Network protocol address allocation method and apparatus, and computer readable storage medium

Abstract

Embodiments of the present application provide a network protocol address allocation method and device and a computer readable storage medium, and relate to the technical field of communication. The method can allocate IP addresses according to the location information of a terminal device in a roaming scenario of the terminal device. The method comprises: a first network element obtaining first location information and second location information of a terminal device; the second location information is used to represent the location information of a second region in which the terminal device is currently registered; the first location information is used to represent the location information of a first region in which the terminal device is registered before registering the second region; the first network element determines that the movement trajectory of the terminal device meets a preset condition according to the first location information and the second location information; the first network element sends indication information to the terminal device, instructing the terminal device to release a first session of a first service and to re-establish a second session for the first service; and the first network element sends the second location information to a second network element, for the second network element to allocate a target IP address for the terminal device.

Description

Technical Field

[0001] This application relates to the field of communication technology, and in particular to network protocol address allocation methods, apparatus and computer-readable storage media. Background Technology

[0002] As the internet becomes increasingly intertwined with real life, operators, for network regulation purposes, have proposed a requirement to trace the location information of terminal devices based on their internet protocol (IP) addresses. To achieve this, a solution is needed where the network side can allocate IP addresses to terminal devices with fine precision based on their location information (e.g., down to the district / county level).

[0003] However, in current roaming scenarios using home routing, the core network elements providing access control for terminal devices and those used to allocate IP addresses to terminal devices are different network elements and may belong to different operators. In this complex scenario, there is no solution for fine-grained allocation of IP addresses to terminal devices, which hinders the monitoring of these devices. Therefore, how to achieve fine-grained allocation of IP addresses based on the location information of terminal devices in roaming scenarios using home routing is a pressing issue that needs to be addressed. Summary of the Invention

[0004] This application provides a network protocol address allocation method, apparatus, and computer-readable storage medium to solve the problem that the network side cannot finely allocate IP addresses based on the location information of the terminal device in scenarios where the terminal device is roaming.

[0005] To achieve the above objectives, this application adopts the following technical solution: Firstly, a method for allocating network protocol IP addresses is provided. The device executing this method can be a network element or a module applied within a network element, such as a chip. The following description uses a first network element as the executing entity. The method includes: the first network element acquiring first location information and second location information of a terminal device; wherein the second location information represents the location information of a second region currently registered by the terminal device; and the first location information represents the location information of a first region registered by the terminal device before registering in the second region. Based on the first and second location information, the first network element determines that the movement trajectory of the terminal device meets preset conditions; the first network element sends instruction information to the terminal device, the instruction information being used to instruct the terminal device to release a first session of a first service and re-establish a second session for the first service; the first network element sends second location information to a second network element, the second location information being used by the second network element to allocate a target IP address to the terminal device during the establishment of the second session.

[0006] Based on this solution, in scenarios where terminal devices roam, if a terminal device moves, the network side can obtain the second location information of the area currently registered by the terminal device and the first location information of the area previously registered by the terminal device. This allows the network side to determine whether the terminal device has moved across districts or counties. If the terminal device's movement trajectory meets preset conditions, the network side instructs the terminal device to go offline and then back online. This allows the network side to reallocate an IP address for the terminal device based on its current location information, i.e., the second location information. Compared to the current solution, where the network side cannot determine whether the terminal device's geographical location has changed before and after movement in roaming scenarios, thus assuming that the terminal device does not need to change its IP address and the IP address does not accurately represent the terminal device's actual geographical location, the IP address allocation scheme provided in this application can achieve fine-grained allocation of terminal device IP addresses in roaming scenarios, which is beneficial for terminal device location management. Furthermore, this solution can instruct the terminal device to go offline and then back online after determining that the terminal device's movement trajectory meets preset conditions, and reallocate an IP address during the back-on process, rather than during session switching, ensuring service consistency.

[0007] In conjunction with the first aspect, in some embodiments of the first aspect, the first area and the second area are located within the coverage area of ​​the visited network of the terminal device, and the first network element is the first network element of the visited network of the terminal device; or, the first area is located within the coverage area of ​​the home network of the terminal device, the second area is located within the coverage area of ​​the visited network of the terminal device, and the first network element is the first network element of the visited network of the terminal device; or, the first area is located within the coverage area of ​​the visited network of the terminal device, the second area is located within the coverage area of ​​the home network of the terminal device, and the first network element is the first network element of the home network of the terminal device. This solution can be applied to roaming scenarios using home routing.

[0008] In conjunction with the first aspect, in some embodiments of the first aspect, determining that the movement trajectory of the terminal device meets preset conditions based on the first location information and the second location information includes: the first network element determining that the movement trajectory of the terminal device meets the condition of moving between different districts and counties based on the first location information and the second location information. Based on this solution, the network side can reassign an IP address to the terminal device after determining that it has moved between different districts and counties.

[0009] In conjunction with the first aspect, in certain embodiments of the first aspect, the first network element determines that the movement trajectory of the terminal device satisfies the condition of moving between different districts and counties based on the first location information and the second location information. This includes: the first network element determining, based on a pre-configured mapping relationship between district and county information and location information, that the district and county corresponding to the first location information is the first district and county, and the district and county corresponding to the second location information is the second district and county, wherein the first district and county and the second district and county are different districts and counties. Based on this scheme, it is possible to determine whether the terminal device is moving across districts and counties based on the pre-configured mapping relationship between district and county information and location information.

[0010] In conjunction with the first aspect, in some embodiments of the first aspect, the first network element is the first network element of the visited network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the visited network of the terminal device, and the mapping relationship between location information and district / county information within a first preset range within the coverage area of ​​the home network of the terminal device; wherein, the first preset range is adjacent to the coverage area of ​​the visited network of the terminal device; or, the first network element is the first network element of the home network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the home network of the terminal device, and the mapping relationship between location information and district / county information within a second preset range within the coverage area of ​​the visited network of the terminal device; wherein, the second preset range is adjacent to the coverage area of ​​the home network of the terminal device.

[0011] In the case where the first network element is the visited network of the terminal device, compared with the existing first network element that only configures the location information within the coverage area of ​​the visited network of the terminal device, the solution of this application adds location information of the home network coverage area of ​​the terminal device related to the movement of the terminal device, and adds a mapping relationship between location information and district / county information. The first network element can determine the district / county corresponding to the first location information based on the first location information of the terminal device and determine the district / county corresponding to the second location information based on the second location information, thereby determining whether the terminal device has moved across districts / counties.

[0012] In the case where the first network element is the home network of the terminal device, compared with the existing first network element that only configures the location information within the coverage area of ​​the home network of the terminal device, in this embodiment of the application, the location information pre-configured by the first network element is added to the location information within the coverage area of ​​the visited network of the terminal device related to the movement of the terminal device, and a mapping relationship between the location information and the district / county information is added. The first network element can determine the district / county corresponding to the first location information based on the first location information of the terminal device and determine the district / county corresponding to the second location information based on the second location information, thereby determining whether the terminal device has moved across districts / counties.

[0013] In conjunction with the first aspect, in some embodiments of the first aspect, the location information includes at least one of the following: Tracking Area Identifier (TAI), Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI). This scheme can determine whether a terminal device is moving across districts or counties based on multiple different pieces of location information.

[0014] In conjunction with the first aspect, in certain embodiments of the first aspect, the first network element sends an indication message to the terminal device, including: when the first service includes a second service, the first network element sends indication information to the terminal device after detecting that the second service has ended; or, when the first service does not include a second service, the first network element sends indication information to the terminal device, wherein the second service is a voice call service or a video call service. This solution can ensure that when the terminal device is running a second service, the second service can end normally and will not be forcibly interrupted.

[0015] Secondly, a method for allocating network protocol IP addresses is provided. The device executing this method can be a network element or a module applied within a network element, such as a chip. The following description uses a second network element as the executing entity. The second network element receives second location information from a first network element; wherein the second location information is used to characterize the location information of the second region currently registered by the terminal device; the second network element determines the identification information of the district / county where the terminal device is currently located based on the second location information and the pre-configured mapping relationship between district / county information and location information; the second network element allocates a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0016] Based on this solution, in roaming scenarios, the second network element can determine the district / county where the terminal device is currently located based on the terminal device's current location information, and allocate a target IP address to the terminal device based on the district / county where the terminal device is currently located. Therefore, this solution can achieve fine-grained allocation of the terminal device's IP address based on the district / county where the terminal device is currently located in roaming scenarios, thereby enabling operators to determine the actual geographical location (district / county) of the terminal device based on its IP address.

[0017] In conjunction with the second aspect, in some embodiments of the second aspect, the first network element assigning a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located includes: the first network element determining one or more IP addresses corresponding to the identification information of the district / county where the terminal device is currently located, and determining the target IP address to be assigned to the terminal device from among the one or more IP addresses. This solution provides a method for assigning a target IP address to a terminal device based on the identification information of the district / county where the terminal device is currently located.

[0018] In conjunction with the second aspect, in some embodiments of the second aspect, the first network element assigning a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located includes: the first network element generating a target IP address to be assigned to the terminal device based on the identification information of the district / county where the terminal device is currently located. This solution provides a method for assigning a target IP address to a terminal device based on the identification information of the district / county where the terminal device is currently located.

[0019] In conjunction with the second aspect, in some embodiments of the second aspect, the first area and the second area are located within the coverage area of ​​the visited network of the terminal device; or, the first area is located within the coverage area of ​​the home network of the terminal device, and the second area is located within the coverage area of ​​the visited network of the terminal device; or, the first area is located within the coverage area of ​​the visited network of the terminal device, and the second area is located within the coverage area of ​​the home network of the terminal device; wherein, the first area is the area registered by the terminal device before registering the second area; and the second network element is the second network element of the home network of the terminal device. This solution can be applied to roaming scenarios under the home routing method.

[0020] In conjunction with the second aspect, in some embodiments of the second aspect, the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the terminal device's home network, and the mapping relationship between location information and district / county information within a third preset range within the coverage area of ​​the terminal device's visited network; wherein, the third preset range is adjacent to the coverage area of ​​the terminal device's home network.

[0021] Compared to existing second network elements that only configure location information within the home network coverage area of ​​the terminal device, the solution in this application adds location information within the visited network coverage area of ​​the terminal device related to the terminal device's movement, as well as a mapping relationship between location information and district / county information. The second network element can determine the district / county information corresponding to the second location information of the terminal device based on the second location information of the terminal device, thereby determining the district / county information where the terminal device is currently located.

[0022] In conjunction with the second aspect, in some embodiments of the second aspect, the location information includes at least one of the following: Tracking Area Identifier (TAI), E-UTRAN Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI). This scheme can determine whether the terminal device is moving across districts or counties based on multiple different pieces of location information.

[0023] In conjunction with the second aspect, in some implementations of the second aspect, the first network element is a session management function network element, a packet data network gateway control plane network element, or a user plane function network element.

[0024] Thirdly, a network protocol IP address allocation device is provided to implement the above-described method. This IP address allocation device includes modules, units, or means corresponding to the above-described method. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above-described functions.

[0025] In conjunction with the third aspect, in some embodiments of the third aspect, the IP address allocation device includes: a communication module and a processing module; the communication module is used to acquire first location information and second location information of the terminal device; wherein, the second location information is used to characterize the location information of the second area currently registered by the terminal device; the first location information is used to characterize the location information of the first area registered by the terminal device before registering the second area; the processing module is used to determine, based on the first location information and the second location information, that the movement trajectory of the terminal device meets preset conditions; the communication module is also used to send instruction information to the terminal device, the instruction information being used to instruct the terminal device to release the first session of the first service and re-establish the second session for the first service; the communication module is also used to send the second location information to the second network element, the second location information being used by the second network element to allocate a target IP address to the terminal device during the establishment of the second session.

[0026] In conjunction with the third aspect, in some embodiments of the third aspect, the first area and the second area are located within the coverage area of ​​the visited network of the terminal device, and the IP address allocation device is an IP address allocation device for the visited network of the terminal device; or, the first area is located within the coverage area of ​​the home network of the terminal device, the second area is located within the coverage area of ​​the visited network of the terminal device, and the IP address allocation device is an IP address allocation device for the visited network of the terminal device; or, the first area is located within the coverage area of ​​the visited network of the terminal device, the second area is located within the coverage area of ​​the home network of the terminal device, and the IP address allocation device is an IP address allocation device for the home network of the terminal device.

[0027] In conjunction with the third aspect, in some embodiments of the third aspect, the processing module is specifically used to: determine, based on the first location information and the second location information, that the movement trajectory of the terminal device meets the condition of moving between different districts and counties.

[0028] In conjunction with the third aspect, in some embodiments of the third aspect, the processing module is specifically used to: determine, based on the pre-configured mapping relationship between district / county information and location information, the district / county corresponding to the first location information as the first district / county, and the district / county corresponding to the second location information as the second district / county, wherein the first district / county and the second district / county are different districts / counties.

[0029] In conjunction with the third aspect, in some embodiments of the third aspect, the IP address allocation device is an IP address allocation device for the visited network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes a mapping relationship between location information and district / county information within the coverage area of ​​the visited network of the terminal device, and a mapping relationship between location information and district / county information within a first preset range within the coverage area of ​​the visited network of the terminal device; wherein, the first preset range is adjacent to the coverage area of ​​the visited network of the terminal device; or, the IP address allocation device is an IP address allocation device for the home network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes a mapping relationship between location information and district / county information within the coverage area of ​​the home network of the terminal device, and a mapping relationship between location information and district / county information within a second preset range within the coverage area of ​​the visited network of the terminal device; wherein, the second preset range is adjacent to the coverage area of ​​the home network of the terminal device.

[0030] In conjunction with the third aspect, in some embodiments of the third aspect, the location information includes at least one of the following: Tracking Area Identifier (TAI), Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI).

[0031] In conjunction with the third aspect, in some embodiments of the third aspect, the communication module is specifically used to: send an indication message to the terminal device after detecting the end of the second service when the first service includes the second service; or, send an indication message to the terminal device when the first service does not include the second service, wherein the second service is a voice call service or a video call service.

[0032] Fourthly, a network protocol IP address allocation apparatus is provided for implementing the above-described method. This IP address allocation apparatus includes modules, units, or means corresponding to the above-described method. These modules, units, or means can be implemented in hardware, software, or by hardware executing corresponding software. The hardware or software includes one or more modules or units corresponding to the above-described functions.

[0033] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the IP address allocation device includes: a transceiver module and a processing module; the transceiver module is used to receive second location information from a first network element; wherein the second location information is used to characterize the location information of a second region currently registered by the terminal device; the processing module is used to determine the identification information of the district / county where the terminal device is currently located based on the second location information and a pre-configured mapping relationship between district / county information and location information; the processing module is also used to allocate a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0034] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the processing module is specifically used to: determine one or more IP addresses corresponding to the identification information of the district / county where the terminal device is currently located, and determine the target IP address to be assigned to the terminal device from among the one or more IP addresses.

[0035] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the processing module is specifically used to: generate a target IP address to be assigned to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0036] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the first region and the second region are located within the coverage area of ​​the visited network of the terminal device; or, the first region is located within the coverage area of ​​the home network of the terminal device, and the second region is located within the coverage area of ​​the visited network of the terminal device; or, the first region is located within the coverage area of ​​the visited network of the terminal device, and the second region is located within the coverage area of ​​the home network of the terminal device; wherein, the first region is the region registered by the terminal device before registering the second region; and the IP address allocation device is the IP address allocation device of the home network of the terminal device.

[0037] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the terminal device's home network, and the mapping relationship between location information and district / county information within a third preset range within the coverage area of ​​the terminal device's visited network; wherein, the third preset range is adjacent to the coverage area of ​​the terminal device's home network.

[0038] In conjunction with the fourth aspect, in some implementations of the fourth aspect, the location information includes at least one of the following: Tracking Area Identifier (TAI), E-UTRAN Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI).

[0039] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the IP address allocation device is a session management function network element, a packet data network gateway control plane network element, or a user plane function network element.

[0040] Fifthly, a network protocol IP address allocation apparatus is provided, comprising: at least one processor; the processor is configured to execute a computer program or instructions to cause the IP address allocation apparatus to perform the IP address allocation method of the first aspect described above.

[0041] In conjunction with the fifth aspect, in some embodiments of the fifth aspect, the IP address allocation device further includes a memory for storing necessary program instructions and data. The memory may be coupled to the processor, or it may be independent of the processor.

[0042] In some possible designs, the IP address allocation device can be a chip or a chip system. When the device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0043] A sixth aspect provides an IP address allocation apparatus, comprising: at least one processor; the processor being configured to execute a computer program or instructions to cause the IP address allocation apparatus to perform the IP address allocation method of the second aspect described above.

[0044] In conjunction with the sixth aspect, in some embodiments of the sixth aspect, the IP address allocation device further includes a memory for storing necessary program instructions and data. The memory may be coupled to the processor, or it may be independent of the processor.

[0045] In some possible designs, the IP address allocation device can be a chip or a chip system. When the device is a chip system, it can be composed of chips or may include chips and other discrete components.

[0046] In a seventh aspect, a computer-readable storage medium is provided that stores computer instructions, which, when executed by a computer, enable the computer to perform the method described in the first aspect.

[0047] Eighthly, a computer-readable storage medium is provided that stores computer instructions, which, when executed by a computer, enable the computer to perform the method of the second aspect described above.

[0048] In a ninth aspect, a computer program product containing instructions is provided that, when run on a computer, enables the computer to perform the method described in the first aspect.

[0049] In a tenth aspect, a computer program product containing instructions is provided, which, when run on a computer, enables the computer to perform the method described in the second aspect.

[0050] Eleventhly, a communication system is provided, which includes: a first network element and a second network element.

[0051] A first network element is used to acquire first location information and second location information of a terminal device. The second location information represents the location information of a first area currently registered by the terminal device; the first location information represents the location information of a second area registered by the terminal device before registering in the first area. The first network element is also used to determine, based on the first and second location information, that the movement trajectory of the terminal device meets preset conditions. Furthermore, the first network element is used to send instruction information to the terminal device, instructing the terminal device to release the first session of the first service and re-establish a second session for the first service. The first network element is also used to send second location information to a second network element. The second network element is used to receive the second location information and, during the establishment of the second session, allocate a target IP address to the terminal device based on the second location information.

[0052] In conjunction with the fourth aspect, in some embodiments of the fourth aspect, the second network element is specifically used to determine the identification information of the district / county where the terminal device is currently located based on the second location information and the pre-configured mapping relationship between district / county information and location information, and to allocate a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0053] The technical effects of any of the design methods in aspects three through eleven can be found in the technical effects of the different design methods in aspects one through two above, and will not be repeated here. Attached Figure Description

[0054] Figure 1 A schematic diagram illustrating network coverage relationships in a terminal device roaming scenario, provided as an embodiment of this application; Figure 2 This application provides a schematic diagram of network interconnection in a terminal device roaming scenario. Figure 3 This application provides a schematic diagram of a network architecture for a terminal device roaming scenario. Figure 4 This application provides a schematic diagram of the structure of a communication system according to an embodiment of the present application. Figure 5 This is a schematic diagram of the structure of a communication device provided in an embodiment of this application; Figure 6 An interactive schematic diagram illustrating an IP address allocation method provided in an embodiment of this application; Figure 7 A schematic diagram illustrating another network coverage relationship provided in an embodiment of this application; Figure 8 A schematic diagram illustrating yet another network coverage relationship provided in an embodiment of this application; Figure 9 An interactive schematic diagram illustrating another IP address allocation method provided in an embodiment of this application; Figure 10 A flowchart illustrating an IP address allocation method provided in an embodiment of this application; Figure 11 This is a schematic diagram of the structure of an IP address allocation device provided in an embodiment of this application; Figure 12 This is a schematic diagram of another IP address allocation device provided in an embodiment of this application. Detailed Implementation

[0055] To facilitate understanding of the technical solutions of the embodiments of this application, a brief introduction to the relevant technologies or terms of this application is given below.

[0056] 1. Tracking area (TA): Due to the amount of signaling, it is impractical for the network to track the terminal device in idle mode every time it moves between different cells. Based on terminal device location management, the Long Term Evolution (LTE) system introduces a new concept: TA (Location Detection), which can be used to update the terminal device's location information on the network side when the device moves.

[0057] A Tracking Area (TA) is a collection of one or more cells, and a cell belongs to only one TA. A TA is characterized by its Tracking Area Identity (TAI), which consists of a Public Land Mobile Network (PLMN) and a Tracking Area Code (TAC). Terminal equipment and core network elements can distinguish TAs based on their TAIs.

[0058] Depending on actual needs, one or more TAIs can form a TA List, which is assigned to terminal devices by the network side. When a terminal device moves within its configured (or registered) TA list, it does not need to perform a TA update, thus reducing frequent interactions with the network side. When a terminal device enters an area corresponding to a new TA that is not in its configured TA list, the terminal device needs to initiate an update registration process to perform a TA update. The core network element then reassigns a TA list containing the TAIs of the new TA to the terminal device. The network side can then obtain the TAI of the new TA the terminal device is currently in, as well as the TAI of the old TA it was in before moving, according to the update registration process, thereby achieving location management of the terminal device. The specific update registration process can be found in the definitions of existing standards.

[0059] The terminal device can initiate the TA update process based on the following steps: The base station broadcasts the TAI of the TA to which the cell belongs in each cell. After the terminal device moves to the cell, it compares the broadcast TAI with one or more TAIs stored in the TA list configured by the terminal device. If the broadcast TAI does not belong to the TA list, the terminal device will initiate the update registration process and notify the network side of the new TA's TAI, that is, the TAI of the TA to which the cell belongs.

[0060] 2. Terminal device roaming: Terminal device roaming refers to a situation where one operator builds a complete network (including wireless network and core network), and other operators' terminal devices access that network through roaming to use mobile communication services.

[0061] 3. Home network and visited network: When a terminal device from one operator roams from the coverage area of ​​that operator's network to the coverage area of ​​another operator's network and uses the network facilities provided by the other operator to access the network, the operator to which the terminal device is contracted is called the terminal device's home operator, the network provided by the terminal device's home operator is called the terminal device's home network (or home location network), the network provided by the other operator to which the terminal device roams is called the terminal device's visited network (or visited location network), and the other operator providing the visited network is called the terminal device's visiting operator.

[0062] For the sake of brevity, the home network of the terminal device will be referred to as the home network, and the visited network of the terminal device will be referred to as the visited network. It is understood that the concepts of home network and visited network are relative to the same terminal device.

[0063] It should be noted that, in the embodiments of this application, the home network can also be referred to as a self-built network, and the visited network can also be referred to as a shared network or a roaming shared network.

[0064] like Figure 1 The diagram illustrates an exemplary coverage relationship between a visiting operator's 5G network and a home operator's 4G / 5G network. The 5G visited network coverage area (or 5G visited network area) is tangent to the 5G home network coverage area (or 5G home network area). Figure 1 The interval in the text describes the movement of the terminal device (the actual relationship is tangent). The coverage area of ​​the home operator's 4G backup network includes the coverage area of ​​the 5G visited network and the coverage area of ​​the 5G home network. Specifically, the home operator's 4G backup network means that if the terminal device does not support or enable 5G, it can connect to the 4G home network within the coverage area of ​​the home operator's 4G backup network.

[0065] It should be noted that in this embodiment, the terminal device prioritizes accessing the higher-level network. For example, if the area where the terminal device is located is simultaneously within the coverage area of ​​the 5G visited network and the 4G home network, the terminal device will choose to access the 5G visited network. If the area where the terminal device is located is simultaneously within the coverage area of ​​the 5G home network and the 4G home network, the terminal device will choose to access the 5G home network. Therefore, in this embodiment, the 5G visited network coverage area can be referred to as the 5G visited network area, and the terminal device accesses the 5G visited network within the 5G visited network area. The 5G home network coverage area can be referred to as the 5G home network area, and the terminal device accesses the 5G home network within the 5G home network area. The area within the 4G home network coverage area, excluding the 5G visited network coverage area and the 5G home network coverage area, can be referred to as the 4G home network area, and the terminal device accesses the 4G home network within the 4G home network area.

[0066] like Figure 1 As shown, in a roaming scenario, the movement of the terminal device includes: (1) The terminal device moves from the 4G home network area to the 5G visited network area.

[0067] (2) The terminal device moves from the 5G visited network area to the 4G home network area.

[0068] (3) The terminal device moves from the 5G home network area to the 5G visited network area.

[0069] (4) The terminal device moves from the 5G visited network area to the 5G home network area.

[0070] (5) The terminal device moves within the 5G visited network area.

[0071] Currently, in the home-roaming architecture, data from roaming terminal devices returns to the home network, and the home network is responsible for processing the terminal device's services. For example... Figure 2 As shown, this is an exemplary roaming scenario using existing home routing methods, suitable for situations such as... Figure 1 The diagram shows the network interconnection relationship of the network coverage.

[0072] like Figure 2As shown, the visited operator's 5G core network can exchange data with the home operator's 5G core network through roaming and interoperability interfaces. The home operator's terminal equipment can move between the home network area and the visited network area. When moving within the home network area, the terminal equipment can access the home operator's 5G radio access network through the 5G radio access network equipment built by the home operator. The home operator's 5G radio access network can then send the terminal equipment's data to the home operator's 5G core network, which processes the terminal equipment's services. When moving within the visited network area, the terminal equipment can access the visited operator's radio access network through the visited operator's 5G radio access network equipment. The visited operator's 5G core network can obtain the terminal equipment's data through the visited operator's 5G radio access network and send the terminal equipment's data to the home operator's 5G core network, which then processes the terminal equipment's services. If the terminal device does not support 5G network or does not enable 5G network, when the terminal device moves in the home network area or the visited network area, it can access the home operator's 4G radio access network through the 4G radio access network equipment built by the home operator. The home operator's 4G radio access network can send the terminal device's data to the home operator's 4G core network, and the home operator's 4G core network will process the terminal device's services.

[0073] Currently, in roaming scenarios using home routing, the signaling planes of the visited network (visiting the operator's core network) and the home network (home to the operator's core network) are connected through their respective Security Edge Protection Proxies (SEPPs), while the user plane is connected through edge routers.

[0074] like Figure 3 As shown, this is an exemplary method applicable to roaming scenarios using home routing, such as... Figure 1 The diagram shows a network architecture with varying network coverage. Figure 3As shown, the network architecture includes a visited public land mobile network (VPLMN) and a home public land mobile network (HPLMN). Terminal devices can move between the HPLMN and VPLMN. The VPLMN includes access and mobility management function (AMF) network elements (or visited AMF (V-AMF) network elements), radio access network (RAN) equipment, network exposure function repository function (NRF) network elements, visited-session management function (V-SMF) network elements / packet data network (PDN) gateway control plane function (PGW-C) network elements, visited-user plane function (V-UPF) network elements / PGW-user plane (PGW-U) network elements, visited-policy control function (V-PCF) network elements, and SEPP network elements.The HPLMN includes AMF network elements (or home-AMF, H-AMF network elements), RAN equipment, evolved Node B (eNB) in the LTE system, NRF network elements, unified data management (UDM) network elements + home subscriber server (HSS) network elements, home-policy control function (H-PCF) network elements / policy and charging rules function (PCRF) network elements, mobility management entity (MME) network elements, serving gateway (SGW) network elements, home-SMF (home-SMF, H-SMF) / PGW-C network elements, home-UPF (home-UPF, H-UPF) network elements / PGW-U network elements, and SEPP network elements.

[0075] Specifically, the terminal equipment communicates with the AMF network element via the N1 interface (N1 for short) and with the RAN equipment; the RAN equipment communicates with the AMF network element via the N2 interface (N2 for short), the RAN equipment in the home location communicates with the H-UPF / PGW-U network element via the N3 interface (N3 for short), and the RAN equipment in the visited location communicates with the V-UPF / PGW-U network element via the N3 interface; the AMF network element in the home location communicates with the H-SMF / PGW-C network element via the N11 interface (N11 for short). The visited AMF network element communicates with the V-SMF / PGW-C network element via N11; the AMF network element communicates with the HSS+UDM network element via the N8 / N12 interface (hereinafter referred to as N8 / N12); the AMF network element communicates with the NRF network element; the home AMF network element communicates with the visited AMF network element via the N14 interface (hereinafter referred to as N14); the eNB communicates with the SGW network element via the S1-U interface; the eNB communicates with the MME network element; the SGW network element communicates with the MME network element; the SGW network element communicates via the S5 interface. The H-SMF / PGW-U network element communicates with the H-SMF / PGW-C network element via interface S5 (abbreviated as S5); the H-UPF / PGW-U network element communicates with the H-SMF / PGW-C network element, and the H-UPF / PGW-U network element communicates with the V-UPF / PGW-U network element; the H-SMF / PGW-C network element communicates with the HSS+UDM network element via interface N10 (abbreviated as N10); the H-SMF / PGW-C network element communicates with the H-PCF / PCRF network element via interface N7 (abbreviated as N7); the H-SMF / PGW-... The C network element communicates with the V-SMF / PGW-C network element through the N16 interface (N16 for short); the H-PCF / PCRF network element communicates with the V-PCF network element through the N24 interface (N24 for short); the NRF network element communicates with other NRF network elements through the N27 interface (N27 for short); the SEPP network element communicates with other SEPP network elements through the N32 interface (N32 for short); and the V-UPF / PGW-U network element communicates with the V-SMF / PGW-C network element through the N4 interface (N4 for short).

[0076] It should be noted that, Figure 3 The control plane network elements shown, such as AMF, V-SMF, H-SMF, H-PCF, or UDM network elements, can also interact using service-oriented interfaces. For example, the service-oriented interface provided by an AMF network element can be Namf; that of a V-SMF network element can be Nvsmf; that of an H-SMF network element can be Nhsmf; that of an H-PCF network element can be Nhpcf; and that of a UDM network element can be Nudm. For related descriptions, please refer to the 5G system architecture diagram in the 23501 standard; further details are omitted here.

[0077] It should be noted that, Figure 3 The names of network elements or interfaces in the network architecture shown are merely examples and may be different in specific implementations. This application does not impose any specific limitations on these names.

[0078] It should be noted that, Figure 3 The network architecture shown is merely an example for illustration. In practical applications, this network architecture may include other network elements or devices, or some of the network elements or devices included may be removed. For details, please refer to the existing 4G / 5G network architecture description, which will not be elaborated here.

[0079] As the internet becomes increasingly intertwined with real life, operators, for network monitoring purposes, have proposed a requirement to obtain the location information of terminal devices based on their IP addresses. To achieve this, a solution is needed where the network side can finely allocate IP addresses to terminal devices based on their location information. Currently, one proposed method is as follows: if the core network element used to allocate IP addresses to a terminal device determines that the geographical location of the terminal device before and after its relocation is inconsistent during session transfer (handover) for a moved terminal device, then the core network element can reallocate an IP address to the terminal device based on its new location information.

[0080] However, for the roaming architecture using the home-based routing method described above, there is currently no solution for the network side to finely allocate IP addresses based on the location information of the terminal device. The specific reasons are as follows: First, to ensure a good user experience, the protocol stipulates that when a terminal device is moved, during the process of transferring its original Protocol Data Unit (PDU) session or Packet Data Network (PDN) connection to a different network or a different network element within the same network, the terminal device's IP address or IP address prefix must not change. If the core network element directly reassigns an IP address to the terminal device based on its new location during the session transfer process, the consistency of the terminal device's services cannot be guaranteed.

[0081] Secondly, currently, under the home-roaming roaming architecture, when a terminal device roams, access control is provided by the core network element (e.g., mobility management element) of the network corresponding to the area after the move (visited network or home network). This core network element can obtain the location information of the terminal device before and after the move (see the above introduction on how to update TA), while the core network element of the home network (e.g., session management element) assigns an IP address to the terminal device. It can be seen that, on the one hand, under the home-roaming roaming architecture, the core network element providing access control for the terminal device and the core network element used to assign an IP address to the terminal device are different network elements and may belong to different operators. The core network element used to assign an IP address cannot determine whether the geographical location of the terminal device before and after the move is consistent based on the location information before and after the move.

[0082] On the other hand, currently, the core network elements of the visiting operator only configure a list of TAs within the coverage area of ​​the visited network, and similarly, the core network elements of the home operator only configure a list of TAs within the coverage area of ​​the home network. When a terminal device is roaming, if the terminal device enters different TAs within the coverage areas of different operator networks before and after the move, the core network elements used to provide access control for the terminal device cannot determine the location information of the terminal device before the move, and therefore cannot determine whether the geographical location of the terminal device has changed before and after the move. For example, when the terminal device roams, it moves from TA1 to TA2. TA1 belongs to the visited network area, and TA2 belongs to the home network area. In other words, the terminal device moves from the visited network area to the home network area. In this case, the core network elements of the home network, such as the AMF (Advanced Management Function) elements of the home network, provide access control for the terminal device. However, the AMF network element of the home network is not configured with a TA list within the visited network area, nor with the corresponding area information (such as district / county information) for the TA list within the visited network area. It cannot determine the geographical location of the terminal device before the move based on the old TA before the terminal device moved. Therefore, the AMF network element of the home network cannot determine whether the geographical location of the terminal device has changed before and after the move, and thus assumes that the terminal device does not need to change its IP address.

[0083] Therefore, how to allocate IP addresses to terminal devices in a fine-grained manner in the scenario of terminal device roaming is an urgent problem to be solved.

[0084] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0085] In the description of this application, unless otherwise stated, " / " indicates that the objects before and after are in an "or" relationship. For example, A / B can mean A or B. "And / or" in this application is merely a description of the relationship between the related objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. A and B can be singular or plural.

[0086] In the description of this application, unless otherwise stated, "multiple" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of a single item or a plurality of items. For example, at least one of a, b, or c can mean: a, b, c, ab, ac, bc, or abc, where a, b, and c can be single or multiple.

[0087] Furthermore, to facilitate a clear description of the technical solutions in the embodiments of this application, the terms "first" and "second" are used in the embodiments of this application to distinguish identical or similar items with substantially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that "first" and "second" are not necessarily different. Meanwhile, in the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is being used as an example, illustration, or description. Any embodiment or design scheme described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design schemes. Specifically, the use of terms such as "exemplary" or "for example" is intended to present related concepts in a concrete manner for ease of understanding.

[0088] It is understood that the term "embodiment" used throughout the specification means that a specific feature, structure, or characteristic related to an embodiment is included in at least one embodiment of this application. Therefore, various embodiments throughout the specification do not necessarily refer to the same embodiment. Furthermore, these specific features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. It is understood that in the various embodiments of this application, the sequence number of each process does not imply the order of execution; the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0089] It is understood that in this application, "when," "if," and "if" all refer to the corresponding processing that will be carried out under certain objective circumstances, and are not limited to a specific time, nor do they require that there must be a judgment action when implemented, nor do they imply any other limitations.

[0090] In this application, "simultaneously" can be understood as at the same point in time, within a period of time, or within the same cycle.

[0091] It is understood that some optional features in the embodiments of this application can be implemented independently in certain scenarios without relying on other features, such as the current solution on which they are based, to solve the corresponding technical problems and achieve the corresponding effects. Alternatively, they can be combined with other features as needed in certain scenarios. Correspondingly, the apparatus given in the embodiments of this application can also implement these features or functions, which will not be elaborated here.

[0092] In this application, unless otherwise specified, the same or similar parts between the various embodiments can be referred to each other. In the various embodiments of this application, and in the various implementation methods / methods / implementations within each embodiment, unless otherwise specified or logically conflicting, the terminology and / or descriptions between different embodiments and between the various implementation methods / methods / implementations within each embodiment are consistent and can be mutually referenced. The technical features in different embodiments and the various implementation methods / methods / implementations within each embodiment can be combined according to their inherent logical relationships to form new embodiments, implementation methods, methods, or implementation approaches. The following embodiments of this application do not constitute a limitation on the scope of protection of this application.

[0093] The technical solutions of this application embodiment can be used in various communication systems, such as third-generation partnership project (3GPP) communication systems, for example, long-term evolution (LTE) systems, 5G systems, new radio (NR) systems, vehicle-to-everything (V2X) systems, LTE and 5G hybrid networking systems, device-to-device (D2D) communication systems, machine-to-machine (M2M) communication systems, Internet of Things (IoT) systems, and other next-generation communication systems. They can also be non-3GPP communication systems, without limitation.

[0094] The communication systems and scenarios applicable to this application mentioned above are merely illustrative examples, and are not limited to these examples. This will be explained uniformly here and will not be repeated below.

[0095] like Figure 4The diagram shown is an architectural schematic of a communication system 10 applying the IP address allocation method provided in this application. The communication system 10 includes a first network element 101 and a second network element 102.

[0096] The first network element 101 is used to acquire first location information and second location information of the terminal device. The second location information represents the location information of the first area currently registered by the terminal device; the first location information represents the location information of the second area registered by the terminal device before registering in the first area. The first network element 101 is also used to determine, based on the first and second location information, that the movement trajectory of the terminal device meets preset conditions. The first network element 101 is also used to send instruction information to the terminal device, instructing the terminal device to release the first session of the first service and re-establish a second session for the first service. The first network element is also used to send the second location information to the second network element 102.

[0097] The second network element 102 is used to receive the second location information and allocate a target IP address to the terminal device based on the second location information during the establishment of the second session.

[0098] Optionally, the second network element 102 is specifically used to determine the identification information of the district / county where the terminal device is currently located based on the second location information and the pre-configured mapping relationship between district / county information and location information, and to allocate a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0099] The specific implementation and technical effects of the above solution will be described in detail in the subsequent method embodiments, and will not be repeated here.

[0100] Optionally, in this embodiment, the first network element 101 can be a mobility management network element, and the second network element 102 can be a session management network element, a packet data network gateway control plane network element, or a user plane network element. This embodiment does not specifically limit this.

[0101] Optionally, the first network element 101 and the second network element 102 can communicate directly or through forwarding by other devices. This application embodiment does not specifically limit this.

[0102] Optional, Figure 4 The communication system shown can be applied to Figure 1 The diagram shows the coverage relationship between the visited operator's 5G network and the home operator's 4G / 5G network. Figure 2 In the network interconnection relationship of the roaming scenario shown by the home routing method, or Figure 3 The network architecture shown in the home routing method for roaming scenarios can also be applied to other roaming network architectures in the future, and this application embodiment does not specifically limit it.

[0103] For example, if Figure 4 The communication system shown is used in, for example Figure 3 In the network architecture of the roaming scenario shown by the home routing method, then Figure 4 The network element or entity corresponding to the first network element 101 in the diagram can be... Figure 3 The network architecture shown refers to either the AMF network element or the MME network element in the HPLMN, or the AMF network element in the VPLMN. The network element or entity corresponding to the second network element 102 can be... Figure 3 The H-SMF / PGW-C network element or H-UPF network element in the network architecture shown are not specifically limited in this application embodiment.

[0104] Optional, such as Figure 4 As shown, the communication system may further include a terminal device 103. The terminal device 103 can communicate with the first network element 101. Optionally, in this embodiment, the first network element 101 and the terminal device 103 can communicate directly or through forwarding by other devices; this embodiment does not specifically limit this.

[0105] The terminal device 103 is configured to receive indication information from the first network element 101, and according to the indication information, release the first session of the first service and re-establish a second session for the first service. The terminal device 103 is also configured to receive a target IP address allocated to the terminal device 103 by the second network element 102.

[0106] Optionally, the terminal involved in the embodiments of this application may include various handheld devices, vehicle-mounted devices, wearable devices, computing devices, or other processing devices connected to a wireless modem with wireless communication capabilities; it may also include a subscriber unit, cellular phone, smartphone, wireless data card, personal digital assistant (PDA) computer, tablet computer, wireless modem, handheld device, laptop computer, cordless phone, wireless local loop (WLL) station, machine type communication (MTC) terminal, user equipment (UE), mobile station (MS), terminal device, or relay user equipment, etc. Among them, relay user equipment may be, for example, a 5G residential gateway (RG). For ease of description, in this application, the devices mentioned above are collectively referred to as terminal devices.

[0107] It should be understood that the terminal devices in the embodiments of this application can be terminal devices in various vertical industry application fields such as Internet of Things terminal devices, ports, smart factories, railway transportation, logistics, drones, and autonomous vehicles. For example, mobile robots, automated guided vehicles (AGVs), autonomous vehicles, control equipment and sensors on trains, and control equipment and sensors deployed in factories.

[0108] As an example, in this embodiment, the terminal device can also be a wearable device. Wearable devices, also known as wearable smart devices, are a general term for devices that utilize wearable technology to intelligently design and develop everyday wearables, such as glasses, gloves, watches, clothing, and shoes. Wearable devices are portable devices that are worn directly on the body or integrated into the user's clothing or accessories. Wearable devices are not merely hardware devices, but also achieve powerful functions through software support, data interaction, and cloud interaction. Broadly speaking, wearable smart devices include those that are feature-rich, large in size, and can achieve complete or partial functions without relying on a smartphone, such as smartwatches or smart glasses, as well as those that focus on a specific type of application function and require the use of other devices such as smartphones, such as various smart bracelets and smart jewelry for vital sign monitoring. The terminal can also be a sensor device used in factories.

[0109] Optionally, the access device involved in the embodiments of this application can manage wireless resources, provide access services for terminal devices, and then complete the forwarding of control signals and terminal data between the terminal and the core network. The access device can be understood as a base station in a traditional network. The base station can include various forms of base stations, such as macro base stations, micro base stations (also known as small stations), relay stations, access points, etc.

[0110] In some examples, access devices can be Next Generation Node B (gNB), Transmission Reception Point (TRP), eNB, Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), Home Evolved Node B (HNB), Base Band Unit (BBU), or Wireless Fidelity (Wi-Fi) Access Point (AP) in a 5G system. In a network architecture, network devices can include centralized unit (CU) nodes, distributed unit (DU) nodes, or RAN equipment including both CU and DU nodes. RAN equipment can also be wireless backhaul equipment, vehicular equipment, wearable devices, and network equipment in future 5G networks or future evolved PLMN networks. In third-generation (3G) systems, they are referred to as Node B. Broadband network gateway (BNG), aggregation switch, non-3rd generation partnership project (3GPP) access equipment, etc.

[0111] Optionally, embodiments of this application Figure 4 The functions of the first network element 101, the second network element 102, or the terminal device 103 can be implemented by one device, multiple devices working together, or a functional module within a single device. This application embodiment does not specifically limit this. It is understood that the aforementioned functions can be network elements in hardware devices, software functions running on dedicated hardware, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0112] For example, embodiments of this application Figure 4 The first network element 101, the second network element 102, or the terminal device 103 can be accessed through... Figure 5 It is implemented through communication devices. Figure 5The diagram shown is a hardware structure schematic of a communication device provided in an embodiment of this application. The communication device 500 includes a processor 501, a communication line 502, a memory 503, and at least one communication interface. Figure 5 (The following is an example illustration using communication interface 504 as an example only).

[0113] The processor 501 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits used to control the execution of the program of the present application.

[0114] Communication line 502 may include a path for transmitting information between the aforementioned components.

[0115] Communication interface 504 uses any transceiver-like device for communicating with other devices or communication networks, such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.

[0116] Memory 503 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or electrically erasable programmable read-only memory (EEPROM), compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed discs, laser discs, optical discs, digital universal discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but not limited thereto. Memory may exist independently and be connected to the processor via communication line 502. Memory may also be integrated with the processor.

[0117] The memory 503 stores computer execution instructions for implementing the scheme of this application, and its execution is controlled by the processor 501. The processor 501 executes the computer execution instructions stored in the memory 503, thereby implementing the IP address allocation method provided in the following embodiments of this application.

[0118] Optionally, the computer execution instructions in the embodiments of this application may also be referred to as application code, and the embodiments of this application do not specifically limit this.

[0119] In a specific implementation, as one example, the processor 501 may include one or more CPUs, for example... Figure 5 CPU0 and CPU1 in the CPU.

[0120] In a specific implementation, as one example, the communication device 500 may include multiple processors, such as... Figure 5 Processors 501 and 508 are shown in the diagram. Each of these processors may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor here may refer to one or more devices, circuits, and / or processing cores used to process data (such as computer program instructions).

[0121] In a specific implementation, as one embodiment, the communication device 500 may further include an output device 505 and an input device 506. The output device 505 communicates with the processor 501 and can display information in various ways. For example, the output device 505 may be a liquid crystal display (LCD), a light-emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector, etc. The input device 506 communicates with the processor 501 and can receive user input in various ways. For example, the input device 506 may be a mouse, keyboard, touchscreen device, or sensing device, etc.

[0122] The aforementioned communication device 500 can be a general-purpose device or a dedicated device. In specific implementations, the communication device 500 can be a desktop computer, laptop computer, network server, PDA (personal digital assistant), mobile phone, tablet computer, wireless terminal device, embedded device, or other similar device. Figure 5 Devices with similar structures. This application does not limit the type of communication device 500 to any particular embodiment.

[0123] The following will combine Figures 1 to 5 The IP address allocation method provided in the embodiments of this application will be described in detail. For example... Figure 6 As shown, the IP address allocation method provided in this application embodiment includes S601-S606.

[0124] S601, the first network element obtains the first location information and the second location information of the terminal device.

[0125] The second location information is used to characterize the location information of the second region currently registered by the terminal device; the first location information is used to characterize the location information of the first region registered by the terminal device before registering the second region.

[0126] S602, the first network element determines that the movement trajectory of the terminal device meets the preset conditions based on the first location information and the second location information.

[0127] S603. The first network element sends an instruction message to the terminal device. Correspondingly, the terminal device receives the instruction message from the first network element.

[0128] S604. According to the instruction information, the terminal device releases the first session of the first service and re-establishes the second session for the first service.

[0129] S605, the first network element sends the second location information to the second network element. Correspondingly, the second network element receives the second location information from the first network element.

[0130] S606, the second network element allocates a target IP address to the terminal device based on the second location information during the establishment of the second session.

[0131] The following is Figure 6 The IP address allocation method shown is applied to Figure 1 or Figure 2 The roaming scene shown, or applied to, for example Figure 3 Taking the network architecture shown in the roaming scenario as an example, we will elaborate on S601-S606.

[0132] For S601, in scenarios where the terminal device moves within or at the edge of the visited network area, after the terminal device moves from the first area to the second area, the first network element managing the second area can obtain the terminal device's first location information and second location information. The second location information represents the location information of the second area currently registered by the terminal device; the first location information represents the location information of the first area registered by the terminal device before registering in the second area.

[0133] In this embodiment, the method by which the terminal device moves from the first region to the second region includes idle state reselection, connected state redirection, or connected state switching. Specific details can be found in the definitions of existing standards or protocols, and will not be elaborated upon here.

[0134] Taking the visited network area as the 5G visited network area and the home network area as including the 4G home network area and the 5G home network area as an example, the scenarios in which the aforementioned terminal device moves at the edge of the visited network area can include: (1) The terminal device moves from the 4G home network area to the 5G visited network area.

[0135] (2) The terminal device moves from the 5G visited network area to the 4G home network area.

[0136] (3) The terminal device moves from the 5G home network area to the 5G visited network area.

[0137] (4) The terminal device moves from the 5G visited network area to the 5G home network area.

[0138] In this embodiment, the movement of the terminal device at the edge of the visited network area can be understood as the terminal device moving across operators. Of course, it can also be referred to as the movement of the terminal device at the edge of the home network area, or the movement of the terminal device at the boundary between the visited network area and the home network area. This embodiment does not impose any specific limitations on this.

[0139] In this embodiment, the first network element can be a network element that provides services to the network of the second area registered after the terminal device moves. The first network element varies depending on the different movement scenarios of the terminal device. For example, if the first area and the second area are within the coverage of the visited network of the terminal device, then the first network element is a network element within the visited network that provides services to the network of the second area. Alternatively, if the first area is within the coverage of the home network of the terminal device, and the second area is within the coverage of the visited network of the terminal device, then the first network element is a network element within the visited network that provides services to the network of the second area. Or, if the first area is within the coverage of the visited network of the terminal device, and the second area is within the coverage of the home network of the terminal device, then the first network element is a network element within the home network that provides services to the network of the second area.

[0140] Optionally, if the first area and the second area before and after the terminal device moves belong to the same visited network area, the first network element can also provide services to the network in the first area. In other words, when the terminal device moves within the visited network area, and the first area and the second area are within the coverage area of ​​the visited network of the terminal device, the first network element can provide services to the network in the first area.

[0141] In one possible implementation, after a terminal device moves from a first area to a second area, it can determine whether an update registration is needed based on its current location information (location information in the second area) and its previous location information (location information in the first area). If the update registration is needed, the terminal device initiates an update registration process to register itself with the core network of the second area, enabling the first network element managing the second area to obtain the terminal device's first and second location information. If the update registration is not needed, the terminal device will not initiate an update registration process.

[0142] The process of determining whether a terminal device needs to update its registration is based on its current location information and its location information before moving. Please refer to the above introduction on the process of starting a TA update for the terminal device, which will not be repeated here.

[0143] In this embodiment of the application, the first network element obtains the first location information and the second location information in the following two ways: In one implementation, the terminal device can send the first location information and the second location information to the first network element during the update registration process initiated after moving to the second area. For example, during the update registration process, the terminal device sends its globally unique temporary user equipment identity (GUTI) and last visited TAI to the first network element. The GUTI includes the second location information, such as the TAI of the second area, and the last visited TAI is the first location information.

[0144] In another possible implementation, where the first network element provides services to the network of the first area previously registered by the terminal device, the first network element can obtain the first location information when the terminal device registers with the first area, and store the terminal device's identification information and the first location information accordingly. During the update registration process initiated when the terminal device moves to the second area, the terminal device sends a GUTI to the first network element. The first network element obtains the GUTI sent by the terminal device and the terminal device's identification information. The GUTI includes second location information. Based on the terminal device's identification information, the first network element queries the previously stored first location information of the terminal device.

[0145] Optionally, the correspondence between the first location information and the terminal device identification information can be stored in the first network element, or in other network elements, or in a database. This application embodiment does not impose specific limitations on this.

[0146] In this embodiment, the GUTI carried by the terminal device varies depending on the movement of the terminal device. When the terminal device moves within the 5G visited network area, the GUTI carried by the terminal device is the 5G-GUTI, which is assigned by the current 5G visited network (Serving PLMN ID). In this case, the first network element is the first network element of the current 5G visited network, such as the AMF network element.

[0147] When a terminal device moves from a 4G home network area to a 5G visited network area, the GUTI carried by the terminal device is the 5G-GUTI. The 5G-GUTI carried by the terminal device is mapped from the evolved packet system GUTI (EPS-GUTI). The EPS-GUTI is allocated by other networks (the PLMN of the 4G home network). In this case, the first network element is the first network element of the current 5G visited network, such as the AMF network element.

[0148] When a terminal device moves from a 5G home network area to a 5G visited network area, the GUTI carried by the terminal device is a 5G-GUTI. The 5G-GUTI carried by the terminal device is assigned by other networks (the PLMN of the 5G home network). In this case, the first network element is the first network element of the current 5G visited network, such as the AMF network element.

[0149] When a terminal device moves from a 5G visited network area to a 5G home network area, the GUTI carried by the terminal device is a 5G-GUTI. The 5G-GUTI carried by the terminal device is assigned by other networks (PLMN of the 5G visited network). In this case, the first network element is the first network element of the current 5G home network, such as the AMF network element.

[0150] When a terminal device moves from a 5G visited network area to a 4G home network area, the EPS-GUTI carried by the terminal device is mapped from the 5G-GUTI. The 5G-GUTI is allocated by other networks (PLMN of the 5G visited network). In this case, the first network element is the first network element of the current 4G home network, such as the MME network element.

[0151] In this embodiment, the location information may include at least one of the following: TAI, Evolved Universal Terrestrial Radio Access Network (E-UTRAN) cell global identifier (ECGI), and NR cell global identifier (NCGI). The TAI is detailed above in the relevant technology description and will not be repeated here. The ECGI or NCGI consists of the PLMN identifier to which the cell belongs and the cell identity, and is used to globally identify a cell within the PLMN.

[0152] For S602, after the first network element obtains the first location information and the second location information of the terminal device, it can determine whether the movement trajectory of the terminal device meets the preset conditions based on the first location information and the second location information. If the first network element determines that the movement trajectory of the terminal device meets the preset conditions, it executes the following S603-S604; otherwise, it does not execute S603-S604, and the process ends.

[0153] In this embodiment, the preset condition can be movement between different districts and counties. That is, the first network element can determine that the movement trajectory of the terminal device meets the condition of movement between different districts and counties based on the first location information and the second location information. The fact that the movement trajectory of the terminal device meets the condition of movement between different districts and counties can also be referred to as the terminal device moving across districts and counties.

[0154] In this embodiment, "district" or "county" refers to either a district or a county. That is, the first network element can determine the terminal device's movement trajectory based on the first location information and the second location information, ensuring that the device can move between different districts or counties. It is understood that, depending on actual planning, when the technical solution of this application is applied to different scenarios, the "district" or "county" can be adaptively replaced with other geographical areas, such as cities or townships. This application does not impose any restrictions on this.

[0155] In one possible implementation, the first network element can perform the following steps to determine whether the terminal device's movement trajectory meets preset conditions: The first network element determines the district / county corresponding to the first location information and the district / county corresponding to the second location information based on a pre-configured mapping relationship between district / county information and location information. The district / county corresponding to the first location information can be referred to as the first district / county, and the district / county corresponding to the second location information as the second district / county. If the first district / county and the second district / county are different districts / counties, the first network element determines that the terminal device's movement trajectory meets the condition of movement between different districts / counties, and the terminal device has moved across districts / counties. If the first district / county and the second district / county are the same district / county, the first network element determines that the terminal device's movement trajectory does not meet the condition of movement between different districts / counties, and the terminal device has not moved across districts / counties.

[0156] In this embodiment, the district / county information can be the identification information of the district / county, such as the district / county code. The first network element can use the location information to query the pre-configured mapping relationship between the district / county information and the location information to determine the district / county code corresponding to the location information.

[0157] Optionally, in this embodiment, the location information, district / county information, and / or the mapping relationship between district / county information and location information can be stored in the first network element, or in other network elements, or in a database. This embodiment does not impose specific limitations on this. The pre-configured mapping relationship between district / county information and location information can be in list form or array form, without limitation.

[0158] For example, assuming the location information is TAI, the pre-configured location information of the first network element can be a TA list, and the mapping relationship between the pre-configured location information of the first network element and the district / county information can be the correspondence between the TA list and the district / county code. After obtaining the TAI of the terminal device, the first network element can determine the TA list corresponding to the TAI, and then further determine the district / county corresponding to the TA list.

[0159] It should be noted that in this embodiment of the application, if the location information is TAI, in order to determine whether the device is moving across districts and counties based on the location information of the terminal device, the TAIs included in the same TA list will not correspond to different districts and counties.

[0160] In this embodiment of the application, depending on the region managed by the first network element, the pre-configured location information and / or the mapping relationship between the location information and the district / county information of the first network element are also different, which will be described in detail below.

[0161] When the first network element is the first network element of the visited network of the terminal device, the mapping relationship between district / county information and location information pre-configured in the first network element includes the mapping relationship between location information and district / county information of certain areas within the coverage of the visited network of the terminal device, and the mapping relationship between location information and district / county information of certain areas within the coverage of the home network of the terminal device; wherein, certain areas within the coverage of the home network can be areas adjacent to the coverage of the visited network of the terminal device, and these areas can be set according to actual needs, and this application embodiment does not specifically limit them.

[0162] For example, Figure 7 This is a diagram illustrating the coverage area of ​​a visited network and the coverage area of ​​a home network. (Example) Figure 7 As shown, the coverage area of ​​the 5G visited network is tangent to the coverage area of ​​the 5G home network, and the coverage areas of the 5G visited network and the 5G home network are included within the coverage area of ​​the 4G home network.

[0163] Assuming the terminal device moves from the 5G home network coverage area to the 5G visited network coverage area, the first network element is the V-AMF network element of the 5G visited network, and the first preset range can be the coverage area shown in 701, which is the edge area adjacent to the 5G visited network coverage area within the 5G home network coverage area. In this way, after the terminal device moves from the edge area of ​​the 5G home network area to the 5G visited network area, the first network element can determine the district / county where the terminal device was located before moving based on the location information of the terminal device in the edge area of ​​the 5G home network area before moving.

[0164] Assuming a terminal device moves from the 4G home network coverage area to the 5G visited network coverage area, the first network element is a V-AMF network element of the 5G visited network, and the first preset range can be the coverage area shown in 702, including a portion of the 4G home network coverage area adjacent to the edge of the 5G visited network coverage area. Thus, after the terminal device moves from the 4G home network area to the 5G visited network area, the first network element can determine the district / county where the terminal device was located before the move, based on the terminal device's location information in the 4G home network area.

[0165] Understandably, in this case, compared to the existing first network element that only configures the location information within the coverage area of ​​the visited network of the terminal device, the location information configured by the first network element in this application embodiment adds the location information of the home network coverage area of ​​the terminal device related to the movement of the terminal device, and adds the mapping relationship between the location information and the district / county information. The first network element can determine the district / county corresponding to the first location information based on the first location information of the terminal device and determine the district / county corresponding to the second location information based on the second location information, thereby determining whether the terminal device has moved across districts / counties.

[0166] When the first network element is the home network of the terminal device, the mapping relationship between district / county information and location information pre-configured in the first network element includes the mapping relationship between location information and district / county information within the coverage area of ​​the home network of the terminal device, and the mapping relationship between location information and district / county information within a second preset range within the coverage area of ​​the visited network of the terminal device; wherein, the second preset range is adjacent to the coverage area of ​​the home network of the terminal device.

[0167] In this embodiment of the application, the second preset range can be set according to actual needs, and this embodiment of the application does not impose specific limitations on it.

[0168] For example, in combination Figure 8 This is a schematic diagram illustrating the coverage area of ​​a visited network and the coverage area of ​​a home network. For example... Figure 8 As shown, the coverage area of ​​the 5G visited network is tangent to the coverage area of ​​the 5G home network, and the coverage areas of the 5G visited network and the 5G home network are included within the coverage area of ​​the 4G home network.

[0169] Assuming the terminal device moves from the 5G visited network coverage area to the 5G home network coverage area, the first network element is the H-AMF network element of the 5G home network, and the second preset range can be the coverage area shown in 801, which is the edge area adjacent to the 5G home network coverage area within the 5G visited network coverage area. In this way, after the terminal device moves from the edge area of ​​the 5G visited network area to the 5G home network area, the first network element can determine the district / county where the terminal device was located before the move based on the location information of the terminal device in the edge area of ​​the 5G visited network area before the move.

[0170] Assuming a terminal device moves from the coverage area of ​​the 5G visited network to the coverage area of ​​the 4G home network, the first network element is the MME network element of the 4G home network, and the second preset range can be the coverage area shown in Figure 802, which is the edge area of ​​the 5G visited network. Thus, after the terminal device moves from the edge area of ​​the 5G visited network to the 4G home network area, the first network element can determine the district / county where the terminal device was located before the move, based on the terminal device's location information in the edge area of ​​the 5G visited network.

[0171] Understandably, in this case, compared to the existing first network element that only configures location information within the coverage area of ​​the terminal device's home network, the location information pre-configured by the first network element in this application embodiment adds location information within the coverage area of ​​the visited network of the terminal device related to the terminal device's movement, and adds a mapping relationship between location information and district / county information. The first network element can determine the district / county corresponding to the first location information based on the terminal device's first location information and determine the district / county corresponding to the second location information based on the second location information, thereby determining whether the terminal device has moved across districts / counties.

[0172] The following is a specific example for explanation. For instance, suppose the location information is TAI, and the boundary area between the visited network area and the home network area is within district / county 1. In this case, district / county 1 geographically includes part of the visited network area, the boundary area between the visited network and the home network, and part of the home network area.

[0173] When the first network element is the AMF network element of the visited network of the terminal device, the location information pre-configured by the AMF network element of the visited network used to manage the visited network area within district / county 1, corresponding to district / county 1, includes: (1) Visit the operator’s 5G TA list in district / county 1, or the 5G TA list of the 5G visited network area in district / county 1.

[0174] (2) The list of 5G TAs belonging to the operator in district / county 1, or the list of 5G TAs belonging to the 5G network area included in district / county 1.

[0175] (3) The 5G TA list of the operator in district / county 1, or the 4G TA list of the 4G home network area included in district / county 1.

[0176] In this embodiment of the application, compared with the existing AMF network element used to manage the visited network area within the county 1, the location information configured in the AMF network element used to manage the visited network area within the county 1 is extended to the location information corresponding to (2) and (3).

[0177] When the first network element is the AMF (or MME) network element of the home network of the terminal device, the location information pre-configured by the AMF network element (or MME) of the home network used to manage the home network area within district / county 1, corresponding to district / county 1, includes: (4) Visit the operator’s 5G TA list in district / county 1, or the 5G TA list of the 5G visited network area in district / county 1.

[0178] (5) The list of 5G TAs belonging to the operator in district / county 1, or the list of 5G TAs belonging to the 5G network area in district / county 1.

[0179] (6) The list of 4G TAs belonging to the operator in district / county 1, or the list of 5G TAs belonging to the 4G network area in district / county 1.

[0180] In this embodiment, compared to the existing AMF network element (or MME network element) used to manage the home network area within the county 1, the location information configured in the AMF network element (or MME network element) used to manage the home network area within the county 1 is extended to the location information corresponding to (4).

[0181] For S603-S604, after the first network element determines that the movement trajectory of the terminal device meets the preset conditions, it needs to take the terminal device offline and then bring it back online so that the second network element can reallocate an IP address for the terminal device that has come back online.

[0182] Specifically, the first network element sends an instruction message to the terminal device, instructing the terminal device to release the first session of the first service and re-establish a second session for the first service. After receiving the instruction message from the first network element, the terminal device releases the first session of the first service according to the instruction message, and then sends a session establishment request to the first network element, requesting to re-establish a second session for the first service. Here, the first service is the service currently running on the terminal device.

[0183] Optionally, in order to ensure that some important services of the terminal device are not interrupted, after the first network element determines that the movement trajectory of the terminal device meets the preset conditions, the first network element can detect the service status of the terminal device and decide whether to immediately instruct the terminal device to go offline based on the service status of the terminal device.

[0184] For example, to ensure that ongoing call services on the terminal device are not interrupted, if the first service includes the second service (i.e., if the terminal device is running the second service), the first network element can send an indication message to the terminal device only after detecting that the second service has ended, thus ensuring that the second service ends normally and is not forcibly interrupted. Alternatively, if the first service does not include the second service (i.e., if the terminal device is not currently running the second service), the first network element can immediately send an indication message to the terminal device, where the second service is a voice call or a video call.

[0185] For example, in a scenario where the first network element is either the first network element of a 5G visited network or the first network element of a 5G home network, assuming there is a PDU session with a data network name (DNN) of IP Multimedia Subsystem (IMS) and a 5G QoS stream with a 5G QoS identifier (5QI) = 1, then the 5G QoS stream with 5QI = 1 is a service stream for voice or video calls. If the first network element detects that the terminal device has a PDU session with an IMS DNN and a 5G QoS stream with 5QI = 1, it can determine that the terminal device has a running second service. The first network element can wait for the 5G QoS stream with 5QI = 1 to be deleted before allowing the terminal device to go offline across regions. In a scenario where the first network element is the first network element of the 4G home network, assuming there is a PDU session with an access point name (APN) of IMS and a 4G IMS dedicated bearer with a QoS class identifier (QCI) of 1, then this 4G IMS dedicated bearer with QCI=1 is a dedicated bearer for voice or video call services. If the first network element detects that the terminal device has a PDU session with an APN of IMS and a 4G IMS dedicated bearer with QCI=1, it can determine that the terminal device has a second service running. The first network element can wait until the 4G IMS dedicated bearer with QCI=1 is deleted before allowing the terminal device to go offline across regions.

[0186] For S605-S606, the first network element sends the second location information to the second network element. After receiving the second location information, the second network element can reallocate the target IP address for the terminal device based on the second location information during the establishment of the second session.

[0187] It should be noted that in roaming scenarios under home routing, the second network element in this embodiment is the second network element of the terminal device's home network. In other words, after the terminal device moves from the first area to the second area, in the following situations: the first area and the second area are within the coverage of the terminal device's visited network; or, the first area is within the coverage of the terminal device's home network and the second area is within the coverage of the terminal device's visited network; or, the first area is within the coverage of the terminal device's visited network and the second area is within the coverage of the terminal device's home network, the second network element is always the second network element of the terminal device's home network.

[0188] In this embodiment, the second network element is used to allocate a destination IP address to the terminal device, and can be a session management function network element, a packet data network gateway control plane network element, or a user plane function network element. The second network element is related to the type of network the terminal device accesses after moving to the second area. For example, assuming the second area is within a 5G visited network area or a 5G home network area, the second network element can be an H-SMF network element or an H-UPF network element of the 5G home network. Assuming the second area is within a 4G home network area, the second network element can be a PGWC network element of the 4G home network.

[0189] In one possible implementation, after the first network element instructs the terminal device to re-establish a session, it can receive a session establishment request from the terminal device. Then, the first network element forwards the session establishment request to the second network element and sends the terminal device's second location information to the second network element. Upon receiving the session establishment request and the second location information, the second network element establishes a second session according to the session establishment request and reassigns a target IP address to the terminal device based on the second location information. In this way, if the terminal device moves across districts or counties, the second network element can reassign a new IP address to the terminal device based on its current location information, thus enabling the network side to determine the terminal device's current actual geographical location based on its IP address.

[0190] Optionally, in this embodiment, if the first network element and the second network element are from different operators, the first network element can interact with the second network element through other network elements or devices. For example, if the first network element is a V-AMF network element of the visited network and the second network element is an H-SMF network element of the home network, the V-AMF network element can send information to the V-SMF network element of the visited network, and the V-SMF network element can then send the information to the H-SMF network element.

[0191] Based on this solution, in scenarios where terminal devices roam, if a terminal device moves, the network side can obtain the second location information of the area currently registered by the terminal device and the first location information of the area previously registered by the terminal device. This allows the network side to determine whether the terminal device has moved across districts / counties. If it is determined that the terminal device has moved across districts / counties, the network side instructs the terminal device to go offline and then back online. This allows the network side to reallocate an IP address for the terminal device based on its current location information, i.e., the second location information. Compared to the current solution, where the network side cannot determine whether the geographical location of the terminal device has changed before and after movement in roaming scenarios, thus assuming that the terminal device does not need to change its IP address and the IP address does not accurately represent the actual geographical location of the terminal device, the IP address allocation scheme provided in this application can achieve fine-grained allocation of IP addresses for terminal devices in roaming scenarios, which is beneficial for terminal device location management. Furthermore, this solution can instruct the terminal device to go offline and then back online after determining that the terminal device has moved across districts / counties, and reallocate an IP address for the terminal device during the back-on process, rather than reallocating an IP address during session switching, thus ensuring service consistency.

[0192] The following describes how the second network element assigns a target IP address to the terminal device based on the second location information. For example... Figure 9 As shown, it includes S901-S903: S901, the second network element receives second location information from the first network element, the second location information being used to characterize the location information of the second area currently registered by the terminal device.

[0193] S902, the second network element determines the identification information of the district / county where the terminal device is currently located based on the second location information and the mapping relationship between the pre-configured district / county information and location information.

[0194] S903, the second network element, assigns a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0195] For S901, please refer to the introduction of S605 above, and it will not be repeated here.

[0196] For S902, in this embodiment of the application, the second network element can determine the identification information of the district / county corresponding to the second location information, i.e., the identification information of the district / county where the terminal device is currently located, based on the second location information and the pre-configured mapping relationship between district / county information and location information.

[0197] In roaming scenarios using home routing, when a terminal device moves within or to the edge of the visited network area, the second location information may be either the location information of the home network area or the location information of the visited network area. Therefore, to enable the second network element to determine the district / county information corresponding to the second location information, the mapping relationship between district / county information and location information pre-configured by the second network element includes the mapping relationship between location information and district / county information within the coverage area of ​​the terminal device's home network, and the mapping relationship between location information and district / county information within a third preset range within the coverage area of ​​the terminal device's visited network; wherein the third preset range is adjacent to the coverage area of ​​the terminal device's home network.

[0198] The third preset range can be referred to as the second preset range in the above introduction of S602, and will not be repeated here.

[0199] Compared to existing second network elements that only configure location information within the home network coverage area of ​​the terminal device, in this embodiment, the location information pre-configured by the second network element adds location information within the visited network coverage area of ​​the terminal device related to the movement of the terminal device, and adds a mapping relationship between location information and district / county information. The second network element can determine the district / county information corresponding to the second location information of the terminal device based on the second location information of the terminal device, thereby determining the district / county information where the terminal device is currently located.

[0200] For example, assuming the location information is TAI, and the visited network area and the home network area are geographically located at the boundary within county 1, in other words, county 1 geographically includes a portion of the visited network area, the boundary area between the visited network and the home network, and a portion of the home network area. Then, the location information pre-configured for county 1 by the second network element used to manage the home network within county 1 includes: (1) Visit the operator’s 5G TA list in district / county 1, or the 5G TA list of the 5G visited network area in district / county 1.

[0201] (2) The 5G TA list of the operator in district / county 1, or the 5G TA list of the 5G network area in district / county 1.

[0202] (3) The 4G TA list of the operator in district / county 1, or the 5G TA list of the 4G network area in district / county 1.

[0203] Optionally, in this embodiment of the application, the identification information of the district / county can be the district / county code.

[0204] For S903, in this embodiment of the application, the second network element can allocate a target IP address to the terminal device during the process of re-establishing a PDU session or re-establishing a PDU connection for the terminal device.

[0205] In one possible implementation, the second network element can determine the target IP address to be assigned to the terminal device according to the following steps.

[0206] The second network element determines one or more IP addresses corresponding to the identification information of the district / county where the terminal device is currently located, and determines the target IP address to be assigned to the terminal device from among the one or more IP addresses.

[0207] In this implementation, the second network element is pre-configured with an IP address pool corresponding to the identification information of the district / county. After the second network element determines the district / county where the terminal device is currently located, it can determine the IP address pool corresponding to the identification information of the district / county where it is currently located, and then select an IP address from one or more IP addresses included in the IP address pool as the target IP address to be assigned to the terminal device.

[0208] In another possible implementation, the second network element generates a target IP address to be assigned to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0209] In this implementation, after the second network element determines the identification information of the district / county where the terminal device is currently located, it can generate a prefix for the target IP address assigned to the terminal device based on the identification information.

[0210] Optionally, in this embodiment of the application, after the second network element determines the target IP address of the terminal device, it can send a notification message to the terminal device to notify the terminal device of the assigned target IP address.

[0211] Based on this solution, in roaming scenarios, the second network element can determine the district / county where the terminal device is currently located based on the terminal device's current location information, and allocate a target IP address to the terminal device based on the district / county where the terminal device is currently located. Therefore, this solution can achieve fine-grained allocation of the terminal device's IP address based on the district / county where the terminal device is currently located in roaming scenarios, thereby enabling operators to determine the actual geographical location (district / county) of the terminal device based on its IP address.

[0212] For ease of understanding, the following is combined with Figure 10 Taking a first network element as a V-AMF network element, H-AMF network element, or H-MME network element, and a second network element as an H-SMF network element, PGWC network element, or H-UPF network element as an example, an exemplary process of the IP address allocation method provided in the embodiments of this application will be described.

[0213] S1001. The terminal device moves in a roaming scenario with home routing.

[0214] In this embodiment of the application, in the roaming scenario under the home routing mode, the movement state of the terminal device includes idle state reselection, connected state redirection, or connected state switching.

[0215] In this embodiment of the application, the situation where the terminal device moves includes five scenarios S1002.1-S1002.5: S1002.1 The terminal equipment moves within the 5G visited network area.

[0216] S1002.2 The terminal device moves from the 4G home network area to the 5G visited network area.

[0217] S1002.3 The terminal device moves from the 5G home network area to the 5G visited network area.

[0218] S1002.4 The terminal device moves from the 5G visited network area to the 5G home network area.

[0219] S1002.5 The terminal device moves from the 5G visited network area to the 4G home network area.

[0220] For the three movement scenarios S1002.1, S1002.2, and S1002.3, the next step of the IP address allocation method provided in this application embodiment is S1003.1.

[0221] S1003.1 The AMF network element (V-AMF network element) of the visited network determines the movement trajectory of the terminal device based on the location information of the terminal device to meet the preset conditions.

[0222] V-AMF queries the pre-configured district / county list based on the terminal device's current TAI (NCGI) to determine the district / county code where the terminal device is currently located. It also queries the pre-configured district / county list based on the TAI (NCGI, ECGI) accessed before the move to determine the district / county code where the terminal device was located before the move. If the terminal device is located in a different district / county before and after the move, then the terminal device's movement trajectory is considered to meet preset conditions. For details, please refer to the above description of S602.

[0223] Regarding the movement scenario in S1002.4, the next step of the IP address allocation method provided in this application embodiment is S1003.2.

[0224] S1003.2 The AMF network element (H-AMF network element) of the home network determines the movement trajectory of the terminal device based on the location information of the terminal device to meet the preset conditions. For the specific implementation of S1003.2, please refer to the introduction of S1003.1 above.

[0225] Regarding the movement scenario in S1002.5, the next step of the IP address allocation method provided in this application embodiment is S1003.3.

[0226] S1003.3 The MME network element (H-MME network element) of the home network determines the movement trajectory of the terminal device based on the location information of the terminal device to meet the preset conditions. For the specific implementation of S1003.3, please refer to the introduction of S1003.1 above.

[0227] Following S1003.1, the next step in the IP address allocation method provided in this application embodiment is S1004.1.

[0228] S1004.1. The V-AMF network element detects whether the terminal device has a QoS flow with 5QI=1 and DNN=IMS to detect whether the terminal device is making a voice or video call. If the V-AMF network element detects that the terminal device has a QoS flow with 5QI=1 and DNN=IMS, then execute S1005.1.1; otherwise, execute S1005.1.2.

[0229] S1005.1.1, V-AMF network element monitors the service status of terminal equipment, waits for the deletion of QoS flow with 5QI=1, and executes S1005.1.2 after the voice call or video call service ends.

[0230] S1005.1.2, the V-AMF network element performs a cross-regional offline operation, initiates a PDU session release process, and instructs the UE to re-establish the PDU session.

[0231] Following S1003.2, the next step in the IP address allocation method provided in this application embodiment is S1004.2.

[0232] S1004.2. The H-AMF network element detects whether the terminal device has a QoS flow with 5QI=1 and DNN=IMS to detect whether the terminal device is making a voice or video call. If the H-AMF network element detects that the terminal device has a QoS flow with 5QI=1 and DNN=IMS, then execute S1005.2.1; otherwise, execute S1005.2.2.

[0233] S1005.2.1 H-AMF network element monitors the service status of terminal equipment, waits for the deletion of QoS flow with 5QI=1, and executes S1005.2.2 after the voice call or video call service ends.

[0234] S1005.2.2, The H-AMF network element performs a cross-regional offline operation, initiates a PDU session release process, and instructs the UE to re-establish the PDU session.

[0235] Following S1003.3, the next step in the IP address allocation method provided in this application embodiment is S1004.3.

[0236] S1004.3. The H-MME network element detects whether the terminal device has a dedicated bearer with QCI=1 and APN=IMS to detect whether the terminal device is making a voice or video call. If the H-AMF network element detects that the terminal device has a dedicated bearer with QCI=1 and APN=IMS, then execute S1005.3.1; otherwise, execute S1005.3.2.

[0237] S1005.3.1 H-MME network element monitors the service status of terminal equipment, waits for the deletion of the dedicated bearer with QCI=1, and executes S1005.3.2 after the voice call service or video call service ends.

[0238] S1005.3.2, the H-MME network element performs a cross-regional offline operation, initiates a PDU session release process, and instructs the UE to re-establish the PDU session.

[0239] Following S1005.1.2 or S1005.2.2, the next step in the IP address allocation method provided in this application embodiment is S1006.1.

[0240] S1006.1 During the PDU session reconstruction or PDN connection re-establishment process, the H-SMF or H-UPF network element of the home network determines the district / county where the terminal device is currently located based on the terminal device's current location information (TAI, NCGI, and / or ECGI), reallocates an IP address for the terminal device within the IP address pool corresponding to that district / county, and notifies the terminal device.

[0241] Following S1005.3.2, the next step in the IP address allocation method provided in this application embodiment is S1006.2.

[0242] S1006.2. During the PDU session reconstruction or PDU connection re-establishment process, the PGWC network element of the home network reallocates the IP address in the new district / county address pool according to the current location information (TAI, NCGI, and / or ECGI) of the terminal device and notifies the terminal device.

[0243] It is understood that in the above embodiments, the methods and / or steps implemented by the first network element can also be implemented by components (e.g., chips or circuits) that can be used in the first network element; the methods and / or steps implemented by the second network element can also be implemented by components (e.g., chips or circuits) that can be used in the second network element; and the methods and / or steps implemented by the terminal device can also be implemented by components (e.g., chips or circuits) that can be used in the terminal device.

[0244] The above mainly describes the solution provided in the embodiments of this application from the perspective of interaction between various network elements. Optionally, the first network element, the second network element, or the terminal device in the embodiments of this application can be a general-purpose device or a special-purpose device, and the embodiments of this application do not specifically limit this.

[0245] Optionally, the functions of the first network element, the second network element, or the terminal device in the embodiments of this application can be implemented by one device, multiple devices, or one or more functional modules within a single device. This application does not specifically limit these functions. It is understood that the aforementioned functions can be network elements in hardware devices, software functions running on dedicated hardware, a combination of hardware and software, or virtualization functions instantiated on a platform (e.g., a cloud platform).

[0246] For example, embodiments of this application also provide an IP address allocation device for implementing the various methods described above. This IP address allocation device can be a first network element in the above method embodiments, or a device containing the first network element, or a component usable in the first network element; or, the IP address allocation device can be a second network element in the above method embodiments, or a device containing the second network element, or a component usable in the second network element; or, the IP address allocation device can be a terminal device in the above method embodiments, or a device containing the terminal device, or a component usable in the terminal device. It is understood that, in order to implement the above functions, the IP address allocation device includes hardware structures and / or software modules corresponding to the execution of each function. Those skilled in the art should readily recognize that, based on the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein, this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in hardware or by computer software driving hardware depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0247] This application embodiment can divide the IP address allocation device into functional modules according to the above method embodiment. For example, each function can be divided into its own functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. It should be noted that the module division in this application embodiment is illustrative and only represents one logical functional division. In actual implementation, there may be other division methods.

[0248] Taking the IP address allocation device as the first network element in the above method embodiment as an example, when using functional module division, this approach employs a functional module division. Figure 11 A schematic diagram of an IP address allocation device 110 is shown. Figure 11 As shown, the IP address allocation device 110 includes a communication module 1101 and a processing module 1102.

[0249] In some embodiments, the IP address allocation device 110 may further include a storage module ( Figure 11 (not shown in the image) is used to store program instructions and data.

[0250] The communication module 1101 is used to acquire first location information and second location information of the terminal device; wherein the second location information is used to represent the location information of the second area currently registered by the terminal device; the first location information is used to represent the location information of the first area registered by the terminal device before registering the second area; the processing module 1102 is used to determine, based on the first location information and the second location information, that the movement trajectory of the terminal device meets preset conditions; the communication module 1101 is also used to send instruction information to the terminal device, the instruction information being used to instruct the terminal device to release the first session of the first service and re-establish the second session for the first service; the communication module 1101 is also used to send second location information to the second network element, the second location information being used by the second network element to allocate a target IP address to the terminal device during the establishment of the second session.

[0251] In one possible implementation, the first area and the second area are located within the coverage area of ​​the visited network of the terminal device, and the IP address allocation device 110 is the IP address allocation device 110 of the visited network of the terminal device; or, the first area is located within the coverage area of ​​the home network of the terminal device, and the second area is located within the coverage area of ​​the visited network of the terminal device, and the IP address allocation device 110 is the IP address allocation device 110 of the visited network of the terminal device; or, the first area is located within the coverage area of ​​the visited network of the terminal device, and the second area is located within the coverage area of ​​the home network of the terminal device, and the IP address allocation device 110 is the IP address allocation device 110 of the home network of the terminal device.

[0252] As one possible implementation, the processing module 1102 is specifically used to: determine, based on the first location information and the second location information, whether the movement trajectory of the terminal device satisfies the condition of moving between different districts and counties.

[0253] As one possible implementation, the processing module 1102 is specifically used to: determine the district / county corresponding to the first location information as the first district / county, and the district / county corresponding to the second location information as the second district / county, based on the pre-configured mapping relationship between district / county information and location information, wherein the first district / county and the second district / county are different districts / counties.

[0254] As one possible implementation, the IP address allocation device 110 is an IP address allocation device for the visited network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the visited network of the terminal device, and the mapping relationship between location information and district / county information within a first preset range within the coverage area of ​​the home network of the terminal device; wherein, the first preset range is adjacent to the coverage area of ​​the visited network of the terminal device; or, the IP address allocation device 110 is an IP address allocation device for the home network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the home network of the terminal device, and the mapping relationship between location information and district / county information within a second preset range within the coverage area of ​​the visited network of the terminal device; wherein, the second preset range is adjacent to the coverage area of ​​the home network of the terminal device.

[0255] As one possible implementation, the location information includes at least one of the following: Tracking Area Identifier (TAI), Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI).

[0256] As one possible implementation, the communication module 1101 is specifically used to: send an indication message to the terminal device after the second service has ended when the first service includes the second service; or, send an indication message to the terminal device when the first service does not include the second service, wherein the second service is a voice call service or a video call service.

[0257] All relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0258] In one possible implementation, Figure 11 The functions / implementation process of the communication module 1101 and the processing module 1102 can be obtained through Figure 5 The processor 501 in the memory calls computer execution instructions stored in memory 503 to implement the function. Alternatively, Figure 11 The function / implementation process of the processing module 1102 can be achieved through... Figure 5 The processor 501 in the memory calls computer execution instructions stored in the memory 503 to implement this. Figure 11 The function / implementation process of the communication module 1101 can be obtained through Figure 5 It is implemented using the communication interface 504.

[0259] Taking the IP address allocation device as the second network element in the above method embodiment as an example, when using functional module division, this approach employs a functional module division. Figure 12 A schematic diagram of an IP address allocation device 120 is shown. Figure 12 As shown, the IP address allocation device 120 includes a transceiver module 1201 and a processing module 1202.

[0260] In some embodiments, the IP address allocation device 120 may further include a storage module ( Figure 12 (not shown in the image) is used to store program instructions and data.

[0261] The transceiver module 1201 is used to receive second location information from the first network element; wherein the second location information is used to characterize the location information of the second area currently registered by the terminal device; the processing module 1202 is used to determine the identification information of the district / county where the terminal device is currently located based on the second location information and the pre-configured mapping relationship between district / county information and location information; the processing module 1202 is also used to allocate a target IP address to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0262] As one possible implementation, the processing module 1202 is specifically used to: determine one or more IP addresses corresponding to the identification information of the district / county where the terminal device is currently located, and determine the target IP address to be assigned to the terminal device from among the one or more IP addresses.

[0263] As one possible implementation, the processing module 1202 is specifically used to: generate a target IP address to be assigned to the terminal device based on the identification information of the district / county where the terminal device is currently located.

[0264] As one possible implementation, the first region and the second region are located within the coverage area of ​​the visited network of the terminal device; or, the first region is located within the coverage area of ​​the home network of the terminal device, and the second region is located within the coverage area of ​​the visited network of the terminal device; or, the first region is located within the coverage area of ​​the visited network of the terminal device, and the second region is located within the coverage area of ​​the home network of the terminal device; wherein, the first region is the region registered by the terminal device before registering the second region; and the IP address allocation device 120 is the IP address allocation device 120 of the home network of the terminal device.

[0265] As one possible implementation, the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the terminal device's home network, and the mapping relationship between location information and district / county information within a third preset range within the coverage area of ​​the terminal device's visited network; wherein, the third preset range is adjacent to the coverage area of ​​the terminal device's home network.

[0266] As one possible implementation, the location information includes at least one of the following: Tracking Area Identifier (TAI), E-UTRAN Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI).

[0267] As one possible implementation, the IP address allocation device 120 can be a session management function network element, a packet data network gateway control plane network element, or a user plane function network element.

[0268] All relevant content of each step involved in the above method embodiments can be referenced from the functional description of the corresponding functional module, and will not be repeated here.

[0269] In one possible implementation, Figure 12 The functions / implementation process of the transceiver module 1201 and the processing module 1202 can be obtained through Figure 5 The processor 501 in the memory calls computer execution instructions stored in memory 503 to implement the function. Alternatively, Figure 12 The function / implementation process of the processing module 1202 can be achieved through... Figure 5 The processor 501 in the memory calls computer execution instructions stored in the memory 503 to implement this. Figure 12 The function / implementation process of the transceiver module 1201 can be obtained through Figure 5 It is implemented using the communication interface 404.

[0270] As a possible product form, the IP address allocation device of this application embodiment can also be implemented using the following: one or more field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gate logic, discrete hardware components, any other suitable circuits, or any combination of circuits capable of performing the various functions described throughout this application.

[0271] Through the above description of the embodiments, those skilled in the art will clearly understand that, for the sake of convenience and brevity, only the division of the above functional units is used as an example. In practical applications, the above functions can be assigned to different functional units as needed, that is, the internal structure of the device can be divided into different functional units to complete all or part of the functions described above. The specific working process of the system, device, and unit described above can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0272] This invention also provides a computer-readable storage medium storing instructions, which, when executed by a computer, perform each step of the method flow shown in the above-described method embodiments.

[0273] Embodiments of the present invention provide a computer program product containing instructions that, when executed on a computer, cause the computer to perform the various steps in the method flow shown in the above method embodiments.

[0274] The computer-readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), registers, hard disks, optical fibers, compact disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing, or any other form of computer-readable storage medium in the art. An exemplary storage medium is coupled to a processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium may also be a component of the processor. The processor and the storage medium may reside in a purpose-specific ASIC. In the embodiments of this application, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0275] Since the IP address allocation device, computer-readable storage medium, and computer program product provided in this embodiment can be applied to the network protocol IP address allocation method provided in this embodiment, the technical effects obtained can also be referred to the above method embodiments. The embodiments of the present invention will not be described again here.

[0276] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0277] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A method for allocating network protocol IP addresses, characterized in that, Applied to the first network element, the method includes: Obtain first location information and second location information of the terminal device; wherein, the second location information is used to characterize the location information of the second region currently registered by the terminal device; and the first location information is used to characterize the location information of the first region registered by the terminal device before registering the second region. Based on the first location information and the second location information, it is determined that the movement trajectory of the terminal device meets preset conditions; Send an instruction message to the terminal device, the instruction message being used to instruct the terminal device to release the first session of the first service and re-establish a second session for the first service; The second location information is sent to the second network element. The second location information is used by the second network element to allocate a target IP address to the terminal device during the establishment of the second session.

2. The method according to claim 1, characterized in that, The first area and the second area are located within the coverage area of ​​the visited network of the terminal device, and the first network element is the first network element of the visited network of the terminal device; Alternatively, the first area is located within the coverage area of ​​the home network of the terminal device, the second area is located within the coverage area of ​​the visited network of the terminal device, and the first network element is the first network element of the visited network of the terminal device; Alternatively, the first area is located within the coverage of the visited network of the terminal device, the second area is located within the coverage of the home network of the terminal device, and the first network element is the first network element of the home network of the terminal device.

3. The method according to claim 1, characterized in that, The step of determining that the movement trajectory of the terminal device meets the preset conditions based on the first location information and the second location information includes: Based on the first location information and the second location information, it is determined that the movement trajectory of the terminal device meets the condition of moving between different districts and counties.

4. The method according to claim 3, characterized in that, The step of determining that the movement trajectory of the terminal device satisfies the condition of moving between different districts and counties based on the first location information and the second location information includes: Based on the pre-configured mapping relationship between district / county information and location information, the district / county corresponding to the first location information is determined as the first district / county, and the district / county corresponding to the second location information is determined as the second district / county, wherein the first district / county and the second district / county are different districts / counties.

5. The method according to claim 4, characterized in that, The first network element is the first network element of the visited network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the visited network of the terminal device, and the mapping relationship between location information and district / county information within a first preset range within the coverage area of ​​the home network of the terminal device; wherein, the first preset range is adjacent to the coverage area of ​​the visited network of the terminal device. Alternatively, the first network element is the first network element of the home network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the home network of the terminal device, and the mapping relationship between location information and district / county information within a second preset range within the coverage area of ​​the visited network of the terminal device; wherein, the second preset range is adjacent to the coverage area of ​​the home network of the terminal device.

6. The method according to any one of claims 1-5, characterized in that, The location information includes at least one of the following: Tracking Area Identifier (TAI), Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI).

7. The method according to any one of claims 1-5, characterized in that, Sending an indication message to the terminal device includes: If the first service includes the second service, the indication information is sent to the terminal device after the second service is detected to have ended. Alternatively, if the first service does not include the second service, the instruction information may be sent to the terminal device, wherein the second service is a voice call service or a video call service.

8. A network protocol IP address allocation device, characterized in that, The IP address allocation device includes a communication module and a processing module: The communication module is used to acquire first location information and second location information of the terminal device; wherein, the second location information is used to represent the location information of the second region currently registered by the terminal device; and the first location information is used to represent the location information of the first region registered by the terminal device before registering the second region. The processing module is used to determine, based on the first location information and the second location information, whether the movement trajectory of the terminal device meets preset conditions. The communication module is further configured to send indication information to the terminal device, the indication information being used to instruct the terminal device to release the first session of the first service and re-establish a second session for the first service; The communication module is further configured to send the second location information to the second network element, wherein the second location information is used by the second network element to allocate a target IP address to the terminal device during the establishment of the second session.

9. The IP address allocation device according to claim 8, characterized in that, The first region and the second region are located within the coverage area of ​​the visited network of the terminal device, and the IP address allocation device is the IP address allocation device of the visited network of the terminal device; Alternatively, the first area is within the coverage of the home network of the terminal device, the second area is within the coverage of the visited network of the terminal device, and the IP address allocation device is the IP address allocation device of the visited network of the terminal device. Alternatively, the first area is located within the coverage of the visited network of the terminal device, the second area is located within the coverage of the home network of the terminal device, and the IP address allocation device is the IP address allocation device of the home network of the terminal device.

10. The IP address allocation device according to claim 8, characterized in that, The processing module is specifically used for: Based on the first location information and the second location information, it is determined that the movement trajectory of the terminal device meets the condition of moving between different districts and counties.

11. The IP address allocation device according to claim 10, characterized in that, The processing module is specifically used for: Based on the pre-configured mapping relationship between district / county information and location information, the district / county corresponding to the first location information is determined as the first district / county, and the district / county corresponding to the second location information is determined as the second district / county, wherein the first district / county and the second district / county are different districts / counties.

12. The IP address allocation device according to claim 11, characterized in that, The IP address allocation device is the IP address allocation device for the visited network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the visited network of the terminal device, and the mapping relationship between location information and district / county information within a first preset range within the coverage area of ​​the home network of the terminal device; wherein, the first preset range is adjacent to the coverage area of ​​the visited network of the terminal device. Alternatively, the IP address allocation device is the IP address allocation device of the home network of the terminal device; the pre-configured mapping relationship between district / county information and location information includes the mapping relationship between location information and district / county information within the coverage area of ​​the home network of the terminal device, and the mapping relationship between location information and district / county information within a second preset range within the coverage area of ​​the visited network of the terminal device; wherein, the second preset range is adjacent to the coverage area of ​​the home network of the terminal device.

13. The IP address allocation device according to any one of claims 8-12, characterized in that, The location information includes at least one of the following: Tracking Area Identifier (TAI), Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Cell Global Identifier (ECGI), and New Radio Interface (NR) Cell Global Identifier (NCGI).

14. The IP address allocation device according to any one of claims 8-12, characterized in that, The communication module is specifically used for: If the first service includes the second service, the indication information is sent to the terminal device after the second service is detected to have ended. Alternatively, if the first service does not include the second service, the instruction information may be sent to the terminal device, wherein the second service is a voice call service or a video call service.

15. An IP address allocation device, characterized in that, The IP address allocation device includes: a processor; The processor is configured to read computer execution instructions from memory and execute the computer execution instructions to cause the IP address allocation device to perform the method as described in any one of claims 1-7.

16. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program or instructions that, when executed by an IP address allocation device, implement the method as described in any one of claims 1-7.

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