods for monitoring a Type0 / 0A / 1 / 2-PDCCH (Physical Downlink Control Channel) CSS (Common Search Space) set for power saving benefits.

[0142] Up to 10 SS (Search Space) sets can be configured for a terminal per BWP. Additionally, the terminal can monitor PDCCH candidates included in the SS sets (hereinafter referred to as SS set monitoring).

[0143] Since the terminal must perform blind decoding (BD) on PDCCHs that it does not know at what time and in which DCI format they will be received, PDCCH monitoring during DRX operation accounts for a large portion of power consumption.

[0144] As a power saving technique for wireless communication systems (e.g., Rel-17 NR systems), PDCCH monitoring adaptation is discussed in which the terminal adjusts the number of PDCCH monitoring cycles to reduce power consumption during the DRX active time. Generally, PDCCH monitoring adaptation may refer to an action to reduce the number of PDCCH monitoring cycles.

[0145] Examples of PDCCH monitoring adaptation include PDCCH monitoring skipping (hereinafter, skipping) and SS set group switching (hereinafter, switching).

[0146] For PDCCH monitoring adaptation, the base station can utilize various DCI formats to instruct the terminal on information related to PDCCH monitoring adaptation. The terminal can monitor the PDCCH (Physical Downlink Control Channel) according to the PDCCH monitoring adaptation operation based on the instruction.

[0147] In the embodiments of the present disclosure, methods of operation of a terminal are proposed for the terminal to control the number of monitorings for Type0 / 0A / 1 / 2-PDCCH CSS sets. [Table 3] is a definition of Type0 / 0A / 1 / 2-PDCCH CSS set extracted from 3GPP TS 38.213.

[0148] A set of PDCCH candidates for a UE to monitor is defined in terms of PDCCH search space sets. A search space set can be a CSS set or a USS set. A UE monitors PDCCH candidates in one or more of the following search spaces sets- a Type0-PDCCH CSS set configured by pdcch-ConfigSIB1 in MIB or by searchSpaceSIB1 in PDCCH-ConfigCommon or by searchSpaceZero in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI on the primary cell of the MCG- a Type0A-PDCCH CSS set configured by searchSpaceOtherSystemInformation in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a SI-RNTI on the primary cell of the MCG- a Type1-PDCCH CSS set configured by ra-SearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a RA-RNTI, a MsgB-RNTI, or a TC-RNTI on the primary cell- a Type2-PDCCH CSS set configured by pagingSearchSpace in PDCCH-ConfigCommon for a DCI format with CRC scrambled by a P-RNTI on the primary cell of the MCG- a Type3-PDCCH CSS set configured by SearchSpace in PDCCH-Config with searchSpaceType = common for DCI formats with CRC scrambled by INT-RNTI, SFI-RNTI, TPC-PUSCH-RNTI, TPC-PUCCH-RNTI, TPC-SRS-RNTI, CI-RNTI, or PS-RNTI and, only for the primary cell, C-RNTI, MCS-C-RNTI, or CS-RNTI(s), and- a USS set configured by SearchSpace in PDCCH-Config with searchSpaceType = ue-Specific for DCI formats with CRC scrambled by C-RNTI, MCS-C-RNTI, SP-CSI-RNTI, CS-RNTI(s), SL-RNTI, SL-CS-RNTI, or SL-L-CS-RNTI.

[0149] In [Table 3], the uses of each CSS (Common Search Space) can be classified as follows: - Type0-PDCCH CSS Set: Initial access

[0150] - Type0A-PDCCH CSS Set: Receiving additional system information at the terminal's request (On-demand System Information, OSI)

[0151] - Type1-PDCCH CSS Set: Reception of network response to terminal request during random access phase

[0152] - Type2-PDCCH CSS Set: System information changes and PWS (public warning system) indications (or paging)

[0153] - Type3-PDCCH CSS Set: Other CSS

[0154] As can be seen in [Table 3], the Type0 / 0A / 1 / 2-PDCCH CSS set (hereinafter Type0 / 0A / 1 / 2-CSS) each has a Radio Network Temporary Identifier (RNTI) that scrambles Downlink Control Information (DCI) using Cyclic Redundancy Check (CRC). For example, DCI transmitted via Type0 / 0A-CSS is scrambled based on SI-RNTI. Additionally, DCI transmitted via Type1-CSS is scrambled based on RA-RNTI, MsgB-RNTI, and TC-RNTI. Additionally, DCI transmitted via Type2-CSS is scrambled based on P-RNTI.

[0155] Meanwhile, the TC-RNTI of Type 1-CSS is an RNTI associated with Msg3 and Msg4 according to the terminal’s random access procedure, and is not considered to be a target to which the PDCCH monitoring adaptation of the present disclosure applies. Additionally, when a corresponding RNTI is described in the present disclosure, it refers to a distinct RNTI that CRC scrambles the DCI in each Type of CSS.

[0156] For example, the RNTI corresponding to Type 0 / 0A-CSS is SI-RNTI, the RNTI corresponding to Type 1-CSS is RA-RNTI and MsgB-RNTI, and the RNTI corresponding to Type 2-CSS may be P-RNTI.

[0157] In addition, referring to [Table 4] extracted from 3GPP TS38.213, for Type0 / 0A / 1 / 2-CSS, the terminal can monitor with C-RNTI in addition to the corresponding RNTI.

[0158] If a UE is provided - one or more search space sets by corresponding one or more of searchSpaceZero, searchSpaceSIB1 , searchSpaceOtherSystemInformation , pagingSearchSpace , ra-SearchSpace , and - a C-RNTI, an MCS-C-RNTI, a CS-RNTI, a SL-RNTI, a SL-CS-RNTI, or a SL Semi-Persistent Scheduling V-RNTIthe UE monitors PDCCH candidates for DCI format 0_0 and DCI format 1_0 with CRC scrambled by the C-RNTI, the MCS-C-RNTI, or the CS-RNTI in the one or more search space sets in a slot where the UE monitors PDCCH candidates for at least a DCI format 0_0 or a DCI format 1_0 with CRC scrambled by SI-RNTI, RA-RNTI, MsgB-RNTI, or P-RNTI.

[0159] The present disclosure proposes a method for performing PDCCH monitoring differently for each RNTI. Additionally, the operation of a terminal receiving and decoding a DCI and the operation of descrambling the CRC of a corresponding DCI based on a specific RNTI, which are terminal operations in the NR standard, are referred to as specific RNTI monitoring. For example, the operation of a terminal receiving DCI 0_0 or DCI 1_0 in Type 2-CSS and descrambling the CRC to a P-RNTI can be referred to as P-RNTI monitoring. Furthermore, a monitoring adaptation that adjusts the number of P-RNTI monitoring operations of the terminal (e.g., reducing or eliminating the number of P-RNTI monitoring operations) can be simply referred to as P-RNTI monitoring adaptation.

[0160] For convenience of explanation, in this disclosure, the operation of a terminal in the current NR standard, in which the terminal monitors the PDCCH based on SI-RNTI, RA-RNTI, MsgB-RNTI, or P-RNTI for a Type0 / 0A / 1 / 2-PDCCH CSS set, is referred to as the first PDCCH monitoring. That is, the operation in which the PDCCH is monitored based on an RNTI other than C-RNTI is referred to as the first PDCCH monitoring. For example, the first PDCCH monitoring may mean monitoring the PDCCH based on SI-RNTI for Type0 / 0A-CSS, monitoring the PDCCH based on RA-RNTI or MsgB-RNTI for Type1-CSS, and monitoring the PDCCH based on P-RNTI for Type2-CSS.

[0161] Meanwhile, monitoring the PDCCH based on C-RNTI for the Type0 / 0A / 1 / 2-PDCCH CSS set by the terminal is referred to as 2nd PDCCH monitoring.

[0162] In this disclosure, the expressions "first" and "second" may be omitted if a person skilled in the art can clearly understand their meaning without confusion. For example, PDCCH monitoring may mean either the first PDCCH monitoring method or the second PDCCH monitoring method, or both of the first and second PDCCH monitoring methods, depending on the flow of the explanation.

[0163] SSSG (Search Space Set Group) switching, introduced for power saving in NR Rel-17, is based on technology introduced in the NR Rel-16 standard. In Rel-16-based SSSG switching, Type0 / 0A / 1 / 2-CSS cannot be included in any SSSG. In other words, the terminal must always monitor Type0 / 0A / 1 / 2-CSS regardless of the SSSG the terminal is currently monitoring.

[0164] However, for Rel-17 power saving, PDCCH monitoring skipping, in which the terminal does not monitor all PDCCHs, is also being considered. Yet, if the terminal is instructed to perform PDCCH monitoring skipping but must still monitor Type0 / 0A / 1 / 2-CSSs at all times, problems may arise in terms of the efficiency of power saving, which is the intended effect of the PDCCH monitoring skipping operation.

[0165] In order to solve such problems, the present disclosure proposes methods in which a terminal may or may not perform a monitoring operation of Type0 / 0A / 1 / 2-CSS. Accordingly, by the method proposed in the present disclosure, a terminal that monitors PDCCH using the existing (Rel-15 / 16 / 17 NR) DRX cycle can have an advantageous effect in improving power consumption efficiency by adjusting the number of PDCCH monitoring cycles.

[0166] Hereinafter, the present disclosure describes a method proposed based on a C-DRX applied to a terminal in the RRC_CONNECTED state, but is not limited thereto. For example, a person skilled in the art can easily infer that it can be extended and applied to other methods (e.g., a DRX applied to a terminal in the RRC_IDLE state) in which a certain interval in which the terminal does not expect to receive a DL (Downlink) signal can be defined with periodicity.

[0167] Therefore, it is obvious that the methods proposed in this disclosure can be applied to all types of transmission and reception methods expected by base stations and terminals, even without separate explanation, as long as the principles of this disclosure are not compromised. Hereinafter, for convenience of explanation, the term DRX is used in this disclosure as a general concept that includes the term C-DRX.

[0168] In addition, although the present disclosure provides examples based on an NR system to explain the principles of the present disclosure, the proposed methods are not limited to a specific transmission and reception form of NR unless otherwise stated. Furthermore, although the present disclosure provides examples based on the characteristics and structure of a terminal supporting C-DRX to explain the principles of the present disclosure, the proposed methods are not limited to a terminal supporting C-DRX unless otherwise stated. Therefore, it is obvious that the methods proposed in the present disclosure can be applied to all wireless communication transmission and reception structures and services, even without separate explanation, as long as the principles of the present disclosure are not infringed.

[0169] In the following description, the distinction between each method or option is intended to clarify the explanation and should not be interpreted restrictively to mean that each must be implemented as an independent method. For example, while the methods / options described below may each be implemented individually, they may also be implemented in a combined form, at least in part, to the extent that they do not conflict with one another.

[0170] Now, let us examine the operation process of the terminal and base station according to the embodiment of the present disclosure.

[0171] For example, in a communication system such as LTE and NR, when a terminal in RRC_CONNECTED mode receives DCI format x_1 and / or DCI format x_2 when DRX operation and operation according to the embodiments proposed in this disclosure are set, it may operate as shown in FIGS. 7 to 9. In this case, x is any integer and may mean various DCI formats.

[0172] FIG. 7 is intended to explain the overall operation process of a terminal according to an embodiment of the present disclosure.

[0173] Referring to FIG. 7, the terminal can receive RRC (Radio Resource Control) parameters related to PDCCH monitoring adaptation (S701). For example, the information included in the RRC parameters may be based on at least one of [Method 1] to [Method 3] described below.

[0174] The terminal can receive information related to PDCCH monitoring adaptation for CSS Set (S703). For example, the terminal can receive such information through MAC-CE (Medium Access Control - Control Element) or DCI (Downlink Control Information).

[0175] The terminal can monitor and receive PDCCH through a CSS Set and / or a USS Set based on the received information (S705~S707). For example, the terminal can receive the information and perform monitoring and receiving of PDCCH based on at least one of [Method 1] to [Method 3] described below.

[0176] FIG. 8 is intended to explain the overall operation process of a base station according to an embodiment of the present disclosure.

[0177] Referring to FIG. 8, the base station can transmit RRC (Radio Resource Control) parameters related to PDCCH monitoring adaptation (S801). For example, the information included in the RRC parameters may be based on at least one of [Method 1] to [Method 3] described below.

[0178] The base station can transmit information related to PDCCH monitoring adaptation for CSS Set (S803). For example, the base station can transmit such information via MAC-CE (Medium Access Control - Control Element) or DCI (Downlink Control Information).

[0179] The base station may transmit a PDCCH through a CSS Set and / or a USS Set based on the transmitted information (S805). For example, the base station may transmit the information and the PDCCH based on at least one of [Method 1] to [Method 3] described below.

[0180] FIG. 9 is intended to explain the overall operation process of a network according to an embodiment of the present disclosure.

[0181] Referring to FIG. 9, the base station can transmit RRC (Radio Resource Control) parameters related to PDCCH monitoring adaptation to the terminal (S901). For example, the information included in the RRC parameters may be based on at least one of [Method 1] to [Method 3] described below.

[0182] The base station can transmit information related to PDCCH monitoring adaptation for CSS Set to the terminal (S903). For example, the base station can transmit the information to the terminal via MAC-CE (Medium Access Control - Control Element) or DCI (Downlink Control Information).

[0183] The base station may transmit the PDCCH to the terminal via the CSS Set and / or USS Set based on the transmitted information (S805). For example, the base station may transmit the information and the PDCCH to the terminal based on at least one of [Method 1] to [Method 3] described below.

[0184] The terminal can monitor and receive PDCCH through a CSS Set and / or a USS Set based on information transmitted by a base station (S907). For example, the terminal can receive the information from the base station and perform monitoring and receiving of PDCCH based on at least one of [Method 1] to [Method 3] described below.

[0185] In other words, terminal behavior based on PDCCH monitoring adaptation (e.g., modified PDCCH monitoring method) may be applied using at least one of the embodiments described below. In FIGS. 7 through 9, it is assumed that the network explicitly or implicitly instructs the terminal to perform terminal behavior based on PDCCH monitoring adaptation through the DCI, but this is not limited thereto. For example, PDCCH monitoring adaptation may be instructed through the MAC-CE (Medium Access Control - Control Element).

[0186] Meanwhile, PDCCH monitoring adaptation may be initiated after a certain period of time from the reception of DCI format x_1 and / or DCI format x_2 or the termination of reception. For example, the certain period of time may be predefined, signaled via RRC, or determined through the corresponding DCI format x_1 and / or DCI format x_2.

[0187] Additionally, for the instruction of release / termination of terminal operations based on PDCCH monitoring adaptation, the same method used for the initiation of terminal operations based on PDCCH monitoring adaptation may be used. For example, if the initiation of PDCCH monitoring adaptation was indicated via DCI, the release / termination of PDCCH monitoring adaptation may also be indicated via DCI. As another example, if the initiation of PDCCH monitoring adaptation was indicated via MAC-CE, the release / termination of PDCCH monitoring adaptation may also be indicated via MAC-CE.

[0188] Meanwhile, as PDCCH monitoring adaptation is initiated, the terminal may continuously perform the operation according to the PDCCH monitoring adaptation described below until the time of the termination instruction of the operation, or perform the operation periodically, or perform the operation only for a certain period of time (e.g., timer-based), or terminate the operation when an event condition for the termination of the operation is satisfied.

[0189] Meanwhile, the PDCCH monitoring adaptation described below can be configured for each AL (Aggregation Level) / SS set / DCI format that is the monitoring target. Additionally, it may not be applied exceptionally to specific AL / specific SS set / specific DCI format. Furthermore, fallback actions for terminals / base stations may be defined in relation to the PDCCH monitoring adaptation. For example, actions may be defined to handle error cases, such as a misalignment of PDCCH monitoring adaptation between the base station and the terminal because the terminal fails to detect the DCI indicating the PDCCH monitoring adaptation.

[0190] In relation to all operations described in FIGS. 7 through 9, the base station (gNB) may set RRC parameters related to the terminal. The RRC parameters may include settings regarding the PDCCH monitoring adaptation described in this disclosure (e.g., configuration of SSSG, interval of PDCCH monitoring adaptation, etc.).

[0191] In the embodiments proposed in this disclosure, some of the proposed methods may be selected and applied. Each method may operate independently without separate combination, or one or more methods may be combined and operated in an interconnected manner. Some terms, symbols, sequences, etc. used for the description of this disclosure may be replaced with other terms, symbols, sequences, etc., as long as the applicable principles are maintained.

[0192] Hereinafter, in order to explain the principles, the present disclosure describes an arbitrary structure for PDCCH monitoring adaptation and transmission and reception of DCI format x_1 and / or DCI format x_2 as an example, but the proposed methods do not specify or limit the transmission and reception forms of DRX or DCI unless otherwise stated. Therefore, it is obvious that the embodiments proposed in the present disclosure can be applied to the PDCCH monitoring operation of the Type0 / 0A / 1 / 2-PDCCH CSS set without further explanation, as long as the principles are not compromised.

[0193] In the present disclosure, it is assumed that while a terminal is performing a DRX operation, a PDCCH monitoring adaptation (e.g., SS set group switching and / or PDCCH monitoring skipping) is instructed from a base station, and the terminal performs the corresponding PDCCH monitoring adaptation. Here, SS set group switching is reducing the number of SS sets being monitored to some rather than all, and PDCCH monitoring skipping is suspending PDCCH monitoring for a certain period of time.

[0194] For example, SS Set group switching can define two SS set groups containing SS sets. In this case, each SS set group can generally contain fewer SS sets than the number of SS sets that can be configured in a single Bandwidth Part (BWP) of the terminal. The terminal is instructed to monitor only one of the two SS Set groups; compared to monitoring all SS sets that can be configured in a single BWP of the NR terminal, this results in power savings as fewer SS sets are monitored. However, the number of SS Set Groups configured for the terminal does not necessarily have to be two, and three or more SS set groups may be configured depending on the settings.

[0195] In addition, for example, PDCCH monitoring skipping is to stop PDCCH monitoring for a specific duration instructed to the terminal. The terminal's PDCCH monitoring skipping duration may be set to one or more symbols or one or more slots, or it may be set until the next DRX cycle. By stopping PDCCH monitoring for a short period through the PDCCH monitoring skipping operation, the terminal can achieve a micro-sleep effect and achieve power saving effects.

[0196] The present disclosure proposes methods for a terminal to control monitoring of Type 0 / 0A / 1 / 2-CSS. By proposing RNTI-specific operations of the terminal for the corresponding CSSs, the terminal can achieve advantageous effects in controlling the number of PDCCH monitoring cycles while improving power consumption efficiency. Additionally, a C-RNTI monitoring method for the terminal is proposed, and further, adaptation of P-RNTI monitoring for Type 2-CSS is proposed. Furthermore, in addition to these monitoring methods, a method is proposed in which the terminal can temporarily prioritize USS (UE-Specific Search Space) over CSSs to monitor PDCCH candidates and non-overlapped CCEs.

[0197] [Method 1] The number of C-RNTI monitoring cycles for the terminal for Type0 / 0A / 1 / 2-PDCCH CSS set(s) can be adjusted.

[0198] As described above, according to the SSSG switching introduced in the Rel-16 NR standard, Type0 / 0A / 1 / 2-CSS is not affected by the corresponding SSSG switching operation. In other words, Type0 / 0A / 1 / 2-CSS is always monitored regardless of the SSSG that the terminal is currently monitoring.

[0199] However, in Rel-17 power saving, it was agreed that SSSG switching and PDCCH monitoring skipping would be common design. Therefore, it may not be suitable for a terminal to always continuously monitor Type0 / 0A / 1 / 2-CSS to which PDCCH monitoring adaptive behavior for Rel-17 power saving can be configured.

[0200] Therefore, to solve the aforementioned problem and enhance power saving effects, an adaptive PDCCH monitoring operation for Type0 / 0A / 1 / 2-CSS can be considered, unlike the Rel-16 SSSG switching operation.

[0201] The first PDCCH monitoring for the Type0 / 0A / 1 / 2-CSS of the terminal (e.g., PDCCH monitoring based on SI-RNTI, RA-RNTI, MsgB-RNTI and / or P-RNTI) is performed by the terminal as needed in specific situations. That is, the terminal does not perform PDCCH monitoring operations based on SI-RNTI, RA-RNTI, MsgB-RNTI and / or P-RNTI for the Type0 / 0A / 1 / 2-CSS when the first PDCCH monitoring is not required. In other words, a terminal operating in a general C-DRX state, rather than in specific situations, may not require PDCCH monitoring adaptation for the first PDCCH monitoring.

[0202] The terminal also performs second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS (e.g., C-RNTI-based PDCCH monitoring), and through the second PDCCH monitoring, a Physical Downlink Shared Channel (PDSCH) may be scheduled from the base station. Generally, considering that a C-RNTI-based PDSCH can also be scheduled through Type3-CSS and USS, which may be included in the PDCCH monitoring adaptation, the C-RNTI monitoring operation for Type0 / 0A / 1 / 2-CSS needs to be controlled through the PDCCH monitoring adaptation.

[0203] [Method 1] proposed in the present disclosure proposes a method in which a terminal performs C-RNTI monitoring adaptation for Type0 / 0A / 1 / 2-CSS.

[0204] Meanwhile, for the C-RNTI monitoring operation of the terminal described above, the base station may instruct / set the terminal to perform the second PDCCH monitoring operation proposed in [Method 1-1] to [Method 1-3]. For example, the base station may set a higher layer parameter (e.g., RRC parameter) to operate in at least one of [Method 1-1] to [Method 1-3] or not operate in any of [Method 1-1] to [Method 1-3]. If the base station is set not to operate in any way, the terminal can perform PDCCH monitoring based on C-RNTI, SI-RNTI, RA-RNTI, MsgB-RNTI, and / or P-RNTI for Type0 / 0A / 1 / 2-PDCCH CSS set(s) as before.

[0205] Alternatively, the base station may configure a plurality of methods among [Method 1-1] to [Method 1-3] to be available through upper layer parameters, and then direct one of the plurality of methods through DCI and / or MAC CE.

[0206] [Method 1-1] The terminal performs first PDCCH monitoring for Type0 / 0A / 1 / 2-PDCCH CSS set(s) as needed, and does not perform second PDCCH monitoring.

[0207] As described above, the terminal performs C-RNTI monitoring for Type0 / 0A / 1 / 2-CSS. Furthermore, this implies that the base station can schedule PDSCH to the terminal using fallback DCI through Type0 / 0A / 1 / 2-CSS.

[0208] However, the base station will instruct the terminal to adapt to PDCCH monitoring in situations where there is little or no expected data transmission, and generally, the terminal can expect power saving effects by reducing the number of PDCCH monitoring cycles through SSSG switching or PDCCH monitoring skipping operations in such situations.

[0209] Therefore, in this situation, it may be unlikely that the base station will schedule a PDSCH to the terminal using a fallback DCI via Type0 / 0A / 1 / 2-CSS. If the terminal is monitoring SSSG#1, the base station may schedule the PDSCH using a scheduling DCI instead of a fallback DCI and simultaneously instruct a switching to SSSG#0. Alternatively, the base station may instruct a switching to SSSG#0 first via another DCI format (e.g., DCI format 2_6), and then allow the terminal to expect PDSCH scheduling. Here, SSSG#1 is an SS Set Group with a relatively small number of SS sets included or a low monitoring frequency, and SSSG#1 monitoring may be instructed for the purpose of power saving. Additionally, SSSG#0 is an SS Set Group with a relatively large number of SS sets included or a high monitoring frequency, and when there is a large amount of data traffic or data traffic needs to be transmitted over a relatively long period, SSSG#0 monitoring may be directed for effective data transmission.

[0210] As in the example described above, if the base station schedules the switching instruction to SSSG#0 and / or the PDSCH through scheduling DCI or another DCI format (e.g., DCI format 2_6), the terminal may not perform the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS. In this case, the terminal can achieve power saving effects by adjusting the number of times the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS is performed. Therefore, the terminal may be configured to perform the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in addition to the PDCCH monitoring adaptation operation currently being discussed.

[0211] That is, [Method 1-1] proposes that the terminal performs the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same way as before, and does not perform the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS.

[0212] Under what circumstances the terminal will perform the operation of [Method 1-1], it can be configured in various ways.

[0213] For example, the terminal may be configured to perform the operation of [Method 1-1] for all PDCCHs of the terminal, or only when PDCCH monitoring adaptation is instructed by the base station. The terminal may perform PDCCH monitoring adaptation according to [Method 1-1] during the duration for the instructed PDCCH monitoring adaptation. For example, the duration of the PDCCH monitoring adaptation for performing [Method 1-1] may be (i) a specific duration set by the base station, (ii) a predetermined duration, (iii) from the moment the DCI instruction is received until the end of the DRX Active Time, or (iv) for N slots (where N is a natural number) from the start of the DRX Active Time.

[0214] For example, the terminal may perform the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS as before, but may not perform the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS. Meanwhile, since the first PDCCH monitoring is performed only when such an operation is required, such as beam failure recovery, it can be expected that a normal C-DRX terminal will perform the first PDCCH monitoring operation with a low probability. Therefore, if the terminal does not perform the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS through [Method 1-1], significant power saving benefits can be obtained.

[0215] For example, when a terminal receives an SS Set Group switching instruction to SSSG#1 that includes only Type1-CSS and does not include Type0 / 0A / 2-CSS, the terminal may perform the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same manner as before for a predetermined specific duration, perform the second PDCCH monitoring only for Type1-CSS, and not perform the second PDCCH monitoring for Type0 / 0A / 2-CSS. Here, the specific duration is, for example, the time for which monitoring for the corresponding SSSG is sustained when switching to a specific SSSG is instructed, and may be a value determined or fixed through a higher layer parameter (e.g., RRC).

[0216] In addition, unlike Rel-16 SS Set Group switching, Type0 / 0A / 1 / 2-CSS can also be configured to be included in a specific SSSG. The SSSG containing Type0 / 0A / 1 / 2-CSS can be configured independently. Furthermore, each CSS may be included in all SSSGs or not included in any SSSG. If Type0 / 0A / 1 / 2-CSS is not included in a specific SSSG, it may be necessary to explicitly indicate that the terminal operates so that C-RNTI monitoring is not performed only for that CSS. For example, if a specific CSS is not included in a specific SSSG, when monitoring for a specific SSSG is instructed, the terminal may be explicitly instructed that C-RNTI monitoring is not performed on the specific CSS, but SI-RNTI, RA-RNTI, MsgB-RNTI, and / or P-RNTI monitoring is performed.

[0217] [Method 1-2] The terminal performs the second PDCCH monitoring only on the SS set where the first PDCCH monitoring for Type0 / 0A / 1 / 2-PDCCH CSS set(s) was actually performed.

[0218] [Method 1-2] proposes an operation in which the terminal performs the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same manner as before, and performs the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS only for the SS set where the first PDCCH monitoring was actually performed. The circumstances under which the terminal performs the operation of [Method 1-2] can be configured in various ways.

[0219] For example, the terminal may be configured to perform the operation of [Method 1-2] for all PDCCHs of the terminal, or only when PDCCH monitoring adaptation is instructed by the base station. The terminal may perform PDCCH monitoring adaptation according to [Method 1-2] during the duration for the instructed PDCCH monitoring adaptation.

[0220] For example, the PDCCH monitoring adaptation period for performing [Method 1-2] may be (i) a specific period set by the base station, (ii) a predetermined period, (iii) from the moment the DCI instruction is received until the end of the DRX Active Time, or (iv) for N slots (where N is a natural number) from the start of the DRX Active Time.

[0221] In [Method 1-2], whether to perform second PDCCH monitoring is determined based on whether the terminal actually performs first PDCCH monitoring. Whether to perform second PDCCH monitoring in Type0 / 0A-CSS may be determined based on whether the terminal performs SI-RNTI monitoring for Type0 / 0A-CSS. Additionally, whether to perform second PDCCH monitoring in Type1-CSS may be determined based on whether RA-RNTI or MsgB-RNTI monitoring is performed for Type1-CSS. Additionally, whether to perform second PDCCH monitoring in Type2-CSS may be determined based on whether P-RNTI monitoring is performed for Type2-CSS.

[0222] For example, the terminal may perform the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same manner as before, and the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS may be determined based on whether the first PDCCH monitoring is performed. Since the first PDCCH monitoring is performed only in situations where such operation is required (e.g., beam failure recovery), it can be expected that a normal C-DRX terminal will perform the first PDCCH monitoring operation with a low probability. Therefore, the operation of [Method 1-2] for a terminal instructed to skip PDCCH monitoring may be the same as [Method 1-1]. For example, since the first PDCCH monitoring operation itself will be performed by the terminal with a low probability, the same effect as the terminal not monitoring the PDCCH at all may occur during a certain period. In addition, as another example, if the terminal is configured to have a PDCCH monitoring skipping operation for the first PDCCH monitoring, the second PDCCH monitoring can be automatically skipped by [Method 1-2] during the PDCCH monitoring skipping period.

[0223] Therefore, the terminal can obtain power saving benefits by not performing second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS through [Method 1-2]. That is, the terminal can obtain significant power saving benefits by performing second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS at a very low frequency through [Method 1-2].

[0224] In addition, by performing the second PDCCH monitoring only on the CSS for which the first PDCCH monitoring was performed through [Method 1-2], scheduling data associated with the first PDCCH monitoring or data that needs to be scheduled at the time when the CSS for which the first PDCCH monitoring was performed is set can be efficiently scheduled.

[0225] For example, when a terminal receives an SS Set Group switching instruction to SSSG#1 that includes only Type1-CSS and does not include Type0 / 0A / 2-CSS, the terminal performs the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same manner as before for a predetermined specific duration, and performs the second PDCCH monitoring only when the first PDCCH monitoring for Type1-CSS has been performed. Additionally, the second PDCCH monitoring for Type0 / 0A / 2 / -CSS may not be performed. Here, the specific duration is, for example, the time for which monitoring for a corresponding SSSG is sustained when switching to a specific SSSG is instructed, and may be a value determined or fixed through a higher layer parameter (e.g., RRC).

[0226] In addition, unlike Rel-16 SS Set Group switching, Type0 / 0A / 1 / 2-CSS can also be configured to be included in a specific SSSG. The SSSG containing Type0 / 0A / 1 / 2-CSS can be configured independently. Additionally, each CSS may be included in all SSSGs or not included in any SSSG. If Type0 / 0A / 1 / 2-CSS is not included in a specific SSSG, it may be necessary to explicitly indicate that C-RNTI monitoring for said CSS is performed only when the terminal performs first PDCCH monitoring. For example, if a specific CSS is not included in a specific SSSG, it may be explicitly indicated that when monitoring for a specific SSSG is instructed, C-RNTI monitoring for said CSS is performed only when SI-RNTI, RA-RNTI, MsgB-RNTI, and / or P-RNTI monitoring is performed.

[0227] Meanwhile, if a PDCCH monitoring adaptation operation is instructed to the terminal, the terminal may be configured to automatically perform a second PDCCH monitoring operation for Type0 / 0A / 1 / 2-CSS based on [Method 1-1] or [Method 1-2] without instruction and / or setting by a separate base station.

[0228] [Method 1-3] As needed, the timing / period of the second PDCCH monitoring for Type0 / 0A / 1 / 2-PDCCH CSS set(s) can be set from the base station to the terminal.

[0229] [Method 1-3] proposes an operation in which the terminal performs the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same manner as before, and the base station sets the timing and / or period for the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS. For example, the terminal performing [Method 1-3] performs the second PDCCH monitoring for Type0 / 0A / 1 / 2-PDCCH CSS set(s) only at the timing and / or period set by the base station, and does not perform the second PDCCH monitoring at other PDCCH MOs (Monitoring Occasions). According to [Method 1-3], by performing the second PDCCH monitoring only at some of the PDCCH MOs set for Type0 / 0A / 1 / 2-PDCCH CSS set(s), the number of PDCCH monitorings can be reduced, thereby obtaining power saving benefits.

[0230] For example, the timing and / or period for performing the second PDCCH monitoring for Type0 / 0A / 1 / 2-PDCCH CSS set(s) can be set in various ways, such as (i) the odd or even PDCCH MO among the set PDCCH MOs, (ii) the PDCCH MO corresponding to a multiple of n (where n is a natural number), or (iii) the first and last PDCCH MO within the DRX Active Time, or (iv) m (where m is a natural number) PDCCH MOs after the specified PDCCH monitoring adaptation (e.g., SS Set Group Switching or PDCCH monitoring skipping) has ended.

[0231] Meanwhile, according to [Method 1-3], the terminal may perform second PDCCH monitoring based on a time and / or period instructed / set by the base station. For example, SI-RNTI monitoring for Type0 / 0A-CSS, RA-RNTI or MsgB-RNTI monitoring for Type1-CSS, and P-RNTI monitoring for Type2-CSS may be performed as needed regardless of the instructed PDCCH monitoring adaptation, and C-RNTI monitoring for Type0 / 0A / 1 / 2-CSS may be performed only at a set time and / or period.

[0232] For example, the terminal may perform the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in the same way as before, and perform the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS only at a specific time or period.

[0233] Since the first PDCCH monitoring is performed only when the operation is required (e.g., beam failure recovery), it can be expected that a normal C-DRX terminal will perform the first PDCCH monitoring operation with a low probability. Unlike [Method 1-1] and [Method 1-2], [Method 1-3] sets the time when the second PDCCH monitoring for Type0 / 0A / 1 / 2-PDCCH CSS set(s) must be performed, thereby preventing the monitoring from not being performed at all.

[0234] Therefore, if the Type0 / 0A / 1 / 2-PDCCH CSS set is present at the time when the base station wants to schedule the PDSCH, the PDSCH can be scheduled using the CSS set at that time through [Method 1-3], and scheduling flexibility can also be expected.

[0235] In addition, the terminal can expect power saving benefits by reducing the number of 2nd PDCCH monitoring sessions for Type0 / 0A / 1 / 2-CSS through [Method 1-3].

[0236] The base station may instruct / set the terminal to perform a second PDCCH monitoring operation for Type0 / 0A / 1 / 2-CSS by selecting at least one of [Method 1-1] to [Method 1-3].

[0237] In addition, the instructions / settings are not fixed and can be individually configured on the terminal according to various conditions such as the terminal, BWP, SCS (Subcarrier Spacing), and Cell through higher layer parameters (e.g., RRC layer). For example, if the operation of [Method 1-2] is configured on a specific terminal, the terminal can determine whether to always perform 2nd PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in a C-DRX situation based on whether to perform 1st PDCCH monitoring for the corresponding CSS. If [Method 1-2] is configured per BWP, the terminal always performs 2nd PDCCH monitoring for Type0 / 0A / 1 / 2-CSS in BWP #1, just like an existing NR terminal, but in BWP #2, it can perform 2nd PDCCH monitoring in the corresponding CSS based on whether to perform 1st PDCCH monitoring in the CSS.

[0238] Meanwhile, as described above, a plurality of methods among [Method 1-1] to [Method 1-3] may be used, and this can be configured to the terminal through an upper layer parameter (e.g., RRC layer), and any one of the plurality of methods may be indicated through DCI or MAC CE, so that the terminal can perform 2 PDCCH monitoring based on the indicated method.

[0239] Meanwhile, according to [Method 1-1] to [Method 1-3], by not performing C-RNTI monitoring operations in Type0 / 0A / 1 / 2-CSS or by reducing the number of C-RNTI monitoring operations in Type0 / 0A / 1 / 2-CSS, it is possible to reduce power consumption caused by PDCCH monitoring.

[0240] [Method 2] P-RNTI monitoring for Type2-PDCCH CSS set may not be performed based on the PDCCH monitoring adaptation instructed to the terminal.

[0241] In [Method 1], the operation of the terminal was proposed so that the first PDCCH monitoring for Type0 / 0A / 1 / 2-CSS is always possible without being affected by the PDCCH monitoring adaptation instruction, just like the existing Rel-16 NR terminal.

[0242] On the other hand, in [Method 2], the first PDCCH monitoring (i.e., P-RNTI monitoring) for Type 2-CSS can be configured to be included in the PDCCH monitoring operation differently from the terminal operation proposed in [Method 1]. For example, SI-RNTI, RA-RNTI, MsgB-RNTI, and / or P-RNTI monitoring for Type 0 / 0A / 1 / 2-CSS is performed according to [Method 1-1], and C-RNTI monitoring for Type 0 / 0A / 1 / 2-CSS is not performed, but when PDCCH monitoring adaptation for the operation of [Method 2] is instructed to the terminal, SI-RNTI, RA-RNTI, and / or MsgB-RNTI monitoring for Type 0 / 0A / 1-CSS is performed, and C-RNTI monitoring for Type 0 / 0A / 1 / 2-CSS and P-RNTI monitoring for Type 2-CSS may not be performed.

[0243] In addition, when [Method 1-2] or [Method 1-3] is configured, the terminal performs a PDCCH monitoring adaptation operation according to [Method 1-2] or [Method 1-3], and when the terminal is instructed to perform a PDCCH monitoring adaptation for the operation of [Method 2], P-RNTI monitoring for Type 2-CSS can be excluded from the PDCCH monitoring target.

[0244] Alternatively, if there is no setting for the operation of [Method 1], SI-RNTI, RA-RNTI, MsgB-RNTI, P-RNTI, and / or C-RNTI monitoring for Type0 / 0A / 1 / 2-CSS is performed, and when the terminal is instructed to adapt PDCCH monitoring for the operation of [Method 2], P-RNTI monitoring for Type2-CSS is not performed, and SI-RNTI, RA-RNTI, MsgB-RNTI, and / or C-RNTI monitoring for Type0 / 0A / 1 / 2-CSS can be performed.

[0245] The operation of a terminal in the RRC_CONNECTED state performing first PDCCH monitoring for Type2-CSS is described in [Table 5] below, extracted from 3GPP TS 38.331.

[0246] The modification period boundaries are defined by SFN values for which SFN mod m = 0, where m is the number of radio frames comprising the modification period. The modification period is configured by system information.... UEs in RRC_CONNECTED shall monitor for SI change indication in any paging occasion at least once per modification period if the UE is provided with common search space, including pagingSearchSpace , searchSpaceSIB1 and searchSpaceOtherSystemInformation , on the active BWP to monitor paging,...ETWS or CMAS capable UEs in RRC_CONNECTED shall monitor for indication about PWS notification in any paging occasion at least once every defaultPagingCycle if the UE is provided with common search space, including pagingSearchSpace , searchSpaceSIB1 and searchSpaceOtherSystemInformation, on the active BWP to monitor paging. ...

[0247] The modification period of the standard document is described in [Table 6] below, extracted from 3GPP TS 38.331. [Table 6] is a compilation of the contents regarding the modification period from 3GPP TS 38.331 to make the explanation of the modification period easier to understand.

[0248] BCCH-Config ::= SEQUENCE { modificationPeriodCoeff ENUMERATED {n2, n4, n8, n16}, modificationPeriodCoeffActual modification period, expressed in number of radio frames m = modificationPeriodCoeff * defaultPagingCycle , see clause 5.2.2.2.2. n2 corresponds to value 2, n4 corresponds to value 4, and so on. PCCH-Config ::= SEQUENCE { defaultPagingCycle PagingCycle, PagingCycle ::= ENUMERATED {rf32, rf64, rf128, rf256}

[0249] The terminal is defined to page System Information (SI) change indications at one or more Paging Occasions (PO) per modification period, and to page Public Warning System (PWS) notifications at one or more POs per default Paging Cycle.

[0250] In other words, since the terminal must perform paging at regular intervals, the P-RNTI monitoring of Type2-CSS can be configured to be affected by PDCCH monitoring adaptation, unlike Type0 / 0A / 1-CSS, which monitors only in specific situations. Referring to [Table 6], the defaultPagingCycle is set to a multiple of at least 32 radio frames, and the modification period is set to a multiple of at least 64 radio frames.

[0251] Considering that the duration of PDCCH monitoring skipping or SSSG switching that can be instructed to the terminal is in symbol or slot units, paging is performed at one or more POs based on a time unit longer than the duration of the PDCCH monitoring adaptation that can be instructed. Therefore, the base station can instruct the terminal that it is not necessary to temporarily suspend P-RNTI monitoring for Type 2-CSS during the PDCCH monitoring adaptation duration.

[0252] In other words, [Method 2] suggests that when the terminal is instructed to perform a PDCCH monitoring adaptation based on [Method 2], the terminal does not perform P-RNTI monitoring for the Type2-PDCCH CSS set. For example, the PDCCH monitoring adaptation in [Method 2] may be PDCCH monitoring skipping, which does not monitor any PDCCHs, or SSSG switching to an SSSG that does not include Type2-CSS. To this end, similar to [Method 1-1] and [Method 1-2], Type2-CSS may be configured not to be included in any SSSG or to be included in one or more SSSGs.

[0253] If SSSG Switching instructing monitoring for a specific SSSG is instructed, or if the SSSG currently being monitored by the terminal is a specific SSSG and Type2-CSS is not included in the specific SSSG, the terminal may not perform P-RNTI monitoring for Type2-CSS. In this case, it may be necessary to explicitly indicate that the terminal performs the second PDCCH monitoring in accordance with [Method 1-1] or [Method 1-2], or in the same way as the existing NR terminal.

[0254] The terminal operation for Type0 / 0A / 1-CSS may be the same as the existing NR operation. Alternatively, if [Method 1-1] or [Method 1-2] is configured, the operation of [Method 1-1] or [Method 1-2] is performed excluding P-RNTI monitoring for Type2-CSS. That is, while the first PDCCH monitoring for Type0 / 0A / 1-CSS is performed in the same way as the existing NR terminal, the first PDCCH monitoring for Type2-CSS may follow the operation of [Method 2], and the second PDCCH monitoring for Type0 / 0A / 1 / 2-CSS may follow the operation of [Method 1-1] or [Method 1-2].

[0255] As described above, the terminal performs paging at least once per period with a long time unit period. Therefore, even if paging is not performed during the PDCCH monitoring adaptation period, which is a relatively short time within the long time unit period, the overall operation of the terminal may not be affected.

[0256] However, there is a very low probability that the terminal has not yet performed paging within the modification period, and monitoring adaptation for a duration including all POs within the modification period may be indicated.

[0257] In such cases, a problem may arise where the terminal is unable to perform paging within the modification period. To resolve this problem, if the terminal operation of [Method 2] is configured and, while the terminal has not yet performed paging, a PDCCH monitoring adaptation for a duration containing all POs within the modification period (e.g., PDCCH monitoring skipping that skips PDCCH monitoring in that duration, or SSSG switching for an SSSG that does not include Type 2-CSS in that duration) is instructed, the terminal may perform paging at the earliest PO in time within the instructed PDCCH monitoring adaptation duration. Alternatively, the terminal may be configured to perform paging at the latest PO in time. This operation may be configured as a fixed value, or it may be pre-configured at a higher layer and instructed by being distinguished via DCI.

[0258] If, due to an application delay, there is a difference of a certain interval between the time when the actual PDCCH monitoring adaptation is instructed and the DCI reception time, and there is one or more POs within that interval, the terminal can perform paging through the POs within that interval.

[0259] Alternatively, to fully guarantee the PDCCH monitoring adaptation period, the terminal may perform paging at the earliest PO (or a specific n-th PO from the earliest PO) after the specified PDCCH monitoring adaptation has ended. That is, the base station can guarantee the terminal's paging until a specific time prior to the end of the PDCCH monitoring adaptation.

[0260] Through [Method 2], the base station can expect power saving benefits by ensuring that the terminal does not have to perform paging at least once per cycle, thereby ensuring that the terminal can sleep.

[0261] [Method 3] The terminal can monitor PDCCH candidates and non-overlapped CCEs by temporarily prioritizing USS over CSS during DRX Active Time.

[0262] In existing NR systems, the maximum number of PDCCH monitoring and channel measurements during one slot or span of a terminal is set to a specific value. The maximum number of PDCCH monitorings per slot of a terminal refers to the maximum number of monitoring PDCCH candidates per slot, which is defined in the standard document 3GPP TS 38.213 as shown in [Table 7] below.

[0263] Maximum number of monitored PDCCH candidates per slot and per serving cell M PDCCH max,slot,u 0 44 1 36 2 22 3 20

[0264] The maximum number of channel measurements per slot of a terminal refers to the maximum number of non-overlapped CCEs per slot, which is defined in the standard document 3GPP TS 38.213 as shown in [Table 8] below.

[0265] Maximum number of non-overlapped CCEs per slot and per serving cell C PDCCH max,slot,u 0 56 1 56 2 48 3 32

[0266] In the present invention, [Table 7] and [Table 8], which limit the number of PDCCH monitoring and channel measurements per slot of a terminal, are collectively referred to as the BD / CCE limit. That is, the BD / CCE limit refers to the maximum number of monitoring PDCCH candidates and the number of non-overlapped CCEs per slot.

[0267] The operation of the BD / CCE limit mentioned above for NR standard terminals is as shown in [Table 9] extracted from the standard document 3GPP TS 38.213.

[0268]

[0269] Referring to [Table 9], the terminal can monitor the CSS first and then monitor the USS in the order of SS set ID using the remaining BD / CCE limit. While the C-DRX terminal is monitoring SSSG#1 for sparse monitoring purposes for power saving purposes, if a large amount of data transmission is expected, the base station may instruct the terminal to switch to SSSG to monitor SSSG#0 for dense monitoring purposes.

[0270] In such cases, the base station can instruct the terminal on scheduling information for data by transmitting a non-fallback DCI for scheduling through the USS. However, there are multiple monitoring occasions (MOs) for CSS such as Type0 / 0A / 1 / 2-CSS in the slot of the USS where the scheduling information can be received with a low probability, and as the terminal performs first PDCCH monitoring and second PDCCH monitoring for the CSS, the terminal may not be able to receive the non-fallback DCI that the base station intends to transmit through the USS due to the BD / CCE limit.

[0271] To prevent the aforementioned problem, [Method 3] proposes an action in which the terminal temporarily prioritizes USS over CSS to monitor PDCCH candidates and non-overlapped CCEs. In other words, in [Method 3], USS takes precedence over CSS only during certain periods in the BD / CCE limit application order. That is, the terminal performing [Method 3] can monitor PDCCH candidates and non-overlapped CCEs for USS within a single slot and begin monitoring CSS after monitoring for all USS is completed. At this time, the monitoring order for CSS may be from CSS Type 0 to Type 3. Alternatively, Type 3 may be prioritized, followed by Type 0, Type 1, and Type 2.

[0272] The base station may instruct / set the operation of [Method 3] to the terminal. For example, the base station may instruct / set the operation of [Method 3] in advance through a higher layer parameter or may be instructed through DCI. Additionally, the operation of [Method 3] may be a fixed value. For example, [Method 3] may be applied in a specific slot or a specific span.

[0273] For example, the operation of the terminal according to [Method 3] may be performed according to at least one of the following examples.

[0274] 1) When PDCCH monitoring adaptation is indicated, the terminal may perform the operation according to [Method 3] in the entire duration or a part of the duration for which the PDCCH monitoring adaptation is indicated. Meanwhile, when [Method 3] is applied to a part of the indicated duration, [Method 3] may be applied for a specific proportion of the indicated duration, or [Method 3] may be applied in fixed symbol, slot, or ms units.

[0275] 2) The terminal can perform the operation according to [Method 3] throughout the entire configured DRX Active Time.

[0276] 3) The terminal may perform the operation according to [Method 3] during the first part of the configured DRX Active Time (e.g., 10 slots).

[0277] When [Method 3] is configured so that the terminal applies the BD / CCE limit with USS over CSS during the specified duration, the specified duration may not coincide with the slot boundary. In this case, the terminal behavior of having USS over CSS can be configured to apply up to the boundary of the slot containing the last symbol of the specified duration and the next slot.

[0278] Alternatively, it may follow the existing NR terminal behavior of prioritizing USS up to the last symbol of the specified duration and prioritizing CSS from the very next symbol. For example, when applying a BD / CCE limit within a slot, it may prioritize USS up to a specific symbol and then prioritize CSS after that specific symbol.

[0279] Even if the terminal operates as described above, if the USS has already been monitored with priority over the CSS within a single slot, it can be considered that the effect expected in [Method 3] has been achieved.

[0280] [Method 3] may be applied to all general PDCCH monitoring adaptation situations or limited to specific PDCCH monitoring adaptations. For example, it may be limited to the SSSG switching from SSSG#1 for sparse monitoring purposes to SSSG#0 for dense monitoring purposes as described above. That is, the operation of [Method 3] is performed during SSSG switching from SSSG#1 to SSSG#0, and the operation of [Method 3] may not be performed when SSSG switching from SSSG#0 to SSSG#1 or PDCCH monitoring skipping is instructed.

[0281] Previously, since CSS had to be monitored before USS, the terminal had to perform PDCCH monitoring equal to the number of CSSs allocated to at least one slot in order for the base station to transmit DCI through USS, which could result in a large load on the terminal due to PDCCH monitoring. However, according to [Method 3], in situations where the base station does not use CSS or wants to use it sparingly, when transmitting DCI through USS, the monitoring priority of USS is set higher than the monitoring priority of CSS, so that the terminal performs PDCCH monitoring starting from USS, thereby reducing the load on the terminal due to PDCCH monitoring.

[0282] Although not limited thereto, the various descriptions, functions, procedures, proposals, methods, and / or flowcharts of the disclosure disclosed in this document may be applied to various fields requiring wireless communication / connection (e.g., 5G) between devices.

[0283] Examples are provided in more detail below with reference to the drawings. In the following drawings and descriptions, the same reference numerals may represent the same or corresponding hardware blocks, software blocks, or function blocks unless otherwise described.

[0284] FIG. 10 illustrates a communication system (1) to which the present disclosure applies.

[0285] Referring to FIG. 10, the communication system (1) to which the present disclosure applies includes a wireless device, a base station, and a network. Here, the wireless device refers to a device that performs communication using wireless access technology (e.g., 5G NR (New RAT), LTE (Long Term Evolution)) and may be referred to as a communication / wireless / 5G device. Although not limited thereto, the wireless device may include a robot (100a), a vehicle (100b-1, 100b-2), an XR (eXtended Reality) device (100c), a hand-held device (100d), a home appliance (100e), an IoT (Internet of Thing) device (100f), and an AI device / server (400). For example, the vehicle may include a vehicle equipped with wireless communication capabilities, an autonomous vehicle, a vehicle capable of performing inter-vehicle communication, etc. Here, the vehicle may include an Unmanned Aerial Vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and can be implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) equipped in vehicles, televisions, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Portable devices may include smartphones, smartpads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., laptops, etc.). Home appliances may include TVs, refrigerators, washing machines, etc. IoT devices may include sensors, smart meters, etc. For example, base stations and networks may be implemented as wireless devices, and a specific wireless device (200a) may operate as a base station / network node to other wireless devices.

[0286] Wireless devices (100a to 100f) can be connected to a network (300) through a base station (200). Artificial Intelligence (AI) technology may be applied to the wireless devices (100a to 100f), and the wireless devices (100a to 100f) can be connected to an AI server (400) through the network (300). The network (300) can be configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices (100a to 100f) may communicate with each other through the base station (200) / network (300), but they may also communicate directly (e.g., sidelink communication) without going through the base station / network. For example, vehicles (100b-1, 100b-2) can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices (100a to 100f).

[0287] Wireless communication / connection (150a, 150b, 150c) can be established between wireless devices (100a~100f) / base station (200) and base station (200) / base station (200). Here, wireless communication / connection can be achieved through various wireless access technologies (e.g., 5G NR), such as uplink / downlink communication (150a), sidelink communication (150b) (or D2D communication), and inter-base station communication (150c) (e.g., relay, IAB (Integrated Access Backhaul)). Through wireless communication / connection (150a, 150b, 150c), wireless devices and base stations / wireless devices, and base stations and base stations can transmit / receive wireless signals to / from each other. For example, wireless communication / connection (150a, 150b, 150c) can transmit / receive signals through various physical channels. To this end, based on various proposals of the present disclosure, at least some of the following may be performed: various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel encoding / decoding, modulation / demodulation, resource mapping / demapping, etc.), resource allocation processes, etc.

[0288] FIG. 11 illustrates a wireless device that can be applied to the present disclosure.

[0289] Referring to FIG. 11, the first wireless device (100) and the second wireless device (200) can transmit and receive wireless signals through various wireless access technologies (e.g., LTE, NR). Here, {the first wireless device (100), the second wireless device (200)} may correspond to {wireless device (100x), base station (200)} and / or {wireless device (100x), wireless device (100x)} of FIG. 18.

[0290] The first wireless device (100) includes one or more processors (102) and one or more memories (104), and may additionally include one or more transceivers (106) and / or one or more antennas (108). The processor (102) controls the memory (104) and / or transceivers (106) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or sequences of operation disclosed in this document. For example, the processor (102) may process information within the memory (104) to generate a first information / signal and then transmit a wireless signal containing the first information / signal through the transceiver (106). Additionally, the processor (102) may receive a wireless signal containing a second information / signal through the transceiver (106) and then store information obtained from the signal processing of the second information / signal in the memory (104). The memory (104) may be connected to the processor (102) and may store various information related to the operation of the processor (102). For example, the memory (104) may store software code containing instructions for performing some or all of the processes controlled by the processor (102) or for performing the descriptions, functions, procedures, proposals, methods, and / or operation sequence diagrams disclosed in this document. Here, the processor (102) and the memory (104) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). The transceiver (106) may be connected to the processor (102) and may transmit and / or receive wireless signals through one or more antennas (108). The transceiver (106) may include a transmitter and / or receiver. The transceiver (106) may be combined with an RF (Radio Frequency) unit. In the present disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0291] Specifically, we will examine the commands and / or operations that are controlled by the processor (102) of the first wireless device (100) according to an embodiment of the present disclosure and stored in the memory (104).

[0292] The following operations are described based on the control operations of the processor (102) from the perspective of the processor (102), but may be stored in memory (104) in the form of software code, etc., for performing these operations. For example, in the present disclosure, at least one memory (104) may be a computer-readable storage medium and may store instructions or programs, and said instructions or programs may, when executed, cause at least one processor operablely connected to said at least one memory to perform operations according to embodiments or implementations of the present disclosure related to the following operations.

[0293] For example, the processor (102) can receive RRC (Radio Resource Control) parameters related to PDCCH monitoring adaptation through the transceiver (106) (S701). For example, the information included in the RRC parameters may be based on at least one of [Method 1] to [Method 3] described below.

[0294] The processor (102) can receive information related to PDCCH monitoring adaptation for the CSS Set through the transceiver (106). For example, the processor (102) can receive such information through the transceiver (106) via MAC-CE (Medium Access Control - Control Element) or DCI (Downlink Control Information).

[0295] The processor (102) can monitor the PDCCH through the CSS Set and / or USS Set based on the received information and receive the PDCCH through the transceiver (106). For example, the processor (102) can receive the information through the transceiver (106) based on at least one of [Method 1] to [Method 3] described below and perform monitoring and receiving of the PDCCH.

[0296] The second wireless device (200) includes one or more processors (202) and one or more memories (204), and may additionally include one or more transceivers (206) and / or one or more antennas (208). The processor (202) controls the memory (204) and / or transceivers (206) and may be configured to implement the descriptions, functions, procedures, proposals, methods and / or operation sequences disclosed in this document. For example, the processor (202) may process information within the memory (204) to generate a third information / signal and then transmit a wireless signal containing the third information / signal through the transceiver (206). Additionally, the processor (202) may receive a wireless signal containing a fourth information / signal through the transceiver (206) and then store information obtained from the signal processing of the fourth information / signal in the memory (204). Memory (204) may be connected to the processor (202) and may store various information related to the operation of the processor (202). For example, memory (204) may store software code containing instructions for performing some or all of the processes controlled by the processor (202) or for performing the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. Here, the processor (202) and memory (204) may be part of a communication modem / circuit / chip designed to implement wireless communication technology (e.g., LTE, NR). A transceiver (206) may be connected to the processor (202) and may transmit and / or receive wireless signals through one or more antennas (208). The transceiver (206) may include a transmitter and / or receiver. The transceiver (206) may be interchangeable with an RF unit. In this disclosure, a wireless device may refer to a communication modem / circuit / chip.

[0297] Specifically, we will examine the commands and / or operations that are controlled by the processor (202) of the second wireless device (200) according to an embodiment of the present disclosure and stored in memory (204).

[0298] The following operations are described based on the control operations of the processor (202) from the perspective of the processor (202), but may be stored in memory (204) in the form of software code, etc., for performing these operations. For example, in the present disclosure, at least one memory (204) may be a computer-readable storage medium and may store instructions or programs, and said instructions or programs may, when executed, cause at least one processor operablely connected to said at least one memory to perform operations according to embodiments or implementations of the present disclosure related to the following operations.

[0299] For example, the processor (202) can transmit RRC (Radio Resource Control) parameters related to PDCCH monitoring adaptation through the transceiver (206). For example, the information included in the RRC parameters may be based on at least one of [Method 1] to [Method 3] described below.

[0300] The processor (202) can transmit information related to PDCCH monitoring adaptation for CSS Set through the transceiver (206). For example, the processor (202) can transmit such information through the transceiver (206) via MAC-CE (Medium Access Control - Control Element) or DCI (Downlink Control Information).

[0301] The processor (202) can transmit a PDCCH through a CSS Set and / or a USS Set based on information transmitted through a transceiver (206) (S805). For example, the processor (202) can transmit the information and the PDCCH based on at least one of [Method 1] to [Method 3] described below through a transceiver (206).

[0302] Hereinafter, hardware elements of the wireless device (100, 200) will be described in more detail. Although not limited thereto, one or more protocol layers may be implemented by one or more processors (102, 202). For example, one or more processors (102, 202) may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). One or more processors (102, 202) may generate one or more Protocol Data Units (PDUs) and / or Service Data Units (SDUs) according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate messages, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document. One or more processors (102, 202) may generate a signal (e.g., baseband signal) containing a PDU, SDU, message, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in this document and provide it to one or more transceivers (106, 206). One or more processors (102, 202) may receive a signal (e.g., baseband signal) from one or more transceivers (106, 206) and may obtain a PDU, SDU, message, control information, data, or information according to the descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document.

[0303] One or more processors (102, 202) may be referred to as a controller, microcontroller, microprocessor, or microcomputer. One or more processors (102, 202) may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more Application Specific Integrated Circuits (ASICs), one or more Digital Signal Processors (DSPs), one or more Digital Signal Processing Devices (DSPDs), one or more Programmable Logic Devices (PLDs), or one or more Field Programmable Gate Arrays (FPGAs) may be included in one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or flowcharts disclosed in this document may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be contained in one or more processors (102, 202) or stored in one or more memories (104, 204) and driven by one or more processors (102, 202). The descriptions, functions, procedures, proposals, methods, and / or operation sequences disclosed in this document may be implemented using firmware or software in the form of code, instructions, and / or sets of instructions.

[0304] One or more memories (104, 204) may be connected to one or more processors (102, 202) and may store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memories (104, 204) may be composed of ROM, RAM, EPROM, flash memory, hard drive, registers, cache memory, computer read storage media, and / or combinations thereof. One or more memories (104, 204) may be located inside and / or outside of one or more processors (102, 202). Additionally, one or more memories (104, 204) may be connected to one or more processors (102, 202) through various technologies such as wired or wireless connections.

[0305] One or more transceivers (106, 206) may transmit user data, control information, wireless signals / channels, etc., as mentioned in the methods and / or operation flowcharts, etc., of this document to one or more other devices. One or more transceivers (106, 206) may receive user data, control information, wireless signals / channels, etc., as mentioned in the descriptions, functions, procedures, proposals, methods and / or operation flowcharts, etc., disclosed in this document from one or more other devices. For example, one or more transceivers (106, 206) may be connected to one or more processors (102, 202) and may transmit and receive wireless signals. For example, one or more processors (102, 202) may control one or more transceivers (106, 206) to transmit user data, control information, or wireless signals to one or more other devices. Additionally, one or more processors (102, 202) may control one or more transceivers (106, 206) to receive user data, control information, or wireless signals from one or more other devices. Additionally, one or more transceivers (106, 206) may be connected to one or more antennas (108, 208), and one or more transceivers (106, 206) may be configured to transmit and receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, proposals, methods, and / or flowcharts of operation disclosed in this document through one or more antennas (108, 208). In this document, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers (106, 206) can convert the received wireless signal / channel, etc. from an RF band signal to a baseband signal in order to process the received user data, control information, wireless signal / channel, etc. using one or more processors (102, 202).One or more transceivers (106, 206) can convert user data, control information, wireless signals / channels, etc. processed using one or more processors (102, 202) from baseband signals to RF band signals. To this end, one or more transceivers (106, 206) may include (analog) oscillators and / or filters.

[0306] FIG. 12 illustrates a vehicle or autonomous vehicle to which the present disclosure applies. The vehicle or autonomous vehicle may be implemented as a mobile robot, vehicle, train, manned / unmanned aerial vehicle (AV), ship, etc.

[0307] Referring to FIG. 12, a vehicle or autonomous vehicle (100) may include an antenna unit (108), a communication unit (110), a control unit (120), a driving unit (140a), a power supply unit (140b), a sensor unit (140c), and an autonomous driving unit (140d). The antenna unit (108) may be configured as part of the communication unit (110).

[0308] The communication unit (110) can transmit and receive signals (e.g., data, control signals, etc.) with external devices such as other vehicles, base stations (e.g., base stations, roadside base stations (Roadside units), etc.), and servers. The control unit (120) can perform various operations by controlling elements of the vehicle or autonomous vehicle (100). The control unit (120) may include an Electronic Control Unit (ECU). The driving unit (140a) can drive the vehicle or autonomous vehicle (100) on the ground. The driving unit (140a) may include an engine, motor, power train, wheels, brakes, steering device, etc. The power supply unit (140b) supplies power to the vehicle or autonomous vehicle (100) and may include wired / wireless charging circuits, batteries, etc. The sensor unit (140c) can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit (140c) may include an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, an inclination sensor, a weight detection sensor, a heading sensor, a position module, a vehicle forward / reverse sensor, a battery sensor, a fuel sensor, a tire sensor, a steering sensor, a temperature sensor, a humidity sensor, an ultrasonic sensor, an illuminance sensor, a pedal position sensor, etc. The autonomous driving unit (140d) may implement technologies such as maintaining the driving lane, technologies for automatically adjusting speed such as adaptive cruise control, technologies for automatically driving along a predetermined path, and technologies for automatically setting a path and driving when a destination is set.

[0309] For example, the communication unit (110) can receive map data, traffic information data, etc. from an external server. The autonomous driving unit (140d) can generate an autonomous driving path and a driving plan based on the acquired data. The control unit (120) can control the drive unit (140a) so that the vehicle or the autonomous vehicle (100) moves along the autonomous driving path according to the driving plan (e.g., speed / direction control). During autonomous driving, the communication unit (110) can acquire the latest traffic information data from an external server non-periodically and can acquire surrounding traffic information data from surrounding vehicles. Additionally, during autonomous driving, the sensor unit (140c) can acquire vehicle status and surrounding environment information. The autonomous driving unit (140d) can update the autonomous driving path and the driving plan based on the newly acquired data / information. The communication unit (110) can transmit information regarding the vehicle location, autonomous driving path, driving plan, etc. to an external server. An external server can predict traffic information data in advance using AI technology, etc., based on information collected from vehicles or autonomous vehicles, and can provide the predicted traffic information data to vehicles or autonomous vehicles.

[0310] FIG. 13 illustrates an XR device to which the present invention is applied. The XR device may be implemented as an HMD, a Head-Up Display (HUD) equipped in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance, digital signage, a vehicle, a robot, etc.

[0311] Referring to FIG. 13, the XR device (100a) may include a communication unit (110), a control unit (120), a memory unit (130), an input / output unit (140a), a sensor unit (140b), and a power supply unit (140c).

[0312] The communication unit (110) can transmit and receive signals (e.g., media data, control signals, etc.) with external devices such as other wireless devices, mobile devices, or media servers. The media data may include video, images, sound, etc. The control unit (120) can perform various operations by controlling the components of the XR device (100a). For example, the control unit (120) may be configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation, and processing. The memory unit (130) may store data / parameters / programs / codes / commands required for driving the XR device (100a) or creating an XR object. The input / output unit (140a) acquires control information, data, etc. from the outside and can output the created XR object. The input / output unit (140a) may include a camera, microphone, user input unit, display unit, speaker and / or haptic module, etc. The sensor unit (140b) can obtain XR device status, surrounding environment information, user information, etc. The sensor unit (140b) may include a proximity sensor, an illuminance sensor, an accelerometer, a magnetic sensor, a gyroscope, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone and / or radar, etc. The power supply unit (140c) supplies power to the XR device (100a) and may include a wired / wireless charging circuit, a battery, etc.

[0313] For example, the memory unit (130) of the XR device (100a) may contain information (e.g., data, etc.) necessary for creating an XR object (e.g., AR / VR / MR object). The input / output unit (140a) may receive a command to operate the XR device (100a) from the user, and the control unit (120) may operate the XR device (100a) according to the user's operation command. For example, if the user intends to watch movies, news, etc. through the XR device (100a), the control unit (120) may transmit content request information to another device (e.g., mobile device (100b)) or a media server through the communication unit (130). The communication unit (130) may download / stream content such as movies, news, etc. from another device (e.g., mobile device (100b)) or a media server to the memory unit (130). The control unit (120) controls and / or performs procedures such as video / image acquisition, (video / image) encoding, and metadata generation / processing for the content, and can generate / output an XR object based on information about the surrounding space or real object acquired through the input / output unit (140a) / sensor unit (140b).

[0314] Additionally, the XR device (100a) is wirelessly connected to the mobile device (100b) through the communication unit (110), and the operation of the XR device (100a) can be controlled by the mobile device (100b). For example, the mobile device (100b) can act as a controller for the XR device (100a). To this end, the XR device (100a) can acquire three-dimensional position information of the mobile device (100b), and then generate and output an XR object corresponding to the mobile device (100b).

[0315] The embodiments described above are combinations of the components and features of the present disclosure in a specific form. Each component or feature should be considered optional unless otherwise explicitly stated. Each component or feature may be implemented in a form not combined with other components or features. Additionally, it is possible to construct embodiments of the present disclosure by combining some components and / or features. The order of operations described in the embodiments of the present disclosure may be changed. Some components or features of one embodiment may be included in another embodiment, or may be replaced with corresponding components or features of another embodiment. It is obvious that embodiments may be constructed by combining claims that are not explicitly related in the claims, or that they may be included as new claims by amendment after filing.

[0316] Specific operations described in this document as being performed by a base station may, in some cases, be performed by its upper node. That is, it is self-evident that various operations performed for communication with a terminal in a network consisting of multiple network nodes, including a base station, may be performed by the base station or other network nodes other than the base station. The base station may be replaced by terms such as fixed station, gNode B (gNB), Node B, eNode B (eNB), and access point.

[0317] It is obvious to those skilled in the art that the present disclosure may be embodied in other specific forms without departing from the features of the present disclosure. Accordingly, the foregoing detailed description should not be interpreted restrictively in all respects and should be considered illustrative. The scope of the present disclosure shall be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present disclosure are included within the scope of the present disclosure. Industrial applicability

[0318] Although the method for transmitting and receiving a downlink control channel as described above and the device for doing so have been explained mainly with an example applied to a 5th generation NewRAT system, it is possible to apply them to various wireless communication systems in addition to the 5th generation NewRAT system.

Claims

Claim 1 A method by means of a terminal, comprising receiving parameters related to PDCCH (Physical Downlink Control Channel) monitoring adaptation through a higher layer, receiving information instructing an operation related to the PDCCH monitoring adaptation based on the parameters, and receiving the PDCCH based on the information, wherein receiving the PDCCH includes monitoring the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Cell-Radio Network Temporary Identifier) ​​during a time interval associated with the information, and wherein monitoring of the C-RNTI-based PDCCH through the CSS set is skipped during the time interval. Claim 2 A method according to claim 1, further comprising monitoring the PDCCH through the CSS set based on the C-RNTI based on receiving the PDCCH through the CSS set based on the RNTI. Claim 3 A method according to claim 1, further comprising receiving information related to time for monitoring a PDCCH based on the C-RNTI, and monitoring the PDCCH based on the C-RNTI through the CSS set based on the information related to time. Claim 4 A method according to claim 1, wherein the PDCCH monitoring adaptation is based on SS set switching that directs switching to a specific SS set, and further comprises monitoring the PDCCH based on the C-RNTI for the type of CSS set included in the specific SS set. Claim 5 In claim 1, the method wherein the CSS set is a CSS set having a type different from type 2. Claim 6 A method according to claim 1, wherein the PDCCH is monitored with priority over the USS (UE-Specific Search Space) over the CSS during the time interval. Claim 7 In claim 1, the method wherein the CSS set is a CSS set having a type different from type 3. Claim 8 In the terminal, at least one transceiver; at least one processor; A terminal comprising at least one memory connected to enable operation on at least one processor and storing instructions that, when executed, cause at least one processor to perform an operation, wherein the operation comprises: receiving parameters related to a PDCCH (Physical Downlink Control Channel) monitoring adaptation through at least one transceiver, through a higher layer, receiving information directing an operation related to the PDCCH monitoring adaptation based on the parameters through at least one transceiver, and receiving the PDCCH based on the information through at least one transceiver, wherein receiving the PDCCH comprises monitoring the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Cell-Radio Network Temporary Identifier) ​​during a time interval associated with the information, wherein monitoring of the C-RNTI-based PDCCH through the CSS set is skipped during the time interval. Claim 9 A terminal according to claim 8, further comprising monitoring the PDCCH through the CSS set based on the C-RNTI based on receiving the PDCCH through the CSS set based on the RNTI. Claim 10 A terminal according to claim 8, further comprising receiving information related to time for monitoring a PDCCH based on the C-RNTI, and monitoring the PDCCH based on the C-RNTI through the CSS set based on the information related to time. Claim 11 A terminal according to claim 8, wherein the PDCCH monitoring adaptation further comprises monitoring the PDCCH based on the C-RNTI for the type of CSS set included in the specific SS set, based on SS set switching that directs switching to a specific SS set. Claim 12 In claim 8, the above CSS set is a terminal that is a CSS set having a type different from type 2. Claim 13 In claim 8, a terminal in which the PDCCH is monitored with priority over the USS (UE-Specific Search Space) over the CSS during the above time interval. Claim 14 In claim 8, the above CSS set is a terminal that is a CSS set having a type different from type 3. Claim 15 A device comprising: at least one processor; and at least one memory connected to the at least one processor so as to be operable, and storing instructions that, when executed, cause the at least one processor to perform an operation, wherein the operation comprises: receiving parameters related to a PDCCH (Physical Downlink Control Channel) monitoring adaptation through a higher layer; receiving information directing an operation related to the PDCCH monitoring adaptation based on the parameters; and receiving the PDCCH based on the information, wherein receiving the PDCCH comprises monitoring the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Cell-Radio Network Temporary Identifier) ​​during a time interval associated with the information, wherein monitoring of the C-RNTI-based PDCCH through the CSS set is skipped during the time interval. Claim 16 A computer-readable storage medium comprising at least one computer program that causes at least one processor to perform an operation, wherein the operation comprises: receiving parameters related to a PDCCH (Physical Downlink Control Channel) monitoring adaptation through a higher layer; receiving information directing an operation related to the PDCCH monitoring adaptation based on the parameters; and receiving the PDCCH based on the information, wherein receiving the PDCCH comprises monitoring the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Cell-Radio Network Temporary Identifier) ​​during a time interval associated with the information, and wherein monitoring of the C-RNTI-based PDCCH through the CSS set is skipped during the time interval. Claim 17 A method by a base station, comprising transmitting parameters related to PDCCH (Physical Downlink Control Channel) monitoring adaptation through a higher layer, transmitting information instructing an operation related to the PDCCH monitoring adaptation based on said parameters, and transmitting said PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Cell-Radio Network Temporary Identifier) ​​during a time interval associated with said information, wherein the transmission of said C-RNTI-based PDCCH through the CSS set is not performed during said time interval. Claim 18 A base station comprises: at least one transceiver; at least one processor; and at least one memory connected to the at least one processor to enable operation and storing instructions that, when executed, cause the at least one processor to perform an operation, wherein the operation includes: transmitting parameters related to a PDCCH (Physical Downlink Control Channel) monitoring adaptation through the at least one transceiver, through a higher layer; transmitting information instructing an operation related to the PDCCH monitoring adaptation based on the parameters through the at least one transceiver; and transmitting the PDCCH through a CSS (Common Search Space) set based on an RNTI different from a C-RNTI (Cell-Radio Network Temporary Identifier) ​​through the at least one transceiver during a time interval associated with the information, wherein the transmission of the C-RNTI-based PDCCH through the CSS set is not performed during the time interval.

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