CN111586772B

CN111586772B - Communication method and device

Info

Publication number: CN111586772B
Application number: CN201910123531.2A
Authority: CN
Inventors: 朱方园; 李岩; 陈中平
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-02-18
Filing date: 2019-02-18
Publication date: 2021-06-22
Anticipated expiration: 2039-02-18
Also published as: WO2020168753A1; CN111586772A

Abstract

The application provides a communication method and device. The method comprises the following steps: when the state of the first slice in the network slice set allowed to access of the terminal device at a certain position (i.e. the first position) in the registration area of the terminal device is updated from the "available" state to the "unavailable" state, the network side can update the registration area of the terminal device and notify the terminal device to update the registration area, which helps to ensure that the terminal device can access the "available" slice at any position in the updated registration area, and realize that the terminal device and the network side maintain correct and effective communication, or, it is understood that the problem of communication failure with the network side caused by the terminal device initiating a service request associated with the first slice at the first position due to the fact that the terminal device does not update the registration area in time is avoided.

Description

Communication method and device

Technical Field

The present application relates to the field of mobile communications technologies, and in particular, to a communication method and apparatus.

Background

When the terminal device carries the requested network slice set and successfully registers to the network, the terminal device obtains the network slice set and the registration area which are allowed to be accessed from the network side, and then any tracking area of the terminal device in the registration area can be accessed to the network slice indicated by any network slice identifier in the network slice set which is allowed to be accessed, and the service provided by the network slice is used.

The operator may decide at any time whether the status of a network slice deployed in a certain tracking area can be changed. If the core network does not notify the terminal device in time, a tracking area where a network slice in the registration area is unavailable may be requested to access the network slice by the terminal device, which may cause failure and affect the service experience of the terminal device, so how the core network determines whether to notify the terminal device that a corresponding mechanism is not available at present is needed.

Disclosure of Invention

The application provides a communication method and a communication device, which are used for notifying a terminal device in time after the state of a network slice is changed in a certain tracking area, so that the terminal device and a network side can keep correct and effective communication.

In a first aspect, the present application provides a communication method, including: if the first slice is unavailable at the first position and is available at the second position, the terminal device receives an updated registration area of the terminal device, the registration area before the update of the terminal device comprises information of the first position and information of the second position, and a network slice set allowing access of the terminal device comprises the information of the first slice; the terminal device updates the registration area of the terminal device. Based on the scheme, when the state of the first slice in the network slice set allowing access of the terminal device at a certain position (namely the first position) in the registration area of the terminal device is updated from the "available" state to the "unavailable" state, the network side can update the registration area of the terminal device and notify the terminal device to update the registration area, which is helpful for ensuring that the terminal device can access the "available" slice at any position in the updated registration area, and realizing that the terminal device and the network side keep correct and effective communication, or is understood as being helpful for avoiding the problem that the terminal device initiates a service request associated with the first slice at the first position to cause communication failure with the network side because the terminal device does not update the registration area in time.

In a possible implementation method, a terminal device receives an updated network slice set allowed to be accessed by the terminal device; the terminal device updates the set of network slices of the terminal device that are allowed to access.

In a possible implementation method, the current location of the terminal device is the first location, the updated set of network slices allowed to access by the terminal device does not include information of the first slice, and the updated registration area of the terminal device includes information of the first location and does not include information of the second location.

In a possible implementation method, a terminal device sends a request message, where the request message is used to request to establish or activate a session associated with a first slice; the terminal device receives a request reject message, the request reject message including a cause value indicating that the first slice is not available.

In one possible implementation method, the terminal device receives information of a rejected network slice, where the information of the rejected network slice includes identification information of the first slice.

In a possible implementation method, the current location of the terminal device is the second location, and the updated registration area of the terminal device includes information of the second location and does not include information of the first location.

In a possible implementation method, the terminal device receives indication information, where the indication information is used to indicate the terminal device to initiate a re-registration process.

In a second aspect, the present application provides a communication method, including: the mobility management network element determines that the first slice is unavailable at the first position and available at the second position, and the mobility management network element updates the registration area of the terminal equipment; the registration area before updating of the terminal device comprises information of a first position and information of a second position, and the network slice set allowing access of the terminal device comprises the information of the first slice; and the mobility management network element sends the updated registration area of the terminal equipment to the terminal equipment. Based on the scheme, when the state of the first slice in the network slice set allowing access of the terminal device at a certain position (namely the first position) in the registration area of the terminal device is updated from the "available" state to the "unavailable" state, the network side can update the registration area of the terminal device and notify the terminal device to update the registration area, which is helpful for ensuring that the terminal device can access the "available" slice at any position in the updated registration area, and realizing that the terminal device and the network side keep correct and effective communication, or is understood as being helpful for avoiding the problem that the terminal device initiates a service request associated with the first slice at the first position to cause communication failure with the network side because the terminal device does not update the registration area in time.

In a possible implementation method, a mobility management network element updates a network slice set of a terminal device allowed to be accessed; and the mobility management network element sends the updated network slice set which is allowed to be accessed to the terminal equipment.

In one possible implementation, the mobility management element triggers the release of the session associated with the first slice.

In a possible implementation method, a mobility management network element receives a request message from a terminal device, where the request message is used to request to establish or activate a session associated with a first slice; the mobility management network element sends a request rejection message to the terminal device, the request rejection message including a cause value, the cause value indicating that the first slice is unavailable.

In a possible implementation method, the mobility management network element sends information of the rejected network slice to the terminal device, where the information of the rejected network slice includes identification information of the first slice.

In a possible implementation method, the mobility management network element stores information of rejected network slices in the context of the terminal device, the information of rejected network slices including information of the first slice, the information of rejected network slices being used to indicate that the first slice is not available within the updated registration area of the terminal device.

In a third aspect, the present application provides a communication apparatus having a function of a communication method that implements the method of any of the above aspects or any of the aspects. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In a fourth aspect, the present application provides a communication apparatus comprising: a processor and a memory; the memory is configured to store computer-executable instructions, and when the apparatus is running, the processor executes the computer-executable instructions stored by the memory to cause the apparatus to perform the communication method as described above in any aspect or any aspect implementing the method.

In a fifth aspect, the present application provides a communication device, comprising: comprising means or units for performing the steps of any of the above aspects.

In a sixth aspect, the present application provides a communications device comprising a processor and an interface circuit, the processor being configured to communicate with other devices via the interface circuit and to perform any of the methods provided in any of the above aspects. The processor includes one or more.

In a seventh aspect, the present application provides a communication device, including a processor, connected to a memory, and configured to invoke a program stored in the memory to perform a method in any implementation manner of any aspect. The memory may be located within the device or external to the device. And the processor includes one or more.

In an eighth aspect, the present application further provides a computer-readable storage medium having stored therein instructions, which, when run on a computer, cause the processor to perform the method of any of the above aspects.

In a ninth aspect, the present application also provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any of the above aspects.

In a tenth aspect, the present application further provides a chip system, including: a processor configured to perform the method of the above aspects.

In an eleventh aspect, the present application further provides a communication system, including a terminal device configured to execute any of the implementation methods of the first aspect or the first aspect, and a mobility management network element configured to execute any of the implementation methods of the second aspect or the second aspect.

Drawings

FIG. 1 is a schematic diagram of a 5G network architecture;

FIG. 2 is a schematic view of a service area of a slice provided in the present application;

fig. 3 is a schematic flow chart of a communication method provided in the present application;

fig. 4 is a schematic flow chart of another communication method provided in the present application;

fig. 5 is a schematic flow chart of another communication method provided in the present application;

fig. 6 is a schematic flow chart of another communication method provided in the present application;

fig. 7 is a schematic flow chart of another communication method provided in the present application;

fig. 8 is a schematic flow chart of another communication method provided in the present application;

fig. 9 is a schematic flow chart of another communication method provided in the present application;

fig. 10 is a schematic flow chart of another communication method provided in the present application;

fig. 11 is a schematic flow chart of another communication method provided in the present application;

fig. 12 is a schematic flow chart of another communication method provided in the present application;

fig. 13 is a schematic flow chart of another communication method provided in the present application;

fig. 14 is a schematic diagram of a communication device provided in the present application;

fig. 15 is a schematic diagram of yet another communication device provided herein;

fig. 16 is a schematic diagram of another communication device provided in the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more clear, the present application will be further described in detail with reference to the accompanying drawings. The particular methods of operation in the method embodiments may also be applied to apparatus embodiments or system embodiments. In the description of the present application, the term "plurality" means two or more unless otherwise specified.

Fig. 1 is a schematic diagram of the 5th generation (5G) network architecture. The figure shows a part of the network elements in the 5G architecture. The User Plane Function (UPF) network element includes user plane related functions such as packet routing and transmission, packet detection, Service usage reporting, Quality of Service (QoS) processing, lawful interception, uplink packet detection, and downlink packet storage.

An access and mobility management function (AMF) network element is responsible for mobility management of users, including mobility state management, allocating user temporary identity, authenticating and authorizing users.

Session Management Function (SMF) network elements include Session management (e.g., Session establishment, modification, and release, including tunnel maintenance between UPF and AN), selection and control of UPF network elements, Service and Session Continuity (SSC) mode selection, roaming, and other Session-related functions.

A Network Slice Selection Function (NSSF) Network element, which is responsible for determining a Network Slice instance, selecting an AMF Network element, and the like.

The mobility management network element in this application may be the AMF network element shown in fig. 1, or may be a network element having the function of the AMF network element in a future communication system. The user plane network element in this application may be the UPF network element shown in fig. 1, or may be a network element having the function of the UPF network element in a future communication system. The session management network element in this application may be the SMF network element shown in fig. 1, or may be a network element having the function of the SMF network element in a future communication system. The slice selection network element in this application may be the NSSF network element shown in fig. 1, or may be a network element having the function of the NSSF network element in a future communication system.

An access network device (also referred to as a Radio Access Network (RAN) device) in the present application is a device that provides a terminal with a wireless communication function. Access network devices include, but are not limited to: next generation base station (gndeb, gNB), evolved node B (eNB), Radio Network Controller (RNC), Node B (NB), Base Station Controller (BSC), Base Transceiver Station (BTS), home base station (e.g., home evolved node B, or home node B, HNB), Base Band Unit (BBU), transmission point (TRP), Transmission Point (TP), mobile switching center, etc. in 5G.

The terminal device (also referred to as User Equipment (UE)) of the present application is a device with a wireless transceiving function, and can be deployed on land, including indoors or outdoors, handheld or vehicle-mounted; can also be deployed on the water surface (such as a ship and the like); and may also be deployed in the air (e.g., airplanes, balloons, satellites, etc.). The terminal may be a mobile phone (mobile phone), a tablet computer (pad), a computer with a wireless transceiving function, a Virtual Reality (VR) terminal, an Augmented Reality (AR) terminal, a wireless terminal in industrial control (industrial control), a wireless terminal in self driving (self driving), a wireless terminal in remote medical (remote medical), a wireless terminal in smart grid (smart grid), a wireless terminal in transportation safety (transportation safety), a wireless terminal in smart city (smart city), a wireless terminal in smart home (smart home), and the like.

For convenience of description, in the following description, a mobility management network element is an AMF network element, a slice selection network element is an NSSF network element, a session management network element is an SMF network element, and a user plane network element is an UPF network element. Further, the AMF network element is abbreviated as AMF, the NSSF network element is abbreviated as NSSF, the SMF network element is abbreviated as SMF, the UPF network element is abbreviated as UPF, the terminal device is abbreviated as UE, and the access network device is abbreviated as RAN. That is, AMFs described later in this application may be replaced with a mobility management network element, NSSF may be replaced with a slice selection network element, SMF may be replaced with a session management network element, UPF may be replaced with a user plane network element, RAN may be replaced with an access network device, and UE may be replaced with a terminal device.

It should be noted that, in the present application, "network slice" and "slice" refer to the same content, and one of the descriptions is used in different places, and the two may be interchanged.

Currently, various scenarios place different requirements on the 3rd Generation Partnership Project (3 GPP) ecosystem, such as charging, policy, security, mobility, etc. requirements. 3GPP emphasizes that network slices do not affect each other, for example, a large amount of bursty meter reading traffic should not affect normal mobile broadband traffic. In order to meet the diversity requirement and the isolation between slices, relatively independent management and operation and maintenance between services are required, and customized service functions and analysis capability are provided. Instances of different types of services are deployed on different network slices, and different instances of the same service type may also be deployed on different network slices.

When a core network deploys a network slice and a user initially attaches (or is called to register) to the network, a selection process of the network slice is triggered. The selection process of the slice depends on the subscription data of the user, local configuration information, roaming agreements, policies of the operator, etc. In the selection process of the network slice, the above parameters need to be considered comprehensively to select the optimal slice type for the UE.

When the UE needs to access a certain network slice, the UE may provide the requested network slice to the core network for the core network to select a network slice instance for the UE. The network slice requested by the UE may be represented by a requested network slice set, or may also be represented by requested network slice selection assistance information (requested NSSAI). The requested NSSAI is formed by one or more single network slice selection assistance information (S-NSSAI), where each S-NSSAI is used to identify a network slice type, and may also be understood as S-NSSAI is used to identify a network slice, or may be understood as S-NSSAI is identification information of a network slice.

After the UE registers to the network, a core network element (e.g., AMF or NSSF) selects a network slice set allowed to access for the UE according to comprehensive judgment of subscription data of the UE, requested NSSAI of the UE, roaming agreement, local configuration, and other information. The set of network slices allowed to be accessed may be represented by allowed (allowed) NSSAIs, and all the S-NSSAIs included in the allowed NSSAIs are all valid S-NSSAIs of the current network.

An AMF in an AMF set (AMF set) may provide the NSSF with the slicing capability supported by the AMF in a certain Tracking Area (TA), and may subsequently update the slicing capability supported by the AMF network element in a certain TA to the NSSF if the slice corresponding to the TA is changed. The NSSF may inform the AMFs in the AMF set according to operator policy or under certain conditions (e.g., when network slices are congested): whether the slice state deployed under a certain TA has changed.

For example, when a network slice is congested, the NSSF may inform the AMF: a slice deployed under a certain TA is prohibited from being used (it can also be understood that the TA is a restricted area of the slice), that is, the slice is updated from an "available" status to an "unavailable" status, so that when a UE located at the TA requests to access the slice, since the AMF knows from the NSSF that the slice is "unavailable" under the TA, the AMF will refuse the UE to access the slice.

The slice available state (available state) refers to the slice being accessible or accessible; a slice unavailable state (restriction state) refers to the slice being inaccessible or inaccessible. The slice may be updated from an available state to an unavailable state, or from an unavailable state to an available state.

Fig. 2 is a schematic view of a service area of a slice provided in the present application. Suppose that the service areas of slice A (slice-A, identified by S-NSSAI-A) and slice B (slice-B, identified by S-NSSAI-B) are both: TA-1, TA-2, TA-3, … …, TA-10 (only TA-1, TA-2, and TA-3 are shown by way of example in the figure), and all 10 TAs are "available" status. At some point, the operator decides to update the service area TA-3 of slice a from "available" to "unavailable" due to congestion or the like, and then at location TA-3, the UE is not allowed to access the service provided by slice a using slice a. At this time, the slice A is in TA-1, TA-2, TA-4, … …, TA-10 is in "available" state, and TA-3 is in "unavailable" state. It is also understood that TA-1, TA-2, TA-4, … …, TA-10 are available regions of slice A and TA-3 is an unavailable region (or restricted region) of slice A. For slice B above, its usable area remains: TA-1, TA-2, TA-3, … …, TA-10, or, as understood, section B remained in the "available" state at TA-1, TA-2, TA-3, … …, TA-10.

In order to solve the problems mentioned in the background art, the present application provides a plurality of communication methods, based on which, when the state of a slice identified by an S-NSSAI in an allowed NSSAI of a UE changes, a core network can determine whether to notify the UE, and define which information needs to be notified to the UE, so as to implement correct and effective communication between the UE and the core network.

The application scenario aimed at by the application is as follows: the state of a slice identified by a certain S-NSSAI (referred to herein as a first slice) in an allowed NSSAI of a UE changes (either from an "available" state to an "unavailable" state or from an "unavailable" state to an "available" state) within one or more TAs within a Registration Area (RA) of the UE.

For convenience of explanation, the present application will be described with reference to a specific example shown in fig. 2, and it is assumed that the allowed NSSAI of the UE includes: S-NSSAI-A and S-NSSAI-B, wherein S-NSSAI-A is the mark of the section A, and S-NSSAI-B is the mark of the section B; the registration Area of the UE includes TAI-1, TAI-2 and TAI-3, wherein TAI refers to Tracking Area Identity (Tracking Area Identity), TAI-1 is used for identifying TA-1, TAI-2 is used for identifying TA-2, and TAI-3 is used for identifying TA-3.

In the first scenario, the state of the first slice (taking the first slice as slice A for example) is updated from the "available" state to the "unavailable" state at TA-3, and the state of the first slice at TA-1 and TA-2 remains in the "available" state.

In the second scenario, after the first scenario described above occurs, the state of the first slice (taking the first slice as slice A for example) is updated from the "not available" state to the "available" state at TA-3, and the state of the first slice at TA-1 and TA-2 remains in the "available" state.

It should be noted that, the present application is only illustrated by taking fig. 2 as an example, but is not limited to the specific example shown in fig. 2.

Based on the network architecture shown in fig. 1, as shown in fig. 3, the present application provides a flowchart of a communication method for updating a state of a certain slice (referred to as a first slice) of an allowed NSSAI of a UE from an "available" state to an "unavailable" state in a certain TA of a registration area of the UE. I.e. the method can be used in the first case described above.

The method comprises the following steps:

step 301, the AMF determines that the first slice is unavailable at the first position and available at the second position; the registration area of the UE comprises information of a first position and information of a second position, and the network slice set allowing access of the UE comprises the information of the first slice.

Here, the first location and the second location may be TAs within a registration area of the UE, respectively, and taking fig. 2 as an example, the first location may be TA-3, the second location may be TA-1 and/or TA-2, the information of the first location may be TAI-3, and the information of the second location may be TAI-1 and/or TAI-2.

The set of network slices allowed to be accessed by the UE is allowed NSSAI of the UE, and taking fig. 2 as an example, the first slice may be slice a.

Wherein, the AMF determines that the first slice is unavailable at the first position, which means that the AMF determines that the state of the first slice at the first position is "unavailable"; the AMF determining that the first slice is available at the second location means that the AMF determines that the status of the first slice at the second location is "available".

In this application, the second location refers to any one or any plurality of locations within the registration area of the UE other than the first location.

In step 302, the AMF updates the registration area of the UE.

For example, the AMF may update the registration area of the UE according to the current location of the UE. Of course, the AMF may also update the registration area of the UE according to the current location of the UE and in combination with other information. Other information of the UE here includes, for example, the state of the UE (connected state, idle state, etc.).

Step 303, the AMF sends the updated registration area of the UE to the UE.

In step 304, the UE updates the registration area of the UE.

That is, the UE updates the received updated registration area of the UE to the registration area of the UE.

Based on the above scheme, when the status of the first slice in the allowed NSSAI of the UE is updated from the "available" status to the "unavailable" status at a certain TA (i.e., the first location) in the registration area of the UE, the network side (e.g., the AMF) may update the registration area of the UE and notify the UE to update the registration area, which is helpful to ensure that the UE can access the "available" slice at any location in the updated registration area, so that the UE and the network side can maintain correct and effective communication, or it is understood that the UE is helpful to avoid the problem that the UE initiates a service request associated with the first slice at the first location and fails communication with the network side due to the fact that the UE does not update the registration area in time.

Optionally, before step 303, the AMF may send indication information to the UE, where the indication information is used to indicate the UE to initiate a re-registration procedure, and then the AMF performs step 303 in the re-registration procedure initiated by the UE.

The embodiment of fig. 3 is further explained below in connection with the example of fig. 2 in two cases, respectively, wherein:

allowed NSSAI of the UE { S-NSSAI-a, S-NSSAI-B };

RA of the UE { TAI-1, TAI-2, TAI-3 };

first cutting: slicing A;

a first position: TA-3;

a second position: TA-1 and/or TA-2;

current location of UE: a first position or a second position;

the state of the first slice at TA-3 is updated from "available" to "unavailable".

Situation one, the current location of the UE is the first location

In this case, if the first slice is not available at the current location of the UE, the specific method for the AMF to update the registration area of the UE in step 302 may be, for example: the updated registration area of the UE includes information of the first location and does not include information of the second location. Taking the above example as an example, the updated registration area (new RA) of the UE is: TAI-3. Therefore, in step 304, the UE updates the registration area of the UE, specifically: the UE updates the registration area to: TAI-3.

In this case, further, the following steps 305 to 307 may also be performed.

At step 305, the AMF updates the UE's set of allowed access network slices.

For example, the AMF may update the UE's set of network slices allowed to access based on the UE's current location. Of course, the AMF may also update the UE's set of network slices allowed to access based on the UE's current location and in conjunction with other information. Other information of the UE here includes, for example, the state of the UE (connected state, idle state, etc.).

In step 306, the AMF sends the UE an updated set of network slices allowed to access.

In step 307, the UE updates the UE's set of allowed access network slices.

In step 305, the specific method for the AMF to update the network slice set allowed to be accessed by the UE may be, for example: the updated set of allowed access network slices for the UE does not include information for the first slice. Taking the above example as an example, the updated allowed access network slice set (new allowed NSSAI) of the UE is: S-NSSAI-B. Therefore, in step 307, the UE updates the network slice set allowed to be accessed by the UE, specifically: the UE updates the network slice set allowed to be accessed into: S-NSSAI-B.

Thus, in this case one, for the above example, then:

the updated registration area (new RA) of the UE is: TAI-3;

the updated set of allowed access network slices (new allowed NSSAI) for the UE is: S-NSSAI-B.

It should be noted that there is no strict execution sequence between the above steps 305 to 307 and the above steps 302 to 304. For example, step 302-step 304 may be performed first, and then step 305-step 307 may be performed; for another example, step 305-step 307 may be performed first, and then step 302-step 304 may be performed; for another example, step 302 and step 305 may be performed in parallel, then step 303 and step 306 may be performed in parallel, then step 304 and step 307 may be performed in parallel, and so on.

In one implementation, if a first slice is associated with one or some already established sessions, the AMF may also trigger the release of the sessions associated with the first slice.

In one implementation, if a first slice is associated with a session or sessions requested to be established or activated by a UE or UEs, the AMF may also refuse to establish or activate the session or sessions associated with the first slice. For example, the method shown in fig. 3 may be executed in a session establishment procedure of the UE, and then in the session establishment procedure, the following steps may also be executed:

step a, the AMF receives a request message from the UE, the request message requesting to establish or activate a session associated with the first slice.

Step B, the AMF sends a request rejection message to the UE, wherein the request rejection message comprises a reason value, and the reason value is used for indicating that the first slice is unavailable.

Alternatively, the request reject message may not include a cause value, i.e. only the UE is informed of the rejection of establishing or activating the session, but not the reason for the rejection.

In one implementation, the AMF may further send information of the rejected network slice to the UE, where the information of the rejected network slice includes identification information of the first slice. That is, the AMF notifies the UE of the information of the rejected network slice, and may transmit the information of the rejected network slice to the UE through, for example, step 303 or step 306 described above, or through a separate step.

In one implementation, the AMF may store, in the context of the UE, information of the rejected network slice including information of the first slice, the information of the rejected network slice indicating that the first slice is not available within the updated registration area of the UE.

Case two, the current location of the UE is the second location

In this case, if the first slice is available at the current location of the UE, the specific method for the AMF to update the registration area of the UE in step 302 may be, for example: the updated registration area of the UE includes information of the second location and does not include information of the first location. Taking the above example as an example, the updated registration area of the UE is: TAI-1 and TAI-2. Therefore, in step 304, the UE updates the registration area of the UE, specifically: the UE updates the registration area to: TAI-1 and TAI-2.

The application of the embodiment shown in fig. 3 will be described with reference to different specific application scenarios.

Application scenario 1, UE initiates a session establishment procedure or UE has completed session establishment

Application scenario 1.1, the UE requests to establish a session, the session is associated with the first slice, the first slice is unavailable at the first location, the second slice is available at the second location, and the current location of the UE is the first location (i.e., scenario one above)

Fig. 4 is a schematic flow chart of a communication method for the application scenario 1.1. The method comprises the following steps:

in step 400, the AMF sends a TAI to the NSSF, and the slice type (identified by S-NSSAI) that the AMF supports under the TA identified by the TAI.

For example, the AMF may call the NSSF _ nssaiiavailability _ Update of the servization operation of the NSSF, carrying the TAI, and the slice type (identified by S-NSSAI) supported by the AMF under the TA identified by the TAI.

Step 401, the UE initiates a registration procedure, which carries a requested NSSAI, the AMF receives the registration request of the UE, and allocates a Registration Area (RA) to the UE, and the AMF returns an allowed NSSAI and RA to the UE.

Wherein, the RA includes a TA list composed of multiple TAIs, and any S-NSSAI included in the allowed NSSAI can be accessed by any TA in the RA, or it can be understood that any S-NSSAI included in the allowed NSSAI can provide services for the UE by any TA in the RA.

At some point, the NSSF decides to change the status of the first slice at the first location (e.g., because the congestion condition of the first slice exceeds a threshold), and updates the first slice from "available" to "unavailable", step 402.

The first slice and the first position may refer to the description of the foregoing embodiments, and are not described herein again.

In step 403, the NSSF notifies the AMF: the first slice is updated as unavailable at the first location.

For example, the NSSF may call an NSSF _ nssaiiavailability _ Notify servization operation, notifying the AMF: the first slice is updated as unavailable at the first location.

Of course, if the status of a plurality of slices at a certain location or locations is updated to be unavailable, the NSSF may send a plurality of S-NSSAIs and corresponding unavailable location lists to the AMF. For example, if S-NSSAI-A is updated to be unavailable at TA-11, TA-12, S-NSSAI-B is updated to be unavailable at TA-13, TA-14, then the NSSF may send to the AMF: (S-NSSAI-A, (TA-11, TA-12)), (S-NSSAI-B, (TA-13, TA-14)).

Step 404, the current location of the UE is a first location, and the UE sends a non-access stratum (NAS) message to the AMF, where the NAS message may carry a session establishment request, a session identifier (protocol Data unit (PDU) session ID), and an S-NSSAI and a Data Network Name (DNN) corresponding to the session.

Here, the slice identified by the S-NSSAI in the NAS message includes the first slice described above.

In step 405, after receiving the session establishment request of the UE, the AMF determines that the first slice of the S-NSSAI identifier requested by the UE is not available in the current location of the UE.

That is, the AMF determines that the first slice of the session association that the UE requests to establish is not available at the current location (i.e., the first location) of the UE.

Step 406, the AMF rejects the NAS message sent by the UE, carrying a cause value: the S-NSSAI requested by the UE is not available at the current location of the UE.

That is, the AMF rejects the session establishment request of the UE.

Step 407, AMF triggers updating allowed NSSAI and RA of the UE due to session establishment failure.

Step 408, the AMF sends a configuration update message to the UE, carrying the new allowed NSSAI and the new RA, wherein:

the new allowed NSSAI does not contain an unavailable S-NSSAI, and the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-3 }. And the old allowed NSSAI is { S-NSSAI-A, S-NSSAI-B }, and the new allowed NSSAI is { S-NSSAI-B }. For a description of specific update, reference may be made to the related description in the first case of the embodiment in fig. 3, which is not repeated herein.

Optionally, the configuration update message may further carry a rejected network slice (rejected S-NSSAI in current RA) in the current registration area of the UE, so as to notify the UE of: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session requested by the UE in step 404.

Optionally, as an alternative implementation manner, the configuration update message in step 408 does not carry the new allowed NSSAI and the new RA, but carries re-registration indication information (or referred to as indication information) for indicating the UE to initiate a registration procedure.

In step 409, the UE returns a configuration update complete message to the AMF.

Step 410, if the UE receives the re-registration instruction information in step 408, the UE initiates a registration procedure after step 409, the UE sends a registration request message, and the AMF carries a new allowed NSSAI and a new RA in a registration accept message sent to the UE.

Wherein the new allowed NSSAI does not contain an unavailable S-NSSAI, and the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

Optionally, the registration accept message may also carry a rejected network slice (rejected S-NSSAI in current RA) in the current registration area of the UE, for notifying the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the establishment session requested by the UE in step 404.

In step 411, AMF stores the rejected S-NSSAI in current RA in the context of the UE, which is used to record the rejected S-NSSAI sent to which UE.

This step 411 is an optional step.

Based on the above scheme, when the slice associated with the session requested to be established by the UE is unavailable at the current location of the UE, the network side rejects the UE to establish the session, so that the UE knows that the slice cannot be accessed at the current location, and updates the registration area of the UE, which is helpful to ensure that the UE can access the "available" slice at any location in the updated registration area, thereby realizing correct and effective communication between the UE and the network side.

Application scenario 1.2, the UE requests to establish a session, the session being associated with the first slice, the first slice being unavailable at the first location, available at the second location, and the current location of the UE being the second location (i.e. scenario two above)

Fig. 5 is a schematic flow chart of a communication method for the application scenario 1.2. The method comprises the following steps:

the steps 500 to 503, like the steps 400 to 403 in the embodiment 4, can refer to the foregoing description, and are not repeated herein.

Step 504, the current location of the UE is the second location, and the UE sends an NAS message to the AMF, where the NAS message may carry a session establishment request, a session identifier (PDU session ID), and S-NSSAI and DNN corresponding to the session.

Here, the slice identified by S-NSSAI in the NAS message is the first slice described above.

In step 505, after receiving the session setup request from the UE, the AMF determines that the first slice of the S-NSSAI id requested by the UE is available in the current location of the UE, but the registration area of the UE includes the TA (i.e., the first location) for which the S-NSSAI requested by the UE is not available.

I.e., the AMF determines that the first slice of the session association that the UE requests to establish is available at the current location (i.e., the second location) of the UE. And, the first slice is not available within a TA (i.e., the first location) identified by a certain TAI of the registration area of the UE.

Step 506, continue with other steps of the session establishment procedure, such as including AMF selecting SMF according to S-NSSAI and DNN, SMF selecting UPF according to S-NSSAI and DNN, etc., until the session is successfully established.

In step 507, since the registration area of the UE includes the TA requested by the UE and unavailable for S-NSSAI, the AMF determines to trigger updating the registration area of the UE, and the AMF sends a configuration update message to the UE, carrying the new RA.

Where the new RA deletes the TA of the slice state change, i.e., the new RA does not include the TA of the slice state change, where the AMF acquires the TA of the state change in step 503. For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-1, TA-2 }.

Optionally, as an alternative implementation manner, the configuration update message in step 507 does not carry the new RA, but carries re-registration indication information, which is used for indicating the UE to initiate a registration procedure.

In step 508, the UE returns a configuration update complete message to the AMF.

In step 509, if the UE receives the re-registration instruction information in step 507, the UE initiates a registration procedure after step 508, and the UE sends a registration request message, where the AMF carries the new RA in a registration accept message sent to the UE.

Based on the above scheme, when the slice associated with the session requested to be established by the UE is available at the current location of the UE, the network side accepts the UE to establish the session, so that the UE knows that the slice can be accessed at the current location, and updates the registration area of the UE, which is helpful to ensure that the UE can access the "available" slice at any location in the updated registration area, thereby realizing correct and effective communication between the UE and the network side.

Application scenario 1.3, the session requested to be established by the UE has been established and is associated with the first slice, which is not available in the first location

Fig. 6 is a schematic flow chart of a communication method for the application scenario 1.3. The method comprises the following steps:

step 600, like step 400 of example 4, can be referred to the above description.

Step 601a, UE initiates a registration flow, carries a requested NSSAI, AMF receives the registration request of the UE, allocates a registration area to the UE, and AMF returns an allowed NSSAI and the registration area to the UE.

Step 601b, the UE initiates a session establishment process to request to establish a session corresponding to the S-NSSAI, the session is successfully established, and the AMF stores the association relationship of a session identifier (PDU session ID), the S-NSSAI and the SMF ID.

The slice identified by S-NSSAI here is the first slice.

Reference is made to the above description for steps 602 to 603, similar to steps 402 to 403 in embodiment 4.

In step 604, if the UE is in the connected state, the current location of the UE is the first location, and the AMF determines that the first slice is not available at the current location of the UE. If the UE is in the idle state, at this time, the AMF does not determine the specific location where the UE is currently located, in this case, the AMF may wait for the UE to update from the idle state to the connected state (for example, after the UE initiates signaling such as a service request), acquire the current location of the UE (which is the first location), and determine that the first slice is not available at the current location of the UE.

Step 605, the AMF determines to trigger and release the session corresponding to the first slice that is unavailable at the current location, the AMF determines the SMF corresponding to the session according to the context, and then sends a session release request to the SMF to request to release the session.

For example, the AMF may call Nsmf _ pdusesion _ UpdateSMContext, and carry a PDU session release request (including a cause value: the S-NSSAI corresponding to the session is not available at the current location of the UE).

Step 606, because the UE is currently located in the area where the first slice is unavailable, the AMF triggers to update allowed NSSAI and RA of the UE, and the AMF sends a configuration update message to the UE, carrying new allowed NSSAI and new RA, where:

the new allowed NSSAI does not contain an unavailable S-NSSAI; the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

For a description of specific update, reference may be made to the related description in the first case of the embodiment in fig. 3, which is not repeated herein.

Optionally, the configuration update message may further carry a rejected S-NSSAI in current RA, which is used to notify the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session requested by the UE in step 601 b.

Optionally, as an alternative implementation manner, the configuration update message in step 606 does not carry the new allowed NSSAI and the new RA, but carries re-registration indication information for indicating the UE to initiate a registration procedure.

In step 607, the UE returns a configuration update complete message to the AMF.

Step 608, if the UE receives the re-registration indication information in step 606, the UE initiates a registration procedure after step 607, the UE sends a registration request message, and the AMF carries a new allowed NSSAI and a new RA in a registration accept message sent to the UE.

Optionally, the registration accept message may also carry a rejected network slice (rejected S-NSSAI in current RA) in the current registration area of the UE, for notifying the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session requested by the UE in step 601 b.

In step 609, the AMF stores the rejected network slice (rejected S-NSSAI in current RA) in the current registration area of the UE in the context of the UE to record which UEs have sent the rejected S-NSSAI.

This step 609 is an optional step.

Based on the above scheme, when the slice of the session association requested to be established by the UE is unavailable at the current location of the UE, the network side may release the established session, so that the UE knows that the slice cannot be accessed at the current location, which is helpful to ensure that the UE can access the "available" slice at any location in the updated registration area, thereby achieving correct and effective communication between the UE and the network side.

Application scenario 2, switching process of UE

Taking the example shown in fig. 2 as an example, the NSSF decides to update the service area TA-3 (i.e., the first location) of slice a (i.e., the first slice) from the "available" to the "unavailable" state due to congestion or the like.

At time T1, the UE initiates the session corresponding to the first slice in the area (e.g. TA-2) where the first slice is available, i.e. the PDU session is established in the first slice.

At time T2, when the UE in the connected state moves from TA-2 to TA-3 (i.e. the first location), the UE is handed over from a Source-side RAN (Source-RAN, S-RAN) to a Target-side RAN (Target-RAN, T-RAN) through a handover procedure, where the Source-side RAN is located in an area where the first slice is available and the Target-side RAN is located in an area where the first slice is not available.

Before the UE is switched to the target RAN, the TA where the source RAN is located of the first slice corresponding to the session established by the UE is available, and after the UE is switched to the target RAN, the network side releases the session because the TA where the target RAN is located of the first slice is unavailable. Or it may be understood that the source-side RAN is located in a certain TA or certain TAs in the registration area of the UE, and the first slice is available in the source-side RAN, the target-side RAN is located in a certain TA or certain TAs in the registration area of the UE, and the first slice is unavailable in the target-side RAN, that is, after the UE is handed over to the target-side RAN, the first slice is not supported in the TA in which the target-side RAN is located.

Fig. 7 is a schematic flow chart of a communication method for the application scenario 2. The method comprises the following steps:

the steps 700 to 703 are similar to the steps 400 to 403 of the embodiment 4, and reference is made to the above description.

In step 704a, the source RAN initiates the Xn interface handover, and determines the target RAN according to the measurement report of the UE.

Step 704b, the target RAN sends a Path Switch Request (Path Switch Request) message To the AMF, carrying a session List (List of PDU Sessions To Be Switched) and the TAI corresponding To the TA where the target RAN is located.

Step 705, the AMF determines that the first slice first position associated with the PDU session included in the session list is unavailable according to the PDU session IDs included in the session list to be switched and the S-NSSAI corresponding to each PDU session ID stored in the context.

For example, the session list to be switched contains the information as table 1:

TABLE 1

List of PDU Sessions To Be Switched
	PDU session ID-1
PDU session ID-2

The S-NSSAI corresponding to each PDU session ID stored by the AMF is table 2:

TABLE 2

Taking the example shown in fig. 2 as an example, the first slice corresponds to S-NSSAI-a, and the first slice corresponding to S-NSSAI-a is not available at the first location.

The first location here refers to a TA where the target RAN is located, and the registration area of the UE includes a TAI corresponding to the TA. For example, taking the example shown in fig. 2 as an example, the TA where the target RAN is located is TA-3, and the registration area of the UE includes TA-3.

In step 706a, the AMF decides to trigger the release of the session corresponding to the first slice that is not available in the first location.

Taking the example shown in table 2 as an example, in the first position, the session corresponding to the unavailable first slice is PDU session ID-1.

Step 706b, the AMF determines the SMF corresponding to the session according to the context, and then sends a session release request to the SMF to request to release the session.

For example, AMF may call Nsmf _ pdusesion _ UpdateSMContext, and carry PDU session release request (including a cause value: S-NSSAI corresponding to the session is not available at the target RAN).

In step 706c, the AMF sends a Path Switch Request acknowledgement (Path Switch Request ACK) message to the target RAN, which carries the new allowed NSSAI.

Optionally, the path switch request acknowledgement message further carries a PDU session list of a switch failure.

Where the new allowed NSSAI does not include an S-NSSAI that is not available at the first location, e.g., based on the embodiment shown in fig. 2, the new allowed NSSAI is { S-NSSAI-B }. The handover failure PDU session list contains the identity of the handover failure session.

Step 707, after the handover is completed, if the UE initiates a mobility registration update procedure and carries a requested NSSAI, the AMF determines a new allowed NSSAI and a new RA according to the requested NSSAI of the UE and the current location (i.e. the first location) of the UE, and sends the new allowed NSSAI and the new RA to the UE.

Specifically, the new allowed NSSAI does not contain an identification of the first slice, and the new RA includes information of the first position.

Based on the scheme, in the handover process, the AMF determines that the first slice is not available at the first location where the target RAN is located, and allocates a new allowed NSSAI or RA by deleting the session corresponding to the first slice that is not available at the target RAN, so that the UE knows that the UE cannot access the slice at the current location (i.e., the first location).

Application scenario 3, idle-state UE initiated activation process

At time T1, the UE initiates session establishment corresponding to the first slice in an area (e.g., TA-2) where the first slice is available, i.e., a PDU session is established in the first slice.

At time T2, the UE is in idle state, moving from TA-2 to TA-3, i.e., from an area where the first slice is available to an area where the first slice is not available.

In application scenario 3.1, the idle UE initiates a service request in an area (e.g. TA-3) where the first slice is unavailable, and requests to activate a session (PDU session) user plane data connection corresponding to the first slice.

Fig. 8 is a schematic flow chart of a communication method for the application scenario 3.1. The method comprises the following steps:

step 800 to step 803, similar to step 600 to step 603 of the embodiment shown in fig. 6, can refer to the foregoing description, and are not repeated here.

Step 804a, the idle UE initiates a service request To the (R) AN, and carries a To-Be-Activated session List (List of PDU Sessions To Be Activated), where the List includes a PDU session ID.

For example, the session list to be activated contains the information as table 3:

TABLE 3

List of PDU Sessions To Be Switched
	PDU session ID-1
PDU session ID-2

Step 804b, (R) the AN forwards the service request of the UE, and reports the current location of the UE to the AMF.

As AN alternative implementation, the service request in step 804a may carry the current location of the UE, and in step 804b, (R) the AN sends the service request to the AMF.

Wherein the current position of the UE is the first position. Taking the example shown in FIG. 2 as an example, the current location of the UE is at TA-3.

In step 805, the AMF determines that a first slice corresponding to a session in the session list to be activated is not available at the current location of the UE.

The AMF stores the corresponding relation between the session identifier (PDU session ID) and the slice identifier (S-NSSAI).

For example, the S-NSSAI corresponding to each PDU session ID stored in the AMF is shown in table 4:

TABLE 4

In step 806a, AMF rejects the service request of the UE and returns the cause value: the first slice is not available at the current location of the UE.

Step 806b, the AMF determines to trigger release of the session corresponding to the first slice that is unavailable at the current location, determines, by the AMF, the SMF corresponding to the session according to the context, and then sends a session release request to the SMF to request release of the session.

Taking the example shown in fig. 2 as an example, in the current position, the session corresponding to the unavailable first slice is PDU session ID-1.

Step 807, due to the failure of the service request, the AMF triggers to update allowed NSSAI and RA of the UE, and the AMF sends a configuration update message to the UE, carrying new allowed NSSAI and new RA, where:

the new allowed NSSAI does not contain an unusable S-NSSAI (i.e., the identification of the first slice described above); the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

Optionally, the configuration update message may further carry a rejected S-NSSAI in current RA, which is used to notify the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session the UE requested to be activated in step 804 a.

Optionally, as an alternative implementation manner, the configuration update message in step 807 does not carry the new allowed NSSAI and the new RA, but carries re-registration indication information for indicating the UE to initiate a registration procedure.

In step 808, the UE returns a configuration update complete message to the AMF.

Step 809, if the UE receives the re-registration indication information in step 807, the UE initiates a registration procedure after step 808, the UE sends a registration request message, and the AMF carries a new allowed NSSAI and a new RA in a registration accept message sent to the UE.

Wherein the new allowed NSSAI does not contain the S-NSSAI requested by the UE (i.e. does not contain the unavailable S-NSSAI), and the new RA comprises information of the first location.

Optionally, the registration accept message may also carry a rejected network slice (rejected S-NSSAI in current RA) in the current registration area of the UE, for notifying the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session the UE requested to be activated in step 804 a.

In step 810, the AMF stores rejected network slices (rejected S-NSSAI in current RA) in the current registration area of the UE in the context of the UE to record which UEs have sent the rejected S-NSSAI.

This step 810 is an optional step.

Based on the above scheme, if the AMF determines that the state of the first slice is "unavailable" at the current location (first location) of the UE, the new allowed NSSAI or RA is allocated by rejecting the service request of the UE, so that the UE knows that the UE cannot access the first slice at the current location, which is helpful to ensure that the UE can access the "available" slice at any location in the updated registration area, thereby achieving correct and effective communication between the UE and the network side.

In application scenario 3.2, the idle UE initiates a service request in an area (e.g. TA-2) where the first slice is available, and requests to activate a session (PDU session) user plane data connection corresponding to the first slice.

Fig. 9 is a schematic flow chart of a communication method for the application scenario 3.2. The method comprises the following steps:

step 900 to step 903, similar to step 800 to step 803 in the embodiment shown in fig. 8, refer to the foregoing description, and are not repeated here.

Step 904a, the idle UE initiates a service request To the (R) AN, carrying a To-Be-Activated session List (List of PDU Sessions To Be Activated), where the List includes a PDU session ID.

For example, the session list to be activated contains the information of table 5:

TABLE 5

List of PDU Sessions To Be Switched
	PDU session ID-1
PDU session ID-2

Step 904b, (R) the AN forwards the service request of the UE, while reporting the current location of the UE to the AMF.

As AN alternative implementation, the service request in step 904a may carry the current location of the UE, and in step 904b, (R) AN sends the service request to the AMF.

And the current position of the UE is the second position.

Taking the example shown in FIG. 2 as an example, the current location of the UE is at TA-1 or TA-2. In step 905, the AMF determines that a first slice corresponding to the session in the session list to be activated is available at the current location (second location) of the UE.

For example, the S-NSSAI corresponding to each PDU session ID stored in the AMF is table 6:

TABLE 6

Taking the example shown in fig. 2 as an example, the first slice corresponds to S-NSSAI-a, and the first slice corresponding to S-NSSAI-a is available at the second location.

Step 906, continue other flows of the service request until the flow is successfully ended.

In step 907, since the registration area of the UE includes the TA (i.e. the first location) that the S-NSSAI corresponding to the session to be activated is unavailable, the AMF decides to trigger updating the registration area of the UE, and the AMF sends a configuration update message to the UE, carrying the new RA.

Where the new RA deletes the TA of the slice state change, i.e., the new RA does not include the TA of the slice state change, where the AMF acquires the TA of the state change in step 903. For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-1, TA-2 }.

Optionally, as an alternative implementation manner, the configuration update message in step 907 does not carry the new RA, but carries re-registration indication information for indicating the UE to initiate a registration procedure.

In step 908, the UE returns a configuration update complete message to the AMF.

In step 909, if the UE receives the re-registration indication information in step 907, the UE initiates a registration procedure after step 908, where the UE carries a registration request message and the AMF carries a new RA in a registration accept message.

Where the new RA deletes the TA of the slice state change, i.e., the new RA does not include the TA of the slice state change, where the AMF acquires the TA of the state change in step 903. Identification of the slice in the new allowed NSSAI the slice corresponding to the slice is available in the new RA.

For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-1, TA-2 }.

Based on the above scheme, if the AMF determines that the state of the first slice is "available" at the current location (second location) of the UE, the network side receives the service request of the UE, so that the UE knows that the UE can access the slice at the current location, and updates the registration area of the UE, which helps to ensure that the UE can access the "available" slice at any location in the updated registration area, thereby achieving correct and effective communication between the UE and the network side.

Application scenario 4, network side initiates activation flow of UE

The main differences between this application scenario 4 and the above application scenario 3 are: the application scenario 3 is a service request flow initiated by idle UE actively, and the application scenario 4 is a service request flow triggered by the network side.

In application scenario 4.1, the idle UE initiates a service request in an area (e.g. TA-3) where the first slice is unavailable, and requests to activate a session (PDU session) user plane data connection corresponding to the first slice.

Fig. 10 is a schematic flow chart of a communication method for the application scenario 4.1. The method comprises the following steps:

step 1000 to step 1003 are similar to step 800 to step 803 of the embodiment shown in fig. 8, and reference may be made to the foregoing description, which is not repeated herein.

Step 1004a, the UE is in idle state, and the downlink data reaches the UPF.

At step 1004b, the UPF sends a data arrival notification to the SMF.

In step 1005, the SMF sends the session identification (PDU session ID) and the permanent identification of the UE to the AMF.

For example, the SMF invokes a Namf _ Communication _ N1N2MessageTransfer service operation of the AMF, carrying a session identification (PDU session ID) and a permanent identification of the UE.

In step 1006, the AMF triggers paging for the UE.

Step 1007a, after receiving the paging message, the UE sends a service request to the (R) AN.

Step 1007b, (R) the AN forwards the service request of the UE, and simultaneously reports the current location of the UE to the AMF.

As AN alternative implementation method, in the step 1007a, the service request may carry the current location of the UE, and in this step 1007b, (R) the AN sends the service request to the AMF.

Wherein the current position of the UE is the first position.

At step 1008, the AMF determines that the first slice corresponding to the session to be activated is not available at the current location of the UE.

In step 1009a, the AMF rejects the service request of the UE and returns the cause value: the first slice is not available at the current location of the UE.

Step 1009b, the AMF determines to trigger release of the session corresponding to the first slice that is unavailable at the current location, and the AMF determines the SMF corresponding to the session according to the context, and then sends a session release request to the SMF to request release of the session.

Step 1010, because the service request fails, the AMF triggers to update allowed NSSAI and RA of the UE, and the AMF sends a configuration update message to the UE, carrying new allowed NSSAI and new RA, where:

Optionally, the configuration update message may further carry a rejected S-NSSAI in current RA, which is used to notify the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session requested by the UE in step 1001 b.

Optionally, as an alternative implementation manner, the configuration update message in step 1010 does not carry the new allowed NSSAI and the new RA, but carries re-registration indication information for indicating the UE to initiate a registration procedure. In step 1011, the UE returns a configuration update complete message to the AMF.

Step 1012, if the UE receives the re-registration instruction information in step 1010, the UE initiates a registration procedure after step 1011, the UE sends a registration request message, and the AMF carries a new allowed NSSAI and a new RA in a registration accept message sent to the UE.

Wherein the new allowed NSSAI does not contain an unusable S-NSSAI (i.e., the identification of the first slice); the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

Optionally, the registration accept message may further carry a rejected S-NSSAI in current RA, which is used to notify the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI corresponding to the session requested by the UE in step 1001 b.

Step 1013, the AMF stores the rejected network slices (rejected S-NSSAI in current RA) in the current registration area of the UE in the context of the UE to record which UEs have sent the rejected S-NSSAI.

This step 1013 is an optional step.

Based on the above scheme, if the AMF determines that the state of the first slice is "unavailable" at the current location (first location) of the UE, the new allowed NSSAI and RA are allocated by rejecting the service request of the UE, so that the UE knows that the UE cannot access the first slice at the current location, which is helpful to ensure that the UE can access the "available" slice at any location in the updated registration area, thereby achieving correct and effective communication between the UE and the network side.

In application scenario 4.2, the idle UE initiates a service request in an area (e.g. TA-2) where the first slice is available, and requests to activate a session (PDU session) user plane data connection corresponding to the first slice.

Fig. 11 is a schematic flow chart of a communication method for the application scenario 4.2. The method comprises the following steps:

step 1100 to step 1106 are similar to step 1000 to step 1006 in the embodiment shown in fig. 10, and reference may be made to the foregoing description, which is not repeated herein.

Step 1107a, after receiving the paging message, the UE sends a service request to the (R) AN.

Step 1107b, (R) the AN forwards the service request of the UE, and reports the current location of the UE to the AMF.

And the current position of the UE is the second position.

In step 1108, the AMF determines that a first slice corresponding to the session to be activated is available at the current location of the UE.

Step 1109, continue other flows of the service request until the flow is successfully ended.

In step 1110, since the registration area of the UE includes the TA (i.e. the first location) that the S-NSSAI corresponding to the session to be activated is unavailable, the AMF determines to trigger updating of the registration area of the UE, and the AMF sends a configuration update message to the UE, where the configuration update message carries the new RA.

Where the new RA deletes the TA of the slice state change, i.e., the new RA does not include the TA of the slice state change, where the AMF acquires the TA of the state change in step 1103. For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-1, TA-2 }.

Optionally, as an alternative implementation manner, the configuration update message in step 1110 does not carry the new RA, but carries re-registration indication information, which is used to indicate the UE to initiate a registration procedure.

In step 1111, the UE returns a configuration update complete message to the AMF.

Step 1112, if the UE receives the re-registration instruction information in step 1110, the UE initiates a registration procedure after step 1111, the UE sends a registration request message, and the AMF carries the new RA in the registration accept message sent to the UE.

In the above application scenarios 1 to 4, for a first slice with a changed state at a first location, when a UE or a network performs a service, in a process of establishing, activating, and switching a session corresponding to the first slice, it is determined whether the first slice is available at a current location of the UE, and then a method for updating an RA or an allowed NSSAI of the UE is determined. As another application scenario, it may be determined whether the allowed NSSAI or RA of the UE needs to be updated according to whether the allowed NSSAI of the UE includes the first slice with the changed state and whether the registration area of the UE includes the first location, without executing the communication method in the process of establishing, activating, and switching the session. A specific example is given below.

Fig. 12 is a schematic flow chart of another communication method provided in the present application. The method comprises the following steps:

step 1200 to step 1203, similar to step 400 to step 403 in embodiment 4, refer to the foregoing description, and are not repeated here.

In step 1204, the AMF determines that the allowed NSSAI includes an unavailable S-NSSAI (i.e., an identifier of the first slice) according to the allowed NSSAI in the context of the UE, and the registration area of the UE includes information of the first location, and the UE is in a connected state.

In step 1205, the AMF determines whether the first slice is available at the current location of the UE.

For example, if the current location of the UE is the first location, the AMF determines that the first slice is not available at the current location of the UE.

For example, if the current location of the UE is a second location (the second location is different from the first location), the AMF determines that the first slice is available at the current location of the UE.

In step 1206, the AMF sends a configuration update message to the UE.

If, in step 1205, the AMF determines that the first slice is not available in the current location of the UE, the AMF triggers to update the allowed NSSAI and RA of the UE, and the AMF sends a configuration update message to the UE, where the new allowed NSSAI carries a new allowed NSSAI and a new RA, and the new allowed NSSAI does not include an unavailable S-NSSAI; the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

Optionally, the configuration update message may further carry a rejected S-NSSAI in current RA, which is used to notify the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI (i.e., the identification of the first slice) notified in step 1203.

If in step 1205, the AMF determines that the first slice is available at the current location of the UE, the AMF determines to trigger updating of the registration area of the UE, and the AMF sends a configuration update message to the UE, where the configuration update message carries the new RA. Where the new RA deletes the TA of the slice state change, i.e., the new RA does not include the TA of the slice state change, where the AMF acquires the TA of the state change in step 1203. For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-1, TA-2 }.

Optionally, as an alternative implementation manner, the configuration update message in step 1206 does not carry a new allowed NSSAI and/or a new RA, but carries re-registration indication information for indicating the UE to initiate a registration procedure.

In step 1207, the UE returns a configuration update complete message to the AMF.

In step 1208, if the UE receives the re-registration indication information in step 1206, the UE initiates a registration procedure after step 1207, and the UE sends a registration request message.

If, in the above step 1205, the AMF determines that the first slice is not available in the current location of the UE, the AMF triggers to update allowed NSSAI and RA of the UE, and the AMF sends a registration accept message to the UE, carrying new allowed NSSAI and new RA, where the new allowed NSSAI does not include an unavailable S-NSSAI; the new RA includes information of the first location. Wherein the slice corresponding to the identification of the slice in the new allowed NSSAI is available in the new RA.

Optionally, the registration accept message may further carry a rejected S-NSSAI in current RA, which is used to notify the UE to: the rejected S-NSSAI is not available in the new RA, i.e., the rejected S-NSSAI includes the S-NSSAI (i.e., the identification of the first slice) notified in step 1203.

If in step 1205, the AMF determines that the current location of the first slice in the UE is available, the AMF determines to trigger updating of the registration area of the UE, and the AMF sends a registration accept message to the UE, where the registration accept message carries the new RA. Where the new RA deletes the TA of the slice state change, i.e., the new RA does not include the TA of the slice state change, where the AMF acquires the TA of the state change in step 1203. For example, based on the example of fig. 2, old RA ═ { TA-1, TA-2, TA-3}, and new RA ═ TA-1, TA-2 }. In step 1209, the AMF stores the rejected network slice (rejected S-NSSAI in current RA) in the current registration area of the UE in the context of the UE to record which UEs have sent the rejected S-NSSAI.

This step 1209 is an optional step, and when the AMF determines that the first slice is not available at the current location of the UE in the above step 1205, the AMF may perform this step 1209, or may not perform this step 1209. When the AMF determines that the first slice is available at the current location of the UE in step 1205 above, then the AMF does not perform this step 1209.

Based on the above scheme, when the status of the first slice in the allowed NSSAI of the UE in a certain TA (i.e. the first location) in the registration area of the UE is updated from the "available" status to the "unavailable" status, the network side (e.g. the AMF) may update the registration area of the UE and notify the UE to update the registration area, and the AMF only determines whether the allowed NSSAI or RA of the UE needs to be updated according to the status and the current location of the UE, which helps to ensure that the UE can access the "available" slice at any location in the updated registration area, and the UE and the network side maintain correct and effective communication, or it is understood that the UE fails to communicate with the network side due to the UE initiating a service request associated with the first slice at the first location because the UE does not update the registration area in time.

The embodiments shown in fig. 2 to 12 above are implementations for the first case, that is, the first slice is updated from the "available" state to the "unavailable" state at the first location. An embodiment is given below, which is directed to an implementation of the second scenario, i.e. the first slice is updated from an "unavailable" state to an "available" state in the first location.

Fig. 13 is a schematic flow chart of another communication method provided in the present application. The method comprises the following steps:

in step 1301, NSSF determines that the state of the first slice at the first position has changed: from unavailable to available.

For example, after the embodiments shown in fig. 2-12 described above, at some point the NSSF decides to change the status of the first slice at the first location (e.g., due to the congestion condition of the slice being below a threshold), updating the first slice from an "unavailable" status to an "available".

In step 1302, the NSSF notifies the AMF: the first slice is updated as available at the first location.

For example, the NSSF may call an NSSF _ nssaiiavailability _ Notify servization operation, notifying the AMF: the first slice is updated as available at the first location.

Of course, if there are multiple slices whose status at one or some locations is updated to be available, the NSSF may send multiple S-NSSAIs and corresponding available location lists to the AMF. For example, if S-NSSAI-A is available at TA-11, TA-12 update, S-NSSAI-B is available at TA-13, TA-14 update, then NSSF may send to AMF: (S-NSSAI-A, (TA-11, TA-12)), (S-NSSAI-B, (TA-13, TA-14)).

Step 1303, AMF determines to which UE S-nsai-rejected in RA was sent according to the information (S-nsai-rejected in RA) of the rejected network slices stored in the context of each UE, and the RA of the UE includes the information of the first location.

In step 1304, the AMF pages the UE if the UE is in an idle state.

This step is optional and is performed when the UE is in idle state, and then step 1305 is performed. When the UE is in the connected state, step 1305 may be directly performed by skipping step 1304.

Step 1305, the UE is in connected state, and the AMF sends a configuration information message to the UE.

In one implementation, the configuration update message carries a new allowed NSSAI, which is the rejected S-NSSAI (i.e., the identifier of the first slice) added to the current allowed NSSAI of the UE.

In yet another implementation, the configuration update message carries a rejected S-NSSAI available indication, triggering the UE to construct a new requested NSSAI itself to attempt to access the slice (i.e., the first slice). The UE, upon receiving the rejected S-NSSAI available indication, may decide whether to construct a new requested NSSAI and attempt to access the slice.

In step 1306, the UE returns a configuration update complete message to the AMF.

In step 1307, the AMF deletes the identity of the first slice in the rejected network slices (rejected S-NSSAI in current RA) in the current registration area of the UE, which is stored in the context of the UE.

Based on the scheme, the AMF judges that the slice state of the first slice at the first position is updated to be available, and then the AMF is triggered to notify the UE through the Rejected S-NSSAI in current RA stored in the UE context, so that the UE can know that the slice can be accessed at the first position, the UE can be ensured to access the available slice in time, and the UE can be enabled to keep correct and effective communication with the network side.

The above-mentioned scheme provided by the present application is mainly introduced from the perspective of interaction between network elements. It is to be understood that the above-described implementation of each network element includes, in order to implement the above-described functions, a corresponding hardware structure and/or software module for performing each function. Those of skill in the art will readily appreciate that the present invention can be implemented in hardware or a combination of hardware and computer software, with the exemplary elements and algorithm steps described in connection with the embodiments disclosed herein. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

As shown in fig. 14, which is a possible exemplary block diagram of a communication device according to the present application, the communication device 1400 may be in the form of software or hardware. The communication device 1400 may include: a processing unit 1402 and a communication unit 1403. As an implementation, the communication unit 1403 may include a receiving unit and a transmitting unit. The processing unit 1402 is used to control and manage the operation of the communication apparatus 1400. A communication unit 1403 is used to support communication of the communication device 1400 with other network entities. The communication device 1400 may also include a storage unit 1401 for storing program codes and data of the communication device 1400.

The processing unit 1402 may be a processor or a controller, such as a general Central Processing Unit (CPU), a general purpose processor, a Digital Signal Processing (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, a transistor logic device, a hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The storage unit 1401 may be a memory. The communication unit 1403 is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented in the form of a chip, the communication unit 1403 is an interface circuit for the chip to receive a signal from another chip or device, or an interface circuit for the chip to transmit a signal to another chip or device.

The communication device 1400 may be a terminal device in any of the above embodiments, and may also be a chip for a terminal device. For example, when the communication apparatus 1400 is a terminal device, the processing unit 1402 can be a processor, and the communication unit 1403 can be a transceiver. Optionally, the transceiver may comprise radio frequency circuitry and the storage unit may be, for example, a memory. For example, when the communication apparatus 1400 is a chip for a terminal device, the processing unit 1402 may be a processor, and the communication unit 1403 may be an input/output interface, a pin, a circuit, or the like. The processing unit 1402 can execute a computer execution instruction stored in a storage unit, optionally, the storage unit is a storage unit in the chip, such as a register, a cache, and the like, and the storage unit can also be a storage unit located outside the chip in the terminal device, such as a read-only memory (ROM) or another type of static storage device that can store static information and instructions, a Random Access Memory (RAM), and the like.

In one embodiment, the communication apparatus 1400 is a terminal device, and the receiving unit is configured to receive an updated registration area of the terminal device if the first slice is unavailable at the first location and available at the second location, where the registration area before updating of the terminal device includes information of the first location and information of the second location, and the set of network slices allowed to be accessed by the terminal device includes information of the first slice; and the processing unit is used for updating the registration area of the terminal equipment.

In a possible implementation method, the receiving unit is further configured to receive an updated set of network slices allowed to be accessed by the terminal device; and the processing unit is further used for updating the network slice set allowing access of the terminal equipment.

In a possible implementation method, a sending unit is configured to send a request message, where the request message is used to request to establish or activate a session associated with a first slice; the apparatus further includes a receiving unit configured to receive a request reject message, the request reject message including a cause value, the cause value indicating that the first slice is unavailable.

In a possible implementation method, the receiving unit is further configured to receive information of the rejected network slice, where the information of the rejected network slice includes identification information of the first slice.

In a possible implementation method, the receiving unit is further configured to receive indication information, where the indication information is used to indicate the terminal device to initiate a re-registration procedure.

It can be understood that, when the communication apparatus is used in the foregoing communication method, specific implementation procedures and corresponding beneficial effects may refer to the related description in the foregoing method embodiment, and are not described herein again.

As shown in fig. 15, which is a possible exemplary block diagram of a communication device according to the present application, the communication device 1500 may be in the form of software or hardware. The communication apparatus 1500 may include: a processing unit 1502 and a communication unit 1503. As one implementation, the communication unit 1503 may include a receiving unit and a transmitting unit. The processing unit 1502 is configured to control and manage operations of the communication apparatus 1500. The communication unit 1503 is used to support communication of the communication apparatus 1500 with other network entities. The communication apparatus 1500 may further include a storage unit 1501 for storing program codes and data of the communication apparatus 1500.

The processing unit 1502 may be a processor or controller, such as a CPU, general purpose processor, DSP, ASIC, FPGA or other programmable logic device, transistor logic device, hardware component, or any combination thereof. Which may implement or perform the various illustrative logical blocks, modules, and circuits described in connection with the disclosure. The processor may also be a combination of computing functions, e.g., comprising one or more microprocessors, DSPs, and microprocessors, among others. The storage unit 1501 may be a memory. The communication unit 1503 is an interface circuit of the device for receiving signals from other devices. For example, when the device is implemented in the form of a chip, the communication unit 1503 is an interface circuit for the chip to receive a signal from another chip or device, or an interface circuit for the chip to transmit a signal to another chip or device.

The communication apparatus 1500 may be a mobility management network element in any of the above embodiments, and may also be a chip for a mobility management network element. For example, when the communication device 1500 is a mobility management network element, the processing unit 1502 may be a processor, and the communication unit 1503 may be a transceiver, for example. Optionally, the transceiver may comprise radio frequency circuitry and the storage unit may be, for example, a memory. For example, when the communication device 1500 is a chip for a mobility management network element, the processing unit 1502 may be a processor, for example, and the communication unit 1503 may be an input/output interface, a pin, a circuit, or the like, for example. The processing unit 1502 may execute computer-executable instructions stored by a storage unit, which may alternatively be a storage unit within the chip, such as a register, a cache, etc., or a storage unit located outside the chip within the mobility management network element, such as a ROM or other types of static storage devices that may store static information and instructions, a RAM, etc.

In one embodiment, the communication apparatus 1500 is a mobility management network element, and a processing unit configured to determine that a first slice is unavailable at a first location and available at a second location, and update a registration area of a terminal device, where the registration area before update of the terminal device includes information of the first location and information of the second location, and a set of network slices allowed to be accessed by the terminal device includes information of the first slice; and the sending unit is used for sending the updated registration area of the terminal equipment to the terminal equipment.

In a possible implementation method, the processing unit is further configured to update a network slice set of the terminal device that is allowed to access; and the sending unit is further configured to send the updated network slice set allowed to be accessed of the terminal device to the terminal device.

In a possible implementation method, the processing unit is further configured to trigger release of a session associated with the first slice.

In a possible implementation method, a receiving unit is configured to receive a request message from a terminal device, where the request message is used to request to establish or activate a session associated with a first slice; and the sending unit is further used for sending a request rejection message to the terminal equipment, wherein the request rejection message comprises a reason value, and the reason value is used for indicating that the first slice is unavailable.

In a possible implementation method, the sending unit is further configured to send information of the rejected network slice to the terminal device, where the information of the rejected network slice includes identification information of the first slice.

In a possible implementation method, the processing unit is further configured to store information of the rejected network slice in a context of the terminal device, the information of the rejected network slice including information of the first slice, the information of the rejected network slice being used to indicate that the first slice is not available within the updated registration area of the terminal device.

Referring to fig. 16, a schematic diagram of a communication device provided in the present application is shown, where the communication device may be the mobility management network element or the terminal device. The communication device 1600 includes: a processor 1602, a communication interface 1603, and a memory 1601. Optionally, the communication device 1600 may also include communication lines 1604. Wherein, the communication interface 1603, the processor 1602 and the memory 1601 are connected to each other via a communication line 1604; the communication line 1604 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The communication lines 1604 may be divided into address buses, data buses, control buses, and the like. For ease of illustration, only one thick line is shown in FIG. 16, but this is not intended to represent only one bus or type of bus.

The processor 1602 may be a CPU, microprocessor, ASIC, or one or more integrated circuits configured to control the execution of programs in accordance with the present invention.

Communication interface 1603 may be any device, such as a transceiver, for communicating with other devices or communication networks, such as an ethernet, a Radio Access Network (RAN), a Wireless Local Area Network (WLAN), a wired access network, etc.

The memory 1601 may be, but is not limited to, a ROM or other type of static storage device that can store static information and instructions, a RAM or other type of dynamic storage device that can store information and instructions, an electrically erasable programmable read-only memory (EEPROM), a compact disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. The memory may be separate and coupled to the processor via a communication line 1604. The memory may also be integral to the processor.

The memory 1601 is used for storing computer executable instructions for executing the present application, and is controlled by the processor 1602 to execute. The processor 1602 is configured to execute computer-executable instructions stored in the memory 1601 to implement the communication methods provided by the above-described embodiments of the present application.

Optionally, the computer-executable instructions in the embodiments of the present application may also be referred to as application program codes, which are not specifically limited in the embodiments of the present application.

Those of ordinary skill in the art will understand that: the various numbers of the first, second, etc. mentioned in this application are only used for the convenience of description and are not used to limit the scope of the embodiments of this application, but also to indicate the sequence. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a exists alone, A and B exist simultaneously, and B exists alone. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one" means one or more. At least two means two or more. "at least one," "any," or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, at least one (one ) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple. "plurality" means two or more, and other terms are analogous. Furthermore, for elements (elements) that appear in the singular form "a," an, "and" the, "they are not intended to mean" one or only one "unless the context clearly dictates otherwise, but rather" one or more than one. For example, "a device" means for one or more such devices.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, from one website site, computer, server, or data center to another website site, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device including one or more available media integrated servers, data centers, and the like. The usable medium may be a magnetic medium (e.g., floppy Disk, hard Disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., Solid State Disk (SSD)), among others.

The various illustrative logical units and circuits described in this application may be implemented or operated upon by design of a general purpose processor, a digital signal processor, an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a digital signal processor and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a digital signal processor core, or any other similar configuration.

The steps of a method or algorithm described in the embodiments herein may be embodied directly in hardware, in a software element executed by a processor, or in a combination of the two. The software cells may be stored in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. For example, a storage medium may be coupled to the processor such the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is also intended to include such modifications and variations.

Claims

1. A method of communication, comprising:

if the first slice is unavailable at the first position and available at the second position, the terminal device receives an updated registration area of the terminal device, wherein the registration area before updating of the terminal device comprises information of the first position and information of the second position, and a network slice set allowing access of the terminal device comprises the information of the first slice;

and the terminal equipment updates the registration area of the terminal equipment, wherein the terminal equipment can access the slice allowing the terminal equipment to access in the updated registration area.

2. The method of claim 1, further comprising:

the terminal equipment receives an updated network slice set which is allowed to be accessed and is received by the terminal equipment;

and the terminal equipment updates the network slice set which is allowed to be accessed by the terminal equipment.

3. The method of claim 2, wherein the current location of the terminal device is the first location, then the updated set of network slices for which access is allowed for the terminal device does not include information for the first slice, and the updated registration area of the terminal device includes information for the first location and does not include information for the second location.

4. The method of claim 3, further comprising:

the terminal equipment sends a request message, wherein the request message is used for requesting to establish or activate a session associated with the first slice;

the terminal device receives a request rejection message, wherein the request rejection message comprises a reason value, and the reason value is used for indicating that the first slice is unavailable.

5. The method of claim 3 or 4, further comprising:

the terminal equipment receives information of the rejected network slices, wherein the information of the rejected network slices comprises identification information of the first slice.

6. The method of claim 1, wherein the current location of the terminal device is the second location, and the updated registration area of the terminal device includes information of the second location and does not include information of the first location.

7. The method of any of claims 1-4, 6, further comprising:

and the terminal equipment receives indication information, wherein the indication information is used for indicating the terminal equipment to initiate a re-registration process.

8. A method of communication, comprising:

a mobility management network element determines that a first slice is unavailable at a first position and available at a second position, and the mobility management network element updates a registration area of a terminal device, wherein the registration area of the terminal device before updating comprises information of the first position and information of the second position, and a network slice set allowing access of the terminal device comprises the information of the first slice;

and the mobility management network element sends the updated registration area of the terminal equipment to the terminal equipment, wherein the terminal equipment can access the slice allowing the terminal equipment to access in the updated registration area.

9. The method of claim 8, further comprising:

the mobility management network element updates the network slice set which is allowed to be accessed by the terminal equipment;

and the mobility management network element sends the updated network slice set which is allowed to be accessed to the terminal equipment.

10. The method of claim 9, wherein the current location of the terminal device is the first location, then the updated set of network slices for which access is allowed for the terminal device does not include information for the first slice, and the updated registration area of the terminal device includes information for the first location and does not include information for the second location.

11. The method of claim 10, further comprising:

the mobility management network element triggers release of a session associated with the first slice.

12. The method of claim 10, further comprising:

the mobility management network element receives a request message from the terminal equipment, wherein the request message is used for requesting to establish or activate a session associated with the first slice;

the mobility management network element sends a request rejection message to the terminal device, where the request rejection message includes a cause value, and the cause value is used to indicate that the first slice is unavailable.

13. The method of any of claims 10-12, further comprising:

and the mobility management network element sends the information of the rejected network slice to the terminal equipment, wherein the information of the rejected network slice comprises the identification information of the first slice.

14. The method of any of claims 8-12, further comprising:

the mobility management network element stores information of rejected network slices in the context of the terminal device, where the information of rejected network slices includes information of the first slice, and the information of rejected network slices is used to indicate that the first slice is unavailable in the updated registration area of the terminal device.

15. The method of claim 8, wherein the current location of the terminal device is the second location, and the updated registration area of the terminal device includes information of the second location and does not include information of the first location.

16. A communications apparatus, comprising:

a receiving unit, configured to receive an updated registration area of a terminal device if a first slice is unavailable at a first location and available at a second location, where the registration area before update of the terminal device includes information of the first location and information of the second location, and a network slice set of the terminal device allowed to access includes information of the first slice;

and the processing unit is used for updating the registration area of the terminal equipment, wherein the terminal equipment can access the slice which is allowed to be accessed by the terminal equipment in the updated registration area.

17. The apparatus of claim 16, wherein the receiving unit is further configured to receive an updated set of allowed access network slices for the terminal device;

the processing unit is further configured to update the network slice set allowed to be accessed by the terminal device.

18. The apparatus of claim 17, wherein the current location of the terminal device is the first location, the updated set of network slices for which access is allowed for the terminal device does not include information for the first slice, and the updated registration area of the terminal device includes information for the first location and does not include information for the second location.

19. The apparatus of claim 18, wherein the apparatus further comprises a sending unit configured to send a request message requesting establishment or activation of a session associated with the first slice;

the receiving unit is further configured to receive a request rejection message, where the request rejection message includes a cause value, and the cause value is used to indicate that the first slice is unavailable.

20. The apparatus of claim 18 or 19, wherein the receiving unit is further configured to receive information of a rejected network slice, the information of the rejected network slice including identification information of the first slice.

21. The apparatus of claim 16, wherein the current location of the terminal device is the second location, and the updated registration area of the terminal device includes information of the second location and does not include information of the first location.

22. The apparatus according to any one of claims 16 to 19 and 21, wherein the receiving unit is further configured to receive indication information, where the indication information is used to indicate that the terminal device initiates a re-registration procedure.

23. A communications apparatus, comprising:

a processing unit for determining that the first slice is unavailable at the first location and available at the second location; and updating a registration area of the terminal device, wherein the registration area before updating of the terminal device includes the information of the first location and the information of the second location, and the network slice set allowing access of the terminal device includes the information of the first slice;

a sending unit, configured to send the updated registration area of the terminal device to the terminal device, where the terminal device can access the slice that the terminal device is allowed to access in the updated registration area.

24. The apparatus of claim 23, wherein the processing unit is further configured to update a set of allowed access network slices for the terminal device;

the sending unit is further configured to send the updated network slice set allowed to be accessed of the terminal device to the terminal device.

25. The apparatus of claim 24, wherein the current location of the terminal device is the first location, the updated set of network slices for which access is allowed for the terminal device does not include information for the first slice, and the updated registration area of the terminal device includes information for the first location and does not include information for the second location.

26. The apparatus of claim 25, wherein the processing unit is further to trigger release of a session associated with the first slice.

27. The apparatus of claim 25, wherein the apparatus further comprises a receiving unit configured to receive a request message from the terminal device, the request message requesting to establish or activate a session associated with the first slice;

the sending unit is further configured to send a request rejection message to the terminal device, where the request rejection message includes a cause value, and the cause value is used to indicate that the first slice is unavailable.

28. The apparatus of any one of claims 25 to 27, wherein the sending unit is further configured to send information of a rejected network slice to the terminal device, the information of the rejected network slice including identification information of the first slice.

29. The apparatus of any of claims 23-27, wherein the processing unit is further configured to store information of rejected network slices in the context of the terminal device, the information of rejected network slices including the information of the first slice, the information of rejected network slices indicating that the first slice is not available within the updated registration area of the terminal device.

30. The apparatus of claim 23, wherein the current location of the terminal device is the second location, and the updated registration area of the terminal device includes information of the second location and does not include information of the first location.