Communication method, terminal equipment, access network equipment, readable storage medium and chip

Abstract

The invention relates to the technical field of communication, in particular to a communication method, terminal equipment, access network equipment, a readable storage medium and a chip. The communication method is applied to a non-access stratum (NAS) of a terminal device, and comprises: sending first indication information to an access stratum (AS) of the terminal device, the first indication information being used for indicating a radio resource control (RRC) state when the AS sends a serving cell identifier of the terminal device to the NAS; receiving a serving cell identifier from the AS; wherein the serving cell identifier is used for determining whether the terminal device is located in a network slice service area (NS-AoS) of a first network slice, and the first network slice belongs to a configured network slice of the terminal device. In the application, the AS of the terminal device reports the serving cell identifier to the NAS according to the RRC state indicated by the NAS, which is helpful for saving the power consumption of the terminal device.

Description

Technical Field

[0001] This application relates to the field of communication technologies, and in particular, to a communication method, a terminal device, an access network device, a readable storage medium, and a chip. Background Art

[0002] Currently, the 5th generation (5G) communication technology supports providing customized services for different services through network slicing technology to meet different service requirements. To facilitate the management of network slices, a network slice area of service (NS-AoS) is introduced in network slicing technology. The NS-AoS is indicated by a core network device to a terminal device and is used to represent the service area of a specific network slice, which includes identification information of one or more cells that can provide services for this network slice. It can be understood that according to the NS-AoS of the network slice, the terminal device can select an appropriate cell to access and thus use this network slice.

[0003] Since the relevant processes of registration and protocol data unit (PDU) session management are decided by the non-access stratum (NAS) of the terminal device, after the introduction of NS-AoS, the NAS of the terminal device needs to determine the position of the serving cell relative to the NS-AoS based on the received NS-AoS of the specific network slice, and then determine the subsequent behavior of the terminal device for this network slice. Therefore, the access stratum (AS) of the terminal device needs to report the serving cell identifier to the NAS of the terminal device. Summary of the Invention

[0004] This application provides a communication method, a terminal device, an access network device, a readable storage medium, and a chip, which are used for the AS of the terminal device to report the serving cell to the NAS of the terminal device according to a specific mechanism, and can reduce the power consumption of the terminal device.

[0005] In a first aspect, an embodiment of this application provides a communication method, which is applied to the NAS of a terminal device. The method includes: sending first indication information to the AS of the terminal device, where the first indication information is used to indicate the radio resource control (RRC) state when the AS sends the serving cell identifier of the terminal device to the NAS; receiving the serving cell identifier from the AS. The serving cell identifier is used to determine whether the terminal device is located within the NS-AoS of a first network slice, and the first network slice is the network slice configured by the network device for the terminal device.

[0006] Exemplarily, the RRC state includes at least one of an RRC connected state, an RRC idle state, and an RRC inactive state.

[0007] Through the communication method provided in this embodiment, the NAS of the terminal device can instruct the AS to report the serving cell identifier to the NAS according to a specific RRC state, avoiding the situation where the AS frequently reports the serving cell identifier to the NAS, which helps to save the power consumption of the terminal device.

[0008] In some embodiments, the first indication information further includes a first timer or a first period. The first timer is used to instruct the AS to send the serving cell identifier to the NAS after the first timer expires; the first period is used to instruct the AS to send the serving cell identifier to the NAS according to the first period. In this embodiment, the NAS of the terminal device can control the timing of the AS reporting the serving cell identifier, for example, controlling the AS to report the serving cell identifier after a period of time, or reporting the serving cell identifier periodically.

[0009] In some embodiments, the conditions for the NAS to send the first indication information to the AS include any one of the following conditions 1 to 3.

[0010] Condition 1, the NAS supports the NS-AoS capability.

[0011] Condition 2, the NAS supports the NS-AoS capability and receives the NS-AoS information of the first network slice of the terminal device within the registration area.

[0012] Condition 3, the NAS supports the NS-AoS capability, receives the NS-AoS information of the first network slice of the terminal device within the registration area, and the NAS determines that a registration request for the first network slice needs to be initiated / determines that the user plane of the PDU session associated with the first network slice needs to be activated.

[0013] In this embodiment, the NAS of the terminal device can instruct the AS to report the serving cell identifier when it supports the NS-AoS capability and / or has a need to use network slices, avoiding the situation of useless reporting by the AS, that is, avoiding the situation where the serving cell identifier reported by the AS is not used by the NAS or cannot be used by the NAS.

[0014] Second aspect, this embodiment provides a communication method applied to the AS of a terminal device. The method includes: receiving first indication information from the NAS of the terminal device, and / or receiving second indication information from an access network device; wherein, the first indication information is used to indicate that the NAS supports the NS-AoS capability, and the second indication information is used to indicate that the AS sends the serving cell identifier of the terminal device to the NAS; and sending the serving cell identifier to the NAS. The serving cell identifier is used to determine whether the terminal device is located within the NS-AoS of a first network slice, and the first network slice belongs to the network slices configured by the network device for the terminal device.

[0015] Through the communication method provided in this embodiment, the AS of the terminal device can report the serving cell identifier to the AS of the terminal device according to the indication information sent by the NAS and / or the access network device. This method clarifies the mechanism for the AS to report the serving cell identifier to the NAS, which helps to save the power consumption of the terminal device.

[0016] In some embodiments, the first indication information includes any one of the following indication methods, or a combination of the following multiple indication methods:

[0017] The first indication information is used to indicate that the AS sends the serving cell identifier of the terminal device to the NAS.

[0018] The first indication information includes the NS-AoS information of the first network slice.

[0019] The first indication information is further used to indicate the RRC state when the AS sends the serving cell identifier to the NAS. Exemplarily, the RRC state includes at least one of RRC connected state, RRC idle state, and RRC inactive state.

[0020] In some embodiments, the second indication information includes any one of the following indication methods, or a combination of the following multiple indication methods:

[0021] The second indication information is used to indicate that 0 resources are configured for the serving cell of the terminal device for a second network slice, and the second network slice is a network slice supported by the tracking area where the serving cell of the terminal device is located.

[0022] The second indication information is used to indicate the RRC state when the AS sends the serving cell identifier to the NAS. Exemplarily, the RRC state includes at least one of RRC connected state, RRC idle state, and RRC inactive state.

[0023] In some embodiments, the first indication information, and / or the second indication information further includes a first timer or a first period, where the first timer is used to indicate that the AS sends the serving cell identifier to the NAS after the first timer expires; the first period is used to indicate that the AS sends the serving cell identifier to the NAS according to the first period.

[0024] In this embodiment, the AS can control the timing of reporting the serving cell identifier. For example, the AS can report the serving cell identifier after a period of time according to the first timer, or report the serving cell identifier periodically according to the first period.

[0025] In some embodiments, when the first indication information and / or the second indication information indicate the RRC state when the AS sends the serving cell identifier to the NAS, sending the serving cell identifier to the NAS includes: sending the serving cell identifier to the NAS when the RRC state is satisfied.

[0026] It should be noted that when the RRC states indicated by the first indication information and the second indication information are different, the AS reports the serving cell identifier to the NAS based on the RRC state in the first indication information. Or, the AS reports the serving cell identifier to the NAS based on the RRC state in the second indication information. Or, the AS can determine which indication information to use as the basis for determining the RRC state when reporting the serving cell identifier according to further indications from the NAS or the access network device.

[0027] In some embodiments, when the AS sends the serving cell identifier to the NAS when the RRC state is satisfied, it includes: if the terminal device does not meet the first condition, the AS sends the serving cell identifier to the NAS when the RRC state is satisfied.

[0028] In some embodiments, the first condition includes at least one of the terminal device being in a capacity - limited state, a low - power state, and a frequently - moving state.

[0029] In a third aspect, this embodiment provides a communication method applied to the AS of a terminal device. The method includes:

[0030] Receiving the first indication information from the NAS of the terminal device, and / or receiving the second indication information from the access network device; wherein, the first indication information is used to indicate that the NAS supports the NS - AoS capability, and the second indication information is used to indicate that the AS sends the serving cell identifier of the terminal device to the NAS; and,

[0031] When the terminal device meets the first condition, not sending the serving cell identifier to the NAS; or,

[0032] When the terminal device meets the first condition, sending the third indication information to the NAS, where the third indication information is used to indicate to the NAS that the AS does not send the serving cell identifier to the NAS; or,

[0033] When the terminal device meets the first condition, reporting the serving cell identifier to the NAS according to a second timer or a second period determined by the AS itself.

[0034] Among them, the serving cell identifier is used to determine whether the terminal device is within the NS-AoS of the first network slice, and the first network slice belongs to the network slice configured by the network device for the terminal device. Exemplarily, the first condition includes at least one of the terminal device being in a capacity-limited state, a low-power state, and a frequently moving state.

[0035] The communication method provided in this embodiment clarifies the mechanism for the AS to report or not report the serving cell identifier to the NAS when the terminal device does not meet the first condition.

[0036] In a fourth aspect, this embodiment provides a communication method applied to an access network device. The method includes: sending second indication information to the terminal device, where the second indication information is used to instruct the AS of the terminal device to send the serving cell identifier to the NAS. Among them, the serving cell identifier is used to determine whether the terminal device is within the NS-AoS of the first network slice, and the first network slice belongs to the network slice configured by the network device for the terminal device.

[0037] Through the method provided in this embodiment, the access network device can instruct the AS to report the serving cell identifier to the NAS, avoiding the situation where the AS frequently reports the serving cell identifier to the NAS, which helps to save the power consumption of the terminal device.

[0038] In some embodiments, the second indication information is used to instruct the AS of the terminal device to send the serving cell identifier to the NAS, including any one of the following methods, or a combination of the following multiple indication methods:

[0039] The second indication information is used to indicate that 0 resources are configured for the serving cell of the terminal device for the second network slice, and the second network slice is the network slice supported by the tracking area where the serving cell is located;

[0040] The second indication information is used to indicate the RRC state when the AS sends the serving cell identifier of the terminal device to the NAS. Exemplarily, the RRC state includes at least one of the RRC connected state, the RRC idle state, and the RRC inactive state.

[0041] In some embodiments, the second indication information further includes a first timer or a first period, where

[0042] The first timer is used to instruct the AS to send the serving cell identifier to the NAS after the first timer expires;

[0043] The first period is used to instruct the AS to send the serving cell identifier to the NAS according to the first period.

[0044] In this embodiment, the access network device can control the timing for the AS to report the serving cell identifier to the NAS. For example, it can control the AS to report the serving cell identifier after a period of time, or report the serving cell identifier periodically.

[0045] In some embodiments, the access network device sends second indication information to the terminal device, including: if the serving cell does not meet the second condition, sending the second indication information to the terminal device. Exemplarily, the second condition includes that the serving cell supports terminal devices in at least one of the states of being in a capacity - limited state, a low - power state, and a frequently - moving state.

[0046] In some embodiments, if the serving cell does not meet the second condition, sending the second indication information to the terminal device includes: if the serving cell does not meet the second condition and the serving cell is configured with 0 resources for the second network slice, sending the second indication information to the terminal device; where the second network slice is a network slice supported by the tracking area (TA) where the serving cell is located.

[0047] In a fifth aspect, this embodiment provides a communication method applied to an access network device. The method includes:

[0048] If the serving cell of the terminal device meets the second condition, not sending the second indication information to the terminal device, where the second indication information is used to instruct the access stratum (AS) of the terminal device to send the serving cell identifier to the non - access stratum (NAS) of the terminal device; or,

[0049] If the serving cell of the terminal device meets the second condition, sending fourth indication information to the terminal device, where the fourth indication information is used to instruct the AS of the terminal device not to send the serving cell identifier to the NAS.

[0050] The serving cell identifier is used to determine whether the terminal device is located within the NS - AoS of the first network slice, and the first network slice belongs to the network slices configured by the network device for the terminal device. Exemplarily, the second condition includes that the serving cell supports terminal devices in at least one of the states of being in a capacity - limited state, a low - power state, and a frequently - moving state.

[0051] In a sixth aspect, this embodiment provides a communication method applied to an access network device. The method includes:

[0052] Determining that the serving cell does not meet the second condition and the serving cell of the terminal device is not configured with 0 resources for the first network slice;

[0053] Not sending the second indication information to the terminal device, where the second information is used to instruct the AS of the terminal device to send the serving cell identifier to the NAS; or,

[0054] Send fourth indication information to the terminal device, where the fourth indication information is used to instruct the AS of the terminal device not to send the serving cell identifier to the NAS.

[0055] The serving cell identifier is used to determine whether the terminal device is within the NS-AoS of the first network slice, and the first network slice belongs to the network slices configured by the network device for the terminal device. Exemplarily, the second condition is that the serving cell supports terminal devices in at least one of the capacity-limited state, low-power state, and frequent movement state.

[0056] In a seventh aspect, this embodiment provides a terminal device, which includes a NAS and an AS. The NAS is configured to perform the various methods shown in the first aspect, and the AS is configured to perform the various methods shown in the second aspect or the third aspect.

[0057] In an eighth aspect, this embodiment provides an access network device, which is configured to perform the various methods shown in the above fourth aspect, fifth aspect, or sixth aspect.

[0058] In a ninth aspect, this embodiment provides a communication device, which is configured to perform the method shown in any one of the first aspect to the sixth aspect above. The functions of the communication device can be implemented by hardware, or by hardware executing corresponding software. The hardware or software includes one or more units or modules corresponding to the above functions. The unit or module can be software and / or hardware.

[0059] In a tenth aspect, this embodiment provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it implements the method shown in any one of the first aspect to the sixth aspect above.

[0060] In an eleventh aspect, this embodiment provides a chip, which includes a processor and a memory. The memory stores a computer program. When the computer program is executed by the processor, it implements the method shown in any one of the first aspect to the sixth aspect above.

[0061] In a twelfth aspect, this embodiment provides a computer program product, which includes a computer program. When the computer program is run by a processor, it implements the method shown in any one of the first aspect to the sixth aspect above.

[0062] In a thirteenth aspect, this embodiment further provides a communication system, which includes the terminal device shown in the above seventh aspect and the access network device shown in the above eighth aspect.

[0063] It should be understood that for the beneficial effects of the above seventh aspect to the thirteenth aspect, reference may be made to the relevant descriptions in the above first aspect to the sixth aspect, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1 FIG. is a schematic block diagram of a 5G communication system architecture provided by an embodiment of the present application;

[0065] Figure 2 FIG. is a schematic diagram of the distribution of cells within a TA provided by an embodiment of the present application;

[0066] Figure 3 FIG. is a schematic diagram of NS-AoS provided by an embodiment of the present application;

[0067] Figure 4 FIG. is a schematic flowchart of a communication method provided by an embodiment of the present application;

[0068] Figure 5 FIG. is a schematic flowchart of a communication method provided by another embodiment of the present application;

[0069] Figure 6 FIG. is a schematic structural diagram of a communication device 600 provided by an embodiment of the present application;

[0070] Figure 7 FIG. is a schematic structural diagram of a communication device 700 provided by another embodiment of the present application;

[0071] Figure 8 FIG. is a schematic structural diagram of a communication device 800 provided by yet another embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0072] The technical solutions provided by the embodiments of the present application will be described below with reference to the accompanying drawings.

[0073] It should be understood that in the description of the embodiments of the present application, unless otherwise specified, " / " means "or", for example, A / B may represent A or B; herein, "and / or" is merely a description of the association relationship between associated objects, indicating that three relationships may exist, for example, A and / or B may represent: A exists alone, A and B exist simultaneously, and B exists alone.

[0074] In this embodiment, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this embodiment, unless otherwise specified, "a plurality of" means two or more.

[0075] The embodiments of the present application provide a communication method, which is applicable to a fifth-generation (5G) communication system, also known as a new radio (NR) communication system, or a sixth-generation (6G) communication system, or other future communication systems, a future evolved public land mobile network (PLMN), and communication systems that support subsequent 3rd generation partnership project (3GPP) protocol versions. The embodiments of the present application do not limit this.

[0076] Taking the 5G communication system as an example, the communication method provided by the embodiments of the present application will be described by way of example below.

[0077] Figure 1 It is a schematic block diagram of the 5G communication system architecture provided by the embodiments of the present application. Refer to Figure 1 As shown, the 5G communication system includes: a terminal device and a network device. The network device includes an access network device, a core network device, and a data network (DN). They will be introduced separately below.

[0078] The terminal device can be connected to the access network device deployed by the operator through the wireless air interface, and then connected to the data network through the core network device. The terminal device includes an AS and a NAS. When the terminal device selects the network to connect to, for example, when selecting the serving cell to access or the network slice to use, the NAS needs to select a suitable network according to certain policies and belongs to the decision maker for network selection. The AS searches on the radio access technology (RAT) and frequency bands supported by the terminal device to connect to the corresponding network and belongs to the executor for network selection.

[0079] In this embodiment, the terminal device includes, but is not limited to: user equipment (UE), access terminal device, user unit, user station, mobile station, mobile platform, remote station, remote terminal device, mobile device, user terminal device, user agent or user device, etc. For another example, the terminal device can be a mobile phone, a tablet computer (Pad), a computer with wireless transceiver function, an augmented reality (AR) / virtual reality (VR) device, a wireless terminal device in industrial control, a wireless terminal device in unmanned driving, a wireless terminal device in remote medical treatment, a wireless terminal device in smart grid, a wireless terminal device in transportation safety, a wireless terminal device in smart city, a wireless terminal device in smart home, a wireless terminal device in vehicle-to-everything (V2X) or a road side unit (RSU) of the wireless terminal device type, etc.

[0080] The access network device is mainly used to implement functions such as wireless physical layer function, resource scheduling and wireless resource management, wireless access control, and mobility management. In this embodiment, the access network device can be an access network (AN) or a radio access network (RAN) device.

[0081] In the embodiments of the present application, the access network device includes but is not limited to: evolved node B (eNB), radio network controller (RNC), Node B (NB), base station controller (BSC), base transceiver station (BTS), home network device (e.g., home evolved Node B, or home Node B, HNB), baseband unit (BBU), access point (AP) in a wireless fidelity (WIFI) system, wireless relay node, wireless backhaul node, transmission and reception point (TRP), transmission point (TP), etc.; it can also be a device used in 5G, 6G, etc. systems, such as gNB in an NR system, or a transmission point (TRP or TP), one or a group of antenna panels of a network device in a 5G system (including multiple antenna panels), or, it can also be a network node constituting a gNB or a transmission point, such as a baseband unit (BBU), or a distributed unit (DU), or a road side unit (RSU) in a vehicle to everything (V2X) or intelligent driving scenario.

[0082] In some deployments, the gNB may include a centralized unit (CU) and a DU. The gNB may also include a radio unit (RU). The CU implements some functions of the gNB, and the DU implements some functions of the gNB. For example, the CU implements the functions of the radio resource control (RRC) and packet data convergence protocol (PDCP) layers, and the DU implements the functions of the radio link control (RLC) layer, media access control (MAC) layer, and physical (PHY) layer. Since the information of the RRC layer will ultimately become the information of the PHY layer, or is transformed from the information of the PHY layer, therefore, in this architecture, high-layer signaling, such as RRC layer signaling, can also be considered to be sent by the DU, or sent by the DU + CU. It can be understood that the network device can be a CU node, or a DU node, or a device including a CU node and a DU node. In addition, the CU can be classified as a network device in the radio access network (RAN), or the CU can be classified as a network device in the core network (CN), and this application does not make any restrictions on this.

[0083] In addition, the RAN can also be an open RAN (O-RAN or ORAN). In the ORAN system, the CU can also be called an O-CU (open CU), the DU can also be called an O-DU, the CU-CP can also be called an O-CU-CP, the CU-UP can also be called an O-CU-UP, and the RU can also be called an O-RU.

[0084] The core network device includes functional units such as access and mobility management function (AMF), session management function (SMF), policy control function (PCF), operation, administration and maintenance (OAM), etc. These functional units can work independently or be combined to implement certain control functions. For example, AMF, SMF, and PCF can work together to complete access control and mobility management functions such as access authentication, security encryption, and location registration of terminal devices, as well as session management functions such as establishment, release, and change of the user plane transmission path, and functions such as analyzing some network slice-related data and terminal device-related data. In this embodiment, the core network device can implement the above network element functions, and this embodiment does not limit the specific network element deployment method in the core network device.

[0085] The data network can correspond to multiple different service domains, such as IP multimedia subsystem (IMS), Internet, service domains related to third-party applications, etc., and is mainly used to provide various data service services for terminal devices, which may include devices such as servers (such as third-party application servers), routers, gateways, etc.

[0086] It should be noted that Figure 1 is only an exemplary architecture diagram of the 5G communication system. Except for Figure 1 the functional units shown therein, the network architecture of the 5G communication system may also include other functional units or functional entities, which are not limited in this embodiment.

[0087] With the development of 5G communication technology, various new services have emerged continuously, and the requirements of different services for network functions, connection performance, security, etc. usually vary greatly. For example, services such as mobile communication, smart home, environmental monitoring, smart agriculture, and smart meter reading require the network to support massive device connections and frequent transmission of a large number of small packets; services such as network live broadcast, video backhaul, and mobile medical care have higher requirements for transmission rate; services such as vehicle networking, smart grid, and industrial control require millisecond-level latency and nearly 100% reliability. It can be understood that if a single network is used to carry these services, it will be very difficult to meet the different requirements of each service for high bandwidth, low latency, and high reliability at the same time. In addition, building a separate network for each service will bring huge costs. This requires that the 5G communication system be flexible and scalable while being able to meet different service requirements.

[0088] Facing the above requirements, network slicing technology has emerged as the times require. Through network slicing, by flexibly allocating network resources and networking on demand, operators can build multiple dedicated, virtualized, and mutually isolated logical subnets on a common physical network to meet the different customers' differentiated requirements for network capabilities, so as to provide services for users specifically.

[0089] In network slicing technology, different logical subnets are identified and differentiated by single network slice selection assistance information (S-NSSAI). Among them, each S-NSSAI includes the following contents (1) to (2):

[0090] (1) Slice / Service Type (SST), which is used to indicate the specific characteristics and service types of the network slice.

[0091] (2) Slice Differentiator (SD), as a supplement to the SST, can further distinguish multiple network slice instances that meet the same SST; the SD is optional content.

[0092] It should be noted that for the convenience of description, NSSAI is usually used to generally refer to multiple single network slices. In other words, an NSSAI includes multiple S-NSSAIs.

[0093] Regarding the NSSAI, the classifications involved in this embodiment include the following contents (1) to (7):

[0094] (1) Subscribed NSSAI, the subscribed NSSAI, which belongs to the subscription data of the terminal device.

[0095] (2) Configured NSSAI: The configured NSSAI, that is, the NSSAI configured by the network device for the terminal device to use, in order to inform the terminal device which S-NSSAI(s) are available under this network. The network device will bring the Configured NSSAI to the terminal device in the Configured NSSAI information element (IE) of the Registration Accept message. If there is a change in the configuration of the terminal device after registration, the network device can notify the terminal device to update the Configured NSSAI through the Configuration update command. The terminal device will save the Configured NSSAI configured by each network for it in the non-volatile storage space.

[0096] (3) Requested NSSAI: The requested NSSAI, which is the NSSAI carried by the terminal device in the Registration Request message.

[0097] (4) Allowed NSSAI: The allowed NSSAI, that is, the S-NSSAI(s) determined by the network device from the Requested NSSAI for the terminal device to use according to the request of the terminal device. The network device will carry the Allowed NSSAI in the Registration Accept message to the terminal device to inform the terminal device which S-NSSAI(s) in its requested NSSAI are allowed by the network device to be used. The Allowed NSSAI can be supported within the registration area (RA) of the terminal device. Among them, one RA includes at least one tracking area (TA).

[0098] (5) Rejected NSSAI: The rejected NSSAI, which represents the S-NSSAI(s) in the NSSAI requested by the terminal device that are rejected by the network device. For example, when the core network or the access network side does not support these S-NSSAI(s), these S-NSSAI(s) are the Rejected NSSAI.

[0099] (6) Partially Allowed NSSAI: The partially allowed NSSAI is similar to the concept of Allowed NSSAI, the difference being that these S-NSSAI(s) can only be supported in some of the TAs in the terminal device's RA.

[0100] (7) Partially Rejected NSSAI: The partially rejected NSSAI is similar to the concept of Rejected NSSAI, the difference being that these S-NSSAI(s) can only not be supported in some of the TAs in the terminal device's RA.

[0101] In the 5G communication system, after the network slices are deployed, they are not fixed. According to the changes in the operator's requirements, some network slices may be withdrawn from the network, while some other network slices may be newly added (i.e., newly deployed). These changes in the network slices will affect the configurations of the network devices and the terminal devices. Specifically, it is as follows.

[0102] Currently, network slices are deployed according to TAs on the access network device side, that is, all cells within the same TA support the same network slice. When some network slices become unavailable or available, the Allowed NSSAI and other parameters of the terminal device may change, and thus the RA and TA of the terminal device may also need to change.

[0103] For example Figure 2 As shown, the RA of the terminal device includes TA#1. Among them, the Cells deployed in TA#1 include Cell#1, Cell#2, Cell#3, and Cell#4. Since network slices are deployed according to TAs on the access network device side, then Cell#1 to Cell#4 within TA#1 support the same network slice, such as network slice 2 (which can be represented as Slice#2). Taking the example that the network device allows the terminal device to use Slice#2, that is, the Allowed NSSAI of this terminal device is Slice#2. It can be understood that the terminal device can use Slice#2 when accessing any one of Cell#1 to Cell#4.

[0104] However, during the service of Slice#2, due to reasons such as network deployment changes, the resources allocated for Slice#2 by Cell#2 within TA#1 are suddenly limited. For example, Cell#2 suddenly withdraws any resources configured for Slice#2, resulting in Cell#2 actually being unable to provide the service of Slice#2 for the terminal device. Then it can be understood that assuming the terminal device accesses Cell#2 within TA#1, then Slice#2 actually cannot provide services for this terminal device, and the terminal device may experience situations such as network connection failure, resulting in a poor user experience. To avoid the above situation, in some implementations, the network device can readjust the deployment of RA and TA and allocate a new Allowed NSSAI for this terminal device. However, this process is complex and costly, and it is not convenient for popular use.

[0105] Therefore, 3GPP introduced the concept of NS-AoS. Among them, NS-AoS is used to indicate the service area for a specific network slice. NS-AoS includes the identifiers of one or more cells, such as NR cell global identifier (NCGI), physical cell identifier (PCI), etc. During the process of using a certain network slice, the terminal device can select a cell that can provide services for this network slice according to the NS-AoS of this network slice to avoid the situation of being unable to use this network slice.

[0106] After introducing NS-AoS, combined with Figure 2As shown, if all Cells in TA#1 support Slice#2, then the service area of Slice#2 in TA#1 includes Cell#1, Cell#2, Cell#3, and Cell#4. If the resources allocated to Slice#2 by Cell#2 in TA#1 are suddenly limited, then, for example Figure 3 As shown, the service area of Slice#2 will not include Cell#2, that is, the NS-AoS of Slice#2 includes Cell#1, Cell#3, and Cell#4. Based on this, when the terminal device is using Slice#2, it can select a cell that supports Slice#2 for access according to the NS-AoS of Slice#2, so as to avoid the situation where Slice#2 cannot be used.

[0107] The NS-AoS is deployed on the RAN side, and the AMF of the network device can obtain the NS-AoS configured for each network slice in the RA of the terminal device through OAM. Also, when the terminal device indicates support for S-NSSAI location availability information, the AMF will send the NS-AoS for the Configured NSSAI in the RA to the terminal device through the RegistrationAccept message or the UE Configuration Update message. Among them, the terminal device's support for S-NSSAI location availability information can be interpreted as that the terminal device can parse the S-NSSAI location availability information.

[0108] After the network device configures the NS-AoS for a certain network slice, since the NS-AoS may include some cells in the TA or all cells in the TA, the serving cell of the terminal device may be within the NS-AoS or outside the NS-AoS. According to the different relative positions between the terminal device and the NS-AoS, the terminal device and the network device can perform the following operations:

[0109] Operation 1: If the terminal device receives the NS-AoS for the Requested NSSAI, then after the terminal device initiates a registration request for this network slice outside the NS-AoS, this network slice will be determined by the AMF as the Allowed NSSAI or the Partially Allowed NSSAI. For example, combined with Figure 3As shown in the figure, if the terminal device initiates a registration request for Slice#2 to the network device while connected to Cell#2, since the terminal device is outside the NS-AoS of Slice#2, that is, the terminal device has a need to use Slice#2, then Slice#2 will be determined by the AMF as the Allowed NSSAI or Partially Allowed NSSAI for the terminal device to use this Slice#2.

[0110] Operation 2: If the terminal device receives the NS-AoS for the Rejected NSSAI or Partially Rejected NSSAI, then the terminal device can only initiate a registration request for these network slices in the cells within the NS-AoS of the above-mentioned network slices. Taking the NS-AoS of the Rejected NSSAI including Cell#5 and Cell#6 as an example, then the terminal device can only initiate a registration request for the network slices corresponding to Cell#5 and Cell#6 when connected to Cell#5 or Cell#6.

[0111] Operation 3: If the terminal device receives the NS-AoS for the Allowed NSSAI or Partially Allowed NSSAI, then the terminal device can only activate the user plane for the established PDU session within the NS-AoS of the above-mentioned network slices.

[0112] Since the relevant processes of registration and PDU session management are determined by the NAS of the terminal device, therefore, after introducing the NS-AoS, the NAS of the terminal device needs to determine the position of the serving cell relative to the NS-AoS according to the received NS-AoS of the specific network slice, and then determine the subsequent behavior of the terminal device for this network slice.

[0113] Currently, the way for the terminal device to determine the serving cell is that the AS reports the identifier of the serving cell to the NAS. According to the identifier of the serving cell, the NAS can know which serving cell the terminal device is located in. It can be understood that if the AS of the terminal device reports the serving cell identifier unconditionally and frequently, it will bring relatively high power consumption to the terminal device. Therefore, it is necessary to clarify the triggering mechanism for the terminal device to report the serving cell identifier.

[0114] Therefore, the embodiment of the present application provides a communication method, which involves the process that the AS of the terminal device reports the serving cell identifier according to the indication of the NAS and / or the access network device of the terminal device, thereby avoiding the AS of the terminal device from frequently reporting the serving cell identifier to the NAS of the terminal device and being able to reduce the power consumption of the terminal device.

[0115] Figure 4It is a schematic flowchart of a communication method provided by an embodiment of the present application. This method involves the process in which the AS of the terminal device reports the serving cell identifier according to the indication of the NAS. Taking the terminal device as a UE as an example, the method specifically includes the following steps.

[0116] S401, the UE NAS determines that it meets the trigger condition.

[0117] In S401, the UE NAS determines that it meets the trigger condition mainly for determining that the UE NAS supports the NS-AoS capability and / or has a requirement to use a network slice. Based on this, the trigger condition can include the following situations.

[0118] In some embodiments, the trigger condition is that the NAS determines that it supports the NS-AoS capability. For example, if the UE NAS indicates support for the S-NSSAI location availability information in the 5G mobility management core network capability cell of the uplink NAS message, it means that the UE supports the NS-AoS capability.

[0119] In some other embodiments, the trigger condition is that the NAS determines that it supports the NS-AoS capability and receives the S-NSSAI location availability information of the first network slice of the UE within the RA. Among them, the S-NSSAI location availability information includes the S-NSSAI and its corresponding NS-AoS information.

[0120] In still some other embodiments, the trigger condition is that the NAS determines that it supports the NS-AoS capability, receives the S-NSSAI location availability information of the first network slice of the UE within the RA, and the NAS also determines that it is necessary to initiate a registration request for the first network slice / determines that it is necessary to activate the user plane of the PDU session associated with the first network slice.

[0121] It should be noted that the first network slice belongs to the Configured NSSAI of the UE. Exemplarily, when the UE is in the RRC idle state or the RRC inactive state, the first network slice can be the network slice requested by the UE from the network device. Or, when the UE is in the RRC connected state, the first network slice can be the network slice corresponding to the service that the UE is currently performing or the network slice corresponding to the service that the UE is about to request.

[0122] S402, the UE NAS sends the first indication information to the UE AS.

[0123] In this embodiment, the first indication information is used to indicate that the UE NAS supports the NS-AoS capability, so that the UE AS can send the serving cell identifier to the UE NAS according to the first indication information. According to the serving cell identifier, the UE NAS can determine whether the UE is within the NS-AoS of the first network slice, and then determine the subsequent behavior of the UE.

[0124] It should be noted that "indicating that the UE NAS supports the NS-AoS capability" is the function or effect that the first indication information can achieve, and this embodiment does not limit the specific indication form of the first indication information. Specifically, it is as follows.

[0125] In some embodiments, the first indication information directly indicates that the UE NAS supports the NS-AoS capability. For example, the UE NAS sends a relevant indication field to the UE AS. After receiving the indication field, the UE AS considers that the UE NAS supports the NS-AoS capability.

[0126] In other embodiments, the first indication information indirectly indicates that the UE NAS supports the NS-AoS capability. Specifically, refer to Examples 1 to 4.

[0127] Example 1, the first indication information is used to indicate that the UE AS sends the serving cell identifier of the UE to the UE NAS.

[0128] Example 2, the first indication information includes the NS-AoS information of the first network slice.

[0129] Example 3, the first indication information is used to indicate the RRC state when the UE AS reports the serving cell identifier of the UE to the UE NAS, that is, the target RRC state. Exemplarily, the target RRC state can be at least one of RRC_CONNECTED, RRC_IDLE, and RRC_INACTIVE.

[0130] Example 4, the first indication information includes a first timer or a first period, where the first timer or the first period is used to control the time when the UE AS reports the serving cell identifier to the UE NAS. For example, based on the first timer, it can be controlled that the UE AS reports the serving cell identifier to the UE NAS after the first timer expires, rather than reporting it immediately. Another example is that based on the first period, it can be controlled that the UE AS reports the serving cell identifier to the UE NAS once every certain period of time, so that the UE NAS can update the serving cell identifier in time after the serving cell of the UE changes.

[0131] It should be noted that the first indication information may also include, at the same time, the content directly indicated above and one or more of the content indirectly indicated. For example, the first indication information indicates both "UE NAS supports NS-AoS capability" and "target RRC state" at the same time. Or, the first indication information indicates both "UE NAS supports NS-AoS capability" and "send the serving cell identifier of the UE to UE NAS" at the same time. Or, the first indication information indicates "UE NAS supports NS-AoS capability", "send the serving cell identifier of the UE to UE NAS", and "first timer / first period" at the same time.

[0132] In addition, the first indication information may also include, at the same time, multiple pieces of content indirectly indicated. For example, the first indication information indicates both "send the serving cell identifier of the UE to UE NAS" and "target RRC state" at the same time. Or, the first indication information indicates both "send the serving cell identifier of the UE to UE NAS" and "first timer / first period" at the same time.

[0133] Next, the three RRC states involved in this embodiment will be explained separately.

[0134] RRC_CONNECTED: That is, the RRC connected state. If the terminal device establishes an RRC connection with the network device, the terminal device is in the RRC connected state. In the RRC connected state, a user plane and a control plane connection can be established between the terminal device and the network device, and the terminal device can transmit user plane data and control plane signaling to the network device through the first terminal device.

[0135] RRC_IDLE: That is, the RRC idle state. If the terminal device does not establish an RRC connection with the network device, the terminal device is in the RRC idle state. When the terminal device is in the RRC idle state, the terminal device can perform PLMN selection and cell reselection and other operations.

[0136] RRC_INACTIVE: That is, the RRC inactive state. If the terminal device has no data transmission requirements with the network device within a preset time period in the RRC connected state, the network device can determine that the terminal device enters the RRC inactive state, and the network device can send an RRC Release with suspend indication message carrying a suspend indication to the terminal device. After receiving the RRC Release with suspend indication message, the terminal device retains its own context and enters the RRC inactive state.

[0137] S403, the UE AS reports the serving cell identifier to the UE NAS.

[0138] After the UE AS receives the first indication information, as shown in S403a, it may not consider the UE's own capabilities and status, but directly report the serving cell identifier to the UE NAS according to the indication of the first indication information. Or, as shown in S403b1 - S403b2, according to the UE's own capabilities and status, combined with the indication of the first indication information, report the serving cell identifier to the UE NAS. The following will explain them separately.

[0139] First, in combination with S403a, an exemplary description will be given of the process in which the UE AS does not consider the UE's own capabilities and status and reports the serving cell identifier to the UE NAS according to the indication of the first indication information.

[0140] In S403a, the UE AS directly reports the serving cell identifier to the UE NAS.

[0141] In this embodiment, depending on the specific content of the first indication information, the specific process of the UE AS reporting the serving cell identifier to the UE NAS is usually also different, as follows.

[0142] For example, if the first indication information is only used to indicate that the UE NAS supports the NS - AoS capability, then after the UE AS receives the first indication information, it immediately reports the serving cell identifier to the UE NAS.

[0143] For another example, if the first indication information is not only used to indicate that the UE NAS supports the NS - AoS capability, but also used to indicate the RRC state when the UE AS reports the serving cell identifier to the UE NAS, that is, the target RRC state, then after the UE AS receives the first indication information, it needs to report the serving cell identifier to the UE NAS when the target RRC state is satisfied. Taking the target RRC state being the RRC connected state as an example, after the UE AS receives the first indication information, it needs to report the serving cell identifier to the UE NAS in the RRC connected state.

[0144] For another example, if the first indication information is not only used to indicate that the UE NAS supports the NS - AoS capability, but also used to indicate the first timer or the first period. Then, after the UE AS receives the first indication information, it reports the serving cell identifier to the UE NAS after the first timer expires, or reports the serving cell identifier to the UE NAS once every certain period according to the first period.

[0145] For another example, if the first indication information is used to indicate that the UE NAS supports the NS-AoS capability and the target RRC state when the UE AS reports the serving cell identifier to the UE NAS, and is further used to indicate the first timer or the first period, then after receiving the first indication information, the UE AS needs to report the serving cell identifier to the UE NAS after the first timer expires and when the UE meets the target RRC state; or, report the serving cell identifier to the UE NAS once every certain period according to the first period when the UE meets the target RRC state.

[0146] The following uses S403b1 to S403b2 to give an exemplary description of the process in which the UE AS reports the serving cell identifier to the UE NAS according to the UE's own capabilities and status and in combination with the indication of the first indication information.

[0147] S403b1, the UE AS determines whether the UE meets the first condition.

[0148] In this embodiment, the first condition includes at least one of the following: the UE is in a capability-limited state, a low-power state, and a frequently moving state. For example, the UE being in a capability-limited state includes: the UE uses the capability-limited RedCap technology. The UE being in a low-power state includes: the UE enables the energy-saving mode, and / or the UE is connected to the narrowband Internet of Things (NB-IoT). The UE being in a frequently moving state includes: the UE accesses a mobile integrated access and backhaul (IAB) cell; or, the UE accesses a high-speed dedicated network (HSDN) cell.

[0149] S403b2, when the UE does not meet the first condition, the UE AS reports the serving cell identifier to the UE NAS.

[0150] In other words, when reporting the serving cell identifier to the UE NAS, the UE AS needs to consider the UE's own capabilities or the UE's moving state to avoid wasting power or reporting failure. For example, the UE AS needs to avoid reporting the serving cell identifier when the UE is in a low-power state, resulting in wasted power of the UE; or, the UE AS needs to avoid reporting the serving cell identifier when the UE's capabilities are limited, resulting in reporting failure; or, the UE AS needs to avoid frequently reporting the serving cell identifier during the rapid movement of the UE, resulting in wasted power.

[0151] It should be noted that in S403b2, after the UE AS determines to report the serving cell identifier to the UE NAS according to the first condition, the specific reporting process can refer to S403a and will not be elaborated here.

[0152] It can be understood that there are usually also cases where the UE satisfies the first condition, that is, the UE is in at least one of the states of capacity limitation, low power consumption, and frequent movement. The following will be specifically described.

[0153] When the UE satisfies the first condition, the UE AS does not report the serving cell identifier to the UE NAS, or the UE AS sends an indication message to the UE NAS, such as a third indication message, which is used to indicate to the UE NAS that the UE AS does not report the serving cell identifier to the UE NAS. Or, when the UE satisfies the first condition, the UE AS still reports the serving cell identifier to the UE NAS, but the reporting time or period can be determined by the UE AS according to its own capabilities. For example, the UE AS reports the serving cell identifier to the UE NAS according to the second timer or the second period. The second period can be determined with reference to the discontinuous reception (DRX) period of the UE. For example, the second period is the same as the DRX period. In addition, the UE AS can also notify the UE NAS of the second timer or the second period so that the UE AS and the UE NAS can understand and synchronize.

[0154] For example, for the UE in the low power consumption state, if the UE AS receives the first indication message from the UE NAS, since it needs to save power or has entered the sleep state, then the UE AS can choose not to report the serving cell identifier to the UE NAS to avoid power consumption waste.

[0155] Another example is that for the UE in the capacity limitation state, if the UE AS receives the first indication message from the UE NAS, since the UE's capacity limitation may result in not supporting the use of network slices, then the UE AS also does not report the serving cell identifier to the UE NAS.

[0156] For another example, when the UE is in a frequently moving state, such as the UE being a vehicle-mounted UE and the vehicle-mounted UE accessing a mobile IAB cell, that is, the serving cell of the UE is a mobile IAB cell. Since the mobile IAB node is installed on the vehicle, the vehicle-mounted UE moves together with the mobile IAB node, and the vehicle-mounted UE and the serving cell are relatively stationary. In this case, although the NCGI of the serving cell will be frequently updated due to the mobility of the mobile IAB node, the physical cell actually connected by the vehicle-mounted UE remains unchanged. Therefore, it is not necessary for the UE AS to report the serving cell identifier to the UE NAS every time the NCGI of the serving cell is changed. Based on this, after receiving the first indication information, the UE AS may not report the serving cell identifier; or, the UE AS may decide the reporting policy by itself. For example, the UE AS will not report the serving cell identifier after reporting it once until the UE gets off the vehicle and changes the serving cell.

[0157] Alternatively, when the UE is in a high-mobility state, the UE AS may also determine not to report the serving cell identifier temporarily until the mobility state is no longer a high-mobility state. This is because when the UE is in a high-mobility state, it may frequently perform cell reselection or handover, resulting in frequent changes of the serving cell. At this time, if the UE AS reports the serving cell identifier, it will not only increase the power consumption of the UE, but also, even if the UE AS reports the serving cell identifier, the information reported by the UE AS may become outdated due to high-speed movement, affecting the accuracy of the subsequent behavior of the UE.

[0158] In summary, through the communication method provided in this embodiment, the UE AS can report the serving cell identifier to the UE NAS according to the indication of the UE NAS, such as according to the target RRC state, the first timer, the first period, etc. indicated by the UE NAS, which clarifies the mechanism for the UE AS to report the serving cell identifier to the UE NAS and helps to save the power consumption of the UE.

[0159] Figure 5 It is a schematic flowchart of a communication method provided in another embodiment of the present application. This method involves the process in which the AS of the terminal device reports the serving cell identifier according to the indication of the access network device. Taking the terminal device as the UE as an example, this method specifically includes the following steps.

[0160] S501, the access network device sends the second indication information to the UE AS.

[0161] In this embodiment, the second indication information is used to instruct the UE AS to send the serving cell identifier to the UE NAS, so that the UE NAS can determine whether the UE is located within the NS-AoS of the first network slice according to the serving cell identifier. For the relevant description of the first network slice, refer to the foregoing text and will not be elaborated here.

[0162] In this embodiment, the access network device may send the second indication information to the UE through broadcast or RRC dedicated signaling. For example, a UE in the RRC idle state or the RRC inactive state can receive the second indication information through broadcast, and a UE in the RRC connected state can receive the second indication information through RRC dedicated information, such as an RRC reconfiguration message.

[0163] It should be noted that "instructing the UE AS to send the serving cell identifier to the UE NAS" is the indication function or effect that the second indication information can achieve, and the specific form of the second indication information is not limited in this embodiment. The specific details are as follows.

[0164] In some embodiments, the second indication information directly instructs the UE AS to send the serving cell identifier to the UE NAS. For example, the access network device sends a relevant indication field to the UE AS, and after receiving the indication field, the UE AS determines that the access network device instructs the UE AS to send the serving cell identifier to the UE NAS.

[0165] In some other embodiments, the second indication information indirectly instructs the UE AS to send the serving cell identifier to the UE NAS. For specific details, refer to Examples A to C.

[0166] Example A: The second indication information is used to indicate that 0 resources are configured for the serving cell of the UE for the second network slice. The second network slice is the network slice supported by the TA where the serving cell of the UE is located. For example Figure 3 As shown, when the serving cell of the UE is Cell#2, Cell#2 is located within TA#1, and Slice#2 supported by TA#1 is the second network slice. At this time, the second indication information is used to indicate that 0 resources are configured for the serving cell Cell#2 of the UE for the second network slice Slice#2, or it can be understood that no resources are allocated.

[0167] Example B: The second indication information is used to indicate the RRC state that needs to be satisfied when the UE AS sends the serving cell identifier to the UE NAS, that is, the target RRC state. Exemplarily, the target RRC state may be at least one of the RRC connected state, the RRC idle state, and the RRC inactive state.

[0168] Example C, the second indication information includes a first timer or a first period. The first timer is used to indicate that the UE AS sends the serving cell identifier to the UE NAS after the first timer expires; the first period is used to indicate that the UE AS sends the serving cell identifier to the UE NAS according to the first period.

[0169] It should be noted that the second indication information may also include one or more of the above directly indicated content and indirectly indicated content at the same time. For example, the second indication information simultaneously indicates "UE AS sends the serving cell identifier to UE NAS" and "target RRC state". Or, the second indication information simultaneously indicates "UE AS sends the serving cell identifier to UE NAS" and "first timer / first period", etc. This embodiment does not limit this.

[0170] In addition, the second indication information may also include multiple indirectly indicated contents at the same time. For example, the second indication information simultaneously indicates that "the serving cell of the UE is configured with 0 resources for the second network slice" and "target RRC state". Or, the second indication information simultaneously indicates "target RRC state" and "first timer / first period".

[0171] In S501, the access network device sends the second indication information to the UE AS, which can be implemented in the following ways.

[0172] In some embodiments, the access network device directly sends the second indication information to the UE AS. That is, when the access network device sends the second indication information to the UE AS, it does not judge whether it should send the second indication information to the UE AS.

[0173] In other embodiments, when the serving cell of the UE does not meet the second condition, the access network device sends the second indication information to the UE AS. The second condition includes: the serving cell of the UE supports at least one of the states of a UE in a capacity-limited state, a low-power state, and a frequently moving state. For example, the serving cell of the UE is a mobile IAB cell, an NB-IoT cell, or an HSDN cell, etc. The specific content of the capacity-limited state, the low-power state, and the frequently moving state can be seen in the previous text and will not be elaborated here.

[0174] In still other embodiments, when the serving cell of the UE is configured with 0 resources for the second network slice, the access network device sends the second indication information to the UE AS. In addition, if the serving cell of the UE is not configured with 0 resources for the second network slice, the access network device does not send the second indication information to the UE AS, or the access network device does not make any relevant indication, or the access network device can also send indication information to the UE AS indicating that the UE AS does not send the serving cell identifier to the UE NAS, such as the fourth indication information.

[0175] In some other embodiments, when the serving cell of the UE does not meet the second condition, the access network device may further determine whether the serving cell of the UE is configured with 0 resources for the second network slice. If the serving cell of the UE is configured with 0 resources for the second network slice, it indicates that the serving cell of the UE cannot provide services for the UE in the second network slice. At this time, the access network device sends second indication information to the UE AS. If the serving cell of the UE is not configured with 0 resources for the second network slice, it indicates that the serving cell of the UE can provide services for the UE in the second network slice. At this time, the access network device does not send second indication information to the UE AS, or the access network device does not make any relevant indication, or the access network device may also send indication information to the UE AS to indicate that the UE AS does not send the serving cell identifier to the UE NAS, such as the fourth indication information.

[0176] Of course, there will also be cases where the UE meets the second condition. Specifically, when the UE meets the second condition, for example, when the serving cell of the UE is a mobile IAB cell, an NB-IoT cell, or an HSDN cell, in order to avoid wasting the UE power consumption, the access network device may not send second indication information to the UE AS, or the access network device does not make any relevant indication, or the access network device may also send indication information to the UE AS to indicate that the UE AS does not send the serving cell identifier to the UE NAS, such as the fourth indication information.

[0177] In addition, optionally, for a UE in the RRC connected state, the access network device may decide whether to send second indication information to the UE AS by itself, or may also send second indication information to the UE AS according to the indication of the core network device. For example, the AMF of the core network device may determine whether the UE is located outside the NS-AoS of the second network slice according to the location of the UE, and then decide whether to instruct the access network device to send second indication information or fourth indication information to the UE AS. The judgment logic for the AMF to decide whether to instruct the access network device to send second indication information or fourth indication information may refer to the judgment logic for the access network device itself to judge whether to send second indication information or fourth indication information to the UE AS, which will not be elaborated here.

[0178] S502, the UE AS reports the serving cell identifier to the UE NAS.

[0179] After the UE AS receives the second indication information, as shown in S502a, it may not consider the UE's own capabilities and status, but directly report the serving cell identifier to the UE NAS according to the indication of the second indication information. Alternatively, as shown in S502b1 to S502b2, according to the UE's own capabilities and status, combined with the indication of the second indication information, report the serving cell identifier to the UE NAS.

[0180] First, an exemplary description is given of the process in which the UE AS does not consider the UE's own capabilities and status and reports the serving cell identifier to the UE NAS according to the indication of the second indication information in combination with S502a.

[0181] In S502a, the UE AS directly reports the serving cell identifier to the UE NAS.

[0182] In this embodiment, depending on the specific content of the second indication information, the specific process of the UE AS reporting the serving cell identifier to the UE NAS is usually also different, as follows.

[0183] For example, if the second indication information is only used to indicate that the UE AS reports the serving cell identifier to the UE NAS, then after receiving the second indication information, the UE AS immediately reports the serving cell identifier to the UE NAS.

[0184] For another example, if the second indication information is used to indicate the RRC state, i.e., the target RRC state, when the UE AS reports the serving cell identifier to the UE NAS in addition to indicating that the UE AS reports the serving cell identifier to the UE NAS, then after receiving the second indication information, the UE AS needs to report the serving cell identifier to the UE NAS when the RRC state is satisfied. Taking the target RRC state being the RRC connected state as an example, after receiving the second indication information, the UE AS needs to report the serving cell identifier to the UE NAS in the RRC connected state.

[0185] For another example, if the second indication information includes a first timer or a first period in addition to indicating that the UE AS reports the serving cell identifier to the UE NAS. Then, after receiving the first indication information, the UE AS reports the serving cell identifier to the UE NAS after the first timer expires, or reports the serving cell identifier to the UE NAS once every certain period according to the first period.

[0186] For another example, if the second indication information, on the basis of indicating the UE AS to report the serving cell identifier to the UE NAS and the target RRC state when indicating the UE AS to report the serving cell identifier to the UE NAS, further includes a first timer or a first period, then after receiving the second indication information, the UE AS needs to report the serving cell identifier to the UE NAS after the first timer expires and when the UE meets the target RRC state, or report the serving cell identifier to the UE NAS once every certain period according to the first period when the UE meets the target RRC state.

[0187] The following will exemplarily describe the process of the UE AS reporting the serving cell identifier to the UE NAS according to the UE's own capabilities and status and in combination with the indication of the second indication information with reference to S502b1 to S502b2.

[0188] S502b1, the UE AS determines whether the UE meets the first condition.

[0189] S502b2, when the UE does not meet the first condition, the UE AS reports the serving cell identifier to the UE NAS.

[0190] It should be noted that for S502b1 to S502b2, please refer to S403b1 to S403b2 for details and will not be elaborated here.

[0191] In addition, if the UE determines that it meets the first condition, the UE AS does not report the serving cell identifier to the UE NAS, or the UE AS sends an indication information to the UE NAS, such as a third indication information, which is used to indicate to the UE NAS that the UE AS does not report the serving cell identifier to the UE NAS. Or, when the UE meets the first condition, the UE AS still reports the serving cell identifier to the UE NAS, but the reporting time or period can be determined by the UE AS according to its own capabilities. Please refer to the foregoing for details.

[0192] In summary, through the communication method provided in this embodiment, the UE AS can report the serving cell identifier to the UE NAS according to the indication of the access network device, such as the target RRC state, the first timer, the first period, etc. indicated by the access network device. This method clarifies the mechanism for the UE AS to report the serving cell identifier to the UE NAS, which helps to save the power consumption of the UE.

[0193] It should be noted that since the process of the UE NAS sending the first indication information to the UE AS and the process of the access network device sending the second indication information to the UE AS are independent of each other, the UE AS may receive both the first indication information and the second indication information. In addition, the content indicated by the first indication information and the second indication information may be the same, may be different, or even have opposite indication effects. In this case, the UE AS can use the following method to report the serving cell identifier to the UE NAS.

[0194] In some embodiments, if the UE AS receives both the first indication information from the UE NAS and the second indication information from the access network device, the UE AS reports the serving cell identifier to the UE NAS according to the second indication information from the access network device.

[0195] For example, if the UE AS receives both the first indication information from the UE NAS including a first timer (e.g., 2S (seconds)) and the second indication information from the access network device including a first timer (e.g., 1S), the terminal device reports the serving cell identifier to the UE NAS according to the first timer indicated by the second indication information, e.g., 1S.

[0196] For another example, if the UE AS receives both the first indication information from the UE NAS indicating to report the serving cell identifier to the UE NAS in the RRC connected state and the second indication information from the access network device indicating to report the serving cell identifier to the UE NAS in the RRC connected state and the RRC inactive state, the UE AS takes the second indication information as the criterion and reports the serving cell identifier to the UE NAS in the RRC connected state and the RRC inactive state.

[0197] For another example, the UE AS receives both the first indication information from the UE NAS indicating to report the serving cell identifier to the UE NAS and the fourth indication information (see the foregoing) from the access network device indicating not to report the serving cell identifier to the UE NAS. In this case, the UE AS does not report the serving cell identifier to the UE NAS according to the fourth indication information of the access network device.

[0198] For yet another example, the UE AS may receive both the third indication information (see the foregoing) from the UE NAS indicating not to report the serving cell identifier to the UE NAS and the second indication information from the access network device reporting the serving cell identifier to the UE NAS. In this case, the UE AS reports the serving cell identifier to the UE NAS according to the second indication information of the access network device.

[0199] It should be noted that after the UE AS determines to report the serving cell identifier to the UE NAS according to the second indication information, the process shown in step S403 can be referred to, which will not be elaborated here.

[0200] In some other embodiments, if the UE AS receives both the first indication information from the UE NAS and the second indication information from the access network device, then the UE AS reports the serving cell identifier to the UE NAS according to the first indication information from the UE NAS. The specific process of the UE AS reporting the serving cell identifier to the UE NAS can refer to the process shown in step S403, which will not be elaborated here.

[0201] In some other embodiments, when the UE NAS sends the first indication information to the UE AS, and / or when the access network device sends the second indication information to the UE AS, it can further indicate which indication information the UE AS should follow in case of receiving multiple conflicting indication information. For example, when the UE NAS sends the first indication information to the UE AS, it can also send the fifth indication information to the UE AS, and the fifth indication information is used to indicate that after the UE AS receives conflicting indication information, it should follow the indication of the UE NAS or the indication of the access network device.

[0202] Through the communication method provided by the embodiments of the present application, the UE AS can report the serving cell identifier to the UE NAS according to the indication of the UE NAS and / or the access network device, avoiding the situation that the UE AS unconditionally and frequently reports the serving cell identifier, which helps to save the power consumption of the UE.

[0203] It should be noted that in the above embodiments, the descriptions of the various embodiments have their own focuses. To avoid redundancy, for the parts not elaborated in a certain embodiment, the relevant descriptions of other embodiments can be referred to. In addition, it should be understood that the sequence numbers of the steps in the above embodiments do not mean the order of execution. The execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present application.

[0204] Based on the same inventive concept, as an implementation of the above method, the present embodiment also provides the following technical solutions.

[0205] The embodiments of the present application also provide a terminal device, which includes a NAS and an AS. Among them, the NAS and the AS are respectively configured to execute the methods corresponding to the NAS and the AS in the above embodiments.

[0206] The present embodiment provides an access network device, which is configured to execute the method performed by the access network device in the above embodiments.

[0207] This embodiment provides a communication device, which is configured to execute the methods performed by the NAS, AS, or access network device in the above embodiments.

[0208] Figure 6 FIG. 4 is a schematic structural diagram of a communication device provided by an embodiment of the present application. This communication device is applied to the NAS of a terminal device and specifically includes a sending unit 601 and a receiving unit 602.

[0209] The sending unit 601 is configured to send first indication information to the AS of the terminal device. The first indication information is used to indicate the RRC state when the AS sends the serving cell identifier of the terminal device to the NAS.

[0210] The receiving unit 602 is configured to receive the serving cell identifier from the AS.

[0211] Wherein, the serving cell identifier is used to determine whether the terminal device is located within the network slice service area NS-AoS of the first network slice, and the first network slice belongs to the network slices configured by the terminal device.

[0212] In some embodiments, the first indication information further includes a first timer or a first period. Wherein, the first timer is used to indicate that the AS sends the serving cell identifier to the NAS after the first timer expires; the first period is used to indicate that the AS sends the serving cell identifier to the NAS according to the first period.

[0213] In some embodiments, the conditions for the NAS to send the first indication information to the AS include:

[0214] The NAS supports the NS-AoS capability; or,

[0215] The NAS supports the NS-AoS capability and receives the NS-AoS information of the first network slice of the terminal device within the registration area; or,

[0216] The NAS supports the NS-AoS capability, receives the NS-AoS information of the first network slice of the terminal device within the registration area, and the NAS determines that a registration request for the first network slice needs to be initiated / determines that the user plane of the PDU session associated with the first network slice needs to be activated.

[0217] Figure 7 FIG. 5 is a communication device 700 provided by another embodiment of the present application. This communication device 700 is applied to the access stratum AS of the terminal device and includes a receiving unit 701 and a sending unit 702.

[0218] A receiving unit 701, configured to receive first indication information from a non-access stratum (NAS) of a terminal device, and / or receive second indication information from an access network device; wherein the first indication information is used to indicate that the NAS supports a network slice service area (NS-AoS) capability, and the second indication information is used to indicate that the access stratum (AS) sends a serving cell identifier of the terminal device to the NAS.

[0219] A sending unit 702, configured to send the serving cell identifier to the NAS.

[0220] Wherein, the serving cell identifier is used to determine whether the terminal device is within the NS-AoS of a first network slice, and the first network slice belongs to the network slices configured for the terminal device.

[0221] Optionally, the sending unit 702 is further configured to send the serving cell identifier to the NAS when the RRC state is satisfied.

[0222] Optionally, the sending unit 702 is further configured to send the serving cell identifier to the NAS when the RRC state is satisfied if the terminal device does not meet a first condition.

[0223] It should be noted that in the apparatus provided in this embodiment, for the specific content of the first indication information and the second indication information, please refer to the foregoing, which will not be elaborated herein.

[0224] Figure 8 A communication apparatus 800 provided in another embodiment of this application. The communication apparatus 800 is applied to an access network device and includes a sending and receiving unit 801.

[0225] A sending unit 801, configured to send second indication information to the terminal device, where the second indication information is used to indicate that the access stratum (AS) of the terminal device sends a serving cell identifier to the non-access stratum (NAS) of the terminal device. Wherein, the serving cell identifier is used to determine whether the terminal device is within the network slice service area (NS-AoS) of a first network slice, and the first network slice belongs to the network slices configured for the terminal device.

[0226] Optionally, the sending unit 801 is further configured to send the second indication information to the terminal device if the serving cell of the terminal device does not meet a second condition.

[0227] Optionally, the sending unit 801 is further configured to send the second indication information to the terminal device if the serving cell does not meet the second condition and the serving cell is configured with 0 resources for a second network slice; wherein, the second network slice is a network slice supported by the tracking area (TA) where the serving cell is located.

[0228] In this embodiment, the second condition includes: the serving cell supports terminal devices in at least one of a capability-limited state, a low-power state, and a frequently moving state.

[0229] It should be noted that for the specific content of the second indication information in the device provided in this embodiment, please refer to the foregoing text, and details are not described herein again.

[0230] This embodiment provides a computer-readable storage medium storing a computer program, which when executed by a processor implements the methods performed by the NAS, AS, or access network device in the foregoing embodiments.

[0231] This application embodiment further provides a chip, which includes a processor and a memory. The memory stores a computer program, which when executed by the processor implements the methods performed by the NAS, AS, or access network device in the foregoing embodiments.

[0232] This application embodiment further provides a computer-readable storage medium storing a computer program, which when executed by a processor implements the methods performed by the NAS, AS, or access network device in the foregoing embodiments.

[0233] This application embodiment further provides a computer program product, which includes a computer program. When the computer program runs on an electronic device, the electronic device is enabled to implement the methods performed by the NAS, AS, or access network device in the foregoing embodiments.

[0234] This embodiment further provides a communication system, which includes a terminal device as shown in the foregoing embodiment and an access network device as shown in the foregoing embodiment.

[0235] It should be understood that the processor mentioned in the embodiments of this application may be a central processing unit (CPU), or may also be other general-purpose processors, digital signal processors (DSPs), application specific integrated circuits (ASICs), field programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor may be a microprocessor or the processor may also be any conventional processor, etc.

[0236] It should also be understood that the memory mentioned in the embodiments of the present application may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memories. Among them, the non-volatile memory may be a read-only memory (ROM), a programmable ROM (PROM), an erasable programmable ROM (EPROM), an electrically erasable programmable ROM (EEPROM), or a flash memory. The volatile memory may be a random access memory (RAM), which is used as an external cache. By way of example but not limitation, many forms of RAM are available, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDR SDRAM), enhanced SDRAM (ESDRAM), synchlink DRAM (SLDRAM), and direct rambus RAM (DR RAM).

[0237] In the embodiments provided in the present application, the division of each framework or module is only a logical function division. In actual implementation, there may be other division methods. For example, multiple frameworks or modules may be combined or integrated into another system, or some features may be ignored or not executed.

[0238] In addition, each functional module in the various embodiments of the present application may be integrated in a processing module, or each module may exist physically alone, or two or more modules may be integrated in one module. The above integrated modules may be implemented in the form of hardware or in the form of software functional modules.

[0239] Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the systems, devices, and units described above may refer to the corresponding processes in the foregoing method embodiments, and will not be elaborated herein.

[0240] Reference to "one embodiment" or "some embodiments" etc. described in the specification of the present application means that a specific feature, structure or characteristic described in connection with that embodiment is included in one or more embodiments of the present application. Thus, statements such as "in one embodiment", "in some embodiments", "in other some embodiments", "in still other embodiments" etc. that appear in different places in this specification do not necessarily all refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized. The terms "comprising", "including", "having" and their variants all mean "including but not limited to", unless otherwise specifically emphasized.

[0241] The above-described embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements for some of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the various embodiments of the present application, and should all be included within the protection scope of the present application.

Claims

1. A communication method, characterized in that, applied to the non-access stratum (NAS) of a terminal device, the method includes: sending first indication information to the access stratum (AS) of the terminal device, the first indication information being used to indicate the radio resource control (RRC) state when the AS sends the serving cell identifier of the terminal device to the NAS; receiving the serving cell identifier from the AS; wherein, the serving cell identifier is used to determine whether the terminal device is located within the network slice service area (NS-AoS) of a first network slice, and the first network slice belongs to the network slices configured for the terminal device.

2. The method according to claim 1, characterized in that, the first indication information further includes a first timer or a first period, the first timer is used to indicate that the AS sends the serving cell identifier to the NAS after the first timer expires; the first period is used to indicate that the AS sends the serving cell identifier to the NAS according to the first period.

3. The method according to claim 1 or 2, characterized in that, the conditions for the NAS to send the first indication information to the AS include: the NAS supports NS-AoS capability; or, the NAS supports NS-AoS capability and receives the NS-AoS information of the first network slice of the terminal device within the registration area; or, the NAS supports NS-AoS capability, receives the NS-AoS information of the first network slice of the terminal device within the registration area, and the NAS determines that a registration request for the first network slice needs to be initiated / determines that the user plane of the protocol data unit (PDU) session associated with the first network slice needs to be activated.

4. A communication method, characterized in that, applied to the access stratum (AS) of a terminal device, the method includes: receiving first indication information from the non-access stratum (NAS) of the terminal device, and / or receiving second indication information from an access network device; wherein, the first indication information is used to indicate that the NAS supports the network slice service area (NS-AoS) capability, and the second indication information is used to indicate that the AS sends the serving cell identifier of the terminal device to the NAS; sending the serving cell identifier to the NAS; wherein, the serving cell identifier is used to determine whether the terminal device is located within the NS-AoS of a first network slice, and the first network slice belongs to the network slices configured for the terminal device.

5. The method according to claim 4, characterized in that, the first indication information being used to indicate that the NAS supports NS-AoS capability includes: the first indication information is used to indicate that the AS sends the serving cell identifier of the terminal device to the NAS; or, the first indication information includes the NS-AoS information of the first network slice.

6. The method according to claim 4 or 5, characterized in that, the first indication information is further used to indicate the RRC state when the AS sends the serving cell identifier to the NAS.

7. The method according to any one of claims 4 to 6, characterized in that, the second indication information is used to instruct the AS to send the serving cell identifier of the terminal device to the NAS, including: the second indication information is used to indicate that the serving cell is configured with 0 resources for a second network slice, and the second network slice is a network slice supported by a tracking area TA where the serving cell is located.

8. The method according to any one of claims 4 to 7, characterized in that, the second indication information is further used to indicate the RRC state when the AS sends the serving cell identifier to the NAS.

9. The method according to any one of claims 4 to 8, characterized in that, the first indication information, and / or, the second indication information further includes a first timer or a first period, wherein, the first timer is used to instruct the AS to send the serving cell identifier to the NAS after the first timer expires; the first period is used to instruct the AS to send the serving cell identifier to the NAS according to the first period.

10. The method according to any one of claims 4 to 9, characterized in that, in the case where the first indication information and / or the second indication information indicates the RRC state when the AS sends the serving cell identifier to the NAS, the sending the serving cell identifier to the NAS includes: sending the serving cell identifier to the NAS when the RRC state is satisfied.

11. The method according to claim 10, characterized in that, the sending the serving cell identifier to the NAS when the RRC state is satisfied includes: if the terminal device does not meet a first condition, then sending the serving cell identifier to the NAS when the RRC state is satisfied.

12. The method according to claim 11, characterized in that, the first condition includes at least one of the terminal device being in a capacity-limited state, a low-power state, and a frequently moving state.

13. A communication method, characterized in that, the method includes: sending second indication information to a terminal device, where the second indication information is used to instruct an access stratum AS of the terminal device to send a serving cell identifier to a non-access stratum NAS of the terminal device; wherein, the serving cell identifier is used to determine whether the terminal device is located within a network slice service area NS-AoS of a first network slice, and the first network slice belongs to network slices configured for the terminal device.

14. The method according to claim 13, characterized in that, the second indication information is used to instruct the access stratum AS of the terminal device to send the serving cell identifier to the non-access stratum NAS of the terminal device, including: the second indication information is used to indicate that the serving cell of the terminal device is configured with 0 resources for a second network slice, and the second network slice is a network slice supported by a tracking area where the serving cell is located.

15. The method according to claim 13 or 14, characterized in that, The second indication information is further used to indicate the radio resource control (RRC) state when the AS sends the serving cell identifier of the terminal device to the NAS.

16. The method according to any one of claims 13 to 15, wherein, the second indication information further includes a first timer or a first period, wherein, the first timer is used to indicate that the AS sends the serving cell identifier to the NAS after the first timer expires; the first period is used to indicate that the AS sends the serving cell identifier to the NAS according to the first period.

17. The method according to any one of claims 13 to 16, wherein, sending the second indication information to the terminal device includes: if the serving cell does not meet the second condition, sending the second indication information to the terminal device.

18. The method according to claim 17, wherein, the step of if the serving cell does not meet the second condition, sending the second indication information to the terminal device includes: if the serving cell does not meet the second condition and the serving cell is configured with 0 resources for the second network slice, sending the second indication information to the terminal device; wherein, the second network slice is a network slice supported by a tracking area (TA) where the serving cell is located.

19. The method according to claim 17 or 18, wherein, the second condition includes: the serving cell supports a terminal device in at least one of a capacity - limited state, a low - power state, and a frequently - moving state.

20. A terminal device, wherein, it includes a non - access stratum (NAS) and an access stratum (AS), the NAS is configured to execute the method according to any one of claims 1 to 3, and the AS is configured to execute the method according to any one of claims 4 to 12.

21. An access network device, wherein, the access network device is configured to execute the method according to any one of claims 13 to 19.

22. A computer - readable storage medium, wherein, the computer - readable storage medium stores a computer program, and when the computer program is executed by a processor, it implements the method according to any one of claims 1 to 19.

23. A chip, wherein, it includes a processor and a memory, the memory stores a computer program, and when the computer program is executed by the processor, it implements the method according to any one of claims 1 to 19.

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