Method and apparatus for handling DRX retransmission timer for multicast retransmission in wireless communication system

Abstract

The present disclosure relates to a method of performing an operation for a user equipment (UE) in a wireless communication system. Specifically, the method comprises the steps of: monitoring a first Physical Downlink Control Channel (PDCCH) addressed to a Scheduling-Radio Network Temporary Identifier (G-CS-RNTI) of a group configuration; receiving the data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH based on detecting the first PDCCH and indicating a downlink (DL) multicast transmission, in which a configured scheduling-radio network temporary identifier (CS-RNTI) is configured, starting a HARQ round trip time (RTT) timer related to a unicast transmission for the HARQ process; and monitoring a second PDCCH addressed to the CS-RNTI based on expiration of a HARQ RTT timer related to the unicast transmission.

Description

Technical Field

[0001] The present disclosure relates to a wireless communication system, and more particularly, to a method and apparatus for handling a discontinuous reception (DRX) retransmission timer for multicast retransmission in the wireless communication system. Background Art

[0002] The introduction of new radio communication technologies has led to an increase in the number of user equipment (UE) that a base station (BS) can serve within a specified resource area, and has also led to an increase in the amount of control information and data that the BS transmits to the UE. Because the resources available for communication between the BS and the UE are typically limited, new technologies are needed to enable the BS to efficiently utilize limited radio resources to receive / transmit uplink / downlink data and / or uplink / downlink control information. In particular, in applications where performance is critically dependent on latency, overcoming latency has become a significant challenge. Summary of the Invention

[0003] Technical issues

[0004] Therefore, an object of the present disclosure is to provide a method for handling a discontinuous reception (DRX) retransmission timer for multicast retransmission in a wireless communication system and an apparatus thereof.

[0005] Technical Solution

[0006] The purpose of the present disclosure can be achieved by a method for performing operations of a user equipment (UE) in a wireless communication system, the method comprising the following steps: monitoring a first physical downlink control channel (PDCCH) addressed to a group-configured scheduling-radio network temporary identifier (G-CS-RNTI); based on detecting the first PDCCH and indicating a downlink (DL) multicast transmission, receiving a data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH, wherein a HARQ round-trip time (RTT) timer associated with a unicast transmission for the HARQ process is started based on a configured scheduling-radio network temporary identifier (CS-RNTI); and based on expiration of the HARQ RTT timer associated with the unicast transmission, monitoring a second PDCCH addressed to the CS-RNTI.

[0007] In addition, 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, the at least one computer memory being operatively connected to the at least one processor and storing instructions, the instructions causing the at least one processor to perform operations when executed, the operations comprising: monitoring a first physical downlink control channel (PDCCH) addressed to a group configured scheduling-radio network temporary identifier (G-CS-RNTI); based on detecting the first PDCCH and indicating a downlink (DL) multicast transmission, receiving a data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH, wherein a HARQ round trip time (RTT) timer associated with a unicast transmission for the HARQ process is started based on a configured scheduling-radio network temporary identifier (CS-RNTI); and based on expiration of the HARQ RTT timer associated with the unicast transmission, monitoring a second PDCCH addressed to the CS-RNTI.

[0008] Preferably, the step of receiving the data unit comprises: independently of the step of configuring the CS-RNTI, starting a HARQ RTT timer associated with the multicast transmission for the HARQ process.

[0009] Preferably, the first PDCCH indicates a DL multicast transmission associated with the retransmission of the data unit.However, the second PDCCH indicates a DL unicast transmission associated with the retransmission of the data unit.

[0010] Preferably, the RTT timer associated with the unicast transmission is a minimum duration before a DL assignment associated with the unicast transmission for the HARQ process is expected.

[0011] Those skilled in the art will understand that the effects that can be achieved by the present disclosure are not limited to the effects that have been particularly described above, and other advantages of the present disclosure will be more clearly understood from the following detailed description.

[0012] Beneficial effects

[0013] According to the present disclosure, when receiving using the G-CS-RNTI, the UE starts the unicast DRX RTT timer only when a PTP retransmission is expected. This allows the UE to avoid situations where the UE is in the active time of unicast DRX operation when no PTP retransmission is expected. This facilitates UE power conservation.

[0014] Effects obtainable from the present disclosure may not be limited to the above-mentioned effects. In addition, those skilled in the art in the art to which the present disclosure pertains may clearly understand other unmentioned effects from the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The accompanying drawings, which are included to provide a further understanding of the disclosure, illustrate embodiments of the disclosure and together with the description serve to explain the principle of the disclosure:

[0016] Figure 1 An example of a communication system 1 to which an implementation of the present disclosure is applied is illustrated;

[0017] Figure 2 is a block diagram illustrating an example of a communication device that can perform the method according to the present disclosure;

[0018] Figure 3 An example of a frame structure in a 3GPP-based wireless communication system is illustrated;

[0019] Figure 4 An example of a protocol stack in a wireless communication system based on the 3rd Generation Partnership Project (3GPP) is illustrated;

[0020] Figure 5 An example of data flow in a 3GPP New Radio (NR) system is illustrated;

[0021] Figure 6 An example of PDSCH time domain resource allocation through PDCCH and an example of PUSCH time resource allocation through PDCCH are illustrated;

[0022] Figure 7 An example of physical layer processing on the transmission side is illustrated;

[0023] Figure 8 An example of physical layer processing on the receiving side is illustrated;

[0024] Figure 9 An example of handling DRX operations for multicast transmissions according to the present disclosure is shown. DETAILED DESCRIPTION

[0025] Reference will now be made in detail to exemplary embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings. The detailed description given below with reference to the accompanying drawings is intended to explain exemplary embodiments of the present disclosure, rather than to illustrate the only embodiments that can be implemented according to the present disclosure. The following detailed description includes specific details to provide a thorough understanding of the present disclosure. However, it will be apparent to those skilled in the art that the present disclosure can be practiced without these specific details.

[0026] The following techniques, devices, and systems can be applied to various wireless multiple access systems. Examples of multiple access systems include code division multiple access (CDMA) systems, frequency division multiple access (FDMA) systems, time division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and multi-carrier frequency division multiple access (MC-FDMA) systems. CDMA can be implemented using radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be implemented using radio technologies such as Global System for Mobile Communications (GSM), General Packet Radio Service (GPRS), or Enhanced Data Rates for GSM Evolution (EDGE). OFDMA can be implemented using radio technologies such as Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, or Evolved UTRA (E-UTRA). UTRA is part of Universal Mobile Telecommunications System (UMTS). 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is part of Evolved UMTS (E-UMTS) using E-UTRA. 3GPP LTE adopts OFDMA in DL and SC-FDMA in UL. LTE-Advanced (LTE-A) is an evolved version of 3GPP LTE.

[0027] For ease of description, the implementation of the present disclosure will be primarily described with respect to a 3GPP-based wireless communication system. However, the technical features of the present disclosure are not limited thereto. For example, although the following detailed description is based on a mobile communication system corresponding to a 3GPP-based wireless communication system, aspects of the present disclosure that are not limited to 3GPP-based wireless communication systems are applicable to other mobile communication systems. For terms and techniques used in this disclosure that are not specifically described, reference may be made to wireless communication standard documents published prior to the present disclosure. For example, the following documents may be referenced.

[0028] 3GPP LTE

[0029] -3GPP TS 36.211: Physical channels and modulation

[0030] -3GPP TS 36.212: Multiplexing and channel coding

[0031] -3GPP TS 36.213: Physical layer procedures

[0032] -3GPP TS 36.214: Physical layer; Measurement

[0033] -3GPP TS 36.300: General Description

[0034] -3GPP TS 36.304: User Equipment (UE) Procedures in Idle Mode

[0035] -3GPP TS 36.314: Layer 2 - Measurement

[0036] -3GPP TS 36.321: Medium Access Control (MAC) Protocol

[0037] -3GPP TS 36.322: Radio Link Control (RLC) protocol

[0038] -3GPP TS 36.323: Packet Data Convergence Protocol (PDCP)

[0039] -3GPP TS 36.331: Radio Resource Control (RRC) Protocol

[0040] 3GPP NR (e.g., 5G)

[0041] -3GPP TS 38.211: Physical channels and modulation

[0042] -3GPP TS 38.212: Multiplexing and channel coding

[0043] -3GPP TS 38.213: Physical layer procedures for control

[0044] -3GPP TS 38.214: Physical layer procedures for data

[0045] -3GPP TS 38.215: Physical layer measurements

[0046] -3GPP TS 38.300: General Description

[0047] -3GPP TS 38.304: User Equipment (UE) Procedures in Idle Mode and in RRC Inactive State

[0048] -3GPP TS 38.321: Medium Access Control (MAC) Protocol

[0049] -3GPP TS 38.322: Radio Link Control (RLC) protocol

[0050] -3GPP TS 38.323: Packet Data Convergence Protocol (PDCP)

[0051] -3GPP TS 38.331: Radio Resource Control (RRC) Protocol

[0052] -3GPP TS 37.324: Service Data Adaptation Protocol (SDAP)

[0053] -3GPP TS 37.340: Multiple Connectivity; General Description

[0054] In the present disclosure, a user equipment (UE) may be a fixed or mobile device. Examples of UE include various devices that send user data and / or various control information to a base station (BS) and receive user data and / or various control information from a base station (BS). In the present disclosure, a BS generally refers to a fixed station that communicates with a UE and / or other BSs and exchanges various data and control information with the UE and other BSs. A BS may be referred to as an advanced base station (ABS), a node B (NB), an evolved node B (eNB), a base transceiver system (BTS), an access point (AP), a processing server (PS), and the like. In particular, a BS of a UMTS is referred to as an NB, a BS of an enhanced packet core (EPC) / long term evolution (LTE) system is referred to as an eNB, and a BS of a new radio (NR) system is referred to as a gNB.

[0055] In the present disclosure, a node refers to a point that can send / receive radio signals by communicating with a UE. Various types of BSs can be used as nodes regardless of their terminology. For example, a BS, a Node B (NB), an e-Node B (eNB), a picocell eNB (PeNB), a home eNB (HeNB), a repeater, a transponder, etc. can be a node. In addition, a node may not be a BS. For example, a node may be a radio remote head (RRH) or a radio remote unit (RRU). The power level of an RRH or RRU is generally lower than that of a BS. Since an RRH or RRU (hereinafter referred to as RRH / RRU) is generally connected to a BS via a dedicated line such as an optical cable, collaborative communication between RRH / RRU and a BS can be performed smoothly compared to collaborative communication between BSs connected via radio lines. Each node is equipped with at least one antenna. The antenna may include a physical antenna or an antenna port or a virtual antenna.

[0056] In the present disclosure, the term "cell" may refer to a geographical area to which one or more nodes provide a communication system, or to a radio resource. A "cell" of a geographical area may be understood as a coverage area in which a node can provide services using a carrier, and a "cell" as a radio resource (e.g., a time-frequency resource) is associated with a bandwidth (BW) as a frequency range configured by a carrier. A "cell" associated with a radio resource is defined by a combination of downlink resources and uplink resources (e.g., a combination of a downlink (DL) component carrier (CC) and an uplink (UL) CC). A cell may be configured only by downlink resources, or may be configured by downlink resources and uplink resources. Since the DL coverage, which is the range in which a node can send a valid signal, and the UL coverage, which is the range in which a node can receive a valid signal from a UE, depend on the carrier carrying the signal, the coverage of a node may be associated with the coverage of a "cell" of the radio resource used by the node. Therefore, the term "cell" may sometimes be used to refer to the service coverage of a node, other times to refer to a radio resource, or other times to refer to a range in which a signal using a radio resource can reach with effective strength.

[0057] In the present disclosure, the physical downlink control channel (PDCCH) and the 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. In addition, the physical uplink control channel (PUCCH), the physical uplink shared channel (PUSCH), and the 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.

[0058] In carrier aggregation (CA), two or more CCs are aggregated. The UE can receive or transmit simultaneously on one or more CCs depending on its capabilities. Both contiguous CCs and non-contiguous CCs support CA. When CA is configured, the UE has only one radio resource control (RRC) connection with the network. During RRC connection establishment / reestablishment / handover, one serving cell provides non-access stratum (NAS) mobility information, and during RRC connection reestablishment / handover, one serving cell provides security input. This cell is called a primary cell (PCell). A PCell is a cell operating on the primary frequency, where the UE performs an initial connection establishment procedure or initiates a connection reestablishment procedure. Depending on the capabilities of the UE, a secondary cell (SCell) can be configured to form a group of serving cells together with the PCell. An SCell is a cell that provides additional radio resources on a special cell. Therefore, a group of serving cells configured for a UE always consists of one PCell and one or more SCells. In the present disclosure, for dual connectivity (DC) operation, the term "special cell" refers to the PCell of a primary cell group (MCG) or the PSCell of a secondary cell group (SCG), and otherwise the term special cell refers to the PCell. SpCell supports physical uplink control channel (PUCCH) transmission and contention-based random access and is always active. MCG is a set of service cells associated with the master node, including SpCell (PCell) and optionally one or more SCells. SCG is a subset of service cells associated with the secondary node, including PSCell and zero or more SCells, for UEs configured with DC. For RRC_CONNECTED UEs that are not configured with CA / DC, there is only one service cell consisting of PCell. For RRC_CONNECTED UEs configured with CA / DC, the term "service cell" is used to refer to a set of cells consisting of SpCell and all SCells.

[0059] MCG is a group of service cells associated with a primary BS that terminates at least S1-MME, and SCG is a group of service cells associated with a secondary BS that provides additional radio resources for the UE but is not a primary BS. The SCG includes a primary SCell (PSCell) and optionally one or more SCells. In DC, two MAC entities are configured in the UE: one for MCG and one for SCG. Each MAC entity is configured by RRC with a service cell that supports PUCCH transmission and contention-based random access. In the present disclosure, the term SpCell refers to such a cell, while the term SCell refers to other service cells. Depending on whether the MAC entity is associated with an MCG or an SCG, respectively, the term SpCell refers to the PCell of the MCG or the PSCell of the SCG.

[0060] In this disclosure, monitoring a channel refers to attempting to decode the channel. For example, monitoring a physical downlink control channel (PDCCH) refers to attempting to decode the PDCCH (or a PDCCH candidate).

[0061] In the present disclosure, "C-RNTI" refers to cell RNTI, "SI-RNTI" refers to system information RNTI, "P-RNTI" refers to paging RNTI, "RA-RNTI" refers to random access RNTI, "SC-RNTI" refers to single cell RNTI, "SL-RNTI" refers to side link RNTI, "SPS C-RNTI" refers to semi-persistent scheduling C-RNTI, and "CS-RNTI" refers to configured scheduling RNTI.

[0062] Figure 1 An example of the communication system 1 to which the implementation of the present disclosure is applied is illustrated.

[0063] The three main demand categories for 5G include: (1) enhanced mobile broadband (eMBB) category, (2) massive machine type communication (mMTC) category, and (3) ultra-reliable and low-latency communication (URLLC) category.

[0064] Some use cases may require multiple categories for optimization, while others may focus on just one key performance indicator (KPI). 5G supports such a variety of use cases using a flexible and reliable approach.

[0065] eMBB goes far beyond basic mobile internet access and covers rich two-way work and media and entertainment applications in the cloud and augmented reality. Data is one of the core driving forces of 5G, and for the first time in the 5G era, dedicated voice services may not be provided. In 5G, voice is expected to be simply processed as an application using the data connection provided by the communication system. The main reasons for the increase in service capacity are the increase in content size and the increase in the number of applications requiring high data transmission rates. As more and more devices connect to the internet, streaming services (audio and video), conversational video, and mobile internet access will become more widely used. Many of these applications require always-on connections to push real-time information and alerts to users. Cloud storage and applications are rapidly increasing in mobile communication platforms and can be applied to both work and entertainment. Cloud storage is a special use case that is accelerating the growth of uplink data transmission rates. 5G is also used for remote work in the cloud. When using tactile interfaces, 5G requires much lower end-to-end latency to maintain a good user experience. Entertainment, such as cloud gaming and video streaming, is another core element that is increasing the demand for mobile broadband capabilities. Entertainment is essential for smartphones and tablets anywhere, including in highly mobile environments such as trains, cars, and airplanes. Another use case is augmented reality for entertainment and information search. In this case, augmented reality requires very low latency and instantaneous data capacity.

[0066] Furthermore, one of the most anticipated 5G use cases involves the ability to seamlessly connect embedded sensors across all fields, known as mMTC. It is expected that the number of potential IoT devices will reach 204 billion by 2020. Industrial IoT is one of the key categories that will play a major role in enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure through 5G.

[0067] URLLC, which includes remote control and ultra-reliable / available low-latency links over the primary infrastructure, will transform new industrial services (such as autonomous vehicles). This level of reliability and latency is necessary to control smart grids, automate industry, enable robotics, and control and coordinate drones.

[0068] 5G is a means of providing streams estimated to be hundreds of megabits per second to gigabits per second, and can supplement fiber to the home (FTTH) and cable-based broadband (or DOCSIS). Such fast speeds are needed to deliver TV with a resolution of 4K or more (6K, 8K and more), as well as virtual reality and augmented reality. Virtual reality (VR) and augmented reality (AR) applications include almost immersive sports games. Specific applications may require special network configurations. For example, for VR games, game companies need to merge core servers into the network operator's edge network servers to minimize latency.

[0069] Automobiles, along with their numerous use cases for mobile communications, are expected to be a significant new driver for 5G. For example, passenger entertainment will require high simultaneous capacity and mobile broadband with high mobility. 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 (AR) dashboards. AR dashboards allow drivers to identify objects in the dark, in addition to those visible through the front window, and display distance to and movement of objects by overlaying information spoken to the driver. In the future, wireless modules will enable communication between vehicles, information exchange between vehicles and supporting infrastructure, and information exchange between vehicles and other connected devices (e.g., devices accompanying pedestrians). Safety systems will guide alternative routes, enabling drivers to drive more safely and thus reducing the risk of accidents. The next stage will be remotely controlled or autonomous vehicles. This requires extremely high reliability and extremely fast communication between autonomous vehicles and between vehicles and infrastructure. In the future, autonomous vehicles will perform all driving activities, and drivers will only focus on unusual traffic events that the vehicle cannot identify. The technical requirements for autonomous vehicles require ultra-low latency and ultra-high reliability, increasing traffic safety to a level that cannot be achieved by humans.

[0070] Smart cities and smart homes / buildings, often referred to as smart societies, will be embedded in high-density wireless sensor networks. Distributed networks of smart sensors will identify conditions for cost- and energy-efficient maintenance in cities or homes. Similar configurations can be implemented for corresponding homes. All temperature sensors, window and heating controls, burglar alarms, and household appliances will be wirelessly connected. Many of these sensors are typically low in terms of data transmission rate, power, and cost. However, certain types of devices may require real-time HD video for monitoring.

[0071] The consumption and distribution of energy, including heat and gas, is becoming increasingly distributed, necessitating the automated control of distribution sensor networks. Smart grids collect information and use digital information and communication technologies to connect sensors to each other, thereby acting upon this information. Because this information can include the behavior of both supply companies and consumers, smart grids can improve the distribution of fuels such as electricity through methods that enhance efficiency, reliability, economic viability, sustainable production, and automation. Smart grids can also be considered another sensor network with low latency.

[0072] Mission-critical applications (e.g., e-health) are one of the 5G use cases. The health sector includes many applications that can benefit from mobile communications. Communication systems can support telemedicine, which provides clinical treatment in remote locations. Telemedicine can help reduce the barriers of distance and improve access to medical services that are not continuously available in remote rural areas. Telemedicine is also used to perform important treatments and save lives in emergency situations. Wireless sensor networks based on mobile communications can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0073] Wireless and mobile communications are becoming increasingly important in industrial applications. Cabling is expensive to install and maintain. Therefore, the potential to replace cables with reconfigurable wireless links presents an attractive opportunity in many industrial sectors. However, to achieve this replacement, wireless connections must have similar latency, reliability, and capacity to cables, and their management must be simplified. When it comes to 5G connectivity, low latency and a very low probability of error are new requirements.

[0074] Logistics and freight tracking are important use cases for mobile communications, allowing inventory and packages to be tracked anywhere using location-based information systems. Logistics and freight tracking use cases typically require low data rates but require location information with wide range and reliability.

[0075] Reference Figure 1 , the communication system 1 includes a wireless device, a base station (BS) and a network. Figure 1 A 5G network is illustrated as an example of the network of the communication system 1 , but implementations of the present disclosure are not limited to the 5G system and may be applied to future communication systems other than the 5G system.

[0076] The BS and the network may be implemented as wireless devices, and the specific wireless device 200a may operate as a BS / network node with respect to other wireless devices.

[0077] A wireless device refers to a device that performs communication using a radio access technology (RAT) (e.g., 5G New RAT (NR) or Long Term Evolution LTE) and may be referred to as a communication / wireless / 5G device. The wireless device may include, but is not limited to, a robot 100a, vehicles 100b-1 and 100b-2, an extended reality (XR) device 100c, a handheld device 100d, a home appliance 100e, an Internet of Things (IoT) device 100f, and an artificial intelligence (AI) device / server 400. For example, a vehicle may include a vehicle with a wireless communication function, an autonomous vehicle, and a vehicle capable of performing communication between vehicles. A vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). An XR device may include an augmented reality (AR) / virtual reality (VR) / mixed reality (MR) device and may be implemented in the form of a head-mounted device (HMD), a head-up display (HUD) installed in a vehicle, a television, a smartphone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices can include smartphones, smart tablets, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., laptops). Home appliances can include TVs, refrigerators, and washing machines. IoT devices can include sensors and smart meters.

[0078] In the present disclosure, wireless devices 100a to 100f may be referred to as user equipment (UE). User equipment (UE) may include, for example, a cellular phone, a smartphone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a tablet-shaped personal computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle with an autonomous driving function, a connected car, an unmanned aerial vehicle (UAV), an artificial intelligence (AI) module, a robot, an augmented reality (AR) device, a virtual reality (VR) device, a mixed reality (MR) device, a hologram device, a public safety device, an MTC device, an IoT device, a medical device, a Fintech device (or a financial device), a security device, a weather / environmental device, a device related to 5G services, or a device related to the fourth industrial evolution field. An unmanned aerial vehicle (UAV) may be, for example, an aircraft that is driven by a wireless control signal without a person on board. A VR device may include, for example, a device for realizing an object or background of a virtual world. An AR device may include, for example, a device that is realized by connecting an object or background of a virtual world to an object or background of a real world. MR devices may include, for example, devices that merge virtual objects or backgrounds into real-world objects or backgrounds. Holographic devices may include, for example, devices that record and reproduce stereoscopic information to achieve 360-degree stereoscopic images, utilizing the interference phenomenon of light generated when two lasers meet, known as holographic imaging. Public safety devices may include, for example, image relay devices or wearable imaging devices. MTC devices and IoT devices may be, for example, devices that do not require direct human intervention or manipulation. For example, MTC devices and IoT devices may include smart meters, vending machines, thermometers, smart light bulbs, door locks, or various sensors. Medical devices may be, for example, devices used for the diagnosis, treatment, alleviation, cure, or prevention of disease. For example, medical devices may be devices used for the diagnosis, treatment, alleviation, or correction of injury or damage. For example, medical devices may be devices used for the inspection, replacement, or modification of structure or function. For example, medical devices may be devices used for the regulation of pregnancy. For example, medical devices may include devices used for treatment, devices used for manipulation, devices used for (in vitro) diagnosis, hearing aids, or devices used for surgery. A safety device can be, for example, a device installed to prevent possible dangers and maintain safety. For example, a safety device can be a camera, CCTV, recorder, or black box. A fintech device can be, for example, a device capable of providing financial services such as mobile payments. For example, a fintech device can include a payment device or a point-of-sale (POS) system. A weather / environmental device can include, for example, a device for monitoring or predicting the weather / environment.

[0079] Wireless devices 100a to 100f can connect to network 300 via BS 200. AI technology can be applied to wireless devices 100a to 100f, and wireless devices 100a to 100f can connect to AI server 400 via network 300. Network 300 can be configured using 3G networks, 4G (e.g., LTE) networks, 5G (e.g., NR) networks, and beyond 5G networks. Although wireless devices 100a to 100f can communicate with each other via BS 200 / network 300, wireless devices 100a to 100f can perform direct communication with each other (e.g., sidelink communication) without going through the BS / network. For example, vehicles 100b-1 and 100b-2 can perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). IoT devices (e.g., sensors) can perform direct communication with other IoT devices (e.g., sensors) or other wireless devices 100a to 100f.

[0080] Wireless communication / connections 150A and 150B can be established between wireless devices 100a to 100f / BS200-BS200. In this document, wireless communication / connections can be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a and sidelink communication 150b (or D2D communication). The wireless devices and the BS / wireless devices can send / receive radio signals to each other through wireless communication / connections 150a and 150b. For example, wireless communication / connections 150a and 150b can send / receive signals through various physical channels. To this end, various configuration information configuration processes for sending / receiving radio signals, various signal processing processes (e.g., channel coding / decoding, modulation / demodulation, and resource mapping / demapping), and at least a portion of the resource allocation process can be performed based on various proposals in the present disclosure.

[0081] Figure 2 is a block diagram illustrating an example of a communication device that can perform the method according to the present disclosure.

[0082] Reference Figure 2 , the first wireless device 100 and the second wireless device 200 can transmit / receive radio signals to / from an external device through various RATs (eg, LTE and NR). Figure 2 In the example, {the first wireless device 100 and the second wireless device 200} can communicate with Figure 1 The {wireless devices 100a to 100f and BS 200} and / or {wireless devices 100a to 100f and wireless devices 100a to 100f} correspond to each other.

[0083] The first wireless device 100 may include one or more processors 102 and one or more memories 104, and additionally include one or more transceivers 106 and / or one or more antennas 108. The processor 102 may control the memory 104 and / or the transceiver 106 and may be configured to implement the functions, processes, and / or methods described in this disclosure. For example, the processor 102 may process information within the memory 104 to generate first information / signals, and then transmit a radio signal including the first information / signals through the transceiver 106. The processor 102 may receive a radio signal including second information / signals through the transceiver 106, and then store information obtained by processing the second information / signals in the memory 104. The memory 104 may be connected to the processor 102 and may store various information related to the operation of the processor 102. For example, the memory 104 may store software code including commands for executing part or all of the processes controlled by the processor 102 or for executing the processes and / or methods described in this disclosure. In this document, the processor 102 and the memory 104 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 106 may be connected to the processor 102 and transmit and / or receive radio signals via one or more antennas 108. Each of the transceivers 106 may include a transmitter and / or a receiver. The transceiver 106 may be used interchangeably with a radio frequency (RF) unit. In this disclosure, a wireless device may represent a communication modem / circuit / chip.

[0084] The second wireless device 200 may include one or more processors 202 and one or more memories 204, and may additionally include one or more transceivers 206 and / or one or more antennas 208. The processor 202 may control the memory 204 and / or the transceiver 206 and may be configured to implement the functions, processes, and / or methods described in this disclosure. For example, the processor 202 may process information within the memory 204 to generate third information / signals, and then transmit a radio signal including the third information / signals through the transceiver 206. The processor 202 may receive a radio signal including fourth information / signals through the transceiver 206, and then store information obtained by processing the fourth information / signals in the memory 204. The memory 204 may be connected to the processor 202 and may store various information related to the operation of the processor 202. For example, the memory 204 may store software code including commands for executing part or all of the processes controlled by the processor 202 or for executing the processes and / or methods described in this disclosure. In this document, the processor 202 and the memory 204 may be part of a communication modem / circuit / chip designed to implement a RAT (e.g., LTE or NR). The transceiver 206 may be connected to the processor 202 and transmit and / or receive radio signals via one or more antennas 208. Each of the transceivers 206 may include a transmitter and / or a receiver. The transceiver 206 may be used interchangeably with an RF unit. In this disclosure, a wireless device may represent a communication modem / circuit / chip.

[0085] In the following, the hardware elements of the wireless devices 100 and 200 will be described in more detail. One or more protocol layers may be implemented by, but are not limited to, one or more processors 102 and 202. For example, one or more processors 102 and 202 may implement one or more layers (e.g., functional layers such as PHY, MAC, RLC, PDCP, RRC, and SDAP). One or more processors 102 and 202 may generate one or more protocol data units (PDUs) and / or one or more service data units (SDUs) according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure. One or more processors 102 and 202 may generate signals (e.g., baseband signals) including PDUs, SDUs, messages, control information, data, or information according to the functions, procedures, proposals, and / or methods disclosed in the present disclosure and provide the generated signals to one or more transceivers 106 and 206. One or more processors 102 and 202 may receive signals (e.g., baseband signals) from one or more transceivers 106 and 206 and obtain PDUs, SDUs, messages, control information, data, or information according to the functions, processes, proposals, and / or methods disclosed in this disclosure.

[0086] One or more processors 102 and 202 may be referred to as controllers, microcontrollers, microprocessors, or microcomputers. One or more processors 102 and 202 may be implemented by hardware, firmware, software, or a combination thereof. For example, one or more application-specific integrated circuits (ASICs), one or more digital signal processors (DSPs), one or more digital signal processing devices (DSPDs), one or more programmable logic devices (PLDs), or one or more field-programmable gate arrays (FPGAs) may be included in one or more processors 102 and 202. The functions, processes, proposals, and / or methods disclosed in this disclosure may be implemented using firmware or software, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to perform the functions, processes, proposals, and / or methods disclosed in this disclosure may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 to facilitate being driven by one or more processors 102 and 202. The functions, processes, proposals, and / or methods disclosed in this disclosure may be implemented using firmware or software in the form of code, commands, and / or command sets.

[0087] One or more memories 104 and 204 can be connected to one or more processors 102 and 202 and store various types of data, signals, messages, information, programs, codes, instructions and / or commands. One or more memories 104 and 204 can be configured by read-only memory (ROM), random access memory (RAM), electrically erasable programmable read-only memory (EPROM), flash memory, hard drive, registers, cache memory, computer-readable storage media and / or combinations thereof. One or more memories 104 and 204 can be located internally and / or externally to one or more processors 102 and 202. One or more memories 104 and 204 can be connected to one or more processors 102 and 202 via various technologies such as wired or wireless connections.

[0088] One or more transceivers 106 and 206 can transmit user data, control information, and / or radio signals / channels mentioned in the methods and / or operational flow charts of the present disclosure to one or more other devices. One or more transceivers 106 and 206 can receive user data, control information, and / or radio signals / channels mentioned in the functions, processes, proposals, methods, and / or operational flow charts disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106 and 206 can be connected to one or more processors 102 and 202 and transmit and receive radio signals. For example, one or more processors 102 and 202 can perform control so that one or more transceivers 106 and 206 can transmit user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 can perform control so that one or more transceivers 106 and 206 can receive user data, control information, or radio signals from one or more other devices. One or more transceivers 106 and 206 may be connected to one or more antennas 108 and 208, and one or more transceivers 106 and 206 may be configured to transmit and receive user data, control information, and / or radio signals / channels mentioned in the functional, process, proposal, method, and / or operational flow charts disclosed in the present disclosure through one or more antennas 108 and 208. In the present disclosure, one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports). One or more transceivers 106 and 206 may convert received radio signals / channels, etc. from RF band signals to baseband signals to facilitate processing of received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 may convert user data, control information, radio signals / channels, etc. processed using one or more processors 102 and 202 from baseband signals to RF band signals. To this end, one or more transceivers 106 and 206 may include (analog) oscillators and / or filters. For example, transceivers 106 and 206 may up-convert an OFDM baseband signal to a carrier frequency through their (analog) oscillators and / or filters under the control of processors 102 and 202 and transmit the up-converted OFDM signal at the carrier frequency. Transceivers 106 and 206 may receive an OFDM signal at a carrier frequency and down-convert the OFDM signal to an OFDM baseband signal through their (analog) oscillators and / or filters under the control of processors 102 and 202.

[0089] In implementations of the present disclosure, a UE may function as a transmitter in the uplink (UL) and a receiver in the downlink (DL). In implementations of the present disclosure, a base station (BS) may function as a receiver in the UL and a transmitter in the DL. Hereinafter, for ease of description, unless otherwise specified or described, it is primarily assumed that the first wireless device 100 functions as a UE and the second wireless device 200 functions as a base station (BS). For example, the processor 102 connected to, installed on, or activated in the first wireless device 100 may be configured to perform UE behavior according to implementations of the present disclosure or to control the transceiver 106 to perform UE behavior according to implementations of the present disclosure. The processor 202 connected to, installed on, or activated in the second wireless device 200 may be configured to perform BS behavior according to implementations of the present disclosure or to control the transceiver 206 to perform BS behavior according to implementations of the present disclosure.

[0090] In the present disclosure, at least one memory (eg, 104 or 204 ) may store instructions or programs that, when executed, cause at least one processor operatively connected thereto to perform operations according to some embodiments or implementations of the present disclosure.

[0091] In the present disclosure, a computer-readable storage medium stores at least one instruction or computer program that, when executed by at least one processor, causes the at least one processor to perform operations according to some embodiments or implementations of the present disclosure.

[0092] In the present disclosure, a processing device or apparatus may include at least one processor, and at least one computer memory, which is connectable to the at least one processor and stores instructions that, when executed, cause the at least one processor to perform operations according to some embodiments or implementations of the present disclosure.

[0093] Figure 3 An example of a frame structure in a 3GPP-based wireless communication system is illustrated.

[0094] Figure 3The frame structure shown is only exemplary, and the number of subframes, the number of time slots and / or the number of symbols in a frame may vary. In a 3GPP-based wireless communication system, OFDM parameter sets (e.g., subcarrier spacing (SCS), transmission time interval (TTI) duration) may be configured differently between multiple cells aggregated for one UE. For example, if a UE is configured with different SCSs for cells aggregated for a cell, the (absolute time) duration of time resources (e.g., subframes, time slots, or TTIs) comprising the same number of symbols may be different among the aggregated cells. In this document, symbols may include OFDM symbols (or CP-OFDM symbols), SC-FDMA symbols (or discrete Fourier transform-spread-OFDM (DFT-s-OFDM) symbols).

[0095] Reference Figure 3 , downlink and uplink transmissions are organized into frames. Each frame has T f = 10ms duration. Each frame is divided into two half-frames, where each half-frame has a duration of 5ms. Each half-frame includes 5 sub-frames, where the duration of each sub-frame is T sf is 1 ms. Each subframe is divided into slots, and the number of slots in a subframe depends on the subcarrier spacing. Each slot includes 14 or 12 OFDM symbols based on the cyclic prefix (CP). In normal CP, each slot includes 14 OFDM symbols, and in extended CP, each slot includes 12 OFDM symbols. The parameter set is based on an exponentially scalable subcarrier spacing Δf=2 u *15kHz. The following table shows the subcarrier spacing Δf = 2 u *The number of OFDM symbols per slot of 15 kHz, the number of slots per frame, and the number of slots per subframe for normal CP.

[0096] [Table 1]

[0097] u <![CDATA[N slot symb ]]> <![CDATA[N frame，u slot ]]> <![CDATA[N subframe，u slot ]]> 0 14 10 1 1 14 20 2 2 14 40 4 3 14 80 8 4 14 160 16

[0098] The following table shows the subcarrier spacing Δf = 2 u *The number of OFDM symbols per slot for 15 kHz, the number of slots per frame, and the number of slots per subframe for extended CP.

[0099] [Table 2]

[0100] u <![CDATA[N slot symb ]]> <![CDATA[N frame，u slot ]]> <![CDATA[N subframe,u slot ]]> 2 12 40 4

[0101] A slot includes a plurality of symbols (e.g., 14 or 12 symbols) in the time domain. For each parameter set (e.g., subcarrier spacing) and carrier, a common resource block (CRB) N is allocated from the common resource blocks (CRBs) N indicated by higher layer signaling (e.g., radio resource control (RRC) signaling). start,u grid To begin, define N size,u grid,x *N RB sc subcarriers and N subframe,u symb OFDM symbol resource grid, where N size,u grid,x is the number of resource blocks in the resource grid, and the subscript x is DL for downlink and UL for uplink. N RB sc is the number of subcarriers per resource block. In 3GPP-based wireless communication systems, N RB sc Typically 12. For a given antenna port p, subcarrier spacing configuration u, and transmission direction (DL or UL), there is one resource grid. The carrier bandwidth N for subcarrier spacing configuration u is size,u grid Given by higher-layer parameters (e.g., RRC parameters). Each element in the resource grid for antenna port p and subcarrier spacing configuration u is called a resource element (RE), and one complex symbol can be mapped to each RE. Each RE in the resource grid is uniquely identified by an index k in the frequency domain and an index l representing the symbol position relative to a reference point in the time domain. In a 3GPP-based wireless communication system, a resource block is defined by 12 consecutive subcarriers in the frequency domain.

[0102] In 3GPP NR systems, resource blocks are classified into common resource blocks (CRBs) and physical resource blocks (PRBs). CRBs are numbered upwards from 0 in the frequency domain for subcarrier spacing configuration u. The center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with "point A", which is used as a common reference point for the resource block grid. In 3GPP NR systems, PRBs are defined within bandwidth parts (BWPs) and are numbered from 0 to N. size BWP,i -1 numbering, where i is the number of the bandwidth part. Physical resource block n in bandwidth part i PRB With public resource block n CRB The relationship between them is as follows: PRB =n CRB +N size BWP,i , where N size BWP,iA BWP is a common resource block that begins the bandwidth portion relative to CRB 0. A BWP consists of multiple contiguous resource blocks. A carrier can include up to N (e.g., 5) BWPs. A UE can be configured with one or more BWPs on a given component carrier. Of the BWPs configured for a UE, only one can be active at a time. The active BWP defines the UE's operating bandwidth within the cell's operating bandwidth.

[0103] NR frequency bands can be defined as two types of frequency ranges, FR1 and FR2. FR2 can also be called millimeter wave (mmW). The frequency ranges in which NR can operate are shown as described in Table 3.

[0104] [Table 3]

[0105] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0106] Figure 4 An example of a protocol stack in a 3GPP-based wireless communication system is illustrated.

[0107] Specifically, Figure 4 (a) illustrates an example of a radio interface user plane protocol stack between a UE and a base station (BS) and Figure 4 (b) illustrates an example of a radio interface control plane protocol stack between a UE and a BS. The control plane refers to a path through which control messages for managing calls by the UE and the network are transmitted. The user plane refers to a path for transmitting data generated in the application layer (for example, voice data or Internet packet data). Figure 4 (a), the user plane protocol stack can be divided into a first layer (Layer 1) (ie, a physical (PHY) layer) and a second layer (Layer 2). Figure 4 (b), the control plane protocol stack can be divided into layer 1 (ie, PHY layer), layer 2, layer 3 (eg, radio resource control (RRC) layer) and non-access stratum (NAS) layer. Layer 1, layer 2 and layer 3 are called access stratum (AS).

[0108] The NAS control protocol is terminated at an Access Management Function (AMF) on the network side and performs functions such as authentication, mobility management, security control, etc.

[0109] 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 New Radio (NR) systems, Layer 2 is divided into the following sublayers: MAC, RLC, PDCP, and SDAP. The PHY layer provides transport 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 Quality of Service (QoS) flows to the 5G core network.

[0110] In 3GPP NR systems, the main services and functions of SDAP include: mapping between QoS flows and data radio bearers; marking QoS flow IDs (QFIs) in both DL and UL packets; and configuring a single SDAP protocol entity for each separate PDU session.

[0111] In the 3GPP NR system, the main services and functions of the RRC sublayer include: broadcast of system information related to AS and NAS; paging initiated by the 5G Core (5GC) or NG-RAN; establishment, maintenance and release of RRC connections between UE and NG-RAN; security functions including key management; establishment, configuration, maintenance and release of signaling radio bearers (SRBs) and data radio bearers (DRBs); mobility functions (including: handover and context transfer; UE cell selection and reselection and control of cell selection and reselection; inter-RAT mobility); QoS management functions; UE measurement reporting and control of reporting; detection and recovery of radio link failures; and transmission of NAS messages from UE to NAS / from NAS to UE.

[0112] In the 3GPP NR system, the main services and functions of the PDCP sublayer for the user plane include: sequence numbering; header compression and decompression (ROHC only); delivery of user data; reordering and duplicate detection; in-sequence delivery; PDCP PDU routing (in the case of split bearers); retransmission of PDCP SDUs; ciphering, deciphering, and integrity protection; PDCP SDU discard; PDCP re-establishment and data recovery for RLC AM; PDCP status reporting for RLC AM; PDCP PDU duplication and duplicate discard indication to lower layers. The main services and functions of the PDCP sublayer for the control plane include: sequence numbering; ciphering, deciphering, and integrity protection; delivery of control plane data; reordering and duplicate detection; in-sequence delivery; PDCP PDU duplication and duplicate discard indication to lower layers.

[0113] The RLC sublayer supports three transmission modes: transparent mode (TM); unacknowledged mode (UM); and acknowledged mode (AM). RLC configuration is specific to each logical channel and does not depend on the parameter set and / or transmission duration. In 3GPP NR systems, the main services and functions of the RLC sublayer depend on the transmission mode and include: delivery of upper layer PDUs; sequence numbering independent of PDCP (UM and AM); error correction through ARQ (AM only); segmentation (AM and UM) and re-segmentation (AM only) of RLC SDUs; reassembly of SDUs (AM and UM); duplicate detection (AM only); RLC SDU discard (AM and UM); RLC re-establishment; protocol error detection (AM only).

[0114] In 3GPP NR systems, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing / demultiplexing MAC SDUs belonging to one or different logical channels onto / from transport blocks (TBs) on transport channels for delivery to / from the physical layer; scheduling information reporting; error correction through HARQ (one HARQ entity per cell in the case of carrier aggregation (CA)); priority handling between UEs through dynamic scheduling; priority handling between logical channels of a UE through logical channel prioritization; and padding. A single MAC entity can support multiple parameter sets, transmission timings, and cells. Mapping constraints in logical channel prioritization control which parameter sets, cells, and transmission timings can be used by a logical channel. MAC provides different types of data transmission services. To accommodate these different types of data transmission services, multiple logical channel types are defined, each supporting the transmission of a specific type of information. Each logical channel type is defined by the type of information it transmits. Logical channels are divided into two groups: control channels and traffic channels. Control channels are used only for the transmission of control plane information, while traffic channels are used only for the transmission of user plane information. The Broadcast Control Channel (BCCH) is a downlink logical channel used to broadcast system control information. The Paging Control Channel (PCCH) is a downlink logical channel that transmits paging information, system information change notifications, and indications of ongoing PWS broadcasts. The Common Control Channel (CCCH) is a logical channel used to send 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 that sends 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 one UE and is used to transmit user information. The DTCH can exist in both the uplink and downlink. In the downlink, the following connections exist between logical channels and transport channels: the BCCH can be mapped to the BCH; the BCCH can be mapped to the downlink shared channel (DL-SCH); the PCCH can be mapped to the PCH; the CCCH can be mapped to the DL-SCH; the DCCH can be mapped to the DL-SCH; and the DTCH can be mapped to the DL-SCH. In the uplink, the following connections between logical channels and transport channels exist: CCCH may be mapped to the Uplink Shared Channel (UL-SCH); DCCH may be mapped to UL-SCH; and DTCH may be mapped to UL-SCH.

[0115] Figure 5 This section illustrates an example of data flow in a 3GPP NR system.

[0116] exist Figure 5In the MAC protocol, "RB" represents a radio bearer, and "H" represents a header. Radio bearers are categorized 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 to and from external devices via the PHY layer using radio resources. MAC PDUs arrive at the PHY layer in the form of transport blocks.

[0117] At the PHY layer, the uplink transport channels UL-SCH and RACH are mapped to the physical uplink shared channel (PUSCH) and the physical random access channel (PRACH), respectively, and the downlink transport channels DL-SCH, BCH, and PCH are mapped to the physical downlink shared channel (PDSCH), the physical broadcast channel (PBCH), and the PDSCH, respectively. At the PHY layer, uplink control information (UCI) is mapped to the PUCCH, and downlink control information (DCI) is mapped to the PDCCH. The UE sends a MAC PDU related to the UL-SCH via the PUSCH based on the UL grant, and the BS sends a MAC PDU related to the DL-SCH via the PDSCH based on the DL assignment.

[0118] In order to send the data unit of the present disclosure on the UL-SCH, the UE should have uplink resources available to the UE. In order to receive the data unit of the present disclosure on the DL-SCH, the UE should have downlink resources available to the UE. Resource allocation includes time domain resource allocation and frequency domain resource allocation. In the present disclosure, uplink resource allocation is also referred to as uplink grant, and downlink resource allocation is also referred to as downlink assignment. The uplink grant is either dynamically received by the UE on the PDCCH in the random access response or semi-persistently configured to the UE by the RRC. The downlink assignment is either dynamically received by the UE on the PDCCH or semi-persistently configured to the UE by RRC signaling from the BS.

[0119] In the UL, the BS can dynamically allocate resources to the UE via the Cell Radio Network Temporary Identifier (C-RNTI) on the PDCCH. The UE always monitors the PDCCH in order to find possible grants for uplink transmission when its downlink reception is enabled (active by discontinuous reception (DRX) control when configured). In addition, by configuring the grant, the BS can allocate uplink resources for the initial HARQ transmission to the UE. Two types of configured uplink grants are defined: type 1 and type 2. For type 1, the RRC directly provides the configured uplink grant (including periodicity). For type 2, the RRC defines the periodicity of the configured uplink grant, and the PDCCH addressed to the configured scheduling RNTI (CS-RNTI) can signal and activate the configured uplink grant, or deactivate it; that is, the PDCCH addressed to the CS-RNTI indicates that the uplink grant can be implicitly reused according to the periodicity defined by the RRC until deactivated.

[0120] In the DL, the BS can dynamically allocate resources to the UE via the C-RNTI on the PDCCH. The UE always monitors the PDCCH in order to find possible assignments when its downlink reception is enabled (active by DRX control when configured). In addition, through semi-persistent scheduling (SPS), the BS can allocate downlink resources for the initial HARQ transmission to the UE: RRC defines the periodicity of the configured downlink assignments, and the PDCCH addressed to the CS-RNTI can signal and activate the configured downlink assignment, or deactivate it. In other words, the PDCCH addressed to the CS-RNTI indicates that the downlink assignment can be implicitly reused according to the periodicity defined by the RRC until deactivated.

[0121] <Resource Allocation via PDCCH (i.e., Resource Allocation via DCI)>

[0122] The PDCCH can be used to schedule DL transmissions on the PDSCH and UL transmissions on the PUSCH, wherein the downlink control information (DCI) on the PDCCH includes: a downlink assignment containing at least the modulation and coding format (e.g., modulation and coding scheme (MCS) index IMCS), resource allocation, and hybrid ARQ information related to the DL-SCH; or an uplink scheduling grant containing at least the modulation and coding format, resource allocation, and hybrid ARQ information related to the UL-SCH. The size and purpose of the DCI carried by one PDCCH vary depending on 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.

[0123] Figure 6 An example of PDSCH time domain resource allocation through the PDCCH and an example of PUSCH time resource allocation through the PDCCH are illustrated.

[0124] The downlink control information (DCI) carried by the PDCCH for scheduling PDSCH or PUSCH includes the value m of the row index m+1 of the allocation table for PDSCH or PUSCH. The predefined default PDSCH time domain allocation A, B or C is applied as the allocation table for PDSCH, or the RRC-configured pdsch-TimeDomainAllocationList is applied as the allocation table for PDSCH. The predefined default PUSCH time domain allocation A is applied as the allocation table for PUSCH, or the RRC-configured pusch-TimeDomainAllocationList is applied as the allocation table for PUSCH. Which PDSCH time domain resource allocation configuration is applied and which PUSCH time domain resource allocation table is applied are determined according to fixed / predefined rules (e.g., Table 5.1.2.1.1-1 in 3GPP TS 38.214v15.3.0, Table 6.1.2.1.1-1 in 3GPP TS 38.214v15.3.0).

[0125] Each index row in the PDSCH time domain allocation configuration defines the slot offset K0, the start and length indicator SLIV or directly defines the starting symbol S and the allocation length L, and the PDSCH mapping type assumed in PDSCH reception. Each index row in the PUSCH time domain allocation configuration defines the slot offset K2, the start and length indicator SLIV or directly defines the starting symbol S and the allocation length L, and the PUSCH mapping type assumed in PUSCH reception. K0 for PDSCH or K2 for PUSCH is the timing difference between the time slot with PDCCH and the time slot with PDSCH or PUSCH corresponding to the PDCCH. SLIV is a joint indication of the starting symbol S relative to the start of the time slot with PDSCH or PUSCH and the number of consecutive symbols L counted from symbol S. For PDSCH / PUSCH mapping type, there are two mapping types: one is mapping type A, in which the demodulation reference signal (DMRS) is located in the 3rd or 4th symbol of the time slot according to RRC signaling; and the other is mapping type B, in which the DMRS is located in the first allocated symbol.

[0126] The scheduling DCI includes a frequency domain resource assignment field that provides assignment information about resource blocks for PDSCH or PUSCH. For example, the frequency domain resource assignment field can provide the UE with information about the cell for PDSCH or PUSCH transmission, information about the bandwidth part for PDSCH or PUSCH transmission, and information about resource blocks for PDSCH or PUSCH transmission.

[0127] <Resource Allocation via RRC>

[0128] As mentioned above, in the uplink, there are two types of transmissions without dynamic grants: configured grant type 1, in which the uplink grant is provided by RRC and stored as a configured grant; and configured grant type 2, in which the uplink grant is provided by PDCCH and is stored or cleared as a configured uplink grant based on L1 signaling indicating activation or deactivation of the configured uplink grant. Type 1 and Type 2 are configured by RRC for each serving cell and each BWP. Multiple configurations are only active simultaneously on different serving cells. For type 2, activation and deactivation are independent between serving cells. For the same serving cell, the MAC entity is configured as type 1 or type 2.

[0129] When configured grant type 1 is configured, the UE is provided with at least the following parameters via RRC signaling from the BS:

[0130] -cs-RNTI, which is the CS-RNTI for retransmissions;

[0131] - Periodicity, which provides the configured periodicity of grant type 1;

[0132] -timeDomainOffset, which represents the offset of the resource in the time domain relative to SFN=0;

[0133] - timeDomainAllocation value m, which provides the row index m+1 pointing to the allocation table, indicating the combination of starting symbol S and length L and PUSCH mapping type;

[0134] -frequencyDomainAllocation, which provides frequency domain resource allocation; and

[0135] -mcsAndTBS, which provides IMCS indicating the modulation order, target code rate, and transport block size. When a configured grant type 1 is configured by RRC for a serving cell, the UE stores the uplink grant provided by RRC as the configured uplink grant for the indicated serving cell, and initializes or reinitializes the configured uplink grant to start in the symbol according to timeDomainOffset and S (derived from SLIV), and reappears periodically. After configuring an uplink grant for the configured grant type 1, the UE considers that the uplink grant is associated with each symbol, where: [(SFN*numberOfSlotsPerFrame(numberOfSymbolsPerSlot)+(number of slots in frame×numberOfSymbolsPerSlot)+number of symbols in a slot]=(timeDomainOffset*numberOfSymbolsPerSlot+S+N*periodicity)modulo(1024*numberOfSlotsPerFrame*numberOfSymbolsPerSlot), for all N>=0.

[0136] When configured grant type 2 is configured, at least the following parameters are provided to the UE via RRC signaling from the BS:

[0137] -cs-RNTI, which is the CS-RNTI for activation, deactivation, and retransmission; and

[0138] - Periodicity, which provides the periodicity of the configured grant type 2. The actual uplink grant is provided to the UE via PDCCH (addressed to the CS-RNTI). After configuring the uplink grant for the configured grant type 2, the UE considers the uplink grant to be associated with each symbol, where: [(SFN*numberOfSlotsPerFrame*numberOfSymbolsPerSlot)+(number of slots in a frame*numberOfSymbolsPerSlot)+number of symbols in a slot]=[(SFN start time *numberOfSlotsPerFrame*numberOfSymbolsPerSlot+slot start 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 are the SFN, timeslot and symbol of the first transmission opportunity of the PUSCH in which the configured uplink link is (re)initialized, respectively. numberOfSlotsPerFrame and numberOfSymbolsPerSlot refer to the number of consecutive timeslots per frame and the number of consecutive OFDM symbols per timeslot, respectively.

[0139] For a configured uplink grant, the HARQ process ID associated with the first symbol of a UL transmission is derived from the following equation:

[0140] HARQ process ID = [floor(CURRENT_symbol / periodicity)] modulo nrofHARQ-Processes

[0141] Where CURRENT_symbol = (SFN × numberOfSlotsPerFrame × numberOfSymbolsPerSlot + number of slots in a frame × numberOfSymbolsPerSlot + number of symbols in a slot), where numberOfSlotsPerFrame and numberOfSymbolsPerSlot refer to the number of consecutive slots per frame and the number of consecutive symbols per slot, respectively, as specified in TS 38.211. CURRENT_symbol refers to the symbol index of the first transmission opportunity where duplicate bundling occurs. If a configured uplink grant is activated and the associated HARQ process ID is less than nrofHARQ-Processes, a HARQ process is configured for the configured uplink grant.

[0142] For the downlink, the UE can be configured with semi-persistent scheduling (SPS) for each serving cell and each BWP via RRC signaling from the BS. Multiple configurations can only be active simultaneously on different serving cells. The activation and deactivation of DL SPS are independent between serving cells. For DL SPS, the DL assignment is provided to the UE via PDCCH and is stored or cleared based on L1 signaling indicating SPS activation or deactivation. When configuring SPS, the following parameters are provided to the UE via RRC signaling from the BS:

[0143] -cs-RNTI, which is the CS-RNTI for activation, deactivation and retransmission;

[0144] -nrofHARQ-Processes: provides the number of HARQ processes configured for SPS;

[0145] - Periodicity, which provides the periodicity of downlink assignments for SPS configuration.

[0146] When the SPS is released by upper layers, all corresponding configurations should be released.

[0147] After downlink assignments are configured for SPS, the UE considers that the Nth downlink assignment occurs in the following time slots: (numberOfSlotsPerFrame*SFN+number of time slots in a frame)=[(numberOfSlotsPerFrame*SFN start time +slot start time )+N*periodicity*numberOfSlotsPerFrame / 10]modulo(1024*numberOfSlotsPerFrame), where SFN start time and slot start time are the SFN and timeslot, respectively, of the first transmission of the PDSCH for which the configured downlink assignment is (re)initialized.

[0148] For a configured downlink assignment, the HARQ process ID associated with the time slot where the DL transmission starts is derived from the following equation:

[0149] HARQ process ID = [floor (CURRENT_slot × 10 / (numberOfSlotsPerFrame × periodicity))] modulo nrofHARQ-Processes

[0150] Wherein, CURRENT_slot=[(SFN×numberOfSlotsPerFrame)+number of slots in a frame], and numberOfSlotsPerFrame refers to the number of consecutive slots per frame as specified in TS 38.211.

[0151] If the cyclic redundancy check (CRC) of the corresponding DCI format is scrambled by the CS-RNTI provided by the RRC parameter cs-RNTI and the new data indicator field for the enabled transport block is set to 0, the UE verifies the DL SPS assignment PDCCH or the configured UL grant type 2 PDCCH for scheduling activation or scheduling release. If all fields for the DCI format are set according to Table 4 or Table 5, the verification of the DCI format is achieved. Table 4 shows the special fields for DL SPS and UL grant type 2 scheduling activation PDCCH verification, and Table 5 shows the special fields for DL SPS and UL grant type 2 scheduling release PDCCH verification.

[0152] [Table 4]

[0153]

[0154] [Table 5]

[0155] DCI format 0_0 DCI format 1_0 HARQ process number Set to all "0" Set to all "0" Redundant version Set to "00" Set to "00" Modulation and coding schemes Set to all "1" Set to all "1" Resource Block Assignment Set to all "1" Set to all "1"

[0156] The actual DL assignment and actual UL grant, as well as the corresponding modulation and coding scheme, are provided by the resource assignment fields (e.g., the time domain resource assignment field providing the time domain resource assignment value m, the frequency domain resource assignment field providing the frequency resource block allocation, and the modulation and coding scheme field) in the DCI format carried by the DL SPS and UL grant type 2 scheduling activation PDCCH. If verification is achieved, the UE regards the information in the DCI format as a valid activation or release of the DL SPS or the configured UL grant type 2.

[0157] For UL, the processor 102 of the present disclosure may transmit (or control the transceiver 106 to transmit) the data unit of the present disclosure based on the UL grant available to the UE. The processor 202 of the present disclosure may receive (or control the transceiver 206 to receive) the data unit of the present disclosure based on the UL grant available to the UE.

[0158] For DL, the processor 102 of the present disclosure may receive (or control the transceiver 106 to receive) the DL data of the present disclosure based on the DL assignment available to the UE. The processor 202 of the present disclosure may send (or control the transceiver 206 to send) the DL data of the present disclosure based on the DL assignment available to the UE.

[0159] The data units of the present disclosure are subjected to physical layer processing at the transmitting side before being sent via the radio interface, and the radio signals carrying the data units of the present disclosure are subjected to physical layer processing at the receiving side. For example, a MAC PDU including a PDCP PDU according to the present disclosure may be subjected to physical layer processing as follows.

[0160] Figure 7An example of physical layer processing at the transmission side is illustrated.

[0161] The following tables show the mapping of transport channels (TrCHs) and control information to their corresponding physical channels. Specifically, Table 6 specifies the mapping of uplink transport channels to their corresponding physical channels, Table 7 specifies the mapping of uplink control channel information to its corresponding physical channels, Table 8 specifies the mapping of downlink transport channels to their corresponding physical channels, and Table 9 specifies the mapping of downlink control channel information to its corresponding physical channels.

[0162] [Table 6]

[0163] TrCH Physical Channel UL-SCH PUSCH RACH PRACH

[0164] [Table 7]

[0165] Control Information Physical Channel UCI PUCCH, PUSCH

[0166] [Table 8]

[0167] TrCH Physical Channel DL-SCH PDSCH BCH PBCH PCH PDSCH

[0168] [Table 9]

[0169] Control Information Physical Channel DCI PDCCH

[0170] <code>

[0171] Data and control streams from / to the MAC layer are encoded to provide transport and control services over the radio transmission link in the PHY layer. For example, transport blocks from the MAC layer are encoded into codewords on the transmit side. The channel coding scheme is a combination of error detection, error correction, rate matching, interleaving, and mapping transport channels or control information to / from physical channels.

[0172] In the 3GPP NR system, the following channel coding schemes are used for different types of TrCHs and different control information types.

[0173] [Table 10]

[0174]

[0175] [Table 11]

[0176]

[0177] For the transmission of a DL transport block (i.e., DL MAC PDU) or an UL transport block (i.e., UL MAC PDU), a transport block CRC sequence is attached to provide error detection for the receiving side. In the 3GPP NR system, the communication device uses a low-density parity-check (LDPC) code when encoding / decoding UL-SCH and DL-SCH. The 3GPP NR system supports two LDPC basis graphs (i.e., two LDPC basis matrices): an LDPC basis optimized for small transport blocks and an LDPC basis matrix optimized for small transport blocks. Figure 1 and LDPC foundation optimized for larger transport blocks Figure 2 LDPC basis is selected based on the transport block size and code rate R Figure 1 or LDPC basis Figure 2 . The code rate R is indicated by the modulation and coding scheme (MCS) index IMCS. The MCS index is dynamically provided to the UE via the PDCCH that schedules the PUSCH or PDSCH, is provided to the UE via the PDCCH that activates or (re)initializes the UL configured grant 2 or DL SPS, or is provided to the UE via RRC signaling associated with the UL configured grant type 1. If the CRC attached transport block is larger than the maximum code block size for the selected LDPC basis map, the CRC attached transport block may be split into code blocks and an additional CRC sequence is attached to each code block. For LDPC basis map Figure 1 and LDPC Basics Figure 2 The maximum code block size is 8448 bits and 3480 bits respectively. If the CRC attached transport block is not larger than the maximum code block size of the selected LDPC basis graph, the CRC attached transport block is encoded using the selected LDPC basis graph. Each code block of the transport block is encoded using the selected LDPC basis graph. The LDPC coded blocks are then rate matched individually. Code block concatenation is performed to create codewords for transmission on PDSCH or PUSCH. For PDSCH, up to 2 codewords (i.e., up to 2 transport blocks) can be sent simultaneously on PDSCH. PUSCH can be used for transmission of UL-SCH data and layer 1 / 2 control information. Although in Figure 8 Not shown, but layer 1 / 2 control information may be multiplexed with the codeword for UL-SCH data.

[0178] <Scrambling and Modulation>

[0179] The bits of the codeword are scrambled and modulated to generate blocks of complex-valued modulation symbols.

[0180] <Layer Mapping>

[0181] The complex-valued modulation symbols of a codeword are mapped to one or more multiple-input multiple-output (MIMO) layers. A codeword can be mapped to a maximum of 4 layers. The PDSCH can carry two codewords, and thus the PDSCH can support a maximum of 8-layer transmission. The PUSCH supports a single codeword, and thus the PUSCH can support a maximum of 4-layer transmission.

[0182] <Transform precoding>

[0183] The DL transmission waveform is conventional OFDM with a cyclic prefix (CP). For DL, transform precoding (i.e., discrete Fourier transform (DFT)) is not applied.

[0184] The UL transmission waveform is conventional OFDM with CP, where the transform precoding function that performs DFT spreading can be disabled or enabled. In the 3GPP NR system, for UL, if enabled, transform precoding can be selectively applied. Transform precoding extends the UL data in a special way to reduce the peak-to-average power ratio (PAPR) of the waveform. Transform precoding is a form of DFT. In other words, the 3GPP NR system supports two options for the UL waveform: one is CP-OFDM (the same as the DL waveform), and the other is DFT-s-OFDM. Whether the UE must use CP-OFDM or DFT-s-OFDM is configured by the BS via RRC parameters.

[0185] <Subcarrier mapping>

[0186] Layers are mapped to antenna ports. In DL, for the mapping from layers to antenna ports, transparent (non-codebook-based) mapping is supported, and how beamforming or MIMO precoding is performed is transparent to the UE. In UL, for the mapping from layers to antenna ports, both non-codebook-based mapping and codebook-based mapping are supported.

[0187] For each antenna port (i.e., layer) used for the transmission of a physical channel (e.g., PDSCH, PUSCH), the complex-valued modulation symbols are mapped to subcarriers in the resource blocks allocated to the physical channel.

[0188] <OFDM modulation>

[0189] The communication device on the transmitting side generates a time-continuous OFDM baseband signal on the subcarrier spacing configuration u and antenna port p in the TTI for the physical channel by adding a cyclic prefix (CP) and performing IFFT. For example, for each OFDM symbol, the communication device on the transmitting side can perform an inverse fast Fourier transform (IFFT) on the complex-valued modulation symbols mapped to the resource blocks in the corresponding OFDM symbol and add CP to the IFFT'ed signal to generate the OFDM baseband signal.

[0190] <Up-conversion>

[0191] The communication device at the transmitting side up-converts the OFDM baseband signal for antenna port p, subcarrier spacing configuration u, and OFDM symbol l to the carrier frequency f0 of the cell assigned to the physical channel.

[0192] Figure 2 The processors 102 and 202 in can be configured to perform encoding, scrambling, modulation, layer mapping, transform precoding (for UL), subcarrier mapping, and OFDM modulation. The processors 102 and 202 can control the transceivers 106 and 206 connected to the processors 102 and 202 to up-convert the OFDM baseband signal to the carrier frequency to generate a radio frequency (RF) signal. The RF signal is transmitted to an external device through the antennas 108 and 208.

[0193] Figure 8 An example of the physical layer processing at the receiving side is illustrated.

[0194] The physical layer processing at the receiving side is basically the inverse processing of the physical layer processing at the transmitting side.

[0195] <Frequency down-conversion>[[ID=二十]]

[0196] The communication device at the receiving side receives the RF signal at the carrier frequency through the antenna. The transceivers 106 and 206 that receive the RF signal at the carrier frequency down-convert the carrier frequency of the RF signal to the baseband to obtain an OFDM baseband signal.

[0197] <OFDM demodulation>

[0198] The communication device at the receiving side obtains complex-valued modulation symbols via CP separation and FFT. For example, for each OFDM symbol, the communication device at the receiving side removes the CP from the OFDM baseband signal and performs FFT on the OFDM baseband signal from which the CP has been removed to obtain complex-valued modulation symbols for antenna port p, subcarrier spacing u, and OFDM symbol l.

[0199] <Subcarrier demapping>

[0200] Subcarrier demapping is performed on the complex-valued modulation symbols to obtain the complex-valued modulation symbols of the corresponding physical channel. For example, the processor 102 can obtain the complex-valued modulation symbols mapped to the subcarriers belonging to the PDSCH from the complex-valued modulation symbols received in the bandwidth part. For another example, the processor 202 can obtain the complex-valued modulation symbols mapped to the subcarriers belonging to the PUSCH from the complex-valued modulation symbols received in the bandwidth part.

[0201] <Transform de-precoding>

[0202] If transform precoding is enabled for an uplink physical channel, transform deprecoding (eg, IDFT) is performed on the complex-valued modulation symbols of the uplink physical channel. Transform deprecoding is not performed for downlink physical channels and uplink physical channels for which transform precoding is disabled.

[0203] <Layer Demapping>

[0204] The complex-valued modulation symbols are demapped into one or two codewords.

[0205] <Demodulation and Descrambling>

[0206] The complex-valued modulation symbols of the codeword are demodulated and descrambled into the bits of the codeword.

[0207] <Decode>

[0208] The codeword is decoded into a transport block. For UL-SCH and DL-SCH, the LDPC basis is selected according to the transport block size and code rate R. Figure 1 or LDPC basis Figure 2 . A codeword may include one or more coding blocks. Each coding block is decoded into a CRC-attached code block or a CRC-attached transport block using the selected LDPC base graph. If code block segmentation is performed on the CRC-attached transport block at the transmitting side, the CRC sequence is removed from each of the CRC-attached code blocks, thereby obtaining a code block. The code blocks are concatenated into a CRC-attached transport block. The transport block CRC sequence is removed from the CRC-attached transport block, thereby obtaining a transport block. The transport block is passed to the MAC layer.

[0209] In the physical layer processing at the above-mentioned transmitting and receiving sides, the time domain and frequency domain resources (e.g., OFDM symbols, subcarriers, carrier frequencies) related to subcarrier mapping, OFDM modulation, and frequency up-conversion / down-conversion can be determined based on resource allocation (e.g., UL authorization, DL assignment).

[0210] For uplink data transmission, the processor 102 of the present disclosure may apply the above-mentioned physical layer processing of the transmitting side (or control the transceiver 106 to apply it) to the data unit of the present disclosure to wirelessly transmit the data unit. For downlink data reception, the processor 102 of the present disclosure may apply (or control the transceiver 106 to apply) the above-mentioned physical layer processing of the receiving side to the received radio signal to obtain the data unit of the present disclosure.

[0211] For downlink data transmission, the processor 202 of the present disclosure may apply the above-mentioned physical layer processing of the transmitting side (or control the transceiver 206 to apply it) to the data unit of the present disclosure to wirelessly transmit the data unit. For uplink data reception, the processor 202 of the present disclosure may apply (or control the transceiver 206 to apply) the above-mentioned physical layer processing of the receiving side to the received radio signal to obtain the data unit of the present disclosure.

[0212] Hereinafter, a discontinuous reception (DRX) operation is described.

[0213] The MAC entity may be configured by RRC with DRX functionality, which controls the UE's PDCCH monitoring activities for C-RNTI, CI-RNTI, CS-RNTI, INT-RNTI, SFI-RNTI, SP-CSI-RNTI, TPC-PUCCH-RNTI, TPC-PUSCH-RNTI, TPC-SRS-RNTI and AI-RNTI for the MAC entity.

[0214] When using DRX operation, the MAC entity shall also monitor the PDCCH. When in RRC_CONNECTED, if DRX is configured, the MAC entity may use DRX operation to discontinuously monitor the PDCCH for all activated serving cells; otherwise, the MAC entity shall monitor the PDCCH.

[0215] RRC controls DRX operation by configuring the following parameters in Table 12:

[0216] [Table 12]

[0217]

[0218] The serving cells of the MAC entity can be configured by RRC with two DRX groups with separate DRX parameters. When RRC does not configure a secondary DRX group, there is only one DRX group, and all serving cells belong to that one DRX group. When two DRX groups are configured, each serving cell is uniquely assigned to either group.

[0219] When DRX is configured, the active time for the serving cells in the DRX group includes the following times:

[0220] - The drx-onDurationTimer or drx-InactivityTimer configured for the DRX group is running; or

[0221] - drx-RetransmissionTimerDL or drx-RetransmissionTimerUL is running on any serving cell in the DRX group.

[0222] When DRX is configured, if a MAC PDU is received in a configured downlink assignment, the MAC entity shall start the drx-HARQ-RTT-TimerDL for the corresponding HARQ process in the first symbol after the corresponding transmission carrying DL HARQ feedback ends, and stop the drx-RetransmissionTimerDL for the corresponding HARQ process.

[0223] If a MAC PDU is sent in a configured uplink grant and no LBT failure indication is received from the lower layer, the MAC entity shall start the drx-HARQ-RTT-TimerUL for the corresponding HARQ process in the first symbol after the end of the first transmission (within a series) of the corresponding PUSCH transmission, and stop the drx-RetransmissionTimerUL for the corresponding HARQ process at the first transmission (within a series) of the corresponding PUSCH transmission.

[0224] If the drx-HARQ-RTT-TimerDL expires, and if the data of the corresponding HARQ process is not successfully decoded, the MAC entity shall start the drx-RetransmissionTimerDL for the corresponding HARQ process in the first symbol after the expiration of the drx-HARQ-RTT-TimerDL.

[0225] If the drx-HARQ-RTT-TimerUL expires, the MAC entity shall start the drx-RetransmissionTimerUL for the corresponding HARQ process in the first symbol after the expiration of the drx-HARQ-RTT-TimerUL.

[0226] If the DRX group is in active time, the MAC entity shall monitor the PDCCH on the serving cells in the DRX group.

[0227] If the PDCCH indicates a DL transmission, the MAC entity shall start the drx-HARQ-RTT-TimerDL for the corresponding HARQ process in the first symbol after the corresponding transmission carrying DL HARQ feedback ends, and stop the drx-RetransmissionTimerDL for the corresponding HARQ process. In addition, if the PDSCH-to-HARQ_feedback timing indicates a non-numeric k1 value, the MAC entity shall start the drx-RetransmissionTimerDL in the first symbol after the PDSCH transmission for the corresponding HARQ process.

[0228] If the PDCCH indicates UL transmission, the MAC entity shall start the drx-HARQ-RTT-TimerUL for the corresponding HARQ process in the first symbol after the first transmission (in a series) of the corresponding PUSCH transmission ends, and stop the drx-RetransmissionTimerUL for the corresponding HARQ process.

[0229] If the PDCCH indicates a new transmission (DL or UL) on the serving cell in this DRX group, the MAC entity shall start or restart the drx-InactivityTimer for this DRX group in the first symbol after the end of PDCCH reception.

[0230] If the HARQ process receives downlink feedback information and indicates acknowledgment, the MAC entity shall stop the drx-RetransmissionTimerUL for the corresponding HARQ process.

[0231] Regardless of whether the MAC entity monitors the PDCCH on the serving cells in the DRX group, the MAC entity sends HARQ feedback, aperiodic CSI on the PUSCH, and aperiodic SRS on the serving cells in the DRX group when desired.

[0232] If it is not a complete PDCCH occasion (eg, the active time starts or ends in the middle of a PDCCH occasion), the MAC entity does not need to monitor the PDCCH.

[0233] For multicast transmission, the Multicast Broadcast Service (MBS) is introduced in 5G NR. Point-to-multipoint (PTM) transmission and point-to-point (PTP) transmission can serve MBS data transmission (including new transmission and retransmission).

[0234] In case of PTM transmission, UEs in the same MBS group schedule a group-common PDSCH using a group-common PDCCH with a CRC scrambled by a group-common RNTI (G-RNTI).

[0235] In addition, the UE may receive the group-common PDSCH via the configured downlink multicast assignment. This may be referred to as multicast semi-persistent scheduling (multicast SPS).

[0236] When the UE fails to receive the MAC PDU via PTM transmission, the MAC PDU can be retransmitted to the UE using C-RNTI or G-RNTI. In the case of multicast SPS transmission, the MAC PDU can be retransmitted to the UE using CS (Configured Scheduling)-RNTI or G-CS (Group Configured Scheduling)-RNTI.

[0237] When the UE fails to receive the MAC PDU via PTP transmission or the UE fails to receive the MAC PDU via traditional unicast transmission, the MAC PDU can be retransmitted to the UE using the C-RNTI. In the case of SPS, the MAC PDU can be retransmitted to the UE using the CS-RNTI.

[0238] HARQ retransmissions for PTM transmissions using C-RNTI may be referred to as PTP retransmissions. In the case of multicast SPS, HARQ retransmissions for PTM transmissions using CS-RNTI may be referred to as PTP retransmissions.

[0239] In addition, DRX operation for MBS broadcast and MBS multicast is introduced.

[0240] When discontinuous reception (DRX) is configured, the UE does not have to continuously monitor the PDCCH. The UE can use DRX operation to discontinuously monitor the PDCCH. The active time has a varying length based on scheduling decisions and UE decoding success.

[0241] Specifically, the UE manages multiple timers to determine the UE's active time and (re)starts those timers by sending / receiving a scheduled PDCCH or MAC PDU. DRX is designed to ensure the reception of scheduled PDCCHs. The duration (i.e., active time) that the UE should monitor the PDCCH is extended by starting or restarting a DRX timer (such as drx-InactivityTimer) when a scheduled PDCCH is received or starting or restarting a drx-RetransmissionTimer when a MAC PDU is sent or received. It can be called a unicast DRX scheme.

[0242] Data is delivered to a group of UEs via PTM transmission. When the UEs in the group fail to receive data via PTM transmission, the data can be retransmitted to the UEs via PTP transmission. DRX operation for reception of PTM transmission is performed independently of DRX operation for PTP transmission.

[0243] The UE receives data via PTM transmission during the active time of DRX operation for PTM transmission. If the UE does not successfully decode the data, it sends a NACK to notify the gNB of the reception failure. The gNB then retransmits the data to the UE via PTP transmission. To enable the UE to receive the retransmission, the UE starts the unicast DRX RTT timer (drx-HARQ-RTT-TimerDL for the corresponding HARQ process).

[0244] In the case of multicast SPS, when the UE fails to receive data via the configured downlink multicast assignment, the data can be retransmitted to the UE via PTP transmission using the CS-RNTI. In addition, when the UE fails to receive data on the PDCCH addressed to the G-CS-RNTI, the data can be retransmitted to the UE via PTP transmission using the CS-RNTI. Therefore, the UE starts the unicast DRX RTT timer (drx-HARQ-RTT-TimerDL for the corresponding HARQ process). However, if the CS-RNTI is not configured, the UE cannot receive the retransmission that would be sent using the CS-RNTI. In this case, if the UE starts the unicast DRX RTT timer, the state of the DRX operation for unicast or PTP transmission unnecessarily becomes active time. Therefore, the UE wastes its power unnecessarily.

[0245] When a UE receives data on a PDCCH addressed to a G-CS-RNTI and the PDCCH indicates a DL multicast transmission, the UE determines whether a CS-RNTI is configured. If a CS-RNTI is configured, the UE starts a unicast DRX RTT timer. Otherwise, the UE may not start a unicast DRX RTT timer.

[0246] Considering that HARQ feedback is possible when HARQ feedback is enabled, and the network can determine the UE for HARQ feedback when ack-nack HARQ mode is used, if HARQ feedback is enabled, the UE starts the unicast DRX RTT timer, uses ack-nack HARQ mode, and configures the CS-RNTI when the UE monitors the PDCCH for G-CS-RNTI and the PDCCH indicates DL multicast transmission. Then, when PTP retransmission is not expected, the UE can avoid the situation where the UE is in the active time of unicast DRX operation.

[0247] In particular, when CS-RNTI is not configured, PTP retransmission for data received using G-CS-RNTI cannot occur. Therefore, if CS-RNTI is configured, the UE needs to start the unicast DRX RTT timer.

[0248] In this disclosure, it is assumed that the UE is configured with CS-RNTI and G-CS-RNTI through RRC signaling from the network. In addition, it can be assumed that DRX configuration for multicast (PTM transmission) and DRX configuration for unicast (PTP transmission) are configured. Then, the UE can operate as follows:

[0249] 1) receiving a first DRX configuration for a first DRX operation—the first DRX operation is for PTM transmission, and receiving MAC PDUs using a HARQ process;

[0250] 2) receiving a second DRX configuration for a second DRX operation—the second DRX operation is for unicast or PTP transmission, and receiving new MAC PDUs using a HARQ process;

[0251] 3) receiving a MAC PDU during the active time of the first DRX configuration;

[0252] 4) Sending HARQ feedback based on the decoding result of the MAC PDU; and

[0253] 5) if a MAC PDU is received on a PDCCH addressed to the G-CS-RNTI and the CS-RNTI is configured, changing the state of the second DRX operation to Active Time - starting the RTT timer of the HARQ process after sending HARQ feedback through the HARQ process to change the state of the second DRX operation to Active Time; and

[0254] 6) Receiving a new MAC PDU containing data of the first MAC PDU during the active time of the second DRX operation

[0255] In other options, it can be assumed that DRX configuration for unicast (PTP transmission) is configured and multicast DRX configuration is not configured. In this case, the UE can operate as follows:

[0256] a) Receive DRX configuration for DRX operation - DRX operation is for unicast or PTP transmission, and receive new MAC PDUs using HARQ process;

[0257] b) Receive MAC PDU using G-CS-RNTI;

[0258] c) Sending HARQ feedback based on the decoding result of the MAC PDU; and

[0259] d) If CS-RNTI is configured, change the state of DRX operation to Active Time - start the RTT timer of the HARQ process after sending the HARQ feedback to change the state of DRX operation to Active Time;

[0260] e) Receiving a new MAC PDU containing data of the first MAC PDU during the active time of the DRX operation.

[0261] Based on the above discussion, the relevant parts of the 3GPP NR standard can be described as shown in Tables 13 and 14 below.

[0262] [Table 13]

[0263]

[0264] [Table 14]

[0265]

[0266]

[0267] In Table 13 and Table 14, it is shown that the CS-RNTI should be configured to start the RTT timer (drx-HARQ-RTT-TimerDL) of the HARQ process.

[0268] Figure 9 An example of handling DRX operations for multicast transmissions according to the present disclosure is shown.

[0269] Reference Figure 9 At A05 , the UE may monitor a first PDCCH addressed to the G-CS-RNTI, where the first PDCCH indicates a DL multicast transmission related to a retransmission of a data unit.

[0270] If the first PDCCH is detected and indicates DL multicast transmission, at A10 , the UE may receive a data unit using a HARQ process based on the first PDCCH.

[0271] Next, at A15, the UE may start a HARQ RTT timer associated with the multicast transmission for the HARQ process. Here, the RTT timer associated with the multicast transmission is the minimum duration before a DL assignment associated with the multicast transmission for the HARQ process is expected.

[0272] If the CS-RNTI is configured, then at A20, the UE may start the HARQ RTT timer associated with unicast transmission for the HARQ process. If the CS-RNTI is not configured, the UE does not start the HARQ RTT timer associated with unicast transmission for the HARQ process. Here, the RTT timer associated with unicast transmission is the minimum duration before a DL assignment associated with unicast transmission for the HARQ process is expected.

[0273] Finally, at A25 , if the HARQ RTT timer associated with the unicast transmission expires, the UE may monitor the second PDCCH addressed to the CS-RNTI.

[0274] According to the present disclosure, when receiving using the G-CS-RNTI, the UE only starts the unicast DRX RTT timer when a PTP retransmission is expected. This avoids the situation where the UE is in the active time of unicast DRX operation when a PTP retransmission is not expected. This is beneficial for UE power conservation.

Claims

1. A method for performing an operation by a user equipment (UE) in a wireless communication system, the method comprising the following steps: monitoring a first physical downlink control channel (PDCCH) addressed to a group configured scheduling-radio network temporary identifier (G-CS-RNTI); receiving a data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH, based on the first PDCCH being detected and indicating a downlink (DL) multicast transmission; wherein, based on the configured scheduling-radio network temporary identifier CS-RNTI being configured, starting a HARQ round trip time RTT timer associated with unicast transmission for the HARQ process; and Based on expiration of the HARQ RTT timer associated with the unicast transmission, a second PDCCH addressed to the CS-RNTI is monitored.

2. The method according to claim 1, wherein The step of receiving the data unit includes starting a HARQ RTT timer associated with the multicast transmission for the HARQ process independently of the step of configuring the CS-RNTI.

3. The method according to claim 1, wherein The first PDCCH indicates a DL multicast transmission related to a retransmission of the data unit.

4. The method according to claim 1, wherein The second PDCCH indicates a DL unicast transmission related to a retransmission of the data unit.

5. The method according to claim 1, wherein The RTT timer associated with the unicast transmission is a minimum duration before a DL assignment associated with the unicast transmission for the HARQ process is expected.

6. A user equipment (UE) in a wireless communication system, the UE comprising: at least one transceiver; at least one processor; as well as at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations comprising: monitoring a first physical downlink control channel (PDCCH) addressed to a group configured scheduling-radio network temporary identifier (G-CS-RNTI); receiving a data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH, based on the first PDCCH being detected and indicating a downlink (DL) multicast transmission; wherein, based on the configured scheduling-radio network temporary identifier CS-RNTI being configured, starting a HARQ round trip time RTT timer associated with unicast transmission for the HARQ process; and Based on expiration of the HARQ RTT timer associated with the unicast transmission, a second PDCCH addressed to the CS-RNTI is monitored.

7. The UE according to claim 6, wherein: Receiving the data unit includes starting a HARQ RTT timer associated with the multicast transmission for the HARQ process independent of configuring the CS-RNTI.

8. The UE according to claim 6, wherein: The first PDCCH indicates a DL multicast transmission related to a retransmission of the data unit.

9. The UE according to claim 6, wherein: The second PDCCH indicates a DL unicast transmission related to a retransmission of the data unit.

10. The UE according to claim 6, wherein: The RTT timer associated with the unicast transmission is a minimum duration before a DL assignment associated with the unicast transmission for the HARQ process is expected.

11. A device for a user equipment (UE), the device comprising: at least one processor; as well as at least one computer memory operatively connected to the at least one processor and storing instructions that, when executed, cause the at least one processor to perform operations comprising: monitoring a first physical downlink control channel (PDCCH) addressed to a group configured scheduling-radio network temporary identifier (G-CS-RNTI); receiving a data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH, based on the first PDCCH being detected and indicating a downlink (DL) multicast transmission; wherein, based on the configured scheduling-radio network temporary identifier CS-RNTI being configured, starting a HARQ round trip time RTT timer associated with unicast transmission for the HARQ process; and Based on expiration of the HARQ RTT timer associated with the unicast transmission, a second PDCCH addressed to the CS-RNTI is monitored.

12. A computer-readable storage medium storing at least one computer program, the computer program comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations for a user equipment (UE), the operations comprising: monitoring a first physical downlink control channel (PDCCH) addressed to a group configured scheduling-radio network temporary identifier (G-CS-RNTI); receiving a data unit using a hybrid automatic repeat and request (HARQ) process based on the first PDCCH, based on the first PDCCH being detected and indicating a downlink (DL) multicast transmission; wherein, based on the configured scheduling-radio network temporary identifier CS-RNTI being configured, starting a HARQ round trip time RTT timer associated with unicast transmission for the HARQ process; and Based on expiration of the HARQ RTT timer associated with the unicast transmission, a second PDCCH addressed to the CS-RNTI is monitored.

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