WO2022077363A1

WO2022077363A1 - Cell selection method and apparatus

Info

Publication number: WO2022077363A1
Application number: PCT/CN2020/121223
Authority: WO
Inventors: 孙飞; 罗海燕
Original assignee: 华为技术有限公司
Priority date: 2020-10-15
Filing date: 2020-10-15
Publication date: 2022-04-21
Also published as: CN116420385A

Abstract

The embodiments of the present application provide a cell selection method and apparatus. Said method comprises: a terminal device determining first network slice information, the first network slice information containing the identifier of at least one network slice; the terminal device receiving second network slice information sent from a resident cell, the second network slice information containing the identifier of at least one network slice; and the terminal device performing cell re-selection according to the first network slice information and the second network slice information. The implementation of the embodiments of the present application improves the efficiency of cell selection, facilitates quick and effective selection of an appropriate cell, and reduces the time delay and resource overheads of cell selection.

Description

Method and device for cell selection

technical field

The present invention relates to the field of wireless communication, and in particular, to a method and device for cell selection.

Background technique

With the rapid development of wireless communication technology, the 5th Generation (5G) wireless communication technology has become a hot spot in the current industry. 5G will support diverse application requirements, including access capabilities that support higher speed experience and larger bandwidth, lower latency and highly reliable information exchange, and the connection of larger-scale and low-cost machine-type communication equipment. entry and management. Supporting the ubiquitous needs of various vertical industries and ensuring energy saving are the key factors for the application of 5G.

To this end, 5G introduces the important concept of network slicing. A network slice is a combination of network functions and corresponding resource requirements for realizing communication services and network capabilities, including the core network (CN) part and the radio access network (RAN) part. A network slice constitutes an end-to-end logical network to meet the performance requirements of one or more network services on the demand side of the slice. Multiple network slices are deployed in one CN to meet the needs of different users and different services; one RAN can support multiple network slices. Generally, network slices supported by cells controlled by one RAN device are a subset of network slices deployed by the CN, and network slices supported by cells controlled by different RAN devices may also be different. In other words, different cells have different network slice support capabilities. There may be a situation where a terminal device can initiate a service in the first cell, but cannot initiate the service in the second cell, because the first cell supports the network slice to which the service belongs, but the second cell does not support the network slice to which the service belongs. network slice.

In the prior art, a terminal device selects a cell according to cell link quality, priority, etc., but because different cells have different support capabilities for network slices, the cell selected by the terminal device may not support the network slice required by the terminal device. In the case of network slicing, how to effectively select a suitable cell, there is currently no suitable solution.

SUMMARY OF THE INVENTION

The embodiment of the present application provides a method for cell selection, which can improve the efficiency of cell selection, select a suitable cell quickly and effectively, and reduce the time delay and resource overhead of cell selection.

The present application is described below from various aspects, and it is easy to understand that the implementation manners of the following various aspects can be referred to each other.

In a first aspect, the present application provides a method for cell selection, and the execution body of the method may be a terminal device or a chip applied in the terminal device. The method includes: the terminal device determines first network slice information, where the first network slice information includes an identifier of at least one network slice; the terminal device receives second network slice information sent from the residing cell, where the second network slice information includes an identifier of at least one network slice; and the terminal device performs cell reselection according to the first network slice information and the second network slice information.

It can be seen that the method provided by the embodiment of the present application realizes that when the terminal device in the RRC non-connected state is about to initiate a service, it can choose to camp on a suitable cell that supports the service, so that the terminal device can quickly access the appropriate cell when initiating a service subsequently. cell, effectively reducing the delay of service establishment and reducing signaling overhead.

In a possible implementation, the first network slice information is used to indicate an identifier of at least one network slice to which at least one service to be initiated by the terminal device belongs.

In a possible implementation, the second network slice information includes an identifier of at least one network slice supported by the camping cell.

In a possible implementation, the second network slice information includes an identifier of at least one network slice supported by the residing cell and an identifier of at least one network slice supported by at least one neighboring cell of the residing cell.

In a possible implementation, the terminal device performs cell reselection according to the first network slice information and the second network slice information, including: if the network slice identifier of the residing cell does not include the first network slice identifier, The terminal device performs cell reselection; wherein, the network slice identifier of the residing cell is used to indicate the identifier of at least one network slice included in the second network slice information, and the first network slice identifier is used to indicate the first network slice information. The identity of at least one of the included network slices.

In a possible implementation, the terminal device performs cell reselection according to the first network slice information and the second network slice information, including: the network slice identifier of the residing cell does not include the first network slice identifier, and at least one When the neighbor network slice identifier partially or completely includes the first network slice identifier, the terminal device performs cell reselection; wherein the network slice identifier of the residing cell is used to indicate the network slice identifier of at least one network slice supported by the residing cell. an identifier, where the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the neighbor network slice identifier is used to indicate at least one network slice supported by a neighbor of the residing cell 's identification.

In a possible implementation, the terminal device performs cell reselection according to the first network slice information and the second network slice information, including: the network slice identifier part of the residing cell includes a first network slice identifier and at least one In the case where the number of network slices of the intersection of the neighbor network slice identifier and the first network slice identifier is greater than the number of network slices of the intersection of the network slice identifier of the residing cell and the first network slice identifier, the terminal device performs cell reselection ; wherein, the network slice identifier of the residing cell is used to indicate the identifier of at least one network slice supported by the residing cell, and the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information , the neighbor network slice identifier is used to indicate the identifier of at least one network slice supported by at least one neighbor cell of the residing cell.

In a possible implementation, the terminal device performs cell reselection according to the first network slice information and the second network slice information, including: a network slice at the intersection of the network slice identifier of the residing cell and the first network slice identifier When the number is equal to the number of network slices in the intersection of at least one neighbor network slice identifier and the first network slice identifier, and the link quality of the residing cell is lower than the link quality of the at least one neighbor cell, the terminal device performs Cell reselection; wherein the network slice identifier of the residing cell is used to indicate the identifier of at least one network slice supported by the residing cell, and the first network slice identifier is used to indicate at least one network slice included in the first network slice information The identifier of the slice, where the neighbor network slice identifier is used to indicate the identifier of at least one network slice supported by at least one neighbor of the residing cell.

In a possible implementation, performing cell reselection by the terminal device includes: selecting, by the terminal device in the at least one neighboring cell, the network slice with the largest number of network slices in the intersection of the neighboring network slice identifier and the first network slice identifier. Neighbors to stay.

In a possible implementation, performing cell reselection by the terminal device includes: in the case that the number of network slices in the intersection of multiple adjacent cell network slice identifiers and the first network slice identifier is the largest, the terminal device performs cell reselection in the The adjacent cell with the highest link quality is selected from among the plurality of adjacent cells for camping; or, the terminal device selects the adjacent cell with the highest priority among the plurality of adjacent cells for camping.

In a possible implementation, performing cell reselection by the terminal device includes: the terminal device selects a neighboring cell with the highest link quality in the at least one neighboring cell for camping; or the terminal device is in the at least one neighboring cell to camp on. The neighbor cell with the highest priority is selected for camping in the zone.

In a second aspect, the present application provides a method for PLMN selection. The execution of the method may be a terminal device or a chip applied to the terminal device. The method includes: the terminal device determines third network slice information, where the third network slice information includes an identifier of at least one network slice; the terminal device performs PLMN selection according to the third network slice information.

It can be seen that the method provided by the embodiment of the present application realizes that the terminal device in the RRC disconnected state considers the network slice to which the service that may be initiated subsequently belongs when selecting a PLMN, so that the terminal device can select an appropriate PLMN, so that when the terminal device subsequently initiates a service It can quickly select cell access in a suitable PLMN, effectively reduce the delay of service establishment and reduce signaling overhead.

In a possible implementation, the third network slice information is used to indicate an identifier of at least one network slice to which at least one service expected by the terminal device belongs.

In a possible implementation, the terminal device acquires PLMN subscription information, where the PLMN subscription information includes a set of multiple subscribed PLMN identities of the terminal device and fourth network slice information of each subscribed PLMN, where the fourth network slice information is used for Indicates the identity of at least one network slice supported by the subscribing PLMN.

In a possible implementation, the terminal device acquires network PLMN information, where the network PLMN information includes an identifier of at least one PLMN in the network acquired by the terminal device on at least one RF channel.

In a possible implementation, the terminal device determines a potential PLMN set according to the set of subscribed PLMN identities and the network PLMN information; the potential PLMN set is the intersection of the set of subscribed PLMN identities and the network PLMN information.

In a possible implementation, the terminal device determines a candidate PLMN set from the potential PLMN set according to the third network slice information; the candidate PLMN set is at least one of the potential PLMN sets supported by the third network slice information identified by the third network slice information The identity of one or more PLMNs of the network slice.

In a possible implementation, the terminal device determines that the selected PLMN is the subscribed PLMN with the largest number of network slices in the intersection of the fourth network slice information and the third network slice information in the candidate PLMN set.

In a possible implementation, the terminal device acquires PLMN subscription information, where the PLMN subscription information includes a set of multiple subscribed PLMN identities of the terminal device, the RAT identities of each subscribed PLMN, and the fifth network slice of each RAT under each subscribed PLMN. information, where the fifth network slice information is used to indicate the identifier of at least one network slice supported by a RAT under the subscribed PLMN.

In a possible implementation, the terminal device determines, according to the third network slice information and the fifth network slice information in the network PLMN information, that the selected PLMN is the fifth network slice information and the third network slice information in the candidate PLMN set. The subscribed PLMN with the largest number of network slices in the intersection of network slice information.

In a third aspect, the present application provides another method for cell selection, and the execution body of the method may be a terminal device or a chip applied in the terminal device. The method includes: the NAS entity sends a sixth network slice identifier to the AS entity, where the sixth network slice identifier includes an identifier of a network slice; the AS entity listens to a cell broadcast message; and the AS entity performs a process according to the sixth network slice identifier Cell selection.

It can be seen that the method provided by the embodiment of the present application realizes that the AS entity of the terminal device in the RRC non-connected state considers a network slice to which a service that may be initiated subsequently belongs when selecting a cell, so that the AS entity can select a suitable cell to camp on, so that the When the NAS entity subsequently initiates a service, it can quickly access an appropriate cell, effectively reducing the delay of service establishment and reducing signaling overhead.

In a possible implementation, the sixth network slice identifier is used to indicate the identifier of the network slice to which the service that the terminal device wishes to initiate subsequently belongs to.

In a possible implementation, the terminal device may select a cell to camp on from a plurality of cells in the selected PLMN according to the RSRP, priority or preset criteria of the cell.

In a possible implementation, the terminal device selects one cell to camp on from multiple cells in one RAT in the selected PLMN according to the priority of the RAT or a preset criterion.

In a fourth aspect, the present application provides another method for cell selection, and the execution body of the method may be a terminal device or a chip applied in the terminal device. The method includes: the NAS entity sends a seventh network slice identifier to the AS entity, where the seventh network slice identifier includes identifiers of multiple network slices; the AS entity listens to a cell broadcast message; and the AS entity according to the sixth network slice identifier Make cell selection.

It can be seen that the method provided by the embodiment of the present application realizes that the AS entity of the terminal device in the RRC non-connected state considers multiple network slices to which different services belong when selecting a cell, so that the AS entity can select a suitable cell to camp on, so that the NAS entity can When initiating a service subsequently, it can quickly access a suitable cell, effectively reducing the delay of service establishment and reducing signaling overhead.

In a possible implementation, the seventh network slice identifier is used to indicate identifiers of multiple network slices to which multiple services that the terminal device wishes to initiate subsequently belong to.

In a possible implementation, the AS entity may select a cell to camp on from a plurality of cells in the selected PLMN according to the RSRP, priority or preset criteria of the cell.

In a fifth aspect, the present application provides another method for cell selection, and the execution body of the method may be a terminal device or a chip applied in the terminal device. The method includes: the NAS entity sends a seventh network slice identifier to the AS entity, where the seventh network slice identifier includes identifiers of multiple network slices; the AS entity listens to a cell broadcast message; and the AS entity according to the seventh network slice identifier Make cell selection.

It can be seen that the method provided by the embodiment of the present application realizes that the AS entity of the terminal device in the RRC disconnected state considers the network slice to which one or more services that may be initiated subsequently belong when selecting a cell, so that the AS entity can select a suitable cell to camp on. It is reserved so that the NAS entity can quickly access a suitable cell when it subsequently initiates a service, effectively reducing the delay of service establishment and reducing signaling overhead.

In a possible implementation, in the case that the network slice identifiers supported by each cell obtained by the AS entity from the broadcast message contain the seventh network slice identifier to different degrees, the AS entity selects a network slice identifier that can support at most the seventh network slice identifier. The cells of the network slice are camped on.

In a sixth aspect, the present application provides a communication device, and the device may be a terminal device, or a device in a terminal device, or a device that can be matched and used with the terminal device. Wherein, the communication device may also be a chip system. The communication device is configured to perform the first aspect or any possible implementation manner of the first aspect, or the second aspect or any possible implementation manner of the second aspect, or the third aspect or any one of the third aspects A possible implementation manner, or the fourth aspect or any possible implementation manner of the fourth aspect, or the fifth aspect or a method in any possible implementation manner of the fifth aspect. The functions of the communication device may be implemented by hardware, or by executing corresponding software by hardware. The hardware or software includes one or more units corresponding to the above-mentioned functions. The unit may be software and/or hardware. For operations and beneficial effects performed by the communication device, reference may be made to the methods and beneficial effects described in the first to fifth aspects above, and repeated details will not be repeated.

In a seventh aspect, the present application provides a communication device, the communication device includes a processor, when the processor calls a computer program in a memory, the first aspect or any possible implementation manner of the first aspect, or the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect, or the fourth aspect or any possible implementation of the fourth aspect , or the method in the fifth aspect or any possible implementation manner of the fifth aspect is performed.

In an eighth aspect, the present application provides a communication device, the communication device includes a processor, a memory, and a transceiver, the transceiver is used to receive a channel or a signal, or send a channel or signal; the memory is used for Store program code; the processor is configured to call the program code from the memory to execute the first aspect or any possible implementation manner of the first aspect, or the second aspect or any possible implementation manner of the second aspect implementation, or the third aspect or any possible implementation of the third aspect, or the fourth aspect or any possible implementation of the fourth aspect, or any of the fifth or fifth aspect methods in possible implementations.

In a ninth aspect, the present application provides a communication device, the communication device includes a processor and an interface circuit, the interface circuit is configured to receive a code instruction and transmit it to the processor; the processor executes the code instructions to perform the first aspect or any possible implementation of the first aspect, or the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect An implementation manner, or the fourth aspect or any possible implementation manner of the fourth aspect, or the fifth aspect or a method in any possible implementation manner of the fifth aspect.

In a tenth aspect, the present application provides a computer-readable storage medium, the computer-readable storage medium is used to store instructions, and when the instructions are executed, the first aspect or any one of the first aspects is possible. Implementation, or the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect, or the fourth aspect or any possible implementation of the fourth aspect The implementation manner of the fifth aspect or the method in any possible implementation manner of the fifth aspect is implemented.

In an eleventh aspect, the present application provides a computer program product comprising instructions which, when executed, enable the first aspect or any possible implementation of the first aspect, or the second aspect or the second aspect Any possible implementation of the third aspect or any possible implementation of the third aspect, or the fourth aspect or any possible implementation of the fourth aspect, or the fifth aspect or the fifth The method of any possible implementation of the aspect is implemented.

In a twelfth aspect, the present application provides a chip, the chip includes a logic circuit and an input-output interface, the input-output interface is used for communicating with modules other than the chip, and the logic circuit is used for running a computer program or instruction to realize the first aspect or any possible implementation of the first aspect, or the second aspect or any possible implementation of the second aspect, or the third aspect or any possible implementation of the third aspect, or the fourth aspect or any possible implementation manner of the fourth aspect, or the fifth aspect or the method in any possible implementation manner of the fifth aspect.

These and other aspects of the invention will be more clearly understood in the following description of the embodiment(s).

Description of drawings

The accompanying drawings used in the embodiments of the present application or the description of the prior art are briefly introduced below:

1 is a schematic diagram of a communication system provided by an embodiment of the present application;

2 is a schematic diagram of a protocol stack of a terminal device provided by an embodiment of the present application;

3 is a schematic flowchart of a method for cell reselection provided by an embodiment of the present application;

4 is a schematic flowchart of a method for PLMN selection provided by an embodiment of the present application;

5 is a schematic flowchart of a method for cell selection provided by an embodiment of the present application;

6 is a schematic flowchart of another method for cell selection provided by an embodiment of the present application;

7 is a schematic flowchart of another method for cell selection provided by an embodiment of the present application;

8 is a schematic flowchart of still another method for cell selection provided by an embodiment of the present application;

9 is a schematic flowchart of another method for cell reselection provided by an embodiment of the present application;

10 is a schematic flowchart of a method for cell reselection provided by an embodiment of the present application;

11 is a schematic flowchart of still another method for cell reselection provided by an embodiment of the present application;

FIG. 12 is a schematic block diagram of a terminal device provided by an embodiment of the present application;

FIG. 13 is another schematic block diagram of a terminal device provided by an embodiment of the present application;

FIG. 14 is a schematic block diagram of the structure of a chip provided by an embodiment of the present application.

Detailed ways

The embodiments of the present application will be described below with reference to the accompanying drawings in the embodiments of the present application.

In this application, the word "exemplary" is used to mean "serving as an example, illustration, or illustration." Any embodiment described in this application as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. The following description is presented to enable any person skilled in the art to make and use the present invention. In the following description, details are set forth for the purpose of explanation. It will be understood by one of ordinary skill in the art that the present invention may be practiced without the use of these specific details. In other instances, well-known structures and procedures have not been described in detail so as not to obscure the description of the present invention with unnecessary detail. Thus, the present invention is not intended to be limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and features disclosed herein.

The terms "first", "second", "third", "fourth", etc. (if any) in the description and claims of this application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It is to be understood that data so used may be interchanged under appropriate circumstances so that the embodiments of the application described herein can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having" and any variations thereof, are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those expressly listed Rather, those steps or units may include other steps or units not expressly listed or inherent to these processes, methods, products or devices.

The terms "system" and "network" are often used interchangeably herein.

The technical solutions of the present invention will be described in detail below with specific examples. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments.

The technical solutions of the embodiments of the present application can be applied to various wireless communication systems, such as: long term evolution (Long Term Evolution, LTE) system, fifth generation (5th generation, 5G) mobile communication system, new radio (new radio, NR) Communication systems, next generation (NG) communication systems and future mobile communication systems, etc.

In a wireless communication system, a terminal device is connected to a RAN device through a wireless link, and communicates with other terminal devices or accesses the wireless Internet through a CN device connected to the RAN device. Typically, a terminal device is wirelessly connected to a RAN device for communication. FIG. 1 shows a schematic diagram of a wireless communication system 100 provided by an embodiment of the present application. The terminal device 120 establishes a wireless connection with the RAN device 140 through the air interface, and accesses the core network 160 . In an actual system, in order to meet the coverage of a wireless network, multiple RAN devices are usually deployed in an area, and cells controlled by different RAN devices need to provide seamless coverage as much as possible. As shown in FIG. 1 , a RAN device 142 , a RAN device 144 and a RAN device 146 are deployed around the RAN device 140 . Different RAN devices may have interfaces for mutual communication, such as X2 interface or Xn interface. In a possible scenario, these RAN devices operate on the same frequency band and are deployed in different geographic locations, and the cells controlled by each of them jointly provide seamless coverage, such as the cells controlled by the RAN device 140 and the RAN device 142 There is a certain degree of overlapping coverage between the cells under control. The overlapping coverage area is usually neither too large nor too small, and the determination of the size of the overlapping coverage area needs to consider the interference between intra-frequency cells and the compromise between the performance of handover between cells. In another possible scenario, some RAN devices work in different frequency bands to form heterogeneous network coverage. For example, the cells controlled by the RAN device 140 work in lower frequency bands and have a larger coverage area, and the cells controlled by the RAN device 142 Cells operate in higher frequency bands and have smaller coverage areas, these RAN devices may be deployed in the same or different geographic locations, and the cells controlled by each may have completely overlapping coverage areas, e.g. RAN device 140 operates in lower frequency bands , the RAN device 142 operates in a higher frequency band, and the coverage area of the cell controlled by the RAN device 140 can completely or mostly cover the coverage area of the cell controlled by the RAN device 142 .

In an actual system, the RAN device shown in Figure 1 can be a next-generation base station, such as a next-generation Node B (gNB) or a next-generation evolved Node B (ng-eNB) ), etc., it can also be an access point (AP) in a wireless local area network (Wireless Local Area Networks, WLAN), or an evolved base station (evolved Node B, eNB or eNodeB) in LTE, or a relay station or access point. point, or in-vehicle equipment, wearable equipment, and transmission and reception point (TRP), etc. It should be understood that the terminal device communicates with the RAN device through transmission resources (eg, frequency domain resources, time domain resources, code domain resources, etc.) used by one or more cells managed by the RAN device, and the cell may belong to a macro cell (macro cell). cell), super cell (hyper cell), can also belong to small cell (small cell), the small cell here can include: urban cell (metro cell), micro cell (micro cell), pico cell (pico cell), femto cell These small cells have the characteristics of small coverage and low transmission power, and are suitable for providing high-speed data transmission services. The terminal equipment in FIG. 1 may also be referred to as user equipment (UE), access terminal, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless Communication equipment, user agent or user equipment. The terminal device can be a station (station, ST) in the WLAN, and can be a cellular phone, a cordless phone, a SIP phone, a wireless local loop (WLL) station, a personal digital assistant (PDA) device, Handheld devices, relay devices, computing devices or other processing devices coupled to wireless modems, in-vehicle devices, wearable devices, and next-generation communication systems with wireless communication capabilities, such as end devices in 5G networks or future evolution of public terrestrial Terminal equipment in the mobile network (public land mobile network, PLMN) network, etc. As an example and not a limitation, in this embodiment of the present application, the terminal device may also be a wearable device. Wearable devices can also be called wearable smart devices, which are the general term for the intelligent design of daily wear and the development of wearable devices using wearable technology, such as glasses, gloves, watches, clothing and shoes. A wearable device is a portable device that is worn directly on the body or integrated into the user's clothing or accessories. Wearable device is not only a hardware device, but also realizes powerful functions through software support, data interaction, and cloud interaction. In a broad sense, wearable smart devices include full-featured, large-scale, complete or partial functions without relying on smart phones, such as smart watches or smart glasses, and only focus on a certain type of application function, which needs to cooperate with other devices such as smart phones. Use, such as all kinds of smart bracelets, smart jewelry, etc. for physical sign monitoring.

For ease of understanding, several concepts involved in the embodiments of the present application are first introduced. It should be understood that the following concept explanations may be limited due to the specific circumstances of the embodiments of the present application, but it does not mean that the present application can only be limited to the specific circumstances. There will be differences:

1) RRC state: The RRC state usually includes three states, namely, the RRC connected (RRC_CONNECTED) state, the RRC idle (RRC_IDLE) state, and the RRC inactive (RRC_INACTIVE) state. The RRC idle state and the RRC inactive state may be collectively referred to as the RRC disconnected state. When the terminal equipment is in the RRC connection state, the terminal equipment has established a communication connection with the RAN and CN. When data arrives at the CN, it can be sent to the terminal equipment through the RAN, or the terminal equipment can send data to the RAN; When the RRC is idle, the terminal equipment is connected to the RAN and CN. When there is data to be transmitted, a communication link between the terminal equipment and the RAN and CN needs to be established; when the terminal equipment is in the RRC inactive state, it means The terminal device has established a communication connection with the RAN and CN before, but the communication link between the terminal device and the RAN is released. Although the communication link is released, the RAN will store the context of the terminal device. When data needs to be transmitted , the RAN can quickly restore this communication link.

2) Non-access stratum (NAS) and access stratum (access stratum, AS): Depending on the destination of the communication connection with the terminal device, the protocol stack of the terminal device can be divided into the NAS layer and the AS layer. The NAS layer protocol implements the communication connection between the terminal equipment and the CN side, and the AS layer protocol implements the communication connection between the terminal equipment and the RAN side. FIG. 2 shows the protocol stack structure of a possible terminal device. The AS layer includes multiple protocol layers, such as radio resource control (RRC) layer, service data adaptation protocol (SDAP) layer, packet data convergence protocol (PDCP) ) layer, radio link control (RLC) layer, media access control (MAC) layer and physical (physical, PHY) layer; correspondingly, there is also an equivalent protocol layer on the RAN side In order to realize the communication connection with the terminal equipment. The NAS layer implements the communication connection between the terminal device and the CN side. Correspondingly, the CN side also has an equivalent NAS layer. It should be understood that the terminal device does not directly communicate with the CN side, and the NAS message that the terminal device communicates with the CN is usually encapsulated in the AS message that the terminal device communicates with the RAN.

3) Network slice identification: In the network, a network slice needs to have corresponding identification information to identify it. Currently, 3GPP SA2 defines a single network slice selection assistance information (S-network slice SAI) to identify a network slice. Each S-network slice SAI consists of slice/service type (SST) and slice differentiater (SD), where SST is used to differentiate services and SD is used to differentiate tenants. One or more S-network slices SI constitute a network slice SAI. The network slice identifier of each network slice may be characterized by at least one of the following parameters:

1. Network slice type information, for example, network slice type information can indicate enhanced mobile broadband services (enhanced Mobile BroadBand, eMBB), ultra-reliable low-latency communications (Ultra-Reliable Low Latency Communications, URLLC), massive machine type communication ( Massive Machine Type Communication, mMTC) and other network slice types, optionally, the network slice type information can also indicate the end-to-end network slice type, including the network slice type from RAN to CN, or the network slice type on the RAN side, or CN side network slice type;

2. Service type information, which is related to a specific service. For example, the service type information can indicate service features such as video service, Internet of Vehicles service, and voice service, or information about specific services;

3. Tenant information, which is used to indicate the customer information that creates or leases the network slice, such as Tencent, State Grid, etc.;

4. User group information, which is used to indicate grouping information for grouping users according to certain characteristics, such as user levels;

5. Slice group information, which is used to indicate that according to a certain characteristic, for example, all network slices that can be accessed by the terminal device can be regarded as a slice group, or the grouping of network slices can also be divided according to other standards;

6. Network slice instance information, which is used to indicate the instance identifier and feature information created for the network slice. For example, an identifier can be assigned to the network slice instance to indicate the network slice instance, or it can be based on the network slice instance identifier. A new identifier is mapped on it, which is associated with the network slice instance, and the receiver can identify the specific network slice instance indicated by the identifier according to the identifier;

7. Dedicated Core Network (DCN) identifier, which is used to uniquely indicate a dedicated core network in an LTE system or an eLTE system, such as a dedicated core network of the Internet of Things. Optionally, the DCN identifier can be Mapping with the network slice identifier, the network slice identifier can be mapped from the DCN identifier, and the DCN identifier can also be mapped through the network slice identifier.

When the terminal device is switched on, the terminal device needs to select a public land mobile network (PLMN) to select a network that provides services for the terminal device. The NAS entity of the terminal device may notify the AS entity of the selected PLMN for the AS entity to perform cell selection and cell reselection. In addition, the terminal device can also periodically search for PLMNs with higher priority. Alternatively, after the terminal device leaves the coverage of a previously registered PLMN, a new PLMN may be automatically selected, or an indication may be received from the available PLMNs to achieve manual PLMN selection. Cell selection means that the terminal equipment selects a suitable cell in the selected PLMN to provide available services after completing the PLMN selection, and monitors the control channel of the cell. This procedure is also referred to as the terminal equipment camping on a cell. Camping on a cell allows the terminal device to receive system information of the camped cell, access the control channel of the camped cell to establish or restore an RRC connection, receive network paging messages from the control channel of the camped cell, and so on. Cell reselection means that after the terminal equipment camps on a cell, it finds a more suitable cell according to the cell reselection criteria, and the terminal equipment reselection to the more suitable cell and camps on the cell.

In NR, different PLMNs can support different network slices, and different cells can also support different network slices. The inventor found that in the prior art, when the terminal equipment performs cell selection (reselection), the network slice support of the selected cell is not considered, and there may be a cell selected by the terminal equipment that does not support the needs of the terminal equipment. network slicing, resulting in wrong cell selection and wasting network resources. Further, when the terminal equipment selects the PLMN, it does not consider whether the selected PLMN supports the network slice subscribed by the terminal equipment or the desired network slice, which also causes wrong PLMNU selection and wastes network resources. To this end, the embodiments of the present application provide a technical solution for cell selection, where a terminal device performs cell selection (reselection) based on a required network slice. Further, the embodiments of the present application also provide a technical solution for the terminal device to select a PLMN based on a subscribed network slice or a desired network slice.

The following embodiments are specifically provided herein, and the technical solutions of the present application will be described in detail below with reference to FIG. 3 to FIG. 11 with specific method embodiments. The following specific embodiments may be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. It should be noted that FIG. 3 to FIG. 11 are schematic flow charts of method embodiments of the present application, showing detailed communication steps or operations of the method, but these steps or operations are only examples, and the embodiments of the present application also further Other operations or variations of the various operations in FIGS. 3-11 may be performed. Furthermore, the various steps in FIGS. 3 to 11 may be performed in a different order than those presented in FIGS. 3 to 11 , respectively, and it is possible that not all operations in FIGS. 3 to 11 are performed.

FIG. 3 is a schematic flowchart of a method for cell selection provided by an embodiment of the present application. The method 300 is applied to a scenario where a terminal device camping on a cell selects a new cell for camping when about to initiate a service. In this scenario, the camped cell does not support the network slice to which the service to be initiated by the terminal device belongs, and the terminal device needs to choose to camp in a new cell to support the network slice to which the service to be initiated by the terminal device belongs; or the camped cell supports For the part of the network slice to which the service to be initiated by the terminal device belongs, the terminal device needs to choose to camp in a new cell to more or fully support the network slice to which the service to be initiated by the terminal device belongs. The selection of the new cell is also called cell reselection, that is, the terminal device reselection from the camping cell to a new cell for camping. The process described in Figure 3 includes the following steps:

S301. A terminal device determines target network slice information.

The terminal equipment can camp on a cell when it is in the RRC disconnected state, and the cell where the terminal equipment camps is called the camping cell. When a terminal device is about to initiate a service, the terminal device acquires network slice information corresponding to the service (called a target service), and the network slice is called a target network slice. It should be understood that the fact that the terminal device is about to initiate a service may also be referred to as the state of the terminal device will change from the RRC disconnected state to the RRC connected state due to the service. Generally, the terminal device needs to establish a PDU session with the network to carry the target service, so the target network slice is also the network slice associated with the PDU session to which the target service belongs. It should be understood that the terminal device may initiate multiple services at the same time, that is, the target service includes multiple services, and these services may belong to one PDU session or multiple PDU sessions. When these services belong to one PDU session, the target network slice corresponds to a network slice associated with the PDU session; when these services belong to multiple PDU sessions respectively, the target network slice corresponds to one or more PDU sessions associated with the multiple PDU sessions. Multiple network slices. In other words, the target service may be one or more services, and the target network slice may be one or more network slices. This application does not specifically limit the number of services included in the target service and the number of network slices included in the target network slice.

Specifically, determining the target network slice information by the terminal device may be implemented in the following manner: first, the NAS entity of the terminal device determines the target service and the target network slice; secondly, the NAS entity of the terminal device identifies the network slice of the target network slice (referred to as the target network slice). network slice identifier) sent to the AS entity of the terminal device. Therefore, the AS entity of the terminal device obtains the target network slice identifier. Optionally, the NAS entity sends the target network slice identifier together when sending the access category (access category, AC) and access identity (access identity, AI) corresponding to the target service to the AS entity. It should be understood that when the target service includes multiple services, each of the services may have the same or different AC and AI; the target network slice identifier may include network slice identifiers of one or more network slices.

S302, the camping cell sends network slice information to the terminal device. Accordingly, the terminal device receives the network slice information from the camped cell.

In this step, the camped cell sends the network slice information to the terminal equipment camped on the cell by means of cell broadcast.

In a possible implementation, the network slice information is used to indicate network slice information of network slices supported by the residing cell. Exemplarily, the network slice information includes network slice identifiers of one or more network slices supported by the camping cell.

In another possible implementation, the network slice information is used to indicate the network slice information of the network slice supported by the residing cell and the network slice information of the network slice supported by the neighbor cell. Exemplarily, the network slice information includes network slice identifiers of one or more network slices supported by the residing cell and network slice identifiers of one or more network slices supported by the neighbor cell. It should be understood that a neighboring cell corresponds to one or more cells adjacent to the camping cell.

S303, the terminal device determines to perform cell reselection.

In this step, the terminal device determines to perform cell reselection based on the information of the target network slice and the information of the network slices of the camping cell and neighboring cells obtained from the above step S302.

Exemplarily, the terminal device determines to perform cell reselection based on the target network slice identifier and the network slice identifier obtained in step S302. The network slice identifiers of one or more network slices supported by the camping cell are called network slice identifiers of the camping cell. Correspondingly, any cell in the neighbor cell is defined as the first neighbor cell, and the identifier of the network slice supported by the first neighbor cell is called the identifier of the first neighbor cell network slice. It should be understood that the network slice identifier of the residing cell and the network slice identifier of the first neighbor cell may respectively include one or more network slice identifiers. Corresponding to the two possible implementation manners of the foregoing step S302, in this step, there are the following two manners:

Cell reselection method 1:

This method corresponds to the case where the network slice information sent by the camping cell only includes the network slice identifier of the camping cell.

When the network slice identifier of the residing cell does not include the target network slice identifier, the terminal device determines to perform cell reselection. In this case, since the camping cell does not support the target network slice, the terminal device needs to reselect a cell that can support the target network slice for camping.

Cell reselection method 2:

This manner corresponds to the case where the network slice information sent by the residing cell includes the network slice identifier of the residing cell and the identifiers of one or more first neighbor network slices.

In a possible implementation, the terminal device determines to perform cell reselection when the network slice identifier of the residing cell does not include the target network slice identifier, and there are one or more first neighbor network slice identifiers that include the target network slice identifier. In this case, since the camping cell does not support the target network slice, the terminal device needs to reselect a cell that can support the target network slice for camping.

In another possible implementation, when the network slice identifier of the residing cell does not include the target network slice identifier, and there are one or more first neighbor network slice identifiers that include part of the target network slice identifier, the terminal device determines to perform a cell reset. select. In this case, since the camping cell does not support the target network slice, the terminal device needs to reselect a cell that supports as many target network slices as possible for camping. For example, target network slices are identified as network slice #1, network slice #2, and network slice #3, while the network slices of neighbor #1 are identified as network slice #1, network slice #4, and network slice #5, and neighbor #3 is identified as network slice #1, network slice #4, and network slice #5. The network slices of the network are identified as network slice #2, network slice #3 and network slice #5, and the network slice identifiers of neighbor cell #5 are network slice #3 and network slice #4, then the terminal device can reselect neighbor cell #3 for Residue because Neighbor #3 can support the most network slices in the target network slice.

In yet another possible implementation, when the network slice identifier of the residing cell includes part of the target network slice identifier, and there are one or more first neighbor cell network slice identifiers that also include part of the target network slice identifier, the terminal device determines to perform Cell reselection. When there are more network slice identifiers in the target network slice identifier than the network slice identifier of the camping cell, the terminal device can reselect a cell that supports as many target network slice identifiers as possible for camping. For example, when the network slice identifier of the first neighbor cell and the network slice identifier of the residing cell contain the same number of network slice identifiers in the target network slice identifier, and the first neighbor cell has better link quality, the terminal device can reselect one The first neighbor that can support the same number of target network slices and has better link quality resides. Exemplarily, the link quality of a cell can be measured by the value of the RSRP of the cell received by the terminal. When the RSRP value is larger, it indicates that the link quality of the cell is higher; on the contrary, when the RSRP value is smaller, it indicates that the The link quality of the cell is lower.

In yet another possible implementation, although the network slice identifier of the residing cell includes the target network slice identifier, the network slice identifier of the first neighbor cell also includes the target network slice identifier, and when the first neighbor cell has better link quality, The terminal device can reselect a first neighbor cell that can support the target network slice and has better link quality for camping.

S304, the terminal device performs cell reselection and camps on the target cell.

For the above-mentioned cell reselection mode 1, the terminal device searches the neighboring cells of the camping cell and selects a cell to camp on. Exemplarily, the terminal device reads the network slice identifiers of one or more first neighboring areas of the neighboring area respectively. If the network slice identifier of the first neighboring area completely or to the greatest extent contains the target network slice identifier, the first neighboring area is called the network slice identifier. candidate cell. When only one candidate cell exists, the terminal device camps on the candidate cell; when there are multiple candidate cells, the terminal device selects one or more candidate cells, and selects one cell to camp on. The terminal device may select a cell among the candidate cells to camp on according to link quality, priority or other preset criteria. The cell selected by the terminal equipment to camp on is called the target cell. It should be noted that, for this cell reselection manner, the terminal device may select a target cell for camping in various manners in the prior art. This application does not specifically limit this.

For the above cell reselection method 2, if the network slice identifier of the first neighbor cell completely or maximally includes the target network slice identifier, the first neighbor cell is called a candidate cell. When only one candidate cell exists, the terminal device camps on the candidate cell; when there are multiple candidate cells, the terminal device selects one or more candidate cells, and selects one cell to camp on. The terminal device may select a cell among the candidate cells to camp on according to link quality, priority or other preset criteria. The cell selected by the terminal equipment to camp on is called the target cell.

After the terminal equipment completes the cell reselection and chooses to camp on the target cell, the terminal equipment synchronizes with the downlink signal of the target cell and listens to the control channel of the target cell, thereby camping on the target cell.

It should be noted that, in the above step S302, the camping cell broadcasts the network slice information to the terminal equipment in the RRC disconnected state. In the actual system, if the camping cell is the serving cell connected to the RRC_CONNECTED state before the terminal equipment enters the RRC disconnected state, the serving cell can also be unicast before the terminal equipment enters the RRC disconnected state from the RRC_CONNECTED state. The above-mentioned network slice information is sent to the terminal device in a manner (eg, through RRC signaling). In this way, when the terminal device enters the RRC disconnected state and the cell it camps on is the serving cell, the terminal device can directly determine whether to perform cell reselection according to the network slice information previously obtained from the serving cell.

Through the above steps in this embodiment, when the terminal equipment in the RRC non-connected state is about to initiate a service, it can choose to reside in a suitable cell that supports the service, so that the terminal equipment can quickly access the appropriate cell when initiating a service subsequently. Effectively reduce the delay of service establishment and reduce signaling overhead.

FIG. 4 is a schematic flowchart of a method for PLMN selection provided by an embodiment of the present application. The method 400 is applied to a scenario where a terminal device performs initial PLMN selection when it is powered on or periodically performs PLMN selection after registering with a network. In this scenario, the terminal device is subscribed to multiple PLMNs, and different PLMNs can support different network slices. When the terminal device performs initial PLMN selection or periodic selection, the terminal device does not communicate with the network, but the terminal device has a desired network slice, that is, the terminal device may initiate services belonging to the desired network slice in the future. Therefore, the terminal device needs to select a PLMN that can support the desired network slice. The process shown in Figure 4 includes the following steps:

S401. The terminal device acquires network slice information supported by the subscribed PLMN.

Optionally, if the terminal device has the capability of supporting multiple RAT systems, the terminal device also acquires network slice information supported by each RAT system. In this case, the network slice information supported by the subscribed PLMN acquired by the terminal device also includes the network slice information supported by each RAT system supported by the terminal device. In this case, the network slice information supported by the subscribed PLMN may also be referred to as the subscribed PLMN. Network slice information supported by multiple RATs.

The terminal equipment is subscribed to multiple PLMNs. There may be multiple implementation manners for the terminal device to obtain the network slice information supported by the subscribed PLMN. Exemplarily, in a possible implementation, the network slice information supported by multiple PLMNs subscribed by the terminal device is pre-configured, for example, exists in a SIM card inserted into the terminal device, or is pre-stored on the terminal device. Similarly, the network slice information supported by different RAT systems of the terminal device may also be pre-configured in the above manner. In another possible implementation, the network slice information supported by multiple PLMNs subscribed by the terminal device is stored on the terminal device based on the communication interface between the network and the terminal device, and the network can update the information stored on the terminal device through the communication interface. Network slice information. For example, an operator's network management system saves and updates the network slice information supported by the operator's PLMN in the terminal device through a communication interface with the terminal device. Similarly, the network slice information supported by different RAT standards of the terminal device may also be saved and updated in the above-mentioned manner.

Exemplarily, the terminal device obtains the network slice identifiers of one or more network slices supported by each of the subscribed multiple PLMNs (also referred to as the network slice identifiers supported by the subscribed PLMNs), and the terminal device may further obtain the network slice identifiers of each of its different RAT systems. Network slice identifiers of one or more supported network slices (also referred to as network slice identifiers supported by multiple RATs under a subscribed PLMN). It should be understood that the network slice identifier supported by the subscribed PLMN and the network slice identifier supported by multiple RATs under the subscribed PLMN may respectively include one or more network slice identifiers.

Exemplarily, Table 1 provides a schematic illustration of the network slice identifiers supported by a subscribed PLMN of a terminal device.

Table 1

PLMN列表List of PLMNs
>PLMN标识>PLMN ID
>网络切片标识列表> List of network slice identifiers

The PLMN list contains multiple PLMN identifiers; each PLMN identifier corresponds to a network slice identifier list, the network slice identifier list includes network slice identifiers of one or more network slices, and the network slice identifier list indicates the network slice identifiers supported by the PLMN. Network Slicing.

Exemplarily, Table 2 provides a schematic diagram of network slice identifiers supported by multiple RATs under a subscribed PLMN of a terminal device.

Table 2

PLMN列表List of PLMNs
>PLMN标识>PLMN ID
>RAT列表>RAT List
>>RAT标识>>RAT logo
>>网络切片标识列表>>list of network slice identifiers

The PLMN list contains multiple PLMN identifiers; each PLMN identifier corresponds to a RAT list; each RAT list contains one or more RAT identifiers, each RAT identifier corresponds to a network slice identifier list, and the network slice identifier list contains Network slice identifiers of one or more network slices, where the network slice identifier list indicates the network slices supported by the RAT. It should be understood that the RAT identifier may be the name of the RAT, an index, or other forms of characters or character strings that can be used to identify a RAT, which are not specifically limited herein.

S402. The terminal device determines the desired network slice.

Specifically, the NAS entity of the terminal device determines the desired network slice. Wherein, the desired network slice is used to indicate the network slice to which the service that the terminal device may initiate subsequently belongs to. It should be understood that it is contemplated that a network slice may contain one or more network slices. When one or more services that may be subsequently initiated by the terminal device belong to one PDU session, the network slice is expected to be a network slice associated with the PDU session; when multiple services that may be subsequently initiated by the terminal device belong to multiple PDU sessions, respectively, The desired network slice is one or more network slices associated with the plurality of PDU sessions.

S403, the terminal device selects the PLMN based on the desired network slice.

Based on the different RAT formats supported by the terminal device, there may be multiple implementations for the terminal device to select the PLMN based on the desired network slice. Exemplarily, in a possible implementation, the terminal device supports only one RAT format. In this case, the terminal device scans the radio frequency (RF) channel corresponding to the RAT system to find multiple PLMNs available. On each frequency point (carrier), the terminal device searches for the cell with the strongest signal and reads the system information of the cell to find out which PLMN or PLMNs the cell belongs to. If the terminal device reads one or more PLMN identifiers in the cell with the strongest signal, the AS entity will report each read PLMN identifier to the NAS entity. Exemplarily, when the terminal device measures that the RSRP value of the cell with the strongest signal is greater than or equal to -110dBm, the AS layer of the terminal device reports the read one or more PLMN identifiers to which the cell belongs to the NAS layer; When the terminal device measures that the RSRP value of the cell with the strongest signal is less than -110dBm, the AS entity of the terminal device reports the read one or more PLMN identifiers to which the cell belongs and the corresponding RSRP value to the NAS entity.

After acquiring multiple PLMN identities (referred to as PLMN identity sets) reported by the AS, the NAS entity of the terminal device performs PLMN selection according to the desired network slice. Specifically, the terminal device performs PLMN selection in combination with the PLMN identity set obtained by the NAS entity, the network slice identity supported by the contracted PLMN obtained in step S401, and the desired network slice.

Exemplarily, Table 3 shows the network slice identities supported by the PLMN subscribed by the terminal device.

table 3

PLMN列表List of PLMNs
>PLMN#1>PLMN#1
>NS#1,NS#2,NS#3>NS#1,NS#2,NS#3
>PLMN#2>PLMN#2
>NS#3,NS#5>NS#3,NS#5
>PLMN#3>PLMN#3
>NS#2,NS#7,NS#8>NS#2,NS#7,NS#8

In this example, the terminal device is subscribed to PLMN#1, PLMN#2 and PLMN#3. The PLMN#1 subscribed by the terminal equipment supports NS#1, NS#2 and NS#3; the PLMN#2 subscribed by the terminal equipment supports NS#3 and NS#5; the PLMN#3 subscribed by the terminal equipment supports NS#2, NS#7 and NS#8.

Exemplarily, it is assumed that the expected NS determined by the terminal device in the above step S402 is NS#3, and the multiple PLMN identifiers acquired by the terminal device by scanning the RF channel are PLMN#1, PLMN#3, PLMN#4 and PLMN#5. Then in this step, the terminal device can determine the set of potential PLMNs as {PLMN#1, PLMN#3} in combination with Table 3 and the PLMN identifier obtained by scanning the RF channel. In this example, the potential PLMN set is the intersection of the PLMN set subscribed by the terminal device and the PLMN set acquired by the terminal device scanning the RF channel. Further, since the expected network slice is NS#3, and both PLMN#1 and PLMN#2 in Table 3 support NS#3, but PLMN#2 does not belong to the potential PLMN set, the PLMN selected by the terminal device is PLMN#1 .

Exemplarily, it is assumed that the desired network slice determined by the terminal device in the above step S402 is NS#2, and the multiple PLMN identifiers obtained by the terminal device scanning the RF channel are PLMN#1, PLMN#3, PLMN#4 and PLMN#5. . Then in this step, the terminal device can determine the set of potential PLMNs as {PLMN#1, PLMN#3} in combination with Table 3 and the PLMN identifier obtained by scanning the RF channel. Likewise, in this example, the set of potential PLMNs is the intersection of the set of PLMNs subscribed by the terminal device and the set of PLMNs acquired by the terminal device scanning the RF channel. Further, since it is expected that the network slice is NS#2, and both PLMN#1 and PLMN#3 in Table 3 support NS#2, the terminal device needs to select one PLMN from PLMN#1 and PLMN#3. The PLMN set {PLMN#1, PLMN#3} is also called the candidate PLMN set. In this example, the set of candidate PLMNs is a subset or full set of potential PLMN sets that contain one or more PLMN identities in the potential set of PLMNs that support the desired network slice. The terminal device performs PLMN selection in the set of candidate PLMNs. For example, if the terminal device reads PLMN#1 and PLMN#3 in different cells, the terminal device can select the PLMN according to the RSRP value of each cell. For example, the RSRP value of the cell that reads PLMN#1 is less than If the RSRP value of the cell of PLMN#3 is obtained, the PLMN selected by the terminal equipment is PLMN#3; if the terminal equipment reads PLMN#1 and PLMN#3 in the same cell, the terminal equipment can read PLMN#1 and PLMN#3 according to the preset criteria (such as operator priority) to select a PLMN, for example, the priority of PLMN#1 is higher than that of PLMN#3, then the PLMN selected by the terminal device is PLMN#1.

It should be noted that when the desired network slice is multiple network slices, the terminal device selects a PLMN that can fully support or maximally support the desired network slice. If there are multiple PLMNs that meet the above conditions, the terminal device can select a PLMN according to the RSRP value of the cell that reads the corresponding PLMN; or select a PLMN according to preset criteria (such as operator priority).

In another possible implementation, the terminal device supports multiple RAT formats. In this case, the terminal device can scan the RF channels corresponding to each RAT system in order from high to bottom according to the RAT priority to find multiple available PLMNs; Find multiple available PLMNs; or, the terminal device can scan the RF channels corresponding to each RAT system in turn according to a preset rule to find multiple available PLMNs. In this embodiment of the present application, the terminal device may first consider which RAT system or RAT systems it supports support the desired network slice, and then perform RF channel scanning, thereby saving time, resources and improving efficiency of RF channel scanning; the terminal device may also In the traditional way, the RF channel scan is performed on all the RAT systems it supports first, and then the desired network slice is considered, which has better backward compatibility.

The terminal device performs PLMN selection in combination with the PLMN identity set obtained by the NAS entity, the network slice identity supported by the multi-RAT under the contracted PLMN obtained in step S401, and the desired network slice. There are two ways to implement it:

PLMN selection method 1:

The terminal device first selects the candidate RAT set from the network slice identifiers supported by multiple RATs under the PLMN signed by the terminal device according to the desired network slice, and then performs RF channel scanning for various RAT formats in the candidate RAT set to find the potential PLMN set, and then The terminal device finds a candidate PLMN set from the potential PLMN set according to the support capability of the desired network slice indicated by the RAT it supports, and then selects a PLMN from the candidate PLMN set.

Exemplarily, Table 4 shows the network slice identifiers supported by the multi-RAT under the PLMN subscribed by the terminal device.

Table 4

PLMN列表List of PLMNs
>PLMN#1>PLMN#1
>>RAT#1>>RAT#1
>>NS#1,NS#2,NS#3>>NS#1,NS#2,NS#3
>>RAT#2>>RAT#2
>>NS#2,NS#3>>NS#2,NS#3
>PLMN#2>PLMN#2
>>RAT#2>>RAT#2
>>NS#1,NS#2,NS#3>>NS#1,NS#2,NS#3
>>RAT#3>>RAT#3
>>NS#1,NS#3,NS#4>>NS#1,NS#3,NS#4
>>RAT#5>>RAT#5
>>NS#4,NS#5>>NS#4,NS#5
>PLMN#3>PLMN#3
>>RAT#4>>RAT#4
>>NS#1,NS#2,NS#3>>NS#1,NS#2,NS#3
>>RAT#6>>RAT#6
>>NS#3,NS#4>>NS#3,NS#4

Table 4 shows that the terminal equipment subscribes to PLMN#1, PLMN#2 and PLMN#3, and supports six RAT systems of RAT#1, RAT#2, RAT#3, RAT#4, RAT#5 and RAT#6. The PLMN#1 subscribed by the terminal equipment supports RAT#1 and RAT#2; RAT#1 supports NS#1, NS#2 and NS#3, and RAT#2 supports NS#2 and NS#3. PLMN#2 subscribed by terminal equipment supports RAT#2, RAT#3 and RAT#5; RAT#2 supports NS#1, NS#2 and NS#3, and RAT#3 supports NS#1, NS#3 and NS #4, RAT#5 supports NS#4 and NS#5. The PLMN#3 subscribed by the terminal equipment supports RAT#4 and RAT#6; wherein RAT#4 supports NS#1, NS#2 and NS#3, and RAT#6 supports NS#3 and NS#4.

Exemplarily, assuming that the desired network slice determined by the terminal device in the above step S402 is NS#4, the terminal device selects the RAT system that can support NS#4 from the six RAT systems supported by the terminal device, and obtains RAT#3, RAT #5 and RAT#6. Next, the terminal device may scan the multiple PLMN identities obtained by scanning the RF channels of RAT#3, RAT#5 and RAT#6 respectively. Assume that the PLMN IDs obtained by the terminal device by scanning on the RF channel of RAT#3 are PLMN#1, PLMN#2 and PLMN#3, and the PLMN IDs obtained by scanning on the RF channel of RAT#5 are PLMN#2 and PLMN#4 and PLMN#5, the PLMN identifiers obtained by scanning on the RF channel of RAT#6 are PLMN#1, PLMN#2 and PLMN#4, and the potential PLMN set {PLMN#1, PLMN#2, PLMN#3, PLMN# is obtained 4, PLMN #5}. Then, the terminal device further selects the candidate PLMN set from the potential PLMN set according to the support capability of the RAT system supported by the terminal device for the desired network slice. For example, for PLMN#1, although it includes RAT#1 and RAT#2, it does not support NS#4, so PLMN#1 does not belong to the candidate PLMN set; for PLMN#2, it includes RAT#3 and RAT#3 that support NS#4 and RAT#5, so PLMN#2 belongs to the set of candidate PLMNs; for PLMN#3, it includes RAT#6 supporting NS#4, so PLMN#3 belongs to the set of candidate PLMNs; for PLMN#4 and PLMN#5, since the terminal equipment subscribes The PLMN does not include PLMN#4 and PLMN#5, so PLMN#4 and PLMN#5 also do not belong to the candidate PLMN set. Thus, the set of candidate PLMNs is {PLMN#2, PLMN#3}. Further, if the terminal device reads PLMN#2 and PLMN#3 in different cells, the terminal device can select the PLMN according to the RSRP value of each cell, for example, the RSRP value of the cell that reads PLMN#2 is less than If the RSRP value of the cell of PLMN#3 is read, the PLMN selected by the terminal equipment is PLMN#3; if the terminal equipment reads PLMN#2 and PLMN#3 in the same cell, the terminal equipment can Criteria (such as operator priority) are used to select a PLMN. For example, the priority of PLMN#2 is higher than that of PLMN#3, and the PLMN selected by the terminal device is PLMN#1. It should be understood that, in this example, the terminal device may also scan the RF channels of RAT#3, RAT#5 and RAT#6 in a specific order according to the RAT priority or preset criteria, or scan only the RF channels of some RAT systems. channel, which is not specifically limited in this application.

To select a PLMN in this way, the terminal device first considers which RAT system or RAT systems it supports support the desired network slice, and then performs RF channel scanning, thereby saving RF channel scanning time, saving resources and improving efficiency.

PLMN selection method two:

The terminal device first scans the RF channels of various RAT systems it supports in the traditional way, finds a set of potential PLMNs, and then selects PLMNs according to the desired network slice.

Exemplarily, Table 4 is still used as the identifier of the network slice supported by the multi-RAT under the PLMN subscribed by the terminal device, and it is assumed that the desired network slice determined by the terminal device in the above step S402 is still NS#4. First, the terminal device scans the RF channels of each RAT system (RAT#1, RAT#2, RAT#3, RAT#4, RAT#5, and RAT#6) it supports to obtain multiple PLMN identities, and a set of potential PLMNs { PLMN#1, PLMN#2, PLMN#3, PLMN#4, PLMN#5}. Then, the terminal device further selects a candidate PLMN set from the potential PLMN set according to the support capability of the RAT standard it supports for the desired network slice. For example, for PLMN#1, since both RAT#1 and RAT#2 it contains do not support NS#4, PLMN#1 does not belong to the candidate PLMN set; for PLMN#2, since it contains RAT#3 and RAT# 5 all support NS#4, so PLMN#2 belongs to the candidate PLMN set; for PLMN#3, since it includes RAT#6 to support NS#4, PLMN#3 belongs to the candidate PLMN set; for PLMN#4 and PLMN#5, Since the PLMN subscribed by the terminal device does not include PLMN#4 and PLMN#5, PLMN#4 and PLMN#5 also do not belong to the candidate PLMN set. Thus, the set of candidate PLMNs is {PLMN#2, PLMN#3}. Further, if the terminal device reads PLMN#2 and PLMN#3 in different cells, the terminal device can select the PLMN according to the RSRP value of each cell, for example, the RSRP value of the cell that reads PLMN#2 is less than If the RSRP value of the cell of PLMN#3 is read, the PLMN selected by the terminal equipment is PLMN#3; if the terminal equipment reads PLMN#2 and PLMN#3 in the same cell, the terminal equipment can Criteria (such as operator priority) are used to select a PLMN. For example, the priority of PLMN#2 is higher than that of PLMN#3, and the PLMN selected by the terminal device is PLMN#1. It should be understood that, in this example, the terminal device may also scan the RF channels of RAT#3, RAT#5 and RAT#6 in a specific order according to the RAT priority or preset criteria, or scan only the RF channels of some RAT systems. channel, which is not specifically limited in this application.

In this way, PLMN selection is performed. The terminal device first performs RF channel scanning of all the RAT systems it supports in the traditional way, and then obtains a set of potential PLMNs, and then selects PLMNs according to the desired network slice, so as to have better backward compatibility. sex.

It should be noted that, in the above two manners, when the desired network slice is multiple network slices, the terminal device selects a PLMN that can fully support or maximally support the desired network slice. If there are multiple PLMNs that meet the above conditions, the terminal device can select a PLMN according to the RSRP value of the cell that reads the corresponding PLMN; or select a PLMN according to preset criteria (such as operator priority).

Through the above steps in this embodiment, the terminal equipment in the RRC non-connected state is implemented to consider the network slice to which the services that may be initiated subsequently belong when selecting a PLMN, so that the terminal equipment can select an appropriate PLMN, so that the terminal equipment can initiate services in the future. Quickly select cell access in a suitable PLMN, effectively reducing the delay of service establishment and reducing signaling overhead.

After the terminal device finishes selecting a PLMN, the terminal device performs cell selection to select a cell under the PLMN to camp on. After completing the PLMN selection, the terminal equipment performs cell selection and camps on the selected cell. Optionally, the terminal device periodically searches for a PLMN with a higher priority and after selecting a new PLMN, searches for a suitable cell to camp on.

FIG. 5 is a schematic flowchart of another method for cell selection provided by an embodiment of the present application. The method 500 is applied to a scenario where the terminal device performs cell selection to select a cell under the PLMN for camping after the terminal device completes the selection of the PLMN. The process shown in Figure 5 includes the following steps:

S501. A terminal device determines a desired network slice.

S502. The terminal device selects a cell according to the desired network slice.

The terminal device completes the PLMN selection after the aforementioned embodiment in FIG. 4 . In this step, the terminal equipment selects one of the cells to camp on according to the desired network slice in one or more cells in the selected PLMN.

In a possible implementation, when the PLMN selected by the terminal device includes multiple cells, and each cell supports the desired network slice, the terminal device can select a cell to camp on according to the cell RSRP, priority or preset criteria. . When the terminal device supports multiple RAT systems, the terminal device can also select an appropriate cell in one RAT to camp on according to the priority of the RATs or the preset criteria.

In another possible implementation, when the PLMN selected by the terminal device includes multiple cells, and each cell has different network slice support capabilities, the terminal device selects one of the multiple cells according to the desired network slice that can support the desired network slice. The cells of the network slice are camped on. If there are a plurality of such cells, the terminal device may further select one cell to camp on according to the cell RSRP, priority or preset criteria. When the terminal device supports multiple RAT systems, the terminal device can also select an appropriate cell in one RAT to camp on according to the priority of the RATs or the preset criteria.

Through the above steps in this embodiment, the terminal equipment in the RRC non-connected state is implemented to consider the network slice to which the services that may be initiated subsequently belong when selecting a cell, so that the terminal equipment can select an appropriate cell to camp on, so that when the terminal equipment subsequently initiates services It can quickly access suitable cells, effectively reduce the delay of service establishment and reduce signaling overhead.

Corresponding to the flow of the cell selection method shown in FIG. 5 , FIG. 6 to FIG. 8 respectively provide different ways of how the NAS entity and the AS entity inside the terminal device interact to realize the cell selection.

FIG. 6 provides a schematic flowchart of still another cell selection method. The method 600 is applied to a scenario where the NAS entity of the terminal device determines that the desired network slice is one network slice. The process described in Figure 6 includes the following steps:

S601. The NAS entity sends the desired network slice identifier of one network slice to the AS entity. Correspondingly, the AS entity receives the network slice identifier of the desired one network slice from the NAS entity.

In this step, the NAS entity sends its determined desired network slice identity to the AS entity. Among them, the expected network slice is a network slice, so the expected network slice identifier corresponds to a network slice identifier.

S602, the AS entity listens to the cell broadcast message.

After the PLMN selection is completed, in this step, the terminal device listens to broadcast messages of each cell in one or more cells in the PLMN it selects. The broadcast message includes information about network slices supported by the cell that sends the broadcast message, for example, network slice identifiers of one or more network slices supported by the cell.

S603, the AS entity selects a cell according to the desired network slice identifier.

In this step, the AS entity performs cell selection according to the network slice identifier of the desired network slice obtained in the above step S601 and the network slice identifier supported by one or more cells obtained in the above step S602.

In a possible implementation, the AS entity acquires in the above step S602 that the network slice identifier supported by only one cell contains the desired network slice identifier, and the AS entity selects the cell to camp on.

In another possible implementation, the AS entity obtains the network slice identifiers supported by multiple cells in the above step S602 and includes the desired network slice identifiers, and the AS entity can obtain the network slice identifiers from the multiple cells according to the cell RSRP, priority or preset criteria. Select one of the cells to camp on.

Through the above steps in this embodiment, it is realized that the AS entity of the terminal equipment in the RRC non-connected state considers a network slice to which a service that may be initiated subsequently belongs during cell selection, so that the AS entity can select a suitable cell to camp on, so that the NAS entity can When initiating a service subsequently, it can quickly access a suitable cell, effectively reducing the delay of service establishment and reducing signaling overhead.

FIG. 7 provides a schematic flowchart of yet another cell selection method. The method 700 is applied to a scenario in which the NAS entity of the terminal device selects a camping cell for multiple network slices. The process shown in Figure 7 includes the following steps:

S701. The NAS entity sends network slice identifiers of multiple first network slices to the AS entity. Correspondingly, the AS entity receives the network slice identifiers of the plurality of first network slices from the NAS entity.

In this step, the NAS entity sends multiple first network slice identifiers to the AS entity. The multiple first network slice identifiers are determined by the NAS entity, where the first network slice identifier is an identifier of a network slice that the terminal device signs with the selected PLMN. The NAS entity may send the identification of part or all of the network slices that the terminal device subscribes to the selected PLMN to the AS layer. Optionally, the plurality of first network slices are desired network slices with a plurality of network slices determined by the NAS entity.

S702, the AS entity listens to the cell broadcast message.

After completing the PLMN selection, in this step, the terminal device listens to the broadcast message of each cell in one or more cells in the PLMN it selects. The broadcast message includes information about network slices supported by the cell that sends the broadcast message, for example, network slice identifiers of one or more network slices supported by the cell.

S703. The AS entity selects a cell according to the multiple first network slice identifiers.

In this step, the AS entity performs cell selection according to the network slice identifiers of the multiple first network slices acquired in the above step S701 and the network slice identifiers supported by one or more cells acquired in the above step S702.

In a possible implementation, the network slice identifiers supported by each cell acquired by the AS entity in the foregoing step S702 include the above-mentioned multiple first network slice identifiers to varying degrees, and the AS entity selects one of the cells to camp on. For example, some cells do not support the first network slice, some cells support part of the first network slice, and some cells support all the first network slices. The AS entity selects the cell that can support the most first network slices for camping; or the AS entity selects a specific cell for camping according to preset criteria, for example, the specific cell does not support the most first network slices, but the specific cell The RSRP value of the cell is the largest.

In another possible implementation, the network slice identifiers supported by each cell acquired by the AS entity in the foregoing step S702 contain the above-mentioned multiple first network slice identifiers to the same extent, and the AS entity can use the cell RSRP, priority or The preset criterion selects one cell from the plurality of cells to camp on.

Through the above steps in this embodiment, it is realized that the AS entity of the terminal equipment in the RRC non-connected state considers multiple network slices to which different services belong when selecting a cell, so that the AS entity can select an appropriate cell to camp on, so that the NAS entity can subsequently initiate During the service, it can quickly access the appropriate cell, effectively reducing the delay of service establishment and reducing signaling overhead.

FIG. 8 provides a schematic flowchart of yet another cell selection method. The method 800 is applied to a scenario where the NAS entity of the terminal device provides multiple network slices and the AS entity determines the desired network slice. The process shown in Figure 8 includes the following steps:

S801. The NAS entity sends network slice identifiers of multiple first network slices to the AS entity. Correspondingly, the AS entity receives the network slice identifiers of the plurality of first network slices from the NAS entity.

S802, the AS entity determines the desired network slice.

In this step, the AS entity determines the desired network slice from the plurality of first network slices acquired in the above step S801. It is expected that the network slice is used to indicate the network slice to which the service that the terminal device may initiate subsequently belongs to. It should be understood that it is contemplated that a network slice may contain one or more network slices. When one or more services that may be subsequently initiated by the terminal device belong to one PDU session, the network slice is expected to be a network slice associated with the PDU session; when multiple services that may be subsequently initiated by the terminal device belong to multiple PDU sessions, respectively, The desired network slice is one or more network slices associated with the plurality of PDU sessions.

S803, the AS entity listens to the cell broadcast message.

S804, the AS entity selects a cell according to the desired network slice identifier.

In this step, the AS entity performs cell selection according to the network slice identifier of the desired network slice determined in the above step S802 and the network slice identifier supported by one or more cells obtained in the above step S803.

In a possible implementation, when the expected network slice identifier contains a network slice identifier, the AS entity determines in the above step S803 that the network slice identifier supported by only one cell contains the desired network slice identifier, and the AS entity selects the cell to stay.

In another possible implementation, when the expected network slice identifier includes a network slice identifier, the AS entity obtains the network slice identifiers supported by multiple cells in the above step S803 and includes the expected network slice identifier, then the AS entity can be based on the cell. RSRP, priority or preset criteria select one cell from the plurality of cells to camp on.

In yet another possible implementation, when the expected network slice identifier contains multiple network slice identifiers, the network slice identifiers supported by each cell obtained by the AS entity in the above step S803 contain the expected network slice identifiers to different degrees, then the AS entity The entity selects one of the cells to camp on. For example, some cells do not support desired network slices, some cells support some desired network slices, and some cells support all desired network slices. The AS entity selects the cell that can support the most desired network slices for camping; or the AS entity selects a specific cell for camping according to preset criteria, for example, the specific cell does not support the most desired network slices, but the specific cell The RSRP value is the largest.

In yet another possible implementation, when the expected network slice identifier contains multiple network slice identifiers, the network slice identifiers supported by each cell obtained by the AS entity in the above step S803 contain the expected network slice identifier to the same extent, then the AS entity The entity may select a cell from the plurality of cells to camp on according to the cell RSRP, priority or preset criteria.

Through the above steps in this embodiment, it is realized that the AS entity of the terminal equipment in the RRC non-connected state considers the network slice to which one or more services that may be initiated subsequently belong when selecting a cell, so that the AS entity can select a suitable cell to camp on. Therefore, when the NAS entity subsequently initiates a service, it can quickly access a suitable cell, effectively reducing the delay of service establishment and reducing signaling overhead.

The terminal equipment completes PLMN and cell selection and camps on a cell. Thereafter, the terminal device may also perform cell reselection based on the desired network slice, and reselect a new cell for camping. The difference from the cell reselection scenario described in the embodiment shown in FIG. 3 is that the terminal device is not about to initiate a service at this time, that is to say, the terminal device will not switch from the RRC disconnected state to the RRC connected state, and the terminal device is still in the RRC connected state. It will continue to be in the RRC disconnected state, but the terminal device may subsequently initiate services belonging to the desired network slice.

FIG. 9 provides a schematic flowchart of yet another cell selection method. The method 900 is applied to a scenario where the NAS entity of the terminal device determines that the desired network slice is a network slice and reselects a new cell for camping. In this scenario, the camping cell does not support the desired network slice of the terminal device, and the terminal device needs to camp on a new cell to support the desired network slice. The process described in Figure 9 includes the following steps:

S901. The NAS entity of the terminal device sends the network slice identifier of a desired network slice to the AS entity. Correspondingly, the AS entity receives the network slice identifier of the desired one network slice from the NAS entity.

S902, the camping cell sends AS information to the terminal device. Accordingly, the terminal device receives the network slice information from the camped cell.

Specifically, the AS entity of the terminal device receives the network slice information from the camping cell.

In this step, the camped cell sends the network slice information to the terminal equipment camped on the cell by means of cell broadcast. In a possible implementation, the network slice information is used to indicate network slice information of network slices supported by the residing cell. Exemplarily, the network slice information includes network slice identifiers of one or more network slices supported by the camping cell.

S903, the terminal device determines to perform cell reselection.

Specifically, the AS entity of the terminal device determines to perform cell reselection according to the desired network slice identifier.

S904, the terminal device performs cell reselection and camps on the target cell.

Specifically, the AS entity of the terminal device performs cell reselection according to the desired network slice identifier and camps on the target cell.

The foregoing steps S903 and S904 are similar to the steps S303 and S304 in the foregoing embodiment, and details are not described herein again.

It should be noted that, in the above step S902, the camping cell broadcasts the network slice information to the terminal equipment in the RRC disconnected state. In an actual system, if the camping cell is a serving cell connected to the terminal equipment in the RRC connected state before the terminal equipment enters the RRC disconnected state, the serving cell can also use a single The above-mentioned network slice information is sent to the terminal device by means of broadcast (for example, through RRC signaling). In this way, when the terminal device enters the RRC disconnected state and the cell it camps on is the serving cell, the terminal device can directly determine whether to perform cell reselection according to the network slice information previously obtained from the serving cell.

Through the above steps in this embodiment, the terminal device realizes that in the case that the terminal device in the RRC disconnected state may initiate a service belonging to a network slice later, the AS entity can choose to reside in a suitable cell that supports the network slice, so that When the terminal equipment subsequently initiates a service, it can quickly access an appropriate cell, effectively reducing the delay of service establishment and reducing signaling overhead.

FIG. 10 provides a schematic flowchart of yet another cell selection method. The method 1000 is applied to a scenario where the NAS entity of the terminal device reselections a new cell for multiple network slices to camp on. In this scenario, the camping cell does not support the multiple network slices of the terminal equipment, and the terminal equipment needs to camp on a new cell to support the multiple network slices; or the camping cell partially supports the multiple networks of the terminal equipment Slicing, the terminal device needs to camp on a new cell to support the multiple network slices more or fully. The process described in Figure 1000 includes the following steps:

S1001. The NAS entity of the terminal device sends the network slice identifiers of the multiple first network slices to the AS entity. Correspondingly, the AS entity receives the network slice identifiers of the plurality of first network slices from the NAS entity.

The foregoing step S1001 is similar to the step S701 in the foregoing embodiment, and details are not described herein again.

S1002, the camping cell sends AS information to the terminal device. Accordingly, the terminal device receives the network slice information from the camped cell.

S1003, the terminal device determines to perform cell reselection.

Specifically, the AS entity of the terminal device determines to perform cell reselection according to the multiple first network slice identifiers.

S1004, the terminal device performs cell reselection and camps on the target cell.

Specifically, the AS entity of the terminal device performs cell reselection according to the multiple first network slice identifiers and camps on the target cell.

The foregoing steps S1002 to S1004 are respectively similar to the steps S902 to S904 of the foregoing embodiment, and details are not described herein again.

It should be noted that, in the above step S1002, the camping cell broadcasts the network slice information to the terminal device in the RRC disconnected state. In the actual system, if the camping cell is the serving cell connected to the RRC_CONNECTED state before the terminal equipment enters the RRC disconnected state, the serving cell can also be unicast before the terminal equipment enters the RRC disconnected state from the RRC_CONNECTED state. The above-mentioned network slice information is sent to the terminal device in a manner (eg, through RRC signaling). In this way, when the terminal device enters the RRC disconnected state and the cell it camps on is the serving cell, the terminal device can directly determine whether to perform cell reselection according to the network slice information it previously obtained from the serving cell.

Through the above steps in this embodiment, the AS entity can realize that the terminal equipment supporting multiple network slices is in the RRC disconnected state, or the terminal equipment in the RRC disconnected state may subsequently initiate services belonging to multiple network slices. Selecting to reside in an appropriate cell that supports the multiple network slices enables the terminal device to quickly access the appropriate cell when subsequently initiating a service, effectively reducing service establishment delay and signaling overhead.

FIG. 11 provides a schematic flowchart of yet another cell selection method. The method 1100 is applied to a scenario where the NAS entity of the terminal device provides multiple network slices and the AS entity determines the desired network slice. In this scenario, the camping cell does not support the desired network slice of the terminal equipment, and the terminal equipment needs to camp on a new cell to support the desired network slice; or the camping cell supports part of the desired network slice of the terminal equipment, and the terminal equipment needs to camp on Stay in a new cell to support the desired network slice more or fully. The process shown in Figure 11 includes the following steps:

S1101. The NAS entity of the terminal device sends the network slice identifiers of the multiple first network slices to the AS entity. Correspondingly, the AS entity receives the network slice identifiers of the plurality of first network slices from the NAS entity.

S1102, the AS entity of the terminal device determines the desired network slice.

The foregoing steps S1101 and S1102 are respectively similar to the steps S801 and S802 in the foregoing embodiment, and details are not described herein again.

S1103, the camping cell sends AS information to the terminal device. Accordingly, the terminal device receives the network slice information from the camped cell.

The foregoing step S1103 is similar to the step S902 in the foregoing embodiment, and details are not described herein again.

S1104, the terminal device determines to perform cell reselection.

Specifically, the AS entity of the terminal device determines to perform cell reselection.

S1105, the terminal device performs cell reselection and camps on the target cell.

Specifically, the AS entity of the terminal equipment performs cell reselection and camps on the target cell.

The foregoing steps S1104 and S1105 are respectively similar to the steps S303 and S304 in the foregoing embodiment, and details are not described herein again.

It should be noted that, in the above step S1103, the camping cell broadcasts the network slice information to the terminal equipment in the RRC disconnected state. In the actual system, if the camping cell is the serving cell connected to the RRC_CONNECTED state before the terminal equipment enters the RRC disconnected state, the serving cell can also be unicast before the terminal equipment enters the RRC disconnected state from the RRC_CONNECTED state. The above-mentioned network slice information is sent to the terminal device in a manner (eg, through RRC signaling). In this way, when the terminal device enters the RRC disconnected state and the cell it camps on is the serving cell, the terminal device can directly determine whether to perform cell reselection according to the network slice information previously obtained from the serving cell.

Through the above steps in this embodiment, when the terminal device supporting multiple network slices is in the RRC non-connected state and the terminal device may subsequently initiate services belonging to one network slice, the AS entity can choose to reside in the network slice supporting this network slice. The appropriate cell is selected, so that the terminal equipment can quickly access the appropriate cell when initiating a service subsequently, effectively reducing the delay of service establishment and reducing signaling overhead.

It should be noted that, in the embodiments shown in FIG. 9 to FIG. 11 , although the terminal device is in the RRC disconnected state, the core network side may store the context information of the PDU session performed by the terminal device before entering the RRC disconnected state. .

In the case where the core network side saves the context information of a PDU session of the terminal device, in the embodiments shown in FIG. 9 to FIG. 11 , correspondingly, the NAS entity sends the network slice associated with the PDU session as the desired network slice to the The AS, or the AS entity, stores the network slice associated with the PDU session and determines the desired network slice. The AS entity performs cell reselection according to the desired network slice.

In the case where the core network side stores the context information of multiple PDU sessions of the terminal device, in the embodiments shown in FIG. 9 to FIG. 11 , correspondingly, in a possible implementation, the NAS entity stores the multiple PDUs The network slice associated with the session, the NAS entity determines one network slice as the desired network slice from the multiple network slices associated with the multiple PDU sessions, and sends the desired network slice identifier to the AS entity, and the AS entity determines the desired network slice according to the desired network slice. ID for cell reselection. In another possible implementation, the NAS entity stores the network slices associated with the multiple PDU sessions, the NAS entity sends the network slice identifiers of the multiple network slices associated with the multiple PDU sessions to the AS entity, and the AS entity A network slice identifier is determined from these network slice identifiers as a desired network slice identifier, and cell reselection is performed according to the desired network slice identifier. In another possible implementation, the NAS entity stores the network slices associated with the multiple PDU sessions, the NAS entity sends the network slice identifiers of the multiple network slices associated with the multiple PDU sessions to the AS entity, and the AS entity The reselection camp is determined from the cell broadcast message to the cell that can support the plurality of network slices to the greatest extent. In another possible implementation, the AS entity stores the network slices associated with the multiple PDU sessions, the AS entity determines one network slice as the desired network slice from the multiple network slices associated with the multiple PDU sessions, and the AS The entity performs cell reselection according to the desired network slice identifier. In another possible implementation, the AS entity stores the network slices associated with the multiple PDU sessions, and the AS entity determines from the cell broadcast message to reselection to a cell that can support the multiple network slices to the greatest extent.

It should be noted that the terminal equipment in the RRC disconnected state may move, causing the terminal equipment to move from one registration area to another registration area. In this case, the terminal device needs to initiate a registration area update process to obtain a new registered network slice. The newly registered network slice is used as the candidate network slice in the above-mentioned cell reselection, that is, the target network slice or the expected network slice considered by the terminal device when initiating cell reselection is one or more network slices in the candidate network slices.

In the above-mentioned embodiments, it may be implemented in whole or in part by software, hardware, firmware or any combination thereof. When implemented in software, it can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of the present application are generated. The computer may be a general purpose computer, special purpose computer, computer network, or other programmable device. The computer instructions may be stored in or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be downloaded from a website site, computer, server, or data center Transmission to another website site, computer, server, or data center is by wire (eg, coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (eg, infrared, wireless, microwave, etc.). The computer-readable storage medium may be any available medium that can be accessed by a computer or a data storage device such as a server, data center, etc. that includes an integration of one or more available media. The usable media may be magnetic media (eg, floppy disks, hard disks, magnetic tapes), optical media (eg, DVDs), or semiconductor media (eg, solid state disks (SSDs)), and the like. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of this patent application.

The method embodiments of the present application are described in detail above with reference to FIGS. 3 to 11 , and the apparatus embodiments of the present application are described in detail below with reference to FIGS. 12 to 14 . It should be understood that the apparatus embodiments and the method embodiments correspond to each other, and for similar descriptions, reference may be made to the method embodiments. Notably, the apparatus embodiments may be used in conjunction with the above-described methods, or may be used alone.

FIG. 12 shows a schematic block diagram of a terminal device 1200 according to an embodiment of the present application. The terminal device 1200 may correspond to (for example, may be configured in or be itself) the terminal device described in the foregoing method 300, or the foregoing method 400. or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or described in the above method 900 The terminal device, or the terminal device described in the above method 1000, or the terminal device described in the above method 1100, or the terminal device described in other implementation manners.

The terminal device 1200 may include a communication unit 1201 and a processing unit 1202 . The communication unit 1201 may include a sending unit and/or a receiving unit, the sending unit is used to implement the sending function, the receiving unit is used to implement the receiving function, and the communication unit 1201 may implement the sending function and/or the receiving function. The communication unit may also be described as a transceiving unit. The terminal device 1200 may further include a storage unit 1203 for storing programs or data to be executed by the processing unit 1202 or storing information received and/or transmitted through the communication unit 1201 . The terminal device 1200 may be a terminal device, a device in another device, or a device that can be used in combination with the terminal device.

Each unit in the terminal device 1200 is respectively configured to execute the terminal device described in the above method 300, or the terminal device described in the above method 400, or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in the above method 900, or the terminal device described in the above method 1000, or the terminal device described in the above method 1100, or the terminal device described in other implementation manners, each action or processing process performed. Here, in order to avoid redundant description, the detailed description thereof is omitted.

FIG. 13 shows a schematic block diagram of a terminal device 1300 according to an embodiment of the present application. The terminal device 1300 may correspond to (for example, may be configured in or be itself) the terminal device described in the foregoing method 300, or the foregoing method 400. or the terminal device described in the above method 500, or the terminal device described in the above method 600, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or described in the above method 900 The terminal device, or the terminal device described in the above method 1000, or the terminal device described in the above method 1100, or the terminal device described in other implementation manners.

The terminal device 1300 may include one or more processors 1301 . The processor 1301 may be a general-purpose processor or a special-purpose processor, or the like. For example, it may be a baseband processor or a central processing unit. The baseband processor can be used to process the communication protocol and communication data, and the central processing unit can be used to control the terminal equipment, execute the computer program, and process the data of the computer program.

The terminal device 1300 may further include a transceiver 1302 and an antenna 1303 . The transceiver 1302 may be called a transceiver unit, a transceiver, or a transceiver circuit, etc., and is used to implement a transceiver function. The transceiver 1302 may include a receiver and a transmitter, the receiver may be called a receiver or a receiving circuit, etc., for implementing a receiving function; the transmitter may be called a transmitter or a transmitting circuit, etc., for implementing a transmitting function.

Optionally, the terminal device 1300 may include one or more memories 1304 on which a computer program 1305 may be stored, and the computer program may be executed on the terminal device 1300, so that the terminal device 1300 executes the methods described in the foregoing method embodiments. method. Optionally, the memory 1304 may also store data. The terminal device 1300 and the memory 1304 can be set separately or integrated together.

In a possible implementation, the processor 1301 may include a transceiver for implementing the functions of receiving and transmitting. For example, the transceiver may be a transceiver circuit, or an interface, or an interface circuit. Transceiver circuits, interfaces or interface circuits used to implement receiving and transmitting functions may be separate or integrated. The above-mentioned transceiver circuit, interface or interface circuit can be used for reading and writing code/data, or the above-mentioned transceiver circuit, interface or interface circuit can be used for signal transmission or transmission.

In a possible implementation, the processor 1301 may store a computer program 1306, and the computer program 1306 runs on the processor 1301 to enable the terminal device 1300 to execute the methods described in the above method embodiments. The computer program 1306 may be embodied in the processor 1301, in which case the processor 1301 may be implemented by hardware.

In a possible implementation, the terminal device 1300 may include a circuit, and the circuit may implement the functions of sending or receiving or communicating in the foregoing method embodiments. The processors and transceivers described in this application can be implemented in integrated circuits (ICs), analog ICs, radio frequency integrated circuits (RFICs), mixed-signal ICs, application specific integrated circuits (ASICs), printed circuit boards ( printed circuit board, PCB), electronic equipment, etc. The processor and transceiver can also be fabricated using various IC process technologies, such as complementary metal oxide semiconductor (CMOS), nMetal-oxide-semiconductor (NMOS), P-type Metal oxide semiconductor (positive channel metal oxide semiconductor, PMOS), bipolar junction transistor (BJT), bipolar CMOS (BiCMOS), silicon germanium (SiGe), gallium arsenide (GaAs), etc.

It should be understood that the processor 1301 may be a central processing unit (CPU), a network processor (NP), a hardware chip or any combination thereof. The above-mentioned hardware chip may be an application-specific integrated circuit (ASIC), a programmable logic device (PLD) or a combination thereof. The above-mentioned PLD can be a complex programmable logic device (CPLD), a field-programmable gate array (FPGA), a generic array logic (GAL) or any combination thereof. The memory 1304 can be a volatile memory (volatile memory), such as random-access memory (RAM); or a non-volatile memory (non-volatile memory), such as read-only memory (read-only memory) , ROM), flash memory (flash memory), hard disk drive (HDD) or solid-state drive (solid-state drive, SSD); it can also be a combination of the above types of memory.

Each processor 1301 and transceiver 1302 in the terminal device 1300 are respectively configured to execute the terminal device described in the above method 300, or the terminal device described in the above method 400, or the terminal device described in the above method 500, or the above method 600 The terminal device described in the above method, or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in the above method 900, or the terminal device described in the above method 1000, or the above method 1100 Each action or process performed by the terminal device described in , or the terminal device described in other implementation manners. Here, in order to avoid redundant description, the detailed description thereof is omitted.

The structure of the terminal device 1300 may not be limited by FIG. 13 . Terminal device 1300 may be a stand-alone device or may be part of a larger device. For example, the terminal device 1300 may be:

(1) Independent integrated circuit IC, or chip, or, chip system or subsystem;

(2) a set with one or more ICs, optionally, the IC set can also include a storage component for storing data and computer programs;

(3) ASIC, such as modem (Modem);

(4) Modules that can be embedded in other equipment;

(5) Receivers, terminals, smart terminals, cellular phones, wireless devices, handsets, mobile units, vehicle-mounted devices, network devices, cloud devices, artificial intelligence devices, etc.;

(6) Others, etc.

For the case that the terminal device 1300 may be a chip or a chip system, reference may be made to the schematic structural diagram of the chip 1400 shown in FIG. 14 . The chip 1400 shown in FIG. 14 includes a logic circuit 1401 and an input-output interface 1402, the input-output interface 1402 is used for communicating with modules other than the chip 1400, and the logic circuit 1401 is used for running a computer program or instruction to realize the above-mentioned Function of any method embodiment. The number of input and output interfaces 1402 may be multiple.

Optionally, the chip 1400 further includes a memory 1403 for storing necessary computer programs (or instructions) and data.

The logic circuit 1401 and the input/output interface 1402 in the chip 1400 are respectively used to execute the terminal device described in the above method 300, or the terminal device described in the above method 400, or the terminal device described in the above method 500, or the above method 600. or the terminal device described in the above method 700, or the terminal device described in the above method 800, or the terminal device described in the above method 900, or the terminal device described in the above method 1000, or described in the above method 1100 Each action or process performed by the terminal device, or the terminal device described in other implementation manners. Here, in order to avoid redundant description, the detailed description thereof is omitted.

In the several embodiments provided in this application, it should be understood that the disclosed apparatus and method may be implemented in other manners. For example, the device embodiments described above are only illustrative. For example, the division of units is only a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated. to another system, or some features can be ignored, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication coupling may be through some interfaces, indirect coupling or communication coupling of devices or units, and may be in electrical, mechanical or other forms.

Units described as separate components may or may not be physically separated, and components shown as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

In addition, each functional unit in each embodiment of the present patent application may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit.

The functions, if implemented in the form of software functional units and sold or used as stand-alone products, may be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present patent application can be embodied in the form of a software product in essence, or the part that contributes to the prior art or the part of the technical solution, and the computer software product is stored in a storage medium, Several instructions are included to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of the present patent application. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk and other media that can store program codes .

The above are only specific implementations of this patent application, but the protection scope of this patent application is not limited to this. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed in this patent application, All should be covered within the scope of protection of this patent application. Therefore, the protection scope of this patent application shall be subject to the protection scope of the claims.

Claims

A method for cell selection, comprising:

The terminal device determines first network slice information, where the first network slice information includes an identifier of at least one network slice;

receiving, by the terminal device, second network slice information sent from the residing cell, where the second network slice information includes an identifier of at least one network slice; and

The terminal device performs cell reselection according to the first network slice information and the second network slice information.
The method according to claim 1, wherein the first network slice information is used to indicate an identifier of at least one network slice to which at least one service to be initiated by the terminal device belongs.
The method according to claim 1, wherein the second network slice information includes an identifier of at least one network slice supported by the camping cell.
The method according to claim 1, wherein the second network slice information includes an identifier of at least one network slice supported by the camping cell and at least one network slice supported by at least one neighboring cell of the camping cell. An identifier for a network slice.
The method according to any one of claims 1 to 3, wherein the terminal device performs cell reselection according to the first network slice information and the second network slice information, comprising:

In the case that the network slice identifier of the residing cell does not include the first network slice identifier, the terminal device performs cell reselection; wherein the network slice identifier of the residing cell is used to indicate that the second network slice information includes at least An identifier of a network slice, where the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information.
The method according to claim 1, 2 or 4, wherein the terminal device performs cell reselection according to the first network slice information and the second network slice information, comprising:

In the case where the network slice identifier of the residing cell does not include the first network slice identifier, and the network slice identifier of at least one neighboring cell partially or completely includes the first network slice identifier, the terminal device performs cell reselection; The residing cell network slice identifier is used to indicate the identifier of at least one network slice supported by the residing cell, the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the The neighbor network slice identifier is used to indicate an identifier of at least one network slice supported by a neighbor cell of the camping cell.
The method according to claim 1, 2 or 4, wherein the terminal device performs cell reselection according to the first network slice information and the second network slice information, comprising:

The network slice identifier part of the residing cell contains the first network slice identifier, and the number of network slices in the intersection of at least one neighbor network slice identifier and the first network slice identifier is greater than the network slice identifier of the residing cell and the first network slice identifier. In the case of the number of network slices in the intersection of a network slice identifier, the terminal device performs cell reselection; wherein the network slice identifier of the residing cell is used to indicate the identifier of at least one network slice supported by the residing cell , the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the neighbor network slice identifier is used to indicate the network slice supported by at least one neighbor of the residing cell. The identifier of at least one network slice.
The method according to claim 1, 2 or 4, wherein the terminal device performs cell reselection according to the first network slice information and the second network slice information, comprising:

The number of network slices in the intersection of the network slice identifier of the residing cell and the first network slice identifier is equal to the number of network slices in the intersection of the network slice identifier of at least one neighbor cell and the first network slice identifier, and the chain of the residing cell When the road quality is lower than the link quality of the at least one neighboring cell, the terminal device performs cell reselection; wherein the network slice identifier of the camping cell is used to indicate at least one network supported by the camping cell The identifier of the slice, the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the neighbor network slice identifier is used to indicate at least one neighbor of the residing cell Identification of at least one network slice supported.
The method according to claim 6 or 7, wherein the terminal equipment performs cell reselection, comprising:

The terminal device selects, in the at least one neighbor cell, a neighbor cell with the largest number of network slices in the intersection of the neighbor cell network slice identifier and the first network slice identifier to reside there.
The method according to claim 9, wherein the terminal equipment performs cell reselection, comprising:

In the case where the number of network slices in the intersection of the plurality of neighbor network slice identifiers and the first network slice identifier is the largest,

The terminal device selects an adjacent cell with the highest link quality among the plurality of adjacent cells for camping; or, the terminal device selects the adjacent cell with the highest priority among the plurality of adjacent cells to camp on .
The method according to claim 8, wherein the terminal equipment performs cell reselection, comprising:

The terminal device selects an adjacent cell with the highest link quality in the at least one adjacent cell for camping; or the terminal device selects an adjacent cell with the highest priority in the at least one adjacent cell for camping.
A terminal device, the terminal device includes a processing unit and a communication unit, wherein,

the processing unit, configured to determine first network slice information, where the first network slice information includes an identifier of at least one network slice;

The communication unit is communicatively coupled to the processing unit, and is configured to receive second network slice information sent from the residing cell, where the second network slice information includes an identifier of at least one network slice;

The processing unit is further configured to perform cell reselection according to the first network slice information and the second network slice information.
The terminal device according to claim 12, wherein the first network slice information is used to indicate an identifier of at least one network slice to which at least one service to be initiated by the terminal device belongs.
The terminal device according to claim 12, wherein the second network slice information includes an identifier of at least one network slice supported by the camping cell.
The terminal device according to claim 12, wherein the second network slice information comprises an identifier of at least one network slice supported by the camping cell and a network slice supported by at least one neighboring cell of the camping cell. The identifier of at least one network slice.
The terminal device according to any one of claims 12 to 14, wherein the processing unit performs cell reselection according to the first network slice information and the second network slice information, comprising:

In the case that the network slice identifier of the residing cell does not include the first network slice identifier, the processing unit performs cell reselection; wherein the network slice identifier of the residing cell is used to indicate that the second network slice information includes at least An identifier of a network slice, where the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information.
The terminal device according to claim 12, 13 or 15, wherein the processing unit performs cell reselection according to the first network slice information and the second network slice information, comprising:

In the case where the network slice identifier of the residing cell does not include the first network slice identifier, and the network slice identifier of at least one neighboring cell partially or completely includes the first network slice identifier, the processing unit performs cell reselection; The residing cell network slice identifier is used to indicate the identifier of at least one network slice supported by the residing cell, the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the The neighbor network slice identifier is used to indicate an identifier of at least one network slice supported by a neighbor cell of the camping cell.
The terminal device according to claim 12, 13 or 15, wherein the processing unit performs cell reselection according to the first network slice information and the second network slice information, comprising:

The network slice identifier part of the residing cell contains the first network slice identifier, and the number of network slices in the intersection of at least one neighbor network slice identifier and the first network slice identifier is greater than the network slice identifier of the residing cell and the first network slice identifier. In the case of the number of network slices in the intersection of a network slice identifier, the processing unit performs cell reselection; wherein the network slice identifier of the residing cell is used to indicate the identifier of at least one network slice supported by the residing cell , the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the neighbor network slice identifier is used to indicate the network slice supported by at least one neighbor of the residing cell. The identifier of at least one network slice.
The terminal device according to claim 12, 13 or 15, wherein the processing unit performs cell reselection according to the first network slice information and the second network slice information, comprising:

The number of network slices in the intersection of the network slice identifier of the residing cell and the first network slice identifier is equal to the number of network slices in the intersection of the network slice identifier of at least one neighbor cell and the first network slice identifier, and the chain of the residing cell When the road quality is lower than the link quality of the at least one neighboring cell, the processing unit performs cell reselection; wherein, the network slice identifier of the residing cell is used to indicate at least one network supported by the residing cell The identifier of the slice, the first network slice identifier is used to indicate the identifier of at least one network slice included in the first network slice information, and the neighbor network slice identifier is used to indicate at least one neighbor of the residing cell Identification of at least one network slice supported.
The terminal device according to claim 17 or 18, wherein the processing unit performs cell reselection, comprising:

The processing unit selects, in the at least one neighbor cell, a neighbor cell with the largest number of network slices in the intersection of the neighbor cell network slice identifier and the first network slice identifier to reside there.
The terminal device according to claim 20, wherein the processing unit performs cell reselection, comprising:

In the case where the number of network slices in the intersection of the plurality of neighbor network slice identifiers and the first network slice identifier is the largest,

The processing unit selects an adjacent cell with the highest link quality among the plurality of adjacent cells for camping; or, the terminal device selects the adjacent cell with the highest priority among the plurality of adjacent cells to camp on .
The terminal device according to claim 19, wherein the processing unit performs cell reselection, comprising:

The processing unit selects an adjacent cell with the highest link quality in the at least one adjacent cell for camping; or the terminal device selects an adjacent cell with the highest priority in the at least one adjacent cell for camping.
A communication device, comprising: a processor and a memory, wherein the processor and the memory are communicatively coupled, the memory stores program instructions, and when the program instructions stored in the memory are executed by the processor , the cell selection method according to any one of claims 1 to 11 is implemented.
A chip, characterized in that the chip includes a logic circuit and an input/output interface, the input/output interface is used to communicate with modules other than the chip, and the logic circuit is used to run a computer program or instruction to achieve A method as claimed in any one of claims 1 to 11.
A computer-readable storage medium, characterized in that the computer-readable storage medium stores a computer program, and the computer program includes program instructions, and when the program instructions are executed by a communication device, the communication device can execute the program as claimed in the claims The method of any one of 1 to 11.