Communication method and apparatus, device, chip, storage medium, program product, and computer program

Abstract

Provided in the embodiments of the present application are a communication method and apparatus, a device, a chip, a storage medium, a program product, and a computer program. A terminal device sends first information, and a first network device receives the first information which is sent by the terminal device, the first information being used for indicating first access stratum context information to a first network under a first RAT, wherein the terminal device has accessed a second network under a second RAT and is in an inactive state.

Description

Communication methods and devices, equipment, chips, storage media, program products, computer programs Technical Field

[0001] This application relates to the field of side-to-side communication technology, specifically to a communication method and apparatus, device, chip, storage medium, program product, and computer program. Background Technology

[0002] When a user equipment (UE) switches from the coverage area of ​​one radio access technology (RAT) to the coverage area of ​​another RAT, it is necessary to ensure the continuity and consistency of the user.

[0003] The Radio Resource Control (RRC) inactive state (INACTIVE), also known as the RRC_INACTIVE state, can be used to maintain some Access Stratum (AS) context between the UE and the network.

[0004] However, the AS context defined by different RATs is also different. If the UE is in RRC_INACTIVE, then the connection between the AS context, core network and radio access network (RAN) needs to be re-established during inter-frequency handover. This will cause problems such as large signaling overhead, large handover delay and information loss.

[0005] Summary of the Invention

[0006] This application provides a communication method and apparatus, device, chip, computer-readable storage medium, computer program product, and computer program.

[0007] In a first aspect, embodiments of this application provide a communication method applied to a terminal device, the method comprising:

[0008] Send first information, which is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0009] Secondly, embodiments of this application provide a communication method applied to a first network device, the method comprising:

[0010] Receive first information, the first information being used to indicate first access layer context information to the first network under the first RAT;

[0011] The first information is sent by the terminal device, which has been connected to the second network under the second RAT and is in an inactive state.

[0012] Thirdly, embodiments of this application provide a communication device applied to a terminal device, the communication device comprising:

[0013] The sending unit is used to send first information, which is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0014] Fourthly, embodiments of this application provide a communication device applied to a first network device, the communication device comprising:

[0015] A receiving unit is configured to receive first information, wherein the first information is used to indicate first access layer context information to the first network under the first RAT.

[0016] The first information is sent by the terminal device, which has been connected to the second network under the second RAT and is in an inactive state.

[0017] Fifthly, embodiments of this application provide a terminal device, which includes a memory and a processor; wherein the memory is used to store computer-executable instructions; and the processor is connected to the memory and is used to implement the method described in the first aspect above by executing the computer-executable instructions.

[0018] In a sixth aspect, embodiments of this application provide a first network device, the first network device including a memory and a processor; wherein, the memory is used to store computer-executable instructions; the processor is connected to the memory and is used to implement the method described in the second aspect above by executing the computer-executable instructions.

[0019] In a seventh aspect, embodiments of this application provide a chip, the chip comprising: a processor for calling and running a computer program from a memory, causing a device on which the chip is installed to perform the method as described in any of the preceding aspects.

[0020] Eighthly, embodiments of this application provide a computer-readable storage medium storing a computer program that, when executed by at least one processor, implements the method as described in any of the preceding aspects.

[0021] Ninthly, embodiments of this application provide a computer program product including computer program instructions that cause a computer to perform the method as described in any of the preceding aspects.

[0022] In a tenth aspect, embodiments of this application provide a computer program that causes a computer to execute the method as described in any of the preceding aspects.

[0023] This application proposes a communication method, apparatus, device, chip, storage medium, program product, and computer program. A terminal device sends first information, and a first network device receives the first information sent by the terminal device. The first information is used to indicate first access layer context information to a first network under a first RAT; wherein, the terminal device has already accessed a second network under a second RAT and is in an inactive state. That is, in the embodiments of this application, when the terminal device is already accessed by the second network under the second RAT and is in an inactive state, it can send first information to indicate first access layer context information to the first network under the first RAT. By receiving the first information, the first network device can determine the identity information of the terminal device through the first access layer context information, thereby avoiding the re-establishment of AS context and the loss of service-related information during the handover from the second network to the first network, thus reducing signaling overhead and handover latency, and improving communication performance. Attached Figure Description

[0024] The accompanying drawings, which are included to provide a further understanding of this application and form part of this application, illustrate exemplary embodiments and are used to explain this application, but do not constitute an undue limitation of this application. In the drawings:

[0025] Figure 1 is a schematic diagram of the implementation process of the communication method provided in an embodiment of this application;

[0026] Figure 2 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0027] Figure 3 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0028] Figure 4 is a schematic diagram of the implementation process of the communication method provided in the embodiments of this application;

[0029] Figure 5 is a schematic diagram of the implementation process of the communication method provided in the embodiments of this application;

[0030] Figure 6 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0031] Figure 7 is a schematic diagram of the implementation process of the communication method provided in the embodiments of this application;

[0032] Figure 8 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0033] Figure 9 is a schematic diagram of the implementation process of the communication method provided in the embodiments of this application;

[0034] Figure 10 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0035] Figure 11 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0036] Figure 12 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0037] Figure 13 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application.

[0038] Figure 14 is a schematic diagram of the implementation process of the communication method provided in the embodiments of this application;

[0039] Figure 15 is a schematic diagram of the implementation process of the communication method provided in the embodiments of this application;

[0040] Figure 16 is a schematic diagram of the implementation process of the communication method provided in the embodiment of this application;

[0041] Figure 17 is a schematic diagram of the inter-frequency switching method provided in an embodiment of this application;

[0042] Figure 18 is a schematic diagram of the frequency switching method provided in the embodiment of this application;

[0043] Figure 19 is a schematic diagram of the frequency switching method provided in the embodiment of this application;

[0044] Figure 20 is a schematic diagram of the structural composition of the communication device provided in an embodiment of this application;

[0045] Figure 21 is a schematic diagram of the structural composition of the communication device provided in an embodiment of this application;

[0046] Figure 22 is a schematic structural diagram of a terminal device provided in an embodiment of this application;

[0047] Figure 23 is a schematic structural diagram of a first network device provided in an embodiment of this application;

[0048] Figure 24 is a schematic structural diagram of the chip provided in an embodiment of this application. Detailed Implementation

[0049] The technical solutions of the embodiments of this application will now be described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0050] The technical solutions of the embodiments of this application can be applied to various side-link communication systems (also referred to as side-link systems). To facilitate understanding of the technical solutions of the embodiments of this application, the relevant technologies in the side-link communication system are described below. The following relevant technologies are optional solutions and can be combined with the technical solutions of the embodiments of this application in any way, and they all fall within the protection scope of the embodiments of this application.

[0051] Currently, 5G (5th Generation Mobile Communication Technology) has been commercially deployed, providing users with high-speed, low-latency, and massive connectivity services. However, with the continuous growth of user demands and the emergence of new applications, 5G alone cannot meet the needs of future mobile networks. Therefore, 6G (6th Generation Mobile Networks), as a further extension and innovation of 5G, has received widespread attention in the research and industry communities. 6G is expected to achieve many technical goals based on 5G, including higher speeds, lower latency, stronger reliability, more connections, wider coverage, and a more intelligent network.

[0052] To enable users to enjoy the advantages of 5G and 6G, it is necessary to achieve a smooth handover between user equipment (UE) and 6G. This involves mobility between different radio access technologies (RATs), specifically an Inter-RAT Mobility technology.

[0053] Inter-RAT Mobility refers to a user switching from the coverage area of ​​one Radio Access Technology (RAT) to the coverage area of ​​another RAT. Inter-RAT Mobility is an important function in mobile communication systems, ensuring user continuity and consistency.

[0054] However, a technical challenge in implementing inter-frequency handover between 5G and 6G is handling a UE state in either 5G or 6G: the Radio Resource Control (RRC) inactive state (RRC_INACTIVE). RRC_INACTIVE lies between the Radio Resource Control idle state (RRC_IDLE) and the Radio Resource Control connected state (RRC_CONNECTED), aiming to reduce control plane usage and save terminal power.

[0055] RRC_INACTIVE is a new state introduced in 5G, used to maintain some Access Stratum (AS) context between the UE and the network so that the UE can be quickly reactivated while reducing signaling overhead and battery consumption. When the UE is in RRC_INACTIVE state, it periodically listens to the broadcast channel to obtain network information, such as a neighboring cell list. If the UE detects a better cell, it will actively or passively perform an Intra-RAT Handover and return to the RRC_INACTIVE state after the handover.

[0056] Intra-RAT Handover refers to a handover performed by a UE within the same RAT, but possibly between different base stations or cells. This handover typically occurs on the same frequency, hence it is called single-frequency handover or intra-frequency handover.

[0057] However, because 5G and 6G use different RATs, their defined AS contexts are also different. This leads to a problem: when a UE is in the RRC_INACTIVE state in 5G or 6G, because the AS context is defined by the source RAT, it cannot switch to the network node of the target RAT and remain in the RRC_INACTIVE state. In other words, the UE cannot perform inter-frequency handover in the RRC_INACTIVE state.

[0058] If the traditional method is used, when the UE switches from the 5G RRC_INACTIVE state to 4G, it falls back to the Radio Resource Control (RRC_IDLE) state, releases the AS context, and then switches to the 4G network node. While this method is feasible, it has the following drawbacks:

[0059] (1) The UE needs to re-establish the AS context, which will increase signaling overhead and battery consumption;

[0060] (2) The UE needs to re-establish the connection between the core network and the radio access network (RAN), which will increase the handover latency;

[0061] (3) The UE may lose some service-related information, such as measurement configuration and connection configuration, which will affect the user experience.

[0062] In other words, when the UE is in RRC_INACTIVE, the current common inter-frequency handover schemes have problems such as high signaling overhead, long handover delay and information loss.

[0063] To address the aforementioned issues, in the embodiments of this application, a terminal device sends first information, and a first network device receives the first information sent by the terminal device. The first information is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has already accessed the second network under the second RAT and is in an inactive state. In other words, in the embodiments of this application, when the terminal device is already accessed by the second network under the second RAT and is in an inactive state, it can send first information to indicate first access layer context information to the first network under the first RAT. By receiving the first information, the first network device can determine the identity information of the terminal device through the first access layer context information. This avoids the re-establishment of the AS context and the loss of service-related information during the handover from the second network to the first network, thereby reducing signaling overhead and handover latency, and improving communication performance.

[0064] It should be understood that the terms "system" and "network" are often used interchangeably in this document. The term "and / or" in this document merely describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship. It should also be understood that "instruction" mentioned in the embodiments of this application can be a direct instruction, an indirect instruction, or an indication of a related relationship. For example, A instructing B can mean that A directly instructs B, for example, B can be obtained through A; it can also mean that A indirectly instructs B, for example, A instructs C, B can be obtained through C; or it can mean that there is a related relationship between A and B. It should also be understood that "correspondence" mentioned in the embodiments of this application can indicate a direct or indirect correspondence between two things, or an related relationship between two things, or a relationship of instruction and being instructed, configuration and being configured, etc. It should also be understood that the "predefined" or "predefined rules" mentioned in the embodiments of this application can be implemented by pre-storing corresponding codes, tables, or other means that can be used to indicate relevant information in the device (e.g., including terminal devices and network devices), and this application does not limit the specific implementation method. For example, predefined can refer to what is defined in a protocol. It should also be understood that in the embodiments of this application, the "protocol" can refer to a standard protocol in the field of communications.

[0065] To facilitate understanding of the technical solutions of the embodiments of this application, the technical solutions of this application are described in detail below through specific embodiments. The above-mentioned related technologies are optional solutions and can be arbitrarily combined with the technical solutions of the embodiments of this application, all of which fall within the protection scope of the embodiments of this application. The embodiments of this application include at least some of the following contents.

[0066] One embodiment of this application proposes a communication method that can be applied to a terminal device. Figure 1 is a schematic diagram of the implementation flow of the communication method provided in this embodiment. As shown in Figure 1, the communication method may include the following steps:

[0067] S101. Send first information, which is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0068] In embodiments of this application, when a terminal device is connected to a second network under a second RAT and is in an inactive state, it can send first information to indicate first access layer context information to a first network under a first RAT.

[0069] In embodiments of this application, the first network and the second network can be different networks, wherein the first network and the second network can use different RATs. For example, the first network is a network under a first RAT, and the second network is a network under a second RAT, wherein the first RAT and the second RAT are different.

[0070] For example, in some embodiments, the first network may include, but is not limited to, 5G or 6G, and the second network may include, but is not limited to, 5G or 6G. For example, the first network is 5G and the second network is 6G, or the first network is 6G and the second network is 5G.

[0071] In the embodiments of this application, inter-frequency handover can be understood as handover from a source RAT to a target RAT. Specifically, the first RAT corresponding to the first network can be understood as the target RAT in the inter-frequency handover, and the second RAT corresponding to the second network can be understood as the source RAT in the inter-frequency handover.

[0072] In the embodiments of this application, the communication method proposed in this application is illustrated by taking a first network of 6G and a second network of 5G as an example, but no specific limitation is made on the first network and the second network.

[0073] In the embodiments of this application, when the terminal device has been connected to the second network under the second RAT, the first network can be determined by scanning frequency points or receiving the first broadcast message.

[0074] It is understood that, in the embodiments of this application, when the terminal device has been connected to the second network under the second RAT, when moving from the coverage area of ​​the second network to the coverage area of ​​the first network, the signal of the first network can be detected by scanning frequency points or receiving the first broadcast message, thereby determining the first network.

[0075] For example, in some embodiments, when a terminal device moves from a 5G coverage area to a 6G coverage area, a 6G signal is detected by scanning frequency points.

[0076] In embodiments of this application, the inactive state can be used to maintain the radio access layer (AS) context between the terminal device and the network device, thereby enabling the terminal device to be quickly reactivated while reducing signaling overhead and battery consumption. The inactive state can be understood as a state between the idle state and the connected state.

[0077] For example, in some embodiments, the inactive state can be the Radio Resource Control inactive state (RRC_INACTIVE). RRC_INACTIVE is between RRC_IDLE (idle state) and RRC_CONNECTED (connected state).

[0078] It should be noted that when a terminal device (UE) switches from one RAT (such as 5G NR) to another RAT (such as 6G), the AS context information of the source RAT refers to the AS-level context information established by the terminal device under the source RAT before the handover, i.e., the access layer context information. Access layer context information is crucial for ensuring a smooth handover process and maintaining service continuity.

[0079] For example, in some embodiments, AS context information may be state information related to the user equipment maintained at the AS level, including security context, radio resource allocation, QoS (Quality of Service) parameters, etc.

[0080] In embodiments of this application, the first information may be carried in a first message, wherein the first message is used to request access to the first network.

[0081] In other words, in the embodiments of this application, the terminal device can send a first message for requesting access to the first network. This first message may carry first information for indicating first access layer context information to the first network under the first RAT. The first information may indicate the terminal device's identity information included in the first access layer context information, such as the UE's ID information. This allows the first network device to determine the terminal device's identity information after obtaining the first information, and thus correctly identify the AS context corresponding to the terminal device based on the terminal device's identity information. Furthermore, the first network device can obtain the AS context corresponding to the terminal device from the second network device (source RAT) based on the terminal device's identity information.

[0082] In embodiments of this application, the first message used to request access to the first network may include, but is not limited to, RRC connection reconstruction or connection restoration. The terminal device may send the first message to a first network device, which may be a network device associated with the first network.

[0083] In the embodiments of this application, the first access layer context information can be understood as an AS context that conforms to the format requirements of the first network, that is, an AS context in a format (i.e., the first format) that the first network can use.

[0084] Therefore, in the embodiments of this application, when the terminal device has already accessed the second network under the second RAT and is in an inactive state, when the first network is determined by scanning frequency points or receiving the first broadcast message, a first message carrying first information can be further sent to the first network. This first information is used to indicate first access layer context information to the first network under the first RAT. By sending the first message indicating the first access layer context information, the network device can obtain the terminal device's identity information and / or its configuration information, such as measurement configuration, connection configuration, etc.

[0085] In the embodiments of this application, first information indicating the AS context corresponding to the format of the first network can be determined and sent. Therefore, during inter-frequency handover, the terminal device does not release the AS context, nor does it need to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. Simultaneously, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thus improving communication performance.

[0086] In the embodiments of this application, during the switching process between different RATs, it is only necessary to determine and send the first information for indicating the AS context corresponding to the format of the first network. It is not necessary to release and re-establish the AS context related to the second network under the second RAT. Accordingly, it is not necessary to re-establish the connection between the core network and the RAN, and the terminal device does not need to fall back to the idle state.

[0087] In other words, in the embodiments of this application, during the inter-frequency handover process, the terminal device can remain inactive. For example, while sending the first message to the first network device, the terminal device can resume the inactive state.

[0088] Furthermore, in the embodiments of this application, Figure 2 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 2, the communication method may further include the following steps:

[0089] S102, Receive a second message from the first network device; the second message is a response message to the first message; the first network device is a network device related to the first network.

[0090] In embodiments of this application, after sending first information to the first network device to indicate first access layer context information of the first network, the terminal device may receive a second message sent by the first network device.

[0091] In embodiments of this application, a terminal device sends a first message to a first network device to request access to the first network, and correspondingly, the terminal device can receive a second message sent by the first network device in response to the first message.

[0092] In the embodiments of this application, the first network device can be a network device related to a first network. For example, assuming the first network is 5G, the first network device can be a network device related to the 5G network; assuming the first network is 6G, the first network device can be a network device related to the 6G network.

[0093] In embodiments of this application, the second message may include, but is not limited to, a reconnection command or a connection recovery command, used to instruct the terminal device to reconnect or recover in response to a reconnection request or a connection recovery request.

[0094] Step 103: In response to the second message, send a third message; the third message is used to indicate whether the connection establishment is complete or the connection restoration is complete.

[0095] In embodiments of this application, after receiving a second message from the first network device, the terminal device may respond to the second message by sending a third message to the first network device.

[0096] In embodiments of this application, the third message can be used to indicate that the connection establishment is complete or the connection restoration is complete. Specifically, after completing the inter-frequency handover, the terminal device can respond to the connection rebuild command or connection restoration command by sending a third message to the first network device, thereby informing the first network device that the connection establishment or restoration is complete.

[0097] In summary, the communication method proposed in this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, can send first information to indicate the first access layer context information to the first network under the first RAT. This enables the network device to determine the identity information of the terminal device through the first access layer context information, thereby avoiding the re-establishment of AS context and the loss of service-related information during the handover from the second network to the first network, thus reducing signaling overhead and handover latency and improving communication performance.

[0098] Based on the above embodiments, another embodiment of this application proposes a communication method. In the embodiments of this application, the communication method proposed in this application is illustrated by taking a first network of 6G and a second network of 5G as an example.

[0099] The communication method proposed in this application can be a frequency switching method, which can realize frequency switching between 5G and 6G without losing the AS context. This frequency switching method is a method that can restore the RRC_INACTIVE state after switching.

[0100] Furthermore, in the embodiments of this application, the communication method proposed in the embodiments of this application can mainly achieve inter-frequency handover through the following three schemes:

[0101] A. A scheme based on two-sided context mapping.

[0102] B. A scheme based on one-sided context mapping.

[0103] C. A dual-configuration-based solution.

[0104] In some embodiments, for a scheme based on two-sided context mapping, the terminal device can map the AS context based on predefined rules.

[0105] In embodiments of this application, the first information used to indicate the first access layer context information to the first network under the first RAT can be obtained by mapping the second access layer context information of the second network.

[0106] It is understood that, in the embodiments of this application, the first information can be used to indicate the identity information of the terminal device included in the first access layer context information, such as the UE's ID information, so that the first network device can determine the identity information of the terminal device after obtaining the first information, and then correctly identify the AS context corresponding to the terminal device based on the identity information of the terminal device. Specifically, the first network device can either directly obtain the AS context corresponding to the terminal device through context mapping processing based on the identity information of the terminal device, or it can obtain the AS context corresponding to the terminal device from the second network device (source RAT) based on the identity information of the terminal device.

[0107] In the embodiments of this application, the first information is obtained by mapping the second access layer context information of the second network; the second access layer context information is the context information related to the second network that is retained by the terminal device.

[0108] In the embodiments of this application, the second access layer context information can be understood as an AS context that conforms to the format requirements of the second network, that is, an AS context in a format that the second network can use.

[0109] In the embodiments of this application, when a terminal device is in an inactive state while accessing a second network, it can maintain the AS context of the second network. That is, the second access layer context information is the context information of the second network maintained between the terminal device and the network device in the inactive state.

[0110] In the embodiments of this application, the terminal device can map the second access layer context information of the second network according to predefined rules. The predefined rules can be used to indicate the signaling format requirements and / or protocol specifications corresponding to the first network. Therefore, after mapping the second access layer context information according to the predefined rules, the terminal device can obtain the first access layer context information that conforms to the format requirements of the first network.

[0111] In embodiments of this application, when determining the first information, the second information in the second access layer context information corresponding to the second format of the second network can be mapped to the first information in the first access layer context information corresponding to the first format of the first network. The first format can be a format determined based on predefined rules that meets the signaling format requirements and / or protocol specifications of the first network, and the second format can be a format that meets the signaling format requirements and / or protocol specifications of the second network. For example, if the first network is 6G, the first format can be a 6G signaling format; if the second network is 5G, the first format can be a 5G signaling format.

[0112] In an embodiment of this application, when performing context mapping, one implementation method is as follows: the second information in the second item of the second access layer context information corresponding to the second format of the second network can be mapped to the first information in the first item of the first access layer context information corresponding to the first format of the first network; wherein, the second format of the second network contains a second item corresponding to the first item of the first format of the first network, and the second information is the value corresponding to the second item.

[0113] It is understood that, in the embodiments of this application, if the second format of the second network contains a second item corresponding to the first item of the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to the first information in the first item of the first access layer context information. The second information in the second access layer context information can be the value corresponding to the second item.

[0114] In the embodiments of this application, the first or second item may include one or more of the following: corresponding parameters; corresponding information elements; and corresponding fields.

[0115] It is understood that in the embodiments of this application, the first item and the second item are consistent. If the first item is a field in the first format of the first network, then the second item is a corresponding field in the second format of the second network.

[0116] In other words, in the embodiments of this application, when performing context mapping according to predefined rules, if there is a corresponding second item in the second format of the second network for the first item in the first format of the first network, the terminal device can map the value corresponding to the second item in the second format of the second network, i.e., the second information, to obtain the first information in the first item in the first format of the first network.

[0117] For example, in some embodiments, for a first item of content in the first network, such as a parameter / information element / field, if the first item of content has a corresponding parameter / information element / field in the second network, that is, there is a corresponding second item of content, then the terminal device can map the value of the second item of content, that is, the second information, to the corresponding parameter / information element / field in the first network, that is, map to obtain the first information in the first item of content.

[0118] In an embodiment of this application, another method for performing context mapping is to map the second information in the second item of the second access layer context information corresponding to the second format of the second network to predefined information; wherein, the second format of the second network does not contain a second item corresponding to the first item of the first format of the first network.

[0119] It is understood that, in the embodiments of this application, if there is no second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to predefined information to obtain the first information.

[0120] In the embodiments of this application, the first or second item may include one or more of the following: corresponding parameters; corresponding information elements; and corresponding fields.

[0121] In embodiments of this application, the predefined information includes, but is not limited to, one of the following: default value, null value, and invalid value.

[0122] In other words, in the embodiments of this application, when performing context mapping according to predefined rules, if there is no corresponding second item in the second format of the second network for the first item in the first format of the first network, the terminal device can map the second information in the second access layer context information to predefined information to obtain the corresponding first information.

[0123] For example, in some embodiments, for a first item in the first network, such as a parameter / information element / field, if the first item does not have a corresponding parameter / information element / field in the second network, that is, there is no corresponding second item, then the terminal device can map the second information to a predefined value (predefined information), such as a default value, a null value, or an invalid value.

[0124] For example, in some embodiments, Figure 3 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 3, for a scheme based on two-sided context mapping, the method for terminal devices to communicate may include the following steps:

[0125] S201. Determine the first access layer context information of the first network; wherein the terminal device has been connected to the second network and is in an inactive state.

[0126] In the embodiments of this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, it can first determine the first access layer context information. The first access layer context information can be understood as an AS context that conforms to the format requirements of the first network, i.e., an AS context in a format usable by the first network.

[0127] S202. Send first information, which is used to indicate first access layer context information to the first network under the first RAT; the first information is carried in a first message, which is used to request access to the first network.

[0128] In embodiments of this application, the terminal device may send first information.

[0129] In embodiments of this application, a terminal device may send a first message to a first network device to request access to the first network. The first message carries first information, which is used to indicate first access layer context information to the first network under the first RAT.

[0130] In the embodiments of this application, when the terminal device has been connected to the second network under the second RAT, the first network can be determined by scanning frequency points or receiving the first broadcast message.

[0131] In embodiments of this application, the first information used to indicate the first access layer context information to the first network under the first RAT can be obtained by mapping the second access layer context information of the second network. The second access layer context information is context information related to the second network that is retained by the terminal device.

[0132] In the embodiments of this application, the terminal device can map the second access layer context information of the second network according to predefined rules to obtain the first access layer context information that conforms to the format requirements of the first network.

[0133] In the embodiments of this application, when determining the first information, the second information in the second access layer context information corresponding to the second format of the second network can be mapped to the first information in the first access layer context information corresponding to the first format of the first network.

[0134] In embodiments of this application, if a second content item exists in the second format of the second network that corresponds to the first content item of the first format of the first network, then the terminal device can map the second information in the second content item of the second access layer context information to the first information in the first content item of the first access layer context information. The second information in the second access layer context information can be the value corresponding to the second content item.

[0135] In the embodiments of this application, if there is no second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to predefined information to obtain the first information.

[0136] In the embodiments of this application, first information indicating the AS context corresponding to the format of the first network can be determined and sent. Therefore, during the handover between different RATs, the terminal device does not release the AS context, nor does it need to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thus improving communication performance.

[0137] In the embodiments of this application, during the handover process between different RATs, it is only necessary to determine and send the first information indicating the AS context corresponding to the format of the first network. It is not necessary to release and re-establish the AS context related to the second network under the second RAT. Consequently, it is not necessary to re-establish the connection between the core network and the RAN, and the terminal device does not need to fall back to the idle state. For example, while sending the first message to the first network device, the terminal device can resume its inactive state.

[0138] S203, Receive a second message from the first network device; the second message is a response message to the first message; the first network device is a network device related to the first network.

[0139] In embodiments of this application, the terminal device may receive a second message from the first network device.

[0140] In embodiments of this application, the second message is a response message to the first message. For example, the second message may include, but is not limited to, a connection rebuild command or a connection restore command, used to instruct the terminal device to rebuild or restore the connection in response to a connection rebuild request or connection restore request.

[0141] In the embodiments of this application, the first network device may be a network device associated with a first network.

[0142] S204. In response to the second message, a third message is sent; the third message is used to indicate whether the connection establishment is complete or the connection restoration is complete.

[0143] In embodiments of this application, in response to the second message, the terminal device can send a third message. The third message can be used to indicate that the connection establishment is complete or the connection restoration is complete. Specifically, after completing the inter-frequency handover, the terminal device can send the third message to the first network device in response to a connection rebuild command or connection restoration command, so that the first network device is aware that the connection establishment or connection restoration is complete.

[0144] For example, in some embodiments, the communication method proposed in this application is illustrated by taking the first network (the network of the target RAT) as 6G and the second network (the network of the source RAT) as 5G as an example, but no specific limitation is made on the first network and the second network.

[0145] In the embodiments of this application, when the UE is already connected to 5G and in the RRC_INACTIVE state, it can first determine the 6G AS context. The 6G AS context can be understood as an AS context that conforms to the format requirements corresponding to 6G.

[0146] In embodiments of this application, the UE may send first information for indicating the AS context of 6G.

[0147] In embodiments of this application, the UE may send a first message for requesting access to a first network, such as an RRC resume request, which carries first information.

[0148] In embodiments of this application, the UE can receive a second message sent by a 6G network device.

[0149] In embodiments of this application, the second message is a response message to the first message. For example, the second message may include, but is not limited to, a reconnection command or a connection restoration command, used to instruct the UE to reconnect or restore the connection in response to a reconnection request or a connection restoration request.

[0150] In embodiments of this application, in response to the second message, the UE may send a third message. The third message may be used to indicate that connection establishment is complete or connection restoration is complete.

[0151] In the embodiments of this application, after the UE completes the inter-frequency handover, it can send a third message to the 6G network device in response to the re-establish connection command or the connection restoration command, so that the 6G network device knows that the connection establishment is complete or the connection restoration is complete.

[0152] In some embodiments, for schemes based on one-sided context mapping, the mapping of AS context is performed on the network side, and the terminal device only needs to obtain the already mapped AS context from the network side.

[0153] In embodiments of this application, when the first RAT is different from the second RAT, the terminal device may delete some configuration-related information in the second access layer context information of the second network, and retain at least the third information, which is related to the identity information.

[0154] In the embodiments of this application, the second access layer context information can be understood as an AS context that conforms to the format requirements of the second network, that is, an AS context in a format (i.e., the second format) that the second network can use.

[0155] It is understood that, in the embodiments of this application, after determining that the first RAT is different from the second RAT, the terminal device may choose to delete some information in the second access layer context information of the second network. For example, it may delete the configuration-related information in the second access layer context information that is unrelated to the identity information, while retaining the third information in the second access layer context information that is related to the identity information.

[0156] In embodiments of this application, the first information may include any of the following: third information; mapping the third information to first access layer context information corresponding to a first format of the first network.

[0157] It is understood that, in the embodiments of this application, the first information can be used to indicate the identity information of the terminal device included in the first access layer context information, such as the UE's ID information, so that the first network device can determine the identity information of the terminal device after obtaining the first information, and then correctly identify the AS context corresponding to the terminal device based on the identity information of the terminal device. Specifically, the first network device can either directly obtain the AS context corresponding to the terminal device through context mapping processing based on the identity information of the terminal device, or it can obtain the AS context corresponding to the terminal device from the second network device (source RAT) based on the identity information of the terminal device.

[0158] In the embodiments of this application, after retaining the third information related to identity information in the second access layer context information, the terminal device may choose to directly determine the first information for indicating the first access layer context information to the first network under the first RAT based on the third information.

[0159] In other words, in the embodiments of this application, the terminal device can directly use the third information that meets the signaling format requirements and / or protocol specifications of the second network as the first information, without performing conversion and mapping.

[0160] In embodiments of this application, after retaining the third information related to identity information in the second access layer context information, the terminal device can choose to map the third information according to predefined rules to obtain the first access layer context information corresponding to the first format of the first network. The first format can be a format determined based on predefined rules that meets the signaling format requirements and / or protocol specifications of the first network. For example, if the first network is 6G, the first format can be a 6G signaling format.

[0161] In other words, in the embodiments of this application, the terminal device may also convert and map the third information that meets the signaling format requirements and / or protocol specifications of the second network through predefined rules to obtain the first access layer context information corresponding to the first format of the first network, and use the first access layer context information as the corresponding first information.

[0162] In embodiments of this application, the terminal device may also receive fourth information corresponding to the first format sent by the first network device.

[0163] In embodiments of this application, the fourth information may include access layer context information corresponding to the first network.

[0164] In other words, in the embodiments of this application, after the terminal device sends a first message to the first network device to request access to the first network, it can also receive fourth information sent by the first network device. The fourth information may include access layer context information corresponding to the first network determined by the first network device.

[0165] In embodiments of this application, the terminal device can receive a second message sent by the first network device. The second message carries fourth information.

[0166] Therefore, in the embodiments of this application, the mapping of AS context is performed on the network side. The terminal device does not perform AS context mapping based on predefined rules, but directly obtains the access layer context information corresponding to the first network that has been mapped from the network side.

[0167] For example, in some embodiments, Figure 4 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 4, for a scheme based on two-sided context mapping, the method for terminal devices to communicate may include the following steps:

[0168] S301. If the first RAT is different from the second RAT, delete some configuration-related information in the second access layer context information of the second network, and retain at least the third information, which is related to the identity information.

[0169] In embodiments of this application, when a second network under a second RAT is connected and is inactive, if the first RAT corresponding to the first network is different from the second RAT corresponding to the second network, the terminal device may choose to delete some configuration-related information in the second access layer context information of the second network, and retain at least the third information. The second access layer context information can be understood as an AS context conforming to the format requirements of the second network.

[0170] In embodiments of this application, the terminal device may choose to delete some information in the second access layer context information of the second network. For example, it may delete some configuration-related information in the second access layer context information that is unrelated to identity information, and retain the third information in the second access layer context information that is related to identity information.

[0171] In the embodiments of this application, when the terminal device has already accessed the second network, the first network can be determined by scanning frequency points or receiving the first broadcast message.

[0172] S302. Send first information, which is used to indicate first access layer context information to the first network under the first RAT; the first information is carried in a first message, which is used to request access to the first network.

[0173] In embodiments of this application, the terminal device may send first information. The first information includes any one of the following: third information; and first access layer context information mapped to a first format corresponding to the first network.

[0174] In the embodiments of this application, the first information is carried in the first message, which is used to request access to the first network.

[0175] In the embodiments of this application, the terminal device can directly use the third information that meets the signaling format requirements and / or protocol specifications of the second network as the first information, without performing conversion and mapping.

[0176] In embodiments of this application, the terminal device may also convert and map the third information that meets the signaling format requirements and / or protocol specifications of the second network through predefined rules to obtain the first access layer context information corresponding to the first format of the first network, and use the first access layer context information as the corresponding first information.

[0177] In embodiments of this application, a terminal device may send a first message to a first network device to request access to the first network, the first message carrying first information.

[0178] In the embodiments of this application, first information indicating the AS context corresponding to the format of the first network can be determined and sent. Therefore, during the handover between different RATs, the terminal device does not release the AS context, nor does it need to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thus improving communication performance.

[0179] In the embodiments of this application, during the handover process between different RATs, it is only necessary to determine and send the first information indicating the AS context corresponding to the format of the first network. It is not necessary to release and re-establish the AS context related to the second network under the second RAT. Consequently, it is not necessary to re-establish the connection between the core network and the RAN, and the terminal device does not need to fall back to the idle state. For example, while sending the first message to the first network device, the terminal device can resume its inactive state.

[0180] S303. Receive fourth information sent by the first network device; wherein the fourth information is carried in the second message; the fourth information includes access layer context information corresponding to the first network.

[0181] In embodiments of this application, the terminal device may receive a second message from the first network device.

[0182] In embodiments of this application, the second message is a response message to the first message. For example, the second message may include, but is not limited to, a connection rebuild command or a connection restore command, used to instruct the terminal device to rebuild or restore the connection in response to a connection rebuild request or connection restore request.

[0183] In the embodiments of this application, the first network device may be a network device associated with a first network.

[0184] In embodiments of this application, the second message received by the terminal device may carry fourth information. This fourth information corresponds to a first format. The first format may be a format determined based on predefined rules and that satisfies the signaling format requirements and / or protocol specifications of the first network.

[0185] In other words, in the embodiments of the application, the terminal device can receive fourth information corresponding to the first format sent by the first network device; wherein, the fourth information includes access layer context information corresponding to the first network.

[0186] S304. In response to the second message, a third message is sent; the third message is used to indicate whether the connection establishment is complete or the connection recovery is complete.

[0187] In embodiments of this application, in response to the second message, the terminal device can send a third message. The third message can be used to indicate that the connection establishment is complete or the connection restoration is complete. Specifically, after completing the inter-frequency handover, the terminal device can send the third message to the first network device in response to a connection rebuild command or connection restoration command, so that the first network device is aware that the connection establishment or connection restoration is complete.

[0188] For example, in some embodiments, the communication method proposed in this application is illustrated by taking the first network (the network of the target RAT) as 6G and the second network (the network of the source RAT) as 5G as an example, but no specific limitation is made on the first network and the second network.

[0189] In the embodiments of this application, when the UE is connected to 5G and in the RRC_INACTIVE state, it can choose to delete the configuration-related information in the 5G AS context and retain at least the third-party information. Here, the AS context can be understood as an AS context conforming to the format requirements corresponding to 5G.

[0190] In embodiments of this application, the UE may choose to delete some information in the 5G AS context. For example, it may delete configuration-related information in the 5G AS context that is unrelated to identity information and retain only the third information related to identity information in the 5G AS context.

[0191] In the embodiments of this application, when the UE has already accessed 5G, the network to be switched to, such as 6G, can be determined by scanning frequency points or receiving a first broadcast message.

[0192] In embodiments of this application, the UE may send first information. The first information includes any one of the following: third information; mapping the third information to an AS context corresponding to a first format of 6G; the first information being carried in a first message, the first message being used to request access to the 6G network.

[0193] In the embodiments of this application, the UE can directly use the third information that meets the signaling format requirements and / or protocol specifications of 5G as the first information without conversion and mapping.

[0194] In embodiments of this application, the UE may also convert and map the third information that meets the signaling format requirements and / or protocol specifications of 5G through predefined rules to obtain the AS context corresponding to the first format of 6G, and use the AS context as the corresponding first information.

[0195] In an embodiment of this application, the UE may send a first message to the 6G network device to request access to the 6G network, the first message carrying first information.

[0196] In embodiments of this application, the UE may receive a second message from a 6G network device.

[0197] In embodiments of this application, the second message is a response message to the first message. For example, the second message may include, but is not limited to, a reconnection command or a connection restoration command, used to instruct the UE to reconnect or restore the connection in response to a reconnection request or a connection restoration request.

[0198] In the embodiments of this application, the 6G network device can be a network device related to a 6G network.

[0199] In embodiments of this application, the second message received by the UE may carry fourth information. This fourth information corresponds to a first format. The first format may be a format determined based on predefined rules, satisfying 6G signaling format requirements and / or protocol specifications.

[0200] In other words, in the embodiments of the application, the UE can receive fourth information corresponding to the first format sent by the first network device; wherein, the fourth information is the 6G AS context of the 6G network device in response to the first message.

[0201] In embodiments of this application, in response to the second message, the UE may send a third message. The third message may be used to indicate that connection establishment is complete or connection restoration is complete.

[0202] In the embodiments of this application, after the UE completes the inter-frequency handover, it can send a third message to the 6G network device in response to the re-establish connection command or the connection restoration command, so that the 6G network device knows that the connection establishment is complete or the connection restoration is complete.

[0203] In some embodiments, for a dual-configuration-based scheme, the AS context corresponding to different networks can be obtained in advance; that is, the AS context of the first network is not obtained by mapping, but is pre-configured.

[0204] In embodiments of this application, the terminal device can determine the access layer context information corresponding to the type of the first network from the first access layer context information and the second access layer context information, based on the type of the first network.

[0205] In embodiments of this application, the type of the first network can be used to indicate and determine the RAT of the first network. Different networks use different RATs, thus corresponding to different network types. For example, 5G and 6G use different RATs, therefore their corresponding types are also different.

[0206] In the embodiments of this application, the first access layer context information can be obtained through the access status of the terminal device to the first network. The first access layer context information can be understood as an AS context conforming to the format requirements of the first network, that is, an AS context in a format usable by the first network.

[0207] It is understood that, in the embodiments of this application, the terminal device can obtain the first access layer context information in advance. For example, the terminal device can obtain the corresponding first access layer context information in advance through a certain access to the first network.

[0208] In the embodiments of this application, the second access layer context information can be obtained through the access status of the second network accessed by the terminal device. The second access layer context information can be understood as an AS context conforming to the format requirements of the second network, that is, an AS context in a format usable by the second network.

[0209] It is understood that, in the embodiments of this application, the terminal device can obtain the second access layer context information in advance. For example, the terminal device can obtain the corresponding second access layer context information in advance by the access status of the second network it accesses.

[0210] Therefore, in the embodiments of this application, the terminal device can pre-configure relevant contexts under different RATs, such as the first access layer context information corresponding to the first network and the second access layer context information corresponding to the second network. Thus, when inter-frequency handover is required, such as switching from the second network to the first network, i.e., switching from the source RAT to the target RAT, the terminal device can directly use the pre-acquired first access layer context information to send first information indicating that first access layer context information.

[0211] It is understood that, in the embodiments of this application, the first information can be used to indicate the identity information of the terminal device included in the first access layer context information, such as the UE's ID information, so that the first network device can determine the identity information of the terminal device after obtaining the first information, and then correctly identify the AS context corresponding to the terminal device based on the identity information of the terminal device. Specifically, the first network device can either directly obtain the AS context corresponding to the terminal device through context mapping processing based on the identity information of the terminal device, or it can obtain the AS context corresponding to the terminal device from the second network device (source RAT) based on the identity information of the terminal device.

[0212] In the embodiments of this application, when the first RAT and the second RAT are different, the first information is the first access layer context information; when the first RAT and the second RAT are the same, the first information is the second access layer context information.

[0213] In other words, in the embodiments of this application, when performing inter-frequency handover, i.e. when the source RAT and the target RAT are different, the first information sent can be the context information corresponding to the target RAT.

[0214] For example, in some embodiments, assuming the first network is 6G and the second network is 5G, during the switching from 5G to 6G, the terminal device can determine the first information based on the 6G context obtained in advance, and then send the first message carrying the first information to the 6G network device.

[0215] For example, in some embodiments, Figure 5 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 5, for a dual-configuration-based scheme, the method for terminal devices to communicate may include the following steps:

[0216] S401. Based on the type of the first network, determine the access layer context information corresponding to the type of the first network from the first access layer context information and the second access layer context information; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0217] In the embodiments of this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, it can first determine the access layer context information corresponding to the type of the first network from the first access layer context information and the second access layer context information according to the type of the first network.

[0218] In the embodiments of this application, the access layer context information corresponding to the type of the first network can be understood as the AS context that conforms to the format requirements of the first network, that is, the AS context in a format that the first network can use.

[0219] In the embodiments of this application, the terminal device can pre-obtain first access layer context information. For example, the terminal device can pre-obtain the corresponding first access layer context information based on the access status of a certain access to the first network. Alternatively, it can pre-obtain second access layer context information. For example, the terminal device can pre-obtain the corresponding second access layer context information based on the access status of the second network it accesses.

[0220] When the first RAT and the second RAT are different, the first information is the first access layer context information; when the first RAT and the second RAT are the same, the first information is the second access layer context information.

[0221] In embodiments of this application, the terminal device can pre-configure relevant contexts under different RATs, such as first access layer context information corresponding to the first network and second access layer context information corresponding to the second network. Thus, when inter-frequency handover is required, such as switching from the second network to the first network, i.e., switching from the source RAT to the target RAT, the terminal device can directly use the pre-acquired first access layer context information to send first information indicating that first access layer context information.

[0222] S402. Send first information, which is carried in a first message. The first message is used to request access to the first network.

[0223] In embodiments of this application, the terminal device may send first information.

[0224] In embodiments of this application, a terminal device may send a first message to a first network device to request access to the first network. The first message carries first information, which is used to indicate first access layer context information to the first network under the first RAT.

[0225] In the embodiments of this application, when the terminal device has been connected to the second network under the second RAT, the first network can be determined by scanning frequency points or receiving the first broadcast message.

[0226] In the embodiments of this application, first information indicating the AS context corresponding to the format of the first network can be determined and sent. Therefore, during the handover between different RATs, the terminal device does not release the AS context, nor does it need to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thus improving communication performance.

[0227] In the embodiments of this application, during the handover process between different RATs, it is only necessary to determine and send the first information indicating the AS context corresponding to the format of the first network. It is not necessary to release and re-establish the AS context related to the second network under the second RAT. Consequently, it is not necessary to re-establish the connection between the core network and the RAN, and the terminal device does not need to fall back to the idle state. For example, while sending the first message to the first network device, the terminal device can resume its inactive state.

[0228] S403, Receive a second message from the first network device; the second message is a response message to the first message; the first network device is a network device related to the first network.

[0229] In embodiments of this application, the terminal device may receive a second message from the first network device.

[0230] In embodiments of this application, the second message is a response message to the first message. For example, the second message may include, but is not limited to, a connection rebuild command or a connection restore command, used to instruct the terminal device to rebuild or restore the connection in response to a connection rebuild request or connection restore request.

[0231] In the embodiments of this application, the first network device may be a network device associated with a first network.

[0232] S304. In response to the second message, a third message is sent; the third message is used to indicate whether the connection establishment is complete or the connection recovery is complete.

[0233] In embodiments of this application, in response to the second message, the terminal device can send a third message. The third message can be used to indicate that the connection establishment is complete or the connection restoration is complete. Specifically, after completing the inter-frequency handover, the terminal device can send the third message to the first network device in response to a connection rebuild command or connection restoration command, so that the first network device is aware that the connection establishment or connection restoration is complete.

[0234] In summary, the communication method proposed in this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, can send first information to indicate the first access layer context information to the first network under the first RAT. This enables the network device to determine the identity information of the terminal device through the first access layer context information, thereby avoiding the re-establishment of AS context and the loss of service-related information during the handover from the second network to the first network, thus reducing signaling overhead and handover latency and improving communication performance.

[0235] In the embodiments of this application, the first information may be obtained by mapping the AS context, such as a scheme based on two-sided context mapping or a scheme based on one-sided context mapping, or it may be obtained by a pre-configured AS context, such as a dual-configuration scheme. This application does not make any specific limitations.

[0236] In other words, the communication method proposed in this application realizes the switching from 5G or 6G to 6G or 5G without losing the AS context by mapping the AS context from the source RAT to the target RAT autonomously or by network control, and restores the RRC_INACTIVE state in the target RAT.

[0237] One embodiment of this application proposes a communication method that can be applied to a first network device. Figure 6 is a schematic diagram of the implementation flow of the communication method provided in this embodiment. As shown in Figure 6, the communication method may include the following steps:

[0238] S501. Receive first information, the first information being used to indicate first access layer context information to the first network under the first RAT; wherein the first information is sent by the terminal device, the terminal device has been connected to the second network under the second RAT, and is in an inactive state.

[0239] In embodiments of this application, the first network device may receive first information sent by the terminal device for instructing the first access layer context information to the first network under the first RAT.

[0240] In the embodiments of this application, the first network device can be a network device related to a first network. For example, assuming the first network is 5G, the first network device can be a network device related to the 5G network; assuming the first network is 6G, the first network device can be a network device related to the 6G network.

[0241] In the embodiments of this application, the first access layer context information can be understood as an AS context that conforms to the format requirements of the first network, that is, an AS context in a format that the first network can use.

[0242] In the embodiments of this application, the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0243] In embodiments of this application, the first network and the second network can be different networks, wherein the first network and the second network can use different RATs. For example, the first network is a network under a first RAT, and the second network is a network under a second RAT, wherein the first RAT and the second RAT are different.

[0244] For example, in some embodiments, the first network may include, but is not limited to, 5G or 6G, and the second network may include, but is not limited to, 5G or 6G. For example, the first network is 5G and the second network is 6G, or the first network is 6G and the second network is 5G.

[0245] In the embodiments of this application, inter-frequency handover can be understood as handover from a source RAT to a target RAT. Specifically, the first RAT corresponding to the first network can be understood as the target RAT in the inter-frequency handover, and the second RAT corresponding to the second network can be understood as the source RAT in the inter-frequency handover.

[0246] In the embodiments of this application, the communication method proposed in this application is illustrated by taking a first network of 6G and a second network of 5G as an example, but no specific limitation is made on the first network and the second network.

[0247] In embodiments of this application, the inactive state can be used to maintain the radio access layer (AS) context between the terminal device and the network device, thereby enabling the terminal device to be quickly reactivated while reducing signaling overhead and battery consumption. The inactive state can be understood as a state between the idle state and the connected state.

[0248] For example, in some embodiments, the inactive state can be the Radio Resource Control inactive state (RRC_INACTIVE). RRC_INACTIVE is between RRC_IDLE (idle state) and RRC_CONNECTED (connected state).

[0249] In embodiments of this application, the first information may be carried in a first message, wherein the first message is used to request access to the first network.

[0250] In other words, in the embodiments of this application, the first network device can receive a first message sent by the terminal device for requesting access to the first network, wherein the first message may carry first information for indicating first access layer context information to the first network under the first RAT.

[0251] In embodiments of this application, the first message used to request access to the first network may include, but is not limited to, RRC connection reconstruction or connection restoration.

[0252] Therefore, in the embodiments of this application, the first network device can receive a first message carrying first information sent by the terminal. This first information is used to indicate first access layer context information to the first network under the first RAT. By receiving the first message indicating the first access layer context information, the first network device can obtain the identity information of the terminal device and / or the configuration information of the terminal device, such as measurement configuration, connection configuration, etc.

[0253] In the embodiments of this application, the first network device can receive first information indicating the AS context corresponding to the format of the first network. Therefore, during the switching process between different RATs, the AS context is not released, nor is it necessary to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thereby improving communication performance.

[0254] Furthermore, in the embodiments of this application, Figure 7 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 7, the communication method may further include the following steps:

[0255] S502, Send a fourth message; the fourth message is a message requesting context information from the second network device; the second network device is a network device related to the second network.

[0256] In the embodiments of this application, after receiving a first message carrying first information sent by a terminal device, the first network device may send a fourth message to the second network device.

[0257] It is understood that, in the embodiments of this application, receiving the first information sent by the terminal device to indicate the first access layer context information to the first network under the first RAT triggers the first network device to request context information from the second network device. That is, after receiving the first message carrying the first information, the first network device will trigger the sending of the fourth message.

[0258] In the embodiments of this application, the fourth message can be used to request context information, that is, the fourth message is a message requesting context information from the second network device.

[0259] In the embodiments of this application, the second network device is a network device related to a second network. For example, assuming the second network is 5G, the second network device can be a network device related to the 5G network; assuming the second network is 6G, the second network device can be a network device related to the 6G network.

[0260] S503, Receive the fifth message in response to the fourth message; the fifth message carries the third access layer context information.

[0261] In embodiments of this application, after sending a fourth message to a second network device, a fifth message sent by the second network device in response to the fourth message can be received.

[0262] In the embodiments of this application, the fifth message carries third access layer context information. This third access layer context information can be used to verify the first message sent by the terminal device.

[0263] In embodiments of this application, the third access layer context information may include one or more of the following: the second access layer context information of the second network; and the first access layer context information of the first network.

[0264] Furthermore, in the embodiments of this application, after sending a fourth message for requesting context information to the second network device, the second network device can directly respond to the fourth message by sending a fifth message carrying third access layer context information, and then the first network device can verify the first information sent by the terminal device based on the third access layer context information carried in the fifth message; alternatively, the second network device can directly perform the verification process based on the fourth message, and send a fifth message carrying third access layer context information to the first network device when the verification result indicates success.

[0265] In other words, in the embodiments of this application, the verification process can be performed by the first network device or by the second network device, and this application does not make any specific limitation.

[0266] It is understood that, in the embodiments of this application, if the verification process is performed by the second network device, then if the verification result obtained after the second network device verification indicates success, the first network device can receive the fifth message carrying the third access layer context information sent by the second network device; if the verification result obtained after the second network device verification indicates failure, the first network device can receive the verification failure message sent by the second network device.

[0267] In other words, in the embodiments of this application, when the second network device performs the verification process, it will send detailed context information (such as third access layer context information) to the first network device only when the second network device checks and confirms that the UE information verification is correct; otherwise, the second network device will respond with failure information.

[0268] Furthermore, in the embodiments of this application, the fourth message sent by the first network device to the second network device may also carry relevant information about the terminal device, such as the first message sent by the terminal device, so that the second network device can perform verification processing based on the relevant information about the terminal device carried in the fourth message after receiving the fourth message.

[0269] In the embodiments of this application, the first access layer context information of the first network can be obtained through the access status of the terminal device to the first network, or it can be determined by mapping the second access layer context information of the second network to a first format through the first network device or the second network device. The first access layer context information can be understood as an AS context that conforms to the format requirements of the first network, that is, an AS context in a format that the first network can use.

[0270] It is understood that, in the embodiments of this application, the first access layer context information may be obtained by the terminal device based on the corresponding access situation when it accesses the first network once.

[0271] It is understood that, in the embodiments of this application, the first access layer context information can also be obtained by mapping the second access layer context information of the second network. Specifically, this can be determined by mapping the second access layer context information of the second network to a first format on the network side. The network side can be a first network device or a second network device; this application does not specifically limit this.

[0272] In the embodiments of this application, the first format can be a format determined based on predefined rules that meets the signaling format requirements and / or protocol specifications of the first network. For example, if the first network is 6G, the first format can be a 6G signaling format.

[0273] S504. Verify the first information based on the third access layer context information and determine the verification result.

[0274] In the embodiments of this application, after receiving the fifth message sent by the second network device that carries the third access layer context information, the first information can be further verified based on the third access layer context information, that is, the first access layer context information indicated by the first information can be verified based on the third access layer context information to obtain the verification result corresponding to the first access layer context information.

[0275] In the embodiments of this application, when verifying the first information based on the third access layer context information, various verifications can be performed on the first access layer context information indicated by the first information, such as integrity, validity, identity of the terminal device, and security credentials of the terminal device.

[0276] In other words, in the embodiments of this application, through the first message sent by the terminal device to indicate the first access layer context information, the first network device can obtain the identity information of the terminal device and / or the configuration information of the terminal device. Thus, it can verify the integrity and / or validity of the first access layer context information sent by the terminal device through the third access layer context information obtained from the second network device, and can also verify the identity and / or security credentials of the terminal device.

[0277] Furthermore, in the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the process of sending the second message to the terminal can be executed.

[0278] Furthermore, in the embodiments of this application, Figure 8 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 8, the communication method may further include the following steps:

[0279] S505, Send a second message to the terminal device; the second message is a response message to the first message.

[0280] In embodiments of this application, after receiving first information from a terminal device that indicates first access layer context information of the first network, the first network device may send a second message to the terminal device.

[0281] In embodiments of this application, the second message may be a response message sent by the first network device that corresponds to the first message.

[0282] In embodiments of this application, the second message may include, but is not limited to, a reconnection command or a connection recovery command, used to instruct the terminal device to reconnect or recover in response to a reconnection request or a connection recovery request.

[0283] It is understood that, in the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the first network device may send a second message to the terminal.

[0284] S506, Receive the third message; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0285] In an embodiment of this application, after the first network device sends a second message to the terminal device, it can receive a third message sent by the terminal device.

[0286] In embodiments of this application, the third message can be used to indicate that the connection establishment is complete or the connection restoration is complete. Specifically, after completing the inter-frequency handover, the terminal device can respond to the connection rebuild command or connection restoration command by sending a third message to the first network device, thereby informing the first network device that the connection establishment or restoration is complete.

[0287] In summary, the communication method proposed in this application, by receiving first information sent by the terminal device to indicate the first access layer context information to the first network under the first RAT, allows the first network device to determine the identity information of the terminal device through the first access layer context information. This avoids the re-establishment of the AS context and the loss of service-related information during the handover from the second network to the first network, thereby reducing signaling overhead and handover latency and improving communication performance.

[0288] Based on the above embodiments, another embodiment of this application proposes a communication method. In the embodiments of this application, the communication method proposed in this application is illustrated by taking a first network of 6G and a second network of 5G as an example.

[0289] The communication method proposed in this application can be a frequency switching method, which can realize frequency switching between 5G and 6G without losing the AS context. This frequency switching method is a method that can restore the RRC_INACTIVE state after switching.

[0290] Furthermore, in the embodiments of this application, the communication method proposed in the embodiments of this application can mainly achieve inter-frequency handover through the following three schemes:

[0291] A. A scheme based on two-sided context mapping.

[0292] B. A scheme based on one-sided context mapping.

[0293] C. A dual-configuration-based solution.

[0294] In some embodiments, for a scheme based on two-sided context mapping, the network side (first network device or second network device) can perform AS context mapping based on predefined rules.

[0295] In embodiments of this application, the first information used to indicate the first access layer context information to the first network under the first RAT can be obtained by mapping the second access layer context information of the second network.

[0296] It is understood that, in the embodiments of this application, the first information can be used to indicate the identity information of the terminal device included in the first access layer context information, such as the UE's ID information, so that the first network device can determine the identity information of the terminal device after obtaining the first information, and then correctly identify the AS context corresponding to the terminal device based on the identity information of the terminal device. Specifically, the first network device can either directly obtain the AS context corresponding to the terminal device through context mapping processing based on the identity information of the terminal device, or it can obtain the AS context corresponding to the terminal device from the second network device (source RAT) based on the identity information of the terminal device.

[0297] In the embodiments of this application, the first information is obtained by mapping the second access layer context information of the second network; the second access layer context information is the context information related to the second network that is retained by the terminal device.

[0298] In the embodiments of this application, the second access layer context information can be understood as an AS context that conforms to the format requirements of the second network, that is, an AS context in a format that the second network can use.

[0299] In the embodiments of this application, the second access layer context information of the second network can be mapped according to predefined rules. The predefined rules can be used to indicate the signaling format requirements and / or protocol specifications corresponding to the first network. Therefore, after mapping the second access layer context information according to the predefined rules, the first access layer context information that conforms to the format requirements of the first network can be obtained.

[0300] In embodiments of this application, when determining the first information, the second information in the second access layer context information corresponding to the second format of the second network can be mapped to the first information in the first access layer context information corresponding to the first format of the first network. The first format can be a format determined based on predefined rules that meets the signaling format requirements and / or protocol specifications of the first network, and the second format can be a format that meets the signaling format requirements and / or protocol specifications of the second network. For example, if the first network is 6G, the first format can be a 6G signaling format; if the second network is 5G, the first format can be a 5G signaling format.

[0301] In an embodiment of this application, when performing context mapping, one implementation method is as follows: the second information in the second item of the second access layer context information corresponding to the second format of the second network can be mapped to the first information in the first item of the first access layer context information corresponding to the first format of the first network; wherein, the second format of the second network contains a second item corresponding to the first item of the first format of the first network, and the second information is the value corresponding to the second item.

[0302] It is understood that, in the embodiments of this application, if the second format of the second network contains a second item corresponding to the first item of the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to the first information in the first item of the first access layer context information. The second information in the second access layer context information can be the value corresponding to the second item.

[0303] In the embodiments of this application, the first or second item may include one or more of the following: corresponding parameters; corresponding information elements; and corresponding fields.

[0304] It is understood that in the embodiments of this application, the first item and the second item are consistent. If the first item is a field in the first format of the first network, then the second item is a corresponding field in the second format of the second network.

[0305] In other words, in the embodiments of this application, when performing context mapping according to predefined rules, if there is a corresponding second item in the second format of the second network for the first item in the first format of the first network, the terminal device can map the value corresponding to the second item in the second format of the second network, i.e., the second information, to obtain the first information in the first item in the first format of the first network.

[0306] For example, in some embodiments, for a first item of content in the first network, such as a parameter / information element / field, if the first item of content has a corresponding parameter / information element / field in the second network, that is, there is a corresponding second item of content, then the terminal device can map the value of the second item of content, that is, the second information, to the corresponding parameter / information element / field in the first network, that is, map to obtain the first information in the first item of content.

[0307] In an embodiment of this application, another method for performing context mapping is to map the second information in the second item of the second access layer context information corresponding to the second format of the second network to predefined information; wherein, the second format of the second network does not contain a second item corresponding to the first item of the first format of the first network.

[0308] It is understood that, in the embodiments of this application, if there is no second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to predefined information to obtain the first information.

[0309] In the embodiments of this application, the first or second item may include one or more of the following: corresponding parameters; corresponding information elements; and corresponding fields.

[0310] In embodiments of this application, the predefined information includes, but is not limited to, one of the following: default value, null value, and invalid value.

[0311] In other words, in the embodiments of this application, when performing context mapping according to predefined rules, if there is no corresponding second item in the second format of the second network for the first item in the first format of the first network, the terminal device can map the second information in the second access layer context information to predefined information to obtain the corresponding first information.

[0312] For example, in some embodiments, for a first item in the first network, such as a parameter / information element / field, if the first item does not have a corresponding parameter / information element / field in the second network, that is, there is no corresponding second item, then the terminal device can map the second information to a predefined value (predefined information), such as a default value, a null value, or an invalid value.

[0313] For example, in some embodiments, FIG9 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in FIG9, for a scheme based on two-sided context mapping, the method for the first network device to communicate may include the following steps:

[0314] S601. Receive first information sent by the terminal device, the first information being used to indicate first access layer context information to the first network under the first RAT.

[0315] In embodiments of this application, the first network device can receive first information sent by the terminal device, used to indicate first access layer context information to the first network under the first RAT. The terminal device is already connected to the second network under the second RAT and is in an inactive state.

[0316] In the embodiments of this application, the first access layer context information can be understood as an AS context that conforms to the format requirements of the first network, that is, an AS context in a format that the first network can use.

[0317] In embodiments of this application, the first information may be carried in a first message, wherein the first message is used to request access to the first network. The first message for requesting access to the first network may include, but is not limited to, RRC connection reconstruction or connection restoration.

[0318] In embodiments of this application, the first information used to indicate the first access layer context information to the first network under the first RAT can be obtained by mapping the second access layer context information of the second network.

[0319] In the embodiments of this application, if there is a second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item in the second access layer context information to the first information in the first item in the first access layer context information; wherein, the second information is the value corresponding to the second item.

[0320] In the embodiments of this application, if there is no second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to predefined information to obtain the first information.

[0321] In the embodiments of this application, the first network device can receive first information indicating the AS context corresponding to the format of the first network. Therefore, during the switching process between different RATs, the AS context is not released, nor is it necessary to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thereby improving communication performance.

[0322] S602, Send a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0323] In the embodiments of this application, after receiving a first message carrying first information sent by a terminal device, the first network device may send a fourth message to the second network device.

[0324] In embodiments of this application, after receiving a first message carrying first information, the first network device triggers the sending of a fourth message. This fourth message can be used to request context information.

[0325] S603, Receive the fifth message in response to the fourth message; the fifth message carries the third access layer context information.

[0326] In embodiments of this application, after sending a fourth message to the second network device, a fifth message in response to the fourth message can be received from the second network device. The third access layer context information can be used to verify the first information sent by the terminal device.

[0327] S604. Verify the first information based on the third access layer context information and determine the verification result.

[0328] In the embodiments of this application, after receiving the fifth message sent by the second network device that carries the third access layer context information, the first access layer context information indicated by the first information can be further verified based on the third access layer context information to obtain the verification result corresponding to the first access layer context information.

[0329] S605. If the verification result indicates success, send a second message to the terminal device.

[0330] In the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the first network device can send a second message to the terminal. The second message can be a response message sent by the first network device corresponding to the first message.

[0331] S606, Receive a third message sent by the terminal device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0332] In embodiments of this application, after sending a second message to a terminal device, the first network device can receive a third message sent by the terminal device. The third message indicates whether the connection establishment or restoration is complete, thereby indicating that the terminal device has completed either connection establishment or restoration.

[0333] In some embodiments, for schemes based on one-sided context mapping, the mapping of AS context is performed on the network side, and the terminal device only needs to obtain the already mapped AS context from the network side.

[0334] In embodiments of this application, the first information may include any of the following: third information; mapping the third information to first access layer context information corresponding to a first format of the first network.

[0335] In other words, in the embodiments of this application, the first information received by the first network device from the terminal device can be determined directly by the terminal device based on the third information in a format that meets the signaling format requirements and / or protocol specifications of the second network, or it can be obtained by the terminal device after converting and mapping the third information in a format that meets the signaling format requirements and / or protocol specifications of the second network through predefined rules.

[0336] In embodiments of this application, the first network device may also send fourth information corresponding to the first format to the terminal device.

[0337] In embodiments of this application, the fourth information may include access layer context information corresponding to the first network.

[0338] In other words, in the embodiments of this application, after receiving the first message sent by the terminal device for requesting access to the first network, a fourth message can also be sent to the terminal device. The fourth message may include access layer context information corresponding to the first network determined by the first network device.

[0339] In the embodiments of this application, the access layer context information corresponding to the first network included in the fourth information can be determined by the first network device. The method by which the first network device determines the access layer context information corresponding to the first network can be obtained by the first network device through conversion and mapping using predefined rules, or it can be obtained by the first network device from the second network device; this application does not impose specific limitations.

[0340] In embodiments of this application, the fourth information can be sent via a second message. That is, the first network device can send a second message to the terminal device. The second message carries the fourth information.

[0341] Therefore, in the embodiments of this application, the mapping of AS context is performed on the network side, that is, it is obtained by the first network device or the second network device according to predefined rules. The terminal device does not perform AS context mapping based on predefined rules, but directly obtains the access layer context information corresponding to the first network that has been mapped from the network side.

[0342] For example, in some embodiments, FIG10 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in FIG10, for a scheme based on two-sided context mapping, the method for the first network device to communicate may include the following steps:

[0343] S701. Receive first information sent by the terminal device, the first information being used to indicate first access layer context information to the first network under the first RAT.

[0344] In embodiments of this application, the first network device can receive first information sent by the terminal device, used to indicate first access layer context information to the first network under the first RAT. The terminal device is already connected to the second network under the second RAT and is in an inactive state.

[0345] In embodiments of this application, the first information may be carried in a first message, wherein the first message is used to request access to the first network. The first message for requesting access to the first network may include, but is not limited to, RRC connection reconstruction or connection restoration.

[0346] In embodiments of this application, the first information may include any of the following: third information; mapping the third information to first access layer context information corresponding to a first format of the first network.

[0347] In other words, in the embodiments of this application, the first information received by the first network device from the terminal device can be determined directly by the terminal device based on the third information in a format that meets the signaling format requirements and / or protocol specifications of the second network, or it can be obtained by the terminal device after converting and mapping the third information in a format that meets the signaling format requirements and / or protocol specifications of the second network through predefined rules.

[0348] S702, Send a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0349] In the embodiments of this application, after receiving a first message carrying first information sent by a terminal device, the first network device may send a fourth message to the second network device.

[0350] S703, Receive the fifth message in response to the fourth message; the fifth message carries the third access layer context information.

[0351] In the embodiments of this application, after sending a fourth message to the second network device, a fifth message in response to the fourth message can be received from the second network device. The third access layer context information can be used to verify the first information sent by the terminal device.

[0352] S704. Verify the first information based on the third access layer context information and determine the verification result.

[0353] In the embodiments of this application, after receiving the fifth message sent by the second network device that carries the third access layer context information, the first access layer context information indicated by the first information can be further verified based on the third access layer context information to obtain the verification result corresponding to the first access layer context information.

[0354] S705. If the verification result is successful, a second message is sent to the terminal device; wherein the second message carries fourth information.

[0355] In the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the first network device can send a second message to the terminal. The second message can be a response message sent by the first network device corresponding to the first message.

[0356] In embodiments of this application, the first network device may further send fourth information corresponding to the first format to the terminal device. This fourth information can be sent via a second message. That is, the first network device can send a second message to the terminal device.

[0357] In embodiments of this application, the fourth information may include access layer context information corresponding to the first network.

[0358] In other words, in the embodiments of this application, after receiving the first message sent by the terminal device for requesting access to the first network, a fourth message can also be sent to the terminal device. The fourth message may include access layer context information corresponding to the first network determined by the first network device.

[0359] In the embodiments of this application, the access layer context information corresponding to the first network included in the fourth information can be determined by the first network device. The method by which the first network device determines the access layer context information corresponding to the first network can be obtained by the first network device through conversion and mapping using predefined rules, or it can be obtained by the first network device from the second network device; this application does not impose specific limitations.

[0360] S706, Receive a third message sent by the terminal device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0361] In embodiments of this application, after sending a second message to a terminal device, the first network device can receive a third message sent by the terminal device. The third message indicates whether the connection establishment or restoration is complete, thereby indicating that the terminal device has completed either connection establishment or restoration.

[0362] In some embodiments, for a dual-configuration-based scheme, the AS context corresponding to different networks can be obtained in advance; that is, the AS context of the first network is not obtained by mapping, but is pre-configured.

[0363] In the embodiments of this application, the first access layer context information can be obtained through the access status of the terminal device to the first network. The first access layer context information can be understood as an AS context conforming to the format requirements of the first network, that is, an AS context in a format usable by the first network.

[0364] It is understood that, in the embodiments of this application, the first access layer context information can be obtained in advance. For example, the corresponding first access layer context information can be obtained in advance through the access situation of a terminal device accessing the first network once.

[0365] In the embodiments of this application, the second access layer context information can be obtained through the access status of the second network accessed by the terminal device. The second access layer context information can be understood as an AS context conforming to the format requirements of the second network, that is, an AS context in a format usable by the second network.

[0366] It is understood that, in the embodiments of this application, the second access layer context information can be obtained in advance. For example, the corresponding second access layer context information can be obtained in advance through the access status of the second network accessed by the terminal device.

[0367] Therefore, in the embodiments of this application, relevant contexts under different RATs can be pre-configured, such as the first access layer context information corresponding to the first network and the second access layer context information corresponding to the second network. Thus, when inter-frequency handover is required, such as switching from the second network to the first network, i.e., switching from the source RAT to the target RAT, the pre-acquired first access layer context information can be directly used to determine the first information used to indicate that first access layer context information.

[0368] In the embodiments of this application, when the first RAT and the second RAT are different, the first information is the first access layer context information; when the first RAT and the second RAT are the same, the first information is the second access layer context information.

[0369] In other words, in the embodiments of this application, when performing inter-frequency handover, i.e. when the source RAT and the target RAT are different, the first information received by the first network device can be the context information corresponding to the target RAT.

[0370] For example, in some embodiments, FIG11 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in FIG11, for a dual-configuration-based scheme, the method for the first network device to communicate may include the following steps:

[0371] S801. Receive first information sent by the terminal device, the first information being used to indicate first access layer context information to the first network under the first RAT.

[0372] In embodiments of this application, the first network device can receive first information sent by the terminal device, used to indicate first access layer context information to the first network under the first RAT. The terminal device is already connected to the second network under the second RAT and is in an inactive state.

[0373] In the embodiments of this application, the first access layer context information can be obtained in advance. For example, the corresponding first access layer context information can be obtained in advance based on the access situation of a certain access to the first network. The second access layer context information can also be obtained in advance. For example, the corresponding second access layer context information can be obtained in advance based on the access situation of the second network accessed.

[0374] When the first RAT and the second RAT are different, the first information is the first access layer context information; when the first RAT and the second RAT are the same, the first information is the second access layer context information.

[0375] In the embodiments of this application, the first network device can receive first information indicating the AS context corresponding to the format of the first network. Therefore, during the switching process between different RATs, the AS context is not released, nor is it necessary to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thereby improving communication performance.

[0376] S802, Send a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0377] In the embodiments of this application, after receiving a first message carrying first information sent by a terminal device, the first network device may send a fourth message to the second network device.

[0378] In embodiments of this application, after receiving a first message carrying first information, the first network device triggers the sending of a fourth message. This fourth message can be used to request context information.

[0379] S803, Receive the fifth message in response to the fourth message; the fifth message carries the third access layer context information.

[0380] In the embodiments of this application, after sending a fourth message to the second network device, a fifth message in response to the fourth message can be received from the second network device. The third access layer context information can be used to verify the first information sent by the terminal device.

[0381] S804. Verify the first information based on the third access layer context information and determine the verification result.

[0382] In the embodiments of this application, after receiving the fifth message sent by the second network device that carries the third access layer context information, the first access layer context information indicated by the first information can be further verified based on the third access layer context information to obtain the verification result corresponding to the first access layer context information.

[0383] S805. If the verification result indicates success, send a second message to the terminal device.

[0384] In the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the first network device can send a second message to the terminal. The second message can be a response message sent by the first network device corresponding to the first message.

[0385] S806, Receive a third message sent by the terminal device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0386] In embodiments of this application, after sending a second message to a terminal device, the first network device can receive a third message sent by the terminal device. The third message indicates whether the connection establishment or restoration is complete, thereby indicating that the terminal device has completed either connection establishment or restoration.

[0387] In summary, the communication method proposed in this application, by receiving first information sent by the terminal device to indicate the first access layer context information to the first network under the first RAT, allows the first network device to determine the identity information of the terminal device through the first access layer context information. This avoids the re-establishment of the AS context and the loss of service-related information during the handover from the second network to the first network, thereby reducing signaling overhead and handover latency and improving communication performance.

[0388] In the embodiments of this application, the first information may be obtained by mapping the AS context, such as a scheme based on two-sided context mapping or a scheme based on one-sided context mapping, or it may be obtained by a pre-configured AS context, such as a dual-configuration scheme. This application does not make any specific limitations.

[0389] In other words, the communication method proposed in this application realizes the switching from 5G or 6G to 6G or 5G without losing the AS context by mapping the AS context from the source RAT to the target RAT autonomously or by network control, and restores the RRC_INACTIVE state in the target RAT.

[0390] Based on the above embodiments, another embodiment of this application proposes a communication method, which can be applied to a terminal device and a first network device. Figure 12 is a schematic diagram of the implementation flow of the communication method provided in the embodiment of this application. As shown in Figure 12, the communication method may include the following steps:

[0391] S901, The terminal device sends a first message to the first network device. The first message carries first information, which is used to indicate the first access layer context information to the first network under the first RAT. The terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0392] In embodiments of this application, when a terminal device is connected to a second network under a second RAT and is in an inactive state, it can send first information to a first network device to indicate first access layer context information to the first network under the first RAT. The first network device can be a network device associated with the first network.

[0393] In embodiments of this application, the first information may be carried in a first message, wherein the first message is used to request access to the first network.

[0394] S902, the first network device sends a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0395] In embodiments of this application, after receiving a first message carrying first information from a terminal device, the first network device may send a fourth message to the second network device. The second network device is a network device associated with a second network.

[0396] In the embodiments of this application, the fourth message can be used to request context information, that is, the fourth message is a message requesting context information from the second network device.

[0397] S903, the first network device receives a fifth message in response to the fourth message; the fifth message carries third access layer context information.

[0398] In embodiments of this application, after sending a fourth message to a second network device, a fifth message sent by the second network device in response to the fourth message can be received.

[0399] In the embodiments of this application, the fifth message carries third access layer context information. This third access layer context information can be used to verify the first message sent by the terminal device.

[0400] S904. The first network device verifies the first information based on the third access layer context information and determines the verification result.

[0401] In the embodiments of this application, after receiving the fifth message sent by the second network device that carries the third access layer context information, the first information can be further verified based on the third access layer context information, that is, the first access layer context information indicated by the first information can be verified based on the third access layer context information to obtain the verification result corresponding to the first access layer context information.

[0402] S905. If the verification result indicates success, the first network device sends a second message to the terminal device; the second message is a response message to the first message.

[0403] In the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the first network device can send a second message to the terminal.

[0404] In embodiments of this application, the second message can be a response message sent by the first network device corresponding to the first message. The second message may include, but is not limited to, a connection rebuild command or a connection restoration command, used to instruct the terminal device to rebuild or restore the connection in response to a connection rebuild request or connection restoration request.

[0405] S906. In response to the second message, the terminal device sends a third message to the first network device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0406] In embodiments of this application, after receiving a second message from the first network device, the terminal device may, in response to the second message, send a third message to the first network device. The third message may be used to indicate that the connection establishment is complete or the connection restoration is complete.

[0407] Furthermore, in the embodiments of this application, Figure 13 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in Figure 13, the communication method may include the following steps:

[0408] S901, The terminal device sends a first message to the first network device. The first message carries first information, which is used to indicate the first access layer context information to the first network under the first RAT. The terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0409] S907, The first network device sends a fourth message to the second network device; the fourth message carries relevant information about the terminal device so that the second network device can perform verification processing.

[0410] In the embodiments of this application, the fourth message sent by the first network device to the second network device may also carry relevant information about the terminal device, such as the first message sent by the terminal device, so that the second network device can perform verification processing based on the relevant information about the terminal device carried in the fourth message after receiving the fourth message.

[0411] S908. If the verification result obtained after the second network device verification indicates success, the first network device receives a fifth message in response to the fourth message; the fifth message carries the third access layer context information.

[0412] In the embodiments of this application, if the verification process is performed by the second network device, then if the verification result obtained after the second network device verification indicates success, the first network device can receive a fifth message carrying third access layer context information sent by the second network device; if the verification result obtained after the second network device verification indicates failure, the first network device can receive a verification failure message sent by the second network device.

[0413] In other words, in the embodiments of this application, when the second network device performs the verification process, it will only send detailed context information (such as third access layer context information) to the first network device when the second network device checks and confirms that the UE information is correct; otherwise, the second network device will only respond with failure information.

[0414] S909, The first network device sends a second message to the terminal device; the second message is a response message to the first message.

[0415] In the embodiments of this application, after verifying the first information based on the third access layer context information, if the verification result indicates success, the first network device can send a second message to the terminal.

[0416] In embodiments of this application, the second message can be a response message sent by the first network device corresponding to the first message. The second message may include, but is not limited to, a connection rebuild command or a connection restoration command, used to instruct the terminal device to rebuild or restore the connection in response to a connection rebuild request or connection restoration request.

[0417] S906. In response to the second message, the terminal device sends a third message to the first network device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0418] In some embodiments, for a scheme based on two-sided context mapping, the terminal device and the network side (first network device or second network device) can perform AS context mapping based on predefined rules.

[0419] For example, in some embodiments, FIG14 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in FIG14, the communication method may include the following steps:

[0420] S1001, The terminal device determines the first access layer context information of the first network.

[0421] In the embodiments of this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, it can first determine the first access layer context information. The first access layer context information can be understood as an AS context that conforms to the format requirements of the first network, i.e., an AS context in a format usable by the first network.

[0422] S1002, The terminal device sends a first message to the first network device. The first message carries first information, which is used to indicate the first access layer context information to the first network under the first RAT.

[0423] In embodiments of this application, the first information used to indicate the first access layer context information to the first network under the first RAT can be obtained by mapping the second access layer context information of the second network. The second access layer context information is context information related to the second network that is retained by the terminal device.

[0424] In the embodiments of this application, the terminal device can map the second access layer context information of the second network according to predefined rules to obtain the first access layer context information that conforms to the format requirements of the first network.

[0425] In the embodiments of this application, when determining the first information, the second information in the second access layer context information corresponding to the second format of the second network can be mapped to the first information in the first access layer context information corresponding to the first format of the first network.

[0426] In the embodiments of this application, if there is a second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item in the second access layer context information to the first information in the first item in the first access layer context information; wherein, the second information is the value corresponding to the second item.

[0427] In the embodiments of this application, if there is no second item in the second format of the second network that corresponds to the first item in the first format of the first network, then the terminal device can map the second information in the second item of the second access layer context information to predefined information to obtain the first information.

[0428] In the embodiments of this application, first information indicating the AS context corresponding to the format of the first network can be determined and sent. Therefore, during the handover between different RATs, the terminal device does not release the AS context, nor does it need to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thus improving communication performance.

[0429] In the embodiments of this application, during the handover process between different RATs, it is only necessary to determine and send the first information indicating the AS context corresponding to the format of the first network. It is not necessary to release and re-establish the AS context related to the second network under the second RAT. Consequently, it is not necessary to re-establish the connection between the core network and the RAN, and the terminal device does not need to fall back to the idle state. For example, while sending the first message to the first network device, the terminal device can resume its inactive state.

[0430] S1003, the first network device sends a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0431] S1004, the first network device receives a fifth message in response to the fourth message; the fifth message carries third access layer context information.

[0432] S1005. The first network device verifies the first information based on the third access layer context information and determines the verification result.

[0433] S1006. If the verification result indicates success, the first network device sends a second message to the terminal device; the second message is a response message to the first message.

[0434] S1007. In response to the second message, the terminal device sends a third message to the first network device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0435] In some embodiments, for schemes based on one-sided context mapping, the mapping of AS context is performed on the network side, and the terminal device only needs to obtain the already mapped AS context from the network side.

[0436] For example, in some embodiments, FIG15 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in FIG15, the communication method may include the following steps:

[0437] S1101. In cases where the first RAT differs from the second RAT, the terminal device deletes some configuration-related information from the second access layer context information of the second network, while retaining at least the third information, which is related to the identity information.

[0438] In embodiments of this application, when a second network under a second RAT is connected and is inactive, if the first RAT corresponding to the first network is different from the second RAT corresponding to the second network, the terminal device may choose to delete some configuration-related information in the second access layer context information of the second network, and retain at least the third information. The second access layer context information can be understood as an AS context conforming to the format requirements of the second network.

[0439] In embodiments of this application, the terminal device may choose to delete some information in the second access layer context information of the second network. For example, it may delete some configuration-related information in the second access layer context information that is unrelated to identity information, and retain the third information in the second access layer context information that is related to identity information.

[0440] S1102. The terminal device sends a first message to the first network device. The first message carries first information, which is used to indicate the first access layer context information to the first network under the first RAT.

[0441] In embodiments of this application, the terminal device may send first information. The first information includes any one of the following: third information; and first access layer context information mapped to a first format corresponding to the first network.

[0442] In the embodiments of this application, the first information is carried in the first message, which is used to request access to the first network.

[0443] In the embodiments of this application, the terminal device can directly use the third information that meets the signaling format requirements and / or protocol specifications of the second network as the first information, without performing conversion and mapping.

[0444] In embodiments of this application, the terminal device may also convert and map the third information that meets the signaling format requirements and / or protocol specifications of the second network through predefined rules to obtain the first access layer context information corresponding to the first format of the first network, and use the first access layer context information as the corresponding first information.

[0445] In embodiments of this application, a terminal device may send a first message to a first network device to request access to the first network, the first message carrying first information.

[0446] In the embodiments of this application, first information indicating the AS context corresponding to the format of the first network can be determined and sent. Therefore, during the handover between different RATs, the terminal device does not release the AS context, nor does it need to re-establish the AS context, which reduces signaling overhead and battery consumption to a certain extent. At the same time, it can also avoid the loss of some service-related information such as measurement configuration and connection configuration, thus improving communication performance.

[0447] In the embodiments of this application, during the handover process between different RATs, it is only necessary to determine and send the first information indicating the AS context corresponding to the format of the first network. It is not necessary to release and re-establish the AS context related to the second network under the second RAT. Consequently, it is not necessary to re-establish the connection between the core network and the RAN, and the terminal device does not need to fall back to the idle state. For example, while sending the first message to the first network device, the terminal device can resume its inactive state.

[0448] S1103, The first network device sends a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0449] S1104, the first network device receives a fifth message in response to the fourth message; the fifth message carries third access layer context information.

[0450] S1105. The first network device verifies the first information based on the third access layer context information and determines the verification result.

[0451] S1106. If the verification result indicates success, the first network device sends a second message to the terminal device; the second message is a response message to the first message and carries fourth information.

[0452] In embodiments of this application, the second message may carry fourth information. This fourth information corresponds to the first format. The first format may be a format determined based on predefined rules, satisfying the signaling format requirements and / or protocol specifications of the first network.

[0453] In other words, in the embodiments of the application, the first network device can send fourth information corresponding to the first format to the terminal device; wherein, the fourth information includes access layer context information corresponding to the first network.

[0454] S1107. In response to the second message, the terminal device sends a third message to the first network device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0455] In some embodiments, for a dual-configuration-based scheme, the AS context corresponding to different networks can be obtained in advance; that is, the AS context of the first network is not obtained by mapping, but is pre-configured.

[0456] For example, in some embodiments, FIG16 is a schematic diagram of the implementation flow of the communication method provided in the embodiments of this application. As shown in FIG16, the communication method may include the following steps:

[0457] S1201. The terminal device determines the access layer context information corresponding to the type of the first network from the first access layer context information and the second access layer context information, based on the type of the first network; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0458] In the embodiments of this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, it can first determine the access layer context information corresponding to the type of the first network from the first access layer context information and the second access layer context information according to the type of the first network.

[0459] In the embodiments of this application, the terminal device can pre-obtain first access layer context information. For example, the terminal device can pre-obtain the corresponding first access layer context information based on the access status of a certain access to the first network. Alternatively, it can pre-obtain second access layer context information. For example, the terminal device can pre-obtain the corresponding second access layer context information based on the access status of the second network it accesses.

[0460] When the first RAT and the second RAT are different, the first information is the first access layer context information; when the first RAT and the second RAT are the same, the first information is the second access layer context information.

[0461] S1202, The terminal device sends a first message to the first network device. The first message carries first information, which is used to indicate the first access layer context information to the first network under the first RAT.

[0462] S1203, the first network device sends a fourth message to the second network device; the fourth message is a message requesting context information from the second network device.

[0463] S1204, the first network device receives a fifth message in response to the fourth message; the fifth message carries third access layer context information.

[0464] S1205. The first network device verifies the first information based on the third access layer context information and determines the verification result.

[0465] S1206. If the verification result indicates success, the first network device sends a second message to the terminal device; the second message is a response message to the first message.

[0466] S1207. In response to the second message, the terminal device sends a third message to the first network device; the third message is used to indicate that the connection establishment is complete or the connection restoration is complete.

[0467] In summary, the communication method proposed in this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, can send first information to indicate the first access layer context information to the first network under the first RAT. By receiving the first information, the first network device can determine the identity information of the terminal device through the first access layer context information. This avoids the re-establishment of AS context and the loss of service-related information during the handover from the second network to the first network, thereby reducing signaling overhead and handover latency and improving communication performance.

[0468] In the embodiments of this application, the first information may be obtained by mapping the AS context, such as a scheme based on two-sided context mapping or a scheme based on one-sided context mapping, or it may be obtained by a pre-configured AS context, such as a dual-configuration scheme. This application does not make any specific limitations.

[0469] In other words, the communication method proposed in this application realizes the switching from 5G or 6G to 6G or 5G without losing the AS context by mapping the AS context from the source RAT to the target RAT autonomously or by network control, and restores the RRC_INACTIVE state in the target RAT.

[0470] Based on the above embodiments, another embodiment of this application proposes a communication method. In the embodiments of this application, the communication method proposed in this application is illustrated by taking a first network of 6G and a second network of 5G as an example.

[0471] The communication method proposed in this application can be a frequency switching method, which can realize frequency switching between 5G and 6G without losing the AS context. This frequency switching method is a method that can restore the RRC_INACTIVE state after switching.

[0472] Furthermore, in the embodiments of this application, the communication method proposed in the embodiments of this application can mainly achieve inter-frequency handover through the following three schemes:

[0473] A. A scheme based on two-sided context mapping.

[0474] B. A scheme based on one-sided context mapping.

[0475] C. A dual-configuration-based solution.

[0476] Furthermore, in the embodiments of this application, for the scheme based on dual-side context mapping, context mapping is performed on both the UE side and the network side.

[0477] In the embodiments of this application, on the UE side, the UE autonomously maps the AS context from 5G to 6G without the assistance of the network. For example, when the UE switches from 5G to 6G, the UE will convert the 5G AS context into a format that can be used by 6G according to predefined rules and store it locally.

[0478] In the embodiments of this application, the UE will actively or passively select a 6G cell and send an access request to it, along with its pre-mapped 6G AS context. The 6G network node will verify the UE's AS context and allow the UE to resume the RRC_INACTIVE state in 6G.

[0479] In the embodiments of this application, on the network side, when the UE switches from 5G to 6G, the 5G-AMF forwards the UE's AS context to the 6G network node, such as the 6G-AMF (Access and Mobility Management Function, AMF). Then, the 6G-AMF maps the AS context to a format that can be used by 6G according to the protocol specifications of 5G and 6G.

[0480] For example, in some embodiments, Figure 17 is a schematic diagram of an inter-frequency handover method provided in the embodiments of this application. As shown in Figure 17, during the handover from the source RAT to the target RAT, the UE (terminal device) and the network nodes (the target network node of the target RAT, such as the first network device NW1, and the source network node of the source RAT, such as the second network device NW2) can respectively perform the following interactive processes:

[0481] 1. When the UE is in the Radio Resource Control (RRC) inactive state (RRC_INACTIVE) in 5G or 6G, it retains a portion of the AS context, which is defined based on RAT1 (source RAT).

[0482] 2. The UE detects a second network, that is, it detects the signal of the target RAT (RAT2), for example, by scanning frequency points or receiving broadcast information.

[0483] 3. The UE performs AS context mapping according to predefined rules, mapping the AS context from the source RAT to the target RAT. These predefined rules may include, but are not limited to:

[0484] (1) For a certain parameter / information element / field in the source RAT, if it has a corresponding parameter / information element / field in the target RAT, then the UE maps its value to the corresponding parameter / information element / field in the target RAT.

[0485] (2) For a parameter / information element / field in the source RAT, if there is no corresponding parameter / information element / field in the target RAT, then the UE sets its value to a predefined value, such as a default value, a null value, or an invalid value.

[0486] 4. The UE uses the mapped AS context to send a connection establishment request (RRC resume request) in the target RAT and restores the RRC_INACTIVE state.

[0487] 5. The network node of the target RAT obtains the UE context from the source network node. The source network node or the target network node translates the AS context of the source RAT into the context of the target RAT, and performs AS context retrieval and mapping, that is, maps the AS context from the source RAT to the target RAT.

[0488] 6. The network node of the target RAT sends a connection resume command (RRC resume) to the UE.

[0489] 7. The UE sends a Resume Complete (RRC) signal to the network node of the target RAT.

[0490] Therefore, in the embodiments of this application, the UE side and the network side can perform context mapping to map the AS context from the source RAT to the target RAT, thereby enabling inter-frequency handover without losing the AS context, and allowing the UE to restore the RRC_INACTIVE state in the target RAT.

[0491] Furthermore, in the embodiments of this application, for a scheme based on one-sided context mapping, the UE side may choose not to perform context mapping, while the network side may perform context mapping.

[0492] In the embodiments of this application, on the network side, when the UE switches from 5G to 6G, the 5G-AMF forwards the UE's AS context to the 6G network node, such as the 6G-AMF. Then, the 6G-AMF maps the AS context to a format that can be used by 6G according to the protocol specifications of 5G and 6G, and optionally sends it to the UE via signaling, enabling the UE to resume the RRC_INACTIVE state in 6G.

[0493] For example, in some embodiments, Figure 18 is a schematic diagram of the inter-frequency handover method provided in the embodiments of this application. As shown in Figure 18, during the handover from the source RAT to the target RAT, the UE (terminal device) and the network nodes (the target network node of the target RAT, such as the first network device NW1, and the source network node of the source RAT, such as the second network device NW2) can respectively perform the following interactive processes:

[0494] 1. When the UE is in the Radio Resource Control (RRC) inactive state (RRC_INACTIVE) in 5G or 6G, it retains a portion of the AS context, which is defined based on RAT1 (source RAT).

[0495] 2. The UE detects a second network, that is, it detects the signal of the target RAT (RAT2), for example, by scanning frequency points or receiving broadcast information.

[0496] 3. The UE performs AS context deletion, which deletes a portion of the retained context based on the type of the target RAT, where the target RAT is different from the source RAT.

[0497] 4. The UE uses the remaining relevant information from the source RAT (such as cell ID, UE ID, MAC-I) to send a connection establishment request (RRC resume request) in the target RAT and restores the RRC_INACTIVE state. This connection request can be defined in the source RAT format, i.e., without context mapping; or it can be defined in the target RAT format, i.e., with context mapping performed.

[0498] 5. The network node of the target RAT obtains the UE context from the source network node. The source network node or the target network node translates the AS context of the source RAT into the context of the target RAT, and performs AS context retrieval and mapping, that is, maps the AS context from the source RAT to the target RAT.

[0499] 6. The network node of the target RAT sends a connection resume command (RRC resume) to the UE, and sends the relevant configuration under the target RAT to the UE.

[0500] 7. The UE sends a Resume Complete (RRC) signal to the network node of the target RAT.

[0501] Therefore, in the embodiments of this application, the network side can perform context mapping to map the AS context from the source RAT to the target RAT, and send the AS context of the target RAT after mapping to the UE, so that inter-frequency handover can be completed without losing the AS context, and the UE can restore the RRC_INACTIVE state in the target RAT.

[0502] Furthermore, in the embodiments of this application, for the dual-configuration scheme, the UE side can choose to obtain the AS context defined based on the source RAT and the AS context defined based on the target RAT in advance. The network side can choose to obtain both AS contexts including the source RAT and the target RAT, or it can only obtain the AS context of the target RAT.

[0503] In the embodiments of this application, on the UE side, the UE obtains the relevant context under both RATs in advance. For example, when the UE switches from 5G to 6G, the UE will obtain the context that can be used by 6G from the network in advance and store it locally.

[0504] In the embodiments of this application, the UE will actively or passively select a 6G cell and send an access request to it, along with its stored 6G AS context. The 6G network node will verify the UE's AS context and allow the UE to resume the RRC_INACTIVE state in 6G.

[0505] In the embodiments of this application, on the network side, when the UE switches from 5G to 6G, the 5G-AMF will forward the UE's 6G-AS context to the 6G network node, such as the 6G-AMF, so that the UE can restore the RRC_INACTIVE state in 6G.

[0506] For example, in some embodiments, Figure 19 is a schematic diagram of the inter-frequency handover method provided in the embodiments of this application. As shown in Figure 19, during the handover from the source RAT to the target RAT, the UE (terminal device) and the network nodes (the target network node of the target RAT, such as the first network device NW1, and the source network node of the source RAT, such as the second network device NW2) can respectively perform the following interactive processes:

[0507] 1. When the UE is in the Radio Resource Control (RRC) inactive state (RRC_INACTIVE) in 5G or 6G, it retains a portion of the AS context, which is defined based on RAT1 (source RAT).

[0508] 2. The UE detects a second network, that is, it detects the signal of the target RAT (RAT2), for example, by scanning frequency points or receiving broadcast information.

[0509] 3. The UE performs AS context switching, switching the context to the target RAT's context based on the target RAT's type (AS context switching).

[0510] 4. The UE uses the AS context after the handover to send a connection establishment request (RRC resume request) in the target RAT and restores the RRC_INACTIVE state.

[0511] 5. The target RAT's network node obtains the UE context from the source network node. The obtained AS context can include the following two cases:

[0512] (1) Obtain the AS context of the source RAT and the AS context of the target RAT;

[0513] (2) Only obtain the AS context of the target RAT.

[0514] 6. The network node of the target RAT sends a connection resumption command (RRC resume) to the UE;

[0515] 7. The UE sends a Resume Complete (RRC) signal to the network node of the target RAT.

[0516] Therefore, in the embodiments of this application, the two AS contexts of the source RAT and the target RAT can be obtained in advance, so that inter-frequency handover can be completed without losing the AS context, and the UE can restore the RRC_INACTIVE state in the target RAT.

[0517] In summary, the communication method proposed in this application, when the terminal device is connected to the second network under the second RAT and is in an inactive state, can send first information to indicate the first access layer context information to the first network under the first RAT. By receiving the first information, the first network device can determine the identity information of the terminal device through the first access layer context information. This avoids the re-establishment of AS context and the loss of service-related information during the handover from the second network to the first network, thereby reducing signaling overhead and handover latency and improving communication performance.

[0518] In the embodiments of this application, the first information may be obtained by mapping the AS context, such as a scheme based on two-sided context mapping or a scheme based on one-sided context mapping, or it may be obtained by a pre-configured AS context, such as a dual-configuration scheme. This application does not make any specific limitations.

[0519] In other words, the communication method proposed in this application realizes the switching from 5G or 6G to 6G or 5G without losing the AS context by mapping the AS context from the source RAT to the target RAT autonomously or by network control, and restores the RRC_INACTIVE state in the target RAT.

[0520] The preferred embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the specific details of the above embodiments. Within the scope of the technical concept of this application, various simple modifications can be made to the technical solutions of this application, and these simple modifications all fall within the protection scope of this application. For example, the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, this application will not describe the various possible combinations separately. Furthermore, various different embodiments of this application can also be arbitrarily combined, as long as they do not violate the spirit of this application, they should also be considered as the content disclosed in this application. Moreover, without conflict, the various embodiments and / or the technical features in the various embodiments described in this application can be arbitrarily combined with the prior art, and the resulting technical solutions should also fall within the protection scope of this application.

[0521] It should also be understood that in the various method embodiments of this application, the sequence number of each process does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application. Furthermore, in the embodiments of this application, the terms "downlink," "uplink," and "sidelink" are used to indicate the transmission direction of signals or data. "Downlink" indicates that the transmission direction of signals or data is a first direction from the site to the user equipment in the cell; "uplink" indicates that the transmission direction of signals or data is a second direction from the user equipment in the cell to the site; and "sidelink" indicates that the transmission direction of signals or data is a third direction from user equipment 1 to user equipment 2. For example, "downlink signal" indicates that the transmission direction of the signal is the first direction. Additionally, in the embodiments of this application, the term "and / or" is merely a description of the association relationship between related objects, indicating that three relationships can exist. Specifically, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Furthermore, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0522] Figure 20 is a schematic diagram of the structure of a communication device provided in an embodiment of this application, applied to a terminal device. As shown in Figure 20, the communication device 200 includes:

[0523] The sending unit 2001 is used to send first information, which is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

[0524] Figure 21 is a schematic diagram of the structure of a communication device provided in an embodiment of this application, applied to a first network device. As shown in Figure 21, the communication device 210 includes:

[0525] The receiving unit 2101 is configured to receive first information, which is used to indicate first access layer context information to the first network under the first RAT.

[0526] The first information is sent by the terminal device, which has been connected to the second network under the second RAT and is in an inactive state.

[0527] Those skilled in the art should understand that the description of the communication device in the embodiments of this application can be understood with reference to the description of the communication method in the embodiments of this application.

[0528] Figure 22 is a schematic structural diagram of a terminal device provided in an embodiment of this application. The terminal device 220 shown in Figure 22 includes a processor 2201. The processor 2201 can call and run computer programs from the memory to implement the methods in the embodiments of this application.

[0529] Optionally, as shown in FIG22, the terminal device 220 may further include a memory 2202. The processor 2201 can retrieve and run computer programs from the memory 2202 to implement the methods in the embodiments of this application.

[0530] The memory 2202 can be a separate device independent of the processor 2201, or it can be integrated into the processor 2201.

[0531] Optionally, as shown in FIG22, the terminal device 220 may further include a transceiver 2203, and the processor 2201 may control the transceiver 2203 to communicate with other devices. Specifically, it may send information or data to other devices or receive information or data sent by other devices.

[0532] The transceiver 2203 may include a transmitter and a receiver. The transceiver 2203 may further include an antenna, and the number of antennas may be one or more.

[0533] The terminal device 220 may specifically be the terminal in the embodiments of this application, and the terminal device 220 may implement the corresponding processes implemented by the terminal in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0534] Figure 23 is a schematic structural diagram of a first network device provided in an embodiment of this application. The first network device 230 shown in Figure 23 includes a processor 2301. The processor 2301 can call and run computer programs from memory to implement the methods in the embodiments of this application.

[0535] Optionally, as shown in FIG23, the first network device 230 may further include a memory 2302. The processor 2301 may retrieve and run computer programs from the memory 2302 to implement the methods in the embodiments of this application.

[0536] The memory 2302 can be a separate device independent of the processor 2301, or it can be integrated into the processor 2301.

[0537] Optionally, as shown in FIG23, the first network device 230 may further include a transceiver 2303, and the processor 2301 may control the transceiver 2303 to communicate with other devices. Specifically, it may send information or data to other devices or receive information or data sent by other devices.

[0538] The transceiver 2303 may include a transmitter and a receiver. The transceiver 2303 may further include an antenna, and the number of antennas may be one or more.

[0539] The first network device 230 may specifically be a terminal in the embodiments of this application, and the first network device 230 may implement the corresponding processes implemented by the terminal in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0540] Figure 24 is a schematic structural diagram of a chip provided in an embodiment of this application. The chip 240 shown in Figure 24 includes a processor 2401, which can call and run computer programs from memory to implement the methods in the embodiments of this application.

[0541] Optionally, as shown in FIG24, chip 240 may further include memory 2402. Processor 2401 can retrieve and run computer programs from memory 2402 to implement the methods in the embodiments of this application.

[0542] The memory 2402 can be a separate device independent of the processor 2401, or it can be integrated into the processor 2401.

[0543] Optionally, the chip 240 may also include an input interface 2403. The processor 2401 can control the input interface 2403 to communicate with other devices or chips; specifically, it can acquire information or data sent by other devices or chips.

[0544] Optionally, the chip 240 may also include an output interface 2404. The processor 2401 can control the output interface 2404 to communicate with other devices or chips, specifically, to output information or data to other devices or chips.

[0545] This chip can be applied to the terminal in the embodiments of this application, and the chip can implement the corresponding processes implemented by the terminal in the various methods of the embodiments of this application. For the sake of brevity, it will not be described in detail here.

[0546] It should be understood that the chip mentioned in the embodiments of this application may also be referred to as a system-on-a-chip, system chip, chip system, or system-on-a-chip, etc.

[0547] It should be understood that the processor in the embodiments of this application may be an integrated circuit chip with signal processing capabilities. In implementation, the steps of the above method embodiments can be completed by integrated logic circuits in the processor's hardware or by instructions in software form. The processor described above can be a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly embodied in the execution of a hardware decoding processor, or executed by a combination of hardware and software modules in the decoding processor. The software modules can be located in random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, registers, or other mature storage media in the art. The storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps of the above method.

[0548] It is understood that the memory in the embodiments of this application can be volatile memory or non-volatile memory, or may include both volatile and non-volatile memory. The non-volatile memory can be read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), or flash memory. The volatile memory can be random access memory (RAM), which is used as an external cache. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), Dynamic Random Access Memory (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous DRAM (ESDRAM), Synchlink DRAM (SLDRAM), and Direct Rambus RAM (DR RAM). It should be noted that the memory used in the systems and methods described herein is intended to include, but is not limited to, these and any other suitable types of memory.

[0549] It should be understood that the above-described memory is exemplary and not a limiting description. For example, the memory in the embodiments of this application may also be static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDRAM), enhanced synchronous dynamic random access memory (ESDRAM), synchronous link dynamic random access memory (SLDRAM), and direct memory bus RAM (DR RAM), etc. That is to say, the memory in the embodiments of this application is intended to include, but is not limited to, these and any other suitable types of memory.

[0550] This application also provides a computer-readable storage medium for storing a computer program. This computer-readable storage medium can be applied to the terminal in this application embodiment, and the computer program causes the computer to execute the corresponding processes implemented by the terminal in the various methods of this application embodiment; for brevity, further details are omitted here.

[0551] This application also provides a computer program product, including computer program instructions. This computer program product can be applied to the terminal in this application embodiment, and the computer program instructions cause the computer to execute the corresponding processes implemented by the terminal in the various methods of this application embodiment; for brevity, further details are omitted here.

[0552] This application also provides a computer program. This computer program can be applied to the terminal in this application's embodiments. When the computer program runs on a computer, it causes the computer to execute the corresponding processes implemented by the terminal in the various methods of this application's embodiments. For simplicity, these will not be elaborated further here.

[0553] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0554] Those skilled in the art will understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0555] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0556] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0557] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0558] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0559] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A communication method applied to a terminal device, the method comprising: Send first information, which is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

2. The method according to claim 1, wherein, The first information is carried in the first message, which is used to request access to the first network.

3. The method according to claim 1 or 2, wherein, The method further includes: The first network is determined by scanning frequency points or receiving the first broadcast message.

4. The method according to any one of claims 1 to 3, wherein, The first information is obtained by mapping the second access layer context information of the second network; the second access layer context information is the context information related to the second network that is retained by the terminal device.

5. The method according to claim 4, wherein, The first information is obtained by mapping the second information in the second access layer context information of the second network to the first access layer context information corresponding to the first format of the first network.

6. The method according to claim 4 or 5, wherein, The first information is obtained by mapping the second information in the second access layer context information to the first item of the first network; wherein, The second format of the second network contains a second item that corresponds to the first item in the first format of the first network, and the second information is the value corresponding to the second item.

7. The method according to claim 4 or 5, wherein, The first information is obtained by mapping the second information in the second access layer context information to predefined information; wherein, The second format of the second network does not contain the second item content that corresponds to the first item content of the first format of the first network.

8. The method according to claim 6 or 7, wherein, The first item or the second item includes one or more of the following: Corresponding relevant parameters; Corresponding information elements; The corresponding fields.

9. The method according to claim 7, wherein, The predefined information includes one of the following: default value, null value, and invalid value.

10. The method according to any one of claims 1 to 3, wherein, The method further includes: In cases where the first RAT differs from the second RAT, some configuration-related information in the second access layer context information of the second network is deleted, while at least the third information, which is related to identity information, is retained.

11. The method according to claim 10, wherein, The first information includes any one of the following: The third information; The third information is mapped to first access layer context information corresponding to the first format of the first network.

12. The method according to claim 10 or 11, wherein, The method further includes: Receive the fourth information corresponding to the first format sent by the first network device.

13. The method according to claim 12, wherein, The fourth piece of information includes the access layer context information corresponding to the first network.

14. The method according to any one of claims 1 to 3, wherein, The method further includes: Based on the type of the first network, access layer context information corresponding to the type of the first network is determined from the first access context layer information and the second access layer context information.

15. The method according to claim 14, wherein, The first access layer context information is obtained through the access status of the terminal device to the first network; The second access layer context information is obtained through the access status of the second network accessed by the terminal device.

16. The method according to claim 14 or 15, wherein, If the first RAT is different from the second RAT, the first information is the first access layer context information; If the first RAT and the second RAT are the same, then the first information is the second access layer context information.

17. The method according to any one of claims 1 to 16, wherein, The method further includes: Receive a second message from the first network device; the second message is a response message to the first message; the first network device is the... The network equipment related to the first network; In response to the second message, a third message is sent; the third message is used to indicate that the connection establishment is complete or the connection recovery is complete.

18. A communication method applied to a first network device, the method comprising: Receive first information, the first information being used to indicate first access layer context information to the first network under the first RAT; The first information is sent by the terminal device, which has been connected to the second network under the second RAT and is in an inactive state.

19. The method according to claim 18, wherein, The first information is carried in the first message, which is used to request access to the first network.

20. The method according to claim 18 or 19, wherein, The first information is obtained by mapping the second access layer context information of the second network; the second access layer context information is the context information related to the second network that is retained by the terminal device.

21. The method according to claim 20, wherein, The first information is obtained by mapping the second information in the second access layer context information of the second network to the first access layer context information corresponding to the first format of the first network.

22. The method according to claim 20 or 21, wherein, The first information is obtained by mapping the second information in the second access layer context information to the first item of the first network; wherein, The second format of the second network contains a second item that corresponds to the first item in the first format of the first network, and the second information is the value corresponding to the second item.

23. The method according to claim 20 or 21, wherein, The first information is obtained by mapping the second information in the second access layer context information to predefined information; wherein, The second format of the second network does not contain the second item content that corresponds to the first item content of the first format of the first network.

24. The method according to claim 22 or 23, wherein, The first item or the second item includes one or more of the following: Corresponding relevant parameters; Corresponding information elements; The corresponding fields.

25. The method according to claim 23, wherein, The predefined information includes one of the following: default value, null value, and invalid value.

26. The method according to claim 18 or 19, wherein, The first information includes any one of the following: The third information is obtained by deleting some configuration-related information from the second access layer context information of the second network when the first RAT is different from the second RAT. The third information is related to identity information. The third information is mapped to the first access layer context information corresponding to the first format of the first network.

27. The method according to claim 26, wherein, The method further includes: Send the fourth information corresponding to the first format to the terminal device.

28. The method according to claim 27, wherein, The fourth piece of information includes the access layer context information corresponding to the first network.

29. The method according to claim 18 or 19, wherein, If the first RAT is different from the second RAT, the first information is the first access layer context information; If the first RAT and the second RAT are the same, then the first information is the second access layer context information; wherein... The first access layer context information is obtained through the access status of the terminal device to the first network; The second access layer context information is obtained through the access status of the second network accessed by the terminal device.

30. The method according to any one of claims 18 to 29, wherein, The method further includes: Send a second message to the terminal device; the second message is a response message to the first message; Receive a third message; the third message is used to indicate that the connection establishment is complete or the connection recovery is complete.

31. The method according to any one of claims 18 to 30, wherein, The method further includes: Send a fourth message; the fourth message is a message requesting context information from the second network device; the second network device is a network device related to the second network; Receive a fifth message in response to the fourth message; the fifth message carries third access layer context information.

32. The method according to claim 31, wherein, The third access layer context information includes one or more of the following: Second access layer context information of the second network; The first access layer context information of the first network; the first access layer context information of the first network is obtained through the access status of the terminal device to the first network, or determined by mapping the second access layer context information of the second network to a first format through the first network device or the second network device.

33. The method according to claim 31 or 32, wherein, The method further includes: The first information is verified based on the third access layer context information to determine the verification result; If the verification result indicates success, a second message is sent to the terminal device.

34. A communication device applied to a terminal equipment, the communication device comprising: The sending unit is used to send first information, which is used to indicate first access layer context information to the first network under the first RAT; wherein the terminal device has been connected to the second network under the second RAT and is in an inactive state.

35. A communication device applied to a first network device, the communication device comprising: A receiving unit is configured to receive first information, wherein the first information is used to indicate first access layer context information to the first network under the first RAT. The first information is sent by the terminal device, which has been connected to the second network under the second RAT and is in an inactive state.

36. A terminal device, the terminal device comprising a memory and a processor; in, Memory is used to store executable instructions for a computer; A processor, connected to the memory, is configured to implement the method as described in claims 1 to 17 by executing the computer-executable instructions.

37. A first network device, the first network device comprising a memory and a processor; in, Memory is used to store executable instructions for a computer; A processor, connected to the memory, is configured to implement the method as described in claims 18 to 33 by executing the computer-executable instructions.

38. A chip, comprising: A processor for retrieving and running a computer program from memory, causing a device having the chip mounted to perform the method as described in any one of claims 1 to 17 or 18 to 33.

39. A computer-readable storage medium for storing a computer program that causes a computer to perform the method as claimed in any one of claims 1 to 17 or 18 to 33.

40. A computer program product comprising computer program instructions that cause a computer to perform the method as claimed in any one of claims 1 to 17 or 18 to 33.

41. A computer program that causes a computer to perform the method as claimed in any one of claims 1 to 17 or 18 to 33.

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