Patent Description:
A next generation mobile communications network architecture (next generation system), also referred to as a 5th generation (fifth generation, <NUM>) network architecture, has been released in the 3rd generation partnership project (3rd generation partnership project, 3GPP).

In the <NUM> network architecture, transmission may be performed by using an access and mobility management function (access and mobility management function, AMF) in a process in which a policy control function (policy control function, PCF) network element communicates with a terminal apparatus (for example, the PCF sends a policy rule to the terminal apparatus). As subscription information, a location, a time, and the like change in the terminal apparatus, the PCF updates the policy rule delivered to the terminal apparatus.

When the terminal apparatus is in an idle mode, the terminal apparatus does not immediately update the policy rule. In this case, signaling overheads are unnecessary due to the policy rule delivered by the PCF to the terminal apparatus. Therefore, in the communication process in which the PCF delivers the policy rule to the terminal apparatus, how to reduce signaling overheads becomes an urgent problem to be resolved currently. Document "<NPL> discloses PCF re-transmits the undelivered UE policy containers for the delivery failure. Document "<NPL> discloses when UE is in CM-CONNECTED, the AMF transfers transparently the UE policy from PCF to the UE; and when the UE in CM-IDLE and paging fails, then AMF reports failure to deliver the UE policy to the PCF. Document "<NPL> discloses service control for traffic transmitted via a combination of wireline access and wireless 3GPP access. If wireline access is no more available, the PCF notices this status change and performs PDU session modification procedure for the traffic transmitted over the wireless 3GPP access.

This application provides wireless network communication methods, a policy control network element, an access and mobility managing network element, a system and computer program products, so that signaling overheads can be reduced in a communication process in which a PCF delivers a policy rule to a terminal apparatus.

In the foregoing technical solution, the PCF network element can dispose the connection management state trigger of the terminal apparatus in the AMF, and can trigger, when the connection management state of the terminal apparatus is switched to the connected mode, the AMF to notify the PCF that the terminal apparatus is in the connected mode. The PCF can deliver the policy rule to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode, to avoid a problem that the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced.

The embodiments corresponding to <FIG>, <FIG> and <FIG> are not according to the invention and are present for illustration purposes.

It should be understood that the technical solutions of the embodiments of this application may be applied to various communications systems, for example, a global system for mobile communications (global system of mobile communication, GSM), a code division multiple access (code division multiple access, CDMA) system, a wideband code division multiple access (wideband code division multiple access, WCDMA) system, a general packet radio service (general packet radio service, GPRS), a long term evolution (Long Term Evolution, LTE) system, an LTE frequency division duplex (frequency division duplex, FDD) system, an LTE time division duplex (Time Division Duplex, TDD) system, a universal mobile telecommunications system (universal mobile telecommunication system, UMTS), a worldwide interoperability for microwave access (worldwide interoperability for microwave access, WiMAX) communications system, a future 5th generation (5th generation, <NUM>) system, or a new radio (new radio, NR) system.

A type of a terminal apparatus is not specifically limited in the embodiments of this application. For example, the terminal apparatus may be user equipment (user equipment, UE), an access terminal, a terminal apparatus, a subscriber unit, a subscriber station, a mobile station, a mobile console, a remote station, a remote terminal, a mobile device, a user terminal, a wireless network device, a user agent, or a user apparatus. The terminal may include but is not limited to a mobile station (mobile station, MS), a mobile phone (mobile telephone), user equipment (user equipment, UE), a handset (handset), a portable device (portable equipment), a cellular phone, a cordless phone, a session initiation protocol (session initiation protocol, SIP) phone, a wireless local loop (wireless local loop, WLL) station, personal digital processing (personal digital assistant, PDA), a radio frequency identification (radio frequency identification, RFID) terminal apparatus for logistics, a handheld device having a wireless communication function, a computing device, another device connected to a wireless modem, a vehicle-mounted device, a wearable device, a terminal apparatus in internet of things or internet of vehicles, a terminal apparatus in a future <NUM> network, a terminal apparatus in a future evolved public land mobile network (public land mobile network, PLMN) network, or the like.

In an example instead of limitation, in the embodiments of this application, the terminal apparatus may alternatively be a wearable device. The wearable device may also be referred to as a wearable intelligent device, and is a general term for wearable devices such as glasses, gloves, a watch, clothes, and shoes that are developed by applying wearable technologies in intelligent designs of daily wear. The wearable device is a portable device that is directly worn on a body or integrated into clothes or an accessory of a user. The wearable device is not merely a hardware device, but implements a powerful function through software support, data exchange, and cloud interaction. In a broad sense, the wearable intelligent device includes a full-featured and large-sized device that can implement complete or partial functions without depending on a smartphone, such as a smartwatch or smart glasses, and a device that focuses on only one type of application function and needs to work with another device such as a smartphone, such as various smart bands or smart jewelry for monitoring physical signs.

A type of a network device is not specifically limited in the embodiments of this application. The network device may be any device configured to communicate with a terminal apparatus. For example, the network device may be a base transceiver station (base transceiver station, BTS) in a global system for mobile communications (global system of mobile communication, GSM) or a code division multiple access (code division multiple access, CDMA) system, or may be a NodeB (NodeB, NB) in a wideband code division multiple access (wideband code division multiple access, WCDMA) system, or may be an evolved NodeB (evolutional Node B, eNB or eNodeB) in a long term evolution (long term evolution, LTE) system, or may be a radio controller in a cloud radio access network (cloud radio access network, CRAN) scenario. Alternatively, for example, the network device may be a relay node, an access point, a vehicle-mounted device, a wearable device, a network device in a future <NUM> network, a network device in a future evolved PLMN network, or the like.

In a possible manner, the network device may include a centralized unit (centralized unit, CU) and a distributed unit (distributed unit, DU). One CU may be connected to one DU, or a plurality of DUs may share one CU, to save costs and facilitate network expansion. The CU and the DU may be split based on a protocol stack. In a possible manner, a radio resource control (radio resource control, RRC) layer, a service data mapping protocol stack (service data adaptation protocol, SDAP) layer, and a packet data convergence protocol (packet data convergence protocol, PDCP) layer are deployed in the CU, and a radio link control (radio link control, RLC) layer, a media access control (media access control, MAC) layer, and a physical layer are deployed in the DU.

In addition, in the embodiments of this application, the network device provides a service for a cell, and the terminal apparatus communicates with the network device by using a transmission resource (for example, a frequency domain resource or a spectrum resource) used in the cell. The cell may be a cell corresponding to the network device (for example, a base station). The cell may belong to a macro base station, or may belong to a base station corresponding to a small cell (small cell). The small cell herein may include a metro cell (Metro cell), a micro cell (Micro cell), a pico cell (Pico cell), a femto cell (Femto cell), and the like. These small cells are characterized by a small coverage area and low transmit power, and are applicable to providing a high-rate data transmission service.

A method provided in the embodiments of this application can be applied to a terminal apparatus or a network device. The terminal apparatus or the network device includes a hardware layer, an operating system layer running above the hardware layer, and an application layer running above the operating system layer. The hardware layer includes hardware such as a central processing unit (central processing unit, CPU), a memory management unit (memory management unit, MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement service processing by using a process (process), for example, a Linux operating system, a UNIX operating system, an Android operating system, an iOS operating system, or a Windows operating system. The application layer includes an application such as a browser, an address book, word processing software, and instant messaging software. In addition, in the embodiments of this application, a specific structure of an execution body of the signal transmission method is not particularly limited in the embodiments of this application, provided that communication can be performed according to the signal transmission method in the embodiments of this application by running a program that records code of the signal transmission method in the embodiments of this application. For example, the wireless communication method in the embodiments of this application may be performed by the terminal apparatus or the network device, or a function module that is in the terminal apparatus or the network device and that can invoke the program and execute the program.

In addition, aspects or features in the embodiments of this application may be implemented as a method, an apparatus, or a product that uses standard programming and/or engineering technologies. The term "product" used in this application covers a computer program that can be accessed from any computer readable device, carrier, or medium. For example, the computer readable medium may include but is not limited to a magnetic storage device (for example, a hard disk, a floppy disk, or a magnetic tape), an optical disc (for example, a compact disc (compact disc, CD) or a digital versatile disc (digital versatile disc, DVD), a smart card, and a flash memory device (for example, an erasable programmable read-only memory (erasable programmable read-only memory, EPROM), a card, a stick, or a key drive). In addition, various storage media described in this specification may represent one or more devices and/or other machine readable media that are configured to store information. The term "machine readable media" may include but is not limited to a radio channel and various other media that can store, include, and/or carry an instruction and/or data.

<FIG> is a schematic diagram of a scenario of a communications system <NUM> to which an embodiment of this application can be applied. As shown in <FIG>, the communications system <NUM> includes a network device <NUM>, and the network device <NUM> may include a plurality of antenna groups. Each antenna group may include a plurality of antennas. For example, one antenna group may include antennas <NUM> and <NUM>, another antenna group may include antennas <NUM> and <NUM>, and an additional group may include antennas <NUM> and <NUM>. Each antenna group in <FIG> shows two antennas. However, each group may include more or fewer antennas. The network device <NUM> may additionally include a transmitter chain and a receiver chain. A person of ordinary skill in the art may understand that the transmitter chain and the receiver chain may each include a plurality of components (for example, a processor, a modulator, a multiplexer, a demodulator, a demultiplexer, or an antenna) related to signal sending and receiving.

The network device <NUM> may communicate with a plurality of terminal apparatuses (for example, a terminal apparatus <NUM> and a terminal apparatus <NUM>). However, it may be understood that the network device <NUM> may communicate with any quantity of terminal apparatuses similar to the terminal apparatus <NUM> or <NUM>. For example, the terminal apparatuses <NUM> and <NUM> may each be a cellular phone, a smartphone, a portable computer, a handheld communications device, a handheld computing device, a satellite radio apparatus, a global positioning system, a PDA, and/or any other proper device configured to perform communication in the wireless communications system <NUM>.

As shown in <FIG>, the terminal apparatus <NUM> communicates with the antennas <NUM> and <NUM>. The antennas <NUM> and <NUM> send information to the terminal apparatus <NUM> by using a forward link <NUM>, and receive information from the terminal apparatus <NUM> by using a reverse link <NUM>. In addition, the terminal apparatus <NUM> communicates with the antennas <NUM> and <NUM>. The antennas <NUM> and <NUM> send information to the terminal apparatus <NUM> by using a forward link <NUM>, and receive information from the terminal apparatus <NUM> by using a reverse link <NUM>.

For example, in a frequency division duplex (frequency division duplex, FDD) system, the forward link <NUM> may use a frequency band different from that used by the reverse link <NUM>, and the forward link <NUM> may use a frequency band different from that used by the reverse link <NUM>.

For another example, in a time division duplex (time division duplex, TDD) system and a full duplex (full duplex) system, the forward link <NUM> and the reverse link <NUM> may use a same frequency band, and the forward link <NUM> and the reverse link <NUM> may use a same frequency band.

Each antenna group and/or each area that are/is designed for communication are/is referred to as a sector of the network device <NUM>. For example, an antenna group may be designed to communicate with a terminal apparatus in a sector of a coverage area of the network device <NUM>. In a process in which the network device <NUM> respectively communicates with the terminal apparatuses <NUM> and <NUM> by using the forward links <NUM> and <NUM>, a transmit antenna of the network device <NUM> can improve signal-to-noise ratios of the forward links <NUM> and <NUM> through beamforming. In addition, in comparison with a manner in which the network device sends a signal to all terminal apparatuses of the network device by using a single antenna, less interference is caused to a mobile device in a neighboring cell in a manner in which the network device <NUM> sends, through beamforming, a signal to the terminal apparatuses <NUM> and <NUM> that are randomly scattered in a related coverage area.

At a given time, the network device <NUM>, the terminal apparatus <NUM>, or the terminal apparatus <NUM> may be a wireless communications sending apparatus and/or a wireless communications receiving apparatus. When sending data, the wireless communications sending apparatus may encode the data for transmission. Specifically, the wireless communications sending apparatus may obtain (for example, generate, receive from another communications apparatus, or store in a memory) a specific quantity of data bits that need to be sent to the wireless communications receiving apparatus through a channel. The data bits may be included in a transport block (or a plurality of transport blocks) of data, and the transport block may be segmented to generate a plurality of code blocks.

In addition, the communications system <NUM> may be a public land mobile network PLMN network, a device-to-device (device to device, D2D) network, a machine-to-machine (machine to machine, M2M) network, or another network. <FIG> is merely a simplified schematic diagram of an example for ease of understanding. The network may further include another network device that is not shown in <FIG>.

<FIG> is a schematic diagram of an architecture of a system to which an embodiment of this application can be applied. As shown in <FIG>, the system <NUM> includes an AMF <NUM>, a session management function (session management function, SMF) device <NUM>, a radio access network (radio access network, RAN) <NUM>, an authentication server function (authentication server function, AUSF) device <NUM>, a unified data management (unified data management, UDM) device <NUM>, a policy control function (policy control function, PCF) device <NUM>, a data network (data network, DN) <NUM>, a user plane function (user plane function, UPF) device <NUM>, user equipment (user equipment, UE) <NUM>, and an application function (application function, AF) <NUM>. The UE <NUM> is connected to the AMF <NUM> by using an N1 interface, and the UE <NUM> is connected to the RAN <NUM> by using a radio resource control (Radio Resource Control, RRC) protocol. The RAN <NUM> is connected to the AMF <NUM> by using an N2 interface, and the RAN <NUM> is connected to the UPF <NUM> by using an N3 interface. A plurality of UPFs <NUM> are connected to each other by using an N9 interface, and the UPF <NUM> is connected to the DN <NUM> by using an N6 interface. In addition, the UPF <NUM> is connected to the SMF <NUM> by using an N4 interface. The SMF <NUM> is connected to the PCF <NUM> by using an N7 interface, and the SMF <NUM> is connected to the UDM <NUM> by using an N20 interface. In addition, the SMF <NUM> is connected to the AMF <NUM> by using an N11 interface. A plurality of AMFs <NUM> are connected to each other by using an N14 interface, the AMF <NUM> is connected to the UDM <NUM> by using an N8 interface, and the AMF <NUM> is connected to the AUSF <NUM> by using an N12 interface. In addition, the AMF <NUM> is connected to the PCF <NUM> by using an N15 interface. The AUSF <NUM> is connected to the UDM <NUM> by using an N13 interface. The AMF <NUM> and the SMF <NUM> respectively obtain user subscription data from the UDM <NUM> by using the N8 and N20 interfaces, and obtain policy data from the PCF <NUM> by using the N15 and N7 interfaces. The AF <NUM> is connected to the PCF <NUM> by using an N5 interface. The SMF <NUM> controls the UPF <NUM> by using the N4 interface.

The following describes in detail functions of network elements in <FIG> that are related to this embodiment of this application.

AMF network element: is responsible for access and mobility management, and mainly includes functions related to access and mobility such as connection management, mobility management, registration management, access authentication and authorization, accessibility management, security context management, user authentication, handover, and location update.

PCF network element: mainly includes policy-related functions of making a unified policy, providing a control policy, obtaining subscription information related to policy decision from a unified data repository (unified data management, UDR), and the like.

UPF network element: is responsible for a user plane function, and mainly includes user plane-related functions such as data packet routing and transmission, packet detection, service usage reporting, QoS processing, lawful interception, uplink packet detection, and downlink data packet storage.

SMF network element: is responsible for a session management function, and mainly includes session-related functions such as session management (for example, session establishment, modification, and release, including maintenance for a tunnel between a UPF and an AN), UPF selection and control, SSC (service and session continuity, service and session continuity) mode selection, and roaming.

AF network element: is responsible for interacting with a 3GPP core network to provide a service or a service, and includes interaction with an NEF, policy architecture interaction, and the like. The network exposure function (network exposure function, NEF) mainly includes a function of securely exposing, internally exposing, exposing, to a third party, a service and a capability that are provided by a 3GPP network function, or the like. The network exposure function converts or translates information exchanged with the AF and information exchanged with an internal network function, such as an AF service identifier and internal <NUM> core network information such as a DNN and S-NSSAI.

Network data analytics (network data analytics function, NWDA) network element: mainly includes a logical function representing operator's management network analytics.

It should be noted that names of the network elements (for example, the SMF <NUM>, the AF <NUM>, and the UPF <NUM>) included in <FIG> are merely names, and the names constitute no limitation on functions of the network elements. In a <NUM> network and another future network, the foregoing network elements may also be in other names. This is not specifically limited in this embodiment of this application. For example, in a <NUM> network, some or all of the foregoing network elements may follow the terms in <NUM>, may be in other names, or the like, and are centrally described herein. Details are not described below again.

As noted above, when a terminal apparatus is in an idle mode, the terminal apparatus does not immediately (does not need to) update a policy rule. In this case, signaling overheads are unnecessary due to the policy rule delivered by the PCF to the terminal apparatus.

It should be understood that the policy rule sent by the PCF to the terminal apparatus may include an access network discovery and selection policy (access network discovery & selection polity, ANDSP) and a UE route selection policy (UE route selection policy, URSP). The ANDSP may be used by the terminal apparatus to select an access manner, and the URSP may be used by the terminal apparatus to select a PDU session.

As subscription information, a location, a time, and the like change in the terminal apparatus, the PCF updates the policy rule delivered to the terminal apparatus. When the terminal apparatus is in the idle mode, the terminal apparatus does not immediately update the policy rule. For example, the terminal apparatus does not immediately update the URSP in the policy rule. In this case, signaling overheads are unnecessary due to the policy rule delivered by the PCF to the terminal apparatus.

An embodiment of this application provides a control policy transmission method, so that signaling overheads can be reduced in a communication process in which a PCF delivers a policy rule to a terminal apparatus.

The following describes in detail the wireless network communication method provided in this embodiment of this application.

<FIG> is a schematic flowchart of a wireless network communication method according to an embodiment of this application. The method in <FIG> includes steps <NUM> and <NUM>. The following separately describes steps <NUM> and <NUM> in detail.

Step <NUM>: A PCF obtains a connection management state of a terminal apparatus.

The connection management state of the terminal apparatus may be a connected mode (connected mode) or an idle mode (idle mode).

It should be understood that there may be two connection management (connection management, CM) states of the terminal apparatus: CM-connected and CM-idle. The two states may be used to reflect a status of a NAS signaling connection between the terminal apparatus and the AMF.

An example in which the terminal apparatus is UE is used below for detailed description.

Referring to <FIG>, if the UE is in the idle mode, it may indicate that there is no NAS signaling connection on the N1 interface between the UE and the AMF. There is no N2 connection between the AN and the AMF, and there is no N3 connection between the AN and the UPF. When the UE is in the idle mode, the UE may respond to a paging initiation service request procedure on a network side or actively initiate a service request procedure to enter the connected mode.

If the UE is in the connected mode, it may indicate that there is a NAS signaling connection on the N11 interface between the UE and the AMF. When the UE is in the connected mode, the UE may access the idle mode by using an AN release procedure.

The PCF obtains the connection management state of the terminal apparatus by using the AMF. The following describes a plurality of implementations in step <NUM> in detail with reference to <FIG> or <FIG>.

Step <NUM>: The PCF sends policy rule information to the terminal apparatus when the connection management state of the terminal apparatus is a connected mode.

In this embodiment of this application, the PCF may obtain the connection management state of the terminal apparatus in a communication process in which the PCF delivers the policy rule to the terminal apparatus. The PCF may send a UE control policy rule to the terminal apparatus when the terminal apparatus is in the connected mode, to reduce a quantity of times that the UE control policy rule fails to be delivered, so that signaling overheads can be reduced.

The PCF obtains the connection management state of the terminal apparatus by using the AMF.

The AMF notifies the PCF of a current connection management state of the terminal apparatus The AMF can notify the PCF whether the current connection management state of the terminal apparatus is the connected mode, and the PCF can deliver a UE policy rule to the terminal apparatus when the terminal apparatus is in the connected mode.

The following describes in detail a specific implementation in which the AMF can notify the PCF whether the current connection management state of the terminal apparatus is in the connected mode.

In this embodiment of this application, the AMF can instruct the PCF to learn, in a plurality of specific implementations, whether the terminal apparatus is in the connected mode. The PCF can dispose a trigger in the AMF, and the AMF can trigger the trigger by using an event, to notify the PCF of the connection management state of the terminal apparatus.

A method in which the PCF disposes the trigger in the AMF, and the AMF can trigger the trigger by using the event, to notify the PCF of the connection management state of the terminal apparatus is used below for description.

The PCF can send a message that includes information about a trigger to the AMF, and can dispose a trigger in the AMF. The trigger may be a connection management state trigger of the terminal apparatus. When the connection management state of the terminal apparatus changes (the connection management state of the terminal apparatus is switched to the connected mode), the trigger can trigger the AMF to notify the PCF that the terminal apparatus is currently in the connected mode. The PCF can send a policy rule to the terminal apparatus when the terminal apparatus is in the connected mode.

The trigger disposed by the PCF in the AMF can specifically subscribe to an event that the terminal apparatus enters the idle mode or the connected mode. The PCF can actively deliver an updated policy rule of the terminal apparatus only after the terminal apparatus enters the connected mode. Detailed descriptions are provided below with reference to <FIG>.

It should be understood that in some embodiments, if the terminal apparatus has not entered the connected mode, the policy rule that has been generated by the PCF can be stored in a buffer (buffer) without being delivered, and the updated policy rule of the terminal apparatus can be actively delivered only after the terminal apparatus enters the connected mode.

In this embodiment of this application, the PCF network element can dispose the connection management state trigger of the terminal apparatus in the AMF, and can trigger, when the connection management state of the terminal apparatus is switched to the connected mode, the AMF to notify the PCF that the terminal apparatus is in the connected mode. The PCF can deliver the policy rule to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode, to avoid a problem that the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced.

Optionally, in some embodiments, a URSP may carry an indication indicating whether policy content needs to be immediately modified or may be later modified.

When the URSP carries an indication that policy rule information of the terminal apparatus may be later modified, the PCF may not need to immediately deliver the policy rule information, and the PCF may actively deliver the policy rule information of the terminal device only after the terminal apparatus enters the connected mode.

When the URSP carries an indication that policy rule information of the terminal apparatus needs to be immediately modified, the PCF needs to immediately deliver the policy rule information of the terminal apparatus, and may initiate paging to the terminal apparatus if the terminal apparatus is in the idle mode.

In this embodiment of this application, if the PCF needs to immediately deliver the policy rule information of the terminal apparatus, a "paging priority" can be carried when the PCF transfers the policy rule information of the terminal apparatus to the AMF. After one paging failure, the PCF can improve the paging priority and retrigger paging. The AMF reinitiates paging only in a case of a higher priority. The PCF can consider, only after a plurality of paging failures, that the terminal apparatus fails to be paged (this may indicate that the policy rule fails to be sent). In this case, the PCF can re-subscribe to a connection state of the UE from the AMF.

Optionally, in some embodiments, the AMF may send indication information to the PCF before the PCF sends the message that includes the information about the trigger to the AMF, where the indication information may be used to indicate that the policy rule fails to be sent. The PCF may send the message that includes the information about the trigger to the AMF after receiving the indication information sent by the AMF. Detailed descriptions are provided below with reference to <FIG>.

It should be understood that the AMF can send a UE connected mode setting instruction to the PCF, to instruct the PCF to dispose the trigger. The PCF can dispose the trigger after receiving the instruction.

In this embodiment of this application, the AMF and the SMF may select different PCFs to perform policy control. For ease of distinguishing, a PCF used for AM policy control may be referred to as an AM-PCF, and a PCF connected to SM may be referred to as an SM-PCF.

It should be understood that both local break out (local break out, LBO) and home route (home route, HR) roaming scenarios may be SM-related policy control scenarios, and are not related to a UE policy.

In a roaming scenario, there may be two AM-PCFs: a visited visited AM-PCF (vAM-PCF) and a home home AM-PCF (hAM-PCF). In an LBO scenario, a visited visited SM-PCF (vSM-PCF) may be connected to a vSMF and may perform SM-related policy control. In an HR scenario, a home home SM-PCF (hSM-PCF) may be connected to an hSMF and may perform SM-related policy control. Optionally, in some embodiments, when the foregoing mentioned SM-PCF and AM-PCF are a same PCF, the SM-PCF may subscribe to a CM state of the UE from the SMF. In this case, the SMF may subscribe to information about the state from the AMF.

Specific implementations in the embodiments of this application are described below in more detail with reference to specific examples. It should be noted that the following example is merely intended to help a person skilled in the art understand the embodiments of this application, instead of limiting the embodiments of this application to a specific value or a specific scenario shown in the example.

<FIG> is a schematic flowchart of a possible implementation in step <NUM> in <FIG>. The method in <FIG> may include steps <NUM> to <NUM>. The following separately describes steps <NUM> to <NUM> in detail.

<FIG> is a schematic flowchart of an AM policy association establishment process.

Step <NUM>: The AMF determines to establish policy association (decision to establish policy association).

Step <NUM>: The AMF sends a policy control create (AM policy control create) request to an H-PCF.

The H-PCF may be used to represent a PCF in a home domain (home PLMN).

Step <NUM>: The H-PCF feeds back a policy control create request response (AM policy control create response) to the AMF, and carries a CM state change trigger of the UE (trigger: UE CM state change).

The policy control create request response that may be fed back by the H-PCF to the AMF may include information about a trigger. The trigger may be the connection management state change trigger of the UE. When a connection management state of the UE changes, the trigger may trigger the AMF to notify the H-PCF that the UE is currently in a connected mode. The following describes in detail modification of the trigger disposed by the PCF in the AMF.

Step <NUM>: The AMF deploys an access and mobility control policy (deploy access and mobility control policy).

The method in <FIG> may subsequently include the following two cases.

Case <NUM>: Step <NUM>: The AMF deploys UE access selection and PDU session selection policy information (deploy UE access selection and PDU session selection policy information).

Case <NUM>: Step <NUM>: The H-PCF sends a policy control update notification (AM policy control update notify) request to the AMF.

Step <NUM>: The AMF feeds back a policy control update notification request response (AM policy control update notify response) to the H-PCF.

Step <NUM>: The AMF deploys UE access selection and PDU session selection policy information (deploy UE access selection and PDU session selection policy information).

It should be understood that in the foregoing AM policy association establishment process, the modification of the trigger disposed by the PCF in the AMF is shown in the following table:.

As shown in the foregoing table, the trigger disposed by the PCF in the AMF may specifically subscribe to the change of the connection management state of the UE. When the connection management state of the UE changes (the UE switches to a connected mode), the trigger triggers the AMF to notify the PCF that the UE is in the connected mode.

Optionally, in some embodiments, the trigger does not trigger the AMF when the connection management state of the UE is switched to an idle mode. It should be understood that in this embodiment of this application, a control policy may be delivered by the H-PCF, or may be delivered by a V-PCF.

The V-PCF may be used to represent a PCF in a visited domain (visited PLMN).

When a control policy that needs to be delivered is delivered by the H-PCF (in other words, the V-PCF forwards, to the AMF, only an event to which the H-PCF subscribes), the forwarding procedure is the same as that in the prior art.

When a control policy that needs to be delivered is delivered by the V-PCF, the V-PCF subscribes to an event from the AMF, and the H-PCF delivers, to the V-PCF based on policy information corresponding to a policy identifier set (policy section identifier, PSI), an indication indicating whether to immediately deliver a policy corresponding to the PSI.

Optionally, a corresponding PSI may be sent when policy content stored in a UDR is updated. If the PCF determines that updated policy information corresponding to the PSI may not need to be immediately updated, the PCF may actively deliver, only after the UE enters the connected mode, the updated UE policy corresponding to the PSI. In an example, when the policy information corresponding to the PSI is only a URSP, the policy information may not need to be immediately updated in this case, and the PCF may deliver, after the UE enters the connected mode, a UE policy that needs to correspond to the PSI. In another example, when it is identified that the policy information corresponding to the PSI does not need to be immediately updated, the PCF may deliver, after the UE enters the connected mode, a UE policy that needs to correspond to the PSI.

The foregoing mentioned AMF can send a UE connected mode setting instruction to the PCF, to instruct the PCF to dispose the trigger. The PCF can dispose the trigger after receiving the instruction.

In this embodiment of this application, the AMF can send the connected mode setting instruction to the PCF in step <NUM>, to instruct the PCF to dispose the trigger. The PCF can dispose the trigger in the AMF in step <NUM>.

The following describes, in detail with reference to <FIG>, the foregoing mentioned implementation in which if the PCF needs to immediately deliver the policy rule information of the terminal apparatus, a "paging priority" can be carried when the PCF transfers the policy rule information of the terminal apparatus to the AMF.

<FIG> is a schematic flowchart of a possible implementation according to an example of this application outside the subject-matter of the claims. The method in <FIG> may include steps <NUM> to <NUM>. The following separately describes steps <NUM> to <NUM> in detail.

Step <NUM>: The PCF sends an AM policy control get request response (AM policy control get response) to the AMF.

When the PCF sends the AM policy control get response request response to the AMF, a paging priority of a UE control policy (UE policy) can be carried.

Step <NUM>: The PCF sends an AM policy control update notification (AM policy control update notify) to the AMF.

When the PCF sends the AM policy control update notification to the AMF, a paging priority of a UE control policy (UE policy) can be carried.

It should be noted that a time at which the PCF adds the paging priority of the UE control policy is not specifically limited in this example of this application which is outside the subject-matter of the claims. The PCF may add the paging priority of the policy in step <NUM>, or the PCF may add the paging priority of the policy in step <NUM>.

After the AMF performs paging one time, the PCF can improve the paging priority of the UE policy, and can re-initiate paging. The AMF can re-initiate paging in a case of a higher paging priority. After one or more paging failures, the PCF can subscribe to a connection state of the UE from the AMF, and can deliver a control policy to the UE when the UE is in a connected mode. For details that the PCF subscribes to the connection state of the UE from the AMF, refer to the description in <FIG>. The details are not described herein again.

Step <NUM>: The AMF delivers a UE control policy (delivery of UE policies) to the UE.

Step <NUM>: The UE sends a UE control policy delivery response result (result of the delivery of UE policies) to the AMF.

Step <NUM>: The AMF sends an event exposure notification request (event exposure notify request) to the PCF.

It should be understood that that the AMF sends the exposure notification to the PCF may be: The AMF reports a transfer result of the UE policy to the PCF.

Step <NUM>: The PCF sends an event exposure notification request response (event exposure notify response) to the AMF.

An example outside the subject-matter of the claims in which the AMF can notify the PCF of the connection management state of the terminal apparatus through logic of the AMF is used below for description.

The terminal apparatus is in the idle mode when there is no signaling connection on an interface between the terminal apparatus and the AMF. When the terminal apparatus is in the idle mode, the AMF can forbid the PCF to deliver a control policy, and can set a flag (flag). In an example, the AMF can notify the PCF that the terminal apparatus is currently in the idle mode.

The terminal apparatus is in the connected mode when there is a signaling connection on an interface between the terminal apparatus and the AMF. When the terminal apparatus is in the connected mode, the AMF sends a notification request to the PCF, to notify the PCF that the terminal apparatus is currently in the connected mode, and deletes a flag. The PCF can send a control policy to the terminal device after receiving the notification request sent by the AMF.

It should be understood that the foregoing flag may be a flag set by the AMF. The AMF can set the flag when detecting that there is no signaling connection on the interface between the AMF and the terminal apparatus. When detecting that there is the signaling connection on the interface between the AMF and the terminal apparatus, the AMF can notify, after deleting the flag, the PCF that the PCF can deliver the control policy to the terminal apparatus. For example, the AMF can notify the PCF that the terminal apparatus enters the connected mode.

In this example outside the subject-matter of the claims of this application, the AMF can notify, through logic of the AMF, the PCF that the connection management state of the terminal apparatus is the connected mode, and can deliver the policy rule to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode, to avoid unnecessary signaling overheads caused because the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced. Further, implementation is simple because there is no need to add a trigger.

An example outside the subject-matter of the claims in which the AMF notifies the PCF of the time period in which the terminal apparatus is in the connected mode, and the PCF can deliver the UE policy rule to the terminal apparatus in the time period in which the terminal apparatus is in the connected mode is used below for detailed description.

The AMF may send one piece of time information to the PCF, where the time information may include a time in which the terminal apparatus enters the connected mode next time, and the PCF may deliver an updated policy rule to the terminal apparatus in the time in which the terminal apparatus enters the connected mode next time.

An example outside the subject-matter of the claims in which the terminal apparatus performs periodic tracking area update (tracking area update, TAU) is used below for detailed description.

A tracking area (tracking area, TA) of the terminal apparatus enables a network device to know a location of the terminal apparatus in a timely manner. When paging the terminal apparatus, the network device searches for all cells in a location area of the terminal apparatus. The location of the terminal apparatus does not need to be updated in a location area. When moving across TAs, the terminal apparatus needs to initiate a TA update process, so that a network knows the location area of the terminal apparatus. In addition, the terminal apparatus needs to periodically perform the TA update process to maintain close contact with a network side.

After a TAU timer of the terminal apparatus expires, the terminal apparatus needs to update a TA location in a timely manner. When the terminal apparatus performs periodic TAU, the AMF can learn of a time period in which the terminal apparatus periodically enters the connected mode.

Time information of which the AMF notifies the PCF is not specifically limited in this example of this application which is outside the subject-matter of the claims. In an example, the AMF may notify the PCF of the time in which the terminal apparatus enters the connected mode next time, and the PCF may not generate a control rule for the terminal apparatus before a timer arrives. In another example, the time information sent by the AMF to the PCF may include all time periods that are in a period and in which the terminal apparatus enters the connected mode, and the PCF may not generate a control rule for the terminal apparatus before each time period in which the terminal apparatus enters the connected mode. Detailed descriptions are provided below with reference to <FIG>.

In this example outside the subject-matter of the claims of this application, the PCF can obtain, from the AMF, a time at which the terminal apparatus enters the connected mode (a time in which the terminal apparatus is in the connected mode next time), and can deliver the policy rule to the terminal apparatus in the time in which the terminal apparatus is in the connected mode next time, to avoid unnecessary signaling overheads caused because the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced. The PCF can determine, based on the time in which the terminal apparatus enters the connected mode next time, when and whether to prepare to deliver the policy rule, so that implementation is more flexible.

Optionally, after learning that the terminal apparatus is in the connected mode, the PCF can subscribe, from the AMF, to the time in which the terminal apparatus enters the connected mode next time.

Specific implementations of this application are described below in more detail with reference to specific examples. It should be noted that the following example is merely intended to help a person skilled in the art understand this application, instead of limiting to a specific value or a specific scenario shown in the example.

<FIG> is a schematic flowchart of a possible implementation in step <NUM> in <FIG> outside the subject-matter of the claims. The method in <FIG> may include steps <NUM> to <NUM>. The following separately describes steps <NUM> to <NUM> in detail.

<FIG> is a schematic flowchart of a process in which an AMF reports an event exposure notification to a PCF after RAN connection release.

Step <NUM>: The RAN and a UER perform access network connection release (RAN connection release).

Step <NUM>: The RAN sends a UE context release request (UE context release request) to the AMF.

Step <NUM>: The AMF feeds back UE context release (UE context release command) to the RAN.

Step <NUM>: The RAN and the UER perform access network connection release (RAN connection release).

Step <NUM>: The RAN sends UE context release complete (UE context release complete) to the AMF.

Step <NUM>: The RAN sends a PDU session update SM context (PDU session update SM context) to the SMF.

Step <NUM>: The SMF sends a session modification request (session modification request) to the UPF.

Step <NUM>: The UPF feeds back a session modification request response (session modification response) to the SMF.

Step <NUM>: The SMF sends an update SM context request acknowledgement (PDU session update SM context ACK) to the AMF.

Step <NUM>: The AMF sends an event exposure notification to the PCF, where the event exposure notification includes a timeline (event exposure notify (timeline)).

It should be understood that that the AMF sends the exposure notification to the PCF may be: The AMF reports a transfer result of a UE policy to the PCF.

The AMF can send a timeline (timeline) to the PCF through periodic TAU after the UE disconnects from the RAN/AMF (the UE is in an idle mode). The timeline may be used to indicate a time period in which the UE enters a connected mode next time. After receiving the timeline, the PCF can deliver a policy rule to the UE in the timeline.

The foregoing mentioned implementation in which after learning that the terminal apparatus is in the connected mode, the PCF can subscribe, from the AMF, to the time in which the terminal apparatus enters the connected mode next time is described by using <FIG> as an example.

In this example of this application which is outside the subject-matter of the claims, after receiving, in step <NUM>, the timeline sent by the AMF, the PCF can subscribe, from the AMF, to the time in which the terminal apparatus enters the connected mode next time.

An example outside the subject-matter of the claims in which an NWDAF notifies the PCF of a time period in which the terminal apparatus is in the connected mode, and the PCF can deliver a UE policy rule to the terminal apparatus in the time period in which the terminal apparatus is in the connected mode is used below for detailed description.

The NWDAF network element may send one piece of time information to the PCF, where the time information may include a time in which the terminal apparatus enters the connected mode, and the PCF may deliver an updated policy rule to the terminal apparatus in the time in which the terminal apparatus enters the connected mode. Detailed descriptions are provided below with reference to <FIG>.

In this example outside the subject-matter of the claims of this application, the PCF can obtain, from the NWDAF, a time at which the terminal apparatus enters the connected mode (a time in which the terminal apparatus is in the connected mode), and can deliver the policy rule to the terminal apparatus in the time in which the terminal apparatus is in the connected mode, to avoid unnecessary signaling overheads caused because the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced. The PCF can determine, based on the time in which the terminal apparatus enters the connected mode next time, when and whether to prepare to deliver the policy rule, so that implementation is more flexible.

Optionally, in some examples outside the subject-matter of the claims after learning that the terminal apparatus is in the connected mode, the PCF can request, from the NWDAF, the time in which the terminal apparatus enters the connected mode next time.

Step <NUM>: The AMF sends a policy control update request (AM policy control update request) to the V-PCF/H-PCF.

The AMF may send a policy control request trigger to the V-PCF/H-PCF, and the UE may be in an idle mode (policy control request trigger: UE in idle mode).

Step <NUM>: The V-PCF/H-PCF sends an analytics information request (UE connected time) (analytics Info request (UE connected time)) to the NWDAF.

When the UE may be in the idle mode, the V-PCF/H-PCF can request, from the NWDAF, a time in which the UE enters a connected mode.

Step <NUM>: The NWDAF feeds back an analytics information request response to the V-PCF/H-PCF, where the analytics information request response carries a timeline (analytics Info response (timeline)).

The NWDAF may send, to the V-PCF/H-PCF based on a request that is for the time in which the UE enters the connected mode and that is sent by the V-PCF/H-PCF, the time (timeline) in which the UE enters the connected mode.

Step <NUM>: The V-PCF/H-PCF makes a policy decision (policy decision).

Step <NUM>: The V-PCF/H-PCF sends a policy control update request response (AM policy control update response) to the AMF.

An example outside the subject-matter of the claims in which an AF notifies the PCF of a time period in which the terminal apparatus is in the connected mode, and the PCF can deliver a UE policy rule to the terminal apparatus in the time period in which the terminal apparatus is in the connected mode is used below for detailed description.

It should be understood that when an SMF and an AMF select a same PCF, and the application AF network element needs to deliver a downlink data packet or needs to receive an uplink data packet, the AF can send a download data packet request to a UPF, and the UPF can send a data notification (data notification, DN) to the SMF after receiving the download data packet request. The SMF can notify, after receiving the DN, the PCF that a terminal apparatus is currently in a connected mode, and the PCF can send a policy rule to the terminal apparatus after receiving the notification.

An implementation in which the SMF can notify, after receiving the DN, the PCF that the terminal apparatus is currently in the connected mode is not specifically limited in this example of this application which is outside the subject-matter of the claims. In an example, a trigger may be disposed in the SMF when the SMF and the AMF select the same PCF. The trigger may be configured to: when there is the data notification DN, trigger the SMF to notify the PCF of a current connection state of the terminal apparatus. Detailed descriptions are provided below with reference to <FIG>.

Step <NUM>: The UPF receives a downlink data (downlink data) request.

For example, the UPF can receive the downlink data request sent by the AF (application). Step <NUM>: The UPF sends a data notification (data notification, DN) to the SMF.

After receiving the DN sent by the UPF, the SMF may report the DN to the PCF. After receiving the DN, the PCF may deliver a control policy of the terminal apparatus.

For example, a trigger may be disposed in the SMF. The trigger may be configured to: when there is the data notification DN, trigger the SMF to notify the PCF of a current connection state of the terminal apparatus. Because the SMF and the AMF select a same PCF, the PCF may deliver the control policy of the terminal apparatus to the UE by using the AMF when the AMF sends paging to the RAN in step <NUM>.

Step <NUM>: The SMF sends a data notification acknowledgement (data notification ACK) to the UPF.

Step <NUM>: The UPF sends the downlink data (downlink data) request to the SMF.

Step <NUM>: The SMF sends an information transfer (message transfer) request to the AMF.

Step <NUM>: The AMF sends an information transfer request response (message transfer response) to the SMF.

Step <NUM>: The SMF sends a failure indication to the UPF.

Step <NUM>: The UE, the RAN, and the AMF perform UP activation (connected) (UP reactivation (connected)).

Step <NUM>: The AMF sends paging (paging) to the RAN.

Step <NUM>: The RAN sends the paging (paging) to the UE.

Step <NUM>: The AMF sends a NAS signaling notification (NAS notification) to the UE.

Step <NUM>: The AMF sends an event exposure notification (event exposure notify) to the SMF.

Step <NUM>: The UPF, the SMF, the AMF, the RAN, and the UE perform a service request procedure (service request procedure).

Step <NUM>: The UPF sends the downlink data (downlink data) request to the RAN and the RAN sends the downlink data (downlink data) request to the UE.

The foregoing describes, in detail with reference to <FIG>, the control policy transmission method provided in the embodiments of this application. The following describes in detail apparatus embodiments of this application with reference to <FIG>. It should be understood that descriptions of the method embodiments correspond to descriptions of the apparatus embodiments. Therefore, for parts that are not described in detail, refer to the foregoing method embodiments.

<FIG> is a schematic block diagram of a PCF network element <NUM> according to an embodiment of this application. The PCF network element <NUM> may include:.

The PCF network element can obtain the connection management state of the terminal apparatus, and can deliver the policy rule to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode, to avoid unnecessary signaling overheads caused because the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced.

The first obtaining module <NUM> is specifically configured to obtain the connection management state of the terminal apparatus from an access and mobility management AMF network element.

Optionally, in some embodiments outside the subject-matter of the claims, the first obtaining module <NUM> is specifically configured to: receive first flag information sent by the AMF, where the first flag information is used to indicate that the connection management state of the terminal apparatus is the idle mode; and receive, by the terminal apparatus, a first notification message sent by the AMF, where the first notification message is used to notify the PCF that the connection management state of the terminal apparatus is the connected mode.

The first obtaining module <NUM> is specifically configured to: send a first message to the AMF, where the first message includes information about a trigger, and the trigger is configured to: when the connection management state of the terminal apparatus is switched to the connected mode, trigger the AMF to send a second notification message to the PCF; and receive the second notification message sent by the AMF, where the second notification message is used to notify the PCF that the connection management state of the terminal apparatus is the connected mode.

Optionally, in some embodiments, the PCF further includes:
a second transceiver module <NUM>, configured to: receive first indication information sent by the AMF, where the first indication information is used to indicate that the policy rule information fails to be sent; and send, by the PCF, the first message to the AMF after receiving the first indication information.

Optionally, in some embodiments, the first obtaining module <NUM> is specifically configured to receive first time information sent by the AMF, where the first time information includes a time indicating that the terminal apparatus enters the connected mode next time. The first transceiver module <NUM> is specifically configured to send, by the PCF, the policy rule information to the terminal apparatus when the time at which the terminal apparatus enters the connected mode next time arrives.

Optionally, in some embodiments outside the subject-matter of the claims, the PCF further includes:
a second obtaining module <NUM>, configured to obtain second time information sent by a network data analytics NWDAF network element, where the second time information is used to indicate a time in which the terminal apparatus enters the connected mode; and the first obtaining module <NUM> is specifically configured to send, by the PCF, the policy rule information to the terminal apparatus when the time at which the terminal apparatus enters the connected mode arrives.

Optionally, in some embodiments outside the subject-matter of the claims, the PCF further includes:
a third obtaining module <NUM>, configured to obtain third time information sent by an application AF network element, where the third time information is used to instruct the AF to send a downlink data packet and/or accept an uplink data packet or indicate a time at which the AF sends a downlink data packet and/or accepts an uplink data packet; and the first obtaining module <NUM> is specifically configured to send, by the PCF, the policy rule information to the terminal apparatus when the time at which the AF sends the downlink data packet and/or accepts the uplink data packet arrives.

Optionally, in some embodiments outside the subject-matter of the claims, the third obtaining module <NUM> is specifically configured to receive a third notification message sent by a session management SMF network element, where the third notification message is used to notify the PCF that the connection management state of the terminal apparatus is the connected mode.

In this embodiment of this application, the PCF network element can obtain the connection management state of the terminal apparatus, and can deliver the policy rule to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode, to avoid unnecessary signaling overheads caused because the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced.

<FIG> is a schematic block diagram of an AMF network element <NUM> according to an embodiment of this application. Each module in the AMF network element <NUM> is configured to perform each action or processing process performed by the AMF network element in the foregoing method. Herein, for detailed descriptions, refer to the foregoing descriptions to avoid repetition.

The AMF network element <NUM> may include:
a notification module <NUM>, configured to: receive a first message sent by the PCF, where the first message includes information about a trigger, and the trigger is configured to: when the connection management state of the terminal apparatus is switched to the connected mode, trigger the AMF to send a second notification message to the PCF; and send the second notification message to the PCF when the connection management state of the terminal apparatus is switched to the connected mode.

In the foregoing technical solution, the AMF network element can notify the PCF of a current connection management state of the terminal apparatus when the connection management state of the terminal apparatus is switched to the connected mode, and the PCF can deliver a policy rule to the terminal apparatus when the connection management state of the terminal apparatus is the connected mode, to avoid a problem that the terminal apparatus updates, when the terminal apparatus is in the idle mode, the policy rule delivered by the PCF, so that signaling overheads can be reduced.

Optionally, in some embodiments, the notification module <NUM> is specifically configured to: receive a first message sent by the PCF, where the first message includes information about a trigger, and the trigger is configured to: when the connection management state of the terminal apparatus is switched to the connected mode, trigger the AMF to send a second notification message to the PCF; and send the second notification message to the PCF when the connection management state of the terminal apparatus is switched to the connected mode.

Optionally, in some embodiments, the AMF network element <NUM> further includes:
a transceiver module <NUM>, configured to send first indication information to the PCF, where the first indication information is used to indicate that the policy rule fails to be sent.

Optionally, in some embodiments is outside the subject-matter of the claims, the notification module <NUM> is specifically configured to send first time information to the PCF, where the first time information includes a time indicating that the terminal apparatus enters the connected mode next time.

<FIG> is a schematic block diagram of a PCF network element <NUM> according to an embodiment of this application. The PCF network element <NUM> may include a processor <NUM>, a receiver <NUM>, a transmitter <NUM>, and a memory <NUM>.

The processor <NUM> may be communicatively connected to the receiver <NUM> and the transmitter <NUM>. The memory <NUM> may be configured to store program code and data that are of the network device. Therefore, the memory <NUM> may be a storage unit inside the processor <NUM>, or an external storage unit independent of the processor <NUM>, or a component that includes a storage unit inside the processor <NUM> and an external storage unit independent of the processor <NUM>.

Optionally, the network device may further include a bus <NUM>. The receiver <NUM>, the transmitter <NUM>, and the memory <NUM> may be connected to the processor <NUM> by using the bus <NUM>. The bus <NUM> may be a peripheral component interconnect (Peripheral Component Interconnect, PCI) bus, an extended industry standard architecture (Extended Industry Standard Architecture, EISA) bus, or the like. The bus <NUM> may be classified into an address bus, a data bus, a control bus, and the like. For ease of representation, only one thick line is used to represent the bus <NUM> in <FIG>, but this does not mean that there is only one bus or only one type of bus.

For example, the processor <NUM> may be a central processing unit (Central Processing Unit, CPU), a general purpose processor, a digital signal processor (Digital Signal Processor, DSP), an application-specific integrated circuit (Application-Specific Integrated Circuit, ASIC), a field programmable gate array (Field Programmable Gate Array, FPGA), or another programmable logical device, a transistor logical device, a hardware component, or any combination thereof. The processor <NUM> may implement or execute various example logical blocks, modules, and circuits described with reference to content disclosed in this application. Alternatively, the processor may be a combination of processors implementing a computing function, for example, a combination of one or more microprocessors or a combination of a DSP and a microprocessor.

The receiver <NUM> and the transmitter <NUM> may be a circuit including the foregoing antenna, transmitter chain, and receiver chain, and may be independent circuits or a same circuit.

<FIG> is a schematic block diagram of an AMF network element <NUM> according to an embodiment of this application. The AMF network element <NUM> may include a processor <NUM>, a receiver <NUM>, a transmitter <NUM>, and a memory <NUM>.

An embodiment of this application outside the subject-matter of the claims further provides a network data analytics NWDAF network element, including a transceiver, a memory, and a processor. The transceiver, the memory, and the processor communicate with each other by using an internal connection channel. The memory is configured to store an instruction. The processor is configured to execute the instruction stored in the memory, to control a receiver to receive a signal and control a transmitter to send a signal, so that the NWDAF performs the method in any one of the foregoing possible implementations.

An embodiment of this application outside the subject-matter of the claims further provides an application AF network element, including a transceiver, a memory, and a processor. The transceiver, the memory, and the processor communicate with each other by using an internal connection channel. The memory is configured to store an instruction. The processor is configured to execute the instruction stored in the memory, to control a receiver to receive a signal and control a transmitter to send a signal, so that the AF performs the method in any one of the foregoing possible implementations.

An embodiment of this application which is outside the subject-matter of the claims further provides a computer readable medium, configured to store a computer program. The computer program includes an instruction used to perform the method in any possible implementation of any aspect.

An embodiment of this application which is outside the subject-matter of the claims further provides a computer program product. The computer program product includes computer program code. When the computer program code is run on a computer, the computer is enabled to perform the method in any possible implementation of any aspect.

An embodiment of this application which is outside the subject-matter of the claims further provides a chip system, applied to a communications device. The chip system includes at least one processor, at least one memory, and an interface circuit. The interface circuit is responsible for information exchange between the chip system and the outside. The at least one memory, the interface circuit, and the at least one processor are interconnected by using a line. The at least one memory stores an instruction. The instruction is executed by the at least one processor to perform an operation of the network element in the method in the foregoing aspects.

An embodiment of this application further provides a computer program product, applied to a communications device. The computer program product includes a series of instructions, and when the instructions are run, an operation of the network element in the method in the foregoing aspects is performed.

In addition, the terms "system" and "network" may be often used interchangeably in this specification. The term "and/or" in this specification describes only an association relationship for describing associated objects and represents that three relationships may exist. In addition, the character "/" in this specification usually indicates an "or" relationship between the associated objects.

It should be understood that in the embodiments of this application, "B corresponding to A" indicates that B is associated with A, and B may be determined based on A. However, it should further be understood that determining B based on A does not mean that B is determined based on A only, and B may also be determined based on A and/or other information.

All or some of the foregoing embodiments may be implemented by using software, hardware, firmware, or any combination thereof. When software is used to implement the embodiments, all or some of the embodiments may be implemented in a form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or some of the procedures or functions according to the embodiments of this application are generated. The computer may be a general-purpose computer, a dedicated computer, a computer network, or another programmable apparatus. The computer instructions may be stored in a computer readable storage medium or may be transmitted from a computer readable storage medium to another computer readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (for example, a coaxial cable, an optical fiber, or a digital subscriber line (digital subscriber line, DSL)) or wireless (for example, infrared, radio, or microwave) manner. The computer readable storage medium may be any usable medium accessible to the computer, or a data storage device, such as a server or a data center, integrating one or more usable media. The usable medium may be a magnetic medium (for example, a floppy disk, a hard disk, or a magnetic tape), an optical medium (for example, a digital video disc (digital video disc, DVD)), a semiconductor medium (for example, a solid state disk (solid state disk, SSD)), or the like.

A person of ordinary skill in the art may be aware that units and algorithm steps in the examples described with reference to the embodiments disclosed in this specification can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed by hardware or software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use different methods to implement the described functions for each particular application.

It may be clearly understood by a person skilled in the art that for the purpose of convenient and brief description, for a detailed working process of the foregoing described system, apparatus, and unit, refer to a corresponding process in the foregoing method embodiments.

In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in another manner. For example, the unit division is merely logical function division. There may be another division manner in actual implementation. The indirect couplings or communication connections between the apparatuses or units may be implemented in electronic, mechanical, or another form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, and may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected based on an actual requirement to achieve the objectives of the solutions of the embodiments.

Claim 1:
A wireless network communication method performed by a policy control network element, wherein the method comprises:
sending information about a trigger to an access and mobility management network element, wherein the trigger is configured to notify the policy control network element of a connection management state of a terminal apparatus when the connection management state changes;
receiving (<NUM>, <NUM>) a notification message from the access and mobility management network element when the connection management state of the terminal apparatus changes to a connected mode; and
sending (<NUM>) policy rule information to the terminal apparatus when the notification message is used to notify the policy control network element that the connection management state of the terminal apparatus is the connected mode.