Method and device for saving network energy in wireless communication system

Abstract

The present disclosure relates to a 5G or 6G communication system for supporting higher data transmission rates. According to an embodiment of the present disclosure, a method performed by a first network entity in a wireless communication system may comprise the steps of: receiving, from a unified data management (UDM) entity, energy saving-related subscription information about at least one first terminal; receiving an energy saving-related message from a second network entity; and selecting, in response to the energy saving-related message, at least one second terminal that is to perform energy saving based on the energy saving-related subscription information about the at least one first terminal.

Description

Method and device for saving network energy in a wireless communication system

[0001] The present disclosure relates to a wireless communication system or a mobile communication system. Specifically, it relates to a method and device for applying energy saving in a wireless communication system.

[0002] 5G mobile communication technology defines a wide frequency band to enable fast transmission speeds and new services, and can be implemented not only in the sub-6GHz frequency band such as 3.5 gigahertz (3.5GHz), but also in the ultra-high frequency band called millimeter wave (mmWave) such as 28GHz and 39GHz ('Above 6GHz'). In addition, for 6G mobile communication technology, which is called the system after 5G communication (Beyond 5G), implementation in the terahertz band (for example, the 3 terahertz (3THz) band at 95GHz) is being considered to achieve a transmission speed that is 50 times faster than 5G mobile communication technology and an ultra-low latency time that is reduced to one-tenth.

[0003] In the early stages of 5G mobile communication technology, the goal is to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). These include beamforming and massive MIMO to mitigate path loss of radio waves in ultra-high frequency bands and increase the transmission distance of radio waves, support for various numerologies (such as operation of multiple subcarrier intervals) and dynamic operation of slot formats for efficient use of ultra-high frequency resources, initial access technology to support multi-beam transmission and wideband, definition and operation of BWP (Bidth Part), new channel coding methods such as LDPC (Low Density Parity Check) codes for large-capacity data transmission and Polar Code for reliable transmission of control information, and L2 pre-processing (L2). Standardization has been made for network slicing, which provides dedicated networks specialized for specific services, and pre-processing.

[0004] Currently, discussions are underway to improve and enhance the initial 5G mobile communication technology in consideration of the services that 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to help autonomous vehicles make driving decisions and increase user convenience based on their own location and status information transmitted by vehicles, NR-U (New Radio Unlicensed) for the purpose of system operation that complies with various regulatory requirements in unlicensed bands, NR terminal low power consumption technology (UE Power Saving), Non-Terrestrial Network (NTN), which is direct terminal-satellite communication to secure coverage in areas where communication with terrestrial networks is impossible, and Positioning.

[0005] In addition, standardization of wireless interface architecture / protocols is in progress for technologies such as intelligent factories (Industrial Internet of Things, IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) that provides nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement technology including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step random access (2-step RACH for NR) that simplifies random access procedures. Standardization is also in progress for system architecture / services such as 5G baseline architecture (e.g., Service-based Architecture, Service-based Interface) for grafting Network Functions Virtualization (NFV) and Software-Defined Networking (SDN) technologies, and Mobile Edge Computing (MEC) that provides services based on the location of the terminal.

[0006] Once these 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, necessitating enhanced functionality and performance of 5G mobile communication systems and integrated operation of these connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity, supporting AI services, supporting metaverse services, and drone communications by utilizing eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR).

[0007] In addition, the development of these 5G mobile communication systems includes new waveforms to ensure coverage in the terahertz band of 6G mobile communication technology, multi-antenna transmission technologies such as Full Dimensional MIMO (FD-MIMO), Array Antenna, and Large Scale Antenna, metamaterial-based lenses and antennas to improve the coverage of terahertz band signals, high-dimensional spatial multiplexing technology using Orbital Angular Momentum (OAM), Reconfigurable Intelligent Surface (RIS) technology, as well as full duplex technology to improve the frequency efficiency and system network of 6G mobile communication technology, satellite, AI (Artificial Intelligence) from the design stage and AI-based communication technology that realizes system optimization by internalizing end-to-end AI support functions, and ultra-high-performance communication and computing resources to provide services with complexity that exceeds the limits of terminal computing capabilities. It can serve as a basis for the development of next-generation distributed computing technologies that can be realized by utilizing them.

[0008] The present disclosure proposes a method and device for reducing energy consumption for providing a service in a wireless communication system or a mobile communication system.

[0009] The present disclosure proposes a method for performing policy change or access control based on subscriber information of a terminal to reduce network energy usage.

[0010] According to one embodiment of the present disclosure, a method of a first network entity in a wireless communication system includes the steps of: receiving energy saving-related subscription information for at least one first terminal from a unified data management (UDM) entity; receiving an energy saving-related message from a second network entity; and, in response to the energy saving-related message, selecting at least one second terminal to perform energy saving based on the energy saving-related subscription information of the at least one first terminal.

[0011] According to one embodiment of the present disclosure, in a wireless communication system, a first network entity includes a transceiver; at least one processor; and the at least one processor is configured to transmit a subscription information request message of at least one first terminal to a unified data management (UDM) entity, receive energy-saving-related subscription information for at least one first terminal from the UDM entity, receive an energy-saving-related message from a second network entity, and select at least one second terminal to perform energy-saving based on the energy-saving-related subscription information of the at least one first terminal in response to the energy-saving-related message.

[0012] The present disclosure proposes a method for performing policy change or access control based on subscriber information of a terminal, thereby reducing network energy usage.

[0013] Through this disclosure, a network operator can perform actions such as terminal access control, policy reset (e.g., reducing the maximum allowable data rate), etc. for terminal(s) that have agreed to energy saving (or energy-based control) based on the network energy usage situation, to comply with energy usage regulations or reduce costs due to power consumption.

[0014] Figure 1 illustrates the structure of a 5G system.

[0015] FIG. 2 is a diagram illustrating a method for AMF to obtain energy saving related information of a terminal in a terminal registration procedure according to an embodiment of the present disclosure.

[0016] FIG. 3 is a flowchart illustrating an AMF-based network energy saving method according to an embodiment of the present disclosure.

[0017] FIG. 4 is a flowchart illustrating a network energy saving method based on SMF according to an embodiment of the present disclosure.

[0018] FIG. 5 is a flowchart illustrating a PCF-based network energy saving method according to an embodiment of the present disclosure.

[0019] FIG. 6 is a structural diagram illustrating a network entity according to an embodiment of the present disclosure.

[0020] Hereinafter, one embodiment of the present disclosure will be described in detail with reference to the attached drawings.

[0021] In describing this disclosure, descriptions of technical details that are well-known in the technical field to which this disclosure pertains and are not directly related to this disclosure will be omitted. This is to avoid obscuring the gist of this disclosure by omitting unnecessary explanations and to convey it more clearly. Furthermore, the terms described below are defined based on their functions in this disclosure and may vary depending on the intent or custom of the user or operator. Therefore, their definitions should be based on the overall content of this specification.

[0022] For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically depicted. Furthermore, the dimensions of each component do not entirely reflect its actual size. Identical or corresponding components in each drawing are assigned the same reference numbers.

[0023] Hereinafter, a base station (BS) is an entity that performs resource allocation of a terminal, and may be at least one of a gNode B, an eNode B, a Node B (or an xNode B (where x is an alphabet including g or e)), a wireless access unit, a base station controller, a satellite, an airborn, or a node on a network. A user equipment (UE) may include a mobile station (MS), a vehicle, a satellite, an airborn, a cellular phone, a smartphone, a computer, or a multimedia system capable of performing a communication function. In the present disclosure, a downlink (DL) is a wireless transmission path of a signal transmitted from a base station to a terminal, and an uplink (UL) is a wireless transmission path of a signal transmitted from a terminal to an air station. Additionally, a sidelink (SL) may exist, which means a wireless transmission path of a signal transmitted from a terminal to another terminal.

[0024] In addition, although LTE, LTE-A, or 5G systems may be described below as examples, embodiments of the present disclosure may also be applied to other communication systems having similar technical backgrounds or channel types. For example, this may include 5G-Advance or NR-Advance, or 6th generation mobile communication technology (6G) developed after 5G mobile communication technology (or new radio, NR), and the 5G described below may also include existing LTE, LTE-A, and other similar services. In addition, the present disclosure may be applied to other communication systems with some modifications within a range that does not significantly deviate from the scope of the present disclosure, as determined by a person having skilled technical knowledge.

[0025] At this time, it will be understood that each block of the processing flowchart drawings and combinations of the flowchart drawings can be performed by computer program instructions. These computer program instructions can be installed in a processor of a general-purpose computer, a special-purpose computer, or other programmable data processing equipment, so that the instructions executed by the processor of the computer or other programmable data processing equipment create a means for performing the functions described in the flowchart block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can direct a computer or other programmable data processing equipment to implement the functions in a specific manner, so that the instructions stored in the computer-available or computer-readable memory can also produce a manufactured item that includes an instruction means for performing the functions described in the flowchart block(s). Since the computer program instructions may be installed on a computer or other programmable data processing device, a series of operational steps may be performed on the computer or other programmable data processing device to create a computer-executable process, and the instructions that cause the computer or other programmable data processing device to perform the steps for performing the functions described in the flowchart block(s) may also provide steps for performing the functions described in the flowchart block(s).

[0026] Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a specific logical function(s). It should also be noted that in some alternative implementations, the functions described in the blocks may occur out of order. For example, two blocks depicted in succession may actually be executed substantially concurrently, or the blocks may sometimes be executed in reverse order, depending on their respective functions.

[0027] Here, the term '~ part' used in this embodiment means software or hardware components such as FPGA (Field Programmable Gate Array) or ASIC (Application Specific Integrated Circuit), and the '~ part' performs certain roles. However, the '~ part' is not limited to software or hardware. The '~ part' may be configured to be on an addressable storage medium or may be configured to play one or more processors. Therefore, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided within the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. Additionally, the components and '~parts' may be implemented to activate one or more CPUs within a device or secure multimedia card. In addition, in an embodiment, the '~parts' may include one or more processors.

[0028] 3GPP, responsible for cellular mobile communications standards, is currently standardizing a new core network architecture called 5G Core (5GC) to facilitate the evolution of 4G LTE systems to 5G systems. Compared to the Evolved Packet Core (EPC), the network core for 4G, 5GC supports the following differentiated features:

[0029] 5GC introduces the Network Slice feature. As a requirement of 5G, 5GC must support a variety of terminal types and services, such as enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC). These terminals and services each have different requirements for the core network. For example, eMBB services may require high data rates, while URLLC services may require high reliability and low latency. To meet these diverse service requirements, Network Slice technology has been proposed.

[0030] Network slicing can refer to a method of virtualizing a single physical network to create multiple logical networks (e.g., network slices). An activated network slice can be called a network slice instance, and each network slice instance (NSI) can have different characteristics. By configuring a network function (NF) for each NSI according to its characteristics, mobile carriers can satisfy various service requirements according to terminals / services. For example, mobile carriers can efficiently support various 5G services (e.g., eMBB, URLLC, or mMTC) by allocating an NSI that matches the characteristics of the service required for each terminal.

[0031] 5GC can easily support the network virtualization paradigm by separating the mobility management function from the session management function. In 4G LTE, all terminals can receive services from the network through signaling exchanges with a single core entity called the mobility management entity (MME), which is responsible for registration, authentication, mobility management, and session management. In 5G, the number of terminals (including MTC terminals) will explode, and the mobility and traffic / session characteristics that must be supported depending on the terminal type will become more specialized. Therefore, supporting all functions from a single entity (such as the MME) will inevitably reduce scalability by adding entities for each required function. Therefore, various functions are being developed based on a structure that separates the mobility management function from the session management function to improve scalability in terms of the functional / implementation complexity and signaling load of the core entity responsible for the control plane.

[0032] Figure 1 illustrates the structure of a 5G system.

[0033] A 5G mobile communication network is composed of a 5G UE (100) (user equipment, terminal), a 5G RAN (110) (radio access network, base station, gNB (5g nodeB), eNB (evolved nodeB, etc.), and a 5G core network. The 5G core network may be composed of NFs such as an access and mobility management function (AMF) (120) that provides a mobility management function of the UE, a session management function (SMF) (135) that provides a session management function, a user plane function (UPF) (130) that performs a data transfer role, a policy control function (PCF) (140) that provides a policy control function, a unified data management (UDM) (145) that provides a data management function such as subscriber data and policy control data, and a unified data repository (UDR) that stores data of various network functions (NFs) such as the UDM (145).

[0034] Additionally, the 5G core network may additionally include a network slice selection function (NSSF) (160), a network data analytics function (NWDAF) (165), a network slice admission control function (NSACF) (180), and a data network (DN) (175).

[0035] In the 3GPP system, a conceptual link connecting NFs within a 5G system is defined as a reference point. The following illustrates a reference point included in the 5G system architecture depicted in Figure 1.

[0036] - N1: Reference point between UE and AMF

[0037] - N2: Reference point between (R)AN and AMF

[0038] - N3: Reference point between (R)AN and UPF

[0039] - N4: Reference point between SMF and UPF

[0040] - N5: Reference point between PCF and AF

[0041] - N6: Reference point between UPF and DN

[0042] - N7: Reference point between SMF and PCF

[0043] - N8: Reference point between UDM and AMF

[0044] - N9: Reference point between two core UPFs

[0045] - N10: Reference point between UDM and SMF

[0046] - N11: Reference point between AMF and SMF

[0047] - N12: Reference point between AMF and AUSF

[0048] - N13: Reference point between UDM and authentication server function (AUSF)

[0049] - N14: Reference point between two AMFs

[0050] - N15: Reference point between PCF and AMF for non-roaming scenarios, reference point between PCF and AMF in visited network for roaming scenarios.

[0051] In 5G systems, network slicing technology refers to the technology and architecture that enables multiple virtualized, independent, logical networks within a single physical network. To meet the specialized requirements of services / applications, network operators configure virtual end-to-end networks called network slices to provide services. At this time, network slices are identified by an identifier called single-network slice selection assistance information (S-NSSAI). During the UE registration procedure (e.g., UE registration procedure), the network transmits a set of allowed slices (e.g., allowed NSSAI(s)) to the UE, and the UE transmits and receives application data through a PDU (protocol data unit) session created through one of these S-NSSAIs (i.e., network slices).

[0052] The mobile communication system receives identifier information and QoS (quality of service) requirements of terminals that can participate in federated learning from an external third-party server (application function, AF) (170), and the mobile communication system selects terminals that can allocate network resources based on the requirements and allocates self-network resources (i.e., QoS Flow), and transmits the results to the AF. Among the terms used in the description of the present disclosure, aggregated QoS can be used and interpreted with the same meaning as same QoS, identical QoS, and group QoS. For example, aggregated QoS request indicator and same QoS request indicator, aggregated QoS information and same QoS information, and aggregated QoS notification indicator and same QoS notification indicator can be interpreted and used with the same meaning, respectively.

[0053] In the present disclosure, the network energy saving function (NESF) is a function that monitors network energy consumption and requests actions for network energy saving based on the results. The NESF may be located in one of the following NFs: NSSF, AMF, SMF, PCF, NWDAF, OAM, and RAN. However, the present disclosure is not limited thereto.

[0054] FIG. 2 is a diagram illustrating a method for AMF to obtain energy saving related information of a terminal in a registration procedure according to an embodiment of the present disclosure.

[0055] In step 201, the terminal may transmit an N2 message containing a registration request to the RAN. The message may include at least one of the following information:

[0056] - UE ID: This is the terminal identifier information. If the terminal has an available 5G-GUTI (global unique temporary identifier) ​​allocated from the network, it can be included. If not, the SUCI (subscription concealed identifier) ​​can be included.

[0057] - UE MM Core Network Capability: Indicates terminal capability information. For each function, the terminal can include information indicating support for the function it supports.

[0058] At step 202, the RAN may transmit a registration request in the N2 message received from the terminal to the AMF.

[0059] In step 203, the AMF may send a message to the UDM to register itself as the serving NF for the UE. In one embodiment, the message may include a Nudm_UECM_Registration request. The message may include at least one of an NF ID, an NF Type (here, an AMF), a SUPI (an identifier of the UE), an Access Type, a RAT Type, and a GUAMI (a globally unique AMF identifier).

[0060] In step 204, the UDM may send a response message to the AMF including the result of processing the request message in step 203. In one embodiment, the response message may include a Nudm_UECM_Registration response.

[0061] In step 205, if the registration is successful and there is no subscription data for the UE, the AMF may send the UDM a Nudm_SDM_Get request message containing the UE ID. If the AMF does not have Access and Mobility Subscription data subscription information for the UE, the message may include an indicator requesting Access and Mobility Subscription data subscription information.

[0062] In step 206, if the UDM has stored subscription information in the UDR, UE subscription information can be obtained from the UDR. In one embodiment, the request message transmitted to the UDR may include a Nudr_DM_Query request. In one embodiment, the request message may include a UE ID (e.g., SUPI).

[0063] In step 207, the UDR may include the UE subscription information corresponding to the request message included in step 206 in a response message transmitted to the UDM. In one embodiment, the response message may include a Nudr_DM_Query response.

[0064] In step 208, the UDM may include UE subscription information acquired from the UDR or stored internally in the Nudm_SDM_Get response message transmitted to the AMF. The message may include the following information:

[0065] - Energy Saving Allowed (or, Energy Saving Operation Allowed): Information indicating whether a network energy saving operation (i.e., a network energy saving operation) of a terminal is allowed may be included. In one embodiment, the network energy saving operation may mean at least one of various operations that can be applied to a terminal (or resources allocated to the terminal) to reduce energy consumed in a network (e.g., an operation of rejecting a network connection (e.g., a registration request) of a terminal in a situation where network energy must be reduced, an operation of rejecting a session establishment request of the terminal, or an operation of lowering the maximum allowed data rate (e.g., maximum uplink data rate, maximum downlink data rate, maximum uplink delay, maximum downlink delay, etc.) of the terminal). Energy Saving Allowed (or, Energy Saving Operation Allowed) may indicate whether at least one network energy saving operation is allowed, information indicating one or more allowed operation(s), and whether one or more network energy saving operations are allowed.

[0066] In one embodiment, if the subscriber consents or if the subscriber subscribes to a rate plan that allows his / her terminal to be restricted in connection or speed depending on network operation conditions, the Energy Saving Allowed (or Energy Saving Operation Allowed) may include information allowing a network energy saving operation. In one embodiment, if the Energy Saving Allowed (or Energy Saving Operation Allowed) information needs to be updated based on the subscriber consent or rate plan, and if the subscriber information is stored in the UDR, the OAM (Operations, administration, and management) may update the Energy Saving Allowed information for the subscriber terminal in the UDR (e.g., add information allowing a network energy saving operation).

[0067] - Energy Saving Time: This may include information about the time when network energy saving operations can be applied to the terminal. This may be expressed as a specific time of day (e.g., 3:00 PM to 5:00 PM) or an absolute time zone.

[0068] - Energy Saving area: This area may contain information about areas where network energy saving operations can be applied to the terminal. This area information may consist of cell ID(s) or geographic location information.

[0069] AMF may store the information obtained in step 208. The information may be stored in the UE Context of AMF.

[0070] In step 209, the AMF may send a subscription request message to the UDM requesting to be notified of any future changes to the information acquired in step 208. The UDM may perform the subscription to the UDR.

[0071] At step 210, the UDM may send a response message to step 209 to the AMF.

[0072] In step 211, the AMF may include a registration accept message to be sent to the terminal in the message sent to the RAN.

[0073] At step 212, the RAN may send the UE a registration accept message received from the AMF.

[0074] Figure 3 shows an AMF-based network energy saving method.

[0075] In step 301, the network energy saving function (NESF) may transmit an energy saving request to the AMF(s) when the network's energy usage (or the network energy usage per hour) needs to be reduced (e.g., when the network's power usage is temporarily too high, etc.). In one embodiment, when energy saving is to be performed on a network slice-by-network basis, the NESF function may be incorporated into the network slicing selection function (NSSF). In this case, the NSSF equipped with the NESF function (e.g., the NSSF supporting the NESF function) may include S-NSSAI(s) corresponding to the request message when it wants to activate energy saving for specific network slice(s).

[0076] In one embodiment, when energy savings are desired based on operator policy, the NESF function may be included in the PCF. In one embodiment, when energy savings are provided for a specific base station or cell, the NESF may be included in the RAN. In the case of a RAN including the NESF function (e.g., a RAN supporting the NESF function), if energy usage for a specific cell or base station is too high, an energy savings request message may be transmitted to the AMF, and the energy savings request message may include cell ID(s) or TA information. In one embodiment, the NESF may also be included in the OAM.

[0077] At this time, the energy saving request message transmitted by NESF to AMF in step 301 may include at least one of the following information:

[0078] - Energy Saving Activation Indication (or Energy Saving Deactivation Indication): An energy saving activation indicator may be included. If deactivation of energy saving-enabled UEs is requested, an energy saving deactivation indicator may be included.

[0079] -required amount of UEs: The number of terminals to which network energy saving operations should be applied for energy conservation (required amount of UEs) may be included.

[0080] -sum of bitrates: may contain the sum of bitrates that must be reduced to save energy.

[0081] -energy saving area: If NESF is located in PCF, OAM, or RAN, it may include information about the area where energy saving is required (e.g., Tracking Area information, Cell ID information).

[0082] -S-NSSAI: When NESF is located in NSSF, network slice identifier information (i.e., S-NSSAI) that requires energy saving may be included.

[0083] In step 302, if the message of step 301 includes an energy saving activation indication, the AMF may select registered UEs to which network energy saving is to be applied, and store information indicating that energy saving is being applied to the selected UE(s). For example, the AMF may include an indicator indicating that network energy saving is being applied in the UE Context for each newly selected UE.

[0084] In one embodiment, the AMF may determine UEs to which network energy saving is to be applied among UEs whose subscription information includes Energy Saving Allowed (or Energy Saving Operation Allowed).

[0085] In one embodiment, if the message of step 301 includes an energy saving area, the AMF may determine UEs to which network energy saving is to be applied among UEs located in the TA or cell according to the information. In one embodiment, if the message of step 301 includes an S-NSSAI, the AMF may determine UEs to which network energy saving is to be applied among UEs to which the S-NSSAI is included in the Allowed NSSAI or UEs that have a PDU Session established for the S-NSSAI.

[0086] In one embodiment, if the message of step 301 includes an amount of UEs, the AMF may select at least that many UEs. In one embodiment, if the message of step 301 includes a sum of bitrates, the AMF may select PDU session(s) to deactivate in steps 305a-305c so that the bitrates are reduced by at least the sum of bitrates.

[0087] Steps 303a to 303c illustrate the operations when AMF receives a PDU session establishment request message from a terminal to which network energy saving is applied.

[0088] In step 303a, the AMF may receive a PDU session establishment request message from the terminal.

[0089] In step 303b, the AMF can determine whether the terminal is a terminal to which network energy saving is applied. In one embodiment, the AMF can determine whether the terminal is a terminal to which network energy saving is applied based on information indicating terminals to which network energy saving is applied among the registered terminals stored in step 302. In one embodiment, if energy saving is activated and the terminal is to which energy saving is applied, the AMF can decide to reject the terminal along with a back-off timer (BOT).

[0090] In step 303c, if the AMF determines that the corresponding UE is a UE to which network energy saving is applied in step 303b and decides to reject the PDU session establishment request, the AMF transmits a PDU session establishment reject message to the UE, and the message may include at least one of a Back-off Timer (BOT) and a reject cause (e.g., rejection due to network energy saving operation). If the received PDU session establishment reject message includes a Back-off Timer, the UE may start the timer and not transmit a PDU session establishment request message until the timer expires. Steps 304a to 304c illustrate operations performed when the AMF receives a registration request message from a UE to which network energy saving is applied.

[0091] In step 304a, AMF may receive a registration request message from the terminal.

[0092] In step 304b, the AMF can determine whether the terminal is a terminal to which network energy saving is applied. In one embodiment, the AMF can determine whether the terminal is a terminal to which network energy saving is applied based on the information indicating the terminal to which network energy saving is applied, stored in step 302. In one embodiment, if the energy saving is activated and the terminal is to which energy saving is applied, the AMF can decide to reject the terminal along with a back-off timer (BOT).

[0093] If the AMF decides to reject the UE in step 304b at step 304c, it sends a registration reject message to the UE, which may include a Back-off Timer (BOT) and a cause of rejection (e.g., rejection due to network energy saving operations). If the received registration reject message includes a Back-off Timer, the UE may start the timer and not send a registration request message until it expires.

[0094] In step 305, the AMF may perform User-plane deactivation for the PDU Session(s) of the UE(s) for which the network energy saving operation has been decided to be applied in step 302. In one embodiment, the AMF may transmit a request message for deactivation to the SMF in charge of the PDU Session for each UE(s) for which the network energy saving operation has been decided to be applied. At this time, the message that the AMF transmits to the SMF for each PDU Session that it wishes to deactivate may be an Nsmf_PDUSession_UpdateSMContext request message, and the message may include an SM Context ID and an Operation Type set to User Plane Deactivate. When the SMF receives the message, it performs UP Deactivation for the PDU Session.

[0095] In step 305a, the SMF may send the UPF an N4 Session Modification message to delete the AN Tunnel Info (i.e., the tunnel from the UPF to the RAN) for the PDU session. Upon receiving the message, the UPF may delete the AN tunnel Info (e.g., the RAN Tunnel Endpoint address, etc.) for the PDU session and drop the downlink packets for the PDU session.

[0096] At step 305b, the SMF may send the following message to the AMF: Namf_Communication_N1N2MessageTransfer service operation (PDU Session ID, N2 SM Information (N2 Resource Release Request (PDU Session ID))).

[0097] In step 305c, when the AMF receives the message from the SMF, it transmits an N2 PDU Session Resource Release Command to the RAN, and may include the N2 SM Information included in the message received from the SMF in the message. When the RAN receives the N2 PDU Session Resource Release Command from the AMF, it may send an RRC Connection Reconfiguration message to the UE to release NG-RAN resources for the PDU session included in the message. After that, the RAN may transmit an N2 PDU Session Resource Release Command Ack message to the AMF. When the AMF receives the Ack message from the RAN, it may transmit the Ack message for step 305b to the SMF.

[0098] FIG. 4 illustrates an SMF-based network energy saving method according to an embodiment of the present disclosure.

[0099] In step 401, if the NESF needs to reduce the energy usage of the network (or the network energy usage per hour) (e.g., if the network power usage is temporarily too high), it can send an energy saving request to the SMF(s). In one embodiment, if energy saving is to be performed on a network slice-by-network basis, the NESF function can be embedded in the NSSF. In this case, if the NSSF embedded with the NESF function (e.g., the NSSF supporting the NESF function) wants to activate energy saving for specific network slice(s), it can include the S-NSSAI(s) corresponding to the request message.

[0100] In one embodiment, when energy saving is desired based on operator policy, NESF function may be included in PCF. In one embodiment, when providing energy saving function for a specific base station or cell, NESF may be included in RAN. In case of RAN including NESF function (e.g., RAN supporting NESF function), if energy usage for a specific cell or base station is too high, energy saving request message may be transmitted to SMF through AMF, and cell ID(s) or TA information may be included in the energy saving request message. In one embodiment, NESF may also be included in OAM.

[0101] At this time, the energy saving request message that NESF transmits to SMF in step 401 may include at least one of the following information:

[0102] - Energy Saving Activation Indication (or Energy Saving Deactivation Indication): An energy saving activation indicator may be included. If deactivation of energy saving-enabled UEs is requested, an energy saving deactivation indicator may be included.

[0103] -required amount of PDU Sessions: This may include the number of sessions (required amount of PDU Sessions) to which network energy saving actions should be applied to save energy.

[0104] -sum of bitrates: may contain the sum of bitrates that must be reduced to save energy.

[0105] -energy saving area: If NESF is located in PCF, OAM, or RAN, it may include information about the area where energy saving is required (e.g., Tracking Area information, Cell ID information).

[0106] -S-NSSAI: When NESF is located in NSSF, network slice identifier information (i.e., S-NSSAI) that requires energy saving may be included.

[0107] In step 402, if the message of step 401 includes an energy saving activation indication, the SMF may select registered UEs to which network energy saving is to be applied, and store information indicating that energy saving is being applied to the selected UE(s). For example, the SMF may include an indicator indicating that network energy saving is being applied in the UE Context for each newly selected UE.

[0108] In one embodiment, the SMF may determine which UEs among those whose subscription information includes Energy Saving Allowed (or Energy Saving Operation Allowed) are eligible for network energy saving. For UEs without subscription information, the SMF may send a subscription information request message to the UDM, including the UE ID, and the UDM may include the subscription information in a response message sent to the SMF.

[0109] In one embodiment, if the message of step 401 includes an energy saving area, the SMF can determine UEs to which network energy saving is to be applied among UEs located in the TA or cell according to the information. In one embodiment, if the message of step 401 includes S-NSSAI, the SMF can determine UEs to which network energy saving is to be applied among UEs having a PDU Session established for the S-NSSAI.

[0110] In one embodiment, if the message of step 401 includes an amount of PDU Sessions, the SMF may select at least that many PDU Sessions. In one embodiment, if the message of step 401 includes a sum of bitrates, the SMF may select PDU session(s) to be deactivated in steps 405a-405c such that the bitrates are reduced by at least the sum of bitrates. For example, if the message of step 401 includes a sum of bitrates, the SMF may select PDU sessions such that the sum of Session AMBR (aggregate maximum bitrate) (maximum allowed bitrate) of the PDU sessions for which deactivation is determined exceeds at least the sum of bitrates.

[0111] Steps 403a to 403c illustrate the operations when the SMF receives a PDU session establishment request message through the AMF from a terminal to which network energy saving is applied.

[0112] When the AMF receives a PDU session establishment request message from the UE in step 403a, it may select an SMF for the PDU session and then send an Nsmf_CreateSMContext request message to the SMF. The message may include at least one of SUPI (an identifier of the UE used within the network), S-NSSAI (a network slice identifier), DNN (a data network name), and PDU Session ID.

[0113] In step 403b, the SMF can determine whether the terminal is a terminal to which network energy saving is applied. In one embodiment, the SMF can determine whether the terminal is a terminal to which network energy saving is applied based on the information indicating the terminal to which network energy saving is applied among the registered terminals stored in step 402. In one embodiment, if energy saving is activated and the terminal is to which energy saving is applied, the SMF can decide to reject the terminal along with a back-off timer (BOT).

[0114] In step 403c, if the SMF determines that the corresponding terminal is a terminal to which network energy saving is applied in step 403b and decides to reject the PDU session establishment request, the SMF may include at least one of a Result indication indicating failure, a cause indicating failure due to a network energy saving operation, and an N1 SM container (PDU Session Reject (Cause, BOT))) in the Nsmf_CreateSMContext response message transmitted to the AMF. In one embodiment, the SMF may include a Back-off Timer (BOT) and a reject cause (e.g., rejection due to a network energy saving operation, etc.) in the N1 SM container. The AMF may include information included in the N1 SM Container included in the message received from the SMF in the PDU session establishment reject and transmit it to the terminal. If the received PDU session establishment reject message includes a Back-off Timer, the terminal may start the corresponding timer and not transmit a PDU session establishment request message until the timer expires.

[0115] In step 405, the SMF may perform User-plane deactivation for the PDU Session(s) for which it decided to apply a network energy saving operation in step 402.

[0116] In step 405a, the SMF may send the UPF an N4 Session Modification message to delete the AN Tunnel Info (i.e., the tunnel from the UPF to the RAN) for the PDU session. Upon receiving the message, the UPF may delete the AN tunnel Info (e.g., the RAN Tunnel Endpoint address, etc.) for the PDU session and drop the downlink packets for the PDU session.

[0117] At step 405b, the SMF may send the following message to the AMF: Namf_Communication_N1N2MessageTransfer service operation (PDU Session ID, N2 SM Information (N2 Resource Release Request (PDU Session ID))).

[0118] In step 405c, when the AMF receives the message from the SMF, it transmits an N2 PDU Session Resource Release Command to the RAN, and may include the N2 SM Information included in the message received from the SMF in the message. When the RAN receives the N2 PDU Session Resource Release Command from the AMF, it may send an RRC Connection Reconfiguration message to the UE to release NG-RAN resources for the PDU session included in the message. After that, the RAN may transmit an N2 PDU Session Resource Release Command Ack message to the AMF. When the AMF receives the Ack message from the RAN, it may transmit the Ack message for step 405b to the SMF.

[0119] FIG. 5 illustrates a PCF-based energy saving operation according to an embodiment of the present disclosure.

[0120] At step 501, the NESF may send an energy reduction request or notification to the PCF(s) if the network's energy usage (or the network's energy usage per hour) needs to be reduced (e.g., if the network's power usage is temporarily too high, etc.).

[0121] In one embodiment, when energy saving is to be performed on a network slice-by-network basis, the NESF function may be incorporated into the NSSF. In this case, the NSSF equipped with the NESF function (e.g., the NSSF supporting the NESF function) may include S-NSSAI(s) corresponding to the request message when activating energy saving for specific network slice(s). In one embodiment, when energy saving is to be performed based on operator policy, the NESF function may be incorporated into the PCF or may be co-located with the PCF (i.e., the NESF may be co-located with the PCF). In one embodiment, the PCF equipped with the NESF may be a different PCF from the PCF of FIG. 5. In one embodiment, when providing energy saving function for a specific base station or cell, the NESF may be incorporated into the RAN. In one embodiment, for a RAN including NESF functionality (e.g., a RAN supporting NESF functionality), if energy usage is too high for a specific cell or base station, an energy saving request message may be transmitted to the SMF via the AMF, and the energy saving request message may include cell ID(s) or TA information. In one embodiment, NESF may also be included in OAM.

[0122] At this time, the energy saving request message that NESF transmits to PCF in step 501 may include at least one of the following information:

[0123] - Energy Saving Activation Indication (or Energy Saving Deactivation Indication): An energy saving activation indicator may be included. If deactivation of energy saving-enabled UEs is requested, an energy saving deactivation indicator may be included.

[0124] -required amount of PDU Sessions: This may include the number of sessions (required amount of PDU Sessions) to which network energy saving actions should be applied to save energy.

[0125] -sum of bitrates: may contain the sum of bitrates that must be reduced to save energy.

[0126] -S-NSSAI: When NESF is located in NSSF, network slice identifier information (i.e., S-NSSAI) that requires energy saving may be included.

[0127] In step 502, for terminals without subscription information, the PCF may transmit a request message to the UDR, including SUPI, DNN, and S-NSSAI. In one embodiment, for terminals without application data, the PCF may transmit a request message to the UDR, including the app ID, DNN, and S-NSSAI. In one embodiment, the request message may include Nudr_DM_Query.

[0128] In step 503, if the request message received from the PCF includes SUPI, DNN, and S-NSSAI, the UDR may include the corresponding subscriber information in the response message transmitted to the PCF. In one embodiment, if the message received from the PCF includes app ID, DNN, and S-NSSAI, the UDR may include the corresponding application data information in the response message transmitted to the PCF. In one embodiment, the response message may include Nudr_DM_Query response.

[0129] In one embodiment, if the message of step 501 (e.g., a notification message or a request message) includes an energy saving activation indication, the PCF may decide to apply energy saving to some or all of the terminals under its charge whose subscriber information (or application data information) includes Energy Saving Allowed information. The PCF may decide to update the session-related policy for the terminals to which energy saving has been applied in step 503.

[0130] In step 504, if the PCF decides to update the session-related policy for the terminals to which energy saving is to be applied, the PCF may include the newly determined PCC rule(s) in a notification message transmitted to the SMF. In one embodiment, the PCF may determine the Uplink Authorized Session-AMBR and Downlink Authorized Session-AMBR included in the PCC rule(s) based on pre-stored configuration information or by considering the sum of bitrates included in step 501.

[0131] In step 505, if the SMF receives updated PCC rule(s) from the PCF, the SMF may derive parameters to be transmitted to the UE / RAN / UPF for the PDU session based on the PCC rule(s). At this time, the SMF may transmit the Uplink Session-AMBR and / or the Downlink Session-AMBR to the UE / RAN / UPF.

[0132] FIG. 6 is a structural diagram illustrating a network entity according to an embodiment of the present disclosure.

[0133] The network entities illustrated in FIG. 6 may include all of the network entities according to the embodiment of the present disclosure, such as AMF, SMF, PCF, UPF, UDM, RAN, NSSF, etc.

[0134] A network entity according to one embodiment of the present disclosure may include a processor (620) that controls the overall operation of the network entity, a transceiver (600) including a transmitter and a receiver, and a memory (610). Of course, the present invention is not limited to the above example, and the network entity may include more or fewer components than those illustrated in FIG. 6.

[0135] According to one embodiment of the present disclosure, the transceiver (600) can transmit and receive signals with network entities or other network nodes. The signals transmitted and received with the network entities can include control information and data. In addition, the transceiver (600) can receive signals via a wireless channel, output them to the processor (620), and transmit the signals output from the processor (620) via the wireless channel.

[0136] According to one embodiment of the present disclosure, the processor (620) can control a network entity to perform any one of the operations described above. Meanwhile, the processor (620), the memory (610), and the transceiver (600) do not necessarily have to be implemented as separate modules, and can of course be implemented as a single component in the form of a single chip. In addition, the processor (620) and the transceiver (600) can be electrically connected. In addition, the processor (620) can be an Application Processor (AP), a Communication Processor (CP), a circuit, an application-specific circuit, or at least one processor.

[0137] According to one embodiment of the present disclosure, the processor (620) may control transmitting a subscription information request message of at least one first terminal to a unified data management (UDM) entity. The processor (620) may control receiving a subscription information response message including information on whether energy saving of the at least one first terminal is permitted from the UDM entity. The processor (620) may control receiving an energy saving request message including an activation indicator for energy saving from a second network entity. The processor (620) may select at least one second terminal to perform energy saving based on the information on whether energy saving of the at least one first terminal is permitted and the activation indicator for energy saving.

[0138] According to one embodiment of the present disclosure, the subscription information response message may include at least one of time information related to an energy saving operation and area information related to an energy saving operation, and the energy saving request message may include at least one of the number of terminals to which the energy saving operation needs to be applied for energy saving, the sum of bit rates to be reduced for energy saving, area information related to energy saving, and network slice identifier information requiring energy saving.

[0139] According to one embodiment of the present disclosure, the processor (620) controls receiving a registration request message from the at least one first terminal, and the subscription information request message of the at least one first terminal may be transmitted in response to the registration request message.

[0140] According to one embodiment of the present disclosure, the processor (620) may control receiving a PDU session establishment request message from a third terminal, determine whether the third terminal corresponds to at least one second terminal to perform the selected energy saving, and, if the third terminal corresponds to at least one second terminal to perform the selected energy saving, control transmitting a PDU session establishment request rejection message to the third terminal.

[0141] According to one embodiment of the present disclosure, the processor (620) determines whether the at least one first terminal corresponds to at least one second terminal to perform the selected energy saving, and if the at least one first terminal corresponds to at least one second terminal to perform the selected energy saving, the processor (620) can control to transmit a registration request rejection message to the at least one first terminal.

[0142] According to one embodiment of the present disclosure, the second network entity may include one of a network slicing selection function (NSSF) entity, a PCF entity, and a radio access network (RAN).

[0143] The methods according to the embodiments described in the claims or specification of the present disclosure may be implemented in the form of hardware, software, or a combination of hardware and software.

[0144] When implemented in software, a computer-readable storage medium storing one or more programs (software modules) may be provided. The one or more programs stored in the computer-readable storage medium are configured for execution by one or more processors within an electronic device. The one or more programs include instructions that cause the electronic device to execute methods according to the embodiments described in the claims or specification of the present disclosure.

[0145] These programs (software modules, software) may be stored in a non-volatile memory including random access memory, flash memory, read only memory (ROM), electrically erasable programmable read only memory (EEPROM), magnetic disc storage devices, compact disc ROMs (CD-ROMs), digital versatile discs (DVDs) or other forms of optical storage devices, magnetic cassettes, or may be stored in a memory configured as a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

[0146] Additionally, the program may be stored on an attachable storage device that is accessible via a communication network such as the Internet, an intranet, a local area network (LAN), a wide local area network (WLAN), a storage area network (SAN), or a combination thereof. Such a storage device may be connected to a device implementing an embodiment of the present disclosure via an external port. Additionally, a separate storage device on the communication network may be connected to a device implementing an embodiment of the present disclosure.

[0147] In the specific embodiments of the present disclosure described above, components included in the present disclosure are expressed singularly or plurally, depending on the specific embodiment presented. However, the singular or plural expressions are selected to suit the presented situation for convenience of explanation, and the present disclosure is not limited to singular or plural components. Components expressed in plural may be composed of singular elements, or components expressed in singular may be composed of plural elements.

[0148] While the detailed description of this disclosure has described specific embodiments, it should be understood that various modifications are possible without departing from the scope of this disclosure. Therefore, the scope of this disclosure should not be limited to the described embodiments, but should be defined not only by the scope of the claims described below, but also by equivalents thereof.

Claims

1. In a method of a first network entity in a wireless communication system, A step of receiving energy saving related subscription information for at least one first terminal from a UDM (unified data management) entity; A step of receiving an energy saving related message from a second network entity; and A method characterized by comprising: a step of selecting at least one second terminal to perform energy saving based on the energy saving-related subscription information of the at least one first terminal in response to the energy saving-related message.

2. In paragraph 1, The above energy saving related subscription information includes at least one of time information related to energy saving operation and area information related to energy saving operation, and A method characterized in that the energy saving related message includes at least one of the number of terminals to which energy saving operation needs to be applied for energy saving, the sum of bit rates to be reduced for energy saving, regional information related to energy saving, and network slice identifier information requiring energy saving.

3. In paragraph 1, A step of receiving at least one registration request message from at least one first terminal; and In response to at least one registration request message, the method comprises the step of transmitting a subscription information request message of at least one first terminal to the UDM (unified data management) entity. A method characterized in that the energy saving related subscription information of at least one first terminal is received in response to the subscription information request message.

4. In paragraph 1, A step of receiving a PDU session establishment request message from a third terminal; a step of determining whether the third terminal corresponds to at least one second terminal that performs the selected energy saving; and A method characterized by comprising the step of transmitting a PDU session establishment request rejection message to the third terminal when the third terminal corresponds to at least one second terminal that performs the selected energy saving.

5. In paragraph 3, A step of determining at least one fourth terminal corresponding to at least one second terminal to perform the selected energy saving among the at least one first terminal; and A method characterized by further comprising the step of transmitting at least one registration request rejection message to at least one fourth terminal.

6. In paragraph 1, The above first network entity includes one of an access and mobility management function (AMF) entity, a session management function (SMF) entity, and a policy control function (PCF) entity, and A method, characterized in that the second network entity comprises one of a network slicing selection function (NSSF) entity, a PCF entity, and a radio access network (RAN).

7. In the first paragraph, the energy saving related message includes an activation indicator for energy saving, A method characterized in that at least one second terminal to perform the energy saving is determined based on the activation indicator.

8. In paragraph 6, if the first network entity is the PCF entity, A method characterized by further comprising the step of updating a session related policy for at least one second terminal.

9. In a first network entity in a wireless communication system, Transmitter and receiver; comprising at least one processor; wherein the at least one processor comprises: Receive energy saving related subscription information for at least one first terminal from a UDM (unified data management) entity, Receive energy saving related messages from a second network entity, and A first network entity characterized in that, in response to the energy saving related message, it is configured to select at least one second terminal to perform energy saving based on the energy saving related subscription information of the at least one first terminal.

10. In paragraph 9, The above energy saving related subscription information includes at least one of time information related to energy saving operation and area information related to energy saving operation. A first network entity, characterized in that the energy saving related message includes at least one of an activation indicator for energy saving, the number of terminals to which energy saving operation needs to be applied for energy saving, a sum of bit rates to be reduced for energy saving, area information related to energy saving, and network slice identifier information requiring energy saving.

11. In the 9th paragraph, the at least one processor receives a registration request message from the at least one first terminal, configured to transmit a subscription information request message of at least one first terminal to the UDM (unified data management) entity, and A first network entity, characterized in that the energy saving related subscription information of the at least one first terminal is received in response to the subscription information request message.

12. In the 9th paragraph, at least one processor, Receive a PDU session establishment request message from a third terminal, determines whether the third terminal corresponds to at least one second terminal that performs the selected energy saving, and A first network entity characterized in that it is configured to transmit a PDU session establishment request rejection message to the third terminal if the third terminal corresponds to at least one second terminal that performs the selected energy saving.

13. In the 11th paragraph, at least one processor, determining at least one fourth terminal corresponding to at least one second terminal to perform the selected energy saving among the at least one first terminal; and A first network entity characterized in that it is configured to transmit at least one registration request rejection message to at least one fourth terminal.

14. In paragraph 9, The above first network entity includes one of an access and mobility management function (AMF) entity, a session management function (SMF) entity, and a policy control function (PCF) entity, and A first network entity, characterized in that the second network entity comprises one of a network slicing selection function (NSSF) entity, a PCF entity, and a radio access network (RAN).

15. In paragraph 9, the energy saving related message includes an activation indicator for energy saving, A first network entity, characterized in that at least one second terminal to perform the energy saving is determined based on the activation indicator.

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