CN108833181B - NG-CN network slice system and network slice selection method - Google Patents

Abstract

The invention discloses a network slicing system of a next generation mobile communication core network NG-CN, which is characterized by comprising a default slice and a service slice, wherein the default slice is used for controlling User Equipment (UE) and the next generation communication access network NG-RAN, and the service slice is used for supporting a corresponding service type. The invention can provide the capability of wide service application and can more efficiently improve the utilization of network resources. The method can effectively solve the problem that the current mobile communication network cannot meet the requirements of low time delay and high reliability, and simultaneously solves the problem of mismatching of space-time resources in the current communication network.

Description

NG-CN network slice system and network slice selection method

Technical Field

The invention relates to the field of mobile communication, in particular to a network slice system of a next generation mobile communication core network and a network slice selection, reselection and NAS route forwarding method based on the system.

Background

New mobile network requirements are generated by the user's demand for new service scenarios for mobile communications. Due to some basic problems in the current Evolved Packet Core (EPC), such as a centralized routing mechanism, the current 4G LTE (long term evolution) network is not sufficient to meet the new requirements. In this regard, next generation mobile network architectures need to be redesigned for emerging scenario requirements. The most important point is network enhanced mobile broadband (eMBB), massive Internet of things (mMTC) and low-delay high-reliability connection (UPLLC) service.

These emerging use cases bring new requirements for next generation mobile networks, such as delays in the RAN (radio access network) domain of less than 1ms, data transmission rates of 1Gbs/s per user on average, and traffic densities of up to 10^6 devices/km ^ 2. They require different types of functions and networks in terms of network data rate, delay and number of connections. The current 4G network cannot meet these emerging demands because it has been optimized for current mobile phone services. However, the next generation mobile communication network must serve various devices having different characteristics and requirements.

Next generation mobile communication networks will provide many logical networks, so called network slices, by using network virtualization technology, configuring specific network functions to provide services of various characteristics.

Fig. 1 shows a scenario of multiple communication networks operating simultaneously on the same infrastructure. For example, by setting up functionality in a distributed network, next generation communication network slicing of typical smartphone services may be implemented. For next generation communication network slices supporting automotive use cases, all functions can be instantiated at cloud edge nodes, including vertical applications necessary due to delay constraints. For next generation communication network slices supporting a large number of machine type devices, basic control plane functionality may be configured, which may improve some mobility functions and slow contention based access resources.

However, under the NG-CN architecture of the next generation mobile communication core network, the network functions, slice selection, and non-access stratum NAS message routing mechanisms of the existing next generation communication network slices are still unclear.

Disclosure of Invention

Technical problem to be solved

In order to solve the problems in the prior art, the invention provides a network slice system of a NG-CN (network-specific-core-network) of a next-generation mobile communication core network, and provides a network slice selection method, a network slice NAS (network attached storage) route forwarding method and a network slice reselection method based on the system, so that a plurality of logical networks can be supported by a single physical network.

(II) technical scheme

According to an aspect of the present invention, a network slicing system for a next generation mobile communication core network NG-CN is proposed, the system comprising a default slice for controlling a user equipment UE and a next generation communication access network NG-RAN and a service slice for supporting a corresponding service type.

According to another aspect of the present invention, a NAS routing method is provided, which includes the steps of: step 100, UE sends NAS message to NG-RAN that UE wants to access through wireless channel; step 110, the NG-RAN forwards NAS messages not containing the network slice ID to a default slice of the NG-RAN; and step 120, for the NAS message containing the network slice ID, the NG-RAN verifies the default slice ID of the UE, if the default slice ID is not changed, the NG-RAN sends the NAS message to the default slice, and if the default slice ID is changed, the NG-RAN forwards the NAS message to the default slice accessed by the NG-RAN, wherein the default slice is a network slice of a next generation mobile communication core network and is used for controlling the UE and the NG-RAN of the next generation communication access network.

According to still another aspect of the present invention, there is provided a network slice selection method, including the steps of: step 200, when the UE is started, the UE sends a registration request message to the NG-RAN; step 210, after receiving the 'registration request' message, NG-RAN searches for a default slice associated with itself, and obtains an address of an AMF instance to send the 'registration request' message to the default slice from the default slice database, thereby activating AMF; step 220, when the default slice receives the message of 'registration request', if the UE is not allowed to use the NG-CN, AMF directly terminates the NAS message from the UE, if the UE is allowed to use the NG-CN, the default slice selects the service slice ID corresponding to the service type received from the UE; step 230, the default slice allocates a temporary ID and an IP address to the UE while transmitting the data packet, and stores all information about the UE to the DSF after transmitting the "registration accept" message to the NG-RAN; in step 240, the NG-RAN sends a "registration accept" message to the UE over a radio channel, and the UE checks the received information, wherein the default slice is a network slice of the next generation mobile communication core network, and is used for controlling the user equipment UE and the next generation communication access network NG-RAN.

According to another aspect of the present invention, a NAS route forwarding method is provided, which includes: step 300, when user data flow is transmitted to NG-CN, UE establishes channel with NG-RAN wireless link; step 310, the UE sends a 'service request' message to the NG-RAN; step 320, after receiving the service request message, the NG-RAN verifies whether the default slice registered by the UE changes, and if not, the NG-RAN obtains the address of the AMF instance sending the service request message from the received network slice ID, and then forwards the NG-RAN service request message to the corresponding network service slice according to the service slice ID; step 330, when the AMF receives the service request message, it confirms whether the UE is authorized to use the service slice, if it is allowed, the AMF determines which service slice to use by calling the service interface from the SSF, and then the AMF forwards the service request message to the specific SMF instance to maintain connectivity for the user data service; step 340, the SMF selects the NG-GW executing the data forwarding function according to the position of the NG-RAN, and sends a 'path request' message to the NG-GW, the NG-GW establishes a path for the user data traffic between the NG-RAN and the NG-GW, and informs the SMF of the result, after receiving the 'path ready' message, if the path establishment is successful, the SMF sends a 'service permission' message to the AMF; step 350, the AMF in the service slice determined in step 330 sends a "service request" message to the NG-RAN, which contains information about the data traffic path, the NG-RAN establishes a path for user data traffic with the NG-GW, and then sends a "allow traffic" message to the UE, and the UE sends user data through the IP address allocated by the data traffic path, wherein the default slice is a network slice of the next generation mobile communication core network for controlling the user equipment UE and the next generation communication access network NG-RAN.

According to still another aspect of the present invention, a network slice reselection method includes the steps of: step 400, after the UE leaves the registration location, when the application in the UE generates user data to be sent to the NG-CN, activating a service request procedure; step 410, the UE sends a service request message to a newly accessed NG-RAN, the NG-RAN verifies whether a default slice registered by the UE is changed, and if the default slice is changed, the NG-RAN sends the service request message to the default slice accessed by the NG-RAN; step 420, when the default slice receives the service request message, when the UE sends a data packet and the NG-RAN sends a retry message to the UE, the default slice is used to allocate a new IP address, and after sending the retry message including the above information to the UE, the default slice updates all information about the UE to the DSF; step 430, after receiving the retry message, the UE updates the mapping relationship between the service type and the slice ID, and reconstructs the service request message using the changed network slice ID, wherein the default slice is a network slice of the next generation mobile communication core network, and is used for controlling the user equipment UE and the next generation communication access network NG-RAN.

According to yet another aspect of the invention, a computer storage medium is proposed, on which a computer program is stored, which program can be executed to implement the method of the invention.

(III) advantageous effects

The solution proposed by the present invention can support multiple logical networks through a single physical network, meet various requirements through a network slicing architecture using network virtualization technology, divide a single physical network into many logical networks, so-called network slices, configure specific network functions to provide services of various characteristics. Because each slice customizes the capability and resource needed by the network service according to the business service requirement, the capability of wide business application is provided, and the network resource utilization can be more efficiently improved. The method can effectively solve the problem that the current mobile communication network cannot meet the requirements of low time delay and high reliability, and simultaneously solves the problem of mismatching of space-time resources in the current communication network.

Drawings

Fig. 1 is a detailed scene diagram of a next generation wireless communication network slice in the prior art;

fig. 2 is a network slicing function diagram of a next generation wireless communication core network according to the present invention;

fig. 3 is a schematic diagram of a network slicing system of a next generation wireless communication core network according to the present invention;

FIG. 4 is a flow diagram of a NAS routing method according to the present invention;

FIG. 5 shows a schematic diagram and a flow chart of a network slice selection method according to the invention;

FIG. 6 illustrates a NAS route forwarding method according to the present invention;

fig. 7 illustrates a network slice reselection method according to the present invention.

Detailed Description

Reference will now be made in detail to the exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, like numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatus and methods consistent with certain aspects of the invention, as detailed in the appended claims.

The next generation mobile communication core network architecture is defined in 3GPP to support data connections and services. The main problem preventing current communication networks from efficiently meeting traffic demands in fourth generation mobile communications is the centralized architecture, rather than the control and data planes, which have been completely separated. Centralized architectures can lead to problems such as inefficient traffic paths and single point of failure risks. Due to the decoupling of the functions of the control plane and the data plane in the 4G core network, the openness and flexibility of the 4G LTE network are limited. This adds to the capital expenditure of operators to build up a network, while at the same time bringing difficulties in developing innovations for new network services.

The basic concept of the next generation mobile communication network is to completely separate a control plane and a data plane and construct the next generation mobile communication network based on a network function basis rather than a node basis. In addition, unlike the 4G network, a logical private network suitable for each service characteristic may be defined to effectively support enhanced mobile broadband (eMBB), mass internet of things (mtc), and low-latency high-reliability connection (UPLLC) services.

The next generation wireless communication core network (NG-CN) architecture and corresponding support for data connectivity and services are defined in 3GPP, enabling deployments such as Network Function Virtualization (NFV) and Software Defined Networking (SDN). Some key principles and concepts are as follows:

i. the Data Plane (DP) functions are separated from the Control Plane (CP) functions.

Minimizing dependencies between the Access Network (AN) and the Core Network (CN).

And iii, modular functional design is adopted, and flexible and efficient network slicing is realized.

A series of interactions between network functions are defined as services, whenever applicable.

v. support "stateless" network functions, where "compute" resources are separated from "store" resources.

Fig. 2 depicts a reference architecture based on the 3GPP reference model, with a service-based interface in the control plane.

The next generation mobile communication core network architecture includes the following content Network Functions (NF).

-access and mobility management functions (AMF)

Authentication server function (AUSF)

Session Management Function (SMF)

-Policy Control Function (PCF)

Unified Data Management Function (UDMF)

Slice Selection Function (SSF)

-Data Storage Function (DSF)

User data plane function (UPF)

-User Equipment (UE)

-Radio Access Network (RAN)

The invention provides a slice-based architecture reference model of a next generation mobile communication core network NG-CN on the basis of 3 GPP.

Fig. 3 is a structural diagram of a network slicing system of a next generation mobile communication core network NG-CN according to the present invention, which is a configuration scheme as a logical network supporting a specific service.

Referring to fig. 3, the system of the present invention is composed of four slice types, which are a default slice for UE management and three slice types for supporting enhanced mobile broadband eMBB, large connectivity internet of things mtc, and low latency high reliability communication URLLC service, and these three slice types are hereinafter referred to as traffic slices. Three service slices are presented here by way of example only, and in a specific application of the present invention, the type of service slice can be designed according to actual needs.

Wherein the UE and the next generation communications access network NG-RAN are controlled by the same default slice.

The application installed in the UE has its own ID and is classified into three types of services, enhanced mobile broadband eMBB, large-scale internet of things mtc, and low-latency high-reliability communication URLLC.

And in the same type of business slices, the business slices corresponding to each third-party service provider are distinguished by the application program identification. Slice ID ═ AMF ID + slice type (default slice/traffic slice) + final NF instance ID.

The default slice is composed of common network functions such as AMF, SSF, AUSF, PCF and UDMF, and is used for supporting all service slices registered by UE in NG-CN. When the UE is connected to the NG-CN for the first time, the default slice authenticates that the UE is allowed to access the network, maps the service type brought by the UE to the corresponding service slice ID to be used by the UE, and allocates one service slice ID and an IP address to the UE. The default slice can be installed according to the decisions of load balancing, area distribution and the like. In this case, each default slice is assigned a separate slice ID.

The service slice for each service type consists of two parts: sharing network functions that are shared among traffic slices in the control plane, and specific network functions that involve the control plane and the data plane.

Each service slice operates independently from the service provider. The shared network function in the control plane consists of AMF, SSF and AUSF. The specific network functions in the control plane are performed by the SMF and the specific network functions in the data plane are performed by the UPF for the data forwarding function. The service slices of various service types may be controlled by a default slice, or may be operated according to a decision, such as a decision for load balancing and area distribution.

The present invention also provides a NAS routing method based on the network slice system of the present invention, which routes NAS messages from UE to appropriate network slices, as shown in fig. 4, the method includes the steps of:

in step 100, the UE sends various NAS messages including UE _ ID, traffic slice type and application ID (if needed), and network slice ID (including default slice and traffic slice), if any, to the NG-RAN to which the UE is to access over a radio channel.

The NAS message is used to enable interaction of data information or control information between the user terminal and the slice-based NG-RAN and NG-CN. The UE _ ID is a unique identity of the UE (e.g., service establishment, release, or mobility management information) for identifying the corresponding UE.

The service slice type includes an eMBB service slice, an mMTC service slice or a URRLC service slice.

The application ID is used in the present invention to identify different applications.

Network slice IDs (the system assigns a set of hexadecimal numbers as slice IDs when a network slice is generated) are used to identify different kinds of network slices, the IDs of which include default slice IDs and traffic slice IDs. The default slice is composed of common network functions such as AMF, SSF, AUSF, PCF and UDMF, and is used for supporting the service slice registered by the UE of the NG-CN. When the UE is connected to the NG-CN for the first time, the default fragment authenticates that the UE is allowed to access the network, maps the service type brought by the UE to the corresponding slice ID to be used by the UE, and allocates one service slice ID and an IP address to the UE.

Step 110, the NG-RAN forwards NAS messages not containing the network slice ID to a default slice of the NG-RAN; since the UE and the NG-RAN are controlled by the same default slice, if the NAS message does not contain the network slice ID, the default slice of the NG-RAN contains the ID in the NSA information, and normal random access of the UE is guaranteed.

Step 120, for the NAS message containing the network slice ID, the NG-RAN verifies the default slice ID of the UE, since the UE and the NG-RAN are controlled by the same default slice, if the default slice ID in the NAS message is the same as the default slice ID of the NG-RAN, the default slice ID is not changed, the NG-RAN sends the NAS message to the default slice, if the default slice ID is different, the default slice ID is changed, and the NG-RAN forwards the NAS message to the default slice accessed by the NG-RAN.

This is done for the purpose of slicing service customization, and when a handset customizes a particular slicing service, the NSA information must carry the correct network slice ID to correspond to the particular slicing service customization. When no customized slicing service is required, only normal random access is required, the network slice ID is not carried or the service slice ID which fails to pass verification (or the network can not provide the required slicing customization type)

The UE classifies all application services installed in the UE into three service types, namely enhanced mobile broadband eMBB, massive Internet of things mMTC and low-delay high-reliability connection URLLC service. The UE assigns a traffic slice ID to each traffic type by a default slice during the registration procedure. The NAS routing method can flexibly customize the capacity and resources required by the network service according to the service requirement, thereby providing the capacity of wide service application and more efficiently improving the utilization of the network resources. This solves the problem of mismatch of space-time resources in current communication networks. Meanwhile, the distributed slice network structure solves the problems of low efficiency of traffic paths, single point of failure risks and the like caused by the traditional centralized architecture.

The invention also provides a network slice selection method based on the network slice system, and the method uses the NAS routing method. Slice selection is performed when the UE registers with the NG-CN. Under the slice structure of fig. 3, the UE registration process and the slice selection process are as shown in fig. 5, and are used for the UE to access the NG-CN immediately after the UE is powered on.

Referring to fig. 5, the network slice selection method includes the steps of:

step 200, when the UE is powered on, the UE receives radio signals from the surrounding NG-RAN and synchronizes with radio channels, and in order to access the NG-CN, the UE sends a registration request message comprising UE information (such as UE ID and service type) which can be processed by the UE to the NG-RAN;

step 210, since the UE and the NG-RAN are controlled by the same default slice, after receiving the "registration request" message (encapsulating the corresponding default slice ID, requesting the service slice type), the NG-RAN searches the default slice associated with itself, and obtains the address of the AMF instance that is to send the "registration request" message to the default slice from the default slice database, thereby activating the AMF (the AMF terminates the NAS message from the UE and is responsible for managing the IP connection service of the UE, which is specifically shown in the following steps);

step 220, when the default slice receives the "registration request" message, it requests UE registration information from UDMF, after the default slice receives UE registration information from UDMF, it confirms whether UE is allowed to use NG-CN, if not, AMF directly terminates NAS message from UE, if it is allowed, the default slice will generate key required for mutual authentication and security, and the default slice selects the service slice ID corresponding to the service type (included in registration request information) received from UE.

Step 230, the default slice allocates a temporary ID and an IP address for identifying the UE identity to the UE while transmitting the data packet, and stores all information about the UE to the DSF after transmitting the "registration accept" message to the NG-RAN;

the NG-RAN sends a "registration accept" message to the UE over the wireless channel, and the UE checks the received information, such as a key for mutual authentication and security, a network slice ID, a time ID, and an IP address for data transmission, step 240.

The invention also provides a network slice NAS route forwarding method, and after the NAS route forwarding method is registered to the NG-CN, the application in the UE can access the Internet. Fig. 6 is a service request procedure under the network slice structure of fig. 3 when an application in the UE is activated.

Referring to fig. 6, the network slice NAS route forwarding method includes the steps of:

step 300, when user data flow is transmitted to NG-CN, UE establishes channel with NG-RAN wireless link;

in step 310, the UE sends a "service request" message, which includes a time ID, an authorization key, a current application ID and a currently assigned network slice ID (including default slices and corresponding traffic slices), to the NG-RAN, and user data may be included in the "service request" message for connectionless-oriented data transmission;

step 320, after NG-RAN receives the "service request" message, it verifies whether the default slice registered by UE changes by comparing the default slice ID in the received network slice ID with the default slice ID accessed by NG-RAN, if the AMF ID in the two default slice IDs is the same, it indicates that the default slice registered by UE does not change, in this case, NG-RAN obtains the address of the AMF instance sending the "service request" message from the received network slice ID, then forwards the NG-RAN 'service request' message to the corresponding network service slice according to the service slice ID, and executes step 330; if the default slice registered by the UE has changed, a step of selecting the network slice again is needed;

step 330, when the AMF receives the "service request" message, it confirms whether the UE is authorized to use the network slice (traffic slice) by checking the application ID based on the subscriber information in the application server, if allowed, the AMF determines which traffic slice (eMBB slice, mtc slice or URRLC slice) to use by calling the service interface from the SSF, and then the AMF forwards the "service request" message to the specific SMF instance to maintain connectivity for the user data traffic;

in step 340, the SMF selects a NG-GW (gateway) performing a data forwarding function based on the NG-RAN location and sends a "path request" message to the NG-GW for routing user data traffic. The NG-GW establishes a path for user data traffic between the NG-RAN and the NG-GW and informs the SMF of the result. Upon receipt of the 'path ready' message, the SMF sends a 'service allow' message to the AMF if the path establishment is successful.

In step 350, the AMF in the traffic slice determined in step 330 sends a "service request" message to the NG-RAN containing information about the data traffic path. The NG-RAN establishes a path with the NG-GW for user data traffic and then sends a "service setup" message to the UE. And the UE sends the user data through the IP address distributed by the data service path.

The present invention further provides a network slice reselection method, and fig. 7 illustrates a process of selecting a new network slice after the UE moves out of the registration location. Referring to fig. 7, the network slice reselection method includes the steps of:

step 400, after the UE leaves the registration location, when the application in the UE generates user data to be sent to the NG-CN, activating a service request procedure;

in step 410, the UE sends a service request message to the new NG-RAN, which includes a temporary ID for identifying the UE identity, an authorization key, an application identifier and a pre-stored service slice ID corresponding to the application service type. The NG-RAN verifies whether the default slice registered by the UE is changed by comparing the default slice ID in the received network slice with the AMF ID in the default slice ID accessed by the NG-RAN, if the AMF IDs are different, the default slice registered by the UE is changed, and the NG-RAN sends a service request message to the default slice accessed by the NG-RAN, and step 420 is executed; if the AMF IDs are the same, the default slice registered by the UE is not changed, and the network continues to operate normally without triggering the following steps.

When the default slice receives the service request message (containing the UE registration information stored in the DSF), the NG-RAN will use the default slice to assign a new IP address when the UE sends a packet and the NG-RAN sends a retry message to the UE, step 420. After sending a "retry" message to the UE including the above information, the default slice updates all information about the UE to the DSF;

step 430, after receiving the retry message, the UE updates the mapping relationship between the service type and the slice ID, and reconstructs the service request message using the changed network slice ID, and the subsequent steps are the same as the service request process.

In summary, the present invention meets all these needs by a network slicing system that uses network virtualization technology. A single physical network will be divided into many logical networks, so-called network slices, with specific network functions configured to provide services of various characteristics.

Because each slice customizes the capability and resource needed by the network service according to the service requirement of the slice, the capability of wide service application can be provided, and the network resource utilization can be more efficiently improved.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention following, in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

It will be understood that the invention is not limited to the precise arrangements described above and shown in the drawings and that various modifications and changes may be made without departing from the scope thereof. The scope of the invention is limited only by the appended claims.

Claims (3)

1. A method for network slice selection, the method comprising the steps of:

step 200, when the UE is started, the UE sends a registration request message to the NG-RAN;

step 210, after receiving the "registration request" message, NG-RAN searches for a default slice associated with itself, and obtains, from the default slice database, an address of an AMF instance that is to send the "registration request" message to the default slice, thereby activating AMF;

step 220, when the default slice receives the message of 'registration request', if the UE is not allowed to use the NG-CN, AMF directly terminates the NAS message from the UE, if the UE is allowed to use the NG-CN, the default slice selects the service slice ID corresponding to the service type received from the UE;

step 230, the default slice allocates a temporary ID and an IP address for identifying the UE identity to the UE while transmitting the data packet, and stores all information about the UE to the DSF after transmitting the "registration accept" message to the NG-RAN;

the NG-RAN sends a "registration accept" message to the UE over the radio channel, the UE checks the received information,

wherein the default slice is a network slice of a next generation mobile communication core network for controlling the user equipment UE and the next generation communication access network NG-RAN.

2. A NAS routing forwarding method is characterized by comprising the following steps:

step 300, when user data flow is transmitted to NG-CN, UE establishes channel with NG-RAN wireless link;

step 310, the UE sends a 'service request' message to the NG-RAN;

step 320, after receiving the service request message, the NG-RAN verifies whether the default slice registered by the UE changes, and if not, the NG-RAN obtains the address of the AMF instance sending the service request message from the received network slice ID, and then forwards the NG-RAN service request message to the corresponding network service slice according to the service slice ID;

step 330, when the AMF receives the service request message, it confirms whether the UE is authorized to use the service slice, if it is allowed, the AMF determines which service slice to use by calling the service interface from the SSF, and then the AMF forwards the service request message to the specific SMF instance to maintain connectivity for the user data service;

step 340, the SMF selects the NG-GW executing the data forwarding function according to the position of the NG-RAN, and sends a 'path request' message to the NG-GW, the NG-GW establishes a path for the user data traffic between the NG-RAN and the NG-GW, and informs the SMF of the result, after receiving the 'path ready' message, if the path establishment is successful, the SMF sends a 'service permission' message to the AMF;

step 350, the AMF in the traffic slice determined in step 330 sends a "service request" message to the NG-RAN, which contains information about the data traffic path, the NG-RAN establishes a path for user data traffic with the NG-GW, and then sends a "service setup" message to the UE, the UE sends user data via the IP address allocated for the data traffic path,

wherein the default slice is a network slice of a next generation mobile communication core network for controlling the user equipment UE and the next generation communication access network NG-RAN.

3. A method for network slice reselection, the method comprising the steps of:

step 400, after the UE leaves the registration location, when the application in the UE generates user data to be sent to the NG-CN, activating a service request procedure;

step 410, the UE sends a service request message to a newly accessed NG-RAN, the NG-RAN verifies whether a default slice registered by the UE is changed, and if the default slice is changed, the NG-RAN sends the service request message to the default slice accessed by the NG-RAN;

step 420, when the default slice receives the service request message, when the UE sends a data packet and the NG-RAN sends a retry message to the UE, the default slice is used to allocate a new IP address, and after sending the retry message to the UE, the default slice updates all information about the UE to the DSF;

step 430, after receiving the retry message, the UE updates the mapping relationship between the service type and the service slice ID, and reconstructs a service request message using the changed network slice ID,

wherein the default slice is a network slice of a next generation mobile communication core network for controlling the user equipment UE and the next generation communication access network NG-RAN.

Images