A method for requesting status reports based on the importance of data units in a wireless communication system, and an apparatus for the same.

Abstract

This disclosure relates to a method by which User Equipment (UE) performs an operation in a wireless communication system. In particular, the method includes the steps of: receiving a service data unit (SDU) from a higher layer at the start of a discard timer; generating a protocol data unit (PDU) containing the SDU based on an uplink grant, based on the fact that the discard timer is running; and transmitting the PDU over the uplink grant, wherein the PDU includes a poll to request a status report related to the SDU, based on the fact that the remaining time of the discard timer is less than a first threshold.

Description

[Technical Field]

[0001] This disclosure relates to a wireless communication system, and more particularly to a method and apparatus for requesting status reporting based on the importance of data units in a wireless communication system. [Background technology]

[0002] With the introduction of new wireless communication technologies, not only is the number of UEs (Users) that a base station provides services to increasing within a given resource area, but the amount of data and control information that the base station sends and receives with the UEs it provides services to is also increasing. Since the amount of radio resources available to a base station for communication with UEs is finite, new methods are needed for base stations to efficiently send and receive uplink / downlink data and / or uplink / downlink control information to and from UEs using these finite radio resources. In particular, there is an increasing number of applications whose performance is heavily dependent on delay. Therefore, methods are needed to reduce delay compared to conventional systems. [Overview of the project] [Problems that the invention aims to solve]

[0003] The object of the present invention is to provide a method and apparatus for requesting status reports based on the importance of data units in a wireless communication system. [Means for solving the problem]

[0004] The object of the present invention is achieved by a method relating to an operation performed by user equipment (UE), the method comprising the steps of: receiving a service data unit (SDU) from a higher level upon the start of a discard timer; generating a protocol data unit (PDU) containing the SDU based on an uplink grant, based on the fact that the discard timer is running; and transmitting the PDU over the uplink grant, wherein the PDU includes a poll for requesting a status report related to the SDU, based on the fact that the remaining time of the discard timer is less than a first threshold.

[0005] Furthermore, a user equipment (UE) in a wireless communication system is proposed, the UE comprising at least one transceiver; at least one processor; and at least one computer memory operably connectable to the at least one processor and, when executed, storing instructions for causing the at least one processor to perform an operation, the operation comprising: receiving a service data unit (SDU) from a higher layer with the start of a discard timer; generating a protocol data unit (PDU) containing the SDU based on an uplink grant, based on the fact that the discard timer is running; and transmitting the PDU over the uplink grant, the PDU including a poll for requesting a status report related to the SDU, based on the fact that the remaining time of the discard timer is less than a first threshold.

[0006] Preferably, if the SDU has an importance level greater than the second threshold, the PDU includes the Pol. Here, the importance of the SDU is indicated by the higher hierarchy.

[0007] Preferably, based on the SDU being included in the PDU, the UE increases the counter by the size of the SDU or by 1. In this case, if the counter is greater than or equal to a third threshold, the PDU includes the POL.

[0008] More preferably, if the remaining time of the discard timer is less than the first threshold, the PDU includes the POL without comparing the counter with the third threshold. Also, in this case, the counter is initialized.

[0009] The effects achievable by the present invention are not limited to the content mentioned above, and other advantages of the present invention will be clearly understood by those skilled in the art from the following detailed description.

Advantages of the Invention

[0010] According to the present disclosure, the UE can receive the status report for important data earlier and can more quickly determine whether retransmission of the important data is necessary. Thereby, an additional retransmission opportunity for important XR data can be ensured, and it becomes possible to grasp whether the important data transmitted before the UE executes subsequent transmission has been confirmed, so that the quality of the XR service can be improved.

[0011] The effects obtained by the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those having ordinary knowledge in the technical field to which the present invention pertains from the following description.

Brief Description of the Drawings

[0012] The drawings attached below are for helping the understanding of the present invention and explain the principle of the present invention together with the detailed description. [Figure 1] It is a diagram showing an example of a communication system to which the realization of the present invention is applied. [Figure 2] It is a block diagram showing an example of a communication device for executing the method according to the present invention. [Figure 3]FIG. is a diagram showing an example of a frame structure in a wireless communication system based on 3GPP (registered trademark; the same shall apply hereinafter). [Figure 4] FIG. is a diagram showing an example of a protocol stack in a wireless communication system based on 3GPP (third generation partnership project). [Figure 5] FIG. is a diagram showing an example of a data flow in a 3GPP NR system. [Figure 6] FIG. shows an example of PDSCH time domain resource allocation by PDCCH and an example of PUSCH time resource allocation by PDCCH. [Figure 7] FIG. is a diagram showing an example of physical layer processing on the transmission side. [Figure 8] FIG. is a diagram showing an example of physical layer processing on the reception side. [Figure 9] FIG. shows an example of data transmission including a poll in accordance with the present disclosure. [Figure 10] FIG. shows an example of an operation performed by a UE in accordance with the present disclosure.

BEST MODE FOR CARRYING OUT THE INVENTION

[0015] For the sake of clarity, this specification will be described below in relation to 3GPP-based communication systems. However, the technical features of this specification are not limited thereto. For example, even if the following detailed description is based on a mobile communication system corresponding to a 3GPP-based system, it is applicable to any other mobile communication system except for matters specific to 3GPP-based systems. For terms and technologies described in this specification that are not specifically mentioned, refer to the radio communication standards documents prior to the publication of this specification. For example, refer to the following documents.

[0016] 3GPP LTE

[0017] - 3GPP TS36.211:Physical channels and modulation

[0018] - 3GPP TS36.212:Multiplexing and channel coding

[0019] - 3GPP TS36.213:Physical layer procedures

[0020] - 3GPP TS36.214:Physical layer; Measurements

[0021] - 3GPP TS36.300:Overall description

[0022] - 3GPP TS36.304:User Equipment(UE) procedures in idle mode

[0023] - 3GPP TS36.314:Layer 2-Measurements

[0024] - 3GPP TS36.321:Medium Access Control (MAC) protocol

[0025] - 3GPP TS36.322:Radio Link Control(RLC) protocol

[0026] - 3GPP TS36.323:Packet Data Convergence Protocol(PDCP)

[0027] - 3GPP TS36.331:Radio Resource Control(RRC) protocol

[0028] 3GPP NR(e.g.5G)

[0029] - 3GPP TS38.211:Physical channels and modulation

[0030] - 3GPP TS38.212:Multiplexing and channel coding

[0031] - 3GPP TS38.213:Physical layer procedures for control

[0032] - 3GPP TS38.214:Physical layer procedures for data

[0033] - 3GPP TS38.215:Physical layer measurements

[0034] - 3GPP TS38.300:Overall description

[0035] - 3GPP TS38.304:User Equipment(UE) procedures in idle mode and in RRC inactive state

[0036] - 3GPP TS38.321:Medium Access Control(MAC) protocol

[0037] - 3GPP TS38.322:Radio Link Control(RLC) protocol

[0038] - 3GPP TS38.323:Packet Data Convergence Protocol(PDCP)

[0039] - 3GPP TS38.331:Radio Resource Control(RRC) protocol

[0040] - 3GPP TS37.324:Service Data Adaptation Protocol(SDAP)

[0041] - 3GPP TS37.340:Multi-connectivity;Overall description

[0042] In this specification, UE refers to various devices that may be fixed or mobile and communicate with a base station (BS) to send and receive user data and / or various control information. UE can also be called Terminal Equipment, MS (Mobile Station), MT (Mobile Terminal), UT (User Terminal), SS (Subscribe Station), wireless device, PDA (Personal Digital Assistant), wireless modem, handheld device, etc. Furthermore, in this specification, BS generally refers to a fixed station that communicates with UE and / or other BSs, exchanging various data and control information. BS can also be called by other terms such as ABS (Advanced Base Station), NB (Node-B), eNB (evolved-Node-B), BTS (Base Transceiver System), Access Point, PS (Processing Server), etc. Specifically, BS in UMTS is called NB, BS in EPC / LTE is called eNB, and BS in NR (new radio) systems is called gNB.

[0043] In this specification, a "node" refers to a fixed point that can communicate with a UE and send / receive wireless signals. Various forms of eNBs can be used as nodes, regardless of their name. For example, BS, NB, eNB, picocell eNB (PeNB), home eNB (HeNB), relays, repeaters, etc., can be used as nodes. Furthermore, a node does not have to be an eNB. For example, a radio remote head (RRH) or radio remote unit (RRU) can also be used. RRHs and RRUs generally have a lower power level than the eNB. Since RRHs or RRUs (hereinafter, RRH / RRU) are generally connected to the eNB by a dedicated line such as an optical cable, cooperative communication between RRHs / RRUs and eNBs can generally be performed more smoothly than cooperative communication by eNBs connected by wireless lines. At least one antenna is installed at each node. The term "antenna" above can refer to a physical antenna, an antenna port, a virtual antenna, or an antenna group.

[0044] In this specification, "cell" refers to a specific geographical area where one or more nodes provide communication services, or to a radio resource. A geographical "cell" can be understood as the coverage over which a node can provide services using a carrier wave, while a "cell" as a radio resource (e.g., a time-frequency resource) is related to the bandwidth (BW), which is the frequency range configured by the carrier wave. A "cell" associated with a radio resource 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 as a downlink resource alone, or as a combination of downlink and uplink resources. Downlink coverage, which is the range over which a node can transmit a valid signal, and uplink coverage, which is the range over which a node can receive a valid signal from a UE, depend on the carrier wave carrying the signal; therefore, a node's coverage may also be related to the coverage of the "cell" of the radio resource used by that node. Therefore, the term "cell" can sometimes refer to the service coverage provided by a node, sometimes to wireless resources, and sometimes to the range over which signals using those wireless resources can reach with effective strength.

[0045] In this invention, a physical downlink control channel (PDCCH) and a physical downlink shared channel (PDSCH) refer to a set of time-frequency resources or resource elements (REs) that carry downlink control information (DCI), and a set of time-frequency resources or REs that carry downlink data, respectively. Similarly, a physical uplink control channel (PUCCH), a physical uplink shared channel (PUSCH), and a physical random access channel (PRACH) refer to a set of time-frequency resources or REs that carry uplink control information (UCI), a set of time-frequency resources or REs that carry uplink data, and a set of time-frequency resources or REs that carry random access signals, respectively.

[0046] In carrier aggregation (CA), two or more CCs are aggregated. Depending on its capabilities, a UE can receive or transmit one or more CCs simultaneously. CA supports both continuous and discontinuous CCs. Once a CA is configured, only the UE forms a single 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 a cell that operates at the primary frequency, at which the UE performs the initial connection establishment procedure or initiates the connection re-establishment procedure. Depending on the UE's capabilities, a secondary cell (SCell) may be configured to form a set of serving cells together with the PCell. An SCell is a cell that provides additional radio resources in addition to the special cell. Therefore, the set of serving cells 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 in a master cell group (MCG) or a PSCell in a secondary cell group (SCG). SpCells support any connection of PUCCH transmission and competitive infrastructure and are always activated. An MCG is a serving cell group associated with a master node and includes SpCells (PCells) 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 for dual connectivity (DC). For RRC_CONNECTED UEs not configured for CA / DC, there is only one serving cell consisting of a PCell.For UEs with RRC_CONNECTED set in CA / DC, the term "serving cell" is used to refer to the cell set consisting of SpCell and all SCells.

[0047] The MCG is a group of serving cells associated with a master BS that terminates at least S1-MME, while the SCG is a group of serving cells associated with a secondary BS that is not the master BS but provides additional radio resources for the UE. The SCG consists of a primary SCell (PSCell) and optionally one or more SCells. In the DC, two MAC entities, namely the MAC entity for the MCG and the MAC entity for the SCG, are configured at the UE. Each MAC entity is a serving cell configured by the RRC to support PUCCH transmission and optional connections of the competitive infrastructure. In this invention, the term SPCell refers to such a cell, while the term SCell refers to the other serving cell. The term SPCell indicates either the PCell of the MCG or the PSCell of the SCG, depending on whether the MAC entity is associated with the MCG or the SCG, respectively.

[0048] In this invention, channel monitoring means attempting to decode a channel. For example, PDCCH monitoring means attempting to decode a PDCCH (or a candidate PDCCH).

[0049] In this specification, "C-RNTI" indicates a cell RNTI, "SI-RNTI" indicates a system information RNTI, "P-RNTI" indicates a paging RNTI, "RA-RNTI" indicates an arbitrary connection RNTI, "SC-RNTI" indicates a single cell RNTI, "SL-RNTI" indicates a sidelink RNTI, "SPS C-RNTI" indicates a semi-persistent scheduling C-RNTI, and "CS-RNTI" indicates a configured scale RNTI.

[0050] Figure 1 illustrates a communication system to which the present invention applies.

[0051] The three main requirements areas for 5G include (1) Enhanced Mobile Broadband (eMBB), (2) Massive Machine Type Communication (mMTC), and (3) Ultra-reliable and Low Latency Communications (URLLC).

[0052] In some use cases, optimization may require addressing numerous domains, while in others, the focus may be on only a single key performance indicator (KPI). 5G supports these diverse use cases in a flexible and reliable manner.

[0053] eMBB goes far beyond basic mobile internet access, covering rich two-way communication, cloud, or augmented reality media and entertainment applications. Data is one of the core drivers of 5G, and for the first time in the 5G era, we may not see dedicated voice services. In 5G, voice is expected to be processed as an application program using the data connectivity provided by the communication system. The main causes of the increased traffic volume are the increasing size of content and the increasing number of applications that demand high data transmission rates. Streaming services (audio and video), conversational video, and mobile internet connectivity will be used more widely as more devices connect to the internet. Many of these applications require always-on connectivity to push real-time information and notifications to users. Cloud storage and applications are rapidly increasing on mobile communication platforms, and this is applicable to both business and entertainment. Cloud storage is also a particular use case that drives the growth of uplink data transmission rates. 5G will also be used for cloud-based remote work, demanding the lowest end-to-end latency to maintain a superior user experience when haptic interfaces are used. Entertainment, such as cloud gaming and video streaming, is another core element increasing the demand for mobile highband capacity. Entertainment is essential on smartphones and tablets everywhere, including in highly mobile environments such as trains, vehicles, and airplanes. Another use case is augmented reality and information retrieval for entertainment, where augmented reality requires extremely low latency and instantaneous data volumes.

[0054] Furthermore, one of the most anticipated use cases for 5G is its ability to seamlessly connect embedded sensors across all sectors, namely mMTC (Mechanical Microcontrollers). The potential number of IoT devices is projected to reach 20.4 billion 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.

[0055] URLLCs include new services that will transform industries through ultra-reliable / available low-latency links for remote control of critical infrastructure and self-driving vehicles. Levels of reliability and latency are essential for smart grid control, industrial automation, robotics, and drone control and coordination.

[0056] 5G is a means of delivering streams rated at hundreds of megabits per second to gigabits per second, and can complement FTTH (fiber-to-the-home) and cable-based broadband (or DOCSIS). Such high speeds are required not only for virtual and augmented reality but also for transmitting TV at resolutions of 4K and above (6K, 8K and beyond). VR (Virtual Reality) and AR (Augmented Reality) applications mostly include immersive sports competitions. Certain application programs may require special network configurations. For example, in the case of VR games, game companies must integrate their core servers with the network operator's edge network servers to minimize latency.

[0057] Automotive is expected to be a key new driving force in 5G, along with numerous use cases for mobile communications within vehicles. For example, passenger entertainment simultaneously demands high capacity and high mobility mobile broadband. This is because future users will continue to expect high-quality connectivity regardless of their location and speed. Another use case in the automotive sector is augmented reality dashboards, which overlay information on what the driver sees through the windshield, identifying objects in the dark and telling the driver about their distance and movement. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure structures, and information exchange between vehicles and other connected devices (e.g., devices accompanied by pedestrians). Safety systems can guide drivers to alternative routes of action to enable safer driving and reduce the risk of accidents. The next stage will be remotely controlled or self-driven vehicles, which will require extremely reliable and very fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, autonomous vehicles will perform all driving activities, allowing drivers to focus only on traffic anomalies that the vehicle itself cannot identify. The technical requirements for autonomous vehicles demand ultra-low latency and ultra-high-speed reliability so that traffic safety increases to a level unattainable by humans.

[0058] Smart cities and smart homes, often referred to as smart societies, are embedded in high-density wireless sensor networks. A distributed network of intelligent sensors identifies the cost and energy-efficient maintenance requirements for a city or home. Similar setups can be made for individual homes. Temperature sensors, window and heating controllers, burglar alarms, and household appliances are all connected wirelessly. Many of these sensors typically have low data transmission speeds, low power consumption, and low cost. However, real-time HD video, for example, may require specific types of equipment for monitoring.

[0059] The consumption and distribution of energy, including heat or gas, is highly decentralized, requiring automated control of distributed sensor networks. Smart grids interconnect such sensors, using digital information and communication technologies to collect information and act accordingly. This information can include the behavior of suppliers and consumers, allowing smart grids to improve the efficiency, reliability, economics, production sustainability, and automated distribution of fuels like electricity. Smart grids can also be viewed as other low-latency sensor networks.

[0060] Mission-critical applications (e.g., e-health) are one of the 5G use scenarios. The healthcare sector has many application programs that can benefit from mobile communications. Communication systems can support telemedicine, which provides clinical care in remote locations. This helps reduce the barrier of distance and can improve access to medical services that are not sustainably available in remote rural areas. This can also be used to save lives in critical medical and emergency situations. Mobile communication-based wireless sensor networks can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0061] Wireless and mobile communications are becoming increasingly important in industrial applications. Wiring is expensive to install and maintain. Therefore, the possibility of replacing cables with reconfigurable wireless links presents an attractive opportunity in many industrial sectors. However, achieving this requires wireless connections to operate with similar latency, reliability, and capacity to cables, and to simplify their management. Low latency and extremely low error rates are new requirements that must be met by 5G.

[0062] Logistics and freight tracking are important use cases for mobile communications, using location-based information systems to enable inventory and package tracking anywhere. Logistics and freight tracking use cases typically require low data speeds but demand wide-area and reliable location information.

[0063] Referring to Figure 1, communication system 1 includes wireless equipment, a base station (BS), and a network. However, although Figure 1 shows a 5G network as an example of the network of communication system 1, the realization of the present invention is not limited to 5G systems and can be applied to next-generation communication systems beyond 5G systems.

[0064] BS and the network are implemented using wireless equipment, and certain wireless equipment 200a can operate as a BS / network node for other wireless equipment.

[0065] Wireless devices refer to devices that communicate using wireless access technology (RAT) (e.g., 5G NR, LTE), and can be called communication / wireless / 5G devices. However, wireless devices include, but are not limited to, robots 100a, vehicles 100b-1, 100b-2, XR (eXtended Reality) devices 100c, handheld devices 100d, home appliances 100e, IoT (Internet of Things) devices 100f, and AI devices / servers 400. For example, vehicles include vehicles equipped with wireless communication capabilities, autonomous vehicles, and vehicles capable of vehicle-to-vehicle communication. Here, vehicles include UAVs (Unmanned Aerial Vehicles) (e.g., drones). XR devices include AR (Augmented Reality) / VR (Virtual Reality) / MR (Mixed Reality) devices and are implemented in the form of HMDs (Head-Mounted Devices), HUDs (Head-Up Displays) installed in vehicles, TVs, smartphones, computers, wearable devices, home appliances, digital signage, vehicles, robots, etc. Mobile devices include smartphones, smart pads, wearable devices (e.g., smartwatches, smart glasses), computers (e.g., notebook computers, etc.). Home appliances include TVs, refrigerators, washing machines, etc. IoT devices include sensors, smart meters, etc.

[0066] In the present invention, wireless devices 100a to 100f are also called UEs. UEs include, for example, mobile phones, smartphones, notebook computers, digital broadcasting terminals, PDAs (personal digital assistants), PMPs (portable multimedia players), car navigation systems, slate PCs, tablet PCs, ultrabooks, vehicles, vehicles with autonomous driving capabilities, connected cars, UAVs, AI (artificial intelligence) modules, robots, AR (augmented reality) devices, VR (virtual reality) devices, MR (mixed reality) devices, hologram devices, devices for public safety, MTC devices, IoT devices, medical devices, fintech devices (or financial devices), security devices, weather / environmental devices, devices related to 5G services, or devices related to the field of the Fourth Industrial Revolution. A UAV is, for example, an aircraft that flies using wireless control signals without carrying a person. A VR device includes, for example, a device for realizing objects or backgrounds in a virtual world. AR devices include, for example, devices that connect objects or backgrounds in a virtual world to objects or backgrounds in the real world. MR devices include, for example, devices that merge objects or backgrounds in a virtual world to objects or backgrounds in the real world. Holographic devices include, for example, devices that realize 360° stereoscopic images by recording and reproducing three-dimensional information using a phenomenon called holography, which is the interference of light produced when two lasers meet. Public safety devices include, for example, wearable video relay devices or video devices. MTC devices and IoT devices include devices that do not require direct human interference or operation. For example, MTC devices and IoT devices include smart meters, vending machines, thermometers, smart light bulbs, door locks, or various sensors. Medical devices are, for example, devices used for diagnosis, treatment, palliative care, therapy, and disease prevention. Medical devices are, for example, devices for diagnosing, treating, palliative care, or correcting injuries or disabilities.For example, medical devices are devices used to rescue or examine, replace, or modify functions. For example, medical devices are devices for pregnancy control. For example, medical devices include devices for medical treatment, devices for surgery, devices for (in vitro) diagnosis, hearing aids, and devices for procedures. Safety devices are devices installed to prevent potential hazards and ensure safety. For example, safety devices include cameras, CCTV, recording devices (recorders), or black boxes. Fintech devices are devices that provide financial services, such as mobile payments. For example, fintech devices include payment devices or POS (point of sales) systems. Weather / environmental devices include devices for monitoring weather / environment.

[0067] Wireless devices 100a to 100f are connected to network 300 via BS200. Artificial Intelligence (AI) technology is applied to wireless devices 100a to 100f, and wireless devices 100a to 100f are connected to AI server 400 via network 300. Network 300 is composed of 3G networks, 4G (e.g., LTE) networks, or 5G (e.g., NR) networks, and beyond 5G networks. Wireless devices 100a to 100f can communicate with each other via BS200 / network 300, but can also communicate directly without going through BS / network (e.g., side-link communication). For example, vehicles 100b-1 and 100b-2 can communicate directly (e.g., V2V (Vehicle to Vehicle) / V2X (Vehicle to everything) communication). Also, IoT devices (e.g., sensors) can communicate directly with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0068] Wireless communication / connection 150a and 150b are performed between wireless devices 100a-100f / BS200-BS200. Here, wireless communication / connection is performed by various RATs (e.g., 5G NR) such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication). Wireless communication / connection 150a and 150b allow wireless devices and BS / wireless devices to send / receive wireless signals from each other. For example, wireless communication / connection 150a and 150b can send / receive signals via various physical channels. To this end, based on various proposals of the present invention, one of the following is performed: a process of setting various configuration information for sending / receiving wireless signals, a process of various signal processing (e.g., channel coding / decoding, modulation / demodulation, resource mapping / demapping, etc.), or a resource allocation process.

[0069] Figure 2 is a block diagram showing an example of a communication device that implements the method according to the present invention.

[0070] Referring to Figure 2, the first wireless device 100 and the second wireless device 200 can send and receive wireless signals to and from external devices via various RATs (e.g., LTE, NR). In Figure 2, {the first wireless device 100 and the second wireless device 200} correspond to {wireless devices 100a~100f and BS200} and / or {wireless devices 100a~100f and wireless devices 100a~100f} in Figure 1.

[0071] 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 controls the memory 104 and / or the transceivers 106 and is configured to implement the functions, procedures and / or methods disclosed in this specification. For example, the processor 102 processes information in the memory 104 to generate first information / signals, and then transmits a wireless signal containing the first information / signals with the transceiver 106. The processor 102 also receives a wireless signal containing second information / signals with the transceiver 106, and then stores the information obtained from signal processing of the second information / signals in the memory 104. The memory 104 is connected to the processor 102 and stores various information related to the operation of the processor 102. For example, the memory 104 stores software code containing instructions for performing some or all of the processes controlled by the processor 102, or for performing the procedures and / or methods disclosed in this specification. Here, the processor 102 and memory 104 are part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE, NR). The transceiver 106 is connected to the processor 102 and transmits and / or receives radio signals via one or more antennas 108. The transceiver 106 includes a transmitter and / or receiver. The transceiver 106 can also be mixed with an RF (radio frequency) unit. In this disclosure, radio equipment can also mean a communication modem / circuit / chip.

[0072] 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 controls the memory 204 and / or the transceivers 206 and is configured to implement the functions, procedures and / or methods disclosed in this specification. For example, the processor 202 processes information in the memory 204 to generate third information / signals, and then transmits a wireless signal containing the third information / signals with the transceiver 206. The processor 202 also receives a wireless signal containing fourth information / signals with the transceiver 206, and then stores the information obtained from signal processing of the fourth information / signals in the memory 204. The memory 204 is connected to the processor 202 and stores various information related to the operation of the processor 202. For example, the memory 204 stores software code containing instructions for performing some or all of the processes controlled by the processor 202, or for performing the procedures and / or methods disclosed in this specification. Here, the processor 202 and memory 204 are part of a communication modem / circuit / chip designed to implement RAT (e.g., LTE, NR). A transceiver 206 is connected 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 receiver. The transceiver 206 can also be mixed with an RF unit. In this disclosure, radio equipment can also mean a communication modem / circuit / chip.

[0073] The hardware elements of the wireless devices 100 and 200 will be described in more detail below. However, one or more protocol layers are implemented by one or more processors 102 and 202. For example, one or more processors 102 and 202 implement one or more layers (e.g., 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 functional layer such as a Service data adaptation protocol (SDAP)). One or more processors 102 and 202 generate one or more Protocol Data Units (PDUs) and / or one or more Service Data Units (SDUs) by means of the descriptions, functions, procedures, proposals, and / or methods disclosed in this specification. One or more processors 102 and 202 generate messages, control information, data, or information by means of the functions, procedures, proposals, and / or methods disclosed in this specification. One or more processors 102, 202 generate signals (e.g., baseband signals) containing PDUs, SDUs, messages, control information, data, or information by the functions, procedures, suggestions, and / or methods disclosed in this specification and provide them to one or more transceivers 106, 206. One or more processors 102, 202 receive signals (e.g., baseband signals) from one or more transceivers 106, 206 and obtain PDUs, SDUs, messages, control information, data, or information by the descriptions, functions, procedures, suggestions, and / or methods disclosed in this specification.

[0074] One or more processors 102, 202 are also referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102, 202 are implemented by hardware, firmware, software, or a combination thereof. For example, one or more ASICs (Application Specific Integrated Circuits), one or more DSPs (Digital Signal Processors), one or more DSPDs (Digital Signal Processing Devices), one or more PLDs (Programmable Logic Devices), or one or more FPGAs (Field Programmable Gate Arrays) are included in one or more processors 102, 202. The functions, procedures, suggestions, and / or methods disclosed in this specification are implemented using firmware or software, and the firmware or software is implemented to include modules, procedures, functions, etc. Firmware or software configured to perform the functions, procedures, suggestions, and / or methods disclosed in this specification is included in one or more processors 102, 202, or stored in one or more memories 104, 204 and driven by one or more processors 102, 202. The functions, procedures, suggestions, and / or methods disclosed in this specification are implemented using firmware or software in the form of code, instructions, and / or sets of instruction words.

[0075] One or more memory units 104, 204 are connected to one or more processors 102, 202 and store various forms of data, signals, messages, information, programs, code, instructions, and / or commands. One or more memory units 104, 204 consist of ROM, RAM, EPROM, flash memory, hard drives, registers, cache memory, computer-readable storage media, and / or combinations thereof. One or more memory units 104, 204 are located inside and / or outside one or more processors 102, 202. Also, one or more memory units 104, 204 are connected to one or more processors 102, 202 by various technologies such as wired or wireless connections.

[0076] One or more transceivers 106, 206 can transmit user data, control information, radio signals / channels, etc., as described in the methods and / or flowcharts in this specification to one or more other devices. One or more transceivers 106, 206 can receive user data, control information, radio signals / channels, etc., as described in the descriptions, functions, procedures, suggestions, methods and / or flowcharts disclosed in this specification from one or more other devices. For example, one or more transceivers 106, 206 are connected to one or more processors 102, 202 to transmit and receive radio signals. For example, one or more processors 102, 202 can control one or more transceivers 106, 206 to transmit user data, control information or radio signals to one or more other devices. Also, one or more processors 102, 202 can control one or more transceivers 106, 206 to receive user data, control information or radio signals from one or more other devices. One or more transceivers 106, 206 are connected to one or more antennas 108, 208, and are configured by one or more antennas 108, 208 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 in this specification. In this specification, one or more antennas are multiple physical antennas or multiple logical antennas (e.g., antenna ports). 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. 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, one or more transceivers 106, 206 include (analog) oscillators and / or filters.For example, under the control of processors 102 and 202, transceivers 106 and 206 convert the OFDM baseband signal up to the carrier frequency using their (analog) oscillators and / or filters, and transmit the OFDM signal converted up to the carrier frequency. Transceivers 106 and 206 can receive the OFDM signal at the carrier frequency and, under the control of processors 102 and 202, convert the OFDM signal down to the OFDM baseband signal using their (analog) oscillators and / or filters.

[0077] In the realization of this invention, the UE operates as a transmission device on the uplink and as a receiving device on the downlink. In the realization of this invention, the BS operates as a receiving device on the uplink and as a transmission device on the downlink. For the convenience of explanation, unless otherwise specified, the first wireless device 100 operates as the UE and the second wireless device 200 operates as the BS. For example, the processor 102 connected to, mounted on, or launched in the first wireless device 100 is configured to perform UE operation according to the realization of this invention, or to control the transceiver 106 to perform UE operation according to the realization of this invention. The processor 202 connected to, mounted on, or launched in the second wireless device 200 is configured to perform BS operation according to the realization of this invention, or to control the transceiver 206 to perform BS operation according to the realization of this invention.

[0078] In the present invention, at least one memory (e.g., 104 or 204) stores instructions or programs that, when executed, cause to perform some embodiment or implementation of the present invention as at least one processor operably connected thereto.

[0079] 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 at least one processor to perform an operation according to several embodiments or implementations of the present invention.

[0080] In the present invention, the processing device or apparatus includes at least one processor and at least one computer memory that is connectable to the at least one processor and, when executed, stores instructions for causing the at least one processor to perform operations according to several embodiments or implementations of the present invention.

[0081] Figure 3 illustrates the frame structure in a 3GPP-based wireless communication system.

[0082] The frame structure in Figure 3 is merely an example, and the number of subframes, slots, and / or symbols in a frame can be varied in various ways. In 3GPP-based wireless communication systems, OFDM numerology (e.g., subcarrier spacing (SCS), transmission time interval (TTI) intervals) are set to differ between multiple cells aggregated for a single UE. For example, if a UE is configured with different SCSs for cells aggregated for a cell, the (absolute time) intervals of time resources (e.g., subframes, slots, or TTI) consisting of the same number of symbols can differ between the aggregated cells. Here, symbols include OFDM symbols (or CP-OFDM symbols) and SC-FDMA symbols (or DFT-s-OFDM (discrete Fourier transform-spread-OFDM) symbols).

[0083] Referring to Figure 3, uplink and downlink transmissions consist of frames. Each frame is T f = has a 10ms interval, which is divided into two half-frames of 5ms each. Each half-frame consists of five subframes, and each subframe has an interval (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 is composed of 14 or 12 OFDM symbols based on the CP (cyclic prefix). In the case of normal CP, each slot is composed of 14 OFDM symbols, and in the case of extended CP, each slot is composed of 12 OFDM symbols. The numerology is based on an exponentially scalable subcarrier spacing (Δf = 2 u *15 kHz). The following table shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots according to the subcarrier spacing (Δf = 2 u *15 kHz) for normal CP.

[0084]

Table 1

[0085] The following table shows the number of OFDM symbols per slot, the number of slots per frame, and the number of slots per subframe for extended CP according to the subcarrier spacing (Δf = 2 u *15 kHz).

[0086]

Table 2

[0087] A slot contains a plurality (e.g., 14 or 12) of symbols in the time domain. For each numerology (e.g., subcarrier spacing) and carrier, a common resource block (CRB) (N start,u grid ) indicated by higher layer signaling (e.g., radio resource control (RRC) signaling) starts from, N size,u grid,x *N RB scIndividual subcarriers and N subframe,u symb A resource grid of OFDM symbols is defined, where N size,u grid,x is the number of resource blocks (RB) in the resource grid, and the subscript x is DL for downlinks and UL for uplinks. RB sc This is the number of subcarriers per RB. In a 3GPP-based wireless communication system, N RB sc It is generally 12. There is one resource grid for a given antenna port (p), subcarrier spacing configuration (u), and transmission direction (DL or UL). Carrier bandwidth (N) for subcarrier spacing configuration (u) size,u grid The RB is given by higher-level parameters (e.g., RRC parameters). Each element in the resource grid for the antenna port (p) and subcarrier spacing settings (u) is called a Resource Element (RE), and each resource element is mapped to a single complex symbol. Each resource element in the resource grid is uniquely identified by an index (k) in the frequency domain and an index (l) in the time domain that indicates the symbol position relative to a reference point. In 3GPP-based wireless communication systems, RB is defined by 12 consecutive subcarriers in the frequency domain.

[0088] In the 3GPP NR system, RBs are classified into Common Resource Blocks (CRBs) and Physical Resource Blocks (PRBs). CRBs are numbered in an increasing direction from 0 in the frequency domain relative to the subcarrier spacing setting (u). The center of subcarrier 0 of CRB 0 relative to the subcarrier spacing setting (u) coincides with "point A," which is a common reference point for the resource block grid. In the 3GPP NR system, PRBs are defined within the bandwidth part (BWP) and numbered from 0 to N sizeBWP,i Numbered down to -1, where i is the number of the bandwidth part. The physical resource blocks (n) within the bandwidth part (i) PRB ) and common resource blocks (n CRB The relationship between ) is as follows: n PRB =n CRB +N size BWP,i Here, N size BWP,i The bandwidth part is a common resource block that starts with CRB 0. A BWP contains multiple consecutive RBs in the frequency domain. A carrier wave contains up to N (e.g., 5) BWPs. A UE is configured as one or more BWPs with a given configuration carrier wave. Of the BWPs configured for a UE, only one BWP is activated at a time. The activated BWP defines the operating bandwidth of the UE within the cell's operating bandwidth.

[0089] 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.

[0090] [Table 3]

[0091] Figure 4 illustrates a protocol stack in a 3GPP-based wireless communication system.

[0092] Specifically, Figure 4(a) illustrates the user-plane protocol stack of the radio interface between the UE and the base station (BS), and Figure 4(b) illustrates the control-plane protocol stack of the radio interface between the UE and the BS. The control plane refers to the path through which control messages used by the UE and the network to manage calls are transmitted. The user plane refers to the path through which data generated in the application layer, such as voice data or internet packet data, is transmitted. Referring to Figure 4(a), the user-plane protocol stack is divided into the first layer (layer 1) (i.e., the physical (PHY) layer) and the second layer (layer 2). Referring to Figure 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) layer). Layers 1, 2, and 3 are called the access stratum (AS).

[0093] The NAS control protocol is terminated by the network-side access management function (AMF), which handles authentication, mobility management, security control, and other related functions.

[0094] In 3GPP LTE systems, Layer 2 is divided into the following sublayers: Medium Access Control (MAC), Radio Link Control (RLC), and Packet Data Convergence Protocol (PDCP). In 3GPP NR (New Radio) systems, 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, the MAC sublayer provides logical channels to the RLC sublayer, the RLC sublayer 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.

[0095] In a 3GPP NR system, the main services and functions of SDAP include: mapping between QoS flows and data radio bearers; marking of QoS flow IDs (QoS flow ID, QFI) in both DL and UL packets; and a single SDAP protocol entity is configured for each PDU section.

[0096] In a 3GPP NR system, the main services and functions of the RRC sub-tier include: broadcasting system information related to the AS and NAS; paging disclosed by 5GC or NG-RAN; setting up, maintaining, and disconnecting RRC connections between the UE and NG-RAN; security functions including key management; setting up, maintaining, and disconnecting signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including handover and context transmission; UE cell selection, reselection, and control of cell selection and reselection; mobility between RATs); QoS management functions, UE measurement reporting, and reporting control; detection and recovery from radio link failures; and transmission of NAS messages from the UE to the NAS and from the NAS to the UE.

[0097] In a 3GPP NR system, the main services and functions of the PDCP sub-tier 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; sequential transmission; PDCP PDU routing (in the case of split bearer); PDCP SDU retransmission; encryption, deciphering and integrity protection; PDCP SDU disposal; PDCP re-establishment and data recovery for RLC AM; PDCH status reporting for RLC AM; PDCP PDU duplication and duplicate disposal instructions to lower tiers. The main services and functions of the PDCP sub-tier for the control plane include: sequence numbering; encryption, deciphering and integrity protection; control plane data transmission; reordering and duplicate detection; sequential transmission; PDCP PDU duplication and duplicate disposal instructions to lower tiers.

[0098] In the 3GPP NR system, the RLC sub-tier supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged mode (AM). RLC configuration is applied per logical channel, independent of the pneumatics and / or transmission interval. In the 3GPP NR system, the main services and functions of the RLC sub-tier depend on the transmission mode and include: transmission of higher-tier PDUs; sequence numbering independent of numbering in PDCP (for UM and AM); error correction by ARQ (automatic repeat request) (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).

[0099] In the 3GPP NR system, the main services and functions of the MAC sub-tier include: mapping between logical channels and transmission channels; multiplexing / demultiplexing of MAC SDUs belonging to one or more logical channels to / from the transport block (TB) transmitted to / from the PHY tier via the transmission channel; scale information reporting; error correction by HARQ (hybrid automatic repeat request) (one HARQ entity per cell in the case of CA); priority handling between UEs using dynamic scheduling; priority handling between logical channels of a single UE using logical channel prioritization; and padding. A single MAC entity supports multiple pneumatics, transmission timings, and cells. In logical channel prioritization, mapping constraints control which pneumatics, cells, and transmission timings a logical channel uses. Different types of data transmission services are provided by MACs. To accommodate different types of data transmission services, a number of logical channel types are defined, each supporting a specific type of information transmission. Each logical channel type is defined by the type of information transmitted through it. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used to transmit only control-plane information, while traffic-control channels are used to transmit 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 transmitting paging information, system information change notifications, and instructions for ongoing PWS broadcasts; the common control channel (CCCH) is a logical channel for transmitting control information between the UE and the network, and is used by 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 the UE and the network, and is used by UEs with an RRC connection; the dedicated traffic channel (DTCH) is a point-to-point logical channel dedicated to a single UE for transmitting user information. DTCHs exist on both uplink and downlink. In the downlink, the connections between logical channels and transmission channels are as follows: BCCH is mapped to BCH; BCCH is mapped to the 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 transmission channels are as follows: CCCH is mapped to the uplink shared channel (UL-SCH); DCCH is mapped to UL-SCH; DTCH is mapped to UL-SCH.

[0100] Figure 5 shows an example of data flow in a 3GPP NR system.

[0101] In Figure 5, "RB" represents the radio bearer and "H" represents the header. Radio bearers are classified into two groups: data radio bearers (DRBs) for user plane data and signaling radio bearers (SRBs) for control plane data. MAC PDUs are transmitted and received with external devices via the PHY hierarchy using radio resources. MAC PDUs reach the PHY hierarchy in the form of transport blocks.

[0102] In the PHY hierarchy, the uplink transport channels UL-SCH and RACH are mapped to PUSCH and PRACH, respectively, while the downlink transport channels DL-SCH, BCH, and PCH are mapped to PDSCH, the physical broadcast channel (PBCH), and PDSCH, respectively. In the PHY hierarchy, uplink control information (UCI) is mapped to PUCCH, and downlink control information (DCI) is mapped to PDCCH. MAC PDUs associated with UL-SCH are transmitted by the UE via PUSCH based on uplink grants, and MAC PDUs associated with DL-SCH are transmitted by the BS via PDSCH based on downlink assignments.

[0103] To transmit the data unit of the present invention via the UL-SCH, the UE must have uplink resources available to the UE. To receive the 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 the present invention, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink allocation. Uplink grant is dynamically received by the UE via the PDCCH in an arbitrary connection response, or quasi-persistently configured to the UE by RRC signaling. Downlink allocation is dynamically received by the UE via the PDCCH, or quasi-persistently configured to the UE by RRC signaling from the BS.

[0104] On the uplink, the BS can dynamically allocate resources to the UE via a cell radio network temporary identifier (C-RNTI) on the PDCCH. When the UE's downlink reception is enabled (activity controlled by discontinuous reception, DRX), the UE constantly monitors the PDCCH to find possible grants for uplink transmission. Using the configured grants, the BS can also allocate uplink resources to the UE for initial HARQ transmission. 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 its period). In Type 2, the RRC defines the period of the configured uplink grant while the PDCCH, addressed to a configured scheduling RNTI (CS-RNTI), signals and activates or deactivates the configured uplink grant. In other words, PDCCH addressed to CS-RNTI indicates that the upstream link grant can be implicitly reused by a period defined by RRC until the upstream link grant is deactivated.

[0105] In the downlink, the BS can dynamically allocate resources to the UE by means of C-RNTI on the PDCCH. When the UE's downlink reception is enabled (at setup, active controlled by DRX), the UE always monitors the PDCCH to search for possible grants. Also, using semi-persistent scheduling (SPS), the BS can allocate downlink resources to the UE for initial HARQ transmissions. The RRC signals and activates or deactivates a downlink allocation when a PDCCH addressed to the CS-RNTI is set, or defines the period of a set downlink allocation while it can be signaled and activated. That is, the PDCCH addressed to the CS-RNTI indicates that the downlink allocation can be implicitly reused by the period defined by the RRC until the downlink allocation is deactivated.

[0106] <Resource Allocation by PDCCH (i.e., Resource Allocation by DCI)>

[0107] 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.

[0108] Figure 6 shows examples of PDSCH time domain resource allocation by PDCCH and PUSCH time resource allocation by PDCCH.

[0109] To schedule a PDSCH or 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 setting to apply and which PUSCH time domain resource allocation table to apply is 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).

[0110] 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 the 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 RRC signaling mapping, and the other is mapping type B where the DMRS is located in the first allocated symbol.

[0111] 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.

[0112] <Resource Allocation by RRC>

[0113] As described above, there are two types of transmission without dynamic grants in the uplink: configured grant type 1 and configured grant type 2. In the case of configured grant type 1, the uplink grant is provided by the RRC and stored as a configured grant. In the case of configured grant type 2, the uplink grant is provided by the PDCCH and stored or cleared as a configured uplink grant based on L1 signaling that instructs the activation or deactivation of the configured uplink grant. Types 1 and 2 are configured by RRC signaling per serving cell and per BWP. Multiple configurations can be activated simultaneously only on different serving cells. In the case of type 2, activation and deactivation are independent between serving cells. For the same serving cell, the MAC entity is configured as either type 1 or type 2.

[0114] When a set grant type 1 is configured, the UE is provided with at least the following parameters from the BS via RRC signaling:

[0115] - s-RNTI, which is CS-RNTI for retransmission;

[0116] - A periodicity that provides the set grant type 1 period;

[0117] - `timeDomainOffset` indicates the resource offset for System frame number (SFN) = 0 in the time domain;

[0118] - A timeDomainAllocation value m provides a row index m+1 pointing to an allocation table, indicating a combination of start symbol S, length L, and PUSCH mapping type;

[0119] - frequencyDomainAllocation, which provides frequency domain resource allocation; and

[0120] - mcsAndTBS provides an IMCS indicating the number of modulations, target code rate, and transport block size. When a configured grant type 1 is configured for a serving cell by the RRC, the UE stores the uplink grant provided by the RRC as the configured uplink grant for the directed serving cell and initializes or re-initializes the configured uplink grant so that the uplink grant configured by timeDomainOffset and S (derived from SLIV) starts and re-occurs periodically. After an uplink grant is set for grant type 1, the UE assumes that the uplink grant recurs in relation to 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.

[0121] When a set grant type 2 is configured, the UE is provided with at least the following parameters from the BS via RRC signaling:

[0122] - cs-RNTI, which is CS-RNTI for activation, deactivation, and retransmission; and

[0123] - A periodicity that provides the period for the set grant type 2. The actual uplink grant is provided to the UE by PDCCH (addressed to CS-RNTI). After the uplink grant is set for the set grant type 2, the UE considers the uplink grant to recur in relation to 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 These represent the SFN, slot, and symbol of the first transmission opportunity of PUSCH, where the configured grant was (re)initialized. numberOfSlotsPerFrame and numberOfSymbolsPerSlot represent the number of consecutive slots per frame and the number of consecutive OFDM symbols per slot, respectively.

[0124] For a configured uplink grant, the HARQ process ID associated with the first symbol of the uplink transmission is derived from the following formula:

[0125] HARQ Process ID=[floor(CURRENT_symbol / periodicity)] modulo nrofHARQ-Processes

[0126] Here, CURRENT_symbol = (SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot + slot number in the frame × numberOfSymbolsPerSlot + symbol number in the slot), where numberOfSlotsPerFrame and numberOfSymbolsPerSlot represent the number of consecutive slots and the number of consecutive symbols per slot, respectively, as explicitly stated in TS 38.211. CURRENT_symbol indicates the symbol index of the first transmission opportunity in the recurring iteration. HARQ processes are configured for configured uplink grants if configured uplink grants are activated, and the associated HARQ process ID is smaller than nrofHARQ-Processes.

[0127] For downlinks, the UE is configured from the BS via RRC signaling with SPS for each serving cell and each BWP. Multiple configurations are activated simultaneously on different serving cells. Activation or deactivation of downlink SPS is independent between serving cells. For downlink SPS, the downlink assignment is provided to the UE by the PDCCH and stored or removed based on L1 signaling indicating SPS activation or deactivation. When an SPS is configured, the UE is provided with the following parameters from the BS via RRC signaling:

[0128] - CS-RNTI is a type of CS-RNTI used for activation, deactivation, and retransmission;

[0129] - Provides the number of HARQ processes configured for SPS;

[0130] - periodicity that provides the set downlink allocation period for SPS.

[0131] When SPS is deactivated by a higher level, all corresponding settings must also be deactivated.

[0132] After a downlink assignment is set for SPS, the UE assumes that the Nth downlink assignment will occur sequentially in slots that satisfy the following condition: (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 These represent the SFN, slot, and symbol of the first transmission of the PDSCH, respectively, after the configured downlink assignment has been (re)initialized.

[0133] For configured downlink assignments, the HARQ process ID associated with the slot where downlink transmission begins is derived from the following formula:

[0134] HARQ Process ID=[floor (CURRENT_slot×10 / (numberOfSlotsPerFrame×periodicity))] modulo nrofHARQ-Processes

[0135] Here, CURRENT_slot = [(SFN × numberOfSlotsPerFrame) + slot number in the frame], where numberOfSlotsPerFrame indicates the number of consecutive slots per frame, as explicitly stated in TS38.211.

[0136] If the cyclic redundancy check (CRC) for the relevant DCI format has been scrambled with 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 verifies that the downlink SPS assigned PDCCH or the configured uplink grant type 2 PDCCH is enabled for scheduling activation or descheduling. DCI format validity verification is achieved when all fields for the DCI format are set according to Table 4 or Table 5. Table 4 exemplifies the specific fields for verifying the validity of the downlink SPS and uplink grant type 2 scheduling activated PDCCH, and Table 5 exemplifies the specific fields for verifying the validity of the downlink SPS and uplink grant type 2 descheduled PDCCH.

[0137] [Table 4]

[0138] [Table 5]

[0139] The actual downlink allocation and 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 a time domain allocation value m, a frequency domain resource allocation field providing frequency resource block allocations, and a modulation and coding scheme field) within the DCI format carried by the scheduling activation PDCCH of the downlink SPS or uplink grant type 2. Once validity is achieved, the UE considers the information in the DCI format to be a valid activation or deactivation of the downlink SPS or the configured uplink grant type 2.

[0140] In the case of an uplink, 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. 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.

[0141] In the case of a 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. 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.

[0142] Before the data unit of the present invention is transmitted via a wireless interface, physical hierarchical processing is performed on the transmitting side, and the wireless signal carrying the data unit of the present invention is subjected to physical hierarchical processing on the receiving side. For example, a MAC PDU including a PDCP PDU according to the present invention is subjected to physical hierarchical processing as follows.

[0143] Figure 7 shows an example of physical layer processing on the transmitting side.

[0144] The following tables show how transport channels (TrCH) and control information are mapped to the corresponding physical channels. Specifically, Table 6 shows how uplink transport channels are mapped to the corresponding physical channels, Table 7 shows how uplink control channel information is mapped to the corresponding physical channels, Table 8 shows how downlink transport channels are mapped to the corresponding physical channels, and Table 9 shows how downlink control channel information is mapped to the corresponding physical channels.

[0145] [Table 6]

[0146] [Table 7]

[0147] [Table 8]

[0148] [Table 9]

[0149] <encoding>

[0150] Data and control streams to and from the MAC layer are encoded and then transmitted via a radio transmission link at the PHY layer to provide transport and control services. For example, transport blocks from the MAC layer are encoded into codewords at the transmitting end. Channel coding schemes are a combination of misdetection, miscorrection, rate matching, interleaving, and transport channels that are mapped to or split from physical channels, or control information.

[0151] In 3GPP NR systems, the following channel coding schemes are used for different types of TrCHs and different types of control information.

[0152] [Table 10]

[0153] [Table 11]

[0154] For the transmission of downlink transport blocks (i.e., DL MAC PDUs) or uplink transport blocks (i.e., UL MAC PDUs), a transport block CRC sequence is attached to provide miss detection to the receiver. In the 3GPP NR system, communication equipment uses low-density parity check (LDPC) codes when encoding / decoding UL-SCH and DL-SCH. The 3GPP NR system supports two LDPC base graphs (i.e., two LDPC base matrices): LDPC base graph 1 optimized for smaller transport blocks and LDPC base graph 2 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 by a PDCCH that activates or (re)initializes an uplink-configured Grant 2 or downlink SPS, or is provided to the UE by RRC signaling associated with an uplink-configured Grant Type 1, and is dynamically applied to the UE by a PDCCH that schedules a PUSCH or PDSCH. If a transport block with a CRC attached is larger than the maximum code block size for the selected LDPC base graph, the transport block with the CRC attached is divided into code blocks, each code block having an additional CRC sequence attached. The maximum code block sizes for LDPC base graph 1 and LDPC base graph 2 are 8448 bits and 3480 bits, respectively. If a transport block with a CRC attached is not larger than the maximum code block size for the selected LDPC base graph, the transport block with the CRC attached is encoded using the selected LDPC base graph. Each code block of the transport block is encoded 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.In the case of PDSCH, up to two codewords (i.e., up to two transmission blocks) can be transmitted simultaneously on the PDSCH. PUSCH can be used for transmitting 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 the UL-SCH data.

[0155] <Scrambling and Modulation>

[0156] The bits of the codeword are scrambled and modulated to generate a block of complex-valued modulated symbols.

[0157] <Layer Mapping>

[0158] The complex numerical 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 PDSCH can transmit two codewords, it can support up to eight layers of transmission. Since PUSCH supports a single codeword, it can support up to four layers of transmission.

[0159] <Transform Precoding>

[0160] The downlink transmission waveform is conventional OFDM using a cyclic prefix (CP). For downlinks, transform precoding (i.e., discrete Fourier transform, DFT) is not applied.

[0161] The uplink transmission waveform is a conventional OFDM that uses a CP with a transform precoding function that can perform DFT spreading that 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.

[0162] <Subcarrier mapping>

[0163] Layers are mapped to antenna ports. In the downlink, a mapping in a manner transparent to the layer-antenna port mapping (non-codebook based) is supported, and how beamforming or MIMO precoding is performed is transparent to the UE. In the uplink, both non-codebook based and codebook based mappings are supported for the layer-antenna port mapping.

[0164] 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 resource blocks allocated to the physical channel.

[0165] <OFDM modulation>

[0166] The transmitting communication equipment adds a CP and performs an inverse fast Fourier transform (IFFT) to generate a time-continuous OFDM baseband signal with a TTI for the physical channel and a setting u for the antenna port p and subcarrier interval for the OFDM symbol l. For example, for each OFDM symbol, the transmitting communication equipment can perform an IFFT on the complex-valued modulation symbol mapped to the resource block in that OFDM symbol, and then add a CP to the IFFT-generated signal to generate an OFDM baseband signal.

[0167] <Up-conversion>

[0168] On the transmitting side, the communication equipment converts the OFDM baseband signal for the antenna port p, subcarrier interval setting u, and OFDM symbol l up to the carrier frequency f0 of the cell to which the physical channel is assigned.

[0169] In Figure 2, processors 102 and 202 are configured to perform coding, scrambling, modulation, hierarchical mapping, (uplink) conversion precoding, subcarrier mapping, and OFDM modulation. Processors 102 and 202 control transceivers 106 and 206 connected to them to convert the OFDM baseband signal up to the carrier frequency to generate a radio frequency (RF) signal. The radio frequency signal is transmitted to external devices via antennas 108 and 208.

[0170] Figure 8 shows an example of physical layer processing on the receiving side.

[0171] Physical hierarchical processing on the receiving end is essentially the reverse of physical hierarchical processing on the transmitting end.

[0172] <Frequency down-conversion>

[0173] 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.

[0174] <00​​​​​​​​​​​​​​​​​​​​​​​​​​​​Complex-valued modulation symbols are demmapped to one or two codewords.

[0182] <Recovery and Descrambling>

[0183] The complex numerical modulation symbols of the codeword are demodulated into the bits of the codeword and then descrambled.

[0184] <decrypt>

[0185] 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 and coding rate of the transport block. The codeword contains one or more coded blocks. Each coded block is decoded into a code block with a CRC attached or a transport block with a CRC attached using the selected LDPC base graph. If the sender splits a code block for a transport block with a CRC attached, the CRC sequence is removed from each of the code blocks with a CRC attached to obtain a code block. The code block is concatenated to the transport block with a CRC attached. The transport block CRC sequence is removed from the transport block with a CRC attached to obtain a transport block. The transport block is transmitted to the MAC hierarchy.

[0186] In the physical hierarchical processing at the transmitting and receiving ends described above, time and frequency domain resources (e.g., OFDM symbols, subcarriers, carrier frequencies) related to subcarrier mapping, OFDM modulation, and frequency up / down conversion are determined based on resource allocation (e.g., uplink grants, downlink allocations).

[0187] For uplink data transmission, the processor 102 of the present invention applies the above-described physical hierarchical processing on the transmitting side to the data unit of the present invention (or controls the transceiver 106 to apply it) and transmits the data unit wirelessly. For downlink data reception, the processor 102 of the present invention applies the above-described physical hierarchical processing on the receiving side to the received wireless signal (or controls the transceiver 106 to apply it) and obtains the data unit of the present invention.

[0188] For downlink data transmission, the processor 202 of the present invention applies the above-described physical hierarchical processing at the transmitting side to the data unit of the present invention (or controls the transceiver 206 to apply it) and transmits the data unit wirelessly. For uplink data reception, the processor 202 of the present invention applies the above-described physical hierarchical processing at the receiving side to the received wireless signal (or controls the transceiver 206 to apply it) and obtains the data unit of the present invention.

[0189] <LCP(Logical channel prioritization)>

[0190] The following section explains Logical Channel Prioritization (LCP) in NR systems.

[0191] The LCP procedure is applied when a new transmission is performed. RRC controls the scheduling of uplink data by signaling for each logical channel: priority, where the priority level decreases as the priority value increases; priorityBitRate, which sets the Prioritized Bit Rate (PBR); and bucketSizeDuration, which sets the Bucket Size Duration (BSD).

[0192] A MAC entity must maintain a variable Bj for each logical channel j. The value of Bj can be negative.

[0193] The MAC entity initializes Bj to 0 when the associated logical channel is configured.

[0194] For each logical channel j, the MAC entity must increment Bj by the product of PBR × T before every instance of the LCP procedure, where T is the elapsed time since Bj was last incremented.

[0195] If the value of Bj is greater than the bucket size (i.e., PBR × BSD), the MAC entity must set Bj to the bucket size.

[0196] When a new transmission is initiated, the MAC entity must allocate resources to the logical channel as follows:

[0197] - Logical channels selected for an uplink grant where Bj > 0 are allocated resources in decreasing priority order. If a logical channel's PBR is set to infinity, the MAC entity must allocate resources for all data available for transmission on that logical channel before satisfying the PBR of the lower-priority logical channels.

[0198] - Reduce Bj by the total size of the MAC SDU provided to the logical channel j mentioned above.

[0199] - If resources remain, all selected logical channels will be applied in descending order of priority (regardless of the Bj value) until all data or uplink grants to the logical channel are consumed (until one of both is consumed first). Logical channels configured with the same priority will be applied similarly.

[0200] If a MAC entity is requested to transmit multiple MAC PDUs simultaneously, or if a MAC entity receives multiple uplink grants within one or more matching PDCCH occasions (in different serving cells), the order in which the grants are processed depends on the UE's implementation.

[0201] Furthermore, the UE must adhere to the following rules a) through d) in the scheduling procedure described above.

[0202] a) If the entire SDU (or partially transmitted SDU or retransmitted RLC PDU) fits the remaining resources of the relevant MAC entity, the UE shall not split the RLC SDU (or partially transmitted SDU or retransmitted RLC PDU).

[0203] b) When the UE partitions an RLC SDU in a logical channel, it must maximize the size of the segment and fill as many grants of the associated MAC entities as possible.

[0204] c) The UE must maximize data transmission.

[0205] d) If a MAC entity is granted a UL grant size of 4 bytes or more while there is data that can be transmitted (except when the UL grant size is less than 7 bytes and an AMD PDU segment must be transmitted), the MAC entity shall not transmit the padding BSR and / or padding alone.

[0206] When enhancedSkipUplinkTxDynamic with a value of true is set in the MAC entity and the grant indicating the MAC entity is addressed with a C-RNTI, or when enhancedSkipUplinkTxDynamic with a value of true is set in the MAC entity and the grant indicating the MAC entity is an uplink CG (Configured grant), if there is no UCI multiplexed on the PUSCH, there is no aperiodic CSI request for the PUSCH, the MAC PDU does not contain a MAC SDU, the MAC PDU contains only a periodic BSR, there is no available data for any LCG (Logical Channel Group), or if the MAC PDU contains only a padding BSR, the MAC entity does not generate a MAC PDU for the HARQ entity.

[0207] When skipUplinkTxDynamic with a value of true is set in the MAC entity and the grant indicating the MAC entity is addressed with a C-RNTI, or when the grant indicating the MAC entity is an uplink CG (Configured grant), if there is no aperiodic CSI request for the PUSCH, the MAC PDU does not contain a MAC SDU, the MAC PDU contains only a periodic BSR, there is no available data for any LCG (Logical Channel Group), or if the MAC PDU contains only a padding BSR, the MAC entity does not generate a MAC PDU for the HARQ entity.

[0208] <Discarding in the RLC entity>

[0209] In NR, when the PDCP discard timer for a PDCP SDU expires, or when the successful transmission of the PDCP SDU is confirmed by a lower layer, the transmitting PDCP entity (e.g., UE) instructs the lower layer to discard the PDCP SDU. If the transmitting RLC entity receives an instruction from a higher layer to discard a particular RLC SDU, the transmitting RLC entity checks whether the RLC SDU has been submitted to the lower layer and discards the RLC SDU only if the particular RLC SDU or its segment has not been submitted to the lower layer. On the other hand, if the particular RLC SDU or its segment has already been submitted to the lower layer, the RLC entity does not discard it and continues to transmit it to the network.

[0210] When a receiving RLC entity (e.g., a network) receives one segment of a particular RLC SDU, the receiving RLC entity waits until it has received all segments of that RLC SDU, and only after receiving all segments does it attempt to reassemble the RLC SDU.

[0211] When the transmitting RLC entity operates in Unacknowledged Mode (UM), retransmission does not occur. Therefore, if one segment of a particular RLC SDU is lost due to a transmission failure or MAC reset, all successfully received segments of that RLC SDU cannot be reassembled and are ultimately discarded by the receiving RLC entity. In other words, if a segment of a particular RLC SDU is lost at the transmitting end due to a transmission failure or MAC reset, the transmitting RLC entity does not need to transmit the remaining segments of that RLC SDU. This is because even if the remaining segments are successfully transmitted, they will all ultimately be discarded because one segment is missing.

[0212] However, since there is no way to selectively discard only RLC SDU segments, radio resources can be wasted by transmitting unnecessary RLC SDU segments. That is, when a transmitting RLC entity submits a segment of a particular RLC SDU to a lower layer for transmission, the transmitting MAC entity transmits the MAC PDU containing that RLC SDU segment to the network. However, if the transmitting RLC entity receives a missing indication for a particular RLC SDU segment, this disclosure proposes that the RLC entity discard the remaining RLC SDU segment or the entire RLC SDU containing the missing segment.

[0213] <Polling based on data importance>

[0214] XR (extended reality) is expected to be one of the most promising services in recent mobile communication systems. However, conventional mechanisms may not be suitable for supporting XR services. In particular, XR traffic has strict latency and delay requirements, and the importance of data varies even within a single XR traffic. Many XR use cases have quasi-periodic traffic characteristics, combining high data-rate DL traffic (e.g., video streams) and frequent UL traffic (e.g., pose / control updates) and / or UL video streams. Both these DL and UL traffics have relatively strict PDB (packet delay budget) characteristics. Also, because XR is based on video codecs, some of the data generated by the codec is more important than other data. For example, an I-frame is more important than a P-frame or a B-frame.

[0215] Therefore, in order to support smooth XR services, it is important to satisfy strict PDBs for XR traffic and provide appropriate processing according to the importance of the data.

[0216] To satisfy delay requirements, delay reporting is being considered to identify data volumes with a remaining time shorter than a predetermined threshold. This involves identifying data with long buffering times and extremely short remaining time to reach the PDU boundary. This allows the network to understand the volume of urgent data within the UE and schedule an appropriate-sized uplink grant for the transmission of that urgent data.

[0217] Subsequently, the UE can transmit all urgent data with a remaining time shorter than the threshold to the network. However, when an ARQ (Automatic Repeat Request) for AM (Acknowledged Mode) is used for data transmission, the UE must wait for confirmation of the data before retransmitting the already transmitted data, and this confirmation is determined by a status report from the peer entity.

[0218] There are two possible methods for receiving status reports. The first method involves the sender including a poll, and the second method involves the receiver triggering a status report when it detects data loss. The problem with the second method is that it is not controllable by the sender, meaning the sender cannot receive status reports at the desired time. The first method also has its problems. In the current mechanism, the amount or number of bytes of data being transmitted must exceed a predetermined threshold in order to include a poll. Therefore, if only a small amount of urgent data is transmitted, a poll may not be included, and as a result, the sender may not be able to give the data a sufficient opportunity to be transmitted. In this case, the data may ultimately not satisfy the strict delay requirements.

[0219] To properly handle the diverse data importance of XR traffic, it is necessary to provide more transmission opportunities for critical data. However, current mechanisms determine the presence or absence of a packet based solely on the size or number of bytes of transmitted data. As a result, critical data is not given priority, and if the cumulative delay exceeds the PDB boundary, critical data may be discarded just like ordinary data. Therefore, resolving these issues is crucial for smooth XR services.

[0220] According to this disclosure, when a UE receives an uplink grant while holding data, the UE generates a PDU containing the data. When the UE includes data in the PDU, it increments a first counter by the number of data points and a second counter by the total number of bytes of data. When either counter exceeds a predetermined threshold, the UE includes the data in the PDU along with the pol. However, if the data is critical data, the UE must include the data in the PDU along with the pol regardless of whether the values ​​of the first and / or second counters exceed the threshold. The UE then transmits the generated PDU using an uplink grant. If the pol is included in the PDU, the UE initializes both counters to 0.

[0221] The UE can be configured to AM (Acknowledged Mode) or UM (Unacknowledged Mode) via L3 (e.g., RRC) signaling, including parameters such as the number threshold, byte threshold, poll retransmission timer, latency threshold, discard timer, SN (sequence number) size, and transmission window (which can be determined by subtracting 1 from the SN size).

[0222] When the UE receives data from a higher layer, the UE assigns an SN to the data and starts a discard timer for the data. When the discard timer for the data expires, the UE discards the data. In this disclosure, data can be considered an SDU before a header is added and a PDU after a header is added.

[0223] When a UE receives an uplink grant, it generates a PDU containing the data. When the UE includes data in the PDU, it increments a first counter by the number of data points and a second counter by the total number of bytes in the data. If the first counter exceeds the quantity threshold or the second counter exceeds the byte threshold, the UE includes the data in the PDU along with the pol.

[0224] In particular, when data is included in a PDU, if the data is critical data, the UE will include the PDU in the PDU regardless of whether the values ​​of the first and / or second counters exceed predetermined thresholds (i.e., it will be applied regardless of whether the current values ​​of the first and second counters exceed the first and second thresholds, respectively).

[0225] As mentioned above, separate counters and thresholds may exist for critical data, and these counters can only be incremented by critical data and not by ordinary (general) data. If a PDU contains a poll, the UE initializes all counters to 0. The UE can start or restart the poll retransmission timer when the PDU contains data. If the poll retransmission timer expires, the UE includes the poll in the retransmitted PDU or the newly transmitted PDU.

[0226] Data can be considered important data if one or more of the following conditions are met:

[0227] - If the remaining data time is equal to or less than the latency threshold.

[0228] - When the importance of the data is higher than that of other data (i.e., when the importance level of the data is higher than the importance threshold)

[0229] - If the data is retransmitted data

[0230] Regarding data importance, data importance can be configured or indicated (in advance) by the network or higher layers. For example, I-frames have a higher priority than P-frames, and P-frames have a higher priority than B-frames. Alternatively, higher-layer control packets / PDUs may have a higher priority than general data. A threshold can be set for determining data importance, and if the data's priority / importance is higher than that threshold, the UE can determine that the data is important data.

[0231] When a network receives a PDU containing a pole, it generates a status report indicating whether all received data can be acknowledged and transmits it back to the UE. Upon receiving the status report, the UE can determine whether the important data transmitted up to the PDU containing the pole can be acknowledged and can retransmit any important data that was denied in the status report.

[0232] Alternatively, the UE may have a separate hierarchical structure for processing this disclosure, in which case the following behavior may apply: RLC entities can be configured by L3 (e.g., RRC) signaling, including AM (Acknowledged Mode) or UM (Unacknowledged Mode), count threshold, byte threshold, pole retransmission timer, SN (sequence number) size, and transmit window (which can be determined by subtracting 1 from the SN size). PDCP entities associated with RLC entities can also be configured by L3 signaling. RLC and PDCP entities can be configured with latency thresholds and / or discard timers.

[0233] When a PDCP entity receives data from a higher layer, it assigns an SN to the data and starts a discard timer for the data. The PDCP entity may add a header to the data and then submit it to the RLC entity for transmission to the network. When the discard timer for the data expires, the PDCP entity instructs the RLC entity to discard the data. In this disclosure, data may be considered as an SDU before the header is added and as a PDU after the header is added.

[0234] When an RLC entity receives data from a PDCP entity, the RLC entity assigns an RLC SN to the data. When a UE receives an uplink grant, a portion of the uplink grant is allocated to an RLC entity (i.e., a specific logical channel), and data that can be transmitted within the allocated uplink grant can be submitted to the MAC entity. The MAC entity generates a MAC PDU containing the data submitted by the RLC entity. When data is submitted to the MAC entity, the RLC entity increments the first counter by the number of data points and the second counter by the total number of bytes of the data. If the first counter exceeds the count threshold, or if the second counter exceeds the byte threshold, the RLC entity includes the data in the MAC PDU along with the pole. In particular, when data is included in the MAC PDU, if the data is critical data, the RLC entity must include a pole for that data regardless of the cumulative values ​​of the first and second counters.

[0235] For particularly important data, separate counters and thresholds may exist, and these counters can only be incremented by important data, not general data. When a pole is included in a PDU, the RLC entity initializes both counters to zero. The RLC entity can also start or restart the pole retransmission timer when the data is included in the PDU. When the pole retransmission timer expires, the RLC entity can include the pole in the retransmitted or newly transmitted data and insert it into another MAC PDU.

[0236] If the remaining time of data is equal to or less than the latency threshold, the PDCP entity can transmit this information to the RLC entity. Upon receiving this instruction from the PDCP entity, the RLC entity will consider the data with a remaining time less than or equal to the latency threshold as critical data. Furthermore, when the PDCP entity submits data to the RLC entity, if the importance of that data is higher than that of other data, the PDCP entity can indicate this as critical data and transmit this information to the RLC entity. Here, the importance of data can be configured or indicated (in advance) by the network or higher layers. For example, I-frames have a higher priority than P-frames, and P-frames have a higher priority than B-frames. Also, higher-layer control packets / PDUs may have a higher priority than general data. A threshold can be set for determining the importance of data, and if the priority / importance of the data exceeds this threshold, the RLC entity can determine that the data is critical. In addition, the RLC entity can consider retransmitted data as critical data. That is, if one or more of the above conditions are met, the RLC entity can consider the data as critical data.

[0237] When the network receives a PDU containing a Pol, it generates a status report indicating whether all received data is verifiable or not, and retransmits it to the UE. When an RLC entity receives the status report, it can determine whether the important data transmitted up to the PDU containing the Pol is verifiable or not, and can retransmit any important data that was negatively verified in the status report.

[0238] Figure 9 shows an example of data transmission including a poll in accordance with this disclosure. In Figure 9, it is assumed that the RLC entity consists of a PDU counter and a first threshold with a value of 11. It is also assumed that the RLC entity consists of a byte counter and a second threshold with a value of 1500 bytes.

[0239] In Figure 9, we assume that all data are the same size, 100 bytes, and that data 14 is important data. Preferably, data 14 is indicated as important data by a higher hierarchy (e.g., the RRC hierarchy). We also assume that data 1 through 9 have already been transmitted, the current PDU counter is 9, and the byte counter is 900 bytes.

[0240] Referring to Figure 9, it is shown that at time T1, the critical data 14 is not yet included in the MAC PDU, and therefore the MAC PDU was generated based on the PDU counter and byte counter.

[0241] Specifically, when a UE receives an uplink grant, the UE's MAC entity distributes the uplink grant to each logical channel associated with each RLC entity via the LCP (Logical Channel Prioritization) procedure. The UE's RLC entity receives a notification along with the transmission opportunity regarding the total size (i.e., 200 bytes) to be transmitted in that transmission opportunity.

[0242] When the RLC entity submits data 10 and data 11 to the MAC entity, the RLC entity increments the PDU counter to 11 and the byte counter to 1100 bytes. As the PDU counter reaches the first threshold of 11, the RLC entity includes a poll when including data 11 in MAC PDU1. Subsequently, the inclusion of the poll initializes both the PDU counter and the byte counter to 0. The MAC entity then transmits MAC PDU1 to the network.

[0243] Next, at time point T2, it is shown that critical data 14 is included in the MAC PDU. As mentioned above, critical data 14 is data whose remaining time is equal to or less than the latency threshold, data whose importance level is higher than the importance threshold, or data that is retransmitted.

[0244] Specifically, when a UE receives another uplink grant, the UE's RLC entity receives a notification about the transmission opportunity, along with the total size (300 bytes) to be transmitted in that transmission opportunity.

[0245] When the UE's RLC entity submits data 12, data 13, and data 14 to the MAC entity, the RLC entity increments its PDU counter to 3 and its byte counter to 300 bytes.

[0246] Even though the PDU counter and byte counter have not reached the first threshold of 11 and the second threshold of 1500 bytes, respectively, the RLC entity includes a poll when including data 14 in MAC PDU2 because data 14 is important data. Once the poll is included in MAC PDU2 along with data 14, both the PDU counter and byte counter are initialized to 0. The MAC entity then transmits MAC PDU2 to the network.

[0247] Figure 10 shows an example of the actions that the UE performs in accordance with this disclosure.

[0248] Referring to Figure 10, in S1005, the UE (preferably the UE's RLC entity) receives a service data unit (SDU) from the higher layer and simultaneously starts the discard timer. Here, the higher layer may be the UE's PDCP layer.

[0249] In S1010, while the discard timer is operating, the UE (preferably an RLC entity) generates a protocol data unit (PDU) containing the SDU based on the uplink grant. That is, the UE (preferably an RLC entity) includes the SDU in the PDU.

[0250] Next, in S1015, the UE (preferably an RLC entity) increments a counter by the size of the SDU or by 1 when the SDU is included in the PDU.

[0251] In S1020, the UE (preferably an RLC entity) determines whether or not to include a poll in the PDU to request a status report related to the SDU.

[0252] Specifically, if an SDU is considered critical information, the PDU must include the poll. That is, if the remaining time on the discard timer is shorter than the first threshold, the PDU must include the poll. Also, if the SDU's importance level is higher than the second threshold, the PDU must include the poll. Here, the SDU's importance level is indicated by the higher hierarchy.

[0253] Of course, if the counter is above the third threshold, the PDU will include Pol. However, even if the counter is below the third threshold, if the remaining time of the discard timer is shorter than the first threshold, the PDU will always include Pol without comparing the counter to the third threshold.

[0254] Next, in S1025, Pol is included in the PDU according to the decision made in S1020. Preferably, if Pol is included in the PDU, the counter is initialized.

[0255] Finally, at S1030, the UE transmits the PDU using the uplink grant.

[0256] According to the present disclosure, the UE can receive a status report for important data earlier and can more quickly determine whether retransmission of the important data is necessary. Thereby, an additional retransmission opportunity for important XR data can be ensured, and it becomes possible to grasp whether the important data transmitted before the UE performs subsequent transmission can be confirmed, so that the XR service quality can be improved.

[0257] [Claims at the time of international filing] [Claim 1] A method performed by a UE (User Equipment) in a wireless communication system, comprising: receiving an SDU (service data unit) from a higher layer together with the start of a discard timer; generating a PDU (protocol data unit) including the SDU based on an uplink grant based on the discard timer being in operation; and transmitting the PDU on the uplink grant; wherein based on the remaining time of the discard timer being less than a first threshold, the PDU includes a poll for requesting a STATUS report related to the SDU. [Claim 2] Based on the SDU having an importance level greater than a second threshold, the PDU includes the poll, wherein the importance level of the SDU is indicated by the higher layer, the method according to claim 1. [Claim 3] further comprising increasing a counter by the size of the SDU or by 1 based on the SDU being included in the PDU; based on the counter being greater than or equal to a third threshold, the PDU includes the poll, the method according to claim 1. [Claim 4] The method according to claim 3, wherein the counter is initialized based on the fact that the poll is included in the PDU. [Claim 5] The method according to claim 3, wherein the PDU includes the poll without comparing the counter with a third threshold value based on the remaining time of the discard timer being less than a first threshold value. [Claim 6] A UE (user equipment) in a wireless communication system, comprising: At least one transceiver; At least one processor; and At least one computer memory operably connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations, The operations include: Receiving an SDU (service data unit) from a higher layer at the start of a discard timer; Generating a PDU (protocol data unit) including the SDU based on an uplink grant based on the discard timer being in operation; and Transmitting the PDU on the uplink grant, The UE, wherein the PDU includes a poll for requesting a STATUS report related to the SDU based on the remaining time of the discard timer being less than a first threshold value. [Claim 7] The PDU includes the poll based on the SDU having an importance level greater than a second threshold value, The UE according to claim 6, wherein the importance level of the SDU is indicated by the higher layer. [Claim 8] The operations include: The step of increasing the counter by the size of the SDU or by 1, based on the fact that the SDU is included in the PDU; The UE according to claim 6, wherein the PDU includes the Pol based on the counter being equal to or greater than a third threshold. [Claim 9] The UE according to claim 8, wherein the counter is initialized based on the fact that the pol is included in the PDU. [Claim 10] The UE according to claim 8, wherein the PDU includes the Pol without comparison between the counter and the third threshold, based on the remaining time of the discard timer being less than the first threshold. [Claim 11] It is a device for UE (user equipment), At least one processor, and The system comprises at least one computer memory that is operablely connectable to the at least one processor and stores instructions that cause the at least one processor to perform an operation when executed, The aforementioned operation is, The stage where a service data unit (SDU) is received from a higher level at the start of the discard timer; A step of generating a PDU (protocol data unit) including the SDU based on the uplink grant, based on the fact that the discard timer is running; and The step of transmitting the PDU over the uplink grant; The device includes a PDU that, based on the remaining time of the discard timer being less than a first threshold, includes a poll for requesting a status report related to the SDU. [Claim 12] A computer-readable storage medium, The storage medium stores at least one computer program that, when executed by at least one processor, includes instructions that cause the UE (user equipment) to perform an action. The aforementioned operation is, The stage where a service data unit (SDU) is received from a higher level at the start of the discard timer; A step of generating a PDU (protocol data unit) including the SDU based on the uplink grant, based on the fact that the discard timer is running; and The step of transmitting the PDU over the uplink grant; A computer-readable storage medium in which the PDU includes a poll for requesting a status report related to the SDU, based on the remaining time of the discard timer being less than a first threshold.

Claims

1. A method performed by a UE (User Equipment) in a wireless communication system, The stage in which the discard timer starts and the service data unit (SDU) is received from the higher level; A step of generating a PDU (protocol data unit) including the SDU based on the uplink grant, based on the fact that the discard timer is running; and The step of transmitting the PDU over the uplink grant; A method comprising: a PDU polling a STATUS report related to the SDU, based on the remaining time of the discard timer being less than a first threshold.

2. Based on the fact that the SDU has an importance level greater than the second threshold, the PDU includes the POL, The method according to claim 1, wherein the importance of the SDU is indicated by the higher hierarchy.

3. The step of increasing the counter by the size of the SDU or by 1, based on the fact that the SDU is included in the PDU; further comprising The method according to claim 1, wherein the PDU includes the POL based on the counter being equal to or greater than a third threshold.

4. The method according to claim 3, wherein the counter is initialized based on the fact that the pole is included in the PDU.

5. The method of claim 3, wherein the PDU includes the Pol without comparison between the counter and the third threshold, based on the remaining time of the discard timer being less than the first threshold.

6. UE (user equipment) in a wireless communication system, At least one transceiver, At least one processor, and The system comprises at least one computer memory that is operablely connectable to the at least one processor and stores instructions that, when executed, cause the at least one processor to perform an operation. The aforementioned operation is, The stage in which the discard timer starts and the service data unit (SDU) is received from the higher level; A step of generating a PDU (protocol data unit) including the SDU based on the uplink grant, based on the fact that the discard timer is running; and The step of transmitting the PDU over the uplink grant; Based on the remaining time of the discard timer being less than a first threshold, the PDU includes a poll for requesting a status report related to the SDU, UE.

7. Based on the fact that the SDU has an importance level greater than the second threshold, the PDU includes the POL, The importance of the SDU is indicated by the higher hierarchy, as per claim 6.

8. The aforementioned operation is, The step of increasing the counter by the size of the SDU or by 1, based on the fact that the SDU is included in the PDU; further comprising The UE according to claim 6, wherein the PDU includes the POL based on the counter being equal to or greater than a third threshold.

9. The UE according to claim 8, wherein the counter is initialized based on the fact that the pol is included in the PDU.

10. The UE according to claim 8, wherein the PDU includes the Pol without comparison between the counter and the third threshold, based on the remaining time of the discard timer being less than the first threshold.

11. It is a device for UE (user equipment), At least one processor, and The system comprises at least one computer memory that is operablely connectable to the at least one processor and stores instructions that, when executed, cause the at least one processor to perform an operation. The aforementioned operation is, The stage in which the discard timer starts and the service data unit (SDU) is received from the higher level; A step of generating a PDU (protocol data unit) including the SDU based on the uplink grant, based on the fact that the discard timer is running; and The step of transmitting the PDU over the uplink grant; The apparatus includes a PDU that, based on the remaining time of the discard timer being less than a first threshold, requests a status report related to the SDU.

12. A computer-readable storage medium, The storage medium stores at least one computer program that, when executed by at least one processor, includes instructions that cause a UE (user equipment) to perform an action. The aforementioned operation is, The stage in which the discard timer starts and the service data unit (SDU) is received from the higher level; A step of generating a PDU (protocol data unit) including the SDU based on the uplink grant, based on the fact that the discard timer is running; and The step of transmitting the PDU over the uplink grant; A computer-readable storage medium, the PDU, includes a poll for requesting a status report related to the SDU, based on the remaining time of the discard timer being less than a first threshold.

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