METHOD AND APPARATUS FOR PERFORMING QoS FLOW-BASED DISCARD PROCEDURES IN A WIRELESS COMMUNICATION SYSTEM - Patent application

Abstract

The present invention relates to a method performed by a user equipment (UE) in a wireless communication system, particularly the method includes the steps of receiving configuration information for a plurality of data radio bearers (DRBs), performing transmissions based on the plurality of DRBs, and activating congestion-related discard procedures for at least one of the plurality of DRBs based on receiving a congestion indicator indicating the at least one DRB, and deactivating the congestion-related discard procedures based on receiving a resume indicator indicating the at least one DRB.

Description

[Technical Field]

[0001] The present invention relates to a wireless communication system, and more particularly to a method and apparatus for performing a QoS flow-based discard procedure in a wireless communication system. [Background technology]

[0002] With the introduction of new wireless communication technologies, not only the number of UEs served by a base station in a given resource region but also the amount of data and control information transmitted and received by the base station to and from the served UEs is increasing. Because the amount of radio resources available for a base station to communicate with a UE is finite, a new scheme is needed for a base station to efficiently transmit and receive uplink / downlink data and / or uplink / downlink control information to and from a UE using the finite radio resources. In particular, there is an increasing number of applications whose performance is significantly affected by delay / latency. Therefore, a scheme for reducing delay / latency compared to existing systems is needed. Summary of the Invention [Problem to be solved by the invention]

[0003] An object of the present invention is to provide a method and apparatus for performing a QoS flow-based discard procedure in a wireless communication system. [Means for solving the problem]

[0004] The object of the present invention can be achieved by a method for a UE (User Equipment) operating in a wireless communication system, the method comprising the steps of receiving configuration information for a plurality of DRBs (Data Radio Bearers), performing transmissions based on the plurality of DRBs, and activating congestion-related discard procedures for the at least one DRB based on receiving a congestion indicator indicating at least one of the plurality of DRBs, and deactivating the congestion-related discard procedures based on receiving a resume indicator indicating the at least one DRB.

[0005] Also proposed is a UE (user equipment) in a wireless communication system, the UE including at least one transceiver, at least one processor, and at least one computer 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 receiving configuration information for a plurality of data radio bearers (DRBs); transmitting based on the plurality of DRBs; activating congestion-related discard procedures for the at least one DRB based on receiving a congestion indicator indicating at least one of the plurality of DRBs; and deactivating the congestion-related discard procedures based on receiving a resume indicator indicating the at least one DRB.

[0006] Preferably, if at least a portion of a protocol data unit (PDU) belonging to said at least one DRB has already been transmitted, said discarding procedure is not applied to said PDU.

[0007] Preferably, the congestion indicator and the resume indicator are transmitted via a medium access control (MAC) control element (CE).

[0008] Preferably, the multiple DRBs are mapped to multiple logical channels.

[0009] Preferably, if a congestion-related discard procedure for the at least one DRB is activated, the UE performs transmission based on the plurality of DRBs except for the at least one DRB.

[0010] Preferably, the congestion related discard procedure is applied to low importance protocol data units (PDUs) belonging to the at least one DRB.

[0011] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Effects of the Invention]

[0012] According to the present invention, the network can instruct the discarding of packets belonging to a specific QoS flow. Therefore, in a congested situation, the network can control uplink transmissions, allowing only important uplink traffic. This method can guarantee the minimum QoS requirements for XR applications even in a congested network.

[0013] The effects obtained by the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art to which the present invention pertains from the following description. [Brief explanation of the drawings]

[0014] The accompanying drawings are provided to aid in the understanding of the present invention and, together with the detailed description, serve to explain the principles of the invention.

[0015] [Figure 1] 1 is a diagram illustrating an example of a communication system to which the present invention is applied; [Figure 2] 1 is a block diagram showing an example of a communication device for carrying out a method according to the present invention; [Figure 3] 1 is a diagram illustrating an example of a frame structure in a 3GPP (registered trademark) based (3GPP-based) wireless communication system. [Figure 4] 1 is a diagram illustrating an example of a protocol stack in a wireless communication system based on 3GPP (third generation partnership project). [Figure 5] FIG. 1 is a diagram illustrating an example of data flow in a 3GPP NR system. [Figure 6] 1 is a diagram illustrating an example of PDSCH time domain resource allocation by PDCCH and an example of PUSCH time resource allocation by PDCCH. [Figure 7] FIG. 10 is a diagram illustrating an example of physical layer processing on the transmitting side. [Figure 8] FIG. 10 is a diagram illustrating an example of physical layer processing on the receiving side. [Figure 9] FIG. 1 is a diagram illustrating the concept of a PDU set for an XR service in an NR system. [Figure 10] FIG. 1 is a diagram illustrating an example of a discard procedure based on the importance of a PDU set according to the prior art. [Figure 11] FIG. 1 is a diagram illustrating an example of QoS flow-DRB-LoCH mapping according to the prior art. [Figure 12] FIG. 1 is a diagram illustrating an example of a disposal procedure according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The detailed description described with the accompanying drawings is intended to describe exemplary embodiments of the present invention and is not the only embodiment that can be implemented by the present invention. The following detailed description includes specific details to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention can be implemented without such specific details.

[0017] The following technologies can be used for various wireless access systems, such as CDMA (Code Division Multiple Access), FDMA (Frequency Division Multiple Access), TDMA (Time Division Multiple Access), OFDMA (Orthogonal Frequency Division Multiple Access), and SC-FDMA (Single Carrier Frequency Division Multiple Access). CDMA can be implemented using radio technologies such as UTRA (Universal Terrestrial Radio Access) and CDMA2000. TDMA can be implemented using radio technologies such as GSM (Global System for Mobile communications), GPRS (General Packet Radio Service), and EDGE (Enhanced Data Rates for GSM Evolution). OFDMA can be implemented using radio technologies such as IEEE802.11 (Wi-Fi), IEEE802.16 (WiMAX), IEEE802-20, and E-UTRA (Evolved UTRA). IEEE 802.16m is an evolution of IEEE 802.16e and provides backward compatibility with systems based on IEEE 802.16e. UTRA is part of the Universal Mobile Telecommunications System (UMTS). 3GPP (3rd Generation Partnership Project) LTE (long term evolution) is part of E-UMTS (Evolved UMTS) that uses E-UTRA and employs OFDMA on the downlink and SC-FDMA on the uplink. LTE-Advanced (LTE-A) is an evolution of 3GPP LTE.

[0018] For convenience of explanation, the following description will be made in relation to a 3GPP-based communication system. However, the technical features of the present description are not limited thereto. For example, even if the following detailed description is made based on a mobile communication system corresponding to a 3GPP-based system, the details other than those specific to the 3GPP-based system can be applied to any other mobile communication system. For terms and techniques described in the present description that are not specifically mentioned, reference may be made to wireless communication standard documents prior to the publication of the present specification. For example, the following documents may be referred to:

[0019] 3GPP LTE

[0020] - 3GPP TS36.211:Physical channels and modulation

[0021] - 3GPP TS36.212:Multiplexing and channel coding

[0022] - 3GPP TS36.213:Physical layer procedures

[0023] - 3GPP TS36.214:Physical layer; Measurements

[0024] - 3GPP TS36.300:Overall description

[0025] - 3GPP TS36.304:User Equipment(UE) procedures in idle mode

[0026] - 3GPP TS36.314:Layer 2-Measurements

[0027] - 3GPP TS36.321:Medium Access Control (MAC) protocol

[0028] - 3GPP TS36.322:Radio Link Control(RLC) protocol

[0029] - 3GPP TS36.323:Packet Data Convergence Protocol(PDCP)

[0030] - 3GPP TS36.331:Radio Resource Control(RRC) protocol

[0031] 3GPP NR(e.g.5G)

[0032] - 3GPP TS38.211:Physical channels and modulation

[0033] - 3GPP TS38.212:Multiplexing and channel coding

[0034] - 3GPP TS38.213:Physical layer procedures for control

[0035] - 3GPP TS38.214:Physical layer procedures for data

[0036] - 3GPP TS38.215:Physical layer measurements

[0037] - 3GPP TS38.300:Overall description

[0038] - 3GPP TS38.304:User Equipment(UE) procedures in idle mode and in RRC inactive state

[0039] - 3GPP TS38.321:Medium Access Control(MAC) protocol

[0040] - 3GPP TS38.322:Radio Link Control(RLC) protocol

[0041] - 3GPP TS38.323:Packet Data Convergence Protocol(PDCP)

[0042] - 3GPP TS38.331:Radio Resource Control(RRC) protocol

[0043] - 3GPP TS37.324:Service Data Adaptation Protocol(SDAP)

[0044] - 3GPP TS37.340:Multi-connectivity;Overall description

[0045] In this specification, a UE may be fixed or mobile, and includes various devices that communicate with a base station (BS) to transmit and receive user data and / or various control information. A UE may also be referred to as a terminal equipment (Terminal Equipment), a mobile station (MS), a mobile terminal (MT), a user terminal (UT), a subscriber station (SS), a wireless device, a personal digital assistant (PDA), a wireless modem, a handheld device, etc. In addition, in this specification, a BS generally refers to a fixed station that communicates with a UE and / or other BSs, and communicates with the UE and other BSs to exchange various data and control information. A BS may also be referred to by other terms, such as an advanced base station (ABS), a node-B (NB), an evolved-nodeB (eNB), a base transceiver system (BTS), an access point (Access Point), or a processing server (PS). In particular, a BS in UMTS is called an NB, a BS in EPC / LTE is called an eNB, and a BS in the NR (new radio) system is called a gNB.

[0046] In this specification, a node refers to a fixed point that can communicate with a UE and transmit / receive wireless signals. Various types of eNBs can be used as nodes, regardless of their names. For example, a BS, NB, eNB, picocell eNB (PeNB), home eNB (HeNB), relay, repeater, etc. can be used as a node. A node does not have to be an eNB. For example, a radio remote head (RRH) or a radio remote unit (RRU) can also be used. RRHs and RRUs generally have a lower power level than the eNB. Because RRHs or RRUs (hereinafter referred to as RRHs / RRUs) are generally connected to an eNB via a dedicated line such as an optical cable, cooperative communication between the RRHs / RRUs and the eNB can be performed more smoothly than cooperative communication between eNBs connected via a wireless line. At least one antenna is installed in each node. The antenna may refer to a physical antenna, an antenna port, a virtual antenna, or an antenna group.

[0047] As used herein, a "cell" refers to a geographical area or radio resource where one or more nodes provide communication services. A "cell" of a geographical area can be understood as the coverage where a node can provide services using carriers. A "cell" as a radio resource (e.g., time-frequency resource) is related to a bandwidth (BW), which is a frequency range configured by carriers. A "cell" related to radio resources is defined by a combination of downlink and uplink resources, for example, a combination of a downlink (DL) component carrier (CC) and an uplink (UL) CC. A cell can be configured with only downlink resources or a combination of downlink and uplink resources. Downlink coverage, which is the range where a node can transmit a valid signal, and uplink coverage, which is the range where a node can receive a valid signal from a UE, depend on the carriers carrying the signal. Therefore, the coverage of a node can also be related to the coverage of a "cell" of radio resources used by the node. Thus, the term "cell" can sometimes refer to the coverage of a service by a node, sometimes to radio resources, and sometimes to the area that a signal using said radio resources can reach with sufficient strength.

[0048] In the present invention, a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) respectively refer to a set of time-frequency resources or resource elements (REs) carrying downlink control information (DCI) and a set of time-frequency resources or REs carrying downlink data. A physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), and a physical random access channel (PRACH) respectively refer to a set of time-frequency resources or REs carrying uplink control information (UCI), a set of time-frequency resources or REs carrying uplink data, and a set of time-frequency resources or REs carrying an optional access signal.

[0049] In carrier aggregation (CA), two or more CCs are aggregated. A UE can simultaneously receive or transmit one or multiple CCs depending on its capabilities. CA is supported for both contiguous and non-contiguous CCs. When CA is configured, the UE only establishes one radio resource control (RRC) connection with the network. During RRC connection establishment / re-establishment / handover, one serving cell provides non-access stratum (NAS) mobility information, and during RRC connection re-establishment / handover, one serving cell provides security input. This cell is called the primary cell (PCell). The PCell is the cell operating on the primary frequency, where the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on the UE capabilities, a secondary cell (SCell) is configured to form a serving cell set together with the PCell. An SCell is a cell that provides additional radio resources in addition to the special cell. Therefore, the serving cell set configured for a UE always consists of one PCell and one or more SCells. For dual connectivity operation, the term special cell (SpCell) refers to a PCell of a master cell group (MCG) or a PSCell of a secondary cell group (SCG). An SpCell supports PUCCH transmission and contention-based optional connections and is always activated. An MCG is a serving cell group associated with a master node and includes an SpCell (PCell) and optionally one or more SCells. An SCG is a subset of serving cells associated with a secondary node and consists of a PSCell and zero or more SCells for a UE configured with dual connectivity (DC). For an RRC_CONNECTED UE not configured with CA / DC, there is only one serving cell consisting of a PCell.For an RRC_CONNECTED UE configured for CA / DC, the term "serving cell" is used to refer to the cell set consisting of the SpCell and all SCells.

[0050] The MCG is a group of serving cells associated with a master BS that terminates at least the S1-MME, and the SCG is a group of serving cells associated with a secondary BS that provides additional radio resources for the UE but is not the master BS. The SCG consists of a primary SCell (PSCell) and, optionally, one or more SCells. In a DC, two MAC entities, i.e., a MAC entity for the MCG and a MAC entity for the SCG, are configured in the UE. Each MAC entity is configured by RRC as a serving cell that supports PUCCH transmission and contention-based voluntary access. In the present invention, the term SPCell refers to such a cell, while the term SCell refers to another serving cell. The term SPCell refers to a PCell of the MCG or a PSCell of the SCG depending on whether the MAC entity is associated with the MCG or the SCG, respectively.

[0051] In the present invention, channel monitoring means attempting to decode a channel, for example, PDCCH monitoring means attempting to decode a PDCCH (or a PDCCH candidate).

[0052] In this specification, "C-RNTI" denotes a cell RNTI, "SI-RNTI" denotes a system information RNTI, "P-RNTI" denotes a paging RNTI, "RA-RNTI" denotes an optional connection RNTI, "SC-RNTI" denotes a single cell RNTI, "SL-RNTI" denotes a sidelink RNTI, "SPS C-RNTI" denotes a semi-persistent scheduling C-RNTI, and "CS-RNTI" denotes a configured scaled RNTI.

[0053] FIG. 1 illustrates a communication system to which the present invention is applied.

[0054] 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.

[0055] Some use cases may require multiple areas for optimization, while others may focus on just one key performance indicator (KPI). 5G supports these various use cases in a flexible and reliable way.

[0056] eMBB goes far beyond basic mobile Internet access, covering media and entertainment applications in rich two-way work, cloud, or augmented reality. 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 increased traffic volume is primarily due to the increase in content size and the growing number of applications requiring high data transmission rates. Streaming services (audio and video), conversational video, and mobile Internet connections will become more widespread 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 work and entertainment. Cloud storage is also a particular use case driving the growth of uplink data transmission rates. 5G will also be used for cloud remote work, which requires lower end-to-end latency to maintain a good user experience when haptic interfaces are used. Entertainment, such as cloud gaming and video streaming, is another key element that increases the demand for mobile broadband capabilities. Entertainment is essential on smartphones and tablets everywhere, including in highly mobile environments such as trains, cars, and airplanes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires very low latency and instantaneous data volume.

[0057] One of the most anticipated use cases for 5G is its ability to seamlessly connect embedded sensors across all sectors, or 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.

[0058] URLLC encompasses new services that will transform industries through ultra-reliable / available low-latency links, such as remote control of key infrastructure and self-driving vehicles. Reliability and latency levels are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0059] 5G is a means of delivering streams rated at hundreds of megabits per second to gigabits per second, complementing fiber-to-the-home (FTTH) and cable-based broadband (or DOCSIS). Such high speeds are required to transmit TV at resolutions above 4K (6K, 8K, and beyond), as well as virtual and augmented reality. Virtual reality (VR) and augmented reality (AR) applications often involve 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.

[0060] Automotive is expected to be a key new driver of 5G, with many use cases for mobile communications within vehicles. For example, passenger entertainment will require simultaneous high-capacity and highly mobile broadband, as future users will expect continuous, high-quality connectivity regardless of their location and speed. Another example of an automotive application is an augmented reality dashboard, which overlays a display on top of what the driver sees through the front window, identifying objects in the dark and providing information to the driver about their distance and movement. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure, and information exchange between vehicles and other connected devices (e.g., devices accompanied by pedestrians). Safety systems will guide drivers through alternative courses of action to enable safer driving and reduce the risk of accidents. The next step will be remotely piloted or self-driven vehicles, which will require highly reliable and fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, self-driving vehicles will perform all driving activities, allowing drivers to focus only on traffic anomalies that the vehicle itself cannot identify. The technical requirements for self-driving vehicles demand ultra-low latency and ultra-high-speed reliability, so that traffic safety will increase to a level not achievable by humans.

[0061] Smart cities and smart homes, often referred to as smart societies, are embedded with dense wireless sensor networks. A distributed network of intelligent sensors identifies requirements for cost- and energy-efficient maintenance of a city or home. A similar setup can be created 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 consumption, and low cost. However, real-time HD video, for example, may be required for certain types of devices for surveillance.

[0062] The consumption and distribution of energy, including heat and 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 on 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 low-latency sensor network.

[0063] Mission-critical applications (e.g., e-health) are one of the 5G usage scenarios. The health sector has many applications that can benefit from mobile communications. Communication systems can support telemedicine, which provides 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.

[0064] Wireless and mobile communications are becoming increasingly important in industrial applications. Cabling is expensive to install and maintain. The ability to replace cables with reconfigurable wireless links is therefore an attractive opportunity in many industrial sectors. However, achieving this requires that wireless connections operate with similar latency, reliability and capacity to cables, while simplifying their management. Low latency and very low error probability are new requirements that need to be met with 5G.

[0065] 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.

[0066] 1, a communication system 1 includes wireless devices, a base station (BS), and a network. Although FIG. 1 illustrates a 5G network as an example of the network of the communication system 1, the present invention is not limited to the 5G system and can be applied to next-generation communication systems beyond the 5G system.

[0067] The BS and network are embodied in wireless devices, and a particular wireless device 200a can act as a BS / network node relative to other wireless devices.

[0068] The wireless device refers to a device that communicates using a wireless connection technology (radio access technology, RAT) (e.g., 5G NR, LTE) and may be referred to as a communication / wireless / 5G device. The wireless device includes, but is not limited to, a robot 100a, vehicles 100b-1, 100b-2, an XR (eXtended Reality) device 100c, a handheld device 100d, a home appliance 100e, an IoT (Internet of Things) device 100f, and an AI device / server 400. For example, the vehicle includes a vehicle equipped with a wireless communication function, an autonomous vehicle, and a vehicle capable of vehicle-to-vehicle communication. Here, the vehicle includes an unmanned aerial vehicle (UAV) (e.g., a drone). XR devices include AR (Augmented Reality), VR (Virtual Reality), and MR (Mixed Reality) devices, and are embodied in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) installed in vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital billboards, vehicles, robots, etc. Mobile devices include smartphones, smart pads, wearable devices (e.g., smart watches, smart glasses), computers (e.g., laptops, etc.), etc. Home appliances include TVs, refrigerators, washing machines, etc. IoT devices include sensors, smart meters, etc.

[0069] In the present invention, the wireless devices 100a to 100f are also referred to as UEs. Examples of UEs include mobile phones, smartphones, notebook computers, digital broadcasting terminals, personal digital assistants (PDAs), portable multimedia players (PMPs), car navigation systems, slate PCs, tablet PCs, ultrabooks, vehicles, vehicles with autonomous driving capabilities, connected cars, UAVs, artificial intelligence (AI) modules, robots, augmented reality (AR) devices, virtual reality (VR) devices, mixed reality (MR) devices, hologram devices, public safety devices, MTC devices, IoT devices, medical devices, fintech devices (or financial devices), security devices, meteorological / environmental devices, devices related to 5G services, and devices related to the Fourth Industrial Revolution. UAVs are, for example, aircraft that fly without a human on board and are controlled by wireless control signals. VR devices include, for example, devices for implementing objects or backgrounds in a virtual world. AR devices include, for example, devices embodied to connect virtual world objects or backgrounds with real world objects or backgrounds. MR devices include, for example, devices embodied to merge virtual world objects or backgrounds with real world objects or backgrounds. Hologram devices include, for example, devices for realizing 360-degree stereoscopic images by recording and reproducing three-dimensional information using the optical interference phenomenon generated when two lasers converge, known as holography. Public safety devices include, for example, wearable image relay devices or imaging devices. MTC devices and IoT devices include devices that do not require direct human intervention or operation. For example, MTC devices and IoT devices include smart meters, vending machines, thermometers, smart light bulbs, door locks, and various sensors. Medical devices are, for example, devices used for diagnosis, treatment, mitigation, cure, and disease prevention. Medical devices are, for example, devices for diagnosing, treating, mitigating, or correcting injuries or disabilities. For example, medical devices are devices used to rescue, examine, replace, or correct functions.For example, a medical device is a device for birth control. For example, medical devices include devices for medical examination, surgery, (in-vitro) diagnostics, hearing aids, and treatment devices. A security device is, for example, a device installed to prevent possible dangers and ensure safety. For example, security devices include cameras, CCTV, recorders, and black boxes. A fintech device is, for example, a device that provides financial services such as mobile payments. For example, a fintech device includes a payment device or a POS (point of sales) system. A weather / environment device includes, for example, a device for monitoring the weather / environment.

[0070] The wireless devices 100a to 100f are connected to a network 300 via a BS 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, a 5G (e.g., NR) network, or a beyond 5G network. The wireless devices 100a to 100f can communicate with each other via the BS 200 / network 300, but can also communicate directly without going through the BS / 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). Furthermore, an IoT device (for example, a sensor) can directly communicate with other IoT devices (for example, sensors) or other wireless devices 100a to 100f.

[0071] Wireless communication / connections 150a, 150b are performed between the wireless devices 100a-100f / BSs 200. Here, the wireless communication / connections are performed using various RATs (e.g., 5G NR) such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication). The wireless communication / connections 150a, 150b enable the wireless devices and BSs / wireless devices to transmit / receive wireless signals with each other. For example, the wireless communication / connections 150a, 150b can transmit / receive signals via various physical channels. To this end, according to 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.

[0072] FIG. 2 is a block diagram illustrating an example of a communication device that can perform the method according to the present invention.

[0073] 2, a first wireless device 100 and a second wireless device 200 can transmit and receive wireless signals to and from external devices via various RATs (e.g., LTE, NR). In Fig. 2, {the first wireless device 100 and the second wireless device 200} correspond to {wireless devices 100a-100f and BS 200} and / or {wireless devices 100a-100f and wireless devices 100a-100f} in Fig. 1.

[0074] 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 functions, procedures, and / or methods disclosed herein. For example, the processor 102 processes information in the memory 104 to generate first information / signals and then transmits a wireless signal including the first information / signals via the transceiver 106. The processor 102 also receives a wireless signal including second information / signals via the transceiver 106 and then stores information obtained from signal processing of the second information / signals 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 procedures and / or methods disclosed herein. Here, the processor 102 and memory 104 are part of a communications modem / circuit / chip designed to implement a RAT (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 this disclosure, wireless equipment may also refer to a communications modem / circuit / chip.

[0075] 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 functions, procedures, and / or methods disclosed herein. For example, the processor 202 processes information in the memory 204 to generate 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 fourth information / signal via the transceiver 206, and then stores information obtained from 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 procedures and / or methods disclosed herein. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE, NR). The transceiver 206 is coupled to the processor 202 and transmits and / or receives radio signals via 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 this disclosure, a wireless device may also refer to a communication modem / circuit / chip.

[0076] The hardware elements of the wireless devices 100, 200 are described in more detail below. Without limitation, one or more protocol layers may be implemented by one or more processors 102, 202. For example, the one or more processors 102, 202 may implement one or more layers (e.g., functional layers such as a physical PHY layer, a medium access control (MAC) layer, a radio link control (RLC) layer, a packet data convergence protocol (PDCP) layer, a radio resource control (RRC) layer, and a service data adaptation protocol (SDAP) layer). 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, and / or methods disclosed herein. The one or more processors 102, 202 may generate messages, control information, data, or information according to the functions, procedures, suggestions, and / or methods disclosed herein. The one or more processors 102, 202 may generate 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 and provide them 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 functions, procedures, suggestions, and / or methods disclosed herein.

[0077] 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. For 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 functions, procedures, suggestions, and / or methods disclosed herein may be implemented using firmware or software, and the firmware or software may be embodied to include modules, procedures, functions, etc. Firmware or software configured to perform the functions, procedures, suggestions, and / or methods 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 executed by the one or more processors 102, 202. The functions, procedures, suggestions and / or methods disclosed in this specification may be implemented using firmware or software in the form of code, instructions and / or sets of instructions.

[0078] The one or more memories 104, 204 are coupled to the one or more processors 102, 202 and 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.

[0079] One or more transceivers 106, 206 may transmit user data, control information, wireless signals / channels, etc., as described in the methods and / or flowcharts herein to one or more other devices. 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 flowcharts herein from one or more other devices. For example, one or more transceivers 106, 206 may be coupled to one or more processors 102, 202 to transmit and receive wireless signals. For example, one or more processors 102, 202 may control one or more transceivers 106, 206 to transmit user data, control information, or wireless signals to one or more other devices. Also, one or more processors 102, 202 may control one or more transceivers 106, 206 to receive user data, control information, or wireless signals from one or more other devices. One or more transceivers 106, 206 are coupled to one or more antennas 108, 208 and 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 flowcharts disclosed herein via the one or more antennas 108, 208. In this specification, one or more antennas may refer to 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 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 one or more processors 102, 202, from baseband signals to RF band signals. For this purpose, the one or more transceivers 106, 206 include (analog) oscillators and / or filters.For example, the transceiver 106, 206 may upconvert an OFDM baseband signal to a carrier frequency using the transceiver's (analog) oscillator and / or filter under control of the processor 102, 202, and transmit the upconverted OFDM signal at the carrier frequency. The transceiver 106, 206 may receive an OFDM signal at the carrier frequency and downconvert the OFDM signal to an OFDM baseband signal using the transceiver's (analog) oscillator and / or filter under control of the processor 102, 202.

[0080] In an embodiment of the present invention, a UE operates as a transmitter in the uplink and as a receiver in the downlink. In an embodiment of the present invention, a BS operates as a receiver in the uplink and as a transmitter in the downlink. Hereinafter, for convenience of explanation, unless otherwise specified or explained, it is assumed that a first wireless device 100 operates as a UE and a second wireless device 200 operates as a BS. For example, a processor 102 coupled to, mounted on, or launched in the first wireless device 100 is configured to perform a UE operation according to an embodiment of the present invention or to control a transceiver 106 to perform a UE operation according to an embodiment of the present invention. A processor 202 coupled to, mounted on, or launched in the second wireless device 200 is configured to perform a BS operation according to an embodiment of the present invention or to control a transceiver 206 to perform a BS operation according to an embodiment of the present invention.

[0081] In the present invention, at least one memory (e.g., 104 or 204) stores instructions or programs that, when executed, cause at least one processor operably coupled thereto to perform operations according to some embodiment or implementation of the present invention.

[0082] In the present invention, a computer-readable storage medium stores at least one instruction or computer program that, when executed by at least one processor, causes the at least one processor to perform operations according to any of the embodiments or implementations of the present invention.

[0083] In the present invention, a processing device or apparatus includes at least one processor and at least one computer memory coupleable to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations according to some embodiments or implementations of the present invention.

[0084] FIG. 3 is a diagram illustrating a frame structure in a 3GPP-based wireless communication system.

[0085] The frame structure of Figure 3 is merely an example, and the number of subframes, slots, and / or symbols in a frame may be variously changed. In a 3GPP-based wireless communication system, OFDM numerology (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) is configured to be different among multiple cells aggregated for one UE. For example, if a UE is configured with different SCSs for aggregated cells, the (absolute time) duration of time resources (e.g., subframes, slots, or TTIs) consisting of the same number of symbols may be different among the aggregated cells. Here, the symbols include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or DFT-s-OFDM (discrete Fourier transform-spread-OFDM) symbols).

[0086] Referring to Figure 3, uplink and downlink transmissions are organized into frames. Each frame is T f Each half-frame is composed of five subframes, and the duration of each subframe (T sf) is 1 ms. Each subframe is divided into slots, and the number of slots in a subframe varies depending on the subcarrier spacing. Each slot consists of 14 or 12 OFDM symbols depending on the cyclic prefix (CP). In normal CP, each slot consists of 14 OFDM symbols, and in extended CP, each slot consists of 12 OFDM symbols. Pneumatology uses exponentially scalable subcarrier spacing (△f=2 u *Based on 15kHz. The following table shows the subcarrier spacing (△f=2 u *15 kHz) indicates the number of OFDM symbols per slot, the number of slots per frame, and the number of slots for the general CP.

[0087] [Table 1]

[0088] The following table shows the subcarrier spacing (△f=2 u *15 kHz) indicates the number of OFDM symbols per slot, the number of slots per frame and the number of slots per subframe for the extended CP.

[0089] [Table 2]

[0090] A slot includes multiple (e.g., 14 or 12) symbols in the time domain. For each pneumatic (e.g., subcarrier spacing) and carrier, a common resource block (CRB) (N) is allocated as indicated by higher layer signaling (e.g., radio resource control (RRC) signaling). start,u grid ), N size,u grid,x *N RB sc subcarriers and Nsubframe,u symb A resource grid of N OFDM symbols is defined, where N size,u grid,x is the number of resource blocks (RB) in the resource grid, the subscript x is DL for downlink and UL for uplink, N RB sc is the number of subcarriers per RB. In a 3GPP-based wireless communication system, N RB sc is typically 12. For a given antenna port (p), subcarrier spacing configuration (u) and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth (N size,u grid ) is given by higher layer parameters (e.g., RRC parameters). Each element in the resource grid for an antenna port (p) and subcarrier spacing setting (u) is called a resource element (RE), and one complex symbol is mapped to each resource element. Each resource element in the resource grid is uniquely identified by an index (k) in the frequency domain and an index (l) indicating the symbol position relative to a reference point in the time domain. In 3GPP-based wireless communication systems, an RB is defined by 12 consecutive subcarriers in the frequency domain.

[0091] In a 3GPP NR system, RBs are classified into common resource blocks (CRBs) and physical resource blocks (PRBs). CRBs are numbered in the frequency domain, starting from 0 and increasing for a subcarrier spacing setting (u). The center of subcarrier 0 of CRB 0 for a subcarrier spacing setting (u) coincides with 'point A', the common reference point for the resource block grid. In a 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and are numbered from 0 to N. size BWP,iThe numbering is from -1 to i, where i is the number of the bandwidth part. PRB ) and common resource blocks (n CRB ) the relationship between them is as follows:

number

[0092] The NR frequency band is defined by two types of frequency ranges, FR1 and FR2. FR2 is also called millimeter wave (mmW). The frequency ranges in which NR can operate are distinguished as shown in Table 3.

[0093] [Table 3]

[0094] FIG. 4 is a diagram illustrating a protocol stack in a 3GPP-based wireless communication system.

[0095] In particular, FIG. 4(a) illustrates an example of a radio interface user plane protocol stack between a UE and a base station (BS), and FIG. 4(b) illustrates an example of a radio interface control plane protocol stack between a UE and a BS. The control plane refers to the path through which control messages used by the UE and the network to manage a call are transmitted. The user plane refers to the path through which data generated at the application layer, such as voice data or Internet packet data, is transmitted. Referring to FIG. 4(a), the user plane protocol stack is divided into layer 1 (i.e., the physical (PHY) layer) and layer 2 (i.e., layer 2). Referring to FIG. 4(b), the control plane protocol stack is divided into layer 1 (i.e., the PHY layer), layer 2, layer 3 (e.g., the radio resource control (RRC) layer, and the non-access stratum (NAS)). Layers 1, 2, and 3 are referred to as the access stratum (AS).

[0096] The NAS control protocol is terminated by the access management function (AMF) on the network side, and performs authentication, mobility management, security control, etc.

[0097] In a 3GPP LTE system, Layer 2 is divided into the following sublayers: medium access control (MAC), radio link control (RLC), and packet data convergence protocol (PDCP). In a 3GPP New Radio (NR) system, Layer 2 is divided into the following sublayers: MAC, RLC, PDCP, and service data adaptation protocol (SDAP). The PHY layer provides transmission channels to the MAC sublayer, which provides logical channels to the RLC sublayer, which provides RLC channels to the PDCP sublayer, and the PDCP sublayer provides radio bearers to the SDAP sublayer. The SDAP sublayer provides QoS flows to the 5G core network.

[0098] In 3GPP NR systems, the main services and functions of SDAP include: mapping between QoS flows and data radio bearers; marking of QoS flow ID (QFI) in both DL and UL packets. A single protocol entity of SDAP is configured for each PDU section.

[0099] In a 3GPP NR system, the main services and functions of the RRC sublayer include: broadcasting of system information related to AS and NAS; paging initiated by 5GC or NG-RAN; setting up, maintaining and releasing the RRC connection between the UE and the NG-RAN; security functions including key management; establishment, setting up, maintaining and releasing of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including handover and context transfer; UE cell selection, reselection and control of cell selection and reselection; inter-RAT mobility); QoS management functions, UE measurement reporting and reporting control; detection of and recovery from radio link failures; and transmission of NAS messages from the UE to the NAS and from the NAS to the UE.

[0100] In a 3GPP NR system, the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression (only in the case of robust header compression (ROHC)); user data transmission; reordering and duplicate detection; in-order transmission; PDCP PDU routing (in the case of split bearer); retransmission of PDCP SDUs; ciphering, deciphering, and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCH status reporting for RLC AM; PDCP PDU duplication and indication to lower layers that duplicates should be discarded. The main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering, and integrity protection; transmission of control plane data; reordering and duplicate detection; in-order transmission; PDCP PDU duplication and indication to lower layers that duplicates should be discarded.

[0101] In a 3GPP NR system, the RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). RLC configuration is applied per logical channel, independent of pneumatology and / or transmission duration. In a 3GPP NR system, the main services and functions of the RLC sublayer depend on the transmission mode and include delivery of upper layer PDUs; sequence numbering independent of PDCP numbering (for UM and AM); error correction using automatic repeat request (ARQ) (for AM only); RLC SDU segmentation (for UM and AM) and re-segmentation (for AM only); SDU reassembly (for UM and AM); RLC SDU discard (for UM and AM); RLC re-establishment; and protocol error detection (for AM only).

[0102] In a 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transmission channels; multiplexing / demultiplexing of MAC SDUs belonging to one or different logical channels to / from transport blocks (TBs) transmitted to / from the PHY layer via transmission channels; scale information reporting; error correction using hybrid automatic repeat request (HARQ) (one HARQ entity per cell in the case of CA); priority handling between UEs using dynamic scheduling; priority handling between logical channels of one UE using logical channel priorities; and padding. A single MAC entity supports multiple pneumatics, transmission timings, and cells. In logical channel priorities, mapping constraints control which pneumatics, cells, and transmission timings a logical channel uses. Different types of data transmission services are provided by the MAC. To accommodate different types of data transmission services, multiple logical channel types are defined, each supporting a specific type of information transmission. Each logical channel type is defined according to the type of information it carries. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used to carry only control plane information, while traffic control channels are used to carry only user plane information.The broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information. The paging control channel (PCCH) is a downlink logical channel for carrying paging information, system information change notifications, and indications of ongoing PWS broadcasts. The common control channel (CCCH) is a logical channel for transmitting control information between a UE and a network and is used for UEs that do not have an RRC connection with the network. The dedicated control channel (DCCH) is a point-to-point bidirectional logical channel for transmitting dedicated control information between a UE and a network and is used by UEs that have an RRC connection. The dedicated traffic channel (DTCH) is a point-to-point logical channel dedicated to a single UE for carrying user information. DTCH exists in both the uplink and downlink. In the downlink, the connections between logical channels and transport channels are as follows: BCCH is mapped to BCH; BCCH is mapped to downlink shared channel (DL-SCH); PCCH is mapped to PCH; CCCH is mapped to DL-SCH; DCCH is mapped to DL-SCH; DTCH is mapped to DL-SCH. In the uplink, the connections between logical channels and transport channels are as follows: CCCH is mapped to uplink shared channel (UL-SCH); DCCH is mapped to UL-SCH; DTCH is mapped to UL-SCH.

[0103] FIG. 5 shows an example of a data flow in a 3GPP NR system.

[0104] In Figure 5, "RB" stands for radio bearer, and "H" stands for header. Radio bearers are divided into two groups: data radio bearers (DRB) for user plane data and signaling radio bearers (SRB) for control plane data. MAC PDUs are transmitted to and received from external devices via the PHY layer using radio resources. MAC PDUs arrive at the PHY layer in the form of transport blocks.

[0105] At the PHY layer, the uplink transport channels UL-SCH and RACH are mapped to PUSCH and PRACH, respectively, and the downlink transport channels DL-SCH, BCH, and PCH are mapped to PDSCH, physical broadcast channel (PBCH), and PDSCH, respectively. At the PHY layer, uplink control information (UCI) is mapped to PUCCH, and downlink control information (DCI) is mapped to PDCCH. MAC PDUs associated with the UL-SCH are transmitted by the UE via PUSCH based on an uplink grant, and MAC PDUs associated with the DL-SCH are transmitted by the BS via PDSCH based on a downlink allocation.

[0106] To transmit a data unit of the present invention via the UL-SCH, the UE must have uplink resources available to the UE. To receive a data unit of the present invention via the DL-SCH, the UE must have downlink resources available to the UE. Resource allocation includes time domain resource allocation and frequency domain resource allocation. In this invention, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink assignment. The uplink grant is dynamically received by the UE via the PDCCH within an Optional Access Response or semi-persistently configured to the UE by RRC. The downlink assignment is dynamically received by the UE via the PDCCH or semi-persistently configured to the UE by RRC signaling from the BS.

[0107] In the uplink, the BS can dynamically allocate resources to the UE using the cell radio network temporary identifier (C-RNTI) on the PDCCH. When the UE's downlink reception is enabled (activity governed by discontinuous reception (DRX) at the time of configuration), the UE constantly monitors the PDCCH to look for possible grants for uplink transmission. Using the configured grant, the BS can also allocate uplink resources for initial HARQ transmission to the UE. Two types of configured uplink grants are defined: Type 1 and Type 2. In Type 1, the RRC directly provides the configured uplink grant (including the periodicity). In Type 2, the RRC defines the periodicity of the configured uplink grant, during which the PDCCH addressed to the configured scheduling RNTI (CS-RNTI) signals and activates or deactivates the configured uplink grant. That is, the PDCCH addressed to the CS-RNTI indicates that the uplink grant can be implicitly reused at a period defined by the RRC until the uplink grant is deactivated.

[0108] In the downlink, the BS can dynamically allocate resources to the UE by means of C-RNTI on the PDCCH. The UE always monitors the PDCCH to search for possible grants when the UE's downlink reception is enabled (at setup, activity controlled by DRX). Also, using semi-persistent scheduling (SPS), the BS can allocate downlink resources for the initial HARQ transmission to the UE. The RRC signals and activates or deactivates the downlink allocation where the PDCCH addressed to the CS-RNTI is set, or defines the period of the set downlink allocation while it can be signaled and activated or deactivated. That is, the PDCCH addressed to the CS-RNTI indicates that the downlink allocation can be implicitly reused according to the period defined by the RRC until the downlink allocation is deactivated.

[0109] <Resource Allocation by PDCCH (i.e., Resource Allocation by DCI)>

[0110] The PDCCH is used to schedule downlink transmissions on the PDSCH and uplink transmissions on the PUSCH, where the DCI on the PDCCH includes: a downlink allocation related to the DL-SCH, at least including modulation and coding format (e.g., modulation and coding scheme (MCS) index (IMCS)), resource allocation, and hybrid ARQ information; or an uplink scheduling grant related to the UL-SCH, including modulation and coding format, resource allocation, and hybrid ARQ information. The size and use of the DCI carried by one PDCCH vary according to the DCI format. For example, in the 3GPP NR system, DCI format 0_0 or DCI format 0_1 is used for scheduling the PUSCH in one cell, and DCI format 1_0 or DCI format 1_1 is used for scheduling the PDSCH in one cell.

[0111] FIG. 6 is a diagram showing an example of PDSCH time domain resource allocation by PDCCH and an example of PUSCH time domain resource allocation by PDCCH.

[0112] To schedule a PDSCH or a PUSCH, the DCI carried by the PDCCH includes a value m for row index m+1 in the allocation table for the PDSCH or PUSCH. Either a predetermined default PDSCH time domain allocation A, B, or C is applied to the allocation table for the PDSCH, or an RRC-configured PDSCH-TimeDomainAllocationList is applied to the allocation table for the PDSCH. Either a predetermined default PUSCH time domain allocation A is applied to the allocation table for the PUSCH, or an RRC-configured PUSCH-TimeDomainAllocationList is applied to the allocation table for the PUSCH. Which PDSCH time domain resource allocation configuration and which PUSCH time domain resource allocation table are applied are determined by fixed / predetermined rules (e.g., Table 5.1.2.1.1-1 of 3GPP TS 38.214 v15.3.0, Table 6.1.2.1.1-1 of 3GPP TS 38.214 v15.3.0).

[0113] In the configuration of PDSCH time domain allocation, each indexed row directly defines the slot offset K0, the start and length indicator SLIV or the start symbol S and the allocation length L, and the PDSCH mapping type assumed for PDSCH reception. In the configuration of PUSCH time domain allocation, each indexed row directly defines the slot offset K2, the start and length indicator SLIV or the start symbol S and the allocation length L, and the PUSCH mapping type assumed for PUSCH reception. K0 for PDSCH or K2 for PUSCH is the time difference between the slot where the PDCCH is located and the slot where the PDSCH or PUSCH corresponding to the PDCCH is located. SLIV is a joint indicator of the start symbol S regarding the start of the slot where PDSCH or PUSCH is located and the number L of consecutive symbols counted from symbol S. In the case of the PDSCH / PUSCH mapping type, there are two mapping types: one is mapping type A where the demodulation reference signal (DMRS) is located in the third or fourth symbol of the slot by mapping RRC signaling, and the other is mapping type B where the DMRS is located in the first allocated symbol.

[0114] The scheduling DCI includes a frequency domain resource allocation field that provides allocation information regarding the resource blocks used for PDSCH or PUSCH. For example, the frequency domain resource allocation field provides the UE with information regarding the cell for PDSCH or PUSCH transmission, information regarding the bandwidth part for PDSCH or PUSCH transmission, and information regarding the resource blocks for PDSCH or PUSCH transmission.

[0115] <Resource Allocation by RRC>

[0116] As mentioned above, there are two types of transmissions in the uplink that do not have dynamic grants: configured grant type 1 and configured grant type 2. In the case of configured grant type 1, an uplink grant is provided by RRC and stored as a configured grant. In the case of configured grant type 2, an uplink grant is provided by PDCCH and stored or cleared as a configured uplink grant based on L1 signaling that indicates configured uplink grant activation or deactivation. Type 1 and Type 2 are configured by RRC signaling for each serving cell and for each BWP. Multiple configurations can be simultaneously activated only on different serving cells. In the case of Type 2, activation and deactivation are independent between serving cells. A MAC entity for the same serving cell is configured as Type 1 or Type 2.

[0117] When grant type 1 is configured, the UE is provided with at least the following parameters by the BS via RRC signaling:

[0118] - s-RNTI, which is the CS-RNTI for the retransmission;

[0119] - periodicity providing the configured grant type 1 periodicity;

[0120] - timeDomainOffset, which indicates the offset of the resource relative to System frame number (SFN) = 0 in the time domain;

[0121] - a timeDomainAllocation value m providing a row index m+1 pointing to an allocation table indicating the combination of starting symbol S, length L and PUSCH mapping type;

[0122] - frequencyDomainAllocation, which provides frequency domain resource allocation; and

[0123] - mcsAndTBS providing IMCS indicating modulation number, target code rate and transport block size. When configuring grant type 1 for the serving cell by RRC, the UE stores the uplink grant provided by RRC as the configured uplink grant for the indicated serving cell and initializes or re-initializes the configured uplink grant so that it starts and reoccurs periodically at a symbol according to timeDomainOffset and S (derived from SLIV). After an uplink grant is configured for configured grant type 1, the UE shall consider the uplink grant to recur associated with each symbol that satisfies the following: [(SFN*numberOfSlotsPerFrame (numberOfSymbolsPerSlot)+(Slot number in the frame*numberOfSymbolsPerSlot)+symbol number in the slot]=(timeDomainOffset*numberOfSymbolsPerSlot+S+N*periodicity) modulo (1024*numberOfSlotsPerFrame*numberOfSymbolsPerSlot), for all N>=0.

[0124] When grant type 2 is configured, the UE is provided with at least the following parameters by the BS via RRC signaling:

[0125] -cs-RNTI, which is the CS-RNTI for activation, deactivation, and retransmission; and

[0126] - periodicity, which provides the periodicity of the configured grant type 2. The actual uplink grant is provided to the UE via the PDCCH (addressed to CS-RNTI). After an uplink grant is configured for the configured grant type 2, the UE considers the uplink grant to recur in association with each symbol that satisfies the following: [(SFN*numberOfSlotsPerFrame*numberOfSymbolsPerSlot)+(Slot number in the frame*numberOfSymbolsPerSlot)+symbol number in the slot]=[(SFNstart time*numberOfSlotsPerFrame*numberOfSymbolsPerSlot+slotstart time*numberOfSymbolsPerSlot+symbol start time )+N*periodicity] modulo (1024×numberOfSlotsPerFrame*numberOfSymbolsPerSlot), for all N>=0, where SFN start time , slot start time and symbol start time denote the SFN, slot, and symbol of the first PUSCH transmission opportunity for which the configured grant is (re)initialized. numberOfSlotsPerFrame and numberOfSymbolsPerSlot denote the number of consecutive slots per frame and the number of consecutive OFDM symbols per slot, respectively.

[0127] For a configured uplink grant, the HARQ process ID associated with the first symbol of the uplink transmission is derived from the following formula:

[0128] HARQ Process ID=[floor(CURRENT_symbol / periodicity)] modulo nrofHARQ-Processes

[0129] where CURRENT_symbol = (SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot + slot number in the frame × numberOfSymbolsPerSlot + symbol number in the slot), where numberOfSlotsPerFrame and numberOfSymbolsPerSlot indicate the number of consecutive slots per frame and the number of consecutive symbols per slot, respectively, as specified in TS 38.211. CURRENT_symbol indicates the symbol index of the first transmission opportunity of the occurring recurrence. An HARQ process is configured for a configured uplink grant if the configured uplink grant is activated, and the associated HARQ process ID is less than nrofHARQ-Processes.

[0130] For downlink, the UE is configured with SPS per serving cell and per BWP via RRC signaling from the BS. Multiple configurations may be simultaneously activated on different serving cells. Activation or deactivation of downlink SPS is independent between serving cells. For downlink SPS, a downlink allocation is provided to the UE via PDCCH and is stored or removed based on L1 signaling indicating SPS activation or deactivation. When SPS is configured, the UE is provided with the following parameters from the BS via RRC signaling:

[0131] - cs-RNTI, which is the CS-RNTI for activation, deactivation and retransmission;

[0132] - nrofHARQ-Processes, providing the number of configured HARQ processes for SPS;

[0133] - periodicity, which provides the periodicity of the configured downlink allocation for SPS.

[0134] When an SPS is released by a higher layer, all corresponding settings must be released.

[0135] After the downlink allocation for SPS is configured, the UE considers the Nth downlink allocation to occur in the sequential slot that satisfies: (numberOfSlotsPerFrame*SFN+slot number in the frame)=[(numberOfSlotsPerFrame*SFN start time +slot start time )+N*periodicity*numberOfSlotsPerFrame / 10] modulo (1024*numberOfSlotsPerFrame), where SFN start time and slot start time indicate the SFN, slot, and symbol of the first transmission of the PDSCH, respectively, at which the configured downlink allocation is (re)initialized.

[0136] For a configured downlink allocation, the HARQ process ID associated with the slot in which the downlink transmission begins is derived from the following formula:

[0137] HARQ Process ID=[floor (CURRENT_slot×10 / (numberOfSlotsPerFrame×periodicity))] modulo nrofHARQ-Processes

[0138] Here, CURRENT_slot = [(SFN x numberOfSlotsPerFrame) + slot number in the frame], and numberOfSlotsPerFrame indicates the number of consecutive slots per frame as specified in TS38.211.

[0139] If the cyclic redundancy check (CRC) of the corresponding DCI format is scrambled with the CS-RNTI provided by the RRC parameter cs-RNTI and the new data indicator field for the enabled transport block is set to 0, the UE validates the downlink SPS allocated PDCCH or the configured uplink grant type 2 PDCCH for scheduling activation or descheduling. Validity confirmation of a DCI format is achieved when all fields for the DCI format are set according to Table 4 or Table 5. Table 4 illustrates specific fields for validity confirmation of downlink SPS and uplink grant type 2 scheduling activation PDCCH, and Table 5 illustrates specific fields for validity confirmation of downlink SPS and uplink grant type 2 descheduling PDCCH.

[0140] [Table 4]

[0141] [Table 5]

[0142] The actual downlink allocation and the actual uplink grant, as well as the corresponding modulation and coding scheme, are provided by resource allocation fields (e.g., a time domain resource allocation field providing the time domain allocation value m, a frequency domain resource allocation field providing the frequency resource block allocation, and a modulation and coding scheme field) in the DCI format carried by the scheduling activation PDCCH of the downlink SPS or uplink grant type 2. If valid confirmation is achieved, the UE considers the information in the DCI format as valid activation or deactivation of the downlink SPS or configured uplink grant type 2.

[0143] In the uplink case, the processor 102 of the present invention transmits (or controls the transceiver 106 to transmit) the data unit of the present invention based on the uplink grant available to the UE, and the processor 202 of the present invention receives (or controls the transceiver 206 to receive) the data unit of the present invention based on the uplink grant available to the UE.

[0144] For the downlink, the processor 102 of the present invention receives (or controls the transceiver 106 to receive) the downlink data of the present invention based on the downlink allocation available to the UE, and the processor 202 of the present invention transmits (or controls the transceiver 206 to transmit) the downlink data of the present invention based on the downlink allocation available to the UE.

[0145] The data unit of the present invention undergoes physical layer processing at the transmitting end before being transmitted over the radio interface, and the radio signal carrying the data unit of the present invention undergoes physical layer processing at the receiving end. For example, a MAC PDU including a PDCP PDU of the present invention undergoes physical layer processing as follows:

[0146] FIG. 7 is a diagram showing an example of physical layer processing on the transmitting side.

[0147] The following tables show how transport channels (TrCHs) and control information are mapped to corresponding physical channels. In particular, Table 6 shows how uplink transport channels are mapped to corresponding physical channels, Table 7 shows how uplink control channel information is mapped to corresponding physical channels, Table 8 shows how downlink transport channels are mapped to corresponding physical channels, and Table 9 shows how downlink control channel information is mapped to corresponding physical channels.

[0148] [Table 6]

[0149] [Table 7]

[0150] [Table 8]

[0151] [Table 9]

[0152] <encoding>

[0153] Data and control streams from / to the MAC layer are coded and then transported and controlled by the PHY layer over the wireless transmission link. For example, transport blocks from the MAC layer are coded into codewords at the transmitter. Channel coding techniques include error detection, error correction, rate matching, interleaving, and a combination of transport channel or control information that is mapped to or split from physical channels.

[0154] In the 3GPP NR system, the following channel coding schemes are used for different types of TrCHs and different types of control information.

[0155] [Table 10]

[0156] [Table 11]

[0157] For transmission of a downlink transport block (i.e., DL MAC PDU) or an uplink transport block (i.e., UL MAC PDU), a transport block CRC sequence is attached to provide error detection for the receiving side. In a 3GPP NR system, communication devices use low-density parity check (LDPC) codes when encoding / decoding the UL-SCH and DL-SCH. The 3GPP NR system supports two LDPC base graphs (i.e., two LDPC base matrices): LDPC base graph 1, which is optimized for small transport blocks, and LDPC base graph 2, which is optimized for larger transport blocks. LDPC base graph 1 or 2 is selected based on the size of the transport block and the coding rate R. The coding rate R is indicated by the MCS index (IMCS). The MCS index is provided to the UE via an uplink configured grant 2 or a PDCCH for activating or (re)initializing downlink SPS, or is dynamically applied to the UE via a PDCCH for scheduling a PUSCH or PDSCH, which is provided to the UE via RRC signaling related to uplink configured grant type 1. If the CRC-attached transport block is larger than the maximum code block size for the selected LDPC base graph, the CRC-attached transport block is divided into code blocks, and an additional CRC sequence is attached to each code block. The maximum code block sizes for LDPC base graph 1 and LDPC base graph 2 are 8448 bits and 3480 bits, respectively. If the CRC-attached transport block is not larger than the maximum code block size for the selected LDPC base graph, the CRC-attached transport block is coded using the selected LDPC base graph. Each code block of the transport block is then coded using the selected LDPC base graph. The LDPC-coded blocks are then individually rate-matched. Code block concatenation is performed to generate a codeword for transmission on the PDSCH or PUSCH.For PDSCH, up to two codewords (i.e., up to two transmission blocks) are transmitted simultaneously on the PDSCH. The PUSCH can be used to transmit UL-SCH data and Layer 1 / 2 control information. Although not shown in Figure 8, Layer 1 / 2 control information can be multiplexed with the codeword for UL-SCH data.

[0158] Scrambling and Modulation

[0159] The bits of the codeword are scrambled and modulated to produce a block of complex-valued modulation symbols.

[0160] <Layer Mapping>

[0161] The complex-valued modulation symbols of a codeword are mapped to one or more multiple input multiple output (MIMO) layers. A codeword can be mapped to up to four layers. Since the PDSCH can transmit two codewords, it can support up to eight-layer transmission. Since the PUSCH supports a single codeword, it can support up to four-layer transmission.

[0162] <Transform Precoding>

[0163] The downlink transmit waveform is conventional OFDM with cyclic prefix (CP). For the downlink, no transform precoding (i.e., discrete Fourier transform (DFT)) is applied.

[0164] The uplink transmission waveform is a conventional OFDM that uses a CP with a transform precoding function that can perform DFT spreading which can be made invalid or valid. In the 3GPP NR system, in the case of the uplink, transform precoding is selectively applied when it is enabled. Transform precoding is to spread uplink data in a special manner to reduce the peak-to-average power ratio (PAPR) of the waveform. Transform precoding is a form of DFT. That is, the 3GPP NR system supports two options for the uplink waveform: one is CP-OFDM (the same as the downlink waveform), and the other is DFT-s-OFDM. Whether the UE uses CP-OFDM or DFT-s-OFDM is set by the BS according to the RRC parameter.

[0165] <Subcarrier mapping>

[0166] Layers are mapped to antenna ports. In the downlink, a mapping in a transparent manner (non-codebook based) for layer-antenna port mapping is supported, and how beamforming or MIMO precoding is performed is transparent to the UE. In the uplink, both non-codebook based mapping and codebook based mapping for layer-antenna port mapping are supported.

[0167] For each antenna port (i.e., layer) used for the transmission of a physical channel (e.g., PDSCH, PUSCH), the complex-valued modulation symbols are mapped to subcarriers in the resource blocks allocated to the physical channel.

[0168] <OFDM modulation>

[0169] The communication device at the transmitting side adds a CP and performs an inverse fast Fourier transform (IFFT) to generate a time-continuous OFDM baseband signal at antenna port p and subcarrier spacing setting u for OFDM symbol l in the TTI for the physical channel. For example, for each OFDM symbol, the communication device at the transmitting side may perform an IFFT on complex-valued modulation symbols mapped to resource blocks in the corresponding OFDM symbol, and add a CP to the IFFTed signal to generate an OFDM baseband signal.

[0170] Up-conversion

[0171] The communication equipment at the transmitting side upconverts the OFDM baseband signal for antenna port p, subcarrier spacing setting u and OFDM symbol l to the carrier frequency f0 of the cell to which the physical channel is assigned.

[0172] 2, processors 102, 202 are configured to perform encoding, scrambling, modulation, layer mapping, (uplink) transform precoding, subcarrier mapping, and OFDM modulation. The processors 102, 202 control transceivers 106, 206 coupled thereto to upconvert the OFDM baseband signal to a carrier frequency to generate a radio frequency (RF) signal. The RF signal is transmitted to an external device via antennas 108, 208.

[0173] FIG. 8 is a diagram showing an example of physical layer processing on the receiving side.

[0174] The physical layer processing on the receiving side is basically the reverse of the physical layer processing on the transmitting side.

[0175] <Frequency down-conversion>

[0176] The communication device on the receiving side receives an RF signal at the carrier frequency via an antenna. Transceivers 106 and 206 that receive an RF signal at the carrier frequency down-convert the carrier frequency of the RF signal to the baseband to obtain an OFDM baseband signal.

[0177] <OFDM Demodulation>

[0178] The communication device on the receiving side obtains complex-valued modulation symbols by CP separation (detachment) and FFT. For example, for each OFDM symbol, on the receiving side, the communication device removes the CP from the OFDM baseband signal and performs FFT on the OFDM baseband signal after CP removal to obtain complex-valued modulation symbols for antenna port p, subcarrier spacing u, and OFDM symbol l.

[0179] <Subcarrier Demapping>

[0180] Subcarrier demapping is performed on the complex-valued modulation symbols to obtain the complex-valued modulation symbols of the corresponding physical channel. For example, processor 102 can obtain the complex-valued modulation symbols mapped to the subcarriers belonging to PDSCH from the complex-valued modulation symbols received in the BWP. As another example, processor 202 can obtain the complex-valued modulation symbols mapped to the subcarriers belonging to PUSCH from the complex-valued modulation symbols received in the BWP.

[0181] <Inverse Transform Decoding>

[0182] Inverse transform decoding (e.g., IDFT) is performed on the complex-valued modulation symbols of the uplink physical channel when transform precoding is enabled for the uplink physical channel. Inverse transform decoding is not performed for the downlink physical channel and the uplink physical channel when transform precoding is disabled.

[0183] <Layer Demapping>

[0184] The complex-valued modulation symbols are demapped into one or two codewords.

[0185] Demodulation and descrambling

[0186] The complex-valued modulation symbols of the codeword are demodulated and descrambled into the bits of the codeword.

[0187] <Decryption>

[0188] The codeword is decoded into a transport block. For UL-SCH and DL-SCH, LDPC base graph 1 or 2 is selected based on the size of the transport block and the coding rate. The codeword contains one or more coded blocks. Each coded block is decoded into a CRC-attached code block or a CRC-attached transport block using the selected LDPC base graph. When the transmitter performs code block segmentation on the CRC-attached transport block, the CRC sequence is removed from each CRC-attached code block to obtain a code block. The code block is concatenated with the CRC-attached transport block. The transport block CRC sequence is removed from the CRC-attached transport block to obtain a transport block. The transport block is then passed to the MAC layer.

[0189] In the physical layer processing at the transmitting and receiving sides described above, the time and frequency domain resources (e.g., OFDM symbols, subcarriers, carrier frequencies) associated with subcarrier mapping, OFDM modulation, and frequency up / down conversion are determined based on resource allocation (e.g., uplink grant, downlink allocation).

[0190] For uplink data transmission, the processor 102 of the present invention applies (or controls the transceiver 106 to apply) the above-described physical layer processing on the transmitting side to the data unit of the present invention and transmits the data unit over the air. For downlink data reception, the processor 102 of the present invention applies (or controls the transceiver 106 to apply) the above-described physical layer processing on the receiving side to the received radio signal to obtain the data unit of the present invention.

[0191] For downlink data transmission, the processor 202 of the present invention applies (or controls the transceiver 206 to apply) the above-described physical layer processing on the transmitting side to the data unit of the present invention and transmits the data unit over the air. For uplink data reception, the processor 202 of the present invention applies (or controls the transceiver 206 to apply) the above-described physical layer processing on the receiving side to the received radio signal to obtain the data unit of the present invention.

[0192] Recently, the 3GPP NR standard has introduced the concept of PDU sets to XR services to handle QoS by taking into account various characteristics of PDUs in a QoS flow.

[0193] Here, a PDU set is defined as one or more PDUs that carry the payload of one information unit generated from the application level (e.g., a frame or video slice) for an XR service.

[0194] FIG. 9 is a diagram illustrating the concept of a PDU set for an XR service in an NR system.

[0195] Referring to FIG. 9, one data burst is made up of multiple PDUs, and the multiple PDUs are divided into multiple PDU sets.

[0196] To handle multiple PDU sets, define information about the PDU sets as follows:

[0197] - PDU Set Sequence Number.

[0198] - The last PDU of a PDU set.

[0199] - PDU SN within the PDU set.

[0200] - PDU set size in bytes.

[0201] - The importance of the PDU set.

[0202] In particular, the PDU set importance is used to identify the importance of a PDU set within a QoS flow, allowing the network to take action on PDU set level discarding in the presence of congestion.

[0203] In particular, the network can detect congestion in the uplink and downlink, meaning that it will take discarding action if it detects congestion. Furthermore, the network can provide a congestion indicator to the UE to take discarding action based on the importance of the PDU set.

[0204] FIG. 10 is a diagram showing an example of a discard procedure based on the importance of a PDU set according to the prior art.

[0205] 10, it is assumed that the UE stores PDCP PDUs associated with three PDU sets. The first PDU set including SDU #1 to SDU #6 and the second PDU set including SDU #7 to SDU #12 have the general PDU set importance level, while the third PDU set including SDU #13 to SDU #18 has the highest PDU set importance level.

[0206] When the UE receives a congestion indicator from the network, the UE performs a discard operation on the PDCP SDUs belonging to the first and second PDU sets because the first and second PDU sets have the importance level of a general PDU set.

[0207] After this, the UE continues to transmit PDCP SDUs belonging to the third PDU set.

[0208] Meanwhile, the main function of the SDAP (Service Data Adaptation Protocol) layer is to map between QoS flows and DRBs (data radio bearers) for both DL and UL. RRC configures QoS flow to DRB mapping rules for the SDAP entity, and the SDAP entity follows the mapping rules when transferring packets from the QoS flow to the DRB (in the UL case) or from the DRB to the QoS flow (in the DL case). Since the DRB has a one-to-one relationship with the PDCP entity, the mapping rules between the QoS flow and the DRB are the same as those between the QoS flow and the PDCP entity.

[0209] FIG. 11 is a diagram showing an example of QoS flow-DRB-LoCH mapping according to the prior art.

[0210] Referring to Figure 11, in XR (eXtended Reality), multiple QoS flows are mapped to one DRB. Therefore, in the uplink, packets of different QoS flows are delivered to the same PDCP entity. In addition, in the downlink, packets of the PDCP entity are delivered to different QoS flows.

[0211] When multiple QoS flows are mapped to one DRB, each QoS flow requires different QoS treatment in the RAN, so packets of each QoS flow are transmitted via different logical channels (LoCHs) even though they are mapped to a single DRB.

[0212] Network congestion may occur. For example, in a sports stadium or concert hall, many people may transmit uplink data to the network, resulting in insufficient radio resources. In this case, the network can block the UE's uplink transmission by not providing an uplink grant.

[0213] However, if the network does not provide any uplink grant to the UE, all uplink data from the UE cannot be transmitted, and if it is not transmitted within the maximum allowable delay time, all uplink data may be discarded.

[0214] Another way for the network to alleviate congestion is to send a discard instruction for a specific DRB to the UE. This can be implemented by sending a PDCP status report to acknowledge the PDCP SDU even if the PDCP SDU is not actually received. When the UE receives the PDCP status report, the UE discards the PDCP SDU indicated as ACK, thereby alleviating network congestion.

[0215] However, in XR, where multiple QoS flows are transmitted, not all of the above methods may be applicable. Some QoS flows may be more important than others and must be transmitted even if network congestion occurs. If this is not the case, the user experience of the XR service may be seriously degraded.

[0216] The present invention proposes that when a congestion situation occurs in the network, the network sends a congestion indicator to the UE, which includes an identifier of a QoS flow to be blocked. When the UE receives the congestion indicator including the QoS flow identifier from the network, it discards packets belonging to the QoS flow indicated by the QoS flow identifier.

[0217] Preferably, the congestion indicator is sent via one of a MAC CE, an RLC control PDU, a PDCP control PDU, an SDAP control PDU, or RRC signaling.

[0218] Preferably, the congestion indicator comprises a QoS flow identifier, which is one of a QoS flow ID, an RLC entity ID, or an LCID (Logical Channel ID). If there is a one-to-one relationship between a QoS flow and an RLC entity or LoCH, the RLC entity ID or LCID is used as the QoS flow identifier.

[0219] Preferably, the congestion indicator includes identifiers for a plurality of QoS flows.

[0220] When the UE receives a congestion indication including a QoS flow identifier from the network, the UE discards all SDUs and PDUs belonging to the QoS flow. The UE discards all SDUs and PDUs belonging to the QoS flow stored in at least one of the SDAP entity, the PDCP entity, the RLC entity, and the MAC entity. In the SDAP entity, the UE also discards packets of the QoS flow received from higher layers. In the RLC entity, the UE may not discard a packet if at least a portion of the packet has already been transmitted.

[0221] The UE may also discard packets belonging to other QoS flows with a lower priority than the QoS flow included in the congestion indication. For this purpose, the network may assign a QoS flow priority to each QoS flow. Alternatively, the network may use the logical channel priority or the importance level of the QoS flow as the QoS flow priority.

[0222] If the congestion indicator includes multiple QoS flow identifiers, the UE discards all SDUs and PDUs that belong to any one of the multiple QoS flows.

[0223] When the UE receives an uplink grant after discarding packets of the indicated QoS flow, the UE constructs a MAC PDU without including packets of the indicated QoS flow and transmits the MAC PDU to the network.

[0224] The UE may continue to discard packets of the indicated QoS flow until a resume indicator is received. The resume indicator includes an identifier of the QoS flow to be resumed. When the UE receives a resume indicator including at least one QoS flow identifier, the UE stops discarding packets and performs the normal procedure for uplink transmission of the indicated QoS flow.

[0225] The UE may also stop dropping packets belonging to other QoS flows with a higher priority than the QoS flow included in the resume indicator.

[0226] If the resume indicator includes multiple QoS flow identifiers, the UE will stop dropping packets belonging to any one of the multiple QoS flows.

[0227] The resume indicator may not include a QoS flow identifier. If the UE receives a resume indicator without a QoS flow identifier, the UE will stop dropping packets for all configured QoS flows.

[0228] FIG. 12 is a diagram showing an example of a disposal procedure according to the present invention.

[0229] 12, in S1001, the network provides QoS flow configuration via RRC signaling. Preferably, the QoS flow configuration includes information about QoS flow 1, QoS flow 2, and QoS flow 3. The QoS flow configuration also includes information about associated logical channels (LoCHs). That is, the QoS flow configuration includes information about LoCH1 associated with QoS flow 1, LoCH2 associated with QoS flow 2, and LoCH3 associated with QoS flow 3.

[0230] Then, the UE (preferably the PDCP entity of the UE) receives data packets for QoS flows 1 to 3 in S1002, and transmits uplink data for QoS flows 1 to 3 in S1003.

[0231] In S1004, the network recognizes the congestion state. In Fig. 10, it is assumed that the network detects that congestion has occurred in QoS flow 1 and QoS flow 3.

[0232] At S1005, the UE (preferably a PDCP entity of the UE) receives a congestion indicator from the network. The congestion indicator includes information about LCIDs (Logical Channel Identifiers) associated with QoS Flow 1 and QoS Flow 3. That is, the congestion indicator includes information about LCID1 and LCID3.

[0233] The UE (preferably, the PDCP entity of the UE) that has received the congestion indication performs a procedure to discard QoS flow 1 and QoS flow 3. That is, the UE discards packets of QoS flow 1 and QoS flow 3 in S1006.

[0234] Then, in S1007, the UE (preferably, the PDCP entity of the UE) transmits uplink data of QoS flow 2. Since the discard procedure for QoS flow 1 and QoS flow 3 is in progress, the transmission of uplink data of QoS flow 1 and the transmission of uplink data of QoS flow 3 are not performed.

[0235] At S1008, the network recognizes that the congestion has eased. In Figure 10, assume that the network detects that the congestion associated with QoS Flow 1 has eased.

[0236] At S1009, the UE (preferably, a PDCP entity of the UE) receives a resume indicator from the network, where the resume indicator includes information about the LCID associated with the decongested QoS flow 1. That is, the resume indicator includes information about LCID1.

[0237] Upon receiving the resume indicator, the UE (preferably the PDCP entity of the UE) stops the discard procedure for QoS flow 1 in S1010.

[0238] Finally, the UE (preferably the PDCP entity of the UE) transmits uplink data of QoS flow 1 and QoS flow 2 in S1011.

[0239] According to the present invention, the network can instruct the discarding of packets belonging to a specific QoS flow. Therefore, in a congested situation, the network can control uplink transmissions, allowing only important uplink traffic. This method can guarantee the minimum QoS requirements for XR applications even in a congested network.

Claims

1. A method performed by a user equipment (UE) in a wireless communication system, comprising: receiving configuration information for a plurality of data radio bearers (DRBs); transmitting based on the plurality of DRBs; activating a congestion-related discard procedure for the at least one DRB based on receiving a congestion indicator indicating the at least one DRB; deactivating the congestion-related discard procedure based on receiving a resume indicator indicating the at least one DRB; method.

2. The discarding procedure is not applied to a protocol data unit (PDU) belonging to the at least one DRB based on the fact that at least a portion of the PDU has already been transmitted. The method of claim 1.

3. The congestion indicator and the resume indicator are transmitted via a medium access control (MAC) control element (CE). The method of claim 1.

4. The plurality of DRBs are mapped to a plurality of logical channels. The method of claim 1.

5. and transmitting, based on the plurality of DRBs except for the at least one DRB, based on activation of a congestion-related discard procedure for the at least one DRB. The method of claim 1.

6. The congestion-related discard procedure is applied to low-importance protocol data units (PDUs) belonging to the at least one DRB. The method of claim 1.

7. A UE (User equipment) in a wireless communication system, at least one transceiver; at least one processor; at least one computer memory operatively connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations including: receiving configuration information for a plurality of data radio bearers (DRBs); transmitting based on the plurality of DRBs; activating a congestion-related discard procedure for at least one of the plurality of DRBs based on receiving a congestion indicator indicating the at least one DRB; deactivating the congestion-related discard procedure based on receiving a resume indicator indicating the at least one DRB; UE.

8. The discarding procedure is not applied to a protocol data unit (PDU) belonging to the at least one DRB based on the fact that at least a portion of the PDU has already been transmitted. The UE of claim 7.

9. The congestion indicator and the resume indicator are transmitted via a medium access control (MAC) control element (CE). The UE of claim 7.

10. The plurality of DRBs are mapped to a plurality of logical channels. The UE of claim 7.

11. The operation is and transmitting, based on the plurality of DRBs except for the at least one DRB, based on activation of a congestion-related discard procedure for the at least one DRB. The UE of claim 7.

12. The congestion-related discard procedure is applied to low-importance protocol data units (PDUs) belonging to the at least one DRB. The UE of claim 7.

13. An apparatus for a UE (User Equipment), comprising: at least one processor; at least one computer memory operatively connected to said at least one processor and storing instructions that, when executed, cause said at least one processor to perform operations, said operations including: receiving configuration information for a plurality of data radio bearers (DRBs); transmitting based on the plurality of DRBs; activating a congestion-related discard procedure for at least one of the plurality of DRBs based on receiving a congestion indicator indicating the at least one DRB; deactivating the congestion-related discard procedure based on receiving a resume indicator indicating the at least one DRB; Device.

14. A computer-readable storage medium, comprising: The storage medium stores at least one program code including instructions that, when executed, cause at least one processor to perform an operation for a UE (User Equipment), the operation including: receiving configuration information for a plurality of data radio bearers (DRBs); transmitting based on the plurality of DRBs; activating a congestion-related discard procedure for at least one of the plurality of DRBs based on receiving a congestion indicator indicating the at least one DRB; deactivating the congestion-related discard procedure based on receiving a resume indicator indicating the at least one DRB; A computer-readable storage medium.

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