Communication method and related communication device, medium and chip

Abstract

Embodiments of the present disclosure provide communication methods and associated communication devices, media, and chips. In a communication method, a target access network device receives first information, and the first information indicates a relationship between a first network slice of a first network and a second network slice of a second network, and the first network and the second network are different. The target access network device performs access control of the terminal device to the target access network device based at least on the first information. In this way, the embodiments of the present disclosure enable the target access network device to perform access control on the terminal device when accessing across networks, reduce access delays, reduce service interruption problems caused by session rejections of the terminal device, and ensure service continuity of the terminal device.

Description

Technical Field

[0001] The present disclosure relates to the field of communications, and more particularly, to a communication method and associated communication devices, media, and chips. Background Art

[0002] With the development of mobile communication technology, various new services and application scenarios continue to emerge. These services have very different requirements for network functions, connection performance and security. If a single network is used to carry these services, it will be difficult to meet the diverse requirements of high bandwidth, low latency, high reliability, etc. In addition, building a new network for each service will bring huge costs. This requires the network to be flexible and scalable while being able to meet different business needs. To this end, the new generation of network systems, such as the fifth generation mobile communication technology (5G) system, has proposed network slicing technology, which provides network services for different users and their differentiated services through flexible allocation of network resources and on-demand networking.

[0003] Due to the deployment of network slicing, the network slices supported by different cells or different access network devices may be different. For example, some cells or access network devices do not support certain network slices, or even if they support the network slicing function, due to the deployment or policy of the operator, these cells or access network devices cannot provide the corresponding network slices for the terminal device for service. Considering the mobility of the terminal device and the need for service changes, the terminal device may register or switch to different access network devices. Therefore, it is necessary to be able to achieve access and service of terminal devices under the condition of differentiated support for network slicing by different access network devices. Summary of the invention

[0004] Example embodiments of the present disclosure provide a scheme for supporting access control of a terminal device in a communication system.

[0005] In a first aspect of the present disclosure, a communication method is provided. The method includes a target access network device receiving first information, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network being different; and the target access network device performing access control of a terminal device to the target access network device based at least on the first information.

[0006] By providing the target access network device with information indicating the relationship between network slices of different networks, the target access network device can perform access control on the terminal device across networks. Such a solution can reduce access latency, reduce service interruption problems caused by session rejection of the terminal device, and ensure service continuity of the terminal device.

[0007] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively. In some embodiments, the identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice, respectively. Thus, the relationship between the corresponding network and its network slice can be indicated in the first information by the identifier of the network and the identifier of the slice.

[0008] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice. Based on such first information, the target access network device can determine whether to support the access of the terminal device through the remapping of the network slice during access control.

[0009] In some embodiments, receiving the first information includes: the target access network device receives the first information from the core network device. In such an embodiment, the core network device can determine the first information by integrating the information reported by multiple access network devices, so that the first information is applicable to the access control of the terminal device by multiple access network devices. In some embodiments, the first network and the second network are in the same tracking area. On the core network side, the core network device can determine and provide the first information by comprehensively considering the relationship between network slices of networks in a certain area. Since the first information covers the relationship between network slices of networks in a certain area, no matter which network the terminal device wants to access in the area, the corresponding target access network device can perform access control based on the first information.

[0010] In some embodiments, the first information is included in an NG setup response. The NG setup response may be transmitted from the core network to the target access network device, typically as a response to an NG setup message of the target access network device. In this way, the target access network device may obtain the first information for access control in advance at the interface setup stage.

[0011] In some embodiments, the communication method of the first aspect also includes: the target access network device receives second information from the source access network device, and the second information includes an identifier of a third network slice that the terminal device is allowed to use in the second network. In some embodiments, performing the access control based at least on the first information includes: the target access network device performs the access control based on the first information and the second information. With the help of the first information and the second information, the target access network device can better determine the network slices allowed for the terminal device in the second network, which is particularly beneficial for scenarios where there are differences in the network slices allowed for different terminal devices in different networks.

[0012] In some embodiments, receiving the first information includes: the target access network device receives the first information for the terminal device from the source access network device, and the first network is the service network of the terminal device. In such an embodiment, the target access network device can obtain more targeted first information for performing access control for the terminal device by interacting with the source access network device. Reducing the amount of information in the first information can also reduce the transmission overhead between access network devices.

[0013] In some embodiments, the second network includes a target network of the terminal device. This means that the first information indicates a relationship between a service network specific to the current terminal device and a network slice of the target network. As a result, the target access network device does not need to receive and retain too much redundant information.

[0014] In some embodiments, the first information is included in the handover request for the terminal device. Therefore, the first information is provided to the target access network device in a timely manner when it is determined that the terminal device is to be switched to the target network of the target access network device. The target access network device can perform access control on the terminal device during the handover process based on this information.

[0015] In some embodiments, performing the access control includes: the target access network device determines the identifier of the service network of the terminal device, the identifier of the service network slice of the service network, and the identifier of the target network of the terminal device; the target access network device determines the target network slice related to the service network slice in the target network from the first information based on the identifier of the service network, the identifier of the service network slice, and the identifier of the target network; and the target access network device performs the access control based on the determination of the target network slice. In this way, with the help of the first information, the target access network device can effectively implement access control, avoid switching delays, reduce service interruptions caused by the rejection of the terminal device's session after switching, and ensure service continuity.

[0016] In a second aspect of the present disclosure, a communication method is provided. The method includes: a source access network device receives first information for a terminal device from a core network device, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network is a service network of the terminal device, and the first network and the second network are different; and the source access network device transmits the first information to a target access network device.

[0017] In this way, with the help of the first information specific to the terminal device provided by the source access network device, the target access network device can perform access control on the terminal device across networks, reduce access delay, reduce service interruption problems caused by session rejection of the terminal device, and ensure service continuity of the terminal device. Since the first information involves a service network specific to the terminal device, the amount of information in the first information is reduced, which also reduces the transmission overhead between the core network device and the access network device.

[0018] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively. In some embodiments, the identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice, respectively. Thus, the relationship between the corresponding network and its network slice can be indicated in the first information by the identifier of the network and the identifier of the slice.

[0019] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice. Based on such first information, the target access network device can determine whether to support the access of the terminal device through the remapping of the network slice during access control.

[0020] In some embodiments, the second network includes a target network of the terminal device. This means that the first information indicates a relationship between a service network specific to the current terminal device and a network slice of the target network. As a result, the target access network device does not need to receive and retain too much redundant information.

[0021] In some embodiments, the first information is included in the handover request for the terminal device. Therefore, the first information is provided to the target access network device in a timely manner when it is determined that the terminal device is to be switched to the target network of the target access network device. The target access network device can perform access control on the terminal device during the handover process based on this information.

[0022] In some embodiments, the communication method of the second aspect further includes: if the access of the terminal device to the target access network device is allowed, the source access network device transmits third information to the terminal device, the third information indicating that the service network of the terminal device is switched from the first network to the second network. In this way, in the case of cross-network access, the terminal device can quickly learn about the change of the service network through the received third information.

[0023] In some embodiments, the third information includes an identifier of the second network. Providing the identifier of the second network to the terminal device helps the terminal device to clearly identify the specific network to which it is switched from the current network.

[0024] In some embodiments, the third information is included in a radio resource control reconfiguration message. Thus, the terminal device can determine through the message that the radio resource control connection needs to be reconfigured, and can also be informed of the change of the service network.

[0025] In some embodiments, the communication method of the second aspect further includes: if the access of the terminal device to the target access network device is allowed, the source access network device transmits fourth information to the terminal device, wherein the fourth information indicates that the session of the terminal device is changed to be served by the second network slice of the second network. In this way, in the case of cross-network access, the terminal device can not only quickly learn about the change of the service network, but also determine the network slice to be accessed through the received fourth information.

[0026] In a third aspect of the present disclosure, a communication method is provided. The method includes: a terminal device receives third information from a source access network device, the third information indicating that the service network of the terminal device is switched from a first network to a second network, and the first network and the second network are different; and the terminal device uses the third information. In this way, in the case of cross-network access, the terminal device can quickly learn about the change of the service network through the received third information, and use the third information accordingly.

[0027] In some embodiments, using the third information includes the terminal device performing random access to a target access network device in the second network based on the third information. The third information helps guide the random access process of the terminal device and improves the possibility of successful random access. In some embodiments, using the third information includes the terminal device displaying an identifier of the second network based on the third information. By displaying the identifier of the second network, a user of the terminal device can be notified of a change in the service network.

[0028] In some embodiments, the third information includes an identifier of the second network. Providing the identifier of the second network to the terminal device helps the terminal device to clearly identify the specific network to which it is switched from the current network.

[0029] In some embodiments, the third information is included in a radio resource control reconfiguration message. Thus, the terminal device can determine through the message that the radio resource control connection needs to be reconfigured, and can also be informed of the change of the service network.

[0030] In some embodiments, the communication method of the third aspect further includes: if the access of the terminal device to the target access network device is allowed, the terminal device receives fourth information from the source access network device, and the fourth information indicates that the session of the terminal device is changed to be served by the second network slice of the second network. In this way, in the case of cross-network access, the terminal device can not only quickly learn about the change of the service network, but also determine the network slice to be accessed through the received fourth information.

[0031] In a fourth aspect of the present disclosure, a communication method is provided. The method includes: a core network device determines first information, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network are different; and the core network device transmits the first information to an access network device for access control of a terminal device to the access network device.

[0032] In this way, by providing the first information from the core network device to the target access network device, the target access network device can use the first information to perform access control on the terminal device across the network, reduce access delay, and reduce service interruption problems caused by session rejection, thereby ensuring service continuity of the terminal device.

[0033] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively. In some embodiments, the identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice, respectively. Thus, the relationship between the corresponding network and its network slice can be indicated in the first information by the identifier of the network and the identifier of the slice.

[0034] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice. Based on such first information, the target access network device can determine whether to support the access of the terminal device through the remapping of the network slice during access control.

[0035] In some embodiments, the first network is a service network of the terminal device, and the terminal device is served by the first network via the access network device. In some embodiments, the second network includes a target network of the terminal device. This ensures that when the terminal device switches from the service network to the target network, the target access network device can perform access control according to the obtained first information.

[0036] In some embodiments, the first network and the second network are in the same tracking area. On the core network side, the core network device can comprehensively consider the relationship between network slices of networks in a certain area to determine and provide the first information. Since the first information covers the relationship between network slices of networks in a certain area, no matter which network the terminal device wants to access in the area, the corresponding target access network device can perform access control according to the first information.

[0037] In some embodiments, the first information is included in an NG setup response. The NG setup response may be transmitted from the core network to the target access network device, typically as a response to an NG setup message of the target access network device. In this way, the target access network device may obtain the first information for access control in advance at the interface setup stage.

[0038] In a fifth aspect of the present disclosure, a communication device implemented at a target access network device is provided. The communication device includes a first receiving unit configured to receive first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network being different; and an access control unit configured to perform access control of a terminal device to the target access network device based at least on the first information.

[0039] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively, and the identifier of the first network slice and the identifier of the second network slice include single network slice selection assistance information of the first network slice and the second network slice, respectively.

[0040] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice.

[0041] In some embodiments, the first receiving unit is further configured to receive the first information from a core network device. In some embodiments, the first network and the second network are in the same tracking area.

[0042] In some embodiments, the first information is included in an NG setup response.

[0043] In some embodiments, the communication device further includes: a second receiving unit configured to receive second information from a source access network device, wherein the second information includes an identifier of a third network slice that the terminal device is allowed to use in the second network. In some embodiments, the access control unit is further configured to perform the access control based on the first information and the second information.

[0044] In some embodiments, the first receiving unit is further configured to: receive the first information for the terminal device from a source access network device, and the first network is a service network of the terminal device.

[0045] In some embodiments, the second network comprises a target network of the terminal device.

[0046] In some embodiments, the first information is included in a handover request for the terminal device.

[0047] In some embodiments, the access control unit is further configured as: the target access network device determines the identifier of the service network of the terminal device, the identifier of the service network slice of the service network, and the identifier of the target network of the terminal device; the target access network device determines the target network slice related to the service network slice in the target network from the first information based on the identifier of the service network, the identifier of the service network slice, and the identifier of the target network; and the target access network device performs the access control based on the determination of the target network slice.

[0048] In a sixth aspect of the present disclosure, a communication device implemented at a source access network device is provided. The communication device includes a receiving unit configured to receive first information for a terminal device from a core network device, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network being a service network of the terminal device, and the first network and the second network are different; and a first transmission unit configured to transmit the first information to a target access network device.

[0049] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively, and the identifier of the first network slice and the identifier of the second network slice include single network slice selection assistance information of the first network slice and the second network slice, respectively.

[0050] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice.

[0051] In some embodiments, the second network comprises a target network of the terminal device.

[0052] In some embodiments, the first information is included in a handover request for the terminal device.

[0053] In some embodiments, the communication device also includes: a second transmission unit, configured to transmit third information to the terminal device when access of the terminal device to the target access network device is allowed, and the third information indicates that the service network of the terminal device is switched from the first network to the second network.

[0054] In some embodiments, the third information includes an identification of the second network.

[0055] In some embodiments, the third information is included in a radio resource control reconfiguration message.

[0056] In some embodiments, the communication device also includes: a third transmission unit, configured to transmit fourth information to the terminal device if access of the terminal device to the target access network device is allowed, the fourth information indicating that the session of the terminal device is changed to be served by the second network slice of the second network.

[0057] In a seventh aspect of the present disclosure, a communication device implemented at a terminal device is provided. The communication device includes a first receiving unit configured to receive third information from a source access network device, wherein the third information indicates that a service network of the terminal device is switched from a first network to a second network, and the first network and the second network are different. The communication device also includes an information using unit configured to use the third information.

[0058] In some embodiments, the information using unit is configured to perform random access to a target access network device in the second network based on the third information. In some embodiments, the information using unit is configured to display an identification of the second network based on the third information.

[0059] In some embodiments, the third information includes an identification of the second network.

[0060] In some embodiments, the third information is included in a radio resource control reconfiguration message.

[0061] In some embodiments, the communication device also includes a second receiving unit, configured to receive fourth information from the source access network device if access of the terminal device to the target access network device is allowed, the fourth information indicating that the session of the terminal device is changed to be served by the second network slice of the second network.

[0062] In an eighth aspect of the present disclosure, a communication device implemented at a core network device is provided. The communication device includes a determining unit configured to determine first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network being different; and a transmitting unit configured to transmit the first information to an access network device for access control of a terminal device to the access network device.

[0063] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively, and the identifier of the first network slice and the identifier of the second network slice include single network slice selection assistance information of the first network slice and the second network slice, respectively.

[0064] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice.

[0065] In some embodiments, the first network is a service network of the terminal device, and the terminal device is served by the first network via the access network device; and the second network includes a target network of the terminal device.

[0066] In some embodiments, the first network and the second network are within the same tracking area.

[0067] In some embodiments, the first information is included in an NG setup response.

[0068] In a ninth aspect of the present disclosure, a computer-readable storage medium is provided, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the operation of the method in any possible implementation manner of the first to fourth aspects is implemented.

[0069] In a tenth aspect of the present disclosure, the present disclosure provides a chip, which is configured to perform operations of the method in any possible implementation manner of the first to fourth aspects above.

[0070] In an eleventh aspect of the present disclosure, a communication device is provided. The communication device includes: at least one processing unit; and at least one memory, the at least one memory being coupled to the at least one processing unit and storing instructions for execution by the at least one processing unit, the instructions causing the communication device to implement the operation of the method in any possible implementation of the first to fourth aspects above when executed by the at least one processing unit.

[0071] In a twelfth aspect of the present disclosure, a computer program product is provided. The computer program product is tangibly stored on a computer-readable medium and includes computer-executable instructions, which, when executed, enable a device to implement the operation of the method in any possible implementation of the first to fourth aspects above.

[0072] In the thirteenth aspect of the present disclosure, a communication method is provided. The method includes: a target access network device receives slice identification information from a source access network device, the slice identification information indicates an identification of a home network slice of the terminal device in a home network, and the target access network device is in a visited network of the terminal device; the target access network device receives slice correspondence information from a core network device, the slice correspondence information indicates the correspondence between a network slice of the visited network and a network slice of the home network; and the target access network device performs access control of the terminal device to the target access network device based at least on the slice identification information and the slice correspondence information.

[0073] In this way, the target access network device can perform access control on the terminal device when it accesses across networks, especially access control when the terminal device wants to access the visited network, reduce access delay, reduce service interruption problems caused by session rejection of the terminal device, and ensure service continuity of the terminal device.

[0074] In some embodiments, the communication method of the thirteenth aspect also includes: the target access network device transmits a request for the network slice correspondence information to the core network device, and the request includes at least an identifier of the terminal device and an identifier of the visited network. In some embodiments, receiving the network slice correspondence information includes: the target access network device receives a response to the request from the core network device, and the target access network device obtains the network slice correspondence information from the response. Therefore, the target access network device can request network slice correspondence information from the core network device only when access control needs to be performed.

[0075] In some embodiments, the communication method of the thirteenth aspect also includes: the target access network device receives the fifth information for the home network from the core network device, and the fifth information indicates the relationship between the home network slice and another network slice of the home network. In some embodiments, performing the access control based at least on the slice identification information and the slice correspondence information includes: the target access network device performs the access control based on the slice identification information, the network slice correspondence information and the fifth information. With the help of the fifth information, the target access network device can further determine whether there are other related network slices (for example, other network slices with a remapping relationship) in the visited network corresponding to the home network slice through the relationship between the network slices in the home network.

[0076] In a fourteenth aspect of the present disclosure, a communication method is provided. The method comprises: a source access network device receives slice identification information for a terminal device, the slice identification information indicates an identification of a home network slice of the terminal device in a home network, the source access network device is in a first visited network of the terminal device; and the source access network device transmits the slice identification information to a target access network device to which the terminal device is to switch, the target access network device is in a second visited network of the terminal device.

[0077] In this way, the slice identification information provided by the source access network device to the target access network device can assist in the access control of the terminal device when it accesses across networks, especially when the terminal device wants to access the visited network. This can reduce access latency, reduce service interruption problems caused by session rejection of the terminal device, and ensure service continuity of the terminal device.

[0078] In some embodiments, receiving the slice identification information includes: the source access network device receives the slice identification information from the terminal device or from a core network device. The source access network device can obtain the slice identification information in a variety of ways.

[0079] In some embodiments, the slice identification information is included in a session establishment request received from the terminal device. Thus, the source access network device can obtain the slice identification information from the terminal device at the early stage of session establishment of the terminal device.

[0080] In some embodiments, the slice identification information is included in a session resource establishment request for the terminal device received from the core network device. Thus, the source access network device can obtain the slice identification information from the core network device at the early stage of session establishment of the terminal device.

[0081] In the fifteenth aspect of the present disclosure, a communication method is provided. The method includes: a terminal device transmits slice identification information to a source access network device, the slice identification information indicates the identification of the home network slice of the terminal device in the home network, and the source access network device is in the first visited network of the terminal device; and the terminal device receives third information from the source access network device, the third information indicates that the service network of the terminal device is switched from the first visited network to the second visited network, and the first visited network and the second visited network are different. In this way, the terminal device provides the slice identification information to the source access network device, and then the source access network device can provide the slice identification information to the target access network device to assist the target access network device in performing access control when the terminal device accesses across networks, especially when the terminal device wants to access the visited network. This can reduce access delay, reduce the service interruption problem caused by the rejection of the session of the terminal device, and ensure the service continuity of the terminal device. Further, the terminal device can receive the third information indicating the switching of the service network, so as to quickly learn the change of the service network.

[0082] In some embodiments, transmitting the slice identification information to the source access network device includes: the terminal device transmitting the slice identification information to the source access network device in a session establishment request. Thus, the source access network device can obtain the slice identification information from the terminal device at the early stage of establishing a session with the terminal device.

[0083] In some embodiments, the communication method of the fifteenth aspect also includes the terminal device using the third information. In some embodiments, using the third information includes the terminal device performing random access to the target access network device in the second visited network based on the third information. The third information helps to guide the random access process of the terminal device and improve the possibility of successful random access. In some embodiments, using the third information includes the terminal device displaying the identifier of the second visited network based on the third information. By displaying the identifier of the second visited network, the user of the terminal device can be notified of changes in the service network.

[0084] In some embodiments, the third information includes an identifier of the second visited network. Providing the identifier of the second visited network to the terminal device helps the terminal device to clearly identify the specific network to which it is switched from the current network.

[0085] In some embodiments, the third information is included in a radio resource control reconfiguration message. Thus, the terminal device can determine through the message that the radio resource control connection needs to be reconfigured, and can also be informed of the change of the service network.

[0086] In some embodiments, the communication method of the fifteenth aspect further includes: if the access of the terminal device to the target access network device is allowed, the terminal device receives fourth information from the source access network device, and the fourth information indicates that the session of the terminal device is changed to be served by the second visited network slice of the second visited network. In this way, in the case of cross-network access, the terminal device can not only quickly learn about the change of the service network, but also determine the network slice to be accessed through the received fourth information.

[0087] In the sixteenth aspect of the present disclosure, a communication device implemented at a target access network device is provided. The communication device includes a first receiving unit, configured to receive slice identification information from a source access network device, the slice identification information indicating an identification of a home network slice of the terminal device in a home network, and the target access network device is in a visited network of the terminal device; a second receiving unit, configured to receive slice correspondence information from a core network device, the slice correspondence information indicating the correspondence between a network slice of the visited network and a network slice of the home network; and an access control unit, configured to perform access control of the terminal device to the target access network device based at least on the slice identification information and the slice correspondence information.

[0088] In some embodiments, the communication device of the sixteenth aspect further includes: a transmission unit configured to transmit a request for the network slice correspondence information to the core network device, the request including at least an identifier of the terminal device and an identifier of the visited network. In some embodiments, the first receiving unit is further configured to: receive a response to the request from the core network device, and obtain the network slice correspondence information from the response.

[0089] In some embodiments, the communication device of the sixteenth aspect further includes: a third receiving unit configured to receive fifth information for the home network from the core network device, wherein the fifth information indicates a relationship between the home network slice and another network slice of the home network. In some embodiments, the access control unit is further configured to perform the access control based on the slice identification information, the network slice correspondence information and the fifth information.

[0090] In the seventeenth aspect of the present disclosure, a communication device implemented at a source access network device is provided. The communication device includes a receiving unit configured to receive slice identification information for a terminal device, the slice identification information indicating an identification of a home network slice of the terminal device in a home network, the source access network device being in a first visited network of the terminal device; and a transmission unit configured to transmit the slice identification information to a target access network device to which the terminal device is to be switched, the target access network device being in a second visited network of the terminal device.

[0091] In some embodiments, the receiving unit is further configured as: the source access network device receives the slice identification information from the terminal device or from the core network device.

[0092] In some embodiments, the slice identification information is included in a session establishment request received from the terminal device.

[0093] In some embodiments, the slice identification information is included in a session resource establishment request for the terminal device received from the core network device.

[0094] In the eighteenth aspect of the present disclosure, a communication device implemented at a terminal device is provided. The communication device includes a transmission unit configured to transmit slice identification information, the slice identification information indicates an identification of a home network slice of the terminal device in a home network, the source access network device is in a visited network of the terminal device; and a first receiving unit configured to receive third information from the source access network device, the third information indicating that the service network of the terminal device is switched from the first visited network to a second visited network, and the first visited network and the second visited network are different.

[0095] In some embodiments, the transmission unit is further configured to: the terminal device transmits the slice identification information to the source access network device in a session establishment request.

[0096] In some embodiments, the communication device of the eighteenth aspect further includes an information use unit configured to use the third information. In some embodiments, the information use unit is further configured to perform random access to a target access network device in the second visited network based on the third information. In some embodiments, the information use unit is further configured to display an identification of the second visited network based on the third information.

[0097] In some embodiments, the third information includes an identification of the second visited network.

[0098] In some embodiments, the third information is included in a radio resource control reconfiguration message.

[0099] In some embodiments, the communication device of the eighteenth aspect also includes a second receiving unit, which is configured to receive fourth information from the source access network device if access of the terminal device to the target access network device is allowed, and the fourth information indicates that the session of the terminal device is changed to be served by the second visited network slice of the second visited network.

[0100] In a nineteenth aspect of the present disclosure, a computer-readable storage medium is provided, wherein a computer program is stored on the computer-readable storage medium, and when the computer program is executed by a processor, the operation of the method in any possible implementation manner of the thirteenth to fifteenth aspects is implemented.

[0101] In a twentieth aspect of the present disclosure, the present disclosure provides a chip, which is configured to perform operations of the method in any possible implementation manner of the thirteenth to fifteenth aspects above.

[0102] In a twenty-first aspect of the present disclosure, a communication device is provided. The communication device includes: at least one processing unit; and at least one memory, the at least one memory being coupled to the at least one processing unit and storing instructions for execution by the at least one processing unit, the instructions causing the communication device to implement the operation of the method in any possible implementation manner of the thirteenth to fifteenth aspects above when executed by the at least one processing unit.

[0103] In a twenty-second aspect of the present disclosure, a computer program product is provided. The computer program product is tangibly stored on a computer-readable medium and includes computer-executable instructions, which, when executed, enable a device to implement the operation of the method in any possible implementation of the thirteenth to fifteenth aspects above. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] The features, advantages and other aspects of various implementations of the present disclosure will become more apparent with reference to the following detailed description in conjunction with the accompanying drawings. Several implementations of the present disclosure are shown here in an exemplary and non-limiting manner. In the accompanying drawings:

[0105] Figure 1 A schematic block diagram showing a network slicing-based communication environment in which embodiments of the present disclosure may be implemented;

[0106] Figure 2 A schematic block diagram showing an example networking architecture in which network slicing of embodiments of the present disclosure may be implemented;

[0107] Figure 3 An interactive signaling diagram illustrating a communication process according to some embodiments of the present disclosure;

[0108] Figure 4 An interactive signaling diagram of a communication process according to some other embodiments of the present disclosure is shown;

[0109] Figure 5 An interactive signaling diagram showing a communication process according to still further embodiments of the present disclosure;

[0110] Figure 6 An interactive signaling diagram showing a communication process according to still further embodiments of the present disclosure;

[0111] Figure 7 A schematic block diagram showing a communication apparatus implemented at a target access network device according to some embodiments of the present disclosure;

[0112] Figure 8 A schematic block diagram showing a communication apparatus implemented at a source access network device according to some embodiments of the present disclosure is shown;

[0113] Fig. 9 A schematic block diagram of a communication apparatus implemented at a terminal device according to some embodiments of the present disclosure is shown;

[0114] Fig.10 A schematic block diagram of a communication apparatus implemented in a core network device according to some embodiments of the present disclosure is shown;

[0115] Fig.11 A schematic block diagram showing a communication apparatus implemented at a target access network device according to other embodiments of the present disclosure;

[0116] Fig.12 A schematic block diagram showing a communication apparatus implemented at a source access network device according to other embodiments of the present disclosure;

[0117] Fig.13A schematic block diagram showing a communication apparatus implemented at a terminal device according to other embodiments of the present disclosure; and

[0118] Fig.14 A simplified block diagram of an example device suitable for implementing embodiments of the present disclosure is shown.

[0119] In the various drawings, the same or similar reference numbers denote the same or similar elements. DETAILED DESCRIPTION

[0120] Embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present disclosure. It should be understood that the drawings and embodiments of the present disclosure are only for exemplary purposes and are not intended to limit the scope of protection of the present disclosure.

[0121] In the description of the embodiments of the present disclosure, the term "including" and similar terms should be understood as open inclusion, that is, "including but not limited to". The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc. may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0122] The embodiments of the present disclosure may be implemented according to any appropriate communication protocol, including but not limited to cellular communication protocols such as the fourth generation (4G) and the fifth generation (5G), wireless local area network communication protocols such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol currently known or developed in the future. The technical solutions of the embodiments of the present disclosure are applied to comply with any appropriate communication system, such as: General Packet Radio Service (GPRS), Long Term Evolution (LTE) system, Frequency Division Duplex (FDD) system, Time Division Duplex (TDD), Universal Mobile Telecommunications System (UMTS), Narrowband Internet of Things (NB-IoT) communication system, future fifth generation (5G) system or new wireless (NR), etc.

[0123] For the purpose of illustration, the embodiments of the present disclosure are described below with the 3rd Generation Partnership Project (3GPP) communication system of 5G as the background. However, it should be understood that the embodiments of the present disclosure are not limited to being applied to the 3GPP communication system of 5G, but can be applied to any communication system with similar problems, such as wireless local area network (WLAN), wired communication system, or other communication systems developed in the future.

[0124] The term "terminal device" used in this disclosure refers to any terminal device that can perform wired or wireless communication with network devices or with each other. The terminal device may sometimes be referred to as a user equipment (UE). The terminal device may be any type of mobile terminal, fixed terminal or portable terminal. As an example, the terminal device may include a mobile phone, a site, a unit, a device, a mobile terminal (MT), a subscription station (SS), a portable subscription station (PSS), an Internet node, a communicator, a desktop computer, a laptop computer, a notebook computer, a tablet computer, a personal communication system (PCS) device, a personal navigation device, a personal digital assistant (PDA), a positioning device, a radio broadcast receiver, an e-book device, a gaming device, an Internet of Things (IoT) device, a vehicle-mounted device, an aircraft, a virtual reality (VR) device, an augmented reality (AR) device, a wearable device, a terminal device in a 5G network or any terminal device in a future evolved public land mobile network (PLMN), other devices that can be used for communication, or any combination of the above. The embodiments of the present disclosure do not limit this.

[0125] The term "access network device" used in the present disclosure is an entity or node that can be used to communicate with a terminal device. The access network device may be, for example, a radio access network (RAN) network device. The access network device may include various types of base stations. As an example, the access network device may include various forms of macro base stations, micro base stations, micro-micro base stations, femto base stations, relay stations, access points, remote radio units (RRUs), radio frequency heads (RHs), remote radio heads (RRHs), and the like. In systems using different wireless access technologies, the names of access network devices may be different, such as evolved node Bs (eNBs or eNodeBs) in LTE networks, node Bs (NodeBs) in 3G networks, g node Bs (gNBs) or NR node Bs (NR NBs) in 5G networks, and so on. The embodiments of the present disclosure do not limit this.

[0126] The term "core network device" or "CN device" used in the present disclosure may refer to a network function (NF) or a network element in the core network. The core network device may include a control plane anchor point for a terminal device, providing the terminal with functions such as core network access, registration area update, mobility management, and session management. As an example, the core network device may include an access and mobility management function (AMF), a network slice selection function (NSSF), a network storage function (NRF), a session management function (SMF), a policy control function (PCF), a user plane function (UPF), and the like. In an embodiment of the present disclosure, the functions of the core network described may be implemented on one or more functional entities of the core network.

[0127] The specific embodiments of the present disclosure are mainly implemented on an architecture based on network slicing. Before introducing the specific embodiments of the present disclosure, for ease of understanding, an example environment based on network slicing is first described, and some terms that may appear in this article are explained.

[0128] 1. Sample environment based on network slicing

[0129] Figure 1 A schematic block diagram of a communication environment 100 based on network slicing in which embodiments of the present disclosure may be implemented is shown. As shown in the figure, multiple network slices 120-1, 120-2, ..., 120-N (collectively or separately referred to as network slices 120 in this document for the convenience of discussion) may be virtualized on a single infrastructure pool 110, where N is an integer greater than 1. It should be understood that

[0130] Figure 1 The number of network slices and infrastructure shown are examples only.

[0131] The infrastructure pool 110 may include various physical or virtual network devices required to support network services, such as various access network devices, servers, switches, gateways, etc. The network resources of the infrastructure pool 110 will be allocated to different network slices 120 according to different service requirements or tenant requirements. Therefore, different types of network slices 120 will provide different network capabilities and network characteristics. The type of network slice 120 is generally related to the type of service to be supported, for example, it may include enhanced mobile broadband service (eMBB), ultra-reliable low latency communication (URLLC), massive machine type communication (mMTC) and other types. In some embodiments, there may be multiple network slices 120 for each type.

[0132] In this article, a network slice 120 can be understood as a complete end-to-end logical subnetwork including an access network, a transmission network, a core network, and an application server, which can provide telecommunication services and has certain network capabilities. A network slice 120 can also be any combination of the above-mentioned access network, transmission network, core network, and application server. For example, a network slice 120 can only include an access network and a core network. For a specific network slice 120, an access network may support the network slice or may not support the network slice. The access network may be shared by multiple network slices 120. The characteristics of different network slices 120 and the network function modules that constitute them may be different. Network slices can also be referred to as "slices" for short.

[0133] Figure 2 A schematic diagram of an example network slicing-based networking architecture 200 in which embodiments of the present disclosure may be implemented is shown. Figure 2In the example shown, multiple access network devices 210, 212, 214, etc. are used to implement network functions of the access network in the communication environment. Each access network device can support one or more network slices 120. For example, the access network device 210 supports network slices 120-2 and 120-N, which means that the network slices 120-2 and 120-N have a shared access network. Figure 2 It is also shown that access network device 212 supports network slice 120-2; access network device 214 supports network slices 120-2 and 120-N, and so on.

[0134] Figure 2 The core network equipment of each network slice 120 is also shown, wherein the AMF 230 is shared by multiple network slices 120 to provide access and mobility management for multiple network slices 120. Each network slice 120 also has its own core network equipment, for example, the network slice 120-1 has SMF 240-1, UPF 250-1, etc., the network slice 120-2 has SMF 240-2, UPF 250-2, etc., and the network slice 120-N has SMF 240-N, UPF 250-N, etc., etc. For the convenience of discussion, in this article, SMF 240-1, 240-2, ..., 240-N may be collectively or separately referred to as SMF 240, and UPF 250-1, 250-2, ..., 250-N may be collectively or separately referred to as UPF 250. SMF 240 and UPF 250 can provide network slices 120 with core network session management, user plane functions and other related services based on the different requirements of each network slice 120 for latency, bandwidth, security and other aspects.

[0135] Further, core network devices such as NSSF 260 and NRF 270 can be deployed on a network basis (e.g., on a PLMN basis) to support network slice selection functions and network storage functions within the network. Figure 2 The NSSF and NRF for a single PLMN are only schematically shown.

[0136] The terminal device 220 can access the network slice 120 via the access network device. In the same network, such as the same PLMN, the terminal device 220 can access only one network slice 120 or multiple network slices 120 to use different services provided by multiple network slices 120 at the same time. Figure 2 In the example of FIG. 1 , it is assumed that the terminal device 220 accesses the network slice 120-2 via the access network device 210, thereby realizing the communication between the terminal device 220 and the data network (DN). Different network slices 120 may have access to different DNs. Figure 2In the example of , network slices 120-1 and 120-2 can access DN 280-1, and network slice 120-N can access DN 280-M. For the convenience of discussion, in this article, DN 280-1, ..., 280-M can be collectively or separately referred to as DN 280.

[0137] It should be understood that Figure 2 The figure shows only one example networking mode of network slices. In practical applications, there may be many other different networking modes. For example, different network slices may have their own AMF. In addition, Figure 2 The types of devices, the number of devices, the connection methods between devices, etc. shown in FIG. 1 can all be changed. For example, Figure 2 Only some core network devices are schematically shown, but there may be more, fewer, or other types of core network devices in practice. In addition, there may be more, fewer, or other access network devices, more terminal devices, and so on. The variations of these deployment modes are achievable by those skilled in the art. The embodiments of the present disclosure do not limit this.

[0138] In order to distinguish network slices between terminal devices, access network devices and core network devices, different network slices 120 can be identified by corresponding identification information. In some examples, the identification of the network slice (or also referred to as a slice identification) may include single network slice selection auxiliary information (S-NSSAI). S-NSSAI may include at least slice type / service type (SST) information to indicate the characteristics of the network slice and the type of service served. In addition to SST, S-NSSAI may also include slice differentiation information (SD) to further distinguish multiple network slice instances that meet the same SST. SD is optional.

[0139] There may be multiple classifications for network slice selection assistance information (NSSAI), i.e., a set of S-NSSAI, which are used to indicate the names of NSSAI in different scenarios or conditions. The following will briefly describe some example NSSAI and related information.

[0140] The NSSAI of the network slice 120 may include a configured NSSAI, which may be of the following types:

[0141] - Home PLMN (HPLMN) configured NSSAI: It includes HPLMN S-NSSAI, also known as subscription S-NSSAI; the terminal device 220 in the home network, for example, in the HPLMN, can use the HPLMN configured NSSAI to access the network;

[0142] - Visited PLMN (VPLMN) configured NSSAI: In a visited network, such as a visited PLMN, a terminal device uses the VPLMN configured NSSAI to access the network;

[0143] -Default configuration NSSAI: In a visited network, such as a visited PLMN, if the terminal device 220 does not have a VPLMN-configured NSSAI, the terminal device 220 may register with the network using a default NSSAI; the default configuration NSSAI is usually a standard-defined S-NSSAI.

[0144] Note that the network access mentioned above refers to the terminal device 220 constructing a requested NSSAI (requested NSSAI) based on the configured NSSAI to request access to a certain network slice 120. In different PLMNs, the same network slice 120 may have different identifiers (for example, different NSSAIs).

[0145] Typically, the network slice selection policy (NSSP) obtained by the terminal device 220 includes the correspondence between the service session (e.g., application session) of the terminal device 220 and the HPLMN S-NSSAI of the network slice 120 under the home network. In some embodiments, the terminal device may also obtain mapping information of the configuration NSSAI to the HPLMN S-NSSAI to assist the terminal device 220 in determining the configuration NSSAI corresponding to the network slice 120 to be used to carry the service, so as to include the new configuration NSSAI in a subsequent registration request.

[0146] The NSSAI of the network slice 120 also includes a request NSSAI. The request NSSAI is constructed by the terminal device 220 to indicate to the network side (access network side and core network side) the network slice 120 to which access is requested. The request NSSAI can come from the following parameters:

[0147] - Default configured NSSAI: If the terminal device 220 does not have any configured NSSAI or allowed NSSAI in the current PLMN, the default configured NSSAI may be used;

[0148] -Configuration NSSAI: The terminal device 220 can obtain the configuration NSSAI of the PLMN in the current PLMN;

[0149] - Allowed NSSAI: The terminal device 220 can obtain the NSSAI allowed by the current PLMN in the current PLMN;

[0150] - Allowed NSSAI + configured NSSAI that has not been included: the terminal device 220 has accessed the current PLMN and received the allowed NSSAI, and the terminal device 220 also requests a new configured S-NSSAI in the PLMN.

[0151] The NSSAI of the network slice 120 also includes a subscription S-NSSAI, which may include:

[0152] - Subscribed S-NSSAI: It is the S-NSSAI subscribed by the user, i.e., the HPLMN S-NSSAI; the subscribed S-NSSAI can be a standard value or a non-standard value defined in the HPLMN (for example, a certain HPLMN can define a non-standard value S-NSSAI to identify a network slice that can support both eMBB and URLLC services);

[0153] -Default Subscribed S-NSSAI: According to the network operator's policy, the user's subscribed S-NSSAI may have one or more identifiers set as the default S-NSSAI; if the terminal device 220 does not carry any requested NSSAI when accessing the network, the network element of the core network (for example, NSSF) will determine the network slice 120 that the terminal device 220 requests to access based on the default subscribed S-NSSAI.

[0154] The NSSAI of the network slice 120 also includes an allowed NSSAI, which is used to identify the network slices that the terminal device 220 is allowed to use in the network. The allowed NSSAI is valid within the registration area of ​​the terminal device 220. That is, when the network allocates a tracking area (TA), it is necessary to consider the availability of the network slice 120 to the terminal device 220. If the current serving network of the terminal device 220 is a visited network (e.g., VPLMN), it is also necessary to provide the terminal device 220 with mapping information of the allowed NSSAI of the visited network to the NSSAI of the home network (e.g., the allowed NSSAI of the VPLMN to the HPLMN NSSAI) to indicate the mapping of possible different NSSAIs of the same network slice 120 in the visited network and the home network.

[0155] Similarly, since the NSSP only contains the correspondence between the service session of the terminal device 220 (for example, the application session) and the HPLMN S-NSSAI of the network slice 120 that carries the service, in some embodiments, the terminal device 220 can also obtain the mapping information of the allowed NSSAI to the HPLMN S-NSSAI, which is used to assist the terminal device 220 in determining the allowed NSSAI according to the service, for subsequent session requests for the service, such as protocol data unit (PDU) session requests.

[0156] It should be understood that the NSSAI information given above is only an example of an identifier for identifying the network slice 120. The identifier of the network slice 120 may also include other information in addition or alternatively. Other information used to identify the network slice may include, for example, service type information, which indicates the specific services supported by the network slice 120; tenant information, which is used to indicate customer information for creating or renting the network slice; user group information, which is used to indicate grouping information after grouping users according to certain characteristics, such as user levels; slice group information, which is used to indicate the grouping of network slices according to certain characteristics, for example, all network slices that can be accessed by terminal devices are regarded as a slice group, or the grouping of network slices can also be divided according to other standards; network slice instance information, which is used to indicate the instance identifier and feature information created for the network slice, for example, an identifier can be assigned to the network slice instance to specifically indicate the network slice instance, and so on.

[0157] It should be understood that in the embodiments of the present disclosure, the network slice may use at least one of the above identification information to indicate the network slice, and the embodiments of the present disclosure are not limited to this. If the terminal device, access network device or core network device supports multiple network slices, the identification of the network slice supported by the terminal device, access network device or core network device may be indicated by different identifications in the multiple identification information.

[0158] In order to better understand how terminal devices communicate data in a communication environment based on network slicing, the following will combine Figure 2 The example of the terminal device 220 is used to simply explain how the terminal device establishes service communication. Note that the service of the terminal device 220 mentioned in this article can be a session of the terminal device 220, such as a PDU session, or can be a service flow, a radio bearer, etc. of the terminal device 220. In some embodiments below, the session is mainly used as an example of the service for description.

[0159] Specifically, as mentioned above, the terminal device 220 generally has a corresponding relationship between a session (e.g., a session of a certain application) and the HPLMN S-NSSAI of the network slice 120 under the home network. The corresponding relationship is generally included in the NSSP and can be determined by the home network, such as the core network device PCF ( Figure 2 20. An example of the NSSP is shown in Table 1 below.

[0160] Table 1 Network Slice Selection Strategy (NSSP)

[0161]

[0162]

[0163] Table 1 gives the identifiers of the network slices associated with each application of the terminal device 220 under the HPLMN. Depending on the application to which the PDU session to be initiated belongs, the terminal device 220 can determine the identifier of the network slice to be accessed under the HPLMN. Since the same network slice may have different identifiers in different networks, if the serving network of the terminal device 220 is a visited network instead of a home network when a PDU session request is initiated, the identifier of the associated network slice in the visited network may not be determined according to the NSSP. To solve this problem, the terminal device 220 can also obtain mapping information from the NSSAI allowed by the visited network to the NSSAI of the home network. An example of such mapping information is shown in the following Table 2.

[0164] Table 2 Mapping information of NSSAI allowed by visited network to NSSAI of home network

[0165] Home Network NSSAI NSSAI allowed by the visited network HPLMN S-NSSAI 1 Allowed S-NSSAI 1 HPLMN S-NSSAI 2 Allowed S-NSSAI 1 HPLMN S-NSSAI 3 Allowed S-NSSAI 2 …… ……

[0166] exist Figure 2In the example, if the current serving network of the terminal device 220 is a visited network and a PDU session of application B is to be initiated therein, the terminal device 220 can use the NSSP in Table 1 to determine that the corresponding network slice in the home network is identified as HPLMN S-NSSAI 2. The terminal device 220 also determines, based on the mapping information in Table 2, that the identification information of the network slice identified by HPLMN S-NSSAI 2 in the visited network is the allowed S-NSSAI 1. After determining the identification information, the terminal device 220 will carry the HPLMN S-NSSAI 2 and the allowed S-NSSAI 1 in the PDU session establishment request. The PDU session establishment request will be transmitted to the access network device to which the terminal device 220 is connected, and then transmitted to the core network device, such as AMF 230. On the access network side and the core network side, the type of network slice that the terminal device 220 requests to access can be determined through the information carried in the request.

[0167] In response to the PDU session establishment request from the terminal device 220, the AMF 230 provides the HPLMN S-NSSAI 2 and the allowed S-NSSAI 1 in the request to the NSSF 260 under the visited network. The NSSF 260 selects the network slice-specific NRF and the network slice instance (NSI) identifier (ID) for the AMF 230 based at least on these identifiers. The AMF 230 provides the HPLMN S-NSSAI 2, the allowed S-NSSAI 1, and the NSI ID to the corresponding NRF 270 to select the SMF 240 where the network slice is located.

[0168] The above example illustrates that the same network slice has different identifiers in different networks, so it is necessary to correctly identify the corresponding network slice through the mapping information between the NSSP and the identifiers of network slices of different networks. In some cases, remapping can also be achieved between different network slices. "Remapping" of a network slice means that a network slice can be remapped to another network slice, so that the service carried on one network slice (for example, a PDU session) can be served by another network slice to which it is remapped. In other words, the network resources of another network slice are used to implement the service of the previous network slice.

[0169] The remapping of network slices can be applied in switching scenarios, for example, a terminal device switches from one access network device to another access network device, and the access network device to be switched to does not support the network slice where the current service of the terminal device is located. In order to ensure the service continuity of the terminal device, other network slices can be selected through the remapping of network slices to provide services to the terminal device. Currently, there are some solutions to assist the access network device to perform network slice remapping by providing the remapping relationship between network slices under the same network to the access network device to which the terminal device is connected.

[0170] In addition to handover scenarios, network slice remapping can also be performed in other communication scenarios. In some examples, if the service load on a certain network slice is too large, the access network device can also transfer the terminal device's service to another network slice through remapping, thereby achieving load balancing of the network slice and providing the terminal device with the expected quality of service.

[0171] From the above discussion, it can be seen that taking into account different differentiation factors such as the different support capabilities for network slicing in different networks and the network slices that different terminal devices are allowed to access in different networks, in communications based on network slicing, access network devices often need sufficient information to correctly identify the network slices used to support communications with terminal devices.

[0172] In some scenarios, there may be problems such as communication delays and service interruptions due to insufficient indication of the relationship between network slices. For example, if a terminal device wants to switch from one network to another, the target access network device of the target network may not be able to identify the network slice corresponding to the current PDU session of the terminal device when processing the switching request of the terminal device, and cannot determine the network slice allowed for the terminal device in the target network (no information related to the allowed NSSAI is obtained). In this way, the access network device cannot handle the access control of the terminal device. This mainly occurs in the terminal device switching scenario performed through the Xn interface between access network devices.

[0173] According to the current communication protocol, terminal device switching across networks can be achieved through the N2 (control plane) interface between the access network device and the core network device. The AMF can determine the NSSAI information of the network slice allowed by the terminal device in the target network based on the UE context information of the terminal device maintained in the core network, and control the access of the terminal device to the target access network device based on this information.

[0174] If the handover has been initiated through the Xn interface, since the target access network device does not have sufficient information to perform access control, the terminal device may be allowed to switch to the target network first, and then the terminal device is required to initiate a tracking area update (TAU) or registration according to the conditions, and then obtain the identification information of the network slice allowed by the terminal device in the target network. The target access network device then performs access control on the terminal device. This process will introduce latency issues. If it is determined that the terminal device cannot be allowed to access, the PDU session will be rejected, which will affect the service continuity of the terminal device.

[0175] 2. First Implementation Method of the Present Disclosure

[0176] According to an example embodiment of the present disclosure, an improved scheme is provided for supporting access control of terminal devices. Specifically, in some embodiments, the target access network device to be accessed by the terminal device obtains information indicating the relationship between multiple network slices of different networks from the core network device or the source access network device. The target access network device can perform access control of the terminal device to the target access network device based on the obtained information. Through the scheme of the present disclosure, the target access network device can perform access control on the terminal device when accessing across networks, reduce access delay, reduce service interruption problems caused by session rejection of the terminal device, and ensure service continuity of the terminal device.

[0177] The following will discuss in detail exemplary embodiments of the present disclosure with reference to the accompanying drawings. Figures 3 to 5 For the convenience of discussion, the signaling interaction process will be referred to Figure 2 The example architecture of the present disclosure is used to describe the signaling interaction between communication entities according to the example embodiment of the present disclosure. It should be understood that the example embodiment of the present disclosure can be similarly applied to other communication environments based on network slicing and other networking architectures of network slicing. In the following, network slicing refers to Figure 2 The network slice is 120.

[0178] Figures 3 to 5 The signaling interaction involves the target access network device of the terminal device 220, and in some implementations involves the core network device, and in other implementations involves the source access network device of the terminal device 220. In this document, the target access network device refers to the physical or virtual access network device to be accessed by the terminal device 220, wherein the terminal device 220 may currently be connected to other network devices or is performing initial registration access to the target access network device.

[0179] In this document, the source access network device refers to the physical or virtual access network device to which the terminal device 220 is currently connected. The terminal device 220 can access the network switching service of the source network (e.g., access the network slice of the service network) via the source access network device. If the terminal device 220 is being served by the source network, then the source network is referred to as the service network of the terminal device 220. In the following, for the purpose of discussion, it is assumed that Figure 2 The access network device 210 is the source access network device to which the terminal device 220 is currently connected, and the access network device 212 is the target access network device of the terminal device 220.

[0180] In some cases, if the terminal device 220 is to switch from the current service network to another network, such as a network accessed via a target access network device, the network may be referred to as the target network of the terminal device 220. If the target access network device 212 determines to allow the terminal device 220 to access a network slice of the target network, the target network will become the service network of the terminal device 220 after the switching is completed.

[0181] In this document, core network equipment refers to physical or virtual equipment that implements relevant functions on the core network side, which can be AMF 230 that can directly connect to access network equipment, or it can be a general term for AMF 230 and one or more other network functions in the core network. For the convenience of discussion below, the core network equipment is uniformly labeled as core network equipment 330.

[0182] 2.1 Overall signaling interaction

[0183] Figure 3 FIG. 3 shows an interactive signaling diagram of a communication process 300 according to some embodiments of the present disclosure. Figure 3 In an embodiment of the present invention, information indicating the relationship between network slices of different networks (referred to herein as "first information") is provided to the target access network device 212. The first information specifically indicates the relationship between one or more network slices of the first network or networks and one or more network slices of the second network or networks. Here, the first network and the second network are different networks. In some embodiments, the first network and the second network may be different PLMNs, and different PLMNs may be deployed by different network operators. In some embodiments, the first network and the second network may also be other types of networks. Each network slice of the first network is sometimes referred to herein as a first network slice, and each network slice of the second network is sometimes referred to herein as a second network slice. The network slices indicated in the first information are network slices supported by each of the first network and the second network.

[0184] In some embodiments, if the first information indicates a relationship between a first network slice of the first network and a second network slice of the second network, this means that the service of the terminal device 220 can be changed from corresponding to the first network slice to corresponding to the second network slice, that is, the correspondence between the service of the terminal device 220 and the network slice can change between the first network slice and the second network slice. In this case, the second network slice can provide substantially the same quality of service (QoS) as the first network slice, or can provide a lower or higher QoS than the first network slice, but the reduction or improvement of QoS is within a tolerable range. In some examples, the relationship indicated by the first information can be a remapping relationship from a first network slice of the first network to a second network slice of the second network, wherein the remapping relationship indicates that the service of the terminal device 220 on the first network slice of the first network can be remapped to the second network slice of the second network, so that the communication service is provided by the second network slice. In such an example, the first information may also be referred to as remapping policy information, which specifically indicates how to perform remapping between network slices of different networks. In an embodiment of the present disclosure, the first information indicating the relationship between network slices of different networks helps the target access network device 212 to perform access control for the terminal device 220, especially when the terminal device 220 switches between different networks.

[0185] In some embodiments, the first information may include an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. The identifier of the network is sometimes also referred to as a network identifier, which is used to uniquely identify different networks. The identifier of a network slice is sometimes also referred to as a slice identifier, which is used to identify different network slices in the corresponding network. The same network slice can be supported in different networks, but the identifiers of the same network slice in different networks may be the same or different. In the first information, the relationship between the corresponding network and its network slice can be indicated by the identifier of the network and the identifier of the slice.

[0186] If the first network and the second network are PLMNs, the identifiers of the first network and the second network may, for example, include PLMN identifiers (PLMN IDs) of the first network and the second network, respectively. Of course, the identifier of the network may also include or alternatively include other information that helps identify a specific network, such as the name of the network operator, etc. In different networks, the identifiers of network slices may include their respective S-NSSAIs. Of course, in addition to or as an alternative to the S-NSSAI, the identifier of the network slice may also include other information that helps identify a specific network slice.

[0187] The first information may be provided to the target access network device 212 in a variety of ways. In different ways, the first network and the second network involved in the first information and their network slices may be different. Two possible ways are listed below, including way A and way B.

[0188] like Figure 3 As shown, in method A, the core network device 330 determines 301 first information, wherein the first information indicates a relationship between one or more network slices of one or more first networks and one or more network slices of one or more second networks.

[0189] In some embodiments of mode A, the core network device 330 can be connected from multiple access network devices (e.g., Figure 2 Multiple access network devices 210, 212, 214) receive network slice information, which indicates one or more networks (e.g., PLMN) supported by each access network device and one or more network slices supported in each network. In some embodiments, multiple access network devices can send network slice information to a core network device 330, such as AMF230, during the process of establishing an N2 interface. In some embodiments, the access network device transmits the supported networks and network slices to the core network device 330 through an NG establishment message. The core network device 330, including AMF 230 and other network functions of the core network, can determine the first information based on the network slice information after receiving the network slice information sent by multiple access network devices. In some embodiments, the core device 330 can refer to the policy information of each network maintained on the core network side to determine the relationship between the network slices of each network indicated by the network slice information, such as determining whether these network slices are equivalent, whether they can be remapped, etc., so as to determine the first information to be sent.

[0190] In addition to reporting the supported network slice information through the access network device, the core network device 330 can also determine the first information in other ways. In some embodiments, the first information can be pre-configured in the core network device 330, for example, in the initial stage of network deployment. The embodiments of the present disclosure do not limit how the core network device 330 obtains the first information.

[0191] In some embodiments of method A, the first network indicated by the first information may include one or more networks within a TA range, and the second network may include one or more networks within the same TA range. The set of first networks and the set of second networks may overlap, but for a certain first network, the first information may indicate the relationship between one or more first network slices of the first network and network slices of different second networks. Since the first information covers the relationship between network slices of networks within a certain area, no matter which network the terminal device wants to access within the area, the corresponding target access network device can perform access control based on the first information.

[0192] In mode A, the core network device 330 transmits 302 the first information determined to the target access network device 212, and the target access network device 212 receives 304 the first information from the core network device 330. In some embodiments, the first information is included in the NG establishment response transmitted to the target access network device 212, and the NG establishment response is a response to the NG establishment message sent by the target access network device 212. In this way, the target access network device 212 can obtain the first information for access control in advance during the interface establishment phase. Of course, the core network device 330 can also transmit the first information in other messages or signaling communicated with the target access network device 212, or transmit the first information through dedicated signaling.

[0193] The transmission of the first information by the core network device 330 may be extensive. In some embodiments, the core network device 330 may send the first information to multiple access network devices within a certain TA range, and the target access network device 212 is one of them. In some embodiments, the core network device 330, such as AMF 230, may send the first information to the target access network device 212 through any type of signaling in the interface with the target access network device 212.

[0194] In some embodiments of mode A, a possible form of the first information is given in Table 3 below.

[0195] Table 3 Example form of the first information

[0196]

[0197] Through the example first information in Table 3, the target access network device 212 can determine the relationship between each network slice of each first network and each network slice of each second network slice. It should be understood that Table 3 only shows one possible representation of the first information. In practical applications, the first information can also be represented in any other way.

[0198] In the embodiment of mode A, the core network device 330 may not consider whether the relationship of the network slice is applicable to a specific terminal device 220 when determining the first information, but assumes that the remapping strategies of the network slices of different terminal devices 220 in the first and second networks are the same. Such first information may sometimes be referred to as general first information, general remapping policy information, or remapping policy information not associated with a terminal device.

[0199] If different terminal devices are allowed different network slices in different networks, in some embodiments of method A, the source access network device 210 may send additional information (referred to herein as "second information") to the target access network device 212. The second information may indicate the identifier of the network slice that the terminal device 220 is allowed to use in different networks, where the network includes the second network indicated by the first information. The second information may be used to further assist the target access network device 212 in performing access control, for example, to enable the target access network device 212 to determine which network slices the terminal device 220 is allowed to access in the second network.

[0200] For each second network, the network slice indicated in the second information may not be exactly the same as the network slice indicated in the first information, but may partially overlap. For example, compared with the network slice indicated in the first information, the second information may indicate that fewer network slices in the second network are allowed to be accessed by the terminal device 220. The network slice in the second network indicated by the second information is sometimes referred to as a "third network slice" in this article to distinguish it from the second network slice indicated by the first information, but the second network slice may include or partially include the third network slice.

[0201] In some embodiments, one possible form of the second information is given in Table 4 below.

[0202] Table 4 Example format of the second information

[0203]

[0204] It should be understood that Table 4 only shows one possible representation form of the second information. In practical applications, the second information may also be represented in any other manner.

[0205] In some embodiments, the source access network device 210 may receive the second information for the terminal device 220 from the core network device 330. In one example, the second information may be provided to the source access network device 210 by the core network device 330 as UE context information of the terminal device 220. The source access network device 210 may also obtain the second information in other ways and provide it to the target access network device 212.

[0206] In some embodiments, the source access network device 210 may send the second information to the target access network device 212 when determining to switch the terminal device 220 from the current service network to the target network supported by the target access network device 212. For example, if the switching for the terminal device 220 is triggered, the source access network device 210 sends a switching request to the target access network device 212, and carries the second information in the switching request. Of course, the core network device 330 may also carry the second information in other types of messages or signaling communicated with the target access network device 212, or transmit the second information through dedicated signaling.

[0207] In addition to method A, the first information may also be provided to the target access network device 212 in another method (ie, method B). Figure 3 As shown, in mode B, the core network device 330 determines 311 the first information and sends 312 the first information to the source access network device 210 of the terminal device 220. As a result, the source access network device 210 receives 314 the first information from the core network device 330, and sends 316 part or all of the received first information to the target access network device 212. In this way, the target access network device 212 receives 318 the first information from the source access network device 210.

[0208] In the embodiment of mode B, it is expected to provide the target access network device 212 with slice-related information specific to the terminal device 220. Compared with mode A, in mode B, the first network indicated by the first information sent by the core network device 330 to the source access network device 210 is specifically the service network of the terminal device 220, rather than any network within a certain area. Since the first information is specific to the terminal device 220, the target access network device 212 can directly use the information to perform access control for the terminal device 220. In addition, since the amount of information carried by the first information is less, the overhead of information transmission between devices is reduced.

[0209] When determining the first information specific to the terminal device 220, the core network device 330 can determine the current service network of the terminal device 220 through the source access network device 210 to which the terminal device 220 is currently connected. Specifically, when the terminal device 220 communicates in the service network, it usually initiates a session establishment request to the core network via the source access network device 230, which carries the identifier of the service network of the terminal device 220. The source access network device 230 forwards the session establishment request of the terminal device 220 to the core network device 330. Accordingly, the core network device 330 can determine the service network of the terminal device 220 from the received session establishment request, and further determine the relationship between the one or more network slices of the service network and the one or more network slices of the second network indicated only in the first information sent to the source access network device 210.

[0210] In some embodiments, when determining the first information specific to the terminal device 220, the core network device 330 may also determine which network slice of the service network serves the current session of the terminal device 220. For example, the session establishment request from the source access device 210 may also include an identifier of the network slice that the terminal device 220 requests to access for the session to be established. If the core network device 330 determines that the terminal device 220 is allowed to access the network slice, the core network device 330 may determine the relationship between the network slice of the service network indicated in the first information and the network slices of one or more second networks, such as the remapping relationship of these network slices.

[0211] Therefore, in some embodiments of mode B, the network slice of the service network involved in the first information may be only the network slice currently accessed by the terminal device 220, or may also include one or more other network slices in the service network determined by the core network device 330 to allow the terminal device 220 to access the current service. This can further reduce the amount of information in the first information, making the first information more suitable for access control of the terminal device 220 under the current traffic conditions. In addition, the overhead required for the transmission of the first information is smaller.

[0212] In some embodiments of mode B, the core network device 330 may also determine the first information based on the network slices allowed by the terminal device 220 in one or more second networks, so that the second network and the second network slice involved in the first information are allowed to be used by the terminal device 220. In such an embodiment, the first information provided by the core network device 330 indicates the relationship between the network slice of the service network and the network slice allowed to be used by the terminal device 220 in one or more second networks.

[0213] In some embodiments of mode B, for the current service of the terminal device 220, such as the current PDU session, a possible form is given in the following Table 5.

[0214] Table 5 Example format of the first information

[0215]

[0216] It should be understood that Table 5 only shows one possible representation form of the first information. In practical applications, the first information may also be represented in any other manner.

[0217] In some embodiments of mode B, when transmitting the first information, the core network device 330 may transmit the first information to the source access network device 210 in a session resource establishment request for the session establishment request. Of course, the core network device 330 may also send the first information in other messages or signaling communicated with the source access network device 210, or transmit the first information through dedicated signaling.

[0218] In some embodiments of the method B, after receiving the first information from the core network device 330, the source access network device 210 may forward the first information to the target access network device 212. In such an embodiment, the one or more second networks indicated by the first information received from the core network device 330 include a target network supported by the target access network device 212. In some embodiments, the source access network device 210 may send the first information to the target access network device 212 when determining to switch the terminal device 220 from the current service network to the target network supported by the target access network device 212. For example, if a switch for the terminal device 220 is triggered, the source access network device 210 sends a switch request to the target access network device 212, and carries the first information in the switch request.

[0219] In some embodiments, the source access network device 210 may not directly forward the entire content of the first information received from the core network device 330, but may send the information portion related to the target network to which the terminal device 220 is to switch to the target access network device 212, depending on the target network to which the terminal device 220 is to switch. In other words, the first information sent by the source access network device 210 to the target access network device 212 may indicate the relationship between the network slice of the service network and the network slice of the target network to which the terminal device 220 is to switch. In this way, the transmission overhead between the access network devices can be reduced, so that the target access network device 212 does not need to receive useless information.

[0220] In the embodiment of method B, since the first information is related to the service network of the terminal device 220, and in some embodiments also to the target network of the terminal device 220, such first information may sometimes be referred to as first information specific to the terminal device 220 or remapping policy information specific to the terminal device 220.

[0221] Several ways of obtaining the first information at the target access network device 212 are discussed above. After obtaining the first information, the target access network device 212 performs 320 access control of the terminal device 220 to the target access network device 212 based on the first information. Access control may include various operations related to access of the terminal device 220 to determine whether the terminal device 220 can access the target network supported by the target access network device 212, such as the target PLMN. In some cases, access control is sometimes also referred to as "admission control."

[0222] The target access network device 212 may trigger access control for the terminal device 220 due to various factors. In some embodiments, if the terminal device 220 is being served by the source network supported by the source access network device 210, but is to be switched from the current service network to the target network, the target access network device 212 performs access control. In some examples, the target access network device 212 receives a switching request from the source access network device 210 to request that the terminal device 220 be switched from the current service network to the target network. The target access network device 212 performs access control for the terminal device 220 after receiving the switching request.

[0223] In a switching scenario, when performing access control, the target access network device 212 can determine the identifier of the service network of the terminal device 220 (sometimes also referred to as the "service network identifier"), the identifier of the service network slice accessed by the terminal device 220 in the service network (referred to as the "service slice identifier"), and the identifier of the target network to which the terminal device 220 is to switch (referred to as the "target network identifier"). The identifiers of these networks and network slices can be carried in a switching request from the source access network device 210. For example, the switching request includes the identifier of the network slice corresponding to the current PDU session of the terminal device 220, which indicates the service network slice of the service network. The switching request also includes a mobility constraint list, which indicates the identifier of the target network to be switched to. Of course, in addition to the above information, the slice request may optionally include other information. The embodiments of the present disclosure are not limited in this respect.

[0224] Based on the identification of the above network and network slice, the target access network device 212 can determine the network slice in the target network that is related to the service network slice (referred to as the "target network slice") from the acquired first information. In one embodiment, the target access network device 212 can determine from the first information whether the service of the terminal device 220 can be changed from corresponding to the service network slice to corresponding to the target network slice, for example, whether it can be remapped from the service network slice to the target network slice.

[0225] For example, the target access network device 212 determines from the switching request that the identifier of the service network corresponding to the PDU session of the terminal device 220 is "V1" and the identifier of the service network slice is "S-NSSAI 1", and also determines that the identifier of the target network is "V2". Using the identifiers of these networks and the identifiers of the service slices, the target access network device 212 finds from the first information that the service network slice S-NSSAI 1 of the service network V1 can be remapped to one or more target network slices of the target network V2, such as the target network slices identified by the identifiers S-NSSAI 1' and S-NSSAI 2'.

[0226] Taking into account that the network slices allowed by the terminal device 220 in different networks may be different, if the first information used by the target access network device 212 is the general first information received from the core network device 330 through mode A, as mentioned in some of the above embodiments, the target access network device 212 may also receive additional second information from the source access network device 210. The second information indicates which network slices in the network slices in one or more second networks allow the terminal device 220 to access. The target access network device 212 can use the identifier V2 of the target network to determine one or more target network slices that the terminal device 220 is allowed to use in the target network from the second information. The target access network device 212 can take the intersection of the target network slice results determined from the first information and the second information, thereby determining the target network slice that can be remapped to the current service network slice and is also allowed to be used by the terminal device 220.

[0227] If the first information is first information specific to the terminal device 220 and received through method B, then the one or more target network slices determined by the target access network device 212 from the first information are already defaulted to be network slices allowed to be used by the terminal device 220.

[0228] After determining one or more target network slices, the target access network device 212 may determine whether the access of the terminal device 220 can be allowed based on the determined target network slices. For example, the target access network device 212 may determine whether it can provide the terminal device 220 with access to the target network slices S-NSSAI 1' and / or S-NSSAI 2', whether it is necessary to perform remapping of the service network slice S-NSSAI 1 to the target network slices S-NSSAI 1' and / or S-NSSAI 2', etc. The access control of the terminal device 220 by the target access network device 212 depends on its own specific access control policy, and the embodiments of the present disclosure are not limited in this respect.

[0229] In some embodiments, based on the result of the access control of the target access network device 212, a subsequent switching process 332 is performed between the terminal device 220, the source access device 210, and the target access network device 212. The subsequent switching process 332 depends on the specific communication requirements, and the embodiments of the present disclosure are not limited in this respect.

[0230] In some embodiments involving handover, the terminal device 220 currently accesses a network slice of a service network via the source access network device 210 to obtain the communication service of the network slice. In some embodiments, the current service network of the terminal device 220 may be a visited network of the terminal device 220. That is, the terminal device 220 is roaming. In other embodiments, the current service network of the terminal device 220 may also be the home network of the terminal device 220. In some embodiments, the target network to be accessed by the terminal device 220, the target network to be accessed via the target access network device 212 is another visited network of the terminal device 220.

[0231] The above only describes a specific example of the target access network device 212 performing access control in the handover scenario. The access control process may also include other different operations, more operations, or some of the above operations may be omitted. Regardless of the strategy of the target access network device 212 to perform access control, the first information indicating the relationship between network slices of different networks helps the target access network device 212 to complete the access control process under different conditions.

[0232] In addition to the switching scenario, in other examples, the target access network device 212 may also be triggered by other events to control the access of the terminal device 220. In one example, the target access network device 212 may use the first information to perform initial access control on the terminal device 220. Figure 3 As shown, the terminal device 220 sends 342 an initial access request to the target access network device 212 to request registration to the target network. After receiving 344 the initial access request, the target access network device 212 may perform 320 access control based on the first information. For example, based on the first information, the target access network device 212 may determine whether to allow the terminal device 220 to access the target network and how to implement the access of the terminal device 220, such as which network slice of the target network to access, etc.

[0233] Some embodiments of the present disclosure are discussed above. In these embodiments, with the help of the first information, the target access network device can timely complete the access control of the terminal device, especially the access control in the case of switching across different networks, avoiding the delay in switching across networks, reducing the possibility of service interruption of the terminal device, and thus ensuring the service continuity of the terminal device.

[0234] References Figure 3 The present invention describes a process for supporting a target access network device to control access to a terminal device according to some embodiments of the present disclosure. Figure 4 and Figure 5 They are shown in Figure 3 The specific implementation of signaling interaction between each communication entity in mode A and mode B. Figure 4and Figure 5 The implementation involves a handover scenario of the terminal device 220 between different networks, some of which messages / signaling may have been mentioned as example embodiments above. It should be understood that Figure 4 and Figure 5 For illustrative purposes only Figure 3 Some specific implementations of the signaling interaction process shown in Figure 3 The signaling interaction process shown may also exist in many other variations.

[0235] 2.2 Example implementation based on method A

[0236] Figure 4 Shown in Figure 3 4 is a signaling diagram of the communication process 400 of each communication entity in the embodiment of mode A. The source access network device 210 transmits 402 an NG setup message to the core network device 330, and the target access network device 212 also transmits 406 an NG setup message to the core network device 330. Therefore, the core network device 330 receives 404 an NG setup message from the source access network device 210 and receives 408 an NG setup message from the target access network device 212. Note that when the NG setup message is transmitted, the terminal device 220 may not have or may have accessed the service network via the source access network device 210, and the switching of the terminal device 220 from the service network to the target network may not have been triggered or may have been triggered.

[0237] Each NG setup message includes network slice information, which indicates the networks and supported network slices supported by the source access network device 210 or the target access network device 212 within a certain TA range. For example, each NG setup message includes a TA range identified by a TA code (TAC) and network information under the TA range. The network information includes identifiers of one or more networks, such as a PLMN ID. In addition, each NG setup message also includes network slice information supported by each network in the current TA range, also known as TA identifier (TAI) slice support information. The network slice information includes identifiers of one or more supported network slices, such as S-NSSAI.

[0238] Although not shown, in addition to the source access network device 210 and the target access network device 212, the core network device 330 can also receive NG establishment messages from other access network devices to determine the networks and network slices supported within the corresponding TA range. Of course, in addition to the NG establishment message, the core network device 330 can also learn the network slices supported in different networks through other messages or signaling.

[0239] The core network device 330 determines 409 the first information to be provided to the access network device based on the network slice information of each network received from the access network device, and possibly also based on the policy information of each network maintained on the core network side. The first information includes, for example, the information described above. Figure 3 Refer to the information discussed in Method A.

[0240] Note that although Figure 4 , an example embodiment in which the core network device 330 determines the first information based on the network slice information reported by the access network device is shown, but as mentioned above, in other embodiments, the core network device 330 may be pre-configured with such first information. In the embodiment in which the first information is pre-configured, the core network device 330 may not need to receive the network slice information from the access network device.

[0241] After determining the first information, the core network device 330 transmits 410 the first information to the target access network device 212. In some embodiments, the core network device 330 may send the first information to multiple access network devices within the same TA range. The first information may be included in an NG setup response, for example.

[0242] The target access network device 212 receives 412 the first information from the core network device 330 , so that the first information can be used to perform access control later. Figure 4 The example of FIG. 4 shows access control in a handover scenario. Specifically, if the source access network device 210 determines to initiate a handover for the terminal device 220, for example, determines to switch the terminal device 220 from the current service network (i.e., the first network) to a different target network (i.e., the second network), the source access network device 210 transmits 416 a handover request to the target access network device 212.

[0243] The handover request may, for example, include a list of PDU session resources to be established, including the current PDU session ID of the terminal device 220 and the identifier of the service network and the identifier of the service network slice corresponding to each PDU session. The handover request may also include a mobility constraint list, which indicates the identifier of the target network to be switched to. In some embodiments, the handover request also includes the second information discussed above, which indicates the identifier of the network slice that the terminal device 220 is allowed to use in one or more second networks.

[0244] In response to receiving 418 the handover request from the source access network device 210, the target access network device 212 performs 420 access control of the terminal device 220 to the target access network device 212. Figure 3 Some embodiments of the access control of the target access network device 212 discussed above will not be described in detail here.

[0245] exist Figure 4In the example, it is assumed that the target access network device 212 determines to allow the terminal device 220 to access the target network. The target access network device 212 transmits 422 a handover request response to the source access network device 210, which indicates that the handover request is successful and allows the terminal device 220 to switch from the current service network to the target network.

[0246] In some embodiments, the target access network device 212 may also determine to remap the PDU session of the terminal device 220 from the service network slice (e.g., identified by NSSAI 1) of the current service network (e.g., identified by V1) to the target network slice (e.g., identified by NSSAI 2') of the target network (e.g., identified by V2). The identifier of the target network slice may be carried in the handover request response, for example.

[0247] After receiving 424 the handover request response from the target access network device 212, the source access network device 210 transmits 426 information to the terminal device 220 to indicate that the service network of the terminal device 220 is switched from the current network to another different network, i.e., the target network. Such information is referred to as "third information" in this article. Thus, the terminal device 220 can quickly learn that the handover is successful and the target network to be switched to. In some examples, the third information may include an identifier of the target network to be switched to. In some embodiments, the third information may be included in a radio resource control (RRC) reconfiguration message (e.g., an RRCReconfiguration message) transmitted by the source access network device 210 to the terminal device 220.

[0248] After receiving 428 the third information, the terminal device 220 uses 430 the third information. The third information can have multiple effects at the terminal device 220. In some embodiments, since the transmission of the third information means that the target access network device 212 determines to allow the switching of the terminal device 220, the terminal device 220 can perform random access to the target access network device in the target network. In this case, the terminal device 220 can perform random access to the target access network device based on the third information. With the help of the third information, the possibility of successful random access of the terminal device 220 can be improved. For example, the target access network device 212 supports multiple networks, and the available air interface random access channel (RACH) resource set can be divided according to the supported networks. Since the third information clearly indicates the target network to be switched, the terminal device 220 can determine the RACH resources allocated to the target network from the RACH resource set, and initiate random access to the target access network device 212 on the determined RACH resources. By utilizing the RACH resources associated with the target network, the random access success rate of the terminal device 220 can be improved. In some embodiments, if the random access process is successfully completed, the serving network of the terminal device 220 will become the target network. The terminal device 220 can access the target network via the target access network device 212, in particular, access the target network slice of the target network.

[0249] In addition to or alternatively to guiding the random access process, based on the received third information, the terminal device 220 can also display the identity of the target network. The displayed identity of the target network can be a PLMN or the name of the network operator of the PLMN, etc. In this way, the user of the terminal device 220 can be notified of the change of the service network.

[0250] In some embodiments, in addition to the third information, the source access network device 210 may also transmit additional information to the terminal device 220 to indicate that the terminal device 220 is to access a specific target network slice in the target network, wherein the current session of the terminal device 220 is switched from being served by the current service network slice to being served by the target network slice. Such information is referred to as "fourth information" in this article. In some examples, the fourth information may include an identifier of the target network slice. By receiving the fourth information, the terminal device 220 can quickly learn the target network slice to which the session is to be switched. In some embodiments, the fourth information may be included in the RRC reconfiguration message transmitted by the source access network device 210 to the terminal device 220, for example, the fourth information may be sent to the terminal device 220 together with the above-mentioned third information.

[0251] It should be understood that the above discusses an example in which the target access network device 212 allows access after performing access control. If the target access network device 212 denies access to the terminal device 220 after performing access control, the interaction between the target access network device 212, the source access network device 210, and the terminal device 220 may be different. For example, in the case of denying access, the source access network device 210 will not send an RRC reconfiguration message to the terminal device 220, and the terminal device 220 will not perform random access to the target access network device 212.

[0252] 2.3 Example implementation based on method B

[0253] Figure 5 Shown in Figure 3 5 is a signaling diagram of a communication process 500 of each communication entity in an embodiment of mode A.

[0254] Initially, the terminal device 220 is currently served by the source network via the source access network device 210, that is, the source network is the current service network of the terminal device 220. The terminal device 220 transmits 502 a session establishment request, such as a PDU session establishment request, to the source access network device 210. The session establishment request is a non-access stratum (NAS) message that can be used to request the establishment of a session for a certain type of service, such as a session that carries the service of an application on the terminal device. The session establishment request may carry an identifier of the service network of the terminal device 220. In some embodiments, the session establishment request may also include an identifier of the network slice that the terminal device 220 requests to access for the session to be established.

[0255] The source access network device 210 receives the session establishment request 504 and transmits 506 the session establishment request for the terminal device 220 to the core network device 330. In response to receiving 508 the session establishment request, the core network device 330 may perform a corresponding session establishment process. In addition, the core network device 330 determines the first information to be provided to the source access network device 210. The determination of the first information is as described above in Figure 3 As described above, in mode B, the first information is specific to the terminal device 220, indicating the relationship between one or more network slices of the service network of the terminal device 220 and one or more network slices of the second network. After the first information is determined, the core network device 330 transmits 510 a session resource establishment request to the source access network device 210, and carries the determined first information in the session resource establishment request.

[0256] The source access network device 210 receives 512 the first information from the core network device 330. The first information can be used to assist in implementing access control of the terminal device 220 when the terminal device 220 is to be handed over. Figure 5An example of access control in a handover scenario is further shown. Specifically, if the source access network device 210 determines to initiate a handover for the terminal device 220, for example, determines to switch the terminal device 220 from the current service network (i.e., the first network) to a different target network (i.e., the second network), the source access network device 210 transmits 516 a handover request to the target access network device 212.

[0257] exist Figure 5 In the example above, except for Figure 4 In addition to the information mentioned in the example of , the handover request also includes the first information. The first information carried in the handover request may be the first information received by the source access network device 210 from the core network device 330. In another example, the handover request may include a portion of the first information received from the core network device 330, which indicates a relationship between one or more network slices of the service network and one or more network slices of the target network, such as a remapping relationship.

[0258] In response to receiving 518 the handover request from the source access network device 210, the target access network device 212 performs 520 access control of the terminal device 220 to the target access network device 212. Figure 3 Some embodiments of the access control of the target access network device 212 discussed above will not be described in detail here.

[0259] exist Figure 5 The example of further describes the operations performed by the target access network device 212, the source access network device 210, and the terminal device 220 when it is determined that the terminal device 220 is allowed to access the target network, including the target access network device 212 transmitting 522 a handover request response to the source access network device 210; the source access network device 210 transmitting 526 third information to the terminal device 220 after receiving 524 the handover request response; the terminal device 220 receiving 528 the third information and can use 530 the third information. In some embodiments, if the source access network device 210 determines to perform remapping of the network slice when performing access control, the source access network device 210 can also transmit fourth information to the terminal device. The operations from 522 to 530 in process 500 are similar to the operations from 422 to 430 in process 400, and are not repeated here.

[0260] 3. Second Implementation of the Present Disclosure

[0261] According to some embodiments of the present disclosure, another scheme is also provided for supporting the target access network device to control access to the terminal device. The target access network device obtains the slice identification information of the network slice of the terminal device in the home network, and also obtains the slice correspondence information, which indicates the correspondence information between the network slice of the terminal device in the visited network and the network slice of the home network. Access control of the terminal device to the target access network device is performed based on such slice identification information and slice correspondence information. In this way, the target access network device can perform access control on the terminal device when accessing across networks, especially access control when the terminal device wants to access the visited network, reduce access delay, reduce the service interruption problem of the terminal device due to session rejection, and ensure the service continuity of the terminal device.

[0262] Hereinafter, exemplary embodiments of the present disclosure will be discussed in detail with reference to the accompanying drawings. Figure 6 In the communication, the definitions of the various communication entities, including the terminal device 220, the source access network device 210, the target access network device 212 and the core network device 330 are the same as those in the above reference. Figure 3 Same as discussed.

[0263] Figure 6 FIG. 6 is a signaling interaction diagram of a communication process 600 according to some embodiments of the present disclosure. Figure 6 In the embodiment, the terminal device 220 is to switch from the current serving network to the target network where the target access network device 212 is located, and the target network is a visited network of the terminal device 220 (sometimes referred to as a “second visited network” in this document).

[0264] exist Figure 6 In the embodiment of the invention, in order to assist the target access network device 212 in performing access control for the terminal device 220, slice identification information is provided to the target access network device 212 to indicate the identification of the home network slice of the terminal device in the home network (e.g., HPLMN), and slice correspondence information is also provided to the target access network device 212 to indicate the correspondence between the network slice of the visited network (e.g., VPLMN) and the network slice of the home network of the terminal device 220. The visited network indicated in the slice correspondence information refers to the target network where the target access network device 212 is located. How to provide this information to the target access network device 212 will be discussed in detail below.

[0265] The source access network device 210 may provide the above-mentioned slice identification information to the target access network device 212. In some cases, the source access network device 210 may also be in the visited network of the terminal device 220 (sometimes referred to as the "first visited network" in this article), that is, the terminal device 220 is roaming, and its current service network is the visited network. Since the source access network device 210 is in the visited network of the terminal device 220, it may not have the above-mentioned slice identification information related to the home network of the terminal device 220. In this case, the source access network device 210 can obtain the required slice identification information in a variety of ways, including the first and second ways discussed below.

[0266] In method 1, if Figure 6 As shown, the terminal device 220 transmits 602 slice identification information to the source access network device 210, and the source access network device 210 receives 604 the slice identification information. The slice identification information indicates the identification of the home network slice of the terminal device 220 in the home network. Here, the home network slice refers to the network slice corresponding to the current session of the terminal device 220 in the home network. The terminal device 220 usually has such information about the home network.

[0267] In some embodiments, the slice identification information may include an identifier of the home network slice, such as S-NSSAI. In some embodiments, the slice identification information also carries an identifier of the home network to more clearly indicate that the slice identification information carried therein is identification information supported in the home network. For example, the slice identification information may be represented as H_S-NSSAI 1, where H indicates the identifier of the home network and S-NSSAI 1 indicates the identifier of the home network slice. In some embodiments, the slice identification information may be included in a session establishment request, such as included in a PDU session establishment request. The session establishment request may be transmitted to the source access network device 210 as a NAS message. In other embodiments, the terminal device 220 may also transmit slice identification information to the source access network device 210 through other messages / signaling.

[0268] In some embodiments, the slice identification information may also indicate an identification of a network slice of the terminal device 220 in the source network (i.e., the current service network). The network slice in the service network refers to a service network slice of the service network accessed by the terminal device 220 via the source access network device 210, and the network slice may be used to serve the current session of the terminal device 220. For example, the slice identification information includes an identification of a network slice of the source network, which may be represented as V1_S-NSSAI 2, where V1 indicates the service network, and S-NSSAI 2 indicates the service network slice in the service network.

[0269] In the second method, the core network device 330 transmits 608 slice identification information to the source access network device 210, and the source access network device 210 receives 610 the slice identification information. In some embodiments, the core network device 330 can obtain the identification of the home network slice of the terminal device 220 in the home network from the core network side. In some embodiments, after processing the session establishment request of the terminal device 220, the core network device 330 can determine the identification of the home network slice of the terminal device 220 in the home network. The core network device 330 can carry the slice identification information in the session resource establishment request transmitted to the source access network device 210. In other embodiments, the core network device 330 can also transmit the slice identification information to the source access network device 210 through other messages / signaling.

[0270] In the process 600, after obtaining the slice identification information for the terminal device 220, the source access network device 210 transmits 612 the slice identification information to the target access network device 212. In some embodiments, the source access network device 210 may transmit the slice identification information to the target access network device 212 when determining to initiate a handover for the terminal device 220. The slice identification information may be included in a handover request sent by the source access network device 210 to the target access network device 212. In addition to the slice identification information, as mentioned above, the handover request may also include an identification of the service network of the terminal device 220, an identification of the service network slice accessed by the terminal device 220 in the service network, and an identification of the target network to which the terminal device 220 is to be switched, and so on.

[0271] The target access network device 212 receives 616 the slice identification information. The target access network device 212 may also obtain slice correspondence information to indicate the correspondence between the network slice of the visited network where the target access network device is located and the network slice of the home network of the terminal device 220. The correspondence of two network slices in two networks means that the network slices indicated by different identifiers in the two networks actually correspond to each other, that is, they are the same network slice.

[0272] The reason why slice correspondence information is needed is that the same network slice may be indicated by different identifiers in different networks. Since the target access network device 212 is in the visited network of the terminal device 220, the target access network device 212 cannot determine the network slice corresponding to the current session of the terminal device 220 in the visited network based only on the identification information of the home network slice. With the help of the slice correspondence information, the target access network device 212 can determine the network slice in the visited network corresponding to the home network slice. In some cases, the slice correspondence information can also be called the mapping information of the network slice.

[0273] exist Figure 6, the core network device 330 transmits 622 such slice correspondence information to the target access network device 212. In some embodiments, the core network device 330 may receive 620 a request for slice correspondence information transmitted 618 by the target access network device 212. The request may include a device identifier of the terminal device 220 and an identifier (e.g., PLMN ID) of a visited network to be switched to (i.e., a network in which the target access network device 212 is located, also referred to as a target network during switching). In some embodiments, the request may also include a subscription permanent identifier (SUPI) of the terminal device 220.

[0274] In response to the request from the target access network device 212, the core network device 330 transmits the slice correspondence information to the target access network device 212. Through the device identifier carried in the request, the core network device 330 can determine the home network of the terminal device 220. In some embodiments, if the request also includes SUPI, the core network device 330 can determine the home network more quickly. Further, through the identifier of the visited network in the request, the core network device 330 can determine the corresponding slice correspondence information.

[0275] After receiving 624 the slice correspondence information from the core network device 330, the target access network device 212 performs 626 access control of the terminal device 220 to the target access network device 212 based on the slice correspondence information and the slice identification information mentioned above to determine whether the terminal device 220 is allowed to switch to the network where the target access network device 212 is located.

[0276] In some embodiments, when performing access control, the target access network device 212 determines the network slice (referred to as the "visited network slice") corresponding to the home network slice of the terminal device 220 in the visited network according to the identifier of the home network slice of the terminal device 220 (e.g., H_S-NSSAI 1) and the correspondence of the network slices of the home network and the visited network indicated by the slice correspondence information. The visited network slice can be identified as V2_S-NSSAI 3, for example, where V2 indicates the identifier of the visited network in which the target access network device 212 is located, and S-NSSAI 3 indicates the identifier of the visited network slice in the visited network.

[0277] After determining the visited network slice, the target access network device 212 can determine whether it can provide access to the visited network slice V2_S-NSSAI 3 for the terminal device 220 based on its own support capability for the network slice. At least based on the support capability for the visited network slice, the target access network device 212 determines whether to allow access to the terminal device 220.

[0278] In some embodiments, when performing access control, the target access network device 212 also determines whether the determined visited network slice can be remapped to other network slices in the visited network. This is so that when the visited network slice directly corresponding to the home network slice is not supported, access support for the terminal device 220 is achieved through remapping.

[0279] In order to support the target access network device 212 in determining the network slice to which the visited network slice can be remapped, in some embodiments, the core network device 330 also provides additional information to the target access network device 212 to indicate the relationship between the network slices in the home network, in particular, to indicate the remapping relationship of the network slices in the home network. Such information is sometimes referred to as "fifth information" or remapping policy information of the network slices in the home network in this document. In some embodiments, the core network device 330 can transmit the fifth information to the target access network device 212 together with the slice correspondence information or separately.

[0280] In addition to the slice identification information and the slice correspondence information, the target access network device 212 also performs access control on the terminal device 220 based on the fifth information. Specifically, based on the fifth information, the target access network device 212 can determine one or more network slices in the home network to which the current home network slice H_S-NSSAI 1 of the terminal device 220 can be remapped, for example, identified by H_S-NSSAI 3 and H_S-NSSAI 4. Further, the target access network device 212 also determines whether the network slices (for example, H_S-NSSAI 3 and H_S-NSSAI 4) that can be remapped in the home network have corresponding network slices in the visited network where the target access network device 212 is located based on the slice correspondence information. If there are corresponding network slices (for example, by V2_S-NSSAI 3' and V2_S-NSSAI 4'), the visited network slice V2_S-NSSAI 3 will also be remapped to the network slice in the visited network.

[0281] Through the above process, with the help of the fifth information and the slice correspondence information, the target access network device 212 can perform the determination of the remappable network slice of the visited network slice.

[0282] When performing access control, the target access network device 212 can determine whether to perform network slice remapping based on the determination of the remappable network slice of the visited slice network in order to support access control of the terminal device 220.

[0283] exist Figure 6The example further describes the operations performed by the target access network device 212, the source access network device 210, and the terminal device 220 in the case of determining that the terminal device 220 is allowed to access the visited network of the target access network device 212, including the target access network device 212 transmitting 628 a handover request response to the source access network device 210; the source access network device 210 transmitting 632 third information to the terminal device 220 after receiving 630 the handover request response; the terminal device 220 receiving 634 the third information and using 636 the third information. In some embodiments, if the source access network device 210 determines to perform remapping of the network slice when performing access control, the source access network device 210 may also transmit fourth information to the terminal device. The operations from 628 to 636 in process 600 are similar to the operations from 422 to 430 in process 400, and are not repeated here.

[0284] Some embodiments of the present disclosure are discussed above. In these embodiments, through the interaction between the source access network device, the core network device, the terminal device and the target access network device, the target access network device has sufficient information to timely complete the access control of the terminal device, especially the access control in the case of switching across different networks, avoiding the delay in switching across networks, reducing the possibility of service interruption of the terminal device, and thus ensuring the service continuity of the terminal device.

[0285] 4. Embodiments of the communication device

[0286] 4.1 Implementation of the Device in the First Implementation

[0287] Figure 7 1 shows a schematic block diagram of a communication device 700 implemented at a target access network device according to some embodiments of the present disclosure. The communication device 700 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 700 may be implemented as Figures 2 to 5 The target access network device 212 or a portion of the target access network device 212 is shown in FIG.

[0288] As shown in the figure, the communication device 700 includes a first receiving unit 710, which is configured to receive first information, the first information indicating the relationship between a first network slice of a first network and a second network slice of a second network, and the first network and the second network are different. The communication device 700 also includes an access control unit 720, which is configured to perform access control of a terminal device to a target access network device based at least on the first information.

[0289] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively, and the identifier of the first network slice and the identifier of the second network slice include single network slice selection assistance information of the first network slice and the second network slice, respectively.

[0290] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice.

[0291] In some embodiments, the first receiving unit 710 is further configured to receive first information from a core network device. In some embodiments, the first network and the second network are in the same tracking area.

[0292] In some embodiments, the first information is included in an NG setup response.

[0293] In some embodiments, the communication device 700 further includes: a second receiving unit (not shown), configured to receive second information from a source access network device, the second information including an identifier of a third network slice that the terminal device is allowed to use in the second network. In some embodiments, the access control unit 720 is further configured to perform access control based on the first information and the second information.

[0294] In some embodiments, the first receiving unit 710 is further configured to: receive first information for the terminal device from the source access network device, and the first network is a service network of the terminal device.

[0295] In some embodiments, the second network comprises a target network for the terminal device.

[0296] In some embodiments, the first information is included in a handover request for the terminal device.

[0297] In some embodiments, the access control unit 720 is further configured as: the target access network device determines the identifier of the service network of the terminal device, the identifier of the service network slice of the service network, and the identifier of the target network of the terminal device; the target access network device determines the target network slice related to the service network slice in the target network from the first information based on the identifier of the service network, the identifier of the service network slice, and the identifier of the target network; and the target access network device performs access control based on the determination of the target network slice.

[0298] Figure 8800 is a schematic block diagram of a communication device 800 implemented at a source access network device according to some embodiments of the present disclosure. The communication device 800 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 800 may be implemented as Figures 2 to 5 The source access network device 210 or a part of the source access network device 210 is shown in FIG.

[0299] As shown in the figure, the communication device 800 includes a receiving unit 810, which is configured to receive first information for a terminal device from a core network device, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network is a service network of the terminal device, and the first network and the second network are different. The communication device 800 also includes a first transmission unit 820, which is configured to transmit the first information to a target access network device.

[0300] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively, and the identifier of the first network slice and the identifier of the second network slice include single network slice selection assistance information of the first network slice and the second network slice, respectively.

[0301] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice.

[0302] In some embodiments, the second network comprises a target network for the terminal device.

[0303] In some embodiments, the first information is included in a handover request for the terminal device.

[0304] In some embodiments, the communication device 800 also includes: a second transmission unit (not shown), which is configured to transmit third information to the terminal device when access of the terminal device to the target access network device is allowed, and the third information indicates that the service network of the terminal device is switched from the first network to the second network.

[0305] In some embodiments, the third information includes an identification of the second network.

[0306] In some embodiments, the third information is included in a radio resource control reconfiguration message.

[0307] In some embodiments, the communication device 800 also includes: a third transmission unit (not shown), configured to transmit fourth information to the terminal device if access of the terminal device to the target access network device is allowed, the fourth information indicating that the session of the terminal device is changed to be served by the second network slice of the second network.

[0308] Fig. 9 1 is a schematic block diagram of a communication device 900 implemented at a terminal device according to some embodiments of the present disclosure. The communication device 900 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 900 may be implemented as Figures 2 to 5 The terminal device 220 or a part of the terminal device 220 shown in FIG.

[0309] As shown in the figure, the communication device 900 includes a first receiving unit 910, which is configured to receive third information from a source access network device. The third information indicates that the service network of the terminal device is switched from the first network to the second network, and the first network and the second network are different. The communication device 900 also includes an information using unit 920, which is configured to use the third information.

[0310] In some embodiments, the information using unit 920 is configured to perform random access to a target access network device in the second network based on the third information. In some embodiments, the information using unit 920 is configured to display an identification of the second network based on the third information.

[0311] In some embodiments, the third information includes an identification of the second network.

[0312] In some embodiments, the third information is included in a radio resource control reconfiguration message.

[0313] In some embodiments, the communication device 900 further includes a second receiving unit (not shown) configured to receive fourth information from the source access network device if the access of the terminal device to the target access network device is allowed. The fourth information indicates that the session of the terminal device is changed to be served by the second network slice of the second network.

[0314] Fig.10 1 is a schematic block diagram of a communication device 1000 implemented in a core network device according to some embodiments of the present disclosure. The communication device 1000 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 1000 may be implemented as Figures 2 to 5 The core network device 330 or a part of the core network device 330 shown in the figure. The core network device 330 includes, for example, the AMF 230 and / or other core network network functions.

[0315] As shown in the figure, the communication device 1000 includes a determination unit 1010, which is configured to determine first information, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, and the first network and the second network are different. The communication device 1000 also includes a transmission unit 1020, which is configured to transmit the first information to an access network device, so that the access network device performs access control of a terminal device to the access network device.

[0316] In some embodiments, the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice. In some embodiments, the identifier of the first network and the identifier of the second network include public land mobile network identifiers of the first network and the second network, respectively, and the identifier of the first network slice and the identifier of the second network slice include single network slice selection assistance information of the first network slice and the second network slice, respectively.

[0317] In some embodiments, the first information is remapping policy information for the first network slice and the second network slice.

[0318] In some embodiments, the first network is a service network of the terminal device, and the terminal device is served by the first network via the access network device. In some embodiments, the second network comprises a target network of the terminal device.

[0319] In some embodiments, the first network and the second network are within the same tracking area.

[0320] In some embodiments, the first information is included in an NG setup response.

[0321] 4.2 Implementation of the device in the second implementation

[0322] Fig.11 FIG. 1 is a schematic block diagram of a communication device 1100 at a target access network device according to some embodiments of the present disclosure. The communication device 1100 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 1100 may be implemented as Figure 2 and Figure 6 The target access network device 212 or a portion of the target access network device 212 is shown in FIG.

[0323] As shown in the figure, the communication device 1100 includes a first receiving unit 1110, which is configured to receive slice identification information from a source access network device, the slice identification information indicates the identification of a home network slice of a terminal device in a home network, and the target access network device is in a visited network of the terminal device. The communication device 1100 also includes a second receiving unit 1120, which is configured to receive slice correspondence information from a core network device, the slice correspondence information indicates the correspondence between a network slice of a visited network and a network slice of a home network. The communication device 1100 also includes an access control unit 1130, which is configured to perform access control of a terminal device to a target access network device based at least on the slice identification information and the slice correspondence information.

[0324] In some embodiments, the communication device 1100 further includes: a transmission unit (not shown), configured to transmit a request for network slice correspondence information to a core network device, the request including at least a device identifier of the terminal device and an identifier of the visited network. In some embodiments, the first receiving unit 1110 is further configured to: receive a response to the request from the core network device, and obtain the network slice correspondence information from the response.

[0325] In some embodiments, the communication device 1100 further includes a third receiving unit (not shown), configured to receive fifth information for the home network from the core network device, the fifth information indicating a relationship between the home network slice and another network slice of the home network. In some embodiments, the access control unit 1130 is further configured to perform access control based on the slice identification information, the network slice correspondence information and the fifth information.

[0326] Fig.12 FIG. 1 is a schematic block diagram of a communication device 1200 at a source access network device according to some embodiments of the present disclosure. The communication device 1200 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 1200 may be implemented as Figure 2 and Figure 6 The source access network device 210 or a part of the source access network device 210 is shown in FIG.

[0327] As shown in the figure, the communication device 1200 includes a receiving unit 1210, which is configured to receive slice identification information for a terminal device, the slice identification information indicates an identification of a home network slice of the terminal device in a home network, and the source access network device is in a first visited network of the terminal device. The communication device 1200 also includes a transmission unit 1220, which is configured to transmit the slice identification information to a target access network device to which the terminal device is to switch, and the target access network device is in a second visited network of the terminal device.

[0328] In some embodiments, the receiving unit is further configured as: the source access network device receives slice identification information from the terminal device or from the core network device.

[0329] In some embodiments, slice identification information is included in a session establishment request received from a terminal device.

[0330] In some embodiments, slice identification information is included in a session resource setup request for a terminal device received from a core network device.

[0331] Fig.13 1 is a schematic block diagram of a communication device 1300 at a terminal device according to some embodiments of the present disclosure. The communication device 1300 may be implemented as a device or a chip in a device, and the scope of the present disclosure is not limited in this respect. The communication device 1300 may be implemented as Figure 2 and Figure 6 The terminal device 220 or a part of the terminal device 220 shown in FIG.

[0332] As shown in the figure, the communication device 1300 includes a transmission unit 1310, which is configured to transmit slice identification information, and the slice identification information indicates the identification of the home network slice of the terminal device in the home network. In these embodiments, the source access network device is in the first visited network of the terminal device. The communication device 1300 also includes a first receiving unit 1320, which is configured to receive third information from the source access network device, and the third information indicates that the service network of the terminal device is switched from the first visited network to the second visited network, and the first visited network and the second visited network are different.

[0333] In some embodiments, the transmission unit 1310 is also configured to transmit slice identification information to the source access network device in the session establishment request.

[0334] In some embodiments, the communication device 1300 further includes an information use unit (not shown) configured to use the third information. In some embodiments, the information use unit is further configured to perform random access to the target access network device of the second visited network based on the third information. In some embodiments, the information use unit is further configured to display an identification of the second visited network based on the third information.

[0335] In some embodiments, the third information includes an identification of the second visited network.

[0336] In some embodiments, the third information is included in a radio resource control reconfiguration message.

[0337] In some embodiments, the communication device 1300 also includes a second receiving unit (not shown) configured to receive fourth information from the source access network device if access of the terminal device to the target access network device is allowed, the fourth information indicating that the session of the terminal device is changed to be served by a second visited network slice of the second visited network.

[0338] 5. Embodiment of the device

[0339] Fig.14 1 is a simplified block diagram of an example device 1400 suitable for implementing embodiments of the present disclosure. The device 1400 may be used to implement the following: Figure 2 The terminal device, access network device and one or more core network devices / network functions shown. As shown in the figure, the device 1400 includes one or more processors 1410, one or more memories 1420 coupled to the processor 1410, and a communication module 1440 coupled to the processor 1410.

[0340] The communication module 1440 may be used for two-way communication. The communication module 1440 may have at least one communication interface for communication. The communication interface may include any interface necessary for communication with other devices.

[0341] Processor 1410 may be of any type suitable for the local technology network, and may include, but is not limited to, at least one of a general purpose computer, a special purpose computer, a microcontroller, a digital signal controller (DSP), or one or more of a controller-based multi-core controller architecture. Device 1400 may have multiple processors, such as application specific integrated circuit chips, which are time-slaved to a clock synchronized with a main processor.

[0342] The memory 1420 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, at least one of read-only memory (ROM) 1424, erasable programmable read-only memory (EPROM), flash memory, hard disk, compact disk (CD), digital video disk (DVD), or other magnetic storage and / or optical storage. Examples of volatile memories include, but are not limited to, at least one of random access memory (RAM) 1422, or other volatile memories that do not persist during a power outage.

[0343] Computer program 1430 includes computer executable instructions executed by associated processor 1410. Program 1430 may be stored in ROM 1420. Processor 1410 may perform any suitable actions and processes by loading program 1430 into RAM 1420.

[0344] The embodiment of the present disclosure can be implemented with the help of program 1430, so that the device 1400 can execute the Figures 3 to 6 The embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0345] In some embodiments, the program 1430 may be tangibly embodied in a computer-readable medium that may be included in the device 1400 (such as in the memory 1420) or other storage device accessible by the device 1400. The program 1430 may be loaded from the computer-readable medium to the RAM 1422 for execution. The computer-readable medium may include any type of tangible non-volatile memory, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc.

[0346] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software, which may be performed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representation, it should be understood that the blocks, devices, systems, techniques, or methods described herein may be implemented as, by way of non-limiting example, hardware, software, firmware, dedicated circuits or logic, general purpose hardware or controllers or other computing devices, or some combination thereof.

[0347] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer-readable storage medium. The computer program product includes computer executable instructions, such as instructions included in a program module, which are executed in a device on a real or virtual processor of a target to perform the above-referenced Figures 3 to 6 The process / method described. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. In various embodiments, the functions of program modules can be combined or divided between program modules as needed. Machine executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in local and remote storage media.

[0348] The computer program code for realizing the method of the present disclosure can be written in one or more programming languages. These computer program codes can be provided to the processor of general-purpose computer, special-purpose computer or other programmable data processing device, so that the program code, when being executed by computer or other programmable data processing device, causes the function / operation specified in flow chart and / or block diagram to be implemented. The program code can be executed completely on computer, partly on computer, as independent software package, partly on computer and partly on remote computer or completely on remote computer or server.

[0349] In the context of the present disclosure, computer program codes or related data may be carried by any appropriate carrier to enable a device, apparatus or processor to perform the various processes and operations described above. Examples of carriers include signals, computer readable media, and the like. Examples of signals may include electrical, optical, radio, acoustic or other forms of propagation signals, such as carrier waves, infrared signals, and the like.

[0350] A computer readable medium may be any tangible medium that contains or stores a program for or related to an instruction execution system, apparatus, or device. A computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination thereof. More detailed examples of computer readable storage media include an electrical connection with one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0351] In addition, although the operation of the method of the present disclosure is described in a particular order in the accompanying drawings, this does not require or imply that these operations must be performed in this particular order, or that all the operations shown must be performed to achieve the desired result. On the contrary, the steps depicted in the flow chart can change the order of execution. Additionally or alternatively, some steps can be omitted, multiple steps can be combined into one step for execution, and / or one step can be decomposed into multiple steps for execution. It should also be noted that the features and functions of two or more devices according to the present disclosure can be embodied in one device. Conversely, the features and functions of a device described above can be further divided into being embodied by multiple devices.

[0352] The above descriptions of various implementations of the present disclosure are exemplary, non-exhaustive, and not limited to the disclosed implementations. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described implementations. The selection of terms used herein is intended to explain the principles of the implementations, practical applications, or improvements to the technology in the market, or to enable other persons of ordinary skill in the art to understand the various implementations disclosed herein.

Claims

1. A communication method, comprising: The target access network device transmits an NG establishment message to the core network device, wherein the NG establishment message includes network slice information, the network slice information indicates the networks supported by the target access network device within the TA range and the network slices supported by the target access network device, and wherein the network slice information also includes network slice information supported by each network in the current TA range; The target access network device receives first information from the core network device, wherein the first information is determined by the core network device based on the network slice information, the first information indicates a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network are different, and wherein the first information indicates a remapping relationship between the first network slice and the second network slice; as well as The target access network device performs access control of the terminal device to the target access network device based at least on the first information.

2. The communication method according to claim 1, wherein the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice.

3. The communication method according to claim 2, wherein the identifier of the first network and the identifier of the second network comprise public land mobile network identifiers of the first network and the second network, respectively, and The identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice respectively.

4. The communication method according to claim 1, further comprising: The target access network device receives second information from the source access network device, where the second information includes an identifier of a third network slice that the terminal device is allowed to use in the second network; and The performing of the access control at least based on the first information includes: the target access network device performing the access control based on the first information and the second information. 5 . The communication method according to claim 1 , wherein the first network is a service network of the terminal device.

6. The communication method according to claim 5, wherein the second network comprises a target network of the terminal device.

7. A communication method, comprising: The source access network device transmits an NG establishment message to the core network device, wherein the NG establishment message includes network slice information, the network slice information indicates the networks supported by the source access network device within the TA range and the network slices supported by the source access network device, and wherein the network slice information also includes network slice information supported by each network in the current TA range; The source access network device receives first information for a terminal device from the core network device, wherein the first information is determined by the core network device based on the network slice information, the first information indicates a relationship between a first network slice of a first network and a second network slice of a second network, the first network is a service network of the terminal device, the first network and the second network are different, and the first information indicates a remapping relationship between the first network slice and the second network slice; as well as The source access network device transmits the first information to the target access network device.

8. The communication method according to claim 7, wherein the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice.

9. The communication method according to claim 8, wherein the identification of the first network and the identification of the second network comprise public land mobile network identifications of the first network and the second network, respectively, and The identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice respectively.

10. The communication method according to claim 7, further comprising: If the access of the terminal device to the target access network device is permitted, the source access network device transmits third information to the terminal device, where the third information indicates that the service network of the terminal device is switched from the first network to the second network. The communication method according to claim 10 , wherein the third information comprises an identification of the second network.

12. A communication method, comprising: The core network device receives an NG establishment message from the access network device, wherein the NG establishment message includes network slice information, the network slice information indicates the networks supported by the access network device within a TA range and the network slices supported by the access network device, and wherein the network slice information also includes network slice information supported by each network in the current TA range; The core network device determines first information based on the network slice information, where the first information indicates a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network are different, and wherein the first information indicates a remapping relationship between the first network slice and the second network slice; as well as The core network device transmits the first information to the access network device for use in access control of the terminal device to the access network device.

13. The communication method according to claim 12, wherein the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network, and an identifier of the second network slice.

14. The communication method according to claim 13, wherein the identification of the first network and the identification of the second network comprise public land mobile network identifications of the first network and the second network, respectively, and The identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice respectively.

15. The communication method according to any one of claims 12 to 14, wherein the first network is a service network of the terminal device, and the terminal device is served by the first network via the access network device; and The second network includes a target network of the terminal device.

16. A communication device implemented at a target access network device, comprising: A transmission unit is configured to transmit an NG establishment message to a core network device, wherein the NG establishment message includes network slice information, the network slice information indicates the network supported by the target access network device within a TA range and the network slices supported by the target access network device, and wherein the network slice information also includes network slice information supported by each network in a current TA range; A first receiving unit is configured to receive first information from the core network device, wherein the first information is determined by the core network device based on the network slice information, the first information indicates a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network are different, and wherein the first information indicates a remapping relationship between the first network slice and the second network slice; as well as An access control unit is configured to perform access control of the terminal device to the target access network device based at least on the first information.

17. The communication device according to claim 16, further comprising: A second receiving unit is configured to receive second information from a source access network device, where the second information includes an identifier of a third network slice that the terminal device is allowed to use in the second network; and The access control unit is further configured to perform the access control based on the first information and the second information. 18 . The communication apparatus according to claim 16 , wherein the first network is a service network of the terminal device.

19. The communication apparatus according to claim 18, wherein the second network comprises a target network of the terminal device.

20. A communication device implemented at a source access network device, comprising: A transmission unit is configured to transmit an NG establishment message to a core network device, wherein the NG establishment message includes network slice information, the network slice information indicates the networks supported by the source access network device within a TA range and the network slices supported by the source access network device, and wherein the network slice information also includes network slice information supported by each network in a current TA range; A receiving unit is configured to receive first information for a terminal device from the core network device, wherein the first information is determined by the core network device based on the network slice information, the first information indicates a relationship between a first network slice of a first network and a second network slice of a second network, the first network is a service network of the terminal device, the first network and the second network are different, and wherein the first information indicates a remapping relationship between the first network slice and the second network slice; as well as The first transmission unit is configured to transmit the first information to a target access network device.

21. The communication device according to claim 20, further comprising: The second transmission unit is configured to transmit third information to the terminal device when access of the terminal device to the target access network device is allowed, wherein the third information indicates that the service network of the terminal device is switched from the first network to the second network.

22. The communication device according to claim 21, wherein the third information comprises an identification of the second network.

23. A communication device implemented at a core network device, comprising: A receiving unit is configured to receive an NG setup message from an access network device, wherein the NG setup message includes network slice information, the network slice information indicates the networks supported by the access network device within a TA range and the network slices supported by the access network device, and wherein the network slice information also includes network slice information supported by each network in a current TA range; a determining unit configured to determine first information based on the network slice information, the first information indicating a relationship between a first network slice of a first network and a second network slice of a second network, the first network and the second network are different, and wherein the first information indicates a remapping relationship between the first network slice and the second network slice; as well as The transmission unit is configured to transmit the first information to the access network device for use in access control of the terminal device to the access network device.

24. The communication apparatus according to claim 23, wherein the first network is a service network of the terminal device, and the terminal device is served by the first network via the access network device; and The second network includes a target network of the terminal device.

25. A communication device according to any one of claims 16, 20 and 23, wherein the first information includes an identifier of the first network, an identifier of the first network slice, an identifier of the second network and an identifier of the second network slice.

26. The communication device according to claim 25, wherein the identification of the first network and the identification of the second network comprise public land mobile network identifications of the first network and the second network, respectively, and The identifier of the first network slice and the identifier of the second network slice include single network slice selection auxiliary information of the first network slice and the second network slice respectively.

27. A computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the method according to any one of claims 1 to 6, any one of claims 7 to 11, or any one of claims 12 to 15.

28. A chip comprising a processor configured to perform the method according to any one of claims 1 to 6, any one of claims 7 to 11, or any one of claims 12 to 15.

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