METHOD FOR TRANSMITTING AND RECEIVING DOWNLINK CONTROL CHANNEL AND APPARATUS THEREFOR

Abstract

To provide a method and apparatus for transmitting and receiving downlink control channels.SOLUTION: The present disclosure provides a method of receiving a physical downlink control channel (PDCCH) by a terminal in a wireless communication system. The method may include: receiving (i) a first parameter related to a bandwidth part (BWP) and (ii) a second parameter related to a plurality of search space (SS) sets included in the BWP through higher layers; monitoring only a specific SS set among the plurality of SS sets; based on that a first PDCCH is received in the specific SS set, monitoring all of the plurality of SS sets; and receiving a second PDCCH in one SS set among the plurality of SS sets. Based on that the one SS set is the specific SS set, monitoring of other SS sets except for the specific SS set among the plurality of SS sets may be terminated.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] This disclosure relates to a method and an apparatus for transmitting and receiving a downlink control channel, and more particularly, to a method and an apparatus for configuring PDCCH (Physical Downlink Control Channel) monitoring adaptation for an XR (eXtended Reality) packet, and transmitting and receiving a PDCCH based on the configured PDCCH monitoring adaptation. [Background technology]

[0002] As the times change, more communication devices will require larger communication traffic, and the next-generation 5G system, which is an improved wireless broadband communication compared to the existing LTE system, is required. In the next-generation 5G system, called NewRAT, communication scenarios are divided into Enhanced Mobile BroadBand (eMBB) / Ultra-Reliability and Low-Latency Communication (URLLC) / Massive Machine-type Communications (mMTC), etc.

[0003] Here, eMBB is a next-generation mobile communication scenario having characteristics such as High Spectrum Efficiency, High User Experienced Data Rate, and High Peak Data Rate, URLLC is a next-generation mobile communication scenario having characteristics such as Ultra Reliability, Ultra Low Latency, and Ultra High Availability (e.g., V2X, Emergency Service, Remote Control), and mMTC is a next-generation mobile communication scenario having characteristics such as Low Cost, Low Energy, Short Packet, and Massive Connectivity (e.g., IoT). Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a method and apparatus for transmitting and receiving a downlink control channel.

[0005] The technical problems to be achieved by the present disclosure are not limited to the above technical problems, and other technical problems not mentioned will be clearly understood by a person having ordinary skill in the art to which the present invention pertains from the following description. [Means for solving the problem]

[0006] In a wireless communication system according to an embodiment of the present disclosure, a method for a terminal receiving a PDCCH (Physical Downlink Control Channel), the method including receiving, via a higher layer, (i) a first parameter related to a BWP (Bandwidth Part) and (ii) a second parameter related to a set of multiple SSs (Search Spaces) included in the BWP, monitoring only a specific SS set among the multiple SS sets, and based on a first PDCCH being received via the specific SS set, monitoring all of the multiple SS sets, and receiving a second PDCCH via one SS set among the multiple SS sets, and based on the one SS set being the specific SS set, monitoring of the other SS sets among the multiple SS sets except for the specific SS set is terminated.

[0007] At this time, DRX (Discontinuous Reception) operation does not need to be configured in the terminal.

[0008] In addition, (i) one SS set is not a specific SS set, and (ii) based on the second PDCCH indicating PDCCH monitoring adaptation, an SS set among the multiple SS sets that is not a specific SS set is monitored based on PDCCH monitoring adaptation.

[0009] Also, only a particular SS set is monitored based on the fact that the SS set is a particular SS set.

[0010] In addition, multiple SS sets are set for XR (eXtended Reality) packets.

[0011] In a wireless communication system according to the disclosure, a terminal for receiving a PDCCH (Physical Downlink Control Channel) includes at least one transceiver, at least one processor, and at least one memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform an operation, the operation including receiving, by the at least one transceiver, via an upper layer, (i) a first parameter related to a BWP (Bandwidth Part), and (ii) a second parameter related to a set of SSs (Search Spaces) included in the BWP, monitoring only a specific SS set among the multiple SS sets, and based on a first PDCCH being received via the specific SS set, monitoring all of the multiple SS sets, and receiving, by the at least one transceiver, a second PDCCH via one SS set among the multiple SS sets, and based on a one SS set being a specific SS set, monitoring of other SS sets among the multiple SS sets except for the specific SS set is terminated.

[0012] At this time, DRX (Discontinuous Reception) operation does not need to be configured in the terminal.

[0013] In addition, (i) one SS set is not a specific SS set, and (ii) based on the second PDCCH indicating PDCCH monitoring adaptation, an SS set among the multiple SS sets that is not a specific SS set is monitored based on PDCCH monitoring adaptation.

[0014] Also, only a particular SS set is monitored based on the fact that the SS set is a particular SS set.

[0015] In addition, multiple SS sets are set for XR (eXtended Reality) packets.

[0016] In a wireless communication system according to the present disclosure, an apparatus for receiving a Physical Downlink Control Channel (PDCCH) includes at least one processor and at least one memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform an operation, the operation including receiving, via an upper layer, (i) a first parameter related to a Bandwidth Part (BWP) and (ii) a second parameter related to a set of SSs (Search Spaces) included in the BWP, monitoring only a specific SS set among the multiple SS sets, and based on a first PDCCH being received via the specific SS set, monitoring all of the multiple SS sets, and receiving a second PDCCH via one SS set among the multiple SS sets, and based on the one SS set being a specific SS set, monitoring of other SS sets among the multiple SS sets except for the specific SS set is terminated.

[0017] A computer-readable storage medium including at least one computer program causing at least one processor according to the present disclosure to perform operations, the operations including receiving, via an upper layer, (i) a first parameter related to a BWP (Bandwidth Part) and (ii) a second parameter related to a set of multiple SS (Search Space) sets included in the BWP, monitoring only a specific SS set among the multiple SS sets, and based on a first PDCCH being received via the specific SS set, monitoring all of the multiple SS sets, and receiving a second PDCCH via one SS set among the multiple SS sets, and based on the one SS set being the specific SS set, monitoring of other SS sets among the multiple SS sets except for the specific SS set is terminated.

[0018] In a wireless communication system according to an embodiment of the present disclosure, a method for a base station to transmit a PDCCH (Physical Downlink Control Channel), the method including transmitting, via a higher layer, (i) a first parameter related to a BWP (Bandwidth Part), and (ii) a second parameter related to a set of multiple SSs (Search Spaces) included in the BWP, and transmitting a second PDCCH via one SS set among the multiple SS sets based on the first PDCCH being transmitted only via a specific SS set among the multiple SS sets, and not transmitting a third PDCCH via other SS sets among the multiple SS sets excluding the specific SS set based on the one SS set being the specific SS set.

[0019] In a wireless communication system according to the present disclosure, a base station transmitting a PDCCH (Physical Downlink Control Channel) includes at least one transceiver, at least one processor, and at least one memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, the operations including transmitting, by the at least one transceiver, via an upper layer, (i) a first parameter related to a BWP (Bandwidth Part), and (ii) a second parameter related to a set of multiple SS (Search Space) sets included in the BWP, and transmitting, by the at least one transceiver, a second PDCCH via one SS set among the multiple SS sets based on having transmitted a first PDCCH only via a specific SS set among the multiple SS sets, and not transmitting a third PDCCH via other SS sets among the multiple SS sets excluding the specific SS set based on the one SS set being the specific SS set. Effect of the Invention

[0020] According to this disclosure, when a terminal supporting an eXtended Reality (XR) service monitors a Physical Downlink Control Channel (PDCCH) to periodically receive XR packets, it is possible to support an operation of reducing unnecessary PDCCH monitoring and reducing power consumption.

[0021] This disclosure is not limited to XR services, but can support the operation of a terminal that can be expected to achieve power saving effects regardless of the type of traffic, as long as the traffic is scheduled to be transmitted periodically.

[0022] The effects obtained by the present disclosure are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those having ordinary skill in the art to which the present invention pertains from the following description. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a diagram for explaining DRX (Discontinuous Reception) operation in IDLE mode. [Diagram 2] FIG. 2 is a diagram for explaining DRX (Discontinuous Reception) operation in IDLE mode. [Diagram 3] FIG. 1 is a diagram for explaining DRX operation in RRC (Radio Resource Control) connected mode. [Figure 4] FIG. 1 is a diagram for explaining DRX operation in RRC (Radio Resource Control) connected mode. [Diagram 5] FIG. 1 is a diagram for explaining DRX operation in RRC (Radio Resource Control) connected mode. [Figure 6] FIG. 13 is a diagram for explaining a method of monitoring DCI format 2_6. [Figure 7] FIG. 11 is a diagram for explaining jitter that may occur when receiving an XR (eXtended Reality) packet. [Figure 8] A diagram to explain the overall operation process of a terminal and a base station according to [Method 1] of this disclosure. [Figure 9] A diagram to explain the overall operation process of a terminal and a base station according to [Method 1] of this disclosure. [Figure 10] A diagram to explain the overall operation process of a terminal and a base station according to [Method 1] of this disclosure. [Figure 11] FIG. 1 is a diagram for explaining an example of [Method 1] of this disclosure. [Figure 12] FIG. 1 is a diagram for explaining an example of [Method 1] of this disclosure. [Figure 13] A diagram to explain the overall operation process of a terminal and a base station according to [Method 2] of this disclosure. [Figure 14]A diagram to explain the overall operation process of a terminal and a base station according to [Method 2] of this disclosure. [Figure 15] A diagram to explain the overall operation process of a terminal and a base station according to [Method 2] of this disclosure. [Figure 16] FIG. 13 is a diagram for explaining an example of [Method 2] of this disclosure. [Figure 17] FIG. 1 illustrates a communication system to which the present disclosure applies. [Figure 18] FIG. 1 illustrates an example of a wireless device applicable to this disclosure. [Figure 19] FIG. 1 illustrates an example vehicle or autonomous vehicle applicable to this disclosure. [Figure 20] FIG. 1 is a diagram illustrating an example of an eXtended Reality (XR) device to which this disclosure is applied. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The following technologies can be used for various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. CDMA can be implemented by radio technologies such as Universal Terrestrial Radio Access (UTRA) and CDMA2000. TDMA can be implemented by radio technologies such as Global System for Mobile communications (GSM) / General Packet Radio Service (GPRS) / Enhanced Data Rates for GSM Evolution (EDGE). OFDMA can be implemented by radio technologies such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, Evolved UTRA (E-UTRA), etc. UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is a part of E-UMTS (Evolved UMTS) that uses E-UTRA, and LTE-A 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.

[0025] For clarity of explanation, the 3GPP communication system (e.g., NR) will be mainly described, but the technical idea of ​​the present disclosure is not limited thereto. For background technology, terms, abbreviations, etc. used in the description of this disclosure, reference can be made to matters described in standard documents published before this disclosure (e.g., 38.211, 38.212, 38.213, 38.214, 38.300, 38.331, etc.).

[0026] Here, we will explain 5G communications including NR systems.

[0027] The three main requirement areas for 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 (URLLC) area.

[0028] Some use cases may require multiple areas for optimization, while others may focus on just one key performance indicator (KPI). 5G will support these use cases in a flexible and reliable way.

[0029] eMBB goes far beyond basic mobile Internet access to cover rich two-way work, cloud or augmented reality media and entertainment applications. Data is one of the core drivers of 5G, and for the first time in the 5G era, dedicated voice services may not be seen. In 5G, voice is expected to be handled simply as an application using the data connection provided by the communication system. The main causes of the increased traffic volume are the increase in content size and the increase in the number of applications that require high data transmission rates. Streaming services (audio and video), conversational video and mobile Internet connections will become more widely used as more devices connect to the Internet. Many such applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are proliferating on mobile communication platforms, applicable to both business and entertainment. Cloud storage is also a special use case that drives the growth of uplink data transmission rates. 5G will also be used for cloud remote work, which requires lower end-to-end latency so that a good user experience can be maintained when haptic interfaces are used. Entertainment, such as cloud gaming and video streaming, is another key element that will increase the demand for mobile broadband capabilities. Entertainment is a must on smartphones and tablets everywhere, including in highly mobile environments such as trains, cars and planes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires very low latency and instantaneous data volume.

[0030] Also, one of the most anticipated use cases for 5G is its ability to seamlessly connect embedded sensors across all sectors, i.e. mMTC. It is predicted that there will be 20.4 billion potential IoT devices by 2020. Industrial IoT is one area where 5G will play a key role in enabling smart cities, asset tracking, smart utilities, agriculture and security infrastructure.

[0031] URLLC includes new services transforming industries through ultra-reliable / available low-latency links such as remote control of key infrastructure and self-driving vehicles. The levels of reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0032] Next, a number of use cases in 5G communication systems, including NR systems, will be described in more detail.

[0033] 5G is a means of delivering streams rated at hundreds of megabits per second to gigabits per second, and can complement fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS). Such high speeds are required to deliver TV at resolutions of 4K and above (6K, 8K and beyond), as well as virtual and augmented reality. Virtual reality (VR) and augmented reality (AR) applications include most immersive sports competitions. Certain applications may require special network configurations. For example, in the case of VR games, gaming companies must integrate their core servers with the network operator's edge network servers to minimize latency.

[0034] Automotive is expected to be an important new driver of 5G with many use cases for mobile communications to vehicles. For example, entertainment for passengers will require simultaneous high capacity and high mobility mobile broadband, because future users will expect a continuous high quality connection regardless of their location and speed. Another use case in the automotive field is the augmented reality dashboard, which displays information that identifies objects in the dark and tells the driver about the object's distance and movement over what the driver sees through the front window. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure, and between cars and other connected devices (e.g. devices accompanied by pedestrians). Safety systems will guide the driver through alternative courses of action to make driving safer and reduce the risk of accidents. The next step will be remotely piloted or self-driven vehicles, which will require very reliable and very fast communication between different self-driving vehicles and between cars and infrastructure. In the future, self-driving vehicles will perform all driving activities, allowing the driver to focus only on traffic anomalies that the vehicle itself cannot identify. The technical requirements of self-driving vehicles demand ultra-low latency and ultra-fast reliability so that traffic safety is increased to a level unattainable by humans.

[0035] Smart cities and smart homes, also referred to as smart society, are embedded with dense wireless sensor networks. A distributed network of intelligent sensors identifies requirements for cost and energy-efficient maintenance of the city or home. A similar setup can be made for each home. Temperature sensors, window and heating controllers, burglar alarms and home appliances are all wirelessly connected. Many of these sensors typically have low data transmission rates, low power and low cost. However, for example, real-time HD video may be required for certain types of devices for surveillance.

[0036] The consumption and distribution of energy, including heat or gas, is highly decentralized, requiring automated control of distributed sensor networks. A smart grid interconnects such sensors using digital information and communication technologies to collect and act upon information. This information can include supplier and consumer actions, allowing the smart grid to improve the efficiency, reliability, economy, and sustainability of the production, and distribution of fuels, such as electricity, in an automated manner. A smart grid can also be viewed as another sensor network with low latency.

[0037] The health sector has many applications that can benefit from mobile communications. Communication systems can support telemedicine to provide clinical care over long distances. This helps reduce the barrier of distance and can improve access to medical services that are not sustainably available in remote rural areas. It can also be used to save lives in critical care and emergency situations. Mobile-based wireless sensor networks can provide remote monitoring and sensing for parameters such as heart rate and blood pressure.

[0038] Wireless and mobile communications are becoming more and more important in industrial applications. Wiring is expensive to install and maintain. The possibility to replace cables with reconfigurable wireless links is therefore an attractive opportunity in many industrial sectors. However, to achieve this it is required that the wireless connections operate with similar latency, reliability and capacity as cables, and to simplify their management. Low latency and very low error probability are new requirements that need to be addressed leading to 5G.

[0039] Logistics and freight tracking are important use cases for mobile communications that use location-based information systems to enable inventory and package tracking anywhere. Logistics and freight tracking use cases typically require low data rates, but require wide range and reliable location information.

[0040] DRX (Discontinuous Reception) operation

[0041] In order to reduce power consumption, the UE uses Discontinuous Reception (DRX) in the RRC_IDLE and RRC_INACTIVE states. When DRX is configured, the UE performs DRX operation according to DRX configuration information.

[0042] A UE that operates based on DRX repeatedly switches reception operation ON / OFF. For example, when DRX is set, the terminal attempts PDCCH reception / detection (e.g., PDCCH monitoring) only during a predetermined time interval (e.g., ON) and does not attempt PDCCH reception during the remaining time (e.g., OFF / Sleep).

[0043] At this time, the time during which the terminal attempts to receive the PDCCH is defined as On-duration, and On-duration is defined once per DRX cycle. The UE receives DRX setting information from the base station (e.g., gNB) by RRC signaling, and performs DRX operation by receiving the (Long) DRX command MAC CE.

[0044] On the other hand, the DRX configuration information is included in the MAC-CellGroupConfig IE, which is used to configure the MAC parameters for the cell group including the DRX.

[0045] DRX refers to an operation mode in which a UE (User Equipment) discontinuously receives / monitors a downlink channel to reduce battery consumption. That is, a UE configured for DRX reduces power consumption by discontinuously receiving downlink signals. DRX operation is performed in a DRX period indicating a time interval during which On Duration is periodically repeated. DRX includes On Duration and Sleep Duration (or Opportunity for DRX). On Duration indicates a time interval during which a terminal monitors a PDCCH to receive a PDCCH. DRX is performed in a Radio Resource Control (RRC)_IDLE state (or mode), an RRC_INACTIVE state (or mode), or an RRC_CONNECTED state (or mode). In the RRC_IDLE and RRC_INACTIVE states, DRX is used to discontinuously receive paging signals.

[0046] - RRC_Idle state: A state in which a radio connection (RRC connection) is not established between the base station and the terminal.

[0047] - RRC Inactive state: A wireless connection (RRC connection) is established between the base station and the terminal, but the wireless connection is inactive.

[0048] - RRC_Connected state: A state in which a wireless connection (RRC connection) is established between the base station and the terminal.

[0049] DRX is basically divided into IDLE mode DRX, Connected DRX (C-DRX) and enhanced DRX. DRX applied in the RRC IDLE state is called IDLE mode DRX, and DRX applied in the RRC CONNECTED state is called Connected mode DRX (C-DRX).

[0050] Extended / enhanced DRX (eDRX) is a mechanism that extends the cycles of IDLE mode DRX and C-DRX. Whether or not eDRX is permitted in IDLE mode DRX is set based on system information (e.g., SIB1).

[0051] SIB1 includes an eDRX-Allowed parameter, which indicates whether or not IDLE mode extended DRX is allowed.

[0052] (1) IDLE mode DRX

[0053] In IDLE mode, the UE uses DRX to reduce power consumption. A Paging Occasion (PO) is a time interval (e.g., slot or subframe) during which a P-RNTI (Paging-Radio Network Temporary Identifier)-based PDCCH is transmitted. The P-RNTI-based PDCCH addresses / schedules paging messages. In the case of a P-RNTI-based PDCCH transmission, the PO indicates the starting subframe for PDCCH repetition.

[0054] A paging frame (PF) is a radio frame that includes one or more paging occasions. If DRX is used, the UE is configured to monitor one PO per DRX period. The PF and / or PO are determined based on DRX parameters provided by network signaling (e.g., system information).

[0055] Hereinafter, 'PDCCH' refers to MPDCCH, NPDCCH and / or general PDCCH. Hereinafter, 'UE' refers to MTC UE, BL (Bandwidth Reduced Low Complexity) / CE (Coverage Enhanced) UE, NB-IoT UE, RedCap (RedCap) UE, general UE and / or IAB-MT (Mobile Termination).

[0056] FIG. 1 is a flow chart illustrating an example of a method for performing IDLE mode DRX operation.

[0057] The UE receives IDLE mode DRX setting information from the base station through higher layer signaling (eg, system information) (S110).

[0058] The UE also determines a paging frame (PF) and a paging occasion (PO) for monitoring the PDCCH in a paging DRX cycle based on the IDLE mode DRX configuration information (S120). In this case, the DRX cycle includes an On Duration and a Sleep Duration (or an Opportunity for DRX).

[0059] The UE also monitors the PDCCH in a PO of a given PF (S130). Meanwhile, the UE monitors only one time interval (PO) per paging DRX cycle. For example, the time interval is a slot or a subframe.

[0060] Also, if the UE receives a PDCCH (more precisely, a CRC of the PDCCH) scrambled by the P-RNTI during On Duration (i.e., if paging is detected), the UE transitions to a connected mode to transmit and receive data with the base station.

[0061] FIG. 2 is a diagram showing an example of IDLE mode DRX operation.

[0062] Referring to FIG. 2, when there is traffic (data) directed to a UE in an RRC_Idle state (hereinafter, referred to as an 'idle state'), paging occurs to the corresponding UE.

[0063] Therefore, the UE wakes up every (paging) DRX period to monitor the PDCCH.

[0064] If there is paging, the UE transitions to the Connected state to receive data, otherwise the UE re-enters the sleep mode.

[0065] (2) Connected mode DRX (C-DRX)

[0066] C-DRX is DRX applied in the RRC Connected state. The DRX cycle of C-DRX consists of a short DRX cycle and / or a long DRX cycle. The short DRX cycle is optional.

[0067] When C-DRX is configured, the UE performs PDCCH monitoring during On Duration. If a PDCCH is successfully detected during PDCCH monitoring, the UE operates (or executes) the Inactive Timer and maintains the Awake state. On the other hand, if no PDCCH is successfully detected during PDCCH monitoring, the UE enters the Sleep state after the On Duration ends.

[0068] When C-DRX is configured, PDCCH reception opportunities (e.g., slots having PDCCH search space / candidates) are set discontinuously based on the C-DRX configuration. On the other hand, when C-DRX is not configured, PDCCH reception opportunities (e.g., slots having PDCCH search space / candidates) are set continuously according to the configuration of the PDCCH search space. Meanwhile, PDCCH monitoring is limited by a time interval set as a measurement gap, regardless of the C-DRX configuration.

[0069] FIG. 3 is a flow chart illustrating an example of a method for performing a C-DRX operation.

[0070] The UE receives RRC signaling (e.g., MAC-MainConfig IE) including DRX configuration information from the base station (S310). The DRX configuration information includes the following information:

[0071] -on-duration: Duration during which the UE waits to receive the PDCCH after waking up. When the UE successfully decodes the PDCCH, the UE is awake and starts the drx-inactivityTimer.

[0072] -drx-onDurationTimer: The period when the DRX cycle starts. For example, this means the time period that should be continuously monitored at the start of the DRX cycle, and is expressed in ms.

[0073] -drx-InactivityTimer: Duration after a PDCCH opportunity corresponding to a PDCCH instructing a MAC entity to perform a new UL or DL ​​transmission. For example, the time period in ms after a UE decodes a PDCCH with scheduling information. That is, the period during which the UE waits to successfully decode another PDCCH after the last PDCCH has been decoded. If no other PDCCH is detected within the period, the UE transitions to a sleep mode.

[0074] The UE shall restart the drx-inactivityTimer after successful decoding of the PDCCH for the initial transmission only and not for retransmissions.

[0075] -drx-RetransmissionTimer: In case of DL, the maximum interval until DL retransmission is received. In case of UL, the maximum interval until acknowledgement for UL retransmission is received. For example, in case of UL, it is the number of slots for the BWP (Bandwidth part) in which the TB (Transport Block) to be retransmitted is transmitted, and in case of DL, it is the number of slots for the BWP in which the TB to be retransmitted is received.

[0076] -longDRX-Cycle: On Duration occurrence period

[0077] -drxStartOffset: Subframe number where the DRX cycle starts

[0078] -drxShortCycleTimer: Period during which the UE follows a short DRX cycle

[0079] -shortDRX-Cycle: When the Drx-InactivityTimer ends, the DRX cycle runs for the number of drxShortCycleTimer

[0080] -drx-SlotOffset: Delay before drx-onDurationTimer starts, expressed in ms, expressed as a multiple of 1 / 32ms.

[0081] Active Time: The total period 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-inactivityTimer has not expired, and (c) the time during which the UE performs continuous reception while waiting for a retransmission opportunity.

[0082] More specifically, when the DRX cycle is set, the Active Time for the serving cell of the DRX group includes the following times:

[0083] - (a) the drx-onDurationTimer or (b) the drx-InactivityTimer set for the DRX group.

[0084] -(c) drx-RetransmissionTimerDL or drx-RetransmissionTimerUL for all serving cells of the DRX group.

[0085] -(d)ra-ContentionResolutionTimer or msgB-ResponseWindow.

[0086] (e) A period in which a Scheduling Request is transmitted via a PUCCH and is pending; or

[0087] -(f) If, after successfully receiving a Random Access Response (RAR) for a random access proamble that is not selected by the MAC entity among contention-based random accesses, a PDCCH indicating a new transmission addressed by the MAC entity's C-RNTI is not received.

[0088] Also, when DRX 'ON' is set by a 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).

[0089] FIG. 4 is a diagram illustrating an example of the C-DRX operation.

[0090] Referring to FIG. 4, when a UE receives scheduling information (eg, DL assignment or UL grant) in an RRC_Connected state (hereinafter referred to as the Connected State), the UE executes a DRX Inactivity Timer and an RRC Inactivity Timer.

[0091] After the DRX Inactivity Timer expires, the DRX mode is started. The UE wakes up from the DRX cycle and monitors the PDCCH for a predetermined time (on duration timer).

[0092] In this case, if Short DRX is configured, when the UE starts the DRX mode, the UE starts the short DRX cycle first, and starts the long DRX cycle after the short DRX cycle ends. In this case, the long DRX cycle is a multiple of the short DRX cycle. That is, the UE wakes up more frequently with the short DRX cycle. After the RRC Inactivity Timer expires, the UE transitions to the Idle state and performs IDLE mode DRX operation.

[0093] Figure 5 shows the DRX cycle. C-DRX operation is introduced to save power of the UE. If the UE does not receive a PDCCH within the on-duration defined for each DRX cycle, it enters sleep mode and does not transmit / receive until the next DRX cycle.

[0094] On the other hand, when the UE receives the PDCCH on-duration, the Active Time continues (or increases) based on the operation of the inactivity timer, retransmission timer, etc. If the UE does not receive additional data within the Active Time, it performs a sleep operation until the next DRX operation.

[0095] NR introduces a wake up signal (WUS) to obtain additional power saving benefits from the existing C-DRX operation. The WUS is used to inform the UE whether or not to monitor the PDCCH during the on-duration of each DRX cycle (or multiple DRX cycles). If the UE does not detect the WUS at a given or indicated WUS occasion, it does not monitor the PDCCH during one or multiple DRX cycles associated with the WUS and maintains sleep operation.

[0096] (3) Wake Up signal (DCI Format 2_6)

[0097] In the power saving technology of the Rel-16 NR system, when DRX operation is performed, the terminal can be notified of whether to wake up each DRX cycle by DCI Format 2_6.

[0098] Referring to Figure 6, the PDCCH monitoring occasion for DCI Format 2_6 is determined by the ps-Offset specified by the network and the time gap reported by the terminal. In this case, the time gap reported by the terminal can be interpreted as a preparation period required for operation after the terminal is started.

[0099] 6, the base station instructs the terminal to set a search space (SS) set for monitoring DCI Format 2_6. In the corresponding SS set setting, the base station instructs the terminal to monitor DCI Format 2_6 through consecutive slots of the length of the interval at an interval of a monitoring periodicity.

[0100] In the DRX setting, the monitoring window for monitoring DCI Format 2_6 is determined by the start point of the DRX cycle (e.g., when the on-duration timer starts) and the ps-Offset set by the base station. In addition, PDCCH monitoring may not be required in the time gap interval reported by the terminal. Finally, the monitoring opportunity of the SS Set that the terminal actually monitors is determined to be the first full duration (i.e., the actual monitoring opportunity in FIG. 6) in the monitoring window.

[0101] When the terminal detects DCI Format 2_6 in the monitoring window set based on the ps-Offset, the base station instructs the terminal whether or not to activate it in the future DRX cycle.

[0102] PDCCH monitoring adaptation

[0103] The NR standard defines SS Set Group switching and PDCCH monitoring skipping as methods for reducing UE power consumption, and these SS Set Group switching and PDCCH monitoring skipping are collectively defined as PDCCH monitoring adaptation.

[0104] (1) Search Space Set(SS Set) group Switching

[0105] The current NR standard defines SS Set Group switching as a method to reduce power consumption of a terminal. In SS Set Group switching, multiple SS Set Groups are configured in the terminal, and the SS Set Group to be monitored by the terminal is specified among the multiple SS Set Groups. The terminal monitors the SS Sets included in the corresponding SS Set Group according to the specified command, and omits monitoring of SS Sets not included in the corresponding SS Set Group.

[0106] For example, 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 is provided to the terminal. In addition, when the list of SS Set Groups is provided, the terminal monitors the SS Set corresponding to group index #0.

[0107] Meanwhile, the terminal performs SS Set Group switching depending on whether SearchSpaceSwitchTrigger is set or not.

[0108] If SearchSpaceSwitchTrigger is set in the terminal, the terminal switches the SS Set Group according to the instruction of DCI Format 2_0.

[0109] For example, if the value of the SS Set Group Switching flag field in DCI Format 2_0 is 0, the terminal starts monitoring SS Set Group #0 a certain period of time after receiving DCI Format 2_0 and stops monitoring SS Set Group #1.

[0110] Furthermore, if the value of the SS Set Group Switching flag field in DCI Format 2_0 is 1, the terminal starts monitoring SS Set Group #1 a certain time after receiving DCI Format 2_0 and stops monitoring SS Set Group #0. If the terminal starts monitoring SS Set Group #1, it starts counting the timer set by SearchSpaceSwitchTimer. If the timer expires, the terminal starts monitoring SS Set Group #0 a certain time after the timer expires and stops monitoring SS Set Group #1.

[0111] If SearchSpaceSwitchTrigger is not set in the terminal, the terminal changes the SS Set Group when receiving DCI. For example, if the terminal receives DCI while monitoring SS Set Group #0 (or SS Set Group #1), the terminal starts monitoring SS Set Group #1 (or SS Set Group #0) a certain time after receiving the DCI, and stops monitoring SS Set Group #0 (or SS Set Group #1). At this time, the terminal starts counting the timer set by SearchSpaceSwitchTimer. If the timer expires, the terminal starts monitoring SS Set Group #0 (or SS Set Group #1) a certain time after the timer expires, and stops monitoring SS Set Group #1 (or SS Set Group #0).

[0112] On the other hand, as described above, the terminal starts monitoring SS Set Group #0 (or SS Set Group #1) a certain time after receiving DCI Format 2_0. At this time, after the certain time, the terminal starts monitoring SS Set Group #0 (or SS Set Group #1) from the last symbol of the PDCCH including the received DCI. switch This means that monitoring of SS Set Group #0 (or SS Set Group #1) starts from the first slot (or applicable slot boundary) after symbols. Or, after a certain period of time according to the SCS, monitoring of SS Set Group #0 (or SS Set Group #1) starts from the last symbol of the PDCCH including the received DCI for at least P switch This means that the UE starts monitoring SS Set Group #0 (or SS Set Group #1) from the first slot in a specific slot group after symbols. This is because it takes a certain amount of time for the UE to decode the DCI, confirm the SS Set Group switching instruction, and actually perform the SS Set Group switching operation.

[0113] At this time, P switch is set by RRC signaling. Also, the minimum P is determined based on the minimum SCS(u) of all DL BWP SCSs (Subcarrier Spacings) set in the UE's capability and the serving cell (or a set of serving cells). switch The values ​​are defined as in Table 1 below.

[0114] [Table 1]

[0115] (2) PDCCH monitoring skipping

[0116] Currently, the NR standard defines PDCCH monitoring skipping as a method for reducing power consumption of a terminal. A plurality of PDCCH monitoring skipping intervals are configured in a terminal by an RRC parameter. In this case, the plurality of PDCCH monitoring skipping intervals are configured in slot units. Any one of a plurality of PDCCH monitoring skipping intervals is indicated to the terminal by DCI, and the terminal can skip PDCCH monitoring during the corresponding interval. Meanwhile, the DCI indicating the PDCCH monitoring skipping interval may indicate not to perform PDCCH monitoring skipping (i.e., no PDCCH monitoring skipping). If the PDCCH monitoring adaptation field of the DCI indicates to skip PDCCH monitoring during a specific interval, the terminal performs PDCCH monitoring skipping from the beginning of the first slot after the last symbol of the PDCCH reception including the corresponding DCI.

[0117] (3) Combination of SS Set Group Switching and PDCCH Monitoring Skipping

[0118] When multiple SS Set Groups and multiple PDCCH monitoring skipping intervals are configured for a terminal through the RRC layer, the terminal receives DCI including a PDCCH monitoring adaptation field and performs SS Set Group switching or PDCCH monitoring skipping according to the corresponding PDCCH monitoring adaptation field value.

[0119] For example, depending on whether multiple SS Set Groups are configured and / or whether multiple PDCCH monitoring skipping intervals are configured, each value set in the PDCCH monitoring adaptation field is mapped to one SS Set Group or one PDCCH monitoring skipping interval.

[0120] When the terminal receives the PDCCH monitoring adaptation field, the terminal performs switching to an SS Set Group corresponding to the corresponding PDCCH monitoring adaptation field value, or stops PDCCH monitoring during a PDCCH monitoring skipping interval corresponding to the corresponding PDCCH monitoring adaptation field value.

[0121] On the other hand, when a terminal receives DCI including a PDCCH monitoring adaptation field indicating PDCCH monitoring skipping in a particular slot, the terminal does not expect a value different from the PDCCH monitoring adaptation field value included in the previously received DCI to be indicated in the same particular slot.

[0122] In addition, when the terminal receives DCI including a PDCCH monitoring adaptation field instructing SS Set Group switching in a specific slot, the terminal switch In the slot before the symbol, it is not expected that a value different from the PDCCH monitoring adaptation field value included in the DCI received in the specific slot is indicated. That is, the terminal does not expect at least P switch It is expected that a value different from the PDCCH monitoring adaptation field value included in the DCI received in a particular slot will be indicated in the slot following the symbol.

[0123] Meanwhile, the embodiment described below is applied to, for example, XR. XR (Extended Reality) is a concept that includes AR (Augmented Reality), VR (Virtual Reality), and MR (Mixed Reality). The feature of XR is that the time when traffic can be expected to be received is fixed by fps (frame per second), and traffic may be received later or earlier than the expected time due to the influence of jitter. The jitter of such XR traffic is represented by a truncated Gaussian probability distribution. Therefore, the effect of power saving can be expected by periodically setting DRX according to fps. Also, even if DRX is not set, if PDCCH monitoring adaptation is set, the effect of power saving can be expected only with PDCCH monitoring adaptation. Of course, the effect of power saving can be expected by setting both DRX and PDCCH monitoring adaptation.

[0124] The expected traffic reception time and the expected reception time due to the influence of jitter can be expressed as a probability, and the embodiment described below is applied to expect the effect of power saving in the XR environment as described above.

[0125] For example, at a time point relatively far from the expected traffic reception time, the probability of jitter is low and the reception probability is low, so the UE can sparsely monitor the PDCCH to save power. Conversely, at a time point close to the expected traffic reception time, the probability of jitter is high and the reception probability is high, so the UE can densely monitor the PDCCH to adjust power consumption according to the reception probability. For this purpose, SS Set Group #0 can be set as an SS Set Group including an SS Set for dense PDCCH monitoring, and SS Set Group #1 can be set as an SS Set Group including an SS Set for sparse PDCCH monitoring. In other words, the SS Set Group switching operation is set in consideration of jitter in XR.

[0126] In another example, the terminal may repeat the operation of monitoring the PDCCH during a short period where the probability of jitter is high and the probability of receiving traffic is high, and then going into micro-sleep. In this way, if traffic is not normally received, the terminal may quickly go into micro-sleep to save power, and may then monitor the PDCCH to receive traffic to be transmitted again in the future, thereby improving the efficiency of PDCCH monitoring. In other words, the operation of skipping PDCCH monitoring is set in consideration of jitter in XR.

[0127] In the Rel-18 NR standard, various scenarios and candidate technologies are being discussed to support XR services (e.g., FS_NR_XR_enh). XR services generally must meet the requirements of high data rates and low latency. In addition, since high power consumption of terminals is expected, various techniques for power saving are being considered.

[0128] The traffic model and requirements for XR services are defined in 3GPP TR 38.838, a technical report for the Rel-17 XR study. XR services generally require 60 fps (frames per second), and may require 120 fps. A frame in the XR traffic model can be understood as a packet received in a communication environment. Along with the occurrence of periodic traffic, jitter can occur for various reasons. Here, jitter means that a packet is received earlier or later than the expected packet reception time.

[0129] In the traffic model of the XR service, it is assumed that the jitter follows a truncated Gaussian distribution. For example, referring to FIG. 7, when the periodic packet reception time is T, the range in which the actual packet is received is [Tj, T+j] (e.g., j=4). In this case, the closer to T, the higher the probability of the packet being received, and the farther from T, the lower the probability of the packet being received. In this case, the range of the jitter is [-j, j] (e.g., j=4), which is a range generally assumed in a single stream DL traffic model. Therefore, in order to expect the effect of power saving by DRX operation in the XR service, it is necessary to design the system taking into account the jitter in addition to the transmission and reception of periodic traffic.

[0130] Meanwhile, as a method for saving power of a terminal supporting an XR service, DRX operation and PDCCH monitoring adaptive operation are considered.

[0131] In NR, the features of DRX used to reduce unnecessary power consumption of the terminal are as follows: DRX is defined in structures for terminals in the RRC_IDLE state and for terminals in the RRC_CONNECTED state, and both DRX structures are designed to reduce unnecessary power consumption in other periods by defining the period during which the terminal can expect to receive DL signals to occur periodically. Specifically, in the case of C-DRX (e.g., DRX applied to a terminal in the RRC_CONNECTED state), the start position of on-duration occurs periodically based on the NR Rel-16 standard, and the size of the configured period (e.g., DRX cycle) is determined by higher layer parameters provided by the base station to the terminal.

[0132] Meanwhile, the PDCCH monitoring adaptation operation refers to an operation of adjusting the number of times the UE monitors the PDCCH (generally, reducing the number of times the UE monitors the PDCCH).

[0133] A maximum of 10 SS (Search Space) Sets are configured for each BWP in a terminal, and the terminal can monitor PDCCH candidates included in the SS Set (hereinafter, referred to as SS Set monitoring).

[0134] Since a terminal performs blind decoding (BD) on a PDCCH without knowing at what time and in what DCI format it will be received, PDCCH monitoring accounts for a large proportion of power consumption.

[0135] Examples of PDCCH monitoring adaptation include PDCCH monitoring skipping (hereinafter, referred to as "skipping") and SS Set Group switching (hereinafter, referred to as "switching").

[0136] PDCCH monitoring skipping refers to interrupting PDCCH monitoring for a certain period (e.g., a PDCCH monitoring skipping period), dividing the SS Set for which SSSG (Search Space Set group) switching is set into a number of groups, instructing switching to one of the groups according to the purpose of use, and monitoring the SS Set included in the corresponding group.

[0137] Meanwhile, in this disclosure, for convenience of explanation, SSSGs are divided into SSSG#0 and SSSG#1, where SSSG#0 is an SSSG that includes a relatively large number of SS sets or includes SS sets with a relatively short period in order to increase the number of PDCCH monitoring operations when the expected amount of data transmission is large, and SSSG#1 is an SSSG that includes a relatively small number of SS sets or includes SS sets with a relatively long period in order to reduce the number of PDCCH monitoring operations for the purpose of power saving.

[0138] That is, SSSG Switching means that the terminal stops monitoring an SS Set currently included in a specific SSSG and starts monitoring an SS Set included in another SSSG.

[0139] This disclosure proposes a method in which a PDCCH monitoring adaptive pattern is indicated / set so that a terminal adjusts the number of PDCCH monitoring times to reduce power consumption while receiving an XR packet without problems, thereby performing PDCCH monitoring. DCIs indicating the method proposed in this disclosure include DCI Format 2_6 that can be used as a WUS (Wake-Up Indication Signal) in a DRX cycle in addition to a scheduling DCI. In addition, the method proposed in this disclosure can also be indicated by a non-scheduling DCI that is not currently used and a new DCI introduced for the proposed method.

[0140] On the other hand, although this disclosure proposes an XR service as an example, the proposed method can be applied to any communication service in which periodic transmission is scheduled.

[0141] In this disclosure, a PDCCH monitoring adaptation pattern is defined, which indicates a period during which a terminal monitors the PDCCH, a period during which the terminal stops monitoring the PDCCH, and / or a period during which the terminal reduces the frequency of monitoring the PDCCH. Also, a method is proposed in which a PDCCH monitoring adaptation pattern is instructed / configured to a terminal, and the terminal monitors the PDCCH according to the instructed / configured PDCCH monitoring adaptation pattern.

[0142] Due to the influence of jitter, the XR packet is probabilistically received early or late based on a fixed expected reception time point. Taking this into consideration, the terminal monitors the PDCCH to receive the XR packet at a specific time point. If the PDCCH is not detected, the terminal repeats the operation of saving power by micro-sleep to reduce the number of times to monitor the PDCCH while not missing the reception of the XR packet. This is defined as a PDCCH monitoring pattern. This disclosure also proposes a method for setting / indicating a PDCCH monitoring pattern.

[0143] Meanwhile, this disclosure considers both cases where DRX operation is set and where it is not set to support XR services in the terminal.

[0144] In the following, the method proposed in this disclosure will be described based on the XR service that requires periodic reception, but is not limited thereto. For example, a person skilled in the art can easily deduce that the method can be extended to all signals that a terminal receives with a certain periodicity.

[0145] Therefore, the method proposed in this disclosure can be applied to all types of transmission and reception methods expected by a base station and a terminal without any special description, as long as the principles of this disclosure are not violated. Hereinafter, in this disclosure, for convenience of explanation, the term DRX is used as a general concept including C-DRX.

[0146] In addition, in this disclosure, an example is given based on an NR system to explain the principles of this disclosure, but the proposed method is not limited to a specific NR transmission / reception format unless otherwise specified. In addition, in this disclosure, an example is given based on the characteristics and structure of a terminal supporting C-DRX to explain the principles of this disclosure, but the proposed method is not limited to a terminal supporting C-DRX unless otherwise specified. Therefore, the method proposed in this disclosure can be applied to all wireless communication transmission / reception structures and services without any special description, as long as it does not violate the principles of this disclosure.

[0147] In the following description, the classification of each method or option is for the purpose of clarifying the description, and should not be interpreted as limiting the meaning that each method or option is necessarily implemented in an independent manner. For example, the methods / options described below may be implemented individually, or may be implemented in at least some combination within a range that does not contradict each other.

[0148] Meanwhile, in the proposed method and description of this disclosure, unless otherwise specified, a packet means a packet of the XR service, and a packet in this disclosure is a PDSCH (Physical Downlink Shared Channel) related to traffic or a transport block transmitted for the XR service.

[0149] 8 to 10 are diagrams for explaining the overall operation process of a terminal and a base station according to [Method 1] of this disclosure.

[0150] FIG. 8 shows the overall operation process of the terminal according to [Method 1].

[0151] 8, the UE reports performance information including information related to a PDCCH monitoring adaptation pattern to the base station (S801). At this time, the information related to the PDCCH monitoring adaptation pattern includes whether or not PDCCH monitoring adaptation such as PDCCH monitoring skipping and SSSG switching is supported.

[0152] The terminal receives at least one information for a DRX operation and / or a PDCCH monitoring adaptation pattern determined based on its capability information and / or a PDCCH monitoring adaptation pattern supporting the XR service (S803), where the at least one information is received via a higher layer (e.g., RRC signaling) and / or a PDCCH.

[0153] The terminal receives a first PDCCH associated with a PDCCH monitoring adaptation pattern (S805). The terminal also monitors a second PDCCH based on the first PDCCH and receives a PDSCH (e.g., an XR packet) (S807). On the other hand, if only one PDCCH monitoring adaptation pattern is set in S803, S805 is omitted and the second PDCCH is monitored based on the PDCCH monitoring adaptation pattern set in S803. When the second PDCCH is detected, the terminal also receives a PDSCH (e.g., an XR packet) based on the second PDCCH.

[0154] Meanwhile, detailed operations of S803 to S807 are based on [Method 1-1] and / or [Method 1-2]. In addition, the UE can reduce unnecessary PDCCH monitoring while normally receiving the scheduled XR packet, thereby reducing power consumption.

[0155] FIG. 9 shows the overall operation process of a base station according to [Method 1].

[0156] 9, a base station receives performance information including information related to a PDCCH monitoring adaptation pattern from a terminal (S901). At this time, the information related to the PDCCH monitoring adaptation pattern includes whether or not PDCCH monitoring adaptation such as PDCCH monitoring skipping and SSSG switching is supported.

[0157] The base station determines a DRX operation and / or a PDCCH monitoring adaptation pattern based on the terminal's performance information and / or a PDCCH monitoring adaptation pattern supporting the XR service, and transmits at least one piece of information for the determined DRX operation and / or PDCCH monitoring adaptation pattern (S903). At this time, the at least one piece of information is transmitted by a higher layer (e.g., RRC signaling) and / or a PDCCH.

[0158] The base station transmits a first PDCCH associated with the PDCCH monitoring adaptation pattern (S905). The base station also transmits a second PDCCH and a PDSCH (e.g., an XR packet) based on the first PDCCH (S907). On the other hand, if only one PDCCH monitoring adaptation pattern is set in S903, S905 is omitted, and a second PDCCH is transmitted based on the PDCCH monitoring adaptation pattern set in S903. The base station also transmits a PDSCH (e.g., an XR packet) based on the second PDCCH.

[0159] Meanwhile, detailed operations of S903 to S907 are based on [Method 1-1] and / or [Method 1-2]. In addition, the base station can reduce unnecessary PDCCH transmissions while normally transmitting scheduled XR packets, thereby reducing power consumption.

[0160] FIG. 10 shows the overall operation process of the network according to [Method 1].

[0161] 10, a terminal reports performance information including information related to a PDCCH monitoring adaptation pattern to a base station (S1001). At this time, the information related to the PDCCH monitoring adaptation pattern includes whether or not PDCCH monitoring adaptation such as PDCCH monitoring skipping and SSSG switching is supported.

[0162] The base station determines a DRX operation and / or a PDCCH monitoring adaptation pattern based on the terminal's performance information and / or a PDCCH monitoring adaptation pattern supporting the XR service, and transmits at least one piece of information for the determined DRX operation and / or PDCCH monitoring adaptation pattern (S1003). At this time, the at least one piece of information is transmitted by a higher layer (e.g., RRC signaling) and / or a PDCCH.

[0163] The base station transmits a first PDCCH associated with the PDCCH monitoring adaptation pattern (S1005). The base station also transmits a second PDCCH and a PDSCH (e.g., an XR packet) based on the first PDCCH. The terminal also monitors the second PDCCH based on the first PDCCH and receives a PDSCH (e.g., an XR packet) (S1007). On the other hand, if only one PDCCH monitoring adaptation pattern is set in S1003, S1005 is omitted and the second PDCCH is transmitted based on the PDCCH monitoring adaptation pattern set in S1003. The base station also transmits a PDSCH (e.g., an XR packet) based on the second PDCCH.

[0164] Meanwhile, detailed operations of S1003 to S1007 are based on [Method 1-1] and / or [Method 1-2]. In addition, the base station and the terminal can reduce unnecessary PDCCH transmissions while normally transmitting and receiving scheduled XR packets, thereby reducing power consumption.

[0165] [Method 1] Method of setting / instructing PDCCH monitoring adaptation pattern to terminal with DRX configured

[0166] After the terminal starts the drx-onDurationTimer, a PDCCH monitoring adaptation pattern is indicated. The PDCCH monitoring adaptation pattern is indicated by a wake-up signal (WUS) or a DCI that can be detected at the same time or close to the time when the WUS is detected. For example, the PDCCH monitoring adaptation pattern is indicated by a DCI detected in a monitoring occasion (e.g., DCP (DCI Format 2_6 with CRC scrambled by PS-RNTI occasion) in which the WUS can be detected, or a DCI received within a certain interval (e.g., x ms or y symbols) from the corresponding monitoring occasion. In addition, the PDCCH monitoring adaptation pattern is indicated by a scheduling DCI or a new DCI format after the start of the DRX Active Time. Alternatively, the PDCCH monitoring adaptation pattern is predetermined so that the PDCCH monitoring adaptation pattern is performed simultaneously with the start of the DRX Active Time according to a setting of a higher layer.

[0167] [Method 1-1] PDCCH monitoring adaptation pattern including PDCCH monitoring skipping

[0168] The UE starts drx-onDurationTimer and is instructed to monitor the PDCCH according to a PDCCH monitoring adaptation pattern including PDCCH monitoring skipping. For example, referring to FIG. 11(a), the PDCCH monitoring adaptation pattern is an operation of repeating PDCCH monitoring and PDCCH monitoring skipping at a certain period. From the viewpoint of PDCCH monitoring of the UE, this is similar to repeatedly starting a short DRX Active Time. The difference is that the PDCCH monitoring of the UE is not controlled by the DRX Timer, but the DRX Active Time is continued while the PDCCH monitoring adaptation instruction ensures the micro-sleep of the UE. FIG. 11(a) shows an example of such a PDCCH monitoring adaptation pattern.

[0169] Since the base station and the terminal commonly know the PDCCH monitoring adaptation pattern, the base station transmits an XR packet and / or a PDCCH for scheduling an XR packet at the time when the terminal monitors the PDCCH. If the terminal does not detect a PDCCH during a short PDCCH monitoring period, the terminal repeats an operation of skipping PDCCH monitoring, thereby reducing the number of times the terminal monitors the PDCCH in terms of the entire DRX Active Time, and thus can be expected to have an effect of saving the terminal's power.

[0170] (1) Terminal operation when DRX Active Time is announced

[0171] The terminal monitors the PDCCH for a certain duration (hereinafter, the first duration) after the start of the drx-onDurationTimer, and skips the PDCCH monitoring for another certain duration (hereinafter, the second duration) after the certain duration. As can be seen from FIG. 11(a), the terminal repeats the operation of monitoring the PDCCH for the first duration and skipping the PDCCH monitoring for the second duration. Meanwhile, the above-mentioned first and second durations are each set in time units such as ms, slots, or symbols, or set as a ratio to the entire drx-onDurationTimer.

[0172] (2) Operation of the terminal when detecting the PDCCH in the PDCCH monitoring period (first period in (1))

[0173] When the terminal detects the PDCCH in the period in which the terminal monitors the PDCCH (i.e., the first period in (1)), the terminal can perform the following five operations (i.e., 1) to 5). Each operation can be applied independently or in combination.

[0174] 1) Referring to FIG. 11(a), when the terminal detects the PDCCH, it starts the drx-InactivityTimer. During the drx-InactivityTimer period, the terminal does not skip the PDCCH monitoring and always monitors the PDCCH. That is, while the drx-onDurationTimer is running, the terminal monitors the PDCCH according to the specified / set PDCCH monitoring adaptive pattern operation, and always monitors the PDCCH while the drx-InactivityTimer is running. Meanwhile, for a period where the drx-InactivityTimer and the drx-onDurationTimer overlap, the operation according to the drx-InactivityTimer takes precedence. For example, during a period where the drx-InactivityTimer and the drx-onDurationTimer overlap, the terminal always monitors the PDCCH.

[0175] 2) Referring to FIG. 11(b), when the terminal detects the PDCCH, the drx-InactivityTimer is started. During the drx-InactivityTimer period, the terminal does not skip the PDCCH monitoring and always monitors the PDCCH. At this time, the length of the drx-InactivityTimer period is set to be limited to the length of the currently remaining drx-onDurationTimer. For example, if the drx-onDurationTimer is 8 ms and the terminal detects the PDCCH at 3 ms, the length of the drx-InactivityTimer period is 5 ms. From the perspective of the entire DRX, the drx-InactivityTimer is started at the midpoint of the drx-onDurationTimer, and the drx-onDurationTimer and the drx-InactivityTimer end at the same time.

[0176] 3) drx-InactivityTimer is not set in the terminal. Also, from the time when the terminal detects the PDCCH, the terminal does not skip PDCCH monitoring during the remaining drx-onDurationTimer period and always monitors the PDCCH. That is, 3) is the same as 2) in terms of the terminal's PDCCH monitoring, but there may be differences in timer settings for implementation.

[0177] 4) If the terminal detects the PDCCH, the current DRX cycle ends or PDCCH monitoring skipping is performed for the remaining DRX Active Time.

[0178] 5) When the terminal detects the PDCCH, the drx-InactivityTimer is started. Also, during the drx-InactivityTimer period, the terminal can monitor the PDCCH according to the PDCCH monitoring adaptation indicated via the detected PDCCH. If no special instruction is given, the general PDCCH monitoring operation is performed. Also, for the period where the drx-InactivityTimer and the drx-onDurationTimer overlap, one of the two timers is indicated / set to have priority.

[0179] Each of the above operations 1) to 5) has advantages and disadvantages in terms of power consumption due to PDCCH monitoring of the UE and reception of additional XR packets in the current DRX cycle.

[0180] In the case of 1), the operation is the same as the DRX timer set in a typical NR UE. In this case, the drx-InactivityTimer is used to guarantee a PDCCH monitoring skipping period for a certain period after the UE receives DCI scheduling an XR packet.

[0181] In the cases of 2) and 3), even if the terminal detects the PDCCH, the length of the DRX Active Time is not increased, and a certain period of PDCCH monitoring skipping is indicated. Since the XR traffic is scheduled to be transmitted periodically, the purpose is to reduce power consumption by skipping the PDCCH monitoring and ending the DRX Active Time until the next period after receiving the XR traffic. In this case, it can be assumed that there is no problem with packets other than XR packets being transmitted after waiting until the next DRX cycle.

[0182] In the case of 4), since the purpose of the current DRX cycle, which is to completely receive the XR packet, is achieved, the PDCCH monitoring in the corresponding DRX cycle is stopped after the XR packet is quickly received. In this case, the effect of power saving can be maximized, and as mentioned in 3), packets other than the XR packet may be transmitted after waiting until the next DRX cycle.

[0183] In the case of 5), the terminal performs PDCCH monitoring and PDCCH monitoring adaptation instruction operation in general DRX Active Time, not the PDCCH monitoring adaptation pattern in DRX Active Time, during the drx-InactivityTimer period. Meanwhile, the terminal monitors the PDCCH according to the priority order in the period where the drx-InactivityTimer and the drx-onDurationTimer overlap. For example, if the drx-onDurationTimer has priority, the terminal monitors the PDCCH according to the PDCCH monitoring adaptation pattern during the overlapping period. On the other hand, if the drx-InactivityTimer has priority, the terminal always monitors the PDCCH during the overlapping period, or performs the PDCCH monitoring adaptation operation instructed by the PDCCH that operated the drx-InactivityTimer.

[0184] (3) Setting examples

[0185] As described in relation to FIG. 7, jitter occurs due to a truncated Gaussian distribution. Therefore, the actual reception time of the XR packet is determined probabilistically from the expected reception time. In order to reduce power consumption, the terminal performs PDCCH monitoring in a specific range where the probability of receiving the XR packet is relatively high, rather than in the entire range where the XR packet is received.

[0186] For example, the first PDCCH monitoring period in FIG. 11(a) is determined by the above-mentioned truncated Gaussian distribution. That is, the length of the corresponding PDCCH monitoring period is determined taking into consideration the jitter size of the XR traffic model. If the terminal cannot detect the PDCCH in the first PDCCH monitoring period, it stops monitoring the PDCCH to reduce power consumption. If the terminal detects the PDCCH in the PDCCH monitoring period, it receives the scheduled PDSCH in the future and transmits a HARQ-ACK in response thereto, thereby completing the procedure. It can be known that the base station transmits an XR packet but the terminal fails to receive the XR packet in the PDCCH monitoring period because the base station cannot receive the HARQ-ACK. Therefore, the base station determines the length of the PDCCH monitoring skipping period taking into consideration the associated scheduling offset, HARQ-ACK timing, and / or HARQ RTT (Round Trip Time) time.

[0187] The base station sets a PDCCH monitoring adaptation pattern consisting of the length of the PDCCH monitoring interval and the length of the PDCCH monitoring skipping interval in the terminal, and the terminal can monitor the PDCCH according to the PDCCH monitoring adaptation pattern at the same time as the DRX Active Time starts.

[0188] Alternatively, multiple PDCCH monitoring adaptation patterns are configured by RRC signaling and / or MAC signaling, and one of them is indicated to the terminal by DCI. When multiple PDCCH monitoring adaptation patterns are configured, one PDCCH monitoring adaptation pattern including the lengths of one or more PDCCH monitoring intervals and the lengths of one or more PDCCH monitoring skipping intervals is indicated to the terminal by WUS (or similar DCI). For example, a PDCCH monitoring adaptation pattern including an interval with a relatively long PDCCH monitoring interval and an interval with a relatively short PDCCH monitoring interval is configured to the terminal. When it is necessary to save power of the terminal, the base station configures and indicates a PDCCH monitoring adaptation pattern so that the length of the PDCCH monitoring interval is shortened for intervals other than the interval in which the probability of transmitting at the expected time of receiving the original XR packet is higher than a certain value. In addition, when accurate XR packet reception by the terminal is required, the base station configures and instructs a PDCCH monitoring adaptive pattern to lengthen the length of the PDCCH monitoring period for a period where the probability of transmitting at the expected time of receiving the original XR packet is higher than a certain value.

[0189] Or, the PDCCH monitoring adaptive pattern of the terminal is fixed and set, and only wake-up indication is indicated by the WUS. That is, the PDCCH monitoring adaptive pattern is fixed, and the wake-up indication indicates to the terminal whether to perform the corresponding PDCCH monitoring adaptive pattern. In this case, the wake-up indication is not indicated for the entire DRX cycle, but indicates which PDCCH monitoring period (corresponding period is in ms, slots, or symbols) in the DRX cycle to wake up.

[0190] According to [Method 1-1], by applying a PDCCH monitoring adaptation pattern according to the DRX Active Time interval according to the DRX setting, the terminal can efficiently receive XR packets while improving the power saving effect. In addition, the PDCCH monitoring interval and the PDCCH monitoring skipping interval can be appropriately adjusted according to the XR packet scheduling needs of the base station, so that both the purpose of power saving and the stability of traffic reception can be achieved. In addition, the PDCCH monitoring adaptation operation is instructed in a pattern form, and the PDCCH monitoring adaptation for a long interval is changed and operated by one instruction, thereby improving the efficiency of signaling.

[0191] [Method 1-2] PDCCH monitoring adaptation pattern including SSSG (Search Space Set Group) switching

[0192] The terminal is instructed to start drx-onDurationTimer and monitor the PDCCH according to a PDCCH monitoring adaptation pattern including SSSG switching. For example, referring to FIG. 12(a), when two SSSGs are configured in the terminal, they are configured as a sparse SSSG (i.e., an SSSG with a low PDCCH monitoring frequency) and a dense SSSG (i.e., an SSSG with a high PDCCH monitoring frequency), respectively. FIG. 12(a) is an example of such a PDCCH monitoring adaptation pattern, and shows that switching between the sparse SSSG and the dense SSSG is repeated. From the viewpoint of the PDCCH monitoring of the terminal, only the frequency of PDCCH monitoring is changed to a constant period while maintaining the DRX Active Time.

[0193] In another example, a PDCCH monitoring adaptation pattern including SSSG switching and PDCCH monitoring skipping at the same time is configured as shown in Figures 12(b) and 12(c). Referring to Figure 12(b), the terminal repeats sparse SSSG monitoring, dense SSSG monitoring, sparse SSSG monitoring, and PDCCH monitoring skipping. Meanwhile, each SSSG switching and PDCCH monitoring skipping is set by an SSSG switching timer and a PDCCH monitoring skipping duration. In the Rel-17 NR standard, since a timer is not set for SSSG#0, a timer for SSSG#0 may be further defined and set.

[0194] 1201 in FIG. 12(b) shows a truncated Gaussian distribution of jitter (e.g., reception probability distribution of XR packet) for reference. According to the PDCCH monitoring adaptation pattern of the terminal, the terminal performs sparse PDCCH monitoring in a section where the probability of jitter is low, performs dense PDCCH monitoring in a section where the probability of jitter is high, and then performs PDCCH monitoring skipping operation (1202). This allows the terminal to receive XR packets more accurately and perform efficient PDCCH monitoring to maximize the effect of power saving.

[0195] Unlike the example of Fig. 12(b), referring to Fig. 12(c), the terminal performs dense PDCCH monitoring in a period where the probability of jitter is low, and performs sparse PDCCH monitoring in a period where the probability of jitter is high. Since the terminal is highly likely to be unable to detect the PDCCH in a period where the probability of receiving an XR packet is low, the PDCCH monitoring adaptive pattern may be set so that the terminal performs PDCCH monitoring more frequently.

[0196] (1) Terminal operation at the start of DRX Active Time

[0197] The terminal starts drx-onDurationTimer and performs PDCCH monitoring in sparse SSSG or dense SSSG. If the terminal cannot detect PDCCH until drx-onDurationTimer expires, it switches to a future set SSSG according to a PDCCH monitoring adaptation pattern or performs PDCCH monitoring skipping operation. The SSSG switching timer or PDCCH monitoring skipping interval is set in time units such as ms, slots, or symbols, respectively, or is set as a ratio to the entire drx-onDurationTimer.

[0198] (2) Terminal operation when detecting PDCCH in the PDCCH monitoring period

[0199] When the UE detects the PDCCH in the dense SSSG monitoring or sparse SSSG monitoring period, the UE may perform five different operations. Each operation may be applied independently or in combination. This is commonly applied regardless of the above-mentioned exemplary PDCCH monitoring adaptation pattern.

[0200] 1) When the terminal detects the PDCCH, it can reset the timer associated with the SSSG that it is currently monitoring. This is based on SSSG switching in the Rel-17 standard. When the reset timer expires, it performs the next scheduled action according to the PDCCH monitoring adaptation pattern.

[0201] 2) After the UE first detects a PDCCH within the DRX Active Time, the configured / instructed PDCCH monitoring adaptation pattern is terminated and switched to PDCCH monitoring in general DRX, i.e., switching to dense SSSG without a timer or switching to sparse SSSG and then timer-based SSSG switching are performed.

[0202] 3) Even if the terminal detects the PDCCH, the terminal does not reset the timer related to the SSSG that the terminal is currently monitoring. That is, the currently counting timer continues to count. In other words, the timer continues to operate for the remaining period from the time when the PDCCH was detected. Then, when the timer expires, the terminal performs the next operation according to the PDCCH monitoring adaptation pattern.

[0203] 4) When the terminal detects the PDCCH, it switches to the sparse SSSG. If the terminal is already monitoring the sparse SSSG, it resets the timer. Then, when the timer for the sparse SSSG expires, the terminal performs a PDCCH monitoring skipping operation. That is, the terminal performs SSSG switching and PDCCH monitoring skipping operations in a direction that decreases the PDCCH monitoring frequency (i.e., dense SSSG → sparse SSSG → PDCCH monitoring skipping). However, if the detected DCI is not for scheduling XR traffic, the terminal performs SSSG switching in a direction that increases the PDCCH monitoring frequency (i.e., PDCCH monitoring skipping → sparse SSSG → dense SSSG). This is because the terminal was unable to receive the XR packet it was trying to receive, and so increases the PDCCH monitoring frequency in order to receive the XR packet within the corresponding PDCCH monitoring period.

[0204] 5) If the scheduling DCI indicates PDCCH monitoring adaptation, the corresponding instruction can take precedence over all other operations.

[0205] Each of the above operations 1) to 5) has advantages and disadvantages in terms of power consumption due to PDCCH monitoring of the UE and reception of additional XR packets in the current DRX cycle. Generally, the operation on the PDCCH monitoring adaptation pattern is performed independently of the timer, and the operation on the PDCCH monitoring adaptation pattern is repeated as the DRX Active Time increases.

[0206] For example, the operation of 1) is an operation in which the terminal follows the Rel-17 SSSG switching operation while also following the indicated PDCCH monitoring adaptation pattern. For example, instead of switching to the default SSSG upon expiration of the SSSG switching timer, the terminal may perform the following operation on the PDCCH monitoring adaptation pattern.

[0207] In the operation of 2), the terminal performs the PDCCH monitoring adaptive pattern operation only before the first PDCCH detection to reduce power consumption, and after the PDCCH detection, performs the same DRX operation as the existing NR standard. If the PDCCH at this time is an XR packet scheduling DCI, the subsequent DRX operation is for receiving packets other than XR packets. In this case, a DRX timer such as drx-InactivityTimer is set relatively short to save power.

[0208] The operation of 3) always maintains the operation on the PDCCH monitoring pattern regardless of whether the PDCCH is detected or not. In this case, the drx-InactivityTimer does not need to be set. Also, the drx-onDurationTimer is set taking into account the packet delay budget of the XR traffic model.

[0209] In the operation of 4), the future SSSG switching operation is determined according to the PDCCH detected by the UE. If DCI related to reception of an XR packet in a general case is detected, the UE determines that reception of the expected XR packet in the current DRX cycle is completed. As a result, the UE performs SSSG switching to save power. In this case, the UE does not immediately stop monitoring the PDCCH, but gradually reduces the frequency of PDCCH monitoring so as to receive packets other than the XR packet that may occur. If the detected PDCCH is not related to an XR packet, the UE switches to increase the frequency of PDCCH monitoring in order to receive the expected XR packet in the current DRX cycle.

[0210] Meanwhile, in order to know whether the detected DCI is related to an XR packet, the terminal can check the MAC PDU by actually receiving the PDSCH. The time required for the terminal to actually switch the SSSG is represented by the number of symbols or slots, and the time is used as the application delay of the SSSG switching. Therefore, if the DCI includes an indication other than the PDCCH monitoring adaptation indication such as SSSG switching, the terminal can know that the DCI is not for XR packet scheduling without receiving the PDSCH. For example, if the DCI includes an indication such as BWP switching and / or SCell dormancy indicator, the terminal can know that the DCI is not for XR packet scheduling.

[0211] The operation of 5) is the operation of the terminal when the received DCI includes a PDCCH monitoring adaptation indication. Since the base station transmits a PDCCH monitoring adaptation indication by a scheduling DCI, the dynamic indication by the scheduling DCI takes precedence over the previous PDCCH monitoring adaptation indication / setting.

[0212] (3) Setting examples

[0213] As described above, jitter occurs due to a truncated Gaussian distribution. Therefore, the XR packet is determined probabilistically from the expected reception time. Therefore, in order to reduce the power consumption of the terminal, the frequency of PDCCH monitoring can be set differently by dividing the range where the reception probability is relatively high and the range where the reception probability is relatively low, rather than the entire range where the XR packet can be received.

[0214] When the settings are made as shown in the examples of Fig. 12(b) or 12(c), the application delay of SSSG switching needs to be taken into consideration. The application delay of SSSG switching is applied at least one slot, and at most 2-3 slots. Therefore, in the PDCCH monitoring adaptation pattern that is applied simultaneously with the start of DRX Active Time, the SSSG switching timer is set taking into consideration the application delay.

[0215] Referring to the example of FIG. 12(b), as described above, a PDCCH monitoring adaptation pattern is set in consideration of the probability distribution of jitter. The probability of jitter occurrence is divided into two ranges, and dense PDCCH monitoring is set in the range where the occurrence probability is high, and sparse PDCCH monitoring is set in the range where the occurrence probability is low. This is to allow the terminal to use power in the range where XR packet reception is expected to be frequent, and to reduce power consumption in the range where XR packet reception is expected to be few. When the terminal detects PDCCH, the subsequent operation follows the example of the operation described above.

[0216] The base station sets a PDCCH monitoring adaptation pattern to the terminal and instructs the terminal to monitor the PDCCH according to the corresponding PDCCH monitoring adaptation pattern at the same time as the start of the DRX Active Time, or sets multiple PDCCH monitoring adaptation patterns and instructs one of the PDCCH monitoring adaptation patterns by DCI. If multiple PDCCH monitoring adaptation patterns are set, the PDCCH monitoring adaptation pattern for PDCCH monitoring is instructed by WUS (or a similar DCI). For example, if the base station needs to save power of the terminal, it instructs the terminal to use a PDCCH monitoring adaptation pattern in which the sparse PDCCH monitoring and PDCCH monitoring skipping intervals are set long and the dense PDCCH monitoring interval is set short. On the other hand, if the base station needs accurate XR packet reception of the terminal, it instructs the terminal to use a PDCCH monitoring adaptation pattern in which the dense PDCCH monitoring interval is set long and the sparse PDCCH monitoring and PDCCH monitoring skipping intervals are set short.

[0217] Meanwhile, the SSSG switching operation may be minimized within the PDCCH monitoring adaptation pattern in consideration of the application delay of the SSSG switching. For example, when the DRX Active Time is started, the PDCCH monitoring adaptation pattern may be set so that the terminal performs dense PDCCH monitoring and then performs only one SSSG switching in sparse PDCCH monitoring. Alternatively, the PDCCH monitoring adaptation pattern may be set so that the terminal performs sparse PDCCH monitoring and then performs only one SSSG switching in dense PDCCH monitoring. In addition, the above-mentioned two PDCCH monitoring adaptation patterns may be set in the terminal by the base station, and the base station may indicate one of the PDCCH monitoring adaptation patterns to the terminal by DCI such as WUS. In this case, one PDCCH monitoring adaptation pattern to be indicated by DCI is determined based on the actual occurrence status of jitter or the delay degree of the XR packet.

[0218] According to [Method 1-2], the frequency of monitoring the PDCCH is adjusted according to the probability of occurrence of jitter, thereby minimizing the power consumption for receiving the periodically transmitted XR packet and stably receiving the XR packet. In addition, the PDCCH monitoring adaptation pattern is adjusted according to whether the desired weight is placed on the need to receive the XR packet or the power consumption of the terminal, thereby enabling PDCCH monitoring and reception of the XR packet suited to the purpose. Since multiple PDCCH monitoring adaptation operations are instructed with one instruction, it is efficient in terms of signaling.

[0219] Figures 13 to 15 are diagrams explaining the process in which a PDCCH monitoring pattern is instructed by a base station to a terminal in which DRX operation is not configured according to [Method 2] of this disclosure, and an operation for receiving an XR packet and reducing power consumption is instructed based on the PDCCH monitoring pattern.

[0220] FIG. 13 is a diagram for explaining the overall operation process of a terminal for following [Method 2] of this disclosure.

[0221] 13, the terminal reports first information related to terminal performance, including information related to a PDCCH monitoring pattern, to the base station (S1301). At this time, the information related to the PDCCH monitoring pattern includes information on whether or not PDCCH monitoring adaptive operations, such as PDCCH monitoring skipping and SSSG switching, are supported.

[0222] The terminal receives second information for setting a PDCCH monitoring pattern from the base station (S1303). At this time, the second information is determined in consideration of the first information related to the terminal's capabilities, whether the terminal supports an XR service, and / or a PDCCH monitoring pattern supported by the terminal. For example, the PDCCH monitoring pattern is based on the example described in FIG. 16 and related thereto.

[0223] The terminal receives the first PDCCH through at least one XR SS Set (S1305). The terminal also monitors the second PDCCH according to a PDCCH monitoring pattern based on the at least one XR SS Set (S1307) and receives a PDSCH (e.g., an XR packet) based on the second PDCCH (S1309). At this time, the detailed operation method of S1303 to S1309 is based on any one of [Method 2-1] to [Method 2-3]. If a PDCCH monitoring adaptive operation is indicated by the DCI included in the first PDCCH, the terminal monitors the PDCCH accordingly, or monitors the PDCCH according to a predetermined PDCCH monitoring pattern. As a result, the terminal can reduce unnecessary PDCCH monitoring while normally receiving a predetermined XR packet, thereby reducing power consumption.

[0224] FIG. 14 is a diagram for explaining the overall operation process of a base station for performing [Method 2] of this disclosure.

[0225] 14, a base station receives first information related to the capabilities of a terminal, including information related to a PDCCH monitoring pattern (S1401). At this time, the information related to the PDCCH monitoring pattern includes information on whether or not a PDCCH monitoring adaptive operation, such as PDCCH monitoring skipping and SSSG switching, is supported.

[0226] The base station transmits second information for setting a PDCCH monitoring pattern (S1403). At this time, the second information is determined in consideration of the first information related to the performance of the terminal, whether the terminal supports the XR service, and / or the PDCCH monitoring pattern supported by the terminal. For example, the PDCCH monitoring pattern is based on the example described in FIG. 16 and related thereto.

[0227] The base station transmits a first PDCCH through at least one XR SS Set (S1405). The base station also transmits a second PDCCH according to a PDCCH monitoring pattern based on the at least one XR SS Set (S1407), and transmits a PDSCH (e.g., an XR packet) based on the second PDCCH (S1409). At this time, the detailed operation method of S1403 to S1409 is based on any one of [Method 2-1] to [Method 2-3]. If a PDCCH monitoring adaptive operation is indicated by the DCI included in the first PDCCH, the terminal monitors the PDCCH accordingly, or monitors the PDCCH according to a predetermined PDCCH monitoring pattern. As a result, the terminal can normally receive a predetermined XR packet while reducing unnecessary PDCCH monitoring and reducing power consumption.

[0228] FIG. 15 is a diagram for explaining the overall operation process of a network for carrying out [Method 2] of this disclosure.

[0229] 15, the terminal reports first information related to terminal performance, including information related to a PDCCH monitoring pattern, to the base station (S1501). At this time, the information related to the PDCCH monitoring pattern includes information on whether or not PDCCH monitoring adaptive operations, such as PDCCH monitoring skipping and SSSG switching, are supported.

[0230] The base station transmits second information for setting the PDCCH monitoring pattern (S1503). At this time, the second information is determined in consideration of the first information related to the performance of the terminal, whether the terminal supports the XR service, and / or the PDCCH monitoring pattern supported by the terminal. For example, the PDCCH monitoring pattern is based on the example described in FIG. 16 and related thereto.

[0231] The base station transmits a first PDCCH through at least one XR SS Set (S1505). The base station also transmits a second PDCCH according to a PDCCH monitoring pattern based on the at least one XR SS Set (S1507), and transmits a PDSCH (e.g., an XR packet) based on the second PDCCH (S1509). At this time, the detailed operation method of S1503 to S1509 is based on any one of [Method 2-1] to [Method 2-3]. If a PDCCH monitoring adaptive operation is indicated by the DCI included in the first PDCCH, the terminal monitors the PDCCH accordingly, or monitors the PDCCH according to a predetermined PDCCH monitoring pattern. As a result, the terminal can normally receive a predetermined XR packet while reducing unnecessary PDCCH monitoring and reducing power consumption.

[0232] [Method 2] Method for setting / instructing PDCCH monitoring pattern to terminals where DRX is not configured

[0233] [Method 2] proposes a method in which a terminal without DRX is configured to monitor the PDCCH according to a PDCCH monitoring pattern to reduce power consumption. The terminal expects to receive periodic XR packets with large data size. In addition, a BWP specialized for XR service may be configured in the terminal to support reception of XR packets. Such an XR-specific BWP receives BWPs configured to expect reception of XR packets and packets other than XR. This is because there is no problem with receiving general traffic (e.g., eMBB) other than URLLC in accordance with the period in which XR traffic can be expected (e.g., 16.66667 ms indicated by 60 fps).

[0234] [Method 2-1] How to support XR services on a device without DRX settings

[0235] A method for supporting the XR service without DRX being set in the UE is proposed. For this purpose, a basic PDCCH monitoring operation in the BWP of the UE, a setting of an SS Set for supporting the XR service, an operation after the UE detects DCI and / or a PDCCH monitoring operation for receiving traffic are defined. Figure 16 shows an example of a PDCCH monitoring pattern for supporting the XR service and reducing power consumption in a UE without DRX being set.

[0236] (1) Basic PDCCH monitoring operation in BWP

[0237] Basic PDCCH monitoring operations performed by a terminal in a specific BWP for XR can be broadly divided into three (i.e., the following 1) to 3)). These three operations are the operations at 1601 in FIG. 16. For example, the operation of the terminal at time 1601 triggers the operation of the terminal at time 1602.

[0238] 1) Monitoring only a specific SS Set

[0239] The terminal monitors only a specific SS set that is specified / instructed in the XR specific BWP, and does not monitor other SS sets. In this case, the specific SS set is defined as the XR SS set. The purpose of monitoring the XR SS set is similar to that of receiving a wake-up signal (WUS) when DRX is configured in the terminal. That is, the purpose is to minimize the number and / or frequency of PDCCH monitoring of the terminal according to the period of XR traffic in order to save power. For example, in FIG. 16, when the terminal detects a PDCCH through the XR SS set 1601, the terminal monitors the SS set 1602 to receive a PDCCH for scheduling the XR traffic and the corresponding XR traffic. If the terminal cannot detect a PDCCH through the XR SS set 1601, the terminal omits monitoring the SS set 1602.

[0240] For this purpose, the monitoring occasion (MO) of the XR SS Set is set according to the cycle of the XR traffic. Also, in the period other than MO, the terminal is guaranteed to sleep without monitoring the PDCCH.

[0241] This requires the configuration of a new SS Set. The current standard SS Set configuration defines the SS Set monitoring period and the interval expressed as the number of consecutive slots that the SS Set will last. This defines the XR SS Set to be monitored during B slots for every A slot period. Since the XR SS Set is monitored intensively according to the period, it is necessary to configure an MO that is not aligned with the number of slots. For example, in an XR SS Set, 10 MOs for the XR SS Set are placed within 4 slots.

[0242] 2) PDCCH monitoring only in specific sections

[0243] The terminal performs PDCCH monitoring only for a specific interval. In this case, the specific interval is set by windowing or masking. The specific interval is determined in consideration of the period of the XR traffic and the range of jitter. For example, the specific interval is set to a time point before the time point at which the XR traffic is expected to be received earliest due to jitter. An SS Set(s) for monitoring the PDCCH within the specific interval is set / indicated, and this SS Set is the XR SS Set(s). For example, in FIG. 16, the XR SS Set (1601) is allocated within a specific interval determined in consideration of the range of jitter, and when the PDCCH is monitored through the XR SS Set (1601) within the specific interval, the PDCCH for scheduling the XR traffic is detected through the entire SS Set (1602), and the XR traffic is received based on the detected PDCCH.

[0244] Meanwhile, a specific interval is set by non-consecutive slots or symbols. Therefore, it is set in a structure in which PDCCH monitoring and sleep are repeated during a short interval. If a specific interval is set by non-consecutive slots, the SS Set(s) monitored in the specific interval is set taking this into consideration.

[0245] Meanwhile, a specific section may be set in the form of masking. For example, a parameter for setting masking is defined, and if the parameter is true, the terminal monitors only the XR SS Set(s). Also, if the terminal detects a PDCCH through the XR SS Set(s) or receives a specific instruction through a PDCCH detected by the XR SS Set, the masking parameter is set to false, and the terminal monitors the entire SS Set(s) including the XR SS Set(s). Thereafter, the masking parameter is set to true again based on an instruction by DCI or a timer. For example, if the terminal monitors the entire SS Sets and receives a DCI through any of the SS Sets, or is instructed by the corresponding DCI to set the masking parameter to true again, the masking parameter is set to true again. In another example, when the terminal starts monitoring the entire SS Sets, a timer is operated, and when the timer expires, the masking parameter is set to true again.

[0246] Meanwhile, the specific period is set based on the monitoring of the XR SS Set(s). For example, the terminal monitors all SS Sets during the first monitoring, and then when the terminal monitors the XR SS Set(s) again, it stops monitoring all SS Sets except for the XR SS Set(s). For example, the terminal starts monitoring all SS Sets by monitoring the XR SS Set and detecting a PDCCH, but when the PDCCH is detected again by the XR SS Set among all SS Sets, it stops monitoring the remaining SS Sets except for the XR SS Set.

[0247] 3) XR SS Set monitoring section setting and XR SS Set monitoring based on PDCCH monitoring skipping

[0248] The UE always monitors only the XR SS Set(s) after the previously instructed PDCCH monitoring skipping duration ends. If the UE then detects DCI in the XR SS Set(s), it starts monitoring the entire SS Set(s). At this time, the XR SS Set(s) does not require a separate configuration as in 1). For example, it follows the configuration of the existing NR standard taking into account the periodicity and jitter of the XR traffic.

[0249] In the case of 3), when the terminal completes receiving the scheduled XR traffic, it must receive a PDCCH monitoring skipping instruction from the DCI that scheduled the XR traffic or another DCI. If there is no PDCCH monitoring skipping instruction, the terminal continues to monitor all SS Sets without power saving until the next XR traffic is received.

[0250] (2) XR SS Set(s) Operation and settings of terminals related to monitoring

[0251] The above-mentioned operation and the operation of the terminal related to XR SS Set monitoring are set in the form of SSSG switching. If the entire SS Set in the BWP of the terminal is set to SSSG#1 and the XR SS Set(s) is set to SSSG#0, the terminal monitors the XR SS Set(s), and the process of monitoring the entire SS Set can be interpreted as switching from SSSG#0 to SSSG#1. For example, in FIG. 16, when PDCCH is detected in the XR SS Set (1601) and the terminal starts monitoring the entire SS Set (1602), the SSSG#0 including the XR SS Set is switched to the SSSG#1 including the entire SS Set.

[0252] Meanwhile, the format of DCI monitored in the XR SS Set(s) may be limited. For example, a new DCI format for supporting the XR service is considered. The new DCI format includes an instruction for informing the start time of monitoring the entire SS Set. The instruction indicates how many slots, symbols, or ms after which monitoring of the entire SS Set will start based on the slot, symbol, or ms in which the current DCI was detected. Alternatively, the instruction indicates how early or late the UE should monitor the PDCCH from the expected reception time, assuming that the UE knows the period of the XR packet.

[0253] In addition, the new DCI format may selectively include a PDCCH monitoring adaptation indication. When the terminal starts monitoring the entire SS Set, the PDCCH monitoring adaptation applied to the terminal is indicated by the new DCI format. For example, SSSG#2 is separately configured, and switching to SSSG#2 is indicated by the new DCI format, and the terminal starts PDCCH monitoring for receiving XR traffic based on the corresponding indication.

[0254] In addition, if only a transition to monitoring of the entire SS Set is instructed via the XR SS Set, only a signal instructing a transition to monitoring of the entire SS Set in a sequence-like form is included in the signal received in the XR SS Set, thereby making it possible to reduce power consumption due to blind detection.

[0255] (3) Operation after the terminal detects the PDCCH in the XR SS Set or the entire SS Set

[0256] After detecting the PDCCH through the XR SS Set or the entire SS Set, the UE operates according to the PDCCH monitoring adaptation indication included in the DCI of the corresponding PDCCH. If the PDCCH monitoring adaptation indication is not included in the corresponding DCI, the UE may perform a predetermined operation (e.g., 1) or 2), which is the basic monitoring operation in BWP).

[0257] Alternatively, it may be switched to an SSSG configured for receiving XR traffic as described above.

[0258] Meanwhile, in the above example, it is assumed that the SS Set included in the switched SSSG is the entire SS Set configured for BWP, but the corresponding SSSG may include an SS Set configured only for receiving XR traffic. When SSSG switching is implemented, the location of a specific section for monitoring the XR SS Set is set taking into consideration application delay. It is assumed that a terminal supporting the XR service can support UE processing capability 2. In addition, after detecting the PDCCH, the settings for the window and masking of a specific section may be ignored. Based on the above example, the terminal monitors the PDCCH for receiving XR traffic.

[0259] Meanwhile, the DCI for scheduling the last TB (Transport Block) of the XR traffic includes a PDCCH monitoring adaptation indication field. In connection with the above-mentioned operation, the PDCCH monitoring adaptation indication field may indicate that only the XR SS set(s) for power saving is monitored. Alternatively, when the UE detects a PDCCH in the XR SS set(s) while monitoring the entire current SS set or the SS set for the XR traffic, the UE may change to a power saving operation of monitoring only the XR SS set(s).

[0260] [Method 2-2] When XR traffic is multi-stream

[0261] The XR traffic model can be either single stream or multi-stream, as described above.

[0262] (1) GOP-based I-frame+P-frame

[0263] As one of the multiple streams, a Group of Picture (GOP)-based model can be considered. The definition of the GOP-based model can be seen in the following Table 2 excerpted from TR38.838.

[0264] [Table 2]

[0265] In the GOP-based I-frame+P-frame traffic model, an XR packet is an I-frame or a P-frame, and the I-frame and the P-frame may have different data rates and packet sizes. The reception of the P-frame may be based on the I-frame. For example, the I-frame has a larger data rate and / or packet size than the P-frame. That is, the video information included in the I-frame may be larger than the video information included in the P-frame. The P-frame is received between two I-frames. The terminal outputs a video corresponding to the P-frame using video information of two I-frames received before and after the P-frame. For example, the P-frame includes information about a part that has been changed compared with the previously received I-frame and / or the subsequently received I-frame. Thus, when the terminal outputs a video corresponding to the P-frame, the terminal directly quotes the information of the I-frame for information about a part that is not included in the P-frame or that can be recognized as being the same as the I-frame, and outputs a video corresponding to the P-frame using information included in the P-frame only for a changed part.

[0266] Therefore, it is possible that SS Set monitoring set according to the I-frame and P-frame is indicated / set. Such SS Set monitoring may be set in the form of SSSG. Generally, a major problem occurs when an I-frame is not received. This is because if an I-frame cannot be received, the image cannot be fully output even if a P-frame is received. In addition, an I-frame has a larger packet size and data rate than a P-frame. Therefore, in the case of an I-frame, dense PDCCH monitoring is set at the reception point of the I-frame to increase the reception probability. Conversely, relatively sparse PDCCH monitoring is set for a P-frame (i.e., at the reception point of the P-frame), which is expected to have the effect of saving power for the terminal.

[0267] In addition, when the SS Set is set separately for the I-frame and the P-frame, the SS Set ID can be set to a low value for the I-frame and a high value for the P-frame, thereby preventing the monitoring of the I-frame from being interrupted due to the BD / CCE limit.

[0268] Considering that the terminal receives the P-frame based on the reception of the I-frame, it is possible that the reception result of the I-frame affects the reception of the P-frame. When the terminal receives an I-frame or detects a scheduling DCI for the corresponding I-frame, it is configured to prepare for reception of the P-frame after a certain offset from the corresponding reception / detection point. This takes into consideration that XR traffic is periodic.

[0269] That is, the PDCCH monitoring pattern is not set for reception of one XR packet, but for a set of GOP-based I-frames and P-frames. For example, XR traffic can be received in the order of (I, P, P, P)-frames. In this case, a PDCCH monitoring pattern is configured for a total of four packets, and a PDCCH monitoring pattern for monitoring a future P-frame is determined upon reception of an I-frame. For example, a PDCCH monitoring pattern for monitoring a P-frame after a certain offset from reception of an I-frame is determined.

[0270] For this purpose, the SS Set is configured to be classified into a primary or secondary type. In this case, the primary SS Set is for receiving I-frames, and the secondary SS Set is for receiving P-frames. The primary SS Set and the secondary SS Set may also be configured in the form of an SSSG.

[0271] In the GOP-based I-frame and P-frame, when the PDCCH monitoring pattern is determined based on the I-frame, it is necessary to determine until when the P-frame is received and when the I-frame is to be received again. That is, it is necessary to determine the time when the reception of the P-frame ends and the time when the reception of the I-frame starts again. For example, the corresponding time is determined at a specific time (e.g., based on a timer) or based on how many times the terminal has received the TB.

[0272] (2) Video + Audio / Data

[0273] The video + audio / data model can be considered as one of the multiple streams. The definition of the video + audio / data model can be seen in Table 3 below, which is excerpted from TR38.838.

[0274] [Table 3]

[0275] The video stream is the same as the general XR traffic DL model. Therefore, the transmission period can be assumed to be 16.6667 ms. The audio stream can be assumed to be 10 ms as shown in Table 3. That is, in the case of a video + audio / data model, the periods of the two streams may differ. For this reason, the period of the SS Set for PDCCH monitoring or the position of the 'specific section' is set to receive both streams.

[0276] The two streams with different periods may be displayed as a video stream or an audio stream independently, or may overlap with the video stream and the audio stream. In order to support both of these cases, as in the above-mentioned proposed method, the PDCCH monitoring for XR traffic is adapted to receive an appropriate instruction for receiving the video stream and / or the audio stream. For example, three SSSGs such as SSSG for video, SSSG for audio, and SSSG for both are configured, and an SSSG switching operation is performed based on a PDCCH monitoring adaptation instruction for each frame. Alternatively, an operation of switching to SSSG for video may be performed by setting SSSG for video and SSSG for audio, when two streams are received simultaneously.

[0277] In the case of operation taking into account multiple streams in method 2-2, it can also be applied to method 1 based on the same principle.

[0278] [Method 2-3] Device behavior further considered for power saving

[0279] The CSI reporting and SRS transmission performed by the UE in the BWP may be configured to be different. For example, in a period in which PDCCH monitoring is not performed (e.g., a period in which there is no MO for the XR SS Set during an operation of monitoring only the XR SS Set), the CSI reporting and SRS transmission are suspended to reduce power consumption. When monitoring of the XR SS Set(s) is started, the CSI reporting and SRS transmission are also started at the same time.

[0280] Alternatively, for better channel estimation, the CSI reporting and SRS transmission operations may be performed a certain slot prior to the XR SS Set(s) monitoring (eg, the start or end time of the XR SS Set monitoring).

[0281] According to [Method 2], even if the DRX operation is not configured in the terminal, the PDCCH monitoring pattern is instructed by the XR SS Set, and the terminal monitors the PDCCH according to the instruction, thereby reducing the frequency and number of PDCCH monitoring, thereby reducing the power consumption of the terminal.

[0282] In addition, an appropriate PDCCH monitoring pattern can be set according to the stream characteristics of the XR packet received by the terminal, and the frequency and number of PDCCH monitoring can be adjusted according to the characteristics of the XR packet, thereby increasing the efficiency of data reception.

[0283] The proposed method of this disclosure is applied by selecting some of the following methods. Each method can be operated independently without combination, or can be operated in a linked form by combining one or more methods. Some terms, symbols, sequences, etc. used to explain the proposed method can be replaced with other terms, symbols, sequences, etc. as long as the principle of the invention is maintained.

[0284] In this disclosure, in order to explain the principle of the proposed method, the DRX structure and settings of the terminal, the PDCCH monitoring adaptive operation, and the PDCCH monitoring pattern and terminal operation configuration for transmitting and receiving DCI are described by way of example with arbitrary structures, but unless otherwise specified, the proposed method does not specify or limit the type of terminal operation.

[0285] Therefore, the method proposed in this disclosure can be applied to any DRX structure, PDCCH monitoring adaptive operation or PDCCH monitoring pattern operation without any special description, as long as it does not violate the principles of the invention.

[0286] Without being limited thereto, the various descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed in this document may be applied to various fields requiring device-to-device wireless communication / connections (e.g., 5G).

[0287] Hereinafter, the present invention will be described in more detail with reference to the drawings. In the following drawings / description, the same reference numerals denote the same or corresponding hardware blocks, software blocks or function blocks unless otherwise specified.

[0288] FIG. 17 illustrates a communication system 1 to which the present disclosure is applied.

[0289] Referring to FIG. 17, the communication system 1 applied to the present invention includes wireless devices, base stations, and networks. Here, the wireless devices refer to devices that communicate using wireless connection technology (e.g., 5G NR, LTE), and are also referred to as communication / wireless / 5G devices. The wireless devices include, but are not limited to, a robot 100a, a vehicle 100b-1, 100b-2, an XR (eXtended Reality) device 100c, a handheld device (Hand-held Device) 100d, a home appliance 100e, an IoT (Internet of Thing) device 100f, and an AI server / device 400. For example, the vehicles include vehicles equipped with wireless communication functions, autonomous vehicles, vehicles capable of inter-vehicle communication, and the like. Here, the vehicles include UAVs (Unmanned Aerial Vehicles) (e.g., drones). XR devices include Augmented Reality (AR) / Virtual Reality (VR) / Mixed Reality (MR) devices, and are embodied in the form of Head-Mounted Devices (HMDs), Head-Up Displays (HUDs) mounted on vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital billboards, vehicles, robots, etc. Portable devices include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., notebook computers, etc.), etc. Home appliances include TVs, refrigerators, washing machines, etc. IoT devices include sensors, smart meters, etc. For example, base stations and networks may also be embodied as wireless devices, and a specific wireless device 200a may operate as a base station / network node for other wireless devices.

[0290] The wireless devices 100a to 100f are connected to a network 300 via a base station 200. AI (Artificial Intelligence) technology is applied to the wireless devices 100a to 100f, and the wireless devices 100a to 100f are connected to an AI server 400 via the network 300. The network 300 is configured using a 3G network, a 4G (e.g., LTE) network, or a 5G (e.g., NR) network. The wireless devices 100a to 100f can communicate with each other via the base station 200 / network 300, but can also communicate directly without going through the base station / network (e.g., sidelink communication). For example, the vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, an IoT device (e.g., a sensor) can directly communicate with another IoT device (e.g., a sensor) or another wireless device 100a to 100f.

[0291] Wireless communication / connections 150a, 150b, and 150c are performed between the wireless devices 100a to 100f / base stations 200 and the base stations 200. Here, the wireless communication / connections are performed by various wireless connection technologies such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication) and communication between base stations 150c (e.g., relay, IAB (Integrated Access Backhaul) (e.g., 5G NR). Through the wireless communication / connections 150a, 150b, and 150c, the wireless devices and base stations, and the base stations and base stations can transmit / receive wireless signals to each other. For example, the wireless communication / connections 150a, 150b, and 150c can transmit / receive signals via various physical channels. To this end, based on various proposals of the present invention, any one of various configuration information setting processes for transmitting / receiving wireless signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), and resource allocation processes is performed.

[0292] FIG. 18 illustrates a wireless device applicable to the present disclosure.

[0293] 18, a first wireless device 100 and a second wireless device 200 transmit and receive wireless signals according to various wireless access technologies (e.g., LTE, NR), where {first wireless device 100, second wireless device 200} corresponds to {wireless device 100x, base station 200} and / or {wireless device 100x, wireless device 100x} in FIG.

[0294] The first wireless device 100 includes one or more processors 102 and one or more memories 104, and further includes one or more transceivers 106 and / or one or more antennas 108. The processor 102 is configured to control the memory 104 and / or the transceiver 106 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 102 processes information in the memory 104 to generate a first information / signal, and then transmits a wireless signal including the first information / signal via the transceiver 106. The processor 102 also receives a wireless signal including a second information / signal via the transceiver 106, and then stores information obtained from signal processing of the second information / signal in the memory 104. The memory 104 is coupled to the processor 102 and stores various information related to the operation of the processor 102. For example, the memory 104 stores software code including instructions for performing some or all of the processes controlled by the processor 102 or for performing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 102 and memory 104 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 106 is coupled to the processor 102 and transmits and / or receives wireless signals via one or more antennas 108. The transceiver 106 includes a transmitter and / or a receiver. The transceiver 106 may also be referred to as an RF (radio frequency) unit. In the present invention, a wireless device may also refer to a communication modem / circuit / chip.

[0295] Specifically, the following describes instructions and / or operations controlled by processor 102 and stored in memory 104 of first wireless device 100 according to an embodiment of the disclosure.

[0296] The following operations are described in terms of processor 102 and based on controlling operations of processor 102, with software code or the like for performing such operations stored in memory 104. For example, in this disclosure, at least one memory 104 is a computer readable storage medium that stores instructions or programs that, when executed, cause at least one processor operatively coupled to the at least one memory to perform operations according to embodiments or implementations of this disclosure relating to the following operations.

[0297] For example, the processor 102 reports performance information including information related to a PDCCH monitoring adaptation pattern to the transceiver 106. At this time, the information related to the PDCCH monitoring adaptation pattern includes whether or not PDCCH monitoring adaptation, such as PDCCH monitoring skipping and SSSG switching, is supported.

[0298] The processor 102 receives at least one information for a DRX operation and / or a PDCCH monitoring adaptation pattern determined based on performance information of the processor 102 and / or a PDCCH monitoring adaptation pattern supporting an XR service, via the transceiver 106. In this case, the at least one information is received via a higher layer (e.g., RRC signaling) and / or a PDCCH.

[0299] The processor 102 receives a first PDCCH associated with a PDCCH monitoring adaptation pattern through the transceiver 106. The processor 102 also monitors a second PDCCH based on the first PDCCH and receives a PDSCH (e.g., an XR packet) through the transceiver 106. On the other hand, if only one PDCCH monitoring adaptation pattern is set in the step of receiving at least one piece of information, the first PDCCH monitoring step is omitted, and the second PDCCH is monitored based on the PDCCH monitoring adaptation pattern set in the step of receiving at least one piece of information. The processor 102 also receives a PDSCH (e.g., an XR packet) through the transceiver 106 based on the second PDCCH when the second PDCCH is detected.

[0300] Meanwhile, the detailed operation of the processor 102 is based on [Method 1-1] and / or [Method 1-2].

[0301] In another example, the processor 102 reports first information related to the performance of the terminal, including information related to a PDCCH monitoring pattern, via the transceiver 106. In this case, the information related to the PDCCH monitoring pattern includes information on whether or not a PDCCH monitoring adaptive operation, such as PDCCH monitoring skipping or SSSG switching, is supported.

[0302] The processor 102 receives second information for setting a PDCCH monitoring pattern from the base station via the transceiver 106. At this time, the second information is determined in consideration of the first information related to the performance of the processor 102, whether the processor 102 supports an XR service, and / or a PDCCH monitoring pattern supported by the terminal. For example, the PDCCH monitoring pattern is based on FIG. 16 and the examples related thereto.

[0303] The processor 102 receives the first PDCCH through at least one XR SS Set via the transceiver 106. The processor 102 also monitors the second PDCCH according to a PDCCH monitoring pattern based on the at least one XR SS Set, and receives a PDSCH (e.g., an XR packet) based on the second PDCCH via the transceiver 106. At this time, a detailed operation method of the processor 102 is based on any one of [Method 2-1] to [Method 2-3]. Also, if a PDCCH monitoring adaptive operation is instructed by the DCI included in the first PDCCH, the terminal monitors the PDCCH accordingly or monitors the PDCCH according to a predetermined PDCCH monitoring pattern.

[0304] The second wireless device 200 includes one or more processors 202 and one or more memories 204, and further includes one or more transceivers 206 and / or one or more antennas 208. The processor 202 is configured to control the memory 204 and / or the transceiver 206 to implement the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. For example, the processor 202 processes information in the memory 204 to generate a third information / signal, and then transmits a wireless signal including the third information / signal via the transceiver 206. The processor 202 also receives a wireless signal including a fourth information / signal via the transceiver 206, and then stores information obtained from the signal processing of the fourth information / signal in the memory 204. The memory 204 is coupled to the processor 202 and stores various information related to the operation of the processor 202. For example, the memory 204 stores software code including instructions for performing some or all of the processes controlled by the processor 202 or for performing the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to implement a wireless communication technology (e.g., LTE, NR). The transceiver 206 is coupled to the processor 202 and transmits and / or receives wireless signals by one or more antennas 208. The transceiver 206 includes a transmitter and / or a receiver. The transceiver 206 may also be referred to as an RF unit. In the present invention, a wireless device also means a communication modem / circuit / chip.

[0305] Specifically, the following describes instructions and / or operations controlled by processor 202 and stored in memory 204 of second wireless device 200 according to embodiments of the disclosure.

[0306] The following operations are described in terms of processor 202 and based on controlling operations of processor 202, with software code or the like for performing such operations stored in memory 204. For example, in this disclosure, at least one memory 204 is a computer readable storage medium that stores instructions or programs that, when executed, cause at least one processor operatively coupled to the at least one memory to perform operations according to embodiments or implementations of this disclosure related to the following operations.

[0307] For example, the processor 202 receives performance information including information related to a PDCCH monitoring adaptation pattern from the terminal via the transceiver 206. At this time, the information related to the PDCCH monitoring adaptation pattern includes whether or not PDCCH monitoring adaptation such as PDCCH monitoring skipping and SSSG switching is supported.

[0308] The processor 202 determines a DRX operation and / or a PDCCH monitoring adaptation pattern based on the terminal performance information and / or a PDCCH monitoring adaptation pattern supporting the XR service, and transmits at least one piece of information for the determined DRX operation and / or PDCCH monitoring adaptation pattern via the transceiver 206. In this case, the at least one piece of information is transmitted via a higher layer (e.g., RRC signaling) and / or a PDCCH.

[0309] The processor 202 transmits a first PDCCH associated with the PDCCH monitoring adaptation pattern through the transceiver 206. The processor 202 also transmits a second PDCCH and a PDSCH (e.g., an XR packet) through the transceiver 206 based on the first PDCCH. On the other hand, if only one PDCCH monitoring adaptation pattern is set in the step of transmitting at least one piece of information, the step of transmitting the PDCCH is omitted, and a second PDCCH is transmitted by the transceiver 206 based on the PDCCH monitoring adaptation pattern set in the step of transmitting at least one piece of information. The processor 202 also transmits a PDSCH (e.g., an XR packet) through the transceiver 206 based on the second PDCCH.

[0310] Meanwhile, the detailed operation of the processor 202 described above is based on [Method 1-1] and / or [Method 1-2].

[0311] In another example, the processor 202 receives first information related to the performance of the terminal, including information related to a PDCCH monitoring pattern, via the transceiver 206. In this case, the information related to the PDCCH monitoring pattern includes information regarding whether or not a PDCCH monitoring adaptive operation, such as PDCCH monitoring skipping or SSSG switching, is supported.

[0312] The processor 202 transmits second information for setting a PDCCH monitoring pattern via the transceiver 206. At this time, the second information is determined in consideration of the first information related to the performance of the terminal, whether the terminal supports an XR service, and / or a PDCCH monitoring pattern supported by the terminal. For example, the PDCCH monitoring pattern is based on FIG. 16 and related examples.

[0313] The processor 202 transmits a first PDCCH through the transceiver 206 via at least one XR SS Set. The processor 202 also transmits a second PDCCH through the transceiver 206 according to a PDCCH monitoring pattern based on the at least one XR SS Set, and transmits a PDSCH (e.g., an XR packet) based on the second PDCCH through the transceiver 206. At this time, a detailed operation method of the processor 202 is based on any one of [Method 2-1] to [Method 2-3]. Also, if a PDCCH monitoring adaptive operation is instructed by the DCI included in the first PDCCH, the terminal monitors the PDCCH accordingly or monitors the PDCCH according to a predetermined PDCCH monitoring pattern.

[0314] The hardware elements of the wireless device 100, 200 are described in more detail below. One or more protocol layers may be implemented by one or more processors 102, 202, without limitation. For example, the one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, SDAP). The one or more processors 102, 202 may generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate messages, control information, data, or information according to the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein. The one or more processors 102, 202 may generate and provide signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data or information according to the functions, procedures, suggestions, and / or methods disclosed herein to the one or more transceivers 106, 206. The one or more processors 102, 202 may receive signals (e.g., baseband signals) from the one or more transceivers 106, 206 and derive the PDUs, SDUs, messages, control information, data or information according to the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed herein.

[0315] The one or more processors 102, 202 may also be referred to as a controller, microcontroller, microprocessor, or microcomputer. The one or more processors 102, 202 may be implemented using hardware, firmware, software, or a combination thereof. As an example, the one or more processors 102, 202 may include 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). The descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be implemented using firmware or software, and the firmware or software may be implemented to include modules, procedures, functions, and the like. The firmware or software configured to perform the descriptions, functions, procedures, suggestions, methods, and / or flowcharts disclosed herein may be included in the one or more processors 102, 202, or may be stored in one or more memories 104, 204 and run by the one or more processors 102, 202. The descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed in this specification may be embodied using firmware or software in the form of code, instructions and / or sets of instructions.

[0316] The one or more memories 104, 204 may be coupled to the one or more processors 102, 202 and may store various types of data, signals, messages, information, programs, code, instructions, and / or commands. The one or more memories 104, 204 may be comprised of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer readable storage media, and / or combinations thereof. The one or more memories 104, 204 may be located internal and / or external to the one or more processors 102, 202. Additionally, the one or more memories 104, 204 may be coupled to the one or more processors 102, 202 via various techniques, such as wired or wireless connections.

[0317] The one or more transceivers 106, 206 may transmit user data, control information, wireless signals / channels, etc., as described in the methods and / or flow charts, etc., herein to one or more other devices. The one or more transceivers 106, 206 may receive user data, control information, wireless signals / channels, etc., as described in the descriptions, functions, procedures, suggestions, methods and / or flow charts, etc., disclosed herein from one or more other devices. For example, the one or more transceivers 106, 206 may be coupled to one or more processors 102, 202 to transmit and receive wireless signals. For example, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, the one or more processors 102, 202 may control the one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. The one or more transceivers 106, 206 are also coupled to one or more antennas 108, 208, and the one or more transceivers 106, 206 are configured to transmit and receive user data, control information, radio signals / channels, etc., as referred to in the descriptions, functions, procedures, suggestions, methods and / or flow charts disclosed herein, via the one or more antennas 108, 208. In this specification, the one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). The one or more transceivers 106, 206 convert the received user data, control information, radio signals / channels, etc., from RF band signals to baseband signals for processing by the one or more processors 102, 202. The one or more transceivers 106, 206 convert the user data, control information, radio signals / channels, etc., processed by the one or more processors 102, 202, from baseband signals to RF band signals. To this end, the one or more transceivers 106, 206 include (analog) oscillators and / or filters.

[0318] 19 illustrates an example of a vehicle or an autonomous vehicle to which the present invention is applied. The vehicle or the autonomous vehicle may be realized as a mobile robot, a car, a train, an aerial vehicle (AV), a ship, or the like.

[0319] 19, a vehicle or an autonomous vehicle 100 includes 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 is formed as a part of the communication unit 110.

[0320] The communication unit 110 transmits and receives signals (e.g., data, control signals, etc.) to and from external devices such as other vehicles, base stations (e.g., base stations, road side units, etc.), and servers. The control unit 120 controls elements of the vehicle or autonomous vehicle 100 to perform various operations. The control unit 120 includes an ECU (Electronic Control Unit). The driving unit 140a causes the vehicle or autonomous vehicle 100 to run on the ground. The driving unit 140a includes an engine, a motor, a power train, wheels, brakes, a steering device, etc. The power supply unit 140b supplies power to the vehicle or autonomous vehicle 100 and includes wired / wireless charging circuits, a battery, etc. The sensor unit 140c can obtain vehicle status, surrounding environment information, user information, etc. The sensor unit 140c includes an IMU (inertial measurement unit) sensor, a collision sensor, a wheel sensor, a speed sensor, a tilt sensor, a weight 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 embodies a technology for maintaining a lane while driving, a technology for automatically adjusting speed such as an adaptive cruise control, a technology for automatically driving according to a predetermined route, a technology for automatically setting a route when a destination is set, and the like.

[0321] For example, the communication unit 110 receives map data, traffic information data, etc. from an external server. The autonomous driving unit 140d generates an autonomous driving route and a drive plan based on the obtained data. The control unit 120 controls the driving unit 140a (e.g., speed / direction adjustment) so that the vehicle or autonomous driving vehicle 100 moves along the autonomous driving route according to the drive plan. The communication unit 110 non-periodically obtains the latest traffic information data from an external server during autonomous driving, and also obtains surrounding traffic information data from surrounding vehicles. In addition, the sensor unit 140c obtains vehicle status and surrounding environment information during autonomous driving. The autonomous driving unit 140d updates the autonomous driving route and drive plan based on the newly obtained data / information. The communication unit 110 transmits information regarding the vehicle position, the autonomous driving route, the drive plan, etc. to an external server. The external server predicts traffic information data in advance using AI technology, etc. based on information collected from the vehicle or autonomous driving vehicle, and provides the predicted traffic information data to the vehicle or autonomous driving vehicle.

[0322] 20 illustrates an example of an XR device to which this disclosure is applied. The XR device may be realized in the form of an HMD, a head-up display (HUD) installed in a vehicle, a TV, a smartphone, a computer, a wearable device, a home appliance, a digital sign, a vehicle, a robot, etc.

[0323] Referring to FIG. 20, the XR device 100a includes 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.

[0324] The communication unit 110 can transmit and receive signals (e.g., media data, control signals, etc.) to and from external devices such as other wireless devices, mobile devices, or media servers. Media data includes video, images, sounds, etc. The control unit 120 controls the components of the XR device 100a to perform various operations. For example, the control unit 120 is configured to control and / or perform procedures such as video / image acquisition, (video / image) encoding, metadata generation and processing, etc. The memory unit 130 stores data / parameters / programs / codes / commands required for driving the XR device 100a / generating XR objects. The input / output unit 140a obtains control information, data, etc. from the outside and outputs the generated XR objects. The input / output unit 140a includes a camera, a microphone, a user input unit, a display unit, a speaker, and / or a haptics module, etc. The sensor unit 140b obtains the XR device state, surrounding environment information, user information, etc. The sensor unit 140b includes a proximity sensor, an illuminance sensor, an acceleration sensor, a magnetic sensor, a gyro sensor, an inertial sensor, an RGB sensor, an IR sensor, a fingerprint recognition sensor, an ultrasonic sensor, a light sensor, a microphone, and / or a radar, etc. The power supply unit 140c supplies power to the XR device 100a and includes a wired / wireless charging circuit, a battery, etc.

[0325] As an example, the memory unit 130 of the XR device 100a includes information (e.g., data, etc.) required to generate an XR object (e.g., an AR / VR / MR object). The input / output unit 140a can receive an instruction to operate the XR device 100a from a user, and the control unit 120 drives the XR device 100a according to the user's driving instruction. For example, when a user watches a movie, news, etc. through the XR device 100a, the control unit 120 can transmit content request information to another device (e.g., the portable device 100b) or a media server through the communication unit 130. The communication unit 130 can download / stream content such as movies, news, etc. from another device (e.g., the portable 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 generates / outputs an XR object based on information about the surrounding space or real object obtained by the input / output unit 140a / sensor unit 140b.

[0326] The XR device 100a is wirelessly connected to the portable device 100b via the communication unit 110, and the operation of the XR device 100a is controlled by the portable device 100b. For example, the portable device 100b operates as a controller for the XR device 100a. For this reason, the XR device 100a can obtain three-dimensional position information of the portable device 100b, and then generate and output an XR individual corresponding to the portable device 100b.

[0327] The above-described embodiments are combinations of the components and features of the present invention in a predetermined form. Each component or feature should be considered as optional unless otherwise expressly stated. Each component or feature may be implemented in a form not combined with other components or features. Also, some components and / or features may be combined to form an embodiment of the present invention. The order of each operation described in the embodiments of the present invention may be changed. Some configurations or features of any embodiment may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is obvious that claims that are not explicitly cited in the claims may be combined to form an embodiment, or may be included as a new claim by amendment after filing.

[0328] In this document, a specific operation that is said to be performed by a base station may be performed by its upper node in some cases. That is, in a network consisting of a plurality of network nodes including a base station, various operations performed for communication with a terminal may be performed by the base station or other network nodes other than the base station. In this case, the base station may be replaced with terms such as a fixed station, gNode B (gNB), Node B, eNode B (eNB), or an access point.

[0329] It is obvious to those skilled in the art that the present disclosure can be embodied in other specific forms without departing from the characteristics of the present disclosure. Therefore, the above detailed description should not be interpreted as limiting in all respects, but should be considered as illustrative. The scope of the present invention should be determined by a reasonable interpretation of the appended claims, and all modifications within the equivalent scope of the present invention are included in the scope of the present invention. [Industrial Applicability]

[0330] The above-mentioned method and device for transmitting and receiving a downlink control channel have been described mainly as being applied to a 5th generation NewRAT system, but may be applied to various wireless communication systems other than the 5th generation NewRAT system. [Explanation of symbols]

[0331] 1. Communication Systems 100 First wireless device (vehicle or autonomous vehicle) 100a~100f Wireless equipment 102, 202 processors 104, 204 Memory 106, 206 Transmitter 110, 210 Communications Department 120, 220 Control unit 130, 230 Memory section 200 2nd wireless equipment (base station) 400 AI servers / device

Claims

1. A method for receiving a Physical Downlink Control Channel (PDCCH) by a user equipment (UE) in a wireless communication system, comprising: receiving, via higher layer signaling, (i) a first parameter associated with a Bandwidth Part (BWP) and (ii) a second parameter associated with a set of a plurality of Search Spaces (SSs) included in the BWP; monitoring only a first SS set configured for periodic signal reception among the plurality of SS sets; receiving a first PDCCH for PDCCH monitoring adaptation in the first SS set; starting monitoring all of the plurality of SS sets after the first PDCCH is received in the first SS set; receiving a second PDCCH for data scheduling based on the monitoring of all of the plurality of SS sets; The method of claim 1, further comprising: terminating monitoring of other SS sets, other than the first SS set, among the plurality of SS sets, based on the second PDCCH being received in the first SS set.

2. The method of claim 1 , wherein the UE is not configured for Discontinuous Reception (DRX) operation.

3. The method of claim 1 , wherein the second PDCCH schedules an eXtended Reality (XR) packet.

4. In a wireless communication system, a UE (user equipment) configured to receive a PDCCH (Physical Downlink Control Channel), At least one transceiver; At least one processor; at least one memory operatively coupled to the at least one processor and configured to store instructions; The instructions, when executed, cause the at least one processor to: receiving, via higher layer signaling, (i) a first parameter associated with a Bandwidth Part (BWP) and (ii) a second parameter associated with a set of a plurality of Search Spaces (SSs) included in the BWP; monitoring only a first SS set configured for periodic signal reception among the plurality of SS sets; receiving a first PDCCH for PDCCH monitoring adaptation in the first SS set; starting monitoring all of the plurality of SS sets after the first PDCCH is received in the first SS set; receiving a second PDCCH for data scheduling based on the monitoring of all of the plurality of SS sets; The UE terminates monitoring of other SS sets, excluding the first SS set, among the plurality of SS sets, based on the second PDCCH being received in the first SS set.

5. The UE according to claim 4 , wherein the UE is not configured for Discontinuous Reception (DRX) operation.

6. The UE of claim 4 , wherein the second PDCCH schedules an eXtended Reality (XR) packet.

7. In a wireless communication system, a UE (user equipment) configured to receive a PDCCH (Physical Downlink Control Channel), At least one processor; at least one memory operatively coupled to the at least one processor and configured to store instructions; The instructions, when executed, cause the at least one processor to perform operations; The operation includes: receiving, via higher layer signaling, (i) a first parameter associated with a Bandwidth Part (BWP) and (ii) a second parameter associated with a set of a plurality of Search Spaces (SSs) included in the BWP; monitoring only a first SS set configured for periodic signal reception among the plurality of SS sets; receiving a first PDCCH for PDCCH monitoring adaptation in the first SS set; starting monitoring all of the plurality of SS sets after the first PDCCH is received in the first SS set; receiving a second PDCCH for data scheduling based on the monitoring of all of the plurality of SS sets; The UE terminates monitoring of other SS sets, excluding the first SS set, among the plurality of SS sets, based on the second PDCCH being received in the first SS set.

8. A computer-readable storage medium including at least one program for causing at least one processor of a user equipment (UE) to perform an operation, The operation includes: receiving, via higher layer signaling, (i) a first parameter associated with a Bandwidth Part (BWP) and (ii) a second parameter associated with a set of a plurality of Search Spaces (SSs) included in the BWP; monitoring only a first SS set configured for periodic signal reception among the plurality of SS sets; receiving a first PDCCH for PDCCH monitoring adaptation in the first SS set; starting monitoring all of the plurality of SS sets after the first PDCCH is received in the first SS set; receiving a second PDCCH for data scheduling based on the monitoring of all of the plurality of SS sets; A computer-readable storage medium, wherein monitoring of other SS sets, other than the first SS set, among the plurality of SS sets is terminated based on the second PDCCH being received in the first SS set.

9. A method for transmitting a PDCCH (Physical Downlink Control Channel) by a base station (BS) in a wireless communication system, comprising: Transmitting, via higher layer signaling, (i) a first parameter related to a Bandwidth Part (BWP), and (ii) a second parameter related to a set of a plurality of Search Spaces (SSs) included in the BWP; Transmitting a first PDCCH to a user equipment (UE) that monitors only the first SS set among the plurality of SS sets within a first SS set configured for periodic signal transmission; transmitting a second PDCCH for data scheduling in the first SS set to the UE that starts monitoring all of the plurality of SS sets after the first PDCCH is transmitted in the first SS set; After the second PDCCH is transmitted in the first SS set, other SS sets among the plurality of SS sets, except for the first SS set, are not used for the UE.

10. In a wireless communication system, a base station configured to transmit a physical downlink control channel (PDCCH), At least one transceiver; At least one processor; at least one memory operatively coupled to the at least one processor and configured to store instructions; The instructions, when executed, cause the at least one processor to: Transmitting, via higher layer signaling, (i) a first parameter related to a Bandwidth Part (BWP), and (ii) a second parameter related to a set of a plurality of Search Spaces (SSs) included in the BWP; Transmitting a first PDCCH to a user equipment (UE) that monitors only the first SS set among the plurality of SS sets within a first SS set configured for periodic signal transmission; causing the UE, which starts monitoring all of the plurality of SS sets after the first PDCCH is transmitted in the first SS set, to perform operations including transmitting a second PDCCH for data scheduling in the first SS set; A base station, wherein after the second PDCCH is transmitted in the first SS set, other SS sets among the plurality of SS sets, except for the first SS set, are not used for the UE.

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