WO2018173889A1 - Communication control method and communication system - Google Patents

Abstract

The purpose of the present invention is to prevent waste of resources when performing a handover to a slice. This communication system N1 performs communication control on a communication terminal which communicatively connected with the slice that is a virtualized network generated on a network infrastructure. An SMF 221 determines whether or not the slice is used in a control procedure in which a UE 90 performs the handover. Then, when it is determined that the slice is not used, an AMF 301 performs communication control for not using the slice that is not used.

Description

Communication control method and communication system

The present invention relates to a communication control method and a communication system for performing communication control on a slice that is a virtual network.

In a network system using conventional virtualization technology, a virtual network logically generated on a network infrastructure by using a virtualization technology disclosed in Non-Patent Document 1 to virtually separate hardware resources. Create a slice. And based on allocating a service to the said slice, a service can be provided with respect to the user terminal which a user uses using the network of each independent slice. With this process, when a slice is assigned to each service having various request conditions, it becomes easy to satisfy the request condition of each service, and the signaling process and the like can be reduced. In addition, when using a service assigned to each slice by a user terminal, user data is transmitted and received through the communication path by providing a communication path related to the user terminal to a control node provided in the slice. Is done.

By the way, the user terminal may change its communication path by performing handover while using the service assigned to each slice. Before the user terminal was handed over, the user terminal accessed multiple slices and transmitted / received user data, but when performing handover, one or several slices of the multiple slices were used. There are times when it stops. Handing over such a slice wastes network resources.

The present invention has been made in view of the above, and an object of the present invention is to provide a communication control method and a communication system that can prevent waste of resources when a slice is handed over.

In order to achieve the above object, a communication control method according to an aspect of the present invention is a communication control of a communication system that performs communication control for a communication terminal that is connected to a slice that is a virtual network generated on a network infrastructure. In the method, a determination step of determining whether or not the slice is used in a control procedure in which the communication terminal performs a handover, and a determination is made that the slice is not used in the determination step. A communication control step for performing communication control so as not to establish communication connection with a slice that is not connected.

According to the present invention, when performing a handover, if it is determined that a slice that has been connected for communication before the handover is not used, the slice is not used for the unused slice. Communication control can be performed. Therefore, waste of network resources can be eliminated and the resources can be used efficiently.

According to the present invention, waste of network resources can be eliminated and the resources can be used efficiently.

It is a figure which shows the structure of the system which concerns on embodiment of this invention. It is a figure which shows the relationship between a slice and a communication system. It is a figure which shows the relationship between a slice and hardware. It is a block diagram which shows the function structure of AMF301 and SMF211,221. It is a figure which shows the hardware constitutions which concern on AMF301. It is a figure explaining the condition according to the pattern 1 in the communication system N1. FIG. 10 is a processing sequence diagram of a method for determining whether a slice SL2 is not used in the SMF 221. FIG. 11 is a sequence diagram of processing in which the AMF 301 inquires the PCF 400 about the usage status of each slice. It is a figure explaining the condition according to the pattern 2 in the communication system N1. FIG. 12 is a processing sequence diagram of a method for determining whether a slice SL2 is not used in the SMF 221. FIG. 10 is a processing sequence diagram of processing in which the AMF 301 inquires the PCF 400 about the usage status of each slice. It is a figure explaining the condition according to the pattern 3 in the communication system N1. FIG. 10 is a processing sequence diagram of processing in which the AMF 301 inquires the PCF 400 about the usage status of each slice.

Hereinafter, embodiments for carrying out the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are denoted by the same reference numerals, and redundant description is omitted.

Fig. 1 shows the configuration of the system 1 constituting the virtualized network. The system 1 in FIG. 1 provides a network service to a UE (UserEquipment) 90 that is a terminal (user terminal) used by a service user (Service User) by assigning a service to a slice that is a virtual network. To do. A slice is a virtual network or service network that is created by logically dividing the network device link and node resources and combining the separated resources. They are separated and do not interfere with each other. The network service refers to a service using network resources such as a communication service (private line service or the like) or an application service (service using a sensor device such as moving image distribution or an embedded device). Moreover, UE90 is a terminal device which has communication functions, such as a smart phone, for example.

As shown in FIG. 1, the system 1 includes a BSS / OSS (Business Support System / Operations Support System) 10, an SO (Service Operator) 20, an NFVO 30, a VNFM 40, and a VIM (Virtualized Infrastructure Management) 50. It is comprised including. In addition, the system 1 includes an NFVI (NFV (Network FunctionsNetworkVirtualization) Infrastructure) 60, an eNB (eNodeB) 80, and a UE 90. Among these, NFVO30, VNFM40, and VIM50 are functions of MANO (Management & Orchestration) architecture specified by ETSI NFV-ISG.

These constituent elements constitute a core network in the system 1. Note that the components that need to transmit and receive information to each other are connected by wire and can transmit and receive information.

The system 1 according to the present embodiment provides a communication function for a mobile communication terminal by a virtual server operating in a virtual machine realized on a physical server. That is, the system 1 is a virtualized mobile communication network. The communication function is provided to the mobile communication terminal by executing a communication process corresponding to the communication function by the virtual machine.

The NFVI 60 indicates a network formed from physical resources (node groups) constituting a virtual environment. The physical resources conceptually include computing resources, storage resources, and transmission resources. Specifically, the physical resource includes a node such as a physical server or a switch that is a physical server device that performs communication processing in the system 1. The physical server includes a storage unit such as a CPU (core, processor), a memory, and a hard disk. Normally, a plurality of nodes such as physical servers that constitute the NFVI 60 are arranged together at a base such as a data center (DC). In the data center, the arranged physical servers can communicate with each other via a network inside the data center, and can exchange information with each other. Further, the system 1 is provided with a plurality of data centers. Data centers can communicate with each other via a network, and physical servers provided in different data centers can transmit / receive information to / from each other via the network.

The SO (Service Operator) 20 is a device that requests creation of a network for providing a network service. For example, a terminal device (for example, a personal computer or the like) of a provider that provides services to various users using a virtual network. ).

The BSS / OSS 10 is a node that performs service management in the system 1 and gives instructions related to communication functions in the system 1. For example, the BSS / OSS 10 instructs the NFVO 30 to add a new network service. In addition, the BSS / OSS 10 can be operated by a telecommunications carrier related to the system 1.

The NFVO 30 is an overall management node (functional entity) that manages the entire virtual network (slice) constructed on the NFVI 60 that is a physical resource. The NFVO 30 receives an instruction from the BSS / OSS 10 and performs processing according to the instruction. The NFVO 30 performs management over the entire virtual network constructed in the physical resources of the mobile communication network of infrastructure and network services. The NFVO 30 realizes the network service provided by the virtual network in an appropriate place in cooperation with the VNFM 40 and the VIM 50. For example, network service life cycle management (specifically, for example, network service creation, update, scale control, event collection), resource management over the entire mobile communication network, that is, resource distribution / reservation / allocation management, service -Perform instance management and policy management related to resource allocation (specifically, resource reservation / allocation, optimal allocation based on geography / laws, etc.).

The VNFM 40 is a virtual communication function management node (functional entity) that adds a function that constitutes a network service to the NFVI 60 that is a physical resource (node). A plurality of VNFMs 40 may be provided in the system 1.

The VIM 50 is a physical resource management node (functional entity) that manages each physical resource (node) in the NFVI 60. Specifically, resource allocation / update / recovery management, association between physical resources and virtualized network, and management of hardware resources and SW resources (hypervisor) list are performed. Normally, the VIM 50 performs management for each data center (station building). Management of physical resources is performed by a method according to the data center. Data center management methods (management resource mounting methods) include OPENSTACK and vCenter. Normally, the VIM 50 is provided for each data center management method. That is, a plurality of VIMs 50 that manage each physical resource in the NFVI 60 are included in different ways. Note that the unit of physical resources managed by different management methods is not necessarily a data center unit.

The NFVO 30, VNFM 40, and VIM 50 are realized by executing a program on a physical server device (however, they are not limited to being realized on virtualization, and are separated from a management system). And may be realized on virtualization). The NFVO 30, the VNFM 40, and the VIM 50 may be realized in separate physical server devices, or may be realized in the same server device. The NFVO 30, VNFM 40, and VIM 50 (programs for realizing) may be provided from different vendors.

When the NFVO 30 receives the network service creation request from the BSS / OSS 10, the NFVO 30 makes a resource securing request for the slice (slice SL1, SL2, etc.) to the VIM 50. When the VIM 50 secures resources in the server devices and switches configuring the NFVI 60, the NFVO 30 defines a slice for the NFVI 60.

Further, when the NFVO 30 causes the VIM 50 to reserve resources in the NFVI 60, the NFVO 30 stores information defining slices for the NFVI 60 in a table stored in the NFVO 30. Then, the NFVO 30 makes a software installation request for realizing the functions necessary for the network service to the VNFM 40. In response to the installation request, the VNFM 40 installs the software on the NFVI 60 (node such as a server device, a switch device, or a router device) secured by the VIM 50.

When the software is installed according to the VNFM 40, the NFVO 30 associates the slice and the network service with the table stored in the NFVO 30.

Here, the communication system N1 including each node constituting the slice will be described with reference to FIG. The communication system N1 is a system constructed on the NFVI 60. The eNB 80, the AMF (Core Access and Mobility Management function) 301, the SMF (Slice Management Function) 211 and 221, the UP (User Plane node) 212, the UPX 222, and the PCF ( Policy Control Function) 400. The AMF 301 is a slice connection server that performs communication connection control between the slice and the UE 90. UP 212 and UPX 222 are communication nodes that constitute a slice and transmit / receive user data to / from UE 90. The SMFs 211 and 221 are communication control servers that constitute a slice together with the UP 212 and UPX 222 and perform communication control for the UP 212 and UPX 222. The PCF 400 is a server that performs policy management. In this embodiment, the PCF 400 is a management server that manages user data transmitted and received within a slice. The PCF 400 can grasp the flow of user data in accordance with the management of the SMFs 211 and 221. UPs 212 and 222 are nodes connected to a service providing server DN (Data と Network) to transmit and receive user data.

In the NFVO 30, as shown in FIG. 2, for the second service (service S2) including the slices SL1, SMF221, and UPX222, which are slices for the first service (service S1) including the SMF 211 and UP212. A slice SL2 that is a slice is generated. The NFVO 30 assigns service S1 to slice SL1 and assigns service S2 to slice SL2.

Thus, in the communication system N1, the slice SL1 and the slice SL2 are constructed so as to be logically communicable with each other.

In the present embodiment, the slice SL1 that provides the service S1 includes the SMF 211 that is the C-Plane control node and the UP 212 that is the U-Plane control node. The SMF 211, which is a C-plane control node, transmits and receives control signals and the like related to establishment and disconnection of a communication path when providing the service S1 to the user. The UP 212 also provides a communication path when providing the service S1 to the user, and also provides a communication path with the DN (Data Network) 101, which is a service server that provides the service, to execute transmission / reception of user data. . In addition, the slice SL2 that provides the service S2 includes the SMF 221 and the UPX 222 that is a U-plane control node. The SMF 221 transmits and receives control signals and the like related to the establishment and disconnection of the communication path when providing the service S2 to the user. Further, the UPX 222 provides a communication path when providing the service S2 to the user, and also provides a communication path with the service server 102 that provides the service to execute transmission / reception of user data. The correspondence relationship between the slice and the service is an example and can be changed as appropriate. That is, a node for providing a plurality of services may be assigned to one slice.

Fig. 3 shows an example of the correspondence between each slice and the server. As shown in FIG. 3, the node is a part of the server, and the function of the SMF 211 of the slice 1 (slice SL1) and the function of the SMF 221 of the slice 2 (slice SL2) are performed by the server 1 (110A), the switch, the router, and the like. Realized. The function of the UP 212 of the slice 1 (slice SL1) and the function of the UP 222 of the slice 2 (slice SL2) are realized by the server 2 (110B), a switch, a router, and the like.

When the NFVO 30 assigns a network service to the slice, the access information including the ID of the network service and the destination (for example, IP address) of the logical node that provides the first function of the network service is transmitted to the BSS / OSS 10.

When the BSS / OSS 10 receives the address information, the BSS / OSS 10 notifies the AMF 301 of the address information. The AMF 301 is a server device that can communicate with the eNodeB (eNB) 80 that is a base station device. When a service request is made to the eNB 80 together with the network service ID from the UE 90 that is a service user, The network service ID received from the UE 90 is notified.

When the AMF 301 receives the network service ID from the eNB 80, the destination information of the logical node that provides the first function of the network service of the address information corresponding to the network service ID received from the eNB 80 among the address information stored in the AMF 301 is set to the eNB 80. Send to. The eNB 80 notifies the destination information to the UE 90. With this process, the UE 90 can specify the destination to be accessed first in order to use the network service.

As described above, the AMF 301 holds information on logical nodes that provide network service functions. In other words, the AMF 301 holds information for identifying services that can be handled for each logical node. Although details will be described later, the AMF 301 has a function of providing this information based on an inquiry from another logical node.

Here, a communication system N1 configured based on each node of a slice generated according to the system 1 according to the present embodiment and other devices will be described with reference to FIG. The communication system N1 refers to a core network when the UE 90 communicates and uses a service.

As shown in FIG. 3, in the communication system N1 including the slice constructed in the system 1, the UE 90 transmits the service server 101 (DN) via the eNB 80 and the UP 212 related to the service S1 provided in the slice SL1. : Data Network)), the service S1 provided by the service server 101 can be used. At this time, a communication path for transmitting and receiving user data related to the UE 90 is provided between the eNB 80 and the UP 212. That is, the UP 212 functions as a control node in the slice SL1. In addition, a control signal for performing processing related to establishment and disconnection of a communication path between the eNB 80 and the UP 212 is transmitted / received via the AMF 301 and the SMF 211.

Also, the UE 90 provides the service server 102 by communicating with the service server 102 (DN: Data Network) via the eNB 80 and the UPX 222 related to the service S2 provided in the slice SL2. Service S2 can be used. At this time, a communication path for transmitting and receiving user data related to the UE 90 is provided between the eNB 80 and the UPX 222. That is, the UPX 222 functions as a control node in the slice SL2. In addition, a control signal for performing processing related to establishment and disconnection of a communication path between the eNB 80 and the UPX 222 is transmitted / received via the AMF 301 and the SMF 221.

Thus, in this embodiment, the UE 90 can communicate using the slices SL1 and SL2 by providing a communication path between the eNB 80 in the area where the UE 90 is located and the two slices SL1 and SL2. It has become.

FIG. 4 is a block diagram showing a functional configuration of the AMF 301, SMF 211, 221 and PCF 400 in the present embodiment. As shown in FIG. 4A, the AMF 301 is a node having a connection / mobility management function, and includes a communication control unit 302. The communication control unit 302 performs connection / mobility management for each UE 90 and each slice. The communication control unit 302 performs connection management based on transmitting a request for switching the communication path of the slice to the SMF 211 and receiving the response. When the communication control unit 302 receives a notification that the slice is not used instead of receiving a response to the communication channel switching request, the communication control unit 302 establishes a session of the communication channel forming the slice. Cancel communication processing. If a session has already been established, communication processing for releasing the session is performed.

The SMF 211 is a C-plane control node and a node that controls the UP 212. In the present embodiment, the SMF 211 is a node that forms the slice SL1, and in order to determine whether or not the slice SL1 is used, whether or not a communication packet is transmitted to and received from the slice SL1, for example, the UP 212 within a predetermined time. to decide. When the SMF 211 determines that the slice SL1 is not used, the SMF 211 notifies the AMF 301 to that effect. Similarly, the SMF 221 is a node that controls the UPX 222, and determines whether the slice SL2 is not used.

FIG. 4B is a block diagram showing the AMF 301 that makes an inquiry to the PCF 400 and the functions of the PCF 400. As shown in the figure, the AMF 301 includes a communication control unit 302 and a slice inquiry unit 303. The PCF 400 includes a slice determination unit 401.

The communication control unit 302 is a part that performs communication connection control for the SMFs 211 and 221.

When the communication control unit 302 receives the communication path switching request, the slice inquiry unit 303 makes an inquiry about the usage status of each slice to the PCF 400.

In the PCF 400, the slice determination unit 401 is a part that determines whether or not a packet is transmitted / received in a predetermined unit time when receiving an inquiry about the usage status of each slice performed by the slice inquiry unit 303. Note that, instead of the predetermined unit time, whether or not a packet is transmitted / received may be determined at a predetermined time immediately before receiving the inquiry or at that moment.

FIG. 5 is a diagram illustrating an example of a hardware configuration of a server (for example, a server configuring the AMF 301, the SMF 211, and the like) that realizes the function of each node that executes the processing according to the present embodiment. The server described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, and the like.

In the following description, the term “apparatus” can be read as a circuit, a device, a unit, or the like. The hardware configuration of the server described above may be configured to include one or a plurality of the devices illustrated in the figure, or may be configured not to include some devices.

Each function in the server reads predetermined software (program) on hardware such as the processor 1001 and the memory 1002, so that the processor 1001 performs an operation and the communication performed by the communication device 1004, the memory 1002 and the storage 1003. This is realized by controlling reading and / or writing of data.

The processor 1001 controls the entire computer by operating an operating system, for example. The processor 1001 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like. For example, the communication control unit 302 in the AMF 301 described above may be realized by the processor 1001.

Further, the processor 1001 reads programs (program codes), software modules, and data from the storage 1003 and / or the communication device 1004 to the memory 1002, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above embodiments is used. For example, the above-described communication control unit 302 may be realized by a control program stored in the memory 1002 and operated by the processor 1001, and may be realized similarly for other functional blocks. Although the above-described various processes have been described as being executed by one processor 1001, they may be executed simultaneously or sequentially by two or more processors 1001. The processor 1001 may be implemented by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

The memory 1002 is a computer-readable recording medium, and includes, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), and the like. May be. The memory 1002 may be called a register, a cache, a main memory (main storage device), or the like. The memory 1002 can store a program (program code), a software module, and the like that can be executed to implement the wireless communication method according to the embodiment of the present invention.

The storage 1003 is a computer-readable recording medium such as an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray). (Registered trademark) disk, smart card, flash memory (for example, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. The storage 1003 may be referred to as an auxiliary storage device. The storage medium described above may be, for example, a database, server, or other suitable medium including the memory 1002 and / or the storage 1003.

The communication device 1004 is hardware (transmission / reception device) for performing communication between computers via a wired and / or wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, or the like. For example, the communication control unit 302 described above may be realized by the communication device 1004.

The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that accepts an input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. The input device 1005 and the output device 1006 may have an integrated configuration (for example, a touch panel).

Also, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured with a single bus or may be configured with different buses between apparatuses.

The AMF301 or SMF211 includes hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). A part or all of each functional block may be realized by the hardware. For example, the processor 1001 may be implemented by at least one of these hardware.

Next, specific processing (communication control method) for changing the communication path when the UE 90 in the communication system N1 including the AMF 301 and the SMF 211 is handed over will be described.

(Pattern 1)
Pattern 1 shows a case where the UE 90 moves between eNBs connected to the same UP and SMF. FIG. 6 is a diagram illustrating a situation according to pattern 1 in the communication system N1. The pattern shown in FIG. 6 is a case where the UE 90 moves in the area SA # 1 where the services S1 and S2 can be used by communicating with the slices SL1 and SL2. In this case, the base station apparatus with which the UE 90 communicates is changed from the eNB 81 to the eNB 82 by the handover. At that time, the UE 90 continues to communicate with the slice SL1 and uses the service S1, but the service S2 using the slice SL2 may not be used.

For example, if the SMF 211 or 221 determines that no communication packet is transmitted to or received from the slice SL1 or SL2, it can be determined that the slice is not used. Further, the PCF 400 manages communication of each of the slices SL1 and SL2, and if it is determined that no communication packet is transmitted to or received from the slice SL1 or SL2, it can be determined that the slice is not used.

If it is determined that the slice SL2 is not used, the AMF 301 switches the communication path between the eNB 81 and the UP 212 before movement to the communication path between the eNB 82 and the UP 212, but changes the communication path between the eNB 81 and UP 222 before the movement to the eNB 82. And a process of releasing the communication path using the slice SL2 without switching to the communication path between and UP222.

When determining whether or not a slice is used, a method for determining which slice is not used in the SMF 211 and which slice is used by the AMF 301 making an inquiry to the PCF (Policy Control Function) 400 There is a method to judge whether or not. A specific processing procedure in such a case will be described with reference to the drawings. FIG. 7 is a processing sequence diagram of a method for determining whether or not the slice SL2 is not used in the SMF 221.

First, a signal related to handover is transmitted and received between the eNB 81 before the UE 90 moves and the destination eNB 82 (HO Request, HO Request ACK: S101). With this signal as a trigger, processing related to handover is performed between the UE 90, the eNB 81, and the eNB 82 (Handover Execution: S102).

After this, a signal for making a request for changing the communication path is transmitted from the destination eNB 82 to the AMF 301 (Path Switch Request: S103). Here, since the case where the UE 90 performs handover is described, the signal for making a request for changing the communication path is “Path Switch Request”, but the signal for making a request for changing the communication path is It changes suitably according to the circumstances which change a communication path. This process is the same for other patterns. The request for changing the communication path includes information for identifying the UE 90, information for identifying the communication path (TU-1, TU-2), and information for identifying the session (S-ID1, S-ID2). . In place of information (S-ID: Session ID) for specifying a session, a radio access bearer ID (E-RAB ID: E-UTRANRadio Access Access Bearer ID) or a slice ID (PDU ID) for specifying a slice ) May be used. This also applies to other embodiments and other patterns described later.

When the AMF 301 determines that a plurality of communication paths are provided for the UE 90, the AMF 301 transmits an instruction regarding the change of the communication path to the SMF 211 based on the information specifying the session (Path Switch Request: S105). The instruction regarding the change of the communication path includes information (eNB) ID) for specifying the change destination eNB 82 and information (TU-1) for specifying the communication path to be changed.

When the SMF 211 receives an instruction regarding the change of the communication path, the process related to the change of the communication path is performed according to a known procedure based on the instruction. Specifically, by transmitting information (eNB ID) specifying the change destination eNB 82 together with information (TU-1) specifying the communication path to be changed to the UP 212 of the same slice SL1. Then, the communication path is instructed (Modify （Bearer Request: S106). In response to this, the UP 212 returns to the SMF 211 that the process for creating the communication path has been performed together with the information (UP1 ID) for identifying the own node after performing the process for creating the communication path ( Modify Bearer Response: S107). The SMF 211 that has received the reply from the UP 212 notifies the AMF 301 that the processing related to the change of the communication path has ended as a response to the instruction regarding the change of the communication path (S105) (Path Switch Request ack: S108). .

The same processing is performed in the SMF 221, and when the AMF 301 determines that a plurality of communication paths are provided for the UE 90, the SMF 211 is instructed to change the communication path based on information specifying the session. Transmit (Path Switch Request: S109). In the present embodiment, it is determined that the slice using the SMF 221 is not used by the UE 90 (S110). For example, in the SMF 221, the slice determination unit 221a determines whether or not a slice is used based on the presence / absence of a packet transmitted / received in a predetermined unit time, or the presence / absence of a packet transmitted / received at that moment or the immediately preceding interval. Judging. In the SMF 221, a notification indicating that the slice SL2 is not used is transmitted to the AMF 301 (S111). This notification includes information that can identify an unused slice, and includes a slice ID, a session ID, and the like.

Then, when the AMF 301 receives a notification indicating that the slice SL2 is not used, a release process for the communication path forming the slice SL2 is performed according to a known procedure. Specifically, the AMF 301 transmits a bearer information release request (Bearer release request) to the UP 222 via the SMF 221 and receives a response (Bearer release response) (S112). Thereafter, in AMF 301, Deactivate bearer request is transmitted to eNB 82 to release the path of the radio section of slice SL2, and in eNB 82, RRC connection release is transmitted to UE 90, and radio for slice SL2 is transmitted. The resources of the section are released (S113, S114).

In FIG. 7, the processing in the slice SL2 is performed next to the processing in the slice SL1, but the processing in the slice SL1 and the processing in the slice SL2 are performed separately. The order shown may be different.

Next, processing in which the AMF 301 inquires the PCF 400 about the usage status of each slice will be described. FIG. 8 is a processing sequence diagram thereof. Steps S101 to S103 are the same as in FIG. 7, and a process for handover is performed as the UE 90 moves between eNBs (S101 to S103).

When the AMF 301 receives a signal for making a request for changing the communication path (Path Switch 通信 Request), the slice inquiring unit 303 transmits a slice usage status inquiry signal to the PCF 400 (S104a). . This inquiry signal is generated based on the slice ID for specifying the slice included in the signal for requesting the communication path change, and includes the slice ID. Instead of the slice ID, information for identifying a session, a radio access bearer ID, or the like may be included.

In the PCF 400, the amount of packets communicated in each slice is managed via each SMF, and the slice determination unit 401 determines the use status of the slice (S104b). In the present embodiment, it is determined that the slice SL2 is not used, and the fact is notified by the slice determination unit 401 (S104c). This notification includes information that can identify an unused slice, and includes a slice ID, a session ID, and the like.

When the AMF 301 receives a notification that the slice SL2 is not used, an instruction regarding the change of the communication path is transmitted only to the slice SL1. That is, a communication path switching request process and a bearer request are performed for the SMF 211 and the UP 212 forming the slice SL1 (S105 to S108). In the AMF 301, the SMF 221 and UPX 222 forming the slice SL2 are not requested to switch the communication path, and the bearer information release process is performed on the communication path of the slice SL2 (S112). Thereafter, the resource release processing of the radio section in the slice SL2 is performed (S113, S114). The processes in S105 to S114 are the same as those in FIG.

(Pattern 2)
Pattern 2 shows a case where the UE 90 moves between eNBs connected to different UPs under the same SMF. FIG. 9 is a diagram illustrating a situation according to pattern 2 in the communication system N1. The pattern shown in FIG. 9 is a case where the UE 90 moves from the area SA # 1 where the services S1 and S2 can be used to communicate with the slices SL1 and SL2 to move to a different area SA # 2. is there. The area in the present embodiment is configured such that there are a plurality of UPs managed by one SMF, and these UPs are connected to different eNBs. In this example, the slice SL1 is formed by SMF 211, UP 212a, and UP 212b. The slice SL2 is formed by the SMF 221, UPX 222a, and UPX 222b. And eNB81 and eNB82 are arrange | positioned so that access to either slice SL1 and SL2 is possible. Therefore, the UE 90 can access the slices SL1 and SL2 even when moving to the area SA # 2.

In the present embodiment, the base station apparatus when UE 90 communicates is changed from eNB 81 to eNB 82 by handover, but continues to communicate with slice SL1 and use service S1, but service using slice SL2 S2 may not be used. Therefore, although it is necessary to create a communication path between the eNB 82 and the UP 212, it is not necessary to create a communication path between the eNB 82 and the UP 222.

Similar to pattern 1 above, when determining whether or not a slice is used, which method is used to determine which slice is not used in SMF 211 and 221, and which AMF 301 makes an inquiry to PCF 400 There is a method for determining whether a slice is used. A specific processing procedure in such a case will be described with reference to the drawings. FIG. 10 is a process sequence diagram of a method for determining whether the slice SL2 is not used in the SMF 221.

First, a signal related to handover is transmitted and received between the eNB 81 before the UE 90 moves and the destination eNB 82 (HO Request, HO Request ACK: S201). With this signal as a trigger, processing related to handover is performed between the UE 90, the eNB 81, and the eNB 82 (Handover Execution: S202).

Thereafter, a signal for making a request for changing the communication path is transmitted from the destination eNB 82 to the AMF 301 (Path Switch Request: S203).

The request for changing the communication path includes information for specifying the UE 90, information for specifying the communication path (TU-1, TU-2), and a session (S-ID1, S-ID2). When receiving a request from the eNB 82 in the AMF 301, it is determined whether or not the UE 90 provides a communication path between the two slices based on information included in the request for changing the communication path (S204). In the present embodiment, when a request for changing a communication path includes a plurality of pieces of information for specifying a communication path and a plurality of pieces of information for specifying a session, two communication paths are individually provided for the UE 90. Can be determined.

In the AMF 301, the DNS server 350 is inquired about information related to the slice when the communication path is provided via the eNB 82 (DNS Query Request / Response: S205). More specifically, information specifying SMFs 211 and 221 that can perform communication when using the services S1 and S2 via the eNB 82 is acquired. As a result, in the communication control unit 302, from the information related to the SMF 211 and 221 acquired from the DNS server 350, the APN (Access Point Name) of the service server that is transmitting / receiving user data between the eNBs 82 and the location of the UE 90 ( That is, the SMF 211 of the slice SL1 to be accessed to use the service S1 and the SMF 221 of the slice SL2 to be accessed to use the service S2 are identified based on the information of the eNB 82 to be accessed) (S206). ).

In the AMF 301, a request for providing a new session related to the UE 90 is transmitted to the SMF 211 (Create Session Request: S207). The session creation request includes information (eNB ID) for specifying the access destination eNB 82 and information (TU-1) for specifying the communication path provided according to the session creation.

When the SMF 221 receives a session creation request, the SMF 221 performs processing related to the creation of a communication path according to a known procedure based on the request. Specifically, the UP 212b of the same slice SL1 is selected as the UP for creating the communication path (UP selection: S208). Thereafter, the UP 212b is instructed to create a session by transmitting information (eNB ID) specifying the eNB 82 together with information (TU-1) specifying the communication path (Create Session Request: S209). After performing the process related to session creation, the UP 212b returns to the SMF 211 that the process for creating the session has been performed together with information (UP2 ID) for identifying the own node (Create Session Response: S209). The SMF 211 that has received the reply from the UP 212b notifies the AMF 301 that the processing related to the creation of the communication path has ended as a response to the session creation request (S210) (Create Session Response: S210).

In addition, the AMF 301 transmits a request for creating a new session related to the UE 90 to the SMF 221 (Create Session Request: S211). Here, the SMF 221 determines that the slice SL2 is not used (S212). The determination method is the same as that of the pattern 1 described above. Then, the SMF 221 transmits a notification that the slice SL2 is not used to the AMF 301 (S213). This notification includes information that can identify an unused slice, and includes a slice ID, a session ID, and the like.

When the AMF 301 receives a notification from the SMF 221 that the slice SL2 is not used, the AMF 301 requests the release of the communication path in the wireless section for the slice SL2 without performing the process of creating the communication path for the slice SL2 ( Deactivate bearer request) is transmitted to the eNB 82 (S215). Then, in the eNB 82, RRC connection release is transmitted to the eNB 81, and an instruction to release resources in the radio section for the slice SL2 in the eNB 81 is given (S215, S216).

Next, processing in which the AMF 301 inquires the PCF 400 about the usage status of the slice SL2 will be described. FIG. 11 is a processing sequence diagram thereof. Steps S201 to S205 are the same as in FIG. 10, and the UE 90 moves between eNBs to perform processing for handover, and the eNB 82 transmits a request for switching the communication path to the AMF 301. Then, the AMF 301 inquires DNS about information related to the slice when the communication path is provided via the eNB 82 (S201 to S205).

Thereafter, the AMF 301 makes an inquiry about the usage status of each slice in the information related to the acquired slice to the PCF 400 (S205a). The PCF 400 performs communication management of each slice SL1 (SMF211) and slice SL2 (SMF221). If it is determined that no communication packet is transmitted to or received from the slice SL1 or SL2, it can be determined that the slice is not used. In the present embodiment, the PCF 400 determines that the slice SL2 is not used (S205b), and transmits a notification to that effect (S205c). This notification includes information that can identify an unused slice, and includes a slice ID, a session ID, and the like.

When the AMF 301 receives a notification that the slice SL2 is not used from the PCF 400, the SMF 211 of the slice SL1 is selected according to information such as the APN of the service server, and a request for providing a session for the slice SL1 is transmitted. (S206, S207). In the SMF 211, the UP 212b configuring the slice SL1 is selected based on the ID of the eNB 82 accessed by the UE 90 (S208). Thereafter, in accordance with the processing of S209-S216, a session is created only for slice SL1, and processing for which no session is created is performed for slice SL2.

(Pattern 3)
Pattern 3 shows a case where the UE 90 moves between eNBs connected to different UPs and different SMFs, that is, to an area where there is no slice that has been connected for communication before the handover. FIG. 12 is a diagram for explaining the situation of the pattern 3. This is a case where the UE 90 moves from the area SA # 1 in which the services S1 and S2 can be used to the different area SA # 2 in which the services S1 and S2 cannot be used by communicating with the slices SL1 and SL2. In this case, the base station apparatus used when the UE 90 communicates needs to change not only the eNB 81 to the eNB 82 due to handover, but also the slice in which communication is performed in order to use the services S1 and S2. However, in the destination area SA # 2, there may be no slice corresponding to the slices SL1 and SL2. Therefore, when an inquiry is made to the DNS server, information related to the AMF 301 may not be acquired from the DNS server.

In such a case, as a method of continuously using the two services, the functions of both the communication path between the eNB 81 and the UP 212 before movement and the communication path between the eNB 81 and the UP 222 before movement are It is conceivable to switch to a communication path with UPY 232 provided in slice SL3 that is not related to the service. The slice SL3 here includes SMFY 231 and UPY 232.

It should be noted that eNB 82, AMF 301, UE 90, and the like know whether UE 90 can use services S1 and S2 by providing a communication path with which eNB 82 establishes a communication path in UE SA's destination area SA # 2. Not doing. Also, if the DNS server does not know that the slice SL3 can support the services S1 and S2, the DNS server cannot provide this information to the AMF 301. Therefore, the AMF 301 obtains information by inquiring NSSF (Network （Slice Selection Function). The NSSF is a node that associates a service with a slice, and is a node that answers an appropriate slice to a service request from a request source.

A specific processing procedure in the pattern 3 as described above will be described with reference to FIG.

First, transmission / reception of a signal related to handover is performed between the eNB 81 before the UE 90 moves and the eNB 82 of the movement destination (HO Request, HO Request ACK: S301). Triggered by this signal, processing related to handover is performed among the UE 90, eNB 81, and eNB 82 (Handover Execution: S302).

After this, a signal for making a request for changing the communication path is transmitted from the destination eNB 82 to the AMF 301 (Path Switch Request: S303).

The request for changing the communication path includes information for specifying the UE 90, information for specifying the communication path (TU-1, TU-2), and a session (S-ID1, S-ID2). When receiving a request from the eNB 82 in the AMF 301, whether or not the UE 90 provides a communication path between the two slices and whether or not the slice needs to be changed based on information included in the request for changing the communication path Is determined (S304). In the present embodiment, when a plurality of pieces of information specifying a communication path are included in a request related to a change of a communication path and a plurality of pieces of information specifying a session are included, the AMF 301 has two communication paths for the UE 90. It can be judged that it is provided individually. As described above, the AMF 301 determines whether or not a plurality of communication paths are provided based on the information included in the request for changing the communication path. If the AMF 301 determines that a plurality of communication paths are provided for the UE 90, the following processing is performed.

In the AMF 301, when it is confirmed that a plurality of communication paths are provided for the UE 90 and the slices SL1 and SL2 do not cover the area SA # 2, the communication path is connected to the DNS server via the eNB 82. Inquires about the information related to the slice at the time of providing (DNS Query Request: S305). More specifically, the AMF 301 transmits the services S1 and S2 to the DNS server by transmitting the ECGI (E-UTRAN Cell Global ID) or the service server APN (APN1 & 2) that provides the services S1 and S2. Information for specifying the SMF of a slice to be communicated when using is acquired. The ECGI is information that identifies a cell where the UE 90 is located, that is, information that indicates the position of the UE 90.

The DNS server does not store information in which information specifying an access destination (destination for providing a communication path) is associated with a location and a service type. Accordingly, the DNS server notifies the AMF 301 that there is no information indicating that there is no slice corresponding to the service, that is, no SMF information (DNS Query Response: S306).

Thus, when the information which specifies SMF is not provided from a DNS server, UE90 cannot specify the other party's slice which provides a communication path between eNB82 in order for UE90 to use service S1, S2. It will be. Therefore, the AMF 301 makes an inquiry by transmitting information for identifying the UE 90 to the NSSF, information for identifying the service to be used (APN1 & APN2), and ECGI (PolicyRequest: S307).
.

On the other hand, the NSSF performs communication for using the service in the area where the UE 90 is located based on the information specifying the service to be used, the EGCI, and the information held by the own device. Identify slices that can be routed. Since NSSF holds information for identifying slices that can be handled for each service, this information is used to provide information on the corresponding slices (Policy Response: S308).

Based on the information from NSSF, the AMF 301 determines to establish a session related to two services with the slice SL3 including the SMFY 231 (Selects CPY for boh APN1 & 2 Sessions: S309).

As described above, in the information provided from the DNS server, when an appropriate slice (SMF) cannot be selected, an inquiry is made to the NSSF that holds information for identifying the slice corresponding to the service. With this process, it is possible to acquire information related to an appropriate slice (SMF) for using the two services.

If the DNS server and NSSF cannot provide information for identifying an appropriate slice for the information (APN1 & APN2) for identifying the service to be used, the service cannot be provided and the service itself is interrupted. .

In the AMF 301, after the process of selecting the SMF, an inquiry about the usage status of each slice (SMF 211 and SMF 221) before the movement is transmitted to the PCF 400 (S310). As described above, the PCF 400 performs communication management with respect to the SMFs 211 and 222 constituting the slices SL1 and SL2, and when it is determined that no communication packet is transmitted to or received from the slice SL1 or SL2, the slice is used. It can be judged that it is not done. In the present embodiment, in the PCF 400, it is determined that the slice SL2, that is, the SMF 221 is not used (S311), and a notification to that effect is transmitted to the AMF 301 (S312). This notification includes information that can identify an unused slice, and includes a slice ID, a session ID, and the like.

When the AMF 301 receives the notification of the slice usage status, a session request for the slice being used is transmitted (S313).

The AMF 301 transmits a request for establishing a new session related to the UE 90 to the SMF identified according to the processing so far, that is, the SMFY 231 (Create Session Request: S313). The session creation request includes information (eNB ID) for identifying the access destination eNB 82, information (TU-1) for identifying a communication path provided according to the creation of the session, and information (APN1) for identifying the service. included. By this processing, it is recognized that the session related to the service corresponding to the slice SL1 is opened in the SMFY 231.

When receiving a session creation request, the SMFY 231 performs processing related to creation of a communication path according to a known procedure based on the request. Specifically, the UP 232 of the same slice SL3 is selected as the UP for creating the communication path (UP Selection: S314). Thereafter, the UP 232 is instructed to create a session by transmitting information (eNB ID) specifying the eNB 82 together with information (TU-1) specifying the communication path (Create Session Request: S315). After UP232 performs processing related to creation of a communication path, it performs processing for creating a communication path together with information for identifying the communication path (TU-1) and information for identifying its own node (UPYUPID). A reply is made to the SMFY 231 (Create Session Response: S316). The SMFY 231 that has received the reply from the UP 263 notifies the AMF 301 that the processing related to the creation of the communication path has ended as a response to the session creation request (S313) (Create Session Response: S317).

When the AMF 301 receives the response from the SMFY 231 (S317), the AMF 301 notifies the eNB 82 that the processing related to the change of the communication path has been completed (Path Switch Request ack: S318). This signal includes information (TU-1) for specifying the communication path of slice SL1 and information (S-ID1) for specifying the session of slice SL1 in association with information (UPY ID) for specifying UP232. It is. Based on this information, the eNB 82 can identify the node that is the counterpart of the communication path.

Thereafter, the eNB 82 instructs the eNB 81 to release resources in the wireless section related to the communication path (Release Resource: S319). When the AMF 301 receives a notification from the SMF 221 that the slice SL2 is not used, a request to release a radio section resource for the slice SL2 (Deactivate bearer) without performing a session creation process for the slice SL2 request) is transmitted to the eNB 82 (S320). Then, in the eNB 82, RRC connection release is transmitted to the eNB 81, and a resource release instruction for the slice SL2 in the eNB 81 is performed (S321).

Next, functions and effects of patterns 1 to 3 of the communication system N1 in the present embodiment will be described.

The communication system N1 in the present embodiment can execute a communication control method of a communication system that performs communication control on a communication terminal that is connected to a slice that is a virtual network generated on a network infrastructure.

The communication system N1 is used when it is determined that a slice is not used and a determination step that determines whether a slice is used in a control procedure in which the UE 90 as a communication terminal performs a handover. A communication control step for performing communication control for not using any slice.

By this processing, when it is determined that a slice that has been connected for communication before handover is not used when performing handover, communication control is performed so that the slice that is not used is not used. It can be performed. Therefore, waste of network resources can be eliminated and the resources can be used efficiently.

In the communication system N1 of the present embodiment, the SMF 211, 221 can determine whether or not a slice is being used when performing a handover channel switching process. In that case, the communication system N1 includes an AMF 301 that is a slice connection server that performs communication connection control between the slice and the UE 90, UP 212 and UPX 222 that are communication nodes that configure the slice and transmit user data to and from the UE 90, Slices are configured together with the UP 212 and UPX 222, and include SMFs 211 and 221 that are communication control servers that perform communication control on the UP 212 and UPX 222.

In the determination step (S110 in FIG. 7 or S110 in FIG. 10) executed by the SMF 211 or 221, if the SMF 221 determines that the slice SL2 is not used, identification information (slices) that can identify the slice SL2 that is not used. ID etc.) is notified to the AMF 301. Then, in the communication control step (S112 to S114 in FIG. 7 or S12 to S114 in FIG. 10) executed by the AMF 301, communication control is performed so that unused slices are not used. The communication control step here may include at least bearer release control.

More specifically, in the communication system N1 of the present embodiment, when the UE 90 is handed over to an area that can be communicably connected to the communication node that is communicably connected before the handover (pattern 1), the AMF 301 The communication connection state of the slice SL2 that has not been performed, for example, the bearer can be released.

With this configuration, the SMF 211, 221 can determine the usage status of the slice, and can perform a bearer release process according to the usage status. Therefore, waste of network resources can be eliminated and the resources can be used efficiently.

Further, when the UE 90 is handed over to an area where communication connection to the same slice as before the handover is possible and a communication node different from that before the handover is arranged (Pattern 2), the AMF 301 is used. The communication connection process is not performed for the slice SL2 that is not used, and the communication connection process is performed for the slice SL1 that is being used.

With this configuration, the SMF 211 and 221 can determine the usage status of a slice, and can perform communication connection processing such as establishing a session for the slice according to the usage status. Therefore, waste of network resources can be eliminated and the resources can be used efficiently.

On the other hand, instead of the determination process in the SMF 211 or the like, the PCF 400 can determine the slice usage status.

The communication system N1 includes an AMF 301 that performs communication connection control between the slice and the UE 90, a UP 212 and 222 that configure the slice, and transmits and receives user data to and from the UE 90, and a slice together with the UP 212 and 222. SMF 211 and 221 that perform communication control for 222, and PCF 400 that is a management server that manages the usage status of slices SL1 and SL2.

In response to the switching request in the handover procedure, the AMF 301 makes an inquiry to the PCF 400 about the usage status of the slice to which the UE 90 is connected (S104a in FIG. 8, S205a in FIG. 11, S310 in FIG. 13). Is provided.

In the PCF 400, it is possible to determine whether or not a slice is used based on determining the amount of communication packets transmitted and received by the UP 212 and UPX 222 managed by the SMF 211 and 221 (S104b in FIG. 8, FIG. 11). S205b, S311 of FIG. 13).

The AMF 301 performs communication control so as not to use an unused slice based on the result of the inquiry in this inquiry step.

More specifically, when the UE 90 is handed over to an area that can be communicably connected to a communication node that has been communicably connected before the handover (pattern 1), the AMF 301 uses the result based on the result of the inquiry in the inquiry step. The communication connection state of the slice SL2 that has not been performed, for example, the bearer is released.

By this processing, when it is determined that a slice that has been connected for communication before handover is not used when performing handover, communication control is performed so that the slice that is not used is not used. It can be performed. Therefore, waste of network resources can be eliminated and the resources can be used efficiently.

In addition, when the UE 90 is handed over to an area in which communication connection to the same slice as before the handover is possible and a communication node different from that before the handover is arranged (pattern 2), the AMF 301 performs an inquiry step. On the basis of the result of the inquiry, the communication connection process is not performed on the unused slice, but the communication connection process is performed on the used slice.

With such a configuration, it is possible to determine the slice usage status in the PCF 400, and to perform communication connection processing such as establishing a session for the slice according to the usage status. Therefore, waste of network resources can be eliminated and the resources can be used efficiently.

Furthermore, the UE 90 may be handed over to an area where there is no slice that has been connected for communication before the handover (pattern 3). In this example, the communication system N1 further includes an NSSF that is a slice selection server that selects a slice corresponding to a service from a plurality of slices generated in advance.

Then, when the UE 90 performs handover to an area where communication connection cannot be established with slices (for example, slices SL1 and SL2) that have been connected for communication before the handover, the AMF 301 performs communication connection from the NSSF to the new slice (slice SL3). The SMFY 231 identification information is acquired, and the usage status of the slices SL1 and SL2 to which the UE 90 was connected for communication before the handover is inquired to the PCF 400. Here, since it is determined that the slice SL2 is not used, the communication connection process for the new slice SL3 corresponding to the slice SL1 that has been connected for communication before the handover is performed based on the inquiry result.

By this processing, even if a handover is performed to an area where no slice exists, communication connection can be made to a new slice SL3 selected as a slice used before the handover. At this time, a service using the slice SL2 that is no longer used can be prevented from being wasted by not using the new slice SL3 for communication connection.

As mentioned above, although this embodiment was described in detail, it is clear for those skilled in the art that this embodiment is not limited to embodiment described in this specification. The present embodiment can be implemented as a modification and change without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present embodiment.

The notification of information is not limited to the aspect / embodiment described in this specification, and may be performed by other methods. For example, notification of information includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), It may be implemented by broadcast information (MIB (Master Information Block), SIB (System Information Block)), other signals, or a combination thereof. Further, the RRC signaling may be called an RRC message, and may be, for example, an RRC connection setup (RRC Connection Setup) message, an RRC connection reconfiguration (RRC ConnectionReconfiguration) message, or the like.

Each aspect / embodiment described in this specification includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio Access), W-CDMA. (Registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), The present invention may be applied to a Bluetooth (registered trademark), a system using another appropriate system, and / or a next generation system extended based on the system.

The processing procedures, sequences, flowcharts and the like of each aspect / embodiment described in this specification may be switched in order as long as there is no contradiction. For example, the methods described herein present the elements of the various steps in an exemplary order and are not limited to the specific order presented.

The specific operation performed by a specific device in this specification may be performed by its upper node in some cases. For example, when a specific apparatus is a base station, various operations performed for communication with a terminal in a network including one or a plurality of network nodes (network nodes) having the base station are: Obviously, it can be performed by the base station and / or other network nodes other than the base station. Although the case where there is one network node other than the base station in the above is illustrated, a combination of a plurality of other network nodes may be used.

Information etc. can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

The input / output information or the like may be stored in a specific location (for example, a memory) or may be managed by a management table. Input / output information and the like can be overwritten, updated, or additionally written. The output information or the like may be deleted. The input information or the like may be transmitted to another device.

The determination may be performed by a value represented by 1 bit (0 or 1), may be performed by a true / false value (Boolean: true or false), or may be performed by comparing numerical values (for example, a predetermined value) Comparison with the value).

Each aspect / embodiment described in this specification may be used alone, in combination, or may be switched according to execution. In addition, notification of predetermined information (for example, notification of being “X”) is not limited to explicitly performed, but is performed implicitly (for example, notification of the predetermined information is not performed). Also good.

Software, whether it is called software, firmware, middleware, microcode, hardware description language, or other names, instructions, instruction sets, codes, code segments, program codes, programs, subprograms, software modules , Applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc. should be interpreted broadly.

Further, software, instructions, etc. may be transmitted / received via a transmission medium. For example, software may use websites, servers, or other devices using wired technology such as coaxial cable, fiber optic cable, twisted pair and digital subscriber line (DSL) and / or wireless technology such as infrared, wireless and microwave. When transmitted from a remote source, these wired and / or wireless technologies are included within the definition of transmission media.

The information, signals, etc. described herein may be represented using any of a variety of different technologies. For example, data, commands, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these May be represented by a combination of

Note that the terms described in this specification and / or terms necessary for understanding this specification may be replaced with terms having the same or similar meaning. For example, the signal may be a message.

The terms “system” and “network” used in this specification are used interchangeably.

In addition, information, parameters, and the like described in this specification may be represented by absolute values, may be represented by relative values from a predetermined value, or may be represented by other corresponding information. . For example, the radio resource may be indicated by an index.

The names used for the above parameters are not limited in any way. Further, mathematical formulas and the like that use these parameters may differ from those explicitly disclosed herein. Since various channels (eg, PUCCH, PDCCH, etc.) and information elements (eg, TPC, etc.) can be identified by any suitable name, the various names assigned to these various channels and information elements are However, it is not limited.

The base station can accommodate one or a plurality of (for example, three) cells (also called sectors). When the base station accommodates a plurality of cells, the entire coverage area of the base station can be divided into a plurality of smaller areas, and each smaller area can be divided into a base station subsystem (for example, an indoor small base station RRH: Remote). A communication service can also be provided by Radio Head). The term “cell” or “sector” refers to part or all of the coverage area of a base station and / or base station subsystem that provides communication services in this coverage. Further, the terms “base station”, “eNB”, “cell”, and “sector” may be used interchangeably herein. A base station may also be called in terms such as a fixed station (station), a NodeB, an eNodeB (eNB), an access point, an femtocell, and a small cell.

User terminals can be obtained by those skilled in the art from subscriber stations, mobile units, subscriber units, wireless units, remote units, mobile devices, wireless devices, wireless communication devices, remote devices, mobile subscriber stations, access terminals, mobile terminals, wireless It may also be called terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terminology.

As used herein, the terms “determining” and “determining” may encompass a wide variety of actions. “Judgment” and “determination” are, for example, calculating, computing, processing, deriving, investigating, lookingup (eg, table, database or other data (Search by structure), “acknowledging” (considering as “determining”, “determining”, etc.) may be included. In addition, “determination” and “determination” include receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (accessing) (e.g., accessing data in a memory) may be considered as "determined" or "determined". In addition, “determination” and “decision” means that “resolving”, “selecting”, “choosing”, “establishing”, and “comparing” are regarded as “determining” and “deciding”. May be included. In other words, “determination” and “determination” may include considering some operation as “determination” and “determination”.

The terms “connected”, “coupled”, or any variation thereof, means any direct or indirect connection or coupling between two or more elements and It can include the presence of one or more intermediate elements between two “connected” or “coupled” elements. The coupling or connection between the elements may be physical, logical, or a combination thereof. As used herein, the two elements are radio frequency by using one or more wires, cables and / or printed electrical connections, and as some non-limiting and non-inclusive examples By using electromagnetic energy, such as electromagnetic energy having a wavelength in the region, microwave region, and light (both visible and invisible) region, it can be considered to be “connected” or “coupled” to each other.

As used herein, the phrase “based on” does not mean “based only on”, unless expressly specified otherwise. In other words, the phrase “based on” means both “based only on” and “based at least on.”

In the present specification, when a designation such as “first” or “second” is used, any reference to the element does not generally limit the quantity or order of the elements. These designations can be used herein as a convenient way to distinguish between two or more elements. Thus, a reference to the first and second elements does not mean that only two elements can be employed there, or that in some way the first element must precede the second element.

These terms are similar to the term “comprising” as long as “include”, “including” and variations thereof are used herein or in the claims. It is intended to be comprehensive. Furthermore, the term “or” as used herein or in the claims is not intended to be an exclusive OR.

In this specification, unless there is only one device that is clearly present in context or technically, a plurality of devices are also included.

10 ... BSS / OSS, 20 ... SO, 30 ... NFVO, 40 ... VNFM, 50 ... VIM, 60 ... NFVI, 80, 81, 82 ... eNB, 90 ... UE, 101,102 ... DN, 211,221 ... SMF, 211a, 221a, slice determination unit, 212 ... UP, 222 ... UPX, 400 ... PCF, 302 ... communication control unit, 303 ... slice inquiry unit, 401 ... slice determination unit.

Claims (9)

1. In a communication control method of a communication system that performs communication control for a communication terminal that is connected to a slice that is a virtualized network generated on a network infrastructure,
   A determination step of determining whether or not the slice is used in a control procedure in which the communication terminal performs handover;
   If it is determined that the slice is not used in the determining step, a communication control step for performing communication control so as not to establish communication connection with the unused slice;
   A communication control method comprising:
2. The communication system is:
   A slice connection server that performs communication connection control between the slice and the communication terminal, a slice constituting the slice, a communication node that transmits and receives user data to and from the communication terminal, and the slice together with the communication node, A communication control server that performs communication control on the communication node,
   In the determination step executed by the communication control server, when it is determined that the slice is not used, the slice connection server is notified of identification information that can identify the slice that is not used,
   In the communication control step executed by the slice connection server, communication control is performed so as not to connect to a slice that is not used.
   The communication control method according to claim 1.
3. When the communication terminal is handed over to an area that can be communicably connected to a communication node that is communicably connected before the handover,
   In the communication control step, the communication connection state of the unused slice is released.
   The communication control method according to claim 2.
4. In the case where the communication terminal is handed over to an area where communication connection to the same slice as before the handover is possible and a communication node different from that before the handover is arranged,
   In the communication control step, communication connection processing is not performed on the unused slice, and communication connection processing is performed on the used slice.
   The communication control method according to claim 2 or 3.
5. The communication system is:
   A slice connection server that performs communication connection control between the slice and the communication terminal, a slice constituting the slice, a communication node that transmits and receives user data to and from the communication terminal, and the slice together with the communication node, A communication control server that performs communication control for the communication node, and a management server that manages the usage status of the slice,
   The slice connection server is:
   Upon receiving a switching request in a handover procedure, the management server further includes an inquiry step for inquiring about the usage status of the slice to which the communication terminal is connected for communication.
   In the communication control step executed by the slice connection server, based on the result of the inquiry in the inquiry step, communication control is performed to prevent communication connection with a slice that is not used.
   The communication control method according to claim 1.
6. When the communication terminal is handed over to an area that can be communicably connected to a communication node that is communicably connected before the handover,
   In the communication control step, based on the result of the inquiry in the inquiry step, release a communication connection state of a slice that is not used.
   The communication control method according to claim 5.
7. In the case where the communication terminal is handed over to an area where communication connection to the same slice as before the handover is possible and a communication node different from that before the handover is arranged,
   In the communication control step, based on the result of the inquiry in the inquiry step, the communication connection processing of the unused slice is not performed, and the communication connection processing is performed on the used slice.
   The communication control method according to claim 5 or 6.
8. The communication system further includes a slice selection server that selects a slice corresponding to a service from a plurality of slices generated in advance,
   When the communication terminal is handed over to an area where the communication terminal cannot communicate with the slice with which communication was established before the handover,
   In the communication control step,
   Obtain identification information of a communication control server for communication connection to a new slice from the slice selection server,
   Query the management server for the usage status of the slice that the communication terminal was in communication connection before handover,
   Based on the inquiry result, communication connection processing is performed for a new slice corresponding to the slice that was connected for communication before the handover.
   The communication control method according to any one of claims 5 to 7.
9. In a communication system that performs communication control on a communication terminal that communicates with a slice that is a virtualized network generated on a network infrastructure,
   A determination unit that determines whether or not the slice is used in a control procedure in which the communication terminal performs handover;
   When the determination unit determines that the slice is not used, a communication control unit that performs communication control so as not to use the unused slice;
   A communication system comprising:

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