A cell selection method, a paging method and a device

Abstract

A cell selection method, a paging method and a device, in the cell selection method, when a terminal device performs cell selection, not only the signal measurement result of a cell is considered, but also the cell selection auxiliary information of the terminal device is combined, wherein the cell selection auxiliary information includes the identification of one or more slices corresponding to a session and the slice capability information of the cell, and the cell selection or cell reselection is performed according to the measurement result of the cell and the cell selection auxiliary information, so that the cell selected by the terminal device supports the slice corresponding to the session as much as possible, and the continuity of the service is ensured.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of communication technology, in particular to a cell selection method, a paging method and apparatus. BACKGROUND

[0002] When a terminal is in idle mode, cell selection or cell reselection needs to be performed so as to camp on a cell with higher priority or better channel quality. In idle mode, the terminal triggers cell selection or cell reselection by monitoring the signal measurement results of a serving cell and neighboring cells. The core content of the cell selection or reselection criterion is that there is a cell with better channel quality than the serving cell, and the cell with better channel quality remains better in a period of time, and then the cell with better channel quality is selected or reselected.

[0003] At present, network system architecture is becoming more and more complex, and cell selection or cell reselection based on signal measurement results alone is not suitable for such a more and more complex network system architecture, and therefore corresponding solutions are urgently needed to enable the terminal to select a suitable cell as much as possible. SUMMARY

[0004] The present application provides a cell selection method, a paging method and apparatus, which are used to perform cell selection based on cell selection assistance information from a radio access network device, so as to avoid that a cell selected by a terminal device does not support a slice corresponding to a session.

[0005] In a first aspect, a cell selection method is provided, which includes: obtaining measurement results of N cells; obtaining cell selection assistance information; and performing cell selection or cell reselection according to the measurement results of the N cells and the cell selection assistance information.

[0006] For obtaining the measurement results of the N cells, one possible way is to perform cell measurement to obtain the measurement results of the N cells. Another possible way is to receive an indication from a source radio access network device in a handover process, and the indication includes the measurement results of the N cells.

[0007] The content of the cell selection assistance information can exist in the following two cases. In a first possible case, the cell selection assistance information includes the identities of L slices corresponding to M sessions of a terminal device and slice capability information of the N cells, wherein the slice capability information of the N cells includes the identities of slices supported by the N cells respectively, and M, L and N are positive integers. In a second possible case, the cell selection assistance information includes the identities of L slices corresponding to M sessions of a terminal device and slice capability information of K radio access network devices, wherein the slice capability information of the K radio access network devices includes the identities of slices supported by the K radio access network devices respectively.

[0008] In the embodiments of the present application, based on the cell selection assistance information and the signal measurement result, a cell more suitable for the terminal device to camp on can be selected. In this way, the selected camped cell can support the slice corresponding to the session as much as possible, so that the normal transmission of the service can be ensured with the maximum probability; compared with the prior art, the service discontinuity caused by cell switching can be avoided to some extent, and the cell resources can be used as fully and reasonably as possible.

[0009] In a possible embodiment, when the cell selection assistance information satisfies the first possible case, the specific method of performing cell selection or cell reselection according to the measurement result of the N cells and the cell selection assistance information comprises: determining a candidate target cell for cell selection or cell reselection according to the measurement result of the N cells; and selecting a target cell supporting the L slices from the candidate target cells according to the cell selection assistance information.

[0010] In the embodiments of the present application, the terminal device screens the cells by using the cell selection assistance information, so as to screen the cells supporting the slice corresponding to the session, so that the terminal device can camp on a suitable cell and service discontinuity can be avoided.

[0011] In a possible embodiment, when the cell selection assistance information satisfies the second possible case, the specific method of performing cell selection or cell reselection according to the measurement result of the N cells and the cell selection assistance information comprises: determining a candidate target radio access network device for cell selection or cell reselection according to the measurement result of the N cells; and selecting a target radio access network device supporting the L slices from the candidate target radio access network devices according to the cell selection assistance information.

[0012] In the embodiments of the present application, the radio access network device is screened by using the cell selection assistance information, so as to screen the radio access network device supporting the slice corresponding to the session of the terminal device, so that the terminal device can camp on a suitable cell and service discontinuity can be avoided.

[0013] In a possible embodiment, when the cell selection assistance information satisfies the first possible case, the target cell supporting the L slices is selected from the candidate target cells according to the cell selection assistance information, comprising:

[0014] determining whether there is a target cell in the candidate target cells that supports the L slices; if there is, selecting the target cell; otherwise, in a first manner, selecting a target cell that supports a first slice from the candidate target cells according to the cell selection assistance information and the priority of the L slices, the first slice being a slice with the highest priority among the L slices; or in a second manner, selecting a target cell with the largest number of intersections from the candidate target cells according to the cell selection assistance information and the number of intersections between each slice supported by each cell and the L slices.

[0015] In the embodiments of the present application, the cell in which the terminal device camps can be ensured to support the slice corresponding to the session as much as possible according to the above method, so that the normal transmission of the service can be ensured with the maximum probability; compared with the prior art, the problem of service discontinuity caused by cell switching can be avoided to some extent, and the cell resources can be used as fully and reasonably as possible.

[0016] In a possible embodiment, when the cell selection assistance information satisfies the second possible case, selecting a target radio access network device that supports the L slices from the candidate target radio access network devices according to the cell selection assistance information comprises:

[0017] determining whether there is a target radio access network device in the candidate target radio access network devices that supports the L slices; if there is, selecting the target radio access network device; otherwise, in a first manner, selecting a target radio access network device that supports a first slice from the candidate target radio access network devices according to the cell selection assistance information and the priority of the L slices, the first slice being a slice with the highest priority among the L slices; or in a second manner, selecting a target radio access network device with the largest number of intersections from the candidate target radio access network devices according to the cell selection assistance information and the number of intersections between each slice supported by each cell and the L slices.

[0018] In the embodiments of the present application, the cell of the radio access network device accessed by the terminal device can be ensured to support the slice corresponding to the session as much as possible according to the above method, so that the normal transmission of the service can be ensured with the maximum probability; compared with the prior art, the problem of service discontinuity caused by cell switching can be avoided to some extent, and the cell resources can be used as fully and reasonably as possible.

[0019] In a possible embodiment, the method further comprises: obtaining the priority of the L slices according to preconfigured information; or obtaining the priority of the L slices from the network device side in a network registration process; or obtaining the priority of the L slices from the network device side in an M-session establishment process, that is, obtaining the priority of the slice corresponding to each session from the network device side in each session establishment process, so as to obtain the priority of the L slices of the M sessions.

[0020] In the embodiments of the present application, the priority of the slice can be combined to maximize the probability of ensuring that the terminal device resides in a suitable cell, so as to ensure the continuity of the service.

[0021] In a second aspect, the embodiments of the present application also provide a cell selection method, which comprises: obtaining measurement results of N cells; obtaining cell selection assistance information; and performing cell selection or cell reselection according to the measurement results of the N cells and the cell selection assistance information.

[0022] For obtaining the measurement results of the N cells, one possible way is to perform cell measurement to obtain the measurement results of the N cells. Another possible way is that, in the handover process, an indication including the measurement results of the N cells can be received from the source radio access network device.

[0023] The content of the cell selection assistance information can be in the following two cases: in the first possible case, the cell selection assistance information includes slice capability information of the N cells and allowed slice selection assistance information, wherein the slice capability information of the N cells includes the identification of the slices supported by the N cells respectively, and the allowed slice selection assistance information is the identification of the slices allowed to be accessed by the terminal device. In the second possible case, the cell selection assistance information includes slice capability information of the K radio access network devices and allowed slice selection assistance information, wherein the slice capability information of the K radio access network devices includes the identification of the slices supported by the K radio access network devices respectively.

[0024] In the embodiments of the present application, the allowed slice selection assistance information refers to the identification of the slices allowed to be accessed by the terminal device. The cell selection assistance information is mainly used to enable the terminal to determine the tendency of the cell selection target when performing cell selection or cell reselection. Based on the cell selection assistance information and the signal measurement results, a cell more suitable for the terminal device to reside in can be selected. In this way, the selected cell to reside in can support the slice corresponding to the session as much as possible, so that the normal transmission of the service can be ensured with the maximum probability; compared with the prior art, the problem of service discontinuity caused by cell switching can be avoided to some extent, so that the cell resources can be utilized as fully and reasonably as possible.

[0025] In one possible embodiment, when the cell selection assistance information satisfies the first possible case, the specific method of performing cell selection or cell reselection according to the measurement results of the N cells and the cell selection assistance information comprises: determining candidate target cells for cell selection or cell reselection according to the measurement results of the N cells; and selecting a target cell supporting the slices allowed to be accessed by the terminal device from the candidate target cells according to the cell selection assistance information.

[0026] In the embodiments of the present application, the cells are screened by using the cell selection auxiliary information, so as to screen the cells supporting the slices that allow the terminal device to access, so that the terminal device camps on a suitable cell, and avoids service discontinuity.

[0027] In a possible embodiment, when the cell selection auxiliary information satisfies the second possible case, the specific method of performing cell selection or cell reselection according to the measurement results of the N cells and the cell selection auxiliary information comprises: determining candidate target radio access network devices for cell selection or cell reselection according to the measurement results of the N cells; and selecting target radio access network devices supporting the slices that allow the terminal device to access from the candidate target radio access network devices according to the cell selection auxiliary information.

[0028] In a possible embodiment, when the cell selection auxiliary information satisfies the first possible case, the method of selecting a target cell supporting the slices that allow the terminal device to access from candidate target cells according to the cell selection auxiliary information comprises:

[0029] determining whether there is a target cell supporting the slices that allow the terminal device to access in the candidate target cells; if there is, selecting the target cell; otherwise, in mode one, selecting a target cell supporting a first slice from the candidate target cells according to the cell selection auxiliary information and the priority of the slices that allow the terminal device to access, the first slice being the slice with the highest priority among the slices that allow the terminal device to access; in mode two, selecting a target cell with the largest number of intersections from the candidate target cells according to the cell selection auxiliary information and the number of intersections between each slice supported by the cell and the slices that allow the terminal device to access.

[0030] In the embodiments of the present application, the above method can ensure that the selected camped cell supports the slices that allow the terminal device to access as much as possible, so as to ensure the normal transmission of services with the maximum probability; compared with the prior art, the method can avoid the problem of service discontinuity caused by cell switching to some extent, and makes the cell resources be used as fully and reasonably as possible.

[0031] In a possible embodiment, when the cell selection auxiliary information satisfies the second possible case, the method of selecting a target radio access network device supporting the slices that allow the terminal device to access from candidate target radio access network devices according to the cell selection auxiliary information comprises:

[0032] determining whether there is a target radio access network device supporting a slice allowed to be accessed by the terminal device in the candidate target radio access network devices; if there is, selecting the target radio access network device; otherwise, in a first mode, selecting a target radio access network device supporting a first slice from the candidate target radio access network devices according to the cell selection assistance information and the priority of the slice allowed to be accessed by the terminal device, the first slice being a slice with the highest priority among the slices allowed to be accessed by the terminal device; in a second mode, selecting a target radio access network device with the largest number of intersections from the candidate target radio access network devices according to the cell selection assistance information, the number of intersections between each slice supported by each cell and the slice allowed to be accessed by the terminal device.

[0033] In the embodiments of the present application, the above method can ensure that the cell of the selected radio access network device supports the slice allowed to be accessed by the terminal device to the largest extent, so that the normal transmission of the service can be ensured with the largest probability; compared with the prior art, the service discontinuity caused by cell switching can be avoided to some extent, and the cell resources can be used as fully and reasonably as possible.

[0034] In a possible embodiment, the above method further includes: obtaining the priority of the slice allowed to be accessed by the terminal device according to preconfigured information; or obtaining the priority of the slice allowed to be accessed by the terminal device from the network device side in a network registration process.

[0035] In the embodiments of the present application, the priority of the slice can be combined to ensure that the terminal device camps on a suitable cell with the largest probability, so as to ensure the continuity of the service.

[0036] In a third aspect, a paging method is provided, which includes: obtaining first slice information, the first slice information being used to indicate slices supported by K radio access network devices, K being a positive integer; obtaining second slice information, the second slice information being used to indicate a slice associated with a session to be sent downlink data; determining a target radio access network device set from the K radio access network devices according to the first slice information and the second slice information, the radio access network devices in the target radio access network device set supporting the slice indicated by the second slice information; and sending a paging message to the target radio access network device set.

[0037] In the embodiments of the present application, the K radio access network devices are screened based on the first slice information and the second slice information, so that the target radio access network device set screened can save signaling, reduce the signaling transmission path, and reduce the complexity of the paging process, because the target radio access network device set supports the slice corresponding to the session of the terminal device.

[0038] In a possible embodiment, the first slice information can be acquired in the following manner: receiving slice identifiers from the K radio access network devices; and determining the first slice information according to the slice identifiers.

[0039] In a possible embodiment, the second slice information can be acquired in the following manner: receiving a slice identifier from the session management function network element; and determining the second slice information according to the slice identifier.

[0040] In a possible embodiment, the second slice information can be acquired in the following manner: receiving a session identifier of to-be-sent downlink data from the session management function network element; and determining the second slice information according to a slice corresponding to the session identifier of to-be-sent downlink data.

[0041] In a possible embodiment, the first slice information is used to indicate slices supported by N cells of the K radio access network devices, K and N are positive integers, and a target radio access network device set is determined from the K radio access network devices according to the first slice information and the second slice information, including:

[0042] A target cell set in the target radio access network device set is determined from the N cells of the K radio access network devices according to the first slice information and the second slice information, and the identification of a target cell in the target cell set is included in the paging message.

[0043] In the embodiments of the present application, the target cell set can be screened according to the above method, so that the terminal device is paged in the target cell set, thereby saving signaling overhead.

[0044] In a fourth aspect, another paging method is provided, including:

[0045] First slice information is acquired, the first slice information being used to indicate slices supported by N cells, N being a positive integer;

[0046] Second slice information is acquired, the second slice information being used to indicate a slice associated with a session of to-be-sent downlink data;

[0047] A target cell set is determined from the N cells according to the first slice information and the second slice information, the target cell set including a target cell supporting the slice indicated by the second slice information;

[0048] A paging message is sent to a radio access network device corresponding to the target cell set, and the identification of a target cell in the target cell set is included in the paging message.

[0049] In the embodiments of the present application, the cells are screened based on the first slice information and the second slice information, so that the target cell set screened can save signaling, reduce the signaling transmission path, and reduce the complexity of the paging process, because the target cell set supports the slice corresponding to the session of the terminal device.

[0050] In a fifth aspect, a paging method is provided, the method comprising:

[0051] obtaining a first data notification message, the first data notification message indicating that a first session of a terminal device has downlink data to be transmitted;

[0052] sending an identifier of the first session to an access and mobility management function network element, the identifier of the first session being used for paging of the terminal device;

[0053] receiving a second data notification message from a user plane function network element during a user plane connection activation process of the terminal device, the second data notification message indicating that a second session of the terminal device has downlink data to be transmitted;

[0054] determining that a priority of a slice corresponding to the second session is higher than a priority of a slice corresponding to the first session;

[0055] sending an identifier of the second session to the access and mobility management function network element, the identifier of the second session being used for paging of the terminal device.

[0056] In the embodiments of the present application, according to the above method, in the user plane connection activation process of the terminal device, the access and mobility management function network element is instructed to initiate paging only when the priority of the slice of the received downlink data is higher, which can further reduce the signaling overhead and ensure timely paging of the terminal device.

[0057] In a possible embodiment, when it is determined that the priority of the slice corresponding to the second session is lower than or equal to the priority of the slice corresponding to the first session, no response is made. In this way, the signaling overhead can be saved.

[0058] In a sixth aspect, the present application provides a first communication device. The device has the functions of implementing each embodiment of the above-mentioned first aspect or second aspect. The functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the above-mentioned functions.

[0059] In one possible design, the apparatus includes a transceiver unit, and optionally, a processing unit. The processing unit can be, for example, a processor, and the receiving unit can be, for example, a receiver, and the transmitting unit can be, for example, a transmitter, which can include radio frequency circuitry. The apparatus can also include a storage unit, which can be, for example, a memory. When the apparatus includes the storage unit, the storage unit stores computer-executable instructions, and the processing unit is connected to the storage unit and executes the computer-executable instructions stored in the storage unit to cause the apparatus to perform the method of any one of the first aspect or the second aspect.

[0060] In another possible design, the apparatus is a chip. The chip includes a receiving unit and a transmitting unit, and optionally, a processing unit. The processing unit can be, for example, processing circuitry, and the receiving unit can be, for example, an input interface, a pin, or a circuit, and the transmitting unit can be, for example, an output interface, a pin, or a circuit. The processing unit can execute computer-executable instructions stored in a storage unit to cause the transmitting method of any one of the first aspect or the second aspect to be performed. The storage unit can be, for example, a storage unit in the chip, such as a register, a cache, or the like, or a storage unit in the terminal that is external to the chip, such as a read-only memory (ROM), another type of static storage device that can store static information and instructions, a random access memory (RAM), or the like.

[0061] The processor mentioned in any one of the above can be, for example, a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling execution of a program for the method of the first aspect or the second aspect.

[0062] In a seventh aspect, the present application provides a second communication apparatus. The apparatus has the functions of implementing the embodiments of the third aspect or the fourth aspect. The functions can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more modules corresponding to the functions.

[0063] In an example, the apparatus includes a transceiver, and optionally, a processor. The processor can be a Central Processing Unit (CPU), an Application-Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to control the execution of the method of the third aspect or the fourth aspect. The transceiver can include a radio frequency circuit. The apparatus can further include a memory. When the apparatus includes the memory, the memory stores computer-executable instructions. The processor is connected to the memory and executes the computer-executable instructions stored in the memory to cause the access and mobility management function network element to perform the method of any one of the third aspect or the fourth aspect.

[0064] In another example, the apparatus is a chip. The chip includes a receiver and a transmitter, and optionally, a processor. The processor can be a processing circuit. The receiver can be an input interface, a pin, or a circuit. The transmitter can be an output interface, a pin, or a circuit. The processor can execute computer-executable instructions stored in a memory to cause the method of any one of the third aspect or the fourth aspect to be performed. The memory can be a memory within the chip, such as a register, a cache, or the like. The memory can also be a memory outside the chip, such as a read-only memory (ROM), another type of static memory device that can store static information and instructions, a random access memory (RAM), or the like.

[0065] The processor can be a Central Processing Unit (CPU), an Application-Specific Integrated Circuit (ASIC), or one or more integrated circuits configured to control the execution of the method of the third aspect or the fourth aspect.

[0066] In an eighth aspect, the present disclosure provides a third communication apparatus. The apparatus has the functions of the embodiments of the fifth aspect. The functions can be implemented by hardware, or by hardware executing software. The hardware or software includes one or more modules corresponding to the functions.

[0067] In one possible design, the apparatus includes a transceiver unit, and optionally, a processing unit. The processing unit can be a processor, and the receiving unit can be a receiver, and the transmitting unit can be a transmitter, which include radio frequency circuitry. The apparatus can also include a storage unit, which can be a memory. When the apparatus includes the storage unit, the storage unit stores computer-executable instructions, and the processing unit is connected to the storage unit and executes the computer-executable instructions stored in the storage unit to cause the session management function network element to perform the method of any of the fifth aspect.

[0068] In another possible design, the apparatus is a chip. The chip includes a receiving unit and a transmitting unit, and optionally, a processing unit. The processing unit can be processing circuitry, and the receiving unit can be an input interface, a pin, or circuitry, and the transmitting unit can be an output interface, a pin, or circuitry. The processing unit can execute computer-executable instructions stored in a storage unit to cause the transmitting method of any of the fifth aspect to be performed. The storage unit can be a storage unit in the chip, such as a register, a cache, or the like, and the storage unit can also be a storage unit outside the chip in the terminal, such as a read-only memory (ROM), another type of static storage device that can store static information and instructions, a random access memory (RAM), or the like.

[0069] The processor mentioned in any of the above can be a general-purpose central processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling execution of programs for the method of the fifth aspect.

[0070] In a ninth aspect, an embodiment of the present application provides a chip system including a processor, and optionally, a memory, for implementing the method in any of the design examples of the first aspect or the second aspect or the operations performed by the first communication apparatus. The chip system can be composed of a chip, or can include the chip and other discrete devices.

[0071] In a tenth aspect, an embodiment of the present application provides a chip system including a processor, and optionally, a memory, for implementing the method in any of the design examples of the third aspect or the fourth aspect or the operations performed by the second communication apparatus. The chip system can be composed of a chip, or can include the chip and other discrete devices.

[0072] In an eleventh aspect, an embodiment of the present application provides a chip system, which comprises a processor, and can further comprise a memory, and is configured to implement the method in any of the design examples of the fifth aspect or the operation performed by the third communication device. The chip system can be composed of a chip, or can comprise a chip and other discrete devices.

[0073] In a twelfth aspect, the present application provides a communication system, which comprises any of the communication devices in the sixth aspect to the eighth aspect.

[0074] In a thirteenth aspect, an embodiment of the present application further provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed, the method in any of the design examples of the first aspect can be implemented.

[0075] In a fourteenth aspect, an embodiment of the present application further provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed, the method in any of the design examples of the second aspect can be implemented.

[0076] In a fifteenth aspect, an embodiment of the present application further provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed, the method in any of the design examples of the third aspect can be implemented.

[0077] In a sixteenth aspect, an embodiment of the present application further provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed, the method in any of the design examples of the fourth aspect can be implemented.

[0078] In a seventeenth aspect, an embodiment of the present application further provides a computer readable storage medium, which stores a computer program or instructions, and when the computer program or instructions are executed, the method in any of the design examples of the fifth aspect can be implemented.

[0079] In an eighteenth aspect, an embodiment of the present application further provides a computer program product, which comprises instructions, and when the instructions are run on a computer, the computer is caused to execute the method in any of the design examples of the first aspect or the second aspect.

[0080] In a nineteenth aspect, an embodiment of the present application further provides a computer program product, which comprises instructions, and when the instructions are run on a computer, the computer is caused to execute the method in any of the design examples of the third aspect or the fourth aspect.

[0081] In a twentieth aspect, an embodiment of the present application further provides a computer program product, which comprises instructions, and when the instructions are run on a computer, the computer is caused to execute the method in any of the design examples of the fifth aspect.

[0082] In addition, the technical effects brought by any one of the designs in the sixth aspect to the twentieth aspect can refer to the technical effects brought by the different designs in the first aspect to the fifth aspect, which will not be repeated here. BRIEF DESCRIPTION OF DRAWINGS

[0083] Figure 1A and Figure 1B A schematic diagram of a communication system provided by the embodiments of the present application is shown in the figure.

[0084] Figure 2 A schematic diagram of a cell suitable for the embodiments of the present application is shown in the figure.

[0085] Figure 3 A schematic diagram of a communication scenario provided by the embodiments of the present application is shown in the figure.

[0086] Figure 4 A schematic diagram of a cell selection method provided by the embodiments of the present application is shown in the figure.

[0087] Figure 5 A schematic diagram of a paging method provided by the embodiments of the present application is shown in the figure.

[0088] Figure 6 Another schematic diagram of a communication scenario provided by the embodiments of the present application is shown in the figure.

[0089] Figure 7 A schematic diagram of another paging method provided by the embodiments of the present application is shown in the figure.

[0090] Figure 8 A schematic diagram of a first communication device structure provided by the embodiments of the present application is shown in the figure.

[0091] Figure 9 A schematic diagram of a second communication device structure provided by the embodiments of the present application is shown in the figure.

[0092] Figure 10 A schematic diagram of a third communication device structure provided by the embodiments of the present application is shown in the figure.

[0093] Figure 11 A schematic diagram of a communication device structure provided by the embodiments of the present application is shown in the figure. DETAILED DESCRIPTION

[0094] In order to make the purposes, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the accompanying drawings. The specific operation methods in the method embodiments can also be applied to the device embodiments or system embodiments.

[0095] The technical solutions of the embodiments of the present application can be applied to various communication systems, for example: long term evolution (LTE) system, LTE frequency division duplex (FDD) system, LTE time division duplex (TDD), 5th generation (5G) system or new radio (NR), or future communication system or other similar communication system, etc.

[0096] As shown in the fifth generation (5G) network architecture based on service-oriented architecture is shown in FIG. 1. Figure 1A As shown in the fifth generation (5G) network architecture based on service-oriented architecture is shown in FIG. 1. Figure 1A The 5G network architecture shown can include three parts, which are terminal device part, data network (DN) and operator network part. The functions of some network elements in the network are briefly introduced as follows.

[0097] Among them, the operator network can include one or more of the following network elements: authentication server function (AUSF) network element, network exposure function (NEF) network element, policy control function (PCF) network element, unified data management (UDM) network element, unified data repository (UDR), network repository function (NRF) network element, application function (AF) network element, access and mobility management function (AMF) network element, session management function (SMF) network element, radio access network (RAN) and user plane function (UPF) network element, network slice selection function (NSSF) network element (not shown in the figure) and the like. Among the above operator network, except for the radio access network part, the part can be referred to as the core network part.

[0098] A terminal device is a device with wireless transceiver function, which can be deployed on land, including indoor or outdoor, handheld or vehicle-mounted; can also be deployed on water surface (such as ships, etc.); can also be deployed in the air (such as airplanes, balloons and satellites, etc.). The terminal device can be a mobile phone, a pad, a computer with wireless transceiver function, a virtual reality (VR) terminal, an augmented reality (AR) terminal, a wireless terminal in industrial control, a wireless terminal in self-driving, a wireless terminal in remote medical, a wireless terminal in smart grid, a wireless terminal in transportation safety, a wireless terminal in smart city, a wireless terminal in smart home, a user equipment (UE), etc.

[0099] The terminal device can establish a connection with the operator network through an interface (such as N1, etc.) provided by the operator network, and use data and / or voice services provided by the operator network. The terminal device can also access a DN through the operator network, and use operator services and / or third-party services deployed on the DN. The third party can be a service provider other than the operator network and the terminal device, and can provide the terminal device with data and / or voice services. The specific form of the third party can be determined according to the actual application scenario, which is not limited herein.

[0100] The RAN is a subnetwork of the operator network and is an implementation system between the service nodes and the terminal devices in the operator network. To access the operator network, the terminal device first passes through the RAN and then can be connected to the service nodes of the operator network through the RAN. The RAN device is a device that provides wireless communication functions for the terminal device, and the RAN device is also called an access network device. The RAN device includes but is not limited to: a next-generation base station (g nodeB, gNB) in 5G, an evolved node B (eNB), a radio network controller (RNC), a node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (for example, a home evolved nodeB, or a home node B, HNB), a baseband unit (BBU), a transmitting and receiving point (TRP), a transmitting point (TP), a mobile switching center, and the like.

[0101] The AMF network element is mainly responsible for mobility management, access authentication / authorization, and the like. In addition, the AMF is also responsible for transmitting user policies between the UE and the PCF.

[0102] The SMF network element is mainly responsible for session management, execution of control policies issued by the PCF, selection of the UPF, allocation of the UE internet protocol (IP) address, and the like.

[0103] The UPF network element, as an interface UPF of a data network, is responsible for user plane data forwarding, session / stream level-based charging statistics, bandwidth limitation, and the like.

[0104] The UDM network element is mainly responsible for managing subscription data, user access authorization, and the like.

[0105] The UDR is mainly responsible for accessing functions of subscription data, policy data, application data, and the like.

[0106] The NEF network element is mainly used to support the opening of capabilities and events.

[0107] AF network element, mainly to transfer the demand of application side to network side, for example, Quality of Service (QoS) demand or user state event subscription, etc. AF can be a third-party functional entity, or an application service deployed by the operator, such as IP Multimedia Subsystem (IMS) voice call service.

[0108] PCF network element, mainly responsible for charging, QoS bandwidth guarantee and mobility management at session and service flow level, and policy control functions such as UE policy decision. In this architecture, the PCF connected with AMF and SMF respectively corresponds to AM PCF (PCF for Access and Mobility Control) and SM PCF (PCF for Session Management), which may not be the same PCF entity in actual deployment scenarios.

[0109] NRF network element, which can be used to provide network element discovery function, and provide network element information corresponding to network element type based on the request of other network elements. NRF also provides network element management services, such as network element registration, update, deregistration, and network element state subscription and push, etc.

[0110] AUSF network element: mainly responsible for authenticating users to determine whether to allow users or devices to access the network.

[0111] NSSF network element, mainly used for selecting network slices and counting users in network slices, etc.

[0112] DN is a network located outside the operator network, and the operator network can access multiple DN. Various services can be deployed on DN, and data and / or voice services can be provided for terminal devices. For example, the DN is a private network of a smart factory, and the sensors installed in the workshop of the smart factory can be terminal devices. A control server of the sensors is deployed in the DN, and the control server can provide services for the sensors. The sensors can communicate with the control server to obtain instructions from the control server, and transmit the collected sensor data to the control server according to the instructions, etc. For another example, the DN is an internal office network of a company, and the mobile phones or computers of the employees of the company can be terminal devices. The mobile phones or computers of the employees can access information and data resources on the internal office network of the company.

[0113] It should be noted that different operators have different public land mobile networks (PLMNs). PLMNs are used to distinguish different mobile communication operators in a country or region. A service area can consist of one or several public land mobile communication networks. PLMNs are operated by the government or operators approved by it, and are established and operated for the purpose of providing land mobile communication services to the public. A PLMN is represented by a mobile device country code and a mobile device network code (MNC). Among them, China Mobile's MNC is 00, and China Unicom's MNC is 01.

[0114] Figure 1A Nausf, Nnef, Npcf, Nudm, Naf, Namf, Nsmf, N1, N2, N3, N4, and N6 are interface serial numbers. These interface serial numbers are service-oriented interfaces. The meanings of these interface serial numbers can be found in the definitions of the 3rd Generation Partnership Project (3GPP) standard protocols and are not limited here.

[0115] like Figure 1B The following is a schematic diagram of the 5G network architecture based on point-to-point interfaces. The functions of the network elements can be found in Figure 1A The introduction of the functions of the corresponding network elements will not be repeated here. Figure 1B and Figure 1A The main differences are: Figure 1B The interfaces between network elements in a network are point-to-point interfaces, not service-oriented interfaces.

[0116] exist Figure 1B In the architecture shown, the interface names and functions between the various network elements are as follows:

[0117] 1) N7: The interface between PCF and SMF, which can be used to issue protocol data unit (PDU) session granularity and service data flow granularity control policy.

[0118] 2) N15: The interface between PCF and AMF, which can be used to deliver UE policies and access control related policies.

[0119] 3) N5: The interface between AF and PCF, which can be used to issue application service requests and report network events.

[0120] 4) N4: the interface between SMF and UPF, which can be used to transfer information between control plane and user plane, including the delivery of control plane forwarding rules, QoS control rules, traffic statistics rules, and the information reporting of user plane.

[0121] 5) N11: the interface between SMF and AMF, which can be used to transfer PDU session tunnel information between RAN and UPF, transfer control messages sent to UE, transfer radio resource control information sent to RAN, etc.

[0122] 6) N2: the interface between AMF and RAN, which can be used to transfer radio bearer control information from core network to RAN, etc.

[0123] 7) N1: the interface between AMF and UE, which can be used to transfer QoS control rules to UE, etc.

[0124] 8) N8: the interface between AMF and UDM, which can be used for AMF to obtain access and mobility management related subscription data and authentication data from UDM, and for AMF to register UE current mobility management related information to UDM, etc.

[0125] 9) N10: the interface between SMF and UDM, which can be used for SMF to obtain session management related subscription data from UDM, and for SMF to register UE current session related information to UDM, etc.

[0126] 10) N35: the interface between UDM and UDR, which can be used for UDM to obtain user subscription data information from UDR.

[0127] 11) N36: the interface between PCF and UDR, which can be used for PCF to obtain policy related subscription data and application data related information from UDR.

[0128] 12) N12: the interface between AMF and AUSF, which can be used for AMF to initiate an authentication process to AUSF, wherein SUCI can be carried as a subscription identifier;

[0129] 13) N13: the interface between UDM and AUSF, which can be used for AUSF to obtain user authentication vector from UDM to perform authentication process.

[0130] It can be understood that the above network elements or functions can be network elements in a hardware device, or software functions running on a dedicated hardware, or virtualized functions instantiated on a platform (for example, a cloud platform). Alternatively, the above network elements or functions can be implemented by one device, or by multiple devices together, or can be a functional module in a device, and the embodiments of the present application do not make specific limitations. In actual deployment, the above network elements can be combined. For example, the mobility management network element can be combined with the session management network element; the session management network element can be combined with the user plane network element; the network slice selection function network element, the policy control function network element, and the unified data management function network element can be combined. When two network elements are combined, the interaction between the two network elements provided by the embodiments of the present application becomes an internal operation of the combined network element or can be omitted.

[0131] The access and mobility management function network element, the session management function network element, the policy control network element, the application function network element, the access network device, the network exposure function network element, the user plane function network element, and the network slice selection network element in the present application can be AMF, SMF, PCF, AF, RAN, NEF, UPF, and NSSF in Figure 1A or Figure 1B , or can be network elements with the functions of the above AMF, SMF, PCF, AF, RAN, NEF, UPF, and NSSF in future communications such as the sixth generation (6th generation, 6G) network, and the present application does not make limitations. For convenience of description, the access and mobility management function network element, the session management function network element, the policy control network element, the application function network element, the access network device, the network exposure function network element, the user plane function network element, and the network slice selection network element are taken as examples of the above AMF, SMF, PCF, AF, RAN, NEF, UPF, and NSSF for description. Further, the terminal device is taken as an example of UE for description in the present application.

[0132] In the 5G era, hundreds of billions of Internet of Things devices will access the network, and different types of application scenarios have different demands on the network, and some even conflict with each other. Providing services for different types of application scenarios through a single network will lead to an exceptionally complex network architecture, low network management efficiency, and low resource utilization efficiency. The 5G network slicing technology provides mutually isolated network environments for different application scenarios by virtually creating independent logical networks on the same network infrastructure, so that different application scenarios can customize network functions and characteristics according to their own needs, and can effectively guarantee the QoS requirements of different businesses. The goal of the 5G network slicing technology is to organically combine terminal devices, access network resources, core network resources, and network operation and management systems to provide complete networks that can be independently operated and isolated for different business scenarios or business types.

[0133] Different scenarios impose different requirements on the 3GPP ecosystem: charging, policy, security, mobility, etc. 3GPP emphasizes that network slices are not impacted by each other, e.g. a burst of massive meter reading traffic should not impact normal mobile broadband traffic. To meet the diverse requirements and isolation between slices, there is a need for relatively independent management and operation between services, and to provide tailored service functions and analysis capabilities. Different instances of the same type of service are deployed on different network slices, and different instances of the same type of service can also be deployed on different network slices.

[0134] When the core network is deployed with network slices, if the user initially attaches to the network, the network slice selection process is triggered. The network slice selection process depends on the user's subscription data, local configuration information, roaming agreement, operator's policy, etc. In the network slice selection process, the above parameters need to be considered comprehensively to select the best slice type for the UE.

[0135] In actual deployment, RAN support for slices can be divided into the following four scenarios, as shown in FIG. 1, assuming that the RAN has three cells, such as cell 1, cell 2, and cell 3. Figure 2

[0136] Scenario 1: The three cells under the RAN support the same slice, and work in the same frequency band. As shown in Table 1, cell 1, cell 2, and cell 3 all support slice S-1, slice S-2, and slice S-3, and all work in F1 and F2 frequency bands.

[0137] Table 1

[0138] Cell Slice Frequency band Cell 1 S-1, S-2, S-3 F1, F2 Cell 2 S-1, S-2, S-3 F1, F2 Cell 3 S-1, S-2, S-3 F1, F2

[0139] Scenario 2: The three cells under the RAN support the same slice, but the three cells work in different frequency bands. As shown in Table 2, cell 1, cell 2, and cell 3 all support slice S-1, slice S-2, and slice S-3, cell 1 works in F1 frequency band, cell 2 works in F1 frequency band, and cell 3 works in F3 frequency band.

[0140] Table 2

[0141] Cell Slice Frequency band Cell 1 S-1, S-2, S-3 F1 Cell 2 S-1, S-2, S-3 F1 Cell 3 S-1, S-2, S-3 F3

[0142] Scenario 3: The RAN (i.e. cell 1 or cell 2 or cell 3) supports different slices when working in different frequency bands. As shown in Table 3, when the RAN works in F1 frequency band, it supports slice S1 and slice S3; when the RAN works in F2 frequency band, it supports slice S2; and when the RAN works in F3 frequency band, it supports slice S4 and slice S5.

[0143] Table 3 ​

[0144] Cell Frequency band Slice RAN F1 S1, S3 RAN F2 S2 RAN F3 S4, S5

[0145] Scenario 4: Three cells of the RAN work in different frequency bands respectively, and correspondingly support different slices. As shown in Table 4, cell 1 supports slice S1 and slice S3 when working in F1 frequency band; cell 2 supports slice S2 when working in F2 frequency band; and cell 3 supports slice S4 and slice S5 when working in F3 frequency band.

[0146] Table 4

[0147] Cell Frequency band Slice Cell 1 F1 S1, S3

[0148] Cell 2 F2 S2 Cell 3 F3 S4, S5

[0149] Currently, when the location of the UE moves, the UE needs to perform cell selection. At this time, if the UE only considers the signal measurement result, the target cell finally selected by the UE can not support the slice corresponding to the PDU session of the UE. In this case, the PDU session of the UE corresponding to the slice not supported by the target cell will be released or cannot continue to transmit the data packets of the service carried thereby, and thus the continuity of the service carried by the PDU session cannot be guaranteed. Exemplarily, as shown in FIG. 6, in this scenario, the UE is initially located in the coverage of RAN1, the UE establishes a first PDU session, and accesses slice 1. At this time, the UE moves, and the UE moves to the coverage of RAN2. Among them, RAN1 supports slice 1 and slice 2; and RAN2 supports slice 2 and slice 3. As shown in Table 5, in addition, before the UE moves, the UE can enter an idle (IDLE) state due to a long time of no interaction with the network side, that is, the user plane connection between the UE and the core network is disconnected. Figure 3

[0150] Table 5

[0151] RAN Slice RAN1 Slice 1, Slice 2 RAN2 Slice 2, Slice 3

[0152] Suppose that, at this time, downlink data arrives at the UPF, which triggers paging of the UE. As shown in FIG. 7, the AMF pages the UE in the entire registration area (RA), and the RA includes the coverage of RAN1 and RAN2. Suppose that the AMF pages the UE under RAN2, the UE initiates a service request procedure in RAN2 to restore the user plane connection corresponding to the first PDU session. Figure 3

[0153] In one possible mode, the RAN2 releases the first PDU session.

[0154] ​​In another possible way, the RAN 2 resumes the user plane connection of the first PDU session. However, since the RAN 2 does not support the slice 1 corresponding to the first PDU session, even if the user plane connection is resumed, it is possible that the user plane connection cannot be used to transmit data of the service corresponding to the first PDU session to the UE, and the continuity of the service cannot be guaranteed.

[0155] Therefore, the AMF does not need to send the paging message to the RAN 2. In other words, the current paging procedure has redundant signaling interaction.

[0156] In another possible way, the RAN 2 initiates a redirection procedure to redirect the UE to the RAN 1 supporting the slice 1. However, this will bring additional signaling interaction.

[0157] Based on the above analysis, the embodiments of the present application provide a cell selection method and a paging method. In the cell selection method, when performing cell selection, the terminal device not only considers the signal measurement result of the cell, but also combines the cell selection auxiliary information of the terminal device, wherein the cell selection auxiliary information includes the identifier of one or more slices corresponding to the session and the slice capability information of the cell. The cell selection or cell reselection is performed according to the measurement result of the cell and the cell selection auxiliary information. In this way, the cell selected by the terminal for camping can support the slice corresponding to the session as much as possible. In addition, in the paging method, when paging the radio access network device, the access and mobility management function network element first screens out a target radio access network device set from a plurality of radio access network devices, wherein the radio access network devices in the target radio access network device set support the slice associated with the session to be sent downlink data. The access and mobility management function network element sends a paging message to the target radio access network device set. Therefore, the signaling is saved to a certain extent, the signaling transmission path is reduced, and the complexity of the paging procedure is reduced.

[0158] It should be noted that in the embodiments of the present application, the network slice can also be referred to as a slice, and both have the same meaning. In the embodiments of the present application, the identifier of the slice can also be replaced by other information uniquely indicating the network slice, such as the name of the network slice, the description of the network slice, etc.

[0159] Next, the technical solutions provided by the embodiments of the present application are introduced in combination with the drawings.

[0160] Embodiment one

[0161] The embodiments of the present application provide a cell selection method, please refer to Figure 4 , the flowchart of the method. In the following introduction process, the method is applied to Figure 1AFor example, the network architecture shown in Figure 1B. In addition, the method can be performed by a first communication device, which can be a terminal device, or a communication device capable of supporting the functions required by the terminal device to implement the method, such as components included in the terminal device, or a chip system in the terminal device, etc.

[0162] For ease of introduction, in the following, the cell selection method provided by the embodiments of the application is described in detail by taking the case where the method is performed by a terminal device. Among them, the terminal device performs cell selection in order to find a suitable cell for the terminal device to camp on as soon as possible. Generally, the timing of cell selection can be the process of terminal device power-on, or the process of terminal returning from IDLE state to connected state, or the process of terminal device searching for a higher level PLMN, or the case of RRC connection reestablishment, or the case of terminal device switching in connected state.

[0163] Figure 4 A cell selection flowchart provided by the embodiments of the application, the method can include the following steps.

[0164] Step 401, the terminal device acquires the measurement results of N cells.

[0165] For the acquisition of the measurement results of N cells, one possible way is that the terminal device performs cell measurement to obtain the measurement results of N cells. Illustratively, the terminal device can measure the received reference signal to obtain the measurement results of N cells. The measurement results include, for example, reference signal received power (RSRP), and can also include other information, wherein the reference signal corresponding to the reference signal received power can be the received power of the demodulation reference signal (DMRS) on the physical sidelink share channel (PSSCH) or the physical sidelink control channel (PSCCH). Another possible way is that in the handover process, the terminal device can receive an indication from the source radio access network device, and the indication includes the measurement results of N cells.

[0166] Step 402, the terminal device acquires cell selection assistance information.

[0167] Specifically, the specific content of the cell selection assistance information can be any one of the following four cases.

[0168] Case A, the cell selection assistance information includes the identities of L slices corresponding to M sessions of the terminal device and slice capability information of N cells, wherein the slice capability information of the N cells includes the identities of slices respectively supported by the N cells, and M, L and N are positive integers. The M sessions can be one session, or two or more sessions. The session can refer to a bearer, or a protocol data unit (PDU) session, or a public data network (PDN) connection, or a quality of service (QoS) flow, etc.

[0169] Case B, the cell selection assistance information includes the identities of L slices corresponding to M sessions of the terminal device and slice capability information of K radio access network devices, wherein the slice capability information of the K radio access network devices includes the identities of slices respectively supported by the K radio access network devices. It can also be said that the slice capability information of the K radio access network devices includes the identities of slices respectively supported by all cells covered by the K radio access network devices, that is, in Case B, the slices supported by a radio access network device include the slices supported by each cell covered by the radio access network device.

[0170] Case C, the cell selection assistance information includes allowed slice selection assistance information and slice capability information of N cells.

[0171] It should be noted that the allowed slice selection assistance information (allowed NSSAI) in the embodiments of the present application refers to the identities of slices allowed to be accessed by the terminal device. The allowed slice selection assistance information is used to indicate the slices that can be accessed by the terminal device in the current registration area.

[0172] The slice capability information of the N cells includes the identities of slices respectively supported by the N cells, and M, L and N are positive integers. The session can include a bearer, a protocol data unit (PDU) session, a public data network (PDN) connection, a quality of service (QoS) flow, etc.

[0173] Case D, the cell selection assistance information includes allowed slice selection assistance information and slice capability information of K radio access network devices, wherein the slice capability information of the K radio access network devices includes the identities of slices respectively supported by the K radio access network devices. It can also be said that the slice capability information of the K radio access network devices includes the identities of slices respectively supported by all cells covered by the K radio access network devices, that is, in Case D, the slices supported by a radio access network device include the slices supported by each cell covered by the radio access network device.

[0174] In this embodiment, the cell selection assistance information is mainly used to enable the terminal to determine the tendency of the cell selection target when performing cell selection or cell reselection. The identity of the slice is used to uniquely identify the network slice, and different network slices correspond to different identities of the slice. For example, the identity of the slice can be single network slice selection assistance information (S-NSSAI). In this step 402, the terminal device can obtain the cell selection assistance information in the following ways:

[0175] In one aspect, the wireless access network device sends a broadcast message, and the terminal device can receive the broadcast message from the surrounding wireless access network device, wherein the broadcast message can include the slice capability information of the wireless access network device or the cell. For example, the slice capability information of the cell includes the identity of the cell (cell ID) and the identity of the slice corresponding to the cell, or the slice capability information of the wireless access network device includes the identity of the wireless access network device (RAN ID) and the identity of the slice corresponding to the wireless access network device.

[0176] In another aspect, for the above case A or case B, the terminal device can save the identities of the L slices corresponding to the M sessions during the establishment of the M sessions; or the network device saves the identities of the L slices corresponding to the M sessions during the establishment of the M sessions, and the terminal device can obtain the identities of the L slices corresponding to the M sessions from the network device. For example, during the establishment of a PDU session, the UE or the AMF or the SMF saves the correspondence between the identity of the PDU session (PDU session ID) and the identity of the slice (S-NSSAI index), so the UE can determine the identity of the slice corresponding to the PDU session. For the above case C or case D, the terminal device can obtain the allowed slice selection assistance information from the network device (such as AMF) in the registration process. The S-NSSAI corresponding to the M sessions (such as PDU sessions) initiated by the terminal device is included in the allowed NSSAI.

[0177] In step 403, the terminal device performs cell selection or cell reselection according to the measurement results of the N cells and the cell selection assistance information.

[0178] In a first possible implementation, when the specific content of the cell selection assistance information is as shown in case A, the terminal device can determine candidate target cells for cell selection or cell reselection according to the measurement results of the N cells. Then, the terminal device selects a target cell from the candidate target cells in any one of the following manners A, B or C. It should be noted that when the specific content of the cell selection assistance information is as shown in case A, the terminal device can also directly determine the target cell from the N cells, that is, the process of determining the candidate target cells by the terminal device is optional.

[0179] For example, the process in which the terminal device determines the candidate target cells for cell selection or cell reselection according to the measurement results of the N cells can be that the terminal device selects the candidate target cells from the N cells according to the cell selection criterion or the cell reselection criterion.

[0180] For example, the cell selection criterion or the cell reselection criterion can be the following criterion, and the formula is as follows:

[0181] The terminal device can only select to camp on the cell when Srxlev>0 and Squal>0. Wherein:

[0182] Srxlev=Qrxlevmeas-(Qrxlevmin+Qrxlevminoffset)-Pcompensation

[0183] Squal=Qqualmeas-(Qqualmin+Qqualminoffset)(RSRP or RSRQ reaches a certain threshold)

[0184] Wherein, Qrxlevmeas represents the measured cell received signal level value, that is, RSRP; Qrxlevmin represents the minimum received signal level value of the cell broadcast in SIB1, which represents the minimum downlink RSRP power value required to be satisfied by the terminal device to accept the signal of the cell; Qrxlevminoffset represents the minimum received signal level offset value of the cell broadcast in SIB1; Pcompensation represents the consideration of the uplink signal strength, which is obtained by comparing the maximum transmission power of the terminal device and the maximum transmission power allowed by the cell; Srxlev represents the cell selection received power value; and Squal represents the cell selection quality value.

[0185] Further, based on the selected candidate target cells, the terminal device selects a target cell from the candidate target cells in any one of the following manners A, B or C.

[0186] Manner A: selecting a cell supporting L slices as the target cell.

[0187] Exemplarily, when it is determined that there is a target cell in the candidate target cells that supports L slices, the terminal device selects the target cell.

[0188] Exemplarily, assuming that the UE establishes 3 PDU sessions, PDU session 1 corresponds to slice 1, PDU session 2 corresponds to slice 2, and PDU session 3 corresponds to slice 3. If the UE determines that the target cell of the candidate target cell supports slice 1, slice 2 and slice 3 at the same time, the target cell is selected when cell selection or cell reselection is performed. In this way, even if the terminal device switches from other cells to the target cell, the terminal device can restore the user plane connection of the original PDU session because the target cell still supports the PDU session established before the terminal device switches, thereby ensuring the service continuity of the terminal.

[0189] Option B, selecting a cell that supports the slice with the highest priority among the L slices as the target cell.

[0190] Exemplarily, when it is determined that there is no target cell in the candidate target cells that supports L slices, the terminal device selects a target cell that supports the first slice from the candidate target cells according to the cell selection assistance information and the priority of the L slices, wherein the first slice is the slice with the highest priority among the L slices.

[0191] The priority of the L slices can be obtained according to preconfigured information, or obtained from the network device side during network registration, or obtained from the network device side during the establishment of M sessions, or in other words, the priority of the slice of each session is obtained from the network device side during the establishment of each session, and finally the priority of the L slices of the M sessions is obtained.

[0192] Exemplarily, assuming that the UE establishes 3 PDU sessions, PDU session 1 corresponds to slice 1, PDU session 2 corresponds to slice 2, and PDU session 3 corresponds to slice 3. The UE needs to consider the priority of the slice when performing cell selection, and selects a target cell that supports the first slice from the candidate target cells according to the priority of the slice. Optionally, the UE determines that there is no cell that supports slice 1, slice 2 and slice 3 at the same time, and considers the priority of the slice when performing cell selection. In this way, even if the terminal device switches from other cells to the target cell, the target cell has the highest priority, so it is most likely to support the PDU session established before the terminal device switches, so that the terminal device is most likely to restore the user plane connection of the PDU session of the terminal device after accessing the target cell, thereby ensuring the service continuity of the terminal.

[0193] Exemplarily, the UE can obtain the priority of the slice in any one or combination of the following ways.

[0194] Manner 1: The UE is pre-configured with the slice identifier and the priority corresponding to the slice locally, and the UE obtains the priority of the slice from the pre-configured information locally.

[0195] Manner 2: In the UE-initiated registration procedure, the AMF obtains the priority corresponding to the slice from the local or from the UDM or PCF, and sends it to the UE, so that the UE obtains the priority of the slice.

[0196] Manner 3: In the UE-initiated PDU session establishment procedure, the SMF obtains the priority corresponding to the slice from the local or from the UDM or PCF, and sends it to the UE, so that the UE obtains the priority of the slice.

[0197] Manner C, select the cell supporting the largest number of L slices as the target cell.

[0198] For example, when it is determined that there is no target cell supporting L slices in the candidate target cell, the terminal device selects the target cell with the largest intersection number from the candidate target cell according to the cell selection assistance information, the intersection number between each cell supported slice and L slices.

[0199] For example, assuming that the UE has established 3 PDU sessions, PDU session 1 corresponds to slice 1, PDU session 2 corresponds to slice 2, and PDU session 3 corresponds to slice 3. The UE determines that cell 1 in the candidate target cell supports slice 1 and slice 2, cell 2 supports slice 2, and cell 3 supports slice 3. As shown in Table 6 below. Since the intersection number between cell 1 and slice 1, slice 2 and slice 3 is 2, and the intersection number between cell 2 and cell 3 and slice 1, slice 2 and slice 3 is 1, the UE selects cell 1 as the target cell from the candidate target cell. Alternatively, the UE determines that there is no cell that supports slice 1, slice 2 and slice 3 at the same time, and selects the target cell according to the above method. In this way, even if the terminal device switches from other cells to cell 1, cell 1 is most likely to support the PDU session established by the terminal device before switching, so that the terminal device can most likely restore the user plane connection of the PDU session of the terminal device after accessing the target cell, thereby ensuring the service continuity of the terminal.

[0200] Table 6

[0201] Cell Slice Cell 1 Slice 1, Slice 2 Cell 2 Slice 2 Cell 3 Slice 3

[0202] In the second possible implementation, when the specific content of the cell selection assistance information is as shown in case B, the terminal device can determine candidate target radio access network devices for cell selection or cell reselection according to the measurement results of the N cells, and then select a cell of a target radio access network device from the candidate target radio access network devices according to any one of the following manner D, manner E or manner F. It should be noted that when the specific content of the cell selection assistance information is as shown in case B, the terminal device can also directly determine a target radio access network device from the N radio access network devices, that is, the process of determining the candidate target radio access network devices is optional.

[0203] Manner D: selecting a radio access network device supporting L slices as the target radio access network device, and selecting a cell of the target radio access network device as the target cell.

[0204] For example, when it is determined that there is a target radio access network device supporting L slices in the candidate target radio access network devices, the terminal device selects a cell covered by the target radio access network device as the target cell.

[0205] For example, it is assumed that the UE establishes 3 PDU sessions, PDU session 1 corresponds to slice 1, PDU session 2 corresponds to slice 2, and PDU session 3 corresponds to slice 3. If the UE determines that a target RAN in the candidate target RANs simultaneously supports slice 1, slice 2 and slice 3, a cell of the target RAN is selected in cell selection or cell reselection. In this way, even after the terminal device switches from other cells to the cell of the target RAN, the cell of the target RAN still supports the PDU sessions established before the terminal device switches, so that the terminal device can restore the user plane connection of the original PDU session, thereby ensuring the service continuity of the terminal.

[0206] Manner E: selecting a radio access network device supporting a slice with the highest priority among L slices as the target radio access network device, and selecting a cell of the target radio access network device as the target cell.

[0207] For example, when it is determined that there is no target radio access network device supporting L slices in the candidate target radio access network devices, a target radio access network device supporting a first slice is selected from the candidate target radio access network devices according to the cell selection assistance information and the priorities of the L slices, and a cell covered by the target radio access network device is determined as the target cell. The first slice is a slice with the highest priority among the L slices. The manner of obtaining the priorities of the L slices can be referred to the above manner B, which is not repeated here.

[0208] Exemplarily, assuming that the UE establishes 3 PDU sessions, PDU session 1 corresponds to slice 1, PDU session 2 corresponds to slice 2, and PDU session 3 corresponds to slice 3. The UE needs to consider the priority of the slice when performing cell selection, and select a target RAN supporting the first slice from the candidate target RAN according to the priority of the slice. Optionally, the UE determines that there is no wireless access network device supporting slice 1, slice 2 and slice 3 at the same time, and considers the priority of the slice when performing cell selection. In this way, even if the terminal device performs cell switching, the target RAN cell supports the slice with the highest priority, so the terminal device is most likely to support the PDU session established before the terminal device switches, and thus the terminal device is most likely to restore the user plane connection of the PDU session of the terminal device after accessing the cell of the target RAN, thereby ensuring the service continuity of the terminal.

[0209] Optionally, the method comprises the following steps.

[0210] Exemplarily, when it is determined that there is no target wireless access network device supporting L slices in the candidate target wireless access network device, the terminal device selects a target wireless access network device with the largest number of intersection sets from the candidate target wireless access network device according to the cell selection assistance information, and the number of intersection sets between each wireless access network device supported slice and L slices.

[0211] Exemplarily, assuming that the UE establishes 3 PDU sessions, PDU session 1 corresponds to slice 1, PDU session 2 corresponds to slice 2, and PDU session 3 corresponds to slice 3. The UE determines that RAN1 in the candidate target RAN supports slice 1 and slice 2, RAN2 supports slice 2, and RAN3 supports slice 3. Optionally, when it is determined that there is no cell supporting slice 1, slice 2 and slice 3 at the same time, the target cell is selected according to the above method. As shown in Table 7 below. Because the number of intersection sets between RAN1 and slice 1, slice 2 and slice 3 is 2, and the number of intersection sets between RAN2 and RAN3 and slice 1, slice 2 and slice 3 is 1, the UE selects RAN1 as the target RAN from the candidate target RAN. In this way, even if the terminal device switches from other cells to the cell in RAN1, because RAN1 most likely supports the PDU session established before the terminal device switches, the terminal device is most likely to restore the user plane connection of the PDU session of the terminal device after accessing the target RAN, thereby ensuring the service continuity of the terminal.

[0212] Table 7

[0213] RAN Slice RAN1 Slice 1, Slice 2 RAN2 Slice 2 RAN3 Slice 3

[0214] Exemplarily, the method shown in the above Figure 4 is combined with the method shown in Figure 3In the illustrated scenario, the UE is initially located in the coverage of RAN1, the UE establishes a first PDU session, and accesses slice 1. Then, the UE moves and is located in the coverage of RAN2. Since the location of the UE has changed, the UE needs to perform cell selection again. In this case, the UE considers not only the signal measurement result but also the assistance information of the cell. It is assumed that the cells covered by RAN1 include cell 1 and cell 2, the cells covered by RAN2 include cell 3 and cell 4, and the slice capability information of the four cells is shown in Table 8.

[0215] Table 8

[0216]

[0217] As can be seen from Table 8, among the above four cells, the cells supporting slice 1 corresponding to the first PDU session are cell 1 and cell 3. Therefore, UE 1 selects to switch from cell 1 to cell 3, and the terminal device selects to camp on cell 3, which supports the slice corresponding to the session, so that the normal transmission of the service can be ensured.

[0218] In the embodiments of the present application, the terminal device can select a cell that is more suitable for camping based on the cell selection assistance information and the signal measurement result. In this way, the terminal device selects to camp on a cell that maximally supports the slice corresponding to the session, so that the normal transmission of the service can be ensured with the maximum probability. Compared with the prior art, the service discontinuity caused by cell switching can be avoided to some extent, and the cell resources can be used as fully and reasonably as possible.

[0219] In the third possible implementation, when the specific content of the cell selection assistance information is as shown in case C, the terminal device can determine the candidate target cell for cell selection or cell reselection according to the measurement results of the N cells. Then, the terminal device selects the target cell from the candidate target cells in any one of the following ways A, B or C. It should be noted that in this implementation, the "L slices corresponding to the M sessions of the terminal device" or "L slices" in ways A, B and C are replaced by "slices allowed to be accessed by the terminal device".

[0220] It should be noted that when the specific content of the cell selection assistance information is as shown in case C, the terminal device can also directly determine the target cell from the N cells, that is, the process of determining the candidate target cell by the terminal device is optional.

[0221] In a fourth possible implementation, when the specific content of the cell selection assistance information is as shown in case D, the terminal device can determine candidate target radio access network devices for cell selection or cell reselection according to the measurement results of the N cells, and then the terminal device selects a cell of a target radio access network device from the candidate target radio access network devices in any one of the following manners D, E or F. It should be noted that in this implementation, the "L slices corresponding to the M sessions of the terminal device" or "L slices" in the manners D, E and F are replaced by "slices allowed to be accessed by the terminal device", and the "slices corresponding to the sessions" are replaced by "slices allowed to be accessed by the terminal device".

[0222] It should be noted that when the specific content of the cell selection assistance information is as shown in case D, the terminal device can also directly determine the target radio access network device from the N radio access network devices, that is, the process of determining the candidate target radio access network device by the terminal device is optional.

[0223] It should be noted that the method described in the above steps 401 to 403 can also be performed by other communication devices. For example, the radio access network device can perform the above steps 401 to 403, and in this case the radio access network device in step 402 can obtain the measurement results of the N cells, the slice capability information of the N cells or the slice capability information of the K radio access network devices in at least one of the following ways:

[0224] from the terminal device, locally configured, from other radio access network devices, from a radio access network management device.

[0225] Embodiment two

[0226] The embodiment of the present application provides a paging method, please refer to Figure 5 , which is a flowchart of the method. In the following introduction process, the network architecture shown in Figure 1A or Figure 1B is taken as an example. In addition, the method can be performed by a second communication device, which can be an access and mobility management function network element, or a communication device capable of supporting the functions required by the access and mobility management function network element to implement the method, such as components included in the access and mobility management function network element, or a chip system in the access and mobility management function network element.

[0227] For ease of introduction, in the following, the paging method provided by the embodiment of the present application is described in detail by taking the example that the method is performed by AMF, SMF and RAN network elements. Among them, the paging process is to restore the connection between the terminal and the core network, so that the terminal enters the connected (Connect) state.

[0228] Figure 5 A flowchart of a paging method provided by an embodiment of the present application is shown. The method can include the following steps.

[0229] In step 501, the AMF obtains first slice information from K RANs. The first slice information is used to indicate the slices supported by the K RANs, and K is a positive integer.

[0230] For example, the AMF obtaining the first slice information from the K RANs includes the following steps: in step a, when the K RANs are powered on, the K RANs initiate an NG setup request message to the AMF. In this process, the K RANs send the identity of the RAN (such as RAN ID), the identity of the cell (such as cell ID), or the identity of the slice (S-NSSAI) supported by the cell to the AMF. In step b, the AMF saves the correspondence between the cell and the slice identity, generates the first slice information, or the AMF saves the correspondence between the RAN and the slice identity. In step c, the AMF sends an NG setup response message to the K RANs. The identity of the slice can also be identified by an index value, that is, after the AMF obtains the slice index value from the RAN, the AMF determines the slice supported by the RAN according to the correspondence between the index value and the slice configured locally.

[0231] In step 502, the SMF receives a first data notification message from the UPF. The first data notification message indicates that the first session of the terminal device has downlink data to be transmitted.

[0232] For example, after the UPF receives the downlink data (DL Data) of the first session, the UPF sends a data notification (or simply DN message) to the SMF, carrying the N4 session ID.

[0233] In step 503, the SMF sends second slice information to the AMF. The second slice information is used to indicate the slice associated with the session to be transmitted downlink data.

[0234] In one possible embodiment, the second slice information includes the identity of the first session.

[0235] For example, the SMF sends a Namf_Communication_N1N2MessageTransfer (N11 message) to the AMF, which contains SUPI, PDU session ID, N1 SM container, and N2 SM info.

[0236] In another possible embodiment, the second slice information includes the identity of the slice corresponding to the first session.

[0237] Exemplarily, the SMF sends a Namf_Communication_N1N2MessageTransfer (N11 message) to the AMF, and the N11 message further includes the S-NSSAI.

[0238] At step 504, the AMF determines a target RAN set or a target cell set from the K RANs according to the first slice information and the second slice information.

[0239] The target RAN supports a slice associated with a session of the to-be-sent downlink data indicated by the second slice information, or the target cell set supports the slice associated with the session of the to-be-sent downlink data indicated by the second slice information.

[0240] In a possible embodiment, when the second slice information includes an identifier of the first session, the AMF further needs to determine the slice corresponding to the first session according to the identifier of the first session.

[0241] In another possible embodiment, when the second slice information includes an identifier of the slice corresponding to the first session, the AMF can determine the slice corresponding to the first session according to the second slice information.

[0242] At step 505, the AMF sends a first paging message to the target RAN set, or the AMF sends the first paging message to the target RAN set corresponding to the target cell set.

[0243] Optionally, the first paging message includes an identifier of a RAN in the target RAN set.

[0244] Exemplarily, in combination with the scenario shown in Figure 6 , in the scenario, the UE is initially located in a coverage range of RAN1, the UE establishes a first PDU session, and accesses slice 1. Since the UE has not interacted with the network side for a long time, the UE enters an IDLE state and releases a user plane connection between the UE and the core network. RAN1 supports slice 1 and slice 2; RAN2 supports slice 2 and slice 3; and RAN3 supports slice 1 and slice 4. It is assumed that RAN1 to RAN3 are all located in a registration area. As shown in Table 9.

[0245] Table 9

[0246] RAN Slice RAN1 Slice 1, Slice 2 RAN2 Slice 2, Slice 3 RAN3 Slice 1, Slice 4

[0247] It is assumed that, at this time, downlink data arrives at the UPF, triggering paging of the UE. As shown in Figure 6 , the AMF determines that the target RAN set is RAN1 and RAN3, and thus sends a first paging message to RAN1 and RAN3. According to Figure 6In the scenario shown in FIG. 10, the UE is initially located in the coverage of RAN1, the UE establishes a first PDU session and accesses slice 1, and because the UE has not interacted with the network side for a long time, the UE enters an IDLE state and releases the user plane connection between the UE and the core network. Among them, cell 1 and cell 2 support slice 1 and slice 2; cell 3 and cell 4 support slice 2 and slice 3; and cell 5 supports slice 1 and slice 4. As shown in Table 10.

[0248] In another example, in the scenario shown in FIG. 10, the UE is initially located in the coverage of RAN1, the UE establishes a first PDU session and accesses slice 1, and because the UE has not interacted with the network side for a long time, the UE enters an IDLE state and releases the user plane connection between the UE and the core network. Among them, cell 1 and cell 2 support slice 1 and slice 2; cell 3 and cell 4 support slice 2 and slice 3; and cell 5 supports slice 1 and slice 4. As shown in Table 10. Figure 6

[0249] Table 10

[0250]

[0251] Suppose that there is downlink data to the UPF at this time, which triggers paging of the UE. As shown in FIG. 11, the AMF determines that the target cell set is cell 1, cell 2 and cell 5, and therefore the AMF sends a first paging message to RAN1 and RAN3 corresponding to cell 1, cell 2 and cell 5. Assuming that the UE is paged under RAN3, the UE will initiate a service request procedure through RAN3 to restore the user plane connection corresponding to the first PDU session. Compared with the prior art, in the embodiment, because RAN2 does not support slice 1 corresponding to the first PDU session, the AMF does not need to send the first paging message to RAN2, thereby saving signaling, reducing the signaling transmission path, and improving paging efficiency. Figure 6 Step 506: The target RAN receiving the first paging message sends a second paging message to the terminal device. The second paging message includes the identity of the terminal device being paged.

[0252] Step 507: The terminal device receives the second paging message sent by the target RAN. When the paging identity in the second paging message carries the identity of the terminal device itself, the terminal device responds to the paging message, that is, initiates a service request procedure.

[0253] Optionally, before the terminal device initiates the service request procedure, that is, during the process of activating the user plane connection of the terminal device, the method embodiment can further include the following steps:

[0254]

[0255] ​​At step 508, the SMF receives a second data notification message from the UPF. The second data notification message indicates that there is downlink data to be transmitted for a second session of the terminal device. In this case, the SMF can continue to perform steps 509-510 before the SMF learns that the terminal device initiates the service request procedure.

[0256] At step 509, the SMF determines whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session. If yes, step 510 is performed; otherwise, the SMF does not respond, i.e., does not send a notification message to the AMF, and thus the AMF does not page the RAN again.

[0257] At step 510, the SMF sends an identifier of the second session or an identifier of the slice corresponding to the second session to the AMF. The identifier of the second session or the identifier of the slice corresponding to the second session is used for paging the terminal device.

[0258] For example, the AMF determines a target RAN according to the received identifier of the second session or the identifier of the slice corresponding to the second session, and sends a paging message to the target RAN to page the terminal device.

[0259] The process of determining the target RAN by the AMF and sending the paging message to the target RAN to page the terminal device can refer to the description in steps 504 and 505, which will not be repeated here.

[0260] Optionally, after receiving the identifier of the second session or the identifier of the slice corresponding to the second session, the AMF determines whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session. If yes, the AMF determines a target RAN and sends a paging message to the target RAN to page the terminal device. The reason why the AMF determines the priority of the slice corresponding to the second session is that the first session and the second session correspond to different SMFs. Assuming that the first session corresponds to SMF1 and the second session corresponds to SMF2, at this time, SMF2 cannot determine whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session after receiving the second data notification message from the UPF. Therefore, at this time, the AMF can determine whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session. In other words, in this scenario, SMF1 performs steps 502-503, SMF2 performs steps 508 and 510, and SMF2 cannot perform step 509.

[0261] In the embodiments of the present application, the AMF filters the K RANs based on the first slice information and the second slice information, so that the target RAN set filtered can save signaling, reduce the signaling transmission path, and reduce the complexity of the paging process. In addition, in the user plane connection activation process of the terminal device, the SMF only instructs the AMF to initiate paging when the priority of the slice of the received downlink data is higher, which can further reduce the signaling overhead and ensure timely paging of the terminal device.

[0262] Embodiment three

[0263] The second paging method provided in the embodiments of the present application can include the following steps. Figure 7 The second paging method provided in the embodiments of the present application can include the following steps.

[0264] Step 701, the SMF receives a first data notification message from the UPF. The first data notification message indicates that the first session of the terminal device has downlink data to be transmitted.

[0265] Exemplarily, after the UPF receives the downlink data (DL Data) of the first session, the UPF sends a data notification (or simply DN message) to the SMF, carrying an N4 session ID.

[0266] Step 702, the SMF sends second slice information to the AMF. The second slice information is used to indicate the slice associated with the session to be sent downlink data.

[0267] In one possible embodiment, the second slice information is an identifier of the first session.

[0268] Exemplarily, the SMF sends Namf_Communication_N1N2MessageTransfer (abbreviated as N11 message) to the AMF, which contains SUPI, PDU session ID, N1 SM container, and N2 SM info.

[0269] In another possible embodiment, the second slice information is an identifier of the slice corresponding to the first session.

[0270] Exemplarily, the SMF sends Namf_Communication_N1N2MessageTransfer (abbreviated as N11 message) to the AMF, which also includes the identifier (such as S-NSSAI) of the slice corresponding to the first session.

[0271] At step 703, the AMF sends a first paging message to the K RANs. The first paging message carries the identifier of the slice corresponding to the first session.

[0272] For example, the first paging message carries the S-NSSAI.

[0273] At step 704, the RAN determines whether the slice corresponding to the first session is included in the slices supported by the RAN. If yes, the RAN performs step 705; otherwise, the RAN does not respond, i.e., does not send a second paging message to the UE.

[0274] At step 705, the RAN sends a second paging message to each terminal device residing in the RAN. The second paging message includes the identifier of the terminal device being paged.

[0275] At step 706, the terminal device receives the second paging message. When the paging identifier in the second paging message carries the identifier of the terminal device, the terminal device responds to the paging message, i.e., initiates a service request procedure.

[0276] It should be noted that before performing step 706, i.e., before the terminal device initiates the service request procedure, i.e., during the process of waiting for the user plane connection of the terminal device to be activated, the SMF can further perform the following steps:

[0277] At step 707, the SMF further receives a second data notification message from the UPF. The second data notification message indicates that the second session of the terminal device has downlink data to be transmitted.

[0278] At step 708, the SMF determines whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session. If yes, the SMF performs step 709; otherwise, the SMF does not respond, i.e., does not send a notification message to the AMF, and thus the AMF does not page the RAN again.

[0279] At step 709, the SMF sends the identifier of the second session or the identifier of the slice corresponding to the second session to the AMF. The identifier of the second session is used for paging the terminal device.

[0280] Optionally, after receiving the identifier of the second session or the identifier of the slice corresponding to the second session, the AMF determines whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session. If yes, the AMF sends the paging message to the target RAN again to page the terminal device. The reason why the AMF determines the priority of the slice corresponding to the session is that the first session and the second session correspond to different SMFs. Assuming that the first session corresponds to SMF1 and the second session corresponds to SMF2, at this time, SMF2 cannot determine whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session after receiving the second data notification message from the UPF. Therefore, at this time, the AMF can determine whether the priority of the slice corresponding to the second session is higher than the priority of the slice corresponding to the first session. In other words, in this scenario, SMF1 performs the method steps 701 to 702, SMF2 performs the method steps 707 and 709, and SMF2 cannot perform the step 708.

[0281] In the embodiments of the present application, the RAN determines whether the terminal device needs to be paged based on the identifier of the slice corresponding to the first session obtained from the network device. In the case where the RAN itself does not support the slice corresponding to the first session, the terminal device is no longer paged, so that the signaling can be saved to a certain extent, the signaling transmission path is reduced, and the complexity of the paging process is reduced. In addition, in the user plane connection activation process of the terminal device, the SMF instructs the AMF to initiate paging only in the case where the priority of the slice of the received downlink data is higher, which can further reduce the signaling overhead and ensure that the terminal device is paged in time.

[0282] For the above-mentioned embodiments one to three, it needs to be explained that: (1) the above-mentioned embodiments one to three can be implemented individually in different scenarios, or can be implemented in combination in the same scenario, or different schemes involved in different embodiments can also be implemented in combination (for example, part or all of the schemes involved in embodiment one can be implemented in combination with embodiment two), and the specific implementation is not limited.

[0283] (2) The step numbers of each flowchart described in the embodiments of the present application are only an example of the execution flow, and do not constitute a limitation on the execution sequence of the steps. There is no strict execution order between the steps that have no time sequence dependency relationship in the embodiments of the present application.

[0284] To implement the functions in the cell selection method and the paging method provided in the embodiments of the present application, the terminal can include hardware structures and / or software modules to implement the above functions in the form of hardware structure, software module, or hardware structure and software module. Whether a certain function in the above functions is implemented in the form of hardware structure, software module, or hardware structure and software module depends on specific application and design constraints of the technical solutions.

[0285] The embodiments of the present application also provide a first communication device 800 for implementing the functions of the terminal device in the above method. For example, the first communication device 800 can be a terminal device in the above method, and can also be a device in the terminal device. The device can be a chip system. In the embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices. Figure 4

[0286] As shown in Figure 8 , the first communication device 800 includes a processing unit 801 and a transceiver unit 802.

[0287] For the method shown in Figure 4 , the transceiver unit 802 is configured to obtain measurement results of N cells and obtain cell selection assistance information. The cell selection assistance information includes identifiers of L slices corresponding to M sessions of the terminal device and slice capability information of the N cells, and the slice capability information of the N cells includes identifiers of slices supported by the N cells respectively, or the cell selection assistance information includes slice capability information of K radio access network devices corresponding to the M sessions of the terminal device, and the slice capability information of the K radio access devices includes identifiers of slices supported by the K radio access network devices respectively. For specific contents of the cell selection assistance information, please refer to the cases A to B in the first embodiment, which will not be repeated here. In addition, the specific acquisition method of the cell selection assistance information can also be referred to the introduction of the first embodiment.

[0288] The processing unit 801 is configured to perform cell selection or cell reselection according to the measurement results of the N cells and the cell selection assistance information.

[0289] In some embodiments, the processing unit 801 is configured to determine candidate target cells for cell selection or cell reselection according to the measurement results of the N cells, and select target cells supporting the L slices from the candidate target cells according to the cell selection assistance information.

[0290] In some embodiments, when the processing unit 801 selects target cells supporting the L slices from the candidate target cells according to the cell selection assistance information, it specifically performs:

[0291] ​determining whether there is a target cell supporting the L slices in the candidate target cells; if there is, selecting the target cell; otherwise, selecting a target cell supporting a first slice from the candidate target cells according to the cell selection assistance information and the priority of the L slices, the first slice being a slice with the highest priority among the L slices.

[0292] In some embodiments, the processing unit 801 is configured to determine candidate target radio access network devices for cell selection or cell reselection according to the measurement results of the N cells; and select a target radio access network device supporting the L slices from the candidate target radio access network devices according to the cell selection assistance information.

[0293] In some embodiments, when selecting a target cell supporting the L slices from the candidate target cells according to the cell selection assistance information, the processing unit 801 is specifically configured to:

[0294] determining whether there is a target radio access network device supporting the L slices in the candidate target radio access network devices; if there is, selecting the target radio access network device; otherwise, selecting a target radio access network device supporting a first slice from the candidate target radio access network devices according to the cell selection assistance information and the priority of the L slices, the first slice being a slice with the highest priority among the L slices.

[0295] In some embodiments, the transceiver 802 is further configured to obtain the priority of the L slices according to pre-configuration information; or obtain the priority of the L slices from a network device side in a network registration process.

[0296] In yet another example, for the method shown in the above Figure 4 The transceiver 802 of the first communication device is configured to obtain the measurement results of the N cells and obtain the cell selection assistance information. The cell selection assistance information includes allowed slice selection assistance information and slice capability information of the N cells. The allowed slice selection assistance information is used to indicate the slices that the terminal device can access in the current registration area, and the allowed slice selection assistance information can include the slices corresponding to the M sessions of the terminal device. The slice capability information of the N cells includes the identification of the slices supported by the N cells respectively, or the slice capability information of the K radio access network devices. The specific content of the cell selection assistance information can refer to the cases C to D in the above embodiment one, which will not be repeated here. In addition, the specific acquisition method of the cell selection assistance information can also refer to the above description of the embodiment one.

[0297] The processing unit 801 is configured to perform cell selection or cell reselection according to the measurement results of the N cells and the cell selection assistance information.

[0298] In some embodiments, the processing unit 801 is configured to determine candidate target cells for cell selection or cell reselection according to measurement results of the N cells; and select a target cell supporting a slice that allows the terminal device to access from the candidate target cells according to the cell selection assistance information.

[0299] In some embodiments, when the processing unit 801 selects a target cell supporting a slice that allows the terminal device to access from the candidate target cells according to the cell selection assistance information, the processing unit 801 is specifically configured to:

[0300] determine whether there is a target cell supporting a slice that allows the terminal device to access in the candidate target cells; if so, select the target cell; otherwise, select a target cell supporting a first slice from the candidate target cells according to the cell selection assistance information and a priority of the slice that allows the terminal device to access, the first slice being a slice with the highest priority among the slices that allow the terminal device to access.

[0301] In some embodiments, the processing unit 801 is configured to determine candidate target radio access network devices for cell selection or cell reselection according to measurement results of the N cells; and select a target radio access network device supporting a slice that allows the terminal device to access from the candidate target radio access network devices according to the cell selection assistance information.

[0302] In some embodiments, when the processing unit 801 selects a target cell supporting a slice that allows the terminal device to access from the candidate target cells according to the cell selection assistance information, the processing unit 801 is specifically configured to:

[0303] determine whether there is a target radio access network device supporting a slice that allows the terminal device to access in the candidate target radio access network devices; if so, select the target radio access network device; otherwise, select a target radio access network device supporting a first slice from the candidate target radio access network devices according to the cell selection assistance information and a priority of the slice that allows the terminal device to access, the first slice being a slice with the highest priority among the slices that allow the terminal device to access.

[0304] In some embodiments, the transceiver 802 is further configured to: obtain the priority of the slice that allows the terminal device to access according to pre-configuration information; or obtain the priority of the slice that allows the terminal device to access from a network device side in a network registration process.

[0305] For specific implementation process and beneficial effects of the processing unit 801 and the transceiver 802, refer to the description in the above Figure 4 related method.

[0306] The embodiment of the present application further provides a second communication device 900, which is used to implement the function of the access and mobility management function network element in the above method. The second communication device 900 may, for example, be the access and mobility management function network element or a device in the access and mobility management function network element. The device may be a chip system. In the embodiment of the present application, the chip system may be composed of a chip or may include the chip and other discrete devices.

[0307] In an example, as shown in Figure 9 The second communication device 900 includes a processing unit 901 and a transceiver unit 902.

[0308] For the method shown above, Figure 5 The transceiver unit 902 is configured to obtain the first slice information and the second slice information. The specific content of the first slice information and the second slice information can be referred to the above embodiment two.

[0309] The processing unit 901 is configured to determine a target radio access network device set from the K radio access network devices according to the first slice information and the second slice information, and the radio access network devices in the target radio access network device set support the slice indicated by the second slice information. Alternatively, the processing unit 901 is configured to determine a target cell set from the N cells according to the first slice information and the second slice information, and the target cell set includes a target cell supporting the slice indicated by the second slice information.

[0310] The transceiver unit 902 is further configured to send a paging message to the target radio access network device set. Alternatively, the transceiver unit 902 is configured to send a paging message to the radio access network devices corresponding to the target cell set.

[0311] In some possible embodiments, when obtaining the first slice information, the transceiver unit 902 is specifically configured to receive the identification of the slice from the K radio access network devices; and the processing unit 901 is further configured to determine the first slice information according to the identification of the slice.

[0312] In some possible embodiments, when obtaining the second slice information, the transceiver unit 902 is specifically configured to receive the identification of the slice from the session management function network element; and the processing unit 901 is further configured to determine the second slice information according to the identification of the slice.

[0313] In some possible embodiments, when obtaining the second slice information, the transceiver unit 902 is specifically configured to receive the session identification of the to-be-sent downlink data from the session management function network element; and the processing unit 901 is further configured to determine the second slice information according to the slice corresponding to the session identification of the to-be-sent downlink data.

[0314] In some possible embodiments, the first slice information is used to indicate slices supported by N cells of K radio access network devices, K and N are positive integers, and the processing unit 901 is specifically configured to: determine, according to the first slice information and the second slice information, a target cell set in a target radio access network device set from the N cells of the K radio access network devices; and wherein the identification of the target cell in the target cell set is included in the paging message.

[0315] For specific implementation processes and beneficial effects of the processing unit 901 and the transceiver unit 902, refer to the descriptions in the foregoing Figure 5 related method.

[0316] Embodiments of the present application further provide a third communication apparatus 1000 configured to implement the functions of the session management function network element in the foregoing method. For example, the third communication apparatus 1000 can be a session management function network element, or a device in the session management function network element. The apparatus can be a chip system. In embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices.

[0317] In an example, as shown in Figure 10 the third communication apparatus 1000 includes a processing unit 1001 and a transceiver unit 1002.

[0318] For the method shown in the foregoing Figure 7 , the transceiver unit 1002 acquires a first data notification message, the first data notification message indicating that a first session of a terminal device has downlink data to be transmitted, and sends an identification of the first session to an access and mobility management function network element, the identification of the first session being used for paging of the terminal device.

[0319] In the process of waiting for user plane connection of the terminal device to be activated, the transceiver unit 1002 receives a second data notification message from a user plane function network element, the second data notification message indicating that a second session of the terminal device has downlink data to be transmitted.

[0320] The processing unit 1001 is configured to determine that a priority of a slice corresponding to the second session is higher than a priority of a slice corresponding to the first session.

[0321] The transceiver unit 1002 is configured to send an identification of the second session to an access and mobility management function network element, the identification of the second session being used for paging of the terminal device.

[0322] In some possible embodiments, when it is determined that the priority of the slice corresponding to the second session is lower than or equal to the priority of the slice corresponding to the first session, no response is made.

[0323] For the specific execution process and beneficial effects of the processing unit 1001 and the transceiver unit 1002, please refer to the above Figure 7 Related methods are described.

[0324] The division of modules in the embodiments of the present application is illustrative and is merely a logical functional division. In actual implementation, other division methods may be used. Furthermore, the functional modules in the various embodiments of the present application may be integrated into a single processor, or may exist physically separately, or two or more modules may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0325] In another example, Figure 11 As shown, the first communication device 800, the second communication device 900 and the third communication device 1000 include at least one processor 1110 and a memory 1120. A computer program is stored in the memory 1120. The memory 1120 and the processor 1110 are coupled. The coupling in the embodiment of the present application is an interval coupling or communication connection between devices, units or modules, which can be electrical, mechanical or other forms, and is used for information exchange between devices, units or modules. As another implementation, the memory 1120 can also be located outside the first communication device 800, the second communication device 900 or the third communication device 1000. The processor 1110 can operate in conjunction with the memory 1120. The processor 1110 can call the computer program stored in the memory 1120. At least one of the at least one memory may be included in the processor.

[0326] In some embodiments, the first communication device 800, the second communication device 900, or the third communication device 1000 may further include a communication interface 1130 for communicating with other devices via a transmission medium, thereby enabling the devices in the first communication device 800, the second communication device 900, or the third communication device 1000 to communicate with the other devices. Exemplarily, the communication interface 1130 may be a transceiver, circuit, bus, module, or other type of communication interface, and the other device may be another terminal. The processor 1110 utilizes the communication interface 1130 to send and receive information and implement the methods in the above embodiments. Exemplarily, the communication interface 1130 is used to receive resource indication information. Furthermore, exemplary, the communication interface 1130 is used to send data.

[0327] In the embodiments of the present application, the processor can be a general processor, a digital signal processor, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a discrete gate or transistor logic device, a discrete hardware component, and can implement or execute the disclosed methods, steps and logic block diagrams in the embodiments of the present application. The general processor can be a microprocessor or any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as hardware processor execution or executed by a combination of hardware and software modules in the processor.

[0328] In the embodiments of the present application, the memory can be a non-volatile memory such as a hard disk drive (HDD) or a solid-state drive (SSD), and can also be a volatile memory such as a random-access memory (RAM). The memory can be any other medium capable of carrying or storing desired program code in the form of instructions or data structures and capable of being accessed by a computer, but is not limited to this. The memory in the embodiments of the present application can also be a circuit or any other device capable of realizing a storage function, used for storing computer programs and / or data.

[0329] The method provided by the embodiments of the present application can be implemented by software, hardware, firmware or any combination thereof, in whole or in part. When implemented by software, it can be implemented in the form of a computer program product in whole or in part. The computer program product includes one or more computer instructions. When the computer program is loaded and executed on a computer, the flow or function described in the embodiments of the present application is generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, a network device, a user equipment or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line (DSL)) or wireless (such as infrared, wireless, microwave, etc.) mode. The computer readable storage medium can be any medium that can be accessed by a computer or a data storage device such as a server, data center, etc. integrated with one or more media. The medium can be a magnetic medium (such as a floppy disk, a hard disk, a magnetic tape), an optical medium (such as a digital video disc (digital video disc, DVD)), or a semiconductor medium (such as an SSD), etc.

[0330] Obviously, many modifications and variations of the present application are possible in light of the above teachings. It is, therefore, to be understood that within the scope of the appended claims and their equivalents, the application can be practiced otherwise than as specifically described.

Claims

1. A cell selection method, characterized in that: The method comprises: Obtain measurement results of N cells; Obtain cell selection assistance information, where the cell selection assistance information includes identifiers of L slices corresponding to the M sessions of the terminal device and slice capability information of the N cells, where the slice capability information of the N cells includes identifiers of slices supported by the N cells, respectively, and M, L, and N are positive integers; Cell selection or cell reselection is performed according to the measurement results of the N cells and the cell selection auxiliary information.

2. The method according to claim 1, wherein The performing cell selection or cell reselection according to the measurement results of the N cells and the cell selection auxiliary information includes: determining a candidate target cell for cell selection or cell reselection according to the measurement results of the N cells; According to the cell selection auxiliary information, a target cell supporting the L slices is selected from the candidate target cells.

3. The method according to claim 2, wherein: Selecting, according to the cell selection auxiliary information, a target cell supporting L slices from the candidate target cells, including: Determining whether there is a target cell among the candidate target cells that supports the L slices; If so, selecting the target cell; Otherwise, based on the cell selection assistance information and the priorities of the L slices, a target cell supporting a first slice is selected from the candidate target cells, where the first slice is a slice with the highest priority among the L slices.

4. The method according to claim 3, wherein: The method further comprises: Obtaining the priorities of the L slices according to pre-configured information; or, Obtaining the priorities of the L slices from the network device side during the network registration process; or, During the establishment of the M sessions, the priorities of the L slices are obtained from the network device side.

5. A cell selection method, characterized in that: The method comprises: Obtain measurement results of N cells; Obtain cell selection assistance information, the cell selection assistance information including slice capability information and allowed slice selection assistance information of the N cells, wherein the allowed slice selection assistance information is an identifier of a slice allowed to be accessed by the terminal device, and the slice capability information of the N cells includes identifiers of slices respectively supported by the N cells, where N is a positive integer; Cell selection or cell reselection is performed according to the measurement results of the N cells and the cell selection auxiliary information.

6. The method according to claim 5, wherein: The performing cell selection or cell reselection according to the measurement results of the N cells and the cell selection auxiliary information includes: determining a candidate target cell for cell selection or cell reselection according to the measurement results of the N cells; According to the cell selection auxiliary information, a target cell that supports the slice that allows the terminal device to access is selected from the candidate target cells.

7. The method according to claim 6, wherein: Selecting, from the candidate target cells, a target cell that supports a slice that allows access by the terminal device according to the cell selection auxiliary information, includes: Determining whether there is a target cell among the candidate target cells that supports the slice that the terminal device is allowed to access; If so, selecting the target cell; Otherwise, based on the cell selection auxiliary information and the priority of the slices allowed to be accessed by the terminal device, a target cell supporting the first slice is selected from the candidate target cells, where the first slice is the slice with the highest priority among the slices allowed to be accessed by the terminal device.

8. The method according to claim 7, wherein: The method further comprises: Acquire the priority of the slice that the terminal device is allowed to access according to pre-configuration information; or, During the network registration process, the priority of the slice that the terminal device is allowed to access is obtained from the network device side.

9. A communication device, characterized in that: include: A transceiver unit, configured to obtain measurement results and cell selection assistance information of N cells, where the cell selection assistance information includes identifiers of L slices corresponding to M sessions of the terminal device and slice capability information of the N cells, wherein the slice capability information of the N cells includes identifiers of slices supported by the N cells, respectively, and ML and N are positive integers; A processing unit is configured to perform cell selection or cell reselection according to the measurement results of the N cells and the cell selection auxiliary information.

10. The communication device according to claim 9, wherein: The processing unit is specifically configured to: determining a candidate target cell for cell selection or cell reselection according to the measurement results of the N cells; According to the cell selection auxiliary information, a target cell supporting the L slices is selected from the candidate target cells. The communication device according to claim 10 , wherein: When the processing unit selects a target cell supporting the L slices from the candidate target cells according to the cell selection auxiliary information, the processing unit is specifically configured to: Determining whether there is a target cell among the candidate target cells that supports the L slices; If so, selecting the target cell; Otherwise, based on the cell selection assistance information and the priorities of the L slices, a target cell supporting a first slice is selected from the candidate target cells, where the first slice is a slice with the highest priority among the L slices.

12. The communication device according to claim 11, wherein The transceiver unit is further configured to: Obtaining the priorities of the L slices according to pre-configured information; or, Obtaining the priorities of the L slices from the network device side during the network registration process; or, During the establishment of the M sessions, the priorities of the L slices are obtained from the network device side.

13. A communication device, characterized in that: include: a transceiver unit, configured to obtain measurement results and cell selection assistance information of N cells, where the cell selection assistance information includes slice capability information and allowed slice selection assistance information of the N cells, wherein the allowed slice selection assistance information is an identifier of a slice allowed to be accessed by a terminal device, and the slice capability information of the N cells includes identifiers of slices respectively supported by the N cells, where N is a positive integer; A processing unit is configured to perform cell selection or cell reselection according to the measurement results of the N cells and the cell selection auxiliary information. The communication device according to claim 13 , wherein: The processing unit is specifically configured to: determining a candidate target cell for cell selection or cell reselection according to the measurement results of the N cells; According to the cell selection auxiliary information, a target cell that supports the slice that allows the terminal device to access is selected from the candidate target cells.

15. The communication device according to claim 14, wherein: When the processing unit selects, from the candidate target cells, a target cell that supports the slice to which the terminal device is allowed to access based on the cell selection auxiliary information, the processing unit is specifically configured to: Determining whether there is a target cell among the candidate target cells that supports the slice that the terminal device is allowed to access; If so, selecting the target cell; Otherwise, based on the cell selection auxiliary information and the priority of the slices allowed to be accessed by the terminal device, a target cell supporting the first slice is selected from the candidate target cells, where the first slice is the slice with the highest priority among the slices allowed to be accessed by the terminal device. The communication device according to claim 15 , wherein: The transceiver unit is further configured to: Acquire the priority of the slice that the terminal device is allowed to access according to pre-configuration information; or, During the network registration process, the priority of the slice that the terminal device is allowed to access is obtained from the network device side.

17. A communication device, characterized in that: include: A module for executing the method according to any one of claims 1 to 8.

18. A communication device, characterized in that: The method comprises at least one processor; and a communication interface communicatively connected to the at least one processor; the at least one processor executes instructions stored in a memory, so that the method according to any one of claims 1 to 8 is executed.

19. A chip system, characterized in that: The chip system includes at least one processor, and the processor executes the method according to any one of claims 1 to 8 by running instructions.

20. A computer-readable storage medium, characterized in that A computer program or instruction is stored, and when the computer program or instruction is executed, the method according to any one of claims 1 to 8 is implemented.

21. A computer program product, characterized in that The computer program product stores a computer program or instructions, and when the computer program or instructions are run, the method according to any one of claims 1 to 8 is executed.

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