Network access method and device

Abstract

The invention provides a network access method and device, and the method comprises the steps: enabling a session management function network element of a visiting place to be inserted into an uplink classifier user plane function network element of the visiting place when terminal equipment moves to the visiting place, and enabling the uplink classifier user plane function network element to be used for shunting the service flow of the terminal equipment; and the session management function network element of the visit place sends a second offload rule to the uplink classifier user plane function network element, the second offload rule is used for indicating that the service flow matched with the second offload rule is sent to the main anchor point user plane function network element of the attribution place, and the main anchor point user plane function network element is connected with the local data network of the attribution place. Therefore, when the terminal equipment roams at the visited place, the service flow of the terminal equipment can be shunted to the main anchor point user plane function network element of the attribution place through the uplink classifier user plane function network element, so that the requirement that part of the service flow of the terminal equipment returns to the attribution place is met, and the security of a local data network of the attribution place is improved.

Description

[0001] This application is a divisional application. The application number of the original application is 202110877210.9, and the original application date is July 31, 2021. The entire contents of the original application are incorporated into this application by reference.

[0002] This application claims priority to Chinese patent application No. 202110362662.3 filed on April 2, 2021, and application name “A Campus Network Access Method and Device”, the entire contents of which are incorporated by reference into this application. Technical Field

[0003] The present application relates to the field of wireless communication technology, and in particular to a network access method and device. Background Art

[0004] The roaming scenarios defined in the existing 3rd Generation Partnership Project (3GPP) network architecture are mainly for international roaming scenarios. In my country, when mobile edge computing (MEC) is deployed in cities or parks, new roaming scenarios emerge. Users can roam between provinces or between cities within a province.

[0005] When users roam between provinces or between cities within a province, how to enable users to access the local data network in their home area is a problem that needs to be solved. Summary of the invention

[0006] The present application provides a network access method and apparatus, which are used to enable a terminal device to access a local data network of a home location in a roaming scenario, thereby improving the security of the local data network of the home location and meeting the diverse service needs of users. The service flow of the terminal device can return to the home location and be diverted at the home location, or it can be diverted at the visited location according to a preset diversion rule, so that part of the service flow returns to the home location and the rest is unloaded at the visited location.

[0007] In a first aspect, an embodiment of the present application provides a network access method, which can be executed by a session management function network element at a home location, or can be executed by a component (such as a chip or circuit) configured at the session management function network element at a home location.

[0008] The method includes: inserting a session management function network element at a home location into an uplink classifier user plane function network element at the home location, wherein the uplink classifier user plane function network element is used to divert the service flow of a terminal device; when the terminal device moves to a visited location, the session management function network element sends the address of the uplink classifier user plane function network element to an intermediate user plane function network element at the visited location to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

[0009] The above technical solution can establish a tunnel between the uplink classifier user plane functional network element of the home location and the intermediate user plane functional network element of the visited location. When the terminal device roams in the visited location, the service flow of the terminal device can return to the home location through the tunnel and be diverted under the action of the uplink classifier user plane functional network element of the home location, thereby meeting the service needs of the terminal device.

[0010] In a possible design of the first aspect, the session management function network element at the home location is inserted into the uplink classifier user plane function network element at the home location, including: the session management function network element at the home location is inserted into the uplink classifier user plane function network element according to the data network name DNN signed by the terminal device.

[0011] In a possible design of the first aspect, the session management function network element of the home location is inserted into the uplink classifier user plane function network element of the home location, including: the session management function network element receives the user policy of the terminal device from the policy control function network element, and the user policy is used to indicate that the service flow of the terminal device in a roaming scenario needs to return to the home location and be diverted; the session management function network element inserts the uplink classifier user plane function network element according to the user policy.

[0012] In the above technical solution, the session management function network element at the home location can insert an uplink classifier user plane function network element at the home location when the user policy of the terminal device indicates that the service flow of the terminal device needs to return to the home location and be diverted in a roaming scenario, thereby meeting the needs of the terminal device's full service traffic to return to the home location and be diverted, thereby improving the security of the local data network at the home location.

[0013] In a possible design of the first aspect, the method also includes: the session management function network element sends a first diversion rule to the uplink classifier user plane function network element, and the first diversion rule is used to indicate that the service flow matching the first diversion rule is sent to the secondary anchor user plane function network element of the home location, and the secondary anchor user plane function network element is connected to the local data network of the home location.

[0014] In a possible design of the first aspect, the method also includes: the session management function network element sends the address of the uplink classifier user plane function network element to the secondary anchor point user plane function network element to establish a tunnel between the secondary anchor point user plane function network element and the uplink classifier user plane function network element.

[0015] In a possible design of the first aspect, the first diversion rule is also used to indicate that the service flow that does not match the first diversion rule is sent to the primary anchor user plane function network element of the home location, and the primary anchor user plane function network element is connected to the Internet.

[0016] In a possible design of the first aspect, the method also includes: the session management function network element sends the address of the uplink classifier user plane function network element to the main anchor user plane function network element to establish a tunnel between the main anchor user plane function network element and the uplink classifier user plane function network element.

[0017] In a possible design of the first aspect, the method also includes: the session management function network element sends the address of the uplink classifier user plane function network element to the access network device of the home location to establish a tunnel between the access network device and the uplink classifier user plane function network element.

[0018] In the above technical solution, the uplink classifier user plane functional network element of the home location can adopt a forward diversion method to divert the service flow matching the first diversion rule to the auxiliary anchor user plane functional network element, so that the terminal device can access the local data network of the home location, and divert the service flow that does not match the first diversion rule to the main anchor user plane functional network element, so that the terminal device can access the Internet.

[0019] Furthermore, after the uplink classifier user plane functional network element is inserted in the home location, the session management functional network element in the home location can also update the bearer rules of the main anchor user plane functional network element, the auxiliary anchor user plane functional network element and the access network device in the home location respectively, thereby opening up the transmission path of the uplink and downlink service flows of the terminal device.

[0020] In a possible design of the first aspect, if the terminal device is still in the service area of ​​the session management function network element after moving to the visited location, the method also includes: the session management function network element is inserted into the intermediate user plane function network element of the visited location; the session management function network element sends the address of the intermediate user plane function network element to the uplink classifier user plane function network element to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

[0021] In a possible design of the first aspect, the method also includes: the session management function network element sends the address of the intermediate user plane function network element to the access network device of the visited location to establish a tunnel between the access network device and the intermediate user plane function network element.

[0022] In a possible design of the first aspect, if the terminal device moves to a visited location and leaves the service area of ​​the session management function network element, the session management function network element sends the address of the uplink classifier user plane function network element to the intermediate user plane function network element of the visited location, including: the session management function network element sends the address of the uplink classifier user plane function network element to the intermediate user plane function network element through the intermediate session management function network element of the visited location.

[0023] In a possible design of the first aspect, the method also includes: the session management function network element receives the address of the intermediate user plane function network element from the intermediate user plane function network element through the intermediate session management function network element; the session management function network element sends the address of the intermediate user plane function network element to the uplink classifier user plane function network element to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

[0024] The above technical solution can be applied to two roaming scenarios: the terminal device is still in the service area of ​​the session management function network element at the home location after moving to the visited location, and the terminal device leaves the service area of ​​the session management function network element at the home location after moving to the visited location. In the scenario where the terminal device is still in the service area of ​​the session management function network element at the home location after moving to the visited location, the session management function network element at the home location can be inserted into the intermediate user plane function network element at the visited location, that is, the session management function network element at the home location is also the session management function network element at the visited location.

[0025] In a second aspect, an embodiment of the present application provides a network access method, which can be executed by an intermediate session management function network element of a visited location, or by a component (such as a chip or circuit) configured in the intermediate session management function network element of the visited location.

[0026] The method includes: when the terminal device moves to a visited location, an intermediate session management function network element of the visited location is inserted into an intermediate user plane function network element of the visited location; the intermediate session management function network element receives the address of an uplink classifier user plane function network element from a session management function network element of a home location, the uplink classifier user plane function network element is used to divert the service flow of the terminal device, and the address of the uplink classifier user plane function network element is used to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

[0027] The above technical solution can establish a tunnel between the uplink classifier user plane functional network element of the home location and the intermediate user plane functional network element of the visited location. When the terminal device roams in the visited location, the service flow of the terminal device can return to the home location through the tunnel and be diverted under the action of the uplink classifier user plane functional network element of the home location.

[0028] The above technical solution can be applied to the roaming scenario in which the terminal device moves to the visited location and leaves the service area of ​​the session management function network element of the home location. In this scenario, the intermediate session management function network element of the visited location can be inserted into the intermediate user plane function network element of the visited location.

[0029] In a possible design of the second aspect, the method also includes: the intermediate session management function network element sends the address of the uplink classifier user plane function network element to the intermediate user plane function network element to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

[0030] In a possible design of the second aspect, the method also includes: the intermediate session management function network element sends the address of the intermediate user plane function network element to the session management function network element to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

[0031] In a possible design of the second aspect, the method also includes: the intermediate session management function network element sends the address of the intermediate user plane function network element to the access network device of the visited location to establish a tunnel between the access network device and the intermediate user plane function network element.

[0032] In the above technical solution, after the intermediate session management function network element is inserted into the visited location, the session management function network element of the visited location can also update the bearer rules of the intermediate user plane function network element and the access network device of the visited location respectively, thereby opening up the transmission path of the uplink and downlink service flows of the terminal device.

[0033] In a third aspect, an embodiment of the present application provides a network access method, which can be executed by a session management function network element of a visited location, or can be executed by a component (such as a chip or circuit) configured in the session management function network element of the visited location.

[0034] The method includes: when a terminal device moves to a visited location, a session management function network element of the visited location is inserted into an uplink classifier user plane function network element of the visited location, and the uplink classifier user plane function network element is used to divert the service flow of the terminal device; the session management function network element of the visited location sends a second diversion rule to the uplink classifier user plane function network element, and the second diversion rule is used to indicate that the service flow matching the second diversion rule is sent to the main anchor user plane function network element of the home location, and the main anchor user plane function network element is connected to the local data network of the home location.

[0035] In the above technical solution, by inserting an uplink classifier user plane functional network element in the visited location and issuing a second diversion rule to it, when the terminal device roams in the visited location, the service flow of the terminal device can be diverted to the main anchor user plane functional network element of the home location via the uplink classifier user plane functional network element, thereby meeting the need for part of the terminal device's service flow to return to the home location.

[0036] In a possible design of the third aspect, the session management function network element of the visited site is inserted into the uplink classifier user plane function network element of the visited site, including: the session management function network element of the visited site is inserted into the uplink classifier user plane function network element according to the data network name DNN signed by the terminal device.

[0037] In a possible design of the third aspect, the session management function network element of the visited location is inserted into the uplink classifier user plane function network element of the visited location, including: the session management function network element of the visited location inserts the uplink classifier user plane function network element according to the user policy of the terminal device, and the user policy is used to indicate that the service flow of the terminal device needs to be diverted at the visited location in a roaming scenario, and the service flow accessing the local data network of the home location returns to the home location.

[0038] In the above technical solution, the session management function network element at the visited location can insert an uplink classifier user plane function network element at the visited location when the user policy of the terminal device indicates that the service flow of the terminal device needs to be diverted at the visited location in a roaming scenario, and when the service flow accessing the local data network of the home location returns to the home location, thereby satisfying the requirements of part of the terminal device's service flow that meets the rules returning to the home location, and the remaining traffic being unloaded locally at the visited location.

[0039] Furthermore, since the service flows that do not match the second diversion rule can be unloaded locally at the visited location, there is no need to send all service flows of the terminal device back to the home location. Therefore, the above technical solution can make full use of network resources and reduce the delay for users to access the Internet.

[0040] In a possible design of the third aspect, if the session management function network element of the visited location is the same as the session management function network element of the home location, the method also includes: the session management function network element of the visited location sends the address of the uplink classifier user plane function network element to the main anchor point user plane function network element to establish a tunnel between the main anchor point user plane function network element and the uplink classifier user plane function network element.

[0041] In a possible design of the third aspect, if the session management function network element of the visited location is different from the session management function network element of the home location, the method also includes: the session management function network element of the visited location sends the address of the uplink classifier user plane function network element to the main anchor user plane function network element through the session management function network element of the home location to establish a tunnel between the main anchor user plane function network element and the uplink classifier user plane function network element.

[0042] In a possible design of the third aspect, the second diversion rule is used to indicate that the service flow that does not match the second diversion rule is sent to the auxiliary anchor user plane function network element of the visited location, and the auxiliary anchor user plane function network element is connected to the Internet.

[0043] In the above technical solution, the uplink classifier user plane functional network element of the visited location can adopt the reverse diversion method to divert the service flow matching the second diversion rule to the main anchor user plane functional network element, so that the terminal device can access the local data network of the home location, and divert the service flow that does not match the second diversion rule to the auxiliary anchor user plane functional network element, so that the terminal device can access the Internet.

[0044] In a possible design of the third aspect, the method also includes: the session management function network element of the visited location sends the address of the uplink classifier user plane function network element to the auxiliary anchor point user plane function network element to establish a tunnel between the auxiliary anchor point user plane function network element and the uplink classifier user plane function network element.

[0045] In a possible design of the third aspect, the method also includes: the session management function network element of the visited site sends the address of the uplink classifier user plane function network element to the access network device of the visited site to establish a tunnel between the access network device and the uplink classifier user plane function network element.

[0046] In a fourth aspect, an embodiment of the present application provides a communication device, which may have the function of implementing the session management function network element of the home location in any possible design of the above aspects or the above aspects, or have the function of implementing the intermediate session management function network element of the visited location in any possible design of the above aspects or the above aspects, or have the function of implementing the session management function network element of the visited location in any possible design of the above aspects or the above aspects. The device may be a network device or a chip included in the network device.

[0047] The functions of the above-mentioned communication device can be implemented by hardware, or by hardware executing corresponding software, and the hardware or software includes one or more modules or units or means corresponding to the above-mentioned functions.

[0048] In a possible design, the structure of the communication device includes a processing module and a transceiver module, wherein the processing module is configured to support the communication device to perform the functions corresponding to the first session management function network element in the above aspects or any one of the designs of the various aspects, or to perform the functions corresponding to the session management function network element in the home location in the above aspects or any one of the designs of the various aspects, or to perform the functions corresponding to the intermediate session management function network element in the visited location in the above aspects or any one of the designs of the various aspects, or to perform the functions corresponding to the session management function network element in the visited location in the above aspects or any one of the designs of the various aspects. The transceiver module is used to support the communication between the communication device and other communication devices. For example, when the communication device is the session management function network element in the home location, the address of the uplink classifier user plane function network element can be sent to the intermediate user plane function network element in the visited location. The communication device may also include a storage module, which is coupled to the processing module and stores program instructions and data necessary for the device. As an example, the processing module may be a processor, the communication module may be a transceiver, and the storage module may be a memory. The memory may be integrated with the processor or may be set separately from the processor.

[0049] In another possible design, the structure of the communication device includes a processor and may also include a memory. The processor is coupled to the memory and can be used to execute computer program instructions stored in the memory so that the device performs the above-mentioned aspects or any possible design of each aspect. Optionally, the communication device also includes a communication interface, and the processor is coupled to the communication interface. When the communication device is a network device, the communication interface can be a transceiver or an input / output interface; when the device is a chip included in the network device, the communication interface can be an input / output interface of the chip. Optionally, the transceiver can be a transceiver circuit, and the input / output interface can be an input / output circuit.

[0050] In a fifth aspect, an embodiment of the present application provides a chip system, comprising: a processor, the processor being coupled to a memory, the memory being used to store programs or instructions, and when the programs or instructions are executed by the processor, the chip system implements the above-mentioned aspects or any possible design method of each aspect.

[0051] Optionally, the chip system also includes an interface circuit, which is used to interact with code instructions to the processor.

[0052] Optionally, there may be one or more processors in the chip system, and the processor may be implemented by hardware or software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0053] Optionally, the memory in the chip system may be one or more. The memory may be integrated with the processor or may be separately provided with the processor. Exemplarily, the memory may be a non-transient processor, such as a read-only memory, which may be integrated with the processor on the same chip or may be provided on different chips.

[0054] In a sixth aspect, an embodiment of the present application provides a communication system, which includes a session management function network element at a home location and / or an intermediate session management function network element at a visited location; wherein the session management function network element at the home location is used to implement the method of the first aspect or any possible design of the first aspect, and the intermediate session management function network element at the visited location is used to implement the method of the second aspect or any possible design of the second aspect.

[0055] Optionally, the communication system further includes an uplink classifier user plane function network element at the home location, a primary anchor user plane function network element and a secondary anchor user plane function network element, and an intermediate user plane function network element at the visited location.

[0056] In the seventh aspect, an embodiment of the present application provides a communication system, which includes a session management function network element at a visited location; wherein the session management function network element at the visited location is used to implement the method in the above-mentioned third aspect or any possible design of the third aspect.

[0057] Optionally, the communication system further includes an uplink classifier user plane function network element and a secondary anchor user plane function network element at the visited location, and a primary anchor user plane function network element at the home location.

[0058] In an eighth aspect, an embodiment of the present application provides a computer-readable storage medium having a computer program or instructions stored thereon. When the computer program or instructions are executed, the computer executes the method in any possible design of the above aspects or aspects.

[0059] In a ninth aspect, an embodiment of the present application provides a computer program product. When a computer reads and executes the computer program product, the computer executes the method in any possible design of the above aspects or aspects.

[0060] The present application provides a campus network access method and device, which is used to enable users to access the campus network of their home location when roaming between provinces or between cities within a province, thereby improving the security of the campus network.

[0061] Among them, the user's business flow can be diverted after returning to the local location, or based on the diversion strategy, part of it can be unloaded at the visited location and part of it can be returned to the local location, thereby meeting the diverse business needs of the campus network.

[0062] In a tenth aspect, the present application provides a campus network access method, the method comprising:

[0063] The session management function SMF of the home location inserts the uplink classifier user plane function ULCL UPF in the home location according to the subscription data and current location of the terminal device; the SMF of the home location determines that the service flow of the terminal device in the roaming scenario must return to the home location and be diverted; the SMF of the home location sends the address of the ULCL UPF, and the address of the ULCL UPF is used by the forwarding user plane function I-UPF of the visited location to forward the service flow of the terminal device to the ULCL UPF.

[0064] In one possible design, the method further includes:

[0065] The home SMF receives the address of the I-UPF from the forwarding session management function I-SMF of the visited location;

[0066] The SMF of the home location sends the address of the I-UPF to the ULCL UPF, and the address of the I-UPF is used by the ULCL UPF to forward the service flow of the terminal device to the I-UPF.

[0067] In one possible design, the method further includes:

[0068] The SMF of the home location sends the address of the ULCL UPF to the SMF of the visited location.

[0069] In one possible design, the method further includes:

[0070] The SMF of the home location inserts the I-UPF at the visited location.

[0071] In one possible design, the method further includes:

[0072] The SMF of the home location sends the address of the ULCL UPF to the I-UPF of the visited location;

[0073] The SMF of the home location sends the address of the I-UPF to the ULCL UPF, and the address of the I-UPF is used by the ULCL UPF to forward the service flow of the terminal device to the I-UPF.

[0074] In an eleventh aspect, the present application provides a campus network access method, the method comprising:

[0075] The session management function SMF of the visited location inserts an uplink classifier user plane function ULCL UPF in the visited location according to the subscription data and current location of the terminal device; the SMF of the visited location sends a diversion rule to the ULCL UPF, and the diversion rule includes sending the service flow matching the first address to the UPF of the home location, and sending the service flow matching the second address to the UPF of the visited location, wherein the service flow matching the first address is used to access the local network of the home location, and the service flow matching the second address is used to access the Internet.

[0076] In one possible design, the second address is an address other than the first address. BRIEF DESCRIPTION OF THE DRAWINGS

[0077] Figure 1 A schematic diagram of a network architecture in a roaming scenario applicable to this application;

[0078] Figure 2 This is a schematic diagram of an intra-province roaming scenario in Embodiment 1 of the present application;

[0079] Figure 3 This is a schematic diagram of an inter-provincial roaming scenario in Embodiment 1 of the present application;

[0080] Figure 4 A flowchart of a network access method provided in Embodiment 1 of the present application;

[0081] Figure 5 The network access method in the first embodiment of the present application corresponds to the relevant process when the terminal device is located at the home location;

[0082] Figure 6 The network access method in the first embodiment of the present application corresponds to the relevant process when the terminal device is located in the visited location in the intra-provincial roaming scenario;

[0083] Figure 7 The network access method in the first embodiment of the present application corresponds to the relevant process when the terminal device is located in the visited location in the inter-provincial roaming scenario;

[0084] Figure 8a and Figure 8b This is a specific example of Embodiment 1 of the present application;

[0085] Fig. 9 This is a schematic diagram of the intra-province roaming scenario in the second embodiment of the present application;

[0086] Fig.10 This is a schematic diagram of an inter-provincial roaming scenario in Embodiment 2 of the present application;

[0087] Fig.11 A flowchart of a network access method provided in Embodiment 2 of the present application;

[0088] Fig.12 The network access method in the second embodiment of the present application corresponds to the relevant process when the terminal device is located in the visited location in the intra-provincial roaming scenario;

[0089] Fig.13 The network access method in the second embodiment of the present application corresponds to the relevant process when the terminal device is located in the visited location in the inter-provincial roaming scenario;

[0090] Fig.14 This is a specific example of Embodiment 2 of the present application;

[0091] Fig.15 This is a schematic diagram of an intra-province roaming scenario when a unified UPF is used in Embodiment 2 of the present application;

[0092] Fig.16 This is a schematic diagram of an inter-provincial roaming scenario when a unified UPF is used in Embodiment 2 of the present application;

[0093] Fig.17 and Fig.18 A schematic diagram of the structure of a communication device provided by the present application;

[0094] Fig.19 The network architecture of 5G networks suitable for roaming scenarios defined by the current 3GPP standards;

[0095] Fig. 20 This is a schematic diagram of a campus access scenario in Embodiment 3 of the present application;

[0096] Fig.21 This is a schematic diagram of the intra-province roaming scenario in Embodiment 3 of the present application;

[0097] Fig. 22This is a schematic diagram of the inter-provincial roaming scenario in Embodiment 3 of the present application;

[0098] Fig.23 A schematic diagram of a network architecture applicable to Embodiment 3 of the present application;

[0099] Fig.24 This is a schematic diagram of the business process in Example 3 of the present application;

[0100] Fig.25 This is a schematic diagram of a campus access scenario in Embodiment 4 of the present application;

[0101] Fig.26 This is a schematic diagram of the intra-province roaming scenario in the fourth embodiment of the present application;

[0102] Fig. 27 This is a schematic diagram of the inter-provincial roaming scenario in the fourth embodiment of the present application;

[0103] Fig.28 A schematic diagram of a network architecture applicable to Embodiment 4 of the present application;

[0104] Fig.29 This is a schematic diagram of the business process in Example 4 of the present application;

[0105] Fig.30 This is a schematic diagram of a network architecture applicable to Example 5 of the present application. DETAILED DESCRIPTION

[0106] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the embodiments of the present application will be further described in detail below with reference to the accompanying drawings.

[0107] The technical solutions of the embodiments of the present application can be applied to various communication systems, such as long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD) system, fifth generation (5G) mobile communication system or new radio (NR) system, or to future communication systems or other similar communication systems.

[0108] Please refer to Figure 1 This application takes the 5G network architecture for roaming scenarios defined in the 3GPP standard as an example to introduce the network architecture for roaming scenarios applicable to this application. The network architecture consists of three parts, namely, terminal equipment, data network (DN) and operator network part.

[0109] Among them, the operator network may include but is not limited to one or more of the following network elements or functional entities: access and mobility management function (AMF) network element, session management function (SMF) network element, intermediate SMF (I-SMF) network element, user plane function (UPF) network element, intermediate UPF (I-UPF) network element, uplink classifier UPF (ULCL UPF) network element, protocol data unit (PDU) session anchor UPF (PSA UPF) network element and radio access network (RAN) equipment. Optionally, the network architecture may also include policy control function (PCF) network element, unified data management (UDM) network element, unified data repository (UDR) network element, application function (AF) network element and other network elements or functional entities. Figure 1 Not shown yet.

[0110] In a specific implementation, the terminal device in the embodiment of the present application may be a device for realizing a wireless communication function. The terminal device may be a user equipment (UE), an access terminal, a terminal unit, a terminal station, a mobile station, a mobile station, a remote station, a remote terminal, a mobile device, a wireless communication device, a terminal agent or a terminal device in a 5G network or a future evolved public land mobile network (PLMN). The access terminal may 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 handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device or a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, etc. The terminal device may be mobile or fixed, without limitation.

[0111] The above-mentioned terminal devices can establish a connection with the operator network through the interface provided by the operator network (such as the N1 interface, etc.), and use the data and / or voice services provided by the operator network. The terminal device can also access the DN through the operator network, and use the operator services deployed on the DN and / or services provided by a third party. Among them, the above-mentioned third party may be a service provider other than the operator network and the terminal device, and may provide other data and / or voice services to the terminal device. Among them, the specific form of expression of the above-mentioned third party can be determined according to the actual application scenario, and is not limited here.

[0112] RAN is a subnetwork of the operator network and an implementation system between the service node and the terminal device in the operator network. To access the operator network, the terminal device must first pass through the RAN, and then connect to the service node of the operator network through the RAN. The RAN device in this application is a device that provides wireless communication functions for the terminal device, and the RAN device is also called an access network device. The RAN device in this application includes but is not limited to: the next generation base station (g nodeB, gNB) in 5G, evolved node B (evolved node B, eNB), radio network controller (radio network controller, RNC), node B (node ​​B, NB), base station controller (base station controller, BSC), base transceiver station (base transceiver station, BTS), home base station (for example, home evolved nodeB, or home node B, HNB), baseband unit (baseBand unit, BBU), transmission point (transmitting and receiving point, TRP), transmission point (transmitting point, TP), mobile switching center, etc.

[0113] The AMF network element is mainly responsible for mobility management, access authentication / authorization and other functions, such as terminal device registration, location update, mobility state switching, etc. In addition, it is also responsible for transmitting user policies between terminal devices and PCF.

[0114] The SMF network element is mainly responsible for session management, execution of control policies issued by PCF, selection of UPF, allocation of UE Internet protocol (IP) addresses, etc. In roaming scenarios, the home SMF network element can also be called the anchor SMF (A-SMF) network element of the terminal device.

[0115] I-SMF network element, also known as forwarding SMF network element, is used to forward control plane messages between the visited location and the home location. In roaming scenarios, when the terminal device moves to the visited location, if the location of the terminal device is no longer within the service area of ​​the A-SMF network element, the AMF network element can insert the I-SMF network element in the visited location.

[0116] The UPF network element, as the interface UPF with the data network, is mainly responsible for user plane data forwarding, session / flow-level billing statistics, bandwidth limitation and other functions.

[0117] The PSAUPF network element, also known as the anchor UPF network element, serves as an anchor point connected to the PDU session and is responsible for filtering, forwarding, rate control, and billing of the user plane data of the terminal device. In a roaming scenario, the PSA UPF network element of the home location is called the main PSA UPF network element of the terminal device (i.e., the main anchor UPF network element). The present application supports inserting one or more auxiliary PSA UPF network elements (i.e., auxiliary anchor UPF network elements) on the user plane path of the PDU session of the terminal device so that the terminal device can access the local data network nearby. Among them, the auxiliary PSA UPF network element can be deployed in the home location (e.g., the edge area of ​​the home location) or in the visited location, without limitation. Specifically, the main PSA UPF network element (or main anchor UPF network element) refers to the UPF network element to which the terminal device is connected when the session is initially activated and created, which is used to allocate an IP address to the terminal device and forward user plane data. The auxiliary PSA UPF network element (or auxiliary anchor UPF network element) refers to the UPF network element inserted after the session creation of the terminal device is completed, which is used to forward user plane data for the terminal device.

[0118] The I-UPF network element, also known as the forwarding UPF network element, is used to forward user plane data between the visited location and the home location. In a roaming scenario, when the terminal device moves to the visited location, if the location of the terminal device is no longer within the service area of ​​the main PSA UPF network element, then the A-SMF network element (corresponding to the situation where the location of the terminal device is still within the service area of ​​the A-SMF network element) or the I-SMF network element (corresponding to the situation where the location of the terminal device is no longer within the service area of ​​the A-SMF network element or there is an I-SMF network element) can be inserted into the I-UPF network element at the visited location. The I-UPF network element can be deployed in conjunction with the ULCL UPF network element, such as Figure 1 The ULCLUPF+I-UPF network element in the figure indicates that the network element can also be used as an I-UPF network element to realize the N3 interface capability in the roaming scenario.

[0119] The ULCL UPF network element is a working form of the UPF network element, which is used for service diversion and can determine the direction of the data flow according to the different destination addresses visited by the user. In this application, the ULCL UPF network element can be inserted in the home location or the visited location, without limitation. The ULCL UPF network element can also be deployed in conjunction with other UPF network elements (such as I-UPF network elements or PSA UPF network elements), such as Figure 1 The ULCL UPF+I-UPF network element in the figure indicates that the network element can also be used as a ULCL UPF network element to realize the traffic diversion function.

[0120] The PCF network element is mainly responsible for policy control functions such as billing at the session and service flow level, quality of service (QoS) bandwidth guarantee and mobility management, and UE policy decision-making.

[0121] UDM network element is mainly responsible for managing contract data, user access authorization and other functions.

[0122] The UDR network element is mainly responsible for the storage and access of contract data, policy data, application data and other types of data.

[0123] AF network element is mainly responsible for transmitting the application side's requirements to the network side, such as QoS requirements or user status event subscription. AF can be a third-party functional entity or an application service deployed by an operator. AF network element can also be called an application server or a third-party device.

[0124] DN is a data network that provides business services to users. Generally, the client is located in the terminal device and the server is located in the data network. The data network can be a private network, such as a local area network, or an external network that is not controlled by the operator, such as the Internet. It can also be a proprietary network jointly deployed by operators, such as a configured IP multimedia core network subsystem (IMS) service. In a roaming scenario, the local data network deployed in the home location may be different from the local data network deployed in the visited location. For ease of understanding, the local data network deployed in the home location in this application may also be referred to as a campus network, enterprise network, enterprise private network, local network, etc., without limitation.

[0125] The interfaces and functions between the above network elements or functional entities are as follows:

[0126] The N1 interface refers to the interface between the AMF and the UE, which is used to transmit QoS control rules, etc. to the UE.

[0127] The N2 interface refers to the interface between the AMF and the RAN, and is used to transmit radio bearer control information from the core network side to the RAN.

[0128] The N3 interface refers to the interface between the (R)AN and the UPF, and is used to transmit user plane data between the (R)AN and the UPF.

[0129] The N4 interface refers to the interface between SMF and UPF, which is used to transmit information between the control plane and the user plane, including the control of the forwarding rules, QoS control rules, traffic statistics rules, etc. for the user plane and the reporting of information on the user plane.

[0130] N5 interface refers to the interface between AF and PCF, which is used to send application service requests and report network events. Figure 1 Not shown yet.

[0131] The N6 interface refers to the interface between UPF and DN, and is used to transmit user plane data between UPF and DN.

[0132] The N7 interface is the interface between PCF and SMF, which is used to send control policies for PDU session granularity and service data flow granularity. Figure 1 Not shown yet.

[0133] The N8 interface refers to the interface between AMF and UDM, which is used by AMF to obtain subscription data and authentication data related to access and mobility management from UDM, and AMF to register UE current mobility management related information with UDM. Figure 1 Not shown yet.

[0134] The N9 interface refers to the interface between UPFs, such as the interface between the UPF connected to the DN and the UPF connected to the (R)AN, and is used to transfer user plane data between UPFs.

[0135] The N10 interface is the interface between SMF and UDM, which is used by SMF to obtain the subscription data related to session management from UDM, and SMF to register the current session information of UE with UDM. Figure 1 Not shown yet.

[0136] The N11 interface refers to the interface between SMF and AMF, which is used to transmit PDU session tunnel information between RAN and UPF, transmit control messages sent to UE, transmit radio resource control information sent to RAN, etc.

[0137] The N15 interface is the interface between the PCF and the AMF, used to deliver UE policies and access control related policies. Figure 1 Not shown yet.

[0138] The N16a interface refers to the interface between the SMF and the I-SMF, which is used by the visited I-SMF to obtain the home UPF information from the home SMF.

[0139] The N22 interface refers to the interface between the AMF and the network slice selection function (NSSF), which is used by the AMF to query the NSSF for information such as the Allowed NSSAI (network slice selection assistance information) allowed to be used and the Configured NSSAI configured on the UE by the home network. Figure 1 Not shown yet.

[0140] N35 interface refers to the interface between UDM and UDR, which is used by UDM to obtain user contract data information from UDR. Figure 1 Not shown yet.

[0141] N36 interface refers to the interface between PCF and UDR, which is used by PCF to obtain policy-related contract data and application data-related information from UDR. Figure 1 Not shown yet.

[0142] The above network element or functional entity can be a network element in a hardware device, a software function running on dedicated hardware, or a virtualized function instantiated on a platform (e.g., a cloud platform). Optionally, the above network element or function can be implemented by one device, or by multiple devices, or a functional module in one device, which is not specifically limited in the embodiments of the present application.

[0143] The general user registration process can be simply described as follows: UE sends a registration request to AMF through RAN, AMF obtains the contract data from the specific UDM based on the user identity, and UDM obtains the actual contract data from UDR after receiving the request. In addition, AMF can also initiate a user policy control establishment request (UEPolicyControl_Create) and an access management policy control establishment request (AMPolicyControl_Create) to PCF, which are used to obtain UE policy and access control policy respectively. PCF returns the access control policy to AMF in this process, and provides UE policy to UE via AMF.

[0144] The general session establishment process can be simply described as follows: UE sends a session establishment request to AMF through RAN, AMF selects SMF to provide services for the session, saves the correspondence between SMF and PDU session, and sends the session establishment request to SMF, SMF selects the corresponding UPF for UE and establishes the user plane transmission path, and allocates an IP address for it. During this process, SMF will also initiate a policy control session establishment request to PCF to establish a policy control session between SMF and PCF. During the policy control session establishment process, SMF will save the correspondence between the policy control session and the PDU session. For roaming scenarios, control signaling needs to be forwarded by I-SMF and SMF, and media data needs to be forwarded by I-UPF.

[0145] It should be noted that the terms "system" and "network" in the embodiments of the present application can be used interchangeably. "Multiple" refers to two or more. In view of this, "multiple" can also be understood as "at least two" in the embodiments of the present application. "At least one" can be understood as one or more, for example, one, two or more. For example, including at least one means including one, two or more, and there is no restriction on which ones are included. For example, including at least one of A, B and C, then A, B, C, A and B, A and C, B and C, or A and B and C can be included. Similarly, the understanding of descriptions such as "at least one" is similar. "And / or" describes the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / ", unless otherwise specified, generally indicates that the associated objects before and after are in an "or" relationship.

[0146] Unless otherwise specified, the embodiments of the present application mention ordinal numbers such as "first" and "second" for distinguishing between multiple objects, and are not used to limit the order, timing, priority or importance of multiple objects, and the descriptions of "first" and "second" do not limit the objects to be different.

[0147] For the convenience of description, this application will be described later using A-SMF, I-SMF, UPF, I-UPF, and ULCL UPF as examples. It should be understood that the A-SMF in the following embodiments can be replaced by an anchor session management function network element (or a session management function network element or a home session management function network element), the I-SMF can be replaced by an intermediate session management function network element (or a visited session management function network element), the PSA UPF can be replaced by an anchor user plane function network element, the I-UPF can be replaced by an intermediate user plane function network element, and the ULCL UPF can be replaced by an uplink classifier user plane function network element.

[0148] Embodiment 1

[0149] In the existing 3GPP architecture, the ULCL UPF selection in roaming scenarios is implemented by I-SMF, and it does not support selecting the ULCL UPF in the home location through the SMF in the home location in the existing I-UPF scenario, which results in the terminal device's service flow being unable to be diverted in the home location after returning to the home location. In addition, after the terminal device's service flow returns to the home location, since the UPF in the home location is a main anchor point UPF and has no Internet exit (because after the MEC is sunk to the prefecture-level city, the UPF shared by the prefecture-level city has an Internet exit, and the city where the UPF in the home location is located has no Internet exit), it is unable to meet the needs of further diversion of the terminal device's service flow after returning to the home location.

[0150] To solve the above problems, embodiment 1 of the present application provides a network access method, which allows the terminal device to still access the local data network of the home location in a roaming scenario (for example, when the user leaves the park or roams between provinces or within a province), and the data flow can be diverted at the home location after returning to the home location, and there is no need for the local data network of the home location to access the Internet.

[0151] Embodiment 1 of the present application may have the following features: Figure 2 and Figure 3 For ease of understanding, these two roaming scenarios can be referred to as intra-provincial roaming scenarios and inter-provincial roaming scenarios, where the intra-provincial roaming scenario can also be referred to as cross-city roaming scenarios, and the inter-provincial roaming scenario can also be referred to as cross-provincial roaming scenarios, without limitation.

[0152] Figure 2 Corresponding to the scenario where multiple UPFs are within the management scope of the same SMF (such as the intra-provincial roaming scenario), it means that the I-UPF of the visited location and the PSA UPF1 of the home location are both managed by the A-SMF, wherein the PSA UPF1 of the home location is the main anchor point UPF of the terminal device. This scenario can be understood as that the UPF of the home location and the UPF of the visited location are within the management scope of the same SMF, and the home location and the visited location share the same SMF but correspond to different UPFs. For example, the home location and the visited location can be different cities in a province, which can be respectively referred to as the home city and the visited city, wherein the SMF of the home city and the SMF of the visited city are the same SMF, that is, both are SMFs of the province. In this scenario, if the terminal device moves from the home location to the visited location, the location of the terminal device is still within the service area (service area, SA) of the A-SMF of the home location, but is no longer in the service area of ​​the PSAUPF1 (i.e., the main anchor point UPF) of the home location, at this time, the A-SMF can choose to insert the I-UPF in the visited location to forward user plane data between the visited location and the home location.

[0153] Figure 3Corresponding to the scenario where multiple UPFs are not under the management scope of the same SMF (such as inter-provincial roaming scenario), it means that the I-UPF of the visited location is managed by the I-SMF of the visited location, while the PSA UPF1 of the home location and the ULCL UPF of the home location are both managed by the A-SMF of the home location, where the PSA UPF1 of the home location is the main anchor point UPF of the terminal device. This scenario can also be understood as that the UPF of the home location and the UPF of the visited location are within the management scope of different SMFs, and the home location and the visited location not only correspond to different SMFs, but also to different UPFs. For example, the home location and the visited location can be different provinces in the country, which can be respectively referred to as the home province and the visited province, where the SMF of the home province and the SMF of the visited province are different SMFs, the UPF of the home province and the UPF of the visited province are different UPFs, and the UPF of the home province is managed by the SMF of the home province, and the UPF of the visited province is managed by the SMF of the visited province. In this scenario, if the terminal device moves from the home location to the visited location, the location of the terminal device is no longer in the service area of ​​the A-SMF of the home location, and is also no longer in the service area of ​​the PSA UPF1 (i.e., the primary anchor point UPF) of the home location. At this time, the AMF can choose to insert the I-SMF in the visited location to forward control plane messages or signaling between the visited location and the home location. Furthermore, the I-SMF can select and insert the I-UPF to forward user plane data between the visited location and the home location.

[0154] It should be noted that the intra-provincial roaming scenario and inter-provincial roaming scenario mentioned in this application are described based on China's administrative divisions, because in China, the deployment of SMF and UPF is usually related to administrative divisions, for example, one SMF can be deployed for one province, and one UPF can be deployed for one city. However, it should be understood that the above description is only an example, the purpose is to give readers a vivid understanding of the roaming scenario and to make it easier to understand the relevant features of the roaming scenario. In fact, the distinction between the two roaming scenarios is made based on the deployment of SMF and UPF.

[0155] For example, in some possible embodiments, the intra-provincial roaming scenario may refer to: the terminal device moves within a smaller range, does not leave the service area of ​​the current SMF, but leaves the service area of ​​the current UPF (i.e., the UPF of the home location), and moves from the service area of ​​the current UPF (i.e., the UPF of the home location) to the service area of ​​another UPF (i.e., the UPF of the visited location). These two UPFs are managed by the same SMF, which can be called the SMF of the home location or the SMF of the visited location.

[0156] Inter-provincial roaming scenarios may refer to: the terminal device moves within a larger range, from the service area of ​​the current SMF (i.e., the home SMF) to the area of ​​another SMF (i.e., the visited SMF). Of course, it also moves from the service area of ​​the current UPF (i.e., the home UPF) to the service area of ​​another UPF (i.e., the visited UPF), and these two UPFs are managed by different SMFs.

[0157] Please refer to Figure 4 , is a flow chart of a network access method provided in Embodiment 1 of the present application, the method comprising:

[0158] Step 401: The A-SMF of the home location inserts the ULCL UPF of the home location, and the ULCL UPF is used to distribute the service flow of the terminal device.

[0159] In the embodiment of the present application, the ULCL UPF is used to divert the service flow of the terminal device to the primary anchor point UPF and the secondary anchor point UPF of the home location. Among them, the primary anchor point UPF is located in the non-edge area of ​​the home location, and the non-edge area can also be called a non-MEC area or a central area or a central data plane. The non-edge area can be further connected to the Internet through the core network. Therefore, the terminal device can access the Internet through the primary anchor point UPF in the non-edge area of ​​the home location.

[0160] The ULCL UPF and the auxiliary anchor point UPF are located in the edge area of ​​the home location, which can also be called the MEC area. The edge area can be deployed with the local data network of the home location (such as the MEC network), so the terminal device can access the local data network of the home location through the auxiliary anchor point UPF in the edge area of ​​the home location.

[0161] In a possible implementation, the A-SMF may insert the above-mentioned ULCL UPF and / or auxiliary anchor point UPF in the edge area of ​​the home location when the terminal device moves from a non-edge area of ​​the home location to an edge area. For example, the A-SMF may insert the above-mentioned ULCL UPF and / or auxiliary anchor point UPF according to the data network name (data network name, DNN) contracted by the terminal device, or the A-SMF may also insert the above-mentioned ULCL UPF and / or auxiliary anchor point UPF according to the DNN and location contracted by the terminal device, or the A-SMF may also insert the above-mentioned ULCL UPF and / or auxiliary anchor point UPF according to the DNN, location or data network access id (data network access id, DNAI) contracted by the terminal device and other information. Among them, the DNN can be a dedicated DNN or a dedicated network slice, etc., and is not limited. Inserting the ULCL UPF and the auxiliary anchor point UPF refers to inserting the ULCL UPF and the auxiliary anchor point UPF into a session of the terminal device, such as a PDU session.

[0162] Furthermore, when the terminal device moves from a non-edge area of ​​the home location to an edge area, the A-SMF can obtain the user policy of the terminal device from the PCF, and the user policy is used to indicate that the service flow of the terminal device in the roaming scenario needs to return to the home location and be diverted. Furthermore, the A-SMF can insert the above-mentioned ULCLUPF and / or auxiliary anchor point UPF in the edge area of ​​the home location according to the user policy.

[0163] For example, Figure 5 As shown, when the terminal device is in a non-edge area of ​​the home location, in step 501, the A-SMF of the home location and the main anchor point UPF can create a session for the terminal device, such as a PDU session. Furthermore, in step 502, the terminal device can access the Internet through the main anchor point UPF. Specifically, in the uplink direction, the request for accessing the Internet initiated by the terminal device in the non-edge area of ​​the home location can be sent to the main anchor point UPF via the access network device, and the main anchor point UPF will then send the request to the Internet; in the downlink direction, the response to the above request returned by the Internet can be sent to the main anchor point UPF, and the main anchor point UPF will then return the response to the terminal device via the access network device.

[0164] When the terminal device moves from a non-edge area of ​​the home location to an edge area, in step 503, the PCF may send the user policy of the terminal device to the A-SMF, and the user policy is used to indicate that the service flow of the terminal device in the roaming scenario needs to return to the home location and be diverted. In step 504, the A-SMF may select and insert the ULCL UPF and / or the auxiliary anchor point UPF according to the DNN, DNAI, or location information signed by the terminal device. Among them, the ULCL UPF is used to divert the service flow of the terminal device to the main anchor point UPF and the auxiliary anchor point UPF. The main anchor point UPF is connected to the Internet and can be used to send the received service flow to the Internet. The auxiliary anchor point UPF is connected to the local data network of the home location and can be used to send the received service flow to the local data network of the home location. The ULCL UPF and the auxiliary anchor point UPF can be deployed in one, and this application is not limited here.

[0165] Further, in step 505, the A-SMF may send a first diversion rule to the ULCL UPF, the first diversion rule being used to indicate that the service flow matching the first diversion rule is sent to the secondary anchor point UPF, and optionally, the first diversion rule may further indicate that the service flow not matching the first diversion rule is sent to the primary anchor point UPF. For example, the first diversion rule may include a message filter in the form of an IP five-tuple associated with the local data network of the home location. Optionally, the first diversion rule may also include the address of the primary anchor point UPF and the address of the secondary anchor point UPF.

[0166] In step 506, the A-SMF may send the address of the ULCL UPF to the main anchor point UPF to update the bearer rule of the main anchor point UPF, thereby establishing a tunnel between the main anchor point UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the peer address of the downlink tunnel of the main anchor point UPF, that is, to update the peer address of the downlink tunnel of the main anchor point UPF to the address of the ULCL UPF. For example, the A-SMF may send a first update request to the main anchor point UPF, and the first update request is used to update the bearer rule of the main anchor point UPF, and the first update request includes the address of the ULCL UPF. After receiving the first update request, the main anchor point UPF may update the peer address of the downlink tunnel to the address of the ULCL UPF, and then send a first update response to the A-SMF. The updating of the bearer rule can also be understood as refreshing or modifying or setting the bearer rule, refreshing or modifying or setting the peer address of the tunnel, refreshing or modifying or setting the destination address of the tunnel, etc., which will not be repeated below.

[0167] In step 507, the A-SMF may send the address of the ULCL UPF to the auxiliary anchor point UPF to set the bearer rule of the auxiliary anchor point UPF, thereby establishing a tunnel between the auxiliary anchor point UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set the peer address of the downlink tunnel of the auxiliary anchor point UPF, that is, the peer address of the downlink tunnel of the auxiliary anchor point UPF is set to the address of the ULCL UPF. For example, the A-SMF may send a second update request to the auxiliary anchor point UPF, and the second update request is used to set the bearer rule of the auxiliary anchor point UPF, and the second update request includes the address of the ULCL UPF. After receiving the second update request, the auxiliary anchor point UPF may set the peer address of the downlink tunnel to the address of the ULCL UPF, and then send a second update response to the A-SMF.

[0168] In step 508, the A-SMF may send the address of the ULCL UPF to the access network device of the home location to update the bearer rules of the access network device, thereby establishing a tunnel between the access network device and the ULCL UPF, and the access network device is located in the edge area of ​​the home location. Specifically, the address of the ULCL UPF is used to update the peer address of the uplink tunnel of the access network device, that is, to update the peer address of the uplink tunnel of the access network device to the address of the ULCL UPF. For example, the A-SMF may send a third update request to the access network device of the home location, and the third update request is used to update the bearer rules of the access network device, and the third update request includes the address of the ULCL UPF. After receiving the third update request, the access network device may update the peer address of the uplink tunnel to the address of the ULCL UPF, and then send a third update response to the A-SMF.

[0169] In this way, when the terminal device moves from the non-edge area of ​​the home location to the edge area, under the diversion effect of ULCL UPF, the terminal device can access the Internet through the primary anchor point UPF and access the local data network of the home location through the secondary anchor point UPF.

[0170] When the terminal device accesses the local data network of the home location, as shown in step 509 and step 510, in the uplink direction, the request for accessing the local data network of the home location initiated by the terminal device in the edge area of ​​the home location can be sent to the ULCL UPF via the access network device; the ULCL UPF determines that the request matches the first diversion rule according to the first diversion rule, and then sends the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF can further send the request to the local data network of the home location; in the downlink direction, the response of the local data network of the home location returned to the terminal device in response to the above request can be first sent to the auxiliary anchor point UPF, sent by the auxiliary anchor point UPF to the ULCL UPF, and then returned to the terminal device by the ULCL UPF via the access network device.

[0171] When the terminal device accesses the Internet, as shown in step 510 and step 512, in the uplink direction, the request for accessing the Internet initiated by the terminal device in the edge area of ​​the home location can be sent to the ULCL UPF via the access network device; the ULCL UPF determines that the request does not match the first diversion rule according to the first diversion rule, and then sends the request to the main anchor point UPF; then, the main anchor point UPF can further send the request to the Internet. In the downlink direction, the response to the above request returned by the Internet to the terminal device can be first sent to the main anchor point UPF, sent by the main anchor point UPF to the ULCL UPF, and then returned to the terminal device by the ULCL UPF via the access network device.

[0172] Step 402: When the terminal device moves to a visited location, the A-SMF sends the address of the ULCL UPF to the I-UPF of the visited location to establish a tunnel between the I-UPF and the ULCL UPF.

[0173] Accordingly, the I-UPF receives the address of the ULCL UPF from the A-SMF.

[0174] When the terminal device moves from the home location to the visited location, if the location of the terminal device is still within the service area of ​​the A-SMF, the corresponding Figure 2The intra-provincial roaming scenario shown. In this scenario, the A-SMF can be inserted into the I-UPF of the visited location, and the I-UPF forwards the user plane data between the visited location and the home location. Since the I-UPF is also managed by the A-SMF, the A-SMF can directly send the address of the ULCL UPF to the I-UPF to set the peer address of the uplink tunnel of the I-UPF. The A-SMF can also send the address of the I-UPF to the ULCL UPF to update the peer address of the downlink tunnel of the ULCL UPF, thereby establishing a tunnel between the I-UPF and the ULCL UPF.

[0175] For example, Figure 6 As shown, in step 601, when the terminal device moves from the home location to the visited location, the AMF can determine that the location of the terminal device is in the service area of ​​the A-SMF. In step 602, the A-SMF can determine that the service flow of the terminal device in the roaming scenario needs to return to the home location and be diverted based on the user policy of the terminal device previously received from the PCF, that is, the N9 interface of the I-UPF in the visited location needs to be connected to the ULCL UPF in the home location. In step 603, the A-SMF selects and inserts the I-UPF in the visited location based on the DNN, DNAI, or location information signed by the terminal device.

[0176] In step 604, the A-SMF may send the address of the ULCL UPF to the I-UPF to set the bearer rule of the I-UPF, thereby establishing a tunnel between the I-UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set the peer address of the uplink tunnel of the I-UPF, that is, the peer address of the uplink tunnel of the I-UPF is set to the address of the ULCL UPF, so that the I-UPF can send the uplink service flow of the terminal device to the ULCL UPF. For example, the A-SMF may send a fourth update request to the I-UPF, and the fourth update request is used to set the bearer rule of the I-UPF, and the fourth update request includes the address of the ULCL UPF. After receiving the fourth update request, the I-UPF may set the peer address of the uplink tunnel to the address of the ULCL UPF, and then send a fourth update response to the A-SMF. Optionally, the A-SMF may send the address of the access network device of the visited location to the I-UPF to set the bearer rule of the I-UPF, thereby establishing a tunnel between the I-UPF and the access network device. Specifically, the address of the access network device is used to set the peer address of the downlink tunnel of the I-UPF, that is, the peer address of the downlink tunnel of the I-UPF is set to the address of the access network device, so that the I-UPF can send the downlink service flow of the terminal device to the access network device. For example, the fourth update request also includes the address of the access network device. After receiving the fourth update request, the I-UPF can set the peer address of the uplink tunnel to the address of the ULCL UPF, and set the peer address of the downlink tunnel to the address of the access network device, and then send a fourth update response to the A-SMF.

[0177] In step 605, the A-SMF may send the address of the I-UPF to the access network device of the visited location to update the bearer rules of the access network device, thereby establishing a tunnel between the access network device and the I-UPF. Specifically, the address of the I-UPF is used to update the peer address of the uplink tunnel of the access network device of the visited location, that is, to update the peer address of the uplink tunnel of the access network device of the visited location to the address of the I-UPF, so that the access network device of the visited location can send the uplink service flow of the terminal device to the I-UPF. For example, the A-SMF may send a fifth update request to the access network device of the visited location, and the fifth update request is used to update the bearer rules of the access network device, and the fifth update request includes the address of the I-UPF. After receiving the fifth update request, the access network device of the visited location may update the peer address of the uplink tunnel to the address of the I-UPF, and then send a fifth update response to the A-SMF.

[0178] In step 606, the A-SMF may send the address of the I-UPF to the ULCL UPF to update the bearer rules of the ULCL UPF, thereby establishing a tunnel between the ULCL UPF and the I-UPF. Specifically, the address of the I-UPF is used to update the peer address of the downlink tunnel of the ULCL UPF, that is, to update the peer address of the downlink tunnel of the ULCL UPF to the address of the I-UPF, so that the ULCL UPF can send the downlink service flow of the terminal device to the I-UPF. For example, the A-SMF may send a sixth update request to the ULCL UPF, and the sixth update request is used to update the bearer rules of the ULCL UPF, and the sixth update request includes the address of the I-UPF. After receiving the sixth update request, the ULCL UPF may update the peer address of the downlink tunnel to the address of the I-UPF, and then send a sixth update response to the A-SMF.

[0179] In this way, when the terminal device moves to the visited location, a tunnel for two-way data interaction between the I-UPF and the ULCL UPF can be established through the above method, thereby meeting the service needs of the terminal device's service flow returning to the home location and being diverted in the roaming scenario, and improving the security of the local data network in the home location. After that, under the data forwarding of the I-UPF and the diversion of the ULCL UPF, the terminal device can access the Internet through the primary anchor point UPF and access the local data network in the home location through the secondary anchor point UPF.

[0180] When the terminal device accesses the local data network of the home location, as shown in step 607 and step 608, in the uplink direction, the request for accessing the local data network of the home location initiated by the terminal device at the visited location may be sent to the I-UPF via the access network device, and then forwarded to the ULCL UPF by the I-UPF; the ULCL UPF may determine that the request matches the first diversion rule based on the first diversion rule, and then send the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF may further send the request to the local data network of the home location; in the downlink direction, the response of the local data network of the home location returned to the terminal device in response to the above request may first be sent to the auxiliary anchor point UPF, sent by the auxiliary anchor point UPF to the ULCL UPF, and then forwarded by the ULCL UPF to the I-UPF, and finally returned to the terminal device via the access network device.

[0181] When the terminal device accesses the Internet, as shown in step 609 and step 610, in the uplink direction, the request for accessing the Internet initiated by the terminal device at the visited location can be sent to the I-UPF via the access network device, and then forwarded to the ULCL UPF by the I-UPF; the ULCL UPF can determine that the request does not match the first diversion rule according to the first diversion rule, and then send the request to the main anchor point UPF; then, the main anchor point UPF can further send the request to the Internet. In the downlink direction, the response to the above request returned by the Internet to the terminal device can be first sent to the main anchor point UPF, sent by the main anchor point UPF to the ULCL UPF, and then forwarded by the ULCL UPF to the I-UPF, and finally returned to the terminal device via the access network device.

[0182] When the terminal device moves from the home location to the visited location, if the location of the terminal device has left the service area of ​​the A-SMF, the corresponding Figure 3 The inter-provincial roaming scenario shown in . In this scenario, the AMF can be inserted into the I-SMF of the visited location, and the I-SMF forwards the user plane data between the visited location and the home location. Furthermore, the I-SMF can be inserted into the I-UPF of the visited location, and the I-UPF forwards the user plane data between the visited location and the home location. Since the I-UPF is managed by the I-SMF, the A-SMF can send the address of the ULCL UPF to the I-UPF through the I-SMF to update the peer address of the uplink tunnel of the I-UPF. In addition, the A-SMF can also receive the address of the I-UPF from the I-SMF to update the peer address of the downlink tunnel of the ULCL UPF.

[0183] For example, Figure 7As shown, in step 701, when the terminal device moves from the home location to the visited location, the AMF can determine that the location of the terminal device leaves the service area of ​​the A-SMF. In step 702, the AMF can select and insert the I-SMF of the visited location based on the DNN, DNAI, or location information signed by the terminal device. Further, the AMF can also send the address of the A-SMF to the I-SMF and receive a response from the I-SMF so that the I-SMF and the A-SMF can exchange information. In step 703, the A-SMF can determine that the data flow of the terminal device in the roaming scenario needs to return to the home location and be diverted based on the user policy of the terminal device previously received from the PCF, that is, the N9 interface of the I-UPF of the visited location needs to be connected to the ULCL UPF of the home location. In step 704, the I-SMF can send a request to the A-SMF to obtain the peer address of the uplink tunnel of the I-UPF. In step 705, in response to the request of the I-SMF, the A-SMF may send the address of the ULCL UPF to the I-SMF so that the I-SMF sends the address of the ULCL UPF to the I-UPF. In step 706, the I-SMF may select and insert the I-UPF of the visited location according to the DNN, DNAI, or location information signed by the terminal device. In step 707, the I-SMF may send the address of the I-UPF to the A-SMF. This step 707 is optional. For example, if step 706 is performed before step 704, the I-SMF may also carry the address of the I-UPF in the request for obtaining the peer address of the uplink tunnel of the I-UPF.

[0184] In step 708, the I-SMF may send the address of the ULCL UPF to the I-UPF to set the bearer rule of the I-UPF, thereby establishing a tunnel between the I-UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set the peer address of the uplink tunnel of the I-UPF, that is, the peer address of the uplink tunnel of the I-UPF is set to the address of the ULCL UPF, so that the I-UPF can send the uplink service flow of the terminal device to the ULCL UPF. For example, the A-SMF may send the seventh update request to the I-UPF, and the seventh update request is used to set the bearer rule of the I-UPF, and the seventh update request includes the address of the ULCL UPF. After receiving the seventh update request, the I-UPF may set the peer address of the uplink tunnel to the address of the ULCL UPF, and then send the seventh update response to the I-SMF. Optionally, the I-SMF may send the address of the access network device of the visited location to the I-UPF to set the bearer rule of the I-UPF, thereby establishing a tunnel between the I-UPF and the access network device. Specifically, the address of the access network device is used to set the peer address of the downlink tunnel of the I-UPF, that is, to set the peer address of the downlink tunnel of the I-UPF to the address of the access network device, so that the I-UPF can send the downlink service flow of the terminal device to the access network device. For example, the seventh update request also includes the address of the access network device. After receiving the seventh update request, the I-UPF can set the peer address of the uplink tunnel to the address of the ULCL UPF, and set the peer address of the downlink tunnel to the address of the access network device, and then send the seventh update response to the I-SMF.

[0185] In step 709, the I-SMF may send the address of the I-UPF to the access network device of the visited location to update the bearer rules of the access network device, thereby establishing a tunnel between the access network device and the I-UPF. Specifically, the address of the I-UPF is used to update the peer address of the uplink tunnel of the access network device of the visited location, that is, to update the peer address of the uplink tunnel of the access network device of the visited location to the address of the I-UPF, so that the access network device of the visited location can send the uplink service flow of the terminal device to the I-UPF. For example, the A-SMF may send the eighth update request to the access network device of the visited location, and the eighth update request is used to update the bearer rules of the access network device, and the eighth update request includes the address of the I-UPF. After receiving the eighth update request, the access network device of the visited location may update the peer address of the uplink tunnel to the address of the I-UPF, and then send the eighth update response to the A-SMF.

[0186] In step 710, the A-SMF may send the address of the I-UPF to the ULCL UPF to update the bearer rules of the ULCL UPF, thereby establishing a tunnel between the ULCL UPF and the I-UPF. Specifically, the address of the I-UPF is used to update the peer address of the downlink tunnel of the ULCL UPF, that is, to update the peer address of the downlink tunnel of the ULCL UPF to the address of the I-UPF, so that the ULCL UPF can send the downlink service flow of the terminal device to the I-UPF. For example, the A-SMF may send the ninth update request to the ULCL UPF, and the ninth update request is used to update the bearer rules of the ULCL UPF, and the ninth update request includes the address of the I-UPF. After receiving the ninth update request, the ULCL UPF may update the peer address of the downlink tunnel to the address of the I-UPF, and then send the ninth update response to the A-SMF.

[0187] In this way, when the terminal device moves to the visited location, a tunnel for bidirectional data interaction between the I-UPF and the ULCL UPF can be established through the above method, so that the N9 interface of the I-UPF is connected to the ULCL UPF of the home location, thereby meeting the business needs of returning the data flow of the terminal device to the home location and diverting it in the roaming scenario, and improving the security of the local data network of the home location. After that, under the data forwarding of the I-UPF and the diversion of the ULCL UPF, the terminal device can access the Internet through the primary anchor point UPF, and access the local data network of the home location through the secondary anchor point UPF.

[0188] When the terminal device accesses the local data network of the home location, as shown in step 711 and step 712, in the uplink direction, the request for accessing the local data network of the home location initiated by the terminal device at the visited location may be sent to the I-UPF via the access network device, and then forwarded by the I-UPF to the ULCL UPF; the ULCL UPF may determine that the request matches the first diversion rule based on the first diversion rule, and then send the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF may further send the request to the local data network of the home location; in the downlink direction, the response of the local data network of the home location returned to the terminal device in response to the above request may first be sent to the auxiliary anchor point UPF, sent by the auxiliary anchor point UPF to the ULCL UPF, and then forwarded by the ULCL UPF to the I-UPF, and finally returned to the terminal device via the access network device.

[0189] When the terminal device accesses the Internet, as shown in step 713 and step 714, in the uplink direction, the request for accessing the Internet initiated by the terminal device at the visited location can be sent to the I-UPF via the access network device, and then forwarded to the ULCL UPF by the I-UPF; the ULCL UPF can determine that the request does not match the first diversion rule according to the first diversion rule, and then send the request to the main anchor point UPF; then, the main anchor point UPF can further send the request to the Internet. In the downlink direction, the response to the above request returned by the Internet to the terminal device can be first sent to the main anchor point UPF, sent by the main anchor point UPF to the ULCL UPF, and then forwarded by the ULCL UPF to the I-UPF, and finally returned to the terminal device via the access network device.

[0190] The following takes the inter-provincial roaming scenario as an example to describe in detail the service process related to the first embodiment of the present application. Figure 8a and Figure 8b As shown, the business process includes the following steps:

[0191] Step 801, the A-SMF and PSA UPF1 of the home location create a session, wherein PSA UPF1 refers to the primary anchor point UPF of the home location to which the UE is connected, and the PSA UPF1 may be a shared UPF of the non-edge area of ​​the home location selected according to the subscribed DNN of the UE.

[0192] Step 802: The UE accesses the Internet via PSA UPF1 in the non-edge area of ​​the home location. The request for accessing the Internet initiated by the UE in the non-edge area of ​​the home location is first sent to PSA UPF1 via RAN, and then forwarded to the Internet by PSA UPF1.

[0193] Step 803: The response returned by the Internet to the UE is first sent to PSA UPF1, and then forwarded by PSA UPF1 to the UE via RAN.

[0194] Step 804: The UE moves to an edge area of ​​the home location.

[0195] Step 805: After the UE moves to the edge area of ​​the home location, the PCF is triggered to send the user policy of the UE to the A-SMF. For example, the PCF may send the user policy to the A-SMF via a session management policy update request message.

[0196] Step 806: After receiving the user policy of the UE, the A-SMF replies to the PCF. For example, the A-SMF may reply to the A-SMF via a session management policy update response message.

[0197] Step 807: A-SMF selects ULCL UPF+PSA UPF2 based on the user policy and inserts the user session. PSAUPF2 refers to the auxiliary anchor point UPF to which the terminal device is connected. ULCL UPF and PSA UPF2 can be local UPFs in the edge area of ​​the home area selected according to the DNN, DNAI, or location (such as the tracking area code (TAC)) subscribed by the UE, and the two can be deployed in one.

[0198] Step 808: The A-SMF sends the diversion rule to the ULCL UPF. For example, the A-SMF may send the diversion rule to the ULCL UPF via a PDU session establishment request message.

[0199] Step 809: The ULCL UPF returns a response to the A-SMF. For example, the ULCL UPF may return a response to the A-SMF via a PDU session establishment response message.

[0200] Step 810: A-SMF refreshes the bearer rule of PSA UPF1, and refreshes the peer address of the N9 interface of PSA UPF1 (ie, the peer of the N9 interface) to ULCL UPF.

[0201] Step 811: PSA UPF1 returns a response to A-SMF.

[0202] Step 812: A-SMF refreshes the bearer rule of PSA UPF2, and refreshes the peer address of the N9 interface of PSA UPF2 (ie, the peer of the N9 interface) to ULCL UPF.

[0203] Step 813: PSA UPF2 returns a response to A-SMF.

[0204] Step 814: The A-SMF refreshes the bearer rules of the RAN, and refreshes the peer address of the N3 interface of the RAN (ie, the peer of the N3 interface) to the ULCL UPF.

[0205] Step 815: RAN sends a response to A-SMF.

[0206] For the above steps 810 to 815, reference may be made to the contents of 3GPP 23502 regarding adding a PDU session anchor point, a diversion point or a ULCL.

[0207] Step 816: After the A-SMF of the home location selects ULCL UPF+PSA UPF2 to insert the user session, the UE in the edge area of ​​the home location can access the local data network of the home location through ULCL UPF+PSA UPF2. The request for accessing the local data network of the home location initiated by the UE in the edge area of ​​the home location is first sent to the ULCL UPF via the RAN, and then forwarded by the ULCL UPF to the PSA UPF2, and then forwarded by the PSA UPF2 to the local data network of the home location.

[0208] Step 817: The response returned by the local data network of the home location is returned along the original path mentioned above.

[0209] Step 818: The UE in the edge area of ​​the home location can be forwarded to PSA UPF1 via the N9 interface of ULCL UPF to access the Internet. The request for accessing the Internet initiated by the UE in the edge area of ​​the home location is first sent to ULCL UPF via RAN, and then forwarded by ULCL UPF to PSA UPF1, and then forwarded by PSA UPF1 to the Internet.

[0210] Step 819: The response returned by the Internet is returned along the original path mentioned above.

[0211] Step 820: The UE moves out of the service area of ​​the A-SMF and arrives at the visited location.

[0212] In step 821, the AMF determines that the service area of ​​the A-SMF in the home location does not include the location of the UE, and therefore selects and inserts an I-SMF located in the visited location.

[0213] Step 822, AMF sends the address of A-SMF to I-SMF. For example, AMF can send the address of A-SMF to I-SMF via a PDU session context creation request message.

[0214] Step 823, the I-SMF returns a response to the AMF. For example, the I-SMF may return a response to the AMF via a PDU session context creation response message.

[0215] Step 824: The A-SMF determines, based on the UE user policy, that the service flow of the UE needs to return to the home location and needs to be diverted in the roaming scenario, i.e., determines that the N9 interface of the I-UPF in the visited location is connected to the ULCL UPF in the home location.

[0216] Optionally, the home SMF can identify that the user's service flow needs to return to the home location and be diverted in the roaming scenario by matching the specific policy and charging control rule (PCC) predefined rules issued by the PCF to the configuration on the SMF. The diversion rule can be determined based on the IP quintuple.

[0217] Step 825, the I-SMF requests the A-SMF to obtain the peer address of the N9 interface of the I-UPF. For example, the I-SMF may create a request message through a PDU session to request the peer address of the N9 interface of the I-UPF.

[0218] In step 826, the A-SMF may return the address of the ULCL UPF to the I-SMF. For example, the A-SMF may return the address of the ULCL UPF to the I-SMF via a PDU session creation response message.

[0219] Step 827: The I-SMF selects and inserts the I-UPF to create a packet forwarding control protocol (PFCP) session.

[0220] Step 828, the I-SMF returns the address of the I-UPF to the A-SMF.

[0221] Step 829, the I-SMF updates the bearer rules of the I-UPF, and refreshes the peer address of the N9 interface of the I-UPF to the address of the ULCLUPF.

[0222] Step 830: The I-UPF returns a response to the I-SMF.

[0223] Step 831, the I-SMF updates the bearer rules of the RAN and refreshes the peer address of the N3 interface of the RAN to the I-UPF.

[0224] Step 832: RAN returns a response to the I-SMF.

[0225] Step 833, A-SMF updates the bearer rule of ULCL UPF, and refreshes the peer address of the N9 interface of ULCL UPF to I-UPF. For this step, please refer to the content about changing the PDU session anchor point or ULCL in 3GPP 23502.

[0226] Step 834: The ULCL UPF returns a response to the A-SMF.

[0227] Step 835: The UE connects to the ULCL+PSA UPF2 of the home location through the N9 interface of the I-UPF in the visited location, and accesses the local data network of the home location.

[0228] Step 836: The response returned by the local data network of the home location is returned along the original path mentioned above.

[0229] Step 837: The UE connects to the ULCL UPF in the home location through the N9 interface of the I-UPF in the visited location, and then connects to the PSA UPF1 through the N9 interface of the ULCL UPF to access the Internet.

[0230] Step 838: The response returned by the Internet is returned along the original path mentioned above.

[0231] Business processes and scenarios for intra-provincial roaming Figure 8b The business process of the inter-provincial roaming scenario shown in is similar, the main difference is that only one SMF (i.e., A-SMF) is involved in the intra-provincial roaming scenario. Therefore, the SMF can have the functions of both the A-SMF at the home location and the I-SMF at the visited location in the business process of the inter-provincial roaming scenario. There is no need for AMF to insert the I-SMF at the visited location based on the user's contract and current location.

[0232] It can be seen that in the scheme of the above-mentioned embodiment 1, if the full service traffic of the terminal device needs to return to the home location and be diverted at the home location, then: the SMF at the home location can select and insert the ULCL UPF and the auxiliary anchor point UPF at the home location according to the DNN and location signed by the terminal device; the SMF at the visited location can select and insert the I-UPF at the visited location according to the DNN and location signed by the terminal device; and the present application supports setting the forwarding object of the N9 interface of the I-UPF to the ULCL UPF. In this way, the above scheme can enable users to use one DNN in a roaming scenario, so that all service traffic (including service flows for accessing the Internet) can be returned to the home location and diverted at the home location, thereby improving the security of the campus network and facilitating high-security enterprises to monitor user traffic. The above technical solution can meet the security requirements of the education network.

[0233] Embodiment 2

[0234] The existing 3GPP architecture cannot support the requirement that terminal devices use a DNN in roaming scenarios, and some traffic returns to the home location for unloading, while the rest of the traffic is unloaded in the visited location. To this end, this application proposes another network access method, which uses a customized ULCL UPF diversion rule to divert the data flow of the terminal device in the roaming scenario to the visited location, and the data flow of the local data network accessing the home location returns to the home location, and other data flows (such as data flows accessing the Internet) are directly unloaded in the visited location.

[0235] The second embodiment of the present application may have the following features: Fig. 9 and Fig.10For ease of understanding, the two possible roaming scenarios are referred to as intra-province roaming scenarios and inter-province roaming scenarios.

[0236] Fig. 9 Corresponding to the scenario where multiple UPFs are under the management scope of the same SMF (such as intra-provincial roaming scenario), the I-UPF in the visited location and the PSA UPF1 in the home location are both managed by the A-SMF, and the PSA UPF1 in the home location is the main anchor UPF of the terminal device. Figure 2 The scenarios shown are similar and will not be described in detail.

[0237] Fig.10 Corresponding to the scenario where multiple UPFs are not under the management scope of the same SMF (such as inter-provincial roaming scenario), the I-UPF and ULCL UPF of the visited location are both managed by the I-SMF of the visited location, while the PSA UPF1 of the home location is managed by the A-SMF of the home location. The PSA UPF1 of the home location is the main anchor UPF of the terminal device. This scenario is similar to Figure 3 The main difference in the scenario shown is that the ULCL UPF is located at the visit site.

[0238] Please refer to Fig.11 , is a flow chart of another network access method provided in Embodiment 2 of the present application, the method comprising:

[0239] Step 1101: When a terminal device moves to a visited location, the SMF of the visited location inserts the ULCL UPF of the visited location, and the ULCL UPF is used to divert the service flow of the terminal device.

[0240] In the embodiment of the present application, the ULCL UPF is used to divert the service flow of the terminal device to the primary anchor point UPF and the secondary anchor point UPF. The primary anchor point UPF is located in the home location, and the primary anchor point UPF can be used to send the service flow of the terminal device to the local data network of the home location. The secondary anchor point UPF is located in the visited location, and the secondary anchor point UPF can be used to send the service flow of the terminal device to the Internet.

[0241] In a possible implementation, when the terminal device moves from the home location to the visited location, the SMF at the visited location may insert the ULCL UPF and / or the auxiliary anchor point UPF at the visited location. For example, the SMF at the visited location may insert the above-mentioned ULCL UPF and / or the auxiliary anchor point UPF according to the DNN subscribed by the terminal device, or the SMF at the visited location may also insert the above-mentioned ULCL UPF and / or the auxiliary anchor point UPF according to the DNN and location subscribed by the terminal device, or the SMF at the visited location may also insert the above-mentioned ULCL UPF and / or the auxiliary anchor point UPF according to the DNN subscribed by the terminal device, the location or the data network access id (DNAI) and other information.

[0242] Step 1102: The SMF at the visited location sends a second diversion rule to the ULCL UPF, where the second diversion rule is used to indicate that the service flow matching the second diversion rule is sent to the primary anchor point UPF.

[0243] Correspondingly, the ULCL UPF receives the second traffic diversion rule from the SMF of the visited location.

[0244] Optionally, the second diversion rule is used to indicate that the service flow that does not match the second diversion rule is sent to the auxiliary anchor point UPF.

[0245] In an embodiment of the present application, the SMF at the visited location determines, based on the user policy of the terminal device, that the data flow of the terminal device in a roaming scenario needs to be diverted at the visited location, and the data flow accessing the local data network of the home location returns to the home location, and the data flow accessing the Internet is unloaded at the visited location, and then a second diversion rule is sent to the ULCL UPF.

[0246] For example, if the SMF of the visited location is the same as the SMF of the home location, then Fig. 9 The intra-provincial roaming scenario shown means that after the terminal device moves to the visited location, it is still within the service area of ​​the A-SMF in the home location. At this time, the SMF in the visited location and the SMF in the home location are both A-SMF. In this scenario, the A-SMF can determine, based on the user policy of the terminal device previously received from the PCF, that the service flow of the terminal device in the roaming scenario needs to be diverted at the visited location, and the data flow accessing the local data network of the home location must return to the home location, and the data flow accessing the Internet is unloaded at the visited location. Then, the A-SMF can insert the ULCL UPF and / or the auxiliary anchor point UPF of the visited location, and issue a second diversion rule to the ULCL UPF. Furthermore, the A-SMF can also update the bearer rules of the main anchor point UPF and the access network equipment of the visited location based on the address of the ULCL UPF.

[0247] In one possible implementation, Fig.12As shown, in step 1201, AMF can determine that the location of the terminal device is within the service area of ​​A-SMF. In step 1202, A-SMF can determine that the service flow of the terminal device in the roaming scenario needs to be diverted at the visited location based on the user policy of the terminal device previously received from PCF, and the service flow accessing the local data network of the home location returns to the home location, and the service flow accessing the Internet is unloaded at the visited location, or in other words, it is determined that the terminal device directly accesses the Internet by diverting at the visited location, and returns to the home location to access the local data network of the home location. In step 1203, A-SMF can select and insert the ULCL UPF and / or auxiliary anchor point UPF of the visited location based on the DNN, DNAI, or location information signed by the terminal device, and send the second diversion rule to the ULCL UPF in step 1204.

[0248] In step 1205, the A-SMF may send the address of the ULCL UPF to the primary anchor point UPF to update the bearer rule of the primary anchor point UPF, thereby establishing a tunnel between the primary anchor point UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the peer address of the downlink tunnel of the primary anchor point UPF, that is, to update the peer address of the downlink tunnel of the primary anchor point UPF to the address of the ULCL UPF, so that the primary anchor point UPF can send the downlink service flow of the terminal device to the ULCL UPF. For example, the A-SMF may send the tenth update request to the primary anchor point UPF, and the tenth update request is used to request to update the bearer rule of the primary anchor point UPF, and the tenth update request includes the address of the ULCL UPF. After receiving the tenth update request, the primary anchor point UPF may update the peer address of the downlink tunnel to the address of the ULCL UPF, and then send the tenth update response to the A-SMF.

[0249] In step 1206, the A-SMF may send the address of the ULCL UPF to the auxiliary anchor point UPF to set the bearer rule of the auxiliary anchor point UPF, so as to establish a tunnel between the auxiliary anchor point UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set the peer address of the downlink tunnel of the auxiliary anchor point UPF, that is, the peer address of the downlink tunnel of the auxiliary anchor point UPF is set to the address of the ULCL UPF, so that the auxiliary anchor point UPF can send the downlink service flow of the terminal device to the ULCL UPF. For example, the A-SMF may send the eleventh update request to the auxiliary anchor point UPF, and the eleventh update request is used to request the setting of the bearer rule of the auxiliary anchor point UPF, and the eleventh update request includes the address of the ULCL UPF. After receiving the eleventh update request, the auxiliary anchor point UPF may set the peer address of the downlink tunnel to the address of the ULCL UPF, and then send the eleventh update response to the A-SMF.

[0250] In step 1207, the A-SMF may send the address of the ULCL UPF to the access network device at the visited location to update the bearer rules of the access network device, thereby establishing a tunnel between the access network device and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the peer address of the uplink tunnel of the access network device, that is, to update the peer address of the uplink tunnel of the access network device to the address of the ULCL UPF, so that the access network device can send the uplink service flow of the terminal device to the ULCL UPF. For example, the A-SMF may send a twelfth update request to the access network device, and the twelfth update request is used to request to update the bearer rules of the access network device, and the twelfth update request includes the address of the ULCL UPF. After receiving the twelfth update request, the access network device may update the peer address of the uplink tunnel to the address of the ULCL UPF, and then send a twelfth update response to the A-SMF.

[0251] After that, under the diversion effect of ULCL UPF, the terminal device can access the local data network of the home location through the primary anchor point UPF, and access the Internet through the secondary anchor point UPF.

[0252] When the terminal device accesses the local data network of the home location, as shown in steps 1208 and 1209, in the uplink direction, the request for accessing the local data network of the home location initiated by the terminal device at the visited location may be sent to the ULCL UPF via the access network device; the ULCL UPF may determine, based on the second diversion rule, that the request matches the second diversion rule, and then send the request to the main anchor point UPF; then, the main anchor point UPF may further send the request to the local data network of the home location; in the downlink direction, the response to the above request returned by the local data network of the home location to the terminal device may first be sent to the main anchor point UPF, sent by the main anchor point UPF to the ULCL UPF, and then returned to the terminal device by the ULCL UPF via the access network device.

[0253] When the terminal device accesses the Internet, as shown in step 1210 and step 1211, in the uplink direction, the request for accessing the Internet initiated by the terminal device at the visited location may be sent to the ULCL UPF via the access network device; the ULCL UPF may determine that the request does not match the second diversion rule according to the second diversion rule, and then send the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF may further send the request to the Internet. In the downlink direction, the response to the above request returned by the Internet to the terminal device may be first sent to the auxiliary anchor point UPF, sent by the auxiliary anchor point UPF to the ULCL UPF, and then returned to the terminal device by the ULCL UPF via the access network device.

[0254] If the SMF of the visited location is different from the SMF of the home location, then Fig.10The inter-provincial roaming scenario shown indicates that after the terminal device moves to the visited location, it leaves the service area of ​​the A-SMF in the home location. At this time, the SMF in the visited location is the I-SMF in the visited location, and the SMF in the home location is the A-SMF in the home location. In this scenario, the A-SMF can send the user policy of the terminal device to the I-SMF, and determine according to the user policy that the data flow of the terminal device in the roaming scenario needs to be diverted in the visited location, and the data flow accessing the local data network of the home location must return to the home location, and the data flow accessing the Internet is unloaded in the visited location. Optionally, the user policy can specifically refer to the insertion policy of the ULCL UPF and / or the auxiliary anchor point UPF. Then, the I-SMF can select and insert the ULCL UPF and / or the auxiliary anchor point UPF of the visited location, and send the second diversion rule to the ULCL UPF, and send the address of the ULCL UPF to the A-SMF to update the bearer rule of the main anchor point UPF in the home location. Furthermore, the I-SMF can also update the bearer of the access network device in the visited location according to the address of the ULCL UPF.

[0255] In one possible implementation, Fig.13As shown, in step 1301, AMF can determine that the location of the terminal device leaves the service area of ​​A-SMF. In step 1302, AMF can select and insert the I-SMF of the visited location based on the DNN, DNAI, or location information signed by the terminal device, and the I-SMF forwards the user plane data between the visited location and the home location. Further, AMF can also send the address of A-SMF to I-SMF and receive a response from I-SMF so that I-SMF and A-SMF can exchange information. In step 1303, A-SMF can determine that the data flow of the terminal device in the roaming scenario needs to be diverted at the visited location based on the user policy of the terminal device previously received from PCF, and the data flow accessing the local data network of the home location returns to the home location, and the data flow accessing the Internet is unloaded at the visited location, or in other words, it is determined that the terminal device directly accesses the Internet by diverting at the visited location and returns to the home location to access the local data network of the home location. In step 1304, the I-SMF may send a request to the A-SMF for obtaining the user policy of the terminal device, which request may also be understood as an insertion strategy for obtaining the ULCL UPF and / or the secondary anchor point UPF. In step 1305, in response to the request of the I-SMF, the I-SMF may send the user policy of the terminal device to the A-SMF. In step 1306, the I-SMF may insert the ULCL UPF and / or the secondary anchor point UPF of the visited location according to the DNN, DNAI, or location information signed by the terminal device. In step 1307, the I-SMF may also send the address of the ULCL UPF to the A-SMF to update the bearer rules of the primary anchor point UPF. In step 1308, the I-SMF may send a second diversion rule to the ULCL UPF to establish a tunnel between the ULCL UPF and the primary anchor point UPF and the secondary anchor point UPF.

[0256] In step 1309, the I-SMF may send the address of the ULCL UPF to the secondary anchor point UPF to set the bearer rule of the secondary anchor point UPF, thereby establishing a tunnel between the secondary anchor point UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set the peer address of the downlink tunnel of the secondary anchor point UPF, that is, the peer address of the downlink tunnel of the secondary anchor point UPF is set to the address of the ULCL UPF, so that the secondary anchor point UPF can send the downlink service flow of the terminal device to the ULCL UPF. For example, the I-SMF may send the thirteenth update request to the secondary anchor point UPF, and the thirteenth update request is used to set the bearer rule of the secondary anchor point UPF, and the thirteenth update request includes the address of the ULCL UPF. After receiving the thirteenth update request, the secondary anchor point UPF may set the peer address of the downlink tunnel to the address of the ULCL UPF, and then send the thirteenth update response to the I-SMF.

[0257] In step 1310, the I-SMF may send the address of the ULCL UPF to the access network device at the visited location to update the bearer rules of the access network device, thereby establishing a tunnel between the access network device and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the peer address of the uplink tunnel of the access network device, that is, to update the peer address of the uplink tunnel of the access network device to the address of the ULCL UPF, so that the access network device can send the uplink service flow of the terminal device to the ULCL UPF. For example, the I-SMF may send the fourteenth update request to the access network device, and the fourteenth update request is used to update the bearer rules of the access network device, and the fourteenth update request includes the address of the ULCL UPF. After receiving the fourteenth update request, the access network device may update the peer address of the uplink tunnel to the address of the ULCL UPF, and then send the fourteenth update response to the I-SMF.

[0258] In step 1311, the A-SMF may send the address of the ULCL UPF to the primary anchor point UPF to update the bearer rule of the primary anchor point UPF, thereby establishing a tunnel between the primary anchor point UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the peer address of the downlink tunnel of the primary anchor point UPF, that is, to update the peer address of the downlink tunnel of the primary anchor point UPF to the address of the ULCL UPF, so that the primary anchor point UPF can send the downlink service flow of the terminal device to the ULCL UPF. For example, the A-SMF may send the fifteenth update request to the primary anchor point UPF, and the thirteenth update request is used to update the bearer rule of the primary anchor point UPF, and the fifteenth update request includes the address of the ULCL UPF. After receiving the fifteenth update request, the primary anchor point UPF may update the peer address of the downlink tunnel to the address of the ULCL UPF, and then send the fifteenth update response to the A-SMF.

[0259] After that, under the diversion effect of ULCL UPF, the terminal device can access the local data network of the home location through the primary anchor point UPF, and access the Internet through the secondary anchor point UPF.

[0260] When the terminal device accesses the local data network of the home location, as shown in steps 1312 and 1313, in the uplink direction, the request for accessing the local data network of the home location initiated by the terminal device at the visited location may be sent to the ULCL UPF via the access network device; the ULCL UPF may determine, based on the second diversion rule, that the request matches the second diversion rule, and then send the request to the main anchor point UPF; then, the main anchor point UPF may further send the request to the local data network of the home location; in the downlink direction, the response to the above request returned by the local data network of the home location to the terminal device may first be sent to the main anchor point UPF, sent by the main anchor point UPF to the ULCL UPF, and then returned to the terminal device by the ULCL UPF via the access network device.

[0261] When the terminal device accesses the Internet, as shown in step 1314 and step 1315, in the uplink direction, the request for accessing the Internet initiated by the terminal device at the visited location can be sent to the ULCL UPF via the access network device; the ULCL UPF can determine that the request does not match the second diversion rule according to the second diversion rule, and then send the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF can further send the request to the Internet. In the downlink direction, the response to the above request returned by the Internet to the terminal device can be first sent to the auxiliary anchor point UPF, sent by the auxiliary anchor point UPF to the ULCL UPF, and then returned to the terminal device by the ULCL UPF via the access network device.

[0262] It can be seen that in the above scheme, after inserting ULCL UPF in the visited location and configuring the corresponding second diversion rule for ULCL UPF, under the diversion effect of ULCL UPF, the terminal device can access the Internet through the auxiliary anchor point UPF of the visited location and access the local data network of the home location through the main anchor point UPF of the home location, so as to achieve the effect that the terminal device roams in the visited location, the service flow of the terminal device can be diverted in the visited location, the service flow of the local data network of the home location is connected to the main anchor point UPF of the home location through ULCL UPF and returns to the home location, and other service flows are directly unloaded in the visited location. In this way, network resources can be fully utilized, the security of the local data network of the home location can be improved, and the delay of users accessing the Internet can be reduced.

[0263] The following takes the inter-provincial roaming scenario as an example to describe in detail the service process related to the second embodiment of the present application. Fig.14 As shown, the business process includes the following steps:

[0264] Step 1401, the UE subscribes to a special DN, and the A-SMF and PSA UPF1 of the home location create a user session, where PSAUPF1 refers to the main anchor point UPF of the home location to which the UE is connected, and the PSA UPF1 can be a shared UPF in the non-edge area of ​​the home location selected according to the UE's subscribed DNN.

[0265] Step 1402, the UE accesses the local data network at the home location through PSA UPF1. The request for accessing the local data network at the home location initiated by the UE at the home location is first sent to PSA UPF1 via RAN, and then forwarded to the local data network at the home location by PSA UPF1.

[0266] Step 1403: The response returned by the local data network of the home location to the UE is first sent to PSA UPF1, and then forwarded by PSAUPF1 to the UE via RAN.

[0267] Step 1404: The UE moves out of the service area of ​​the SMF and arrives at the visited location.

[0268] Step 1405, the AMF determines that the service area of ​​the A-SMF in the home location does not include the location of the UE, and therefore selects and inserts an I-SMF that is located in the visited location.

[0269] Step 1406, AMF sends the A-SMF address to I-SMF. For example, AMF can send the A-SMF address to I-SMF via a PDU session context creation request message.

[0270] Step 1407, the I-SMF replies a response to the AMF. For example, the I-SMF may return a response to the AMF via a PDU session context creation response message.

[0271] Step 1408, the A-SMF determines, based on the user policy of the UE obtained from the PCF, that the UE, in a roaming scenario, accesses the Internet through the visited location and returns to the home location to access the local data network of the home location.

[0272] Step 1409, the I-SMF requests the A-SMF to obtain the user policy of the UE, and the user policy may specifically refer to the insertion policy of the ULCLUPF and / or PSA UPF2. For example, the I-SMF may request to obtain the user policy of the UE through a PDU session creation request message.

[0273] Step 1410: A-SMF returns the user policy of the UE to I-SMF. The user policy may include the shunt rule of ULCL UPF and the indication information for indicating that the service flow matching the shunt rule returns to PSA UPF1 of the home location and the remaining services are unloaded at the visited location through PSAUPF2.

[0274] Step 1411: The I-SMF selects and inserts the ULCL UPF and / or PSA UPF2 of the visited site.

[0275] Step 1412: The I-SMF sends the address of the ULCL UPF to the A-SMF.

[0276] Step 1413, the I-SMF sends a diversion rule to the ULCL UPF, which indicates that the peer end of the next hop N9 interface of the service flow matching the diversion rule is PSA UPF1, and the peer end of the next hop N9 interface of the remaining service flows is PSA UPF2.

[0277] Step 1414: The ULCL UPF returns a response to the I-SMF.

[0278] Step 1415: The I-SMF refreshes the bearer rule of PSA UPF2, and refreshes the peer address of the N9 interface of PSA UPF-2 to the address of ULCL UPF.

[0279] Step 1416: PSA UPF2 returns a response to the I-SMF.

[0280] Step 1417, the I-SMF refreshes the bearer rules of the RAN, and refreshes the peer address of the N3 interface of the RAN to the ULCLUPF.

[0281] Step 1418: RAN returns a response to the I-SMF.

[0282] Step 1419: A-SMF refreshes the bearer rule of PSA UPF1, and refreshes the peer address of the N9 interface of PSA UPF1 to ULCL UPF.

[0283] Step 1420: PSA UPF1 returns a response to A-SMF.

[0284] Step 1421, the UE connects to the home location PSA UPF1 through the N9 interface of the ULCL UPF in the visited location to access the local data network of the home location.

[0285] Step 1422: The response returned by the local data network of the home location is returned along the original path mentioned above.

[0286] Step 1423: The UE connects to the PSA UPF2 of the visited location through the ULCL UPF in the visited location to access the Internet.

[0287] Step 1424, the response returned by the Internet is returned along the original path mentioned above.

[0288] Business processes and scenarios for intra-provincial roaming Fig.14The business process of the inter-provincial roaming scenario shown in is similar, the main difference is that only one SMF (i.e., A-SMF) is involved in the intra-provincial roaming scenario. Therefore, the SMF can be used to implement the functions of both the A-SMF at the home location and the I-SMF at the visited location in the business process of the inter-provincial roaming scenario. There is no need for AMF to insert the I-SMF at the visited location based on the user's contract and current location.

[0289] It can be seen that in the technical solution of the above-mentioned embodiment 2, if part of the service traffic of the terminal device that can be defined by rules needs to return to the home location, and the rest of the services can be unloaded at the visited location, then: the SMF at the visited location can select and insert the ULCL UPF and the auxiliary anchor point UPF of the home location according to the DNN, DNAI, location and other information signed by the terminal device; the SMF at the home location can issue diversion rules to the ULCL UPF, instructing the ULCL UPF to send the service flow that matches the diversion rule to the main anchor point UPF of the home location, and send the service flow that does not match the diversion rule to the auxiliary anchor point UPF of the visited location. In this way, the service flow of the terminal device accessing the local data network of the home location in the roaming scenario can reach the local data network of the home location through the main anchor point UPF of the home location, and other service flows can be unloaded at the visited location through the auxiliary anchor point UPF of the visited location. The above-mentioned technical solution can meet the security requirements of the government network.

[0290] The above technical solution does not require the UPF of the visited location to send all the data streams of the terminal device back to the home location, but only sends the data streams accessing the local data network of the visited location back to the home location. Therefore, it can make full use of network resources, while ensuring the security of the local data network of the home location, reducing the delay of the terminal device in accessing the Internet.

[0291] It should be noted that if some services are unloaded at the visited location and some services are returned to the home location, and the UPF at the visited location supports the I-UPF / ULCL / auxiliary anchor point integrated function, then: the unified UPF can decide whether to divert traffic at the local N6 interface or through the N9 interface based on the destination address of the user's service access, and the diversion strategy is implemented by the SMF and UPF.

[0292] In the technical solution using unified UPF, the UPF of the visited location supports the unified deployment of I-UPF, ULCL and auxiliary anchor point UPF. This technical solution can also have two possible roaming scenarios, namely: Fig.15 and Fig.16 As shown, Fig.15 Corresponding to the scenario where multiple UPFs are within the management scope of the same SMF (such as intra-provincial roaming scenario), Fig.16 This corresponds to the scenario where multiple UPFs are not under the management scope of the same SMF (such as inter-provincial roaming scenario). For details, please refer to the relevant description above and will not be repeated here.

[0293] The visited location can determine the diversion strategy based on the services accessed by the user. Some services are unloaded through the local N6 interface, and some services are forwarded to the UPF of the home location through the N9 interface. In this way, the user can access both the local data network of the home location and the Internet using a specific DNN. Furthermore, the home location can define the diversion rules for the service data to return to the home location, and the remaining traffic is routed out of the Internet through the N6 interface of the visited location.

[0294] The present application also provides a communication device, please refer to Fig.17 , is a schematic diagram of the structure of a communication device provided in an embodiment of the present application, the communication device 1700 includes: a transceiver module 1710 and a processing module 1720. The communication device can be used to implement the functions of the session management function network element of the home location or the intermediate session management function network element of the visited location or the session management function network element of the visited location in any of the above method embodiments. The communication device can be a network device, or a device that can support the network device to implement the corresponding functions in the above method embodiments (such as a chip included in the network device), etc.

[0295] Exemplarily, when the communication device executes Figure 4 In the method embodiment shown in , when the operation or step corresponds to the session management function network element of the home location, the processing module 1720 is used to insert the uplink classifier user plane function network element of the home location, and the uplink classifier user plane function network element is used to divert the service flow of the terminal device; when the terminal device moves to the visited location, the transceiver module 1710 is used to send the address of the uplink classifier user plane function network element to the intermediate user plane function network element of the visited location to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

[0296] In one possible design, the processing module 1720 is specifically used to insert an uplink classifier user plane functional network element according to the data network name DNN signed by the terminal device.

[0297] In one possible design, the transceiver module 1710 is also used to receive a user policy of a terminal device from a policy control functional network element, where the user policy is used to indicate that the service flow of the terminal device in a roaming scenario needs to return to a home location and be diverted; the processing module 1720 is specifically used to insert an uplink classifier user plane functional network element according to the user policy.

[0298] In one possible design, the transceiver module 1710 is also used to send a first diversion rule to the uplink classifier user plane functional network element, and the first diversion rule is used to indicate that the service flow matching the first diversion rule is sent to the auxiliary anchor user plane functional network element of the home location, and the auxiliary anchor user plane functional network element is connected to the local data network of the home location.

[0299] In one possible design, the transceiver module 1710 is also used to send the address of the uplink classifier user plane function network element to the auxiliary anchor user plane function network element to establish the opposite end address of the downlink tunnel between the auxiliary anchor user plane function network element and the uplink classifier user plane function network element.

[0300] In a possible design, the first diversion rule is also used to instruct that the service flow that does not match the first diversion rule be sent to the primary anchor user plane function network element of the home location, and the primary anchor user plane function network element is connected to the Internet.

[0301] In one possible design, the transceiver module 1710 is further used to send the address of the uplink classifier user plane function network element to the primary anchor user plane function network element to establish a tunnel between the primary anchor user plane function network element and the uplink classifier user plane function network element.

[0302] In one possible design, the transceiver module 1710 is also used to send the address of the uplink classifier user plane functional network element to the access network device at the home location to establish a tunnel between the access network device and the uplink classifier user plane functional network element.

[0303] In one possible design, if the terminal equipment is still in the service area of ​​the communication device after moving to the visited site, the processing module 1720 is also used to insert the intermediate user plane functional network element of the visited site; the transceiver module 1710 is also used to send the address of the intermediate user plane functional network element to the uplink classifier user plane functional network element to establish a tunnel between the uplink classifier user plane functional network element and the intermediate user plane functional network element.

[0304] In one possible design, the transceiver module 1710 is also used to send the address of the intermediate user plane functional network element to the access network device at the visited location to establish a tunnel between the access network device and the intermediate user plane functional network element.

[0305] In one possible design, if the terminal device moves to a visited location and leaves the service area of ​​the communication device, the transceiver module 1710 is specifically used to send the address of the uplink classifier user plane function network element to the intermediate user plane function network element through the intermediate session management function network element of the visited location.

[0306] In one possible design, the transceiver module 1710 is also used to: receive the address of the intermediate user plane function network element from the intermediate user plane function network element through the intermediate session management function network element; and send the address of the intermediate user plane function network element to the uplink classifier user plane function network element to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

[0307] When the communication device executes Figure 4In the method embodiment shown in , when the operation or step of the intermediate session management function network element of the visited location corresponds to the operation or step of the intermediate session management function network element of the visited location, the processing module 1720 is used to insert the intermediate user plane function network element of the visited location when the terminal device moves to the visited location; the transceiver module 1710 is used to receive the address of the uplink classifier user plane function network element from the session management function network element of the home location, the uplink classifier user plane function network element is used to divert the service flow of the terminal device, and the address of the uplink classifier user plane function network element is used to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

[0308] In one possible design, the transceiver module 1710 is also used to send the address of the uplink classifier user plane functional network element to the intermediate user plane functional network element to establish a tunnel between the intermediate user plane functional network element and the uplink classifier user plane functional network element.

[0309] In one possible design, the transceiver module 1710 is also used to send the address of the intermediate user plane function network element to the session management function network element to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

[0310] In one possible design, the transceiver module 1710 is also used to send the address of the intermediate user plane functional network element to the access network device at the visited location to establish a tunnel between the access network device and the intermediate user plane functional network element.

[0311] When the communication device executes Fig.11 In the method embodiment shown in , when the operation or step of the session management function network element of the visited location corresponds, the processing module 1720 is used to, when the terminal device moves to the visited location, insert the uplink classifier user plane function network element of the visited location, and the uplink classifier user plane function network element is used to divert the service flow of the terminal device; the transceiver module 1710 is used to send a second diversion rule to the uplink classifier user plane function network element, and the second diversion rule is used to indicate that the service flow matching the second diversion rule is sent to the main anchor user plane function network element of the home location, and the main anchor user plane function network element is connected to the local data network of the home location.

[0312] In one possible design, the processing module 1720 is specifically used to insert an uplink classifier user plane functional network element according to the data network name DNN signed by the terminal device.

[0313] In one possible design, the processing module 1720 is specifically used to insert an uplink classifier user plane functional network element according to a user policy of the terminal device, and the user policy is used to indicate that the service flow of the terminal device in a roaming scenario needs to be diverted at the visited location, and the service flow accessing the local data network of the home location needs to be returned to the home location.

[0314] In one possible design, if the session management function network element of the visited location is the same as the session management function network element of the home location, the transceiver module 1710 is used to send the address of the uplink classifier user plane function network element to the main anchor user plane function network element to establish a tunnel between the main anchor user plane function network element and the uplink classifier user plane function network element.

[0315] In one possible design, if the session management function network element of the visited location is different from the session management function network element of the home location, the transceiver module 1710 is used to send the address of the uplink classifier user plane function network element to the main anchor user plane function network element through the session management function network element of the home location, so as to establish a tunnel between the main anchor user plane function network element and the uplink classifier user plane function network element.

[0316] In one possible design, the second diversion rule is used to instruct the service flow that does not match the second diversion rule to be sent to the auxiliary anchor user plane function network element of the visited location, and the auxiliary anchor user plane function network element is connected to the Internet.

[0317] In one possible design, the transceiver module 1710 is further used to send the address of the uplink classifier user plane functional network element to the auxiliary anchor user plane functional network element to establish a tunnel between the auxiliary anchor user plane functional network element and the uplink classifier user plane functional network element.

[0318] In one possible design, the transceiver module 1710 is used to send the address of the uplink classifier user plane functional network element to the access network device of the visited location to establish a tunnel between the access network device and the uplink classifier user plane functional network element.

[0319] The processing module 1720 involved in the communication device can be implemented by at least one processor or processor-related circuit components, and the transceiver module 1710 can be implemented by at least one transceiver or transceiver-related circuit components or communication interfaces. The operations and / or functions of each module in the communication device are respectively to implement Figures 4 to 16 For the sake of brevity, the corresponding process of the method shown in is not repeated here. Optionally, the communication device may also include a storage module, which may be used to store data and / or instructions, and the transceiver module 1710 and / or the processing module 1720 may read the data and / or instructions in the access module, so that the communication device implements the corresponding method. The storage module may be implemented, for example, by at least one memory.

[0320] The above-mentioned storage module, processing module and transceiver module may exist separately, or all or part of the modules may be integrated, for example, the storage module and the processing module may be integrated, or the processing module and the transceiver module may be integrated.

[0321] Please refer to Fig.18, is another structural diagram of a communication device provided in an embodiment of the present application. The communication device can be used to implement the functions corresponding to the session management function network element of the home location or the intermediate session management function network element of the visited location or the session management function network element of the visited location in the above method embodiment. The communication device can be a network device or a device that can support the network device to implement the corresponding functions in the above method embodiment (for example, a chip included in the network device), etc.

[0322] The communication device 1800 may include a processor 1801, a communication interface 1802 and a memory 1803. The communication interface 1802 is used to communicate with other devices through a transmission medium. The communication interface 1802 may be a transceiver or an interface circuit such as a transceiver circuit, a transceiver chip, etc. The memory 1803 is used to store program instructions and / or data, and the processor 1801 is used to execute the program instructions stored in the memory 1803, thereby implementing the method in the above method embodiment. Optionally, the memory 1803 and the processor 1801 are coupled, and the coupling is an indirect coupling or communication connection between devices, units or modules, which may be electrical, mechanical or other forms, and is used for information interaction between devices, units or modules.

[0323] In one embodiment, the communication interface 1802 may be specifically used to execute the actions of the above-mentioned transceiver module 1710, and the processor 1801 may be specifically used to execute the actions of the above-mentioned processing module 1720, which will not be described in detail in this application.

[0324] The specific connection medium between the communication interface 1802, the processor 1801 and the memory 1803 is not limited in the embodiment of the present application. Fig.18 In the embodiment, the memory 1803, the processor 1801 and the communication interface 1802 are connected via a bus 1804. Fig.18 The connections between the other components are shown in bold lines, which are only for illustration and are not intended to be limiting. The bus can be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Fig.18 Only one thick line is used in the diagram, but this does not mean that there is only one bus or only one type of bus.

[0325] An embodiment of the present application also provides a chip system, including: a processor, the processor is coupled to a memory, the memory is used to store programs or instructions, when the program or instructions are executed by the processor, the chip system implements the method corresponding to the session management function network element of the home location or the intermediate session management function network element of the visited location or the session management function network element of the visited location in any of the above method embodiments.

[0326] Optionally, the processor in the chip system may be one or more. The processor may be implemented by hardware or by software. When implemented by hardware, the processor may be a logic circuit, an integrated circuit, etc. When implemented by software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

[0327] Optionally, the memory in the chip system may be one or more. The memory may be integrated with the processor or may be separately provided with the processor, which is not limited in the present application. Exemplarily, the memory may be a non-transient processor, such as a read-only memory (ROM), which may be integrated with the processor on the same chip or may be provided on different chips. The present application does not specifically limit the type of memory and the arrangement of the memory and the processor.

[0328] Exemplarily, the chip system can be a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), a system on chip (SoC), a central processor unit (CPU), a network processor (NP), a digital signal processor (DSP), a microcontroller unit (MCU), a programmable logic device (PLD) or other integrated chips.

[0329] It should be understood that each step in the above method embodiment can be completed by an integrated logic circuit of hardware in a processor or by instructions in the form of software. The method steps disclosed in the embodiments of the present application can be directly embodied as being executed by a hardware processor, or by a combination of hardware and software modules in a processor.

[0330] An embodiment of the present application also provides a communication system, which includes a session management function network element at a home location and / or an intermediate session management function network element at a visited location; wherein the session management function network element at the home location and the intermediate session management function network element at the visited location cooperate with each other and are jointly used to implement the method in embodiment 1 of the present application.

[0331] Optionally, the communication system further includes an uplink classifier user plane function network element at the home location, a primary anchor user plane function network element and a secondary anchor user plane function network element, and an intermediate user plane function network element at the visited location.

[0332] An embodiment of the present application also provides another communication system, which includes a session management function network element of a visited location; wherein the session management function network element of the visited location is used to implement the method in embodiment 2 of the present application.

[0333] Optionally, the communication system further includes an uplink classifier user plane function network element and a secondary anchor user plane function network element at the visited location, and a primary anchor user plane function network element at the home location.

[0334] An embodiment of the present application further provides a computer-readable storage medium, in which computer-readable instructions are stored. When a computer reads and executes the computer-readable instructions, the computer executes a method in any of the above method embodiments.

[0335] The embodiment of the present application also provides a computer program product. When a computer reads and executes the computer program product, the computer executes the method in any of the above method embodiments.

[0336] It should be understood that the processor mentioned in the embodiments of the present application may be a CPU, or other general-purpose processors, DSPs, ASICs, FPGAs or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or the processor may be any conventional processor, etc.

[0337] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a ROM, a programmable read-only memory (programmable ROM, PROM), an erasable programmable read-only memory (erasable PROM, EPROM), an electrically erasable programmable read-only memory (electrically EPROM, EEPROM) or a flash memory. The volatile memory may be a random access memory (random access memory, RAM), which is used as an external cache. By way of example and not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct rambus RAM (DRRAM).

[0338] It should be noted that when the processor is a general-purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component, the memory (storage module) is integrated in the processor.

[0339] It should be noted that the memory described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0340] It should be understood that the various digital numbers involved in the various embodiments of the present application are only distinguished for the convenience of description, and the size of the serial numbers of the above-mentioned processes or steps does not mean the order of execution. The execution order of each process or step should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

[0341] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0342] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments and will not be repeated here.

[0343] In the several embodiments provided in the present application, it should be understood that the disclosed systems, devices and methods can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0344] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0345] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0346] If the functions are implemented in the form of software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, which is stored in a storage medium and includes several instructions for a computer device (which can be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as USB flash drives, mobile hard drives, ROM, RAM, magnetic disks, or optical disks.

[0347] In the various embodiments of the present application, unless otherwise specified or provided for in any logical conflict, the terms and / or descriptions between the different embodiments are consistent and may be referenced to each other, and the technical features in the different embodiments may be combined to form new embodiments according to their inherent logical relationships.

[0348] The current 3GPP standard defines the network architecture of 5G networks suitable for roaming scenarios, such as Fig.19 shown.

[0349] The main functions of each network element / functional entity are:

[0350] User plane function (UPF): As the interface with the data network, UPF performs functions such as user plane data forwarding, session / flow-level billing statistics, and bandwidth limitation.

[0351] Uplink Classifier (ULCL): also known as Uplink Classifier, it is a working form of UPF. It is used for business diversion and determines the direction of data flow according to the different destination addresses accessed by users.

[0352] Session management function (SMF): mainly performs session management, execution of control policies issued by policy control function (PCF), selection of UPF, allocation of Internet protocol (IP) addresses for terminal equipment (UE), etc.

[0353] Access and mobility management function (AMF): mainly performs mobility management, access authentication / authorization, etc. In addition, it is also responsible for transmitting user policies between UE and PCF.

[0354] Intermediate SMF (I-SMF) is used to forward control plane messages between the visited location and the home location.

[0355] (Radio) access network (R)AN): corresponds to different access networks in 5G, such as wired access, wireless base station access, and other methods.

[0356] Protocol data unit (PDU) session: A session service that implements PDU connectivity between the UE and the data network, identified by a PDU Session ID (identifier).

[0357] PDU session anchor (PSA): Figure 1 The UPF PDU Session Anchor in it can be referred to as anchor point UPF for short.

[0358] The architecture may also include:

[0359] Intermediate UPF (I-UPF): used to forward data plane messages between the visited location and the home location.

[0360] Application function (AF): mainly transmits the requirements of the application side to the network side, such as QoS (quality of service) requirements or user status event subscription, etc. AF can be a third-party functional entity or an application service deployed by an operator, such as IMS (IP multimedia subsystem) voice call service.

[0361] Unified data management (UDM): Mainly responsible for managing contract data, user access authorization and other functions.

[0362] Unified data repository (UDR): Mainly responsible for the storage and access functions of contract data, policy data, application data and other types of data.

[0363] Policy Control Function PCF: Mainly responsible for policy control functions such as billing, QoS bandwidth guarantee and mobility management, and UE policy decision-making for sessions and service flows. In this architecture, the PCFs connected to AMF and SMF correspond to AM PCF+UEPCF (PCF for Access and Mobility Control / PCF for UE Policy Control) and SM PCF (PCF for Session Management), respectively. In actual deployment scenarios, the functions of AM PCF and UE PCF are usually provided by the same PCF, but this PCF and SM PCF may not be the same PCF entity. For ease of description, AMPCF may be simply used to refer to this PCF instance that provides both UE Policy and AM Policy.

[0364] Fig.19 The functions of the interfaces between the network elements are as follows:

[0365] The N1 interface refers to the interface between the AMF and the UE. It is access-independent and is used to transmit QoS control rules to the UE.

[0366] The N2 interface refers to the interface between the AMF and the RAN, and is used to transmit radio bearer control information from the core network side to the RAN.

[0367] The N3 interface refers to the interface between the (R)AN and the UPF, and is used to transmit user plane data between the (R)AN and the UPF.

[0368] The N4 interface refers to the interface between SMF and UPF, which is used to transmit information between the control plane and the user plane, including the control of the forwarding rules, QoS control rules, traffic statistics rules, etc. for the user plane and the reporting of information on the user plane.

[0369] The N6 interface refers to the interface between the UPF and DN connection, which is used to transmit user plane data between the UPF and DN.

[0370] The N9 interface refers to the interface between UPFs, such as the interface between the UPF connected to the DN and the UPF connected to the (R)AN, and is used to transmit user plane data between UPFs.

[0371] The N11 interface refers to the interface between SMF and AMF, which is used to transmit PDU session tunnel information between RAN and UPF, transmit control messages sent to UE, transmit radio resource control information sent to RAN, etc.

[0372] The N16a interface refers to the interface between SMF and I-SMF, which is used by the visited I-SMF to obtain the home UPF information from the home SMF.

[0373] The architecture may also include:

[0374] The N5 interface refers to the interface between AF and PCF, which is used to issue application service requests and report network events.

[0375] The N7 interface refers to the interface between PCF and SMF, which is used to send PDU session granularity and service data flow granularity control strategy.

[0376] The N8 interface refers to the interface between AMF and UDM, which is used by AMF to obtain access and mobility management-related subscription data and authentication data from UDM, and AMF to register UE's current mobility management-related information with UDM.

[0377] The N10 interface refers to the interface between SMF and UDM, which is used by SMF to obtain session management-related contract data from UDM, and SMF to register UE current session-related information with UDM.

[0378] The N15 interface refers to the interface between PCF and AMF, which is used to issue UE policies and access control related policies.

[0379] N22 interface refers to the interface between AMF and network slice selection function (NSSF), which is used by AMF to query NSSF for information such as Allowed NSSAI (network slice selection assistance information) allowed to be used and Configured NSSAI configured on the UE by the home network;

[0380] The N35 interface refers to the interface between UDM and UDR, which is used by UDM to obtain user contract data information from UDR.

[0381] The N36 interface refers to the interface between PCF and UDR, which is used by PCF to obtain policy-related contract data and application data-related information from UDR.

[0382] The general user registration process can be simply described as follows: UE sends a registration request to AMF through RAN, AMF obtains the contract data from the specific UDM based on the user identity, and UDM obtains the actual contract data from UDR after receiving the request. In addition, AMF can also initiate a user policy control establishment request (UEPolicyControl_Create) and an access management policy control establishment request (AMPolicyControl_Create) to PCF, which are used to obtain UE policy and access control policy respectively. PCF returns the access control policy to AMF in this process, and provides UE policy to UE via AMF.

[0383] The general session establishment process can be simply described as follows: UE sends a session establishment request to AMF through RAN, AMF selects SMF to provide services for the session, saves the correspondence between SMF and PDU session, and sends the session establishment request to SMF, SMF selects the corresponding UPF for UE and establishes the user plane transmission path, and allocates an IP address for it. During this process, SMF will also initiate a policy control session establishment request to PCF to establish a policy control session between SMF and PCF. During the policy control session establishment process, SMF will save the correspondence between the policy control session and the PDU session. For roaming users, in roaming scenarios, control signaling needs to be forwarded by I-SMF and SMF, and media data needs to be forwarded by I-UPF.

[0384] The primary anchor point UPF mentioned in the embodiment of the present application refers to the UPF connected when the UE initially activates and creates a session, which is used to allocate an IP address to the UE.

[0385] The auxiliary anchor point UPF refers to the UPR inserted after the UE session is created. It is not used to create a session or allocate an IP address.

[0386] In the existing 3GPP architecture, the ULCL UPF selection in the roaming scenario is implemented by I-SMF, and it does not support the selection of the ULCL UPF of the home location through the SMF of the home location. This cannot meet the needs of the campus users to return their service flows to the home location when roaming, which poses a security risk to the campus network. In addition, after the service flows of the campus users return to the home location, since the home location UPF is a main anchor point UPF and has no Internet exit (because the shared UPF of the city has an Internet exit, and the city where the home location UPF is located has no Internet exit), it cannot meet the needs of the campus users to further divert their service flows based on the ULCL UPF after they return to the home location.

[0387] To solve the above problems, the present application provides a campus network access method, which allows users to access the campus network in roaming scenarios, such as when users leave the campus or roam between provinces or within a province, and they do not need the campus network to access the Internet.

[0388] It should be understood that in the roaming scenarios involved in this application, there is a distinction between a home location and a visited location. A home location may be deployed with a campus network, which may also be referred to as an enterprise network or an enterprise private network or a local network or have other names, without limitation. The visited location may also be referred to as a roaming location.

[0389] The technical solution of the third embodiment of the present application:

[0390] In the user roaming scenario, the user's subscribed data network name (DNN) and the user's location determine the selection of the ULCL UPF. The user subscription may include a dedicated DNN, a dedicated slice, etc.

[0391] If all business traffic of the user is required to return to the home location and needs to be diverted at the home location, then:

[0392] The SMF at the home location can select (or allocate or insert) the ULCL UPF and insert the ULCL UPF at the home location based on the user contract and the user's current location; the SMF at the visited location can insert the I-UPF at the visited location based on the user contract and the user's current location; the I-UPF is required to support the forwarding object of the N9 interface as the ULCL UPF, so that the destination address of the N9 interface of the I-UPF can be set to the ULCL UPF.

[0393] Embodiment 3 may include three possible access scenarios, namely: a campus access scenario, an intra-provincial roaming scenario, and an inter-provincial roaming scenario.

[0394] Campus access scenarios can be as follows Fig. 20 As shown, this scene is a non-roaming scene.

[0395] The prerequisites for this scenario may include: 1) configuring the user's default DNN as a dedicated DNN; 2) the user signs a contract with the PCF so that the campus UPF can be enabled as the UPF ULCL for the user when the user roams within or between provinces.

[0396] UPF selection in this scenario may include: 1) SMF can select the main anchor point UPF for the user based on the "dedicated DNN" signed by the user, for example, the shared UPF can be selected as the main anchor point UPF; 2) SMF can select the campus UPF as the UPF ULCL or auxiliary anchor point UPF based on the user's tracking area code (TAC).

[0397] The roaming scenario within the province can be as follows Fig.21 As shown, this scenario can also be called an inter-city roaming scenario, or an inter-city roaming scenario.

[0398] In this scenario, the home location and the visited location can share the same SMF, but each corresponds to a different UPF, that is, there is one SMF in this scenario. This can be understood as the UPF of the home location and the UPF of the visited location are within the management scope of the same SMF, and the management scope can also be called the coverage scope. For example, the home location and the visited location can be different cities in a province, which can be called the home city and the visited city respectively. The SMF can be considered as the SMF of the home province, the SMF of the home location / city, or the SMF of the visited location / city.

[0399] The prerequisites for this scenario may include: 1) configuring the user's default DNN as a dedicated DNN; 2) the user signs a contract with the PCF so that the campus UPF can be enabled for the user as the UPF ULCL when the user roams within or between provinces.

[0400] UPF selection in this scenario may include: 1) SMF determines that the user is a campus user and is not located in the campus; SMF can select the main anchor point UPF for the user, for example, the shared UPF can be selected as the main anchor point UPF; 2) SMF can select the campus UPF as the UPF ULCL or the auxiliary anchor point UPF based on the user's contract; 3) SMF can insert the I-UPF based on the user's current location and inform the I-UPF of the address of the UPF ULCL.

[0401] Inter-provincial roaming scenarios can be Fig. 22 As shown, this scenario can also be called an inter-provincial roaming scenario.

[0402] In this scenario, the home location and the visited location correspond to different SMFs, and each corresponds to a different UPF. That is, in this scenario, there are both SMFs in the home location and SMFs in the visited location. This can be understood as the UPF in the home location and the UPF in the visited location are within the management scope of different SMFs, and the management scope can also be called coverage. For example, the home location and the visited location can be different provinces in the country, which can be called the home province and the visited province, respectively. The SMF in the home location can be the SMF of the home province, and the SMF in the visited location can be the SMF of the visited province.

[0403] The prerequisites for this scenario may include: 1) configuring the user's default DNN as a dedicated DNN; 2) the first-level network repository function (NRF) configures a dedicated DNN for the roaming province; 3) the user signs a contract with the PCF so that the campus UPF can be enabled as the UPF ULCL for the user when the user roams within or between provinces.

[0404] In this scenario, the UPF selection may include: 1) If the SMF at the visited location determines that the user's dedicated DNN is not supported, it will query the SMF corresponding to the DNN at the NRF; 2) The SMF at the home location determines that the user is a campus user and selects the campus UPF as the UPF ULCL or auxiliary anchor point UPF for the user. The SMF at the visited location and the UPF at the home location interact to complete the UE address allocation and return the address of the UPF ULCL to the I-SMF / I-UPF; 3) The SMF at the visited location inserts the I-UPF according to the user's current location.

[0405] The network architecture applicable to the third embodiment can be as follows: Fig.23 As shown, Fig.23 Scenario 1 in the figure corresponds to the intra-province roaming scenario. Fig.23 Scenario 2 in FIG. 2 corresponds to the inter-provincial roaming scenario.

[0406] It should be noted that the intra-provincial roaming scenarios and inter-provincial roaming scenarios mentioned in this application are divisions of roaming scenarios based on the characteristics of my country's administrative divisions, and the purpose is to give readers a vivid understanding of roaming scenarios, but it should be noted that this application is not limited to this. In fact, the division of intra-provincial roaming scenarios and inter-provincial roaming scenarios in this application can be made based on the deployment of SMF and UPF.

[0407] For example, in some embodiments, the intra-provincial roaming scenario may also refer to: the user moves within a smaller area, does not leave the management scope of the current SMF (i.e., the SMF of the home location), but leaves the service scope of the current UPF (i.e., the UPF of the home location), and moves from the service scope of the current UPF (i.e., the UPF of the home location) to the service scope of another UPF (i.e., the UPF of the visited location). The two UPFs are managed by the same SMF.

[0408] Inter-provincial roaming scenarios can also refer to: the user moves within a larger area, from the management scope of the current SMF (i.e., the SMF in the home location) to the management scope of another SMF (i.e., the SMF in the visited location). Of course, it also moves from the service scope of the current UPF (i.e., the UPF in the home location) to the service scope of another UPF (i.e., the UPF in the visited location). The two UPFs are managed by different SMFs.

[0409] The above descriptions of intra-provincial roaming scenarios and inter-provincial roaming scenarios are applicable to embodiments three, four, and five of the present application and will not be repeated below.

[0410] The following is an inter-provincial roaming scenario (corresponding to Fig.23 Take the network architecture shown in scenario 2 in the example as an example to introduce the business process in embodiment 3 of the present application in detail. Fig.24 As shown, the following steps are included:

[0411] Step 2401, the home SMF and UPF PSA-1 create a user session.

[0412] Step 2402: The UE accesses the Internet through UPF PSA-1 in the non-MEC area of ​​its home location.

[0413] Step 2403, when the UE moves to the home edge area TAI, the PCF is triggered to send the diversion strategy to the SMF. The home SMF selects UPF ULCL+PSA-2 based on the diversion strategy and inserts the user session.

[0414] Step 2404, the home SMF sends the diversion rules to the UPF ULCL, updates the bearer rules, and refreshes the peer address of the uplink and downlink data transmission tunnel of the N9 interface of the UPF ULCL to the UPF PSA1 and RAN. This step can refer to the content of adding PDU session anchor points and diversion points or ULCL in 3GPP 23502.

[0415] In step 2405, after the SMF of the home location selects UPF ULCL+PSA2 to insert the user session, when the UE accesses the local services of the home location through UPF ULCL+PSA2 in the MEC area of ​​the home location, the service flow can be forwarded to UPFPSA1 through the N9 interface of UPF ULCL to access the Internet.

[0416] Step 2406, when the UE moves out of the SMF coverage area and arrives at the visited location, the AMF determines that the service area (SA) of the SMF at the home location does not include the current location of the UE. Therefore, it chooses to insert the I-SMF at the visited location and sends the SMF address of the home location to the I-SMF of the visited location.

[0417] Step 2407, based on the diversion policy of the user sent by the PCF, the SMF of the home location determines that the service flow of the user needs to return to the home location and needs to be diverted in the roaming scenario, and determines that the I-UPF N9 interface of the visited location is connected to the UPF ULCL of the home location. In this way, when the I-SMF requests the SMF to obtain the peer address of the N9 interface of the I-UPF, the SMF of the home location returns the UPF ULCL address of the home location to the I-SMF of the visited location.

[0418] The home SMF can be identified by the specific PCC predefined rules issued by the PCF corresponding to the configuration on the SMF. In the roaming scenario, the service flow must return to the home location and be diverted. The diversion rule can be determined based on the IP quintuple.

[0419] In step 2408, the visited I-SMF selects an I-UPF based on the UE's user subscription and current location, creates a packet forwarding control protocol (PFCP) session, and informs the I-UPF of the peer address of its N9 interface (i.e., the address of the UPF ULCL).

[0420] Step 2409, SMF updates the bearer rules and refreshes the UPF ULCL downlink tunnel address to the N9 interface peer end, which is I-UPF. For this step, please refer to the content about changing the PDU session anchor point or ULCL in 3GPP 23502.

[0421] Step 2410, the I-SMF updates the tunnel peer address of the uplink N3 interface on the RAN side to the I-UPF. The tunnel peer address is the destination address (destination IP address) of the tunnel.

[0422] Step 2411, the UE connects to the UPF ULCL+PSA2 of the home location through the N9 interface of the I-UPF at the visited location, and then accesses the local DN of the home location.

[0423] In step 2412, the UE connects to the UPF ULCL at the home location through the N9 interface of the I-UPF at the visited location, and then connects to the UPF-PSA1 through the N9 interface of the UPF ULCL to access the Internet.

[0424] The service process of the intra-province roaming scenario in Example 3 is the same as Fig.24 The service flow of the inter-provincial roaming scenario shown in is similar. The main difference is that only one SMF is involved in the intra-provincial roaming scenario. Therefore, the SMF can have the functions of both the SMF in the home location and the I-SMF in the visited location in the service flow of the inter-provincial roaming scenario. There is no need for the AMF to insert the I-SMF in the visited location based on the user's contract and current location.

[0425] For the sake of brevity, this application will not describe each step of the business process of the intra-provincial roaming scenario one by one. It can be understood that the business process can be based on Fig.23 The network architecture of scenario 1 in Fig.24 The business process shown in the figure is modified accordingly.

[0426] In the above-mentioned third embodiment, I-SMF and I-UPF can be inserted according to "user contract + current location", and the forwarding object of the I-UPF in the visited location is set as UPF ULCL. Therefore, the user can use a DNN to realize that the business flow (including Internet) can be returned to the local park UPF and diverted in the home location, thereby improving the security of the park network and facilitating high-security enterprises to monitor user traffic. For example, the technical solution in the first embodiment can meet the security requirements of the education network.

[0427] The existing 3GPP architecture also cannot support the user's need to use a DNN to unload part of the traffic back to the home location and the rest of the traffic at the visited location. To this end, the present application proposes the following fourth and fifth embodiments.

[0428] The technical solution of the fourth embodiment of the present application is as follows:

[0429] In the user roaming scenario, the DNN subscribed by the user and the user location determine the selection of ULCL UPF. The user subscription can be a proprietary DNN, proprietary slice, etc.

[0430] If some services that can be defined by rules return to the home location, and the rest of the services are unloaded at the visited location, then: the I-SMF at the visited location can select (or allocate or insert) the ULCL UPF and insert the ULCL UPF at the visited location based on the user's contract and current location; the SMF at the home location can select the main anchor point UPF.

[0431] Embodiment 4 may include three possible access scenarios, namely: a campus access scenario, an intra-provincial roaming scenario, and an inter-provincial roaming scenario.

[0432] Campus access scenarios can be as follows Fig.25 As shown, this scene is a non-roaming scene.

[0433] The prerequisites for this scenario may include: 1) configuring the user's default DNN as a dedicated DNN; 2) the user signs a contract with the PCF so that the campus UPF can be enabled as the UPF ULCL for the user when the user roams within or between provinces.

[0434] UPF selection in this scenario may include: UPF selection in this scenario may include: 1) SMF may select the main anchor point UPF for the user based on the "dedicated DNN" signed by the user, for example, the shared UPF may be selected as the main anchor point UPF; 2) SMF may select the campus UPF as the UPF ULCL or the auxiliary anchor point UPF based on the user's tracking area code (TAC).

[0435] The roaming scenario within the province can be as follows Fig.26As shown, this scenario can also be called an inter-city roaming scenario, or an inter-city roaming scenario.

[0436] In this scenario, the home location and the visited location can share the same SMF, but each corresponds to a different UPF, that is, there is one SMF in this scenario. This can be understood as the UPF of the home location and the UPF of the visited location are within the management scope of the same SMF, and the management scope can also be called the coverage scope. For example, the home location and the visited location can be different cities in a province, which can be called the home city and the visited city respectively. The SMF can be considered as the SMF of the home province, the SMF of the home location / city, or the SMF of the visited location / city.

[0437] The prerequisites for this scenario may include: 1) configuring the user's default DNN as a dedicated DNN; 2) the user signs a contract with the PCF so that the campus UPF can be enabled as the main anchor UPF for the user when the user roams within or between provinces.

[0438] In this scenario, the UPF selection may include: 1) SMF determines that the user is a campus user and the location is not in the campus; selects the primary anchor UPF; 2) I-SMF selects UPF ULCL or secondary anchor UPF according to the user contract; 3) I-SMF inserts I-UPF according to the location and informs I-UPF of the address of UPF ULCL. It can be understood that the SMF in this scenario is the SMF of the home province, and then it can be said to be the SMF of the home city / city, or the SMF of the visited city / city.

[0439] Inter-provincial roaming scenarios can be Fig. 27 As shown, this scenario can also be called an inter-provincial roaming scenario.

[0440] In this scenario, the home location and the visited location correspond to different SMFs, and each corresponds to a different UPF. That is, in this scenario, there are both SMFs in the home location and SMFs in the visited location. This can be understood as the UPF in the home location and the UPF in the visited location are within the management scope of different SMFs, and the management scope can also be called coverage. For example, the home location and the visited location can be different provinces in the country, which can be called the home province and the visited province, respectively. The SMF in the home location can be the SMF of the home province, and the SMF in the visited location can be the SMF of the visited province.

[0441] The prerequisites for this scenario may include: 1) configuring the user's default DNN as a dedicated DNN; 2) the first-level NRF configures a dedicated DNN for the roaming province; 3) the user signs a contract with the PCF so that the campus UPF can be enabled as the main anchor UPF for the user when the user roams within or between provinces.

[0442] UPF selection in this scenario may include: 1) The SMF in the visited location does not support dedicated DNN, and queries the SMF corresponding to the DNN to the NRF; 2) The SMF in the home location determines that the user is a campus user, and selects the campus UPF as the main anchor UPF. The SMF in the home location interacts with the UPF in the home location to complete the UE address allocation; 3) The SMF in the roaming location inserts the UPFULCL of the I-UPF according to the user's current location. It can be understood that the home province SMF in this scenario can be said to be the home province SMF, and the SMF in the visited province / roaming province can be said to be the visited SMF.

[0443] The network architecture applicable to the fourth embodiment is as follows Fig.28 As shown, Fig.28 Scenario 1 in the figure corresponds to the intra-province roaming scenario. Fig.28 Scenario 2 in the figure corresponds to the inter-provincial roaming scenario. In the above architecture diagram, I-UPF and ULCL are generally integrated, that is, ULCL can also be used as I-UPF to implement the N3 interface capability during roaming. Generally, they are collectively called UPF ULCL.

[0444] The following is an inter-provincial roaming scenario (corresponding to Fig.28 Take the network architecture shown in scenario 2 in the example as an example to introduce the business process in embodiment 4 of the present application in detail. Fig.29 As shown, the following steps are included:

[0445] Step 2901, the UE subscribes to a special DN, and the home SMF and UPF PSA-1 create a user session.

[0446] Step 2902, the UE accesses the local DN through UPF PSA-1 at its home location.

[0447] Step 2903, when the UE moves out of the SMF coverage area and arrives at the visited location, the AMF determines that the service area SA of the SMF at the home location does not include the UE's location, chooses to insert the I-SMF at the visited location, and sends the SMF address of the home location to the I-SMF.

[0448] In step 2904, the SMF at the home location determines, based on the diversion policy of the user issued by the PCF, that the user, in a roaming scenario, diverts traffic to access the Internet at the visited location and returns to the home location to access the local network. When the I-SMF at the visited location requests the SMF at the home location to obtain the ULCL insertion rule and diversion policy, the SMF at the home location passes the diversion rule of the local DN of the home location to the I-SMF at the visited location, and instructs the service flows matching this rule to return to the home location, and the remaining service flows are unloaded at the visited location.

[0449] In step 2905, the I-SMF at the visited location selects UPF ULCL+PSA2 to insert the user session and sends a diversion rule to UPF ULCL. The diversion rule indicates that the next-hop N9 interface counterpart of the service flow matching the local DN rule of the home location is UPFPSA-1, and the next-hop N9 interface counterpart of the remaining service flows is UPF PSA-2.

[0450] Step 2906, the SMF at the home location updates the bearer rules and refreshes the UPF PSA-1 downlink tunnel to the N9 interface peer end as UPF ULCL.

[0451] Step 2907: The visited I-SMF updates the destination address of the RAN side uplink N3 tunnel interface to the UPF ULCL.

[0452] Step 2908, the UE connects to the home location UPF PSA-1 through the N9 interface of the UPF ULCL at the visited location to access the local DN of the home location.

[0453] Step 2909: The UE accesses the Internet through UPF ULCL+PSA2 at the visited location.

[0454] The service process of the intra-province roaming scenario in the fourth embodiment is Fig.29 The service flow of the inter-provincial roaming scenario shown in is similar. The main difference is that only one SMF is involved in the intra-provincial roaming scenario. Therefore, the SMF can be used to implement the functions of both the SMF in the home location and the I-SMF in the visited location in the service flow of the inter-provincial roaming scenario. There is no need for the AMF to insert the I-SMF in the visited location based on the user's contract and current location.

[0455] For the sake of brevity, this application will not describe each step of the business process of the intra-provincial roaming scenario one by one. It can be understood that the business process can be based on Fig.28 The network architecture of scenario 1 in Fig.29 The business process shown in the figure is modified accordingly.

[0456] In the above-mentioned fourth embodiment, the SMF at the home location can send the diversion rules of the local network at the home location to the I-SMF, and instruct the service flows matching the diversion rules to return to the home location, and the rest to be unloaded at the visited location. The SMF at the visited location can insert the ULCL UPF according to the "user contract + current location" and issue the above-mentioned diversion rules to the ULCL UPF. Therefore, the user can use one DNN to access both the campus network and the Internet. Furthermore, the above-mentioned diversion rules can be determined according to the services accessed by the user. For example, the services that the user accesses to the Internet can be unloaded at the visited location, and the services that access the local network at the home location can be returned to the home location. For example, the technical solution in the fourth embodiment can meet the needs of the government network.

[0457] The technical solution of the fifth embodiment of the present application:

[0458] In the user roaming scenario, the DNN subscribed by the user and the user location determine the selection of ULCL UPF. The user subscription may include a dedicated DNN, a dedicated slice, etc.

[0459] If some services are unloaded locally and some services are returned to the local area, and the UPF at the visited location supports the I-UPF / ULCL / auxiliary anchor point integrated function, then: the unified UPF needs to decide whether to divert traffic on the local N6 interface or through the N9 interface based on the destination address of the user's service access, and the diversion strategy is implemented by the SMF and UPF.

[0460] The network architecture applicable to the fifth embodiment is as follows Fig.30 The network architecture is shown in Fig.10 The difference between the network architecture shown in is that the UPF at the visited location supports the unified deployment of I-UPF, ULCL and auxiliary anchor point UPF.

[0461] The business process in Example 3 is Fig.29 The difference is that the UPF deployed in an integrated manner at the visited location can have the functions of the I-UPF, ULCL and auxiliary anchor point UPF of the visited location in the above business process.

[0462] In the above embodiment three, the visited SMF selects the I-UPF / ULCL UPF according to the "user contract + current location" and unloads the traffic locally through the auxiliary anchor point, sends the campus service (which can be judged by the destination address visited by the user) to the home UPF, and finally to the server of the campus network.

[0463] The visited location can determine the diversion strategy based on the services accessed by the user. Some services are unloaded through the local N6 interface, and some services are forwarded to the UPF at the entrance of the campus network (i.e., the home location UPF) through the N9 interface. In this way, users can access both the campus network and the Internet using a specific DNN. Furthermore, the home location can define the diversion rules for the service data to return to the home location, and the remaining traffic is routed out of the Internet through the visited location N6 interface.

[0464] The above technical solution provided in the embodiment of the present application enables users inside and outside the park to securely access the services of the park network through a unified specific UPF, without the need for the park network to deploy an Internet exit on its own, thereby improving the security of the park network.

[0465] In several embodiments provided in the present application, the disclosed systems, devices and methods can be implemented in other ways. For example, some features of the method embodiments described above can be ignored or not performed. The device embodiments described above are merely schematic, and the division of units is only a logical function division. There may be other division methods in actual implementation, and multiple units or components may be combined or integrated into another system. In addition, the coupling between the units or the coupling between the components may be direct coupling or indirect coupling, and the above coupling includes electrical, mechanical or other forms of connection.

[0466] In various embodiments of the present application, the size of the serial number does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0467] In addition, the term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0468] It should be noted that, in the embodiments of the present application, words such as "first" and "second" are only used for the purpose of distinguishing descriptions, and cannot be understood as indicating or implying relative importance, nor can they be understood as indicating or implying order. Features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present application, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present application should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a concrete way.

[0469] In short, the above is only a preferred embodiment of the technical solution of this application, and is not intended to limit the protection scope of this application. Any modification, equivalent replacement, improvement, etc. made within the principles of this application should be included in the protection scope of this application.

Claims

1. A network access method, characterized in that: The method comprises: When the terminal device moves to a visited location, a session management function network element of the visited location is inserted into an uplink classifier user plane function network element of the visited location, and the uplink classifier user plane function network element is used to divert the service flow of the terminal device; The session management function network element of the visited location sends a second diversion rule to the uplink classifier user plane function network element, and the second diversion rule is used to indicate that the service flow matching the second diversion rule is sent to the main anchor user plane function network element of the home location, and the main anchor user plane function network element is connected to the local data network of the home location.

2. The method according to claim 1, characterized in that The session management function network element of the visited location is inserted into the uplink classifier user plane function network element of the visited location, including: The session management function network element of the visited location is inserted into the uplink classifier user plane function network element according to the data network name DNN subscribed by the terminal device.

3. The method according to claim 1, characterized in that The session management function network element of the visited location is inserted into the uplink classifier user plane function network element of the visited location, including: The session management function network element of the visited location inserts the uplink classifier user plane function network element according to the user policy of the terminal device, and the user policy is used to indicate that the service flow of the terminal device needs to be diverted at the visited location in a roaming scenario, and the service flow accessing the local data network of the home location returns to the home location.

4. The method according to any one of claims 1 to 3, characterized in that If the session management function network element of the visited location is the same as the session management function network element of the home location, the method further includes: The session management function network element of the visited site sends the address of the uplink classifier user plane function network element to the main anchor user plane function network element to establish a tunnel between the main anchor user plane function network element and the uplink classifier user plane function network element.

5. The method according to any one of claims 1 to 3, characterized in that If the session management function network element of the visited location is different from the session management function network element of the home location, the method further includes: The session management function network element of the visited location sends the address of the uplink classifier user plane function network element to the main anchor user plane function network element through the session management function network element of the home location to establish a tunnel between the main anchor user plane function network element and the uplink classifier user plane function network element.

6. The method according to any one of claims 1 to 5, characterized in that The second diversion rule is used to instruct that the service flow that does not match the second diversion rule is sent to the auxiliary anchor user plane function network element of the visited location, and the auxiliary anchor user plane function network element is connected to the Internet.

7. The method according to claim 6, characterized in that The method further comprises: The session management function network element of the visited site sends the address of the uplink classifier user plane function network element to the auxiliary anchor user plane function network element to establish a tunnel between the auxiliary anchor user plane function network element and the uplink classifier user plane function network element.

8. The method according to any one of claims 1 to 6, characterized in that The method further comprises: The session management function network element of the visited site sends the address of the uplink classifier user plane function network element to the access network device of the visited site to establish a tunnel between the access network device and the uplink classifier user plane function network element.

9. A communication device, characterized in that: The apparatus comprises at least one processor coupled to at least one memory: The at least one processor is configured to execute a computer program or instruction stored in the at least one memory, so that the apparatus performs the method according to any one of claims 1 to 8.

10. A communication device, characterized in that: including a processor and an interface circuit; The interface circuit is used to exchange code instructions or data with the processor; The processor is configured to execute the method according to any one of claims 1 to 8.

11. A communication system, characterized in that: The system comprises a session management function network element of a visited location; wherein the session management function network element of the visited location is used to execute the method according to any one of claims 1 to 8.

12. A computer-readable storage medium, characterized in that: Used to store instructions, when the instructions are executed, the method according to any one of claims 1 to 8 is implemented.

13. A computer program product, characterized in that When a computer reads and executes the computer program product, the computer is caused to execute the method according to any one of claims 1 to 8.

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