Method and apparatus for controlling network congestion in a wireless communication system

Abstract

The disclosure relates to a 5G communication system or a 6G communication system for providing higher data transmission rates than a previous 4G communication system, such as LTE. A method performed by a user plane function (UPF) entity in a wireless communication system according to the disclosure can include the steps of receiving N4 session information from a session management function (SMF) entity, the N4 session information including an explicit congestion notification (ECN) activation indicator and an ECN tuning parameter; identifying a QoS flow for which an ECN-related function activation is to be applied based on the ECN activation indicator; and performing data communication based on the ECN activation indicator and the ECN tuning parameter. Various other embodiments identified by the specification are possible.

Description

Technical Field

[0001] This disclosure relates to wireless communication systems, and more specifically, to methods and apparatus for controlling network congestion in wireless communication systems. Background Technology

[0002] Given the successive generations of development in wireless communication, technologies have been developed primarily for human-facing services such as voice calls, multimedia services, and data services. With the commercialization of 5G (fifth-generation) communication systems, the number of connected devices is expected to grow exponentially. These devices will increasingly connect to communication networks. Examples of connected things can include vehicles, robots, drones, home appliances, displays, smart sensors connected to various infrastructures, construction machinery, and factory equipment. Mobile devices are expected to evolve into various forms, such as augmented reality glasses, virtual reality headsets, and holographic devices. To provide a wide range of services by connecting hundreds of billions of devices and things in the 6G (sixth-generation) era, the industry has been working to develop improved 6G communication systems. For these reasons, 6G communication systems are referred to as "beyond 5G" systems.

[0003] The 6G communication system, expected to be commercialized around 2030, will have peak data rates in the terabyte (1000 gigabyte) range and wireless latency of less than 100 microseconds (μsec), and will therefore be 50 times faster than 5G communication systems with 1 / 10 of their wireless latency.

[0004] To achieve such high data rates and ultra-low latency, 6G communication systems have been considered for implementation in the terahertz (THz) band (e.g., the 95 GHz to 3 THz band). Since path loss and atmospheric absorption in the terahertz band are more severe than those in the millimeter-wave (mmWave) band introduced in 5G, technologies that can ensure signal transmission distance (i.e., coverage) are expected to become even more critical. As key technologies for ensuring coverage, it is necessary to develop radio frequency (RF) components, antennas, new waveforms with better coverage than orthogonal frequency division multiplexing (OFDM), beamforming and massive MIMO, full-dimensional MIMO (FD-MIMO), array antennas, and multi-antenna transmission technologies (such as massive MIMO). Furthermore, the industry has been discussing new technologies for improving the coverage of terahertz band signals, such as metamaterial-based lenses and antennas, orbital angular momentum (OAM), and reconfigurable smart surfaces (RIS).

[0005] Furthermore, to improve spectrum efficiency and overall network performance, the following technologies have been developed for 6G communication systems: full-duplex technology to enable uplink and downlink transmissions to use the same frequency resources simultaneously; network technologies to utilize satellites, high-altitude platform stations (HAPS), etc., in an integrated manner; improved network architectures to support mobile base stations and achieve network operation optimization and automation; dynamic spectrum sharing technology via conflict avoidance based on spectrum usage prediction; the use of AI in wireless communication to improve the entire network operation by leveraging artificial intelligence (AI) from the design phase of 6G development and internalizing end-to-end AI support functions; and next-generation distributed computing technologies to overcome the limitations of UE computing capabilities through ultra-high-performance communication and computing resources accessible on the network, such as mobile edge computing (MEC), cloud, etc. In addition, ongoing efforts are underway to design new protocols for use in 6G communication systems, develop mechanisms for achieving hardware-based secure environments and secure data use, develop technologies for maintaining privacy, enhance connectivity between devices, optimize networks, promote the software-defined networking of network entities, and increase the openness of wireless communication.

[0006] The research and development of 6G communication systems in hyper-connectivity (including human-to-machine (P2M) and machine-to-machine (M2M)) is expected to enable next-generation hyper-connected experiences. Specifically, services such as truly immersive extended reality (XR), high-fidelity mobile holograms, and digital twins are anticipated to be available through 6G communication systems. Furthermore, services such as remote surgery for enhanced security and reliability, industrial automation, and emergency response will be provided through 6G communication systems, enabling these technologies to be applied in various fields such as industry, healthcare, automotive, and home appliances. Summary of the Invention

[0007] [Technical Issues]

[0008] The various embodiments described herein provide a method and apparatus for controlling network congestion that may occur within a wireless communication system network.

[0009] [Solution to the problem]

[0010] According to the various embodiments described herein, a method performed by a User Plane Function (UPF) entity in a wireless communication system may include: receiving N4 session information from a Session Management Function (SMF) entity, the N4 session information including an Explicit Congestion Notification (ECN) activation indicator and ECN tuning parameters; identifying an activated QoS flow for which ECN-related functions are to be applied based on the ECN activation indicator; and performing data communication based on the ECN activation indicator and ECN tuning parameters.

[0011] According to the various embodiments described herein, a method performed by a user equipment (UE) in a wireless communication system may include: sending a PDU session establishment request message to a Session Management Function (SMF) entity via a base station, the PDU session establishment request message including ECN information that can be supported in the PDU session connection; receiving a PDU session establishment response message from the SMF entity via the base station, the PDU session establishment response message including an Explicit Congestion Notification (ECN) activation indicator and ECN tuning parameters; and performing data communication based on the PDU session establishment response message, wherein the PDU session establishment response message includes identification information for a QoS flow, wherein activation of ECN-related functions will be applied by the base station to the QoS flow based on the ECN activation indicator.

[0012] According to the various embodiments described herein, a User Plane Function (UPF) entity in a wireless communication system may include at least one transceiver and a controller coupled to the at least one transceiver. The controller may be configured to: receive N4 session information from a Session Management Function (SMF) entity, the N4 session information including an Explicit Congestion Notification (ECN) activation indicator and ECN tuning parameters; identify activated QoS flows for which ECN-related functions are to be applied based on the ECN activation indicator; and perform data communication based on the ECN activation indicator and ECN tuning parameters.

[0013] According to the various embodiments described herein, a user equipment (UE) in a wireless communication system may include at least one transceiver and a controller coupled to the at least one transceiver. The controller may be configured to: send a PDU session establishment request message to a Session Management Function (SMF) entity via a base station, the PDU session establishment request message including ECN information that can be supported in the PDU session connection; receive a PDU session establishment response message from the SMF entity via the base station, the PDU session establishment response message including an Explicit Congestion Notification (ECN) activation indicator and ECN tuning parameters; and perform data communication based on the PDU session establishment response message, wherein the PDU session establishment response message includes identification information for a QoS flow, wherein activation of ECN-related functions will be applied by the base station to the QoS flow based on the ECN activation indicator. Attached Figure Description

[0014] Figure 1 An environment for deploying a 5G network in the cloud according to an embodiment of this disclosure is shown.

[0015] Figure 2 The relationship between a 5G network and a virtual network according to embodiments of this disclosure is illustrated.

[0016] Figure 3The present disclosure illustrates the operation of controlling congestion in a wireless communication system by using explicit congestion notification (ECN) of the transmission control protocol (TCP).

[0017] Figure 4 The structure of a user plane packet header in a 5G network running in the cloud, according to an embodiment of the present disclosure, is shown.

[0018] Figure 5 The operation of activating the ECN function according to an embodiment of this disclosure is illustrated.

[0019] Figure 6 The operation of performing downlink transmission according to an embodiment of this disclosure is illustrated.

[0020] Figure 7 The operation of performing uplink transmission according to an embodiment of this disclosure is illustrated.

[0021] Figure 8 The operation of performing congestion control by using transmission control rules according to an embodiment of this disclosure is illustrated.

[0022] Figure 9 The operation of a User Plane Function (UPF) entity according to an embodiment of this disclosure is illustrated.

[0023] Figure 10 The operation of a terminal according to an embodiment of this disclosure is illustrated.

[0024] Figure 11 The structure of a core network entity according to an embodiment of this disclosure is shown.

[0025] Figure 12 The structure of a base station according to an embodiment of this disclosure is shown.

[0026] Figure 13 The structure of a UE according to an embodiment of this disclosure is shown.

[0027] Regarding the description of the accompanying drawings, the same or similar reference numerals may be used to denote the same or similar elements. Detailed Implementation

[0028] The claimed subject matter will now be described with reference to the accompanying drawings, wherein the same reference numerals are used throughout to refer to the same elements. In the following description, numerous specific details are set forth for purposes of explanation to provide a thorough understanding of one or more embodiments. However, it will be apparent, however, that these embodiments may be practiced without these specific details.

[0029] The terminology used in this disclosure is for the purpose of describing particular embodiments only and may not be intended to limit the scope of other embodiments. Singular expressions may include plural expressions unless the context clearly indicates otherwise. The terminology used herein, including technical and scientific terms, may have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains. Such terms as defined in general dictionaries may be interpreted as having the same meaning as in the context of the relevant field and are not to be construed as having an ideal or overly formal meaning unless clearly defined in this disclosure. In some cases, even terms defined in this disclosure should not be construed as excluding embodiments of this disclosure.

[0030] In the following description, for ease of description, terms referring to signals (e.g., messages, signals, signaling, sequences, and streams), terms relating to resources (e.g., symbols, time slots, frames, subframes, radio frames, subcarriers, resource elements (REs), resource blocks (RBs), bandwidth portions (BWPs), and timings) are used by way of example, terms referring to operations (e.g., steps, methods, procedures, and processes), terms referring to data (e.g., information, parameters, variables, values, bits, symbols, and codewords), terms referring to channels, terms referring to control information (e.g., downlink control information (DCI), media access control element (MAC CE), and radio resource control (RRC) signaling), terms referring to network entities, terms referring to device components, etc., are used. Therefore, this disclosure is not limited to the terms described below, and other terms with equivalent technical meanings may be used.

[0031] This document describes various embodiments of the present disclosure in conjunction with wireless terminals and / or base stations. A wireless terminal can refer to a device that provides voice and / or data connectivity to a user. A wireless terminal can be connected to a computing device such as a laptop or desktop computer, or it can be a standalone device such as a personal digital assistant (PDA). A wireless terminal can also be referred to as a system, user unit, user station, mobile station, mobile station, remote station, remote terminal, access terminal, user terminal, terminal, wireless communication device, user agent, user apparatus, or user equipment. A wireless terminal can be a user station, wireless device, cellular phone, PCS phone, cordless phone, Session Initiation Protocol (SIP) phone, Wireless Local Loop (WLL) station, personal digital assistant (PDA), handheld device with wireless connectivity, or other processing device connected to a wireless modem. A base station (e.g., an access point) can refer to a device in an access network that communicates with a wireless terminal via an air interface through one or more sectors. A base station can act as a router between the wireless terminal and the rest of the access network (which may include an Internet Protocol (IP) network) by converting received air interface frames into IP packets. The base station also coordinates the attribute management of the air interface.

[0032] With the introduction of 5G communication technology, mobile communication networks have been developed based on the software-defined and virtualized nature of network functions. Traditional network functions were developed / deployed in closed architectures configured with dedicated hardware and software. However, with the introduction of 5G communication technology, hardware and software have been separated, and the network functions used to provide actual mobile communication network services have evolved to run in the cloud as software.

[0033] One of the key characteristics of cloud environments is the execution of software within a virtualized environment. This virtualization includes the virtualization of computing resources used for computation and also provides networking in a virtualized form. Virtualization refers to the technology used to partition physical resources and provide functionality or performance to each user in the same way as the actual physical resources. Furthermore, the network provides virtual network capabilities, allowing each user to be provided with the same functionality as if they had dedicated network resources. Such virtual networks include methods for isolating each virtual network in the cloud or in a physical network environment shared by multiple users. These methods specifically employ techniques such as inserting additional headers into packets generated in the virtual network to distinguish them from packets in another network. The advantage of this virtualized environment is the ability to partition and utilize physical resources. However, problems may arise when using functionality that requires non-virtualized devices or networks.

[0034] In the following, the various embodiments disclosed herein relate to a scenario where a Network Function (NF) entity for providing 5G, particularly a User Plane Function (UPF) entity for transmitting user data packets, is deployed in a virtualized environment. The UPF entity connects to a base station (RAN) and performs the role of transmitting user packets between the external network and the terminal. The UPF entity and the base station are typically connected using a General Packet Radio Service (GPRS) Tunneling Protocol-User Plane (GTP-U) tunnel. Packets between the UPF entity operating in the virtualized network and the base station may further include header information for the virtualized network and GTP-U header information for operating the 5G network. In this case, to enable the functions provided to the virtual network device to perform their roles in actual user service, information is transmitted with modified headers, taking into account the virtual network or mobile communication network, or modifications to the headers are required. For example, as a representative function for supporting network device congestion control of user service flows, an Explicit Congestion Notification (ECN) tagging function can be used. The ECN tag indicates a series of operations indicating whether congestion exists in the ECN field of the IP header of transmitted and received data packets. In virtualized networks, to enable network devices to indicate the presence of congestion when sending and receiving uplink or downlink data, an ECN (Entry-Level Communication) tag needs to be included in the innermost IP header to transmit the ECN tag to user terminals and external servers. Therefore, a method is needed to allow functionality provided by virtualized network devices or mobile communication network devices to be transferred to actual data packets.

[0035] In the following section, this paper proposes a method for implementing efficient transport layer transmission control (flow control) and congestion control in virtualized mobile communication networks.

[0036] Virtualization refers to the abstraction of hardware resources (e.g., computing resources, memory resources, and network resources). Under virtualization, the hardware resources of a network device (e.g., a general-purpose server device) are abstracted and / or shared, and a portion of the entire hardware resource is used to perform specific network functions. For example, under virtualization, multiple network functions can be performed within a single network device.

[0037] In the following description, for ease of description, terms referring to network entities, terms referring to device components, etc., are used by way of example. Therefore, this disclosure is not limited to the terms described below, and other terms with equivalent technical meanings may be used.

[0038] For reference, the transport network devices mentioned in this article can refer to devices that operate on the path between the UPF and RAN running in the cloud. For example, virtual switches, virtual routers, physical switches, or physical routers can correspond to transport network devices.

[0039] The names mentioned herein are described using network entities and terminology used in 5G communication systems. For example, a 5G communication system described herein may include a UPF entity that processes data packets and a Session Management Function (SMF) entity that controls the rules relating to the processing of data packets. Furthermore, a 5G communication system described herein may include entities involved in the selection of the SMF and UPF entities, such as a Network Repository Function (NRF) supporting NF discovery and a Service Communication Agent (SCP). Additionally, a Data Session Manager may exist that performs control relating to commands sent from the SMF entity to the UPF entity, and the Data Session Manager may be part of the functionality of the SMF entity or may be implemented as an internal function of the SMF entity. In the following, each network function described herein is described by reference to a 5G communication system, and entities with similar functionality can operate by configuring a communication system according to embodiments of this disclosure, even in post-5G or 6G mobile communication networks.

[0040] Figure 1 An environment for deploying a 5G network in the cloud, according to embodiments of the present disclosure, is illustrated. Specifically, Figure 1 An example of a network system for 5G mobile communications is shown in a cloud or virtualized environment.

[0041] refer to Figure 1 An NFV environment, referring to the environment in which network functions are performed within virtualized network devices, can include applications running in virtual machines (VMs) or containers, virtualized physical resources (e.g., virtual compute, virtual storage, and virtual networks) used to provide applications or network functions (NFs), and hardware resources (e.g., physical compute, physical storage, and physical networks). Virtualized cloud platforms can provide an environment in which applications can run smoothly by providing and connecting virtualized resources to actual virtual machines or containers. Representative cloud platforms can include, for example, Red Hat OpenShift, the Open Compute Project (OCP), and WinDrive. Furthermore, an NFV environment can include an orchestrator or manager responsible for managing the entire virtualized network environment, deploying / managing applications, and managing virtual resources.

[0042] Figure 2 A and Figure 2 B illustrates the relationship between a 5G network and a virtual network according to embodiments of this disclosure. Specifically, Figure 2 A and Figure 2 B illustrates the status of the UPF entity operating in the 5G network and the Next Generation Radio Access Network (NG-RAN) operating on the virtual network.

[0043] Connections between network entities operating in the cloud are established through virtual networks (or overlay networks), and these virtual networks can differ from the forms recognized by the actual 5G network (or underlying network) entities. For example, the configuration of cloud nodes or network devices that provide actual resources to the actual 5G network can differ from the configuration of applications running using virtualized resources or the devices using those applications.

[0044] refer to Figure 2 In (A), the UPF entity and NG-RAN can be connected via the N3 interface, which is a link through which tunneled GTP-U packets are sent. Each entity using the N3 interface, namely the NG-RAN and UPF entities, may have been abstracted to recognize the N3 interface as a single link. However, although the N3 interface between NG-RAN and UPF is a single link from the perspective of the 5G user plane, from the cloud perspective, actual packets can be transmitted through paths of virtual networks embedded in multiple physical links or devices.

[0045] Figure 2 (B) illustrates a scenario where NG-RAN and UPF operate in different clouds, or where only one of NG-RAN and UPF operates in the cloud. Specifically, it illustrates a scenario where only the portion corresponding to the core network of the mobile communication system operates in the cloud, while the NG-RAN corresponding to the base station operates in another location. In this case, the cloud gateway connecting the public network and the cloud network can additionally perform the operation of deleting packet headers from the virtual network, allowing 5G network packets to operate normally in the public network.

[0046] Additionally, to provide a virtual network, header information for facilitating the processing of virtual network packets can be additionally included using protocols such as Virtual Local Area Networks (VLANs) or Virtual Extended Local Area Networks (VxLANs). When header information for facilitating the processing of virtual network packets is added, the physical network can process packets by referring only to the outermost packet header information. In the following text, reference will be made to... Figure 4 Please describe this in detail.

[0047] Figure 3 The present disclosure illustrates the operation of controlling congestion in a wireless communication system by using explicit congestion notification (ECN) of the transmission control protocol (TCP).

[0048] TCP is a representative protocol that provides transmission control and congestion control functions in the transport layer of a network. TCP is typically used in conjunction with the Internet Protocol (IP) protocol, which resides in the network layer. TCP not only provides transmission control (flow control) and congestion control, but also a variety of other functions, and multiple versions of the algorithms actually provided by TCP exist. In TCP-based network connections, network devices can provide congestion-related information.

[0049] When sending data packets using a TCP connection, the network can indicate that the data packet has experienced congestion in the Explicit Congestion Notification (ECN) field of the IP header by taking into account the network's internal queues, buffers, and resource status. Data packets indicated as experiencing congestion can be transmitted from the transmitter side to the receiver side through network devices, and the receiver side can take appropriate actions based on the congestion situation.

[0050] When the two bits of the ECN field are 00, it indicates that ECN functionality is not used. When the two bits of the ECN field are 10 or 01, the ECN Capability Transmit (ECT) flag can be configured, which means that ECN is supported, but the current load level for sending and receiving packets in the network is normal. When the two bits of the ECN field are 11, the Experienced Congestion (CE) flag can be configured, which means that ECN is supported, but the network load is not at a normal level and it may be difficult to maintain the current bit rate.

[0051] refer to Figure 3 This illustrates the operation of network devices (e.g., switches or routers) on the sending side, receiving side, and between the sending and receiving sides in a TCP-based network connection.

[0052] In Operation 310, the sending and receiving sides can establish a TCP connection and send data packets using TCP. Within the TCP connection, when both the sending and receiving sides are capable of using the ECN function, the sending side can indicate the ECN field in the IP header of the data packets sent to the receiving side. For example, Figure 3 The sending side can mark the ECN field in the IP header of the data packet sent to the receiving side with a bit value of 01 or 10. An ECN field marked with 01 or 10 indicates that the ECT flag is configured.

[0053] In operation 320, network devices such as switches or routers located on the path (through which data packets are transmitted between the sending and receiving sides) can autonomously predict that the network device will be in a congested situation. The network device can read the IP header or TCP header, and when congestion is predicted in network communication, it can mark the ECN field in the IP header of the data packet as 11, thereby configuring an experienced congestion (CE) flag. Therefore, the network device can transmit data packets including the marked ECN field to the receiving side to indicate congestion.

[0054] In operation 330, the receiving side, upon receiving a packet from the network device that includes an ECN field marked 11 indicating the CE flag, can configure the ECN-Echo (ECE) flag in the TCP header of the corresponding uplink packet (e.g., a TCP ACK) and send that uplink packet to the sending side. Therefore, the receiving side can send feedback to the sending side indicating that congestion has occurred.

[0055] In operation 340, the sending side, having received feedback from the receiving side, can identify that congestion has occurred and can perform control operations based on the congestion situation. For example, the sending side, having received feedback from the receiving side including the ECE flag in the TCP header, can reduce the size of the congestion window to decrease the data transmission rate.

[0056] In operation 350, the sending side may send a response message to the receiving side, which includes information indicating that congestion control operations have been performed (e.g., reducing the size of the congestion window according to the ECE field). For example, the sending side may configure the Congestion Window Reduction (CWR) flag in the TCP header of the data transmitted to the receiving side, indicating that the size of the congestion window has been reduced, and then send the data.

[0057] The receiving side can identify that the sending side has performed congestion control operations by receiving packets with the CWR flag configured in the TCP header.

[0058] As mentioned above, the sending side, receiving side, and network devices can use TCP to control network congestion. However, the meanings of the fields and algorithms used in controlling network congestion using TCP can vary depending on the version of TCP used.

[0059] Figure 4 The structure of a user plane packet header in a 5G network running in the cloud, according to an embodiment of the present disclosure, is shown.

[0060] User plane packet headers transmitted over virtual networks can include additional header information to enable smooth transmission over virtual networks. As additional header information, for example, a Virtual Local Area Network (VLAN) field from an extended Ethernet header can be used. Furthermore, as additional header information, Virtual Extensible LAN (VxLAN) can be used, in which a Layer 3 corresponding packet header is added to remove the limitation on the maximum number of virtual networks that VLANs can provide and to provide additional information.

[0061] In the example, when implementing a 5G network in the cloud, VLAN headers for supporting virtual networks and GTP-U headers for tunneling in mobile communication networks can be additionally inserted into the packet headers sent in the N9 interface connecting the UPF entity and another UPF entity, and the N3 interface connecting the UPF entity and the RAN.

[0062] Figure 4 This illustrates the header structure of user plane packets that can be measured in a link of a mobile communication network operating on a virtual network. (Reference) Figure 4 The user plane packets used in the virtual network may include an outer header portion 410 processed in the virtual network, a GTP-U header portion 420 processed in the N3 interface between the UPF entity and the base station, and an actual application packet portion 430 actually used between the transmitting side and the receiving side (e.g., the server and the UE).

[0063] As described above, when packets pass through network devices, in addition to the payload including the actual data and header of the packet being sent, GTP-U and VXLAN headers can also be added. In this case, the virtual network device processing the packet can process the packet by using the outer header including VXLAN located on the outside. Furthermore, packets sent and received by applications in the cloud (such as UPF entities or RANs) can be processed using IP headers including GTP-U, from which the virtual header has been removed. Therefore, in the transmission of packets between the sending and receiving sides, even when the ECN field in the IP header is marked by a network device supporting virtualized networks (e.g., a switch or router) or a device supporting GTP-U, there may be a problem where the ECN field is not delivered to the sending and receiving sides. Moreover, network devices supporting virtualized networks or devices supporting GTP-U cannot determine whether the ECN field is configured to be marked in the VXLAN IP header or in the GTP-U header.

[0064] In the following text, Figures 5 to 10A method for controlling congestion is proposed, wherein network devices supporting virtualized networks (e.g., switches or routers) or devices supporting GTP-U mark an ECN field in the IP header, and the marked ECN field is transmitted to the sending and receiving sides.

[0065] Figure 5 The operation of activating the ECN function according to an embodiment of this disclosure is illustrated. Specifically, Figure 5 The process of activating the ECN function to control congestion through interactions between 5G core network entities, UEs, and base stations is illustrated. The ECN function can refer to either the general term for marking the ECN field in the packet header, or the functionality required to mark the ECN field.

[0066] In Operation 510, the UE can send a PDU session establishment request message to the SMF entity to establish a new PDU session. For example, the UE can send the PDU session establishment request message to the SMF entity through the connected base station and the Access and Mobility Management Function (AMF) entity. The transmission process of the PDU session establishment request message can follow the message transmission procedures and methods in the control plane of the 5G core network. However, this disclosure is not limited thereto.

[0067] According to embodiments of this disclosure, ECN capability information can be included in the PDU session establishment request message. ECN capabilities can include ECN information supported by the service in the UE or PDU session connection. In the example, ECN capability information may specifically include information such as whether ECN functionality is supported in the PDU session connection, the TCP version, whether round-trip time (RTT) based transmission is controllable, and supported transmission or congestion control algorithms. However, the information included in the ECN capabilities is not limited to this, and may include ECN-related information in addition to the information described above. Simultaneously, the PDU session establishment request message may include information about the Data Network Name (DNN) and Single Network Slice Selection Auxiliary Information (S-NSSAI), which are typically included when sending the PDU session establishment request message, and may also include other information for PDU session establishment.

[0068] In Operation 520, the SMF entity can perform operations to determine the PDU session to be established based on the PDU session establishment request message received from the UE. For example, the SMF entity can perform operations such as retrieving data to subscribe to, authenticating the PDU session to be established, selecting a Policy Control Function (PCF) entity, or establishing an SM policy.

[0069] According to embodiments of this disclosure, the SMF entity can determine whether a UE has permission to activate ECN-related functions by including ECN capability information in a PDU session establishment request message. In the example, even if the SMF entity does not explicitly receive ECN capability information through a PDU session establishment request message, the SMF entity can still obtain, based on local data, whether the UE or user has permission to activate ECN-related functions, or requests related to ECN functions from the UE or user.

[0070] In operation 530, the SMF entity can select a UPF entity and path to establish a PDU session requested by the UE. In the example, the SMF entity can select a UPF entity and path that supports ECN functionality based on information received from the UE in operation 510. The SMF entity can obtain candidate UPF entities according to NRF or local policies, and can select an NF profile that supports ECN functionality from the corresponding network function (NF) profiles of the candidate UPF entities. In this case, the SMF entity can select a UPF entity that matches the selected NF profile as the UPF entity used to establish the PDU session.

[0071] In operation 540, the SMF entity can establish an N4 session to transmit information related to actual packet processing to the UPF entity selected in operation 530. The SMF entity can send rules such as Packet Detection Rules (PDR), Forwarding Action Rules (FAR), and QoS Enforcement Rules (QER) as N4 session information to the UPF entity. These rules are used to identify and manage QoS flows that need to be processed in the newly established PDU session.

[0072] According to embodiments of this disclosure, an SMF entity can send ECN activation-related parameters to a UPF entity by including parameters in N4 session information. The ECN activation-related parameters may include a first ECN indicator causing the UPF entity to process the ECN field and a second ECN indicator causing the network device to process the ECN field. The first ECN indicator may be referred to as a 5G ECN indicator, and the second ECN indicator may be referred to as a TN ECN indicator. However, this disclosure is not limited thereto. ECN activation-related parameters can be sent from the SMF entity to the UPF entity by adding new fields to existing PDR, FAR, and QER. However, the method of transmitting ECN activation-related parameters is not limited thereto, and these parameters can be transmitted separately.

[0073] The first ECN indicator can instruct the UPF entity and RAN to mark "11" in the ECN field of the user packet header according to resource conditions to configure the CE flag indicating congestion. For example, when the current link utilization (link usage or link utilization level) of the UPF entity exceeds a certain threshold, the UPF entity can mark the ECN field in the user packet header as "11" to configure the CE flag.

[0074] In the example, when the ECN field is used for both congestion control and Low Latency, Low Loss, and Scalable Throughput (L4S), the first ECN indicator can indicate a change in the ECT flag configuration to prevent incorrect operations. For example, when the ECN field is marked with "01" to indicate L4S service, a conflict may occur depending on whether the service is L4S. Therefore, to avoid conflict, the ECT flag in the ECN field can be modified to "10". When the ECN field is used for both L4S service and congestion control, this conflict prevention operation can be performed in the operation of the UPF entity receiving packets from the server via the N6 interface link, or in the operation of the RAN receiving packets from the UE and transmitting them to the UPF entity via the N3 interface.

[0075] The second ECN indicator can indicate operations related to ECN functionality in the transport network (TN) through which the UPF processes QoS flows or PDU sessions. In the example, to use ECN in the transport network, packets may need to be processed during the generation of additional packet headers, such as VXLAN, so that packets can pass through the virtual network. The second ECN indicator can instruct the UPF entity to configure ECT so that the ECN field in the packet header can be used during packet transmission and reception, and during packet decapsulation in the virtual network, when CE is configured in the outermost header, the CE is copied to the IP header of the innermost user packet. Furthermore, the second ECN indicator can be used when network devices in the virtual network perform ECN marking on packets transmitted and received between the UPF entity and the base station.

[0076] In the example, the SMF entity can send ECN tuning parameters to the UPF entity by adding ECN tuning parameters to the N4 session information. The ECN tuning parameters can include information related to the conditions under which the UPF entity, the RAN, or the transport network equipment between the UPF entity and the RAN performs ECN marking. For example, the ECN tuning parameters can include information about the following conditions: marking a CE with a 30% probability when the buffer of the UPF entity capable of accommodating packets is equal to or greater than 50%; and marking a CE with a 100% probability when the buffer is equal to or greater than 80%. The ECN tuning parameters sent to the UPF entity can specifically include: monitoring parameters for the buffers of the UPF or RAN capable of accommodating packets, a threshold, and a combination of ECN marking probabilities based on the threshold.

[0077] In operation 545, the UPF entity can receive N4 session information from the SMF entity, which includes information such as a first ECN indicator, a second ECN indicator, and ECN tuning parameters. The UPF entity can activate ECN-related functions so that the QoS flow associated with the received information can use the ECN field.

[0078] In Operation 550, when a PDU session is successfully established, the SMF entity can send a PDU session establishment success message to the UE. In the example, the SMF entity can send parameters related to the activation of the ECN function to the base station by including parameters related to the activation of the ECN function in the PDU session establishment success message.

[0079] Alternatively, the SMF entity can send parameters related to the activation of the ECN function by including the parameters related to the activation of the ECN function in the N2 session information sent to the base station via the AMF entity.

[0080] Parameters associated with activating the ECN function may include a first ECN indicator that causes the base station to process the ECN field and a second ECN indicator that causes the network device to process the ECN field. Since the first and second ECN indicators are the same as those transmitted from the SMF entity to the UPF entity in operation 540, a detailed description of these indicators will be omitted.

[0081] In the example, the SMF entity can send ECN tuning parameters by including them in the PDU session establishment success message or N2 information. The ECN tuning parameters sent to the RAN can specifically include a combination of RAN-specific buffer monitoring parameters reflecting buffer size, received signal strength, and user mobility, thresholds, and ECN tagging probabilities based on those thresholds. Since the RAN can consider additional information related to radio resources compared to the UPF entity, the information included in the ECN tuning parameters sent from the SMF entity to the UPF entity can differ from the information included in the ECN tuning parameters sent from the SMF entity to the RAN. That is, the parameters to be monitored to determine whether ECN conditions are met may differ between the UPF entity and the RAN.

[0082] In Operation 555, the RAN can receive information such as a first ECN indicator, a second ECN indicator, and ECN tuning parameters via a PDU session establishment success message or N2 session information. The RAN can activate ECN-related functions to enable QoS flows associated with the received information to use the ECN field. For example, the RAN can perform ECN marking for QoS rules based on the received first ECN indicator. Furthermore, the RAN entity can request the network's devices to perform ECN marking on the ECN field in the headers of transmitted and received packets based on the received second ECN indicator.

[0083] Based on the above operations, UPF entities and base stations can activate the ECN function in a virtualized network environment. Subsequently, when performing uplink or downlink data communication, UPF entities and base stations can, based on the activated ECN function, mark the ECN field in packets according to the congestion state. In the following text, reference will be made to... Figures 6 to 7 Provide a detailed description.

[0084] Figure 6 The operation of performing downlink transmission according to an embodiment of this disclosure is illustrated.

[0085] refer to Figure 6 In Operation 605, the UE, server, RAN (or base station) of the 5G network, UPF, and network devices (e.g., switches or routers) used in the virtualized network can activate ECN-related functions to enable ECN marking on the ECN field of the header in sent and received packets. In Operation 605, the process for each device to activate ECN-related functions can follow... Figure 5 The process of activating the ECN function.

[0086] In Operation 610, the server can send downlink (DL) data to the UPF via the N6 interface. In the example, the ECN field of the downlink data can be marked as 01 or 10. An ECN field marked as 01 or 10 indicates that the ECT flag is configured. The server can send downlink data configured with the ECT flag to the UPF entity.

[0087] In Operation 615, the UPF entity receiving packets via the N6 interface can execute the ECN function-related algorithm of the UPF entity, and based on the result, can mark the ECN field in the IP header of the packet as 11, thereby configuring the CE flag. In this case, the standard used by the UPF entity to perform ECN marking in the IP header of downlink data packets can be based on the ECN tuning parameters received by the UPF entity from the SMF entity. For example, the UPF entity can base its algorithm on... Figure 5 The ECN tuning parameters received in operation 540 are used to perform ECN tagging.

[0088] In the example, when a function that uses the ECN field (such as L4S) is activated in a mobile communication network, the UPF entity can configure the ECT flag in 01 or 10 with a field value different from the field value configured by L4S to prevent conflicts with the ECN field marked in the IP header of the downlink data packets.

[0089] In the example, an additional outer header, such as VXLAN, can be appended to packets of downlink data sent by the UPF entity to the base station, enabling virtual network devices or network interface devices running virtual machines or virtual containers of the UPF entity to send packets to the base station from within the virtual network. In the example, when the second ECN indicator received from the SMF entity in operation 605 is true, the UPF entity can perform ECN marking in the IP header of the additionally appended VXLAN header, marking it as 01 or 10, indicating the ECT flag.

[0090] In Operation 620, the UPF entity can encapsulate downlink data to transmit it to the base station via a virtual network. In mobile communication networks, the virtual network can be abstracted as the N3 interface using a GTP-U tunnel.

[0091] In operation 625, when a received downlink data packet meets the conditions related to ECN, the virtual network device located between the UPF entity and the base station can perform ECN marking on the packet based on the virtual network device's algorithm. For example, when the IP header of a data packet received from the UPF entity is marked with ECN as ECT (01) or ECT (10), the virtual network device, such as a virtual switch or virtual router located between the UPF entity and the base station, can perform ECN marking on the outer header of the packet using the virtual network device's algorithm, marking it as CE (11). Here, the outer header can refer to the actual application packet (e.g., such as...). Figure 4 (as indicated by reference numeral 430 in the attached figures) and GTP-U header (e.g., as shown in the attached figures) Figure 4 (As indicated by reference numeral 420 in the attached figure) the outer header. For example, the outer header may refer to... Figure 4 The outer header 410 used for virtual networks.

[0092] In Operation 630, the virtual network device can transmit downlink data that has been encapsulated by the UPF entity to the base station.

[0093] In Operation 635, the base station can receive downlink data already encapsulated by the UPF entity from the virtual network. The base station can remove packet headers such as VXLAN, which are added by the UPF entity, to allow data to be sent to the base station via the virtual network.

[0094] The downlink data received by the base station may have an ECN field in the outer header, which has been marked as CE by the virtual network device (11). In the example, the base station operates under 605 (specifically, for example, in...). Figure 5 In operation 550), if a second ECN indicator is received from an SMF entity, when the second ECN indicator is true, the base station can copy the ECN field value of the outer header of the downlink data packet that has been marked as CE (11) to the IP header of the GTP-U header. The base station's copying operation can be performed when the base station removes the packet header (such as VXLAN) that has been added to the encapsulated downlink data packet.

[0095] In the example, the base station can remove the GTP-U header from a packet whose outer header (such as VXLAN) has been removed, according to the base station's algorithm, and perform operations to send the packet to the UE via the radio interface. In the example, the base station can perform ECN marking in the inner header of the packet to be sent to the UE, marking it as CE (11), based on the base station's algorithm or based on the ECN tuning parameters transmitted from the SMF entity via the AMF entity in operation 605. Here, the inner header can refer to the header portion corresponding to the actual application packet (e.g., such as...). Figure 4(As indicated by reference numeral 430 in the attached figure).

[0096] In operation 640, the base station may send downlink data to the UE. In the example, the downlink data sent by the base station to the UE may be a packet whose inner header is marked with ECN as CE(11).

[0097] In operation 645, a UE receiving downlink data from a base station can identify an ECN field marked in the inner header of the downlink data packet. In the example, the UE can control congestion based on the value of the identified ECN field. For example, a UE that identifies an ECN field marked as CE (11) in the inner header can perform congestion control operations, such as reducing the size of the congestion window.

[0098] As described above, when congestion is anticipated based on network conditions, the ECN field can be marked in the data sent and received between the UE and the server to explicitly identify the congestion situation. Therefore, the UE can perform congestion control operations based on the congestion situation to prevent congestion in advance.

[0099] Figure 7 The operation of performing uplink transmission according to an embodiment of this disclosure is illustrated.

[0100] refer to Figure 7 In Operation 705, devices in the UE, server, 5G network RAN ​​(or base station), UPF, and virtualized transport network (e.g., switches or routers) can activate ECN-related functions to enable ECN marking on the ECN field of the header in sent and received packets. In Operation 605, the process for each device to activate ECN-related functions can follow... Figure 5 The process of activating the ECN function.

[0101] In operation 710, the UE can send uplink (UL) data to the base station. In the example, the ECN field of the uplink data can be marked as 01 or 10. An ECN field marked as 01 or 10 can indicate that the ECT flag is configured. The UE can then send downlink data with the ECT flag configured to the base station.

[0102] In Operation 715, the base station (or RAN) receiving packets from the UE can execute the base station's ECN function-related algorithm and, based on the result, mark the ECN field in the packet's IP header as 11, thereby configuring the CE flag. In this case, the standard by which the base station performs ECN marking in the IP header of uplink data packets can be based on ECN tuning parameters received by the base station from the SMF entity. For example, the UPF entity can base it on... Figure 5 The ECN tuning parameters received in operation 550 are used to perform ECN tagging.

[0103] In the example, when a function that uses the ECN field (such as L4S) is activated in a mobile communication network, the base station can configure the ECT flag in 01 or 10 with a field value different from the field value configured by L4S to prevent conflicts with the ECN field marked in the IP header of uplink data packets.

[0104] In the example, an additional outer header such as VXLAN can be appended to packets of downlink data sent by the base station to the UPF entity, enabling virtual network devices or network interface devices running virtual machines or virtual containers of the UPF entity to send packets to the UPF entity from within the virtual network. In the example, when the second ECN indicator received from the SMF entity in operation 605 is true, the base station can perform ECN marking in the IP header of the VXLAN header additionally appended to the uplink data packet, marking it as ECT(01) or ECT(10).

[0105] In Operation 720, the base station can encapsulate uplink data to transmit it to the UPF entity via a virtual network. In mobile communication networks, the virtual network can be abstracted as the N3 interface using a GTP-U tunnel.

[0106] In operation 725, when a received uplink data packet meets the conditions related to ECN, the virtual network device located between the UPF entity and the base station can perform ECN marking on the packet based on the virtual network device's algorithm. For example, when the IP header of an uplink data packet received from the base station is marked with ECN as ECT(01) or ECT(10), the virtual network device, such as a virtual switch or virtual router located between the UPF entity and the base station, can perform ECN marking on the ECN field in the outer header of the packet (marking the ECN field as CE(11)) by using the virtual network device's algorithm. Here, the outer header can refer to the actual application packet (e.g., such as...). Figure 4 (as indicated by reference numeral 430 in the attached figures) and GTP-U header (e.g., as shown in the attached figures) Figure 4 (As indicated by reference numeral 420 in the attached figure) the outer header. For example, the outer header may refer to... Figure 4 The outer header 410 used for virtual networks.

[0107] In Operation 730, the virtual network device can transmit uplink data that has already been encapsulated by the base station to the UPF entity.

[0108] In Operation 735, the UPF entity can receive uplink data that has already been encapsulated by the base station from the virtual network. The UPF entity can remove packet headers such as VXLAN, which are added by the base station, to send data to the UPF entity through the virtual network.

[0109] The uplink data received by the UPF entity may have an ECN field in the outer header, which has been marked as CE by the virtual network device (11). In the example, the UPF entity is in operation 605 (specifically, for example, in Figure 5 In operation 540), if a second ECN indicator is received from the SMF entity, when the second ECN indicator is true, the UPF entity can copy the ECN field value of the outer header of the uplink data packet that has been marked as CE (11) to the IP header of the GTP-U header. The copy operation of the UPF entity can be performed when the UPF entity removes the packet header (such as VXLAN) that has been added to the encapsulated uplink data packet.

[0110] In the example, the UPF entity can remove the GTP-U header from a packet whose outer header (such as VXLAN) has been removed, according to the UPF entity's algorithm, and perform operations to send the packet to the data network (DN) (or a server in the data network) via the N6 interface. In the example, the UPF entity can perform ECN marking in the inner header of the packet to be sent to the UE, marking it as CE (11), based on the UPF entity's algorithm or based on the ECN tuning parameters transmitted from the SMF entity in operation 605. Here, the inner header can refer to the header portion corresponding to the actual application packet (e.g., such as...). Figure 4 (As indicated by reference numeral 430 in the attached figure).

[0111] In operation 740, the UPF entity can send uplink data to the data network. In the example, the uplink data sent by the UPF entity to the data network can be a packet with an inner header marked as CE(11) by ECN.

[0112] In Operation 745, a server in the data network receiving uplink data from a UPF entity can identify the ECN field marked in the inner header of the uplink data packet. In the example, the server in the data network can control congestion based on the identified ECN field value.

[0113] As described above, when congestion is anticipated based on network conditions, the ECN field can be marked in the data sent and received between the UE and the server to explicitly identify the congestion situation. Therefore, the server in the data network can perform congestion control operations to proactively prevent congestion based on the congestion situation.

[0114] Figure 8 The operation of performing congestion control by using transmission control rules according to an embodiment of this disclosure is illustrated.

[0115] When using protocols that support flow control (current control) and congestion control (such as TCP or Quick UDP Internet Connection (QUIC)), networks can efficiently resolve or prevent congestion by detecting it or transmitting information indicating congestion. When using TCP for congestion control, the size of the TCP congestion control window must first be determined. Methods for determining the size of the TCP congestion control window include: the additive increase-multiplicative decrease (AIMD) method (calculating by increasing or decreasing the data rate as it exceeds or falls below a threshold); or a method that utilizes round-trip time (RTT), using the minimum RTT (RTT_min) and bandwidth information for calculation.

[0116] Network operators can drop packets, configure ECN fields in sent and received data packets, or intentionally delay packets to address situations such as increased traffic, resource exhaustion, or congestion.

[0117] According to embodiments of this disclosure, in addition to data processing rules such as Packet Detection Rules (PDR), Forwarding Action Rules (FAR), and QoS Enforcement Rules (QER), Flow Control Rules (FCRs) can also be defined to configure actions to be performed to address specific situations, such as increased traffic, resource exhaustion, or congestion. PDRs can define FCRs by restricting the specifications of the target services for which FCRs need to be applied. Table 1 below describes a structure in which identifiers for FCRs are added to enable service flows corresponding to PDRs defined in 3GPP to apply FCRs. However, FCRs can be defined not only as a method of defining new rules separately from existing rules, but also as a method of adding the action conditions and action content of FCRs to existing rules.

[0118] [Table 1]

[0119] Table 2 describes information about the FCR. The FCR may include information about the performance indicators or parameters that need to be monitored, the conditions used to perform the action, and the action or action ID to be applied.

[0120] [Table 2]

[0121] The performance indicators or parameters that need to be monitored may include, for example, buffer size, buffer usage, overall queuing delay, and CPU / memory usage. The conditions for performing an action can be configured as a combination of the performance indicators or parameters that need to be monitored. When the conditions for performing an action are met, the defined action can be performed. For example, when the total queuing delay exceeds 1 ms, the action of marking the CE (11) indicating congestion in the ECN field of the header of the transmitted and received data packets can be performed with a 50% probability.

[0122] Figure 8 This illustrates a method for controlling QoS, TCP, or QUIC flows using the FCR described above. (Reference) Figure 8 In operation 805, the UE can send a PDU session establishment request message to the SMF entity to establish a new PDU session. For example, the UE can send the PDU session establishment request message to the SMF entity through the connected base station and the Access and Mobility Management Function (AMF) entity. The transmission process of the PDU session establishment request message can follow the message transmission procedures and methods in the control plane of the 5G core network. However, this disclosure is not limited thereto.

[0123] According to embodiments of this disclosure, the PDU session establishment request message may include information such as the TCP or QUIC version supported by the UE, whether ECN functionality is supported in the PDU session connection, and RTT-based queue control indicators. This information may be necessary for communication between the UE and network entities, but not all information needs to be included in the PDU session establishment request message, and it may be selectively included. Furthermore, this information may differ from... Figure 5 Operation 510 includes information in the PDU session establishment request message. Furthermore, the PDU session establishment request message may include information about the DNN and S-NSSAI, which is typically included when sending the PDU session establishment request message, and may also include other information for PDU session establishment.

[0124] In operation 810, the SMF entity can perform operations to determine the PDU session to be established based on the PDU session establishment request message received from the UE. For example, the SMF entity can perform operations such as retrieving data to subscribe to, authenticating the PDU session to be established, selecting a Policy Control Function (PCF) entity, or establishing an SM policy.

[0125] In Operation 815, the SMF entity can generate PDRs and FCRs for QoS flows that may exist in a PDU session for volume control or congestion control. The SMF entity can generate PDRs and FCRs by adding an identifier for the FCR to the existing 3GPP-defined PDRs as shown in Table 1 above, and by defining the monitoring parameters, conditions, and actions for the FCR as shown in Table 2. Figure 5 The SMF entities are different. Figure 8 The SMF entity can define FCR as a new data control rule and can also define additional information related to FCR in PDR for use with FCR. UPF entities and base stations that apply FCR or similar new data control rules configured by the SMF entity can perform operations to control the amount of data transmitted by monitoring data transmission according to the rules.

[0126] Furthermore, the SMF entity can select a UPF entity and path to establish a PDU session requested by the UE. In the example, the SMF entity can select a UPF entity and path that supports ECN functionality based on information received from the UE in Operation 805. The SMF entity can obtain candidate UPF entities based on NRF or local policies and can select an NF profile that supports ECN functionality from the corresponding Network Function (NF) profiles of the candidate UPF entities. In this case, the SMF entity can select a UPF entity that matches the selected NF profile as the UPF entity used to establish the PDU session.

[0127] In operation 820, the SMF entity can establish an N4 session to transmit information related to actual packet processing to the UPF entity selected in operation 815. The SMF entity can send rules such as Forwarding Action Rules (FAR) and QoS Enforcement Rules (QER) (which are used to identify and manage QoS flows that need to be processed in the newly established PDU session) as N4 session information to the UPF entity, as well as rules such as PDR and FCR generated in operation 815.

[0128] In the example, the SMF entity can send ECN activation-related parameters to the UPF entity by including the parameters in the N4 session information. The ECN activation-related parameters may include a first ECN indicator that causes the UPF entity to process the ECN field and a second ECN indicator that causes the network device to process the ECN field. The first ECN indicator may be referred to as a 5G ECN indicator, and the second ECN indicator may be referred to as a TN ECN indicator. However, this disclosure is not limited thereto. ECN activation-related parameters can be sent from the SMF entity to the UPF entity by adding new fields to the existing PDR, FAR, and QER. However, the method of transmitting ECN activation-related parameters is not limited thereto, and these parameters can be transmitted separately.

[0129] The first ECN indicator can instruct the UPF entity and RAN to mark "11" in the ECN field of the user packet header according to resource conditions to configure the CE flag indicating congestion. For example, when the current link utilization (link usage or link utilization level) of the UPF entity exceeds a certain threshold, the UPF entity can mark the ECN field in the user packet header as "11" to configure the CE flag.

[0130] In the example, when the ECN field is used for both congestion control and Low Latency, Low Loss, and Scalable Throughput (L4S), the first ECN indicator can indicate a change in the ECT flag configuration to prevent incorrect operations. For example, when the ECN field is marked with "01" to indicate L4S service, a conflict may occur depending on whether the service is L4S. Therefore, to avoid conflict, the ECT flag in the ECN field can be modified to "10". When the ECN field is used for both L4S service and congestion control, this conflict prevention operation can be performed in the operation of the UPF entity receiving packets from the server via the N6 interface link, or in the operation of the RAN receiving packets from the UE and transmitting them to the UPF entity via the N3 interface.

[0131] The second ECN indicator can indicate operations related to ECN functionality in the transport network (TN) through which the UPF processes QoS flows or PDU sessions. In the example, to use ECN in the transport network, packets may need to be processed during the generation of additional packet headers, such as VXLAN, so that packets can pass through the virtual network. The second ECN indicator can instruct the UPF entity to configure ECT so that the ECN field in the packet header can be used during packet transmission and reception, and during packet decapsulation in the virtual network, when CE is configured in the outermost header, the CE is copied to the IP header of the innermost user packet. Furthermore, the second ECN indicator can be used when network devices in the virtual network perform ECN marking on packets transmitted and received between the UPF entity and the base station.

[0132] In the example, the SMF entity can send ECN tuning parameters to the UPF entity by adding ECN tuning parameters to the N4 session information. The ECN tuning parameters can include information related to the conditions under which the UPF entity, the RAN, or the transport network equipment between the UPF entity and the RAN performs ECN marking. For example, the ECN tuning parameters can include information about the following conditions: marking a CE with a 30% probability when the buffer of the UPF entity capable of accommodating packets is equal to or greater than 50%; and marking a CE with a 100% probability when the buffer is equal to or greater than 80%. The ECN tuning parameters sent to the UPF entity can specifically include: monitoring parameters for the buffers of the UPF or RAN capable of accommodating packets, thresholds, and a combination of ECN marking probabilities based on the thresholds.

[0133] In operation 825, when a PDU session is successfully established, the SMF entity can send a PDU session establishment success message to the UE. In the example, the SMF entity can send ECN function activation-related parameters to the base station by including the ECN function activation-related parameters sent in operation 820 in the PDU session establishment success message.

[0134] Alternatively, the SMF entity can send parameters related to the activation of the ECN function by including the parameters related to the activation of the ECN function in the N2 session information sent to the base station via the AMF entity.

[0135] In the example, the SMF entity can send ECN tuning parameters by including them in the PDU session establishment success message or N2 information. The ECN tuning parameters sent to the RAN can specifically include a combination of RAN-specific buffer monitoring parameters reflecting buffer size, received signal strength, and user mobility, a threshold, and an ECN tagging probability based on the threshold. Because the RAN can additionally consider radio resource-related information compared to the UPF entity, the information included in the ECN tuning parameters sent by the SMF entity to the UPF entity in operation 820 and the information included in the ECN tuning parameters sent by the SMF entity to the RAN in operation 825 can differ. That is, the parameters to be monitored to determine whether ECN conditions are met may differ between the UPF entity and the RAN.

[0136] In the example, the SMF entity may additionally send information related to the parameters, conditions, and actions to be performed when the conditions are met in the PDU session establishment success message or N2 information, concerning packets in the target QoS flow. In this case, the information sent may include information different from the monitoring parameters, conditions, and actions included in the FCR sent from the SMF entity to the UPF entity in operation 820.

[0137] In operation 830, in addition to the method of sending a PDU session establishment success message or separate N2 session information in operation 825, the SMF entity may send a message requesting modification of the PDU session by including a first ECN indicator, a second ECN indicator, ECN tuning parameters, and rules for performing congestion control.

[0138] Operations 825 and 830 are not consecutive operations, and... Figure 8 The diagram illustrates a method for sending a first ECN indicator, a second ECN indicator, ECN tuning parameters, and rules for performing congestion control to a base station. The SMF can transmit the first ECN indicator, the second ECN indicator, the ECN tuning parameters, and the rules for performing congestion control to the base station via at least one of operations 825 or 830, so as to transmit the same information to the base station.

[0139] Subsequently, when uplink or downlink data is transmitted and received between the UE, base station, and core network entities, an operation can be performed to display and indicate congestion control status. This operation is related to the aforementioned... Figure 6 and Figure 7 The operations are the same as those in the previous section, so a detailed description of them will be omitted.

[0140] In Operation 835, the UPF entity, having received congestion control-related rules from the SMF entity, can apply these rules to QoS flows. The UPF entity can then detect resource conditions based on these rules. For example, the UPF entity can detect resources such as buffer size, buffer usage, overall queuing latency, and CPU / memory usage based on the received FCR, and in particular, can detect situations where the overall queuing latency exceeds 1 ms.

[0141] In operation 840, when the conditions defined in the rules related to congestion control are met, the UPF entity may perform the actions defined in the rules related to congestion control. The types of actions may include, for example, packet hold-up time configuration, ECN marking, or random packet dropping. In the example, when a condition defined in the FCR occurs where the overall queuing delay exceeds 1 ms, the UPF entity may perform the action of marking the CE (11) indicating the congestion condition in the ECN field of the header of the transmitted and received data packets with a 50% probability.

[0142] In operation 845, similar to the operation of the UPF entity in operation 835, the base station, having received congestion control-related rules from the SMF entity, can apply these rules to QoS flows. The base station can detect resource conditions based on the rules. However, the congestion control-related rules received by the base station may differ from those received by the UPF entity. Furthermore, the base station can limit the QoS flows to be detected based on the QoS Flow Identifier (QFI) received in operation 825 or operation 830.

[0143] In Operation 850, similar to the operation of the UPF entity in Operation 850, the base station may execute actions defined in the rules related to congestion control when the conditions defined in the rules related to congestion control are met. The types of actions may include, for example, packet hold-up time configuration, ECN marking, or random packet dropping.

[0144] UPF entities or base stations can detect anticipated traffic increases, resource exhaustion, or congestion occurrences through rules related to congestion control, and can control congestion or transmission volume in these situations to efficiently prevent congestion in the network. Therefore, the network can prevent problems that may arise due to congestion, such as degraded service quality and service delays.

[0145] Figure 9 The operation of a User Plane Function (UPF) entity according to an embodiment of this disclosure is illustrated.

[0146] In operation 910, the UPF entity can receive N4 session information, including an ECN activation indicator and ECN tuning parameters, from the SMF entity. In this case, the UPF entity receiving the ECN activation indicator and ECN tuning parameters from the SMF entity can refer to the UPF entity selected based on ECN information supported in the PDU session connection, which is received by the SMF entity from the UE. In the example, the ECN information supported in the PDU session connection can include at least one of the following: whether the UE supports ECN, information related to the Transmission Control Protocol (TCP) version, or whether round-trip time (RTT) based transmission is controlled.

[0147] According to embodiments of this disclosure, the ECN activation indicator may include a first ECN indicator and a second ECN indicator. The first ECN indicator may instruct a UPF entity or base station to perform ECN marking in the ECN field of the inner header of a data packet, the ECN marking indicating whether congestion exists. The second ECN indicator may instruct the UPF entity or base station to: perform ECN marking in the ECN field of the outer header of a data packet, the ECN marking indicating whether congestion exists; or copy the value of the ECN mark in the ECN field of the outer header to the ECN field of the inner header.

[0148] ECN tuning parameters may include information related to the conditions under which transport network devices, such as UPF entities, RANs, or between UPF entities and RANs, perform ECN tagging.

[0149] In Operation 920, the UPF entity can identify the QoS flow to which ECN-related functions should be applied based on the ECN activation indicator received from the SMF entity.

[0150] In Operation 930, UPF entities can perform data communication based on ECN activation indicators and ECN tuning parameters.

[0151] In the example, the UPF entity can receive downlink data from the server. Subsequently, the UPF entity receiving packets via the N6 interface can execute the ECN function-related algorithm of the UPF entity, and based on the result, mark the ECN field in the packet's IP header as 11, thereby configuring the CE flag. To send downlink data to the base station via the virtual network, the UPF entity can encapsulate the downlink data and send the encapsulated downlink data to the base station.

[0152] In the example, the UPF entity can receive uplink data from the base station via a virtual network. The UPF entity can remove packet headers (such as VXLAN headers) that are added by the base station to send data to the UPF entity via the virtual network. Furthermore, when the second ECN indicator is true, the UPF entity can copy the ECN field value of the outer header of the uplink data packet, which has already been marked as CE (11), to the IP header of the GTP-U header. Thereafter, the UPF entity can perform ECN marking as CE (11) in the inner header of the packet to be transmitted to the UE based on the UPF entity's algorithm or based on the ECN tuning parameters transmitted from the SMF entity in operation 910. The UPF entity can send uplink data to the server of the data network, on which the inner header is marked as CE by ECN.

[0153] Figure 10 The operation of a UE according to an embodiment of this disclosure is illustrated.

[0154] In Operation 1010, the UE can send a PDU session establishment request message to the SMF entity via the base station. The PDU session establishment request message includes ECN information that can be supported in the PDU session connection.

[0155] In Operation 1020, the UE can receive a PDU session establishment response message, including an ECN activation indicator and ECN tuning parameters, from the SMF entity via the base station.

[0156] According to embodiments of this disclosure, the ECN activation indicator may include a reference Figure 9 The first ECN indicator and the second ECN indicator described in operation 920. Since the description of the first ECN indicator and the second ECN indicator has already been provided above, the description of the first ECN indicator and the second ECN indicator is omitted.

[0157] In Operation 1030, the UE can perform data communication based on the received PDU session establishment response message.

[0158] In the example, the UE can receive downlink data from the server via a UPF entity and a base station connected through a virtual network. The downlink data received by the UE may be packets whose inner header ECN is marked as CE (11) by the base station. The UE can identify the ECN field marked in the inner header of the downlink data packets and can control congestion based on the value of the ECN field. For example, a UE that identifies an ECN field marked as CE (11) in the inner header can perform congestion control operations, such as reducing the size of the congestion window.

[0159] In the example, the server of the data network can receive uplink data from the UE via a UPF entity and a base station connected through a virtual network. The uplink data received by the server can be packets in which the UPF entity marks the inner header ECN as CE (11). The server can identify the ECN field marked in the inner header of the uplink data packets and can control congestion based on the value of the ECN field.

[0160] Figure 11 The structure of a core network entity according to an embodiment of this disclosure is shown.

[0161] A network entity according to embodiments of this disclosure may include a processor 1120 for controlling the overall operation of the network entity, a transceiver 1100 including a transmitter and a receiver, and a memory 1110. Of course, the examples given above are not limiting, and a network entity may include more than […]. Figure 11 The number of components shown is less or more.

[0162] According to embodiments of this disclosure, transceiver 1100 can transmit / receive signals with at least one of other network entities or UEs. Signals transmitted / received with at least one of other network entities or UEs may include control information and data.

[0163] According to embodiments of this disclosure, processor 1120 can control network entities to perform operations according to any of the above embodiments. Of course, processor 1120, memory 1110, and transceiver 1100 are not necessarily implemented as separate modules, but can be implemented as a single component unit, such as a single chip. Furthermore, processor 1120 and transceiver 1100 can be electrically connected to each other. Additionally, processor 1120 can be an application processor (AP), a communication processor (CP), a circuit, a dedicated circuit, or at least one processor.

[0164] According to embodiments of this disclosure, memory 1110 may store basic programs, application programs, and data (such as configuration information) for the operation of network entities. Specifically, memory 1110 provides the stored data upon request from processor 1120. Memory 1110 may include storage media (such as ROM, RAM, hard disk, CD-ROM, and DVD) or combinations of storage media. Furthermore, memory 1110 may include multiple memories. Additionally, processor 1120 may execute the above embodiments of this disclosure based on programs stored in memory 1110 for executing embodiments.

[0165] Figure 12 The structure of a base station 1200 according to various embodiments of the present disclosure is shown.

[0166] refer to Figure 12The base station 1200 includes a communication unit 1210, a memory 1220, and a controller 1230.

[0167] Communication unit 1210 performs functions for transmitting / receiving signals via a wireless channel. For example, communication unit 1210 performs conversion between baseband signals and bit strings according to the system's physical layer specifications. For instance, during data transmission, communication unit 1210 generates complex symbols by encoding and modulating the transmitted bit stream. Furthermore, during data reception, communication unit 1210 demodulates and decodes the baseband signal to recover the received bit string. Additionally, wireless communication unit 1210 up-converts the baseband signal to a radio frequency (RF) band signal, transmits the up-converted RF band signal via an antenna, and then down-converts the RF band signal received via the antenna back to a baseband signal.

[0168] Therefore, the wireless communication unit 1210 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a digital-to-analog converter (DAC), an analog-to-digital converter (ADC), etc. Furthermore, the communication unit 1210 may include multiple transmit / receive paths. Additionally, the wireless communication unit 1210 may include at least one antenna array comprising multiple antenna elements. In terms of hardware, the wireless communication unit 1210 may include digital and analog units, and the analog unit may include multiple sub-units depending on operating power, frequency, etc.

[0169] Communication unit 1210 can transmit / receive signals. For this purpose, communication unit 1210 may include at least one transceiver. For example, communication unit 1210 can transmit synchronization signals, reference signals, system information, messages, control information, data, etc. Furthermore, communication unit 1210 can perform beamforming.

[0170] As described above, the communication unit 1210 transmits and receives signals. Therefore, all or part of the communication unit 1210 may be referred to as a "transmitter," a "receiver," or a "transceiver." Furthermore, as used in the following description, "transmission and reception performed via a wireless channel" includes the meaning of the above-described processing performed by the communication unit 1210.

[0171] Memory 1220 may store basic programs, application programs, and data (such as configuration information) for the operation of the base station. Memory 1220 may include storage. Storage unit 1220 may include volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Furthermore, memory 1220 provides the stored data upon request from controller 1230.

[0172] The controller 1230 controls the overall operation of the base station 1200. For example, the controller 1230 sends / receives signals through the communication unit 1210. Furthermore, the controller 1230 records data in the memory 1220 and reads data from the memory 1220. Additionally, the controller 1230 can perform the functions of the protocol stack required by the communication specification. For this purpose, the controller 1230 may include at least one processor.

[0173] Figure 12 The structure of the base station 1200 shown is merely an example of a base station, and examples of base stations used to perform the various embodiments of this disclosure are not limited to this. Figure 12 The structure shown is illustrated. That is, according to various embodiments of this disclosure, some components can be added, deleted, or modified.

[0174] exist Figure 12 In this disclosure, base station 1200 is described as a single entity, but the present disclosure is not limited thereto. In addition to integrated deployment, base station 1200 according to various embodiments of the present disclosure can be implemented to construct an access network with a distributed deployment. According to embodiments, the base station can be divided into a central unit (CU) and a digital unit (DU), the CU can be implemented to perform upper-layer functions (e.g., Packet Data Convergence Protocol (PDCP) and RRC), and the DU can be implemented to perform lower-layer functions (e.g., Media Access Control (MAC) and Physical (PHY)). The DUs of the base station can form beam coverage over the radio channel.

[0175] Figure 13 The structure of UE 1300 according to various embodiments of the present disclosure is shown.

[0176] Figure 13 The structure shown can be understood as the structure of UE 1300. As used herein, terms such as “...unit” or “...device” can refer to a unit configured to perform at least one function or operation and can be implemented as hardware, software or a combination of hardware and software.

[0177] refer to Figure 13 The UE 1300 may include a communication unit 1310, a memory 1320, and a controller 1330.

[0178] Communication unit 1310 performs functions for transmitting / receiving signals via a wireless channel. For example, communication unit 1310 performs conversion between baseband signals and bit strings according to the system's physical layer specifications. For instance, during data transmission, communication unit 1310 generates complex symbols by encoding and modulating the transmitted bit stream. Furthermore, during data reception, communication unit 1310 demodulates and decodes the baseband signal to recover the received bit string. Additionally, communication unit 1310 up-converts the baseband signal to an RF band signal, transmits the RF band signal through an antenna, and down-converts the RF band signal received through the antenna back to a baseband signal. For example, communication unit 1310 may include a transmit filter, a receive filter, an amplifier, a mixer, an oscillator, a DAC, and an ADC.

[0179] Furthermore, communication unit 1310 may include multiple transmit / receive paths. Additionally, communication unit 1310 may include antenna elements. Communication unit 1310 may include at least one antenna array configured with multiple antenna elements. In terms of hardware, communication unit 1310 may include digital and analog circuitry (e.g., radio frequency integrated circuits (RFICs)). Here, the digital and analog circuitry may be configured in a single package. Furthermore, communication unit 1310 may include multiple RF chains. Communication unit 1310 may perform beamforming. In order to assign directivity to the signal to be transmitted / received based on the configuration of controller 1330, communication unit 1310 may apply beamforming weights to the signal. According to an embodiment, communication unit 1310 may include a radio frequency (RF) block (or RF unit). The RF block may include a first RF circuitry associated with an antenna and a second RF circuitry associated with baseband processing. The first RF circuitry may be referred to as an RF antenna (RF-A). The second RF circuitry may be referred to as an RF baseband (RF-B).

[0180] Furthermore, the communication unit 1310 can transmit / receive signals. For this purpose, the communication unit 1310 may include at least one transceiver. The communication unit 1310 can receive downlink signals. Downlink signals may include synchronization signals (SS), reference signals (RS) (e.g., demodulation (DM)-RS or phase tracking reference signals (PTRS)), system information (e.g., MIB, SIB, residual system information (RMSI) or other system information (OSI)), configuration messages, control information, downlink data, etc. The communication unit 1310 can transmit uplink signals. Uplink signals may include random access related signals (e.g., random access preamble (RAP) (or message 1 (Msg1)), message 3 (Msg3)), reference signals (e.g., sounding reference signals (SRS), DMRS, or PTRS), power headroom reports (PHR), etc.

[0181] Furthermore, the communication unit 1310 may include different communication modules to process signals in different frequency bands. Additionally, the communication unit 1310 may include multiple communication modules to support a variety of different wireless access technologies. For example, different radio access technologies may include Bluetooth Low Energy (BLE), Wi-Fi, Wi-Fi Gigabit (WiGig), cellular networks (e.g., Long Term Evolution (LTE)), New Radio (NR), etc. Furthermore, different frequency bands may include ultra-high frequency (SHF) bands (e.g., 2.5 GHz or 5 GHz bands), millimeter wave (mmWave) bands (e.g., 38 GHz or 60 GHz bands), etc. Moreover, the communication unit 1310 can use the same wireless access technology scheme in different frequency bands (e.g., unlicensed bands for Licensed Assisted Access (LAA) and Citizen Broadband Radio Service (CBRS) (e.g., 3.5 GHz)).

[0182] As described above, the communication unit 1310 transmits and receives signals. Therefore, all or part of the communication unit 1310 may be referred to as a "transmitter," a "receiver," or a "transceiver." Furthermore, as used in the following description, "transmission and reception performed via a wireless channel" includes the meaning of the above-described processing performed by the communication unit 1310.

[0183] Memory 1320 may store basic programs, application programs, and data (such as configuration information) for the operation of UE 1300. Memory 1320 may include volatile memory, non-volatile memory, or a combination of volatile memory and non-volatile memory. Furthermore, memory 1320 provides the stored data upon request from controller 1330.

[0184] Controller 1330 controls the overall operation of UE 1300. For example, controller 1330 sends / receives signals via communication unit 1310. Furthermore, controller 1330 records data in memory 1320 and reads data from memory 1320. Additionally, controller 1330 can perform the functions of the protocol stack required by the communication specification. For this purpose, controller 1330 may include at least one processor. Controller 1330 may include at least one processor or microprocessor, or may be part of a processor. Furthermore, communication unit 1310 and a portion of controller 1330 may be referred to as a communication processor (CP). Controller 1330 may include various modules for performing communication. According to various embodiments, controller 1330 can control the UE to perform operations according to various embodiments.

[0185] The embodiments described and illustrated in the specification and accompanying drawings are merely specific examples presented to facilitate the explanation of the technical content of the embodiments of the present disclosure and to aid in the understanding of the embodiments of the present disclosure, and are not intended to limit the scope of the embodiments of the present disclosure. That is, it will be apparent to those skilled in the art that other variations based on the technical concept of the present disclosure can be implemented. Furthermore, the various embodiments described above can be used in combination as needed.

[0186] As described above, a method performed by a User Plane Function (UPF) entity in a wireless communication system according to various embodiments disclosed herein may include: receiving N4 session information from a Session Management Function (SMF) entity, the N4 session information including an Explicit Congestion Notification (ECN) activation indicator and ECN tuning parameters; identifying an activated QoS flow for which ECN-related functions are to be applied based on the ECN activation indicator; and performing data communication based on the ECN activation indicator and ECN tuning parameters.

[0187] According to the various embodiments disclosed herein, the ECN activation indicator may include a first ECN indicator and a second ECN indicator. The first ECN indicator may instruct the UPF entity or base station to perform ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists. The second ECN indicator may instruct the UPF entity or base station to perform the following operations: perform ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the value of the ECN mark in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

[0188] According to various embodiments disclosed herein, the method may further include: receiving downlink data from a server; identifying whether the downlink data meets ECN marking conditions; if the ECN marking conditions are met, performing ECN marking in the ECN field of the outer header of the downlink data; and transmitting the ECN-marked downlink data to a base station via a virtual network.

[0189] According to various embodiments disclosed herein, the method may include: receiving uplink data whose outer header ECN field is marked with ECN from a base station via a virtual network; copying the ECN mark value in the outer header ECN field of the uplink data to the ECN field of the inner header of the uplink data; performing ECN marking in the ECN field of the inner header of the uplink data if the received uplink data satisfies the ECN marking conditions indicated by the ECN tuning parameters; and sending the uplink data whose inner header ECN field is marked with ECN to a server.

[0190] According to the various embodiments disclosed herein, a UPF entity may instruct a UPF entity to select based on ECN information that is supported in a PDU session connection, which is received by an SMF entity from a user equipment (UE), and the ECN information that is supported in a PDU session connection may include at least one of the following: whether the UE supports ECN, information related to the version of the transmission control protocol (TCP), or whether round-trip time (RTT) based transmission is controlled.

[0191] As described above, a method performed by a user equipment (UE) of a wireless communication system according to various embodiments disclosed herein may include: sending a PDU session establishment request message to a session management function (SMF) entity via a base station, the PDU session establishment request message including ECN information supported in the PDU session connection; receiving a PDU session establishment response message from the SMF entity via the base station, including an explicit congestion notification (ECN) activation indicator and ECN tuning parameters; and performing data communication based on the PDU session establishment response message, wherein the PDU session establishment response message includes identification information for a QoS flow, wherein activation of ECN-related functions will be applied by the base station to the QoS flow based on the ECN activation indicator.

[0192] According to the various embodiments disclosed herein, the ECN activation indicator may include a first ECN indicator and a second ECN indicator. The first ECN indicator may instruct the UPF entity or base station to perform ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists. The second ECN indicator may instruct the UPF entity or base station to perform the following operations: perform ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the value of the ECN mark in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

[0193] According to various embodiments disclosed herein, the method may include: receiving downlink data from a base station; identifying an ECN field in the inner header of the received downlink data; and controlling congestion based on the identified ECN field, wherein an ECN flag indicating the presence of congestion has been executed by the base station in the ECN field of the inner header of the downlink data.

[0194] According to the various embodiments disclosed herein, the received downlink data may include an outer header that includes an ECN field in which an ECN flag indicating the presence of congestion has been executed by a UPF entity.

[0195] According to various embodiments disclosed herein, controlling congestion may include: identifying congestion when the ECN flag is indicated by a predetermined value, and performing an operation to reduce the size of the congestion window based on the identified congestion.

[0196] As described above, a user plane function (UPF) entity in a wireless communication system according to various embodiments disclosed herein may include: at least one transceiver and a controller coupled to the at least one transceiver. The controller may be configured to: receive N4 session information from a session management function (SMF) entity, the N4 session information including an explicit congestion notification (ECN) activation indicator and ECN tuning parameters; identify activated QoS flows for which ECN-related functions are to be applied based on the ECN activation indicator; and perform data communication based on the ECN activation indicator and ECN tuning parameters.

[0197] According to the various embodiments disclosed herein, the ECN activation indicator may include a first ECN indicator and a second ECN indicator. The first ECN indicator may instruct the UPF entity or base station to perform ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists. The second ECN indicator may instruct the UPF entity or base station to perform the following operations: perform ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the value of the ECN mark in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

[0198] According to the various embodiments disclosed herein, the controller may be further configured to: receive downlink data from a server; identify whether the downlink data meets the ECN marking conditions; if the ECN marking conditions are met, perform ECN marking in the ECN field of the outer header of the downlink data; and transmit the ECN-marked downlink data to the base station via a virtual network.

[0199] According to the various embodiments disclosed herein, the controller may be further configured to: receive uplink data whose outer header ECN field is marked with ECN from a base station via a virtual network; copy the ECN mark value in the outer header ECN field of the uplink data to the ECN field of the inner header of the uplink data; perform ECN marking in the ECN field of the inner header of the uplink data if the received uplink data satisfies the ECN marking conditions indicated by the ECN tuning parameters; and send the uplink data whose inner header ECN field is marked with ECN to a server.

[0200] According to the various embodiments disclosed herein, a UPF entity may instruct a UPF entity to select based on ECN information that is supported in a PDU session connection, which is received by an SMF entity from a user equipment (UE), and the ECN information that is supported in a PDU session connection may include at least one of the following: whether the UE supports ECN, information related to the version of the transmission control protocol (TCP), or whether round-trip time (RTT) based transmission is controlled.

[0201] As described above, a user equipment (UE) of a wireless communication system according to various embodiments disclosed herein may include: at least one transceiver and a controller coupled to the at least one transceiver. The controller may be configured to: send a PDU session establishment request message to a Session Management Function (SMF) entity via a base station, the PDU session establishment request message including ECN information supported in the PDU session connection; receive a PDU session establishment response message from the SMF entity via the base station, including an Explicit Congestion Notification (ECN) activation indicator and ECN tuning parameters; and perform data communication based on the PDU session establishment response message, wherein the PDU session establishment response message includes identification information for a QoS flow, wherein activation of ECN-related functions will be applied by the base station to the QoS flow based on the ECN activation indicator.

[0202] According to the various embodiments disclosed herein, the ECN activation indicator may include a first ECN indicator and a second ECN indicator. The first ECN indicator may instruct the UPF entity or base station to perform ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists. The second ECN indicator may instruct the UPF entity or base station to perform the following operations: perform ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the value of the ECN mark in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

[0203] According to the various embodiments disclosed herein, the controller may be further configured to: receive downlink data from a base station; identify an ECN field in the inner header of the received downlink data; and control congestion conditions based on the identified ECN field, wherein an ECN flag indicating the presence of congestion has been executed by the base station in the ECN field of the inner header of the downlink data.

[0204] According to the various embodiments disclosed herein, the received downlink data may include an outer header that includes an ECN field in which an ECN flag indicating the presence of congestion has been executed by a UPF entity.

[0205] According to the various embodiments disclosed herein, the controller may be further configured to: identify congestion conditions when the ECN flag is indicated by a predetermined value, and perform an operation to reduce the size of the congestion window based on the identified congestion conditions.

Claims

1. A method performed by a User Plane Function (UPF) entity in a wireless communication system, the method comprising: Receive N4 session information from the Session Management Function (SMF) entity, the N4 session information including an explicit congestion notification (ECN) activation indicator and ECN tuning parameters; Based on the ECN activation indicator, identify the QoS flow to be activated by applying ECN-related functions; as well as Data communication is performed based on the ECN activation indicator and the ECN tuning parameters.

2. The method according to claim 1, wherein, The ECN activation indicator includes a first ECN indicator and a second ECN indicator. The first ECN indicator instructs the UPF entity or base station to perform an ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists, and The second ECN indicator instructs the UPF entity or the base station to perform the following operation: perform an ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the ECN mark value in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

3. The method according to claim 1, further comprising: Receive downlink data from the server; Identify whether the downlink data meets the ECN marking conditions; If the ECN marking conditions are met, ECN marking is performed in the ECN field of the outer header in the downlink data; as well as Downlink data marked with ECN is sent to the base station via a virtual network.

4. The method of claim 1, further comprising: Uplink data whose outer header ECN field is marked with ECN is received from the base station via a virtual network; Copy the ECN flag value from the ECN field of the outer header in the uplink data to the ECN field of the inner header in the uplink data; If the received uplink data meets the ECN marking conditions indicated by the ECN tuning parameters, ECN marking is performed in the ECN field of the inner header in the uplink data. as well as Uplink data whose ECN field in the inner header is marked with ECN is sent to the server.

5. The method according to claim 1, wherein, The UPF entity indicates the UPF entity selected based on ECN information that can be supported in the PDU session connection, wherein the ECN information is received by the SMF entity from the user equipment (UE). The ECN information that can be supported in the PDU session connection may include at least one of the following: whether the UE supports ECN, information related to the version of the Transmission Control Protocol (TCP), or whether the transmission is controlled based on Round Trip Time (RTT).

6. A method performed by a user equipment (UE) in a wireless communication system, the method comprising: The base station sends a PDU session establishment request message to the Session Management Function (SMF) entity, the PDU session establishment request message including ECN information that can be supported in the PDU session connection; The base station receives a PDU session establishment response message from the SMF entity. The PDU session establishment response message includes an explicit congestion notification (ECN) activation indicator and ECN tuning parameters. as well as Based on the PDU session, a response message is established to perform data communication. The PDU session establishment response message includes identification information for QoS flows, wherein the activation of ECN-related functions will be applied to the QoS flows by the base station based on the ECN activation indicator.

7. The method according to claim 6, wherein, The ECN activation indicator includes a first ECN indicator and a second ECN indicator. The first ECN indicator instructs the User Plane Function (UPF) entity or the base station to perform an ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists, and The second ECN indicator instructs the UPF entity or the base station to perform the following operation: perform an ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the ECN mark value in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

8. The method of claim 6, further comprising: Receive downlink data from the base station; Identify the ECN field in the inner header of the received downlink data; as well as Congestion is controlled based on the identified ECN field. The ECN tag indicating whether congestion exists has been executed by the base station in the ECN field of the inner header of the downlink data.

9. The method according to claim 8, wherein, In the received downlink data, the ECN flag indicating the presence of congestion has been executed by the UPF entity in the ECN field of the outer header.

10. The method according to claim 8, wherein, Congestion control includes: When the ECN flag is indicated to a predetermined value, congestion is identified; and Based on the identified congestion situation, the size of the congestion window is reduced.

11. A User Plane Function (UPF) entity in a wireless communication system, the UPF entity comprising: At least one transceiver; as well as The controller is coupled to the at least one transceiver. The controller is configured as follows: Receive N4 session information from the Session Management Function (SMF) entity, the N4 session information including an explicit congestion notification (ECN) activation indicator and ECN tuning parameters; Based on the ECN activation indicator, identify the QoS flow to be activated using ECN-related functions; and Data communication is performed based on the ECN activation indicator and the ECN tuning parameters.

12. The UPF entity according to claim 11, wherein, The ECN activation indicator includes a first ECN indicator and a second ECN indicator. The first ECN indicator instructs the UPF entity or base station to perform an ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists, and The second ECN indicator instructs the UPF entity or the base station to perform the following operation: perform an ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the ECN mark value in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

13. The UPF entity according to claim 1, wherein, The controller is further configured to: Receive downlink data from the server; Identify whether the downlink data meets the ECN marking conditions; If the downlink data meets the ECN marking conditions, perform ECN marking in the ECN field of the outer header of the downlink data; as well as Downlink data marked with ECN is sent to the base station via a virtual network.

14. A user equipment (UE) in a wireless communication system, the UE comprising: At least one transceiver; as well as The controller is coupled to the at least one transceiver. The controller is configured as follows: The base station sends a PDU session establishment request message to the Session Management Function (SMF) entity, the PDU session establishment request message including ECN information that can be supported in the PDU session connection; The base station receives a PDU session establishment response message from the SMF entity, the PDU session establishment response message including an explicit congestion notification ECN activation indicator and ECN tuning parameters; and Based on the PDU session, a response message is established to perform data communication. The PDU session establishment response message includes identification information for QoS flows, wherein the activation of ECN-related functions will be applied to the QoS flows by the base station based on the ECN activation indicator.

15. The UE according to claim 14, wherein, The ECN activation indicator includes a first ECN indicator and a second ECN indicator. The first ECN indicator instructs the User Plane Function (UPF) entity or the base station to perform an ECN marking in the ECN field of the inner header of the data, the ECN marking indicating whether congestion exists, and The second ECN indicator instructs the UPF entity or the base station to perform the following operation: perform an ECN marking in the ECN field of the outer header of the data, the ECN marking indicating whether congestion exists; or copy the ECN mark value in the ECN field of the outer header of the data to the ECN field of the inner header of the data.

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