Communication method and apparatus based on network slices

Abstract

This application provides a communication method and apparatus based on network slices for improving a success rate of accessing a network slice by a terminal, thereby improving service performance and user experience. In the method, a network device receives information about a network slice that a terminal requests to access via a first access network device in a first network, determines a network slice and a registration area that the terminal is allowed to access, and sends information about the registration area to the terminal. The information about the network slice that the terminal requests to access includes an identification information of a first network slice not supported by a first tracking area and includes an identification information of a second network slice, the second tracking area in the first network supports the first network slice, the network slice that the terminal is allowed to access includes the second network slice, and the registration area excludes a tracking area supporting the first network slice and the second network slice, or excludes a tracking area of ​​an access network device supporting the first network slice and the second network slice.

Description

[Technical field]

[0001] [CROSS-REFERENCE TO RELATED APPLICATIONS] This application claims priority to China Patent Application No. 202110176172.4, entitled "NETWORK SLICE-BASED COMMUNICATION METHOD AND APPARATUS," filed with the China National Intellectual Property Office on February 9, 2021, the entire contents of which are incorporated by reference.

[0002] [Technical field] The present application relates to the field of communications, and in particular to a communication method and apparatus based on network slicing. [Background technology]

[0003] Network slicing technology is a method of virtualizing independent logical networks on the same network infrastructure, providing mutually isolated network environments for different application scenarios, so that network functions and features of different application scenarios can be customized based on their respective requirements, and the quality of service (QoS) requirements of different services can be effectively ensured. Generally, a network slice is identified by a single network slice selection assistance information (S-NSSAI), and the network slice selection assistance information (NSSAI) is a set of S-NSSAI.

[0004] The capability of a radio access network (RAN) to support network slices is partitioned using tracking areas (TAs) as a granularity: one TA may support one or more network slices, and cells within the same TA may support the same network slice.

[0005] When a network slice is deployed, the network slice may be selected in the registration procedure. For example, the core network sends an allowed NSSAI to the terminal based on the NSSAI requested by the terminal, the terminal's subscription data, the network slice supported by the TA in which the terminal is currently located, etc. The allowed NSSAI is an NSSAI that can be accessed by the terminal.

[0006] However, in a practical application, the following scenario may exist: In the registration procedure, the TA where the terminal is currently located does not support the network slice that the terminal intends to access, so the terminal does not access the network slice in this registration procedure. Even if the terminal subsequently moves to a TA that supports the network slice, the terminal may still not be able to access the network slice normally. Summary of the Invention

[0007] This application provides a communication method and apparatus based on network slices to improve the success rate of a terminal accessing a network slice, thereby improving service performance and user experience.

[0008] In order to achieve the above objectives, the following technical solutions are used in this application:

[0009] According to a first aspect, a communication method based on a network slice is provided. The method may be performed by a network device or may be performed by a component of the network device, such as a processor, a chip or a chip system of the network device. In this application, an example in which the network device performs the method is used for explanation.

[0010] The method includes: a network device receives, via a first access network device in a first network, information about a network slice that a terminal requests to access, determines a network slice and a registration area that the terminal is allowed to access, and sends information about the registration area to the terminal, where the information about the network slice that the terminal requests to access includes an identification information of a first network slice not supported by a first tracking area and includes an identification information of a second network slice, where a second tracking area in the first network supports the first network slice, where the network slice that the terminal is allowed to access includes the second network slice, and where the registration area excludes a tracking area supporting the first network slice and the second network slice, or excludes a tracking area of ​​an access network device supporting the first network slice and the second network slice.

[0011] Based on this solution, when determining a registration area, the network device excludes a tracking area supporting the first network slice and the second network slice, or excludes a tracking area of ​​an access network device supporting the first network slice and the second network slice. Thus, when a terminal moves within the excluded tracking area, since the registration area of ​​the terminal does not include the tracking area and the tracking area supports the first network slice, the terminal may resume the registration procedure to request access to the first network slice, thereby increasing the success rate of accessing the first network slice, thereby improving service performance and user experience.

[0012] In some possible designs, the method further includes: the network device determines a network slice to which the terminal is denied access, the network slice to which the terminal is denied access includes the first network slice.

[0013] Based on this possible design, when determining a registration area, the network device may exclude tracking areas that support a network slice to which the terminal is denied access, or may exclude tracking areas of access network devices that support a network slice to which the terminal is denied access.

[0014] According to a second aspect, a communication method based on network slices is provided. The method may be executed by a network device, or may be executed by a component of the network device, such as a processor, a chip, or a chip system of the network device. In this application, an example in which the network device executes the method is used for explanation. The method includes: the network device determines a network slice that a terminal is permitted to access and a network slice that the terminal is denied to access, determines a registration area of ​​the terminal based on the network slice that the terminal is permitted to access and the network slice that the terminal is denied to access, and sends information about the registration area to the terminal.

[0015] Based on this solution, the network device may determine the registration area of ​​the terminal based on the network slices the terminal is allowed to access and the network slices the terminal is denied to access, and consider that the tracking area supporting the network slices the terminal is denied to access is excluded from the registration area. For example, the registration area excludes the tracking area supporting the network slices the terminal is denied to access, or the tracking area of ​​the access network device supporting the network slices the terminal is denied to access. Thus, when the terminal moves within the excluded tracking area, since the registration area of ​​the terminal does not include the tracking area and the tracking area supports the first network slice, the terminal may resume the registration procedure to request access to the first network slice, thereby increasing the success rate of accessing the first network slice, thereby improving service performance and user experience.

[0016] In some possible designs, the method further includes: the network device receives, via a first access network device in the first network, information regarding a network slice that the terminal requests to access, the information regarding the network slice that the terminal requests to access includes an identity of a first network slice not supported by a first tracking area and includes an identity of a second network slice supported by the first tracking area, the first tracking area being a tracking area of ​​the first access network device, the network slice that the terminal is allowed to access includes the second network slice and the network slice that the terminal is denied to access includes the first network slice, and the registration area excludes tracking areas supporting the first and second network slices, or the registration area excludes tracking areas of the access network devices supporting the first and second network slices.

[0017] With reference to the first or second aspect, in some possible designs, the first network slice is a network slice that the terminal is allowed to access in the first network.

[0018] With reference to the first aspect or the second aspect, in some possible designs, the method further includes: the network device determines a network slice supported by a tracking area of ​​the first access network device.

[0019] According to a third aspect, a communication method based on a network slice is provided. The method may be executed by a network device, or may be executed by a component of the network device, such as a processor, a chip, or a chip system of the network device. In this application, an example in which the network device executes the method is used for explanation. The method includes: the network device determines a first network slice, where the first network slice does not belong to a network slice that a terminal is allowed to access in a first cell, and a registration area of ​​the terminal includes the first cell and a second cell, and when the terminal is handed over from the first cell to the second cell, the network device determines that the first network slice is available in the second cell, and informs the terminal that the first network slice is available in the second cell.

[0020] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in the second cell, the terminal still cannot access the first network slice in the second cell because it does not initiate a registration procedure in the second cell. Based on this solution, when a terminal is handed over from a first cell to a second cell and it is determined that a first network slice is available in the second cell, the network device notifies the terminal that the first network slice is available in the second cell, thereby allowing the terminal, when still intending to access the first network slice, to initiate a registration procedure to request access to the first network slice, thereby improving the success rate of accessing the first network slice and further improving service performance and user experience.

[0021] In some possible designs, when the second cell belongs to the second access network device, the target access network device is the second access network device, or when the second cell belongs to the first access network device, the target access network device is the first access network device. The first cell belongs to the first access network device. Therefore, it can be understood that the second cell belongs to the second access network device (i.e., the first cell and the second cell belong to different access network devices) to correspond to an inter-eNodeB handover scenario, or the second cell belongs to the first access network device (i.e., the first cell and the second cell belong to the same access network device) to correspond to an intra-eNodeB handover scenario. This is also applicable to designs in other aspects of this application, and details will not be described again below. Based on this possible design, the success rate of accessing the first network slice in either an intra-eNodeB handover scenario or an inter-eNodeB handover scenario can be improved.

[0022] In some possible designs, when the network device is a mobility management device, the network device determining that the first network slice is available in the second cell includes: the network device queries a context of a target access network device, where the context of the target access network device indicates that a tracking area of ​​the target access network device supports the first network slice, and the second cell is a cell in the tracking area of ​​the target access network device. Based on this possible design, the network device may determine that the first network slice is available in the second cell through a locally stored context of the target access network device, without needing to interact with other devices, thereby reducing signaling overhead.

[0023] In some possible designs, when the network device is a mobility management device, determining by the network device that the first network slice is available in the second cell includes: the network device sending an identification information of the first network slice to a target access network device, and learning from the target access network device that the first network slice is accessible to a terminal in the second cell.

[0024] In some possible designs, when the network device is a mobility management device, and the second cell belongs to the second access network device, the network device determining that the first network slice is available in the second cell includes: the network device determines that the first network slice is available in the second cell when receiving a path switch request message from the second access network device, or the network device determines that the first network slice is available in the second cell when receiving a handover required message from the first access network device, where the handover required message includes an identifier of the second access network device.

[0025] Based on this possible design, the network device may check with the target network device whether the terminal can access a first network slice supported by the tracking area of ​​the target access network device, and when the target access network device supports the first network slice but the terminal cannot access the first network slice in the second cell, prevent the network device from notifying the terminal that the first network slice is available in the second cell, thereby improving the success rate of the terminal accessing the first network slice in the second cell.

[0026] In some possible designs, when the network device is a mobility management device, the method further includes: the network device stores an identification information of the first network slice, the network device receives indication information from the terminal after the network device notifies the terminal that the first network slice is available in the second cell, and the network device deletes the identification information of the first network slice based on the indication information.

[0027] In some possible designs, when the network device is a mobility management device, the indication information indicates that the terminal no longer requests to access the first network slice.

[0028] Based on the above two possible designs, when the indication information indicates that the terminal no longer requests to access the first network slice, the network device deletes the identification information of the first network slice. Then, when serving the terminal, the network device no longer needs to inform the terminal of the cells that can access the first network slice, thereby reducing signaling overhead and reducing resource waste.

[0029] In some possible designs, when the second cell belongs to the second access network device, the network device is the second access network device, or when the second cell belongs to the first access network device, the network device is the first access network device. Based on the possible designs, a success rate of accessing the first network slice in either an intra-eNodeB handover scenario or an inter-eNodeB handover scenario can be improved.

[0030] In some possible designs, when the second cell belongs to the first access network device, the network device determining the first network slice includes: the network device transmits information about the network slice that the terminal requests to access to the mobility management device, the information about the network slice that the terminal requests to access includes identification information of the first network slice, and the network device learns from the mobility management device that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell. In other words, the network device may learn from the mobility management device in the registration procedure that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell. This is also applicable to designs in other aspects of this application, and details will not be described again below.

[0031] In some possible designs, when the second cell belongs to the second access network device, the network device determining the first network slice includes: When the terminal is handed over from the first access network device to the second access network device, the network device learns from the mobility management device that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell. In other words, in an inter-eNodeB handover scenario, the network device may learn from the mobility management device that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell. This is also applicable to designs in other aspects of this application, and details will not be described again below.

[0032] In some possible designs, the network device determining that the first network slice is available in the second cell includes: The network device determines that the first network slice is accessible to a terminal in the second cell.

[0033] According to a fourth aspect, a communication method based on network slices is provided. The method may be executed by a network device, or may be executed by a component of the network device, such as a processor, a chip, or a chip system of the network device. In this application, an example in which the network device executes the method is used for explanation. The method includes: the network device determines a first network slice, where the first network slice does not belong to a network slice that a terminal is allowed to access in a first cell, and a registration area of ​​the terminal includes the first cell and a second cell, and when the terminal is handed over from the first cell to the second cell, the network device determines that the first network slice is available in a third cell, and informs the terminal that the first network slice is available in the third cell, and a physical coverage of the third cell partially or completely overlaps with a physical coverage of the second cell.

[0034] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in a third cell whose physical coverage is the same as that of the second cell, the terminal still cannot access the first network slice at the location of the second cell because it does not initiate a registration procedure again in the second cell. Based on this solution, when a terminal is handed over from a first cell to a second cell and it is determined that the first network slice is available in the third cell, the terminal is notified that the first network slice is available in the third cell, thereby allowing the terminal to access the first network slice in the third cell when still intending to access the first network slice, thereby improving the success rate of accessing the first network slice and further improving service performance and user experience.

[0035] In some possible designs, when the second cell belongs to the second access network device, the target access network device is the second access network device, or when the second cell belongs to the first access network device, the target access network device is the first access network device. Based on the possible designs, a success rate of accessing the first network slice in either an intra-eNodeB handover scenario or an inter-eNodeB handover scenario can be improved.

[0036] In some possible designs, when the network device is a mobility management device, the network device determining that the first network slice is available in the third cell includes: the network device queries a context of the target access network device, where the context of the target access network device indicates that a tracking area in which the third cell is located supports the first network slice but a tracking area in which the second cell is located does not support the first network slice, and the second cell and the third cell are cells of the target access network device. Based on this possible design, the network device may determine that the first network slice is available in the third cell through a locally stored context of the target access network device, without needing to interact with other devices, thereby reducing signaling overhead.

[0037] In some possible designs, when the network device is a mobility management device, the network device determining that the first network slice is available in the third cell includes: the network device sending an identification information of the first network slice to a target access network device, and learning from the target access network device that the first network slice is accessible to a terminal in the third cell.

[0038] Based on this possible design, the network device may check with the target network device whether the terminal can access a first network slice supported by the tracking area of ​​the target access network device, and when the target access network device supports the first network slice but the terminal cannot access the first network slice in the third cell, prevent the network device from notifying the terminal that the first network slice is available in the third cell, thereby improving the success rate of the terminal accessing the first network slice in the third cell.

[0039] With reference to the third aspect or the fourth aspect, in some possible designs, when the network device is a mobility management device, the network device determining the first network slice includes: the network device receives, via the first cell, information regarding a network slice that the terminal requests to access, the information regarding the network slice that the terminal requests to access includes identification information of the first network slice, the network device determines a network slice that the terminal is allowed to access, and learns that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0040] With reference to the third or fourth aspect, in some possible designs, the first network slice is included in the network slice configured by the terminal for the first network. In other words, the network device may execute the above method for a first network slice that does not belong to the network slice that the terminal is allowed to access in the first cell, but is included in the network slice configured by the terminal for the first network. That is, regardless of whether the network slice that the terminal requests to access carries an identifier of the first network slice, the first network slice is included in the network slice configured by the terminal for the first network, so the terminal may subsequently intend to access the first network slice. In this case, when intending to access the first network slice, the terminal may access the first network slice in the second or third cell, thereby improving the success rate of accessing the first network slice. This is also applicable to designs in other aspects of this application, and details will not be described again below.

[0041] With reference to the third or fourth aspect, in some possible designs, the first network slice is included in the network slice that the terminal requests to access in the first cell.

[0042] With reference to the third or fourth aspect, in some possible designs, the first cell belongs to a first access network device and the second cell belongs to a second access network device, or the first cell and the second cell belong to the first access network device.

[0043] According to a fifth aspect, a communication method based on a network slice is provided. The method may be executed by a network device, or may be executed by a component of the network device, such as a processor, a chip, or a chip system of the network device. In this application, an example in which the network device executes the method is used for explanation. The method includes: the network device determines a first network slice, where the first network slice does not belong to a network slice that a terminal is allowed to access in a first cell, and a registration area of ​​the terminal includes the first cell and a second cell, the network device determines that the first network slice is available in the second cell, notifies the terminal that the first network slice is available in the second cell, and sends a cell identifier of the second cell to the terminal.

[0044] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in the second cell, the terminal still cannot access the first network slice in the second cell because it does not initiate a registration procedure in the second cell. Based on this solution, when determining that the first network slice is available in the second cell, the network device notifies the terminal that the first network slice is available in the second cell and transmits a cell identifier of the second cell, thereby allowing the terminal, when still intending to access the first network slice, to access the second cell and initiate a registration procedure to request access to the first network slice, thereby improving the success rate of accessing the first network slice and further improving service performance and user experience.

[0045] In some possible designs, the network device determining that the first network slice is available in the second cell includes: the network device receives a cell identifier of the second cell from the first access network device, the second cell being a neighbor cell of the first cell, and the network device determines that the first network slice is accessible to a terminal in the second cell.

[0046] In some possible designs, the network device determining that the first network slice is available in the second cell includes: the network device receives signal quality information of neighboring cells of the first cell from the first access network device, where the neighboring cells of the first cell include a second cell, and the network device determines, based on the signal quality information of the second cell, that the first network slice is accessible to a terminal in the second cell.

[0047] In some possible designs, the method further includes: the network device stores an identification of the first network slice, the network device receiving indication information from the terminal after the network device notifies the terminal that the first network slice is available in the second cell, and deleting the identification of the first network slice based on the indication information.

[0048] In some possible designs, the indication information indicates that the terminal no longer requests access to the first network slice.

[0049] Based on the above two possible designs, when the indication information indicates that the terminal no longer requests to access the first network slice, the network device deletes the identification information of the first network slice. Then, when serving the terminal, the network device no longer needs to inform the terminal of the cells that can access the first network slice, thereby reducing signaling overhead and reducing resource waste.

[0050] According to a sixth aspect, a communication method based on network slices is provided. The method may be executed by a network device, or may be executed by a component of the network device, such as a processor, a chip, or a chip system of the network device. In this application, an example in which the network device executes the method is used for explanation. The method includes: the network device determines a first network slice, where the first network slice does not belong to a network slice that a terminal is allowed to access in a first cell, a registration area of ​​the terminal includes the first cell and a second cell, the network device determines that the first network slice is available in a third cell, notifies the terminal that the first network slice is available in the third cell, and transmits a cell identifier of the third cell to the terminal, where a physical coverage of the third cell partially or completely overlaps with a physical coverage of the second cell.

[0051] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in a third cell whose physical coverage is the same as that of the second cell, the terminal still cannot access the first network slice at the location of the second cell because it does not initiate a registration procedure again in the second cell. Based on this solution, when neighboring cells of a first cell accessed by a terminal include a second cell, and there is a third cell whose physical coverage is the same as that of the second cell, when it determines that the first network slice is available in the third cell, the network device notifies the terminal that the first network slice is available in the third cell and transmits a cell identifier of the third cell, so that when still intending to access the first network slice, the terminal may access the third cell and request to access the first network slice, thereby improving the success rate of accessing the first network slice and further improving service performance and user experience.

[0052] With reference to the fifth or sixth aspect, in some possible designs, the first network slice is included in a network slice configured for the terminal in the first network.

[0053] With reference to the fifth or sixth aspect, in some possible designs, the first network slice is included in the network slice that the terminal requests to access in the first cell.

[0054] With reference to the fifth or sixth aspect, in some possible designs, the network device determining the first network slice includes: the network device receives, via the first cell, information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes identification information of the first network slice, the network device determines a network slice that the terminal is allowed to access, and learns that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0055] With reference to the fifth aspect or the sixth aspect, in some possible designs, the method includes: a network device sends reference frequency information corresponding to a first network slice to a first access network device.

[0056] According to a seventh aspect, a communication method based on a network slice is provided. The method may be executed by a terminal, or may be executed by a component of the terminal, such as a processor, a chip, or a chip system of the terminal. In this application, an example in which the terminal executes the method is used for explanation. The method includes: the terminal learns from a network device that a first network slice is available in a second cell, and initiates a registration procedure for an application corresponding to the first network slice. The first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, and a registration area of ​​the terminal includes the first cell and the second cell.

[0057] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, so the terminal cannot access the first network slice in the first cell. Since the registration area of ​​the terminal includes the first cell and the second cell, even if the terminal moves from the first cell to the coverage of the second cell, the terminal still does not resume the registration procedure and therefore does not request to access the first network slice. Based on this solution, the terminal may learn from the network device that the first network slice is available in the second cell, and therefore, when the application of the terminal corresponds to the first network slice, it may initiate a registration procedure for the application to request to access the first network slice, thereby improving the success rate of accessing the first network slice and further improving service performance and user experience.

[0058] In some possible designs, the first network slice is included in one configured for the terminal in the first network.

[0059] In some possible designs, the first network slice is included in the network slice that the terminal requests to access in the first cell.

[0060] In some possible designs, the method further includes: the terminal receives a cell identifier from the network device, the cell identifier being used for the second cell.

[0061] In some possible designs, the terminal initiating a registration procedure for an application corresponding to the first network slice includes: the terminal accessing a second cell and initiating a registration procedure for the application via the second cell.

[0062] In some possible designs, the terminal initiating a registration procedure for an application corresponding to the first network slice includes: the terminal determines whether the first network slice is a network slice corresponding to the application in response to a context of the terminal not including a session used for the application and not including a routing policy used for the application, and the terminal initiates the registration procedure for the application when the first network slice is a network slice corresponding to the application.

[0063] In some possible designs, the method further includes: the terminal notifies the network device that the terminal no longer requests to access the first network slice. Based on this possible design, when the terminal notifies the network device that the terminal no longer requests to access the first network slice, the network device may delete the identification information of the first network slice stored in the network device. Thereafter, when serving the terminal, the network device may no longer notify the terminal of cells that can access the first network slice, thereby reducing signaling overhead and reducing resource waste.

[0064] In some possible designs, the terminal notifying the network device that the terminal no longer requests to access the first network slice includes: after a first duration starting from a first time point, the terminal notifying the network device that the terminal no longer requests to access the first network slice, the first time point being a time point at which the terminal learns from the network device that the first network slice is available in the second cell.

[0065] According to an eighth aspect, there is provided a communication device for realizing the above method. The communication device may be the network device in the first to sixth aspects, a device including the network device, or a device included in the network device, for example, a chip, or the communication device may be the terminal in the seventh aspect, a device including the terminal, or a device included in the terminal, for example, a chip. The communication device includes a corresponding module, unit, or means for realizing the above method. The module, unit, or means may be realized by hardware, software, or hardware executing the corresponding software. The hardware or software includes one or more modules or units corresponding to the functions.

[0066] In some possible designs, the communication device may include a processing module and a transceiver module. The transceiver module may also be referred to as a transceiver unit and is configured to implement a transmitting function and / or a receiving function in any one of the above aspects and any one of the possible implementations of the above aspects. The transceiver module may include a transceiver circuit, a transceiver machine, a transceiver, or a communication interface. The processing module may be configured to implement a processing function in any one of the above aspects and any one of the possible implementations of the above aspects.

[0067] In some possible designs, the transceiver module includes a transmitting module and a receiving module configured to respectively implement the transmitting and receiving functions in any one of the above aspects and any one of the possible implementation manners of the above aspects.

[0068] A communication device provided in an eighth aspect is configured to perform any one of the above aspects or any one of the possible implementations of the above aspects. For specific details, refer to any one of the above aspects or any one of the possible implementations of the above aspects. Details are not described again here.

[0069] According to a ninth aspect, there is provided a communication device including a processor and a memory. The memory is configured to store computer instructions. When the processor executes the instructions, the communication device is capable of performing a method according to any one of the above aspects. The communication device may be a network device, a device including a network device, or a device included in a network device, such as a chip, according to the first to sixth aspects, or the communication device may be a terminal, a device including a terminal, or a device included in a terminal, such as a chip, according to the seventh aspect.

[0070] According to a tenth aspect, there is provided a communication device including a processor and a communication interface. The communication interface is configured to communicate with a module other than the communication device, and the processor is configured to execute a computer program or instructions to enable the communication device to perform a method according to any one of the above aspects. The communication device may be a network device, a device including a network device, or a device included in a network device, such as a chip, according to any one of the first to sixth aspects, or the communication device may be a terminal, a device including a terminal, or a device included in a terminal, such as a chip, according to the seventh aspect.

[0071] According to an eleventh aspect, there is provided a communication device including an interface circuit and a logic circuit. The interface circuit is configured to obtain input information and / or output output information, and the logic circuit is configured to execute a method according to any one of the above aspects or any one of the possible implementations of the above aspects to perform a process based on the input information and / or generate the output information. The communication device may be the network device, a device including the network device, or a device included in the network device, such as a chip, according to the first to sixth aspects, or the communication device may be the terminal, a device including the terminal, or a device included in the terminal, such as a chip, according to the seventh aspect.

[0072] When the communication device is a network device in the first or second aspect, a device including the network device or a device included in the network device is as follows.

[0073] In some possible designs, the input information may be information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes an identification of a first network slice not supported by the first tracking area and includes an identification of a second network slice. Performing a process based on the input information may be determining a network slice that the terminal is allowed to access or determining a registration area.

[0074] In some possible designs, the output information may be information regarding a registration area, where the registration area excludes a tracking area supporting the first network slice and the second network slice, or where the registration area excludes a tracking area of ​​an access network device supporting the first network slice and the second network slice.

[0075] When the communication device is a network device in the third aspect, a device including the network device or a device included in the network device is as follows.

[0076] In some possible designs, the output information may be information to inform the terminal that the first network slice is available in the second cell.

[0077] In some possible designs, the input information may be information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes an identification of the first network slice. Performing processing based on the input information may be determining a network slice that the terminal is authorized to access, or determining that the first network slice does not belong to a network slice that the terminal is authorized to access in the first cell.

[0078] In some possible designs, the output information may be an identification of the first network slice.

[0079] In some possible designs, the input information may be information used by the network device to learn that the first network slice can access a terminal in the second cell. Performing the process based on the input information may be learning that the first network slice can access a terminal in the second cell.

[0080] In some possible designs, the input information may be a path switch request message. Performing the process based on the input information may be determining that the first network slice is available in the second cell.

[0081] In some possible designs, the input information may be a handover required message. Performing processing based on the input information may be determining that the first network slice is available in the second cell.

[0082] In some possible designs, the input information may be instruction information, and performing the process based on the input information may be removing the identification information of the first network slice based on the instruction information.

[0083] When the communication device is a network device in the fifth aspect, the device including the network device or the device included in the network device is as follows.

[0084] In some possible designs, the output information may be information to inform the terminal that the first network slice is available in the second cell and a cell identifier of the second cell.

[0085] In some possible designs, the input information may be information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes identification information of the first network slice. Performing processing based on the input information may be determining a network slice that the terminal is authorized to access, and learning that the first network slice does not belong to the network slice that the terminal is authorized to access in the first cell.

[0086] In some possible designs, the input information may be a cell identifier of the second cell. Performing the process based on the input information may be determining that the first network slice is available in the second cell.

[0087] In some possible designs, the input information may be signal quality information of neighboring cells of the first cell, where the neighboring cells of the first cell include the second cell, and performing processing based on the input information may be determining, based on the signal quality information of the second cell, that the first network slice can access a terminal in the second cell.

[0088] In some possible designs, the output information may be reference frequency information corresponding to the first network slice.

[0089] In some possible designs, the input information may be instruction information, and performing the process based on the input information may be removing the identification information of the first network slice based on the instruction information.

[0090] When the communication device may be a terminal in the seventh aspect, a device including the terminal or a device included in the terminal is as follows.

[0091] In some possible designs, the input information may be information for learning that the first network slice is available in the second cell. Performing the process based on the input information may be initiating a registration procedure for an application corresponding to the first network slice.

[0092] In some possible designs, the input information may be a cell identifier, the cell identifier being used for the second cell, and performing the process based on the input information may be accessing the second cell.

[0093] In some possible designs, the output information may be information to notify that the terminal no longer requests access to the first network slice.

[0094] According to a twelfth aspect, there is provided a communication device including at least one processor. The processor is configured to execute a computer program or instructions stored in a memory to enable the communication device to perform a method according to any one of the above aspects. The memory may be coupled to the processor or may be independent of the processor. The communication device may be a network device, a device including a network device, or a device included in a network device, such as a chip, according to the first to sixth aspects, or the communication device may be a terminal, a device including a terminal, or a device included in a terminal, such as a chip, according to the seventh aspect.

[0095] According to a thirteenth aspect, there is provided a computer-readable storage medium storing instructions that, when executed on a communication device, enable the communication device to perform a method according to any one of the above aspects.

[0096] According to a fourteenth aspect, there is provided a computer program product comprising instructions, which when executed on a communications device, enable the communications device to perform a method according to any one of the above aspects.

[0097] According to a fifteenth aspect, there is provided a communication device (e.g., the communication device may be a chip or a chip system), the communication device including a processor configured to implement the functionality of any one of the above aspects.

[0098] In some possible designs, the communication device includes a memory configured to store necessary program instructions and data.

[0099] In some possible designs, when the apparatus is a chip system, the apparatus may include a chip or may include a chip and other discrete components.

[0100] When the communication device provided in any one of the eighth to fifteenth aspects is a chip, it may be understood that the above transmission operation / function may be understood as output information, and the above receiving operation / function may be understood as input information.

[0101] Regarding the technical effects brought about by any of the design methods in the eighth to fifteenth aspects, refer to the technical effects brought about by the different design methods in the first to seventh aspects, and the details will not be described again here.

[0102] According to a sixteenth aspect, there is provided a communication system, the communication system including a network device and a terminal according to the above aspect. [Brief description of the drawings]

[0103] [Figure 1] 1 is a schematic diagram of a 5G network architecture according to this application. [Diagram 2]FIG. 1 is a schematic diagram of an application scenario of a network slice according to this application. [Diagram 3] FIG. 1 is a schematic diagram of a network slice supported by an access network device according to this application. [Figure 4] FIG. 2 is a schematic diagram of the registration procedure according to the present application. [Diagram 5] FIG. 2 is a schematic diagram of a redirection procedure according to this application. [Figure 6] 1 is a schematic flow chart of Xn handover according to the present application. [Figure 7] 1 is a schematic flow chart of N2 handover according to the present application. [Figure 8a] FIG. 1 is a schematic diagram of a scenario according to this application. [Figure 8b] FIG. 1 is a schematic diagram of a scenario according to this application. [Figure 8c] FIG. 1 is a schematic diagram of a scenario according to this application. [Figure 9a] 1 is a schematic diagram of the structure of a communication system according to the present application; [Figure 9b] FIG. 2 is a schematic diagram of the structure of another communication system according to the present application. [Figure 9c] FIG. 2 is a schematic diagram of the structure of another communication system according to the present application. [Figure 10] 1 is a schematic diagram of the structure of a communication device according to the present application; [Figure 11] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 12] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 13] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 14] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 15] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 16]1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 17] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 18] 1 is a schematic flowchart of a communication method based on network slicing according to the present application; [Figure 19] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 20] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 21] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 22] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Diagram 23] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 24] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Diagram 25] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 26] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 27] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 28] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Figure 29] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Diagram 30] 1 is a schematic interaction flowchart of a communication method based on network slices according to the present application; [Diagram 31] 1 is a schematic diagram of the structure of a network device according to the present application; [Diagram 32] 1 is a schematic diagram of the structure of a terminal according to this application; [Diagram 33] 1 is a schematic diagram of the structure of a communication device according to this application; DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0104] In the description of this application, unless otherwise specified, " / " indicates that the associated objects are in an "or" relationship. For example, A / B may represent A or B. "And / or" in this application is simply an association relationship to describe the associated objects, and indicates that three relationships may exist. For example, A and / or B may represent that only A is present, that both A and B are present, and that only B is present, and A and B may be singular or plural. Furthermore, in the description of this application, unless otherwise specified, "plurality" means two or more than two. "At least one of the following items (parts)" or similar expressions indicates any combination of these items, including any combination of a singular item (part) or a plurality of items (parts). For example, at least one of a, b, or c may represent a, b, c, a and b, a and c, b and c, and a and b and c, and a, b, and c, and a, b, and c may be singular or plural. Furthermore, in order to clearly describe the technical solutions in the embodiments of this application, terms such as "first" and "second" are used in the embodiments of this application to distinguish between the same or similar items that provide essentially the same function or purpose. Those skilled in the art can understand that terms such as "first" and "second" do not limit the quantity or execution order, and terms such as "first" and "second" do not indicate clear differences.

[0105] It should be noted that in this application, terms such as "example" or "for example" are used to denote giving an example, illustration, or explanation. Any embodiment or design manner described in this application as "example" or "for example" should not be described as being preferred or having more advantages over other embodiments or design manners. Rather, the use of terms such as "example" or "for example" is intended to present a relative concept in a particular manner.

[0106] In order to facilitate understanding of the technical solutions in the embodiments of this application, the following provides a brief description of the related art in this application.

[0107] 1. 5th generation (5G) network architecture

[0108] The 5G network architecture defined in the 3rd Generation Partnership Project (3GPP) TS23.501 standard is mainly divided into two parts: the access network (AN) and the core network.

[0109] The access network may include a radio access network (RAN), which is configured to implement radio access related functions.

[0110] The core network mainly includes the following major logical network elements: an access and mobility management function (AMF) network element, a session management function (SMF) network element, a user plane function (UPF) network element, a policy control function network element, and a unified data management (UDM) network element, and may further include an authentication server function (AUSF) network element, a network slice selection function (NSSF) network element, an application function (AF) network element, etc.

[0111] 1 is a schematic diagram of a 5G network architecture. The terminal may be a user equipment (UE), for example a mobile phone or an Internet of Things terminal.

[0112] DN is a data network (DN), which is mainly configured to provide users with data transmission services, such as Internet Protocol (IP) multimedia services (IMS).

[0113] Access networks that provide wireless access to users are deployed in the RAN, and include, but are not limited to, evolved NodeB (eNB or e-NodeB), wireless fidelity (Wi-Fi), access points (APs), and the like.

[0114] The AMF network element is mainly responsible for mobility management in a mobile network, such as user location update, user network registration and user handover.

[0115] The SMF network element is mainly responsible for session management in a mobile network, such as session establishment, modification and release. Specific functions include allocating IP addresses to users, selecting a UPF that provides packet forwarding functions, etc.

[0116] The PCF network element is mainly responsible for providing policies such as quality of service (QoS) policies and slice selection policies for the AMF and SMF.

[0117] The UDM network element is primarily responsible for storing user data such as subscription information and authentication / authorization information.

[0118] The AF network element is mainly responsible for providing service requirements for the 3GPP network, for example, influencing service paths and interacting with the PCF network element to implement policy control.

[0119] The UPF network element is primarily responsible for processing user packets, eg, forwarding and charging.

[0120] A terminal accesses a DN by establishing a protocol data unit (PDU) session from the terminal to the RAN, the UPF, and the DN.

[0121] The AUSF network element is mainly responsible for providing terminal authentication services for the AMF network element.

[0122] The NSSF network element is primarily responsible for selecting a network slice to serve a terminal.

[0123] Further referring to FIG. 1, Nx represents a logical interface or a service-based interface between two network elements, and is used for communication between the network elements. For example, N1 is an interface between a terminal and an AMF network element. N2 is an interface between an access network device and an AMF network element. N3 is an interface between an access network device and a UPF network element. N9 is an interface between different UPF network elements. N6 is an interface between a UPF network element and a DN. N4 is an interface between a UPF network element and an SMF network element. N11 is an interface between an AMF network element and an SMF network element. N7 is an interface between an SMF network element and a PCF network element. N5 is an interface between a PCF network element and an AF network element. N14 is an interface between different AMF network elements. N15 is an interface between an AMF network element and a PCF network element. N22 is an interface between an NSSF network element and an AMF network element. N12 is an interface between an AUSF network element and an AMF network element. N8 is an interface between the UDM network element and the AMF network element. N13 is an interface between the AUSF network element and the UDM network element.

[0124] 2. Network slice (or slice for short)

[0125] In the 5G era, hundreds of billions of Internet of Things devices will be connected to the network. Different types of application scenarios have different network requirements, and some network requirements may even conflict with each other. When a single network is used to provide services for different types of application scenarios, the network architecture is very complex, and the network management efficiency and resource utilization efficiency are low.

[0126] 5G network slicing technology is a method of virtualizing independent logical networks on the same network infrastructure, providing mutually isolated network environments for different application scenarios, so that the network functions and features of different application scenarios can be customized based on their respective requirements, and the QoS requirements of different services can be effectively ensured.

[0127] The purpose of network slicing is to organically combine terminals, access network resources, core network resources, and network O&M and management systems to provide complete networks that are independently operated and maintained and can be isolated from each other for different business scenarios or service types.

[0128] Various scenarios impose different requirements on the 3GPP ecosystem, i.e., charging, policy, security, mobility, etc. 3GPP emphasizes that network slices do not affect each other. For example, a large amount of sudden meter reading services should not affect normal mobile broadband services. In order to meet the diversified requirements and isolate slices, independent management and O&M of services need to be performed, and customized service functions and analysis capabilities need to be provided. Instances of different types of services may be deployed on different network slices, and different instances of the same service type may also be deployed on different network slices.

[0129] For example, as shown in FIG. 2, mobile broadband services are provided to handheld devices etc. via a mobile broadband (MBB) slice. Services for multiple meter reading services are provided via a massive machine type communications (mMTC) slice. Services for vehicle to everything (V2X) services are provided via a critical MTC slice.

[0130] Details are as follows:

[0131] A network slice represents a logical network that can provide specific network capabilities and network characteristics.

[0132] A network slice instance refers to a group of network functional entities and required resources, such as computing, storage and network resources, that form a network slice.

[0133] Single network slice selection assistance information (S-NSSAI) may be used as a network slice identification information to distinguish between different network slices.

[0134] The S-NSSAI may include slice / service type (SST) information. The SST information describes the expected network slice behavior, for example, used to describe the slice type / service type of the network slice. This is not limited.

[0135] For example, the slice / service type (SST) of a network slice may include, but is not limited to, enhanced mobile broadband (eMBB), ultra-reliable low-latency communications (URLLC), massive Internet of Things (MIoT), vehicle to everything (V2X), etc.

[0136] Optionally, the S-NSSAI further includes slice differentiator (SD) information. The SD information is supplementary information of the SST information and is used to distinguish between different network slices having the same SST characteristics. That is, when the SST information indicates multiple network slices, the SD information may help to correspond to a unique network slice.

[0137] Furthermore, a group of S-NSSAIs may be identified via network slice selection assistance information (NSSAI), i.e., an NSSAI is a set of one group of S-NSSAIs.

[0138] When classified based on different types, the NSSAI includes a subscribed NSSAI, a configured NSSAI, a requested NSSAI, an allowed NSSAI, a rejected NSSAI or a pending NSSAI.

[0139] An example is as follows:

[0140] subscribed NSSAI: The subscribed NSSAI is specific to a Home Public Land Mobile Network (HPLMN) and indicates the subscribed NSSAI that the terminal is authorized to access.

[0141] configured NSSAI: The NSSAI of one or more PLMNs defined in the terminal. The configured NSSAI is determined by the serving PLMN based on the serving PLMN's capability to support network slicing and the network slices to which the terminal subscribes, and is then sent to the terminal via a registration accept message in the registration procedure. For the configured NSSAI, PLMN or stand-alone non-public network (SNPN) is used as the granularity. Different PLMNs or SNPNs can correspond to different parts of the configured NSSAI.

[0142] requested NSSAI: This indicates the NSSAI provided by the terminal to the serving PLMN in the registration procedure. When the terminal stores a configured NSSAI corresponding to the serving PLMN, the requested NSSAI includes the S-NSSAI in the configured NSSAI corresponding to the serving PLMN. When the terminal does not store a configured NSSAI corresponding to the serving PLMN, for example, when the terminal accesses for the first time or deletes the configured NSSAI corresponding to the serving PLMN for a reason such as a reboot, the requested NSSAI may include the S-NSSAI in the default configured NSSAI, and the default configured NSSAI is configured by the HPLMN. In this scenario, the requested NSSAI may include an S-NSSAI that does not belong to the configured NSSAI corresponding to the serving PLMN.

[0143] allowed NSSAI: This indicates, for example, an NSSAI provided by the serving PLMN in the registration procedure, and indicates the network slice of the serving PLMN that the terminal is allowed to access within the current registration area (RA) and that is in the network slice corresponding to the requested NSSAI.

[0144] rejected NSSAI: This indicates, for example, an NSSAI provided by the serving PLMN in the registration procedure, and indicates a network slice that the terminal is denied access to within the current RA and that is in the network slice corresponding to the requested NSSAI.

[0145] Network slices corresponding to rejected NSSAIs may be classified into two types: one type of network slice that is not allowed to be accessed in the current RA but can be accessed in the serving PLMN, and the other type of network slice that is not allowed to be accessed in the entire serving PLMN.

[0146] pending NSSAI: This is the NSSAI provided by the serving PLMN in the registration procedure, and indicates the S-NSSAI for which the network slice-specific authentication and authorization procedure is pending. For details, refer to the definition in the 3GPP 23.501 standard. The details will not be described again here.

[0147] 3. Capability of Access Networks to Support Network Slices

[0148] The RAN's capability to support network slices is divided by using tracking areas (TAs) as a granularity: one TA may support one or more network slices, cells in the same TA support the same network slice, and one cell supports only one frequency band.

[0149] For example, assume that an access network device supports frequency (FR) 1 (FR1) and frequency 2 (FR2). Because each cell supports only one frequency band, FR1 and FR2 are frequencies supported by different cells. For example, FR1 is a frequency supported by cell1, and FR2 is a frequency supported by cell2. Further, assume that cell1 supports network slice 1 (corresponding to S-NSSAI1) and cell2 supports network slice 2 (corresponding to S-NSSAI2). Because cells in the same TA support the same network slice, cell1 and cell2 are cells in different TAs.

[0150] In other words, as shown in Figure 3, cell1 in TA1 supports network slice 1 over FR1, and cell2 in TA2 supports network slice 2 over FR2. Furthermore, it should be noted that the physical coverage of cell1 and the physical coverage of cell2 overlap fully or partially.

[0151] The AMF network element also recognizes the network slices supported by the RAN by using the TA as granularity. When establishing or updating an N2 connection to an AMF network element, the access network device may report the S-NSSAI supported by each TA of the access network device to the AMF network element.

[0152] For example, the access network device may report the TAs supported by the access network device in a supported TA list information element, and may report the S-NSSAIs supported by each TA in each PLMN or SNPN in a tracking area identity (TAI) slice support list information element.

[0153] 4. Slice Selection

[0154] When a network slice is deployed, the network slice may be selected in a registration procedure. For example, a terminal requests a network slice to be accessed during registration, and the core network feeds back to the terminal an allowed NSSAI that can be accessed by the terminal. Then, when performing a service transmission, the terminal selects an S-NSSAI from the allowed NSSAI and establishes a session via the network slice corresponding to the S-NSSAI.

[0155] Referring to FIG. 4, FIG. 4 illustrates a partial procedure related to slice selection in a registration procedure, which specifically includes the following steps:

[0156] S401: A terminal sends a registration request to an access network device. In response, the access network device receives the registration request from the terminal.

[0157] The registration request includes the NSSAI requested by the terminal, ie, the requested NSSAI.

[0158] S402: The access network device forwards the NSSAI requested by the terminal to an initial AMF network element. Correspondingly, the initial AMF network element receives the NSSAI requested by the terminal and forwarded by the access network device.

[0159] The access network device may forward the NSSAI requested by the terminal to the initial AMF network element via an N2 message.

[0160] S403: The initial AMF network element initiates a request to the UDM network element to obtain the terminal's subscribed NSSAI.

[0161] S404: When the allowed NSSAI of the terminal cannot be determined, the initial AMF network element requests slice selection from the NSSF network element and sends the NSSAI requested by the terminal, the NSSAI subscribed by the terminal, and the location information of the terminal to the NSSF network element.

[0162] S405: The NSSF network element returns the terminal's allowed NSSAI to the initial AMF network element.

[0163] Furthermore, if the AMF network element needs to be switched, the NSSF network element further returns the target AMF set (or list) and the identifier (ID) of the network repository function (NRF) network element corresponding to the target AMF network element to the initial AMF network element.

[0164] S406: When an AMF network element needs to be switched, the initial AMF network element queries the corresponding NRF network element for information about the target AMF network element based on the NRF ID returned by the NSSF network element.

[0165] S407: The initial AMF network element sends an AMF relocation request to the target AMF network element. The AMF relocation request includes the allowed NSSAI of the terminal returned by the NSSF network element.

[0166] In a possible implementation manner, the initial AMF network element may send an AMF relocation request to the target AMF network element via an interface between the AMF network elements, for example, as shown in S407a.

[0167] In another possible implementation manner, the initial AMF network element may alternatively forward the AMF relocation request to the target AMF network element via the access network device.

[0168] For example, as shown in S407b, the initial AMF network element sends an AMF relocation request to the access network device. In addition to the allowed NSSAI of the terminal returned by the NSSF network element, the AMF relocation request further includes information about the target AMF network element. After receiving the AMF relocation request from the initial AMF network element, the access network device forwards the AMF relocation request to the target AMF network element based on the information about the target AMF network element included in the AMF relocation request.

[0169] S408: The target AMF network element sends the terminal's allowed NSSAI to the access network device.

[0170] S409: The access network device feeds back the terminal's allowed NSSAI and UE route selection policy (URSP) to the terminal.

[0171] The URSP is generated by the PCF during the registration procedure.

[0172] At this point, the terminal may have learned the network slices that it can subsequently access and the URSPs corresponding to the network slices.

[0173] Furthermore, based on the current 23.502 protocol, the trigger scenarios of the registration procedure mainly include (1) initial registration of a terminal to a core network, (2) mobility registration update caused by the movement of a terminal to a TA outside a registration area (RA), (3) registration update caused by a change in the terminal's capabilities, (4) periodic registration update of a terminal in an inactive state, and (5) emergency registration. In other words, the terminal may select a network slice in the above five scenarios. In other words, in the current technology, the terminal does not initiate a registration procedure in scenarios other than the above five scenarios.

[0174] 5. Redirection

[0175] This application mainly describes a process in which a terminal initiates a registration request in a cell in TA1 of an access network device, and when TA1 does not support a network slice requested by the terminal, but TA2 of an access network device supports the network slice requested by the terminal, the terminal is redirected from a cell in TA1 to a cell in TA2. See Figure 5. The process mainly includes the following steps:

[0176] S501: A terminal sends a registration request to an AMF network element through an access network device. Correspondingly, the AMF network element receives a registration request from a terminal through the access network device.

[0177] The terminal sending a registration request to the AMF network element through the access network device includes: The terminal sends a registration request to the AMF network element through a cell 1 of the access network device, where the cell 1 is a cell in a TA1 of the access network device.

[0178] The registration request includes the NSSAI requested by the terminal, ie, the requested NSSAI.

[0179] S502: The AMF network element and the NSSAI network element perform network slice selection to determine the allowed NSSAI of the terminal. For details, see steps S402 to S405, and the details are not described again here.

[0180] The explanation is given through an example in which the first S-NSSAI included in the requested NSSAI does not belong to the allowed NSSAI, i.e., the network slice corresponding to the first S-NSSAI does not belong to the network slice that the serving PLMN allows the terminal to access in TA1, in other words, TA1 does not support the network slice corresponding to the first S-NSSAI. In other words, when the terminal sends a registration request to the AMF network element through cell 1 of the access network device, the first S-NSSAI belongs to the rejected NSSAI.

[0181] Furthermore, in addition to the allowed NSSAI, at least one of the rejected NSSAI and the configured NSSAI of the terminal is further determined.

[0182] S503: The AMF network element sends an N2 message to the access network device, where the message includes the terminal's allowed NSSAI.

[0183] Additionally, at least one of a rejected NSSAI and a configured NSSAI may be further included.

[0184] S504: The access network device sends a registration accept message to the terminal, where the message includes an allowed NSSAI of the terminal.

[0185] Additionally, at least one of a rejected NSSAI and a configured NSSAI may be further included.

[0186] S505: The access network device determines an access frequency of the terminal based on information acquired from the AMF network element.

[0187] For example, if one S-NSSAI included in the requested NSSAI is not supported by the current TA, in addition to the allowed NSSAI and configured NSSAI to the access network device, the AMF network element further provides a rejected NSSAI to the access network device. In this way, the access network device can redirect or steer the terminal to an access frequency that supports the S-NSSAI. After receiving the rejected NSSAI from the AMF network element, the access network device may perform step S505 to determine the access frequency of the terminal to determine the frequency of the neighboring cell.

[0188] S506: The access network device sends a radio resource control (RRC) connection release message to the terminal, the message including a frequency of the neighboring cell, an identifier of a network slice supported by the neighboring cell, and a cell reselection priority of the neighboring cell.

[0189] S507: The terminal performs an RRC connection release, enters an RRC idle state, and performs cell reselection based on the cell reselection priority configured by the access network device.

[0190] The explanation is given through an example in which a terminal accesses cell 2 in TA2 through cell reselection, TA2 does not belong to the RA in which the TA is located, and TA2 supports a network slice corresponding to the first S-NSSAI.

[0191] S508: The terminal resumes the registration procedure and sends a registration request to the AMF network element via cell 2 of the access network device.

[0192] The registration request may include the first S-NSSAI.

[0193] S509: This is the same as step S502.

[0194] S510: The AMF network element sends a registration accept message to the terminal through the cell 2 of the access network device, the message includes an allowed NSSAI of the terminal, and the allowed NSSAI may include a first S-NSSAI. In other words, when the terminal sends a registration request to the AMF network element through the cell 2 of the access network device, the first S-NSSAI belongs to the allowed NSSAI.

[0195] At this point, the terminal may access the network slice corresponding to the first S-NSSAI via cell 2 and use the services provided by the network slice.

[0196] 6. Xn Handover

[0197] The Xn interface is an interface between access network devices (i.e., between a source access network device to which handover is performed and a target access network device to which handover is performed). When an Xn interface or an Xn connection exists between access network devices, an example is used in which a terminal is handed over from a source access network device to a target access network device, and the Xn handover procedure is shown in Figure 6, which specifically includes:

[0198] S600: The AMF network element distributes mobility control information to a source access network device and a target access network device.

[0199] S601: A terminal reports measurement information to a source access network device.

[0200] For example, the measurement information includes reference signal received power (RSRP).

[0201] S602: The source access network device decides, based on the measurement information reported by the terminal and a local policy, to handover the terminal to the target access network device in an Xn handover manner.

[0202] S603: The source access network device sends a handover request message to the target access network device.

[0203] S604: The target access network device decides whether to accept the handover of the terminal. When the target access network device accepts the handover of the terminal, the following steps continue to be executed.

[0204] S605: The target access network device sends a handover request acknowledge message to the source access network device to indicate that the handover of the terminal is accepted. The handover request acknowledge message may further include a handover command to instruct the terminal to access the target access network device via a random access procedure.

[0205] S606: The source access network device sends a radio resource control (RRC) reconfiguration to the terminal to instruct the terminal to release the connection to the source access network device and attempt to access the target access network device via a random access procedure.

[0206] Steps S600 to S606 may be a handover preparation phase. After the handover preparation phase is completed, a handover execution phase is executed. The handover execution phase mainly includes steps S607 to S609.

[0207] S607: The source access network device sends the SN status to the target access network device via a sequence number (SN) status transfer message to perform packet data convergence protocol (PDCP) SN synchronization.

[0208] S608: The terminal interrupts the connection to the source access network device and establishes a connection to the target access network device via a random access procedure.

[0209] In the process of a terminal establishing a connection to a target access network device, the source access network device forwards user data sent to the source access network device by the UPF network element to the target access network device through a forwarding tunnel between the source access network device and the target access network device, and the target access network device buffers the forwarded user data.

[0210] S609: The terminal completes the random access procedure, establishes an air interface connection to the target access network device, and completes the access network handover. Then, the target access network device starts to transmit the buffered data received from the source access network device.

[0211] Up to this point, the handover of the access network is completed, and the path switching of the core network that is performed afterwards mainly includes the following steps.

[0212] S610: The target access network device sends a path switch request to the AMF network element to notify the AMF network element that the terminal has been switched, and the path switch request may include the session that needs to be switched and the AN tunnel port information for establishing the user plane connection. In addition, the path switch request may further include the location information of the terminal, such as the current TAI of the terminal.

[0213] S611: The AMF network element, the SMF network element, the UPF network element, etc. perform UPF path switching, and at the same time, the UPF network element delivers an end marker from the original path to indicate that data transmission on the original path is completed and new data will be delivered from the switched path.

[0214] S612: The AMF network element sends a path switch request acknowledge message to the target access network device to feedback the path switching status.

[0215] S613: The target access network device sends a UE context release message to the source access network device to instruct the source access network device to release the context of the terminal.

[0216] 7. N2 Handover

[0217] N2 handover is applicable to a scenario where there is no Xn interface or no Xn connection between access network devices. An example is used in which a terminal is handed over from a source access network device to a target access network device, and the N2 handover procedure is shown in Figure 7, which specifically includes:

[0218] S700: A source access network device decides to trigger an N2 handover.

[0219] The source access network device finds out by querying local information that there is no Xn connection between the source access network device and the target access network device and that the handover control plane messages need to be forwarded via the N2 interface.

[0220] S701: A source access network device sends a handover required message to a source AMF network element.

[0221] The HANDOVER REQUIRED message may include a target ID and a session identifier set for handover. The target ID may include an identifier of a target access network device and a target TAI, where the target TAI corresponds to a target TA that the terminal intends to access.

[0222] S702: The source AMF network element selects a target AMF network element.

[0223] If the target access network device is not within the service range of the source AMF network element, the source AMF network element selects a target AMF network element to serve the target access network device based on the identification information of the target access network device.

[0224] S703: The source AMF network element sends a UE context creation request message to the target AMF network element, where the message may include a target identifier and a session identifier set to be handover targeted.

[0225] The UE context create request message may be, for example, a Namf_Communication_CreateUEContext Request message, which is a type of N2 message.

[0226] S704: The target AMF network element sends a session management request message 1 to the SMF network element, which may include a target identifier and a session identifier set to be handover target.

[0227] The session management request message 1 may be, for example, a Namf_PDUSession_UpdateSMContext Request message, which is a type of N2 session management message.

[0228] S705: The SMF network element controls the establishment of an uplink tunnel between a PDU session anchor (PSA) and a target UPF network element.

[0229] S706: The SMF network element sends a session management response message 1 to the target AMF network element, which includes the session for which the target AMF network element has accepted the handover and QoS flow information.

[0230] The session management response message 1 may be, for example, a Namf_PDUSession_UpdateSMContext Response message.

[0231] S707: The target AMF network element monitors session management response messages corresponding to the session management request messages sent to each SMF network element, and begins to send a handover request to the target access network device after each session management response message is received or after a maximum waiting time is reached.

[0232] S708: The target AMF network element sends a handover request to the target access network device, where the handover request includes the session for which the target AMF network element has accepted the handover and the QoS flow information.

[0233] S709: The target access network device feeds back a handover request acknowledge message to the target AMF network element. The handover request acknowledge message includes the session that the target access network device accepts handover to and QoS flow information.

[0234] S710: Based on the session state fed back by the target access network device, the target AMF network element sends a session management request message 2 to the SMF network element to feed back the session for which handover has been accepted by both the target access network device and the target UPF network element and the QoS flow list.

[0235] The session management request message 2 may be, for example, a Namf_PDUSession_UpdateSMContext Request message.

[0236] S711: The SMF network element sends a session management response message 2 to the target AMF network element based on the session state fed back by the target AMF network element, where the message includes information about QoS flow granularity.

[0237] The session management response message 2 may be, for example, a Namf_PDUSession_UpdateSMContext Response message.

[0238] S712: The target AMF network element sends a UE context creation response message to the source AMF network element, where the message includes a list of rejected sessions and corresponding rejection reasons.

[0239] The UE context creation response message may be, for example, a Namf_Communication_CreateUEContext Response message.

[0240] S713: Continue to execute the N2 handover execution step. For details, please refer to the description in the existing protocol. The details will not be described again here.

[0241] The above mainly describes the network slice and the network slice selection process. In practical applications, the following scenarios may exist: In the registration procedure, the TA where the terminal is currently located does not support the network slice that the terminal intends to access, so the terminal cannot access the network slice in the registration procedure. Even if the terminal then moves to a TA that supports the network slice, the terminal still cannot access the network slice normally.

[0242] In a possible scenario, as shown in Figure 8a, assume that TA1 of access network device 1 supports network slice 2 (corresponding to S-NSSAI2) on FR2, TA2 of access network device 2 supports network slice 2 on FR2, TA3 of access network device 2 supports network slice 1 (corresponding to S-NSSAI1) on FR1, the physical coverage of TA2 and the physical coverage of TA3 overlap completely or partially, and TA4 of access network device 3 supports network slice 1 on FR1.

[0243] Currently, when dividing the RA corresponding to a terminal, the AMF network element usually groups TAs that support allowed NSSAI into the same RA. For example, a terminal requests access to S-NSSAI1 and S-NSSAI2 through access network device 1 in TA1, and the allowed NSSAI determined by the network side is S-NSSAI2, and both TA1 and TA2 support S-NSSAI2. Therefore, the AMF network element groups TA1 and TA2 into RA1.

[0244] For example, a terminal accesses a network via access network device 1, performs a registration procedure, and the terminal intends to access network slice 1. At the location of TA1, because TA1 of access network device 1 does not support network slice 1, the terminal cannot access network slice 1 and finally accesses network slice 2.

[0245] Subsequently, when the terminal moves into the service range of TA2 of access network device 2, TA2 is grouped into the range of RA1, and the terminal does not move out of the range of RA1, so the terminal does not resume the registration procedure based on the above five scenarios that trigger the registration procedure. Therefore, even if TA3, whose physical coverage is the same as that of TA2, can support network slice 1, i.e., even if a TA3 that can support network slice 1 exists at the terminal's current location, the terminal still cannot access network slice 1.

[0246] As the terminal moves, when the terminal moves into the service range of TA4 of access network device 3, it may move out of the range of RA1, so the terminal may restart the registration procedure to access network slice 1.

[0247] In other words, in the scenario shown in Figure 8a, when the terminal moves to TA2 that supports network slice 1, the terminal still cannot normally access network slice 1. The terminal can normally access network slice 1 only when it moves to a location of TA4, which affects user experience and service performance.

[0248] In another possible scenario, assume that TA1 of access network device 1 supports network slice 2 (corresponding to S-NSSAI2), TA2 of access network device 2 supports network slice 2 and network slice 1 (corresponding to S-NSSAI1), and TA3 of access network device 3 supports network slice 1, as shown in FIG. 8b.

[0249] When dividing the RA corresponding to the terminal, the AMF network element usually groups TAs that support allowed NSSAI into the same RA. Similarly, for example, the terminal requests access to S-NSSAI1 and S-NSSAI2 through the access network device 1 in TA1, the allowed NSSAI determined by the network side is S-NSSAI2, and both TA1 and TA2 support S-NSSAI2. Therefore, the AMF network element groups TA1 and TA2 into RA1. Based on the grouping of RA1, when the terminal moves into the service range of TA2 of the access network device 2, it still cannot access the network slice 1. For a specific analysis, refer to the scenario shown in FIG. 8a. Details will not be described again here.

[0250] In yet another possible scenario, as shown in FIG. 8c, assume that cells in TA1 of access network device 1 support network slice 2 (corresponding to S-NSSAI2) on FR2, cells in TA2 of access network device 1 support network slice 1 (corresponding to S-NSSAI1) on FR1, and there is a non-overlapping area between the physical coverage of TA1 and that of TA2.

[0251] For example, a terminal accesses a network via a cell in TA1 of access network device 1, performs a registration procedure, and the terminal intends to access network slice 1, but the terminal is not within the physical coverage of TA2. Since TA1 of access network device 1 does not support network slice 1, the terminal cannot access network slice 1 and finally accesses network slice 2.

[0252] When a terminal enters the coverage of TA2 and is handed over from a cell in TA1 to a cell in TA2, an intra-access network device cell handover, or intra-eNodeB handover for short, occurs. In this scenario, even if a cell in TA2 supports network slice 1, the terminal device may still not be able to access network slice 1 based on existing procedures.

[0253] On this basis, this application provides a communication method based on network slices to reduce the probability that a terminal cannot successfully access a network slice, improve the network slice access success rate, and further improve service performance and user experience.

[0254] Below, the technical solutions provided in the embodiments of this application are described with reference to the accompanying drawings.

[0255] The communication method based on network slices provided in the embodiments of this application may be used in any communication system. The communication system may be a 3GPP communication system, such as a 5G mobile communication system or a new radio (NR) system, an NR V2X system or other next-generation communication system, or may be a non-3GPP communication system. This is not limited.

[0256] The communication method based on network slicing provided in the embodiments of this application may be applied to various communication scenarios, for example, one or more of the following communication scenarios: enhanced mobile broadband (eMBB), ultra-reliable low latency communication (URLLC), machine type communication (MTC), massive machine type communications (mMTC), device to device (D2D), vehicle to everything (V2X), vehicle to vehicle (V2V), Internet of Things (IoT), etc.

[0257] The following uses Fig. 9a as an example to describe a communication system provided in an embodiment of this application. As shown in Fig. 9a, the communication system may include at least one terminal and at least one network device.

[0258] In some embodiments, the network device in this application is a mobility management device. In this scenario, the communication system may further include a first access network device. Furthermore, the communication system further includes a second access network device.

[0259] In some other embodiments, the network device in this application is a first access network device. In this scenario, the communication system may further include a mobility management device. Furthermore, the communication system further includes a second access network device.

[0260] Further, in some embodiments, the network device in this application is a second access network device. In this scenario, the communication system may further include a mobility management device and a first access network device.

[0261] In other words, as shown in FIG. 9b, the communication system provided in this application may include one or more of a terminal, a first access network device, a second access network device, and a mobility management device.

[0262] Optionally, as shown in FIG. 9c, the communication system may further include one or more of a session management network element, a policy control network element, a user plane network element, an application function network element, a slice selection function network element, a unified data management network element, or a data network (DN) connected to the operator network.

[0263] In this application, after accessing the network, the terminal may establish a protocol data unit (PDU) session, access an external data network DN through the PDU session, and interact with an application server deployed in the DN. As shown in Figure 9c, based on different DNs accessed by the terminal, the network may select a user plane network element accessing the DN as a PDU session anchor, i.e., a protocol data unit session anchor (PSA), based on a network policy, to access an application server through the N6 interface of the PSA. Application servers of the same application may be deployed in multiple locations. Based on the access location of the terminal, the network may select a PSA that is close to the terminal and can support the terminal in accessing the DN, thereby reducing route recurvation and network delay.

[0264] A terminal in this application may be a device configured to realize wireless communication functions, such as a terminal or a chip usable in a terminal. A terminal may be deployed on the ground, including indoors or outdoors, handheld, or vehicle-mounted, on the water (such as a ship), or in the air (such as an aircraft, balloon, and satellite). A terminal may be a user equipment (UE), access terminal, terminal unit, terminal station, mobile station, remote station, remote terminal, mobile device, wireless communication device, terminal agent, terminal device, etc. in a 5G network or a future evolved public land mobile network (PLMN). An access terminal may be a cellular phone, a cordless phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a personal digital assistant (PDA), a handheld device with wireless communication capabilities, a computing device or other processing device connected to a wireless modem, an in-vehicle device, a wearable device, a virtual reality (VR) terminal device, an augmented reality (AR) terminal device, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in a smart grid, a wireless terminal in transportation safety, a wireless terminal in a smart city, a wireless terminal in a smart home, etc. The terminals may be mobile or fixed.

[0265] The access network device in this application is a device for connecting a terminal to a wireless network, and may be an evolved NodeB (eNB or eNodeB) in LTE, or a base station, a broadband network gateway (BNG), an aggregation switch, or a non-3GPP access device in a 5G network or a future evolved public land mobile network (PLMN). Alternatively, the access network device in the embodiment of this application may be a radio controller in a cloud radio access network (CRAN), or a transmission and reception point (TRP), a device including a TRP, etc. This is not specifically limited in the embodiment of this application. Optionally, the base station in the embodiment of this application may include various types of base stations, for example, a macro base station, a micro base station (also called a small cell), a relay station, or an access point. This is not specifically limited in the embodiment of this application.

[0266] The mobility management device in this application is mainly used for terminal attachment, mobility management and tracking area update procedures in a mobile network. The mobility management device terminates non-access stratum (NAS) messages, completes registration management, connection management, reachability management, tracking area list (TA list) allocation, mobility management, etc., and transparently routes session management (SM) messages to a session management network element. In a 5G communication system, the mobility management network element may be an AMF. In future communications such as 6th generation (6G) communications, the mobility management network element may still be an AMF network element, or may have other names. This is not limited in the embodiments of this application.

[0267] The slice selection function network element in this application is configured to select a network slice for a terminal, etc. In a 5G communication system, the slice selection function network element may be an NSSF network element. In future communications such as 6G communications, the network slice selection function network element may still be an NSSF network element, or may have another name. This is not limited in the embodiments of this application.

[0268] The policy control network element in this application includes a user subscription data management function, a policy control function, a charging policy control function, a QoS control function, etc., and is configured to guide a unified policy framework of network behavior, provide policy rule information to a control plane function network element (e.g., an AMF network element), etc. In a 5G communication system, the policy control network element may be a PCF network element. In future communications such as 6G communications, the policy control function network element may still be a PCF network element, or may have other names. This is not limited in the embodiments of this application.

[0269] A 5G communication system is used as an example. A schematic diagram of a possible network architecture corresponding to the communication system shown in FIG. 9c to which the embodiments of this application are applicable may be that shown in FIG.

[0270] It should be noted that the communication system and service scenarios described in the embodiments of this application are intended to more clearly explain the technical solutions in the embodiments of this application, but do not constitute limitations on the technical solutions provided in the embodiments of this application. Those skilled in the art may learn that the technical solutions provided in the embodiments of this application are also applicable to similar technical problems as network architectures evolve and new service scenarios emerge.

[0271] The functions related to the terminal, the access network device and the core network element in this application may be realized by one device, may be realized jointly by multiple devices, may be realized by one or more functional modules in one device, or may be realized by one or more chips, system-on-chip (SOC) or chip system. A chip system may include a chip, or may include a chip and other discrete components. This is not specifically limited in the embodiments of this application.

[0272] It may be understood that the above functions may be network elements within a hardware device, software functions running on dedicated hardware, a combination of hardware and software, or virtualized functions instantiated on a platform (e.g., a cloud platform).

[0273] For example, functions related to the terminal, the access network device and the core network element in this application may be realized by a communication device 1000 in Fig. 10. Fig. 10 is a schematic diagram of a structure of a communication device 1000 according to an embodiment of this application. The communication device 1000 includes one or more processors 1001, a communication line 1002, and at least one communication interface (the communication interface 1004 and one processor 1001 are used as an example in Fig. 10 for explanation only), and may further include a memory 1003, if desired.

[0274] The processor 1001 may be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to control the execution of programs in the solutions of this application.

[0275] The communication lines 1002 may include paths for connecting different components.

[0276] The communication interface 1004 may be a transceiver module configured to communicate with a communication network such as an Ethernet, a RAN, or a wireless local area network (WLAN) or other device. For example, the transceiver module may be a device such as a transceiver or a transceiver machine. Optionally, the communication interface 1004 may alternatively be a transceiver circuit located in the processor 1001 and configured to provide signal input and signal output for the processor.

[0277] The memory 1003 may be any device having a storage function. For example, the memory may be, but is not limited to, a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, a random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other compact disc storage, an optical disc storage (including compressed optical discs, laser discs, optical discs, digital versatile discs, Blu-ray discs, etc.), a magnetic disc storage medium or other magnetic storage device, or any other medium capable of carrying or storing program code envisaged in the form of instructions or data structures and accessible by a computer. The memory may exist independently and be connected to the processor through a communication line 1002. Alternatively, the memory and the processor may be integrated.

[0278] The memory 1003 is configured to store computer-executable instructions for executing the solution of this application, and the processor 1001 controls the execution. The processor 1001 is configured to execute the computer-executable instructions stored in the memory 1003 to realize the communication method based on the network slice provided in the embodiment of this application.

[0279] Alternatively, optionally, in this embodiment of this application, the processor 1001 may execute processing-related functions in a communication method based on a network slice provided in the following embodiments of this application, and the communication interface 1004 is responsible for communicating with other devices or communication networks, which is not specifically limited in the embodiments of this application.

[0280] Optionally, the computer-executable instructions in this embodiment of the application may also be referred to as application code, which is not specifically limited in the embodiment of the application.

[0281] In a specific implementation, in an embodiment, the processor 1001 may include one or more CPUs, such as CPU0 and CPU1 in FIG.

[0282] In a specific implementation, in an embodiment, the communication device 1000 may include multiple processors, such as processor 1001 and processor 1008 in FIG. 10. Each of these processors may be a single-core processor or a multi-core processor. The processors here may include at least one of various computing devices that execute software, such as, but not limited to, the following: a central processing unit (CPU), a microprocessor, a digital signal processor (DSP), a microcontroller unit (MCU), or an artificial intelligence processor. Each type of computing device may include one or more cores for executing software instructions to perform an operation or process.

[0283] In a specific implementation, in an embodiment, the communication device 1000 may further include an output device 1005 and an input device 1006. The output device 1005 may communicate with the processor 1001 and display information in a number of ways. For example, the output device 1005 may be a liquid crystal display (LCD), a light emitting diode (LED) display device, a cathode ray tube (CRT) display device, or a projector. The input device 1006 may communicate with the processor 1001 and receive user input in a number of ways. For example, the input device 1006 may be a mouse, a keyboard, a touch screen device, or a sensor device.

[0284] In some cases, the communication device 1000 may also be referred to as a communication device, and may be a general-purpose device or a dedicated device. For example, the communication device 1000 may be a desktop computer, a portable computer, a network server, a palmtop computer (PDA), a mobile phone, a tablet computer, a wireless terminal device, an embedded device, the above terminal, the above network device, or a device having a structure similar to that of FIG. 10. The type of the communication device 1000 is not limited in the embodiments of this application.

[0285] Furthermore, the configuration structure shown in Figure 10 does not constitute a limitation on the communication device. In addition to the parts shown in Figure 10, the communication device may include more or less parts than those shown in the drawing, or some parts may be combined, or a different part layout may exist.

[0286] Below, a communication method based on network slices provided in an embodiment of this application will be described with reference to the communication system shown in Figure 9a, Figure 9b or Figure 9c.

[0287] It should be noted that in the following embodiments of this application, the names of messages between network elements, the names of each parameter, the names of each piece of information, etc. are merely examples, and other names may be used in other embodiments, which are not specifically limited in the manner provided in this application.

[0288] It may be understood that in this embodiment of the application, each network element may perform some or all of the steps in this embodiment of the application. These steps or operations are merely examples. In this embodiment of the application, other operations or variations of various operations may also be performed. Furthermore, it is contemplated that the steps may be performed in a different order than presented in the embodiment of the application, and that not all operations in the embodiment of the application need to be performed.

[0289] 11 is a flowchart of a communication method based on network slices according to an embodiment of the present application. FIG 11 is described with reference to the scenarios in FIG 8a and FIG 8b. As shown in FIG 11, the method may include:

[0290] S1101: A network device receives, via a first access network device in a first network, information regarding a network slice that a terminal requests to access.

[0291] In some embodiments, the network device may be a mobility management device. In a 5G system, the mobility management device may be, for example, an AMF network element.

[0292] In some embodiments, the first network may be a PLMN or an SNPN, which is not specifically limited in this application. For example, the first network may be a PLMN including TA1-TA4 in FIG. 8a, or a PLMN including TA1-TA3 in FIG. 8b. The first access network device may be access network device 1 in FIG. 8a, or access network device 1 in FIG. 8b.

[0293] The information on the network slice that the terminal requests to access includes identification information of the first network slice and identification information of the second network slice. In other words, the first network slice and the second network slice are network slices corresponding to the terminal's requested NSSAI. For example, the identification information of the first network slice is S-NSSAI1, and the identification information of the second network slice is S-NSSAI2.

[0294] In one example, the identification information of the slice may be the S-NSSAI, or may be other information for identifying the slice, which is not specifically limited in this application.

[0295] The first network slice is not supported by the first tracking area of ​​the first access network device, in other words, the first tracking area does not support the first network slice.

[0296] In some embodiments, the first tracking area may be a tracking area in which the terminal is located when the terminal transmits information about the network slice that the terminal requests to access. For example, the first tracking area may be TA1 in FIG. 8a or TA1 in FIG. 8b.

[0297] The second tracking area in the first network supports the first network slice. In other words, the first network slice is a network slice that the terminal is allowed to access in the first network. In other words, there is at least one tracking area in the first network that supports the first network slice. For example, the second tracking area may be TA3 in Fig. 8a or TA2 in Fig. 8b.

[0298] In some embodiments, the network device may determine a network slice supported by a tracking area of ​​the first access network device and determine that the first tracking area of ​​the first access network device does not support the first network slice. In addition, the network device may further acquire a configured NSSAI of the terminal to acquire that a tracking area exists in the first network and supports the first network slice. For ease of explanation, in this application, a tracking area in the first network and supporting the first network slice is referred to as a second tracking area, i.e., the second tracking area in the first network supports the first network slice.

[0299] S1102: The network device determines a network slice that the terminal is allowed to access.

[0300] The network slice that the terminal is permitted to access is a network slice that corresponds to the terminal's allowed NSSAI and includes the second network slice. Furthermore, the allowed NSSAI does not include the first network slice. In other words, the first network slice does not belong to the network slice that the terminal is permitted to access. That is, as follows.

[0301] The network slices that the terminal requests to access include a first network slice and a second network slice.

[0302] The network slice that the terminal is allowed to access includes a second network slice.

[0303] The network slices to which the terminal is denied access include the first network slice.

[0304] It may be understood that the network slice that the terminal is permitted to access includes the second network slice, and thus the second network slice is also a network slice that the terminal is permitted to access in the first network.

[0305] In one example, the network device may independently determine the network slice that the terminal is permitted to access. Alternatively, the network device may determine the network slice that the terminal is permitted to access by interacting with a network slice selection function network element (e.g., an NSSF network element), which is not specifically limited in this application.

[0306] In some embodiments, in addition to the network slice that the terminal is permitted to access, the network device further determines a network slice that the terminal is denied to access to determine whether the first network slice is a network slice that the terminal is denied to access. The network slice that the terminal is denied to access is a network slice that corresponds to the rejected NSSAI of the terminal. In this application, the description is given through an example in which the network slice that the terminal is denied to access includes the first network slice. That is, as follows.

[0307] The network slices that the terminal requests to access include a first network slice and a second network slice.

[0308] The network slice that the terminal is permitted to access includes a second network slice, that is, the allowed NSSAI includes S-NSSAI2.

[0309] The network slice to which the terminal is denied access includes the first network slice, i.e., the rejected NSSAI includes S-NSSAI1.

[0310] S1103: The network device determines a registration area.

[0311] In different implementation scenarios of this application, the scope of the registration area may be different. For example, in a possible implementation scenario, the registration area excludes a tracking area supporting the first network slice and the second network slice. The tracking area supporting the first network slice and the second network slice may be understood as a tracking area supporting both the first network slice and the second network slice, or may be understood as a tracking area supporting the first network slice and the second network slice simultaneously. This is applicable to the scenario of FIG. 8b. For example, the tracking area supporting the first network slice and the second network slice may be TA2 in FIG. 8b.

[0312] In some embodiments, a registration area excluding a tracking area may be understood as the registration area not including the tracking area, the tracking area not being in the registration area, or the tracking area being removed from the registration area. Examples are as follows:

[0313] In a possible implementation manner, excluding a tracking area in which a registration area supports a first network slice and a second network slice may be understood as the registration area not including a tracking area that supports the first network slice and the second network slice.

[0314] In a possible implementation manner, the exclusion of a tracking area in which a registration area supports a first network slice and a second network slice may be understood as the absence of a tracking area in which the registration area supports the first network slice and the second network slice.

[0315] In a possible implementation manner, excluding a tracking area in which a registration area supports a first network slice and a second network slice may be understood as the tracking area supporting the first network slice and the second network slice being deleted from the registration area.

[0316] In a possible implementation manner, excluding a tracking area in which a registration area supports a first network slice and a second network slice may be understood as a tracking area included in the registration area supporting the second network slice but not supporting the first network slice. Obviously, a tracking area included in the registration area may support the second network slice or support other network slices other than the first network slice.

[0317] In a possible implementation manner, excluding a tracking area in which a registration area supports a first network slice and a second network slice may be understood as a tracking area included in the registration area supporting the second network slice, and a tracking area supporting the first network slice being excluded from the registration area.

[0318] For example, in the scenario shown in Figure 8b, for example, the identity of the first network slice is S-NSSAI1, and the identity of the second network slice is S-NSSAI2. Assume that TA1 of access network device 1 supports the second network slice, TA2 of access network device 2 supports the first network slice and the second network slice, and TA3 of access network device 3 supports the first network slice.

[0319] When the network device determines the registration area through the method provided in this application, the registration area excludes the tracking area supporting the first network slice and the second network slice. In other words, the registration area excludes TA2. Thus, the registration area determined by the network device does not include TA2. When the terminal subsequently moves from a cell in TA1 to a cell in TA2, since it has moved to a TA outside the registration area, and still intends to access the first network slice, the terminal may resume the registration procedure to access the first network slice and use the service provided by the first network slice.

[0320] In another possible implementation scenario, the registration area excludes the tracking area of ​​the access network device supporting the first and second network slices. This is applicable to the scenario of Fig. 8a. For example, the access network device supporting the first and second network slices may be the access network device 2 in Fig. 8a, and the tracking area of ​​the access network device 2 includes TA2 and TA3.

[0321] It should be noted that in a tracking area of ​​an access network device, a tracking area supporting a first network slice and a tracking area supporting a second network slice may be the same tracking area. For example, a tracking area 1 of an access network device supports a first network slice and a second network slice. Alternatively, a tracking area supporting a first network slice and a tracking area supporting a second network slice may be different tracking areas. For example, a tracking area 1 of an access network device supports a first network slice, and a tracking area 2 of an access network device supports a second network slice.

[0322] In one example, the registration area may exclude all tracking areas of the access network device supporting the first and second network slices. In other words, when one or more tracking areas supporting the first network slice are present in the access network device corresponding to the tracking area supporting the second network slice, the tracking area supporting the second network slice is excluded from the registration area.

[0323] In a possible implementation manner, excluding a tracking area of ​​an access network device in which the registration area supports the first network slice and the second network slice may be understood as the registration area not including the tracking area of ​​the access network device in which the registration area supports the first network slice and the second network slice.

[0324] In a possible implementation manner, excluding the tracking areas of the access network devices supporting the first network slice and the second network slice in a registration area may be understood as the tracking areas of the access network devices supporting the first network slice and the second network slice not being in the registration area.

[0325] In a possible implementation manner, excluding a tracking area of ​​an access network device supporting a first network slice and a second network slice from a registration area may be understood as the tracking area of ​​the access network device supporting the first network slice and the second network slice being removed from the registration area.

[0326] For example, in the scenario shown in Figure 8a, for example, the identity of the first network slice is S-NSSAI1, and the identity of the second network slice is S-NSSAI2. Assume that TA1 of access network device 1 supports the second network slice, TA2 of access network device 2 supports the second network slice, TA3 supports the first network slice, and TA4 of access network device 3 supports the first network slice.

[0327] When the network device determines the registration area through the method provided in this application, the registration area excludes the tracking areas of the access network devices supporting the first network slice and the second network slice. In other words, the registration area excludes the tracking areas of the access network device 2, i.e., TA2 and TA3, and thus the registration area determined by the network device does not include TA2 or TA3. It can be understood that the RA itself does not include TA3, since TA3 does not support allowed NSSAI. However, for TA2, TA2 supports S-NSSAI2, but TA3 still exists under the access network device 2 corresponding to TA2, and TA3 supports S-NSSAI1. In this case, TA2 needs to be excluded from the RA when the RA is determined. When the terminal subsequently moves from a cell in TA1 to a cell in the access network device 2, since it has moved to TA2 outside the registration area, and still intends to access the first network slice, the terminal may resume the registration procedure to access the first network slice and use the service provided by the first network slice.

[0328] S1104: The network device transmits information about the registration area to the terminal.

[0329] In one example, the information about the registration area may include identification information of the tracking area within the registration area. The specific content of the information about the registration area is not specifically limited in this application.

[0330] In one example, when receiving information about a registration area and then leaving the registration area, the terminal may trigger a mobility registration update to re-request a network slice to be accessed, i.e., re-perform the registration procedure.

[0331] For example, the scenario shown in FIG. 8a is used as an example. Suppose the terminal moves from the coverage of TA1 to the coverage of TA2. Because TA2 is not in RA, the terminal resumes the registration procedure. Suppose that in the resumed registration procedure, the terminal still requests to access the first network slice (corresponding to S-NSSAI1). Because TA2 does not support the first network slice, the first network slice in the registration procedure does not belong to the network slice that the terminal is allowed to access. However, TA3, whose physical coverage is the same as that of TA2, supports the first network slice. Therefore, the access network device may send an RRC connection release message to redirect the terminal to a cell in TA3, so that the terminal accesses the first network slice in the cell in TA3. For details, refer to the procedure shown in FIG. 5. The details will not be described again here. It should be noted that the registration request in S501 of FIG. 5 may be understood as a registration request initiated by the terminal in a cell in TA2.

[0332] The scenario shown in Figure 8b is used as an example. Assume that the terminal moves from the coverage of TA1 to the coverage of TA2. Since TA2 is not in the RA, the terminal may resume the registration procedure. Assume that in the resumed registration procedure, the terminal still requests to access the first network slice (corresponding to S-NSSAI1). Since TA2 supports the first network slice, the terminal accesses the first network slice in TA2.

[0333] Based on this solution, when determining a registration area, the network device excludes a tracking area supporting the first network slice and the second network slice, or excludes a tracking area of ​​an access network device supporting the first network slice and the second network slice. Thus, when a terminal moves within the excluded tracking area, since the registration area of ​​the terminal does not include the tracking area and the tracking area supports the first network slice, the terminal may resume the registration procedure to request access to the first network slice, thereby increasing the success rate of accessing the first network slice, thereby improving service performance and user experience.

[0334] 12 is a flowchart of a communication method based on another network slice according to an embodiment of the present application. FIG. 12 is described with reference to FIG. 11. As shown in FIG. 12, the method may include:

[0335] S1201: A network device determines a network slice to which a terminal is permitted to access and a network slice to which the terminal is denied to access.

[0336] In some embodiments, before step S1201, the method may further include: the network device receives, via a first access network device in the first network, information regarding a network slice that the terminal requests to access.

[0337] For the relevant description of the network device and the first network, please refer to step S1101, and the details will not be described again here.

[0338] The information on the network slice that the terminal requests to access includes identification information of the first network slice and identification information of the second network slice, in other words, the first network slice and the second network slice are network slices corresponding to the requested NSSAI of the terminal.

[0339] In some embodiments, the network device determining the network slices that the terminal is allowed to access and the network slices that the terminal is denied to access may include: The network device receives, from a slice selection function network element, information regarding the network slices that the terminal is allowed to access and the network slices that the terminal is denied to access.

[0340] In this application, an explanation is given through an example in which a network slice to which a terminal is permitted to access includes a second network slice, and a network slice to which the terminal is denied access includes a first network slice.

[0341] In some embodiments, the first network slice is not supported by a first tracking area of ​​the first access network device (in other words, the first tracking area does not support the first network slice), and the second network slice is a network slice supported by the first tracking area (in other words, the first tracking area supports the second network slice).

[0342] In some embodiments, the second tracking area in the first network supports the first network slice, in other words, the first network slice is a network slice that the terminal is allowed to access in the first network.

[0343] In one example, the network device may determine a network slice supported by a tracking area of ​​a first access network device and determine that the first tracking area of ​​the first access network device does not support the first network slice. Further, the network device may learn a configured NSSAI of the terminal to learn that there is a tracking area in the first network that supports the first network slice, i.e., the first network slice is a network slice that the terminal is allowed to access in the first network. In this application, the tracking area in the first network that supports the first network slice is referred to as a second tracking area.

[0344] S1202: The network device determines a registration area for the terminal based on a network slice that the terminal is permitted to access and a network slice that the terminal is denied to access.

[0345] In a possible implementation scenario, the registration area excludes a tracking area that supports the first network slice and the second network slice.

[0346] In another possible implementation scenario, the registration area excludes tracking areas of access network devices supporting the first network slice and the second network slice.

[0347] For detailed description, please refer to the relevant description in step S1103. The details will not be described again here. This manner of determining the registration area may be understood as follows: When the registration area is determined, the network slice that is rejected by the network for access because the network slice is not supported by the current TA is taken into account.

[0348] In other possible designs, the registration area excludes tracking areas supporting the network slices that the terminal is permitted to access and the network slices that the terminal is denied to access, or the registration area excludes tracking areas of access network devices supporting the network slices that the terminal is permitted to access and the network slices that the terminal is denied to access. In other words, when the range of the registration area is determined, the reason why the network slice is denied by the network for access may not be considered, provided that the network slice is denied and belongs to the network slice that the terminal is denied to access. Thus, when the range of the registration area is determined, tracking areas supporting the network slices that the terminal is permitted to access and the network slices that the terminal is denied to access, or tracking areas of access network devices supporting the network slices that the terminal is permitted to access and the network slices that the terminal is denied to access, are considered to be excluded from the registration area.

[0349] For example, assume the following scenario exists:

[0350] The network slices that the terminal requests to access include a first network slice, a second network slice, and a third network slice.

[0351] The network slice that the terminal is allowed to access includes a second network slice.

[0352] The network slices to which the terminal is denied access include a first network slice and a third network slice.

[0353] Therefore, when the registration area is determined, the tracking area supporting the first network slice and the second network slice, the tracking area of ​​the access network device supporting the first network slice and the second network slice, the tracking area supporting the third network slice and the second network slice, the tracking area of ​​the access network device supporting the third network slice and the second network slice, the tracking area supporting the first network slice, the second network slice and the third network slice, or the tracking area of ​​the access network device supporting the first network slice, the second network slice and the third network slice may be considered to be excluded from the registration area.

[0354] S1203: The network device transmits information about the registration area to the terminal.

[0355] For details, please refer to the relevant description in step S1104, and the details will not be described again here.

[0356] Based on this solution, the registration area of ​​the terminal is determined based on the network slice the terminal is allowed to access and the network slice the terminal is denied to access, such that the registration area excludes tracking areas supporting the network slice the terminal is allowed to access and the network slice the terminal is denied to access, or tracking areas of access network devices supporting the network slice the terminal is allowed to access and the network slice the terminal is denied to access. Thus, when the terminal moves within the excluded tracking area, since the registration area of ​​the terminal does not include the tracking area and the tracking area supports the first network slice, the terminal may resume the registration procedure to request access to the first network slice, thereby increasing the success rate of accessing the first network slice, thereby improving service performance and user experience.

[0357] The method shown in Figure 11 and Figure 12 provides a registration area division manner. Figure 13 is a flowchart of a communication method based on another network slice according to an embodiment of this application. The method provides another registration area division manner. As shown in Figure 13, the method may include:

[0358] S1301: In a registration procedure of a first network, a network device determines an allowed NSSAI of a terminal.

[0359] For a description of the first network and the network device, refer to step S1101. For a registration procedure and a method for determining an allowed NSSAI by a network device, refer to the procedure shown in Figure 4. Details are not described again here.

[0360] S1302: A network device determines a first type of network slice.

[0361] A first type of network slice is a network slice that does not belong to the terminal's allowed NSSAI in a network slice that the terminal is permitted to access in the first network.

[0362] For example, assume the following scenario exists:

[0363] The network slices that the terminal requests to access include a first network slice, a second network slice, and a third network slice.

[0364] The network slice that the terminal is allowed to access includes a second network slice.

[0365] The network slices to which the terminal is denied access include a first network slice and a third network slice.

[0366] The network slices that the terminal is allowed to access in the first network (e.g., current PLMN) include a first network slice, a second network slice, and a fourth network slice. For example, the network slices that the terminal is allowed to access in the first network may be represented via a configured NSSAI of the terminal in the first network.

[0367] The network slice that the terminal is allowed to access in the second network (e.g., another PLMN) includes a third network slice.

[0368] In this scenario, the first type of network slice includes a first network slice and a fourth network slice.

[0369] S1303: The network device determines a registration area.

[0370] In different implementation scenarios of this application, the scope of the registration area may be different. For example, in a possible implementation scenario, the registration area excludes at least one network slice corresponding to an allowed NSSAI and at least one tracking area supporting a first type of network slice.

[0371] A tracking area supporting at least one network slice corresponding to an allowed NSSAI and at least one network slice of a first type may be understood as a tracking area supporting both at least one network slice corresponding to an allowed NSSAI and at least one network slice of a first type, or a tracking area supporting at least one network slice corresponding to an allowed NSSAI and at least one network slice of a first type simultaneously.

[0372] For example, based on a hypothetical scenario in S1302, the registration area may exclude a tracking area supporting the second network slice and the first network slice, may exclude a tracking area supporting the second network slice and the fourth network slice, or may exclude a tracking area supporting the second network slice, the first network slice, and the fourth network slice.

[0373] In another possible implementation scenario, the registration area excludes at least one network slice corresponding to the allowed NSSAI and a tracking area of ​​an access network device supporting at least one network slice of the first type.

[0374] It should be noted that in a tracking area of ​​an access network device, a tracking area supporting at least one network slice corresponding to an allowed NSSAI and a tracking area supporting at least one network slice of a first type may be the same tracking area. For example, a tracking area 1 of an access network device supports at least one network slice corresponding to an allowed NSSAI and at least one network slice of a first type. Alternatively, a tracking area supporting at least one network slice corresponding to an allowed NSSAI and a tracking area supporting at least one network slice of a first type may be different tracking areas. For example, a tracking area 1 of an access network device supports at least one network slice corresponding to an allowed NSSAI, and a tracking area 2 of an access network device supports at least one network slice of a first type.

[0375] In one example, a registration area may exclude at least one network slice corresponding to the allowed NSSAI and all tracking areas of an access network device supporting at least one first type network slice. In other words, when one or more tracking areas supporting at least one first type network slice are present in an access network device corresponding to a tracking area supporting a second network slice, the tracking area supporting the second network slice is excluded from the registration area.

[0376] For example, based on the hypothetical scenario in S1302, the registration area may exclude tracking areas of access network devices supporting the second network slice and the first network slice, may exclude tracking areas of access network devices supporting the second network slice and the fourth network slice, or may exclude tracking areas of access network devices supporting the second network slice, the first network slice, and the fourth network slice.

[0377] S1304: The network device transmits information about the registration area to the terminal.

[0378] For details, please refer to the relevant description in step S1104, and the details will not be described again here.

[0379] Based on this solution, for a network slice of a first type that does not belong to a network slice that the terminal is allowed to access in the registration procedure of the first network, but is included in a network slice that the terminal is allowed to access in the first network, regardless of whether the network slice that the terminal requests to access in this registration procedure carries an identifier of the first network slice, the terminal may subsequently intend to access the network slice of the first type, since the network slice of the first type is included in the network slice that the terminal is allowed to access in the first network. In this case, the network device takes the network slice of the first type into account when determining a registration area. For example, the registration area excludes at least one network slice corresponding to the allowed NSSAI and a tracking area supporting at least one network slice of the first type, or excludes a tracking area of ​​an access network device supporting at least one network slice corresponding to the allowed NSSAI and at least one network slice of the first type. Therefore, when a terminal moves to an excluded tracking area, since the registration area of ​​the terminal does not include the tracking area and the tracking area supports at least one first type network slice, the terminal may resume the registration procedure when it intends to access the first type network slice and request to access the at least one first type network slice, thereby improving the success rate of accessing the network slice and further improving service performance and user experience.

[0380] 11 to 13, the registration area is divided, thereby reducing the probability that the terminal cannot successfully access the target network slice (e.g., the above-mentioned first network slice), and improving the network slice access success rate. Furthermore, this application further provides a method for improving the network slice access success rate in another manner.

[0381] FIG. 14 is a flowchart of a communication method based on network slice according to this application. The method is applicable to a scenario in which a terminal is handed over from a first cell to a second cell, and a network device informs the terminal of an available network slice in the second cell. The handover scenario may be an intra-eNodeB handover, i.e., the first cell and the second cell belong to the same access network device, or an inter-eNodeB handover, i.e., the first cell and the second cell belong to different access network devices. For example, the method shown in FIG. 14 is applicable to the scenario shown in FIG. 8b or FIG. 8c. As shown in FIG. 14, the method includes the following steps:

[0382] S1401: A network device determines a first network slice.

[0383] In some embodiments, the network device may be a mobility management device. In a 5G system, the mobility management device may be, for example, an AMF network element.

[0384] In some other embodiments, the network device may be an access network device, for example, when the first cell belongs to the first access network device and the second cell belongs to the second access network device, the network device is a second access network device, or when both the first cell and the second cell belong to the first access network device, the network device is a first access network device.

[0385] The first network slice does not belong to the network slices that the terminal is allowed to access in the first cell. In other words, when the terminal starts a registration procedure in the first cell, the network slices corresponding to the allowed NSSAI of the terminal do not include the first network slice. In this application, the network slice that the terminal is denied access to may be referred to as a target network slice, and there may be one or more target network slices.

[0386] The registration area of ​​the terminal includes a first cell and a second cell.

[0387] In some embodiments, the first cell is a cell in a first TA and the second cell is a cell in a second TA, and the first TA and the second TA are different TAs.

[0388] In some embodiments, the first network slice is included in the network slice that the terminal requests to access in the first cell. In other words, the terminal initiates a registration procedure in the first cell and requests to access the first network slice. However, the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell, or the first network slice belongs to the network slice that the terminal is denied to access in the first cell. Thus, the terminal cannot access the first network slice in the first cell. Based on the subsequent steps, the terminal may access in the second cell the first network slice that is inaccessible in the first cell.

[0389] In some embodiments, the first network slice is included in a network slice configured for the terminal in the first network, or the first network slice is included in a network slice corresponding to the configured NSSAI of the terminal, or the first network slice is a network slice that the terminal is authorized to access in the first network. That is, regardless of whether the terminal requests to access the first network slice when the terminal starts a registration procedure in the first cell, the terminal may subsequently intend to access the first network slice because the first network slice is included in a network slice configured for the terminal in the first network. The terminal cannot access the first network slice in the first cell because the first network slice does not belong to the network slice that the terminal is authorized to access in the first cell. Based on the subsequent steps, the terminal may access, in the second cell, the first network slice that is inaccessible in the first cell.

[0390] For example, based on the scenario shown in FIG. 8b, using an example where the first cell is a cell in TA1 of the access network device 1, the second cell is a cell in TA2 of the access network device 2, and the identity of the first network slice is S-NSSAI1, the terminal requests access to S-NSSAI1 and S-NSSAI2 through the access network device 1 in TA1, the allowed NSSAI determined on the network side is S-NSSAI2, and both TA1 and TA2 support S-NSSAI2. Thus, the registration area RA1 of the terminal includes TA1 and TA2. Alternatively, based on the scenario shown in FIG. 8c, using an example where the first cell is a cell in TA1 of the access network device 1, the second cell is a cell in TA2 of the access network device 1, and the identity of the first network slice is S-NSSAI1, the registration area RA1 of the terminal similarly includes TA1 and TA2.

[0391] In the above two scenarios, the terminal initiates a registration request in a first cell, requesting to access a first network slice and a second network slice (e.g., the identity is S-NSSAI2), where the first network slice does not belong to the network slice that the terminal is permitted to access in the first cell, and the second network slice belongs to the network slice that the terminal is permitted to access in the first cell. Thus, the terminal accesses the second network slice in the first cell.

[0392] S1402: The network device determines that a first network slice is available in a second cell when a terminal is handed over from the first cell to the second cell.

[0393] In some embodiments, the reason the network device determines that the first network slice is available in the second cell may be that the second TA in which the second cell is located supports the first network slice.

[0394] For example, based on the scenario shown in Figure 8b or Figure 8c, the network device may determine that when a terminal is handed over from a first cell in TA1 to a second cell in TA2, a first network slice is available in the second cell.

[0395] S1403: The network device notifies the terminal that the first network slice is available in the second cell.

[0396] In some embodiments, when the network device is a mobility management device, the network device may inform the terminal via a non-access stratum (NAS) message that the first network slice is available in the second cell.

[0397] In some other embodiments, when the network device is the first access network device or the second access network device, the network device may notify the terminal that the first network slice is available in the second cell via the mobility management device. For example, the network device notifies the terminal that the first network slice is available in the second cell via the mobility management device. Then, the mobility management device is triggered to notify the terminal that the first network slice is available in the second cell via a NAS message. Obviously, the network device may further notify the terminal in other manners. For example, the network device may notify the terminal that the first network slice is available in the second cell via an RRC message. The notification manner is not specifically limited in this application.

[0398] In one example, the network device may transmit an identification of the first network slice to the terminal to inform the terminal that the first network slice is available in the second cell. Additionally, the network device may further transmit a cell identifier of the second cell to the terminal.

[0399] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in the second cell, the terminal still cannot access the first network slice in the second cell because it does not initiate a registration procedure in the second cell. Based on the solution of this application, when a terminal is handed over from a first cell to a second cell and it is determined that a first network slice is available in the second cell, the terminal is notified that the first network slice is available in the second cell, thereby enabling the terminal, when still intending to access the first network slice, to initiate a registration procedure to request access to the first network slice, thereby improving the success rate of accessing the first network slice and improving service performance and user experience.

[0400] As mentioned above, the network device may be a mobility management device or an access network device. When the network device is a mobility management device, refer to the specific implementation in Figure 20 or Figure 21. When the network device is an access network device in an intra-eNodeB handover scenario, refer to the specific implementation in Figure 22. When the network device is an access network device in an inter-eNodeB handover scenario, refer to the specific implementation in Figure 23.

[0401] In addition to the method shown in Figure 14, reference is made to Figure 15. This application further provides a communication method based on network slices applicable to the following scenarios, namely, in a scenario where a terminal is handed over from a first cell to a second cell, and there is a third cell whose physical coverage is the same as that of the second cell. The handover scenario may be an intra-eNodeB handover, i.e., the first cell and the second cell belong to the same access network device, or an inter-eNodeB handover, i.e., the first cell and the second cell belong to different access network devices. For example, the method shown in Figure 15 is applicable to the scenario shown in Figure 8a. As shown in Figure 15, the method includes the following steps:

[0402] S1501: A network device determines a first network slice.

[0403] In some embodiments, the network device may be a mobility management device, a first access network device or a second access network device. For details, refer to the relevant description in step S1401. The details are not described again here.

[0404] The first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, and a registration area of ​​the terminal includes the first cell and the second cell, and the physical coverage of the third cell fully or partially overlaps with the physical coverage of the second cell.

[0405] In some embodiments, the third cell may be referred to as a cell whose physical coverage is the same as that of the second cell.

[0406] In some embodiments, the first cell is a cell in a first TA, the second cell is a cell in a second TA, and the third cell is a cell in a third TA, and the first TA, second TA, and third TA are different TAs.

[0407] In some embodiments, the first network slice is included in a network slice configured for the terminal in the first network, and / or the first network slice is included in a network slice that the terminal requests to access in the first cell. For details, refer to the relevant description in step S1401. The details will not be described again here.

[0408] For example, based on the scenario shown in FIG. 8a, using an example where the first cell is a cell in TA1 of the access network device 1, the second cell is a cell in TA2 of the access network device 2, and the third cell is a cell in TA3 of the access network device 2, and the identity of the first network slice is S-NSSAI1, the terminal requests access to S-NSSAI1 and S-NSSAI2 via the access network device 1 in TA1, the allowed NSSAI determined on the network side is S-NSSAI2, and both TA1 and TA2 support S-NSSAI2. Thus, the registration area RA1 of the terminal includes TA1 and TA2. The terminal initiates a registration request in the first cell, requesting access to the first network slice and the second network slice (e.g., the identity is S-NSSAI2), where the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell, and the second network slice belongs to the network slice that the terminal is allowed to access in the first cell. Thus, the terminal accesses the second network slice in the first cell.

[0409] S1502: The network device determines that a first network slice is available in a third cell when the terminal is handed over from the first cell to the second cell.

[0410] In some embodiments, the reason the network device determines that the first network slice is available in the third cell may be that the third TA in which the third cell is located supports the first network slice.

[0411] For example, based on the scenario shown in FIG. 8a, when a terminal is handed over from a first cell in TA1 to a second cell in TA2, TA2 is grouped in the range of RA1, and the terminal does not move out of the range of RA1, so the terminal does not resume the registration procedure. Therefore, the terminal still does not access the first network slice. However, the cells of the access network device 2 include a third cell whose physical coverage partially or completely overlaps with that of the second cell, and TA3 in which the third cell is located supports the first network slice, so the network device may determine that the first network slice is available in the third cell.

[0412] S1503: The network device notifies the terminal that the first network slice is available in the third cell.

[0413] For the notification manner, refer to the manner in which the network device notifies the terminal that the first network slice is available in the second cell in step S1403, and the details are not described again here.

[0414] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in a third cell whose physical coverage is the same as that of the second cell, the terminal still cannot access the first network slice at the location of the second cell because it does not initiate a registration procedure again in the second cell. Based on the solution of this application, when a terminal is handed over from a first cell to a second cell and it is determined that the first network slice is available in the third cell, the terminal is notified that the first network slice is available in the third cell, thereby allowing the terminal to access the first network slice in the third cell when still intending to access the first network slice, thereby improving the success rate of accessing the first network slice and using the services provided by the first network slice.

[0415] As mentioned above, the network device may be a mobility management device or an access network device. When the network device is a mobility management device, refer to the specific implementation in Figure 24. When the network device is an access network device in an intra-eNodeB handover scenario, refer to the specific implementation in Figure 25. When the network device is an access network device in an inter-eNodeB handover scenario, refer to the specific implementation in Figure 26.

[0416] In addition to the methods shown in Figures 14 and 15, the application further provides a communication method based on network slices applicable to the following scenarios, namely, in a scenario where a terminal accesses a first cell, and neighboring cells of the first cell include a second cell. The first cell and the second cell may belong to the same access network device, or the first cell and the second cell may belong to different access network devices. For example, the method shown in Figure 16 is applicable to the scenarios shown in Figure 8b or Figure 8c. As shown in Figure 16, the method includes the following steps:

[0417] S1601: A network device determines a first network slice.

[0418] Step S1601 is similar to step S1401. For details, please refer to the relevant description in step S1401. The details will not be described again here.

[0419] S1602: The network device determines that a first network slice is available in a second cell.

[0420] In some embodiments, the reason the network device determines that the first network slice is available in the second cell may be that the second TA in which the second cell is located supports the first network slice.

[0421] In some embodiments, the reason the network device determines that the first network slice is available in the second cell may be because the second TA in which the second cell is located supports the first network slice, the cell signal quality of the second cell is greater than a first threshold, and the terminal may access the second cell.

[0422] In some embodiments, the network device may determine that the first network slice is available in the second cell before the terminal is handed over from the first cell to the second cell.

[0423] S1603: The network device notifies the terminal that the first network slice is available in the second cell.

[0424] Step S1603 is the same as step S1403. For details, please refer to the relevant description in step S1403. The details will not be described again here.

[0425] The difference between step S1603 and step S1403 is that step S1403 is triggered by handover. In other words, in a handover scenario, the network device informs the terminal that the first network slice is available in the second cell. However, step S1603 does not depend on the handover. For example, before the handover procedure occurs, the network device may inform the terminal that the first network slice is available in the second cell.

[0426] S1604: The network device sends a cell identifier of the second cell to the terminal.

[0427] In some embodiments, to access a first network slice available in a second cell, a cell identifier of the second cell may be used by the terminal to access the second cell.

[0428] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in the second cell, the terminal still cannot access the first network slice in the second cell because it does not initiate a registration procedure in the second cell. Based on the solution of this application, when a terminal is handed over from a first cell to a second cell and it is determined that the first network slice is available in the second cell, the terminal is notified that the first network slice is available in the second cell and a cell identifier of the second cell is transmitted, thereby enabling the terminal, when still intending to access the first network slice, to access the second cell and initiate a registration procedure to request access to the first network slice, thereby improving the success rate of accessing the first network slice and using the services provided by the first network slice.

[0429] In addition to the method shown in Figure 16, please refer to Figure 17. This application further provides a communication method based on network slices applicable to the following scenario: A terminal accesses a first cell, the neighboring cells of the first cell include a second cell, and there exists a third cell whose physical coverage is the same as that of the second cell. The first cell and the second cell may belong to the same access network device, or the first cell and the second cell may belong to different access network devices. For example, the method shown in Figure 17 is applicable to the scenario shown in Figure 8a. As shown in Figure 17, the method includes the following steps:

[0430] S1701: A network device determines a first network slice.

[0431] Step S1701 is similar to step S1501. For details, please refer to the relevant description in step S1501. The details will not be described again here.

[0432] S1702: The network device determines that a first network slice is available in a third cell.

[0433] In some embodiments, the reason the network device determines that the first network slice is available in the third cell may be that the third TA in which the third cell is located supports the first network slice.

[0434] In some embodiments, the network device may determine that the first network slice is available in the third cell before the terminal is handed over from the first cell to the second cell.

[0435] S1703: The network device notifies the terminal that the first network slice is available in the third cell.

[0436] For the notification manner, refer to the manner in which the network device notifies the terminal that the first network slice is available in the second cell in step S1403, and the details are not described again here.

[0437] S1704: The network device sends a cell identifier of the third cell to the terminal.

[0438] In some embodiments, to access the first network slice available in the third cell, a cell identifier of the third cell may be used by the terminal to access the third cell.

[0439] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, i.e., when the terminal initiates a registration procedure in the first cell, the terminal cannot access the first network slice. Since the registration area of ​​the terminal includes the first cell and the second cell, the terminal is not triggered to perform a re-registration procedure when the terminal is handed over from the first cell to the second cell. Even if the first network slice is available in a third cell whose physical coverage is the same as that of the second cell, the terminal still cannot access the first network slice at the location of the second cell because it does not initiate a registration procedure again in the second cell. Based on the solution of this application, when it is determined that neighboring cells of a first cell accessed by a terminal include a second cell, there is a third cell whose physical coverage is the same as that of the second cell, and the first network slice is available in the third cell, the terminal is notified that the first network slice is available in the third cell and a cell identifier of the third cell is transmitted, thereby enabling the terminal, when still intending to access the first network slice, to access the third cell and request to access the first network slice, thereby improving the success rate of accessing the first network slice and using the services provided by the first network slice.

[0440] Figures 11 to 17 describe a communication method based on a network slice provided in this application from the perspective of a network device, and below the method is described from the perspective of a terminal.

[0441] Figure 18 illustrates a communication method based on a network slice applied to a terminal according to this application. The method may be applied to the above process in which the network device notifies the terminal that the first network slice is available in the second cell. In other words, the method may be considered as an implementation manner of the terminal after the network device notifies the terminal that the first network slice is available in the second cell in Figure 14 or Figure 16. The method includes the following steps:

[0442] S1801: A terminal learns from a network device that a first network slice is available in a second cell.

[0443] The first network slice does not belong to the network slice that the terminal is allowed to access in the first cell, and the registration area of ​​the terminal includes the first cell and the second cell. For details, please refer to the related description in step S1401. The details will not be described again here.

[0444] S1802: The terminal initiates a registration procedure for an application corresponding to the first network slice.

[0445] In some embodiments, the terminal initiating a registration procedure for an application corresponding to the first network slice may include: the terminal determines whether the first network slice is a network slice corresponding to the application in response to a context of the terminal not including a session used for the application and not including a routing policy used for the application, and the terminal initiates the registration procedure for the application when the first network slice is a network slice corresponding to the application.

[0446] In some embodiments, the terminal further receives a cell identifier from the network device, the cell identifier being used for the second cell. In other words, the terminal receives a cell identifier of the second cell from the network device. In this scenario, the terminal initiating a registration procedure for an application corresponding to the first network slice may include: the terminal accesses the second cell and initiates a registration procedure for an application corresponding to the first network slice via the second cell.

[0447] In the current technology, the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell, so the terminal cannot access the first network slice in the first cell. Since the registration area of ​​the terminal includes the first cell and the second cell, even if the terminal moves from the first cell to the coverage of the second cell, the terminal still does not resume the registration procedure and therefore cannot access the first network slice. Based on the solution of this application, the terminal may learn from the network device that the first network slice is available in the second cell, and therefore, when the application of the terminal corresponds to the first network slice, may initiate a registration procedure for the application to request access to the first network slice, thereby improving the success rate of accessing the first network slice.

[0448] In other words, compared with some scenarios in which the terminal is triggered to initiate a registration procedure in the current technology, a scenario in which the terminal is triggered to initiate a registration procedure is added in this application. After the network device notifies the terminal that the first network slice is available in the second cell, the terminal may initiate the registration procedure based on the initiated application.

[0449] When the terminal learns from the network device that the first network slice is available in the third cell, it can be understood that the implementation manner of the terminal is similar to that of the method shown in Figure 18, and the second cell may be replaced by the third cell for understanding. For details, please refer to the above related description. The details will not be described again here.

[0450] Above, the communication method based on network slices provided in this application has been described from the perspective of each single device. Below, it will be described how the above method is applied to a specific procedure from the perspective of the interaction between the devices.

[0451] Figure 19 is a schematic flowchart of a method for applying the methods shown in Figures 11 to 13 according to this application to a specific procedure through an example in which the network device is a mobility management device. The method shown in Figure 19 is applicable to the scenario in Figure 8a or Figure 8b. The method includes the following steps:

[0452] S1901: A terminal sends a first message to a first access network device. Correspondingly, the first access network device receives the first message from the terminal.

[0453] The first access network device is an access network device in a first network. For the first network, please refer to the relevant description in step S1101. Details will not be described again here.

[0454] In some embodiments, the first message may be an RRC message.

[0455] The first message includes a registration request, where the registration request includes information regarding a network slice that the terminal requests to access (e.g., a requested NSSAI), where the information regarding the network slice that the terminal requests to access includes an identification information of the first network slice and an identification information of the second network slice.

[0456] In this application, the description is given through an example in which a terminal accesses a first network in a first TA of a first access network device and sends a first message to the first access network device. For example, in the scenario in Fig. 8a, the first TA is TA1 in Fig. 8a, and in the scenario in Fig. 8b, the first TA is TA1 in Fig. 8b.

[0457] S1902: The first access network device sends a registration request to the mobility management device. In response, the mobility management device receives the registration request from the first access network device.

[0458] A registration request is received from a terminal by a first access network device in step S1901. Thus, steps S1901 and S1902 may be understood as the mobility management device receiving, via the first access network device in the first network, information regarding a network slice that the terminal requests to access.

[0459] In some embodiments, the mobility management device may determine a network slice supported by a TA of a first access network device. The network slice supported by a TA of a first access network device may be reported by the first access network device to the mobility management device when establishing or updating an N2 connection to the mobility management device. In this application, an example is provided in which the mobility management device determines that a first TA of a first access network device does not support a first network slice, but supports a second network slice.

[0460] S1903: The mobility management device performs slice selection.

[0461] For example, the mobility management device may perform slice selection by interacting with a network slice selection function network element.

[0462] In step S1903, the mobility management device may determine a network slice that the terminal is permitted to access, specifically, may determine a network slice that the terminal is permitted to access in a first TA. In this application, the description is given through an example in which the network slice that the terminal is permitted to access includes a second network slice, and the first network slice does not belong to the network slice that the terminal is permitted to access.

[0463] As mentioned above, the network slice to which the terminal is denied access may be referred to as a target network slice, and there may be one or more target network slices. For example, the network slice to which the terminal requests to access further includes a third network slice, and the third network slice is a network slice to which the terminal is permitted to access in the second network. Thus, in the first TA of the first network, the third network slice does not belong to the network slices to which the terminal is permitted to access. In this scenario, the target network slice includes the first network slice and the third network slice. Alternatively, the target network slice may be a network slice to which the terminal is denied access. For example, the target network slice includes the first network slice.

[0464] In some embodiments, the mobility management device may store information regarding the target network slice and, when the mobility management device serving the terminal is subsequently handed over, may transmit information regarding the target network slice to the mobility management device to which the handover is performed.

[0465] In some embodiments, in step S1903, the mobility management device may further determine a network slice to which the terminal is denied access, specifically, a network slice to which the terminal is denied access in the first TA. In this application, the description is given through an example in which the network slice to which the terminal is denied access includes a first network slice. Furthermore, the network slice to which the terminal is denied access may further include a third network slice.

[0466] In some embodiments, in step S1903, the mobility management device may further determine a network slice that the terminal is permitted to access in the first network. In this application, the description is given through an example in which the network slice that the terminal is permitted to access in the first network includes the first network slice, or the first network slice is the network slice that the terminal is permitted to access in the first network. Furthermore, an example in which a second TA in the first network supports the first network slice is used for the description.

[0467] In other words, the first network slice is a network slice that the terminal is permitted to access in the first network, but does not belong to the network slice that the terminal is permitted to access in the first TA.

[0468] In some embodiments, in step S1903, the mobility management device may further determine a network slice that the terminal is permitted to access by the subscription. In this application, the description is given through an example in which the network slice that the terminal is permitted to access by the subscription includes a first network slice, a second network slice, a third network slice, and a fourth network slice. The fourth network slice is also a network slice that the terminal is permitted to access in the first network.

[0469] S1904: The mobility management device determines a registration area.

[0470] For the features of the registration area, please refer to the description in the method shown in Figure 11, Figure 12 or Figure 13. The details will not be described again here.

[0471] In some embodiments, the mobility management device may determine the registration area based on the network slice that the terminal is allowed to access and the network slice that the terminal is denied to access. Alternatively, the mobility management device may further determine the registration area with reference to one or more of the network slice support capabilities of the access network devices managed by the mobility management device, the network slice that the terminal is allowed to access in the first network, and the network slice that the terminal is allowed to access by the subscription. Alternatively, it may be understood that the mobility management device may determine the registration area based on the network slice that the terminal is allowed to access and the target network slice. The method for determining the registration area by the mobility management device is not specifically limited in this application.

[0472] S1905: The mobility management network element sends a second message to the first access network device. Correspondingly, the first access network device receives a second message from the mobility management network element.

[0473] The second message includes information regarding the registration area, and further includes information regarding the network slice that the terminal is authorized to access.

[0474] In some embodiments, the second message may be an N2 message.

[0475] S1906: The first access network device sends information about the registration area to the terminal. In response, the terminal receives information about the registration area from the first access network device.

[0476] In some embodiments, the first access network device further transmits to the terminal information regarding the network slice that the terminal is allowed to access.

[0477] S1907: Other registration procedures.

[0478] After step S1907, the registration procedure is completed and the terminal accesses the second network slice.

[0479] S1908: Due to mobility, hand over the terminal to a second access network device.

[0480] For example, the TA of the second access network device includes a second TA. As described in step S1903, the second TA supports the first network slice. For example, in the scenario in FIG. 8a, the second TA is TA2 in FIG. 8a, and in the scenario in FIG. 8b, the second TA is TA2 in FIG. 8b. The registration area excludes the tracking area supporting the first network slice and the second network slice, or excludes the tracking area of ​​the access network device supporting the first network slice and the second network slice, so the second TA is outside the registration area. In this case, the terminal moves outside the RA, so step S1909 may be performed.

[0481] S1909: The registration procedure is restarted.

[0482] In some embodiments, the resumed registration procedure is initiated by the terminal, and in the resumed registration procedure, the network slice that the terminal requests to access may include the first network slice. Obviously, the network slice that the terminal requests to access may alternatively not include the first network slice. For example, after being handed over to the second access network device, the terminal no longer needs to access the first network slice. This is not specifically limited in this application.

[0483] Based on this solution, when determining a registration area, the mobility management device excludes a tracking area supporting the network slice and the target network slice that the terminal is permitted to access, or excludes a tracking area of ​​an access network device supporting the network slice and the target network slice that the terminal is permitted to access. Thus, when the terminal moves within the excluded tracking area, since the registration area of ​​the terminal does not include the tracking area and the tracking area supports the target network slice, the terminal may resume the registration procedure to request access to the target network slice, thereby increasing the success rate of accessing the target network slice.

[0484] Figure 20 and Figure 21 are schematic flow charts of a method for applying the method shown in Figure 14 to a specific procedure when a network device is a mobility management device according to this application. The method shown in Figure 20 or Figure 21 is applicable to the scenario in Figure 8b or Figure 8c. The method includes the following steps:

[0485] S2001: A terminal sends a first message to a first access network device. In response, the first access network device receives the first message from the terminal.

[0486] The terminal transmits a first message to the first access network device through a first cell of the first access network device, i.e., the terminal accesses the network in the first cell, the first cell being a cell in a first TA of the first access network device.

[0487] The first message includes a registration request, the registration request includes information regarding a network slice that the terminal requests to access (e.g., a requested NSSAI), and the information regarding the network slice that the terminal requests to access includes an identification of the first network slice. That is, the first network slice is included in the network slice that the terminal requests to access in the first cell. Furthermore, the information regarding the network slice that the terminal requests to access may further include an identification of the second network slice.

[0488] In some embodiments, the first access network device may be an access network device in a first network. For the first network, refer to the above related description. Details are not described again here.

[0489] S2002: The first access network device sends a registration request to the mobility management device. In response, the mobility management device receives the registration request from the first access network device.

[0490] A registration request is received by a first access network device from a terminal in step S2001. Steps S2001 and S2002 may therefore be understood as the mobility management device receiving, via a first cell, information regarding a network slice that the terminal requests to access.

[0491] S2003: The mobility management device performs slice selection.

[0492] For example, the mobility management device may perform slice selection by interacting with a network slice selection function network element.

[0493] In step S2003, the mobility management device may determine a network slice that the terminal is permitted to access, specifically, a network slice that the terminal is permitted to access in the first cell. In this application, the description is given through an example in which the network slice that the terminal is permitted to access in the first cell includes the second network slice.

[0494] In some embodiments, after the mobility management device determines the network slice that the terminal is allowed to access in the first cell, the mobility management device may determine whether the first network slice belongs to the network slice that the terminal is allowed to access in the first cell. In this application, an example is given in which the mobility management device can learn that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0495] Up to this point, the mobility management device may determine the first network slice. Therefore, S2001 to S2003 may be understood as a specific implementation method for determining the first network slice by the mobility management device.

[0496] As mentioned above, the network slice to which the terminal is denied access in the first cell may be referred to as a target network slice, and there may be one or more target network slices. For example, the network slice to which the terminal requests to access in the first cell further includes a third network slice, and the third network slice is a network slice to which the terminal is permitted to access in the second network. Thus, in the first cell of the first network, the third network slice does not belong to the network slices to which the terminal is permitted to access. Alternatively, the target network slice may be a network slice to which the terminal is denied access. For example, the target network slice includes the first network slice.

[0497] In some embodiments, in step S2003, the mobility management device may further determine a network slice configured for the terminal in the first network. In this application, the description is given through an example in which the network slice configured for the terminal in the first network includes the first network slice, or the first network slice is included in the network slice configured for the terminal in the first network.

[0498] The mobility management device further determines a registration area of ​​the terminal. In this application, the description is given through an example in which the registration area of ​​the terminal includes a first cell and a second cell. The second cell may belong to a first access network device, i.e., the first cell and the second cell belong to the same access network device, or the second cell may belong to a second access network device, i.e., the first cell and the second cell belong to different access network devices.

[0499] S2004: The mobility management device stores identification information of a target network slice, where the target network slice includes the first network slice.

[0500] In some embodiments, when the mobility management device serving the terminal is subsequently handed over, the mobility management device may transmit the identification information of the target network slice to the mobility management device to which the handover is performed. When the mobility management device serving the terminal is handed over, the mobility management network element after step S2004 may be considered as the mobility management network element to which the handover is performed.

[0501] S2005: The mobility management network element sends a second message to the first access network device. Correspondingly, the first access network device receives a second message from the mobility management network element.

[0502] The second message includes information regarding the network slice that the terminal is allowed to access.

[0503] In some embodiments, the second message may be an N2 message.

[0504] It should be noted that steps S2005 and S2004 are not necessarily performed in any order. Step S2004 may be performed first, and then step S2005. Alternatively, step S2005 may be performed first, and then step S2004. Alternatively, steps S2004 and S2005 may be performed simultaneously. This is not specifically limited in this application.

[0505] S2006: The first access network device transmits information about the network slice that the terminal is permitted to access to the terminal. In response, the terminal receives information about the network slice that the terminal is permitted to access from the first access network device.

[0506] S2007: Other registration procedures.

[0507] After step S2007, the registration procedure is completed and the terminal accesses the second network slice.

[0508] S2008: Perform handover to hand over the terminal from the first cell to the second cell.

[0509] The second cell is a cell in a second TA.

[0510] In some embodiments, when the second cell belongs to a second access network device and the handover type is an Xn handover, after step S2008, the handover of the terminal in the access network is completed, and step S2009a continues to be executed.

[0511] In some embodiments, when the second cell belongs to the second access network device and the handover type is N2 handover, after step S2008, the first access network device decides to trigger an N2 handover and step S2009b continues to be executed.

[0512] It can be understood that when the second cell belongs to the first access network device, steps S2009a and S2009b are not performed.

[0513] S2009a: The second access network device sends a path switch request message to the mobility management device. In response, the mobility management device receives a path switch request message from the second access network device.

[0514] Step S2011 may be performed after the mobility management device receives a path switch request message from the second access network device.

[0515] S2009b: The first access network device sends a handover required message to the mobility management device. In response, the mobility management device receives a handover required message from the first access network device.

[0516] The handover required message includes an identifier of the second access network device, thereby enabling the mobility management device to learn the second access network device to which the handover will take place.

[0517] Step S2011 may be performed after the mobility management device receives a HANDOVER REQUIRED message from the first access network device.

[0518] S2010: Remaining handover procedures.

[0519] For details, please refer to the method steps shown in Figure 5 or Figure 6, or refer to the handover procedure defined in the protocol, and the details will not be described again here.

[0520] It should be noted that S2010 may be performed in parallel with steps S2011 to S2014, and obviously may alternatively be performed in other orders, which is not specifically limited in this application.

[0521] S2011: The mobility management network element determines a target network slice available in the second cell.

[0522] It may be understood that the target network slice available in the second cell in step S2011 may be a subset of the target network slice in step S2004. For example, the target network slice in step S2004 includes a first network slice and a third network slice, and the target network slice available in the second cell in step S2011 is the first network slice. That is, in this application, a description is given through an example in which the mobility management network element determines that the first network slice is available in the second cell, or determines that the target network slice available in the second cell includes the first network slice.

[0523] In other words, when the second cell belongs to the second access network device and the handover type is an Xn handover, the mobility management device determining that the first network slice is available in the second cell may include: when the mobility management network element receives a path switch request message from the second access network device, it determines that the first network slice is available in the second cell.

[0524] When the second cell belongs to the second access network device and the handover type is an N2 handover, the mobility management network element determining that the first network slice is available in the second cell may include: when the mobility management network element receives a handover required message from the first access network device, determining that the first network slice is available in the second cell.

[0525] In other words, when the second cell belongs to the second access network device, the path switch request message or the handover required message may be used as a trigger condition for the mobility management device to determine that the first network slice is available in the second cell.

[0526] In different embodiments of this application, the manner in which the mobility management device determines the target network slice available in the second cell may also be different, for example:

[0527] In some embodiments, the mobility management device determining a target network slice available in the second cell includes: the mobility management device queries a context of the target access network device to determine whether a network slice supported by a tracking area of ​​the target access network device includes the target network slice.

[0528] When the second cell belongs to the second access network device, the target access network device is the second access network device, or when the second cell belongs to the first access network device, the target access network device is the first access network device.

[0529] In this application, the description is given through an example in which the context of the target access network device indicates that the network slice supported by the tracking area of ​​the target access network device includes the first network slice, or the context of the target access network device indicates that the tracking area of ​​the target access network device supports the first network slice. In this scenario, the second cell is a cell in the tracking area of ​​the target access network device. For example, the second cell is a cell in the second TA of the target access network device.

[0530] In some other embodiments, see FIG. 21. For example, the target access network device is a second access network device. The mobility management device determining a target network slice available in the second cell includes:

[0531] S2011a: The mobility management device sends to the target access network device an identification information of a target network slice supported by a tracking area of ​​the target access network device. In response, the target access network device receives from the mobility management device an identification information of a target network slice supported by a tracking area of ​​the target access network device.

[0532] It is assumed that the target network slice in step S2004 includes a first network slice and a third network slice. In this application, an example is given in which the tracking area of ​​the target access network device supports the first network slice but does not support the third network slice, and the identification information of the first network slice is sent by the mobility management device in step S2011a.

[0533] S2011b: The target access network device determines, based on the measurement report reported by the terminal, whether the terminal can access the first network slice in the second cell.

[0534] In some embodiments, the target access network device first determines whether the second TA in which the second cell is located supports the first network slice. In this application, an example in which the second TA supports the first network slice is used for explanation. Then, the target access network device may determine whether the terminal can access the first network slice in the second cell based on the cell signal quality in the measurement report.

[0535] In one example, the cell signal quality may be measured through one or more of received signal code power (RSCP), reference signal received power (RSRP), reference signal received quality (RSRQ), signal to noise ratio (SNR), signal to interference plus noise ratio (SINR), and reference signal strength indicator (RSSI), which are not specifically limited in this application.

[0536] In one example, when a cell signal quality corresponding to the second cell is greater than a first threshold, the target access network device determines that the terminal can access the first network slice in the second cell.

[0537] In one example, the target access network device may perform step S2011b immediately after S2011a, or may perform step S2011b at any time after S2011a, such that step S2011c is performed after step S2011b is performed at any time.

[0538] S2011c: The target access network device sends notification information to the mobility management device. Correspondingly, the mobility management device receives notification information from the target access network device.

[0539] The notification information is for notifying the terminal that the terminal can access the first network slice in the second cell. Thus, the mobility management device learns from the target access network device that the terminal can access the first network slice in the second cell.

[0540] In one example, when the target network slice supported by the tracking area of ​​the target access network device in step S2011a includes only the first network slice, the notification information may be one-bit information, for example, when the value of the bit is "1", the terminal is notified that the terminal can access the first network slice in the second cell, or when the value of the bit is "0", the terminal is notified that the terminal can access the first network slice in the second cell.

[0541] In another example, when the target network slice supported by the tracking area of ​​the target access network device in step S2011a includes multiple network slices, the notification information may include identification information of the first network slice.

[0542] In yet another example, when the target network slice supported by the tracking area of ​​the target access network device in step S2011a includes multiple network slices, the notification information may include a bitmap, where the number of bits included in the bitmap is equal to the number of target network slices supported by the tracking area of ​​the target access network device, different bits correspond to different target network slices, and values ​​of the bits are used to notify the terminal whether the terminal can access the corresponding target network slice in the second cell.

[0543] For example, in step S2011a, the target network slices supported by the tracking area of ​​the target access network device include network slice 1 and network slice 2. The target access network device determines that the terminal can access network slice 1 but cannot access network slice 2 in the second cell. In this case, the bitmap may include two bits, the first bit corresponding to network slice 1 and the second bit corresponding to network slice 2. For example, the bitmap may be "10" to inform the terminal that the terminal can access network slice 1 but cannot access network slice 2 in the second cell.

[0544] It may be understood that steps S2011a to S2011c are also applicable to a scenario where the target access network device is the first access network device.

[0545] That is, the mobility management device determining that the first network slice is available in the second cell includes: the mobility management device sends identification information of the first network slice to the target access network device, and learns from the target access network device that the terminal can access the first network slice in the second cell.

[0546] Based on this solution, after determining the first network slice supported by the tracking area of ​​the target access network device, the mobility management device further confirms with the target access network device whether the terminal can access the first network slice supported by the tracking area of ​​the target access network device, so as to prevent the mobility management device from notifying the terminal that the first network slice is available in the second cell when the target access network device supports the first network slice but the terminal cannot access the first network slice in the second cell, thereby improving the success rate of accessing the first network slice by the terminal in the second cell.

[0547] S2012: The mobility management device notifies the terminal that the first network slice is available in the second cell.

[0548] In some embodiments, the mobility management device may send a NAS message to the terminal, and notify the terminal through the NAS message that the first network slice is available in the second cell. For the notification manner, see step S2011c. Details will not be described again here.

[0549] Optionally, after step S2012, the communication method based on the network slice may further include steps S2013 and S2014.

[0550] S2013: The terminal sends the instruction information to the mobility management device. In response, the mobility management device receives the instruction information from the terminal.

[0551] In some embodiments, the indication information indicates that the terminal no longer requests access to the first network slice.

[0552] S2014: The mobility management device deletes identification information of the first network slice based on the instruction information.

[0553] In some embodiments, when the indication information indicates that the terminal no longer requires access to the first network slice, the mobility management device deletes the identification information of the first network slice. Then, when serving the terminal, the mobility management device may no longer inform the terminal of cells that can access the first network slice, thereby reducing signaling overhead and reducing resource waste.

[0554] Based on this solution, when a terminal is handed over from a first cell to a second cell and the mobility management device determines that the first network slice is available in the second cell, the terminal is notified that the first network slice is available in the second cell, thereby enabling the terminal, when still intending to access the first network slice, to initiate a registration procedure to request access to the first network slice, thereby improving the success rate of accessing the first network slice and using the services provided by the first network slice.

[0555] Figure 22 is a schematic flow chart of a method for applying the method shown in Figure 14 to a specific procedure when the second cell belongs to the first access network device and the network device is the first access network device according to this application. The method shown in Figure 22 is applicable to the scenario in Figure 8c. The method includes the following steps:

[0556] S2201 to S2207: These are the same as steps S2001 to S2007 shown in Fig. 20. For details, please refer to the related description above. The details will not be described again here.

[0557] S2208: Perform handover to hand over the terminal from the first cell to the second cell.

[0558] The second cell is a cell in a second TA, and the second cell belongs to the first access network device. After S2208 is completed, the terminal may be considered to have completed handover from the first cell to the second cell.

[0559] S2209: The mobility management device sends the identification information of the target network slice stored in step S2204 to the first access network device. Correspondingly, the first access network device receives the identification information of the target network slice from the mobility management device.

[0560] For example, the target network slice stored in S2204 includes a first network slice and a third network slice. In S2209, the mobility management device transmits an identification information of the first network slice and an identification information of the third network slice to the first access network device.

[0561] It should be noted that steps S2209 and S2208 are not necessarily performed in any order. Step S2208 may be performed first, and then step S2209. Alternatively, step S2209 may be performed first, and then step S2208. Alternatively, steps S2208 and S2209 may be performed simultaneously. This is not specifically limited in this application.

[0562] For example, when step S2209 is executed before step S2208 is executed, in step S2209, the first access network device may determine the first network slice. With reference to steps S2201 to S2209, the first access network device determining the first network slice includes: the first access network device sends information about the network slice that the terminal requests to access to a mobility management network element, where the information about the network slice that the terminal requests to access includes identification information of the first network slice; and then the first access network device learns from the mobility management device that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell. In other words, the first access network device may learn from the mobility management device in the above registration procedure that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0563] It may be understood that the features of and / or operations performed on the first network slice are also applicable to the third network slice. For details, please refer to the relevant description of the first network slice. The details will not be described again here.

[0564] S2210: The first access network device determines a target network slice supported by a tracking area of ​​the first access network device.

[0565] In some embodiments, the first access network device may determine a target network slice supported by a tracking area of ​​the first access network device based on a network slice support capability recorded by the first access network device.

[0566] In one example, when the target network slice in step S2209 includes a first network slice and a third network slice, it is assumed that the tracking area of ​​the first access network device supports the first network slice but does not support the third network slice, in which case the target network slice supported by the tracking area of ​​the first access network device and determined by the first access network device in step S2210 is the first network slice.

[0567] S2211: The first access network device determines that a first network slice is available in the second cell.

[0568] In some embodiments, the first access network device determining that the first network slice is available in the second cell includes: The first access network device determines that the terminal can access the first network slice in the second cell. For a method for the first access network device to determine that the terminal can access the first network slice in the second cell, please refer to the related description in step S2011b. Details will not be described again here.

[0569] S2212: The first access network device notifies the terminal that the first network slice is available in the second cell.

[0570] In some embodiments, the first access network device notifying the terminal that the first network slice is available in the second cell includes: the first access network device notifying the terminal, via the mobility management device, that the first network slice is available in the second cell. For example, step S2212 may include S2212a and S2212b.

[0571] S2212a: The first access network device sends notification information to the mobility management device. Correspondingly, the mobility management device receives notification information from the target access network device.

[0572] For step S2212a, please refer to the relevant description in step S2011c, and the details will not be described again here.

[0573] S2212b: The mobility management device notifies the terminal that the first network slice is available in the second cell.

[0574] For step S2212b, please refer to the relevant description in step S2012. Details will not be described again here.

[0575] In some other embodiments, the first access network device may inform the terminal via an RRC message that the first network slice is available in the second cell.

[0576] Optionally, after step S2212, the communication method based on the network slice may further include steps S2213 and S2214. Steps S2213 and S2214 are the same as steps S2013 and S2014. For details, please refer to the relevant descriptions of steps S2013 and S2014. The details will not be described again here.

[0577] By using the method in Figure 22, when it is determined that the first network slice is available in the second cell, the first access network device notifies the terminal that the first network slice is available in the second cell. For the technical effects provided by the method shown in Figure 22, refer to the technical effects provided by the method shown in Figure 20. Details will not be described again here.

[0578] Figure 23 is a schematic flow chart of a method for applying the method shown in Figure 14 to a specific procedure when the second cell belongs to the second access network device and the network device is the second access network device according to this application. The method shown in Figure 23 is applicable to the scenario in Figure 8b. The method includes the following steps:

[0579] S2301 to S2310: These are the same as steps S2001 to S2010 shown in Fig. 20. For details, please refer to the related explanation in Fig. 20. The details will not be described again here.

[0580] S2311: The mobility management device sends the identification information of the target network slice stored in step S2304 to the second access network device. Correspondingly, the second access network device receives the identification information of the target network slice from the mobility management device.

[0581] The manner in which the mobility management device transmits the identification information of the target network slice to the second access network device is similar to the manner in which the mobility management device transmits the identification information of the target network slice to the first access network device in step S2209 of FIG. 22. For details, refer to the relevant description in step S2209. The details will not be described again here. The difference from FIG. 22 is that in an inter-eNodeB handover scenario, the mobility management device may transmit the identification information of the target network slice to the second access network device after receiving a path switch request message or a handover required message.

[0582] S2312: The second access network device determines a target network slice supported by a tracking area of ​​the second access network device.

[0583] In some embodiments, the second access network device may determine a target network slice supported by a tracking area of ​​the second access network device based on network slice support capabilities recorded locally by the second access network device.

[0584] In one example, when the target network slice in step S2311 includes a first network slice and a third network slice, it is assumed that the tracking area of ​​the second access network device supports the first network slice but does not support the third network slice, in which case the target network slice supported by the tracking area of ​​the second access network device and determined by the second access network device in step S2312 is the first network slice.

[0585] S2313: The second access network device determines that the first network slice is available in the second cell.

[0586] In some embodiments, the second access network device determining that the first network slice is available in the second cell includes: The second access network device determines that the terminal can access the first network slice in the second cell. For a method for the second access network device to determine that the terminal can access the first network slice in the second cell, please refer to the related description in step S2011b. Details will not be described again here.

[0587] S2314: The second access network device notifies the terminal that the first network slice is available in the second cell.

[0588] The manner in which the second access network device notifies the terminal that the first network slice is available in the second cell is similar to the manner in which the first access network device notifies the terminal that the first network slice is available in the second cell in step S2212 of Figure 22. For details, please refer to the related description in step S2212. The details will not be described again here.

[0589] Optionally, after step S2314, the communication method based on the network slice may further include steps S2315 and S2316. Steps S2315 and S2316 are the same as steps S2013 and S2014. For details, please refer to the relevant descriptions of steps S2013 and S2014. The details will not be described again here.

[0590] By using the method in Figure 23, when it is determined that the first network slice is available in the second cell, the second access network device notifies the terminal that the first network slice is available in the second cell. For the technical effects provided by the method shown in Figure 23, refer to the technical effects provided by the method shown in Figure 20. Details will not be described again here.

[0591] Fig. 24 is a schematic flow chart of a method for applying the method in Fig. 15 to a specific procedure when a network device is a mobility management device according to this application. The method shown in Fig. 24 is applicable to the scenario in Fig. 8a. The method includes the following steps:

[0592] S2401 to S2407: These are the same as steps S2001 to S2007 shown in Fig. 20. For details, please refer to the relevant explanations of steps S2001 to S2007. The details will not be described again here.

[0593] S2408: Perform handover to handover the terminal from the first cell to the second cell.

[0594] The second cell is a cell in a second TA. A third cell, whose physical coverage is the same as that of the second cell, exists under the access network device to which the second cell belongs, and the third cell is a cell in a third TA.

[0595] In some embodiments, when the second cell belongs to a second access network device and the handover type is an Xn handover, after step S2408, the handover of the terminal in the access network is completed, and step S2409a continues to be executed.

[0596] In some embodiments, when the second cell belongs to the second access network device and the handover type is N2 handover, after step S2408, the first access network device decides to trigger an N2 handover and step S2409b continues to be executed.

[0597] It can be understood that when the second cell belongs to the first access network device, steps S2409a and S2409b are not performed.

[0598] S2409a: This is the same as step S2009a shown in Figure 20. For details, please refer to the relevant description of step S2009a. The details will not be described again here. After the mobility management device receives a path switch request message from the second access network device, step S2411 is performed.

[0599] S2409b: This is the same as step S2009b shown in Figure 20. For details, please refer to the relevant description of step S2009b. The details will not be described again here. After the mobility management device receives a handover required message from the first access network device, step S2411 is performed.

[0600] S2410: This is the same as step S2010 shown in Fig. 20. For details, please refer to the relevant description of step S2010. The details will not be described again here.

[0601] S2411: The mobility management network element determines a target network slice available in the third cell.

[0602] For a description of the target network slice available in the third cell, refer to the description of the target network slice available in the second cell in step S2011. Details will not be described again here.

[0603] In different embodiments of this application, the manner in which the mobility management device determines the target network slice available in the third cell may also be different. For example, as follows:

[0604] In some embodiments, the mobility management device determining a target network slice available in the third cell includes: the mobility management device queries a context of the target access network device to determine whether a network slice supported by a tracking area of ​​the target access network device includes the target network slice.

[0605] When the second cell belongs to the second access network device, the target access network device is the second access network device, or when the second cell belongs to the first access network device, the target access network device is the first access network device.

[0606] In this application, the context of the target access network device is described through an example in which a tracking area (i.e., a third TA) in which a third cell is located supports a first network slice, but a tracking area (i.e., a second TA) in which a second cell is located does not support the first network slice, where the second TA and the third TA are TAs of the target access network device, and the second cell and the third cell are cells of the target access network device.

[0607] In some other embodiments, the mobility management device determining the target network slice available in the third cell includes:

[0608] S2411a: The mobility management device sends to the target access network device an identification information of a target network slice supported by a tracking area of ​​the target access network device. In response, the target access network device receives from the mobility management device an identification information of a target network slice supported by a tracking area of ​​the target access network device.

[0609] For details, please refer to the relevant description in step S2011a, and the details will not be described again here.

[0610] S2411b: The target access network device determines, based on the measurement report reported by the terminal, whether the terminal can access the first network slice in the third cell.

[0611] In some embodiments, the target access network device first determines whether the third TA in which the third cell is located supports the first network slice. In this application, an example in which the third TA supports the first network slice is used for description. Then, the target access network device may determine whether the terminal can access the first network slice in the third cell based on the cell signal quality in the measurement report. For details, please refer to the related description in step S2011b. The details will not be described again here.

[0612] S2411c: The target access network device sends notification information to the mobility management device. Correspondingly, the mobility management device receives notification information from the target access network device.

[0613] The notification information is for notifying the terminal that it can access the first network slice in the third cell. For the notification manner, refer to step S2011c. Details will not be described again here.

[0614] That is, the mobility management device determining that the first network slice is available in the third cell includes: the mobility management device sends identification information of the first network slice to the target access network device, and learns from the target access network device that the terminal can access the first network slice in the third cell.

[0615] S2412: The mobility management device notifies the terminal that the first network slice is available in the third cell.

[0616] In some embodiments, the mobility management device may send a NAS message to the terminal, and notify the terminal through the NAS message that the first network slice is available in the third cell. For the notification manner, refer to step S2012. Details will not be described again here.

[0617] In some embodiments, after the mobility management device informs the terminal that the first network slice is available in the third cell, the terminal learns that the first network slice is available in the third cell. In this scenario, the terminal may perform cell reselection alone to access the third cell and access the first network slice through the third cell, or the terminal may initiate a registration request in the second cell to request to access the first network slice. Then, the target access network device redirects the terminal to the third cell via an RRC connection release message, thereby causing the terminal to access the first network slice through the third cell. For details, refer to the procedure shown in FIG. 5. Details will not be described again here.

[0618] Optionally, after step S2412, the communication method based on the network slice may further include steps S2413 and S2414. Steps S2413 and S2414 are the same as steps S2013 and S2014. For details, please refer to the above related description. The details will not be described again here.

[0619] Based on this solution, when a terminal is handed over from a first cell to a second cell and the mobility management device determines that the first network slice is available in the third cell, the terminal is notified that the first network slice is available in the third cell, thereby allowing the terminal to access the first network slice in the third cell when still intending to access the first network slice, thereby improving the success rate of accessing the first network slice and using the services provided by the first network slice.

[0620] Figure 25 is a schematic flow chart of a method for applying the method shown in Figure 15 to a specific procedure when the second cell belongs to the first access network device and the network device is the first access network device according to this application. The method includes the following steps:

[0621] S2501 to S2507: These are the same as steps S2201 to S2207 shown in Fig. 22. For details, please refer to the relevant explanations of steps S2201 to S2207. The details will not be described again here.

[0622] S2508: Perform handover to handover the terminal from the first cell to the second cell.

[0623] The second cell is a cell in a second TA. A third cell, whose physical coverage is the same as that of the second cell, exists under the first access network device to which the second cell belongs, and the third cell is a cell in a third TA.

[0624] After S2508 is completed, the terminal may be considered to have completed handover from the first cell to the second cell.

[0625] S2509: The mobility management device sends the identification information of the target network slice stored in step S2504 to the first access network device. Correspondingly, the first access network device receives the identification information of the target network slice from the mobility management device.

[0626] For details, please refer to the relevant description in step S2209, and the details will not be described again here.

[0627] S2510: The first access network device determines a target network slice supported by a tracking area of ​​the first access network device.

[0628] For details, please refer to the relevant description in step S2210, and the details will not be described again here.

[0629] S2511: The first access network device determines that a first network slice is available in the third cell.

[0630] In some embodiments, the first access network device determines that the first network slice is available in the third cell includes: The first access network device determines that the terminal can access the first network slice in the third cell. For a method for the first access network device to determine that the terminal can access the first network slice in the third cell, please refer to the related description in step S2411b. Details will not be described again here.

[0631] S2512: The first access network device notifies the terminal that the first network slice is available in the third cell.

[0632] For the notification manner, refer to the manner in which the first access network device notifies the terminal that the first network slice is available in the second cell in step S2212. Details are not described again here.

[0633] In some embodiments, after the first access network device informs the terminal that the first network slice is available in the third cell, the terminal learns that the first network slice is available in the third cell. In this scenario, the terminal may perform cell reselection alone to access the third cell and access the first network slice through the third cell, or the terminal may initiate a registration request in the second cell to request to access the first network slice. Then, the target access network device redirects the terminal to the third cell via an RRC connection release message, thereby causing the terminal to access the first network slice through the third cell. For details, refer to the procedure shown in FIG. 5. Details will not be described again here.

[0634] Optionally, after step S2512, the communication method based on the network slice may further include steps S2513 and S2514. Steps S2513 and S2514 are the same as steps S2013 and S2014. For details, please refer to the relevant descriptions of steps S2013 and S2014. The details will not be described again here.

[0635] By using the method in Figure 25, when it is determined that the first network slice is available in the third cell, the first access network device notifies the terminal that the first network slice is available in the third cell. For the technical effects provided by the method shown in Figure 25, refer to the technical effects provided by the method shown in Figure 24. Details will not be described again here.

[0636] Figure 26 is a schematic flow chart of a method for applying the method shown in Figure 15 to a specific procedure when the second cell belongs to the second access network device and the network device is the second access network device according to this application. The method shown in Figure 26 is applicable to the scenario in Figure 8a. The method includes the following steps:

[0637] S2601 to S2607: These are the same as steps S2001 to S2007 shown in Fig. 20. For details, please refer to the relevant explanations of steps S2001 to S2007. The details will not be described again here.

[0638] S2608: Perform handover to handover the terminal from the first cell to the second cell.

[0639] The second cell is a cell in a second TA. A third cell, whose physical coverage is the same as that of the second cell, exists under the access network device to which the second cell belongs, and the third cell is a cell in a third TA.

[0640] In some embodiments, when the second cell belongs to a second access network device and the handover type is an Xn handover, after step S2608, the handover of the terminal in the access network is completed, and step S2609a continues to be executed.

[0641] In some embodiments, when the second cell belongs to the second access network device and the handover type is N2 handover, after step S2608, the first access network device decides to trigger an N2 handover and step S2609b continues to be executed.

[0642] S2609a: This is the same as step S2009a shown in Figure 20. For details, please refer to the relevant description of step S2009a. The details will not be described again here. After the mobility management device receives a path switch request message from the second access network device, step S2411 is performed.

[0643] S2609b: This is the same as step S2009b shown in Figure 20. For details, please refer to the relevant description of step S2009b. The details will not be described again here. After the mobility management device receives a handover required message from the first access network device, step S2411 is executed.

[0644] S2610: This is the same as step S2010 shown in Fig. 20. For details, please refer to the relevant description of step S2010. The details will not be described again here.

[0645] S2611: The mobility management device sends the identification information of the target network slice stored in step S2604 to the second access network device. Correspondingly, the second access network device receives the identification information of the target network slice from the mobility management device.

[0646] S2612: The second access network device determines a target network slice supported by a tracking area of ​​the second access network device.

[0647] For details, please refer to the relevant descriptions in steps S2311 and S2312, and the details will not be described again here.

[0648] S2613: The second access network device determines that the first network slice is available in the third cell.

[0649] In some embodiments, the second access network device determines that the first network slice is available in the third cell includes: The second access network device determines that the terminal can access the first network slice in the third cell. For a method for the second access network device to determine that the terminal can access the first network slice in the third cell, please refer to the related description in step S2411b. Details will not be described again here.

[0650] S2614: The second access network device notifies the terminal that the first network slice is available in the third cell.

[0651] For the notification manner, refer to the manner in which the first access network device notifies the terminal that the first network slice is available in the second cell in step S2212. Details are not described again here.

[0652] In some embodiments, after the second access network device informs the terminal that the first network slice is available in the third cell, the terminal learns that the first network slice is available in the third cell. In this scenario, the terminal may perform cell reselection alone to access the third cell and access the first network slice through the third cell, or the terminal may initiate a registration request in the second cell to request to access the first network slice. Then, the target access network device redirects the terminal to the third cell via an RRC connection release message, thereby causing the terminal to access the first network slice through the third cell. For details, refer to the procedure shown in FIG. 5. Details will not be described again here.

[0653] Optionally, after step S2614, the communication method based on the network slice may further include steps S2615 and S2616. Steps S2615 and S2616 are the same as steps S2013 and S2014. For details, please refer to the relevant descriptions of steps S2013 and S2014. The details will not be described again here.

[0654] By using the method in Figure 26, when it is determined that the first network slice is available in the third cell, the second access network device notifies the terminal that the first network slice is available in the third cell. For the technical effects provided by the method shown in Figure 26, refer to the technical effects provided by the method shown in Figure 24. Details will not be described again here.

[0655] 27 is a schematic flow chart of a method for applying the method in FIG. 16 to a specific procedure when a network device is a mobility management device according to this application. The method includes the following steps:

[0656] S2701: A terminal sends a first message to a first access network device. Correspondingly, the first access network device receives the first message from the terminal.

[0657] The terminal transmits a first message to the first access network device through a first cell of the first access network device, i.e., the terminal accesses the network in the first cell, the first cell being a cell in a first TA of the first access network device.

[0658] The first message includes a registration request, the registration request includes information regarding a network slice that the terminal requests to access (e.g., a requested NSSAI), and the information regarding the network slice that the terminal requests to access includes an identification of the first network slice. That is, the first network slice is included in the network slice that the terminal requests to access in the first cell. Furthermore, the information regarding the network slice that the terminal requests to access may further include an identification of the second network slice.

[0659] In some embodiments, the first access network device may be an access network device in a first network. For the first network, refer to the above related description. Details are not described again here.

[0660] S2702: The first access network device sends a registration request to the mobility management device. In response, the mobility management device receives the registration request from the first access network device.

[0661] A registration request is received by a first access network device from a terminal in step S2701. Steps S2701 and S2702 may therefore be understood as the mobility management device receiving, via a first cell, information regarding a network slice that the terminal requests to access.

[0662] S2703: The mobility management device performs slice selection.

[0663] For example, the mobility management device may perform slice selection by interacting with a network slice selection function network element.

[0664] In step S2703, the mobility management device may determine a first network slice, and the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell. Therefore, S2701 to S2703 may be understood as a specific implementation manner of determining the first network slice by the mobility management device.

[0665] In step S2703, the mobility management device further determines a registration area of ​​the terminal. In this application, the description is given through an example in which the registration area of ​​the terminal includes a first cell and a second cell. The second cell is a neighboring cell of the first cell and may belong to the first access network device, i.e., the first cell and the second cell belong to the same access network device, or may belong to the second access network device, i.e., the first cell and the second cell belong to different access network devices.

[0666] S2704: The mobility management device stores identification information of a target network slice, where the target network slice includes the first network slice.

[0667] For example, this application provides an example in which the stored target network slices include a first network slice and a third network slice. Specifically, a terminal requests access to a first network slice, a second network slice, and a third network slice in a first cell, and the network slice that the terminal is allowed to access in the first cell is the second network slice, and the network slice that the terminal is denied to access includes the first network slice and the third network slice.

[0668] In some embodiments, when the mobility management device serving the terminal is subsequently handed over, the mobility management device may transmit the identification information of the target network slice to the mobility management device to which the handover is performed. When the mobility management device serving the terminal is handed over, the mobility management network element after step S2004 may be considered as the mobility management network element to which the handover is performed.

[0669] S2705: The mobility management network element sends a second message to the first access network device. Correspondingly, the first access network device receives the second message from the mobility management network element.

[0670] The second message includes information regarding the network slice that the terminal is allowed to access.

[0671] In some embodiments, the second message may be an N2 message.

[0672] It should be noted that steps S2705 and S2704 are not necessarily performed in any order. Step S2704 may be performed first, and then step S2705. Alternatively, step S2705 may be performed first, and then step S2704. Alternatively, steps S2704 and S2705 may be performed simultaneously. This is not specifically limited in this application.

[0673] S2706: The first access network device transmits to the terminal information on the network slice that the terminal is permitted to access. In response, the terminal receives from the first access network device information on the network slice that the terminal is permitted to access.

[0674] S2707: Other registration procedures.

[0675] After step S2007, the registration procedure is completed and the terminal accesses the second network slice.

[0676] S2708: The mobility management device determines that the first network slice is available in the second cell.

[0677] In different embodiments of this application, the manner for determining, by the mobility management device, that the first network slice is available in the second cell may be different. For example, in some embodiments, determining, by the mobility management device, that the first network slice is available in the second cell may include:

[0678] S27081a: The first access network device sends a cell identifier of the second cell to the mobility management device. In response, the mobility management device receives the cell identifier of the second cell from the first access network device.

[0679] In a possible implementation manner, since the second cell is a neighboring cell of the first cell, the terminal may measure the neighboring cell of the first cell and report a measurement report to the first access network device. The measurement report may include an identifier of the neighboring cell of the first cell and a quality of the neighboring cell. After receiving the measurement report from the terminal, the first access network device may perform step S27081a when the measurement report includes a cell identifier of the second cell.

[0680] In one example, the first access network device may determine a cell identifier of the second cell to be reported to the mobility management device through the following method.

[0681] Before step S27081a, the mobility management device may send reference frequency information corresponding to the first network slice to the first access network device. After receiving the measurement report reported by the terminal, the first access network device may determine a second cell based on the reference frequency information, and may therefore report a cell identifier of the second cell to the mobility management device. For example, the second cell is a cell on a frequency indicated by the reference frequency information. When there are multiple cells on a frequency indicated by the reference frequency information, the second cell may be a cell whose signal quality is greater than a second threshold among the multiple cells.

[0682] Further, after receiving the reference frequency information corresponding to the first network slice, the first access network device may configure the frequency indicated by the reference frequency information as a measurement object and send the measurement object to the terminal, thereby enabling the terminal to measure the frequency.

[0683] S27082a: The mobility management device determines a network slice supported by the second TA.

[0684] The second TA is the TA in which the second cell is located.

[0685] In a possible implementation manner, when establishing or updating an N2 connection, the mobility management device may determine the network slice supported by the second TA through information regarding the network slice reported by the first access network device.

[0686] S27083a: When the network slices supported by the second TA include the first network slice, the mobility management device determines that the terminal can access the first network slice in the second cell.

[0687] In some embodiments, the mobility management device determining that the first network slice is available in the second cell may include:

[0688] S27081b: The first access network device sends signal quality information of the neighboring cells of the first cell to the mobility management device. Correspondingly, the mobility management device receives the signal quality information of the neighboring cells of the first cell from the first access network device.

[0689] The neighboring cells of the first cell include the second cell, ie, the signal quality information of the neighboring cells includes the signal quality information of the second cell.

[0690] In a possible implementation, the first access network device transmits the signal quality information of all neighboring cells of the first cell reported by the terminal to the mobility management device.

[0691] In another possible implementation manner, the signal quality information of the neighboring cells of the first cell sent by the first access network device to the mobility management device may be the signal quality of the cells on the frequency indicated by the reference frequency information corresponding to the first network slice. The reference frequency information corresponding to the first network slice may be sent by the mobility management device to the first access network device before step S27081b.

[0692] S27082b: The mobility management device determines, based on signal quality information of the second cell, that the terminal can access the first network slice in the second cell.

[0693] In a possible implementation manner, the mobility management device may first determine whether a second TA in which the second cell is located supports the first network slice, and when the second TA supports the first network slice, further determine whether a cell signal quality indicated by the signal quality information of the second cell is greater than a second threshold, and determine that the terminal can access the first network slice in the second cell when the cell signal quality of the second cell is greater than the second threshold.

[0694] Regardless of the manner in which steps S27081a to S27083a or steps S27082a and S27082b are performed, the mobility management device may determine that the first network slice is available in the second cell before the handover procedure occurs.

[0695] It may be understood that the mobility management device may also determine whether a third network slice is available in the second cell. An example in which the third network slice is unavailable in the second cell is used for explanation in this application.

[0696] S2709: The network device notifies the terminal that the first network slice is available in the second cell.

[0697] For the notification manner, refer to the manner in which the first access network device notifies the terminal that the first network slice is available in the second cell in step S2012. Details are not described again here.

[0698] S2710: The mobility management device sends a cell identifier of the second cell to the terminal. Correspondingly, the terminal receives the cell identifier of the second cell from the mobility management device.

[0699] In some embodiments, a cell identifier of the second cell may be used to handover the terminal from the first cell to the second cell to access the first network slice in the second cell.

[0700] In some embodiments, the cell identifier of the second cell and the information for informing the terminal that the first network slice is available in the second cell may be carried in one message or may be carried in different messages, which is not specifically limited in this application.

[0701] Optionally, after step S2710, the communication method based on the network slice may further include steps S2711 and S2712. Steps S2711 and S2712 are the same as steps S2013 and S2014. For details, please refer to the relevant descriptions of steps S2013 and S2014. The details will not be described again here.

[0702] Based on the solution of this application, when it is determined that the first network slice is available in the second cell, the mobility management device notifies the terminal that the first network slice is available in the second cell and transmits a cell identifier of the second cell, thereby enabling the terminal, when still intending to access the first network slice, to access the second cell and initiate a registration procedure to request access to the first network slice, thereby improving the success rate of accessing the first network slice and using the services provided by the first network slice.

[0703] 28 is a schematic flow chart of a method for applying the method in FIG. 17 to a specific procedure when a network device is a mobility management device according to this application. The method includes the following steps:

[0704] S2801 to S2807: These are the same as steps S2701 to S2707 shown in Fig. 27. For details, please refer to the relevant explanations of steps S2701 to S2707. The details will not be described again here.

[0705] S2808: The mobility management device determines that the first network slice is available in the third cell.

[0706] The physical coverage of the third cell completely or partially overlaps with the physical coverage of the second cell.

[0707] In some embodiments, the third cell may be referred to as a cell whose physical coverage is the same as that of the second cell.

[0708] For a method for determining, by a mobility management device, that a first network slice is available in a third cell, refer to the method for determining, by a mobility management device, that a first network slice is available in a second cell in step S2708, and details are not described again here.

[0709] When the first network slice is available in the third cell, it can be understood that the cells on the frequency indicated by the reference frequency information corresponding to the first network slice include the third cell but do not include the second cell.

[0710] S2809: The network device notifies the terminal that the first network slice is available in the third cell.

[0711] For the notification manner, refer to the manner in which the first access network device notifies the terminal that the first network slice is available in the second cell in step S2012. Details are not described again here.

[0712] S2810: The mobility management device sends a cell identifier of the third cell to the terminal. Correspondingly, the terminal receives the cell identifier of the third cell from the mobility management device.

[0713] In some embodiments, a cell identifier of the third cell may be used to handover the terminal from the second cell to the third cell to access the first network slice in the third cell.

[0714] Optionally, after step S2810, the communication method based on the network slice may further include steps S2811 and S2812. Steps S2811 and S2812 are the same as steps S2013 and S2014. For details, please refer to the relevant descriptions of steps S2013 and S2014. The details will not be described again here.

[0715] Based on this solution, when the mobility management device determines that neighboring cells of a first cell accessed by a terminal include a second cell, there is a third cell whose physical coverage is the same as that of the second cell, and the first network slice is available in the third cell, the terminal is notified that the first network slice is available in the third cell and a cell identifier of the third cell is transmitted, thereby enabling the terminal to access the third cell and request to access the first network slice when still intending to access the first network slice.

[0716] The application of the method realized by the network device in a specific procedure has been described above. The method realized by the terminal shown in FIG. 18 will be described in detail below. The method may be applied to the above process in which the network device notifies the terminal that the first network slice is available in the second cell. In other words, the method may be considered as a terminal implementation method after the network device notifies the terminal that the first network slice is available in the second cell in FIG. 20 to FIG. 23 or FIG. 27.

[0717] 29 and 30 show a communication method based on a network slice for a terminal according to the present application. The method includes:

[0718] S2901: A terminal learns from a network device that a first network slice is available in a second cell.

[0719] The first network slice does not belong to the network slice that the terminal is allowed to access in the first cell, and the registration area of ​​the terminal includes the first cell and the second cell. For details, refer to the above related description. The details will not be described again here.

[0720] In some embodiments, see Figure 30. Step S2901 may be as follows: A first entity of the terminal learns from a network device that a first network slice is available in a second cell.

[0721] In one example, the first entity may be a hardware configuration of the terminal.

[0722] S2902: The terminal stores identification information of the first network slice.

[0723] In some embodiments, see Figure 30. Step S2902 may be as follows: A first entity of the terminal stores an identification information of a first network slice.

[0724] S2903: The application of the terminal initiates a data transmission request.

[0725] In some embodiments, see Figure 30. Step S2903 may be as follows: An application of the terminal initiates a data transmission request to a first entity of the terminal.

[0726] S2904: The terminal inquires about the context of the terminal.

[0727] The terminal context includes information about the URSP and sessions available to the terminal. When the terminal context does not include the URSP used for the application and does not include the session used for the application, this indicates that the network slice corresponding to the data transmission request does not belong to the network slice that the terminal is allowed to access in the first cell, and therefore step S2905 is executed.

[0728] In some embodiments, see Figure 30. Step S2904 may be as follows: A first entity of the terminal interacts with a second entity of the terminal to complete an inquiry of the context of the terminal.

[0729] In one example, the second entity may be a component included in the terminal and configured to store a context of the terminal.

[0730] S2905: The terminal determines whether the first network slice is a network slice corresponding to the application.

[0731] In other words, the terminal determines whether the first network slice is a network slice corresponding to the application in response to the terminal's context not including a session used for the application and not including a URSP used for the application.

[0732] When the first network slice is a network slice corresponding to the application, the application is an application corresponding to the first network slice, and the terminal further performs step S2906a.

[0733] Alternatively, when the first network slice is not the network slice corresponding to the application, step S2906b is executed.

[0734] In some embodiments, see Figure 30. Step S2905 may be as follows: A first entity of the terminal determines whether the first network slice is a network slice corresponding to the application.

[0735] S2906a: The terminal initiates a registration procedure for an application corresponding to the first network slice.

[0736] In some embodiments, see Figure 30. Step S2906a may be as follows: A first entity of the terminal initiates a registration procedure for an application corresponding to the first network slice.

[0737] In some embodiments, for example, when the implementation manner of the terminal shown in Figure 29 is applied to the scenario shown in Figure 27, the terminal further receives a cell identifier from the network device, and the cell identifier is used for the second cell. In other words, the terminal further receives a cell identifier of the second cell from the network device.

[0738] In this scenario, the terminal initiating a registration procedure for an application corresponding to the first network slice may include: the terminal accessing a second cell and initiating a registration procedure for the application via the second cell.

[0739] In some embodiments, the terminal requests access to the first network slice in a registration procedure initiated for the application.

[0740] S2906b: The terminal rejects a data transmission request initiated by an application.

[0741] In some embodiments, see Figure 30. Step S2906b may be as follows: The first entity of the terminal rejects a data transmission request initiated by the application.

[0742] Optionally, the communication method based on network slices provided in this application further includes step S2907.

[0743] S2907: The terminal notifies the network device that the terminal no longer requests to access the first network slice. In response, the network device learns from the terminal that the terminal no longer requests to access the first network slice.

[0744] In some embodiments, see Figure 30. Step S2907 may be as follows: A first entity of the terminal notifies the network device that the terminal no longer requests to access the first network slice.

[0745] In some embodiments, the terminal may send indication information to the network device, the indication information indicating that the terminal no longer requests access to the first network slice.

[0746] In some embodiments, after receiving the indication information, the network device may delete the identification information of the first network slice stored in the network device based on the indication information. For details, refer to the above related description. The details will not be described again here.

[0747] In some embodiments, the terminal informs the network device that the terminal no longer requests to access the first network slice after a first duration starting from a first time point, the first time point being a time point at which the terminal learns from the network device that the first network slice is available in the second cell. In other words, if an application of the terminal does not require using the first network slice available in the second cell for a certain period of time, the terminal may inform the network device that the terminal no longer requests to access the first network slice.

[0748] Optionally, in some embodiments, when a terminal is handed over after learning from the network device that a first network slice is available in the second cell and does not learn a new available network slice from the network device after the handover, the terminal may delete identification information of the first network slice stored in the terminal.

[0749] Based on this solution, the terminal may learn from the network device that a first network slice is available in the second cell, and therefore, when an application of the terminal corresponds to the first network slice, may initiate a registration procedure for the application to request access to the first network slice, thereby improving the success rate of accessing the first network slice.

[0750] When the terminal learns from the network device that the first network slice is available in the third cell, the implementation manner of the terminal is similar to that of the method shown in Figure 29 or Figure 30, and it can be understood that the second cell may be replaced by the third cell for understanding. For details, please refer to the above related description. The details will not be described again here.

[0751] In the embodiments of this application, unless otherwise specified or unless there is a logical contradiction, the terms and / or descriptions in different embodiments are consistent and may be mutually referenced, and the technical features in different embodiments may be combined based on their internal logical relationships to form a new embodiment.

[0752] In the above embodiments, it may be understood that the methods and / or steps implemented by each device may alternatively be implemented by a component (e.g., a chip or circuit) that can be used for the device.

[0753] Above, the solution provided in this application has been described mainly from the viewpoint of interaction between devices. Correspondingly, this application further provides a communication device, which is configured to realize the above method. The communication device may be a network device in the above method embodiment, a device including the above network device, or a component usable for the network device. Alternatively, the communication device may be a terminal in the above method embodiment, a device including the above terminal, or a component usable for the terminal.

[0754] It can be understood that to realize the above functions, the communication device includes a hardware structure and / or a software module for performing the corresponding functions. Those skilled in the art should easily recognize that this application can be realized through hardware or a combination of hardware and computer software based on the units and algorithm steps in the examples described in the embodiments disclosed in this specification. Whether the functions are performed by hardware or by hardware driven by computer software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to realize the described functions for each specific application, but the implementation manner should not be considered to go beyond the scope of this application.

[0755] In the embodiment of this application, the communication device may be divided into functional modules based on the above method embodiment. For example, each functional module may be obtained through division based on its corresponding function, or two or more functions may be integrated into one processing module. The integrated module may be realized in the form of hardware, or in the form of a software functional module. It should be noted that the module division in the embodiment of this application is an example, and is merely a logical function division. In the actual implementation, there may be other division methods.

[0756] For example, the communication device is a network device in the above method embodiment. Figure 31 is a schematic diagram of the structure of a network device 310. The network device 310 includes a processing module 3101 and a transceiver module 3102.

[0757] In some embodiments, the network device 310 may further include a storage module (not shown in FIG. 31) configured to store program instructions and data.

[0758] In some embodiments, the transceiver module 3102 may also be referred to as a transceiver unit and may be configured to perform a transmitting function and / or a receiving function. The transceiver module 3102 may include a transceiver circuit, a transceiver machine, a transceiver, or a communication interface.

[0759] In some embodiments, the transceiver module 3102 may include a receiving module and a transmitting module configured to perform receiving type steps and transmitting type steps, respectively, performed by the network device in the method embodiments described above and / or support other processes of the techniques described in this specification, and the processing module 3101 may be configured to perform processing type (e.g., determining and obtaining) steps performed by the network device in the method embodiments described above and / or support other processes of the techniques described in this specification.

[0760] In some implementation scenarios, the transceiver module 3102 is configured to receive, via a first access network device in a first network, information regarding a network slice that the terminal requests to access, including an identification information of a first network slice not supported by a first tracking area and including an identification information of a second network slice, a second tracking area in the first network supporting the first network slice, the processing module 3101 is configured to determine a network slice that the terminal is permitted to access, including the second network slice, the processing module 3101 is further configured to determine a registration area, the registration area excludes tracking areas supporting the first network slice and the second network slice or excludes tracking areas of access network devices supporting the first network slice and the second network slice, and the transceiver module 3102 is further configured to transmit information regarding the registration area to the terminal.

[0761] In a possible implementation manner, the processing module 3101 is further configured to determine a network slice to which the terminal is denied access, where the network slice to which the terminal is denied access includes the first network slice.

[0762] In a possible implementation, the processing module 3101 is further configured to determine a network slice supported by a tracking area of ​​the first access network device.

[0763] In some implementation scenarios, the processing module 3101 is configured to determine a network slice to which the terminal is permitted to access and a network slice to which the terminal is denied access, the processing module 3101 is further configured to determine a registration area of ​​the terminal based on the network slice to which the terminal is permitted to access and the network slice to which the terminal is denied access, and the transceiver module 3102 is configured to transmit information regarding the registration area to the terminal.

[0764] In a possible implementation manner, the transceiver module 3102 is further configured to receive, via a first access network device in the first network, information regarding a network slice that the terminal requests to access, including an identification of a first network slice not supported by the first tracking area and an identification of a second network slice supported by the first tracking area, the first tracking area being a tracking area of ​​the first access network device, the network slice that the terminal is allowed to access includes the second network slice, the network slice that the terminal is denied to access includes the first network slice, and the registration area excludes tracking areas supporting the first and second network slices, or the registration area excludes tracking areas of the access network devices supporting the first and second network slices.

[0765] In a possible implementation, the processing module 3101 is further configured to determine a network slice supported by a tracking area of ​​the first access network device.

[0766] In some implementation scenarios, the processing module 3101 is configured to determine a first network slice, where the first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, and the registration area of ​​the terminal includes the first cell and the second cell, the processing module 3101 is further configured to determine that the first network slice is available in the second cell when the terminal is handed over from the first cell to the second cell, and the transceiver module 3102 is further configured to notify the terminal that the first network slice is available in the second cell.

[0767] In a possible implementation manner, the processing module 3101 being configured to determine the first network slice includes: the processing module 3101 is configured to control the transceiver module 3102 to receive, via the first cell, information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes identification information of the first network slice, the processing module 3101 is further configured to determine a network slice that the terminal is allowed to access, and the processing module 3101 is further configured to learn that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0768] In a possible implementation manner, the processing module 3101 being configured to determine that the first network slice is available in the second cell includes: the processing module 3101 being configured to query a context of a target access network device, where the context of the target access network device indicates that a tracking area of ​​the target access network device supports the first network slice, and the second cell is a cell in the tracking area of ​​the target access network device.

[0769] In a possible implementation manner, the processing module 3101 being configured to determine that the first network slice is available in the second cell includes: the processing module 3101 being configured to control the transceiver module 3102 to send identification information of the first network slice to a target access network device, and the processing module 3101 is further configured to learn from the target access network device that the terminal can access the first network slice in the second cell.

[0770] In a possible implementation manner, the processing module 3101 being configured to determine that the first network slice is available in the second cell includes: the processing module 3101 being configured to determine that the first network slice is available in the second cell when the transceiver module 3102 receives a path switch request message from the second access network device; or the processing module 3101 being configured to determine that the first network slice is available in the second cell when the transceiver module 3102 receives a handover required message from the first access network device, where the handover required message includes an identifier of the second access network device.

[0771] In a possible implementation manner, the processing module 3101 is further configured to store identification information of the first network slice, the transceiver module 3102 is further configured to receive instruction information from the terminal, and the processing module 3101 is further configured to delete the identification information of the first network slice based on the instruction information.

[0772] In a possible implementation manner, the processing module 3101 being configured to determine the first network slice includes: the processing module 3101 is configured to control the transceiver module 3102 to send information regarding the network slice that the terminal requests to access to the mobility management device, where the information regarding the network slice that the terminal requests to access includes identification information of the first network slice, and the processing module 3101 is further configured to learn from the mobility management device that the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell.

[0773] In a possible implementation manner, the processing module 3101 is configured to determine the first network slice includes: when the terminal is handed over from the first access network device to the second access network device, the processing module 3101 is configured to learn from the mobility management device that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0774] In a possible implementation manner, the processing module 3101 being configured to determine that the first network slice is available in the second cell includes: The processing module 3101 being configured to determine that the terminal can access the first network slice in the second cell.

[0775] In some implementation scenarios, the processing module 3101 is configured to determine a first network slice, where the first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, the registration area of ​​the terminal includes the first cell and the second cell, the processing module 3101 is further configured to determine that the first network slice is available in a third cell when the terminal is handed over from the first cell to the second cell, the physical coverage of the third cell partially or completely overlaps with the physical coverage of the second cell, and the transceiver module 3102 is further configured to inform the terminal that the first network slice is available in the third cell.

[0776] In some implementation scenarios, the processing module 3101 is configured to determine a first network slice, where the first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, the registration area of ​​the terminal includes the first cell and the second cell, the processing module 3101 is further configured to determine that the first network slice is available in the second cell, the transceiver module 3102 is configured to notify the terminal that the first network slice is available in the second cell, and the transceiver module 3102 is further configured to transmit a cell identifier of the second cell to the terminal.

[0777] In a possible implementation manner, the processing module 3101 being configured to determine the first network slice includes: the processing module 3101 is configured to control the transceiver module 3102 to receive, via the first cell, information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes identification information of the first network slice, the processing module 3101 is further configured to determine a network slice that the terminal is allowed to access, and the processing module 3101 is further configured to learn that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0778] In a possible implementation manner, the processing module 3101 being configured to determine that the first network slice is available in the second cell includes: the processing module 3101 is configured to control the transceiver module 3102 to receive a cell identifier of the second cell from the first access network device, the second cell being a neighboring cell of the first cell, and the network device determines that the terminal can access the first network slice in the second cell.

[0779] In a possible implementation manner, the processing module 3101 being configured to determine that the first network slice is available in the second cell includes: the processing module 3101 is configured to control the transceiver module 3102 to receive signal quality information of neighboring cells of the first cell from the first access network device, where the neighboring cells of the first cell include a second cell, and the processing module 3101 is further configured to determine, based on the signal quality information of the second cell, that the terminal can access the first network slice in the second cell.

[0780] In a possible implementation, the transceiver module 3102 is further configured to transmit reference frequency information corresponding to the first network slice to the first access network device.

[0781] In a possible implementation manner, the processing module 3101 is further configured to store identification information of the first network slice, the transceiver module 3102 is further configured to receive instruction information from the terminal, and the processing module 3101 is further configured to delete the identification information of the first network slice based on the instruction information.

[0782] In some implementation scenarios, the processing module 3101 is configured to determine a first network slice, where the first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, the registration area of ​​the terminal includes the first cell and the second cell, the processing module 3101 is further configured to determine that the first network slice is available in a third cell, where the physical coverage of the third cell partially or completely overlaps with the physical coverage of the second cell, the transceiver module 3012 is configured to inform the terminal that the first network slice is available in the third cell, and the transceiver module 3102 is further configured to transmit a cell identifier of the third cell to the terminal.

[0783] All the relevant contents of the steps in the above method embodiments may be cited in the functional descriptions of the corresponding functional modules, and the details will not be described again here.

[0784] In this application, network device 310 is presented in an integrated manner and divided into functional modules, where a "module" may be an application-specific integrated circuit (ASIC), circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices capable of providing the functionality described above.

[0785] In some embodiments, with regard to a hardware implementation, those skilled in the art will appreciate that the network device 310 may take the form of a communications device 1000 shown in FIG.

[0786] In one example, the functions / implementation processes of the processing module 3101 in FIG. 31 may be implemented by the processor 1001 in the communication device 1000 shown in FIG. 10 by invoking computer-executable instructions stored in the memory 1003. The functions / implementation processes of the transceiver module 3102 in FIG. 31 may be implemented via the communication interface 1004 in the communication device 1000 shown in FIG.

[0787] In some embodiments, when the network device 310 in FIG. 31 is a chip or chip system, the functions / implemented processes of the transceiver module 3102 may be realized via an input / output interface (or communication interface) of the chip or chip system, and the functions / implemented processes of the processing module 3101 may be realized through a processor (or processing circuitry) of the chip or chip system.

[0788] The network device 310 provided in this embodiment may implement the above-mentioned communication method based on network slices. Therefore, the technical effects that can be achieved by the network device may refer to the above-mentioned method embodiments. Details are not described again here.

[0789] For example, the communication device is a terminal in the above method embodiment. Figure 32 is a schematic diagram of the structure of a terminal 320. The terminal 320 includes: a processing module 3201 and a transceiver module 3202.

[0790] In some embodiments, terminal 320 may further include a storage module (not shown in FIG. 32) configured to store program instructions and data.

[0791] In some embodiments, the transceiver module 3202 may also be referred to as a transceiver unit and may be configured to perform a transmitting function and / or a receiving function. The transceiver module 3202 may include a transceiver circuit, a transceiver machine, a transceiver, or a communication interface.

[0792] In some embodiments, the transceiver module 3202 may include a receiving module and a transmitting module configured to perform receiving type steps and transmitting type steps, respectively, performed by a terminal in the above method embodiments and / or support other processes of the techniques described in this specification, and the processing module 3201 may be configured to perform processing type (e.g., determining and obtaining) steps performed by a terminal in the above method embodiments and / or support other processes of the techniques described in this specification.

[0793] Specifically, the transceiver module 3202 is configured to learn from the network device that a first network slice is available in the second cell, the first network slice does not belong to a network slice that the terminal is allowed to access in the first cell, and the registration area of ​​the terminal includes the first cell and the second cell, and the processing module 3201 is configured to initiate a registration procedure for an application corresponding to the first network slice.

[0794] In a possible implementation, the transceiver module 3202 is further configured to receive a cell identifier from the network device, the cell identifier being used for the second cell.

[0795] In a possible implementation manner, the processing module 3201 being configured to initiate a registration procedure for an application corresponding to the first network slice includes: the processing module 3201 is configured to access a second cell, and the processing module 3201 is further configured to initiate a registration procedure for the application via the second cell.

[0796] In a possible implementation manner, the processing module 3201 being configured to initiate a registration procedure for an application corresponding to the first network slice includes: In response to the context of the terminal not including a session used for the application and not including a routing policy used for the application, in a possible implementation manner, the processing module 3201 is configured to determine whether the first network slice is a network slice corresponding to the application, and the processing module 3201 is configured to initiate a registration procedure for the application when the first network slice is a network slice corresponding to the application.

[0797] In a possible implementation, the transceiver module 3202 is further configured to notify the network device that the terminal no longer requests access to the first network slice.

[0798] All the relevant contents of the steps in the above method embodiments may be cited in the functional descriptions of the corresponding functional modules, and the details will not be described again here.

[0799] In this application, the terminal 320 is presented in the form of a division into functional modules in an integrated manner, where a "module" may be an application-specific integrated circuit (ASIC), circuitry, a processor and memory executing one or more software or firmware programs, integrated logic circuitry, and / or other devices capable of providing the functionality described above.

[0800] In some embodiments, with regard to a hardware implementation, those skilled in the art will appreciate that the terminal 320 may take the form of a communications device 1000 shown in FIG.

[0801] In one example, the functions / implementation processes of the processing module 3201 in FIG. 32 may be implemented by the processor 1001 in the communication device 1000 shown in FIG. 10 by invoking computer-executable instructions stored in the memory 1003. The functions / implementation processes of the transceiver module 3202 in FIG. 32 may be implemented via the communication interface 1004 in the communication device 1000 shown in FIG. 10.

[0802] In some embodiments, when the terminal 320 in FIG. 32 is a chip or chip system, the functions / implementation processes of the transceiver module 3302 may be realized through an input / output interface (or communication interface) of the chip or chip system, and the functions / implementation processes of the processing module 3201 may be realized through a processor (or processing circuit) of the chip or chip system.

[0803] The terminal 320 provided in this embodiment may perform the above-mentioned communication method based on network slices. Therefore, the technical effects that can be achieved by the terminal are referred to the above-mentioned method embodiments, and the details are not described again here.

[0804] In possible product forms, the network devices and terminals in the embodiments of this application may be further implemented through any combination of the following: one or more field programmable gate arrays (FPGAs), programmable logic devices (PLDs), controllers, state machines, gate logic, discrete hardware components, any other suitable circuitry, or circuitry capable of performing various functions described throughout this application.

[0805] In some embodiments, the embodiments of the present application further provide a communication device, the communication device including a processor configured to implement the method in any one of the above method embodiments.

[0806] In a possible implementation, the communication device further includes a memory. The memory is configured to store necessary program instructions and necessary data. The processor may call the program code stored in the memory to instruct the communication device to execute the method in any one of the above method embodiments. Obviously, the communication device may not include a memory.

[0807] In another possible implementation, the communication device further includes an interface circuit, which is a code / data read / write interface circuit configured to receive computer-executable instructions (which may be stored in a memory and read directly from the memory or read via other components) and to transmit the computer-executable instructions to the processor.

[0808] In yet another possible implementation, the communication device further comprises a communication interface, which is adapted to communicate with modules other than the communication device.

[0809] It can be understood that the communication device may be a chip or a chip system. When the communication device is a chip system, the communication device may include a chip, or may include a chip and other discrete components. This is not specifically limited in the embodiments of this application.

[0810] In some embodiments, the embodiments of the present application further provide a communication device (e.g., the communication device may be a chip or a chip system). The communication device includes an interface circuit and a logic circuit. The interface circuit is configured to obtain input information and / or output output information, and the logic circuit is configured to perform a method in any one of the above method embodiments to perform processing based on the input information and / or generate the output information.

[0811] When the communication device is configured to realize the functions of the network device in the above method embodiment,

[0812] In some implementation scenarios, in a possible implementation manner, the input information may be information regarding a network slice that the terminal requests to access, where the information regarding the network slice that the terminal requests to access includes identification information of a first network slice not supported by the first tracking area and includes identification information of a second network slice. Performing a process based on the input information may be determining a network slice that the terminal is allowed to access or determining a registration area.

[0813] In a possible implementation manner, the output information may be information regarding a registration area, where the registration area excludes a tracking area supporting the first network slice and the second network slice, or where the registration area excludes a tracking area of ​​an access network device supporting the first network slice and the second network slice.

[0814] In some implementation scenarios, in a possible implementation manner, the output information may be information for notifying a terminal that the first network slice is available in the second cell.

[0815] In a possible implementation manner, the input information may be information about a network slice that the terminal requests to access, and the information about the network slice that the terminal requests to access includes identification information of a first network slice. Performing a process based on the input information may be determining a network slice that the terminal is allowed to access, or determining that the first network slice does not belong to the network slices that the terminal is allowed to access in the first cell.

[0816] In a possible implementation, the output information may be an identification of the first network slice.

[0817] In a possible implementation manner, the input information may be information used by the network device to learn that the terminal can access the first network slice in the second cell. Performing the process based on the input information may be learning that the terminal can access the first network slice in the second cell.

[0818] In a possible implementation, the input information may be a path switch request message. Performing the process based on the input information may be determining that the first network slice is available in the second cell.

[0819] In a possible implementation, the input information may be a handover required message. Performing a process based on the input information may be determining that the first network slice is available in the second cell.

[0820] In a possible implementation, the input information may be instruction information. Performing a process based on the input information may be to delete the identification information of the first network slice based on the instruction information.

[0821] In some implementation scenarios, in a possible implementation manner, the output information may be information for notifying the terminal that the first network slice is available in the second cell, and a cell identifier of the second cell.

[0822] In a possible implementation manner, the input information may be information regarding a network slice that the terminal requests to access, and the information that the terminal requests to access may include identification information of a first network slice. Performing processing based on the input information may be determining a network slice that the terminal is allowed to access, and learning that the first network slice does not belong to the network slice that the terminal is allowed to access in the first cell.

[0823] In a possible implementation, the input information may be a cell identifier of the second cell. Performing the process based on the input information may be determining that the first network slice is available in the second cell.

[0824] In a possible implementation, the input information may be signal quality information of neighboring cells of the first cell, where the neighboring cells of the first cell include a second cell. Performing a process based on the input information may be determining that the terminal can access the first network slice in the second cell based on the signal quality information of the second cell.

[0825] In a possible implementation, the output information may be reference frequency information corresponding to the first network slice.

[0826] In a possible implementation, the input information may be instruction information. Performing a process based on the input information may be to delete the identification information of the first network slice based on the instruction information.

[0827] When the communication device is configured to realize the functions of the terminal in the above method embodiment,

[0828] In a possible implementation, the input information may be information for learning that the first network slice is available in the second cell. Performing a process based on the input information may be initiating a registration procedure for an application corresponding to the first network slice.

[0829] In a possible implementation, the input information may be a cell identifier, and the cell identifier is used for the second cell. Performing the process based on the input information may be accessing the second cell.

[0830] In a possible implementation, the output information may be information for notifying the terminal that it no longer requests access to the first network slice.

[0831] The communication device provided in this embodiment may implement the method in the above method embodiment. Therefore, the technical effects that can be achieved by the communication device shall refer to the above method embodiment, and details will not be described again here.

[0832] In a possible product form, the network devices and terminals in the embodiments of this application may be realized through a common bus architecture.

[0833] For ease of explanation, reference is made to FIG. 33. FIG. 33 is a schematic diagram of the structure of a communication device 3300 according to an embodiment of this application. The communication device 3300 includes a processor 3301 and a transceiver 3302. The communication device 3300 may be a network device, a terminal, or a chip in a network device or a terminal. FIG. 33 shows only the main components of the communication device 3300. In addition to the processor 3301 and the transceiver 3302, the communication device may further include a memory 3303 and an input / output device (not shown in the drawing).

[0834] The processor 3301 is mainly configured to process communication protocols and communication data, control the entire communication device, execute software programs, and process data of the software programs. The memory 3303 is mainly configured to store software programs and data. The transceiver 3302 may include a radio frequency circuit and an antenna. The radio frequency circuit is mainly configured to perform conversion between baseband signals and radio frequency signals, and process radio frequency signals. The antenna is mainly configured to receive and transmit radio frequency signals in the form of electromagnetic waves. The input / output device is, for example, a touch screen, a display, or a keyboard, and is mainly configured to receive data input by a user and output data to a user.

[0835] The processor 3301, the transceiver 3302 and the memory 3303 may be connected via a communication bus.

[0836] After the communication device is powered on, the processor 3301 may read the software program in the memory 3303, interpret and execute the instructions of the software program, and process data of the software program. When data needs to be transmitted wirelessly, the processor 3301 performs baseband processing on the data to be transmitted, and then outputs the baseband signal to the radio frequency circuit. The radio frequency circuit performs radio frequency processing on the baseband signal, and then sends out the radio frequency signal through an antenna in the form of electromagnetic waves. When data is transmitted to the communication device, the radio frequency circuit receives the radio frequency signal through the antenna, converts the radio frequency signal into a baseband signal, and outputs the baseband signal to the processor 3301. The processor 3301 converts the baseband signal into data and processes the data.

[0837] In other implementations, the radio frequency circuitry and antenna may be located separately from the processor performing the baseband processing, for example in a distributed scenario, where the radio frequency circuitry and antenna may be located separately from the communication device.

[0838] It should be understood that the sequence numbers of the above processes do not mean the execution order in various embodiments of this application. The execution order of the processes should be determined based on the functions and internal logic of the processes, and should not be construed as any limitation on the implementation process of the embodiments of this application.

[0839] The steps of the methods in the embodiments of this application may be adjusted in terms of sequence, combined, or deleted based on actual requirements.

[0840] The modules in the apparatus in the embodiments of this application may be combined, divided or deleted based on actual requirements.

[0841] All or part of the above embodiments may be realized through software, hardware, firmware, or any combination thereof. When a software program is used to realize the embodiments, all or part of the embodiments may be realized in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, a process or function based on the embodiments of this application is generated in whole or in part. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium, or may be transmitted from a computer-readable storage medium to another computer-readable storage medium. For example, the computer instructions may be transmitted from a website, computer, server, or data center to another website, computer, server, or data center in a wired (e.g., coaxial cable, optical fiber, or digital subscriber line (DSL)) or wireless (e.g., infrared, radio, or microwave) manner. The computer-readable storage medium may be any available medium accessible by a computer, or a data storage device integrating one or more avail...

Claims

1. A communication method, comprising: determining, by a network device, a network slice to which a terminal is permitted to access and a network slice to which the terminal is denied to access; determining, by the network device, a registration area for the terminal based on the network slice to which the terminal is permitted to access and the network slice to which the terminal is denied to access, wherein the network slice to which the terminal is denied to access includes a first network slice, the network slice to which the terminal is permitted to access includes a second network slice, and the registration area excludes a tracking area supporting both the first network slice and the second network slice; transmitting information about the registration area to the terminal by the network device; The method includes:

2. 2. The method of claim 1, wherein the first network slice is a network slice not supported by a current tracking area.

3. A communication method, comprising: receiving information regarding a registration area of ​​a terminal from a network device, wherein a network slice to which the terminal is denied access includes a first network slice and a network slice to which the terminal is permitted to access includes a second network slice, and the registration area excludes a tracking area supporting both the first network slice and the second network slice, or the registration area excludes a tracking area of ​​an access network device supporting both the first network slice and the second network slice; performing a mobility registration update procedure to request access to the first network slice when the terminal moves to a tracking area outside the registration area, the excluded tracking area supporting the first network slice; The method includes:

4. A communication device including a processor, A communications device, the processor being configured to read a program from a memory and to execute the program to implement the method according to claim 1 or 2.

5. A communication device including a processor, A communications device, wherein the processor is configured to read a program from a memory and execute the program to implement the method of claim 3 .

6. 1. A computer-readable medium, comprising: A computer readable medium storing instructions which, when executed on a computer, enable a processor to carry out the method of any one of claims 1 to 3.

7. A program, A program, which when executed on a communication device, performs the method according to any one of claims 1 to 3.

8. 1. A communication device, comprising: The communication device includes a logic circuit and an interface circuit; the interface circuitry is configured to receive input information and / or provide output information; 3. A communications device, comprising: a logic circuit configured to execute a method as claimed in claim 1 or 2 to process the information input through the interface circuit and / or to generate the information output through the interface circuit.

9. 1. A communication device, comprising: The communication device includes a logic circuit and an interface circuit; the interface circuitry is configured to receive input information and / or provide output information; 4. A communications device, comprising: a logic circuit configured to perform a method as claimed in claim 3 to process the information input through the interface circuit and / or to generate the information output through the interface circuit.

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