Switching method, communication device, chip and readable storage medium

Abstract

The invention provides a switching method, communication equipment, a chip and a readable storage medium, and the method comprises the steps: determining that a terminal is switched from first network equipment to second network equipment, and the first network equipment and the second network equipment are network equipment of different systems; a first message is sent to the second network device, the first message carries a first address of the terminal, and the first address is allocated to the terminal by the first network device; receiving a second message sent by a second network device, the second message carrying a second address of the terminal, the second address being different from the first address; therefore, when inter-system switching occurs and the original address of the terminal cannot be allocated by the network, the existing connection is not directly disconnected, a new address can be allocated on the basis of keeping the connection, smooth switching is realized, service interruption is avoided, the service continuity can be ensured, the service interruption time delay is reduced, and the user experience is effectively improved.

Description

Technical Field

[0001] The present application relates to the field of wireless communication technology, and in particular to a switching method, a communication device, a chip and a readable storage medium. Background Art

[0002] With the continuous development of wireless communication technology, 5G New Radio (NR) is a very important foundation for the next generation of cellular mobile technology. However, in actual applications, 4G networks are still widely used. In the case of coexistence of 4G and 5G networks, with the popularization of 5G networks, there will be more and more scenarios in which 5G networks switch to the original 4G networks. In order to ensure the user's service experience, higher requirements are put forward for terminals and networks when switching between different systems. Summary of the invention

[0003] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0004] To this end, the following technical solutions are proposed:

[0005] The first aspect of the present application provides a switching method, which includes: determining that the terminal switches from a first network device to a second network device, and the first network device and the second network device are network devices of different systems; sending a first message to the second network device, wherein the first message carries a first address of the terminal, and the first address is assigned to the terminal by the first network device; and receiving a second message sent by the second network device, wherein the second message carries a second address of the terminal, and the second address is assigned to the terminal by the second network device, and the second address is different from the first address.

[0006] Optionally, the first message is used to request registration to the second network device; the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0007] Optionally, the method further includes: sending a third message to the second network device, wherein the third message is used to indicate that registration of the terminal is completed.

[0008] Optionally, the method also includes: releasing a local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of a third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0009] Optionally, the first message is a registration request message, and the second message is a registration acceptance message.

[0010] Optionally, the method further includes: sending a fourth message to the second network device, wherein the fourth message is used to instruct the terminal to reject the registration.

[0011] Optionally, the method further includes: deleting a local fourth bearer; wherein the fourth bearer is used by the terminal to send the first message.

[0012] Optionally, the method further includes: sending a registration request message to the second network device, the registration request message being of an initial type.

[0013] Optionally, the first message is used to request the second network device to establish a packet data network PDN connection; the second message is used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0014] Optionally, the method further includes: sending a third message to the second network device, wherein the third message is used to indicate that the terminal accepts activation of the first bearer.

[0015] Optionally, the method further includes: updating Internet Protocol IP parameters in relevant modules based on the second address.

[0016] Optionally, the method also includes: sending a fourth message to the second network device, the fourth message being used to instruct the terminal to refuse to activate the first bearer; releasing a local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on a mapping of a third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0017] Optionally, the first message is used to request the second network device to establish a packet data unit PDU session; and the second message is used to indicate that the PDU session establishment request is accepted.

[0018] Optionally, the method further includes: updating Internet Protocol IP parameters in relevant modules based on the second address.

[0019] Optionally, the method also includes: sending a fourth message to the second network device, the fourth message being used to instruct the terminal to end the PDU session; releasing a local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on a mapping of a third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0020] Optionally, the first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

[0021] Optionally, the first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

[0022] The second aspect of the present application proposes a switching method, which includes: receiving a first message sent by a terminal, the first message carrying a first address of the terminal, and the first address is assigned to the terminal by a first network device; determining that the first address cannot be assigned to the terminal, sending a second message to the terminal, the second message carrying a second address of the terminal, the second address is different from the first address, and the second address is assigned to the terminal by a second network device; wherein the terminal switches from the first network device to the second network device, and the first network device and the second network device are network devices of different systems.

[0023] Optionally, the first message is used to request registration to the second network device; the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0024] Optionally, the method further includes: receiving a third message sent by the terminal, wherein the third message is used to indicate that registration of the terminal is completed.

[0025] Optionally, the first message is a registration request message, and the second message is a registration acceptance message.

[0026] Optionally, the method further includes: receiving a fourth message sent by the terminal, wherein the fourth message is used to instruct the terminal to reject the registration.

[0027] Optionally, the method further includes: receiving a registration request message sent by the terminal, the registration request message being of an initial type.

[0028] Optionally, the first message is used to request the second network device to establish a packet data network PDN connection; the second message is used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0029] Optionally, the method further includes: receiving a third message sent by the terminal, wherein the third message is used to indicate that the terminal accepts activation of the first bearer.

[0030] Optionally, the second address is also used by the terminal to update Internet Protocol IP parameters in relevant modules.

[0031] Optionally, the method further includes: receiving a fourth message sent by the terminal, wherein the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0032] Optionally, the first message is used to request the second network device to establish a packet data unit PDU session; and the second message is used to indicate that the PDU session establishment request is accepted.

[0033] Optionally, the second address is also used by the terminal to update Internet Protocol IP parameters in relevant modules.

[0034] Optionally, the method further includes: receiving a fourth message sent by the terminal, wherein the fourth message is used to instruct the terminal to end the PDU session.

[0035] Optionally, the first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

[0036] Optionally, the first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

[0037] In a third aspect of the present application, an embodiment proposes a terminal, comprising: a processing module, used to determine that the terminal switches from a first network device to a second network device, and the first network device and the second network device are network devices of different systems; a transceiver module, used to send a first message to the second network device, the first message carries a first address of the terminal, and the first address is assigned to the terminal by the first network device; the transceiver module is also used to receive a second message sent by the second network device, the second message carries a second address of the terminal, the second address is assigned to the terminal by the second network device, and the second address is different from the first address.

[0038] Optionally, the first message is used to request registration to the second network device; the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0039] Optionally, the transceiver module is further used to: send a third message to the second network device, where the third message is used to indicate that registration of the terminal is completed.

[0040] Optionally, the processing module is also used to: release a local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of a third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0041] Optionally, the first message is a registration request message, and the second message is a registration acceptance message.

[0042] Optionally, the transceiver module is further used to: send a fourth message to the second network device, where the fourth message is used to instruct the terminal to reject the registration.

[0043] Optionally, the processing module is further used to: delete a local fourth bearer; wherein the fourth bearer is used by the terminal to send the first message.

[0044] Optionally, the transceiver module is further used to: send a registration request message to the second network device, and the registration request message is of an initial type.

[0045] Optionally, the first message is used to request the second network device to establish a packet data network PDN connection; the second message is used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0046] Optionally, the transceiver module is further used to: send a third message to the second network device, where the third message is used to instruct the terminal to accept activation of the first bearer.

[0047] Optionally, the processing module is further used to: update Internet Protocol IP parameters in related modules based on the second address.

[0048] Optionally, the transceiver module is also used to: send a fourth message to the second network device, the fourth message being used to instruct the terminal to refuse to activate the first bearer; and release the local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, and the second bearer is obtained based on the mapping of the third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0049] Optionally, the first message is used to request the second network device to establish a packet data unit PDU session; and the second message is used to indicate that the PDU session establishment request is accepted.

[0050] Optionally, the processing module is further used to: update Internet Protocol IP parameters in related modules based on the second address.

[0051] Optionally, the transceiver module is also used to: send a fourth message to the second network device, the fourth message being used to instruct the terminal to end the PDU session; and release a local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, and the second bearer is obtained based on a mapping of a third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0052] Optionally, the first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

[0053] Optionally, the first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

[0054] The fourth aspect embodiment of the present application proposes a second network device, including: a transceiver module, used to receive a first message sent by a terminal, the first message carries a first address of the terminal, and the first address is assigned to the terminal by the first network device; the transceiver module is also used to determine that the first address cannot be assigned to the terminal, and send a second message to the terminal, the second message carries a second address of the terminal, the second address is different from the first address, and the second address is assigned to the terminal by the second network device; wherein the terminal switches from the first network device to the second network device, and the first network device and the second network device are network devices of different systems.

[0055] Optionally, the first message is used to request registration to the second network device; the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0056] Optionally, the transceiver module is further used to: receive a third message sent by the terminal, where the third message is used to indicate that registration of the terminal is completed.

[0057] Optionally, the first message is a registration request message, and the second message is a registration acceptance message.

[0058] Optionally, the transceiver module is further used to: receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to reject the registration.

[0059] Optionally, the transceiver module is further used to: receive a registration request message sent by the terminal, where the registration request message is of an initial type.

[0060] Optionally, the first message is used to request the second network device to establish a packet data network PDN connection; the second message is used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0061] Optionally, the transceiver module is further used to: receive a third message sent by the terminal, where the third message is used to instruct the terminal to accept activation of the first bearer.

[0062] Optionally, the second address is also used by the terminal to update Internet Protocol IP parameters in relevant modules.

[0063] Optionally, the transceiver module is further used to: receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0064] Optionally, the first message is used to request the second network device to establish a packet data unit PDU session; and the second message is used to indicate that the PDU session establishment request is accepted.

[0065] Optionally, the second address is also used by the terminal to update Internet Protocol IP parameters in relevant modules.

[0066] Optionally, the transceiver module is further used to: receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to end the PDU session.

[0067] Optionally, the first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

[0068] Optionally, the first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

[0069] The fifth aspect embodiment of the present application proposes a communication device, including one or more processors; the communication device is used to execute the switching method proposed in the first aspect embodiment of the present application, or to execute the switching method proposed in the second aspect embodiment of the present application.

[0070] The sixth aspect embodiment of the present application proposes a chip, comprising at least one processor and a communication interface; the communication interface is used to receive a signal input into the chip or a signal output from the chip, the processor communicates with the communication interface and implements the switching method proposed in the first aspect embodiment of the present application through a logic circuit or by executing code instructions, or implements the switching method proposed in the second aspect embodiment of the present application.

[0071] The fifth aspect embodiment of the present application proposes a non-temporary computer-readable storage medium. When the instructions in the storage medium are executed by the processor of the communication device, the communication device can execute the switching method proposed in the first aspect embodiment of the present application, or execute the switching method proposed in the second aspect embodiment of the present application.

[0072] The technical solution of the present application determines that a terminal switches from a first network device to a second network device, and the first network device and the second network device are network devices of different systems; sends a first message to the second network device, the first message carries a first address of the terminal, and the first address is assigned to the terminal by the first network device; receives a second message sent by the second network device, the second message carries a second address of the terminal, and the second address is assigned to the terminal by the second network device, and the second address is different from the first address; so that when a switching between different systems occurs, if the terminal cannot be assigned the original address by the switched network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so as to achieve smooth switching without service interruption, ensure service continuity, reduce service interruption delay, and effectively improve user experience. At the same time, it can also reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0073] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0074] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0075] Figure 1A A schematic diagram of the architecture of a communication system provided in an embodiment of the present application;

[0076] Figure 1B-1D A schematic diagram of the interaction of switching between different systems provided in an embodiment of the present application;

[0077] Figure 2 A flowchart of a switching method provided in an embodiment of the present application;

[0078] Figure 3A A flowchart of a switching method provided in an embodiment of the present application;

[0079] Figure 3B An interactive schematic diagram of a switching method provided in an embodiment of the present application;

[0080] Figure 4A A flowchart of a switching method provided in an embodiment of the present application;

[0081] Figure 4B An interactive schematic diagram of a switching method provided in an embodiment of the present application;

[0082] Figure 5A A flowchart of a switching method provided in an embodiment of the present application;

[0083] Figure 5B An interactive schematic diagram of a switching method provided in an embodiment of the present application;

[0084] Fig. 6A A flowchart of a switching method provided in an embodiment of the present application;

[0085] Figure 6B An interactive schematic diagram of a switching method provided in an embodiment of the present application;

[0086] Fig. 7A A flowchart of a switching method provided in an embodiment of the present application;

[0087] Figure 7B An interactive schematic diagram of a switching method provided in an embodiment of the present application;

[0088] Fig. 8A A flowchart of a switching method provided in an embodiment of the present application;

[0089] Figure 8B An interactive schematic diagram of a switching method provided in an embodiment of the present application;

[0090] Figure 9-15 A flowchart of a switching method provided in an embodiment of the present application;

[0091] Fig.16 A schematic diagram of the structure of a terminal provided in an embodiment of the present application;

[0092] Fig.17 A schematic diagram of the structure of a second network device provided in an embodiment of the present application;

[0093] Fig.18 A structural block diagram of a communication device provided in an embodiment of the present application;

[0094] Fig.19 A schematic diagram of a chip system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0095] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0096] The embodiments of the present application provide a switching method, a communication device, a chip, and a readable storage medium. In some embodiments, the terms such as the switching method, the information processing method, and the communication method can be replaced with each other, the terms such as the switching device, the information processing device, and the communication device can be replaced with each other, and the terms such as the switching system, the information processing system, and the communication system can be replaced with each other.

[0097] The embodiments of the present application are not exhaustive, but are only illustrative of some embodiments, and are not intended to be a specific limitation on the scope of protection of the present application. In the absence of contradiction, each step in a certain embodiment can be implemented as an independent embodiment, and the steps can be arbitrarily combined. For example, in a certain embodiment, the solution after removing some steps can also be implemented as an independent embodiment, and the order of the steps in a certain embodiment can be arbitrarily exchanged. In addition, the optional implementations in a certain embodiment can be arbitrarily combined; in addition, the embodiments can be arbitrarily combined, for example, some or all of the steps of different embodiments can be arbitrarily combined, and a certain embodiment can be arbitrarily combined with the optional implementations of other embodiments.

[0098] In each embodiment of the present application, unless otherwise specified or there is a logical conflict, the terms and / or descriptions between the embodiments are consistent and can be referenced to each other. The technical features in different embodiments can be combined to form a new embodiment based on their internal logical relationships.

[0099] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0100] In the embodiments of the present application, unless otherwise specified, elements expressed in the singular form, such as "a", "an", "the", "above", "above", "aforementioned", "this", etc., may mean "one and only one", or "one or more", "at least one", etc. For example, when using articles such as "a", "an", "the" in English in translation, the noun after the article may be understood as a singular expression or a plural expression.

[0101] In the embodiments of the present application, "plurality" refers to two or more.

[0102] In some embodiments, the terms “at least one,” “one or more,” “a plurality of,” “multiple,” etc. may be used interchangeably.

[0103] In some embodiments, "at least one of A and B", "A and / or B", "A in one case, B in another case", "in response to one case A, in response to another case B", etc., may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed); in some embodiments, A and B (both A and B are executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0104] In some embodiments, the recording method of "A or B" may include the following technical solutions according to the situation: in some embodiments, A (A is executed independently of B); in some embodiments, B (B is executed independently of A); in some embodiments, execution is selected from A and B (A and B are selectively executed). When there are more branches such as A, B, C, etc., the above is also similar.

[0105] The prefixes such as "first" and "second" in the embodiments of the present application are only used to distinguish different description objects, and do not constitute restrictions on the position, order, priority, quantity or content of the description objects. The statement of the description object refers to the description in the context of the claims or embodiments, and should not constitute redundant restrictions due to the use of prefixes. For example, if the description object is a "field", the ordinal number before the "field" in the "first field" and the "second field" does not limit the position or order between the "fields", and the "first" and "second" do not limit whether the "fields" they modify are in the same message, nor do they limit the order of the "first field" and the "second field". For another example, if the description object is a "level", the ordinal number before the "level" in the "first level" and the "second level" does not limit the priority between the "levels". For another example, the number of description objects is not limited by the ordinal number, and can be one or more. Taking the "first device" as an example, the number of "devices" can be one or more. In addition, the objects modified by different prefixes may be the same or different. For example, if the description object is "device", then the "first device" and the "second device" may be the same device or different devices, and their types may be the same or different. For another example, if the description object is "information", then the "first information" and the "second information" may be the same information or different information, and their contents may be the same or different.

[0106] In some embodiments, “including A”, “comprising A”, “used to indicate A”, and “carrying A” can be interpreted as directly carrying A or indirectly indicating A.

[0107] In some embodiments, terms such as "in response to ...", "in response to determining ...", "in the case of ...", "at the time of ...", "when ...", "if ...", "if ...", etc. can be used interchangeably.

[0108] In some embodiments, terms such as "greater than", "greater than or equal to", "not less than", "more than", "more than or equal to", "not less than", "higher than", "higher than or equal to", "not lower than", and "above" can be replaced with each other, and terms such as "less than", "less than or equal to", "not greater than", "less than", "less than or equal to", "no more than", "lower than", "lower than or equal to", "not higher than", and "below" can be replaced with each other.

[0109] In some embodiments, devices and equipment may be interpreted as physical or virtual, and their names are not limited to the names recorded in the embodiments. In some cases, they may also be understood as "equipment", "device", "circuit", "network element", "node", "function", "unit", "section", "system", "network", "chip", "chip system", "entity", "subject", etc.

[0110] In some embodiments, "network" can be interpreted as devices included in the network, such as access network equipment, core network equipment, etc.

[0111] In some embodiments, "access network device (AN device)" may also be referred to as "radio access network device (RAN device)", "base station (BS)", "radio base station (radio base station)", "fixed station (fixed station)", and in some embodiments may also be understood as "node (node)", "access point (access point)", "transmission point (TP)", "reception point (reception point, RP)", "transmission and / or reception point (transmission / reception point, TRP)"", "panel (panel)", "antenna panel (antenna panel)", "antenna array (antenna array)"", "cell (cell)", "macro cell (macro cell)", "small cell (small cell)", "femto cell (femto cell)", "pico cell (pico cell)", "sector (sector)", "cell group (cell group)", "serving cell (serving cell)", "carrier (carrier)", "component carrier (component carrier)", "bandwidth part (bandwidth part, BWP)" and the like.

[0112] In some embodiments, "terminal" or "terminal device" can be called "user equipment (UE)", "user terminal", NarrowBand-Internet of Things (NB-IoT) device, "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, etc.

[0113] In some embodiments, the access network device, the core network device, or the network device can be replaced by a terminal. For example, the various embodiments of the present application can also be applied to a structure in which the access network device, the core network device, or the network device and the communication between the terminals is replaced by the communication between multiple terminals (for example, device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it can also be set as a structure in which the terminal has all or part of the functions of the access network device. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels, and uplinks, downlinks, etc. can be replaced by side links.

[0114] In some embodiments, the terminal may be replaced by an access network device, a core network device, or a network device. In this case, the access network device, the core network device, or the network device may also be configured to have a structure that has all or part of the functions of the terminal.

[0115] In some embodiments, acquisition of data, information, etc. may comply with the laws and regulations of the country where the data is obtained.

[0116] In some embodiments, data, information, etc. may be obtained with the user's consent.

[0117] In addition, each element, each row, or each column in the table of the embodiments of the present application can be implemented as an independent embodiment, and the combination of any elements, any rows, and any columns can also be implemented as an independent embodiment.

[0118] Figure 1A It is a schematic diagram of the architecture of a communication system according to an embodiment of the present application.

[0119] like Figure 1A As shown, the communication system 100 includes a terminal 101 , a first network device 102 , and a second network device 103 .

[0120] In some embodiments, the terminal 101 includes, for example, a mobile phone, a wearable device, an Internet of Things device, a Narrow Band-Internet of Things device (NB-IoT), a satellite communication device, a car with communication function, a smart car, a tablet computer (Pad), a computer with wireless transceiver function, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal device in industrial control, a wireless terminal device in self-driving, a wireless terminal device in remote medical surgery, a wireless terminal device in a smart grid, a wireless terminal device in transportation safety, a wireless terminal device in a smart city, a wireless terminal device in a smart home, and at least one of a reduced capability (RedCap) terminal, but is not limited to these.

[0121] In some embodiments, the first network device 102 and the second network device 103 are, for example, nodes or devices that access the terminal to the wireless network. The network device may include nodes such as satellites or drones in the resource determination network, evolved NodeB (eNB) in the 5G communication system, next generation evolved NodeB (ng-eNB), next generation NodeB (gNB), next generation radio access network node (NG-RAN node), node B (NB), home node B (HNB), home evolved nodeB (HeNB), wireless backhaul equipment, radio network controller (RNC), base station controller (BSC), base transceiver station (BTS), base band unit (BBU), mobile switching center, base station in 6G communication system, open base station (Open RAN), cloud base station (Cloud RAN), base station in other communication systems, and at least one of access nodes in Wi-Fi system, but not limited to these. The core network, for example, includes at least one of the Evolved Packet Core (EPC), the 5G Core Network (5GCN), and the Next Generation Core (NGC).

[0122] In some embodiments, the technical solution of the present application may be applicable to the Open RAN architecture. In this case, the interfaces between or within the access network devices involved in the embodiments of the present application may become internal interfaces of the Open RAN, and the processes and information interactions between these internal interfaces may be implemented through software or programs.

[0123] In some embodiments, the access network device may be composed of a centralized unit (central unit, CU) and a distributed unit (distributed unit, DU), wherein the CU may also be referred to as a control unit (control unit). The CU-DU structure may be used to split the protocol layer of the access network device, with some functions of the protocol layer being centrally controlled by the CU, and the remaining part or all of the functions of the protocol layer being distributed in the DU, and the DU being centrally controlled by the CU, but not limited to this.

[0124] It can be understood that the communication system described in the embodiment of the present application is for more clearly illustrating the technical solution of the embodiment of the present application, and does not constitute a limitation on the technical solution proposed in the embodiment of the present application. Ordinary technicians in this field can know that with the evolution of the system architecture and the emergence of new business scenarios, the technical solution proposed in the embodiment of the present application is also applicable to similar technical problems.

[0125] The following embodiments of the present application can be applied to Figure 1A The communication system 100, or a portion thereof, is shown but is not limited thereto. Figure 1A The various entities shown are examples, and the communication system may include Figure 1A All or part of the subject, and may also include Figure 1A The number and form of other entities are arbitrary, each entity can be physical or virtual, the connection relationship between the entities is illustrative, the entities can be connected or disconnected, the connection can be in any way, it can be direct or indirect, and it can be wired or wireless.

[0126] The embodiments of the present application can be applied to non-terrestrial networks (NTN), long term evolution (LTE), LTE-Advanced (LTE-A), LTE-Beyond (LTE-B), SUPER 3G, IMT-Advanced, 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 5G new radio (NR), future radio access (FRA), new radio access technology (RAT), new radio (NR), new radio access (NX), future generation radio access (FX), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), Public Land Mobile Network (PLMN) network, Device-to-Device (D2D) system, Machine-to-Machine (M2M) system, Internet of Things (IoT) system, Narrow Band-IoT (NB-IoT) system, Vehicle-to-Everything (V2X), systems using other communication methods, next-generation systems based on them, etc. In addition, multiple systems can also be combined (for example, a combination of LTE or LTE-A and 5G, etc.) for application.

[0127] In some embodiments, the first network device 102 and the second network device 103 are network devices in different communication systems. For example, the first network device 102 is a network device in a 5G system, and the second network device 103 is a network device in a 4G system; or, the first network device 102 is a network device in a 4G system, and the second network device 103 is a network device in a 5G system, etc.

[0128] In some embodiments, the terminal 101 may perform inter-system switching between the first network device 102 and the second network device 103 .

[0129] In some embodiments, the first network device 102 and the second network device 103 do not support the N26 interface.

[0130] In some embodiments, Figure 1B As shown, the terminal 101 completes the initial registration in the 5G network (for example, through the first network device 102) [the terminal sends a registration request, and the network sends a registration accept], and establishes a packet data unit (PDU) session for the user service, and allocates Internet address 1 (IP Address 1 (IP, Internet Protocol)) [the terminal sends a PDU session establishment request, and the network sends a PDU session establishment accept carrying IP Address 1]. In some cases, the terminal 101 may switch or reselect from 5G to 4G (for example, the second network device 103). After completing the residence in the 4G network, it can initiate a registration process, and the registration type is handover. Furthermore, the 4G network can respond to the attach request of the terminal 101. In some cases, if the previous IP Address 1 cannot be allocated at present, the 4G network will reject the attach request. Then, the terminal 101 needs to re-initiate the initial registration process.

[0131] In some embodiments, Figure 1CAs shown, the terminal 101 completes the initial registration in the 5G network (for example, through the first network device 102) [the terminal sends a registration request, and the network sends a registration accept], and establishes a packet data unit PDU session for the user service, and allocates IP Address 1 [the terminal sends a PDU session establishment request, and the network sends a PDU session establishment accept which carries IP Address 1]. In some cases, the terminal 101 may switch or reselect from 5G to 4G (for example, the second network device 103), and after completing the residency in the 4G network, it can initiate the attach process. After attach is completed, terminal 101 can further initiate the reconstruction of the previous bearer (by requesting to establish a packet data network (PDN) connection), and the parameters used are the context parameters of the PDU session established under the 5G network. In some cases, if the previous IP Address 1 cannot be allocated at present, the 4G network will reject the terminal's request to establish a PDN connection. Then, terminal 101 will release the previous bearer and reactivate it later according to business needs.

[0132] In some embodiments, Figure 1DAs shown, the terminal 101 completes the initial registration in the 4G network (for example, through the first network device 102) [the terminal sends a registration request (attach request) of the initial registration type (initial type), the network sends a registration acceptance (attach accept), and the terminal sends a registration completion (attach complete)], and establishes a PDN connection for the user service, and allocates IP Address 1 [the terminal sends a PDN connection establishment request (PDN connectivity request), the network sends an activation default Evolved Packet System (EPS) bearer context request (activate default EPS bearer context request), and the terminal sends an activation default EPS bearer context acceptance (activate default EPS bearer context accept)]. In some cases, the terminal 101 may switch or reselect from 4G to 5G (for example, the second network device 103), and after completing the residence in the 5G network, it can initiate the 5G registration process. After the 5G registration is completed, the terminal 101 can further initiate the reconstruction of the previous bearer (by requesting to establish a PDU session), and the parameters used are the context parameters of the bearer corresponding to the PDN connection established under the 4G network. In some cases, if the previous IP Address 1 cannot be allocated at present, the 5G network will reject the terminal's PDU session establishment request. Then, the terminal 101 will release the previous bearer and reactivate it later according to business needs.

[0133] It can be seen from this that if the network cannot allocate the previous IP address after switching to a different system, the network will reject the terminal's registration or bearer reconstruction, resulting in service interruption and poor user experience.

[0134] The switching method, communication device, chip and readable storage medium of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0135] Figure 2 The present invention provides a flow chart of a switching method according to an embodiment of the present invention. It should be noted that the method is applied to a terminal.

[0136] like Figure 2 As shown, the switching method may include the following steps:

[0137] Step 201: Determine whether a terminal switches from a first network device to a second network device.

[0138] In some embodiments, the first network device and the second network device are network devices of different systems.

[0139] For example, the first network device is a network device in a 4G system, and the second network device is a network device in a 5G system; or, the first network device is a network device in a 5G system, and the second network device is a network device in a 4G system, and so on.

[0140] In some embodiments, the first network device does not support the N26 interface.

[0141] In some embodiments, the second network device may or may not support the N26 interface.

[0142] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0143] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDN connection or a PDU session for the user service and allocates a corresponding first address.

[0144] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0145] Step 202: Send a first message to the second network device, where the first message carries a first address of the terminal.

[0146] The first address is an address assigned to the terminal by the first network device.

[0147] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0148] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0149] In some embodiments, the first message is used to request registration from the second network device.

[0150] In some embodiments, the first message is used to request the second network device to establish a packet data network PDN connection.

[0151] In some embodiments, the first message is used to request the second network device to establish a packet data unit (PDU) session.

[0152] In some embodiments, the first message may further include other parameters, such as an access point name (APN), a data network name (DNN), etc.

[0153] In some embodiments, the parameters in the first message are obtained based on context parameters of a PDN connection or PDU session that has been previously established between the terminal and the first network device.

[0154] Step 203: Receive a second message sent by the second network device, where the second message carries the second address of the terminal.

[0155] Optionally, the second address is different from the first address.

[0156] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0157] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0158] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0159] In some embodiments, the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate the first bearer.

[0160] In some embodiments, the second message is used to activate the first bearer.

[0161] In some embodiments, the second message is used to indicate that the PDU session establishment request is accepted.

[0162] In some embodiments, the terms "access network device (AN device)", "radio access network device (RAN device)", "base station (BS)", "radio base station (radio base station)", "fixed station (fixed station)", "node (node)", "access point (access point)", "transmission point (TP)", "reception point (reception point, RP)", "transmission and / or reception point (transmission / reception point, TRP)", "panel (panel)", "antenna panel (antenna panel)", "antenna array (antenna array)", "cell (cell)", "macro cell (macro cell)", "small cell (small cell)", "femto cell (femto cell)", "pico cell (pico cell)", "sector (sector)", "cell group (cell)", "serving cell (serving cell)", "carrier (carrier)", "component carrier (component carrier)", "bandwidth part (bandwidth part, BWP)" and the like can be used interchangeably.

[0163] In some embodiments, the terms "terminal", "terminal device", "user equipment (UE)", "user terminal" "mobile station (MS)", "mobile terminal (MT)", subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client and the like can be used interchangeably.

[0164] In some embodiments, the access network device, the core network device, or the network device can be replaced by a terminal. For example, the various embodiments of the present application can also be applied to a structure in which the access network device, the core network device, or the network device and the communication between the terminals is replaced by the communication between multiple terminals (for example, device-to-device (D2D), vehicle-to-everything (V2X), etc.). In this case, it can also be set as a structure in which the terminal has all or part of the functions of the access network device. In addition, terms such as "uplink" and "downlink" can also be replaced by terms corresponding to communication between terminals (for example, "side"). For example, uplink channels, downlink channels, etc. can be replaced by side channels, and uplinks, downlinks, etc. can be replaced by side links.

[0165] In some embodiments, the terminal may be replaced by an access network device, a core network device, or a network device. In this case, the access network device, the core network device, or the network device may also be configured to have a structure that has all or part of the functions of the terminal.

[0166] In some embodiments, the names of information, etc. are not limited to the names recorded in the embodiments, and terms such as "information", "message", "signal", "signaling", "report", "configuration", "indication", "instruction", "command", "channel", "parameter", "domain", "field", "symbol", "symbol", "code element", "codebook", "codeword", "codepoint", "bit", "data", "program", and "chip" can be used interchangeably.

[0167] In some embodiments, terms such as "uplink", "uplink", "physical uplink" can be interchangeable, and terms such as "downlink", "downlink", "physical downlink" can be interchangeable, and terms such as "side", "sidelink", "side communication", "sidelink communication", "direct connection", "direct link", "direct communication", "direct link communication" can be interchangeable.

[0168] In some embodiments, the terms "downlink control information (DCI)", "downlink (DL) assignment", "DL DCI", "uplink (UL) grant", "UL DCI" and the like may be used interchangeably.

[0169] In some embodiments, terms such as "physical downlink shared channel (PDSCH)", "DL data" and the like can be interchangeable, and terms such as "physical uplink shared channel (PUSCH)", "UL data" and the like can be interchangeable.

[0170] In some embodiments, the terms "radio", "wireless", "radio access network (RAN)", "access network (AN)", "RAN-based" and the like may be used interchangeably.

[0171] The embodiment of the present application determines that a terminal switches from a first network device to a second network device, and the first network device and the second network device are network devices of different systems; sends a first message to the second network device, the first message carries a first address of the terminal, and the first address is assigned to the terminal by the first network device; receives a second message sent by the second network device, the second message carries a second address of the terminal, and the second address is different from the first address; so that when a switching of different systems occurs, if the terminal cannot be assigned an original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so as to achieve smooth switching without service interruption, ensure service continuity, reduce service interruption delay, and effectively improve user experience. At the same time, it can also reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0172] Figure 3A This is a flow chart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to a terminal.

[0173] like Figure 3A As shown, the switching method may include the following steps:

[0174] Step 301: Determine whether a terminal switches from a first network device to a second network device.

[0175] In some embodiments, the first network device and the second network device are network devices of different systems.

[0176] In this embodiment, the first network device is a network device in a 5G system, the second network device is a network device in a 4G system, and so on.

[0177] In some embodiments, the first network device does not support the N26 interface.

[0178] In some embodiments, the second network device may or may not support the N26 interface.

[0179] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0180] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDU session for the user service and allocates a corresponding first address.

[0181] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0182] Step 302: Send a first message to the second network device. The first message is used to request registration with the second network device. The first message carries a first address of the terminal.

[0183] In some embodiments, the type of registration requested by the first message is handover.

[0184] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0185] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0186] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0187] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the access point name APN, etc.

[0188] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the PDU session established between the terminal and the first network device. For example, the access point name APN can be mapped from the context parameter data network name DNN of the PDU session.

[0189] In some embodiments, the first message is an attach request.

[0190] Step 303: Receive a second message sent by the second network device, where the second message is used to indicate that the registration of the terminal is accepted, and the second message carries a second address of the terminal.

[0191] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can indicate that the registration request of the terminal is accepted, and the second message carries a second address allocated to the terminal.

[0192] Optionally, the second address is different from the first address.

[0193] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0194] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0195] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0196] In some embodiments, the second message is also used to activate the first bearer.

[0197] The first bearer is a default bearer corresponding to the connection established between the terminal and the second network device.

[0198] In some embodiments, the second message may carry an activate default EPS bearer context request to activate the first bearer.

[0199] In some embodiments, the above-mentioned activation default EPS bearer context request includes the above-mentioned second address.

[0200] In some embodiments, the second message also includes other parameters required by the first bearer.

[0201] In some embodiments, the second message is an attach accept.

[0202] Step 304: Send a third message to the second network device, where the third message is used to indicate that the registration of the terminal is completed.

[0203] In some embodiments, the terminal can send a third message to the second network device, where the third message is used to indicate that registration of the terminal is completed.

[0204] In some embodiments, the third message is attachment complete.

[0205] Step 305: Release the local second bearer.

[0206] Among them, the above-mentioned second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the above-mentioned third bearer is a bearer corresponding to the PDU session established between the terminal and the first network device.

[0207] Furthermore, the terminal can re-initiate establishment of a new PDN connection according to service requirements.

[0208] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 3B shown.

[0209] First, the terminal completes the initial registration on the 5G network (first network device) Figure 3B The terminal sends a registration request, and the first network device sends a registration accept], and the first network device does not support N26 interface operation, the first network device establishes a PDU session for the user service, and the network allocates the corresponding IP address parameters (IP Address 1), the IP address type can be IPv4 single stack, IPv6 single stack or IPv4v6 dual stack, and allocates a DNN, etc. [ Figure 3B The middle terminal sends a PDU session establishment request (PDU session establishment request), and the first network device sends a PDU session establishment accept (PDU session establishment accept) carrying IPAddress 1].

[0210] Due to network or terminal reasons, the inter-system handover from 5G to 4G is triggered. Since the N26 interface operation is not supported, the 5G PDU session cannot be directly mapped to the 4G PDN bearer, but a new PDN connection is initiated in 4G based on the parameters of the PDN session context under 5G. After completing the inter-system handover and residing in the cell, the access layer will notify the non-access stratum (NAS) to register.

[0211] Further, after the registration (attach) is triggered, NAS will use the parameters mapped from the 5G PDU session as the attach parameters, such as the requested IP address type, APN, etc., and send it to the second network device in the handover type. Figure 3B The terminal sends a first message (handover type registration request (attach request)), and the second network device responds to the attach request with a registration accept (attach accept) carrying an activate default EPS bearer context request (activate default EPS bearer context request), activates the default bearer, and the network allocates the IP address and other parameters required for the bearer. Figure 3BThe second network device sends a second message (registration acceptance (attach accept)), the second message carries an activate default EPS bearer context request (activate default EPS bearer context request)), which carries the newly allocated IP Address 2]. The terminal can send a message to respond to the registration acceptance (attach accept) to complete the handover type attach [ Figure 3B The terminal sends a third message (registration completed (attachcomplete))].

[0212] In general, the IP address assigned to the default bearer of ATTACH under 4G should be consistent with the IP address of the previous 5G PDU session, so as to achieve seamless switching of bearers of different systems. However, in some abnormal situations, the IP address assigned by the network during 4G ATTACH cannot be consistent with the previous one. At this time, the network does not need to reject the terminal's attach request, but continues to respond to the terminal with the changed IP address. When this happens, in order to keep the terminal online and improve the user experience, the terminal will not deactivate the bearer and cause deregistration (DETACH), but remain registered.

[0213] Furthermore, since there was a service PDU session in 5G before, under normal circumstances there should also be a PDN bearer in 4G (the bearer mapped from the 5G PDU session). However, since the IP address has changed, NAS will release the bearer locally and notify the upper layer, which can re-initiate a new PDN connection based on service needs.

[0214] The switching method of the embodiment of the present application determines that the terminal switches from the first network device to the second network device; sends a first message to the second network device, the first message is used to request registration with the second network device, and the first message carries the first address of the terminal; receives a second message sent by the second network device, the second message is used to indicate that the registration of the terminal is accepted, and the second message carries the second address of the terminal; sends a third message to the second network device, the third message is used to indicate that the registration of the terminal is completed; releases the local second bearer; enables the terminal to achieve smooth switching when switching between different systems occurs, without service interruption, can ensure service continuity, reduce service interruption delay, effectively improve user experience, and at the same time can reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve terminal stability and system robustness.

[0215] Figure 4A This is a flow chart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to a terminal.

[0216] like Figure 4A As shown, the switching method may include the following steps:

[0217] Step 401: Determine whether a terminal switches from a first network device to a second network device.

[0218] In some embodiments, the first network device and the second network device are network devices of different systems.

[0219] In this embodiment, the first network device is a network device in a 5G system, the second network device is a network device in a 4G system, and so on.

[0220] In some embodiments, the first network device does not support the N26 interface.

[0221] In some embodiments, the second network device may or may not support the N26 interface.

[0222] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0223] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDU session for the user service and allocates a corresponding first address.

[0224] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0225] Step 402: Send a first message to the second network device. The first message is used to request registration with the second network device. The first message carries a first address of the terminal.

[0226] In some embodiments, the type of registration requested by the first message is handover.

[0227] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0228] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0229] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0230] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the access point name APN, etc.

[0231] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the PDU session established between the terminal and the first network device. For example, the access point name APN can be mapped from the context parameter data network name DNN of the PDU session.

[0232] In some embodiments, the first message is an attach request.

[0233] Step 403: Receive a second message sent by the second network device, where the second message is used to indicate that the registration of the terminal is accepted, and the second message carries a second address of the terminal.

[0234] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can indicate that the registration request of the terminal is accepted, and the second message carries a second address allocated to the terminal.

[0235] Optionally, the second address is different from the first address.

[0236] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0237] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0238] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0239] In some embodiments, the second message is also used to activate the first bearer.

[0240] The first bearer is a default bearer corresponding to the connection established between the terminal and the second network device.

[0241] In some embodiments, the second message may carry an activate default EPS bearer context request to activate the first bearer.

[0242] In some embodiments, the above-mentioned activation default EPS bearer context request includes the above-mentioned second address.

[0243] In some embodiments, the second message also includes other parameters required by the first bearer.

[0244] In some embodiments, the second message is an attach accept.

[0245] Step 404: Send a fourth message to the second network device, where the fourth message is used to instruct the terminal to reject the registration.

[0246] In some embodiments, the terminal can send a fourth message to the second network device, where the fourth message is used to instruct the terminal to reject the registration.

[0247] Optionally, the terminal rejects the registration, which can trigger a detach process.

[0248] In some embodiments, after receiving a registration acceptance message carrying a changed new address from the second network device, the terminal may reject the registration. Furthermore, the terminal may delete the local bearer used to initiate the attach process.

[0249] Furthermore, the terminal may re-initiate the initial attach process later.

[0250] Specifically, the terminal may send an initial type registration request (attach request) message to the second network device to initiate an initial attach process.

[0251] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 4B shown.

[0252] First, the terminal completes the initial registration on the 5G network (first network device) Figure 4B The terminal sends a registration request, and the first network device sends a registration accept], and the first network device does not support N26 interface operation, the first network device establishes a PDU session for the user service, and the network allocates the corresponding IP address parameters (IP Address 1), the IP address type can be IPv4 single stack, IPv6 single stack or IPv4v6 dual stack, and allocates a DNN, etc. [ Figure 4B The middle terminal sends a PDU session establishment request (PDU session establishment request), and the first network device sends a PDU session establishment accept (PDU session establishment accept) carrying IPAddress 1].

[0253] Due to network or terminal reasons, the inter-system handover from 5G to 4G is triggered. Since the N26 interface operation is not supported, the 5G PDU session cannot be directly mapped to the 4G PDN bearer, but a new PDN connection is initiated in 4G based on the parameters of the PDN session context under 5G. After completing the inter-system handover and residing in the cell, the access layer will notify the non-access stratum (NAS) to register.

[0254] Further, after the registration (attach) is triggered, NAS will use the parameters mapped from the 5G PDU session as the attach parameters, such as the requested IP address type, APN, etc., and send it to the second network device in the handover type. Figure 4B The terminal sends a first message (handover type registration request (attach request)), and the second network device responds to the attach request with a registration accept (attach accept) carrying an activate default EPS bearer context request (activate default EPS bearer context request), activates the default bearer, and the network allocates the IP address and other parameters required for the bearer. Figure 4B The second network device sends a second message (registration accept (attach accept)), the second message carries an activate default EPS bearer context request (activate default EPS bearer contextrequest)), which carries the newly allocated IP Address 2].

[0255] Generally, the IP address assigned to the default bearer of ATTACH under 4G should be consistent with the IP address of the previous 5G PDU session, so as to achieve seamless switching of bearers of different systems. However, in certain abnormal situations, the IP address assigned by the network during 4G ATTACH cannot be consistent with the previous one. At this time, the network does not need to reject the terminal's attach request, but continues to respond to the terminal with the changed IP address.

[0256] In this case, the terminal can reject the handover type attach. Figure 4B The terminal sends a fourth message], the terminal triggers the detach process, and further, can locally delete the bearer and re-initiate the initial attach process later.

[0257] The switching method of the embodiment of the present application determines that the terminal switches from the first network device to the second network device; sends a first message to the second network device, the first message is used to request registration with the second network device, and the first message carries the first address of the terminal; receives a second message sent by the second network device, the second message is used to indicate that the registration of the terminal is accepted, and the second message carries the second address of the terminal; sends a fourth message to the second network device, the fourth message is used to indicate that the terminal rejects the registration; so that the terminal can achieve smooth switching when switching between different systems occurs, can reduce service interruption delay, effectively improve user experience, and at the same time can reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0258] Figure 5A This is a flow chart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to a terminal.

[0259] like Figure 5A As shown, the switching method may include the following steps:

[0260] Step 501: Determine whether a terminal switches from a first network device to a second network device.

[0261] In some embodiments, the first network device and the second network device are network devices of different systems.

[0262] In this embodiment, the first network device is a network device in a 5G system, the second network device is a network device in a 4G system, and so on.

[0263] In some embodiments, the first network device does not support the N26 interface.

[0264] In some embodiments, the second network device may or may not support the N26 interface.

[0265] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0266] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDU session for the user service and allocates a corresponding first address.

[0267] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0268] Step 502: Send a first message to the second network device. The first message is used to request the second network device to establish a PDN connection. The first message carries a first address of the terminal.

[0269] In some embodiments, the first message is used to request the second network device to establish a PDN connection.

[0270] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0271] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0272] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0273] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the access point name APN, etc.

[0274] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the PDU session established between the terminal and the first network device. For example, the access point name APN can be mapped from the context parameter data network name DNN of the PDU session.

[0275] In some embodiments, the first message is a PDN connectivity request.

[0276] In some embodiments, before sending the first message, the terminal completes a registration process, and the registration type is handover.

[0277] Step 503: Receive a second message sent by the second network device, where the second message is used to activate the first bearer and carries a second address of the terminal.

[0278] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can request activation of the first bearer on the PDN connection, and the second message carries a second address allocated to the terminal. The first bearer is the default bearer corresponding to the connection established between the terminal and the second network device.

[0279] Optionally, the second address is different from the first address.

[0280] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0281] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0282] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0283] In some embodiments, the second message may be an activate default EPS bearer context request (activatedefault EPS bearer context request).

[0284] In some embodiments, the above-mentioned activation default EPS bearer context request includes the above-mentioned second address.

[0285] In some embodiments, the second message also includes other parameters required by the first bearer.

[0286] Step 504: Send a third message to the second network device, where the third message is used to instruct the terminal to accept activation of the first bearer.

[0287] In some embodiments, the terminal can send a third message to the second network device, where the third message is used to indicate that the terminal accepts activation of the first bearer.

[0288] In some embodiments, the third message is activate default EPS bearer context accept.

[0289] Step 505: Based on the second address, update the IP parameters in the relevant modules.

[0290] In some embodiments, after receiving the second message sent by the second network device, the terminal can update the IP parameters in the relevant modules based on the updated second address carried in the second message. For example, the IP parameters of modules including but not limited to wireless network access point (AP) applications and network cards can be updated.

[0291] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 5B shown.

[0292] First, the terminal completes the initial registration on the 5G network (first network device) Figure 5BThe terminal sends a registration request, and the first network device sends a registration accept], and the first network device does not support N26 interface operation, the first network device establishes a PDU session for the user service, and the network allocates the corresponding IP address parameters (IP Address 1), the IP address type can be IPv4 single stack, IPv6 single stack or IPv4v6 dual stack, and allocates a DNN, etc. [ Figure 5B The middle terminal sends a PDU session establishment request (PDU session establishment request), and the first network device sends a PDU session establishment accept (PDU session establishment accept) carrying IPAddress 1].

[0293] Due to network or terminal reasons, the inter-system handover from 5G to 4G is triggered. Since the N26 interface operation is not supported, the 5G PDU session cannot be directly mapped to the 4G PDN bearer, but a new PDN connection is initiated in 4G based on the parameters of the PDN session context under 5G. After completing the inter-system handover and residing in the cell, the access layer will notify the non-access stratum (NAS) to register.

[0294] After the terminal completes the handover type registration under 4G Figure 5B The terminal sends a handover type registration request (attach request), the second network device sends a registration acceptance (attach accept), and the terminal sends a registration completion (attachcomplete). Further, the previous bearer needs to be rebuilt and restored. NAS will use the parameters mapped from the 5GPDU session as the parameters for PDN reconstruction. Figure 5B The terminal sends a first message (PDN connection request), such as the requested IP address type, APN, etc. The second network device responds with activatedefaultEPS bearer context request to activate the default bearer. The network will allocate the IP address and other parameters required for the bearer. Figure 5B The second network device sends a second message (activate default EPS bearer context request), which carries the newly allocated IP Address 2].

[0295] In general, the IP address assigned to the default bearer under 4G should be consistent with the IP address of the previous 5G PDU session, so as to achieve seamless switching of bearers in different systems. However, in some abnormal situations, the IP address assigned by the network in 4G cannot be consistent with the previous one. When this happens, in order to keep the bearer in an activated state, not affect user services, and improve user experience, the network can continue to carry the changed IP address to the terminal, and the terminal will not activate the bearer, but will continue to keep the bearer activated by updating the changed IP parameters to the corresponding modules, including but not limited to AP applications, network cards, etc. In this way, the new bearer can continue to be used for the corresponding services without being deactivated, maintaining business continuity and avoiding interruptions.

[0296] The switching method of the embodiment of the present application determines that the terminal switches from the first network device to the second network device; sends a first message to the second network device, the first message is used to request the second network device to establish a PDN connection, and the first message carries the first address of the terminal; receives a second message sent by the second network device, the second message is used to activate the first bearer, and the second message carries the second address of the terminal; sends a third message to the second network device, the third message is used to instruct the terminal to accept the activation of the first bearer; based on the second address, updates the IP parameters in the relevant modules; enables the terminal to achieve smooth switching when switching between different systems occurs, without service interruption, can ensure service continuity, reduce service interruption delay, effectively improve user experience, and at the same time can reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve terminal stability and system robustness.

[0297] Fig. 6A This is a flow chart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to a terminal.

[0298] like Fig. 6A As shown, the switching method may include the following steps:

[0299] Step 601: Determine whether a terminal switches from a first network device to a second network device.

[0300] In some embodiments, the first network device and the second network device are network devices of different systems.

[0301] In this embodiment, the first network device is a network device in a 5G system, the second network device is a network device in a 4G system, and so on.

[0302] In some embodiments, the first network device does not support the N26 interface.

[0303] In some embodiments, the second network device may or may not support the N26 interface.

[0304] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0305] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDU session for the user service and allocates a corresponding first address.

[0306] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0307] Step 602: Send a first message to the second network device. The first message is used to request the second network device to establish a PDN connection. The first message carries a first address of the terminal.

[0308] In some embodiments, the first message is used to request the second network device to establish a PDN connection.

[0309] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0310] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0311] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0312] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the access point name APN, etc.

[0313] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the PDU session established between the terminal and the first network device. For example, the access point name APN can be mapped from the context parameter data network name DNN of the PDU session.

[0314] In some embodiments, the first message is a PDN connectivity request.

[0315] In some embodiments, before sending the first message, the terminal completes a registration process, and the registration type is handover.

[0316] Step 603: Receive a second message sent by the second network device, where the second message is used to activate the first bearer and carries a second address of the terminal.

[0317] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can request activation of the first bearer on the PDN connection, and the second message carries a second address allocated to the terminal. The first bearer is the default bearer corresponding to the connection established between the terminal and the second network device.

[0318] Optionally, the second address is different from the first address.

[0319] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0320] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0321] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0322] In some embodiments, the second message may be an activate default EPS bearer context request (activatedefault EPS bearer context request).

[0323] In some embodiments, the above-mentioned activation default EPS bearer context request includes the above-mentioned second address.

[0324] In some embodiments, the second message also includes other parameters required by the first bearer.

[0325] Step 604: Send a fourth message to the second network device, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0326] In some embodiments, the terminal can send a fourth message to the second network device, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0327] In some embodiments, after receiving the request from the second network device to activate the default bearer carrying the changed new address, the terminal may reject the request from the second network device and refuse to activate the default bearer.

[0328] Step 605: Release the local second bearer.

[0329] In some embodiments, further, the terminal can release the local second bearer.

[0330] Among them, the above-mentioned second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the above-mentioned third bearer is a bearer corresponding to the PDU session established between the terminal and the first network device.

[0331] Furthermore, the terminal may notify the corresponding module to re-initiate bearer activation later according to service requirements.

[0332] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 6B shown.

[0333] First, the terminal completes the initial registration on the 5G network (first network device) Figure 6B The terminal sends a registration request, and the first network device sends a registration accept], and the first network device does not support N26 interface operation, the first network device establishes a PDU session for the user service, and the network allocates the corresponding IP address parameters (IP Address 1), the IP address type can be IPv4 single stack, IPv6 single stack or IPv4v6 dual stack, and allocates a DNN, etc. [ Figure 6B The middle terminal sends a PDU session establishment request (PDU session establishment request), and the first network device sends a PDU session establishment accept (PDU session establishment accept) carrying IPAddress 1].

[0334] Due to network or terminal reasons, the inter-system handover from 5G to 4G is triggered. Since the N26 interface operation is not supported, the 5G PDU session cannot be directly mapped to the 4G PDN bearer, but a new PDN connection is initiated in 4G based on the parameters of the PDN session context under 5G. After completing the inter-system handover and residing in the cell, the access layer will notify the non-access stratum (NAS) to register.

[0335] After the terminal completes the handover type registration under 4G Figure 6BThe terminal sends a handover type registration request (attach request), the second network device sends a registration acceptance (attach accept), and the terminal sends a registration completion (attachcomplete). Further, the previous bearer needs to be rebuilt and restored. NAS will use the parameters mapped from the 5GPDU session as the parameters for PDN reconstruction. Figure 6B The terminal sends a first message (PDN connection request), such as the requested IP address type, APN, etc. The second network device responds with activatedefaultEPS bearer context request to activate the default bearer. The network will allocate the IP address and other parameters required for the bearer. Figure 6B The second network device sends a second message (activate default EPS bearer context request), which carries the newly allocated IP Address 2].

[0336] Generally, the IP address assigned to the default bearer under 4G should be consistent with the IP address of the previous 5G PDU session, so as to achieve seamless switching of bearers between different systems. However, in some abnormal situations, the IP address assigned by the network in 4G cannot be consistent with the previous one. When this happens, in order to keep the bearer in an activated state, not affect user services, and improve user experience, the network can continue to send the changed IP address to the terminal. In some cases, after receiving the bearer activation request with a changed IP address, the terminal can also reject the network's request. Figure 6B The terminal sends a fourth message (activate default EPS bearer context reject) to release the bearer locally and notify the corresponding module, and then re-initiates bearer activation according to business needs.

[0337] The switching method of the embodiment of the present application determines that the terminal switches from the first network device to the second network device; sends a first message to the second network device, the first message is used to request the second network device to establish a PDN connection, and the first message carries the first address of the terminal; receives a second message sent by the second network device, the second message is used to activate the first bearer, and the second message carries the second address of the terminal; sends a fourth message to the second network device, the fourth message is used to instruct the terminal to refuse to activate the first bearer; releases the local second bearer; enables the terminal to achieve smooth switching when a different system switching occurs, can reduce service interruption delay, effectively improve user experience, and at the same time can also reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0338] Fig. 7A This is a flow chart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to a terminal.

[0339] like Fig. 7A As shown, the switching method may include the following steps:

[0340] Step 701: Determine whether a terminal switches from a first network device to a second network device.

[0341] In some embodiments, the first network device and the second network device are network devices of different systems.

[0342] In this embodiment, the first network device is a network device in a 4G system, the second network device is a network device in a 5G system, and so on.

[0343] In some embodiments, the first network device does not support the N26 interface.

[0344] In some embodiments, the second network device may or may not support the N26 interface.

[0345] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0346] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDN connection and a corresponding bearer for the user service, and allocates a corresponding first address.

[0347] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0348] Step 702: Send a first message to the second network device. The first message is used to request the second network device to establish a PDU session. The first message carries a first address of the terminal.

[0349] In some embodiments, the first message is used to request the second network device to establish a PDU session.

[0350] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0351] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0352] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0353] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the data network name DNN, etc.

[0354] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the bearer corresponding to the PDN connection established between the terminal and the first network device. For example, the data network name DNN can be obtained by mapping the context parameter access point name APN of the bearer corresponding to the PDN connection.

[0355] In some embodiments, the first message is a PDU session establishment request (PDU session establishment request).

[0356] In some embodiments, before sending the first message, the terminal completes a registration process, and the registration type is handover.

[0357] Step 703: Receive a second message sent by the second network device, where the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries a second address of the terminal.

[0358] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can indicate that the PDU session establishment request is accepted, and the second message carries a second address allocated to the terminal.

[0359] Optionally, the second address is different from the first address.

[0360] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0361] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0362] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0363] In some embodiments, the second message may be a PDU session establishment accept.

[0364] In some embodiments, the second message also includes other parameters required for the PDU session reconstruction.

[0365] Step 704: Update IP parameters in related modules based on the second address.

[0366] In some embodiments, after receiving the second message sent by the second network device, the terminal can update the IP parameters in the relevant modules based on the updated second address carried in the second message. For example, the IP parameters of modules including but not limited to wireless network access point AP application, network card, etc. can be updated.

[0367] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 7B shown.

[0368] First, the terminal completes the initial registration on the 4G network. Figure 7B The terminal sends an attach request of the initial type (initial type), the first network device sends an attach accept, and the terminal sends an attach complete], and does not support N26 operations. Then a PDN bearer is established for the user service, and the network allocates corresponding IP address parameters. The IP address type can be IPv4 single stack, IPv6 single stack or IPv4v6 dual stack, and an APN is allocated, etc.

[0369] Due to network or terminal reasons, the inter-system handover from 4G to 5G is triggered. Since the N26 interface operation is not supported, the 4G PDN default bearer cannot be directly mapped to the 5G PDU session. Instead, a new PDU session is initiated in 5G based on the context parameters of the bearer corresponding to the 4G PDN connection. After completing the inter-system handover and residing in the cell, the access layer will notify the non-access stratum (NAS) to register.

[0370] After the terminal completes the handover type registration under 5G Figure 7B The terminal sends a registration request, and the first network device sends a registration accept. The previous bearer needs to be rebuilt and restored. NAS will use the parameters mapped from the 4G PDN bearer as the parameters for PDU session reconstruction. Figure 7B The terminal sends the first message (PDU session establishment request), such as the requested IP address type, APN (DNN), etc. The network responds with PDU session establishment accept to activate the PDU session. The network will allocate the IP address and other parameters required for the bearer. Figure 7B The second network device sends a second message (PDU session establishment accept), which carries the newly allocated IPAddress 2].

[0371] In general, the IP address assigned to the PDU session under 5G should be consistent with the IP address of the previous 4G PDN default bearer, so as to achieve seamless switching of bearers in different systems. However, in certain abnormal situations, the IP address assigned by the network in 5G cannot be consistent with the previous one. When this happens, in order to keep the bearer in an activated state, not affect user services, and improve user experience, the network can continue to carry the changed IP address to the terminal, and the terminal will not activate the bearer, but update the changed IP parameters to the corresponding modules, including but not limited to AP applications, network cards, etc., to continue to keep the bearer activated. In this way, the new bearer can continue to be used for the corresponding business without being deactivated, maintaining business continuity and avoiding interruptions.

[0372] The switching method of the embodiment of the present application determines that the terminal switches from the first network device to the second network device; sends a first message to the second network device, the first message is used to request the second network device to establish a PDU session, and the first message carries the first address of the terminal; receives a second message sent by the second network device, the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries the second address of the terminal; based on the second address, updates the IP parameters in the relevant modules; enables the terminal to achieve smooth switching when switching between different systems occurs, without service interruption, can ensure service continuity, reduce service interruption delay, effectively improve user experience, and at the same time can reduce signaling interaction, effectively reduce the probability of abnormalities, effectively reduce complexity, and improve terminal stability and system robustness.

[0373] Fig. 8A This is a flow chart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to a terminal.

[0374] like Fig. 8A As shown, the switching method may include the following steps:

[0375] Step 801: Determine whether a terminal switches from a first network device to a second network device.

[0376] In some embodiments, the first network device and the second network device are network devices of different systems.

[0377] In this embodiment, the first network device is a network device in a 4G system, the second network device is a network device in a 5G system, and so on.

[0378] In some embodiments, the first network device does not support the N26 interface.

[0379] In some embodiments, the second network device may or may not support the N26 interface.

[0380] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0381] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDN connection and a corresponding bearer for the user service, and allocates a corresponding first address.

[0382] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0383] Step 802: Send a first message to the second network device. The first message is used to request the second network device to establish a PDU session. The first message carries a first address of the terminal.

[0384] In some embodiments, the first message is used to request the second network device to establish a PDU session.

[0385] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0386] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0387] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0388] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the data network name DNN, etc.

[0389] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the bearer corresponding to the PDN connection established between the terminal and the first network device. For example, the data network name DNN can be obtained by mapping the context parameter access point name APN of the bearer corresponding to the PDN connection.

[0390] In some embodiments, the first message is a PDU session establishment request (PDU session establishment request).

[0391] In some embodiments, before sending the first message, the terminal completes a registration process, and the registration type is handover.

[0392] Step 803: Receive a second message sent by the second network device, where the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries a second address of the terminal.

[0393] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can indicate that the PDU session establishment request is accepted, and the second message carries a second address allocated to the terminal.

[0394] Optionally, the second address is different from the first address.

[0395] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0396] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0397] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0398] In some embodiments, the second message may be a PDU session establishment accept.

[0399] In some embodiments, the second message also includes other parameters required for the PDU session reconstruction.

[0400] Step 804: Send a fourth message to the second network device, where the fourth message is used to instruct the terminal to end the PDU session.

[0401] In some embodiments, the terminal is able to send a fourth message to the second network device, where the fourth message is used to instruct the terminal to end the PDU session.

[0402] In some embodiments, after receiving the PDU session establishment acceptance message carrying the changed new address from the second network device, the terminal may end the PDU session, refuse to activate the PDU session, and release the local bearer.

[0403] Step 805: Release the local second bearer.

[0404] In some embodiments, further, the terminal can release the local second bearer.

[0405] The second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the third bearer is a bearer corresponding to the PDN connection established between the terminal and the first network device.

[0406] Furthermore, the terminal may notify the corresponding module to re-initiate activation of the PDU session according to service requirements later.

[0407] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 8B shown.

[0408] First, the terminal completes the initial registration on the 4G network. Figure 8BThe terminal sends an attach request of the initial type (initial type), the first network device sends an attach accept, and the terminal sends an attach complete], and does not support N26 operations. Then a PDN bearer is established for the user service, and the network allocates corresponding IP address parameters. The IP address type can be IPv4 single stack, IPv6 single stack or IPv4v6 dual stack, and an APN is allocated, etc.

[0409] Due to network or terminal reasons, the inter-system handover from 4G to 5G is triggered. Since the N26 interface operation is not supported, the 4G PDN default bearer cannot be directly mapped to the 5G PDU session. Instead, a new PDU session is initiated in 5G based on the context parameters of the bearer corresponding to the 4G PDN connection. After completing the inter-system handover and residing in the cell, the access layer will notify the non-access stratum (NAS) to register.

[0410] After the terminal completes the handover type registration under 5G Figure 8B The terminal sends a registration request, and the first network device sends a registration accept. The previous bearer needs to be rebuilt and restored. NAS will use the parameters mapped from the 4G PDN bearer as the parameters for PDU session reconstruction. Figure 8B The terminal sends the first message (PDU session establishment request), such as the requested IP address type, APN (DNN), etc. The network responds with PDU session establishment accept to activate the PDU session. The network will allocate the IP address and other parameters required for the bearer. Figure 8B The second network device sends a second message (PDU session establishment accept), which carries the newly allocated IPAddress 2].

[0411] In general, the IP address assigned to the PDU session under 5G should be consistent with the IP address of the previous 4G PDN default bearer, so as to achieve seamless switching of bearers in different systems. However, in certain abnormal situations, the IP address assigned by the network in 5G cannot be consistent with the previous one. When this happens, in order to keep the bearer in an activated state, not affect user services, and improve the user experience, the network can continue to carry the changed IP address to the terminal. In some cases, the terminal can end the PDU session, release the bearer locally, and notify the corresponding module, and then re-initiate the activation of the PDU session according to business needs.

[0412] The switching method of the embodiment of the present application determines that the terminal switches from the first network device to the second network device; sends a first message to the second network device, the first message is used to request the second network device to establish a PDU session, and the first message carries the first address of the terminal; receives a second message sent by the second network device, the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries the second address of the terminal; based on the second address, updates the IP parameters in the relevant modules; enables the terminal to achieve smooth switching when switching between different systems occurs, can reduce service interruption delay, effectively improve user experience, and at the same time can also reduce signaling interaction, effectively reduce the probability of abnormalities, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0413] Fig. 9 A schematic flow chart of a switching method provided in an embodiment of the present application. It should be noted that the method is applied to the second network device.

[0414] like Fig. 9 As shown, the switching method may include the following steps:

[0415] Step 901: Receive a first message sent by a terminal, where the first message carries a first address of the terminal.

[0416] In the embodiment of the present application, the terminal switches from the first network device to the second network device.

[0417] In some embodiments, the first network device and the second network device are network devices of different systems.

[0418] For example, the first network device is a network device in a 4G system, and the second network device is a network device in a 5G system; or, the first network device is a network device in a 5G system, and the second network device is a network device in a 4G system, and so on.

[0419] In some embodiments, the first network device does not support the N26 interface.

[0420] In some embodiments, the second network device may or may not support the N26 interface.

[0421] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0422] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDN connection or a PDU session for the user service and allocates a corresponding first address.

[0423] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0424] The first address is an address assigned to the terminal by the first network device.

[0425] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0426] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0427] In some embodiments, the first message is used to request registration from the second network device.

[0428] In some embodiments, the first message is used to request the second network device to establish a packet data network PDN connection.

[0429] In some embodiments, the first message is used to request the second network device to establish a packet data unit (PDU) session.

[0430] In some embodiments, the first message may also include other parameters, such as access point name APN, data network name DNN, etc.

[0431] In some embodiments, the parameters in the first message are obtained based on context parameters of a PDN connection or PDU session that has been previously established between the terminal and the first network device.

[0432] Step 902: Determine that the first address cannot be allocated to the terminal, and send a second message to the terminal, where the second message carries a second address of the terminal.

[0433] Optionally, the second address is different from the first address.

[0434] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0435] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0436] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0437] In some embodiments, the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate the first bearer.

[0438] In some embodiments, the second message is used to activate the first bearer.

[0439] In some embodiments, the second message is used to indicate that the PDU session establishment request is accepted.

[0440] The embodiment of the present application receives a first message sent by a terminal, the first message carrying a first address; determines that the first address cannot be assigned to the terminal, and sends a second message to the terminal, the second message carrying a second address, the second address is assigned to the terminal by a second network device, and the second address is different from the first address; so that when an inter-system switching occurs, if the terminal cannot be assigned the original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality can be effectively reduced, complexity can be effectively reduced, and the stability of the terminal and the robustness of the system can be improved.

[0441] Fig.10 A flowchart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to the second network device.

[0442] like Fig.10 As shown, the switching method may include the following steps:

[0443] Step 1001: Receive a first message sent by a terminal, where the first message is used to request registration with a second network device, and the first message carries a first address of the terminal.

[0444] In some embodiments, the type of registration requested by the first message is handover.

[0445] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0446] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0447] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0448] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the access point name APN, etc.

[0449] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the PDU session established between the terminal and the first network device. For example, the access point name APN can be mapped from the context parameter data network name DNN of the PDU session.

[0450] In some embodiments, the first message is an attach request.

[0451] In the embodiment of the present application, the terminal switches from the first network device to the second network device.

[0452] In some embodiments, the first network device and the second network device are network devices of different systems.

[0453] For example, the first network device is a network device in a 4G system, and the second network device is a network device in a 5G system; or, the first network device is a network device in a 5G system, and the second network device is a network device in a 4G system, and so on.

[0454] In some embodiments, the first network device does not support the N26 interface.

[0455] In some embodiments, the second network device may or may not support the N26 interface.

[0456] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0457] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDN connection or a PDU session for the user service and allocates a corresponding first address.

[0458] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0459] Step 1002: Send a second message to the terminal, where the second message is used to indicate that the registration of the terminal is accepted, and the second message carries a second address of the terminal.

[0460] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can indicate that the registration request of the terminal is accepted, and the second message carries a second address allocated to the terminal.

[0461] Optionally, the second address is different from the first address.

[0462] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0463] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0464] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0465] In some embodiments, the second message is also used to activate the first bearer.

[0466] The first bearer is a default bearer corresponding to the connection established between the terminal and the second network device.

[0467] In some embodiments, the second message may carry an activate default EPS bearer context request to activate the first bearer.

[0468] In some embodiments, the above-mentioned activation default EPS bearer context request includes the above-mentioned second address.

[0469] In some embodiments, the second message also includes other parameters required by the first bearer.

[0470] In some embodiments, the second message is an attach accept.

[0471] Step 1003: Receive a third message sent by the terminal, where the third message is used to indicate that registration of the terminal is completed.

[0472] In some embodiments, the second network device is capable of receiving a third message sent by the terminal, where the third message is used to indicate that registration of the terminal is completed.

[0473] In some embodiments, the third message is attachment complete.

[0474] Optionally, the terminal can release the local second bearer after receiving the third message.

[0475] Among them, the above-mentioned second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the above-mentioned third bearer is a bearer corresponding to the PDU session established between the terminal and the first network device.

[0476] Furthermore, the terminal can re-initiate establishment of a new PDN connection according to service requirements.

[0477] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 3B shown.

[0478] It should be noted that Figure 3B The description can refer to the description in any embodiment of the present application and will not be repeated here.

[0479] The switching method of the embodiment of the present application receives a first message sent by a terminal, the first message is used to request registration with a second network device, and the first message carries a first address of the terminal; sends a second message to the terminal, the second message is used to indicate that the registration of the terminal is accepted, and the second message carries a second address of the terminal; receives a third message sent by the terminal, and the third message is used to indicate that the registration of the terminal is completed; so that when an inter-system switching occurs, if the terminal cannot be assigned an original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality can be effectively reduced, complexity can be effectively reduced, and the stability of the terminal and the robustness of the system can be improved.

[0480] Fig.11 A flowchart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to the second network device.

[0481] like Fig.11 As shown, the switching method may include the following steps:

[0482] Step 1101: Receive a first message sent by a terminal, where the first message is used to request registration with a second network device, and the first message carries a first address of the terminal.

[0483] Step 1102: Send a second message to the terminal, where the second message is used to indicate that the registration of the terminal is accepted, and the second message carries a second address of the terminal.

[0484] It should be noted that the specific implementation of steps 1101-1102 can refer to the various embodiments of the present application and will not be described in detail here.

[0485] Step 1103: Receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to reject the registration.

[0486] In some embodiments, the second network device is capable of receiving a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to reject the registration.

[0487] Optionally, the terminal rejects the registration, which can trigger a detach process.

[0488] In some embodiments, after receiving a registration acceptance message carrying a changed new address from the second network device, the terminal may reject the registration. Furthermore, the terminal may delete the local bearer used to initiate the attach process.

[0489] Furthermore, the terminal may re-initiate the initial attach process later.

[0490] Specifically, the terminal may send an initial type registration request (attach request) message to the second network device to initiate an initial attach process.

[0491] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 4B shown.

[0492] It should be noted that Figure 4B The description can refer to the description in any embodiment of the present application and will not be repeated here.

[0493] The switching method of the embodiment of the present application receives a first message sent by a terminal, the first message is used to request registration with a second network device, and the first message carries a first address of the terminal; sends a second message to the terminal, the second message is used to indicate that the registration of the terminal is accepted, and the second message carries a second address of the terminal; receives a fourth message sent by the terminal, and the fourth message is used to indicate that the terminal rejects the registration; so that when the terminal switches to an alien system and the terminal cannot be assigned the original address by the second network device, it can re-establish a connection with the network in a short time to achieve smooth switching, reduce service interruption delay, and effectively improve user experience. At the same time, it can also reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0494] Fig.12 A flowchart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to the second network device.

[0495] like Fig.12 As shown, the switching method may include the following steps:

[0496] Step 1201: Receive a first message sent by a terminal, where the first message is used to request a second network device to establish a PDN connection, and the first message carries a first address of the terminal.

[0497] In some embodiments, the first message is used to request the second network device to establish a PDN connection.

[0498] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0499] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0500] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0501] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the access point name APN, etc.

[0502] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the PDU session established between the terminal and the first network device. For example, the access point name APN can be mapped from the context parameter data network name DNN of the PDU session.

[0503] In some embodiments, the first message is a PDN connectivity request.

[0504] In some embodiments, before sending the first message, the terminal completes a registration process, and the registration type is handover.

[0505] In the embodiment of the present application, the terminal switches from the first network device to the second network device.

[0506] In some embodiments, the first network device and the second network device are network devices of different systems.

[0507] In this embodiment, the first network device is a network device in a 5G system, the second network device is a network device in a 4G system, and so on.

[0508] In some embodiments, the first network device does not support the N26 interface.

[0509] In some embodiments, the second network device may or may not support the N26 interface.

[0510] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0511] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDU session for the user service and allocates a corresponding first address.

[0512] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0513] Step 1202: Send a second message to the terminal, where the second message is used to activate the first bearer and carries a second address of the terminal.

[0514] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can request activation of the first bearer on the PDN connection, and the second message carries a second address allocated to the terminal. The first bearer is the default bearer corresponding to the connection established between the terminal and the second network device.

[0515] Optionally, the second address is different from the first address.

[0516] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0517] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0518] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0519] In some embodiments, the second message may be an activate default EPS bearer context request (activatedefault EPS bearer context request).

[0520] In some embodiments, the above-mentioned activation default EPS bearer context request includes the above-mentioned second address.

[0521] In some embodiments, the second message also includes other parameters required by the first bearer.

[0522] Step 1203: Receive a third message sent by the terminal, where the third message is used to instruct the terminal to accept activation of the first bearer.

[0523] In some embodiments, the second network device is capable of receiving a third message sent by the terminal, where the third message is used to indicate that the terminal accepts activation of the first bearer.

[0524] In some embodiments, the third message is activate default EPS bearer context accept.

[0525] In some embodiments, the second address is used by the terminal to update IP parameters in related modules.

[0526] In some embodiments, after receiving the second message sent by the second network device, the terminal can update the IP parameters in the relevant modules based on the updated second address carried in the second message. For example, the IP parameters of modules including but not limited to wireless network access point (AP) applications and network cards can be updated.

[0527] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 5B shown.

[0528] It should be noted that Figure 5BThe description can refer to the description in any embodiment of the present application and will not be repeated here.

[0529] The switching method of the embodiment of the present application receives a first message sent by a terminal, the first message is used to request a second network device to establish a PDN connection, and the first message carries a first address of the terminal; sends a second message to the terminal, the second message is used to activate a first bearer, and the second message carries a second address of the terminal; receives a third message sent by the terminal, and the third message is used to instruct the terminal to accept the activation of the first bearer; so that when an inter-system switching occurs, if the terminal cannot be assigned an original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality can be effectively reduced, complexity can be effectively reduced, and the stability of the terminal and the robustness of the system can be improved.

[0530] Fig.13 A flowchart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to the second network device.

[0531] like Fig.13 As shown, the switching method may include the following steps:

[0532] Step 1301: Receive a first message sent by a terminal, where the first message is used to request a second network device to establish a PDN connection, and the first message carries a first address of the terminal.

[0533] Step 1302: Send a second message to the terminal, where the second message is used to activate the first bearer and carries a second address of the terminal.

[0534] It should be noted that the specific implementation of steps 1301-1302 can refer to the various embodiments of the present application and will not be described in detail here.

[0535] Step 1303: Receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0536] In some embodiments, the second network device is capable of receiving a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0537] In some embodiments, after receiving the request from the second network device to activate the default bearer carrying the changed new address, the terminal may reject the request from the second network device and refuse to activate the default bearer.

[0538] In some embodiments, after rejecting the request of the second network device, the terminal can further release the local second bearer.

[0539] Among them, the above-mentioned second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the above-mentioned third bearer is a bearer corresponding to the PDU session established between the terminal and the first network device.

[0540] Furthermore, the terminal may notify the corresponding module to re-initiate bearer activation later according to service requirements.

[0541] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 6B shown.

[0542] It should be noted that Figure 6B The description can refer to the description in any embodiment of the present application and will not be repeated here.

[0543] The switching method of the embodiment of the present application receives a first message sent by a terminal, the first message is used to request a second network device to establish a PDN connection, and the first message carries a first address of the terminal; sends a second message to the terminal, the second message is used to activate a first bearer, and the second message carries a second address of the terminal; receives a fourth message sent by the terminal, and the fourth message is used to instruct the terminal to refuse to activate the first bearer; so that when an inter-system switching occurs, if the terminal cannot be assigned an original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality can be effectively reduced, complexity can be effectively reduced, and the stability of the terminal and the robustness of the system can be improved.

[0544] Fig.14 A flowchart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to the second network device.

[0545] like Fig.14 As shown, the switching method may include the following steps:

[0546] Step 1401: Receive a first message sent by a terminal, where the first message is used to request a second network device to establish a PDU session, and the first message carries a first address of the terminal.

[0547] In some embodiments, the first message is used to request the second network device to establish a PDU session.

[0548] In some embodiments, the first address is an address allocated by the first network device to the terminal.

[0549] Optionally, the first address is a corresponding IP address parameter allocated by the first network device when establishing a connection and bearer for a user service of the terminal.

[0550] Optionally, the type of the first address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0551] In some embodiments, the first message may also include other parameters, such as the type of the requested address, the data network name DNN, etc.

[0552] In some embodiments, the parameters in the first message are obtained by mapping the context parameters of the bearer corresponding to the PDN connection established between the terminal and the first network device. For example, the data network name DNN can be obtained by mapping the context parameter access point name APN of the bearer corresponding to the PDN connection.

[0553] In some embodiments, the first message is a PDU session establishment request (PDU session establishment request).

[0554] In some embodiments, before sending the first message, the terminal completes a registration process, and the registration type is handover.

[0555] In the embodiment of the present application, the terminal switches from the first network device to the second network device.

[0556] In some embodiments, the first network device and the second network device are network devices of different systems.

[0557] In this embodiment, the first network device is a network device in a 4G system, the second network device is a network device in a 5G system, and so on.

[0558] In some embodiments, the first network device does not support the N26 interface.

[0559] In some embodiments, the second network device may or may not support the N26 interface.

[0560] In some embodiments, the terminal can determine that a different system handover from the first network device to the second network device occurs.

[0561] In some embodiments, before the switching occurs, the terminal completes initial registration with the first network device, and the first network device establishes a PDN connection and a corresponding bearer for the user service, and allocates a corresponding first address.

[0562] In each embodiment of the present application, there is no limitation on the reason for the above-mentioned switching, which may be caused by any reason, such as terminal reason or network reason, and the present application does not limit it here.

[0563] Step 1402: Send a second message to the terminal, where the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries a second address of the terminal.

[0564] In some embodiments, the second network device sends a second message to the terminal, the second message is used to respond to the first message, can indicate that the PDU session establishment request is accepted, and the second message carries a second address allocated to the terminal.

[0565] Optionally, the second address is different from the first address.

[0566] In some embodiments, when the terminal switches to the second network device, the second network device may not be able to allocate the previous first address to the terminal, and thus indicates the changed second address to the terminal in the second message.

[0567] Optionally, the second address is a corresponding IP address parameter allocated by the second network device to the terminal.

[0568] Optionally, the type of the second address may be IPv4 single stack, or IPv6 single stack, or IPv4v6 dual stack.

[0569] In some embodiments, the second message may be a PDU session establishment accept.

[0570] In some embodiments, the second message also includes other parameters required for the PDU session reconstruction.

[0571] In some embodiments, the second address is used by the terminal to update IP parameters in related modules.

[0572] In some embodiments, after receiving the second message sent by the second network device, the terminal can update the IP parameters in the relevant modules based on the updated second address carried in the second message. For example, the IP parameters of modules including but not limited to wireless network access point AP application, network card, etc. can be updated.

[0573] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 7B shown.

[0574] It should be noted that Figure 7B The description can refer to the description in any embodiment of the present application and will not be repeated here.

[0575] The switching method of the embodiment of the present application receives a first message sent by a terminal, the first message is used to request a second network device to establish a PDU session, and the first message carries a first address of the terminal; sends a second message to the terminal, the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries a second address of the terminal; so that when an inter-system switching occurs, if the terminal cannot be assigned an original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality can be effectively reduced, complexity can be effectively reduced, and the stability of the terminal and the robustness of the system can be improved.

[0576] Fig.15 A flowchart of another switching method provided in an embodiment of the present application. It should be noted that the above method is applied to the second network device.

[0577] like Fig.15 As shown, the switching method may include the following steps:

[0578] Step 1501: Receive a first message sent by a terminal, where the first message is used to request a second network device to establish a PDU session, and the first message carries a first address of the terminal.

[0579] Step 1502: Send a second message to the terminal, where the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries a second address of the terminal.

[0580] It should be noted that the specific implementation of steps 1501-1502 can refer to the various embodiments of the present application and will not be described in detail here.

[0581] Step 1503: Receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to end the PDU session.

[0582] In some embodiments, the terminal is able to send a fourth message to the second network device, where the fourth message is used to instruct the terminal to end the PDU session.

[0583] In some embodiments, after receiving the PDU session establishment acceptance message carrying the changed new address from the second network device, the terminal may end the PDU session, refuse to activate the PDU session, and release the local bearer.

[0584] In some embodiments, after ending the PDU session, the terminal can further release the local second bearer.

[0585] The second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the third bearer is a bearer corresponding to the PDN connection established between the terminal and the first network device.

[0586] Furthermore, the terminal may notify the corresponding module to re-initiate activation of the PDU session according to service requirements later.

[0587] As an example, the interaction between the terminal and the first network device and the second network device in the embodiment of the present application can be as follows: Figure 8B shown.

[0588] It should be noted that Figure 8B The description can refer to the description in any embodiment of the present application and will not be repeated here.

[0589] The switching method of the embodiment of the present application receives a first message sent by a terminal, wherein the first message is used to request a second network device to establish a PDU session, and the first message carries a first address of the terminal; sends a second message to the terminal, wherein the second message is used to indicate that the PDU session establishment request is accepted, and the second message carries a second address of the terminal; receives a fourth message sent by the terminal, wherein the fourth message is used to instruct the terminal to end the PDU session; so that when an inter-system switching occurs, if the terminal cannot be assigned an original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality can be effectively reduced, complexity can be effectively reduced, and the stability of the terminal and the robustness of the system can be improved.

[0590] In order to implement the above embodiment, the present application also proposes a terminal.

[0591] Fig.16 A schematic diagram of the structure of a terminal provided in an embodiment of the present application.

[0592] like Fig.16 As shown, the terminal includes: a processing module 1610 and a transceiver module 1620.

[0593] Among them, the above-mentioned processing module 1610 is used to determine that the above-mentioned terminal switches from the first network device to the second network device, and the above-mentioned first network device and the above-mentioned second network device are network devices of different systems; the above-mentioned transceiver module 1620 is used to send a first message to the above-mentioned second network device, and the above-mentioned first message carries the first address of the above-mentioned terminal, and the above-mentioned first address is assigned to the above-mentioned terminal by the above-mentioned first network device; the above-mentioned transceiver module 1620 is also used to receive a second message sent by the above-mentioned second network device, and the above-mentioned second message carries the second address of the above-mentioned terminal, and the above-mentioned second address is assigned to the above-mentioned terminal by the above-mentioned second network device, and the above-mentioned second address is different from the above-mentioned first address.

[0594] Optionally, the first message is used to request registration to the second network device; the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate the first bearer; wherein the first bearer is the default bearer on the connection established between the terminal and the second network device.

[0595] Optionally, the transceiver module 1620 is further used to: send a third message to the second network device, where the third message is used to indicate that registration of the terminal is completed.

[0596] Optionally, the processing module 1610 is also used to: release a local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0597] Optionally, the first message is a registration request message, and the second message is a registration acceptance message.

[0598] Optionally, the transceiver module 1620 is further used to: send a fourth message to the second network device, where the fourth message is used to instruct the terminal to reject the registration.

[0599] Optionally, the processing module 1610 is further used to: delete a local fourth bearer; wherein the fourth bearer is used for the terminal to send the first message.

[0600] Optionally, the transceiver module 1620 is further used to: send a registration request message to the second network device, where the registration request message is of an initial type.

[0601] Optionally, the first message is used to request the second network device to establish a packet data network PDN connection; the second message is used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0602] Optionally, the transceiver module 1620 is further used to: send a third message to the second network device, where the third message is used to instruct the terminal to accept activation of the first bearer.

[0603] Optionally, the processing module 1610 is further configured to update Internet Protocol IP parameters in related modules based on the second address.

[0604] Optionally, the transceiver module 1620 is also used to: send a fourth message to the second network device, the fourth message being used to instruct the terminal to refuse to activate the first bearer; and release the local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, the second bearer is obtained based on the mapping of the third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0605] Optionally, the first message is used to request the second network device to establish a packet data unit PDU session; and the second message is used to indicate that the PDU session establishment request is accepted.

[0606] Optionally, the processing module 1610 is further configured to update Internet Protocol IP parameters in related modules based on the second address.

[0607] Optionally, the transceiver module 1620 is also used to: send a fourth message to the second network device, the fourth message being used to instruct the terminal to end the PDU session; and release the local second bearer; wherein the second bearer is a bearer on the connection established between the terminal and the second network device, and the second bearer is obtained based on the mapping of the third bearer, and the third bearer is a bearer on the connection established between the terminal and the first network device.

[0608] Optionally, the first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

[0609] Optionally, the first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

[0610] The terminal of the embodiment of the present application determines that the terminal switches from a first network device to a second network device, and the first network device and the second network device are network devices of different systems; sends a first message to the second network device, the first message carries a first address of the terminal, and the first address is assigned to the terminal by the first network device; receives a second message sent by the second network device, the second message carries a second address of the terminal, and the second address is assigned to the terminal by the second network device, and the second address is different from the first address; so that when a switching of different systems occurs, if the terminal cannot be assigned the original address by the switched network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so as to achieve smooth switching without service interruption, ensure service continuity, reduce service interruption delay, and effectively improve user experience. At the same time, it can also reduce signaling interaction, effectively reduce the probability of abnormality, effectively reduce complexity, and improve the stability of the terminal and the robustness of the system.

[0611] It should be noted that the aforementioned explanations and descriptions of the switching method embodiment applied to the terminal are also applicable to the terminal of this embodiment, and will not be repeated here.

[0612] In order to implement the above embodiment, the present application also proposes a second network device.

[0613] Fig.17 A schematic diagram of the structure of a terminal provided in an embodiment of the present application.

[0614] like Fig.17 As shown, the second network device includes: a processing module 1710 and a transceiver module 1720 .

[0615] Among them, the above-mentioned transceiver module 1720 is used to receive a first message sent by the terminal, the above-mentioned first message carries the first address of the above-mentioned terminal, and the above-mentioned first address is assigned to the above-mentioned terminal by the first network device; the above-mentioned transceiver module 1720 is also used to determine that the above-mentioned first address cannot be assigned to the above-mentioned terminal, and send a second message to the above-mentioned terminal, the above-mentioned second message carries the second address of the above-mentioned terminal, the above-mentioned second address is different from the above-mentioned first address, and the above-mentioned second address is assigned to the above-mentioned terminal by the second network device; wherein the above-mentioned terminal switches from the above-mentioned first network device to the above-mentioned second network device, and the above-mentioned first network device and the above-mentioned second network device are network devices of different systems.

[0616] Optionally, the first message is used to request registration to the second network device; the second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate the first bearer; wherein the first bearer is the default bearer on the connection established between the terminal and the second network device.

[0617] Optionally, the transceiver module 1720 is further used to: receive a third message sent by the terminal, where the third message is used to indicate that registration of the terminal is completed.

[0618] Optionally, the first message is a registration request message, and the second message is a registration acceptance message.

[0619] Optionally, the transceiver module 1720 is further used to: receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to reject the registration.

[0620] Optionally, the transceiver module 1720 is further used to: receive a registration request message sent by the terminal, where the registration request message is of an initial type.

[0621] Optionally, the first message is used to request the second network device to establish a packet data network PDN connection; the second message is used to activate a first bearer; wherein the first bearer is a default bearer on the connection established between the terminal and the second network device.

[0622] Optionally, the transceiver module 1720 is further used to: receive a third message sent by the terminal, where the third message is used to instruct the terminal to accept activation of the first bearer.

[0623] Optionally, the second address is also used for the terminal to update Internet protocol IP parameters in related modules.

[0624] Optionally, the transceiver module 1720 is further used to: receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

[0625] Optionally, the first message is used to request the second network device to establish a packet data unit PDU session; and the second message is used to indicate that the PDU session establishment request is accepted.

[0626] Optionally, the second address is also used for the terminal to update Internet protocol IP parameters in related modules.

[0627] Optionally, the transceiver module 1720 is further used to: receive a fourth message sent by the terminal, where the fourth message is used to instruct the terminal to end the PDU session.

[0628] Optionally, the first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

[0629] Optionally, the first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

[0630] The terminal in the embodiment of the present application receives a first message sent by the terminal, the first message carrying a first address; determines that the first address cannot be assigned to the terminal, and sends a second message to the terminal, the second message carrying a second address, the second address is assigned to the terminal by the second network device, and the second address is different from the first address; so that when an inter-system switching occurs, if the terminal cannot be assigned the original address by the second network device, the existing connection will not be directly disconnected, and a new address can be assigned on the basis of maintaining the connection, so that smooth switching can be achieved without service interruption, service continuity can be guaranteed, service interruption delay can be reduced, and user experience can be effectively improved. At the same time, signaling interaction can be reduced, the probability of abnormality is effectively reduced, complexity is effectively reduced, and the stability of the terminal and the robustness of the system are improved.

[0631] It should be noted that the above explanation of the switching method embodiment applied to the second network device is also applicable to the terminal of this embodiment, which will not be repeated here.

[0632] In order to implement the above embodiment, the present application also proposes a communication device, including one or more processors; wherein the above communication device is used to execute the above Figure 2-Figure 8B The switching method proposed in the embodiment.

[0633] In order to implement the above embodiment, the present application also proposes a communication device, including one or more processors; wherein the above communication device is used to execute the above Figure 9-Figure 15 The switching method proposed in the embodiment.

[0634] In order to implement the above embodiment, the present application also provides a chip, including a processor and an interface; the above processor is used to read instructions to execute the above Figure 2-Figure 8B The switching method proposed in the embodiment.

[0635] In order to implement the above embodiment, the present application also provides a chip, including a processor and an interface; the above processor is used to read instructions to execute the above Figure 9-Figure 15 The switching method proposed in the embodiment.

[0636] In order to implement the above embodiment, the embodiment of the present application also provides another chip, including at least one processor and a communication interface; the above communication interface is used to receive a signal input to the above chip or a signal output from the above chip, and the above processor communicates with the above communication interface and implements the above through a logic circuit or executing a code instruction. Figure 2-Figure 8B The switching method proposed in the embodiment.

[0637] In order to implement the above embodiment, the embodiment of the present application also provides another chip, including at least one processor and a communication interface; the above communication interface is used to receive a signal input to the above chip or a signal output from the above chip, and the above processor communicates with the above communication interface and implements the above through a logic circuit or executing a code instruction. Figure 9-Figure 15 The switching method proposed in the embodiment.

[0638] In order to implement the above embodiment, the present application also proposes a non-temporary computer-readable storage medium, and when the instructions in the storage medium are executed by the processor of the communication device, the communication device can execute the above Figure 2-Figure 8B The switching method proposed in the embodiment.

[0639] In order to implement the above embodiment, the present application also proposes a non-temporary computer-readable storage medium, and when the instructions in the storage medium are executed by the processor of the communication device, the communication device can execute the above Figure 9-Figure 15 The switching method proposed in the embodiment.

[0640] Fig.18 1 is a block diagram of a communication device according to an exemplary embodiment. For example, the communication device 1800 may be a mobile phone, a computer, a digital broadcast terminal, a messaging device, a game console, a tablet device, a medical device, a fitness device, a personal digital assistant, etc.

[0641] Reference Fig.18 , the communication device 1800 may include one or more of the following components: a processing component 1802 , a memory 1804 , a power component 1806 , a multimedia component 1808 , an audio component 1810 , an input / output (I / O) interface 1812 , a sensor component 1814 , and a communication component 1816 .

[0642] The processing component 1802 generally controls the overall operation of the communication device 1800, such as operations associated with display, phone calls, data communications, camera operations, and recording operations. The processing component 1802 may include one or more processors 1820 to execute instructions to complete all or part of the steps of the above-mentioned method. In addition, the processing component 1802 may include one or more modules to facilitate the interaction between the processing component 1802 and other components. For example, the processing component 1802 may include a multimedia module to facilitate the interaction between the multimedia component 1808 and the processing component 1802.

[0643] The memory 1804 is configured to store various types of data to support the operation of the communication device 1800. Examples of such data include instructions for any application or method operating on the communication device 1800, contact data, phone book data, messages, pictures, videos, etc. The memory 1804 can be implemented by any type of volatile or non-volatile storage device or a combination thereof, such as static random access memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic disk or optical disk.

[0644] The power component 1806 provides power to the various components of the communication device 1800. The power component 1806 may include a power management system, one or more power supplies, and other components associated with generating, managing, and distributing power for the communication device 1800.

[0645] The multimedia component 1808 includes a screen that provides an output interface between the communication device 1800 and the user. In some embodiments, the screen may include a liquid crystal display (LCD) and a touch panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from the user. The touch panel includes one or more touch sensors to sense touch, slide, and gestures on the touch panel. The touch sensor may not only sense the boundaries of the touch or slide action, but also detect the duration and pressure associated with the touch or slide operation. In some embodiments, the multimedia component 1808 includes a front camera and / or a rear camera. When the communication device 1800 is in an operating mode, such as a shooting mode or a video mode, the front camera and / or the rear camera may receive external multimedia data. Each front camera and rear camera may be a fixed optical lens system or have a focal length and optical zoom capability.

[0646] The audio component 1810 is configured to output and / or input audio signals. For example, the audio component 1810 includes a microphone (MIC), and when the communication device 1800 is in an operation mode, such as a call mode, a recording mode, and a speech recognition mode, the microphone is configured to receive an external audio signal. The received audio signal can be further stored in the memory 1804 or sent via the communication component 1816. In some embodiments, the audio component 1810 also includes a speaker for outputting audio signals.

[0647] I / O interface 1812 provides an interface between processing component 1802 and peripheral interface modules, such as keyboards, click wheels, buttons, etc. These buttons may include but are not limited to: home button, volume button, start button, and lock button.

[0648] The sensor assembly 1814 includes one or more sensors for providing various aspects of status assessment for the communication device 1800. For example, the sensor assembly 1814 can detect the open / closed state of the communication device 1800, the relative positioning of components, such as the display and keypad of the communication device 1800, the sensor assembly 1814 can also detect the position change of the communication device 1800 or a component of the communication device 1800, the presence or absence of user contact with the communication device 1800, the orientation or acceleration / deceleration of the communication device 1800, and the temperature change of the communication device 1800. The sensor assembly 1814 can include a proximity sensor configured to detect the presence of a nearby object without any physical contact. The sensor assembly 1814 can also include an optical sensor, such as a CMOS or CCD image sensor, for use in imaging applications. In some embodiments, the sensor assembly 1814 can also include an accelerometer, a gyroscope sensor, a magnetic sensor, a pressure sensor, or a temperature sensor.

[0649] The communication component 1816 is configured to facilitate wired or wireless communication between the communication device 1800 and other devices. The communication device 1800 can access a wireless network based on a communication standard, such as WiFi, 4G or 18G, or a combination thereof. In an exemplary embodiment, the communication component 1816 receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In an exemplary embodiment, the communication component 1816 also includes a near field communication (NFC) module to facilitate short-range communication. For example, the NFC module can be implemented based on radio frequency identification (RFID) technology, infrared data association (IrDA) technology, ultra-wideband (UWB) technology, Bluetooth (BT) technology and other technologies.

[0650] In an exemplary embodiment, the communication device 1800 may be implemented by one or more application-specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), controllers, microcontrollers, microprocessors, or other electronic components to perform the above methods.

[0651] In an exemplary embodiment, a non-transitory computer-readable storage medium including instructions is also provided, such as a memory 1804 including instructions, and the instructions can be executed by the processor 1820 of the communication device 1800 to perform the above method. For example, the non-transitory computer-readable storage medium can be a ROM, a random access memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, etc.

[0652] Some embodiments of the present application also provide a chip system, such as Fig.19 As shown, the chip system includes at least one processor 1901 and at least one interface circuit 1902. The processor 1901 and the interface circuit 1902 can be interconnected through lines. For example, the interface circuit 1902 can be used to receive signals from other devices (such as the memory of an electronic device). For another example, the interface circuit 1902 can be used to send signals to other devices (such as the processor 1901). Exemplarily, the interface circuit 1902 can read the instructions stored in the memory and send the instructions to the processor 1901. When the instructions are executed by the processor 1901, the information processing device can perform the various steps in the above embodiments. Of course, the chip system can also include other discrete devices, and some embodiments of the present application do not specifically limit this.

[0653] In some embodiments of the present application, the interface circuit 1902 can obtain data, program instructions and / or information from the internal storage area of ​​the chip system; it can also obtain data, program instructions and / or information from outside the chip system.

[0654] Optionally, the chip system also includes a memory 1903, and the memory 1903 is used to store necessary computer programs and data.

[0655] Those skilled in the art may also understand that the various illustrative logical blocks and steps listed in the embodiments of the present application may be implemented by electronic hardware, computer software, or a combination of the two. Whether such functions are implemented by hardware or software depends on the specific application and the design requirements of the entire system. Those skilled in the art may use various methods to implement the functions described for each specific application, but such implementation should not be understood as exceeding the scope of protection of the embodiments of the present application.

[0656] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0657] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0658] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, fragment or portion of code comprising one or more executable instructions for implementing the steps of a custom logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0659] The logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as an ordered list of executable instructions for implementing logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, device or apparatus (such as a computer-based system, a system including a processor, or other system that can fetch instructions from an instruction execution system, device or apparatus and execute the instructions), or in combination with these instruction execution systems, devices or apparatuses. For the purpose of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate or transmit a program for use by an instruction execution system, device or apparatus, or in combination with these instruction execution systems, devices or apparatuses. More specific examples of computer-readable media (a non-exhaustive list) include the following: an electrical connection with one or more wires (electronic device), a portable computer disk box (magnetic device), a random access memory (RAM), a read-only memory (ROM), an erasable and programmable read-only memory (EPROM or flash memory), a fiber optic device, and a portable compact disk read-only memory (CDROM). In addition, the computer-readable medium may even be paper or other suitable medium on which the program is printed, since the program may be obtained electronically, for example, by optically scanning the paper or other medium and then editing, interpreting or processing in other suitable ways if necessary, and then stored in a computer memory.

[0660] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0661] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0662] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0663] The storage medium mentioned above may be a read-only memory, a magnetic disk or an optical disk, etc. Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present application. A person of ordinary skill in the art may change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A switching method, characterized in that: The method comprises: Determining that a terminal switches from a first network device to a second network device, and that the first network device and the second network device are network devices of different systems; Sending a first message to the second network device, where the first message carries a first address of the terminal, where the first address is allocated to the terminal by the first network device; A second message sent by the second network device is received, where the second message carries a second address of the terminal, where the second address is allocated to the terminal by the second network device, and the second address is different from the first address.

2. The method according to claim 1, characterized in that The first message is used to request registration from the second network device; The second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate the first bearer; The first bearer is a default bearer on the connection established between the terminal and the second network device.

3. The method according to claim 2, characterized in that The method further comprises: A third message is sent to the second network device, where the third message is used to indicate that registration of the terminal is completed.

4. The method according to claim 3, characterized in that The method further comprises: Release the local secondary bearer; The second bearer is a bearer on a connection established between the terminal and the second network device, the second bearer is obtained based on a mapping of a third bearer, and the third bearer is a bearer on a connection established between the terminal and the first network device.

5. The method according to any one of claims 2 to 4, characterized in that: The first message is a registration request message, and the second message is a registration acceptance message.

6. The method according to claim 2, characterized in that The method further comprises: A fourth message is sent to the second network device, where the fourth message is used to instruct the terminal to reject the registration.

7. The method according to claim 6, characterized in that The method further comprises: Delete the local fourth bearer; The fourth bearer is used by the terminal to send the first message.

8. The method according to claim 7, characterized in that The method further comprises: A registration request message is sent to the second network device, where the registration request message is of an initial type.

9. The method according to claim 1, characterized in that: The first message is used to request the second network device to establish a packet data network PDN connection; The second message is used to activate the first bearer; The first bearer is a default bearer on the connection established between the terminal and the second network device.

10. The method according to claim 9, characterized in that The method further comprises: A third message is sent to the second network device, where the third message is used to instruct the terminal to accept activation of the first bearer.

11. The method according to claim 10, characterized in that The method further comprises: Based on the second address, Internet Protocol IP parameters in relevant modules are updated.

12. The method according to claim 9, characterized in that The method further comprises: Sending a fourth message to the second network device, where the fourth message is used to instruct the terminal to refuse to activate the first bearer; Release the local secondary bearer; The second bearer is a bearer on a connection established between the terminal and the second network device, the second bearer is obtained based on a mapping of a third bearer, and the third bearer is a bearer on a connection established between the terminal and the first network device.

13. The method according to claim 1, characterized in that The first message is used to request the second network device to establish a packet data unit PDU session; The second message is used to indicate that the PDU session establishment request is accepted.

14. The method according to claim 13, characterized in that The method further comprises: Based on the second address, Internet Protocol IP parameters in relevant modules are updated.

15. The method according to claim 13, characterized in that The method further comprises: Sending a fourth message to the second network device, where the fourth message is used to instruct the terminal to end the PDU session; Release the local secondary bearer; The second bearer is a bearer on a connection established between the terminal and the second network device, the second bearer is obtained based on a mapping of a third bearer, and the third bearer is a bearer on a connection established between the terminal and the first network device.

16. The method according to any one of claims 2 to 12, characterized in that: The first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

17. The method according to any one of claims 13 to 15, characterized in that: The first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

18. A switching method, characterized in that: The method comprises: receiving a first message sent by a terminal, where the first message carries a first address of the terminal, and the first address is allocated to the terminal by a first network device; Determine that the first address cannot be assigned to the terminal, and send a second message to the terminal, where the second message carries a second address of the terminal, where the second address is different from the first address and is assigned to the terminal by a second network device; The terminal switches from the first network device to the second network device, and the first network device and the second network device are network devices of different systems.

19. The method according to claim 18, characterized in that The first message is used to request registration from the second network device; The second message is used to indicate that the registration of the terminal is accepted, and the second message is also used to activate the first bearer; The first bearer is a default bearer on the connection established between the terminal and the second network device.

20. The method according to claim 19, characterized in that The method further comprises: A third message sent by the terminal is received, where the third message is used to indicate that registration of the terminal is completed.

21. The method according to any one of claims 19-20, characterized in that: The first message is a registration request message, and the second message is a registration acceptance message.

22. The method according to claim 19, characterized in that The method further comprises: A fourth message sent by the terminal is received, where the fourth message is used to instruct the terminal to reject the registration.

23. The method according to claim 22, characterized in that The method further comprises: A registration request message sent by the terminal is received, where the registration request message is of an initial type.

24. The method according to claim 18, characterized in that The first message is used to request the second network device to establish a packet data network PDN connection; The second message is used to activate the first bearer; The first bearer is a default bearer on the connection established between the terminal and the second network device.

25. The method according to claim 24, characterized in that The method further comprises: A third message sent by the terminal is received, where the third message is used to indicate that the terminal accepts activation of the first bearer.

26. The method according to claim 25, characterized in that The second address is also used by the terminal to update Internet Protocol IP parameters in related modules.

27. The method according to claim 24, characterized in that The method further comprises: A fourth message sent by the terminal is received, where the fourth message is used to instruct the terminal to refuse to activate the first bearer.

28. The method according to claim 18, characterized in that The first message is used to request the second network device to establish a packet data unit PDU session; The second message is used to indicate that the PDU session establishment request is accepted.

29. The method according to claim 28, characterized in that The second address is also used by the terminal to update Internet Protocol IP parameters in related modules.

30. The method according to claim 28, characterized in that The method further comprises: A fourth message sent by the terminal is received, where the fourth message is used to instruct the terminal to end the PDU session.

31. The method according to any one of claims 19 to 27, characterized in that: The first network device is a network device in a fifth generation mobile communication system, and the second network device is a network device in a fourth generation mobile communication system.

32. The method according to any one of claims 28 to 30, characterized in that: The first network device is a network device in a fourth generation mobile communication system, and the second network device is a network device in a fifth generation mobile communication system.

33. A terminal, characterized in that: The terminal comprises: A processing module, configured to determine that the terminal switches from a first network device to a second network device, and that the first network device and the second network device are network devices of different systems; a transceiver module, configured to send a first message to the second network device, wherein the first message carries a first address of the terminal, and the first address is allocated to the terminal by the first network device; The transceiver module is further used to receive a second message sent by the second network device, the second message carries a second address of the terminal, the second address is allocated to the terminal by the second network device, and the second address is different from the first address.

34. A second network device, characterized in that: The second network device comprises: a transceiver module, configured to receive a first message sent by a terminal, wherein the first message carries a first address of the terminal, and the first address is allocated to the terminal by a first network device; The transceiver module is further configured to determine that the first address cannot be allocated to the terminal, and send a second message to the terminal, wherein the second message carries a second address of the terminal, the second address is different from the first address, and the second address is allocated to the terminal by a second network device; The terminal switches from the first network device to the second network device, and the first network device and the second network device are network devices of different systems.

35. A communication device comprising: one or more processors; The communication device is used to execute the method described in any one of claims 1 to 17, or to execute the method described in any one of claims 18 to 32.

36. A chip, characterized in that: It includes at least one processor and a communication interface; the communication interface is used to receive a signal input to the chip or a signal output from the chip, and the processor communicates with the communication interface and implements the method according to any one of claims 1-17 through a logic circuit or by executing code instructions, or implements the method according to any one of claims 18-32.

37. A non-transitory computer-readable storage medium, characterized in that: When the instructions in the storage medium are executed by a processor of a communication device, the communication device is enabled to execute the method according to any one of claims 1 to 17, or execute the method according to any one of claims 18 to 32.

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