Method and device for multicast transmission with CP and UP separation in wireless communication system

Abstract

A multicast transmission method and apparatus with CP and UP separation in a wireless communication system are provided. A CU-UP of a RAN node receives a first message for an MBS from a CU-CP of the RAN node, wherein the first message includes (1) an ID of the MBS, and (2) a C-TEID for the MBS. The CU-UP establishes a bearer for the MBS based on the ID of the MBS. The CU-UP receives data for the MBS from a core network via a tunnel indicated by the C-TEID. The CU-UP sends the received data to the DU via the established bearer.

Description

Technical Field

[0001] The present disclosure relates to a method and apparatus for multicast transmission with CP and UP separation in a wireless communication system. Background Art

[0002] The 3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE) is a technology for implementing high-speed packet communications. Many solutions have been proposed for the LTE goal, including those aimed at reducing user and provider costs, improving service quality, and expanding and improving coverage and system capacity. 3GPP LTE requires reduced cost per bit, increased service availability, flexible use of frequency bands, simple structure, open interfaces, and appropriate terminal power consumption as higher-level requirements.

[0003] The International Telecommunication Union (ITU) and 3GPP have begun work to develop requirements and specifications for New Radio (NR) systems. 3GPP has had to identify and develop the technical components required to successfully standardize a new RAT that meets both urgent market needs in a timely manner and longer-term requirements set forth by the ITU Radiocommunication Sector (ITU-R) International Mobile Telecommunications (IMT)-2020 process. In addition, even in the more distant future, NR should be able to use any spectrum band available for wireless communications up to at least 100 GHz.

[0004] NR is a single technology framework that addresses all use cases, requirements, and deployment scenarios, including enhanced mobile broadband (eMBB), massive machine type communications (mMTC), ultra-reliable low latency communications (URLLC), etc. NR will be inherently forward compatible.

[0005] In NR, the separation of the central unit (CU) and the distributed unit (DU) as well as the separation of the control plane (CP) and the user plane (UP) can be supported.

[0006] For example, the gNB Central Unit (gNB-CU) is a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or controls the RRC and PDCP protocols of an en-gNB that operates one or more gNB-DUs. The gNB-CU terminates the F1 interface with the gNB-DU.

[0007] For example, the gNB distributed unit (gNB-DU) is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is partially controlled by the gNB-CU. One gNB-DU supports one or more cells. One cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface connected to the gNB-CU.

[0008] For example, the gNB-CU-Control Plane (gNB-CU-CP) is a logical node that hosts the control plane part of the RRC and PDCP protocols for an en-gNB or a gNB-CU of a gNB. The gNB-CU-CP terminates the E1 interface with the gNB-CU-UP and the F1-C interface with the gNB-DU.

[0009] For example, the gNB-CU-User Plane (gNB-CU-UP) is a logical node that hosts the user plane portion of the PDCP protocol for the gNB-CU of the en-gNB, and the user plane portion of the PDCP protocol and SDAP protocol for the gNB-CU of the gNB. The gNB-CU-UP terminates the E1 interface connected to the gNB-CU-CP and the F1-U interface connected to the gNB-DU. Summary of the invention

[0010] Technical issues

[0011] In NR, multicast and / or broadcast services (MBS) are provided to wireless devices in a connected state. The wireless device can receive the MBS from the network via multicast transmission or unicast transmission. Multicast transmission can be called point-to-multipoint (PTM) transmission. Unicast transmission can be called point-to-point (PTP) transmission.

[0012] The gNB-CU, where the necessary coordination functions reside, can be split into a control plane (CP) and a user plane (UP).

[0013] When the gNB-CU-CP knows that the UE joins the multicast group, for example, through signaling from the CN, the gNB-CU-UP may need to know this. For example, if the gNB-CU-UP knows that the UE joins the multicast group, the gNB-CU-UP can identify and forward the UE's multicast / broadcast data received from the CN to the gNB-DU that serves the UE. That is, the gNB-CU-CP may need to control the gNB-CU-UP to support multicast transmission.

[0014] Therefore, there is a need to study multicast transmission with CP and UP separation in wireless communication systems.

[0015] Technical Solution

[0016] In one aspect, a method performed by a central unit (CU)-user plane (UP) of a radio access network (RAN) node in a wireless communication system is provided. The CU-UP receives a first message for a multicast and / or broadcast service (MBS) from a CU-control plane (CP) of the RAN node, wherein the first message includes (1) an identifier (ID) of the MBS, and (2) a common tunnel endpoint identifier (C-TEID) for the MBS. The CU-UP establishes a bearer for the MBS based on the ID of the MBS. The CU-UP receives data for the MBS from a core network via a tunnel indicated by the C-TEID. The CU-UP sends the received data to the DU via the established bearer.

[0017] In another aspect, a device for implementing the above method is provided.

[0018] Beneficial Effects

[0019] The present disclosure may have various beneficial effects.

[0020] According to some embodiments of the present disclosure, the CU-CP of a radio access network (RAN) node (e.g., a base station such as a gNB) and the CU-UP of the RAN node may effectively perform multicast transmission.

[0021] For example, the gNB-CU-UP is able to identify multicast and / or broadcast data for the UE among the data received from the CN and forward them to the gNB-DU served by the UE.

[0022] Therefore, the network can efficiently provide multicast and / or broadcast data transmission without any loss.

[0023] Additionally, the network can avoid degradation in UE experience by receiving multicast and / or broadcast data through the gNB.

[0024] According to some embodiments of the present disclosure, a wireless communication system may provide an effective solution for multicast transmission with CP and UP separation in a wireless communication system.

[0025] The beneficial effects that can be obtained by the specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, there may be various technical effects that can be understood by a person of ordinary skill in the art and / or derived from the present disclosure. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 An example of a communication system to which an embodiment of the present disclosure is applied is shown.

[0027] Figure 2An example of a wireless device to which an embodiment of the present disclosure is applied is shown.

[0028] Figure 3 An example of a wireless device to which an embodiment of the present disclosure is applied is shown.

[0029] Figure 4 Another example of a wireless device to which the embodiments of the present disclosure are applied is shown.

[0030] Figure 5 An example of a UE to which an embodiment of the present disclosure is applied is shown.

[0031] Figure 6 and Figure 7 An example of a protocol stack in a 3GPP-based wireless communication system to which an embodiment of the present disclosure is applied is shown.

[0032] Figure 8 A frame structure in a 3GPP-based wireless communication system to which an embodiment of the present disclosure is applied is shown.

[0033] Fig. 9 An example of data flow in a 3GPP NR system to which an embodiment of the present disclosure is applied is shown.

[0034] Fig.10 An example of the overall architecture of an NG-RAN to which the technical features of the present disclosure can be applied is shown.

[0035] Fig.11 The interface protocol structure of F1-C to which the technical features of the present disclosure can be applied is shown.

[0036] Fig.12 An example of a method for multicast transmission with CP and UP separation in a wireless communication system is shown.

[0037] Fig.13 An example of a method for multicast transmission with CP and UP separation in a wireless communication system is shown.

[0038] Fig.14 An example of a process for multicast transmission with CP and UP separation in a wireless communication system according to some embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0039] 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 embodied by radio technologies such as Universal Terrestrial Radio Access (UTRA) or CDMA2000. TDMA can be embodied by 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 embodied by 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 a 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.

[0040] For the convenience of description, the embodiments of the present disclosure are mainly described for 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 given based on a mobile communication system corresponding to a 3GPP-based wireless communication system, aspects of the present disclosure that are not limited to a 3GPP-based wireless communication system are applicable to other mobile communication systems.

[0041] For terms and techniques not specifically described among terms and techniques employed in the present invention, reference may be made to wireless communication standard documents issued prior to the present disclosure.

[0042] In the present disclosure, "A or B" may mean "only A", "only B", or "both A and B". In other words, "A or B" in the present disclosure may be interpreted as "A and / or B". For example, "A, B, or C" in the present disclosure may mean "only A", "only B", "only C", or "any combination of A, B, and C".

[0043] In the present disclosure, a slash ( / ) or a comma (,) may mean "and / or". For example, "A / B" may mean "A and / or B". Thus, "A / B" may mean "only A", "only B", or "both A and B". For example, "A, B, C" may mean "A, B, or C".

[0044] In the present disclosure, "at least one of A and B" may mean "only A", "only B", or "both A and B". In addition, the expression "at least one of A or B" or "at least one of A and / or B" in the present disclosure may be interpreted as being the same as "at least one of A and B".

[0045] In addition, in the present disclosure, "at least one of A, B, and C" may mean "only A", "only B", "only C", or "any combination of A, B, and C". In addition, "at least one of A, B, or C" or "at least one of A, B and / or C" may mean "at least one of A, B, and C".

[0046] Likewise, brackets used in the present disclosure may mean "for example". In detail, when shown as "control information (PDCCH)", "PDCCH" may be proposed as an example of "control information". In other words, the "control information" in the present disclosure is not limited to "PDCCH", and "PDDCH" may be proposed as an example of "control information". In addition, even when shown as "control information (ie, PDCCH)", "PDCCH" may be proposed as an example of "control information".

[0047] Technical features described individually in one drawing in the present disclosure may be implemented individually or simultaneously.

[0048] Although not limited to this, the various descriptions, functions, processes, suggestions, methods and / or operational flowcharts of the present disclosure disclosed herein may be applied to various fields requiring wireless communication and / or connection between devices (e.g., 5G).

[0049] Hereinafter, the present disclosure will be described in more detail with reference to the accompanying drawings. Unless otherwise specified, the same reference numerals in the following drawings and / or descriptions may refer to the same and / or corresponding hardware blocks, software blocks and / or functional blocks.

[0050] Figure 1 An example of a communication system to which an embodiment of the present disclosure is applied is shown.

[0051] Figure 1 The 5G usage scenarios shown in are only exemplary, and the technical features of the present disclosure can be applied to Figure 1 Other 5G usage scenarios not shown.

[0052] 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 low latency communication (URLLC) category.

[0053] Some use cases may require multiple categories for optimization, and others may focus on only one key performance indicator (KPI). 5G supports such a variety of use cases using a flexible and reliable approach.

[0054] 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 drivers of 5G, and in the 5G era, dedicated voice services may not be provided for the first time. In 5G, it is expected that voice will be simply processed as an application using the data connection provided by the communication system. The main reason for the increase in traffic is due to the increase in the size of the content and the increase in the number of applications requiring high data transmission rates. As more devices are connected to the Internet, streaming services (audio and video), conversational video and mobile Internet access will be more widely used. Many of these applications require always-on connectivity 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 accelerates the growth of uplink data transmission rates. 5G is also used for remote work in the cloud. When using a tactile interface, 5G requires lower end-to-end latency to maintain a good user experience. Entertainment, such as cloud games and video streaming, is another core element that increases the demand for mobile broadband capabilities. Entertainment is necessary for smartphones and tablets in any place including high mobility environments such as trains, vehicles and airplanes. Other use cases are augmented reality and information search for entertainment. In this case, augmented reality requires very low latency and instantaneous data volume.

[0055] Additionally, one of the most anticipated 5G use cases involves the ability to smoothly connect embedded sensors in all fields, i.e. mMTC. It is expected that the number of potential Internet of Things (IoT) devices will reach 20.4 billion by 2020. Industrial IoT is one of the categories that performs the main role of enabling smart cities, asset tracking, smart utilities, agriculture, and security infrastructure through 5G.

[0056] URLLC includes new services that will transform industries through remote control of key infrastructure and ultra-reliable / available low-latency links, such as self-driving vehicles. The levels of reliability and latency are necessary to control smart grids, automate industry, enable robotics, and control and adjust drones.

[0057] 5G is a means of providing streaming that is rated at hundreds of megabits per second to gigabits per second and can complement fiber to the home (FTTH) and cable-based broadband (or DOCSIS). Such fast speeds are required to deliver TV with a resolution of 4K or higher (6K, 8K, etc.) 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 edge network servers of network operators in order to minimize latency.

[0058] Along with many use cases for vehicle mobile communications, cars are expected to become a new important driving force in 5G. For example, passenger entertainment requires high synchronization capacity and mobile broadband with high mobility. This is because future users continue to expect high-quality connections regardless of their location and speed. Another use case in the automotive field is the AR dashboard. The AR dashboard enables the driver to identify objects in the dark in addition to the objects seen from the front window, and displays the distance from the object and the movement of the object by overlapping the information that talks to the driver. In the future, the wireless module will realize the communication between vehicles, the information exchange between the vehicle and the supporting infrastructure, and the information exchange between the vehicle and other connected devices (for example, devices accompanying pedestrians). The safety system guides alternative routes for behavior so that the driver can drive more safely, thereby reducing the risk of accidents. The next stage will be remote control or self-driving vehicles. This requires very high reliability and very fast communication between different self-driving vehicles and between vehicles and infrastructure. In the future, self-driving vehicles will perform all driving activities and the driver will only focus on abnormal traffic that the vehicle cannot recognize. The technical requirements of self-driving vehicles require ultra-low latency and ultra-high reliability, so that traffic safety is improved to a level that humans cannot reach.

[0059] Smart cities and smart homes / buildings referred to as smart societies will be embedded in high-density wireless sensor networks. Distributed networks of smart sensors will identify the cost and energy-saving maintenance of cities or homes. Similar configurations can be performed for individual residents. All temperature sensors, window and heating controllers, burglar alarms and home appliances are connected wirelessly. Many of these sensors usually have low data transmission rates, power and cost. However, certain types of equipment may require real-time HD video to perform monitoring.

[0060] The consumption and distribution of energy, including heat or gas, is distributed at a high level, requiring automated control of the distribution sensor network. Smart grids use digital information and communication technologies to collect information and connect sensors to each other in order to act according to the collected information. Since this information may include the behavior of supply companies and consumers, smart grids can improve the distribution of fuels such as electricity by methods with efficiency, reliability, economic feasibility, production sustainability and automation. Smart grids can also be considered as another sensor network with low latency.

[0061] Mission-critical applications (e.g., e-health) are one of the 5G use cases. The health section contains many applications that can enjoy the benefits of mobile communications. The communication system can support telemedicine that provides clinical treatment in remote locations. Telemedicine can help reduce distance barriers and improve access to medical services that are not continuously available in remote rural areas. Telemedicine is also used to perform important treatments in emergency situations and save lives. Wireless sensor networks based on mobile communications can provide remote monitoring and sensors for parameters such as heart rate and blood pressure.

[0062] Wireless and mobile communications are becoming increasingly important in the field of industrial applications. Cabling is high in terms of installation and maintenance costs. Therefore, the possibility of replacing cables with reconfigurable wireless links is an attractive opportunity in many industrial fields. However, in order to achieve this replacement, it is necessary to establish wireless connections with latency, reliability and capacity similar to those of cables and to simplify the management of wireless connections. When it is necessary to connect to 5G, low latency and very low error probability are new requirements.

[0063] Logistics and freight tracking are important use cases for mobile communications that use location-based information systems to enable inventory and package tracking anywhere. Logistics and freight use cases typically require low data rates but require location information with wide range and reliability.

[0064] refer to Figure 1 , the communication system 1 includes wireless devices 100a to 100f, a base station (BS) 200, and a network 300. Figure 1 A 5G network is illustrated as an example of the network of the communication system 1 , but the embodiments of the present disclosure are not limited to the 5G system and can be applied to future communication systems beyond the 5G system.

[0065] BS 200 and network 300 may be implemented as wireless devices, and certain wireless devices may operate as BSs / network nodes relative to other wireless devices.

[0066] The wireless devices 100a to 100f represent devices that perform communication using a radio access technology (RAT) (e.g., 5G new RAT (NR) or LTE) and may be referred to as communication / radio / 5G devices. The wireless devices 100a to 100f may include, but are 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 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 driving vehicle, and a vehicle capable of performing communication between vehicles. A vehicle may include an unmanned aerial vehicle (UAV) (e.g., a drone). XR devices may include AR / VR / mixed reality (MR) devices 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 smart phone, a computer, a wearable device, a home appliance device, a digital signage, a vehicle, a robot, and the like. Handheld devices may include smart phones, smart boards, wearable devices (e.g., smart watches or smart glasses), and computers (e.g., notebook computers). Home appliances may include TVs, refrigerators, and washing machines. IoT devices may include sensors and smart meters.

[0067] In the present disclosure, the wireless devices 100a to 100f may be referred to as user equipment (UE). The UE may include, for example, a cellular phone, a smart phone, a laptop computer, a digital broadcast terminal, a personal digital assistant (PDA), a portable multimedia player (PMP), a navigation system, a tablet personal computer (PC), a tablet PC, an ultrabook, a vehicle, a vehicle with an autonomous driving function, a connected car, a UAV, an AI module, a robot, an AR device, a VR device, an 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 field of the fourth industrial revolution.

[0068] A UAV may be, for example, an aerial vehicle that is piloted by wireless control signals without a human on board.

[0069] VR devices may include, for example, devices for realizing objects or backgrounds of a virtual world. AR devices may include, for example, devices realized by connecting objects or backgrounds of a virtual world to objects or backgrounds of a real world. MR devices may include, for example, devices realized by fusing objects or backgrounds of a virtual world into objects or backgrounds of a real world. Hologram devices may include, for example, devices for realizing 360-degree stereoscopic images by recording and reproducing stereoscopic information using an interference phenomenon of light generated when two lasers meet, which is called holography.

[0070] Public safety devices may include, for example, image relay devices or image devices wearable on a user's body.

[0071] 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.

[0072] A medical device may be, for example, a device for the purpose of diagnosing, treating, alleviating, curing or preventing a disease. For example, a medical device may be a device for the purpose of diagnosing, treating, alleviating or correcting an injury or damage. For example, a medical device may be a device for the purpose of inspecting, replacing or modifying a structure or function. For example, a medical device may be a device for the purpose of regulating a pregnancy. For example, a medical device may include a device for treatment, a device for operation, a device for (in vitro) diagnosis, a hearing aid or a device for a procedure.

[0073] The safety device may be, for example, a device installed to prevent possible danger and maintain safety. For example, the safety device may be a camera, a closed-circuit TV (CCTV), a recorder or a black box.

[0074] A fintech device may be, for example, a device that is capable of providing financial services such as mobile payments. For example, a fintech device may include a payment device or a point of sale (POS) system.

[0075] Weather / environmental equipment may include, for example, equipment for monitoring or predicting weather / environmental conditions.

[0076] The wireless devices 100a to 100f may be connected to the network 300 via the BS 200. AI technology may be applied to the wireless devices 100a to 100f and the wireless devices 100a to 100f may be connected to the AI ​​server 400 via the network 300. The network 300 may be configured using a 3G network, a 4G (e.g., LTE) network, a 5G (e.g., NR) network, and a super 5G network. Although the wireless devices 100a to 100f may communicate with each other via the BS 200 / network 300, the wireless devices 100a to 100f may perform direct communication (e.g., side link communication) with each other without passing through the BS 200 / network 300. For example, the vehicles 100b-1 and 100b-2 may perform direct communication (e.g., vehicle-to-vehicle (V2V) / vehicle-to-everything (V2X) communication). An IoT device (e.g., a sensor) may perform direct communication with other IoT devices (e.g., a sensor) or other wireless devices 100a to 100f.

[0077] Wireless communication / connection 150a, 150b, and 150c may be established between wireless devices 100a to 100f and / or between wireless devices 100a to 100f and BS200 and / or between BS200. In this document, wireless communication / connection may be established through various RATs (e.g., 5G NR) such as uplink / downlink communication 150a, sidelink communication (or device-to-device (D2D) communication) 150b, inter-base station communication 150c (e.g., relay, integrated access and backhaul (IAB)), etc. Wireless devices 100a to 100f and BS200 / wireless devices 100a to 100f may send / receive radio signals to each other through wireless communication / connection 150a, 150b, and 150c. For example, wireless communication / connection 150a, 150b, and 150c may send / receive signals through various physical channels. To this end, at least a portion of 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 resource allocation processes can be performed based on various proposals of the present disclosure.

[0078] Here, the radio communication technology implemented in the wireless device of the present disclosure may include narrowband Internet of Things (NB-IoT) technology for low-power communication as well as LTE, NR and 6G. For example, NB-IoT technology may be an example of low-power wide area network (LPWAN) technology, which may be implemented in specifications such as LTE Cat NB1 and / or LTE Cat NB2, and may not be limited to the names mentioned above. In addition and / or alternatively, the radio communication technology implemented in the wireless device of the present disclosure may communicate based on LTE-M technology. For example, LTE-M technology may be an example of LPWAN technology and is called by various names such as enhanced machine type communication (eMTC). For example, LTE-M technology may be implemented in at least one of various specifications, such as 1) LTE Cat 0, 2) LTE Cat M1, 3) LTE Cat M2, 4) LTE non-bandwidth limited (non-BL), 5) LTE-MTC, 6) LTE machine type communication, and / or 7) LTE M, and may not be limited to the names mentioned above. Additionally and / or alternatively, the radio communication technology implemented in the wireless device of the present disclosure may include at least one of ZigBee, Bluetooth, and / or LPWAN, which takes into account low-power communication and may not be limited to the above-mentioned names. For example, ZigBee technology may generate a personal area network (PAN) associated with small / low-power digital communication based on various specifications such as IEEE 802.15.4, and may be referred to by various names.

[0079] Figure 2An example of a wireless device to which an embodiment of the present disclosure is applied is shown.

[0080] refer to Figure 2 , the first wireless device 100 and the second wireless device 200 can transmit / receive radio signals to / from external devices through various RATs (e.g., LTE and NR). Figure 2 In the example, {the first wireless device 100 and the second wireless device 200} may correspond to Figure 1 At least one of {wireless devices 100a to 100f and BS200}, {wireless devices 100a to 100f and wireless devices 100a to 100f} and / or {BS200 and BS200}.

[0081] 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 descriptions, functions, processes, suggestions, methods and / or operational flowcharts described in the present disclosure. For example, the processor 102 may process the information in the memory 104 to generate first information / signals, and then send 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 codes including commands for executing part or all of the processing controlled by the processor 102 or for executing the descriptions, functions, processes, suggestions, methods and / or operational flowcharts described in the present 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 through 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 the present disclosure, the first wireless device 100 may represent a communication modem / circuit / chip.

[0082] The second wireless device 200 may include one or more processors 202 and one or more memories 204 and 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 descriptions, functions, processes, suggestions, methods and / or operation flowcharts described in the present disclosure. For example, the processor 202 may process the information in the memory 204 to generate third information / signals, and then send 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 106, 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 codes including commands for executing part or all of the processing controlled by the processor 202 or for executing the descriptions, functions, processes, suggestions, methods and / or operation flowcharts described in the present 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 through 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 the present disclosure, the second wireless device 200 may represent a communication modem / circuit / chip.

[0083] 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 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 physical (PHY), layer, medium access control (MAC) layer, radio link control (RLC) layer, packet data convergence protocol (PDCP) layer, radio resource control (RRC) layer, and service data adaptation protocol (SDAP) layer). 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 description, function, process, suggestion, method, and / or operation flowchart disclosed in the present disclosure. One or more processors 102 and 202 may generate messages, control information, data, or information according to the description, function, process, suggestion, method, and / or operation flowchart disclosed in the present disclosure. The one or more processors 102 and 202 may generate a signal (e.g., a baseband signal) including a PDU, SDU, message, control information, data, or information according to the description, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure and provide the generated signal to the one or more transceivers 106 and 206. The one or more processors 102 and 202 may receive a signal (e.g., a baseband signal) from the one or more transceivers 106 and 206 and obtain the PDU, SDU, message, control information, data, or information according to the description, functions, procedures, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure.

[0084] 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. Firmware or software may be used to implement the description, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure, and the firmware or software may be configured to include modules, processes, or functions. Firmware or software configured to execute the description, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure may be included in one or more processors 102 and 202 or stored in one or more memories 104 and 204 so as to be driven by one or more processors 102 and 202. Firmware or software in the form of code, commands, and / or command sets may be used to implement the description, functions, processes, suggestions, methods, and / or operational flowcharts disclosed in the present disclosure.

[0085] One or more memories 104 and 204 may 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 may 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 may be located inside and / or outside of one or more processors 102 and 202. One or more memories 104 and 204 may be connected to one or more processors 102 and 202 by various technologies such as wired or wireless connections.

[0086] One or more transceivers 106 and 206 may send user data, control information, and / or radio signals / channels mentioned in the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure to one or more other devices. One or more transceivers 106 and 206 may receive user data, control information, and / or radio signals / channels mentioned in the description, function, process, suggestion, method, and / or operation flow chart disclosed in the present disclosure from one or more other devices. For example, one or more transceivers 106 and 206 may be connected to one or more processors 102 and 202 and send and receive radio signals. For example, one or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may send user data, control information, or radio signals to one or more other devices. One or more processors 102 and 202 may perform control so that one or more transceivers 106 and 206 may receive user data, control information, or radio signals from one or more other devices.

[0087] 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 descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure through one or more antennas 108 and 208. In the present disclosure, the one or more antennas may be multiple physical antennas or multiple logical antennas (e.g., antenna ports).

[0088] One or more transceivers 106 and 206 can convert received radio signals / channels, etc. from RF band signals to baseband signals so as to process received user data, control information, radio signals / channels, etc. using one or more processors 102 and 202. One or more transceivers 106 and 206 can 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 can up-convert OFDM baseband signals to carrier frequencies and transmit up-converted OFDM signals at carrier frequencies through their (analog) oscillators and / or filters under the control of processors 102 and 202. Transceivers 106 and 206 can receive OFDM signals at carrier frequencies and down-convert OFDM signals to OFDM baseband signals through their (analog) oscillators and / or filters under the control of processors 102 and 202.

[0089] In an embodiment of the present disclosure, a UE may operate as a transmitting device in an uplink (UL) and as a receiving device in a downlink (DL). In an embodiment of the present disclosure, a BS may operate as a receiving device in an UL and as a transmitting device in a DL. In the following, for the convenience of description, it is mainly assumed that the first wireless device 100 is a UE and the second wireless device 200 is a BS. For example, a processor 102 connected to, installed on, or started in the first wireless device 100 may be configured to perform a UE behavior according to an embodiment of the present disclosure or control a transceiver 106 to perform a UE behavior according to an embodiment of the present disclosure. A processor 202 connected to, installed on, or started in the second wireless device 200 may be configured to perform a BS behavior according to an embodiment of the present disclosure or control a transceiver 206 to perform a BS behavior according to an embodiment of the present disclosure.

[0090] In the present disclosure, a BS is also referred to as a Node B (NB), an eNode B (eNB), or a gNB.

[0091] Figure 3 An example of a wireless device to which an embodiment of the present disclosure is applied is shown.

[0092] Wireless devices can be implemented in various forms depending on the use case / service (ref. Figure 1 ).

[0093] refer to Figure 3 , the wireless devices 100 and 200 may correspond to Figure 2 The wireless devices 100 and 200 may be configured by various elements, components, units / parts and / or modules. For example, each of the wireless devices 100 and 200 may include a communication unit 1100, a control unit 1200, a memory unit 1300 and an additional component 1400. The communication unit 1100 may include a communication circuit 1120 and a transceiver 1140. For example, the communication circuit 1120 may include Figure 2 One or more processors 102 and 202 and / or Figure 2 One or more memories 104 and 204. For example, the transceiver 1140 may include Figure 2 One or more transceivers 106 and 206 and / or Figure 2The control unit 1200 is electrically connected to the communication unit 1100, the memory 1300, and the additional components 140 and controls the overall operation of each of the wireless devices 100 and 200. For example, the control unit 1200 may control the electrical / mechanical operation of each of the wireless devices 100 and 200 based on the program / code / command / information stored in the memory unit 1300. The control unit 1200 may transmit information stored in the memory unit 1300 to the outside (e.g., other communication devices) via the communication unit 1100 through a wireless / wired interface or store in the memory unit 1300 information received from the outside (e.g., other communication devices) via the communication unit 1100 through a wireless / wired interface.

[0094] The additional component 140 may be configured differently depending on the type of the wireless devices 100 and 200. For example, the additional component 140 may include at least one of a power unit / battery, an input / output (I / O) unit (e.g., an audio I / O port, a video I / O port), a driving unit, and a computing unit. The wireless devices 100 and 200 may be implemented in the following forms (but not limited thereto): a robot ( Figure 1 100a), vehicles ( Figure 1 100b-1 and 100b-2), XR devices ( Figure 1 100c), handheld devices ( Figure 1 100d), household appliances ( Figure 1 100e), IoT devices ( Figure 1 100f), digital broadcasting terminals, hologram equipment, public safety equipment, MTC equipment, medical equipment, fintech equipment (or financial equipment), security equipment, climate / environmental equipment, AI servers / equipment ( Figure 1 400), BS( Figure 1 200 in ), network nodes, etc. The wireless devices 100 and 200 may be used in mobile or fixed locations depending on the usage examples / services.

[0095] exist Figure 3In the wireless devices 100 and 200, all of the various elements, components, units / parts and / or modules in the wireless devices 100 and 200 may be connected to each other through a wired interface, or at least a part thereof may be connected wirelessly through the communication unit 1100. For example, in each of the wireless devices 100 and 200, the control unit 1200 and the communication unit 1100 may be connected by a line, and the control unit 1200 and the first unit (e.g., 1300 and 1400) may be connected wirelessly through the communication unit 1100. Each element, component, unit / part and / or module within the wireless devices 100 and 200 may also include one or more elements. For example, the control unit 1200 may be configured by a set of one or more processors. As an example, the control unit 1200 may be configured by a set of a communication control processor, an application processor (AP), an electronic control unit (ECU), a graphics processing unit and a memory control processor. As another example, the memory unit 1300 may be configured by a RAM, a DRAM, a ROM, a flash memory, a volatile memory, a non-volatile memory and / or a combination thereof.

[0096] Figure 4 Another example of an invisible device to which an embodiment of the present disclosure is applied is shown.

[0097] refer to Figure 4 , the wireless devices 100 and 200 may correspond to Figure 2 The wireless devices 100 and 200 may be configured by various elements, components, units / portions and / or modules.

[0098] The first wireless device 100 may include at least one transceiver such as a transceiver 106 and at least one processing chip such as a processing chip 101. The processing chip 101 may include at least one processor such as a processor 102 and at least one memory such as a memory 104. The memory 104 may be operably connected to the processor 102. The memory 104 may store various types of information and / or instructions. The memory 104 may store software code 105 that implements instructions that, when executed by the processor 102, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the software code 105 may implement instructions that, when executed by the processor 102, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the software code 105 may control the processor 102 to execute one or more protocols. For example, the software code 105 may control the processor 102 to execute one or more layers of a radio interface protocol.

[0099] The second wireless device 200 may include at least one transceiver, such as a transceiver 206, and at least one processing chip, such as a processing chip 201. The processing chip 201 may include at least one processor, such as a processor 202, and at least one memory, such as a memory 204. The memory 204 may be operably connected to the processor 202. The memory 204 may store various types of information and / or instructions. The memory 204 may store software code 205 that implements instructions, which, when executed by the processor 202, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the software code 205 may implement instructions that, when executed by the processor 202, perform the descriptions, functions, processes, suggestions, methods, and / or operational flow charts disclosed in the present disclosure. For example, the software code 205 may control the processor 202 to execute one or more protocols. For example, the software code 205 may control the processor 202 to execute one or more layers of a radio interface protocol.

[0100] Figure 5 An example of a UE to which an embodiment of the present disclosure is applied is shown.

[0101] refer to Figure 5 , UE 100 may correspond to Figure 2 The first wireless device 100 and / or Figure 4 A first wireless device 100 is provided.

[0102] UE 100 includes a processor 102 , a memory 104 , a transceiver 106 , one or more antennas 108 , a power management module 110 , a battery 112 , a display 114 , a keypad 116 , a subscriber identity module (SIM) card 118 , a speaker 120 , and a microphone 122 .

[0103] The processor 102 may be configured to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in the present disclosure. The processor 102 may be configured to control one or more other components of the UE 100 to implement the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in the present disclosure. The layers of the radio interface protocol may be implemented in the processor 102. The processor 102 may include an ASIC, other chipsets, logic circuits and / or data processing devices. The processor 102 may be an application processor. The processor 102 may include at least one of a digital signal processor (DSP), a central processing unit (CPU), a graphics processing unit (GPU), a modem (modulator and demodulator). An example of the processor 102 may be a processor that is configured to include a processor 102 and a processor 102 ... MANUFACTURED BY SNAPDRAGON TM Series processors, Manufactured by EXYNOS TMSeries processors, A series processors manufactured by Made by HELIO TM Series processors, ATOM manufactured TM series processors or the corresponding next-generation processors.

[0104] The memory 104 is operably coupled to the processor 102 and stores various information for operating the processor 102. The memory 104 may include ROM, RAM, flash memory, memory card, storage medium and / or other storage devices. When the embodiment is implemented in software, the technology described herein may be implemented with modules (e.g., processes, functions, etc.) that perform the descriptions, functions, processes, suggestions, methods and / or operational flow charts disclosed in this disclosure. The modules may be stored in the memory 104 and executed by the processor 102. The memory 104 may be implemented within the processor 102 or outside the processor 102, in which case the modules may be communicatively coupled to the processor 102 via various means as known in the art.

[0105] The transceiver 106 is operably coupled to the processor 102 and transmits and / or receives radio signals. The transceiver 106 includes a transmitter and a receiver. The transceiver 106 may include a baseband circuit for processing radio frequency signals. The transceiver 106 controls one or more antennas 108 to transmit and / or receive radio signals.

[0106] The power management module 110 manages the power of the processor 102 and / or the transceiver 106. The battery 112 supplies power to the power management module 110.

[0107] The display 114 outputs the results processed by the processor 102. The keypad 116 receives input used by the processor 102. The keypad 116 may be shown on the display 114.

[0108] The SIM card 118 is an integrated circuit designed to securely store an International Mobile Subscriber Identity (IMSI) number and its associated keys, which are used to identify and authenticate subscribers on mobile telephony devices such as mobile phones and computers. Contact information can also be stored on many SIM cards.

[0109] The speaker 120 outputs sound-related results processed by the processor 102. The microphone 122 receives sound-related input used by the processor 102.

[0110] Figure 6 and Figure 7 An example of a protocol stack in a 3GPP-based wireless communication system to which an embodiment of the present disclosure is applied is shown.

[0111] In particular, Figure 6 An example of a radio interface user plane protocol stack between a UE and a BS is illustrated, and Figure 7 An example of a radio interface control plane protocol stack between a UE and a BS is illustrated. 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 through which data generated in the application layer, such as voice data or Internet packet data, is transmitted. Figure 6 , the user plane protocol stack can be divided into layer 1 (ie, physical (PHY) layer) and layer 2. Figure 7 , the control plane protocol stack can be divided into layer 1 (ie, PHY layer), layer 2, layer 3 (eg, RRC layer), and non-access stratum (NAS) layer. Layer 1, layer 2, and layer 3 are referred to as access stratum (AS).

[0112] In the 3GPP LTE system, Layer 2 is divided into the following sublayers: MAC, RLC, and PDCP. In the 3GPP NR system, 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.

[0113] In the 3GPP NR system, the main services and functions of the MAC sublayer include: mapping between logical channels and transport channels; multiplexing MAC SDUs belonging to one or different logical channels into transport blocks delivered to the physical layer on the transport channel / demultiplexing MAC SDUs belonging to one or different logical channels from transport blocks (TBs) delivered from the physical layer on the transport channel; scheduling information reporting; error correction through hybrid automatic repeat request (HARQ) (one HARQ entity per cell in the case of carrier aggregation (CA)); priority handling between UEs with dynamic scheduling; priority handling between logical channels of one UE with logical channel prioritization; padding. A single MAC entity can support multiple parameter sets, transmission timings, and cells. Mapping restrictions in logical channel prioritization control which parameter sets, cells, and transmission timings a logical channel can use.

[0114] Different types of data transfer services are provided by MAC. In order to accommodate different types of data transfer services, multiple types of logical channels are defined, that is, each supports the transfer of specific types of information. Each logical channel type is defined by what type of information is transferred. Logical channels are classified into two groups: control channels and traffic channels. Control channels are used only for the transfer of control plane information, and traffic channels are used only for the transfer of user plane information. The broadcast control channel (BCCH) is a downlink logical channel for broadcasting system control information, the paging control channel (PCCH) is a downlink logical channel for transmitting paging information, system information change notifications, and indications of ongoing public warning services (PWS) broadcasts, the common control channel (CCCH) is a logical channel for sending control information between the UE and the network and is used for UEs that have no RRC connection with the network, and the dedicated control channel (DCCH) is a point-to-point bidirectional logical channel for sending dedicated control information between the UE and the network and is used by UEs with RRC connections. The dedicated traffic channel (DTCH) is a point-to-point logical channel dedicated to one UE for transferring user information. DTCH can exist in both uplink and downlink. In the downlink, there are the following connections between logical channels and transport channels: BCCH can be mapped to the broadcast channel (BCH); BCCH can be mapped to the downlink shared channel (DL-SCH); PCCH can be mapped to the paging channel (PCH); CCCH can be mapped to DL-SCH; DCCH can be mapped to DL-SCH; and DTCH can be mapped to DL-SCH. In the uplink, there are the following connections between logical channels and transport channels: CCCH can be mapped to the uplink shared channel (UL-SCH); DCCH can be mapped to UL-SCH; and DTCH can be mapped to UL-SCH.

[0115] The RLC sublayer supports three transmission modes: transparent mode (TM), unacknowledged mode (UM), and acknowledged node (AM). The RLC configuration is for each logical channel and does not depend on the parameter set and / or transmission duration. In the 3GPP NR system, the main services and functions of the RLC sublayer depend on the transmission mode and include: delivery of upper layer PDUs; sequence numbering independent of the one in 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 reconstruction; protocol error detection (AM only).

[0116] 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 using robust header compression (ROHC); delivery of user data; reordering and duplicate detection; in-sequence delivery; PDCP PDU routing (in the case of split bearers); retransmission of PDCP SDU; ciphering, deciphering and integrity protection; PDCP SDU discard; PDCP reestablishment and data recovery for RLC AM; PDCP status reporting for RLC AM; duplication of PDCP PDU 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; duplication of PDCP PDU and duplicate discard indication to lower layers.

[0117] In 3GPP NR system, the main services and functions of SDAP include: mapping of QoS flows to data radio bearers; marking QoS flow ID (QFI) in both DL and UL packets. A single SDAP protocol entity is configured for each separate PDU session.

[0118] 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 5GC or NG-RAN; establishment, maintenance and release of RRC connection 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; NAS message delivery from UE to NAS / from NAS to UE.

[0119] Figure 8 A frame structure in a 3GPP-based wireless communication system to which an embodiment of the present disclosure is applied is shown.

[0120] Figure 8The frame structure shown is purely exemplary, and the number of subframes, time slots and / or symbols in the frame may be changed differently. 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 the UE is configured with different SCSs for cell aggregation for a cell, the (absolute time) duration of time resources (e.g., subframes, time slots, or TTIs) including 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).

[0121] refer to Figure 8 , downlink and uplink transmissions are organized into frames. Each frame has T f =10ms duration. Each frame is divided into two half-frames, each half-frame has a duration of 5ms. Each half-frame consists of 5 sub-frames, each of which has a duration of 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 a cyclic prefix (CP). In a normal CP, each slot includes 14 OFDM symbols, and in an extended CP, each slot includes 12 OFDM symbols. The parameter set is based on an exponentially scalable subcarrier spacing Δf=2 u *15kHz.

[0122] The following table is based on the subcarrier spacing △f=2 u *15kHz shows the number of OFDM symbols per slot N for normal CP slot symb , the number of time slots per frame N frame,u slot and the number of time slots per subframe N subframe,u slot .

[0123] [Table 1]

[0124] 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

[0125] Table 2 Based on subcarrier spacing △f=2 u *15kHz shows the number of OFDM symbols per slot N for extended CP slot symb , the number of time slots per frame N frame,u slot and the number of time slots per subframe N subframe,u slot .

[0126] [Table 2]

[0127] u <![CDATA[N slot symb ]]> <![CDATA[N frame,u slot ]]> <![CDATA[N subframe,u slot ]]> 2 12 40 4

[0128] 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 indicated by higher layer signaling (e.g., RRC signaling) is allocated. start,u grid To begin, we 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 N is the number of resource blocks (RBs) in the resource grid and the subscript x is DL for the downlink and UL for the uplink. RB sc is the number of subcarriers per RB. 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 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, an RB is defined by 12 consecutive subcarriers in the frequency domain. In a 3GPP NR system, RBs are classified into CRBs and physical resource blocks (PRBs). For subcarrier spacing configuration u, CRBs are numbered from 0 in the frequency domain and upwards. The center of subcarrier 0 of CRB 0 for subcarrier spacing configuration u coincides with 'point A' used as a common reference point for the resource block grid. In a 3GPP NR system, PRBs are defined within a bandwidth part (BWP) and are numbered from 0 to N. size BWP,i -1 numbering, where i is the number of the bandwidth part. Physical resource block n in bandwidth part i PRB With common resource block n CRB The relationship between them is as follows: PRB =n CRB +N size BWP,i , where Nsize BWP,i It is a common resource block where the bandwidth part starts relative to CRB 0. A BWP includes multiple consecutive RBs. 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. Only one BWP configured to a UE can be activated at a time. The active BWP defines the operating bandwidth of the UE within the operating bandwidth of the cell.

[0129] The NR frequency band can be defined as two types of frequency ranges, namely, FR1 and FR2. The numerical value of the frequency range can be changed. For example, the frequency ranges of the two types (FR1 and FR2) can be shown in Table 3 below. For ease of explanation, in the frequency range used by the NR system, FR1 may mean "sub 6GHz range", FR2 may mean "above 6GHz range", and may be referred to as millimeter wave (mmW).

[0130] [Table 3]

[0131] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 450MHz-6000MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0132] As mentioned above, the value of the frequency range of the NR system can be changed. For example, FR1 may include a frequency band of 410 MHz to 7125 MHz as shown in Table 4 below. That is, FR1 may include a frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more. For example, the frequency band of 6 GHz (or 5850, 5900, 5925 MHz, etc.) or more included in FR1 may include an unlicensed band. The unlicensed band can be used for a variety of purposes, such as for vehicle communications (e.g., autonomous driving).

[0133] [Table 4]

[0134] Frequency range specification Corresponding frequency range Subcarrier spacing FR1 410MHz-7125MHz 15, 30, 60kHz FR2 24250MHz-52600MHz 60, 120, 240kHz

[0135] 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" as a geographical area may be understood as a coverage in which a node can provide a service using a carrier, and a "cell" as a radio resource (e.g., a time-frequency resource) is associated with a bandwidth 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, for example, a combination of a DL component carrier (CC) and a UL CC. A cell can be configured only by downlink resources, or can be configured by downlink resources and uplink resources. Since the DL coverage as a range in which a node can send a valid signal and the UL coverage as a 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 a radio resource used by the node. Therefore, the term "cell" may sometimes be used to represent the service coverage of a node, to represent a radio resource at other times, or to represent a range that a signal using a radio resource can reach with effective strength at other times. In CA, two or more CCs are aggregated. The UE can receive or transmit simultaneously on one or more CCs depending on its capabilities. CA is supported for both continuous CCs and non-continuous CCs. When CA is configured, the UE has only one RRC connection with the network. During RRC connection establishment / reconstruction / switching, one serving cell provides NAS mobility information, and during RRC connection reconstruction / switching, one serving cell provides security input. This cell is called the primary cell (PCell). PCell is a cell operating on the primary frequency, where the UE performs an initial connection establishment process, or initiates a connection reconstruction process. Depending on the UE capabilities, the secondary cell (SCell) can be configured to form a set of serving cells together with the PCell. SCell is a cell that provides additional radio resources on top of a specific cell (SpCell). The set of serving cells configured for the UE is therefore always composed of one PCell and one or more SCells. For dual connectivity (DC) operation, the term SpCell refers to the PCell of the primary cell group (MCG) or the primary SCell (PSCell) of the secondary cell group (SCG). SpCell supports PUCCH transmission and contention-based random access, and is always activated. MCG is the group of serving cells associated with the master node, consisting of SpCell (PCell) and optionally one or more SCells. For UEs configured with DC, SCG is a subset of serving cells associated with the secondary node, consisting of PSCell and zero or more SCells. For UEs in RRC_CONNECTED that are not configured with CA / DC, there is only one serving cell consisting of PCell.For a UE in RRC_CONNECTED configured with CA / DC, the term "serving cell" is used to denote the set of cells consisting of the SpCell and all SCells. In DC, two MAC entities are configured in the UE: one for the MCG and one for the SCG.

[0136] Fig. 9 An example of data flow in a 3GPP NR system to which an embodiment of the present disclosure is applied is shown.

[0137] refer to Fig. 9 , "RB" means radio bearer, and "H" means header. Radio bearers are classified into two groups: DRB for user plane data and SRB for control plane data. MAC PDU is transmitted / received to / from an external device through the PHY layer using radio resources. MAC PDU arrives at the PHY layer in the form of a transport block.

[0138] In the PHY layer, uplink transport channels UL-SCH and RACH are mapped to their PUSCH and PRACH, respectively, and downlink transport channels DL-SCH, BCH and PCH are mapped to PDSCH, PBCH and PDSCH, respectively. In the PHY layer, uplink control information (UCI) is mapped to PUCCH, and downlink control information (DCI) is mapped to PDCCH. MAC PDU related to UL-SCH is sent by UE via PUSCH based on UL grant, and MAC PDU related to DL-SCH is sent by BS via PDSCH based on DL assignment.

[0139] Fig.10 An example of the overall architecture of NG-RAN to which the technical features of the present disclosure can be applied is shown.

[0140] refer to Fig.10 , the gNB may include a gNB-CU (hereinafter, the gNB-CU may be referred to as CU) and at least one gNB-DU (hereinafter, the gNB-DU may be referred to as DU).

[0141] The gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or the RRC and PDCP protocols of an en-gNB. The gNB-CU controls the operation of at least one gNB-DU.

[0142] The gNB-DU is a logical node that hosts the RLC, MAC, and physical layers of a gNB or en-gNB. The operation of the gNB-DU is partially controlled by the gNB-CU. One gNB-DU supports one or more cells. One cell is supported by only one gNB-DU.

[0143] The gNB-CU and gNB-DU are connected via the F1 interface. The gNB-CU terminates the F1 interface connected to the gNB-DU. The gNB-DU terminates the F1 interface connected to the gNB-CU. One gNB-DU is connected to only one gNB-CU. However, a gNB-DU can be connected to multiple gNB-CUs by appropriate implementation. The F1 interface is a logical interface. For NG-RAN, the NG and Xn-C interfaces of the gNB consisting of the gNB-CU and gNB-DU terminate at the gNB-CU. For E-UTRAN-NR Dual Connectivity (EN-DC), the S1-U and X2-C interfaces of the gNB consisting of the gNB-CU and gNB-DU terminate at the gNB-CU. The gNB-CU and the connected gNB-DU are visible only to other gNBs and the 5GC acting as the gNB.

[0144] The functions of the F1 interface include the following F1 control (F1-C) functions.

[0145] (1) F1 interface management function

[0146] The gNB-DU or gNB-CU uses the error indication function to indicate to the gNB-CU or gNB-DU that an error has occurred.

[0147] The reset functionality is used to initialize the peer entity after node setup and after a failure event. Both gNB-DU and gNB-CU can use this procedure.

[0148] The F1 Setup function allows the exchange of application level data required for the gNB-DU and gNB-CU to interoperate correctly over the F1 interface. The F1 Setup is initiated by the gNB-DU.

[0149] The gNB-CU configuration update and gNB-DU configuration update functions allow updating of the application-level configuration data required between the gNB-CU and gNB-DU for correct interoperation over the F1 interface and for activation or deactivation of cells.

[0150] The F1 Setup and gNB-DU Configuration Update functions allow notification of the Single Network Slice Selection Assistance Information (S-NSSAI) supported by the gNB-DU.

[0151] The F1 resource coordination function is used to transfer information about frequency resource sharing between the gNB-CU and gNB-DU.

[0152] (2) System information management function

[0153] The scheduling of system broadcast information is performed in the gNB-DU. The gNB-DU is responsible for sending system information according to the available scheduling parameters.

[0154] The gNB-DU is responsible for the coding of the NR Master Information Block (MIB). In the case where the System Information Block Type 1 (SIB1) and other SI messages need to be broadcast, the gNB-DU is responsible for the coding of SIB1, while the gNB-CU is responsible for the coding of other SI messages.

[0155] (3) F1 UE context management function

[0156] The F1 UE context management function supports the establishment and modification of the necessary overall UE context.

[0157] The establishment of F1 UE context is initiated by the gNB-CU and accepted or rejected by the gNB-DU based on admission control criteria (e.g., resources not available).

[0158] The modification of the F1 UE context can be initiated by the gNB-CU or the gNB-DU. The receiving node can accept or reject the modification. The F1 UE context management function also supports the release of a context previously established in the gNB-DU. The release of the context is triggered by the gNB-CU directly or following a request received from the gNB-DU. The gNB-CU requests the gNB-DU to release the UE context when the UE enters RRC_IDLE or RRC_INACTIVE.

[0159] This functionality can also be used to manage DRBs and SRBs, i.e., establish, modify and release DRB and SRB resources. The establishment and modification of DRB resources is triggered by the gNB-CU and accepted / rejected by the gNB-DU based on the resource reservation information and QoS information to be provided to the gNB-DU. For each DRB to be set up or modified, the S-NSSAI can be provided by the gNB-CU to the gNB-DU during the UE Context Setup procedure and the UE Context Modification procedure.

[0160] The mapping between QoS flows and radio bearers is performed by the gNB-CU, and the granularity of bearer related management on F1 is at the radio bearer level. For NG-RAN, the gNB-CU provides the aggregated DRB QoS profile and QoS flow profile to the gNB-DU, and the gNB-DU accepts the request or rejects it with an appropriate cause value. To support packet duplication for intra-gNB-DU carrier aggregation (CA), one data radio bearer shall be configured with two GPRS Tunneling Protocol (GTP)-U tunnels between the gNB-CU and the gNB-DU.

[0161] Using this function, the gNB-CU requests the gNB-DU to set up or change a special cell (SpCell) for the UE, and the gNB-DU accepts the request or rejects it with an appropriate cause value.

[0162] Using this feature, the gNB-CU requests to set up a secondary cell (SCell) at the gNB-DU side and the gNB-DU accepts all, some or no SCells and replies to the gNB-CU. The gNB-CU requests to remove the SCell for the UE.

[0163] (4)RRC message transmission function

[0164] This feature allows RRC messages to be delivered between gNB-CU and gNB-DU. RRC messages are transported via F1-C. The gNB-CU is responsible for encoding the dedicated RRC messages using the assistance information provided by the gNB-DU.

[0165] (5) Paging function

[0166] The gNB-DU is responsible for sending paging information according to the provided scheduling parameters.

[0167] The gNB-CU provides paging information to enable the gNB-DU to calculate the accurate Paging Occasion (PO) and Paging Frame (PF). The gNB-CU determines the Paging Assignment (PA). The gNB-DU merges all paging records for the special PO, PF, and PA and encodes the final RRC message and broadcasts the paging message on the corresponding PO, PF in the PA.

[0168] (6) Warning message information transmission function

[0169] This feature allows cooperation with the warning message transmission process over the NG interface. The gNB-CU is responsible for encoding the warning related SI message and sending it together with other warning related information for the gNB-DU to broadcast over the radio interface.

[0170] Fig.11 The interface protocol structure of F1-C to which the technical features of the present disclosure can be applied is shown.

[0171] The transport network layer (TNL) is based on the Internet Protocol (IP) transport, including the Stream Control Transmission Protocol (SCTP) layer on top of the IP layer. The application layer signaling protocol is called the F1 Application Protocol (E1AP).

[0172] In the following, PDU session resource setting and PDU session resource modification are described. Reference may be made to 3GPP TS 38.413 v16.0.0 Section 8.2.

[0173] Describes the PDU session resource settings.

[0174] The purpose of the PDU Session Resource Setup procedure is to assign resources on Uu and NG-U for one or several PDU Sessions and the corresponding QoS Flows, and to set up the corresponding DRBs for a given UE. This procedure uses signaling associated with the UE.

[0175] The AMF initiates this procedure by sending a PDU Session Resource Setup Request message to the NG-RAN node.

[0176] The PDU SESSION RESOURCE SETUP REQUEST message shall contain the information required by the NG-RAN node to set up a PDU session related NG-RAN configuration consisting of at least one PDU session resource and including each PDU session resource to be set up in the PDU SESSION RESOURCE SETUP REQUEST LIST IE.

[0177] Upon receipt of the PDU SESSION RESOURCE SETUP REQUEST message, if resources are available for the requested configuration, the NG-RAN node shall perform the requested NG-RAN configuration and allocate the associated resources for each PDU Session listed in the PDU SESSION RESOURCE SETUP REQUEST LIST IE over the NG and Uu.

[0178] Describes PDU session resource modification.

[0179] The purpose of the PDU Session Resource Modification procedure is to enable configuration modification of an established PDU Session for a given UE. It may also enable the setup, modification and release of QoS Flows for an established PDU Session. The procedure uses signalling associated with the UE.

[0180] The AMF initiates the procedure by sending a PDU Session Resource Modification Request message to the NG-RAN node.

[0181] The PDU Session Resource Modification Request message shall contain the information required by the NG-RAN node, which may trigger NG-RAN configuration modifications for existing PDU Sessions listed in the PDU Session Resource Modification Request List IE.

[0182] Upon receiving a PDU SESSION RESOURCE MODIFICATION REQUEST message, if the NG-RAN configuration is triggered to be modified and if resources are available for the modified NG-RAN configuration, the NG-RAN node shall perform the configuration modification for the requested PDU Session.

[0183] In the following, UE context setup and UE context modification (gNB-CU initiated) are described. Please refer to Section 8.3 of 3GPP TS38.473v16.0.0.

[0184] Describes the UE context setup.

[0185] The purpose of the UE context setup procedure is to establish the UE context, which includes SRB and DRB configuration. This procedure uses signaling associated with the UE.

[0186] The gNB-CU initiates the procedure by sending a UE Context Setup Request message to the gNB-DU. If the gNB-DU successfully establishes the UE context, it replies to the gNB-CU with a UE Context Setup Response. If no logical F1 connection associated with the UE exists, a logical F1 connection associated with the UE shall be established as part of this procedure.

[0187] The gNB-DU shall report the results of all requested DRBs and SRBs to the gNB-CU in the UE Context Setup Response message in the following manner:

[0188] - The list of successfully established DRBs shall be included in the DRB Setup List IE;

[0189] - The list of DRBs that failed to be established shall be included in the DRB Setup Failure List IE;

[0190] - The list of SRBs that failed to be established shall be included in the SRB Setup Failure List IE.

[0191] - A list of successfully established SRBs with logical channel identities for the primary path shall be included in the SRB Setup List IE only when CA-based PDCP duplication is started for the relevant SRBs.

[0192] When the gNB-DU reports that DRB or SRB establishment is unsuccessful, the cause value should be precise enough for the gNB-CU to know the reason for the establishment failure.

[0193] If the C-RNTI IE is included in the UE Context Setup Response, the gNB-CU shall consider that the gNB-DU has allocated a C-RNTI for this UE context.

[0194] If the UE CONTEXT SETUP REQUEST message contains the RRC-Container IE, the gNB-DU shall send the corresponding RRC message to the UE via SRB1.

[0195] If the RAN UE ID IE is included in the UE CONTEXT SETUP Request message, the gNB-DU shall store and replace any previously received information.

[0196] Describes UE context modification (gNB-CU initiated).

[0197] The purpose of the UE Context Modification procedure is to modify an established UE context, e.g., establish, modify and release radio resources. This procedure is also used to command the gNB-DU to stop data transmission of the UE to achieve mobility. This procedure uses signaling associated with the UE.

[0198] The UE Context Modification Request message is initiated by the gNB-CU.

[0199] Upon receiving the UE CONTEXT MODIFICATION REQUEST message, the gNB-DU shall perform the modification and, if successful, report the update in a UE CONTEXT MODIFICATION RESPONSE message.

[0200] The gNB-DU shall report the results of all requested or modified DRBs and SRBs to the gNB-CU in the UE Context Modification Response message as follows:

[0201] - The successfully established DRB list shall be included in the DRB Setup List IE;

[0202] - The list of DRBs that failed to be established shall be included in the DRB Setup Failure List IE;

[0203] - The successfully modified DRB list shall be included in the DRB Modification List IE;

[0204] -The list of DRBs for which modification failed shall be included in the DRB modification failure list IE;

[0205] - The list of SRBs that failed to be established shall be included in the SRB Setup Failure List IE.

[0206] - The successfully established SRB list with logical channel identification for the primary path shall be included in the SRB Setup List IE only when CA-based PDCP duplication is initiated for the relevant SRB.

[0207] - The successfully modified SRB list with logical channel identification for the primary path shall be included in the SRB Modification List IE only when CA-based PDCP duplication is initiated for the relevant SRB.

[0208] When the gNB-DU reports that DRB or SRB establishment is unsuccessful, the cause value should be precise enough for the gNB-CU to know the reason for the establishment failure.

[0209] If the C-RNTI IE is included in the UE Context Modification Response, the gNB-CU shall consider that the gNB-DU has allocated a C-RNTI for this UE context.

[0210] If the UE CONTEXT MODIFICATION REQUEST message includes the RRC-Container IE, the gNB-DU shall send a corresponding RRC message to the UE. If the UE CONTEXT MODIFICATION REQUEST message includes the Perform Duplicate IE, the gNB-DU shall perform CA-based duplication (if configured) for the SRBs of the included RRC-Container IE.

[0211] In the following, gNB-CU-CP configuration update, bearer context setup, and bearer context modification (gNB-CU-CP initiated) are described. Reference may be made to Sections 8.2 and 8.3 of 3GPP TS 38.463v16.0.0.

[0212] Describes the gNB-CU-CP configuration update.

[0213] The purpose of the gNB-CU-CP configuration update procedure is to update the application level configuration data required for the correct interoperation between the gNB-CU-CP and the gNB-CU-UP over the E1 interface. This procedure does not affect the existing UE related context, if any. This procedure uses non-UE related signalling.

[0214] The gNB-CU-CP initiates the procedure by sending a GNB-CU-CP Configuration Update message to the gNB-CU-UP, including the appropriate updated configuration data set that it has just put into operation. The gNB-CU-UP responds with a GNB-CU-CP Configuration Update Answer message to confirm that it has successfully updated the configuration data. If the information element is not included in the GNB-CU-CP Configuration Update message, the gNB-CU-UP shall interpret that the corresponding configuration data has not changed and shall continue to operate using the existing relevant configuration data.

[0215] The updated configuration data shall be stored in both nodes and available for use as long as an operational TNL association exists or until any further updates are performed.

[0216] Describes the bearer context setup.

[0217] The purpose of the Bearer Context Setup procedure is to allow the gNB-CU-CP to establish a bearer context in the gNB-CU-UP. This procedure uses signalling associated with the UE.

[0218] The gNB-CU-CP initiates the procedure by sending a Bearer Context Setup Request message to the gNB-CU-UP. If the gNB-CU-UP successfully establishes the requested resources, it replies to the gNB-CU-CP with a Bearer Context Setup Response message.

[0219] The gNB-CU-UP shall report the results of all requested resources to the gNB-CU-CP in the Bearer Context Setup Response message in the following manner:

[0220] For E-UTRAN:

[0221] - The successfully established DRB list shall be included in the DRB Setup List IE;

[0222] - The list of DRBs for which establishment failed shall be included in the DRB Failure List IE;

[0223] For NG-RAN:

[0224] - The successfully established PDU session resource list shall be included in the PDU session resource setting list IE;

[0225] - The list of PDU session resources that failed to be established shall be included in the PDU Session Resource Failure List IE;

[0226] - For each established PDU Session Resource, the list of successfully established DRBs shall be included in the DRB Setup List IE;

[0227] - For each established PDU Session resource, the list of DRBs for which establishment failed shall be included in the DRB Failure List IE;

[0228] - For each established DRB, the list of successfully established QoS flows shall be included in the Flow Setup List IE;

[0229] - For each established DRB, the list of QoS flows for which establishment failed shall be included in the Flow Failure List IE;

[0230] When the gNB-CU-UP reports that PDU session resources, DRB or QoS flow establishment is unsuccessful, the cause value shall be precise enough to enable the gNB-CU-CP to know the reason for the establishment failure.

[0231] If an existing allocated S1 DL UP transport layer information IE or an existing allocated NG DL UP transport layer information IE is included in the BEARER CONTEXT SETUP REQUEST message, the gNB-CU-UP may reuse the indicated resources already allocated for this bearer context. If the gNB-CU-UP decides to reuse the indicated resources, it shall include the S1 DL UP Unchanged IE or the NG DL UP Unchanged IE in the BEARER CONTEXT SETUP RESPONSE message.

[0232] If the PDU Session Resources DL Aggregate Maximum Bit Rate IE is included in the PDU Session Resources Setup List IE in the Bearer Context Setup Request message, the gNB-CU-UP shall store and use the information of the downlink traffic policy for non-GBR QoS flows of the associated UEs.

[0233] If the Data Forwarding Information Request IE, PDU Session Data Forwarding Information Request IE or DRB Data Forwarding Information Request IE is included in the Bearer Context Setup Request message, the gNB-CU-UP shall include the requested forwarding information in the Data Forwarding Information Response IE, PDU Session Data Forwarding Information Response IE or DRB Data Forwarding Information Response IE in the Bearer Context Setup Response message.

[0234] If the DL UP Parameters IE is included in the DRB to be set list IE in the Bearer Context Setup Request message, the gNB-CU-UP shall configure the corresponding information.

[0235] For each PDU Session, the Security Indication IE is included in the PDU Session Resource Setup List IE of the Bearer Context Setup Request message and the Integrity Protection Indication IE or the Confidentiality Protection Indication IE is set to "Preferred", if supported, the gNB-CU-UP shall perform user plane integrity protection or ciphering, respectively, for the relevant PDU Session and shall inform it whether user plane integrity protection or ciphering is performed by including the Integrity Protection Result IE or the Confidentiality Protection Result IE, respectively, in the PDU Session Resource Setup List IE of the Bearer Context Setup Response message.

[0236] For each PDU Session, the Security Indication IE is included in the PDU Session Resources Setup List IE of the Bearer Context Setup Request message, and the Integrity Protection Indication IE or the Confidentiality Protection Indication IE is set to "Required", then the gNB-CU-UP shall perform user plane integrity protection or ciphering, respectively, for the relevant PDU Session. If the gNB-CU-UP cannot perform user plane integrity protection or ciphering, it shall reject the setup of PDU Session resources with an appropriate cause value.

[0237] For each PDU Session that the Security Indication IE is included in the PDU Session Resource Setup List IE of the Bearer Context Setup Request message:

[0238] - If the Integrity Protection Indication IE is set to “Not Required”, the gNB-CU-UP shall not perform user plane integrity protection for the associated PDU Session;

[0239] - If the Confidentiality Protection Indication IE is set to “Not Required”, the gNB-CU-UP shall not perform user plane encryption for the associated PDU Session.

[0240] If the UE DL Maximum Integrity Protected Data Rate IE is included in the Bearer Context Setup Request message, the gNB-CU-UP shall use this value when enforcing the maximum integrity protected data rate for the UE.

[0241] If the Bearer Context State Change IE is included in the Bearer Context Setup Request message, the gNB-CU-UP shall take into account the UE RRC state and take action.

[0242] For each requested DRB, if the PDCP Duplication IE is included in the PDCP Configuration IE included in the Bearer Context Setup Request message and one cell group is included in the Cell Group Information IE, the gNB-CU-UP shall include two UP Transport Layer Information IEs in the Bearer Context Setup Response message to support packet duplication for intra-gNB-DU CA. The first of the two UP Transport Layer Information IEs is for the primary path.

[0243] If the PDCP SN Status Information IE is included in the DRBs to be configured List IE in the Bearer Context Setup Request message, the gNB-CU-UP shall take it into account and act.

[0244] If the QoS flow mapping indication IE contains the QoS flow information to be set IE in the DRB to be set list IE in the bearer context setup request message, the gNB-CU-UP may consider only uplink or downlink QoS flows mapped to the DRB.

[0245] For each PDU Session Resource, if the Network Instance IE is included in the PDU Session Resources to be Set List IE in the Bearer Context Setup Request message and the Common Network Instance IE is not included, the gNB-CU-UP shall use it when selecting the transport network resource, if supported.

[0246] For each PDU Session, if the Common Network Instance IE is included in the PDU Session Resources to be Set List IE in the Bearer Context Setup Request message, the gNB-CU-UP shall use it when selecting the transport network resources, if supported.

[0247] If the UE Inactivity Timer IE or PDU Session Inactivity Timer IE or DRB Inactivity Timer IE is included in the Bearer Context Setup Request message, the gNB-CU-UP shall take it into account when performing inactivity monitoring.

[0248] If the DRB QoS IE is included in the DRBs to be set list IE in the Bearer Context Setup Request message, the gNB-CU-UP shall take it into account, if supported.

[0249] If the gNB-DU-ID IE is included in the BEARER CONTEXT SETUP REQUEST message, the gNB-CU-UP shall store the received information.

[0250] If the RAN UE ID IE is included in the BEARER CONTEXT SETUP Request message, the gNB-CU-UP shall store the received information.

[0251] For each successfully established DRB, the gNB-CU-UP shall provide, in the corresponding UL UP Parameters IE of the Bearer Context Setup Response, one UL UP transport layer information item for each cell group entry contained in the corresponding Cell Group Information IE of the Bearer Context Setup Request message.

[0252] If the Trace Activation IE is included in the Bearer Context Setup Request message, the gNB-CU-UP shall initiate the requested trace functionality, if supported.

[0253] For EN-DC, if the Subscriber Profile ID of RAT / Frequency Priority IE is included in the UE Context Setup Request, the gNB-CU-UP may use it to apply a specific RRM policy. If the Additional RRM Policy Index IE is included in the UE Context Setup Request, the gNB-CU-UP may use it to apply a specific RRM policy.

[0254] Describes bearer context modification (gNB-CU-CP initiated).

[0255] The purpose of the Bearer Context Modification procedure is to allow the gNB-CU-CP to modify the bearer context in the gNB-CU-UP. This procedure uses signalling associated with the UE.

[0256] The gNB-CU-CP initiates the procedure by sending a Bearer Context Modification Request message to the gNB-CU-UP. If the gNB-CU-UP successfully modifies the bearer context, it replies to the gNB-CU-CP with a Bearer Context Modification Response message.

[0257] The gNB-CU-UP shall report the results of all requested resources to the gNB-CU-CP in the Bearer Context Modification Response message in the following manner:

[0258] For E-UTRAN:

[0259] - The successfully established DRB list shall be included in the DRB Setup List IE;

[0260] - The list of DRBs for which establishment failed shall be included in the DRB Failure List IE;

[0261] - The successfully modified DRB list shall be included in the DRB Modification List IE;

[0262] -The list of DRBs for which modification failed shall be included in the DRB modification failure list IE;

[0263] For NG-RAN:

[0264] - The successfully established PDU session resource list shall be included in the PDU session resource setting list IE;

[0265] - The list of PDU session resources that failed to be established shall be included in the PDU Session Resource Failed List IE;

[0266] - The successfully modified PDU session resource list shall be included in the PDU session resource modification list IE;

[0267] -The list of PDU session resources that failed to be modified shall be included in the PDU session resource modification failure list IE;

[0268] - For each successfully established or modified PDU Session Resource, the successfully established DRB list shall be included in the DRB Setup List IE;

[0269] - For each successfully established or modified PDU Session Resource, the list of DRBs for which establishment failed shall be included in the DRB Failure List IE;

[0270] - For each successfully modified PDU session resource, the successfully modified DRB list shall be included in the DRB Modification List IE;

[0271] - For each successfully modified PDU session resource, the list of DRBs for which the modification failed shall be included in the DRB Modification Failed List IE;

[0272] - For each successfully established or modified DRB, the list of successfully established QoS flows shall be included in the Flow Setup List IE;

[0273] - For each successfully established or modified DRB, the list of QoS flows that failed to be established shall be included in the Flow Failure List IE;

[0274] When the gNB-CU-UP reports that PDU session resources, DRB or QoS flow establishment is unsuccessful, the cause value shall be precise enough to enable the gNB-CU-CP to know the reason for the establishment failure.

[0275] If the Security Information IE is included in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0276] If the UE DL aggregate maximum bit rate IE is included in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0277] If the UE DL Maximum Integrity Protection Data Rate IE is included in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0278] If the Bearer Context State Change IE is included in the Bearer Context Modification Request message, the gNB-CU-UP shall take into account the UE RRC state.

[0279] If the Data Forwarding Information Request IE, PDU Session Data Forwarding Information Request IE or DRB Data Forwarding Information Request IE is included in the Bearer Context Modification Request message, the gNB-CU-UP shall include the requested forwarding information in the Data Forwarding Information Response IE, PDU Session Data Forwarding Information Response IE or DRB Data Forwarding Information Response IE in the Bearer Context Modification Request message.

[0280] If the PDCP Configuration IE is included in the DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information except for the PDCP SN UL Size IE, PDCP SN DL Size IE and RLC Mode IE which shall be ignored.

[0281] If the E-UTRAN QoS IE is included in the DRB to be modified List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0282] If the PDCP SN Status Request IE is included in the DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall include the UL Count Value IE and the DL Count Value IE in the Bearer Context Modification Response message.

[0283] If the PDCP SN Status Information IE is included in the DRB To Set List IE or DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall take it into account.

[0284] If the DL UP Parameters IE is included in the DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0285] If the cell group to be added IE or the cell group to be modified IE or the cell group to be removed IE is included in the DRB to be modified list IE in the bearer context modification request message, the gNB-CU-UP shall add or modify or remove the corresponding cell group.

[0286] If the PDU Session Resources DL Aggregate Maximum Bit Rate IE is included in the PDU Session Resources Setup List IE of the Bearer Context Modification Request message, the gNB-CU-UP shall replace the information in the UE context and use it when enforcing downlink traffic policy for non-GBR QoS flows of the associated UE.

[0287] If the PDU Session Resources DL Aggregate Maximum Bit Rate IE is included in the PDU Session Resources Modification List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0288] If the SDAP Configuration IE is included in the DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0289] If the Flow Mapping Information IE is included in the DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall update the corresponding information.

[0290] For each requested DRB, if the PDCP Duplication IE is included in the PDCP Configuration IE included in the Bearer Context Modification Request message and one cell group is included in the Cell Group Information IE, the gNB-CU-CP shall include two UP Transport Layer Information IEs in the Bearer Context Modification Request message and the gNB-CU-UP shall also include two UP Transport Layer Information IEs in the Bearer Context Modification Response message to support packet duplication for intra-gNB-DU CA. The first of the two UP Transport Layer Information IEs is for the primary path.

[0291] For a certain DRB to which two GTP-U tunnels are assigned, if such DRB is modified via the Bearer Context Modification (gNB-CU-CP initiated) procedure and given one GTP-U tunnel, i.e., only one UP transport layer information per cell group ID is present in the DL UP Parameters IE of the concerned DRB, then the gNB-CU-UP shall consider deconfiguring PDCP duplication for this DRB. If such a Bearer Context Modification (gNB-CU-CP initiated) procedure occurs, the Duplication Activation IE of the concerned DRB shall not be included.

[0292] If the new UL TNL Information Requirement IE is included in the Bearer Context Modification Request message, the gNB-CU-UP shall include the new UP transport layer information in the Bearer Context Modification Response message.

[0293] For each PDU Session whose Security Indication IE is included in the PDU Session Resource Setup List IE of the Bearer Context Modification Request message and the Integrity Protection Indication IE or the Confidentiality Protection Indication IE is set to "Preferred", if supported, the gNB-CU-UP shall perform user plane integrity protection or ciphering for the relevant PDU Session, respectively, and shall inform it whether to perform user plane integrity protection or ciphering by including the Integrity Protection Result IE or the Confidentiality Protection Result IE, respectively, in the PDU Session Resource Setup List IE of the Bearer Context Modification Response message.

[0294] For each PDU Session whose Security Indication IE is included in the PDU Session Resources Setup List IE of the Bearer Context Modification Request message, and the Integrity Protection Indication IE or the Confidentiality Protection Indication IE is set to "Required", then the gNB-CU-UP shall perform user plane integrity protection or ciphering, respectively, for the relevant PDU Session. If the gNB-CU-UP cannot perform user plane integrity protection or ciphering, it shall reject the setup of PDU Session resources with an appropriate cause value.

[0295] For each PDU Session whose Security Indication IE is included in the PDU Session Resource Setup List of the Bearer Context Modification Request message:

[0296] - If the Integrity Protection Indication IE is set to “Not Required”, the gNB-CU-UP shall not perform user plane integrity protection for the associated PDU Session;

[0297] - If the Confidentiality Protection Indication IE is set to “Not Required”, the gNB-CU-UP shall not perform user plane encryption for the associated PDU Session.

[0298] For each PDU Session Resource, if the Network Instance IE is included in the PDU Session Resources To Set List IE or the PDU Session Resources To Modify List IE in the Bearer Context Modification Request message, and the Common Network Instance IE is not included, the gNB-CU-UP shall use it when selecting the transport network, if supported.

[0299] For each PDU Session, if the Common Network Instance IE is included in the PDU Session Resources To Set List IE or the PDU Session Resources To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall use it when selecting the transport network resources, if supported.

[0300] If the QoS Flow Mapping Indication IE is included in the QoS Flow QoS Parameters List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall replace any previously received value and take into account that only uplink or downlink QoS flows are mapped to the DRB, if supported.

[0301] If the Data Drop Required IE is included in the Bearer Context Modification Request message and the value is set to "Required", the gNB-CU-UP shall consider that a RAN paging failure has occurred for this UE. The gNB-CU-UP shall drop the user plane data for this UE and consider the bearer context still suspended.

[0302] If the UE Inactivity Timer IE or PDU Session Inactivity Timer IE or DRB Inactivity Timer IE is included in the Bearer Context Modification Request message, the gNB-CU-UP takes it into account when performing inactivity monitoring.

[0303] If the S-NSSAI IE is included in the PDU Session Resource Modification List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall store the corresponding information and replace any existing information.

[0304] If the DRB QoS IE is included in the DRBs to be set list IE in the Bearer Context Modification Request message, the gNB-CU-UP shall consider it for each DRB, if supported.

[0305] If the DRB QoS IE is included in the DRB To Modify List IE in the Bearer Context Modification Request message, the gNB-CU-UP shall replace any previously received value and shall take it into account for each DRB, if supported.

[0306] If the gNB-DU-ID IE is included in the BEARER CONTEXT MODIFICATION REQUEST message, the gNB-CU-UP shall store and replace any previous information received.

[0307] If the RAN UE ID IE is included in the BEARER CONTEXT MODIFICATION REQUEST message, the gNB-CU-UP shall store and replace any previous information received.

[0308] If the gNB-CU-UP receives a BEARER CONTEXT MODIFY REQUEST message including the Active Notification Level IE and its value does not match the current bearer context, the gNB-CU-UP shall ignore the Active Notification Level IE and the requested modification of the inactivity timer.

[0309] For each successfully established DRB, the gNB-CU-UP shall provide in the corresponding UL UP Parameters IE of the Bearer Context Modification Response one UL UP transport layer information item for each cell group entry contained in the corresponding Cell Group Information IE of the Bearer Context Modification Request message.

[0310] If the Old QoS Flow List - UL End Marker Expected IE is included in the PDU Session Resources to be Modified List IE of the Bearer Context Modification Request message for the DRB to be modified, the gNB-CU-UP shall consider that the source NG-RAN node has initiated QoS flow remapping and has not received the SDAP end marker. The gNB-CU-UP shall consider that the Old QoS Flow List - UL End Marker Expected IE contains the UL QoS flow information only for the QoS flows for which the SDAP end marker has not been received on the source side.

[0311] For EN-DC, if the Subscriber Profile ID IE for RAT / Frequency Priority is included in the UE Context Modification Request, the gNB-CU-UP may use it to apply a specific RRM policy. If the Additional RRM Policy Index IE is included in the UE Context Modification Request, the gNB-CU-UP may use it to apply a specific RRM policy.

[0312] If there is at least one DRB removed by the gNB-CU-UP, the gNB-CU-UP shall include the Retainability Measurement Information IE in the Bearer Context Modification Response message, if supported, providing information about the removed DRBs for retainability measurement in the gNB-CU-CP.

[0313] Meanwhile, in NR, multicast and / or broadcast services (MBS) are provided to wireless devices in a connected state. The wireless device can receive MBS from the network via multicast transmission or unicast transmission. Multicast transmission can be called point-to-multipoint (PTM) transmission. Unicast transmission can be called point-to-point (PTP) transmission.

[0314] The gNB-CU, where the necessary coordination functions reside, can be split into a control plane (CP) and a user plane (UP).

[0315] When the gNB-CU-CP learns that the UE joins a multicast group, for example, through signaling from the CN, the gNB-CU-UP may need to know this. For example, if the gNB-CU-UP knows that the UE joins a multicast group, the gNB-CU-UP can identify and forward the UE's multicast and / or broadcast data received from the CN to the gNB-DU serving the UE. That is, the gNB-CU-CP may need to control the gNB-CU-UP to support multicast transmission.

[0316] Therefore, there is a need to study multicast transmission with CP and UP separation in wireless communication systems.

[0317] Hereinafter, a method for multicast transmission with CP and UP separation in a wireless communication system according to some embodiments of the present disclosure will be described.

[0318] Fig.12 An example of a method for multicast transmission with separation of CP and UP in a wireless communication system is shown.

[0319] In particular, Fig.12 An example of a method performed by a Central Unit (CU)-User Plane (UP) of a Radio Access Network (RAN) node in a wireless communication system is shown.

[0320] For example, a RAN node may be connected to a core network node (e.g., an access and mobility function (AMF)) in a wireless communication system. For example, a CU of a RAN node may include a CU-control plane (CP). For example, a RAN node may include a distributed unit (DU) connected to a CU.

[0321] For example, the CU-CP of the RAN node may be a gNB-CU-Control Plane (gNB-CU-CP), which is a logical node hosting the control plane portion of the RRC and PDCP protocols for an en-gNB or gNB. The gNB-CU-CP may terminate the E1 interface connected to the gNB-CU-UP and the F1-C interface connected to the gNB-DU.

[0322] For example, the CU-UP of the RAN node may be a gNB-CU-User Plane (gNB-CU-UP), which is a logical node that hosts the user plane portion of the PDCP protocol for the gNB-CU of the en-gNB, and the user plane portion of the PDCP protocol and the SDAP protocol for the gNB-CU of the gNB. The gNB-CU-UP may terminate the E1 interface connected to the gNB-CU-CP and the F1-U interface connected to the gNB-DU.

[0323] In step S1201, the CU-UP may receive a first message for a multicast and / or broadcast service (MBS) from a CU-control plane (CP) of a RAN node. For example, the first message may include (1) an identifier (ID) of the MBS, and (2) a common tunnel endpoint identifier (C-TEID) for the MBS.

[0324] For example, the first message may be a bearer context setup request message or a bearer context modification request message.

[0325] For example, the first message may include a service identifier for the MBS and / or a flow identifier for the MBS.

[0326] In step S1202, the CU-UP may establish a bearer for the MBS based on the ID of the MBS.

[0327] For example, the bearer may include at least one of a data radio bearer and / or a unicast bearer.

[0328] For example, in response to the first message, the CU-UP may send a second message to the CU-CP of the RAN node to notify that the bearer of the MBS has been established. For example, the second message may be a bearer context setup response message or a bearer context modification response message.

[0329] In step S1203, the CU-UP may receive data for the MBS from the core network via the tunnel indicated by the C-TEID. For example, the core network may be an access and mobility function (AMF).

[0330] In step S1204, the CU-UP may send the received data to the DU via the established bearer.

[0331] For example, the CU-UP may receive traffic for the MBS from the core network via a tunnel, and then the CU-UP may forward the traffic for the MBS to the DU via a bearer.

[0332] According to some embodiments of the present disclosure, the CU-UP may receive a bearer context modification request message for the MBS including the ID of the MBS from the CU-CP.

[0333] For example, in step S1202, the CU-UP may receive a bearer context modification request message after establishing a bearer for the MBS.

[0334] The CU-UP may modify the bearer of the MBS based on the ID of the MBS upon receiving the bearer context modification request message.

[0335] For example, when modifying the bearer for the MBS, the CU-UP may send a bearer context modification response message to the CU-CP in response to the bearer context modification request message.

[0336] For example, the CU-UP may send the received data to the DU via the modified bearer.

[0337] Fig.13 An example of a multicast transmission method with CP and UP separation in a wireless communication system is shown.

[0338] In particular, Fig.13 An example of a method performed by a Central Unit (CU)-Control Plane (CP) of a Radio Access Network (RAN) node in a wireless communication system is shown.

[0339] For example, the RAN node may be connected to a core network node (e.g., AMF) in the wireless communication system. For example, the CU of the RAN node may include a CU-user plane (UP). For example, the RAN node may include a distributed unit (DU) connected to the CU.

[0340] In step S1301, the CU-CP may receive a first message for establishing a PDU session resource for a multicast and / or broadcast service (MBS) from a core network. For example, the first message may include a common tunnel endpoint identifier (C-TEID) for the MBS.

[0341] For example, the first message may include the ID of the MBS.

[0342] For example, the first message may be a PDU session resource setting request message or a PDU session resource modification request message.

[0343] In step S1302, the CU-CP may send a second message to the CU-user plane (UP) of the RAN node to establish a first bearer for the MBS between the CU-UP and the distributed unit (DU) of the RAN node. For example, the second message may include 1) an ID of the MBS, and 2) a C-TEID for the MBS.

[0344] For example, the second message may be a bearer context setup request message or a bearer context modification request message.

[0345] In step S1303 , in response to the second message, the CU-CP may receive a third message from the CU-UP notifying that the first bearer for the MBS is established.

[0346] For example, the third message may be a bearer context setup response message or a bearer context modification response message.

[0347] For example, the third message may include the ID of the MBS to notify that the first bearer is established for the MBS.

[0348] In step S1304, the CU-CP may send a fourth message to the DU to establish a second bearer for the MBS between the DU and the wireless device. For example, the fourth message includes the C-TEID for the MBS.

[0349] For example, the fourth message may include the ID of the MBS.

[0350] For example, the fourth message may be a UE context setup request message or a UE context modification request message.

[0351] For example, the CU-CP may generate the fourth message based on the first bearer when receiving the third message in step S1303.

[0352] According to some embodiments of the present disclosure, in response to the fourth message in step S1304, the CU-CP may receive a fifth message from the DU notifying that the second bearer is established.

[0353] For example, the fifth message may be a UE context setup response message or a UE context modification response message.

[0354] For example, the CU-CP may send a bearer context modification request message to the CU-UP to modify the first bearer upon receiving the fifth message. For example, the bearer context modification request message may include the ID of the MBS. For example, the bearer context modification request message may be sent upon receiving the fifth message.

[0355] For example, the bearer context modification request message may include the C-TEID for the MBS.

[0356] According to some embodiments of the present disclosure, a network (eg, a base station) may support RAN basic functions of broadcast / multicast for UEs in RRC_CONNECTED state.

[0357] For example, the network may support a group scheduling mechanism to allow UEs to receive broadcast / multicast services. For example, the network may support the necessary enhancements required to enable simultaneous operation with unicast reception.

[0358] For example, the network may support dynamic change of broadcast / multicast service delivery between multicast (PTM) and unicast (PTP) with service continuity for a given UE.

[0359] For example, the network may support basic mobility with service continuity.

[0360] For example, the network may assume that the necessary coordination functions (such as those hosted by the MCE) reside in the gNB-CU. For example, the network may support the necessary changes to the RAN architecture and interfaces taking into account the results of SA2 SI for broadcast / multicast.

[0361] For example, the network may support the required changes to improve the reliability of the broadcast / multicast service, for example, through UL feedback. The reliability level may be based on the requirements of the provided application / service.

[0362] For example, the network can support dynamic control of broadcast / multicast transmission areas within a gNB-DU and specify what is needed to enable it.

[0363] According to some embodiments of the present disclosure, a network (eg, a base station) may support RAN basic functions of broadcast / multicast for UEs in RRC_IDLE / RRC_INACTIVE states.

[0364] According to some embodiments of the present disclosure, a network (e.g., a base station) may support the required changes to enable a UE in the RRC_IDLE / RRC_INACTIVE state to receive point-to-multipoint transmission, with the goal of maintaining maximum commonality between the RRC_CONNECTED state and the RRC_IDLE / RRC_INACTIVE state configured for PTM reception.

[0365] The possibility for UEs in RRC_IDLE / RRC_INACTIVE state to receive point-to-multipoint transmissions, without those UEs having previously obtained configuration of PTM bearers carrying broadcast / multicast services in RRC connected state, may be supported by the network to verify service subscription and authorization assumptions.

[0366] According to some embodiments of the present disclosure, a network (e.g., a base station) may support an advanced MBS architecture with the further restriction that only NR in NG-RAN (e.g., connected to 5GC) is considered as a RAT.

[0367] For example, the network may provide multicast and / or broadcast transmissions in FR2.

[0368] For example, the network may support flexible resource allocation between unicast and broadcast / multicast services.

[0369] Hereinafter, a multicast transmission method with CP and UP separation performed by gNB-DU, gNB-CU-CP and gNB-CU-UP in a wireless communication system according to some embodiments of the present disclosure will be described.

[0370] According to some embodiments of the present disclosure, the gNB-CU-CP may provide a multicast and / or broadcast service (MBS) identifier to the gNB-CU-UP to indicate which MBS the requested bearer to which the QoS flow is mapped is related to.

[0371] For example, the gNB-CU-CP may provide the C-TEID received from the AMF or CN to the gNB-CU-UP and gNB-DU joining the multicast and / or broadcast data transmission.

[0372] Fig.14 An example of a multicast transmission process with CP and UP separation in a wireless communication system according to some embodiments of the present disclosure is shown.

[0373] exist Fig.14 In the process of establishing a multicast and / or broadcast bearer between the gNB-CU-UP and the gNB-DU, a process for establishing a multicast and / or broadcast bearer between the gNB-CU-UP and the gNB-DU may be performed.

[0374] In step S1401, the AMF may send a PDU session resource setup request or a PDU session resource modification request message to the gNB-CU-CP to establish a PDU session or set up QoS flow propagation for multicast and / or broadcast data. This message may include a C-TEID to be provided to the network entity joining the multicast and / or broadcast data transmission.

[0375] In step S1402, upon receiving the setup or modification request message, the gNB-CU-CP may send a bearer context setup request or a bearer context modification request to the gNB-CU-UP to request establishment of a bearer (e.g., a data radio bearer or a unicast bearer) for multicast and / or broadcast data transmission between the gNB-CU-UP and the gNB-DU. This message may include an MBS identifier, such as a service identifier and / or an MBS flow identifier, to indicate which MBS the requested bearer is associated with. This message may include a C-TEID received from the AMF or CN to indicate to the gNB-CU-UP the tunnel endpoint to which the MBS service will be sent.

[0376] In step S1403, when the gNB-CU-UP receives the message from the gNB-CU-CP, the gNB-CU-UP is able to identify the MBS to be provided to the UE by requesting the bearer and knows which QoS flow is related to the MBS indicated for the UE. The gNB-CU-UP may send a Bearer Context Setup Response or Bearer Context Modification Response message to the gNB-CU-CP.

[0377] In step S1404, upon receiving the Setup or Modify Response message from the gNB-CU-UP, the gNB-CU-CP may send a UE Context Setup Request or UE Context Modify Request to the gNB-DU to request the setup of a bearer (e.g., a data radio bearer or a unicast bearer) for multicast and / or broadcast data transmission between the gNB-DU and the UE. This message may include the C-TEID received from the AMF or CN to indicate to the gNB-DU the tunnel endpoint to which the MBS service will be sent.

[0378] In step S1405, including the configuration of the requested bearer, the gNB-DU may respond to the gNB-CU-CP with a UE Context Setup Response or UE Context Modification Response message.

[0379] In step S1406, upon receiving the message from the gNB-DU, the gNB-CU-CP may send a bearer context modification request message to the gNB-CU-UP. This message may contain an MBS identifier to indicate which MBS the requested bearer is associated with.

[0380] In step S1407, upon receiving the message from the gNB-CU-CP, the gNB-CU-UP may respond with a bearer context modification response message.

[0381] In step S1408, when the gNB-CU-CP receives the message from the gNB-CU-UP, the gNB-CU-CP may send a PDU Session Resource Setup Response or a PDU Session Resource Modification Response message to the AMF.

[0382] Hereinafter, an apparatus for multicast transmission with CP and UP separation in a wireless communication system according to some embodiments of the present disclosure will be described.

[0383] According to some embodiments of the present disclosure, a Central Unit (CU)-User Plane (UP) of a Radio Access Network (RAN) node may include a processor and a memory.

[0384] For example, a processor may be configured to be operatively coupled to a memory.

[0385] The processor may be configured to receive a first message for a multicast and / or broadcast service (MBS) from a CU-control plane (CP) of a RAN node. The first message may include (1) an identifier (ID) of the MBS, and (2) a common tunnel endpoint identifier (C-TEID) for the MBS. The processor may be configured to establish a bearer for the MBS based on the ID of the MBS. The processor may be configured to receive data for the MBS from a core network via a tunnel indicated by the C-TEID. The processor may be configured to send the received data to the DU via the established bearer.

[0386] For example, the first message may be a bearer context setup request message or a bearer context modification request message.

[0387] For example, the processor may be configured to send a second message to the CU-CP of the RAN node in response to the first message, notifying that the bearer for the MBS has been established. For example, the second message may be a bearer context setup response message or a bearer context modification response message.

[0388] For example, the bearer may include at least one of a data radio bearer and / or a unicast bearer.

[0389] For example, the first message may include a service identifier for the MBS and / or a flow identifier for the MBS.

[0390] For example, the processor may be configured to receive a bearer context modification request message for the MBS including the ID of the MBS from the CU-CP.

[0391] For example, the processor may be configured to modify the bearer for the MBS based on the ID of the MBS upon receiving the bearer context modification request message.

[0392] For example, the processor may be configured to send a bearer context modification response message to the CU-CP in response to the bearer context modification request message.

[0393] According to some embodiments of the present disclosure, a central unit (CU)-control plane (CP) of a radio access network (RAN) node may include a processor and a memory.

[0394] For example, a processor may be configured to be operatively coupled to a memory.

[0395] The processor may be configured to receive a first message from a core network for establishing a packet data unit (PDU) session resource for a multicast and / or broadcast service (MBS). For example, the first message may include a common tunnel endpoint identifier (C-TEID) for the MBS. For example, the first message may include the ID of the MBS. The processor may be configured to send a second message to a CU-user plane (UP) of a RAN node to establish a first bearer for the MBS between the CU-UP and a distributed unit (DU) of the RAN node. For example, the second message may include 1) the ID of the MBS, and 2) the C-TEID for the MBS. The processor may be configured to receive a third message from the CU-UP in response to the second message, the third message notifying that the first bearer for the MBS has been established. The processor may be configured to send a fourth message to the DU to establish a second bearer for the MBS between the DU and the wireless device, wherein the third message includes the C-TEID for the MBS. For example, the fourth message may include the ID of the MBS.

[0396] For example, the processor may be configured to generate a fourth message based on the first bearer upon receiving the third message.

[0397] For example, the processor may be configured to receive, in response to the fourth message, from the DU a fifth message notifying that the second bearer has been established.

[0398] For example, the processor may be configured to send a bearer context modification request message to the CU-UP to modify the first bearer when receiving the fifth message. For example, the bearer context modification request message may include the ID of the MBS.

[0399] For example, the bearer context modification request message includes the C-TEID for the MBS.

[0400] For example, refer to Fig.10 , the gNB-CU can be an example of a CU of a RAN node used to switch between unicast and multicast by considering the degraded user experience.

[0401] Hereinafter, a processor of a central unit (CU)-user plane (UP) of a radio access network (RAN) node for multicast transmission with CP and UP separation in a wireless communication system according to some embodiments of the present invention will be described.

[0402] The processor may be configured to control the CU-UP to receive a first message for a multicast and / or broadcast service (MBS) from a CU-control plane (CP) of a RAN node. The first message may include (1) an identifier (ID) of the MBS, and (2) a common tunnel endpoint identifier (C-TEID) for the MBS. The processor may be configured to control the CU-UP to establish a bearer for the MBS based on the ID of the MBS. The processor may be configured to control the CU-UP to receive data for the MBS from the core network via a tunnel indicated by the C-TEID. The processor may be configured to control the CU-UP to send the received data to the DU via the established bearer.

[0403] For example, the first message may be a bearer context setup request message or a bearer context modification request message.

[0404] For example, the processor may be configured to control the CU-UP to send a second message to the CU-CP of the RAN node in response to the first message, notifying that the bearer for the MBS has been established. For example, the second message may be a bearer context setup response message or a bearer context modification response message.

[0405] For example, the bearer may include at least one of a data radio bearer and / or a unicast bearer.

[0406] For example, the first message may include a service identifier for the MBS and / or a flow identifier for the MBS.

[0407] For example, the processor may be configured to control the CU-UP to receive a bearer context modification request message for the MBS including the ID of the MBS from the CU-CP.

[0408] For example, the processor may be configured to control the CU-UP to modify the bearer for the MBS based on the ID of the MBS upon receiving the bearer context modification request message.

[0409] For example, the processor may be configured to control the CU-UP to send a bearer context modification response message to the CU-CP in response to the bearer context modification request message.

[0410] Hereinafter, a processor of a central unit (CU)-control plane (CP) of a radio access network (RAN) node for multicast transmission with separation of CP and UP in a wireless communication system according to some embodiments of the present invention will be described.

[0411] The processor may be configured to control the CU-CP to receive a first message from the core network for establishing a packet data unit (PDU) session resource for a multicast and / or broadcast service (MBS). For example, the first message may include a common tunnel endpoint identifier (C-TEID) for the MBS. For example, the first message may include the ID of the MBS. The processor may be configured to control the CU-CP to send a second message to the CU-user plane (UP) of the RAN node to establish a first bearer for the MBS between the CU-UP and the distributed unit (DU) of the RAN node. For example, the second message may include 1) the ID of the MBS, and 2) the C-TEID for the MBS. The processor may be configured to control the CU-CP to receive a third message from the CU-UP in response to the second message to notify that the first bearer for the MBS has been established. The processor may be configured to control the CU-CP to send a fourth message to the DU to establish a second bearer for the MBS between the DU and the wireless device, wherein the third message includes the C-TEID for the MBS. For example, the fourth message may include the ID of the MBS.

[0412] For example, the processor may be configured to control the CU-CP to generate a fourth message based on the first bearer upon receiving the third message.

[0413] For example, the processor may be configured to control the CU-CP to receive, in response to the fourth message, a fifth message from the DU notifying that the second bearer is established.

[0414] For example, the processor may be configured to control the CU-CP to send a bearer context modification request message to the CU-UP to modify the first bearer when receiving the fifth message. For example, the bearer context modification request message may include the ID of the MBS.

[0415] For example, the bearer context modification request message includes the C-TEID for the MBS.

[0416] Hereinafter, a non-transitory computer readable medium having stored thereon a plurality of instructions for multicast transmission with separation of CP and UP in a wireless communication system according to some embodiments of the present disclosure will be described.

[0417] According to some embodiments of the present disclosure, the technical features of the present disclosure may be directly embodied in hardware, in software executed by a processor, or in a combination of the two. For example, a method performed by a wireless device in wireless communication may be implemented in hardware, software, firmware, or any combination thereof. For example, the software may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a removable disk, a CD-ROM, or any other storage medium.

[0418] Some examples of storage media are coupled to a processor so that the processor can read information from the storage media. In an alternative, the storage medium can be integrated into the processor. The processor and the storage medium can reside in an ASIC. For example, the processor and the storage medium can exist as discrete components.

[0419] The computer-readable medium may include tangible and non-transitory computer-readable storage media.

[0420] For example, non-transitory computer-readable media may include random access memory (RAM), such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic or optical data storage media, or any other medium that can be used to store instructions or data structures. Non-transitory computer-readable media may also include combinations of the foregoing.

[0421] Furthermore, the methods described herein may be implemented at least in part by a computer-readable communication medium that carries or communicates code in the form of instructions or data structures and can be accessed, read, and / or executed by a computer.

[0422] According to some embodiments of the present disclosure, a plurality of instructions are stored on a non-transitory computer-readable medium. The stored plurality of instructions may be executed by a processor of a central unit (CU).

[0423] The stored multiple instructions may enable the CU-UP to receive a first message for a multicast and / or broadcast service (MBS) from a CU-control plane (CP) of a RAN node. The first message may include (1) an identifier (ID) of the MBS, and (2) a common tunnel endpoint identifier (C-TEID) for the MBS. The stored multiple instructions may enable the CU-UP to establish a bearer for the MBS based on the ID of the MBS. The stored multiple instructions may enable the CU-UP to receive data for the MBS from the core network via a tunnel indicated by the C-TEID. The stored multiple instructions may enable the CU-UP to send the received data to the DU via the established bearer.

[0424] For example, the first message may be a bearer context setup request message or a bearer context modification request message.

[0425] For example, the stored multiple instructions may enable the CU-UP to send a second message to the CU-CP of the RAN node in response to the first message to notify that the bearer for the MBS has been established. For example, the second message may be a bearer context setup response message or a bearer context modification response message.

[0426] For example, the bearer may include at least one of a data radio bearer and / or a unicast bearer.

[0427] For example, the first message may include a service identifier for the MBS and / or a flow identifier for the MBS.

[0428] For example, the stored plurality of instructions may enable the CU-UP to receive a bearer context modification request message for the MBS including the ID of the MBS from the CU-CP.

[0429] For example, the stored plurality of instructions may enable the CU-UP to modify the bearer for the MBS based on the ID of the MBS upon receiving the bearer context modification request message.

[0430] For example, the stored plurality of instructions may enable the CU-UP to send a bearer context modification response message to the CU-CP in response to the bearer context modification request message.

[0431] According to some embodiments of the present disclosure, a plurality of instructions are stored on a non-transitory computer-readable medium. The plurality of stored instructions may be executed by a processor of a central unit (CU)-control plane (CP) of a radio access network (RAN) node.

[0432] The stored multiple instructions may cause the CU-CP to receive a first message from the core network for establishing a packet data unit (PDU) session resource for a multicast and / or broadcast service (MBS). For example, the first message may include a common tunnel endpoint identifier (C-TEID) for the MBS. For example, the first message may include the ID of the MBS. The stored multiple instructions may cause the CU-CP to send a second message to the CU-user plane (UP) of the RAN node to establish a first bearer for the MBS between the CU-UP and the distributed unit (DU) of the RAN node. For example, the second message may include 1) the ID of the MBS, and 2) the C-TEID for the MBS. In response to the second message, the stored multiple instructions may cause the CU-CP to receive a third message from the CU-UP, which notifies that the first bearer for the MBS has been established. The stored multiple instructions may cause the CU-CP to send a fourth message to the DU to establish a second bearer for the MBS between the DU and the wireless device, wherein the third message includes the C-TEID for the MBS. For example, the fourth message may include the ID of the MBS.

[0433] For example, the stored multiple instructions may enable the CU-CP to generate a fourth message based on the first bearer when receiving the third message.

[0434] For example, in response to the fourth message, the stored plurality of instructions may enable the CU-CP to receive a fifth message from the DU notifying that the second bearer has been established.

[0435] For example, the stored multiple instructions may enable the CU-CP to send a bearer context modification request message to the CU-UP to modify the first bearer upon receiving the fifth message. For example, the bearer context modification request message may include the ID of the MBS.

[0436] For example, the bearer context modification request message includes the C-TEID for the MBS.

[0437] The present disclosure may have various beneficial effects.

[0438] According to some embodiments of the present disclosure, the CU-CP of a radio access network (RAN) node (e.g., a base station such as a gNB) and the CU-UP of the RAN node may effectively perform multicast transmission.

[0439] For example, the gNB-CU-UP is able to identify multicast and / or broadcast data for the UE among the data received from the CN and forward them to the gNB-DU served by the UE.

[0440] Therefore, the network can efficiently provide multicast and / or broadcast data transmission without any loss.

[0441] Additionally, the network can avoid degradation in UE experience by receiving multicast and / or broadcast data through the gNB.

[0442] According to some embodiments of the present disclosure, a wireless communication system may provide an effective solution for multicast transmission with CP and UP separation in a wireless communication system.

[0443] The beneficial effects that can be obtained by the specific embodiments of the present disclosure are not limited to the beneficial effects listed above. For example, there may be various technical effects that can be understood by a person of ordinary skill in the art and / or derived from the present disclosure. Therefore, the specific effects of the present disclosure are not limited to those explicitly described herein, but may include various effects that can be understood or derived from the technical features of the present disclosure.

[0444] The claims in this specification can be combined in various ways. For example, the technical features in the method claims of this specification can be combined to be implemented or performed in a device, and the technical features in the device claims can be combined to be implemented or performed in a method. In addition, the technical features in the method claims and the device claims can be combined to be implemented or performed in a device. In addition, the technical features in the method claims and the device claims can be combined to be implemented or performed in a method. Other implementations are within the scope of the attached claims.

Claims

1. A method performed by a Central Unit (CU) - Control Plane (CP) of a Radio Access Network (RAN) node in a wireless communication system (1), the method comprising, sending a bearer context setup request message to a CU-user plane (UP) of the RAN node to request establishment of a bearer for data transmission of a multicast and / or broadcast service (MBS) between the CU-UP and a distributed unit (DU) of the RAN node, in, The bearer context setup request message includes an MBS identifier to indicate which MBS the bearer is associated with; receiving a bearer context setup response message from the CU-UP in response to the bearer context setup request message; sending a context setup request message to the DU, the context setup request message including (i) a request for setup of a bearer for data transmission of the MBS between the DU and a user equipment (UE), and (ii) information notifying a tunnel endpoint to which data for the MBS is to be transmitted; as well as A context setup response message is received from the DU in response to the context setup request message.

2. The method according to claim 1, wherein: The method further comprises, A protocol data unit (PDU) session resource setup request message or a PDU session resource modification request message is received from an access and mobility management function (AMF) to establish a PDU session or set a quality of service (QoS) flow for data transmission of the MBS.

3. The method according to claim 2, in, The PDU session resource setup request message or the PDU session resource modification request message includes a common tunnel endpoint identifier (C-TEID) for at least one network entity to be provided for data transmission joining the MBS.

4. A central unit CU-control plane CP of a radio access network RAN ​​node in a wireless communication system (1), comprising: Memory; as well as at least one processor operably coupled to the memory and configured to: sending a bearer context setup request message to a CU-user plane (UP) of the RAN node to request establishment of a bearer for data transmission of a multicast and / or broadcast service (MBS) between the CU-UP and a distributed unit (DU) of the RAN node, The bearer context setting request message includes an MBS identifier to indicate which MBS the bearer is related to; receiving a bearer context setup response message from the CU-UP in response to the bearer context setup request message; sending a context setup request message to the DU, the context setup request message including (i) a request for setup of a bearer for data transmission of the MBS between the DU and a user equipment (UE), and (ii) information notifying a tunnel endpoint to which data for the MBS is to be transmitted; and A context setup response message is received from the DU in response to the context setup request message.

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