Communication device and communication method

Abstract

To appropriately perform communication when network slices are used.SOLUTION: A communication device according to one aspect of the present disclosure is a communication device that communicates with a terminal and includes a control unit that determines whether a condition for switching a logical network between the terminal and the communication device is satisfied, and a communication unit that, when the condition is satisfied, transmits an instruction for switching the logical network to another logical network to a second communication device for externally disclosing a network function (NF) of a physical network corresponding to the logical network.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a communication device and a communication method in a mobile communication system.

Background Art

[0002] In the specifications for the 5th generation mobile communication system (5G) of the 3rd Generation Partnership Project (3GPP (registered trademark)), which is a standardization project for mobile communication systems, a Network Exposure Function (NEF) is defined to expose the network functions (Network Function (NF)) of the core network to the outside (for example, Non-Patent Documents 1 and 2).

Prior Art Documents

Non-Patent Documents

[0003]

Non-Patent Document 1

Non-Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the 3GPP specifications, network slices that define virtual networks for each user in a physical network are also defined.

[0005] However, in the current 3GPP standard, an application of a service provider communicating with a user equipment (UE) cannot directly select a network slice for the communication of the UE from outside the core network even via the NEF. If the above application cannot dynamically specify a network slice, there is a risk that the communication quality between the UE and the application deteriorates, the communication throughput decreases, or the throughput of the entire system cannot be improved. In this case, it may be difficult for the service provider to provide an appropriate service.

[0006] Therefore, one of the objectives of the present disclosure is to provide a communication device and a communication method that can appropriately perform communication when using a network slice.

Means for Solving the Problem

[0007] A communication device according to an aspect of the present disclosure is a communication device that communicates with a terminal, and includes a control unit that determines whether a condition for switching a logical network between the terminal and the communication device is satisfied, and when the condition is satisfied, a communication unit that transmits an instruction for switching the logical network to another logical network to a second communication device for publicly exposing a network function (NF) of a physical network corresponding to the logical network to the outside.

Effect of the Invention

[0008] According to an aspect of the present disclosure, communication can be appropriately performed when using a network slice.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

[0010] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the present specification and the drawings, elements that can be similarly described may be denoted by the same reference numerals, and redundant description may be omitted.

[0011] In the present disclosure, the language enclosed by “()” in the text may indicate an explanation (for example, a spelling explanation), a paraphrase, a specific example, a supplementary explanation, etc. for the immediately preceding language. Further, in the present disclosure, the language enclosed by “[]” in the text may be interpreted as the meaning of the entire text including this, or may be interpreted as the meaning of the entire text excluding this (ignoring this). Note that “()” and “[]” may be used for other purposes / meanings.

[0012] In the present disclosure, “A / B” and “at least one of A and B” may be read as each other. Further, in the present disclosure, “A / B / C” may mean “at least one of A, B, and C”.

[0013] <Problem Analysis> In the 3GPP specifications, a network slice (hereinafter also simply referred to as a slice), which defines a virtual network for each user in a physical network, is also defined. Specifically, a slice is defined as a logical network that provides specific network capabilities and network characteristics.

[0014] In the current 3GPP specification Rel.18, slice replacement is introduced. For example, when multiple slices are prepared for a UE and the UE moves outside the service area of the slice in use, it is possible to implement controls such as switching to a standby slice or switching slices at the timing of a handover message.

[0015] However, in the current 3GPP specifications, an application of a service provider communicating with a UE cannot select a slice for the communication of the UE from outside the core network even via the NEF. That is, slice switching based on an application-side trigger is not possible. If the above application cannot dynamically specify a network slice, there is a risk that the communication quality between the UE and the application deteriorates, the communication throughput decreases, or the throughput of the entire system cannot be improved. In this case, it may be difficult for the service provider to provide appropriate services.

[0016] Therefore, the inventors of the present invention conceived a control system and a control method for dynamically selecting an appropriate slice from the application side.

[0017] <Configuration of the system> FIG. 1 is a diagram showing an example of a schematic configuration of a system according to an embodiment of the present disclosure. System 1 includes an application server 10, an Application Programming Interface (API) server 21, a Network Function (NF) server 22, a Base Station (BS) 30, and a User Equipment (UE) 40. System 1 may be referred to as a wireless communication system, an information communication system, or the like.

[0018] In the present disclosure, the NF may include at least one of, for example, an Application Function (AF), an Access and Mobility management Function (AMF), a Data Network (DN), a Location Management Function (LMF), a Network Exposure Function (NEF), a Network Slice Selection Function (NSSF), a Network Data Analytics Function (NWDEF), an Operation, Administration and Maintenance (Management) (OAM), a Policy Control Function (PCF), a Session Management Function (SMF), a Unified Data Management (UDM), a User Plane Function (UPF), and the like. It should be noted that these are merely examples, and it is naturally understood that other NFs are also covered in the present disclosure.

[0019] System 1 is a system compliant with, for example, the Technical Specification (TS) of 3GPP. More specifically, for example, System 1 may be a system compliant with the TS of the 5th generation mobile communication system (5G) or New Radio (NR).

[0020] Note that the system 1 is not limited to this example and may include Long Term Evolution (LTE), LTE-Advanced (LTE-A), 4th generation mobile communication system (4G), 5th generation mobile communication system (5G), 6th generation mobile communication system (6G), xth generation mobile communication system (xG (x is, for example, an integer or a decimal)), New Radio (NR), Global System for Mobile communications (GSM (registered trademark)), CDMA2000, Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, Ultra-WideBand (UWB), Bluetooth (registered trademark), systems using other wireless communication methods, and next-generation systems extended, modified, created, or defined based on these, etc.

[0021] That is, the terms related to 5G in the present disclosure can be read as terms of another technology / system. Also, when this reading is made, for example, it is natural for those skilled in the art to understand that NF can be read with a function similar to that of 5G NF.

[0022] In the system 1, the communication link going toward (received by) the BS30 / coming out from (transmitted by) the UE40 may be called an uplink (UL), and the communication link coming out from (transmitted by) the BS30 / going toward (received by) the UE40 may be called a downlink (DL).

[0023] The application server 10 is a server that executes / controls / manages an application that communicates with the UE 40. The application server 10 may correspond to the above-described AF defined for the 5G Core Network (5GC). In the present disclosure, the application server 10, the application, the AF, etc. are mutually interchangeable. Note that the application server 10 belongs to a network outside the 5GC.

[0024] The 5GC may include, for example, an optical fiber network. In the present disclosure, the 5GC, the network, the physical network, and the core network may be mutually interchangeable.

[0025] The API server 21 provides an API for enabling external access to the services (NFs, particularly control NFs) of the 5GC. By means of this API, for example, when a service provider other than a telecommunications carrier provides a service related to the UE 40 using communication, the service provider can request and obtain information regarding the location / status of the UE 40, and can specify the quality of service (such as communication speed) for the UE 40. The API server 21 may correspond to the above-described NEF defined for the 5GC. In the present disclosure, the API server 21 and the NEF are mutually interchangeable.

[0026] The NF server 22 provides at least one function of the above-described NFs. In FIG. 1, an NF server 22 that provides an AMF connected to the BS 30, an NF server 22 that provides an SMF, the BS 30, the SMF, and an NF server 22 that provides a UPF connected to the AF (in a more specific example, via the DN), etc. are shown. In the present disclosure, the NF server 22 and the NFs (other than the NEF. For example, AMF, NSSF, PCF, SMF, etc.) are mutually interchangeable.

[0027] In the present disclosure, for convenience of explanation, the API server 21 is distinguished from the NF server 22. However, it is well known that NEF is also one of the NFs, and the API server 21 may be included in the NF server 22. That is to say, the API server 21 and one or more NF servers 22 may correspond to one server.

[0028] The BS 30 provides a Radio Access Network (RAN) to the UE 40. An area where wireless communication in the radio access network is possible is also called a cell. In the present disclosure, BS and (Radio) Access Network ((R)AN) may be read interchangeably with each other.

[0029] The BS 30 is, for example, a gNB. The gNB provides NR user plane and control plane protocol terminations towards the UE and is connected to the 5GC via the NG interface. The BS 30 may be an en-gNB. The en-gNB provides NR user plane and control plane protocol terminations towards the UE and operates as a secondary node in E-UTRA-NR Dual Connectivity (EN-DC).

[0030] The UE 40 connects to the radio access network in the above-described cell. The UE 40 may be, for example, a mobile terminal (mobile communication terminal) such as a smartphone, a tablet terminal, or a wearable terminal, or may be a fixed communication terminal. The UE 40 may be a device mounted on a moving object (for example, a vehicle) that is a movable object, or may be the moving object itself.

[0031] Note that each of the devices shown in FIG. 1 may also be referred to as a network node, a node, a [wired / wireless] communication device, an information processing device, etc. Also, the lines between the devices in FIG. 1 indicate a logical connection relationship and do not necessarily need to be physically directly connected (they may be indirectly connected via another device).

[0032] <Configuration of Each Device> An example of the configuration of each device (application server 10, API server 21, NF server 22, BS 30, and UE 40) according to an embodiment of the present disclosure will be described.

[0033] <<Functional Configuration>> FIG. 2 is a diagram showing an example of the schematic functional configuration of each device according to an embodiment of the present disclosure. For example, the application server 10 includes a control unit 110, a communication unit 120, an input / output unit 130, and a storage unit 140.

[0034] Note that the API server 21, NF server 22, BS 30, and UE 40 may also have a similar functional configuration. For this reason, in FIG. 2, as the reference numerals of the functional blocks corresponding to each device, the numeral of the largest digit of the reference numeral indicating each device (for example, if it is BS 30, the largest digit "3" of "30") is replaced with "1" is also shown. In the following, the functional blocks related to the application server 10 will be described, but it is understood that the same description will apply to other devices.

[0035] In this example, mainly the functional blocks of the characteristic parts in this embodiment are shown, and each device may also have other functional blocks necessary for other processes. Also, a configuration that does not include some functional blocks may be adopted.

[0036] The control unit 110 controls the application server 10 and provides various functions. For example, the control unit 110 may control communication with other devices via the communication unit 120. Also, the control unit 110 may acquire information necessary for processing based on the information received via the communication unit 120. The control unit 110 may also be referred to as a processing unit.

[0037] The communication unit 120 communicates (transmits / receives) with other devices via wired / wireless means. The communication unit 120 may obtain information from the received signal and output it to the control unit 110, or may convert the information input from the control unit 110 into a signal and transmit it. The communication unit 120 may be referred to as a transmission unit, a reception unit, a transceiver unit, etc.

[0038] The input / output unit 130 may include an input unit that receives an input by an operation from a person. The input unit may be connected to a predetermined device, a storage medium, etc., and may receive an input of data. The input unit may output the input result to, for example, the control unit 110.

[0039] Also, the input / output unit 130 may include an output unit that outputs data, content, etc. in a form perceptible to a person. The output unit may be configured to include a display unit that displays an image, an audio output unit that outputs audio, etc.

[0040] The storage unit 140 stores (holds) various information used by the application server 10 for processing. The control unit 110 may instruct the storage unit 140 to read and write data.

[0041] <<Hardware Configuration>> FIG. 3 is a diagram showing an example of a schematic hardware configuration of each device according to an embodiment of the present disclosure. Each device includes an antenna 510, a Radio Frequency (RF) circuit 520, a processor 530, a network interface 540, an input device / output device 550, a memory 560, and a storage 570.

[0042] Note that the hardware configuration of each device may be configured to include one or more of the elements shown in FIG. 3, or may be configured without including some of the elements. For example, the UE 40 may not have the network interface 540.

[0043] Antenna 510 converts a signal into a radio wave and radiates the radio wave into space. Also, antenna 510 receives a radio wave in space and converts the radio wave into a signal. A plurality of antennas 510 may be mounted, or it may include a transmitting antenna and a receiving antenna, or it may include a single antenna for transmission and reception. Antenna 510 may include a directional antenna or may include a plurality of antenna elements.

[0044] RF circuit 520 performs analog processing of signals transmitted and received via antenna 510. RF circuit 520 may include a filter (e.g., a high-frequency filter, a low-pass filter), an amplifier, a modulator, a frequency synthesizer, an analog-to-digital conversion circuit, a digital-to-analog conversion circuit, a Fast Fourier Transform (FFT) / Inverse Fast Fourier Transform (IFFT) processing circuit, etc.

[0045] RF circuit 520 may perform amplification, filtering, demodulation to a baseband signal, etc. on the received radio frequency band signal and output it to processor 530. RF circuit 520 may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal input from processor 530 and transmit the radio frequency band signal via transmit / receive antenna 510. Note that RF circuit 520 may perform physical layer processing (e.g., processing of lower functions of the physical layer), and may also perform beamforming processing such as analog beamforming processing and digital beamforming processing.

[0046] Processor 530 may control the entire device. Processor 530 may read a program (program code), software (software module), data, etc. from storage 570 into memory 560 and execute various processes according to these. For example, processor 503 may execute a program of an operating system (OS) loaded into memory 560 to perform control.

[0047] The processor 530 may be composed of a Central Processing Unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, registers, etc. Further, the processor 530 may include a microprocessor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Programmable Logic Device (PLD), a Field Programmable Gate Array (FPGA), etc.

[0048] The processor 530 may perform digital processing of signals transmitted and received via the antenna 510 and the RF circuit 520. The digital processing may include physical layer processing (e.g., processing of upper functions of the physical layer), processing of layers above the Medium Access Control (MAC) layer, processing such as modulation, demodulation, encoding, decoding, and scrambling. The processor 530 also processes signals transmitted and received via the network interface 540.

[0049] The processor 530 may include a plurality of processors or may be a single processor. The plurality of processors may include a baseband processor that performs the above digital processing and one or more processors that perform other processing (e.g., overall control).

[0050] The network interface 540 is, for example, a network adapter, and may be connected to an external network by wire and transmit and receive signals.

[0051] Note that the RF circuit 520 / baseband processor / network interface 540 may be integrated. The RF circuit 520 / baseband processor / network interface 540 may be called a network controller, a network card, a communication module, etc.

[0052] The input / output device 550 includes an input device that receives external input (such as a keyboard, mouse, microphone, switch, button, sensor, etc.), an output device that performs output to the outside (such as a display, speaker, Light Emitting Diode (LED) lamp, etc.), and a device in which these are integrated (such as a touch panel).

[0053] The memory 560 is a computer-readable non-transitory recording medium that stores programs executed by the processor 530, parameters related to the programs, and various other information. The memory 560 may include at least one of Read Only Memory (ROM), Erasable Programmable ROM (EPROM), (Electrically EPROM (EEPROM)), Random Access Memory (RAM), and flash memory. All or part of the memory 560 may be included in the processor 530. The memory 560 may be referred to as a register, cache, main memory (main storage device), etc.

[0054] The storage 570 is a computer-readable non-transitory recording medium that stores various information. The storage 570 may include at least one of, for example, a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (such as a Compact Disc ROM (CD-ROM), digital versatile disk, Blu-ray (registered trademark) disk), a removable disk, a hard disk drive (HDD), a smart card, a flash memory device (such as a Solid State Drive (SSD)). The storage 570 may be referred to as an auxiliary storage device.

[0055] Also, each device such as the processor 530 and the memory 560 may be connected by a bus for communicating information. A single bus may be used within the device, or different buses may be used for each device.

[0056] The control unit X10 (where X = 1, 2, 3, 4; the same applies hereinafter) may be implemented by the processor 530. The communication unit X20 may be implemented by the antenna 510 / RF circuit 520 / network interface 540. The input / output unit X30 may be implemented by the input device / output device 550. The storage unit X40 may be implemented by the memory 560 / storage 570.

[0057] Note that the BS30 may be separated into three elements: a Radio Unit (RU), a Distributed Unit (DU), and a Central Unit (CU). The RU realizes RF processing and lower-layer functions of the physical layer. The DU realizes upper-layer functions of the physical layer, functions of the MAC layer, and functions of the Radio Link Control (RLC) layer. The CU realizes functions of the Packet Data Convergence Protocol (PDCP) layer, the Service Data Adaptation Protocol (SDAP), and the Radio Resource Control (RRC) layer.

[0058] In the present disclosure, the BS30 may include one device that realizes all the functions of the RU, DU, and CU, or may include a plurality of devices that respectively realize some of the functions of the RU, DU, and CU.

[0059] Also, other devices in the present disclosure may also be implemented by a plurality of physically separated devices. Conversely, a plurality of different devices in the present disclosure (for example, two or more of the API server 21, NF server 22, and BS30) may be implemented as one device.

[0060] <Operation Example> Hereinafter, an example of the operation of each device / function according to the embodiment of the present disclosure will be described. The communication methods (wireless communication method, control method) described below may be applied in the above-described system 1.

[0061] In the following description of the present disclosure, reference numerals may be omitted. For example, the UE in the following description may mean UE40.

[0062] Each device / function in the following description may be read interchangeably with one or more functional blocks (e.g., control unit 110, communication unit 120) or a hardware configuration (e.g., RF circuit 520, processor 530) within the device / function.

[0063] [[Slice switching due to an instruction from an app]] In one embodiment of the present disclosure, the 5GC dynamically switches the slice that accommodates the traffic between the UE and the AF based on an instruction from an app operating in an application server (AF). Thereby, the app side can dynamically select an appropriate slice.

[0064] This app may be an app for control / monitoring of a moving body (e.g., a vehicle) on which the UE or a person holding the UE rides (or in which the UE is mounted). For example, this app may acquire (e.g., the UE transmits data of video / audio / information collected by a camera, sensor, microphone, etc. mounted on the UE / moving body, and the AF receives it via the DN) and output video / audio / information around the moving body via the UE, or may perform remote control of the moving body (e.g., the AF transmits a control signal for the moving body via the DN and the UE). Of course, this app may have other functions (e.g., video streaming to the UE).

[0065] In the following description, the slice may mean a slice that accommodates the traffic between the UE and the AF, a slice used for communication between the UE and the AF, etc. Note that this traffic may be communicated via at least one of a BS, UPF, DN, etc. In the present disclosure, switch, accommodation change, update, replace, modify, transfer / migrate, etc. are interchangeable with each other.

[0066] Also, in the present disclosure, the UE may be a UE mounted on a mobile body or a UE included in the mobile body (held by a person riding on the mobile body) as described above.

[0067] FIG. 4 is a diagram showing an example of slice switching caused by an instruction from an application according to an embodiment of the present disclosure. In this example, an example of switching from an original slice (which may be referred to as a default slice, an original slice, a base slice, etc.) to a slice with better / higher communication quality (a premium slice) is shown. In the present disclosure, [communication] quality / speed / delay may be mutually read as [communication] performance.

[0068] In step S101, the AF monitors (judges) whether the conditions for slice switching are satisfied, and if satisfied, proceeds to step S102. The above conditions may be defined based on at least one of time, area, quality, the position / speed of the UE, information notified from the 5GC, information notified from the UE, etc.

[0069] The above conditions may include, for example, any one or more of the following conditions: · It has reached a specific time or corresponds to a specific time period. · The UE has entered a specific area, exited a specific area, or is within a specific area. · The communication throughput / communication quality between the UE and the AF is below a threshold or has fluctuated beyond the threshold (in other words, for example, the image quality of a still image / moving image uploaded from the UE has deteriorated). · The fluctuation of the position / speed / acceleration of the UE is below a threshold (in other words, for example, the mobile body including the UE has hardly moved). · Specific information is transmitted from the UE (for example, the mobile body including the UE transfers a message of difficulty in autonomous driving via the UE). · There has been a specific operation in the application (for example, an operation of a specific button / menu).

[0070] The above-mentioned specific time may be specified based on at least one of a start time, an end time, a duration from the start time, a period, an offset [of the period from a specific time], etc. The unit of time may be expressed in, for example, seconds, minutes, hours, etc.

[0071] The above-mentioned specific area may be indicated by at least one of a range of latitude and longitude [from a reference point], a distance [from a reference point], a geographical area, a Tracking Area (TA), etc., or may be predefined in the AF / application. The above-mentioned specific area may be determined based on at least one of a reference point, a range of latitude and longitude [from the reference point], a distance [from the reference point], an address / shape indicating a geographical area, a list of Tracking Area Identities (TAIs), a Public Land Mobile Network (PLMN) ID, an area identifier (Identifier (ID)) predefined in the AF / application, etc. The above-mentioned reference point may be predefined in the AF / application or may be the current location of the UE.

[0072] The satisfaction of the above-mentioned condition may mean that the above-mentioned condition is satisfied once, or may mean that it is satisfied over a certain period of time / a certain number of times. For example, the AF has a counter. When the above-mentioned condition is satisfied once at a certain timing, the counter is incremented each time the above-mentioned condition is satisfied at a specific interval. If the counter exceeds a threshold within a certain period of time from the above-mentioned certain timing, the process proceeds to step S102; otherwise, the counter may be reset (or set to 0).

[0073] Note that AF may determine whether the above conditions are met based on the information obtained from the 5GC [NEF] / application. For example, AF may obtain (receive) information regarding UE / communication quality via APIs for services such as Nnef_EventExposure and Nnef_AnalyticsExposure of NEF, and determine whether the above conditions are met based on this information.

[0074] Nnef_EventExposure is a service for notifying events. The events include at least one of UE reachability, Loss of Connectivity, Location Reporting, the number of UEs present within a geographical area, etc. Nnef_AnalyticsExposure is a service for notifying network statistical information. For example, the statistical information includes at least one of information regarding performance, information regarding Quality of Service (QoS), congestion information, etc.

[0075] The above conditions may vary for each slice (S-NSSAI) or Slice and Service Type (SST). For example, for slices for enhanced Mobile Broad Band (eMBB), massive Machine Type Communication (mMTC), and Ultra Reliable and Low Latency Communications (URLLC), the above conditions may be different from each other. Different conditions may be applied for specific components of the above conditions (e.g., time, the area to which the UE belongs, communication throughput / communication quality between the UE and AF, UE location, etc.). For example, the above conditions may be different in the case where the UE belongs to the first area and the case where the UE belongs to the second area.

[0076] In step S102, AF may send an instruction for slice switching to the NEF of 5GC when any one or more of the above conditions are satisfied. The transmission of the slice switching instruction may be performed by invoking a specific service operation. For example, AF may invoke the specific service operation, update the information [contained in the request], and send the request to the NEF. This request may correspond to the slice switching instruction. In the present disclosure, instructions, specifications, requests, etc. may be read interchangeably with each other.

[0077] In the present disclosure, service operations, APIs [for service operations], interfaces [for service operations], etc. may be read interchangeably with each other.

[0078] The above specific service operation may include an existing service operation (for example, Nnef_ServiceParameter_Update), or may include a new service operation (for example, a new NEF service not defined in the existing NEF service). The invocation of the above specific service operation may be performed via a CAMARA API (for example, Quality On Demand (QoD) API) related to the Global System for Mobile Communications (GSM) Association (GSMA).

[0079] The slice switching instruction may include one or more of the following information: · Information indicating the slice before switching (the slice to be switched), · Information indicating the slice after switching (the destination slice), · Information indicating the UE [using the slice to be switched] (which may be called UE identification information, UE information, etc.), · Information regarding the timing for switching the slice (which may be called timing information).

[0080] The information indicating the slice before switching (the slice to be switched) may be, for example, Single Network Slice Selection Assistance Information (S-NSSAI). The information indicating the slice after switching may be, for example, Alternative S-NSSAI.

[0081] Note that in the current Rel.18 3GPP standard (Non-Patent Document 1), the Alternative S-NSSAI is defined as indicating a compatible S-NSSAI for an S-NSSAI within the Allowed NSSAI that the AMF uses to replace the S-NSSAI when the S-NSSAI is unavailable or congested. The Alternative S-NSSAI in the present disclosure may be defined by reading "when the S-NSSAI is unavailable or congested" in the above definition as "when the S-NSSAI is unavailable or congested, or when it is specified [via the NEF] to be switched". The Alternative S-NSSAI in the present disclosure may also be referred to as the indicated S-NSSAI or the like.

[0082] The UE information may include at least one of the following: · Generic Public Subscription Identifier (GPSI), · Subscription Permanent Identifier (SUPI), · Internet Protocol Version 4 (IPv4) address, · Internet Protocol Version 6 (IPv6) address or IPv6 prefix, · MAC address, · External Group Identifier, · Internal Group Identifier, · Any other identifier for identifying the UE.

[0083] In addition, when the UE information is an external (unique) ID different from the ID (e.g., GPSI) in the 3GPP domain (under the management of 5GS), the AF / NEF may have information regarding the mapping (corresponding relationship) between the ID in the 3GPP domain and the external ID. The subsequent UE information may be mutually read as the UE information converted to the ID in the 3GPP domain by the NEF or other NF.

[0084] The timing information may indicate, for example, any one or more of the following: · Switch immediately, · Switch when a specific time arrives (or during a specific time period), · Switch when the UE enters a specific area, or exits a specific area, or is within a specific area.

[0085] The timing information, as the information indicating the specific time, may include information regarding at least one of the start time, end time, duration from the start time, period, offset [of the period from a specific time] of [the switching], etc. The unit of time may be expressed, for example, in seconds, minutes, hours, etc.

[0086] The specific area may be indicated by at least one of the latitude and longitude range [from a reference point], distance [from a reference point], geographical area, TA, etc., or may be predefined in the AF / application. The timing information, as the information indicating the specific area, may include information regarding at least one of the reference point, latitude and longitude range [from a reference point], distance [from a reference point], address / shape indicating the geographical area, list of TAI[s], PLMN ID, area ID predefined in the AF / application, etc. The reference point may be preset in the AF / application or may be the current location of the UE.

[0087] Note that the specific time / specific area in step S103 and the specific time / specific area in step S101 may be partially or entirely different, or may be partially or entirely the same.

[0088] The timing for switching slices may correspond to the timing that satisfies all the time / area conditions indicated by the above timing information. As described above for step S101, the satisfaction of the conditions may mean that the conditions are satisfied once, or may mean that they are satisfied over a certain period of time / a certain number of times.

[0089] Note that the above instruction not explicitly including information regarding the timing for switching slices may implicitly indicate switching to the default timing (for example, immediately).

[0090] AF may determine at least one of the slice after switching, the timing for switching slices, etc., based on the information obtained from the 5GC [NEF] / application for generating an instruction for slice switching. The acquisition of information may be the same as that described above in step S101. For example, AF may acquire information regarding the [alternate] S-NSSAI and the performance (for example, communication speed, quality, etc.) of the slice corresponding to the [alternate] S-NSSAI.

[0091] Note that AF may preset / notify / store the information of the available S-NSSAI (or permitted NSSAI). The information may be preset / notified by, for example, a 5GC network operator. AF may select an alternate S-NSSAI indicating the slice after switching from among the available S-NSSAI (or permitted NSSAI).

[0092] In step S103, the NEF sends (or instructs) information regarding slice switching to the nodes related to the slice. The information regarding the slice switching may include one or more pieces of information included in the above-mentioned slice switching instruction. In step S104, the above-mentioned nodes perform control to switch the slice based on the information regarding the slice switching. Note that the NEF / node may determine the start timing of the process related to slice switching (e.g., sending information to another node) based on the time / area indicated by the above-mentioned timing information, and start the above-mentioned process at the start timing. Thereby, the AF can perform the slice switching process based on the desired time / area.

[0093] Although not shown in the figure, in step S105, the above-mentioned nodes may send a report regarding the result of the slice switching (such as success or failure) to the NEF. In step S106, the NEF may send a report regarding the result of the slice switching to the AF.

[0094] Note that after the slice is switched, if the conditions are met, the above-mentioned nodes may perform control to return to the original slice (default slice). The above-mentioned conditions may be, for example, that a certain period of time has elapsed since the switching. Also, the above-mentioned conditions may be that the AF sends an instruction to return the switched slice to the NEF of the 5GC. Whether to send the instruction to return the switched slice may be determined in the same way as the conditions for slice switching in step S101 (however, with different rules).

[0095] In FIG. 4, an example is shown in which the target slice has better communication quality / higher speed than the original slice. However, the target slice does not have to have better communication quality / higher speed than the original slice. For example, when the communication quality / throughput between a certain UE and an AF is good enough for the control / monitoring of the mobile body on which the UE or the person holding the UE rides (or on which the UE is mounted), the switching to a slice with lower but acceptable quality / speed may be controlled. In this case, considering the case where a new UE that requires higher quality / higher speed communication starts communication, the network resources can be left with a margin.

[0096] According to the slice switching procedure described above, an appropriate slice can be dynamically / explicitly selected from the application side. For example, usually, a UE in a self-driving vehicle uploads (streams) a video captured by a camera around the vehicle to an AF. In the case of an emergency where the vehicle enters the remote operation (remote driving) mode and a person remotely operates the vehicle while viewing the video in an application in the AF, the AF can specify the switching to a premium slice based on the deterioration of the communication quality, so that the remote operation can be stably performed (human operation errors can be reduced).

[0097] Also, in the above case, during autonomous driving, the UE uploads data using the default slice, and when autonomous driving becomes difficult, the AF can specify the switching so that the UE uploads data using the premium slice, so that the remote operation can be stably performed (human operation errors can be reduced).

[0098] Also, when the application streams a video to the UE, the AF can specify the switching to a premium slice based on the deterioration of the communication quality, so that a high-quality video can be stably delivered to the UE.

[0099] <<First Control Flow of Slice Switching>> FIG. 5 is a diagram showing an example of a first control flow of slice switching according to an embodiment of the present disclosure. This example corresponds to the steps after step S102 described above.

[0100] In step S201 (corresponding to step S102), the AF transmits a request for the Nnef_ServiceParameter_Update service operation to the NEF. This request may include the S-NSSAI indicating the slice before switching (the slice to be switched), the alternative S-NSSAI indicating the slice after switching, and UE information.

[0101] In step S202 (corresponding to step S103), the NEF transmits information (notification) regarding slice switching to the AMF / NSSF / PCF. The notification may include the S-NSSAI, the alternative S-NSSAI, and the UE information. Note that at least one of the S-NSSAI and the UE information may not be included in the notification.

[0102] In step S203 (corresponding to step S104), the AMF / NSSF / PCF performs control to switch the slice that accommodates the traffic between the UE indicated by the UE information and the AF from the slice associated with the S-NSSAI to the slice associated with the alternative S-NSSAI based on the information (notification) regarding slice switching (in other words, triggers the replacement of these slices).

[0103] The slice switching (slice replacement procedure) in step S203 may be performed in the same manner as the procedure of the network slice replacement function used to replace the S-NSSAI with the alternative S-NSSAI described in the current Rel.18 3GPP standard (for example, §5.15.19 Support of Network Slice Replacement in Non-Patent Document 1).

[0104] In the current Rel.18 3GPP standard, when the S-NSSAI becomes unavailable or congested (for example, when the NSSF / PCF / OAM detects that the S-NSSAI has become unavailable or congested), a network slice replacement is triggered when a predetermined notification (such as a "Network Slice Availability Notification" or an "Access and Mobility Related Policy Notification") is sent to the AMF. The above-mentioned predetermined notification may include an alternative S-NSSAI that can be used to replace the S-NSSAI.

[0105] Note that the unavailability or congestion of the S-NSSAI may be detected based on the output of the OAM or NWDEF.

[0106] Upon receiving the above-mentioned predetermined notification, the AMF may determine an alternative S-NSSAI and provide the alternative S-NSSAI for the S-NSSAI to the UEs registered for the S-NSSAI, or provide a mapping from the S-NSSAI to the alternative S-NSSAI. The AMF may include this information in a UE Configuration Update message or the like and send it to the UE. Until the mapping is deleted, the UE may communicate using the slice associated with the alternative S-NSSAI instead of the S-NSSAI.

[0107] In addition, the AMF may provide both the S-NSSAI and the alternative S-NSSAI to the SMF (for example, via a service operation related to a Protocol Data Unit (PDU) session such as Nsmf_PDUSession_UpdateSMContext). For example, for an existing PDU session associated with the S-NSSAI to be replaced by the alternative S-NSSAI, after sending the mapping to the UE, the AMF may send an update to the SMF indicating that the PDU session is to be transferred to the slice associated with the alternative S-NSSAI. The SMF may control the transfer of the PDU session used by the BS, UE, etc. to the slice associated with the alternative S-NSSAI.

[0108] Specifically, the AMF may send an Nsmf_PDUSession_UpdateSMContext request including an SM context ID, an S-NSSAI, an alternative S-NSSAI, etc. to the SMF of the PDU session associated with the S-NSSAI. The SMF may send an N4 Session Modification request message indicating that the S-NSSAI is replaced by the alternative S-NSSAI to the UPF. Further, the SMF may send a PDU Session Modification command including at least one of the alternative S-NSSAI and a cause value indicating that the S-NSSAI of the PDU session is replaced by the alternative S-NSSAI (or PDU session re-establishment in the alternative S-NSSAI is required) to the UE [via the AMF and BS].

[0109] Note that the PDU session may mean the association between the UE and the DN providing the PDU connection service.

[0110] In the current Rel.18 3GPP standard, network slice replacement is triggered in cases where the S-NSSAI is unavailable or congested. On the other hand, in step S203, network slice replacement is triggered even if it is not such a case, when there is information (notification) regarding slice switching from the NEF to the AMF / NSSF / PCF.

[0111] In step S204 (corresponding to step S105), the AMF / NSSF / PCF sends a report on the result of slice switching (such as success or failure) to the NEF. In step S205 (corresponding to step S106), the NEF sends a report on the result of slice switching to the AF. The reports on the result of slice switching in steps S204 and S205 may be different (may include different contents) or may be the same. The report on the result of slice switching in step S205 may also be a response of Nnef_ServiceParameter_Update.

[0112] According to the first control flow described above, control based on a slice switching instruction from an application can be implemented in a form conforming to the existing network slice replacement procedure.

[0113] <<Second Control Flow of Slice Switching>> FIG. 6 is a diagram showing an example of a second control flow of slice switching according to an embodiment of the present disclosure.

[0114] Steps S301 and S305 may be the same as steps S201 and S205 respectively, so the description will not be repeated.

[0115] Steps S302 and S304 may be the same as the contents obtained by replacing the AMF / NSSF / PCF with the SMF in steps S202 and S204 respectively, so the description will not be repeated.

[0116] In step S303, the SMF, based on the above information (notification) regarding slice switching from the NEF, performs control to switch the slice accommodating the traffic between the UE indicated by the above UE information and the AF from the slice associated with the above S-NSSAI to the slice associated with the above alternative S-NSSAI (in other words, triggers the replacement of these slices).

[0117] The slice switching in step S303 may be performed in the same manner as the PDU session modification procedure described in the current Rel.18 3GPP standard (e.g., §4.3.3 PDU Session Modification in Non-Patent Document 2).

[0118] For example, the SMF may send an N4 Session Modification request message indicating that the above S-NSSAI is replaced by the above alternative S-NSSAI to the UPF. Further, the SMF may send a PDU Session Modification command including at least one of the above alternative S-NSSAI and a cause value indicating that the S-NSSAI of the PDU session is replaced by the above alternative S-NSSAI (or PDU session re-establishment in the above alternative S-NSSAI is required) to the UE [via the AMF and BS].

[0119] Note that the SMF may perform [SM policy association modification procedures for the subscribed events and] report to the PCF.

[0120] According to the second control flow described above, control based on a slice switching instruction from an application can be performed in a form conforming to the existing PDU session modification procedure.

[0121] <<Case where the specified target slice for switching is unavailable>> If the slice to be switched to (alternate S-NSSAI) desired by the AF is determined to be unavailable, the 5GC [node] may propose / use another slice to be switched to (which may be called an additional alternate S-NSSAI, another alternate S-NSSAI, etc.) as the slice to be switched to. Note that "unavailable" may be read interchangeably with "not available, without the right to use, or congested". Also, in the above-described network slice replacement procedure, PDU session modification procedure, etc., a report indicating that "the switching has failed (could not be switched)" may be sent to any NF node, which may also fall under the above "unavailable".

[0122] The slice of the additional alternate S-NSSAI may have performance below that of the slice of the alternate S-NSSAI and above that of the slice of the original S-NSSAI.

[0123] For example, when the NEF determines, in cooperation with the NSSF / PCF, etc., that the alternate S-NSSAI indicated by the instruction / request received in step S102 / S201 / S301 described above is unavailable, it may omit the intermediate steps and send a report indicating the unavailability of the alternate S-NSSAI to the AF in step S106 / S205 / S305 described above. Note that when the NEF discovers an additional alternate S-NSSAI while determining, in cooperation with the NSSF / PCF, etc., that the alternate S-NSSAI is unavailable, it may notify the additional alternate S-NSSAI in the above report.

[0124] If the AMF / NSSF / PCF / SMF determines that the alternative S-NSSAI indicated by the information / notification received in step S103 / S202 / S302 described above is not available, it may skip the intermediate steps and, in step S105 / S204 / S304 described above, send a report indicating that the alternative S-NSSAI is not available to the NEF. In addition, if the AMF / NSSF / PCF / SMF cannot use the alternative S-NSSAI but discovers an additional alternative S-NSSAI, it may notify the additional alternative S-NSSAI in the above report. The NEF may send a report indicating that the alternative S-NSSAI is not available to the AF.

[0125] When the AF receives a report indicating an additional alternative S-NSSAI in step S106 / S205 / S305, it may set the additional alternative S-NSSAI in the slice to be switched to (alternative S-NSSAI) and send the instruction / request in step S102 / S201 / S301 described above to the NEF again. In addition, a list (candidate) of additional alternative S-NSSAIs may be notified in the above report. In that case, the AF may select one additional alternative S-NSSAI from among those included in the list, set the selected one additional alternative S-NSSAI in the slice to be switched to (alternative S-NSSAI), and send the instruction / request in step S102 / S201 / S301 described above to the NEF again.

[0126] For example, the NEF may cooperate with the NSSF / PCF, etc., and determine that the alternative S-NSSAI indicated by the instruction / request received in step S102 / S201 / S301 described above is not available, and discover (decide) an additional alternative S-NSSAI.

[0127] The AMF / NSSF / PCF / SMF may [cooperate with the NSSF / PCF, etc.,] determine that the alternative S-NSSAI indicated by the information / notification received in step S103 / S202 / S302 described above is not available, and discover (decide) an additional alternative S-NSSAI.

[0128] When an additional alternative S-NSSAI is discovered, for the subsequent steps, steps in which the above-described alternative S-NSSAI is replaced with the additional alternative S-NSSAI may be used. Note that the NEF may send a report indicating that in step S106 / S205 / S305, the alternative S-NSSAI could not be used [and thus switched to the slice of the additional alternative S-NSSAI] to the AF.

[0129] According to the examples described above, even when the specified target slice for switching is not available, control based on the slice switching instruction from the application can be implemented based on another target slice.

[0130] <Supplementary Note> In the above-described embodiments, slice switching was instructed / controlled, but the coverage scope of the present disclosure is not limited thereto. The slices in the above-described embodiments may be mutually replaced with a network slice instance (NSI) / network slice subnet instance (NSSI). In this case, the S-NSSAI (including S-NSSAI such as alternative S-NSSAI) in the above-described embodiments may be replaced with an NSI ID, an NSSI ID, etc. That is, the present disclosure may cover switching in units of slice instances / slice subnet instances.

[0131] <Appended Note> Regarding one embodiment of the present disclosure, the following inventions are appended. [Appended Note 1] A communication device (for example, application server 10) that communicates with a terminal (for example, UE40), a control unit that determines whether a condition for switching a logical network (for example, a slice) between the terminal and the communication device is satisfied, When the above conditions are satisfied, for a second communication device (e.g., API server 21) for publicly exposing a network function (Network Function (NF)) of a physical network (e.g., 5GC) corresponding to the logical network to the outside, a communication unit that transmits an instruction (e.g., a slice switching instruction) for switching the logical network to another logical network (e.g., another slice). [Appendix 2] The communication device according to Appendix 1, wherein the condition includes that a specific time has come or the condition is satisfied during a specific time period. [Appendix 3] The communication device according to Appendix 1 or Appendix 2, wherein the condition includes that the terminal has entered a specific area, has exited the specific area, or is within the specific area. [Appendix 4] The communication device according to any one of Appendix 1 to Appendix 3, wherein after transmitting the instruction, when the other logical network is unavailable, the communication unit receives information (e.g., additional alternative S-NSSAI) indicating a further available logical network from the second communication device. [Appendix 5] The communication device according to any one of Appendix 1 to Appendix 4, wherein the instruction includes information (e.g., timing information) regarding the timing of switching the logical network slice to the other logical network. [Appendix 6] A communication device (e.g., API server 21), a receiving unit that receives from the second communication device an instruction (e.g., a slice switching instruction) for switching a logical network (e.g., a slice) between a terminal (e.g., UE40) and a second communication device (e.g., application server 10) to another logical network (e.g., another slice); a transmitting unit that transmits information (e.g., alternative S-NSSAI) indicating the other logical network to a third communication device (e.g., AMF / NSSF / PCF / SMF). [Appendix 7] The third communication device is the communication device described in Supplementary Note 6 that triggers a procedure for a network slice replacement function (for example, the procedure described in §5.15.19 Support of Network Slice Replacement in Non-Patent Document 1) for switching the logical network to the other logical network based on information indicating the other logical network. [Supplementary Note 8] The third communication device is the communication device described in Supplementary Note 6 or Supplementary Note 7 that triggers a Protocol Data Unit (PDU) session modification procedure (for example, the procedure described in §4.3.3 PDU Session Modification in Non-Patent Document 2) for switching the logical network to the other logical network based on information indicating the other logical network. [Supplementary Note 9] A communication method of a communication device that communicates with a terminal, a step of determining whether a condition for switching a logical network between the terminal and the communication device is satisfied; a step of, when the condition is satisfied, transmitting an instruction for switching the logical network to another logical network to a second communication device for publicly exposing a network function (Network Function (NF)) of a physical network corresponding to the logical network to the outside.

[0132] [Modification Example] In addition, terms described in the present disclosure and terms necessary for understanding the present disclosure may be replaced with terms having the same or similar meanings.

[0133] In the present disclosure, expressions such as device, circuit, device, section, unit, etc. can be read interchangeably with each other.

[0134] The information, parameters, etc. described in this disclosure may be represented using absolute values, relative values from a predetermined value, or using corresponding other information. For example, radio resources may be indicated by a predetermined index.

[0135] The names used for parameters, etc. in this disclosure are not limiting names in any respect. Furthermore, mathematical formulas, etc. using these parameters may be different from those explicitly disclosed in this disclosure.

[0136] The information, signals, etc. described in this disclosure may be represented using any of various different technologies. For example, data, instructions, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description may be represented by voltage, current, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0137] The input and output information, signals, etc. may be stored in a specific location (e.g., memory) or may be managed using a management table. The input and output information, signals, etc. may be overwritten, updated, or appended. The output information, signals, etc. may be deleted. The input information, signals, etc. may be transmitted to other devices.

[0138] Any information described in this disclosure (e.g., information regarding any parameter / variable) may be notified between any devices in this disclosure. Also, in this disclosure, the notification of information is not limited to the modes / embodiments described in this disclosure and may be performed using other methods.

[0139] Also, the notification of predetermined information (e.g., the notification of "being X") is not limited to explicit notification and may be performed implicitly (e.g., by not performing the notification of the predetermined information or by the notification of other information).

[0140] Software should be broadly construed to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether called software, firmware, middleware, microcode, a hardware description language, or by any other name.

[0141] Also, software, instructions, information, etc. may be transmitted and received via a transmission medium. For example, when software is transmitted from a website, server, or other remote source using at least one of wired technologies (such as coaxial cable, fiber optic cable, twisted pair, Digital Subscriber Line (DSL), etc.) and wireless technologies (such as infrared, microwave, etc.), at least one of these wired and wireless technologies is included within the definition of a transmission medium.

[0142] In the present disclosure, terms such as "Base Station (BS)", "radio base station", "relay station", "fixed station", "NodeB", "eNB (eNodeB)", "gNB (gNodeB)", "access point", "Transmission Point (TP)", "Reception Point (RP)", "Transmission / Reception Point (TRP)", "panel", "cell", "sector", "cell group", "carrier", "component carrier", etc. may be used interchangeably.

[0143] In the present disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. may be used interchangeably.

[0144] Any device in the present disclosure may be referred to as a server, a device, a transmitting device, a receiving device, a wireless communication device, an information processing device, etc., and these may be mutually substituted. Any device in the present disclosure may be a device mounted on a moving object, which is a movable object, or a device included in the moving object (held by a person riding on the moving object), or the moving object itself. The moving object includes, for example, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavator trucks, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, rear cars, rickshaws, ships (ship and other watercraft), airplanes, rockets, artificial satellites, drones, multicopters, quadcopters, balloons, and things mounted on these, and is not limited thereto. Further, the moving object may perform autonomous driving / automated driving. Note that the moving object in the present disclosure may be mutually substituted with an object that does not move (for example, an object that does not move but can be ridden by a person).

[0145] Each aspect / embodiment described in the present disclosure may be used alone, in combination, or switched and used during execution. Also, the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be rearranged as long as there is no contradiction. For example, regarding the method described in the present disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0146] The description "based on" used in the present disclosure does not mean "only based on" unless otherwise specified. In other words, the description "based on" means both "only based on" and "at least based on".

[0147] Any reference to an element using terms such as "first", "second", etc. used in this disclosure does not generally limit the quantity or order of those elements. These terms can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements can be employed or that the first element must precede the second element in any form.

[0148] As used in this disclosure, the terms "connected", "coupled", or any variations thereof, mean any direct or indirect connection or coupling between two or more elements, and can include the presence of one or more intermediate elements between two elements "connected" or "coupled" to each other. The coupling or connection between elements can be physical, logical, or a combination of these. The coupling or connection between elements can be a connection via at least one of wired and wireless.

[0149] In this disclosure, the term "A and B are different" may mean "A and B are different from each other". Note that the term may also mean "A and B are each different from C". Terms such as "separate", "coupled", etc. may also be interpreted in the same way as "different".

[0150] In this disclosure, when the terms "include", "including", and their variations are used, these terms are intended to be inclusive, similar to the term "comprising". Further, the term "or" used in this disclosure is not intended to be an exclusive disjunction.

[0151] In this disclosure, for example, when articles are added by translation, such as a, an, and the in English, this disclosure may include that the nouns following these articles are in the plural form.

[0152] In the present disclosure, words related to "determination", "judgment", "decision", "selection", "calculation", "computation", "processing", "derivation", "search", "confirmation", "assumption", "expectation", etc. may be read interchangeably with each other.

[0153] In the present disclosure, "hereinafter", "less than", "more than", "more", "equal to", etc. may be read interchangeably with each other. Also, in the present disclosure, words meaning "good", "bad", "big", "small", "high", "low", "fast", "slow", "wide", "narrow", etc. may be read interchangeably with each other not limited to the positive degree, comparative degree and superlative degree. Further, in the present disclosure, words meaning "good", "bad", "big", "small", "high", "low", "fast", "slow", "wide", "narrow", etc. may be read interchangeably with each other not limited to the positive degree, comparative degree and superlative degree as expressions with "(the) i-th" (where i is an arbitrary integer) attached (for example, "highest" may be read interchangeably with "(the) i-th highest").

[0154] In the present disclosure, "(of)", "(for)", "(regarding)", "(related to)", "(associated with)", etc. may be read interchangeably with each other.

[0155] As described above, the invention according to the present disclosure has been described in detail. However, it is obvious to those skilled in the art that the invention according to the present disclosure is not limited to the embodiments described in the present disclosure. The description of the present disclosure is for illustrative purposes and does not impose any limiting meaning on the invention according to the present disclosure.

Claims

1. A communication device that communicates with a terminal, a control unit that determines whether a condition for switching a logical network between the terminal and the communication device is satisfied; a communication unit that, when the condition is satisfied, transmits an instruction to switch the logical network to another logical network to a second communication device for publicly exposing a network function (Network Function (NF)) of a physical network corresponding to the logical network to the outside. A communication device having

2. The communication device according to claim 1, wherein the condition includes that a specific time has arrived or that it corresponds during a specific time period.

3. The communication device according to claim 1, wherein the condition includes that the terminal has entered a specific area, has exited the specific area, or is within the specific area.

4. The communication device according to any one of claims 1 to 3, wherein, after transmitting the instruction, when the other logical network is unavailable, the communication unit receives information indicating yet another available logical network from the second communication device.

5. The communication device according to any one of claims 1 to 3, wherein the instruction includes information regarding the timing of switching the logical network slice to the other logical network.

6. A communication device, a receiving unit that receives an instruction to switch a logical network between a terminal and a second communication device to another logical network from the second communication device; a transmitting unit that transmits information indicating the other logical network to a third communication device. A communication device having

7. The communication device according to claim 6, wherein the third communication device triggers a procedure of a network slice replacement function for switching the logical network to the other logical network based on the information indicating the other logical network.

8. The communication device according to claim 6, wherein the third communication device triggers a Protocol Data Unit (PDU) session modification procedure for switching the logical network to the other logical network based on the information indicating the other logical network.

9. A communication method of a communication device that communicates with a terminal, a step of determining whether a condition for switching a logical network between the terminal and the communication device is satisfied; When the above conditions are satisfied, sending an instruction to switch the logical network to another logical network to a second communication device for externally exposing a network function (Network Function (NF)) of a physical network corresponding to the logical network. A communication method of a communication device having this step.

Images