CN115209395A

CN115209395A - Network access method and device

Info

Publication number: CN115209395A
Application number: CN202110877210.9A
Authority: CN
Inventors: 马春燕; 夏林瑾
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-04-02
Filing date: 2021-07-31
Publication date: 2022-10-18

Abstract

The application provides a network access method and a device, wherein the method comprises the following steps: inserting a session management function network element of the home location into an uplink classifier user plane function network element of the home location; when the terminal equipment moves to the visited place, the session management function network element sends the address of the uplink classifier user plane function network element to the middle user plane function network element of the visited place so as to establish a tunnel between the middle user plane function network element and the uplink classifier user plane function network element. Therefore, when the terminal equipment roams at the visit place, the service flow of the terminal equipment can return to the home place through the tunnel and is shunted under the action of the user plane function network element of the uplink classifier of the home place, thereby meeting the service requirement of the terminal equipment and improving the safety of the local data network of the home place.

Description

Network access method and device

The present application claims priority of chinese patent application entitled "a campus network access method and apparatus" filed by the chinese intellectual property office at 2021, 04/02, application No. 202110362662.3, which is incorporated herein by reference in its entirety.

Technical Field

The present application relates to the field of wireless communications technologies, and in particular, to a network access method and apparatus.

Background

Roaming scenarios defined in the existing third generation partnership project (3 rd generation partnership project,3 gpp) network architecture are mainly targeted at international roaming scenarios. In China, when Mobile Edge Computing (MEC) sinks to a city or a park, a new roaming scene appears. The user can roam between provinces and cities within a province.

When a user roams between provinces or between provinces and cities, how to access the user to the home local data network is a problem to be solved.

Disclosure of Invention

The application provides a network access method and a network access device, which are used for enabling terminal equipment to access a local data network of a home location under a roaming scene, so that the security of the local data network of the home location is improved, and meanwhile diversified service requirements of users are met. The service flow of the terminal equipment can return to the home and be shunted at the home, or can be shunted at the visit place according to a preset shunting rule, so that part of the service flow returns to the home, and the rest is unloaded at the visit place.

In a first aspect, an embodiment of the present application provides a network access method, where the method may be executed by a home session management function network element, and may also be executed by a component (e.g., a chip or a circuit) of the home session management function network element.

The method comprises the following steps: a session management function network element of a home location is inserted into an uplink classifier user plane function network element of the home location, and the uplink classifier user plane function network element is used for shunting service flow of terminal equipment; and when the terminal equipment moves to a visited place, 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 of the visited place so as to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

According to the technical scheme, the tunnel between the user plane function network element of the uplink classifier of the home location and the middle user plane function network element of the visited location can be established, when the terminal equipment roams in the visited location, the service flow of the terminal equipment can return to the home location through the tunnel, and is shunted under the action of the user plane function network element of the uplink classifier of the home location, so that the service requirement of the terminal equipment is met.

In a possible design of the first aspect, the inserting, by the session management function network element of the home location, the uplink classifier user plane function network element of the home location includes: and the session management function network element of the home location is inserted into the user plane function network element of the uplink classifier according to the data network name DNN signed by the terminal equipment.

In a possible design of the first aspect, the inserting, by the session management function network element of the home location, the uplink classifier user plane function network element of the home location includes: the session management function network element receives a user policy of the terminal equipment from a policy control function network element, wherein the user policy is used for indicating that the service flow of the terminal equipment needs to return to a home location and be shunted in a roaming scene; and the session management function network element inserts the uplink classifier user plane function network element according to the user strategy.

According to the technical scheme, the session management function network element of the home location can insert the user plane function network element of the uplink classifier into the home location when the service flow of the terminal equipment needs to return to the home location and carry out distribution under the roaming scene indicated by the user policy of the terminal equipment, so that the requirement that the total service flow of the terminal equipment returns to the home location and carries out distribution is met, and the safety of a local data network of the home location is improved.

In one possible design of the first aspect, the method further includes: and the session management function network element sends a first shunt rule to the uplink classifier user plane function network element, wherein the first shunt rule is used for indicating that the service flow matched with the first shunt rule is sent to an auxiliary anchor point user plane function network element of the home location, and the auxiliary anchor point user plane function network element is connected with a local data network of the home location.

In one possible design of the first aspect, the method further includes: and the session management function network element sends the address of the uplink classifier user plane function network element to the auxiliary anchor point user plane function network element so as to establish a tunnel between the auxiliary anchor point user plane function network element and the uplink classifier user plane function network element.

In a possible design of the first aspect, the first offload rule is further configured to instruct to send the service flow that does not match the first offload rule to a home-location master anchor point user plane functional network element, where the master anchor point user plane functional network element is connected to the internet.

In one possible design of the first aspect, the method further includes: and the session management function network element sends the address of the uplink classifier user plane function network element to the main anchor point user plane function network element so as to establish a tunnel between the main anchor point user plane function network element and the uplink classifier user plane function network element.

In one possible design of the first aspect, the method further includes: and the session management function network element sends the address of the uplink classifier user plane function network element to the access network equipment of the home location so as to establish a tunnel between the access network equipment and the uplink classifier user plane function network element.

In the above technical solution, the uplink classifier user plane function network element at the home location may perform splitting in a forward splitting manner, and split the traffic flow matching the first splitting rule to the auxiliary anchor point user plane function network element, so that the terminal device may access the local data network at the home location, and split the traffic flow not matching the first splitting rule to the main anchor point user plane function network element, so that the terminal device may access the internet.

Further, after inserting the user plane function network element of the uplink classifier in the home location, the session management function network element of the home location may also update the bearer rules of the user plane function network element of the master anchor point, the user plane function network element of the auxiliary anchor point, and the access network device of the home location, respectively, so as to get through the transmission path of the uplink and downlink service flows of the terminal device.

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 further includes: the session management function network element is inserted into the middle user plane function network element of the visited place; and the session management function network element sends the address of the middle user plane function network element to the uplink classifier user plane function network element so as to establish a tunnel between the uplink classifier user plane function network element and the middle user plane function network element.

In one possible design of the first aspect, the method further includes: and the session management function network element sends the address of the middle user plane function network element to access network equipment at a visited place so as to establish a tunnel between the access network equipment and the middle user plane function network element.

In a possible design of the first aspect, if the terminal device leaves the service area of the session management function network element after moving to the visited location, the sending, by the session management function network element, the address of the uplink classifier user plane function network element to the middle user plane function network element of the visited location includes: and the session management function network element sends the address of the uplink classifier user plane function network element to the middle user plane function network element through the middle session management function network element of the visited place.

In one possible design of the first aspect, the method further includes: the session management function network element receives the address of the middle user plane function network element from the middle user plane function network element through the middle session management function network element; and the session management function network element sends the address of the middle user plane function network element to the uplink classifier user plane function network element so as to establish a tunnel between the uplink classifier user plane function network element and the middle user plane function network element.

The technical scheme can be applied to two roaming scenes that the terminal equipment is still in the service area of the session management function network element of the home location after moving to the visited location and the terminal equipment leaves the service area of the session management function network element of the home location after moving to the visited location. In the scenario that the terminal device is still in the service area of the session management function network element of the home location after moving to the visited location, the session management function network element of the home location can be inserted into the middle user plane function network element of the visited location, that is, the session management function network element of the home location is also the session management function network element of the visited location at the same time.

In a second aspect, the present application provides a network access method, where the method may be executed by an intermediate session management function network element in a visited place, and may also be executed by a component (e.g., a chip or a circuit) of the intermediate session management function network element configured in the visited place.

The method comprises the following steps: when the terminal equipment moves to the visited place, the middle session management function network element of the visited place is inserted into the middle user plane function network element of the visited place; the intermediate session management function network element receives an address of an uplink classifier user plane function network element of the session management function network element from a home location, the uplink classifier user plane function network element is used for shunting service flow of terminal equipment, and the address of the uplink classifier user plane function network element is used for establishing a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

According to the technical scheme, a tunnel between the user plane function network element of the uplink classifier of the home location and the middle user plane function network element of the visited location can be established, when the terminal equipment roams in the visited location, the service flow of the terminal equipment can return to the home location through the tunnel, and is shunted under the action of the user plane function network element of the uplink classifier of the home location.

The technical scheme can be applied to the roaming scene of the service area of the session management function network element which leaves the home location after the terminal equipment moves to the visited place, and in the scene, the intermediate session management function network element of the visited place can be inserted into the intermediate user plane function network element of the visited place.

In one possible design of the second aspect, the method further includes: and 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 so as to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

In one possible design of the second aspect, the method further includes: and 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 so as to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

In one possible design of the second aspect, the method further includes: and the middle session management function network element sends the address of the middle user plane function network element to access network equipment of a visited place so as to establish a tunnel between the access network equipment and the middle user plane function network element.

In the above technical solution, after the middle session management function network element is inserted in the visited place, the session management function network element in the visited place may further update the bearer rules of the middle user plane function network element and the access network device in the visited place, respectively, thereby completing the transmission path of the uplink and downlink service flows of the terminal device.

In a third aspect, an embodiment of the present application provides a network access method, where the method may be executed by a session management function network element at a visited place, and may also be executed by a component (e.g., a chip or a circuit) of the session management function network element configured at the visited place.

The method comprises the following steps: when the terminal equipment moves to a visit place, a session management function network element of the visit place is inserted into an uplink classifier user plane function network element of the visit place, and the uplink classifier user plane function network element is used for shunting service flow of the terminal equipment; and the session management function network element of the visited place sends a second shunt rule to the user plane function network element of the uplink classifier, wherein the second shunt rule is used for indicating that the service flow matched with the second shunt rule is sent to a main anchor point user plane function network element of the home place, and the main anchor point user plane function network element is connected with a local data network of the home place.

In the above technical solution, by inserting the uplink classifier user plane function network element into the visited place and issuing the second forking rule to the visited place, when the terminal device roams in the visited place, the service flow of the terminal device can be shunted to the main anchor point user plane function network element of the home location through the uplink classifier user plane function network element, thereby meeting the requirement that part of the service flow of the terminal device returns to the home location.

In a possible design of the third aspect, the inserting, by the session management function network element of the visited place, the uplink classifier user plane function network element of the visited place includes: and the session management function network element of the visited place is inserted into the user plane function network element of the uplink classifier according to the data network name DNN signed by the terminal equipment.

In a possible design of the third aspect, the inserting, by the session management function network element of the visited place, the uplink classifier user plane function network element of the visited place includes: and the session management function network element of the visited place inserts the uplink classifier user plane function network element according to the user policy of the terminal equipment, wherein the user policy is used for indicating that the service flow of the terminal equipment needs to be shunted at the visited place in a roaming scene, and the service flow of the local data network of the visited place returns to the home place.

In the above technical solution, the session management function network element at the visited place can insert the uplink classifier user plane function network element at the visited place when the user policy of the terminal device indicates that the service flow of the terminal device needs to be split at the visited place in the roaming scene and the service flow of the local data network at the visited place returns to the home place, so as to meet the requirement that part of the terminal device meets the regular service flow returning home place and the rest of the flow is unloaded locally at the visited place.

Furthermore, the service flow which does not match the second shunt rule can be unloaded locally at the visit place, and all the service flows of the terminal equipment do not need to be sent back to the home place, so that the technical scheme can fully utilize network resources and reduce the time delay of the user for accessing the internet.

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

In a possible design of the third aspect, if the session management function network element of the visited place is different from the session management function network element of the home place, the method further includes: and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the user plane function network element of the main anchor point through the session management function network element of the home place so as to establish a tunnel between the user plane function network element of the main anchor point and the user plane function network element of the uplink classifier.

In a possible design of the third aspect, the second forking rule is used to instruct that a service flow that does not match the second forking rule is sent to an auxiliary anchor point user plane function network element of a visited place, where the auxiliary anchor point user plane function network element is connected to the internet.

In the above technical solution, the uplink classifier user plane function network element at the visited place may adopt a reverse splitting manner to split, and split the service flow matching the second splitting rule to the main anchor point user plane function network element, so that the terminal device may access the local data network at the home place, and split the service flow not matching the second splitting rule to the auxiliary anchor point user plane function network element, so that the terminal device may access the internet.

In one possible design of the third aspect, the method further includes: and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the auxiliary anchor point user plane function network element so as to establish a tunnel between the auxiliary anchor point user plane function network element and the user plane function network element of the uplink classifier.

In one possible design of the third aspect, the method further includes: and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the access network equipment of the visited place so as to establish a tunnel between the access network equipment and the user plane function network element of the uplink classifier.

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

The functions of the communication device may be implemented by hardware, or by hardware executing corresponding software, which includes one or more modules or units or means (means) corresponding to the functions.

In one possible design, the communication apparatus includes a processing module and a transceiver module in its structure, wherein the processing module is configured to support the communication apparatus to perform a function corresponding to the first session management function network element in any one of the above aspects or aspects, or perform a function corresponding to the session management function network element at the home in any one of the above aspects or aspects, or perform a function corresponding to the intermediate session management function network element at the visited place in any one of the above aspects or aspects, or perform a function corresponding to the session management function network element at the visited place in any one of the above aspects or aspects. The transceiver module is configured to support communication between the communication device and other communication devices, for example, when the communication device is a session management function network element of a home location, the transceiver module may send an address of an uplink classifier user plane function network element to an intermediate user plane function network element of a visited location. The communication device may also include a memory module, coupled to the processing module, that retains the necessary program instructions and data for the device. As an example, the processing module may be a processor, the communication module may be a transceiver, the storage module may be a memory, and the memory may be integrated with the processor or provided separately from the processor.

In another possible design, the communication device may be configured to include a processor and may also include a memory. A processor is coupled to the memory and is operable to execute the computer program instructions stored in the memory to cause the apparatus to perform the methods of any of the possible designs of the above-described aspects or aspects. Optionally, the communication device further comprises a communication interface, the processor being coupled to the communication interface. When the communication device is a network device, the communication interface may be a transceiver or an input/output interface; when the apparatus is a chip included in a network device, the communication interface may be an input/output interface of the chip. Alternatively, the transceiver may be a transceiver circuit and the input/output interface may be an input/output circuit.

In a fifth aspect, an embodiment of the present application provides a chip system, including: a processor coupled to a memory for storing a program or instructions that, when executed by the processor, cause the system-on-chip to implement the method in any one of the possible designs of the above-described aspects or aspects.

Optionally, the system-on-chip further comprises an interface circuit for interacting code instructions to the processor.

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

Optionally, the memory in the system-on-chip may also be one or more. The memory may be integral to the processor or may be separate from the processor. For example, the memory may be a non-transitory processor, such as a read-only memory, which may be integrated with the processor on the same chip or may be separately disposed on different chips.

In a sixth aspect, an embodiment of the present application provides a communication system, where the communication system includes a session management function network element of a home location and/or an intermediate session management function network element of a visited location; wherein the session management function network element at the home location is configured to implement the method in any one of the above-mentioned first aspect or any one of the possible designs of the first aspect, and the intermediate session management function network element at the visited location is configured to implement the method in any one of the above-mentioned second aspect or any one of the possible designs of the second aspect.

Optionally, the communication system further includes a home location uplink classifier user plane function network element, a main anchor point user plane function network element, an auxiliary anchor point user plane function network element, and a visited location middle user plane function network element.

In a seventh aspect, an embodiment of the present application provides a communication system, where the communication system includes a session management function network element of a visited place; wherein the session management function network element of the visited place is configured to implement the method in any one of the possible designs of the third aspect or the third aspect.

Optionally, the communication system further includes an uplink classifier user plane function network element and an auxiliary anchor point user plane function network element at the visited place, and a main anchor point user plane function network element at the home place.

In an eighth aspect, embodiments of the present application provide a computer-readable storage medium having stored thereon a computer program or instructions which, when executed, cause a computer to perform the method of any one of the possible designs of the above-described aspects or aspects.

In a ninth aspect, embodiments of the present application provide a computer program product which, when read and executed by a computer, causes the computer to perform the method in any one of the possible designs of the above-described aspect or aspects.

The application provides a park network access method and device, which are used for accessing a park network of a home location when a user roams between provinces or between local cities in a province, so that the security of the park network is improved.

The service flow of the user can be shunted after returning to the home, or based on the shunting strategy, one part is unloaded at the visit place, and the other part returns to the home, thereby meeting the various service requirements of the park network.

In a tenth aspect, the present application provides a campus network access method, including:

a Session Management Function (SMF) of a home location inserts an uplink classifier user plane function (ULCL UPF) into the home location according to subscription data and the current position of terminal equipment; the SMF of the home location determines that the service flow of the terminal equipment returns to the home location and is shunted in a roaming scene; and the SMF of the home location sends the address of the ULCL UPF, wherein the address of the ULCL UPF is used for forwarding the service flow of the terminal equipment to the ULCL UPF by a forwarding user plane function I-UPF of the visited location.

In one possible design, the method further includes:

the SMF of the home location receives the address of the I-UPF from a forwarding session management function I-SMF of a visited location;

and the SMF of the home sends the address of the I-UPF to the ULCL UPF, and the address of the I-UPF is used for forwarding the traffic flow of the terminal equipment to the I-UPF by the ULCL UPF.

In one possible design, the method further includes:

and the SMF of the home sends the address of the ULCL UPF to the SMF of the visit place.

In one possible design, the method further includes:

and the SMF of the home location inserts the I-UPF in the visit location.

In one possible design, the method further includes:

the SMF of the home location sends the address of the ULCL UPF to the I-UPF of the visited location;

In an eleventh aspect, the present application provides a campus network access method, including:

a session management function SMF of a visited place inserts an uplink classifier user plane function ULCL UPF into the visited place according to the signing data and the current position of terminal equipment; and the SMF of the visited place sends a distribution rule to the ULCL UPF, wherein the distribution rule comprises the steps of sending the service flow matched with the first address to the UPF of the home place and sending the service flow matched with the second address to the UPF of the visited place, the service flow matched with the first address is used for accessing the local network of the home place, and the service flow matched with the second address is used for accessing the Internet.

In one possible design, the second address is an address other than the first address.

Drawings

Fig. 1 is a schematic diagram of a network architecture in a roaming scenario to which the present application is applicable;

FIG. 2 is a diagram illustrating an intra-provincial roaming scenario according to an embodiment of the present application;

FIG. 3 is a diagram illustrating an inter-province roaming scenario according to an embodiment of the present application;

fig. 4 is a flowchart illustrating a network access method according to an embodiment of the present application;

fig. 5 is a relevant flow corresponding to the network access method when the terminal device is located in the home location in the first embodiment of the present application;

fig. 6 is a related flow corresponding to a case where a terminal device is located at a visited place in an intra-provincial roaming scenario in the network access method according to the first embodiment of the present application;

fig. 7 is a related flow corresponding to a terminal device located at a visited place in an inter-provincial roaming scenario in the network access method according to the first embodiment of the present application;

fig. 8a and 8b are a specific example of the first embodiment of the present application;

fig. 9 is a schematic diagram of an intra-provincial roaming scenario according to a second embodiment of the present application;

fig. 10 is a schematic diagram of an inter-provincial roaming scenario according to a second embodiment of the present application;

fig. 11 is a flowchart illustrating a network access method according to a second embodiment of the present application;

fig. 12 is a related flow corresponding to the case where the terminal device is located at the visited place in the intra-provincial roaming scenario in the network access method according to the second embodiment of the present application;

fig. 13 is a related flow corresponding to a case where a terminal device is located at a visited place in an inter-provincial roaming scenario of a network access method according to a second embodiment of the present application;

fig. 14 is a specific example of the second embodiment of the present application;

FIG. 15 is a diagram illustrating an intra-provincial roaming scenario when a unified UPF is employed according to a second embodiment of the present application;

fig. 16 is a diagram illustrating an inter-provincial roaming scenario when employing unified UPF according to a second embodiment of the present application;

fig. 17 and fig. 18 are schematic structural diagrams of a communication device provided in the present application;

fig. 19 is a network architecture of a 5G network suitable for roaming scenarios defined by the current 3GPP standard;

fig. 20 is a schematic diagram of a campus access scenario in the third embodiment of the present application;

fig. 21 is a schematic diagram of an intra-provincial roaming scenario in the third embodiment of the present application;

fig. 22 is a schematic diagram illustrating an inter-provincial roaming scenario according to a third embodiment of the present application;

FIG. 23 is a diagram of a network architecture suitable for use in accordance with a third embodiment of the present application;

fig. 24 is a schematic business process diagram in the third embodiment of the present application;

fig. 25 is a schematic diagram of a campus access scenario in the fourth embodiment of the present application;

fig. 26 is a diagram illustrating an intra-provincial roaming scenario according to a fourth embodiment of the present application;

fig. 27 is a diagram illustrating an inter-provincial roaming scenario according to a fourth embodiment of the present application;

FIG. 28 is a diagram of a network architecture suitable for use with the fourth embodiment of the present application;

fig. 29 is a schematic business process diagram in a fourth embodiment of the present application;

fig. 30 is a schematic diagram of a network architecture to which the fifth embodiment of the present application is applicable.

Detailed Description

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

The technical solution of the embodiment of the present application may be applied to various communication systems, for example, a Long Term Evolution (LTE) system, a Frequency Division Duplex (FDD) system, a LTE Time Division Duplex (TDD) system, a fifth generation (5 th generation,5 g) mobile communication system or a New Radio (NR) system, or may be applied to a future communication system or other similar communication systems.

Referring to fig. 1, the present application takes a 5G network architecture related to a roaming scenario defined in the 3GPP standard as an example, and introduces a network architecture in a roaming scenario applicable to the present application. The network architecture includes three parts, a terminal device, a Data Network (DN) and an operator network part.

The operator network may include, but is not limited to, one or more of the following network elements or functional entities: an access and mobility management function (AMF) network element, a Session Management Function (SMF) network element, an intermediate SMF (intermediate SMF, I-SMF) network element, a User Plane Function (UPF) network element, an intermediate UPF (I-UPF) network element, an uplink classifier UPF (upcl UPF) network element, a protocol data unit (protocol unit, PDU) session anchor UPF (PDU session identifier UPF, PSA UPF) network element, and a Radio Access Network (RAN) device. Optionally, the network architecture may further include a Policy Control Function (PCF) network element, a Unified Data Management (UDM) network element, a Unified Data Repository (UDR) network element, an Application Function (AF) network element, and other network elements or functional entities, which are not temporarily shown in fig. 1.

In a specific implementation, the terminal device in the embodiment of the present application may be a device for implementing 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 remote terminal, a mobile device, a wireless communication device, a terminal agent, or a terminal apparatus in a 5G network or a Public Land Mobile Network (PLMN) for future evolution. 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 capability, 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 (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transport security (smart security), a wireless terminal in city (city), a wireless terminal in smart home (home), etc. The terminal device may be mobile or fixed, and is not limited.

The terminal device may establish a connection with the carrier network through an interface (e.g., an N1 interface, etc.) provided by the carrier network, and use services such as data and/or voice provided by the carrier network. The terminal device may also access the DN via the operator network, using operator services deployed on the DN and/or services provided by a third party. The third party may be a service party other than the operator network and the terminal device, and may provide services such as other data and/or voice for the terminal device. The specific expression form of the third party may be specifically determined according to an actual application scenario, and is not limited herein.

The RAN is a sub-network of the operator network and is an implementation system between the service node and the terminal device in the operator network. The terminal device is to access the operator network, first through the RAN, and then may be connected to a service node of the operator network through the RAN. The RAN device in this application is a device that provides a wireless communication function for a terminal device, and is also referred to as an access network device. RAN equipment in this application includes, but is not limited to: next generation base station (G node B, gNB), evolved node B (eNB), radio Network Controller (RNC), node B (NB), base Station Controller (BSC), base Transceiver Station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), base Band Unit (BBU), transmission point (TRP), transmission Point (TP), mobile switching center, etc. in 5G.

The AMF network element is mainly responsible for mobility management, access authentication/authorization and other functions, such as registration, location update, mobility state switching and the like of the terminal device. It is also responsible for communicating user policies between the terminal equipment and the PCF.

The SMF element is mainly responsible for session management, execution of control strategies issued by PCF, selection of UPF, allocation of an Internet Protocol (IP) address of UE, and other functions. In a roaming scenario, the SMF network element of the home may also be referred to as an anchor SMF (a-SMF) network element of the terminal device.

The I-SMF network element, also called a forwarding SMF network element, is used for forwarding the control plane message between the visited place and the home place. In a roaming scenario, after the terminal device moves to a visited place, if the location of the terminal device is not already in the service area of the a-SMF network element, the AMF network element may insert an I-SMF network element in the visited place.

The UPF network element, as an interface UPF with a data network, is mainly responsible for functions such as user plane data forwarding, session/flow level-based charging statistics, bandwidth limitation, and the like.

The PSA UPF network element, also called an anchor UPF network element, is used as an anchor point connected to the PDU session and is responsible for filtering, forwarding, rate control, charging, and the like of user plane data of the terminal device. In the roaming scenario, the PSA UPF network element of the home is referred to as a primary PSA UPF network element of the terminal device (i.e., a primary anchor UPF network element). The application supports the insertion of 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. The secondary PSA UPF network element may be deployed in a home location (e.g., an edge area of the home location), or may be deployed in a visited location, which is not limited. Specifically, the master PSA UPF network element (or master anchor point UPF network element) refers to a UPF network element that a terminal device connects when initially activating a session creation, and is used for allocating an IP address to the terminal device and forwarding user plane data. The auxiliary PSA UPF network element (or auxiliary anchor UPF network element) refers to a UPF network element inserted after the session creation of the terminal device is completed, and is used to forward user plane data for the terminal device.

The I-UPF network element, also called forwarding UPF network element, is used for forwarding user plane data between the visited and home locations. In a roaming scenario, after the terminal device moves to a visited place, if the location of the terminal device is not within the service area of the primary PSA UPF network element, an a-SMF network element (in a case that the location of the corresponding terminal device is still within the service area of the a-SMF network element) or an I-SMF network element (in a case that the location of the corresponding terminal device is not within the service area of the a-SMF network element or in a case that the I-SMF network element exists) may be inserted into the I-UPF network element at the visited place. The I-UPF network element may be deployed in combination with the ULCL UPF network element, such as the ULCL UPF + I-UPF network element in fig. 1, which indicates that the network element may be used as an I-UPF network element at the same time to implement an N3 interface capability in a roaming scenario.

The ULCL UPF network element is a working form of the UPF network element, is used for service distribution, and can determine the trend of data flow according to different destination addresses accessed by a user. In this application, the ULCL UPF network element may be inserted at a home location, or may be inserted at a visited location, without limitation. The ULCL UPF network element may also be deployed in combination with other UPF network elements (e.g., I-UPF network elements or PSA UPF network elements), such as the ULCL UPF + I-UPF network element in fig. 1, which means that the network element can simultaneously serve as the ULCL UPF network element to implement the offloading function.

The PCF network element is mainly responsible for performing policy control functions such as charging, quality of service (QoS) bandwidth guarantee and mobility management, and UE policy decision for a session and a service flow level.

And the UDM network element is mainly responsible for functions of managing subscription data, user access authorization and the like.

And the UDR network element is mainly responsible for the access function of the type data such as subscription data, strategy data, application data and the like.

The AF network element is mainly responsible for transferring the requirements of the application side on the network side, such as QoS requirements or user status event subscriptions. The AF may be a third party functional entity or an application service deployed by an operator. The AF network element may also be referred to as an application server, or a third party device, etc.

The DN is a data network providing service for users, and generally, the client is located in the terminal device, and the server is located in the data network. The data network may be a private network, such as a local area network, an external network that is not controlled by an operator, such as the Internet (Internet), or a private network that is co-deployed by the operator, such as a configured IP multimedia network subsystem (IMS) service. In a roaming scenario, the home deployed local data network may be different from the visited deployed local data network. For convenience of understanding, the home-deployed local data network in this application may also be referred to as a campus network, an enterprise private network, a local network, and the like, which is not limited.

The interfaces and functions between the network elements or functional entities are as follows:

the N1 interface refers to an interface between the AMF and the UE, and is used for delivering QoS control rules and the like to the UE.

The N2 interface refers to an interface between the AMF and the RAN, and is used for transmitting radio bearer control information from the core network side to the RAN.

The N3 interface is AN interface between the (R) AN and the UPF, and is used for transferring user plane data between the (R) AN and the UPF.

The N4 interface is an interface between the SMF and the UPF, and is used for transmitting information between the control plane and the user plane, and includes controlling issuing of a forwarding rule, a QoS control rule, a traffic statistic rule, and the like for the user plane, and reporting of information for the user plane.

The N5 interface is an interface between the AF and the PCF, and is used for issuing an application service request and reporting a network event. This interface is not shown temporarily in fig. 1.

The N6 interface is an interface between the UPF and the DN, and is used for transmitting user plane data between the UPF and the DN.

The N7 interface is an interface between the PCF and the SMF, and is used to issue a control policy of PDU session granularity and service data flow granularity. This interface is not shown temporarily in fig. 1.

The N8 interface is an interface between the AMF and the UDM, and is used for the AMF to obtain, from the UDM, subscription data and authentication data related to access and mobility management, and for the AMF to register, to the UDM, information related to current mobility management of the UE. This interface is not shown temporarily in fig. 1.

The N9 interface refers to AN interface between the UPFs, such as AN interface between a UPF connected to the DN and a UPF connected to the (R) AN, for transferring user plane data between the UPFs.

The N10 interface is an interface between the SMF and the UDM, and is used for the SMF to acquire subscription data related to session management from the UDM, and for the SMF to register the current session related information of the UE with the UDM. This interface is not shown temporarily in fig. 1.

The N11 interface refers to an interface between the SMF and the AMF, and is used for transmitting PDU session tunnel information between the RAN and the UPF, transmitting a control message to the UE, transmitting radio resource control information to the RAN, and the like.

The N15 interface is an interface between the PCF and the AMF and is used for issuing the UE strategy and the access control related strategy. This interface is not shown temporarily in fig. 1.

The N16a interface refers to an interface between the SMF and the I-SMF and is used for the I-SMF of the visit place to acquire the UPF information of the home place from the SMF of the home place.

An N22 interface refers to an interface between the AMF and a network handover selection function (NSSF), the method is used for AMF to inquire the NSSF about Allowed used allowedNSSAI (network slice selection establishment information), configured NSSAI Configured by the home network on the UE, and other information. This interface is not shown temporarily in fig. 1.

And the N35 interface is an interface between the UDM and the UDR and is used for the UDM to acquire user subscription data information from the UDR. This interface is not shown temporarily in fig. 1.

The N36 interface is an interface between the PCF and the UDR, and is used for the PCF to obtain policy-related subscription data and application data-related information from the UDR. This interface is not shown temporarily in fig. 1.

The network element or the functional entity may be a network element in a hardware device, or may be a software function running on dedicated hardware, or a virtualization function instantiated on a platform (e.g., a cloud platform). Optionally, the network element or the function may be implemented by one device, or may be implemented by multiple devices together, or may be a functional module in one device, which is not specifically limited in this embodiment of the present application.

The general user registration procedure can be described simply as: UE sends register request to AMF through RAN, AMF obtains signing data from specific UDM according to user identification, UDM can obtain actual signing data from UDR after receiving the request. In addition, AMF may also initiate a user policy control establishment request (UEPolicyControl _ Create) and an access management policy control establishment request (AMPolicyControl _ Create) to PCF, which are respectively used to obtain UE policy and access control policy. The PCF returns the access control policy to the AMF in the process and provides the UE policy to the UE via the AMF.

The general session establishment procedure can be described simply as: UE sends session establishment request to AMF through RAN, AMF selects SMF for the session to provide service for the session, stores the corresponding relation between SMF and PDU session, sends the session establishment request to SMF, SMF selects corresponding UPF for UE and establishes user plane transmission path, and allocates IP address for the UPF. In the process, the SMF also initiates a policy control session establishment request to the PCF, so as to establish the policy control session between the SMF and the PCF, and in the process of establishing the policy control session, the SMF stores the corresponding relation between the policy control session and the PDU session. For roaming scenarios, control signaling needs to be forwarded by the I-SMF and SMF, and media data needs to be forwarded by the I-UPF.

It should be noted that the terms "system" and "network" in the embodiments of the present application may be used interchangeably. The "plurality" means two or more, and in view of this, the "plurality" may also be understood as "at least two" in the embodiments of the present application. "at least one", is to be understood as meaning one or more, for example one, two or more. For example, the inclusion of at least one is meant to include one, two or more, and is not limiting of which are included. For example, including at least one of A, B, and C, then what is included may be A, B, C, A and B, A and C, B and C, or A and B and C. Similarly, the understanding of the description of "at least one" and the like is similar. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" generally indicates that the preceding and following related objects are in an "or" relationship, unless otherwise specified.

Unless stated to the contrary, the embodiments of the present application refer to the ordinal numbers "first", "second", etc., for distinguishing between a plurality of objects, and do not define the order, sequence, priority, or importance of the plurality of objects, and the descriptions of "first", "second", etc., do not define that the objects are necessarily different.

For convenience of description, the following examples of A-SMF, I-SMF, UPF, I-UPF, and ULCL UPF are used for illustration. It should be understood that, in the following embodiments, a-SMF may be replaced by an anchor session management function network element (or a session management function network element at a home), I-SMF may be replaced by an intermediate session management function network element (or a session management function network element at a visited place), PSA UPF may be replaced by an anchor user plane function network element, I-UPF may be replaced by an intermediate user plane function network element, and ULCL UPF may be replaced by an uplink classifier user plane function network element.

Example one

In the existing 3GPP architecture, the ulsl UPF selection in the roaming scenario is implemented by the I-SMF, and the selection of the ulsl UPF of the home location through the SMF of the home location in the existing I-UPF scenario is not supported, so that the service flow of the terminal device cannot be shunted at the home location after returning to the home location. In addition, after the service flow of the terminal equipment returns to the home, since the UPF of the home is a main anchor point UPF and has no internet outlet (after the MEC sinks to the city, the UPF shared by the city has an internet outlet, and the city where the UPF of the home has no internet outlet), the requirement for further distribution after the service flow of the terminal equipment returns to the home cannot be met.

In order to solve the above problem, an embodiment of the present application provides a network access method, which may enable a terminal device to still access a local data network of a home location in a roaming scenario (for example, when a user goes out of a campus or roams between and in a province), and data streams may be offloaded at the home location after returning to the home location, and the internet is accessed without the local data network of the home location.

The embodiment of the present application may have two possible roaming scenarios as shown in fig. 2 and fig. 3. For convenience of understanding, the two roaming scenarios may be referred to as an intra-province roaming scenario and an inter-province roaming scenario, respectively, where the intra-province roaming scenario may also be referred to as an inter-city roaming scenario, and the inter-province roaming scenario may also be referred to as an inter-province roaming scenario, without limitation.

Fig. 2 corresponds to a scenario where multiple UPFs are within the management range of the same SMF (e.g., an intra-provincial roaming scenario), and shows that both the I-UPF of the visited place and the PSA UPF1 of the home place are managed by the a-SMF, where the PSA UPF1 of the home place is the primary anchor point UPF of the terminal device. The scenario can be understood that the UPF of the home and the UPF of the visited place are in the management range of the same SMF, and the home and the visited place share the same SMF but correspond to different UPFs. For example, the home and visited places may be different cities within one province, which may be referred to as a home city and a visited city, respectively, where the SMF of the home city and the SMF of the visited city are the same SMF, i.e. the SMFs of both provinces. In this scenario, if the location of the terminal device is still within the Service Area (SA) of the a-SMF of the home location after the terminal device moves from the home location to the visited location, but is not already within the service area of the PSA UPF1 of the home location (i.e., the primary anchor UPF), then the a-SMF may choose to insert an I-UPF at the visited location in order to forward the user plane data between the visited location and the home location.

Fig. 3 corresponds to a scenario where a plurality of UPFs are not within the management range of the same SMF (e.g., an inter-provincial roaming scenario), and shows that the I-UPF of the visited place is managed by the I-SMF of the visited place, and the PSA UPF1 of the home place and the ULCL UPF of the home place are both managed by the a-SMF of the home place, where the PSA UPF1 of the home place is the primary anchor point UPF of the terminal device. In this scenario, it can be understood that the UPF of the home location and the UPF of the visited location are in the management ranges of different SMFs, and the home location and the visited location correspond to not only different SMFs but also different UPFs. For example, the home and visited places may be different provinces in the country, which may be referred to as the home and visited provinces, respectively, where the SMF of the home province is a different SMF than the SMF of the visited province, the UPF of the home province is a different UPF than the UPF of the visited province, 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 location of the terminal device is not already in the service area of the a-SMF of the home location and is also not in the service area of the PSA UPF1 (i.e. the primary anchor point UPF) of the home location after the terminal device moves from the home location to the visited location, the AMF may choose to insert the I-SMF at the visited location, so as to forward the message or signaling of the control plane between the visited location and the home location. Further, the I-SMF may select and insert an I-UPF to forward user plane data between the visited and home locations.

It should be noted that the intra-province roaming scenario and the inter-province roaming scenario mentioned in the present application are described based on the administrative division of china, because in china, the deployment of SMFs and UPFs is usually related to the administrative division, for example, one SMF may be deployed for one province and one UPF may be deployed for one city. It should be understood, however, that the above description is merely an example, for the purpose of enabling the reader to have an vivid picture of a roaming scenario, and to more easily understand the relevant features of the roaming scenario. In fact, the distinction between the two roaming scenarios is made based on the deployment scenarios of SMF and UPF.

For example, in some possible embodiments, an intra-provincial roaming scenario may refer to: the terminal device moves in 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), and the two UPFs are managed by the same SMF, and the SMF can be called as the SMF of the home location or as the SMF of the visited location.

An inter-provincial roaming scenario may refer to: the terminal device moves within a larger range from the service area of the current SMF (i.e., the SMF of the home location) to the area of another SMF (i.e., the SMF of the visited location). Of course, the service area of the current UPF (i.e., the UPF of the home location) is also moved to the service area of another UPF (i.e., the UPF of the visited location), and the two UPFs are managed by different SMFs.

Please refer to fig. 4, which is a flowchart illustrating a network access method according to an embodiment of the present application, where the method includes:

step 401, the a-SMF of the home location is inserted into the ULCL UPF of the home location, which is used for shunting the traffic flow of the terminal device.

In the embodiment of the present application, the ULCL UPF is used to distribute the service flow of the terminal device to the primary anchor point UPF and the secondary anchor point UPF of the home location. The main anchor point UPF is located in a non-edge area of the home location, and the non-edge area may also be referred to as a non-MEC area or a central data plane. The non-edge area may be further connected to the internet through the core network, and thus, the terminal device may access the internet through the primary anchor point UPF in the non-edge area of the home location.

The ULCL UPF and the secondary anchor point UPF are located in an edge region of the home, which may also be referred to as the MEC region. The edge area may be deployed with a local data network of the home (e.g., MEC network), and thus, the terminal device may access the local data network of the home through the secondary anchor point UPF in the edge area of the home.

In a possible implementation manner, 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 the non-edge area of the home location to the edge area. For example, the a-SMF may be inserted into the ULCL UPF and/or the auxiliary anchor UPF according to a Data Network Name (DNN) subscribed by the terminal device, or the a-SMF may be inserted into the ULCL UPF and/or the auxiliary anchor UPF according to a DNN and a location subscribed by the terminal device, or the a-SMF may be inserted into the ULCL UPF and/or the auxiliary anchor UPF according to information such as a DNN, a location, or a Data Network Access Identifier (DNAI) subscribed by the terminal device. The DNN may be a dedicated DNN, a dedicated network slice, or the like, and is not limited thereto. Inserting the ULCL UPF and the secondary anchor UPF refers to inserting the ULCL UPF and the secondary anchor UPF into a session of the terminal device, e.g. a PDU session.

Further, the a-SMF may obtain, from the PCF, a user policy of the terminal device when the terminal device moves from a non-edge area of the home location to an edge area, where the user policy is used to indicate that a service flow of the terminal device needs to return to the home location and perform offloading in a roaming scenario. Further, the a-SMF may insert the above-mentioned ULCL UPF and/or the auxiliary anchor UPF in the edge area of the home according to the user policy.

For example, as shown in fig. 5, when the terminal device is in the non-edge area of the home, in step 501, the a-SMF and the primary anchor point UPF of the home may create a session, such as a PDU session, of the terminal device. Further, in step 502, the terminal device may access the internet through the primary anchor UPF. Specifically, in the uplink direction, a request for accessing the internet, which is initiated by the terminal device in a non-edge area of a home location, may be sent to the primary anchor point UPF via the access network device, and the primary anchor point UPF then sends the request to the internet; in the downlink direction, the response to the request returned by the internet can be sent to the main anchor point UPF, and the main anchor point UPF returns the response to the terminal equipment through the access network equipment.

When the terminal device moves from the non-edge area of the home location to the edge area, in step 503, the PCF may send, to the a-SMF, a user policy for the terminal device, where the user policy is used to indicate that the service flow of the terminal device needs to return to the home location and perform offloading in the roaming scenario. In step 504, the a-SMF may select and insert the ULCL UPF and/or the auxiliary anchor UPF according to information such as DNN, DNAI, or location subscribed by the terminal device. The ULCL UPF is used for distributing the service flow of the terminal equipment to the main anchor point UPF and the auxiliary anchor point UPF. The primary anchor point UPF is connected with the Internet and can be used for sending the received service flow to the Internet. The auxiliary anchor point UPF is connected with the local data network of the home location and can be used for sending the received service flow to the local data network of the home location. The ULCL UPF and the secondary anchor UPF may be deployed in one, and the application is not limited herein.

Further, in step 505, the a-SMF may issue a first offload rule to the ULCL UPF, where the first offload rule is used to instruct to send the traffic flow matching the first offload rule to the secondary anchor point UPF, and optionally, the first offload rule may further instruct to send the traffic flow not matching the first offload rule to the primary anchor point UPF. For example, the first offload rule may include a packet filter in the form of an IP quintuple associated with the home's local data network, or the like. Optionally, the first splitting rule may further include an address of the primary anchor UPF and an address of the secondary anchor UPF.

In step 506, the a-SMF may send the address of the ULCL UPF to the primary anchor UPF to update the bearer rules of the primary anchor UPF to establish a tunnel between the primary anchor UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the opposite-end address of the downlink tunnel of the main anchor point UPF, that is, the opposite-end address of the downlink tunnel of the main anchor point UPF is updated to the address of the ULCL UPF. For example, the a-SMF may send a first update request to the primary anchor UPF, the first update request to update the bearer rules of the primary anchor UPF, the first update request including the address of the ULCL UPF. The primary anchor point UPF may update the opposite-end address of the downlink tunnel to the address of the ULCL UPF after receiving the first update request, and then send a first update response to the a-SMF. The updating of the bearer rule may also be understood as meaning of refreshing or modifying or setting the bearer rule, refreshing or modifying or setting an opposite end address of the tunnel, refreshing or modifying or setting a destination address of the tunnel, and the like, which will not be described in detail below.

In step 507, the a-SMF may send an address of the ULCL UPF to the secondary anchor UPF to set a bearer rule of the secondary anchor UPF, thereby establishing a tunnel between the secondary anchor UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set an opposite-end address of the downlink tunnel of the auxiliary anchor point UPF, that is, the opposite-end address of the downlink tunnel of the auxiliary anchor point UPF is set as the address of the ULCL UPF. For example, the a-SMF may send a second update request to the secondary anchor UPF, the second update request being used to set the bearer rules of the secondary anchor UPF, the second update request including the address of the ULCL UPF. The auxiliary anchor point UPF may set the opposite end address of the downlink tunnel as the address of the ULCL UPF after receiving the second update request, and then send a second update response to the a-SMF.

In step 508, the a-SMF may send an 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, the access network device being located in the edge area of the home location. Specifically, the address of the ULCL UPF is used to update the address of the opposite end of the uplink tunnel of the access network device, that is, the address of the opposite end of the uplink tunnel of the access network device is updated to the address of the ULCL UPF. For example, the a-SMF may send a third update request to the home access network device, the third update request for updating the bearer rules of the access network device, the third update request including the address of the ULCL UPF. The access network device may update the address of the opposite end of the uplink tunnel to the address of the ULCL UPF after receiving the third update request, and then send a third update response to the a-SMF.

Therefore, after the terminal equipment moves from the non-edge area of the home location to the edge area, under the shunting action of the ULCL UPF, the terminal equipment 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.

When the terminal device accesses the local data network of the home location, as shown in steps 509 and 510, in the uplink direction, a request initiated by the terminal device in the edge area of the home location to access the local data network of the home location may be sent to the ULCL UPF through the access network device; the ULCL UPF determines that the request is matched with the first shunt rule according to the first shunt rule, and then sends the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF can further send the request to a local data network of the home location; in the downlink direction, the response to the request, which is returned to the terminal device by the local data network of the home location, may be first sent to the auxiliary anchor point UPF, and then sent to the ULCL UPF by the auxiliary anchor point UPF, and then returned to the terminal device by the ULCL UPF through the access network device.

When the terminal device accesses the internet, as shown in steps 510 and 511, in the uplink direction, a request for accessing the internet, which is initiated by the terminal device in the edge area of the home location, may be sent to the ULCL UPF via the access network device; the ULCL UPF determines that the request is not matched with the first shunt rule according to the first shunt rule, and then sends the request to a main anchor point UPF; the primary anchor UPF may then send the request further to the internet. In the downlink direction, the response to the request, which is returned to the terminal device by the internet, may be first sent to the primary anchor point UPF, sent to the ULCL UPF by the primary anchor point UPF, and then returned to the terminal device by the ULCL UPF through the access network device.

Step 402, when the terminal device moves to the visit place, the A-SMF sends the address of the ULCL UPF to the I-UPF of the visit place so as to establish a tunnel between the I-UPF and the ULCL UPF.

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

When the terminal device moves from the home location to the visited location, if the location of the terminal device is still in the service area of the a-SMF, the method corresponds to the intra-provincial roaming scenario shown in fig. 2. In the scene, the A-SMF can be inserted into the I-UPF of the visited place, and the I-UPF forwards the user plane data between the visited place and the home place. 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 opposite end address of the uplink tunnel of the I-UPF, and the A-SMF can also send the address of the I-UPF to the ULCL UPF to update the opposite end address of the downlink tunnel of the ULCL UPF, so as to establish the tunnel between the I-UPF and the ULCL UPF.

Illustratively, as shown in fig. 6, in step 601, when the terminal device moves from a home location to a visited location, the AMF may determine that the location of the terminal device is in the service area of the a-SMF. In step 602, the a-SMF may determine that the service flow of the terminal device needs to return to the home location and perform offloading in the roaming scenario according to the user policy of the terminal device received from the PCF before, that is, the N9 interface of the I-UPF of the visited location needs to interface with the ULCL UPF of the home location. In step 603, the A-SMF selects and inserts the I-UPF of the visit place according to the information of DNN, DNAI, or position, etc. signed by the terminal equipment.

In step 604, the A-SMF may send the address of the ULCL UPF to the I-UPF to set bearer rules for the I-UPF, thereby establishing a tunnel between the I-UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used for setting an opposite end address of the uplink tunnel of the I-UPF, that is, the opposite end address of the uplink tunnel of the I-UPF is set as 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, the fourth update request for setting bearer rules for the I-UPF, the fourth update request including an address of the ULCL UPF. After the I-UPF receives the fourth update request, the I-UPF may set the address of the opposite end of the uplink tunnel as 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 place to the I-UPF to set the bearer rule of the I-UPF, thereby establishing the tunnel between the I-UPF and the access network device. Specifically, the address of the access network device is used to set an address of an opposite end of the downlink tunnel of the I-UPF, that is, the address of the opposite end of the downlink tunnel of the I-UPF is set as 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 further includes an address of the access network device. After receiving the fourth update request, the I-UPF may set the opposite-end address of the uplink tunnel as the address of the ULCL UPF, set the opposite-end address of the downlink tunnel as the address of the access network device, and then send a fourth update response to the a-SMF.

In step 605, the a-SMF may send the address of the I-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 I-UPF. Specifically, the address of the I-UPF is used to update the address of the opposite end of the uplink tunnel of the access network device at the visited location, that is, the address of the opposite end of the uplink tunnel of the access network device at the visited location is updated to the address of the I-UPF, so that the access network device at 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 at the visited place, where the fifth update request is used to update the bearer rule 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 at the visited place can update the opposite terminal address of the uplink tunnel to the address of the I-UPF, and then send a fifth update response to the a-SMF.

In step 606, the a-SMF may send the I-UPF address to the ULCL UPF to update the bearer rules of the ULCL UPF to establish a tunnel between the ULCL UPF and the I-UPF. Specifically, the address of the I-UPF is used to update the opposite-end address of the downlink tunnel of the ULCL UPF, that is, the opposite-end address of the downlink tunnel of the ULCL UPF is updated 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, the sixth update request for updating the bearer rules of the ULCL UPF, the sixth update request including the address of the I-UPF. After receiving the sixth update request, the ULCL UPF may update the opposite-end address of the downlink tunnel to the address of the I-UPF, and then send a sixth update response to the a-SMF.

Therefore, when the terminal equipment moves to the visited place, the tunnel for bidirectional data interaction between the I-UPF and the ULCL UPF can be established through the mode, so that the service requirement that the service flow of the terminal equipment returns to the home location and is shunted under the roaming scene is met, and the safety of the local data network of the home location is improved. And then, under the data forwarding of the I-UPF and the shunting action of the ULCL UPF, the terminal equipment can access the Internet through the primary anchor point UPF and access the local data network of the home through the secondary anchor point UPF.

When the terminal device accesses the local data network of the home location, as shown in steps 607 and 608, in the uplink direction, a request initiated by the terminal device at the visited location to access the local data network of the home location may be sent to the I-UPF through the access network device, and forwarded to the ULCL UPF by the I-UPF; the ULCL UPF can determine that the request is matched with the first shunt rule according to the first shunt 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 to the request, which is returned to the terminal device by the local data network of the home location, may be first sent to the auxiliary anchor UPF, sent to the ULCL UPF by the auxiliary anchor UPF, and then forwarded to the I-UPF by the ULCL UPF, and finally returned to the terminal device by the access network device.

When the terminal device accesses the internet, as shown in step 609 and step 610, in the uplink direction, a request for accessing the internet, which is initiated by the terminal device at a visited place, can be sent to the I-UPF through the access network device, and then forwarded to the ULCL UPF by the I-UPF; the ULCL UPF may determine that the request does not match the first offload rule based on the first offload rule, and then send the request to the primary anchor UPF; the primary anchor UPF may then send the request further to the internet. In the downlink direction, the response to the request returned to the terminal equipment by the internet can be sent to the primary anchor point UPF first, sent to the ULCL UPF by the primary anchor point UPF, then forwarded to the I-UPF by the ULCL UPF, and finally returned to the terminal equipment by the access network equipment.

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, it corresponds to the inter-provincial roaming scenario shown in fig. 3. In this scenario, the AMF may plug in the I-SMF of the visited place, which forwards user plane data between the visited place and the home place. Further, the I-SMF can plug into the I-UPF at the visited place, which forwards the user plane data between the visited place and the home place. Because 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 so as to update the opposite end 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 so as to update the opposite end address of the downstream tunnel of the ULCL UPF.

Illustratively, as shown in fig. 7, in step 701, when the terminal device moves from a home location to a visited location, the AMF may determine that the location of the terminal device leaves the service area of the a-SMF. In step 702, the AMF may select and insert the I-SMF of the visited place according to information such as DNN, DNAI, or location signed up by the terminal device. Further, AMF may also send the address of A-SMF to I-SMF and receive a response from I-SMF for I-SMF to perform information interaction with A-SMF. In step 703, the a-SMF may determine that the data stream of the terminal device needs to return to the home location and perform offloading in the roaming scenario according to the user policy of the terminal device received from the PCF before, that is, the N9 interface of the I-UPF of the visited location needs to interface with the ULCL UPF of the home location. In step 704, the I-SMF may send a request to the A-SMF to obtain an opposite end address of an upstream tunnel of the I-UPF. In step 705, in response to the I-SMF request, 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 an I-UPF of the visited place according to information such as DNN, DNAI, or location signed up 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 executed before step 704, the I-SMF may also carry the address of the I-UPF in the request for obtaining the opposite end address of the uplink tunnel of the I-UPF.

In step 708, the I-SMF may send the address of the ULCL UPF to the I-UPF to set bearer rules for the I-UPF to establish a tunnel between the I-UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used for setting an opposite end address of the uplink tunnel of the I-UPF, that is, the opposite end address of the uplink tunnel of the I-UPF is set as 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 seventh update request to the I-UPF, the seventh update request for setting bearer rules for the I-UPF, the seventh update request including the address of the ULCL UPF. After receiving the seventh update request, the I-UPF may set the address of the opposite end of the uplink tunnel to the address of the ULCL UPF, and then send a seventh update response to the I-SMF. Optionally, the I-SMF may send the address of the access network device of the visited place to the I-UPF to set the bearer rule of the I-UPF, thereby establishing the tunnel between the I-UPF and the access network device. Specifically, the address of the access network device is used to set an address of an opposite end of the downlink tunnel of the I-UPF, that is, the address of the opposite end of the downlink tunnel of the I-UPF is set as 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 further includes an address of the access network device. After receiving the seventh update request, the I-UPF may set the opposite-end address of the uplink tunnel as the address of the ULCL UPF, set the opposite-end address of the downlink tunnel as the address of the access network device, and then send a seventh update response to the I-SMF.

In step 709, the I-SMF may send the address of the I-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 I-UPF. Specifically, the address of the I-UPF is used to update the address of the opposite end of the uplink tunnel of the access network device at the visited location, that is, the address of the opposite end of the uplink tunnel of the access network device at the visited location is updated to the address of the I-UPF, so that the access network device at the visited location can send the uplink service flow of the terminal device to the I-UPF. For example, the a-SMF may send an eighth update request to the access network device at the visited place, where the eighth update request is used to update the bearer rule 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 at the visited place may update the opposite end address of the uplink tunnel to the address of the I-UPF, and then send an eighth update response to the a-SMF.

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 to establish a tunnel between the ULCL UPF and the I-UPF. Specifically, the address of the I-UPF is used to update the opposite end address of the downlink tunnel of the ULCL UPF, that is, the opposite end address of the downlink tunnel of the ULCL UPF is updated 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 ninth update request to the ULCL UPF, the ninth update request to update the bearer rules of the ULCL UPF, the ninth update request including the address of the I-UPF. After receiving the ninth update request, the ULCL UPF may update the opposite-end address of the downlink tunnel to the address of the I-UPF, and then send a ninth update response to the a-SMF.

Therefore, when the terminal equipment moves to the visited place, a tunnel for bidirectional data interaction between the I-UPF and the ULCL UPF can be established through the mode, so that the N9 interface of the I-UPF is butted to the ULCL UPF of the home location, the service requirement that the data stream of the terminal equipment returns to the home location and is shunted in the roaming scene is met, and the safety of the local data network of the home location is improved. And then, under the data forwarding of the I-UPF and the shunting action of the ULCL UPF, the terminal equipment can access the Internet through the primary anchor point UPF and access the local data network of the home through the secondary anchor point UPF.

When the terminal device accesses the local data network of the home location, as shown in steps 711 and 712, in the uplink direction, a request for accessing the local data network of the home location initiated by the terminal device at the access location may be sent to the I-UPF through the access network device, and then forwarded to the ULCL UPF by the I-UPF; the ULCL UPF can determine that the request is matched with the first shunt rule according to the first shunt rule, and then sends the request to the auxiliary anchor point UPF; then, the auxiliary anchor point UPF can further send the request to a local data network of the home location; in the downlink direction, the response to the request, which is returned to the terminal device by the local data network of the home location, may be first sent to the auxiliary anchor UPF, sent to the ULCL UPF by the auxiliary anchor UPF, and then forwarded to the I-UPF by the ULCL UPF, and finally returned to the terminal device by the access network device.

When the terminal device accesses the internet, as shown in steps 713 and 714, in the uplink direction, a request for accessing the internet initiated by the terminal device at a visited place may be sent to the I-UPF through the access network device, and the I-UPF forwards the request to the ULCL UPF; the ULCL UPF may determine that the request does not match the first offload rule based on the first offload rule, and then send the request to the primary anchor UPF; the primary anchor UPF may then send the request further to the internet. In the downlink direction, the response to the request, which is returned to the terminal equipment by the internet, can be sent to the main anchor point UPF, sent to the ULCL UPF by the main anchor point UPF, and then forwarded to the I-UPF by the ULCL UPF, and finally returned to the terminal equipment by the access network equipment.

A related business process of the embodiment of the present application is described in detail below by taking an inter-provincial roaming scenario as an example. As shown in fig. 8a and 8b, the business process includes the following steps:

in step 801, a session is created by a-SMF of a home location and PSA UPF1, where PSA UPF1 refers to a primary anchor point UPF of the home location to which the UE is connected, and PSA UPF1 may be a shared UPF of a non-edge area of the home location selected according to a subscription DNN of the UE.

Step 802, the UE accesses the Internet through PSA UPF1 in the non-edge area of the home. The request for accessing the internet initiated by the UE in the non-edge area of the home location is sent to the PSA UPF1 via the RAN, and then forwarded to the internet by the PSA UPF 1.

In step 803, the response returned to the UE by the internet is first sent to PSA UPF1, and then forwarded to the UE via RAN by PSA UPF 1.

In step 804, the UE moves to the edge area of the home.

And step 805, after the UE moves to the edge area of the home location, triggering the PCF to issue the user strategy of the UE to the A-SMF. For example, the PCF may issue the user policy to the a-SMF via a session management policy update request message.

In step 806, the A-SMF replies a response to the PCF after receiving the UE's user policy. For example, a-SMF may reply with a response to a-SMF via a session management policy update response message.

Step 807, a-SMF selects ULCL UPF + PSA UPF2 based on user policy and inserts the user session. The PSA UPF2 refers to an auxiliary anchor point UPF connected to the terminal device, and the ULCL UPF and the PSA UPF2 may be local UPFs of an edge area of a home location selected according to information such as DNN, DNAI, or location (e.g., tracking Area Code (TAC)) subscribed by the UE, and the two may be deployed in a unified manner.

Step 808, the a-SMF issues the forking rule to the ULCL UPF, e.g., the a-SMF may issue the forking rule to the ULCL UPF via a PDU session setup request message.

The ULCL UPF returns a response to the A-SMF, step 809, e.g., the ULCL UPF may return a response to the A-SMF through a PDU session setup response message.

At step 810, the A-SMF refreshes the bearer rule of PSA UPF1, refreshing the opposite address of the N9 interface of PSA UPF1 (i.e., the opposite of the N9 interface) to ULCL UPF.

In step 811, PSA UPF1 returns a response to A-SMF.

Step 812, A-SMF refreshes the bearer rule of PSA UPF2, refreshing the opposite address of the N9 interface of PSA UPF2 (i.e., the opposite of the N9 interface) to ULCL UPF.

Step 813, PSA UPF2 returns a response to A-SMF.

In step 814, the A-SMF refreshes the bearer rules of the RAN and refreshes the peer address of the N3 interface of the RAN (i.e., the peer of the N3 interface) to the ULCL UPF.

The ran replies a response to the a-SMF, step 815.

The above steps 810 to 815 can refer to the contents of 3gpp23502 about adding PDU session anchor points, forking points or ULCLs.

In step 816, after the home a-SMF selects ULCL UPF + PSA UPF2 to insert the user session, the UE can access the home local data network through ULCL UPF + PSA UPF2 in the edge area of the home. The UE's request to access the home local data network, initiated at the home edge area, is sent to the ULCL UPF via the RAN, then forwarded by the ULCL UPF to the PSA UPF2, and then forwarded by the PSA UPF2 to the home local data network.

And step 817, returning the response returned by the local data network of the home location according to the path.

In step 818, the ue in the edge area of the home may forward to PSA UPF1 via the N9 interface of the ULCL UPF to access the internet. The request for accessing the internet initiated by the UE in the home edge area is sent to the ULCL UPF via the RAN, and then forwarded to PSA UPF1 by the ULCL UPF, and then forwarded to the internet by PSA UPF 1.

Step 819, the response returned from the internet is returned according to the path.

Step 820, the UE moves out of the service area of the A-SMF to the visited place.

In step 821, AMF determines that the service area of the home location A-SMF does not include the location of the UE, and therefore, selects and inserts an I-SMF, which is located at the visited location.

Step 822, AMF sends the address of the A-SMF to the I-SMF, e.g., AMF may send the address of the A-SMF to the I-SMF via a PDU session context creation request message.

In step 823, the I-SMF returns a response to the AMF, e.g., the I-SMF may return a response to the AMF via a PDU session context creation response message.

In step 824, the a-SMF determines that the service flow of the UE needs to return to the home location and needs to be shunted in the roaming scenario according to the user policy of the UE, that is, determines that the N9 interface of the I-UPF of the visited location is coupled to the ULCL UPF of the home location.

Optionally, the SMF in the home location may identify that the service flow is to return to the home location and is to be split in the roaming scenario by a configuration that a specific policy and charging control rule (PCC) predefined rule issued by the PCF corresponds to the SMF. The split rule can be judged according to the IP quintuple.

In step 825, the I-SMF requests the A-SMF to obtain the peer address of the N9 interface of the I-UPF, e.g., the I-SMF may request the obtaining of the peer address of the N9 interface of the I-UPF via a PDU session creation request message.

Step 826, the A-SMF may return the address of the ULCL UPF to the I-SMF, e.g., the A-SMF may return the address of the ULCL UPF to the I-SMF via a PDU session creation response message.

Step 827, I-SMF selects and inserts I-UPF, creates Packet Forwarding Control Protocol (PFCP) session.

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

Step 829, I-SMF updates the bearer rule of I-UPF, and refreshes the opposite address of the N9 interface of I-UPF to the address of ULCL UPF.

Step 830, I-UPF returns a response to I-SMF.

And 831, updating the bearing rule of the RAN by the I-SMF, and refreshing the opposite end address of the N3 interface of the RAN to the I-UPF.

In step 832, the ran returns a response to the I-SMF.

And step 833, updating the bearing rule of the ULCL UPF by the A-SMF, and refreshing the opposite end address of the N9 interface of the ULCL UPF to the I-UPF. This step can be referred to in 3gpp23502 for changing PDU session anchor or ULCL.

Step 834, ULCL UPF returns a response to A-SMF.

Step 835, the UE interfaces to ULCL + PSA UPF2 of the home at the visited site through the N9 interface of I-UPF, accessing the home's local data network.

And step 836, returning the response returned by the local data network of the home location according to the path.

At step 837, the UE interfaces to the ULCL UPF at the home location through the N9 interface of the I-UPF and then connects to the PSA UPF1 through the N9 interface of the ULCL UPF to access the Internet.

Step 838, the response returned from the internet is returned according to the path.

The service flow of the intra-provincial roaming scenario is similar to that of the inter-provincial roaming scenario shown in fig. 8b, and the main difference is that only one SMF (i.e., a-SMF) is involved in the intra-provincial roaming scenario, so that the SMF can have the functions of both the a-SMF of the home location and the I-SMF of the visited location in the service flow of the inter-provincial roaming scenario, and does not need to insert an I-SMF in the visited location according to the subscription of the user and the current location.

Therefore, in the solution of the first embodiment, if the total traffic of the terminal device needs to return to the home and split at the home, then: the SMF of the home location can select and insert the ULCL UPF and the auxiliary anchor UPF at the home location according to the DNN and the position signed by the terminal equipment; the SMF of the visit place can select and insert I-UPF in the visit place according to the DNN signed by the terminal equipment and the position; and the present application supports setting the forwarding object of the N9 interface of I-UPF to ULCL UPF. Therefore, the scheme can enable a user to use one DNN in a roaming scene, and all service flows (including service flows accessing the Internet) can be returned to the home and shunted at the home, so that the safety of a park network is improved, and a high-safety enterprise can conveniently monitor the flow of the user. The technical scheme can meet the safety requirement of the education network.

Example two

The existing 3GPP architecture cannot support the requirement that the terminal device uses one DNN in the roaming scenario, part of the traffic returns to the home to be unloaded, and the rest of the traffic is unloaded at the visited place. Therefore, another network access method is provided in the present application, by means of a customized ULCL UPF offloading rule, data streams of the terminal device in a roaming scenario are offloaded at a visited place, data streams of a local data network accessing the home place return to the home place, and other data streams (such as data streams accessing the internet) are directly offloaded at the visited place.

Embodiment two of the present application may have two possible roaming scenarios as shown in fig. 9 and fig. 10. For ease of understanding, these two roaming scenarios may be referred to as an intra-province roaming scenario and an inter-province roaming scenario, respectively.

Fig. 9 corresponds to a scenario (for example, an intra-provincial roaming scenario) in which multiple UPFs are within the management range of the same SMF, where the I-UPF at the visited location and the PSA UPF1 at the home location are both managed by the a-SMF, and the PSA UPF1 at the home location is the master anchor point UPF of the terminal device. This scenario is similar to the scenario shown in fig. 2 and will not be described again.

Fig. 10 corresponds to a scenario (e.g., an inter-provincial roaming scenario) in which a plurality of UPFs are not within the management range of the same SMF, and shows that the I-UPF of the visited place and the ULCL UPF of the visited place are both managed by the I-SMF of the visited place, while the PSA UPF1 of the home place is managed by the a-SMF of the home place, and the PSA UPF1 of the home place is the master anchor point UPF of the terminal device. This scenario differs from the scenario shown in fig. 3 mainly in that the ULCL UPF is located at the visited place.

Please refer to fig. 11, which is a flowchart illustrating another network access method according to a second embodiment of the present application, where the method includes:

step 1101, when the terminal device moves to the visited place, the SMF of the visited place is inserted into the ULCL UPF of the visited place, and the ULCL UPF is used for shunting the service flow of the terminal device.

In the embodiment of the present application, the ULCL UPF is configured to split a service flow of the terminal device to the primary anchor point UPF and the secondary anchor point UPF. The main anchor point UPF is located at the home location, and the main anchor point UPF can be used for sending the service flow of the terminal device to the local data network of the home location. And the auxiliary anchor point UPF is positioned at the visit place and can be used for sending the service flow of the terminal equipment to the Internet.

In a possible implementation manner, when the terminal device moves from the home location to the visited location, the SMF of the visited location may insert the ULCL UPF and/or the auxiliary anchor UPF in the visited location, for example, the SMF of the visited location may insert the ULCL UPF and/or the auxiliary anchor UPF according to the DNN subscribed by the terminal device, or the SMF of the visited location may insert the ULCL UPF and/or the auxiliary anchor UPF according to the DNN subscribed by the terminal device and the location, or the SMF of the visited location may insert the ULCL UPF and/or the auxiliary anchor UPF according to the information such as the DNN, the location, or a Data Network Access Identifier (DNAI) of the terminal device.

And 1102, the SMF of the visited place sends a second shunt rule to the ULCL UPF, wherein the second shunt rule is used for indicating that the service flow matched with the second shunt rule is sent to the primary anchor point UPF.

Accordingly, the ULCL UPF receives a second breakout rule from the SMF of the visited place.

Optionally, the second offload rule is used to indicate that the traffic flow that does not match the second offload rule is sent to the auxiliary anchor point UPF.

In the embodiment of the application, the SMF of the visited place determines that the data stream of the terminal device needs to be shunted at the visited place in the roaming scene according to the user policy of the terminal device, accesses the data stream returning place of the local data network of the home place, unloads the data stream accessing the internet at the visited place, and further sends the second shunting rule to the ULCL UPF.

Exemplarily, if the SMF of the visited place is the same as the SMF of the home place, corresponding to the intra-provincial roaming scenario shown in fig. 9, it indicates that the terminal device is still in the service area of the a-SMF of the home place after moving to the visited place, and at this time, the SMF of the visited place and the SMF of the home place are both a-SMF. In this scenario, the a-SMF may determine, according to the user policy of the terminal device received from the PCF before, that the service flow of the terminal device needs to be split at the visited location in the roaming scenario, and that the data flow accessing the local data network of the home location needs to return to the home location, and the data flow accessing the internet is offloaded at the visited location. The a-SMF may then insert the ULCL UPF and/or the auxiliary anchor UPF of the visited place and issue a second forking rule to the ULCL UPF. Further, the A-SMF can update the bearing rules of the access network equipment of the main anchor point UPF and the visited place according to the address of the ULCL UPF.

In one possible implementation, as shown in fig. 12, in step 1201, the AMF may determine that the location of the terminal device is within the service area of the a-SMF. In step 1202, the a-SMF may determine that the service flow of the terminal needs to be split at a visited place in a roaming scenario according to the user policy of the terminal received from the PCF before, and access the service flow of the local data network of the home location to return to the home location, and the service flow accessing the internet is offloaded at the visited place, or determine that the terminal directly accesses the internet by splitting at the visited place and returns to the home location to access the local data network of the home location. In step 1203, the a-SMF may select and insert the ULCL UPF and/or the auxiliary anchor UPF of the visited place according to the information of the DNN, the DNAI, or the location, etc. subscribed by the terminal device, and send the second forking rule to the ULCL UPF in step 1204.

In step 1205, the a-SMF may send the address of the ULCL UPF to the primary anchor UPF to update the bearer rules of the primary anchor UPF to establish a tunnel between the primary anchor UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the opposite end address of the downlink tunnel of the main anchor point UPF, that is, the opposite end address of the downlink tunnel of the main anchor point UPF is updated to the address of the ULCL UPF, so that the main anchor point UPF can send the downlink service flow of the terminal device to the ULCL UPF. For example, the a-SMF may send a tenth update request to the primary anchor UPF requesting an update to the bearer rules of the primary anchor UPF, the tenth update request including the address of the ULCL UPF. After receiving the tenth update request, the primary anchor point UPF may update the opposite-end address of the downlink tunnel to the address of the ULCL UPF, and then send a tenth update response to the a-SMF.

In step 1206, the a-SMF may send the address of the ULCL UPF to the secondary anchor UPF to set the bearer rules of the secondary anchor UPF to establish a tunnel between the secondary anchor UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set an opposite end address of the downlink tunnel of the auxiliary anchor point UPF, that is, the opposite end address of the downlink tunnel of the auxiliary anchor point UPF is set as 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 an eleventh update request to the secondary anchor UPF, the eleventh update request requesting setting of a bearer rule of the secondary anchor UPF, the eleventh update request including an address of the ULCL UPF. After receiving the eleventh update request, the auxiliary anchor point UPF may set the opposite-end address of the downlink tunnel to the address of the ULCL UPF, and then send an eleventh update response to the a-SMF.

In step 1207, the a-SMF may send the address of the ULCL UPF to the access network device at the visited place to update the bearer rules of the access network device to establish a tunnel between the access network device and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the address of the opposite end of the uplink tunnel of the access network device, that is, the address of the opposite end of the uplink tunnel of the access network device is updated 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, the twelfth update request requesting an update of the bearer rules of the access network device, the twelfth update request including the address of the ULCL UPF. After receiving the twelfth update request, the access network device may update the address of the opposite end of the uplink tunnel to the address of the ULCL UPF, and then send a twelfth update response to the a-SMF.

After that, under the shunting action of the ULCL UPF, the terminal equipment can access the local data network of the home through the primary anchor UPF and access the Internet through the secondary anchor UPF.

When the terminal device accesses the local data network of the home location, as shown in steps 1208 and 1209, in the uplink direction, a request initiated by the terminal device at the visited location to access the local data network of the home location may be sent to the ULCL UPF through the access network device; the ULCL UPF may determine that the request matches the second breakout rule according to the second breakout rule, and then send the request to the primary anchor UPF; the primary anchor UPF may then send the request further to the home local data network; in the downlink direction, the response to the request, which is returned to the terminal device by the local data network of the home location, may be first sent to the primary anchor point UPF, sent to the ULCL UPF by the primary anchor point UPF, and then returned to the terminal device by the ULCL UPF through the access network device.

When the terminal device accesses the internet, as shown in steps 1210 and 1211, in the uplink direction, a request for accessing the internet, initiated by the terminal device at a visited place, may be sent to the ULCL UPF through the access network device; the ULCL UPF may determine that the request is not matched with the second forking rule according to the second forking rule, and then send the request to the auxiliary anchor UPF; the secondary anchor UPF may then send the request further to the internet. In the downlink direction, the response to the request returned to the terminal equipment by the internet can be sent to the auxiliary anchor point UPF first, sent to the ULCL UPF by the auxiliary anchor point UPF, and then returned to the terminal equipment by the ULCL UPF through the access network equipment.

If the SMF of the visited place is different from the SMF of the home location, corresponding to the inter-province roaming scenario shown in fig. 10, it indicates that the terminal device leaves the service area of the a-SMF of the home location after moving to the visited place, at this time, the SMF of the visited place is the I-SMF of the visited place, and the SMF of the home location is the a-SMF of the home location. In the scenario, the A-SMF can send a user policy of the terminal device to the I-SMF, and determines that the data stream of the terminal device needs to be shunted at a visited place in a roaming scenario according to the user policy, the data stream of the local data network accessing the home place returns to the home place, and the data stream accessing the Internet is unloaded at the visited place. Optionally, the user policy may specifically refer to an insertion policy of the ULCL UPF and/or the secondary anchor UPF. Then, the I-SMF can select and insert the ULCL UPF and/or the auxiliary anchor point UPF of the visited place, issues a second shunting rule to the ULCL UPF, and sends the address of the ULCL UPF to the A-SMF so as to update the bearing rule of the main anchor point UPF of the home location. Further, the I-SMF can also update the load bearing of the access network equipment of the visited place according to the address of the ULCL UPF.

In one possible implementation, as shown in fig. 13, in step 1301, the AMF may determine that the location of the terminal device leaves the service area of the a-SMF. In step 1302, the AMF may select and insert an I-SMF of the visited place according to information such as DNN, DNAI, or location signed by the terminal device, and the I-SMF forwards the user plane data between the visited place and the home place. Further, AMF may also send the address of A-SMF to I-SMF and receive a response from I-SMF for I-SMF to exchange information with A-SMF. In step 1303, the a-SMF may determine, according to the user policy of the terminal device received from the PCF before, that the data stream of the terminal device needs to be shunted at the visited place in the roaming scenario, and the data stream of the local data network of the visited place returns to the home place, and the data stream of the visited internet is offloaded at the visited place, or, determine that the terminal device directly accesses the internet through shunting at the visited place, and returns to the home place to access the local data network of the home place. In step 1304, the I-SMF may send a request to the a-SMF for obtaining a user policy for the terminal device, which may also be understood as an insertion policy for obtaining the ULCL UPF and/or the secondary anchor UPF. In step 1305, the I-SMF may send the user policy of the terminal device to the A-SMF in response to the request of the I-SMF. In step 1306, the I-SMF may insert the ULCL UPF and/or the auxiliary anchor UPF of the visited place according to the information such as the DNN, the DNAI, or the location subscribed 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 for the primary anchor UPF. In step 1308, the I-SMF may send a second breakout rule to the ULCL UPF, thereby establishing a tunnel between the ULCL UPF and the primary and secondary anchor points UPF, UPF.

In step 1309, the I-SMF may send the address of the ULCL UPF to the secondary anchor UPF to set the bearer rule of the secondary anchor UPF, thereby establishing a tunnel between the secondary anchor UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to set an opposite-end address of the downlink tunnel of the auxiliary anchor point UPF, that is, the opposite-end address of the downlink tunnel of the auxiliary anchor point UPF is set as 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 I-SMF may send a thirteenth update request to the secondary anchor UPF, the thirteenth update request to set the bearer rules of the secondary anchor UPF, the thirteenth update request including the address of the ULCL UPF. After receiving the thirteenth update request, the auxiliary anchor point UPF may set the opposite end address of the downlink tunnel as the address of the ULCL UPF, and then send a thirteenth update response to the I-SMF.

In step 1310, the I-SMF may send an address of the ULCL UPF to the access network device of the visited place to update a bearer rule 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 address of the opposite end of the uplink tunnel of the access network device, that is, the address of the opposite end of the uplink tunnel of the access network device is updated 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 a fourteenth update request to the access network device, the fourteenth update request being used to update the bearer rule of the access network device, the fourteenth update request including the address of the ULCL UPF. After receiving the fourteenth update request, the access network device may update the address of the opposite end of the uplink tunnel to the address of the ULCL UPF, and then send a fourteenth update response to the I-SMF.

In step 1311, the a-SMF may send the address of the ULCL UPF to the primary anchor UPF to update the bearer rules of the primary anchor UPF to establish a tunnel between the primary anchor UPF and the ULCL UPF. Specifically, the address of the ULCL UPF is used to update the opposite end address of the downlink tunnel of the main anchor point UPF, that is, the opposite end address of the downlink tunnel of the main anchor point UPF is updated to the address of the ULCL UPF, so that the main anchor point UPF can send the downlink service flow of the terminal device to the ULCL UPF. For example, the a-SMF may send a fifteenth update request to the master anchor UPF, the thirteenth update request to update the bearer rules of the master anchor UPF, the fifteenth update request including the address of the ULCL UPF. After receiving the fifteenth update request, the primary anchor point UPF may update the opposite-end address of the downlink tunnel to the address of the ULCL UPF, and then send a fifteenth update response to the a-SMF.

When the terminal device accesses the local data network of the home location, as shown in steps 1312 and 1313, in the uplink direction, a request initiated by the terminal device at the visited location to access the local data network of the home location may be sent to the ULCL UPF via the access network device; the ULCL UPF may determine that the request matches the second breakout rule according to the second breakout rule, and then send the request to the primary anchor UPF; then, the primary anchor point UPF can further send the request to a local data network of the home location; in the downlink direction, the response to the request, which is returned to the terminal device by the local data network of the home location, may be first sent to the primary anchor point UPF, sent to the ULCL UPF by the primary anchor point UPF, and then returned to the terminal device by the ULCL UPF through the access network device.

When the terminal device accesses the internet, as shown in step 1314 and step 1315, in the uplink direction, a request for accessing the internet, which is initiated by the terminal device at a visited place, may be sent to the ULCL UPF via the access network device; the ULCL UPF may determine that the request is not matched with the second split rule according to the second split rule, and then send the request to the auxiliary anchor UPF; the secondary anchor UPF may then send the request further to the internet. In the downlink direction, the response to the request returned to the terminal equipment by the internet can be sent to the auxiliary anchor point UPF first, sent to the ULCL UPF by the auxiliary anchor point UPF, and then returned to the terminal equipment by the ULCL UPF through the access network equipment.

Therefore, in the above scheme, after inserting the ULCL UPF in the visited place and configuring the corresponding second forking rule for the ULCL UPF, under the forking action of the ULCL UPF, the terminal device can access the internet through the auxiliary anchor point UPF of the visited place in the visited place and access the local data network of the home place through the main anchor point UPF of the home place, thereby achieving the effect that the terminal device roams in the visited place, the service flow of the terminal device can be shunted in the visited place, the service flow of the local data network accessing the home place is connected to the main anchor point UPF of the home place through the ULCL UPF, and other service flows are directly unloaded in the visited place. Therefore, network resources can be fully utilized, the safety of the home local data network is improved, and the time delay of a user for accessing the Internet is reduced.

The service flow related to the embodiment of the present application is described in detail below by taking an inter-provincial roaming scenario as an example. As shown in fig. 14, the business process includes the following steps:

in step 1401, the UE signs up a special DN, and a home a-SMF and PSA UPF1 create a user session, where PSA UPF1 refers to a master anchor point UPF of the home where the UE is connected, and PSA UPF1 may be a shared UPF of a non-edge area of the home selected according to the UE's signed DNN.

In step 1402, the UE accesses the local data network at home via the PSA UPF 1. The request initiated by the UE at home to access the home local data network is sent to PSA UPF1 via the RAN, and then forwarded by PSA UPF1 to the home local data network.

In step 1403, the response returned to the UE by the home local data network is sent to PSA UPF1, and then the PSA UPF1 forwards the response to the UE via the RAN.

In step 1404, the ue moves out of the service area of the SMF to a visited place.

Step 1405, AMF determines that the service area of home A-SMF does not include the location of UE, therefore, I-SMF is selected and inserted, which is located at the visited place.

In step 1406, the AMF sends the address of the A-SMF to the I-SMF, e.g., the AMF may send the address of the A-SMF to the I-SMF via a PDU session context creation request message.

In step 1407, the I-SMF replies a response to the AMF, for example, the I-SMF may return a response to the AMF via the PDU session context creation response message.

And 1408, A-SMF judges that the UE accesses the Internet through the visited place shunt and returns to the home to access the local data network of the home under the roaming scene based on the user policy of the UE acquired from PCF.

In step 1409, the i-SMF requests the a-SMF to obtain the UE user policy, which may specifically refer to the insertion policy of ULCL UPF and/or PSA UPF2. For example, the I-SMF may request to acquire the user policy of the UE through a PDU session creation request message.

In step 1410, the A-SMF returns the UE's user policy to the I-SMF. The user policy may include a breakout rule for the ULCL UPF and an indication that the traffic matching the breakout rule is returned to the home PSA UPF1, and the rest of the traffic is offloaded at the visited site via PSA UPF2.

Step 1411, I-SMF selects and inserts ULCL UPF and/or PSA UPF2 at the visited site.

In step 1412, the I-SMF sends the address of the ULCL UPF to the A-SMF.

In step 1413, the i-SMF issues a splitting rule to the ULCL UPF, where the splitting rule indicates that the opposite end of the next hop N9 interface of the traffic flow matching the splitting rule is PSA UPF1 and the opposite end of the next hop N9 interface of the remaining traffic flows is PSA UPF2.

At step 1414, ULCL UPF returns a response to I-SMF.

Step 1415, I-SMF refreshes the bearer rule of PSA UPF2, refreshing the opposite address of the N9 interface of PSA UPF-2 to the address of ULCL UPF.

At step 1416, PSA UPF2 returns a response to the I-SMF.

In step 1417, the I-SMF refreshes the bearer rules of the RAN and refreshes the correspondent address of the N3 interface of the RAN to the ULCL UPF.

In step 1418, the RAN returns a response to the I-SMF.

In step 1419, the A-SMF refreshes the bearer rule of PSA UPF1, refreshing the peer address of the N9 interface of PSA UPF1 to ULCL UPF.

Step 1420, PSA UPF1 returns a response to A-SMF.

In step 1421, the ue accesses the home local data network at the visited site by interfacing to home PSA UPF1 through the N9 interface of the ULCL UPF.

Step 1422, the response returned by the local data network of the home location is returned according to the original route of the path.

In step 1423, the ue interfaces to the visited PSA UPF2 via the ULCL UPF at the visited site, accessing the internet.

Step 1424, the response returned from the internet is returned according to the path.

The service flow of the intra-province roaming scenario is similar to that of the inter-province roaming scenario shown in fig. 14, and the main difference is that only one SMF (i.e., a-SMF) is involved in the intra-province roaming scenario, so that the SMF can be used to implement the functions of both the a-SMF of the home location and the I-SMF of the visited location in the service flow of the inter-province roaming scenario, and does not require the AMF to insert the I-SMF in the visited location according to the user subscription and the current location.

Therefore, in the technical solution of the second embodiment, if part of the terminal device can be defined by the regular service traffic needs to return to the home, and the rest of the services can be unloaded at the visited place, then: the SMF of the visited place can select and insert the ULCL UPF and the auxiliary anchor point UPF of the home location according to the information of DNN, DNAI, position and the like signed by the terminal equipment; the SMF of the home location can issue a distribution rule to the ULCL UPF, the ULCL UPF is indicated to send the service flow matched with the distribution rule to the main anchor point UPF of the home location, and the service flow not matched with the distribution rule is sent to the auxiliary anchor point UPF of the visit location. Therefore, the service flow of the terminal equipment accessing the local data network of the home location under the roaming scene 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 technical scheme can meet the safety requirements of the government affair network.

According to the technical scheme, the UPF of the visited place is not required to send all data streams of the terminal equipment to the home, but only the data streams of the local data network of the visited place are sent to the home, so that network resources can be fully utilized, the safety of the local data network of the home is guaranteed, and meanwhile, the time delay of the terminal equipment for accessing the Internet is reduced.

It should be noted that if part of the services are unloaded at the visited place, part of the services return to the home place, and the visited place UPF supports the I-UPF/ULCL/auxiliary anchor point integration function, then: the unified UPF can decide whether to shunt at a local N6 interface or to shunt through an N9 interface according to a destination address of user service access and the like, and the shunting strategy is realized by the cooperation of the SMF and the UPF.

In the technical scheme of adopting the unified UPF, the UPF of the visited place supports unified deployment of I-UPF, ULCL and auxiliary anchor point UPF. This solution may also have two possible roaming scenarios, which are shown in fig. 15 and fig. 16, respectively, where fig. 15 corresponds to a scenario where multiple UPFs are within the management range of the same SMF (e.g., intra-provincial roaming scenario), and fig. 16 corresponds to a scenario where multiple UPFs are not within the management range of the same SMF (e.g., inter-provincial roaming scenario). For example, the above description may be referred to, and details are not repeated.

The visiting place can determine a shunting strategy according to the service accessed by the user, part of the service is unloaded through the local N6 interface, and part of the service is forwarded to the UPF of the home location through the N9 interface. Thus, the user has access to both the home local data network and the internet using a particular DNN. Furthermore, the home location can define the business data of the shunting rule to return to the home location, and the rest of traffic is routed out of the Internet at the N6 interface of the visit location.

Referring to fig. 17, a schematic structural diagram of a communication device according to an embodiment of the present application is provided, where the communication device 1700 includes: a transceiver module 1710 and a processing module 1720. The communication device can be used for realizing the functions of the session management function network element of the home location, the middle 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 may be a network device, or a device (for example, a chip included in the network device) capable of supporting the network device to implement the corresponding functions in the foregoing method embodiments, or the like.

Illustratively, when the communication apparatus performs the operation or step corresponding to the session management function network element of the home location in the method embodiment shown in fig. 4, the processing module 1720 is configured to insert an uplink classifier user plane function network element of the home location, where the uplink classifier user plane function network element is configured to offload traffic flow of the terminal device; when the terminal device moves to the visited place, the transceiver module 1710 is configured to send the address of the uplink classifier user plane function network element to the middle user plane function network element of the visited place, so as to establish a tunnel between the middle user plane function network element and the uplink classifier user plane function network element.

In one possible design, the processing module 1720 is specifically configured to insert an uplink classifier user plane function network element according to a data network name DNN subscribed to by the terminal device.

In a possible design, the transceiver module 1710 is further configured to receive a user policy of a terminal device from a policy control function network element, where the user policy is used to indicate that a service flow of the terminal device needs to return to a home location and perform offloading in a roaming scenario; the processing module 1720 is specifically configured to insert an uplink classifier user plane function network element according to a user policy.

In one possible design, the transceiving module 1710 is further configured to send a first offload rule to the upstream classifier user plane functional network element, where the first offload rule is used to instruct that a service flow matching the first offload rule is sent to an auxiliary anchor user plane functional network element of the home, and the auxiliary anchor user plane functional network element is connected to the local data network of the home.

In a possible design, the transceiving module 1710 is further configured to send the address of the uplink classifier user plane function network element to the auxiliary anchor point user plane function network element, so as to establish an opposite-end address of a downlink tunnel between the auxiliary anchor point user plane function network element and the uplink classifier user plane function network element.

In one possible design, the first offload rule is further configured to instruct the service flows that do not match the first offload rule to be sent to a home-based home-anchor-user-plane-function network element, where the home-anchor-user-plane-function network element is connected to the internet.

In a possible design, the transceiver 1710 is further configured to send an address of the uplink classifier user-plane function network element to the master anchor point user-plane function network element, so as to establish a tunnel between the master anchor point user-plane function network element and the uplink classifier user-plane function network element.

In one possible design, the transceiver module 1710 is further configured to send an address of the uplink classifier user plane function network element to the access network device of the home location, so as to establish a tunnel between the access network device and the uplink classifier user plane function network element.

In a possible design, if the terminal device is still in the service area of the communication apparatus after moving to the visited place, the processing module 1720 is further configured to insert an intermediate user plane function network element in the visited place; the transceiver module 1710 is further configured to send the address of the intermediate user plane function network element to the uplink classifier user plane function network element, so as to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

In one possible design, the transceiver module 1710 is further configured to send an address of the intermediate user plane function network element to the access network device at the visited place, so as to establish a tunnel between the access network device and the intermediate user plane function network element.

In a possible design, if the terminal device leaves the service area of the communication apparatus after moving to the visited place, the transceiver module 1710 is specifically configured 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 in the visited place.

In one possible design, transceiver module 1710 is further configured to: receiving an address of an intermediate user plane function network element from an intermediate user plane function network element through an intermediate session management function network element; and sending the address of the middle user plane function network element to the uplink classifier user plane function network element so as to establish a tunnel between the uplink classifier user plane function network element and the middle user plane function network element.

When the communication apparatus executes the operation or step corresponding to the middle session management function network element of the visited place in the method embodiment shown in fig. 4, the processing module 1720 is configured to insert the middle user plane function network element of the visited place when the terminal device moves to the visited place; the transceiver module 1710 is configured to receive an address of an uplink classifier user plane functional network element of a session management functional network element from a home location, where the uplink classifier user plane functional network element is configured to shunt a service flow of a terminal device, and the address of the uplink classifier user plane functional network element is configured to establish a tunnel between an intermediate user plane functional network element and the uplink classifier user plane functional network element.

In a possible design, the transceiver 1710 is further configured to send an address of the uplink classifier user plane function network element to the intermediate user plane function network element, so as to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

In a possible design, the transceiver module 1710 is further configured to send an address of an intermediate user plane function network element to the session management function network element, so as to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

When the communication apparatus executes the operation or step of the session management function network element corresponding to the visited place in the method embodiment shown in fig. 11, the processing module 1720 is configured to insert an uplink classifier user plane function network element of the visited place when the terminal device moves to the visited place, where the uplink classifier user plane function network element is used to offload service flows of the terminal device; the transceiver module 1710 is configured to send a second forking rule to the upstream classifier user plane functional network element, where the second forking rule is used to indicate that the service flow matching the second forking rule is sent to a home-based master anchor point user plane functional network element, and the home-based master anchor point user plane functional network element is connected to a local data network of the home.

In one possible design, the processing module 1720 is specifically configured to insert an uplink classifier user plane function network element according to a data network name DNN subscribed by the terminal device.

In one possible design, the processing module 1720 is specifically configured to insert an uplink classifier user plane function network element according to a user policy of the terminal device, where the user policy is used to indicate that a service flow of the terminal device needs to be split at a visited place in a roaming scenario, and the service flow of the local data network of the visited place returns to the home place.

In a possible design, if the session management function network element of the visited place is the same as the session management function network element of the home place, the transceiver module 1710 is configured to send the address of the uplink classifier user plane function network element to the master anchor point user plane function network element, so as to establish a tunnel between the master anchor point user plane function network element and the uplink classifier user plane function network element.

In a possible design, if the session management function network element of the visited place is different from the session management function network element of the home place, the transceiver module 1710 is configured to send the address of the uplink classifier user plane function network element to the master anchor point user plane function network element through the session management function network element of the home place, so as to establish a tunnel between the master anchor point user plane function network element and the uplink classifier user plane function network element.

In one possible design, the second forking rule is used to indicate that the service flow not matching the second forking rule is sent to an auxiliary anchor point user plane function network element of the visited place, and the auxiliary anchor point user plane function network element is connected to the internet.

In one possible design, the transceiving module 1710 is further configured to send an address of the uplink classifier user plane functional network element to the auxiliary anchor user plane functional network element, so as to establish a tunnel between the auxiliary anchor user plane functional network element and the uplink classifier user plane functional network element.

In one possible design, the transceiver module 1710 is configured to send an address of the uplink classifier user plane function network element to the access network device in the visited place, so as to establish a tunnel between the access network device and the uplink classifier user plane function network element.

The processing module 1720 involved in the communication device may be implemented by at least one processor or processor-related circuit component, and the transceiving module 1710 may be implemented by at least one transceiver or transceiver-related circuit component or communication interface. Operations and/or functions of the modules in the communication apparatus are not described herein again for brevity in order to implement the corresponding flows of the methods shown in fig. 4 to fig. 16, respectively. Optionally, the communication device may further include a storage module, where the storage module may be configured 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 as to enable the communication device to implement the corresponding method. The memory module may be implemented, for example, by at least one memory.

The storage module, the processing module, and the transceiver module may be separated, or all or part of the modules may be integrated, for example, the storage module and the processing module are integrated, or the processing module and the transceiver module are integrated.

Please refer to fig. 18, which is a schematic structural diagram of a communication device according to an embodiment of the present application. The communication device can be used for realizing the functions corresponding to the session management function network element of the home location, the intermediate session management function network element of the visited location or the session management function network element of the visited location in the method embodiment. The communication device may be a network device or a device (e.g., a chip included in the network device) capable of supporting the network device to implement the corresponding functions in the above method embodiments, and the like.

The communications device 1800 may include a processor 1801, a communications interface 1802, and a memory 1803. The communication interface 1802 is used for communicating with other devices through a transmission medium, and the communication interface 1802 may be a transceiver or an interface circuit such as a transceiver circuit, a transceiver chip, or the like. The memory 1803 is configured to store program instructions and/or data, and the processor 1801 is configured to execute the program instructions stored in the memory 1803, so as to implement the method in the above-described method embodiments. Optionally, the memory 1803 is coupled to the processor 1801, and the coupling is indirect coupling or communication connection between devices, units or modules, and may be in an electrical, mechanical or other form, which is used for information interaction between the devices, units or modules.

In an embodiment, the communication interface 1802 may be specifically configured to perform the actions of the transceiver module 1710, and the processor 1801 may be specifically configured to perform the actions of the processing module 1720, which is not described herein again.

The embodiment of the present application does not limit the specific connection medium among the communication interface 1802, the processor 1801, and the memory 1803. In the embodiment of the present application, the memory 1803, the processor 1801, and the communication interface 1802 are connected by a bus 1804 in fig. 18, the bus is indicated by a thick line in fig. 18, and the connection manner between other components is merely illustrative and not limited. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of illustration, only one thick line is shown in FIG. 18, but this does not mean only one bus or one type of bus.

An embodiment of the present application further provides a chip system, including: and the processor is coupled with the memory, and the memory is used for storing a program or instructions, and when the program or instructions are executed by the processor, the chip system is enabled to implement 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.

Optionally, the number of processors in the system on chip may be one or more. The processor may be implemented by hardware or by software. When implemented in hardware, the processor may be a logic circuit, an integrated circuit, or the like. When implemented in software, the processor may be a general-purpose processor implemented by reading software code stored in a memory.

Optionally, the memory in the system-on-chip may also be one or more. The memory may be integrated with the processor or may be separate from the processor, which is not limited in this application. For example, the memory may be a non-transitory processor, such as a read-only memory (ROM), which may be integrated on the same chip as the processor or may be separately disposed on different chips.

The system-on-chip may be, for example, a Field Programmable Gate Array (FPGA), an Application Specific Integrated Circuit (ASIC), a system on chip (SoC), a Central Processing Unit (CPU), a Network Processor (NP), a digital signal processing circuit (DSP), a Microcontroller (MCU), a Programmable Logic Device (PLD), or other integrated chips.

It should be understood that the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or instructions in the form of software. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware processor, or may be implemented by a combination of hardware and software modules in a processor.

The embodiment of the application also provides a communication system, which comprises a session management function network element of a home location and/or an intermediate session management function network element of a visited location; the session management function network element of the home location and the middle session management function network element of the visited location cooperate with each other and are jointly used for implementing the method in the first embodiment of the present application.

Optionally, the communication system further includes a home uplink classifier user plane function network element, a main anchor point user plane function network element, an auxiliary anchor point user plane function network element, and a visited middle user plane function network element.

The embodiment of the application also provides another communication system, which comprises a session management function network element of a visited place; and the session management function network element of the visited place is used for implementing the method in the second embodiment of the application.

The embodiment of the present application further provides a computer-readable storage medium, where computer-readable instructions are stored in the computer-readable storage medium, and when the computer-readable instructions are read and executed by a computer, the computer is enabled to execute the method in any of the above method embodiments.

The embodiments of the present application further provide a computer program product, which when read and executed by a computer, enables the computer to execute the method in any one of the method embodiments.

It should be understood that the processor referred to in the embodiments of the present application may be a CPU, but may also be 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 or the like.

It will also be appreciated that the memory referred to in the embodiments of the application may be either volatile memory or nonvolatile memory, or may include both volatile and nonvolatile memory. The non-volatile memory may be a ROM, a Programmable Read Only Memory (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, and not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), dynamic random access memory (dynamic RAM, DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), SLDRAM (synchronous DRAM), and direct rambus RAM (DR RAM).

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

It should be noted that the memory described herein is intended to comprise, without being limited to, these and any other suitable types of memory.

It should be understood that the various numerical references mentioned in the various embodiments of the present application are merely for convenience of description and differentiation, and the serial numbers of the above-mentioned processes or steps do not imply any order of execution, and the execution order of the processes or steps should be determined by their functions and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the technical solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It can be clearly understood by those skilled in the art that, for convenience and simplicity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as a stand-alone product, may be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or portions thereof that substantially contribute to the prior art may be embodied in the form of a software product stored in a storage medium and including instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute all or part of the steps of the method according to the embodiments of the present application. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

In the embodiments of the present application, unless otherwise specified or conflicting with respect to logic, the terms and/or descriptions in different embodiments have consistency and may be mutually cited, and technical features in different embodiments may be combined to form a new embodiment according to their inherent logic relationship.

The network architecture of a 5G network applicable to roaming scenarios as defined by the current 3GPP standard is shown in fig. 19.

The main functions of each network element/functional entity are as follows:

user Plane Function (UPF): and the UPF is used as an interface with a data network to complete functions of user plane data forwarding, session/stream level-based charging statistics, bandwidth limitation and the like.

Upstream Classifier user plane function (UPF Uplink Classifier, ULCL): the Uplink Classifier is called as UPF for short, and is a working form of UPF; used for service distribution; and determining the trend of the data stream according to different destination addresses accessed by the user.

Session Management Function (SMF): the method mainly performs functions such as session management, execution of Policy Control Function (PCF) issuing control policy, selection of UPF, and allocation of Internet Protocol (IP) address of a User Equipment (UE).

Access and mobility management function (AMF): mainly performs the functions of mobility management, access authentication/authorization and the like. In addition, the method is also responsible for transferring the user policy between the UE and the PCF.

And the forwarding SMF (Intermediate SMF, I-SMF) is used for forwarding the control plane message between the visited place and the home place.

(radio access network, (R) AN): the access method is applicable to different access networks in 5G, such as wired access, wireless base station access and the like.

Protocol Data Unit (PDU) session: the Session service for PDU connectivity between the UE and the data network is identified by a PDU Session ID (identifier).

PDU Session Anchor (PSA): i.e. the UPF PDU Session Anchor in fig. 1, which may be referred to as Anchor point UPF.

The architecture can also comprise:

forward UPF (Intermediate UPF, I-UPF): for forwarding data plane messages between the visited and home locations.

Application Function (AF): requirements of the application side on the network side, such as QoS (quality of service) requirements or user status event subscription, are mainly delivered. The AF may be a third party functional entity or an operator deployed application service, such as an IMS (IP multimedia subsystem) voice call service.

Unified Data Management (UDM): the system is mainly responsible for functions of managing subscription data, user access authorization and the like.

Unified Data Repository (UDR): the access function of the type data such as subscription data, strategy data, application data and the like is mainly responsible.

The policy control function PCF: the method is mainly responsible for carrying out charging, qoS bandwidth guarantee and mobility management, UE policy decision and other policy control functions aiming at the conversation and service flow levels. In the framework, PCFs connected to the AMF and SMF respectively correspond to AM PCF + UE PCF (PCF for Access and Mobility Control/PCF for UE Policy Control) and SM PCF (PCF for Session Management), and in an actual deployment scenario, the functions of the AM PCF and the UE PCF are usually provided by the same PCF, but the PCF and the SM PCF may not be the same PCF entity. For ease of description, this PCF instance that provides both UE Policy and AM Policy may be referred to subsequently simply as AM PCF.

The functions of the interfaces between the various network elements in fig. 19 are as follows:

the N1 interface refers to an interface between the AMF and the UE, is access-independent, and is used for transmitting a QoS control rule to the UE.

The N2 interface is an interface between the AMF and the RAN, and is used for transmitting radio bearer control information from the core network side to the RAN.

The N4 interface is an interface between the SMF and the UPF, and is used for transmitting information between the control plane and the user plane, including controlling the issuing of forwarding rules, qoS control rules, traffic statistics rules, etc. for the user plane and reporting information of the user plane.

The N9 interface refers to AN interface between UPF and UPF, such as AN interface between UPF connected to DN and UPF connected to (R) AN, for transferring user plane data between UPFs.

The architecture can also comprise:

the N5 interface is an interface between the AF and the PCF, and is used for issuing an application service request and reporting a network event.

The N7 interface is an interface between the PCF and the SMF, and is used to issue a PDU session granularity and a service data flow granularity control policy.

The N8 interface is an interface between the AMF and the UDM, and is used for the AMF to acquire subscription data and authentication data related to access and mobility management from the UDM, and for the AMF to register information related to current mobility management of the UE with the UDM.

The N10 interface is an interface between the SMF and the UDM, and is used for the SMF to acquire subscription data related to session management from the UDM, and for the SMF to register information related to the current session of the UE with the UDM.

The N15 interface is an interface between the PCF and the AMF and is used for issuing the UE strategy and the access control related strategy.

An N22 interface, which is an interface between the AMF and a Network Slice Selection Function (NSSF), the method is used for AMF to inquire the Allowed Allowed NSSAI (network slice selection establishment information) and the Configured NSSAI of the home network Configured on the UE from the NSSF;

the N35 interface is an interface between the UDM and the UDR, and is used for the UDM to acquire the user subscription data information from the UDR.

The N36 interface is an interface between the PCF and the UDR, and is used for the PCF to obtain policy-related subscription data and application data-related information from the UDR.

The general session establishment procedure can be described simply as: UE sends session establishing request to AMF through RAN, AMF selects SMF to provide service for the session, stores corresponding relation between SMF and PDU session, sends the session establishing request to SMF, SMF selects corresponding UPF for UE and establishes user plane transmission path, and allocates IP address for it. In the process, the SMF also initiates a policy control session establishment request to the PCF for establishing the policy control session between the SMF and the PCF, and in the process of establishing the policy control session, the SMF stores the corresponding relation between the policy control session and the PDU session. For the roaming user, in the roaming scenario, control signaling needs to be forwarded by the I-SMF and the SMF, and media data needs to be forwarded by the I-UPF.

The primary anchor point UPF mentioned in the embodiment of the present application refers to a UPF connected when the UE initially activates to create a session, and is used for allocating an IP address to the UE.

The secondary anchor point UPF is a UPR inserted after the session creation of the UE is completed, and is not used for creating a session and allocating an IP address.

In the existing 3GPP architecture, the ulsl UPF selection in the roaming scenario is implemented by I-SMF, and the selection of the ulsl UPF of the home location by the SMF of the home location is not supported, which cannot meet the requirement that service flows return to the home location when a campus user is roaming, and thus, a security risk exists in the campus network. In addition, after the business flow of the campus user returns to the home, since the home UPF is a main anchor point UPF and has no Internet exit (since the local share UPF has an Internet exit and the local UPF has no Internet exit), the requirement for further distribution based on the ULCL UPF after the business flow of the campus user returns to the home cannot be satisfied.

In order to solve the above problems, the present application provides a campus network access method, which enables a user to still access a campus network and access the Internet without the campus network in a roaming scenario, for example, when the user goes out of the campus or roams in provinces and provinces.

It should be understood that in the roaming scenario referred to in the present application, there is a distinction between home and visited places. The 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 by other names, without limitation. The visited place may also be referred to as a roaming place.

The third technical scheme of the embodiment of the application is as follows:

in a user roaming scenario, a Data Network Name (DNN) and a user location subscribed by a user determine the selection of the ULCL UPF. The user subscription may include a dedicated DNN, a dedicated slice, etc.

If all the service flows of the user require returning to the home and the shunting processing needs to be carried out at the home, then:

the home SMF may make a selection (or assignment or insertion) of the ULCL UPF and insert the ULCL UPF at home depending on the user subscription and the user's current location; the SMF of the visit place can insert I-UPF in the visit place according to the user subscription and the current position of the user; the forwarding object that requires the I-UPF to support the N9 interface is the ULCL UPF so that the destination address of the N9 interface of the I-UPF can be set to the ULCL UPF.

The third embodiment may include three possible access scenarios, which are: a campus access scenario, an intra-provincial roaming scenario, and an inter-provincial roaming scenario.

A campus access scenario may be as shown in fig. 20, which is a non-roaming scenario.

The preconditions of the scenario may include: 1) Configuring a default DNN of a user as a special DNN; 2) The user signs a subscription at the PCF to enable the park UPF for the user to make a UPF ULCL when the subsequent user roams in/between provinces.

Performing UPF selection in this scenario may include: 1) The SMF may select a primary anchor UPF for the user according to a special DNN subscribed by the user, for example, a shared UPF may be selected as the primary anchor UPF; 2) The SMF may select a park UPF as the UPF ULCL or the auxiliary anchor UPF based on the Tracking Area Code (TAC) of the user.

An intra-provincial roaming scenario may be as shown in fig. 21, which may also be referred to as an inter-city roaming scenario, or a cross-city roaming scenario.

In this scenario, the home and visited locations may share the same SMF, but each correspond to a different UPF, i.e., there is one SMF in the scenario. This is understood to mean that the UPF of the home and the UPF of the visited place are within the management scope of the same SMF, which can also be referred to as coverage. For example, the home and visited places may be different cities within one province, which may be referred to as home city and visited city, respectively. The SMF may be considered as an SMF of a home province, an SMF of a home/city, or an SMF of a visited/city.

The preconditions of the scenario may include: 1) Configuring a default DNN of a user as a special DNN; 2) The user signs up at the PCF to make a UPF ULCL for the user's active campus UPF when the user subsequently roams in/between provinces.

Performing UPF selection in this scenario may include: 1) The SMF judges that the user is a campus user and the position of the user is not in the campus; the SMF may select a primary anchor UPF for the user, e.g., may select a shared UPF as the primary anchor UPF; 2) The SMF can select a park UPF as a UPF ULCL or an auxiliary anchor UPF according to the subscription of a user; 3) The SMF may insert the I-UPF based on the current location of the user and inform the I-UPF of the address of the UPF ULCL.

An inter-province roaming scenario may be as shown in fig. 22, which may also be referred to as a cross-province roaming scenario.

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 is both an SMF of the home location and an SMF of the visited location. This may be understood as the UPF of the home and the UPF of the visited place being within the administrative scope of the different SMFs, which may also be referred to as coverage. For example, the home and visited locations may be different provinces within the country, which may be referred to as home province and visited province, respectively. The SMF of the home location may be an SMF of a home province and the SMF of the visited location may be an SMF of a visited province.

The preconditions of the scenario may include: 1) Configuring a default DNN of a user as a special DNN; 2) A first-level Network Repository Function (NRF) configures a DNN special for roaming province; 3) The user signs up at the PCF for the subsequent use of the campus UPF as a UPF ULCL when the user roams in/between provinces.

Performing UPF selection in this scenario may include: 1) The SMF of the visited place judges that the special DNN of the user is not supported, and then the NRF inquires the SMF corresponding to the DNN; 2) And the SMF of the home location judges that the user is a park user, and selects a park UPF as a UPF ULCL or an auxiliary anchor point UPF for the user. The SMF of the visited place and the UPF of the home place interactively complete the address allocation of the UE and return the address of the UPF ULCL to I-SMF/I-UPF; 3) The SMF of the visiting place inserts the I-UPF according to the current position of the user.

A network architecture suitable for the third embodiment can be shown in fig. 23, where scenario 1 in fig. 23 corresponds to an intra-province roaming scenario, and scenario 2 in fig. 23 corresponds to an inter-province roaming scenario.

It should be noted that the intra-province roaming scenario and the inter-province roaming scenario mentioned in the present application are partitions made to the roaming scenario based on the characteristics of the administrative division of our country, and are intended to make readers have vivid knowledge of the roaming scenario, but it should be noted that the present application is not limited thereto. In fact, the intra-provincial roaming scenario and the inter-provincial roaming scenario in the present application may be divided based on the deployment of SMF and UPF.

For example, in some embodiments, an intra-provincial roaming scenario may also refer to: the user moves in a smaller area range, does not leave the management range of the current SMF (namely the SMF of the attribution), but leaves the service range of the current UPF (namely the UPF of the attribution), and moves from the service range of the current UPF (namely the UPF of the attribution) to the service range of another UPF (namely the UPF of the visiting place). Two UPFs are managed by the same SMF.

The inter-provincial roaming scenario may also refer to: the user moves in a larger area range from the management range of the current SMF (namely the SMF of the home location) to the management range of another SMF (namely the SMF of the visit location). Of course, the service scope of the current UPF (i.e., the home UPF) is also moved to the service scope of another UPF (i.e., the visited UPF). The two UPFs are managed by different SMFs.

The above description about the intra-provincial roaming scenario and the inter-provincial roaming scenario can be applied to the third, fourth, and fifth embodiments of the present application, and will not be described in detail below.

The service flow in the third embodiment of the present application will be described in detail below by taking an inter-province roaming scenario (corresponding to the network architecture shown in scenario 2 in fig. 23) as an example. As shown in fig. 24, the method comprises the following steps:

step 2401, home SMF, UPF PSA-1 creates a user session.

And step 2402, the UE accesses the Internet through UPF PSA-1 in the home non-MEC area.

Step 2403, when the UE moves to the home edge area TAI, triggering the PCF to issue the offloading policy to the SMF, and the home SMF selects UPF ULCL + PSA-2 based on the offloading policy and inserts the user session.

Step 2404, the home SMF issues a offloading rule to the UPF ULCL, updates the bearer rule, and refreshes the opposite end addresses of the uplink and downlink data transmission tunnels of the N9 interface of the UPF ULCL to the UPF PSA1 and the RAN. This step may be referred to in 3GPP23502 for the addition of a PDU session anchor and diversion point or ULCL.

Step 2405, after the SMF at home selects UPF ULCL + PSA2 to insert the user session, when the UE accesses the home local service through UPF ULCL + PSA2 in the home MEC area, the service flow can be forwarded to UPF PSA1 through the N9 interface of UPF ULCL to access Internet.

Step 2406, when the UE moves out of the SMF coverage area to the visited place, the AMF determines that the Service Area (SA) of the SMF of the home location does not include the current location of the UE, and therefore, inserts the I-SMF in the visited place and sends the SMF address of the home location to the I-SMF of the visited place.

Step 2407, the SMF of the home location determines that the service flow is to return to the home location and needs to be shunted in the roaming scenario of the user based on the user shunting policy issued by the PCF, and determines that the I-UPF N9 interface of the visited location is butted to the home location UPF ULCL. Thus, when the I-SMF requests the SMF to acquire the opposite end address of the N9 interface of the I-UPF, the SMF of the home returns the UPF ULCL address of the home to the I-SMF of the visit place.

The SMF of the home location can be identified by the configuration corresponding to the SMF by a specific PCC predefined rule issued by the PCF, and the service flow returns to the home location and needs to be shunted in the roaming scenario of the user. The split rule can be judged according to the IP quintuple.

Step 2408, the I-SMF at the visited place selects an I-UPF according to the user subscription and the current location of the UE, creates a Packet Forwarding Control Protocol (PFCP) session, and informs the I-UPF of an address of an opposite end of an N9 interface of the I-UPF (i.e., an address of an UPF ULCL).

In step 2409, the smf updates the bearer rule and refreshes the UPF ULCL downlink tunnel address to the N9 interface opposite terminal as I-UPF. This step can be referred to in 3gpp23502 for changing PDU session anchor or ULCL.

And step 2410, updating the tunnel opposite terminal address of the uplink N3 interface on the RAN side to the I-UPF by the I-SMF. The tunnel peer address is the destination address (destination IP address) of the tunnel.

Step 2411, the UE is docked to the home UPF ULCL + PSA2 through the N9 interface of the I-UPF at the visited site, and then the home local DN is visited.

Step 2412, the UE is docked to the home UPF ULCL through the N9 interface of the I-UPF at the visit place, and then is docked to the UPF-PSA1 through the N9 interface of the UPF ULCL, so as to access the Internet.

The service flow of the intra-provincial roaming scenario in embodiment three is similar to that of the inter-provincial roaming scenario shown in fig. 24. The main difference is that only one SMF is involved in the intra-provincial roaming scenario, so the SMF can have the functions of both the home SMF and the I-SMF at the visited place in the service flow of the inter-provincial roaming scenario, and does not need the AMF to insert the I-SMF at the visited place according to the user subscription and the current location.

For brevity, the steps of the service flow in the intra-provincial roaming scenario are not described one by one in the present application, and it can be understood that the service flow can be implemented by modifying the service flow shown in fig. 24 based on the network architecture of scenario one in fig. 23.

In the third embodiment, the I-SMF and the I-UPF can be inserted according to the "user subscription + current location", and the forwarding object of the I-UPF at the visited place is set to be the UPF ULCL. Therefore, a user can use one DNN to realize that service flows (including Internet) can all return to the park UPF of the home and shunt at the home, thereby improving the security of the park network and facilitating high-security enterprises to monitor the flow of the user. For example, the technical solution in the first embodiment can meet the security requirements of the education network.

The existing 3GPP architecture cannot support the requirement that a user uses one DNN, part of traffic is unloaded back to the home, and the rest of traffic is unloaded at the visited place. To this end, the present application proposes the following fourth and fifth embodiments.

The fourth technical scheme of the embodiment of the application is as follows:

in a user roaming scene, the selection of the ULCL UPF is determined by the DNN and the user position signed by the user, and the user signing can be a proprietary DNN, a proprietary slice and the like.

If the business with part of the definable rules returns to the home and the rest of the business is unloaded at the visited place, then: the I-SMF of the visit place can select (or distribute or insert) the ULCL UPF, and inserts the ULCL UPF in the visit place according to the user subscription and the current position; the home SMF may make the selection of the primary anchor UPF.

The fourth embodiment may include three possible access scenarios, which are: a campus access scenario, an intra-provincial roaming scenario, and an inter-provincial roaming scenario.

A campus access scenario may be as shown in fig. 25, which is a non-roaming scenario.

Performing UPF selection in this scenario may include: performing UPF selection in this scenario may include: 1) The SMF may select a primary anchor UPF for the user based on the "private DNN" subscribed to by the user, e.g., may select the shared UPF as the primary anchor UPF; 2) The SMF may select a campus UPF as the UPF ULCL or the auxiliary anchor UPF according to a Tracking Area Code (TAC) of the user.

An intra-provincial roaming scenario may be as shown in fig. 26, which may also be referred to as an inter-city roaming scenario, or a cross-city roaming scenario.

In this scenario, the home and visited locations may share the same SMF, but each correspond to a different UPF, i.e., there is one SMF in the scenario. This can be understood as the UPF of the home and the UPF of the visited place are within the management scope of the same SMF, which can also be referred to as coverage. For example, the home and visited places may be different cities within one province, which may be referred to as home city and visited city, respectively. The SMF may be considered as an SMF of a home province, an SMF of a home/city, or an SMF of a visited/city.

The preconditions of the scenario may include: 1) Configuring a default DNN of a user as a special DNN; 2) The user signs a subscription at the PCF to subsequently enable the campus UPF as the primary anchor UPF for the user when the user roams in/between provinces.

Performing UPF selection in this scenario may include: 1) The SMF judges that the user is a campus user and the position of the user is not in the campus; selecting a main anchor point UPF; 2) I-SMF selects UPF ULCL or auxiliary anchor point UPF according to the user contract; 3) The I-SMF inserts the I-UPF according to the position and informs the I-UPF of the address of the UPF ULCL. It is understood that the SMF in this scenario is an SMF of a home province, and further may be said to be an SMF of a home/city, or an SMF of a visited/city.

An inter-provincial roaming scenario, which may also be referred to as a cross-provincial roaming scenario, may be illustrated in fig. 27.

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 at the home location and SMFs at the visited location. This may be understood as the UPF of the home and the UPF of the visited place being within the management scope of different SMFs, which may also be referred to as coverage. For example, the home and visited places may be different provinces within the country, which may be referred to as the home and visited provinces, respectively. The SMF of the home location may be an SMF of a home province and the SMF of the visited place may be an SMF of a visited province.

The preconditions of the scenario may include: 1) Configuring a default DNN of a user as a special DNN; 2) The first-level NRF configures special DNN for roaming province; 3) The user signs a subscription at the PCF to subsequently enable the campus UPF as the primary anchor UPF for the user when the user roams intra-provincial/inter-provincial.

Performing UPF selection in this scenario may include: 1) The SMF of the visiting place does not support the special DNN, and the DNN is inquired to the NRF to correspond to the SMF; 2) And the SMF of the home location judges that the user is a park user, and selects a park UPF as a main anchor point UPF. The SMF of the home location and the UPF of the home location interactively complete the address allocation of the UE; 3) The SMF at the roaming place inserts UPF ULCL of the I-UPF according to the current position of the user. It is understood that the SMF in the home province in this scenario may be said to be the SMF of the home location, and the SMF in the visited/roaming province may be said to be the SMF of the visited location.

Fig. 28 shows a network architecture to which the fourth embodiment is applied, wherein scenario 1 in fig. 28 corresponds to an intra-province roaming scenario, and scenario 2 in fig. 28 corresponds to an inter-province roaming scenario. The I-UPF and ULCL in the above architecture diagram are generally unified, i.e., ULCL can be used as the N3 interface capability of the I-UPF to realize roaming at the same time. Commonly referred to collectively as UPF ULCL.

The service flow in the fourth embodiment of the present application is described in detail below by taking an inter-province roaming scenario (corresponding to the network architecture shown in scenario 2 in fig. 28) as an example. As shown in fig. 29, the method comprises the following steps:

in step 2901, the UE signs up for a special DN and the home SMF, UPF PSA-1 creates a user session.

In step 2902, the UE accesses the local DN at home via UPF PSA-1.

And step 2903, when the UE moves out of the SMF coverage area to the visited place, the AMF determines that the service area SA of the SMF of the home location does not contain the location of the UE, selects to insert the I-SMF in the visited place, and sends the SMF address of the home location to the I-SMF.

Step 2904, the SMF of the home location determines that the user shunts and accesses the Internet at the visited location and the home location accesses the local network in the roaming scenario based on the user shunting policy issued by the PCF, and then when the I-SMF of the visited location requests the SMF of the home location to obtain the ULCL insertion rule and the shunting policy, the SMF of the home location transfers the shunting rule of the local DN of the home location to the I-SMF of the visited location and indicates the service flow matching the rule to return to the home location, and the rest of the service flows are unloaded at the visited location.

Step 2905, the I-SMF of the visited place selects UPF ULCL + PSA2 to insert into the user session, and issues a splitting rule to the UPF ULCL, where the splitting rule indicates that the next hop N9 interface peer of the service flow matching the local DN rule of the home place is UPF PSA-1, and the next hop N9 interface peer of the rest service flows is UPF PSA-2.

And step 2906, the SMF of the home location updates the bearer rule, and refreshes the UPF PSA-1 downlink tunnel to the opposite end of the N9 interface as the UPF ULCL.

Step 2907, the I-SMF of the visited site updates the RAN side upstream N3 tunnel interface destination address to the UPF ULCL.

In step 2908, the UE accesses the home local DN at the visited site by interfacing to the home UPF PSA-1 through the N9 interface of the UPF ULCL.

In step 2909, the UE accesses the Internet at the visited site via UPF ULCL + PSA 2.

The service flow of the intra-provincial roaming scenario in the fourth embodiment is similar to the service flow of the inter-provincial roaming scenario shown in fig. 29. The main difference is that only one SMF is involved in the intra-provincial roaming scenario, and therefore, the SMF can be used for realizing the functions of both the SMF of the home location and the I-SMF of the visited location in the service flow of the inter-provincial roaming scenario, and the AMF is not required to insert the I-SMF in the visited location according to the user subscription and the current location.

For brevity, the steps of the service flow in the intra-provincial roaming scenario are not described in detail in this application, and it should be understood that the service flow can be implemented by modifying the service flow shown in fig. 29 based on the network architecture of scenario one in fig. 28.

In the fourth embodiment, the SMF in the home location may send the offloading rule of the home local network to the I-SMF, and indicate that the service flow matching the offloading rule returns to the home location, and the rest is offloaded at the visited location. The SMF of the visited place can insert the ULCL UPF according to the 'user subscription + current position' and issues the shunting rule to the ULCL UPF. Therefore, the user can access both the campus network and the Internet by using one DNN. Further, the offloading rule may be determined according to a service accessed by the user, for example, a service accessed by the user to the Internet may be offloaded at a visited place, and a service accessed to the home local network may return to the home place. For example, the technical solution in the fourth embodiment can meet the requirements of the government affair network.

The fifth technical scheme of the embodiment of the application is as follows:

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

If partial service is unloaded locally, partial service returns to the home, and the UPF of the visited place supports the integrated function of I-UPF/ULCL/auxiliary anchor point, then: the unified UPF needs to decide whether to shunt at a local N6 interface or through an N9 interface according to a destination address of user service access and the like, and a shunting strategy is realized by the cooperation of the SMF and the UPF.

A network architecture to which the fifth embodiment is applicable is shown in fig. 30. The network architecture differs from the network architecture shown in fig. 10 in that the UPF of the visited place supports a unified deployment of I-UPF, ULCL and secondary anchor UPF.

The service flow in the third embodiment is similar to that shown in fig. 29, except that the UPF deployed in combination with the visited place may have the functions of the I-UPF, the ULCL and the auxiliary anchor UPF of the visited place in the service flow.

In the third embodiment, the visited site SMF selects I-UPF/ULCL UPF according to "user subscription + current location" and performs traffic offload locally through the auxiliary anchor point, sends the campus service (which can be judged by the destination address accessed by the user) to the home site UPF, and finally sends the campus service to the server of the campus network.

The visited place can determine a shunting strategy according to the service accessed by the user, part of the service is unloaded through the local N6 interface, and part of the service is forwarded to the UPF (namely the home UPF) of the campus network entrance through the N9 interface. Thus, a user may access both the campus network and the Internet using a particular DNN. Furthermore, the home location can define the business data of the shunting rule to return to the home location, and the rest of the traffic is routed out of the Internet at the N6 interface of the visit location.

According to the technical scheme provided by the embodiment of the application, the user can uniformly access the business of the park network by the specific UPF in/out of the park, and the park network is not required to deploy an Internet exit by itself, so that the safety of the park network is improved.

In the several embodiments provided in the present application, the disclosed system, apparatus and method can be implemented in other ways. For example, some features of the method embodiments described above may be omitted, or not performed. The above-described embodiments of the apparatus are merely exemplary, the division of the unit is only one logical function division, and there may be other division ways in actual implementation, and a plurality of 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 coupling includes electrical, mechanical or other connections.

In the various embodiments of the present application, the size of the serial number does not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

In addition, the term "and/or" herein is only one kind of association relationship describing an associated object, and means that three kinds of relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. In addition, the character "/" herein generally indicates that the former and latter related objects are in an "or" relationship.

It should be noted that in the embodiments of the present application, the terms "first", "second", and the like are used for distinguishing between descriptions and not necessarily for describing a relative importance or order, respectively. The 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 illustrations. Any embodiment or design described herein as "exemplary" or "such as" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present concepts related in a concrete fashion.

In short, the above description is only a preferred embodiment of the present disclosure, and is not intended to limit the scope of the present disclosure. Any modification, equivalent replacement, improvement and the like made within the principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for network access, the method comprising:

a session management function network element of a home location is inserted into an uplink classifier user plane function network element of the home location, and the uplink classifier user plane function network element is used for shunting service flow of terminal equipment;

and when the terminal equipment moves to a visited place, 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 of the visited place so as to establish a tunnel between the intermediate user plane function network element and the uplink classifier user plane function network element.

2. The method of claim 1, wherein the inserting, by the home session management function element, the home uplink classifier user plane function element comprises:

and the session management function network element of the home location is inserted into the user plane function network element of the uplink classifier according to the data network name DNN signed by the terminal equipment.

3. The method according to claim 1 or 2, wherein the home session management function network element inserts a home uplink classifier user plane function network element, and the method comprises:

the session management function network element receives a user policy of the terminal equipment from a policy control function network element, wherein the user policy is used for indicating that the service flow of the terminal equipment needs to return to the home location and shunt under a roaming scene;

and the session management function network element inserts the uplink classifier user plane function network element according to the user strategy.

4. The method according to any one of claims 1 to 3, further comprising:

and the session management function network element sends a first shunt rule to the uplink classifier user plane function network element, wherein the first shunt rule is used for indicating that the service flow matched with the first shunt rule is sent to an auxiliary anchor point user plane function network element of the home location, and the auxiliary anchor point user plane function network element is connected with a local data network of the home location.

5. The method of claim 4, further comprising:

and the session management function network element sends the address of the uplink classifier user plane function network element to the auxiliary anchor point user plane function network element so as to establish a tunnel between the auxiliary anchor point user plane function network element and the uplink classifier user plane function network element.

6. The method of claim 4, wherein the first offload rule is further configured to instruct a main anchor user plane function network element that sends the traffic flow that does not match the first offload rule to a home, and wherein the main anchor user plane function network element is connected to the Internet.

7. The method of claim 6, further comprising:

and the session management function network element sends the address of the uplink classifier user plane function network element to the main anchor point user plane function network element so as to establish a tunnel between the main anchor point user plane function network element and the uplink classifier user plane function network element.

8. The method of claim 4, further comprising:

and the session management function network element sends the address of the uplink classifier user plane function network element to the access network equipment of the home location so as to establish a tunnel between the access network equipment and the uplink classifier user plane function network element.

9. The method according to any of claims 1 to 8, wherein if the terminal device is still in the service area of the session management function network element after moving to a visited location, the method further comprises:

the session management function network element is inserted into the middle user plane function network element of the visited place;

and the session management function network element sends the address of the middle user plane function network element to the uplink classifier user plane function network element so as to establish a tunnel between the uplink classifier user plane function network element and the middle user plane function network element.

10. The method of claim 9, further comprising:

and the session management function network element sends the address of the middle user plane function network element to access network equipment of a visited place so as to establish a tunnel between the access network equipment and the middle user plane function network element.

11. The method according to any one of claims 1 to 8, wherein if the terminal device leaves the service area of the session management function network element after moving to the visited place, the session management function network element sends the address of the uplink classifier user plane function network element to the middle user plane function network element of the visited place, which includes:

and the session management function network element sends the address of the user plane function network element of the uplink classifier to the middle user plane function network element through the middle session management function network element of the visited place.

12. The method of claim 11, further comprising:

the session management function network element receives the address of the middle user plane function network element from the middle user plane function network element through the middle session management function network element;

13. A method for network access, the method comprising:

when the terminal equipment moves to the visited place, the middle session management function network element of the visited place is inserted into the middle user plane function network element of the visited place;

and the intermediate session management function network element receives an address of an uplink classifier user plane function network element of the session management function network element from the home location, and the uplink classifier user plane function network element is used for shunting the service flow of the terminal equipment.

14. The method of claim 13, further comprising:

and the middle session management function network element sends the address of the uplink classifier user plane function network element to the middle user plane function network element so as to establish a tunnel between the middle user plane function network element and the uplink classifier user plane function network element.

15. The method according to claim 13 or 14, characterized in that the method further comprises:

and 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 so as to establish a tunnel between the uplink classifier user plane function network element and the intermediate user plane function network element.

16. The method of any one of claims 13 to 15, further comprising:

and the middle session management function network element sends the address of the middle user plane function network element to access network equipment of a visited place so as to establish a tunnel between the access network equipment and the middle user plane function network element.

17. A method for network access, the method comprising:

when the terminal equipment moves to a visit place, a session management function network element of the visit place is inserted into an uplink classifier user plane function network element of the visit place, and the uplink classifier user plane function network element is used for shunting service flow of the terminal equipment;

and the session management function network element of the visited place sends a second shunt rule to the user plane function network element of the uplink classifier, wherein the second shunt rule is used for indicating that the service flow matched with the second shunt rule is sent to a main anchor point user plane function network element of the home place, and the main anchor point user plane function network element is connected with a local data network of the home place.

18. The method of claim 17, wherein the inserting of the session management function network element of the visited place into the uplink classifier user plane function network element of the visited place comprises:

and the session management function network element of the visited place is inserted into the user plane function network element of the uplink classifier according to the data network name DNN signed by the terminal equipment.

19. The method of claim 17 or 18, wherein the inserting of the session management function network element of the visited place into the uplink classifier user plane function network element of the visited place comprises:

and the session management function network element of the visited place inserts the uplink classifier user plane function network element according to the user policy of the terminal equipment, wherein the user policy is used for indicating that the service flow of the terminal equipment needs to be shunted in the visited place in a roaming scene, and the service flow of the local data network of the visited place returns to the home place.

20. The method according to any one of claims 17 to 19, wherein if the session management function network element of the visited place is the same as the session management function network element of the home place, the method further comprises:

and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the user plane function network element of the main anchor point so as to establish a tunnel between the user plane function network element of the main anchor point and the user plane function network element of the uplink classifier.

21. The method according to any one of claims 17 to 19, wherein if the session management function network element of the visited place is different from the session management function network element of the home place, the method further comprises:

and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the user plane function network element of the main anchor point through the session management function network element of the home place so as to establish a tunnel between the user plane function network element of the main anchor point and the user plane function network element of the uplink classifier.

22. The method of any of claims 17 to 21, wherein the second forking rule is used to indicate that the traffic flow that does not match the second forking rule is sent to an auxiliary anchor user plane function network element of a visited place, and the auxiliary anchor user plane function network element is connected to the internet.

23. The method of claim 22, further comprising:

and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the auxiliary anchor point user plane function network element so as to establish a tunnel between the auxiliary anchor point user plane function network element and the user plane function network element of the uplink classifier.

24. The method according to any one of claims 17 to 22, further comprising:

and the session management function network element of the visited place sends the address of the user plane function network element of the uplink classifier to the access network equipment of the visited place so as to establish a tunnel between the access network equipment and the user plane function network element of the uplink classifier.

25. An apparatus for communication, the apparatus comprising at least one processor coupled with at least one memory:

the at least one processor configured to execute computer programs or instructions stored in the at least one memory to cause the apparatus to perform the method of any of claims 1-12.

26. A communication device comprising a processor and interface circuitry;

the interface circuit is used for interacting code instructions or data with the processor;

the processor is configured to perform the method of any one of claims 1 to 12.

27. An apparatus for communication, the apparatus comprising at least one processor coupled with at least one memory:

the at least one processor configured to execute computer programs or instructions stored in the at least one memory to cause the apparatus to perform the method of any of claims 13-16.

28. A communication device comprising a processor and an interface circuit;

the processor is configured to perform the method of any one of claims 13 to 16.

29. An apparatus for communication, the apparatus comprising at least one processor coupled with at least one memory:

the at least one processor to execute computer programs or instructions stored in the at least one memory to cause the apparatus to perform the method of any of claims 17-24.

30. A communication device comprising a processor and an interface circuit;

the processor is configured to perform the method of any one of claims 17 to 24.

31. A communication system, characterized in that the system comprises a session management function network element of a home location and an intermediate session management function network element of a visited location; wherein the session management function network element of the home location is configured to perform the method of any of claims 1 to 12, and the intermediate session management function network element of the visited location is configured to perform the method of any of claims 13 to 16.

32. A communication system, characterized in that the system comprises a session management function network element of a visited place; wherein the session management function network element of the visited place is configured to perform the method according to any one of claims 17 to 24.

33. A computer-readable storage medium storing instructions that, when executed, cause the method of any one of claims 1 to 24 to be implemented.