Network element selection method and apparatus

Abstract

A network element selection method and apparatus. In the network element selection method, a first network element receives description information of one or more second network elements in a network, the description information of each second network element among the one or more second network elements being used for indicating whether the second network element is disabled when the network is in an energy-saving state; and on the basis of the description information of the one or more second network elements, the first network element selects from among the one or more second network elements a second network element for a session that a terminal device requests to establish. Hence, when the first network element selects the second network element for the session, network energy saving is taken into consideration, that is, selection is performed on the basis of one or more pieces of received description information, thereby providing a condition for whether the second network element selected for the session is disabled when the network is in the energy-saving state.

Description

Network element selection method and device

[0001] This application claims priority to the Chinese patent application filed with the State Intellectual Property Office of China on November 2, 2023, with application number 202311454004.2 and application name “Network Element Selection Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of communication technology, and in particular to a network element selection method and device. Background Art

[0003] In wireless communication networks, terminal devices can request the establishment of a protocol data unit (PDU) session when they have service needs. A PDU session provides a logical connection between the terminal device and the data network (DN). During the PDU session establishment process, a user plane function (UPF) network element is selected for the PDU session. The UPF network element interconnects the PDU session with the data network. Considering network energy conservation, how to select the UPF network element for the PDU session is a technical issue that needs to be addressed.

[0004] Summary of the Invention

[0005] The embodiments of the present application provide a network element selection method and apparatus, which can select a second network element for a session in consideration of network energy saving.

[0006] In a first aspect, the present application provides a network element selection method, which can be applied to a first network element, a chip in the first network element, or a logic module or software that can implement all or part of the functions of the first network element. The following description takes the first network element as an example. The method includes: the first network element receives description information of one or more second network elements in the network, where the description information of each second network element in the one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state; based on the description information of the one or more second network elements, the first network element selects a second network element from the one or more second network elements for a session requested to be established by a terminal device.

[0007] It can be seen that when the first network element selects the second network element for the session, it will make the selection based on the descriptive information of one or more second network elements received. The descriptive information of the second network element is used to indicate whether the second network element is turned off when the network is in an energy-saving state, which is conducive to providing conditions for whether to turn off the second network element selected for the session when the network is in an energy-saving state.

[0008] In an optional embodiment, the first network element selects a second network element from the one or more second network elements for a session requested to be established by a terminal device based on description information of the one or more second network elements, including: the first network element selects the second network element from the one or more second network elements for the session based on a service continuity requirement corresponding to the session and the description information of the one or more second network elements. It can be seen that when the first network element selects the second network element for the session, it also considers the service continuity requirement corresponding to the session, which is conducive to ensuring that the selected second network element can meet the service continuity requirement corresponding to the session.

[0009] In an optional embodiment, when the service continuity requirement corresponding to the session indicates that the service transmission in the network should be maintained continuously during the duration of the session, the description information of the second network element selected for the session indicates that the second network element should not be shut down when the network is in an energy-saving state.

[0010] In an optional implementation, the service continuity requirement corresponding to the session is a session and service continuity (SSC) mode corresponding to the session.

[0011] In an optional embodiment, the method also includes: the first network element receives first information from the terminal device, the first information is used to indicate the SSC mode requested by the terminal device for the session; the first network element determines the SSC mode corresponding to the session based on the SSC mode requested by the terminal device for the session.

[0012] In an optional embodiment, when the SSC mode corresponding to a session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state. SSC mode 1 indicates that changing the second network element corresponding to the session during the session duration is not supported. This approach, for sessions corresponding to SSC mode 1, facilitates providing conditions for not shutting down the second network element selected for the session when the network is in an energy-saving state, thereby ensuring continuous transmission of services corresponding to the session in the network and guaranteeing session quality.

[0013] In an optional embodiment, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected for the session indicates that the second network element is shut down when the network is in an energy-saving state. SSC mode 2 and SSC mode 3 indicate support for changing the second network element corresponding to the session during the session duration. This approach, for sessions corresponding to SSC mode 2 or SSC mode 3, facilitates shutting down the second network element selected for the session when the network is in an energy-saving state, thereby saving network energy consumption.

[0014] In an optional embodiment, the description information of each second network element in one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state, including: the description information of each second network element in one or more second network elements is used to indicate whether the data network and / or network slice supported by the second network element is turned off when the network is in an energy-saving state.

[0015] The method also includes: the first network element receives second information from the terminal device, and the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device. When the SSC mode corresponding to the session is SSC mode 1, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed, and SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session. This method is beneficial for sessions corresponding to SSC mode 1, and is conducive to providing conditions for not closing the data network and / or network slice associated with the session requested by the terminal device supported by the second network element selected for the session when the network is in an energy-saving state, thereby ensuring that the services corresponding to the session are transmitted continuously in the network.

[0016] Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is closed. SSC mode 2 and SSC mode 3 indicate support for changing the second network element corresponding to the session during the duration of the session. This method, for sessions corresponding to SSC mode 2 or mode 3, is conducive to providing conditions for closing the data network and / or network slice associated with the session requested by the terminal device supported by the second network element selected for the session when the network is in an energy-saving state, thereby saving network energy consumption.

[0017] In an optional embodiment, when the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state, the description information of the second network element is further used to indicate a priority for shutting down the second network element when the network is in an energy-saving state. The first network element selects a second network element for the session from one or more second network elements based on a service continuity requirement corresponding to the session and the description information of the one or more second network elements, including: when the SSC mode corresponding to the session is SSC mode 1 and the description information of each of the one or more second network elements indicates that the second network element is shut down when the network is in an energy-saving state, the first network element selects the second network element for the session based on the priority for shutting down the second network element when the network is in an energy-saving state indicated by the description information of each of the one or more second network elements; wherein SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session.

[0018] In an optional embodiment, the description information of each of the one or more second network elements is further used to indicate a validity period of the description information. Before the first network element selects a second network element from the one or more second network elements for a session requested to be established by the terminal device based on the description information of the one or more second network elements, the method further includes: the first network element receiving third information from the terminal device, the third information being used to indicate a duration of the session requested to be established by the terminal device; and the validity period of the description information of the second network element selected for the session includes part or all of the duration.

[0019] In an optional implementation manner, the first network element receives description information of one or more second network elements in the network, including: the first network element receives description information of the second network element sent by each of the one or more second network elements.

[0020] In an optional implementation manner, the first network element receives description information of one or more second network elements in the network, including: the first network element receives description information of one or more second network elements sent by a third network element.

[0021] In an optional implementation, the method further includes: the first network element receiving a message from the terminal device requesting to establish a session.

[0022] In an optional implementation manner, the first network element is a session management function network element, and the second network element is a user plane function network element.

[0023] In a second aspect, the present application further provides a communication device. The communication device may be a first network element, a chip within the first network element, or a logic module or software capable of implementing all or part of the first network element's functions. The communication device has the function of implementing some or all of the embodiments described in the first aspect above. The functions may be implemented in hardware or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the functions described above.

[0024] In one possible design, the communication device may include a processing unit and a communication unit, wherein the processing unit is configured to support the communication device in performing the corresponding functions of the above method. The communication unit is used to support communication between the communication device and other communication devices. The communication device may also include a storage unit, which is coupled to the processing unit and the communication unit and stores program instructions and data necessary for the communication device. In addition, the processing unit may be used to control the communication unit to transmit and receive data / signaling.

[0025] In one embodiment, a communication unit is configured to receive description information of one or more second network elements in a network, where the description information of each of the one or more second network elements indicates whether the second network element is shut down when the network is in an energy-saving state. A processing unit is configured to select, from the one or more second network elements, a second network element for a session requested to be established by a terminal device based on the description information of the one or more second network elements.

[0026] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the first aspect above and will not be described in detail here.

[0027] As an example, the communication unit may be a transceiver or a communication interface, the storage unit may be a memory, and the processing unit may be a processor. The processor is coupled to the memory, the memory is used to store programs or instructions to the processor, and the processor is configured to cause the communication device to perform the method described in the first aspect when the programs or instructions are executed by the processor. The transceiver or communication interface may be configured to transmit and receive signals and / or data.

[0028] In one embodiment, a transceiver is configured to receive description information of one or more second network elements in a network, where the description information of each of the one or more second network elements indicates whether the second network element is shut down when the network is in an energy-saving state. A processor is configured to select, based on the description information of the one or more second network elements, a second network element from the one or more second network elements for a session requested to be established by a terminal device.

[0029] In addition, in this aspect, other optional implementations of the communication device can refer to the relevant content of the first aspect above and will not be described in detail here.

[0030] In another embodiment, the communication device is a chip or a chip system. The processing unit may also be embodied as a processing circuit or a logic circuit; and the transceiver unit may be an input / output interface, an interface circuit, an output circuit, an input circuit, a pin, or a related circuit on the chip or chip system.

[0031] During implementation, the processor can be used to perform, for example, but not limited to, baseband-related processing, and the transceiver or communication interface can be used to perform, for example, but not limited to, radio frequency transceiver. The above-mentioned devices can be provided on separate chips, or at least partially or entirely on the same chip. For example, the processor can be further divided into an analog baseband processor and a digital baseband processor. The analog baseband processor can be integrated with the transceiver (or communication interface) on the same chip, while the digital baseband processor can be provided on a separate chip. With the continuous development of integrated circuit technology, more and more devices can be integrated on the same chip. For example, a digital baseband processor can be integrated with multiple application processors (such as, but not limited to, a graphics processor, a multimedia processor, etc.) on the same chip. Such a chip can be called a system on a chip (SoC). Whether each device is provided independently on different chips or integrated on one or more chips often depends on the needs of the product design. The embodiments of the present application do not limit the implementation form of the above-mentioned devices.

[0032] In a third aspect, the present application also provides a processor for executing the various methods described above. In the process of executing these methods, the process of sending the above-mentioned signal and receiving the above-mentioned signal in the above-mentioned method can be understood as the process of outputting the above-mentioned signal by the processor, and the process of inputting the above-mentioned signal by the processor. When outputting the above-mentioned signal, the processor outputs the above-mentioned signal to the transceiver so that it is transmitted by the transceiver (or communication interface). After being output by the processor, the above-mentioned signal may also need to undergo other processing before reaching the transceiver (or communication interface). Similarly, when the processor receives the above-mentioned input signal, the transceiver (or communication interface) receives the above-mentioned signal and inputs it into the processor. Furthermore, after the transceiver (or communication interface) receives the above-mentioned signal, the above-mentioned signal may need to undergo other processing before being input into the processor.

[0033] For the sending and receiving operations involved in the processor, unless otherwise specified, or unless they conflict with their actual functions or internal logic in the relevant descriptions, they can be more generally understood as processor output, reception, input and other operations, rather than sending and receiving operations directly performed by the RF circuit and antenna.

[0034] During implementation, the processor may be a processor specifically configured to execute these methods, or may be a processor that executes computer instructions in a memory to execute these methods, such as a general-purpose processor. The memory may be a non-transitory memory, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or disposed on separate chips. The embodiments of the present application do not limit the type of memory or the configuration of the memory and the processor.

[0035] In a fourth aspect, the present application further provides a communication system, comprising the first network element and the second network element of the above aspects. In another possible design, the system may further include other devices that interact with the first network element and / or the second network element in the solution provided by the present application.

[0036] In a fifth aspect, the present application provides a computer-readable storage medium, which stores a computer program. When the computer program is run, the method described in the first aspect above is executed.

[0037] In a sixth aspect, the present application further provides a computer program product comprising instructions, the computer program product comprising: computer program code, which, when the computer program code is run, enables the method described in the first aspect above to be executed.

[0038] In a seventh aspect, the present application provides a chip system, which includes a processor and an interface, wherein the interface is used to obtain a program or instruction, and the processor is used to call the program or instruction to implement the functions involved in the first aspect. In one possible design, the chip system also includes a memory, which is used to store program instructions and data necessary for the terminal. The chip system can be composed of a chip or can include a chip and other discrete devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] FIG1 is a schematic diagram of a 5G network architecture based on a service-oriented interface;

[0040] FIG2 is a schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0041] FIG3 is a schematic diagram of a network state;

[0042] FIG4 is a schematic diagram of a network energy-saving state;

[0043] FIG5 is a flow chart of a network element selection method provided in an embodiment of the present application;

[0044] FIG6 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0045] FIG7 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0046] FIG8 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0047] FIG9 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0048] FIG10 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0049] FIG11 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0050] FIG12 is a schematic diagram of another network element selection method provided in an embodiment of the present application;

[0051] FIG13 is a schematic structural diagram of a communication device provided in an embodiment of the present application;

[0052] FIG14 is a schematic structural diagram of another communication device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0053] The embodiments of the present application are described below in conjunction with the drawings in the embodiments of the present application.

[0054] First, in order to better understand the network element selection method disclosed in the embodiment of the present application, a communication system to which the embodiment of the present application is applicable is described.

[0055] The technical solutions of the embodiments of the present application can be applied to various communication systems. For example, the global mobile communication system, the long term evolution (LTE) system, the universal mobile communication system, the fourth generation (4G) mobile communication system, the fourth and fifth generation (4.5G) mobile communication system, the fifth generation (5G) mobile communication system, and with the continuous development of communication technology, the technical solutions of the embodiments of the present application can also be used for subsequently evolved communication systems, such as the sixth generation (6G) mobile communication system, the seventh generation (7G) mobile communication system, and so on.

[0056] Please refer to Figure 1, which is a schematic diagram of a 5G network architecture based on a service-oriented interface. The 5G network architecture shown in Figure 1 includes terminal equipment, a data network (DN), and an operator network. Among them, the operator network includes the radio access network (RAN) and the core network. The core network includes one or more of the following network elements: network slice selection function (NSSF) network element, network slice-specific authentication and authorization function (NSSAAF) network element, authentication server function (AUSF) network element, network exposure function (NEF) network element, policy control function (PCF) network element, unified data management (UDM) network element, unified data repository (UDR), network storage function (NRF) network element, application function (AF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, user plane function (UPF) network element, service communication proxy (SCP) network element, network slice admission control function (NSACF) network element, etc.

[0057] In the embodiment of the present application, the terminal device may also be referred to as user equipment (UE), terminal, access terminal, user unit, user station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, user agent or user device, and can be applied to 4G, 5G or even 6G systems, etc. The terminal device in the embodiment of the present application can be a joint device that transmits and receives digital signals on an ordinary telephone line, and can also be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a mobile phone, a tablet computer (pad), a computer with wireless transceiver function, a head mounted display (HMD), a virtual reality (VR) terminal device (such as VR glasses), an augmented reality (AR) terminal device (such as AR glasses), a mixed reality (MR) terminal device, a wireless terminal in industrial control, a processing device connected to a wireless modem, a tactile terminal device, a vehicle-mounted terminal device, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, a wireless terminal in a medical device ... home), the aforementioned wireless terminal type road side unit (RSU), wearable terminal equipment, and so on.

[0058] The RAN is used to implement wireless-related functions. RAN equipment includes, but is not limited to, base stations (BS), radio network controllers (RNC), base station controllers (BSC), base transceiver stations (BTS), home network equipment (e.g., home evolved Node B, or HNB), baseband units (BBU), wireless relay nodes, wireless backhaul nodes, and transmission and reception points (TRP; or transmission points, TP). A base station is a device deployed in a radio access network to provide wireless communication functions. It can also be referred to as a base station device, such as an evolved Node B (eNB or e-NodeB) or Node B in an LTE system, a base station (gNodeB or gNB) in a 5G system, or a base station in a 6G system. A base station can include a BBU and a remote radio unit (RRU). The BBU and RRU can be placed in different locations, for example, with the RRU being remotely located in a high-traffic area and the BBU being placed in a central equipment room. The BBU and RRU can also be placed in the same equipment room. They can also be separate components within the same rack. Base stations can be in the following forms: macro base stations, micro base stations (also known as small cells), pico base stations, relay stations, access points, balloon stations, and more.

[0059] The AMF network element is responsible for the mobility management of terminal devices, including mobile state management, allocation of temporary identity identifiers for terminal devices, and authentication and authorization of terminal devices.

[0060] The SMF network element is responsible for UPF network element selection, UPF network element reselection, Internet Protocol (IP) address allocation, bearer establishment, modification and release, and quality of service (QoS) control. In the 5G system, the interface used for communication between the SMF network element and the UPF network element is the N4 interface. Its specific functions include: configuring the data forwarding details of the PDU session (such as forwarding rules, QoS guarantee rules, etc.), event reporting, network element-level configuration information exchange, etc.

[0061] The UDM network element is responsible for managing contract data and notifying the corresponding network element when the contract data is modified.

[0062] The UDR network element is used to store and retrieve contract data, policy data, and public architecture data. It is also used by UDM network elements, PCF network elements, and NEF network elements to obtain relevant data. The UDR network element must have different data access authentication mechanisms for different types of data, such as contract data and policy data, to ensure data access security. The UDR network element must be able to return a failure response with an appropriate reason value for illegal service-based operations or data access requests.

[0063] AF network elements are used to provide certain application layer services to terminal devices. When providing services to terminal devices, AF network elements have requirements for QoS policies and charging policies, and need to notify the network. At the same time, AF network elements also need application-related information fed back by the core network.

[0064] The UPF network element supports all or part of the following functions: interconnecting PDU sessions with the data network, packet routing and forwarding, and data packet inspection. Among them, the UPF network element supports packet routing and forwarding, for example: the UPF network element supports uplink classifier (UL CL) and forwarding traffic to the data network, and supports branching points to support multi-homed PDU sessions.

[0065] In addition, when a new UPF instance needs to be deployed, the UPF instance is configured with the identifier of the NRF network element to be contacted for registration and its UPF provisioning information. The UPF network element does not need to know the specific UPF provisioning information. Thereafter, the UPF instance issues a network function (NF) management registration (i.e., Nnrf_NFManagement_NFRegister) request operation, providing its NF type, the fully qualified domain name (FQDN) or IP address of its N4 interface, and the configured UPF provisioning information. Thereafter, the NRF network element provides the information of the newly deployed UPF instance to the SMF network element.

[0066] In one deployment, the system to which the network element selection method provided in the embodiment of the present application is applicable also includes an energy efficiency network function (EE NF) network element, which is responsible for management functions related to energy saving in the network, and specifically may include all or part of the following functions: determination of energy saving status; execution of energy saving strategies; configuration and instructions related to energy saving with other network elements in the network, etc. The EE NF network element may be an independent logical function network element, or the EE NF network element may also be part of an operation and maintenance (OAM or O&M) system, or the functions of the EE NF network element may be dispersed in existing network elements, without limitation. In addition, "EE NF network element" is an exemplary name for the network element responsible for management functions related to energy saving in the network. The network element responsible for management functions related to energy saving in the network may also have other names, for example, "energy-saving network element", without limitation.

[0067] Please refer to Figure 2, which is a structural diagram of a communication system provided in an embodiment of the present application. The communication system includes a first network element, a second network element, and a terminal device. Among them, the first network element, the second network element, and the terminal device can communicate directly with each other, or can also communicate indirectly through other network elements / devices. Exemplarily, the first network element can be a session management function network element, and the second network element can be a user plane function network element. Taking the 5G network as an example, the first network element can be an SMF network element, and the second network element can be a UPF network element. It can be understood that as the network architecture changes, the network element selection method provided in the embodiment of the present application can also be implemented by network elements with corresponding functions in the new network architecture.

[0068] Next, a brief introduction is given to the relevant concepts involved in the embodiments of this application.

[0069] 1. Network energy consumption status

[0070] The energy consumption state of the network includes a non-energy saving state and an energy saving state. Among them, the non-energy saving state mainly refers to the state when the network is not energy-saving. The energy-saving state may refer to a state in which certain network elements in a cell or network are turned off or dormant. The energy-saving state may also refer to a state in which certain functions of certain network elements in a cell or network are turned off or dormant. For example, the energy-saving state may refer to a state in which data networks and / or network slices supported by certain network elements in a cell or network are turned off or dormant. In conjunction with Figure 3, energy saving activation is performed on a network in a non-energy-saving state, and the network can be switched from a non-energy-saving state to an energy-saving state. Energy saving deactivation is performed on a network in an energy-saving state, and the network can be switched from an energy-saving state to a non-energy-saving state.

[0071] The network enters an energy-saving state or a non-energy-saving state based on the operation and maintenance system. For example, the operation and maintenance system may determine that the network needs to enter an energy-saving state based on the following conditions:

[0072] (1) The data traffic of the network is lower than a certain threshold.

[0073] (2) The power consumption of the network exceeds the preset value.

[0074] (3) The power consumption rate of the network exceeds the preset value.

[0075] (4) The electricity fee for the current period exceeds a preset value.

[0076] (5) The network enters energy-saving state during certain fixed periods.

[0077] It should be noted that the network being in an energy-saving state does not necessarily mean that all network elements in the network are shut down or in hibernation. One possible scenario is that some network elements in the network are shut down or in hibernation while other network elements continue to operate normally. In this case, the "shut down or hibernating network elements are in an energy-saving state." A network element in a dormant (or sleeping) state can be understood as being in either the powered-on or powered-off state, but unable to process or respond to service requests for energy conservation or other reasons.

[0078] For example, taking the 5G network as an example, the network can shut down the edge UPF network elements during traffic peak and valley periods to save energy. During non-peak hours, operators may shut down certain edge UPF network elements based on information about service users to save energy. For example, in conjunction with Figure 4, at night, in some locations where no users pay for low-latency services, the remaining traffic that does not require low latency can be redirected from the edge UPF network element to the central UPF network element. In this scenario, the following operations can be performed to save energy on the network: redirect the remaining traffic passing through the edge UPF network element to the existing central UPF network element; deactivate the edge UPF network element, or shut down some instances in the edge UPF network element, or perform any other operations that can achieve energy saving.

[0079] 2.SSC mode

[0080] The SSC mode is a property related to the continuity of a session established by a terminal device, such as a PDU session. After a session is established, the SSC mode associated with the session remains unchanged for the life of the session, which can also be understood as the duration or duration of the session.

[0081] SSC modes include SSC mode 1, SSC mode 2, and SSC mode 3. SSC mode 1 indicates that the second network element corresponding to the session is not supported for changing during the duration of the session, while SSC mode 2 and SSC mode 3 indicate that the second network element corresponding to the session is supported for changing during the duration of the session. In the embodiment of the present application, the second network element corresponding to the session is the second network element that provides services for the session.

[0082] The following takes the PDU session established by the terminal device, and the second network element corresponding to the PDU session is the anchor user plane function network element of the PDU session as an example to explain the three SSC modes: SSC mode 1, SSC mode 2 and SSC mode 3.

[0083] SSC mode 1: The change of the anchor user plane functional network element of the PDU session is not supported during the duration of the PDU session. It is understandable that the network will retain the connection service of the terminal device, that is, the IP address corresponding to the PDU session of the terminal device will not be changed during the duration of the PDU session, and the IP address corresponds to the anchor user plane functional network element of the PDU session. When the terminal device moves, if the anchor user plane functional network element of the PDU session cannot be connected to the base station where the terminal device currently resides, then an intermediate user plane functional network element can be inserted in the path so that the anchor user plane functional network element and the base station where the terminal device currently resides are connected through the intermediate user plane functional network element.

[0084] SSC mode 2: Supports changing the anchor user plane functional network element of the PDU session during the duration of the PDU session. It can be understood that it supports changing the IP address corresponding to the PDU session during the duration of the PDU session, and the IP address corresponds to the anchor user plane functional network element of the PDU session. When the terminal device moves, if the anchor user plane functional network element of the PDU session cannot connect to the base station where the terminal device currently resides, the network will release the PDU session resources corresponding to the anchor user plane functional network element, and then set a new anchor user plane functional network element for the PDU session based on the latest location of the terminal device. The IP address corresponding to the PDU session of the terminal device will change accordingly.

[0085] SSC mode 3: supports changing the anchor user plane functional network element of the PDU session during the duration of the PDU session. Understandably, it supports changing the IP address corresponding to the PDU session during the duration of the PDU session, and the IP address corresponds to the anchor user plane functional network element of the PDU session. When the terminal device moves, if the anchor user plane functional network element of the PDU session cannot connect to the base station where the terminal device currently resides, the network will set a new anchor user plane functional network element for the PDU session of the terminal device based on the latest location of the terminal device, and then release the PDU session resources corresponding to the old anchor user plane functional network element. The IP address corresponding to the PDU session of the terminal device will change accordingly. Compared with SSC mode 2, SSC mode 3 provides better continuity.

[0086] The following describes an embodiment of the present application in detail with reference to the accompanying drawings. While the present application uses a first network element as an example to illustrate the corresponding method, the present application does not limit the execution of the method. For example, the network element / device in the method may also be a chip, chip system, or processor that supports the network element / device in implementing the corresponding method, or a logic module or software that can implement all or part of the functions of the network element / device.

[0087] Please refer to FIG5 , which is a flow chart of a network element selection method provided in an embodiment of the present application. The network element selection method includes the following steps.

[0088] S101. A first network element receives description information of one or more second network elements in a network, where the description information of each second network element in the one or more second network elements is used to indicate whether the second network element is shut down when the network is in an energy-saving state.

[0089] It is understandable that the description information of the second network element indicates that the second network element is shut down when the network is in an energy-saving state, which does not limit the second network element to being shut down when the network is in an energy-saving state. In addition to being understood as shutting down the second network element when the network is in an energy-saving state, it can also be understood as the possibility that the second network element will be shut down when the network is in an energy-saving state. In addition, the description information of the second network element is used to indicate whether the second network element is shut down when the network is in an energy-saving state, and specifically can be used to indicate whether the second network element will be shut down in the future when the network is in an energy-saving state. It can be seen that the first network element can pre-receive the description information of one or more second network elements in the network before the network is in an energy-saving state, and thereby select a second network element from the one or more second network elements for the session requested by the terminal device based on the description information of the one or more second network elements, which is conducive to providing conditions for whether to shut down the second network element selected for the session when the network is in an energy-saving state in the future.

[0090] The description information of the second network element is further elaborated below, as described in the following optional implementation modes 1.1 to 1.6.

[0091] In implementation 1.1, the description information of the second network element includes a first indication, wherein the first indication is used to indicate whether the second network element is shut down when the network is in an energy-saving state.

[0092] Optionally, the first indication may use "0" or "1" to indicate whether the second network element is shut down when the network is in an energy-saving state. For example, when the first indication is "1", it indicates that the second network element is shut down when the network is in an energy-saving state, and when the first indication is "0", it indicates that the second network element is not shut down when the network is in an energy-saving state. Alternatively, when the first indication is "0", it indicates that the second network element is shut down when the network is in an energy-saving state, and when the first indication is "1", it indicates that the second network element is not shut down when the network is in an energy-saving state. In addition, the first indication may also use other representation methods, such as an enumerated type (enumerated), without limitation.

[0093] For example, a first indication of "1" indicates that the second network element is shut down when the network is in an energy-saving state, and a first indication of "0" indicates that the second network element is not shut down when the network is in an energy-saving state. Description information #1 of second network element #1 indicates that second network element #1 is shut down when the network is in an energy-saving state, which can be represented as follows: description information #1 includes the first indication with a value of "1." Description information #2 of second network element #2 indicates that second network element #2 is not shut down when the network is in an energy-saving state, which can be represented as follows: description information #2 includes the first indication with a value of "0."

[0094] In embodiment 1.2, the description information of the second network element is further used to indicate a priority or probability of the second network element being shut down when the network is in an energy-saving state. It is understandable that a higher priority or probability of the second network element being shut down when the network is in an energy-saving state indicated by the description information of the second network element indicates a greater likelihood of the second network element being shut down when the network is in an energy-saving state.

[0095] In an optional manner, implementation 1.2 can be applied to a situation where the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state. Optionally, when the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state, the description information of the second network element includes a first indication and a second indication. The first indication is used to indicate that the second network element is shut down when the network is in an energy-saving state. For a detailed description, please refer to the relevant description in implementation 1.1 and will not be repeated here. The second indication is used to indicate the priority or probability of the second network element being shut down when the network is in an energy-saving state.

[0096] The embodiments of the present application do not limit the method for expressing the second indication. Exemplarily, the second indication is a number or letter corresponding to the priority. For example, when the network is in an energy-saving state, the priority of the second network element being shut down is divided into A level, B level, and C level from high to low. The second indication included in the description information of the second network element #1 is "A", indicating that the description information of the second network element #1 indicates that when the network is in an energy-saving state, the priority of the second network element #1 being shut down is A level. Another example is that the second indication is a probability value. For example, the second indication included in the description information of the second network element #2 is "75%", indicating that the description information of the second network element #2 indicates that the probability of the second network element #2 being shut down when the network is in an energy-saving state is 75%.

[0097] In an optional manner, the description information of the second network element includes a second indication, and the second indication is used to indicate the priority or probability of the second network element being shut down when the network is in an energy-saving state.

[0098] Exemplarily, the priority for shutting down the second network element when the network is in an energy-saving state is divided into multiple levels, where the multiple levels include a first level, where the first level indicates that the second network element is not shut down when the network is in an energy-saving state. If the priority indicated by the second indication is the first level, it means that the description information of the second network element indicates that the second network element is not shut down when the network is in an energy-saving state. If the priority indicated by the second indication is a level other than the first level among the multiple levels, it means that the description information of the second network element indicates that the second network element is shut down when the network is in an energy-saving state, and the shutdown priority is the priority indicated by the second indication.

[0099] For example, the priority for shutting down the second network element when the network is in an energy-saving state is divided into levels A, B, and C from high to low, where level C indicates that the second network element is not shut down when the network is in an energy-saving state, that is, level C is the aforementioned first level. The second indication included in the description information of the second network element #1 is "A", indicating that the description information of the second network element #1 indicates that the second network element #1 is shut down when the network is in an energy-saving state and that the shutdown priority is level A. The second indication included in the description information of the second network element #2 is "C", indicating that the description information of the second network element #2 indicates that the second network element #2 is not shut down when the network is in an energy-saving state.

[0100] Exemplarily, if the probability indicated by the second indication is not zero, it means that the description information of the second network element indicates that the second network element is shut down when the network is in an energy-saving state, and the probability of being shut down is the probability indicated by the second indication. If the probability indicated by the second indication is zero, it means that the description information of the second network element indicates that the second network element is not shut down when the network is in an energy-saving state. For example, the description information of the second network element #1 includes the second indication of "75%", which means that the description information of the second network element #1 indicates that the second network element #1 is shut down when the network is in an energy-saving state, and the probability of being shut down is "75%". The description information of the second network element #2 includes the second indication of "0%", which means that the description information of the second network element #2 indicates that the second network element #2 is not shut down when the network is in an energy-saving state.

[0101] In implementation 1.3, the description information of the second network element is further used to indicate a time period during which the second network element is shut down when the network is in an energy-saving state.

[0102] In an optional manner, Implementation 1.3 can be applied to a situation where the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state. Optionally, when the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state, the description information of the second network element includes a first indication and a third indication. The first indication is used to indicate that the second network element is shut down when the network is in an energy-saving state. For a detailed description, please refer to the relevant description in Implementation 1.1 and will not be repeated here. The third indication is used to indicate the time period during which the second network element is shut down when the network is in an energy-saving state.

[0103] The embodiment of the present application does not limit the method of expressing the third indication. Exemplarily, the third indication is the start and end time corresponding to the time period. For example, the description information of the second network element #1 includes the third indication of "0 o'clock, 3 o'clock at night", which means that the description information of the second network element #1 indicates that the second network element #1 is turned off from 0 o'clock to 3 o'clock at night when the network is in an energy-saving state. Another example is that the third indication is a time series. For example, the description information of the second network element #1 includes the third indication of "0 o'clock, 1 o'clock, 2 o'clock, 3 o'clock", which means that the description information of the second network element #1 indicates that the second network element #1 is turned off from 0 o'clock to 3 o'clock at night when the network is in an energy-saving state.

[0104] In one optional embodiment, the description information of the second network element includes a third indication, which is used to indicate the time period during which the second network element is shut down when the network is in an energy-saving state. Exemplarily, if the third indication is absent, the description information of the second network element indicates that the second network element is not shut down when the network is in an energy-saving state. If the third indication is present, the description information of the second network element indicates that the second network element is shut down when the network is in an energy-saving state, and the shutdown time period is the time period indicated by the third indication. For example, if the third indication included in the description information of the second network element #1 is all zeros, the third indication can be considered absent, indicating that the description information of the second network element #1 indicates that the second network element #1 is not shut down when the network is in an energy-saving state. For another example, if the third indication included in the description information of the second network element #2 is "midnight, 3:00 AM", the third indication can be considered present, indicating that the description information of the second network element #2 indicates that the second network element #2 is shut down from midnight to 3:00 AM when the network is in an energy-saving state.

[0105] In implementation 1.4, the description information of the second network element is further used to indicate the priority or probability of the second network element being shut down, and the time period during which the second network element is shut down, when the network is in an energy-saving state.

[0106] Optionally, the description information of the second network element includes a second indication and a third indication, the second indication is used to indicate the priority or probability of the second network element being shut down when the network is in an energy-saving state, and the third indication is used to indicate the time period during which the second network element is shut down when the network is in an energy-saving state. For a specific description of the second indication, please refer to the relevant description in Implementation 2, and for a specific description of the third indication, please refer to the relevant description in Implementation 3, which will not be repeated here. Optionally, Implementation 1.4 can be applied to a case where the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state. In this case, the second network element may further include a first indication, and the first indication is used to indicate that the second network element is shut down when the network is in an energy-saving state. For a specific description of the first indication, please refer to the relevant description in Implementation 1.1.

[0107] Implementation 1.5, the description information of the second network element is used to indicate whether the second network element is turned off when the network is in an energy-saving state, including: the description information of the second network element is used to indicate whether the data network and / or network slice supported by the second network element is turned off when the network is in an energy-saving state.

[0108] The number of data networks and / or network slices supported by the second network element may be one or more. The data network supported by the second network element is shut down, which can be understood as: some or all of the one or more data networks supported by the second network element are shut down. The network slice supported by the second network element is shut down, which can be understood as: some or all of the one or more network slices supported by the second network element are shut down.

[0109] In addition, the description information of the second network element is also used to indicate the data networks and / or network slices that are turned off among the data networks and / or network slices supported by the second network element when the network is in an energy-saving state, and / or the data networks and / or network slices that are not turned off among the data networks and / or network slices supported by the second network element.

[0110] In an optional manner, the description information of the second network element includes a fourth indication and an identifier associated with the fourth indication. The fourth indication is used to indicate that the data network and / or network slice supported by the second network element is turned off when the network is in an energy-saving state, and the identifier associated with the fourth indication is an identifier of the data network and / or network slice that is turned off among the data networks and / or network slices supported by the second network element when the network is in an energy-saving state. In an embodiment of the present application, the identifier of the data network may be, for example, a data network name (DNN), and the identifier of the network slice may be, for example, single network slice selection assistance information (S-NSSAI).

[0111] For example, the description information of the second network element #1 indicates that network slice #1 (identified as S-NSSAI#1) and network slice #2 (identified as S-NSSAI#2) in the network slices supported by the second network element #1 are turned off when the network is in an energy-saving state, which can be expressed as: the description information of the second network element #1 includes the fourth indication, S-NSSAI#1, and S-NSSAI#2.

[0112] In another optional manner, the description information of the second network element includes a fifth indication and an identifier associated with the fifth indication. The fifth indication is used to indicate that the data network and / or network slice supported by the second network element is not shut down when the network is in an energy-saving state, and the identifier associated with the fifth indication is an identifier of the data network and / or network slice supported by the second network element that is not shut down when the network is in an energy-saving state.

[0113] For example, the description information of the second network element #1 indicates that network slice #3 (identified as S-NSSAI#3) and network slice #4 (identified as S-NSSAI#4) in the network slices supported by the second network element #1 are turned off when the network is in an energy-saving state, which can be expressed as: the description information of the second network element #1 includes the fifth indication, S-NSSAI#3, and S-NSSAI#4.

[0114] In another optional manner, the description information of the second network element includes a fourth indication, an identifier associated with the fourth indication, a fifth indication, and an identifier associated with the fifth indication. The fourth indication is used to indicate that some data networks and / or network slices supported by the second network element are shut down when the network is in an energy-saving state, and the identifier associated with the fourth indication is the identifier of the data networks and / or network slices that are shut down among the data networks and / or network slices supported by the second network element when the network is in an energy-saving state. The fifth indication is used to indicate that some data networks and / or network slices supported by the second network element are not shut down when the network is in an energy-saving state, and the identifier associated with the fifth indication is the identifier of the data networks and / or network slices that are not shut down among the data networks and / or network slices supported by the second network element when the network is in an energy-saving state.

[0115] For example, the description information of the second network element #1 indicates that when the network is in an energy-saving state, network slice #1 (identified as S-NSSAI#1) and network slice #2 (identified as S-NSSAI#2) in the network slices supported by the second network element #1 are not shut down, and network slice #3 (identified as S-NSSAI#3) and network slice #4 (identified as S-NSSAI#4) are shut down. It can be expressed as: the description information of the second network element #1 includes the fourth indication, S-NSSAI#1 and S-NSSAI#2 associated with the fourth indication, the fifth indication, S-NSSAI#3 and S-NSSAI#4 associated with the fifth indication.

[0116] Optionally, the description information of the second network element is further used to indicate the priority or probability of the data network and / or network slice supported by the second network element being shut down when the network is in an energy-saving state, and / or the description information of the second network element is further used to indicate the time period during which the data network and / or network slice supported by the second network element is shut down when the network is in an energy-saving state. Among them, the "priority or probability of the data network and / or network slice supported by the second network element being shut down" is similar to the "priority or probability of the second network element being shut down" in Implementation 1.2, and reference may be made to the relevant explanation thereof, which will not be repeated here. The "time period during which the data network and / or network slice supported by the second network element is shut down" is similar to the "time period during which the second network element is shut down" in Implementation 1.2, and reference may be made to the relevant explanation thereof, which will not be repeated here. Optionally, this implementation can be applied to the case where the description information of the second network element is used to indicate that the data network and / or network slice supported by the second network element is shut down when the network is in an energy-saving state.

[0117] For example, the description information of the second network element #1 indicates that when the network is in an energy-saving state, among the data networks supported by the second network element #1, data network #1 (identified as DNN#1) has a 75% probability of being shut down, data network #2 (identified as DNN#2) has a 50% probability of being shut down, and data network #3 (identified as DNN#3) will not be shut down.

[0118] The description information of the second network element #1 may include: a fourth indication, DNN #1 and DNN #2 associated with the fourth indication, a probability of DNN #1 being shut down, i.e., "75%", a probability of DNN #2 being shut down, i.e., "50%", a fifth indication, and DNN #3 associated with the fifth indication. The fourth indication is used to indicate that some data networks and / or network slices supported by the second network element #1 are shut down when the network is in an energy-saving state, and the fifth indication is used to indicate that some data networks and / or network slices supported by the second network element #1 are not shut down when the network is in an energy-saving state.

[0119] Alternatively, the description information of the second network element #1 may include: {DNN#1, 75%}, {DNN#2, 50%}, {DNN#3, 0%}.

[0120] In Embodiment 1.6, the description information of the second network element is further used to indicate the validity period of the description information. The validity period of the description information can also be understood as the time during which the description information is available or effective. In addition, in addition to being a standalone embodiment, Embodiment 1.6 can also be combined with any of Embodiments 1.1 to 1.5 above.

[0121] In an optional embodiment, the first network element in FIG5 receives description information of one or more second network elements in the network, including: S101a, each of the one or more second network elements sends the description information of the second network element to the first network element; accordingly, the first network element receives the description information of the second network element sent by each of the one or more second network elements, as shown in FIG6. For example, second network element #1 sends description information #1 to the first network element, and second network element #2 sends description information #2 to the first network element, where description information #1 is used to indicate whether second network element #1 is shut down when the network is in an energy-saving state, and description information #2 is used to indicate whether second network element #2 is shut down when the network is in an energy-saving state.

[0122] In another optional embodiment, the first network element in FIG5 receives description information of one or more second network elements in the network, including: S101b, the third network element sends description information of one or more second network elements to the first network element; correspondingly, the first network element receives description information of one or more second network elements sent by the third network element, as shown in FIG7. The third network element is different from the first network element and the second network element. For example, the third network element sends description information #1 of the second network element #1 and description information #2 of the second network element #2 to the first network element, where description information #1 is used to indicate whether the second network element #1 is shut down when the network is in an energy-saving state, and description information #2 is used to indicate whether the second network element #2 is shut down when the network is in an energy-saving state.

[0123] S102: The first network element selects a second network element from the one or more second network elements for the session requested to be established by the terminal device based on description information of the one or more second network elements.

[0124] Optionally, before step S102, the method further includes: the first network element receiving a message from the terminal device for requesting to establish a session.

[0125] Optionally, the session requested to be established by the terminal device may be a PDU session.

[0126] In an optional embodiment, the first network element selects a second network element from one or more second network elements for a session requested to be established by a terminal device based on the description information of the one or more second network elements, including: the first network element selects a second network element from one or more second network elements for the session based on the service continuity requirements corresponding to the session and the description information of the one or more second network elements.

[0127] Optionally, when the service continuity requirement corresponding to the session indicates that the service transmission in the network is maintained continuously for the duration of the session, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state. Maintaining the service transmission in the network for the duration of the session can be understood as: maintaining the service transmission in the transport layer or the network layer for the duration of the session. Optionally, when the second network element is a user plane function network element, maintaining the service transmission in the network for the duration of the session can also be expressed as: the anchor point of the session (such as the PDU session anchor point) remains unchanged for the duration of the session, or the user plane function of the session accessing the data network remains unchanged for the duration of the session, or the IP address of the session remains unchanged for the duration of the session. Optionally, the service continuity requirement corresponding to the session is the SSC mode corresponding to the session. SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed for the duration of the session, and SSC mode 2 and SSC mode 3 indicate that the second network element corresponding to the session is supported to be changed for the duration of the session. For a detailed description of the SSC mode, please refer to the aforementioned related descriptions and will not be repeated here.

[0128] The following describes step S102 for the case where the service continuity requirement corresponding to the session is the SSC mode corresponding to the session, as described in the following optional implementations 2.1 to 2.4.

[0129] In embodiment 2.1, when the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state. It is understandable that, for a session corresponding to SSC mode 1, to ensure transmission continuity of the session in the network, the second network element corresponding to the session is not shut down when the network is in an energy-saving state. Therefore, selecting for the session in step S102 a second network element whose description information indicates that the second network element is not shut down when the network is in an energy-saving state helps provide a condition for not shutting down the second network element selected for the session when the network is in an energy-saving state.

[0130] For example, the description information of the second network element #1 indicates that the second network element #1 is shut down when the network is in an energy-saving state, and the description information of the second network element #2 indicates that the second network element #2 is not shut down when the network is in an energy-saving state. When the SSC mode corresponding to the session is SSC mode 1, the first network element selects the second network element #2 for the session.

[0131] Optionally, when the SSC mode corresponding to the session is SSC mode 1, the priority of the first network element selecting the second network element of the type whose description information indicates that it is not shut down when the network is in an energy-saving state for the session is higher than the priority of selecting the second network element of the type whose description information indicates that it is shut down when the network is in an energy-saving state. It can be seen that when the session corresponds to SSC mode 1, the description information of the second network element preferentially selected by the first network element for the session indicates that the second network element is not shut down when the network is in an energy-saving state. For example, the description information of the second network element #1 indicates that the second network element #1 is shut down when the network is in an energy-saving state, and the description information of the second network element #2 indicates that the second network element #2 is not shut down when the network is in an energy-saving state. When the session corresponds to SSC mode 1, the priority of the first network element selecting the second network element #2 for the session is higher than the priority of selecting the second network element #1.

[0132] In embodiment 2.2, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected by the first network element for the session indicates that the second network element is shut down when the network is in an energy-saving state. It is understandable that for a session corresponding to SSC mode 2 or SSC mode 3, the second network element corresponding to the session can be shut down when the network is in an energy-saving state to save network energy consumption. In step S102, the second network element whose description information indicates that the second network element is shut down when the network is in an energy-saving state can be selected for the session, which helps to provide conditions for shutting down the second network element selected for the session when the network is in an energy-saving state.

[0133] Optionally, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the priority of the first network element selecting the second network element of the type whose description information indicates that it is shut down when the network is in an energy-saving state for the session is higher than the priority of selecting the second network element of the type whose description information indicates that it is not shut down when the network is in an energy-saving state. It can be seen that when the session corresponds to SSC mode 2 or SSC mode 3, the description information of the second network element preferentially selected by the first network element for the session indicates that the second network element is shut down when the network is in an energy-saving state. For example, the description information of the second network element #1 indicates that the second network element #1 is shut down when the network is in an energy-saving state, and the description information of the second network element #2 indicates that the second network element #2 is not shut down when the network is in an energy-saving state. When the session corresponds to SSC mode 2 or SSC mode 3, the priority of the first network element selecting the second network element #1 for the session is higher than the priority of selecting the second network element #2.

[0134] In implementation 2.3, when the SSC mode corresponding to the session is SSC mode 1, and the description information of each of the one or more second network elements indicates that the second network element is shut down when the network is in an energy-saving state, the first network element selects a second network element for the session based on the priority or probability of the second network element being shut down when the network is in an energy-saving state, as indicated by the description information of each of the one or more second network elements. This approach is applicable to scenarios where the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state, and is also used to indicate the priority or probability of the second network element being shut down when the network is in an energy-saving state.

[0135] Optionally, when the SSC mode corresponding to the session is SSC mode 1, and the description information of each second network element in one or more second network elements indicates that the second network element is turned off when the network is in an energy-saving state, the priority or probability of the second network element being turned off when the network is in an energy-saving state indicated by the description information of the second network element selected by the first network element for the session is the lowest among the one or more second network elements.

[0136] For example, when the network is in an energy-saving state, the priority of shutting down the second network element is divided into levels A, B, C, and D from high to low. The first network element receives description information of second network element #1, second network element #2, and second network element #3. The description information of second network element #1 indicates that second network element #1 is shut down when the network is in an energy-saving state and its shutdown priority is level B. The description information of second network element #2 indicates that second network element #2 is shut down when the network is in an energy-saving state and its shutdown priority is level C. The description information of second network element #3 indicates that second network element #3 is shut down when the network is in an energy-saving state and its shutdown priority is level A. It can be seen that the description information of each second network element received by the first network element indicates that the second network element is shut down when the network is in an energy-saving state. When the SSC mode corresponding to the session is SSC mode 1, the first network element selects second network element #2 for the session.

[0137] Implementation 2.4, the method also includes: the first network element receives second information from the terminal device, the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device. When the SSC mode corresponding to the session is SSC mode 1, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed. Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is closed.

[0138] It can be understood that, for sessions corresponding to SSC mode 1, this embodiment 2.4 facilitates providing conditions for the following operations: when the network is in an energy-saving state, for the second network element selected for the session, the data network and / or network slice associated with the session requested by the supported terminal device is not shut down; thereby ensuring continuous transmission of services corresponding to the session in the network. For sessions corresponding to SSC mode 2 or mode 3, this embodiment 2.4 facilitates providing conditions for the following operations: when the network is in an energy-saving state, for the second network element selected for the session, the data network and / or network slice associated with the session requested by the supported terminal device is shut down; thereby saving network energy consumption.

[0139] In addition, this embodiment 2.4 can be applied to the scenario where the description information of each second network element in one or more second network elements is used to indicate whether the data network and / or network slice supported by the second network element is turned off when the network is in an energy-saving state.

[0140] For example, the first network element receives description information of the second network element #1, the second network element #2, and the second network element #3. The description information of the second network element #1 indicates that when the network is in an energy-saving state, the network slice #1 supported by the second network element #1 is turned off and the network slice #2 is not turned off. The description information of the second network element #2 indicates that when the network is in an energy-saving state, the network element slice #2 and the network element slice #3 supported by the second network element #2 are turned off. The description information of the second network element #3 indicates that when the network is in an energy-saving state, the network element slice #3 supported by the second network element #3 is not turned off. The first network element receives second information from the terminal device, and the second information is used to indicate that the network slice associated with the session requested by the terminal device is network slice #2. When the SSC mode corresponding to the session is SSC mode 1, the first network element selects the second network element #1 for the session. Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the first network element selects the second network element #2 for the session.

[0141] Optionally, when the SSC mode corresponding to the session is SSC mode 1, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the priority of the second network element selected by the first network element for the session, which indicates that the data network and / or network slice associated with the session requested by the terminal device is not shut down when the network is in an energy-saving state, is higher than the priority of the second network element selected by the first network element for the session, which indicates that the data network and / or network slice associated with the session requested by the terminal device is shut down when the network is in an energy-saving state.

[0142] Optionally, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the priority of the second network element selected by the first network element for the session, whose description information indicates that the data network and / or network slice associated with the session requested by the terminal device is shut down when the network is in an energy-saving state, is higher than the priority of the second network element selected by the first network element for the session, whose description information indicates that the data network and / or network slice associated with the session requested by the terminal device is not shut down when the network is in an energy-saving state.

[0143] For example, the description information of the second network element #1 indicates that the network slice #1 supported by the second network element #1 is not shut down when the network is in an energy-saving state, and the description information of the second network element #2 indicates that the network element slice #1 supported by the second network element #2 is shut down when the network is in an energy-saving state. The second information received by the first network element from the terminal device is used to indicate that the network slice associated with the session requested by the terminal device is network slice #1. When the SSC mode corresponding to the session is SSC mode 1, the priority of the first network element in selecting the second network element #1 for the session is higher than the priority of selecting the second network element #2 for the session. Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the priority of the first network element in selecting the second network element #2 for the session is higher than the priority of selecting the second network element #1 for the session.

[0144] Optionally, when the SSC mode corresponding to the session is SSC mode 1, and the description information of each second network element in one or more second network elements that supports the data network and / or network slice associated with the session requested by the terminal device indicates that when the data network and / or network slice associated with the session requested by the terminal device is closed when the network is in an energy-saving state, the first network element selects the second network element for the session based on the priority or probability of the data network and / or network slice associated with the session requested by the terminal device being closed when the network is in an energy-saving state as indicated by the description information of the second network element. This method can be applied to the scenario where the description information of the second network element is used to indicate that the data network and / or network slice supported by the second network element is closed when the network is in an energy-saving state, and is also used to indicate the priority or probability of the data network and / or network slice supported by the second network element being closed when the network is in an energy-saving state. This method is similar to the aforementioned implementation 2.3 and will not be repeated here.

[0145] In addition, in an optional embodiment, for the case where the service continuity requirement corresponding to the session is the SSC mode corresponding to the session, the method further includes: the first network element receives first information from the terminal device, the first information being used to indicate the SSC mode requested by the terminal device for the session; the first network element determines the SSC mode corresponding to the session based on the SSC mode requested by the terminal device for the session. The SSC mode corresponding to the session may be the same as the SSC mode requested by the terminal device for the session, or may be different from the SSC mode requested by the terminal device for the session. This embodiment may be combined with any of the above embodiments 2.1 to 2.4. Optionally, the first information is carried in a message from the terminal device for requesting to establish a session.

[0146] Exemplarily, when a first network element is unable to determine a second network element for a session that matches the SSC mode requested by a terminal device for the session based on the description information of one or more second network elements, the SSC mode corresponding to the session is different from the SSC mode requested by the terminal device for the session. For example, the first network element receives description information of second network element #1 and second network element #2. The description information of second network element #1 indicates that second network element #1 is shut down when the network is in an energy-saving state, and the description information of second network element #2 indicates that second network element #2 is shut down when the network is in an energy-saving state. The SSC mode requested by the terminal device for the session is SSC mode 1. The first network element is unable to select a second network element from second network element #1 and second network element #2 for the session whose description information indicates that the second network element is not shut down when the network is in an energy-saving state. In this case, the first network element can modify the SSC mode and use SSC mode 2 or SSC mode 3 as the SSC mode corresponding to the session, and then the first network element can select second network element #1 or second network element #2 for the session.

[0147] In an optional embodiment, the method further includes: the first network element receives third information from the terminal device, and the third information is used to indicate the duration of the session requested to be established by the terminal device. In this case, the validity period of the description information of the second network element selected by the first network element for the session includes part or all of the duration of the session. This method can be applied to the scenario where the description information of the second network element is also used to indicate the validity period of the description information. This embodiment can be combined with any of the aforementioned embodiments in which the first network element selects the second network element from one or more second network elements for the session requested to be established by the terminal device. For example, this embodiment is combined with the aforementioned embodiment 2.1: when the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state, and the validity period of the description information of the second network element selected for the session includes part or all of the duration of the session.

[0148] In summary, in this network element selection method, a first network element receives description information of one or more second network elements in a network, where the description information of each of the one or more second network elements indicates whether the second network element is shut down when the network is in an energy-saving state. Based on the description information of the one or more second network elements, the first network element selects a second network element from the one or more second network elements for a session requested to be established by a terminal device. It can be seen that when the first network element selects a second network element for a session, it makes the selection based on considerations of network energy conservation, i.e., it makes the selection based on the description information of each received second network element, where the description information of each second network element indicates whether the second network element is shut down when the network is in an energy-saving state. This helps to provide conditions for whether to shut down the second network element selected for the session when the network is in an energy-saving state.

[0149] In another embodiment, in the network element selection method shown in FIG5 , “the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state” can also be replaced with: the description information of the second network element is used to indicate that the second network element enters a dormant state when the network is in an energy-saving state. In the network element selection method shown in FIG5 , “the description information of the second network element is used to indicate that the second network element is not shut down when the network is in an energy-saving state” can also be replaced with: the description information of the second network element is used to indicate that the second network element does not enter a dormant state when the network is in an energy-saving state.

[0150] In this case, the priority or probability of the second network element being shut down can be replaced by: the priority or probability of the second network element entering a dormant state. The time period during which the second network element is shut down can be replaced by: the time period during which the second network element enters a dormant state. The data network / network slice supported by the second network element being shut down can be replaced by: the data network / network slice supported by the second network element entering a dormant state. The data network / network slice supported by the second network element not being shut down can be replaced by: the data network / network slice supported by the second network element not entering a dormant state. The priority or probability of the data network / network slice supported by the second network element being shut down can be replaced by: the priority or probability of the data network / network slice supported by the second network element entering a dormant state. The time period during which the data network / network slice supported by the second network element is shut down can be replaced by: the time period during which the data network / network slice supported by the second network element enters a dormant state.

[0151] Correspondingly, the relevant description of step S102 in the network element selection method shown in FIG. 5 may also be adaptively replaced.

[0152] For example, in the network element selection method shown in Figure 5, "when the service continuity requirement corresponding to the session indicates that the service is to be transmitted continuously in the network during the duration of the session, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state" can be replaced by: when the service continuity requirement corresponding to the session indicates that the service is to be transmitted continuously in the network during the duration of the session, the description information of the second network element selected for the session indicates that the second network element does not enter a sleep state when the network is in an energy-saving state.

[0153] For example, in the above-mentioned embodiment 2.1, "when the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state" can be replaced with: when the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element does not enter a sleep state when the network is in an energy-saving state.

[0154] For example, in the above-mentioned embodiment 2.2, "when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected by the first network element for the session indicates that the second network element is turned off when the network is in an energy-saving state" can be replaced with: when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected by the first network element for the session indicates that the second network element enters a sleep state when the network is in an energy-saving state.

[0155] For example, in the above-mentioned embodiment 2.3, "when the SSC mode corresponding to the session is SSC mode 1, and the description information of each second network element in one or more second network elements indicates that the second network element is turned off when the network is in an energy-saving state, the first network element selects the second network element for the session based on the priority or probability of the second network element being turned off when the network is in an energy-saving state as indicated by the description information of each second network element in one or more second network elements" can be replaced by: when the SSC mode corresponding to the session is SSC mode 1, and the description information of each second network element in one or more second network elements indicates that the second network element enters a sleep state when the network is in an energy-saving state, the first network element selects the second network element for the session based on the priority or probability of the second network element entering a sleep state when the network is in an energy-saving state as indicated by the description information of each second network element in one or more second network elements.

[0156] For example, in the above embodiment 2.4, "when the SSC mode corresponding to the session is SSC mode 1, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed. Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is closed" can be replaced by:

[0157] When the SSC mode corresponding to the session is SSC mode 1, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device does not enter a dormant state. Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected by the first network element for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device enters a dormant state.

[0158] In addition, the embodiment of the present application is not limited to the expression "sleep state". The "sleep state" can also be replaced by other energy-saving states that affect the normal operation of the second network element. The situation is similar and will not be repeated here.

[0159] The following is an example of an example in which the session requested by the terminal device is a PDU session, the first network element is a session management network element, and the second network element is a user plane function network element, to exemplify the network element selection method provided in the embodiment of the present application.

[0160] Example 1: Referring to FIG8 , the network element selection method shown in FIG8 includes the following steps:

[0161] S201. An operation and maintenance network element or an energy-efficient network function network element sends a network element configuration message to one or more user plane function network elements. The network element configuration message sent to each user plane function network element includes description information of the user plane function network element. Accordingly, each of the one or more user plane function network elements receives the network element configuration message from the operation and maintenance network element or the energy-efficient network function network element.

[0162] In the embodiment of the present application, the operation and maintenance network element is the network element responsible for the network element parameter configuration function in the operation and maintenance system, which will not be described in detail below. In addition, the specific description information of the user plane function network element can be found in the above-mentioned related description, which will not be described in detail here.

[0163] S202: The session management function network element sends an N4 association configuration request message to each of the one or more user plane function network elements. Correspondingly, each of the one or more user plane function network elements receives the N4 association configuration request message from the session management function network element.

[0164] The N4 association configuration request message is used to indicate the configuration of the N4 interface, or to request the user plane function network element to feedback description information of the user plane function network element, or to establish an association between the session management function network element and the user plane function network element, or to request to exchange respectively supported functions with the user plane function network element, or to request to obtain resource-related information of the user plane function network element. The N4 association configuration request message may be, for example, an N4 association setup request message, or a packet forwarding control protocol (PFCP) association configuration request message, and the N4 association configuration response message may be, for example, an N4 association setup response message, or a PFCP association configuration response message.

[0165] S203. Each of the one or more user plane function network elements sends an N4 association configuration response message to the session management function network element. The N4 association configuration response message sent by each user plane function network element includes description information of the user plane function network element. Correspondingly, the session management function network element receives the N4 association configuration response message sent by each of the one or more user plane function network elements.

[0166] S204. The policy control function network element sends terminal route selection policy (UE route selection policy, URSP) information to the terminal device.

[0167] Specifically, after the terminal device requests to register with the network, for example, after the terminal device sends a registration request message, the access and mobility management function network element selects the policy control function network element, and the policy control function network element then provides the URSP information to the terminal device through the terminal policy container (UE policy container). The URSP information can be used to select an appropriate PDU session for the terminal device when the terminal device sends data. The URSP information includes an SSC mode selection policy (session and service continuity mode selection policy, SSCMSP), which can be used to assist the terminal device in determining the SSC mode requested for the PDU session when selecting a PDU session.

[0168] S205: The terminal device sends a message for requesting to establish a PDU session to the access and mobility management function network element according to the URSP information. Correspondingly, the access and mobility management function network element receives the message for requesting to establish a PDU session from the terminal device.

[0169] The message for requesting to establish a PDU session may be carried in an uplink non-access stratum (UL NAS) message, for example.

[0170] Optionally, the message for requesting to establish a PDU session may include one or more of the following: an identifier of the PDU session, first information, second information, and third information, wherein the first information is used to indicate the SSC mode requested by the terminal device for the session, the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device, and the third information is used to indicate the duration of the session requested by the terminal device.

[0171] S206: The access and mobility management function network element selects a session management network element.

[0172] Optionally, the access and mobility management function network element selects a session management network element based on one or more of the following: the access technology of the terminal device, the location of the terminal device, the service area of ​​the session management network element, the data network and / or network slice associated with the session requested by the terminal device and the data network and / or network slice supported by the session management network element, whether the session management network element supports network energy saving functions, and whether the session management network element supports the SSC mode requested by the terminal device for the session.

[0173] Correspondingly, the session management network element selected by the access and mobility management function network element supports the data network and / or network slice associated with the session requested by the terminal device, supports the network energy saving function, and supports the SSC mode requested by the terminal device for the session.

[0174] S207: The access and mobility management function network element sends an N11 message to the selected session management network element.

[0175] The N11 message may include one or more of the following: an identifier of the PDU session, first information, second information, and third information, wherein the first information is used to indicate the SSC mode requested by the terminal device for the session, the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device, and the third information is used to indicate the duration of the session requested by the terminal device. The N11 message may, for example, be a PDU session create session management context (Nsmf_PDUSession_CreateSMContext) message.

[0176] S208. The session management network element selects a user plane function network element from the one or more second network elements for the PDU session requested to be established by the terminal device based on the description information of the one or more second network elements.

[0177] For the detailed description of step S208, please refer to the relevant description in the network element selection method shown in FIG5 , which will not be repeated here.

[0178] S209. The session management network element sends an N4 session establishment request message to the selected user plane function network element.

[0179] The N4 session establishment request message may include one or more of the following: an identifier of the PDU session, a packet detection rule for user plane data, a QoS enforcement rule for user plane data, a forward action rule for user plane data, and a usage reporting rule for user plane data. The N4 session establishment request message may be an N4 session establishment request message or a PFCP session establishment request message.

[0180] S210: The user plane function network element sends an N4 session establishment response message to the session management network element. Correspondingly, the session management network element receives the N4 session establishment response message from the user plane function network element.

[0181] Optionally, the N4 session establishment response message includes the SSC mode corresponding to the PDU session.

[0182] Optionally, the N4 session establishment response message may be an N4 session establishment response message, or a PFCP session establishment response (PFCP session establishment response) message.

[0183] S211: The session management network element sends a PDU session establishment response message to the terminal device. Correspondingly, the terminal device receives the PDU session establishment response message from the session management network element.

[0184] Example 2: As shown in the dotted box in Figure 9, the difference between the network element selection method shown in Figure 9 and the network element selection method shown in Figure 8 is that the network element selection method shown in Figure 9 does not include steps S202 and S203 in Figure 8, and the network element selection method shown in Figure 9 also includes steps S301 and S302 after step S201.

[0185] S301. Each of one or more user plane function network elements sends an N4 association update request message or an N4 report message to a session management function network element. The N4 association update request message or N4 report message sent by each user plane function network element includes description information of the user plane function network element. Accordingly, the session management function network element receives the N4 association update request message or N4 report message sent by each of the one or more user plane function network elements.

[0186] The N4 association update request message is used to request the session management function network element to update the configuration of the N4 interface, and the N4 report message is used to indicate relevant information of the N4 session. The N4 association update request message may be, for example, an N4 association update request message or a PFCP association update request message, and the N4 report message may be, for example, an N4 report message or a PFCP node report message. For a detailed description of the second network element, please refer to the aforementioned related description and will not be repeated here.

[0187] S302. The session management function network element sends an N4 association update response message or an N4 report confirmation message to each user plane function network element. The N4 association update response message may be, for example, an N4 association update response message or a PFCP association update response message, and the N4 report confirmation message may be, for example, an N4 report ack message or a PFCP node report ack message.

[0188] Example 3: The third network element is a network storage function network element. As shown in the dotted box in Figure 10, the network element selection method shown in Figure 10 differs from the network element selection method shown in Figure 8 in that the network element selection method shown in Figure 10 does not include steps S201 to S203 in Figure 8, and the network element selection method shown in Figure 10 also includes steps S401 to S403.

[0189] S401: The session management function network element sends a network element status subscription request message to the network storage function network element. Correspondingly, the network storage function network element receives the network element status subscription request message from the session management function network element.

[0190] The network element status subscription request message is used to subscribe to network storage function network elements for network element status update information. When the status of a network element in the network is updated, the network storage function network element can notify the session management function network element of the updated information about the network element. The network element subscribed to by the network element status subscription request message can be a specific network element in the network, or it can be some or all network elements in the network, without limitation. Furthermore, the network element status subscription request message can be, for example, a network function management and network function status subscription (i.e., Nnrf_NFManagement_NFStatusSubscribe) message.

[0191] S402: The operation and maintenance network element or the energy efficiency network function network element sends a first configuration request message or a first configuration update request message to the network storage function network element. The first configuration request message or the first configuration update request message includes: an identifier of each user plane function network element in one or more user plane function network elements and description information of each user plane function network element. Correspondingly, the network storage function network element receives the first configuration request message or the first configuration update request message from the operation and maintenance network element or the energy efficiency network function network element.

[0192] The first configuration request message is used to configure relevant information of the user plane function network element to the network storage function network element, and the first configuration update request message is used to update relevant information of the user plane function network element to the network storage function network element. The first configuration request message sent by the operation and maintenance network element may be, for example, an OAM configuration request (i.e., OAM configuration request) message, and the first configuration update request message sent by the operation and maintenance network element may be, for example, an OAM configuration update request (OAM configuration update request) message.

[0193] Optionally, the first configuration request message or the first configuration update request message may also include one or more of the following of the user plane functional network element: load information, location information, identification of supported data networks, and identification of supported network slices.

[0194] In addition, for the specific description of the second network element, please refer to the above-mentioned related description, which will not be repeated here.

[0195] S403: The network storage function network element sends a network element status notification message to the session management function network element. The network element status notification message includes: an identifier of each user plane function network element in one or more user plane function network elements and description information of each user plane function network element. In response, the session management function network element receives the network element status notification message from the network storage function network element.

[0196] The network element status notification message is used to notify the session management function network element of relevant information of the network element after the status is updated. The network element status notification message can be, for example, a network function management and network function status notification (ie, Nnrf_NFManagement_NFStatusNotify) message.

[0197] Optionally, the network element status notification message may also include one or more of the following of the user plane functional network element: load information, location information, identification of supported data networks, and identification of supported network slices.

[0198] Example 4: The third network element is a network storage function network element. As shown in the dotted box in Figure 11, the network element selection method shown in Figure 11 differs from the network element selection method shown in Figure 10 in that the network element selection method shown in Figure 11 does not include step S402 in Figure 10, and the network element selection method shown in Figure 11 further includes steps S501 and S502 before step S403.

[0199] S501. An operation and maintenance network element or an energy efficiency network function network element sends a second configuration request message or a second configuration update request message to each of one or more user plane function network elements. The second configuration request message or second configuration update request message sent to each user plane function network element includes an identifier of a network storage function network element and description information of the user plane function network element. Accordingly, each of the one or more user plane function network elements receives the second configuration request message or second configuration update request message from the operation and maintenance network element or the energy efficiency network function network element.

[0200] The second configuration request message is used to configure the relevant information of the user plane function network element to the user plane function network element, and the second configuration update request message is used to update the relevant information of the user plane function network element to the user plane function network element. The second configuration request message may be, for example, a UPF configuration request message (i.e., a UPF configuration request message), and the second configuration update request message may be, for example, a UPF configuration update request message (i.e., a UPF configuration update request message).

[0201] Optionally, the second configuration request message or the second configuration update request message may also include one or more of the following of the user plane functional network element: load information, location information, identification of supported data networks, and identification of supported network slices.

[0202] In addition, for the specific description of the second network element, please refer to the above-mentioned related description, which will not be repeated here.

[0203] S502. Each of the one or more user plane function network elements sends a network element registration request message to the network storage function network element. The network element registration request message sent by each user plane function network element includes description information of the user plane function network element. Correspondingly, the network storage function network element receives the network element registration request message from each of the one or more user plane function network elements.

[0204] The network element registration request message is used by the user plane function network element to notify the network storage function network element of its updated information. The network element registration request message may be, for example, a network function management and network function registration (ie, Nnrf_NFManagement_NFRegister) message.

[0205] Optionally, the network element registration request message and / or the network element status notification message in step S403 may also include one or more of the following of the user plane functional network element: load information, location information, identification of supported data networks, and identification of supported network slices.

[0206] Example 5: The third network element is an operation and maintenance network element or an energy efficiency network function network element. As shown in the dashed box in Figure 12, the network element selection method shown in Figure 12 differs from the network element selection method shown in Figure 8 in that the network element selection method shown in Figure 12 does not include steps S201 to S203 in Figure 8, and the network element selection method shown in Figure 12 also includes step S601.

[0207] S601: An operation and maintenance network element or an energy-efficient network function network element sends a network element configuration message to a session management function network element. The network element configuration message includes an identifier of each user plane function network element in one or more user plane function network elements and description information of each user plane function network element. In response, the session management function network element receives the network element configuration message sent by the operation and maintenance network element or the energy-efficient network function network element.

[0208] Among them, the network element configuration message is used to notify the session management function network element: the configuration information or updated information of the network element in the network. The network element configuration message can be, for example, a network function configuration request (i.e., NF Configuration request) message. Optionally, the network element configuration message can also include one or more of the following of the user plane function network element: load information, location information, identification of the supported data network, and identification of the supported network slice. In addition, for the specific elaboration of the description information of the second network element, please refer to the aforementioned related elaboration and will not be repeated here.

[0209] To implement the functions of the methods provided in the embodiments of the present application, the first network element may include a hardware structure and / or a software module, and implement the functions in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module. Whether a particular function is implemented in the form of a hardware structure, a software module, or a combination of a hardware structure and a software module depends on the specific application and design constraints of the technical solution.

[0210] As shown in Figure 13, an embodiment of the present application provides a communication device 1300. The communication device 1300 can be a first network element, or a component of a network element (for example, an integrated circuit, a chip, etc.). The communication device 1300 can also be other communication units for implementing the method in the method embodiment of the present application. The communication device 1300 may include a processing unit 1301. Optionally, the communication device 1300 may also include a communication unit 1302, and the processing unit 1301 is used to control the communication unit 1302 to send and receive data / signaling. The communication unit 1302 may also be referred to as a transceiver unit. Optionally, the communication unit 1302 may include a sending unit and a receiving unit. The sending unit may be used to send data / signaling, and the receiving unit may be used to receive data / signaling. Optionally, the communication device 1300 may also include a storage unit 1303. The storage unit 1303 may be used to store information and / or data and / or instructions, etc. The storage unit 1303 may interact with the processing unit 1301, and may also interact with the communication unit 1302.

[0211] In one possible design, for a case where the communication apparatus 1300 is used to implement the function of the first network element in the above method embodiment:

[0212] a communication unit 1302, configured to receive description information of one or more second network elements in a network, where the description information of each second network element in the one or more second network elements is used to indicate whether the second network element is shut down when the network is in an energy-saving state;

[0213] The processing unit 1301 is configured to select a second network element from the one or more second network elements for a session requested to be established by the terminal device based on description information of the one or more second network elements.

[0214] In an optional embodiment, the processing unit 1301 selects a second network element from one or more second network elements for a session requested to be established by the terminal device based on the description information of the one or more second network elements, and is specifically used to: select a second network element from one or more second network elements for the session based on the service continuity requirements corresponding to the session and the description information of the one or more second network elements.

[0215] In an optional embodiment, when the service continuity requirement corresponding to the session indicates that the service transmission in the network should be maintained continuously during the duration of the session, the description information of the second network element selected for the session indicates that the second network element should not be shut down when the network is in an energy-saving state.

[0216] In an optional implementation, the service continuity requirement corresponding to the session is an SSC mode corresponding to the session.

[0217] In an optional embodiment, the communication unit 1302 is further configured to receive first information from the terminal device, the first information being used to indicate an SSC mode requested by the terminal device for the session. The processing unit 1301 is further configured to determine an SSC mode corresponding to the session based on the SSC mode requested by the terminal device for the session.

[0218] In an optional embodiment, when the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state, and SSC mode 1 indicates that changes to the second network element corresponding to the session during the duration of the session are not supported.

[0219] In an optional embodiment, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected for the session indicates that the second network element is turned off when the network is in an energy-saving state, and SSC mode 2 and SSC mode 3 indicate support for changing the second network element corresponding to the session during the duration of the session.

[0220] In an optional embodiment, the description information of each second network element in one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state, including: the description information of each second network element in one or more second network elements is used to indicate whether the data network and / or network slice supported by the second network element is turned off when the network is in an energy-saving state.

[0221] Communication unit 1302 is also used to receive second information from the terminal device, where the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device.

[0222] When the SSC mode corresponding to the session is SSC mode 1, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed.

[0223] Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is turned off.

[0224] Among them, SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session; SSC mode 2 and SSC mode 3 indicate that the second network element corresponding to the session is supported to be changed during the duration of the session.

[0225] In an optional embodiment, when the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state, the description information of the second network element is also used to indicate the priority of shutting down the second network element when the network is in an energy-saving state.

[0226] The processing unit 1301 selects a second network element for the session from the one or more second network elements based on the service continuity requirement corresponding to the session and description information of the one or more second network elements, and is specifically configured to:

[0227] When the SSC mode corresponding to the session is SSC mode 1, and the description information of each second network element in one or more second network elements indicates that the second network element is turned off when the network is in an energy-saving state, the second network element is selected for the session based on the priority of the second network element being turned off when the network is in an energy-saving state as indicated by the description information of each second network element in one or more second network elements; wherein, SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session.

[0228] In an optional embodiment, the description information of each second network element in the one or more second network elements is further used to indicate the validity period of the description information. Communication unit 1302 is further used to receive third information from the terminal device, the third information being used to indicate the duration of the session requested to be established by the terminal device; the validity period of the description information of the second network element selected for the session includes part or all of the duration.

[0229] In an optional implementation, the communication unit 1302 receives description information of one or more second network elements in the network, and is specifically configured to: receive description information of the second network element sent by each of the one or more second network elements.

[0230] In an optional implementation, the communication unit 1302 receives description information of one or more second network elements in the network, and is specifically configured to receive description information of one or more second network elements sent by a third network element.

[0231] In an optional implementation, the communication unit 1302 is further configured to receive a message from a terminal device requesting to establish a session.

[0232] In an optional implementation, the apparatus 1300 is a session management function network element, and the second network element is a user plane function network element.

[0233] The embodiments of the present application and the method embodiments shown above are based on the same concept, and the technical effects they bring are also the same. For the specific principles, please refer to the description of the embodiments shown above, and no further details will be given.

[0234] The present application also provides a communication device 1400, as shown in Figure 14. Communication device 1400 can be a first network element, or a chip, chip system, or processor that supports the first network element in implementing the above method. This device can be used to implement the method described in the above method embodiment. For details, please refer to the description of the above method embodiment.

[0235] The communication device 1400 may include one or more processors 1401. The processor 1401 may be configured to implement some or all of the functions of the first network element through logic circuits or by running computer programs. The processor 1401 may be a general-purpose processor or a dedicated processor, etc. For example, it may be a baseband processor, a digital signal processor, an application-specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, or a CPU. The baseband processor may be configured to process communication protocols and communication data, and the central processing unit may be configured to control the communication device, execute software programs, and process data of the software programs, wherein the communication device may be, for example, a base station, a baseband chip, a terminal, a terminal chip, a distributed unit (DU), or a centralized unit (CU).

[0236] Optionally, the communication device 1400 may include one or more memories 1402, on which instructions 1404 may be stored. The instructions may be executed on the processor 1401, causing the communication device 1400 to perform the method described in the above method embodiment. Optionally, the memory 1402 may also store data. The processor 1401 and the memory 1402 may be provided separately or integrated together.

[0237] The memory 1402 may include, but is not limited to, non-volatile memory such as a hard disk drive (HDD) or a solid-state drive (SSD), random access memory (RAM), erasable programmable ROM (EPROM), ROM or compact disc read-only memory (CD-ROM), etc.

[0238] Optionally, the communication device 1400 may further include a transceiver 1405 and an antenna 1406. The transceiver 1405 may be referred to as a transceiver unit, a transceiver, or a transceiver circuit, etc., and is configured to implement transceiver functions. The transceiver 1405 may include a receiver and a transmitter. The receiver may be referred to as a receiver or a receiving circuit, etc., and is configured to implement a receiving function; the transmitter may be referred to as a transmitter or a transmitting circuit, etc., and is configured to implement a transmitting function.

[0239] In one possible design, for a case where the communication apparatus 1400 is used to implement the function of the first network element in the above method embodiment:

[0240] a transceiver 1405 configured to receive description information of one or more second network elements in the network, wherein the description information of each second network element in the one or more second network elements is used to indicate whether the second network element is shut down when the network is in an energy-saving state;

[0241] Processor 1401 is configured to select a second network element from one or more second network elements for a session requested to be established by a terminal device based on description information of the one or more second network elements.

[0242] In an optional embodiment, the processor 1401 selects a second network element from one or more second network elements for a session requested to be established by the terminal device based on the description information of the one or more second network elements, and is specifically used to: select a second network element from one or more second network elements for the session based on the service continuity requirements corresponding to the session and the description information of the one or more second network elements.

[0243] In an optional embodiment, when the service continuity requirement corresponding to the session indicates that the service transmission in the network should be maintained continuously during the duration of the session, the description information of the second network element selected for the session indicates that the second network element should not be shut down when the network is in an energy-saving state.

[0244] In an optional implementation, the service continuity requirement corresponding to the session is an SSC mode corresponding to the session.

[0245] In an optional embodiment, the transceiver 1405 is further configured to receive first information from a terminal device, the first information being used to indicate an SSC mode requested by the terminal device for the session. The processor 1401 is further configured to determine an SSC mode corresponding to the session based on the SSC mode requested by the terminal device for the session.

[0246] In an optional embodiment, when the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state, and SSC mode 1 indicates that changes to the second network element corresponding to the session during the duration of the session are not supported.

[0247] In an optional embodiment, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected for the session indicates that the second network element is turned off when the network is in an energy-saving state, and SSC mode 2 and SSC mode 3 indicate support for changing the second network element corresponding to the session during the duration of the session.

[0248] In an optional embodiment, the description information of each second network element in one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state, including: the description information of each second network element in one or more second network elements is used to indicate whether the data network and / or network slice supported by the second network element is turned off when the network is in an energy-saving state.

[0249] Transceiver 1405 is also used to receive second information from the terminal device, where the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device.

[0250] When the SSC mode corresponding to the session is SSC mode 1, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed.

[0251] Alternatively, when the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is turned off.

[0252] Among them, SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session; SSC mode 2 and SSC mode 3 indicate that the second network element corresponding to the session is supported to be changed during the duration of the session.

[0253] In an optional embodiment, when the description information of the second network element is used to indicate that the second network element is shut down when the network is in an energy-saving state, the description information of the second network element is also used to indicate the priority of shutting down the second network element when the network is in an energy-saving state.

[0254] The processor 1401 selects a second network element for the session from the one or more second network elements based on the service continuity requirement corresponding to the session and description information of the one or more second network elements, and is specifically configured to:

[0255] When the SSC mode corresponding to the session is SSC mode 1, and the description information of each second network element in one or more second network elements indicates that the second network element is turned off when the network is in an energy-saving state, the second network element is selected for the session based on the priority of the second network element being turned off when the network is in an energy-saving state as indicated by the description information of each second network element in one or more second network elements; wherein, SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session.

[0256] In an optional embodiment, the description information of each of the one or more second network elements is further used to indicate a validity period of the description information. Transceiver 1405 is further used to receive third information from the terminal device, the third information being used to indicate a duration of a session requested by the terminal device. The validity period of the description information of the second network element selected for the session includes part or all of the duration.

[0257] In an optional implementation manner, the transceiver 1405 receives description information of one or more second network elements in the network, and is specifically configured to: receive description information of the second network element sent by each of the one or more second network elements.

[0258] In an optional implementation manner, the transceiver 1405 receives description information of one or more second network elements in the network, and is specifically configured to receive description information of one or more second network elements sent by a third network element.

[0259] In an optional implementation, the transceiver 1405 is further configured to receive a message from a terminal device requesting to establish a session.

[0260] In an optional implementation, the apparatus 1400 is a session management function network element, and the second network element is a user plane function network element.

[0261] In another possible design, processor 1401 may include a transceiver for implementing receiving and transmitting functions. For example, the transceiver may be a transceiver circuit, an interface, or an interface circuit. The transceiver circuit, interface, or interface circuit for implementing the receiving and transmitting functions may be separate or integrated. The transceiver circuit, interface, or interface circuit may be used for reading and writing code / data, or the transceiver circuit, interface, or interface circuit may be used for transmitting or delivering signals.

[0262] In another possible design, processor 1401 may optionally store instructions 1403. Instructions 1403, when executed on processor 1401, may cause communication device 1400 to perform the method described in the above method embodiment. Instructions 1403 may be fixed in processor 1401. In this case, processor 1401 may be implemented by hardware.

[0263] In another possible design, the communication device 1400 may include a circuit that can implement the functions of sending, receiving, or communicating in the aforementioned method embodiments. The processor and transceiver described in the embodiments of the present application can be implemented in an integrated circuit (IC), an analog IC, a radio frequency integrated circuit (RFIC), a mixed signal IC, an application specific integrated circuit (ASIC), a printed circuit board (PCB), an electronic device, etc. The processor and transceiver can also be manufactured using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), N-type metal oxide semiconductor (nMetal-oxide-semiconductor, NMOS), P-type metal oxide semiconductor (positive channel metal oxide semiconductor, PMOS), bipolar junction transistor (bipolar junction transistor, BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

[0264] Those skilled in the art will also appreciate that the various illustrative logical blocks and steps listed in the embodiments of the present application can be implemented by electronic hardware, computer software, or a combination of both. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the described functions for each specific application, but such implementation should not be construed as exceeding the scope of protection of the embodiments of the present application.

[0265] The embodiments of the present application and the above-mentioned method embodiments are based on the same concept, and the technical effects they bring are also the same. For the specific principles, please refer to the description in the above-mentioned method embodiments, and no further details will be given.

[0266] The present application also provides a computer-readable storage medium for storing computer software instructions, which, when executed by a communication device, implements the functions of any of the above method embodiments.

[0267] The present application also provides a computer program product for storing computer software instructions, which, when executed by a communication device, implements the functions of any of the above method embodiments.

[0268] The present application also provides a computer program that, when executed on a computer, implements the functions of any of the above method embodiments.

[0269] In the above embodiments, all or part of the embodiments may be implemented by software, hardware, firmware, or any combination thereof. When implemented using software, all or part of the embodiments may be implemented in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via a wired (e.g., coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) method. The computer-readable storage medium may be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more available media integrated therein. The available medium may be a magnetic medium (eg, a floppy disk, a hard disk, a magnetic tape), an optical medium (eg, a high-density digital video disc (DVD)), or a semiconductor medium (eg, an SSD).

[0270] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this application should be included in the scope of protection of this application. Therefore, the scope of protection of this application should be based on the scope of protection of the claims.

Claims

1. A network element selection method, characterized in that: The method comprises: receiving description information of one or more second network elements in a network, wherein the description information of each second network element in the one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state; Based on the description information of the one or more second network elements, a second network element is selected from the one or more second network elements for the session requested to be established by the terminal device.

2. The method according to claim 1, characterized in that The selecting, based on the description information of the one or more second network elements, a second network element for a session requested to be established by the terminal device from the one or more second network elements includes: Based on the service continuity requirement corresponding to the session and the description information of the one or more second network elements, a second network element is selected for the session from the one or more second network elements.

3. The method according to claim 2, characterized in that When the service continuity requirement corresponding to the session indicates that the service is to be transmitted continuously in the network during the duration of the session, the description information of the second network element selected for the session indicates that the second network element is not to be shut down when the network is in an energy-saving state.

4. The method according to claim 2 or 3, characterized in that: The service continuity requirement corresponding to the session is the session and service continuity SSC mode corresponding to the session.

5. The method according to claim 4, characterized in that The method further comprises: receiving first information from the terminal device, the first information being used to indicate an SSC mode requested by the terminal device for the session; Based on the SSC mode requested by the terminal device for the session, determine the SSC mode corresponding to the session.

6. The method according to claim 4 or 5, characterized in that: When the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state, and the SSC mode 1 indicates that the change of the second network element corresponding to the session during the duration of the session is not supported.

7. The method according to claim 4 or 5, characterized in that: When the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected for the session indicates that the second network element is turned off when the network is in an energy-saving state, and the SSC mode 2 and the SSC mode 3 indicate support for changing the second network element corresponding to the session during the duration of the session.

8. The method according to claim 4 or 5, characterized in that: The description information of each second network element in the one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state, including: The description information of each second network element in the one or more second network elements is used to indicate whether the data network and / or network slice supported by the second network element is closed when the network is in an energy-saving state; The method further comprises: receiving second information from the terminal device, where the second information is used to indicate a data network and / or a network slice associated with the session requested by the terminal device; When the SSC mode corresponding to the session is SSC mode 1, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed; or, When the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is closed; The SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session; The SSC mode 2 and the SSC mode 3 indicate support for changing the second network element corresponding to the session within the duration of the session.

9. The method according to claim 4 or 5, characterized in that: In a case where the description information of the second network element is used to indicate that the second network element is turned off when the network is in an energy-saving state, the description information of the second network element is further used to indicate a priority for turning off the second network element when the network is in an energy-saving state; The selecting a second network element for the session from the one or more second network elements based on the service continuity requirement corresponding to the session and the description information of the one or more second network elements includes: When the SSC mode corresponding to the session is SSC mode 1, and the description information of each of the one or more second network elements indicates that the second network element is turned off when the network is in an energy-saving state, selecting a second network element for the session based on a priority of the second network element being turned off when the network is in an energy-saving state indicated by the description information of each of the one or more second network elements; Among them, the SSC mode 1 indicates that changing the second network element corresponding to the session during the duration of the session is not supported.

10. The method according to any one of claims 1 to 9, characterized in that: The description information of each second network element in the one or more second network elements is further used to indicate the validity period of the description information; Before selecting a second network element for a session requested to be established by the terminal device from the one or more second network elements based on the description information of the one or more second network elements, the method further includes: receiving third information from the terminal device, wherein the third information is used to indicate the duration of the session requested to be established by the terminal device; The validity period of the description information of the second network element selected for the session includes part or all of the duration.

11. The method according to any one of claims 1 to 10, characterized in that: The receiving description information of one or more second network elements in the network includes: Receive description information of the second network element sent by each second network element among the one or more second network elements.

12. The method according to any one of claims 1 to 10, characterized in that: The receiving description information of one or more second network elements in the network includes: Receive description information of the one or more second network elements sent by the third network element.

13. The method according to any one of claims 1 to 12, characterized in that: The method further comprises: A message for requesting to establish the session is received from the terminal device.

14. The method according to any one of claims 1 to 13, characterized in that: The execution subject of the method is a session management function network element, and the second network element is a user plane function network element.

15. A communication device, characterized in that: The device comprises: A communication unit, configured to receive description information of one or more second network elements in a network, wherein the description information of each second network element in the one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state; A processing unit is used to select a second network element from the one or more second network elements for a session requested to be established by the terminal device based on the description information of the one or more second network elements.

16. The device according to claim 15, characterized in that The processing unit selects a second network element for a session requested to be established by the terminal device from the one or more second network elements based on the description information of the one or more second network elements, specifically configured to: Based on the service continuity requirement corresponding to the session and the description information of the one or more second network elements, a second network element is selected for the session from the one or more second network elements.

17. The device according to claim 16, characterized in that When the service continuity requirement corresponding to the session indicates that the service is to be transmitted continuously in the network during the duration of the session, the description information of the second network element selected for the session indicates that the second network element is not to be shut down when the network is in an energy-saving state.

18. The device according to claim 16 or 17, characterized in that The service continuity requirement corresponding to the session is the session and service continuity SSC mode corresponding to the session.

19. The device according to claim 18, characterized in that The communication unit is further configured to receive first information from the terminal device, wherein the first information is used to indicate an SSC mode requested by the terminal device for the session; The processing unit is further used to determine the SSC mode corresponding to the session based on the SSC mode requested by the terminal device for the session.

20. The device according to claim 18 or 19, characterized in that When the SSC mode corresponding to the session is SSC mode 1, the description information of the second network element selected for the session indicates that the second network element is not shut down when the network is in an energy-saving state, and the SSC mode 1 indicates that the change of the second network element corresponding to the session during the duration of the session is not supported.

21. The device according to claim 18 or 19, characterized in that When the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the description information of the second network element selected for the session indicates that the second network element is turned off when the network is in an energy-saving state, and the SSC mode 2 and the SSC mode 3 indicate support for changing the second network element corresponding to the session during the duration of the session.

22. The device according to claim 18 or 19, characterized in that The description information of each second network element in the one or more second network elements is used to indicate whether the second network element is turned off when the network is in an energy-saving state, including: The description information of each second network element in the one or more second network elements is used to indicate whether the data network and / or network slice supported by the second network element is closed when the network is in an energy-saving state; The communication unit is further used to receive second information from the terminal device, where the second information is used to indicate the data network and / or network slice associated with the session requested by the terminal device; When the SSC mode corresponding to the session is SSC mode 1, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is not closed; or, When the SSC mode corresponding to the session is SSC mode 2 or SSC mode 3, the second network element selected for the session supports the data network and / or network slice associated with the session requested by the terminal device, and the description information of the second network element selected for the session indicates that when the network is in an energy-saving state, the data network and / or network slice associated with the session requested by the terminal device is closed; The SSC mode 1 indicates that the second network element corresponding to the session is not supported to be changed during the duration of the session; The SSC mode 2 and the SSC mode 3 indicate support for changing the second network element corresponding to the session within the duration of the session.

23. The device according to claim 18 or 19, characterized in that In a case where the description information of the second network element is used to indicate that the second network element is turned off when the network is in an energy-saving state, the description information of the second network element is further used to indicate a priority for turning off the second network element when the network is in an energy-saving state; The processing unit selects a second network element for the session from the one or more second network elements based on the service continuity requirement corresponding to the session and the description information of the one or more second network elements, specifically configured to: When the SSC mode corresponding to the session is SSC mode 1, and the description information of each of the one or more second network elements indicates that the second network element is turned off when the network is in an energy-saving state, selecting a second network element for the session based on a priority of the second network element being turned off when the network is in an energy-saving state indicated by the description information of each of the one or more second network elements; Among them, the SSC mode 1 indicates that changing the second network element corresponding to the session during the duration of the session is not supported.

24. The device according to any one of claims 15 to 23, characterized in that The description information of each second network element in the one or more second network elements is further used to indicate the validity period of the description information; The communication unit is further used to receive third information from the terminal device, where the third information is used to indicate the duration of the session requested to be established by the terminal device; The validity period of the description information of the second network element selected for the session includes part or all of the duration.

25. The device according to any one of claims 15 to 24, characterized in that The communication unit receives description information of one or more second network elements in the network, specifically used to: Receive description information of the second network element sent by each second network element among the one or more second network elements.

26. The device according to any one of claims 15 to 24, characterized in that The communication unit receives description information of one or more second network elements in the network, specifically used to: Receive description information of the one or more second network elements sent by the third network element.

27. The device according to any one of claims 15 to 26, characterized in that The communication unit is further configured to receive a message from the terminal device for requesting to establish the session.

28. A communication device, characterized in that: including memory and processor; The memory is used to store instructions or computer programs; The processor is configured to execute the computer program or instructions stored in the memory, so that the communication device executes the method according to any one of claims 1 to 14.

29. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed, the method according to any one of claims 1 to 14 is implemented.

30. A computer program product, the computer program product comprising: Computer program code, when the computer program code is run, implements the method according to any one of claims 1 to 14.

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