WO2025063592A1 - Method and device for saving network energy in wireless communication system - Google Patents

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 wireless communication system

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

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 (㎜Wave), 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 delay time that is reduced by one-tenth.

In the early stages of 5G mobile communication technology, the goal was to support services and satisfy performance requirements for enhanced Mobile Broadband (eMBB), Ultra-Reliable Low-Latency Communications (URLLC), and massive Machine-Type Communications (mMTC). The technologies included 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.

Currently, discussions are underway on improving and enhancing the initial 5G mobile communication technology in consideration of the services that the 5G mobile communication technology was intended to support, and physical layer standardization is in progress for technologies such as V2X (Vehicle-to-Everything) to assist in driving decisions of autonomous vehicles and increase user convenience based on the location and status information transmitted by the vehicle, 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.

In addition, standardization of wireless interface architecture/protocols for technologies such as the Industrial Internet of Things (IIoT) to support new services through linkage and convergence with other industries, Integrated Access and Backhaul (IAB) to provide nodes for expanding network service areas by integrating wireless backhaul links and access links, Mobility Enhancement including Conditional Handover and Dual Active Protocol Stack (DAPS) handover, and 2-step RACH for NR to simplify random access procedures is also in progress, and standardization of system architecture/services for 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 is also in progress.

When such 5G mobile communication systems are commercialized, an explosive increase in connected devices will be connected to the communication network, which will require enhanced functions and performance of 5G mobile communication systems and integrated operation of connected devices. To this end, new research will be conducted on improving 5G performance and reducing complexity using eXtended Reality (XR), Artificial Intelligence (AI), and Machine Learning (ML) to efficiently support Augmented Reality (AR), Virtual Reality (VR), and Mixed Reality (MR), AI service support, metaverse service support, and drone communications.

In addition, the development of these 5G mobile communication systems will require 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), and 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, and AI-based communication technology that utilizes AI (Artificial Intelligence) from the design stage and embeds end-to-end AI support functions to realize system optimization, and ultra-high-performance communication and computing resources to provide services with a level of complexity that goes beyond the limits of terminal computing capabilities. It could serve as a basis for the development of next-generation distributed computing technologies that utilize this technology.

The present disclosure proposes a method and device for reducing energy usage consumed for providing a service in a wireless communication system or a mobile communication system.

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

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 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.

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.

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.

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.

Figure 1 illustrates the structure of a 5G system.

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.

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

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

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

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

Hereinafter, an embodiment of the present disclosure will be described in detail with reference to the attached drawings.

In describing the present disclosure, descriptions of technical contents that are well known in the technical field to which the present disclosure belongs and are not directly related to the present disclosure will be omitted. This is to convey the gist of the present disclosure more clearly without obscuring it by omitting unnecessary explanations. In addition, the terms described below are terms defined in consideration of functions in the present disclosure, and these may vary depending on the intention or custom of the user or operator. Therefore, the definitions should be made based on the contents throughout this specification.

For the same reason, some components in the attached drawings are exaggerated, omitted, or schematically illustrated. In addition, the size of each component does not entirely reflect the actual size. The same or corresponding components in each drawing are given the same reference numbers.

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 xNode B (wherein 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) refers to a wireless transmission path of a signal that a base station transmits to a terminal, and an uplink (UL) refers to a wireless transmission path of a signal that a terminal transmits to an air base station. Additionally, a sidelink (SL) may exist that refers to a wireless transmission path of a signal that a terminal transmits to another terminal.

In addition, although LTE, LTE-A or 5G system may be described as an example below, the embodiment of the present disclosure may be applied to other communication systems having similar technical backgrounds or channel types. For example, 5G-Advance or NR-Advance or 6th generation mobile communication technology (6G) developed after 5G mobile communication technology (or new radio, NR) may be included here, and 5G below may be a concept including existing LTE, LTE-A and other similar services. In addition, the present disclosure may be applied to other communication systems through some modifications without significantly departing from the scope of the present disclosure as judged by a person having skilled technical knowledge.

At this time, it will be understood that each block of the processing flow diagrams and combinations of the flow diagrams can be performed by computer program instructions. These computer program instructions can be loaded onto 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 flow diagram block(s). These computer program instructions can also be stored in a computer-available or computer-readable memory that can be directed to 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 an article of manufacture that includes an instruction means for performing the functions described in the flow diagram block(s). Since the computer program instructions may also be installed on a computer or other programmable data processing apparatus, a series of operational steps may be performed on the computer or other programmable data processing apparatus to produce a computer-executable process, so that the instructions executing the computer or other programmable data processing apparatus may also provide steps for executing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that contains one or more executable instructions for performing a particular logical function(s). It should also be noted that in some alternative implementations, the functions mentioned in the blocks may occur out of order. For example, two blocks shown in succession may in fact be performed substantially concurrently, or the blocks may sometimes be performed in reverse order, depending on the functionality they perform.

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 in an addressable storage medium and may be configured to reproduce one or more processors. Accordingly, as an example, the '~ part' includes components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuits, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ parts' may be combined into a smaller number of components and '~ parts' or further separated into additional components and '~ parts'. In addition, the components and '~parts' may be implemented to regenerate one or more CPUs within the device or secure multimedia card. Also, in an embodiment, the '~part' may include one or more processors.

3GPP, which is in charge of cellular mobile communication standards, is naming a new core network structure as 5G Core (5GC) and standardizing it to promote evolution from 4G LTE system to 5G system. 5GC supports the following differentiated functions compared to Evolved Packet Core (EPC), which is the network core for 4G.

5GC introduces the Network Slice feature. As a requirement of 5G, 5GC must support various types of terminal types and services; e.g., enhanced Mobile Broadband (eMBB), Ultra Reliable Low Latency Communications (URLLC), and massive Machine Type Communications (mMTC). Each of these terminals/services has different requirements for the core network. For example, eMBB service may require high data rate, while URLLC service may require high stability and low latency. To satisfy these various service requirements, Network Slice technology has been proposed.

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

5GC can easily support the network virtualization paradigm by separating the mobility management function and the session management function. In 4G LTE, all terminals can receive services from the network through signaling exchange with a single core entity called the mobility management entity (MME) that is responsible for registration, authentication, mobility management, and session management functions. In 5G, the number of terminals (including, for example, MTC terminals) increases explosively, and the mobility and traffic/session characteristics that must be supported depending on the type of terminal are segmented. Therefore, if a single entity (for example, MME) supports all functions, the scalability that adds entities for each required function will inevitably decrease. Therefore, various functions are being developed based on a structure that separates the mobility management function and 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.

Figure 1 illustrates the structure of a 5G system.

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 AMF (access and mobility management function) (120) that provides a mobility management function of the UE, a SMF (session management function) (135) that provides a session management function, a UPF (user plane function) (130) that performs a data transfer role, a PCF (policy control function) (140) that provides a policy control function, a UDM (unified data management) (145) that provides data management functions such as subscriber data and policy control data, and a UDR (unified data repository) that stores data of various network functions (NFs) such as the UDM (145).

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 (NSAFF) (180), and a data network (DN) (175).

In the 3GPP system, a conceptual link connecting NFs within a 5G system is defined as a reference point. The following is an example of a reference point included in the 5G system architecture represented in Fig. 1.

- N1: Reference point between UE and AMF

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

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

- N4: Reference point between SMF and UPF

- N5: Reference point between PCF and AF

- N6: Reference point between UPF and DN

- N7: Reference point between SMF and PCF

- N8: Reference point between UDM and AMF

- N9: Reference point between two core UPFs

- N10: Reference point between UDM and SMF

- N11: Reference points between AMF and SMF

- N12: Reference point between AMF and AUSF

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

- N14: Reference point between two AMFs

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

In 5G systems, network slicing technology refers to a technology and architecture that enables multiple virtualized, independent, logical networks in a single physical network. To satisfy specialized requirements of services/applications, a network operator configures a virtual end-to-end network called a network slice to provide services. At this time, a network slice is distinguished by an identifier called single-network slice selection assistance information (S-NSSAI). In a 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 generated through one of these S-NSSAIs (i.e., network slices).

The mobile communication system receives identifier information of terminals that can participate in federated learning and QoS (quality of service) requirements 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 result 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.

In the present disclosure, NESF (network energy saving function) is a function that monitors network energy consumption and can request an operation for network energy saving based on the monitoring. NESF can be located in one of the following NFs: NSSF, AMF, SMF, PCF, NWDAF, OAM, RAN. However, it is not limited thereto.

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.

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:

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

- UE MM Core Network Capability: Indicates the capability information of the terminal. For each function, the terminal can include information indicating that it supports the function.

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

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

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.

In step 205, if the registration is successful and there is no subscription data for the UE, the AMF may send a Nudm_SDM_Get request message including the UE ID to the UDM. 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.

In step 206, if the UDM has stored subscription information in the UDR, the 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).

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.

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

- 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 access (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 a maximum allowed data rate (e.g., a maximum uplink data rate, a maximum downlink data rate, a maximum uplink delay, a 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.

In one embodiment, if a subscriber consents or if a subscriber subscribes to a rate plan that allows his/her terminal to have access restricted or speed restricted 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 OAM (Operations, administration, and management) stores subscriber information in the UDR, the OAM may update the Energy Saving Allowed information for the subscriber terminal in the UDR (e.g., add information allowing the network energy saving operation).

- Energy Saving time: May include information on 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 PM to 5 PM) or an absolute time of day.

- Energy Saving area: May include information on areas where network energy saving operations can be applied to terminals. The area information may consist of cell ID(s) or geographical location information, etc.

AMF may store the information acquired in step 208. The information may be stored in the UE Context of AMF.

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

At step 210, UDM may send a response message to AMF for step 209.

In step 211, the AMF may include a registration accept message to be transmitted to the terminal in the message transmitted to the RAN.

At step 212, the RAN may send the registration accept message received from the AMF to the UE.

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

In step 301, the NESF (network energy saving function) may transmit an energy saving request to the AMF(s) when it is necessary to reduce the energy usage of the network (or the network energy usage per hour) (e.g., when the power usage of the network is temporarily too high, etc.). In one embodiment, when it is desired to perform energy saving per network slice, the NESF function may be embedded in the NSSF (network slicing selection function). In this case, the NSSF embedded 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).

In one embodiment, when energy saving is to be done based on an operator policy, the NESF function may be included in the PCF. In one embodiment, when energy saving function is to be 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), when energy usage is too high for a specific cell or base station, an energy saving request message may be transmitted to the AMF, and the energy saving request message may include cell ID(s) or TA information. In one embodiment, the NESF may be included in the OAM.

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:

-energy saving activation indication (or energy saving deactivation indication): An energy saving activation indication may be included. An energy saving deactivation indication may be included when requesting deactivation for UEs with energy saving enabled.

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

-sum of bitrates: may include the sum of bitrates that should be reduced to save energy.

-energy saving area: If NESF is located in PCF, OAM, or RAN, it may include information on areas requiring energy saving (e.g., Tracking Area information, Cell ID information).

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

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

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).

In one embodiment, if the message of step 301 includes energy saving area, the AMF 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 301 includes S-NSSAI, the AMF can determine UEs to which network energy saving is to be applied among UEs to which the S-NSSAI is included in Allowed NSSAI or UEs having a PDU Session established for the S-NSSAI.

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

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.

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

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

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 may include at least one of a Back-off Timer (BOT) and a reject cause (e.g., rejection due to network energy saving operation, etc.) in the message. If the received PDU session establishment reject message includes a Back-off Timer, the UE may start the corresponding 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.

At step 304a, AMF can receive a registration request message from the terminal.

In step 304b, the AMF can verify whether the terminal is a terminal to which network energy saving is applied. In one embodiment, the AMF can verify 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 together with a BOT (back-off timer).

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

In step 305, the AMF may perform User-plane deactivation for PDU Session(s) of the UE(s) that have decided to apply the network energy saving operation 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) that have decided to apply the network energy saving operation. At this time, the message that the AMF transmits to the SMF for each PDU Session that it wishes to deactivate may be a 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.

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

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))).

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 in the message the N2 SM Information included in the message received from the SMF. When the RAN receives the N2 PDU Session Resource Release Command from the AMF, it may transmit an RRC Connection Reconfiguration message to the UE to release NG-RAN resources for the PDU session included in the message. Thereafter, 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.

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

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

In one embodiment, when energy saving is to be done based on an operator policy, the NESF function may be included in the PCF. In one embodiment, when energy saving function is to be 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), when energy usage is too high for a specific cell or base station, an energy saving request message may be transmitted to the SMF through the AMF, and the cell ID(s) or TA information may be included in the energy saving request message. In one embodiment, the NESF may be included in the OAM.

At this time, the energy saving request message transmitted by NESF to SMF in step 401 may include at least one of the following information:

-energy saving activation indication (or energy saving deactivation indication): An energy saving activation indication may be included. An energy saving deactivation indication may be included when requesting deactivation for UEs with energy saving enabled.

-required amount of PDU Sessions: The number of sessions to which network energy saving actions should be applied (required amount of PDU Sessions) may be included.

-sum of bitrates: may include the sum of bitrates that should be reduced to save energy.

-energy saving area: If NESF is located in PCF, OAM, or RAN, it may include information on areas requiring energy saving (e.g., Tracking Area information, Cell ID information).

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

In step 402, if the message of step 401 includes an energy saving activation indication, the SMF may select among the registered UEs the network energy saving is to be applied to, 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 of the newly selected UEs.

In one embodiment, the SMF 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). The SMF may transmit a subscription information request message including a UE ID to the UDM for a UE without subscription information, and the UDM may include the subscription information in a response message transmitted to the SMF.

In one embodiment, if the message of step 401 includes 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 corresponding S-NSSAI.

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

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

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

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

In step 403c, if the SMF determines that the 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 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 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 may not transmit a PDU session establishment request message until it expires.

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

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

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))).

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 in the message the N2 SM Information included in the message received from the SMF. When the RAN receives the N2 PDU Session Resource Release Command from the AMF, it may transmit an RRC Connection Reconfiguration message to the UE to release NG-RAN resources for the PDU session included in the message. Thereafter, 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.

Figure 5 illustrates a PCF-based energy saving operation according to an embodiment of the present disclosure.

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

In one embodiment, when it is desired to perform energy saving on a network slice basis, the NESF function may be embedded in the NSSF. In this case, the NSSF embedded with the NESF function (e.g., the NSSF supporting the NESF function) may include S-NSSAI(s) corresponding to the request message when it is desired to activate energy saving for specific network slice(s). In one embodiment, when it is desired to perform energy saving based on an operator policy, the NESF function may be embedded in the PCF or may be co-located with the PCF (i.e., the NESF is co-located with the PCF). In one embodiment, the PCF embedded with the NESF may be a different PCF from the PCF of FIG. 5. In one embodiment, when providing the energy saving function for a specific base station or cell, the NESF may be embedded in the RAN. In one embodiment, for a RAN with 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 through 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.

At this time, the energy saving request message transmitted by NESF to PCF in step 501 may include at least one of the following information:

-energy saving activation indication (or energy saving deactivation indication): An energy saving activation indication may be included. An energy saving deactivation indication may be included when requesting deactivation for UEs with energy saving enabled.

-required amount of PDU Sessions: The number of sessions to which network energy saving actions should be applied (required amount of PDU Sessions) may be included.

-sum of bitrates: may include the sum of bitrates that should be reduced to save energy.

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

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

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

In one embodiment, if the message (e.g., notification message or request message) of step 501 includes an energy saving activation indication, the PCF may decide to apply energy saving to some or all of the terminals among the terminals it is in charge of, which include Energy Saving Allowed information in their subscriber information (or application data information). The PCF may decide to update the session-related policy for the terminals to which energy saving has been decided in step 503.

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 corresponding PCC rule(s) based on pre-stored configuration information or by considering the sum of bitrates included in step 501.

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 Uplink Session-AMBR and/or Downlink Session-AMBR to the UE/RAN/UPF.

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

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

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 the configuration illustrated in FIG. 6.

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 through a wireless channel and output them to the processor (620), and transmit the signals output from the processor (620) through the wireless channel.

According to one embodiment of the present disclosure, the processor (620) can control a network entity to perform any one of the operations of the above-described embodiments. Meanwhile, the processor (620), the memory (610), and the transceiver (600) do not necessarily have to be implemented as separate modules, and of course, they can 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 AP (Application Processor), a CP (Communication Processor), a circuit, an application-specific circuit, or at least one processor.

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

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 the 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 that need to be reduced for energy saving, area information related to energy saving, and network slice identifier information that needs energy saving.

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.

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

According to one embodiment of the present disclosure, the processor (620) may determine 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, control to transmit a registration request rejection message to the at least one first terminal.

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).

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.

In the case of software implementation, 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 in 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 specifications of the present disclosure.

These programs (software modules, software) may be stored in a random access memory, a non-volatile memory including a flash memory, a ROM (Read Only Memory), an Electrically Erasable Programmable Read Only Memory (EEPROM), a magnetic disc storage device, a Compact Disc-ROM (CD-ROM), a Digital Versatile Discs (DVDs) or other forms of optical storage devices, a magnetic cassette. Or, they may be stored in a memory composed of a combination of some or all of these. In addition, each configuration memory may be included in multiple numbers.

Additionally, the program may be stored in an attachable storage device that is accessible via a communications network, such as the Internet, an Intranet, a Local Area Network (LAN), a Wide LAN (WLAN), or a Storage Area Network (SAN), or a combination thereof. The storage device may be connected to the device performing the embodiments of the present disclosure via an external port. Additionally, a separate storage device on the communications network may be connected to the device performing the embodiments of the present disclosure.

In the specific embodiments of the present disclosure described above, the components included in the present disclosure are expressed in the singular or plural form according to the specific embodiments presented. However, the singular or plural expressions are selected to suit the presented situation for the convenience of explanation, and the present disclosure is not limited to the singular or plural components, and even if a component is expressed in the plural form, it may be composed of the singular form, or even if a component is expressed in the singular form, it may be composed of the plural form.

Meanwhile, although the detailed description of the present disclosure has described specific embodiments, it is obvious that various modifications are possible within the scope of the present disclosure. Therefore, the scope of the present disclosure should not be limited to the described embodiments, but should be determined not only by the scope of the claims described below, but also by equivalents of the scope of the claims.

Claims (15)

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. In the first paragraph, 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. In the first paragraph, 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. In the first paragraph, 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. In the third paragraph, 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. In the first paragraph, 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 includes one of a network slicing selection function (NSSF) entity, a PCF entity, and a radio access network (RAN). 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. In the 6th paragraph, 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. In a wireless communication system, at a first network entity, Transmitter and receiver; At least one processor; comprising: 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, the first network entity 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. In Article 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, a 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. 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. 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. 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. In Article 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). In the 9th paragraph, 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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