Communication device, communication method, terminal, and communication system

Abstract

To appropriately perform communication, when a network slice is used. 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 or not 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 with respect to a second communication device for disclosing a network function (Network Function (NF)) of a physical network corresponding to the logical network to the outside.

Description

Communication device, communication method, terminal and communication system

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

[0002] The 3rd Generation Partnership Project (3GPP (registered trademark)), a standardization project for mobile communication systems, defines a Network Exposure Function (NEF) for exposing the network functions (NF) of a core network to the outside in its standards for 5th generation mobile communication systems (5G) (see, for example, Non-Patent Documents 1 and 2).

[0003] 3GPP TS 23.501 V18.3.0 (2023-09) “System architecture for the 5G System (5GS); Stage 2 (Release 18)”

[0004] The 3GPP standard also defines network slices that define virtual networks for each user in a physical network.

[0005] However, in the current 3GPP standard, a service provider's application that communicates with a user equipment (UE) cannot directly select a network slice for the UE's communication from outside the core network, even via the NEF. If the application cannot dynamically specify a network slice, there is a risk that the communication quality between the UE and the application will deteriorate, communication throughput will decrease, or the throughput of the entire system will not be able to improve. In this case, there is a risk that it will be difficult for the service provider to provide appropriate services.

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

[0007] 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 met, and a communication unit that, when the condition is met, sends an instruction to a second communication device for externally disclosing a network function (Network Function (NF)) of a physical network corresponding to the logical network to switch the logical network to another logical network.

[0008] According to one aspect of the present disclosure, communication can be carried out appropriately when using network slices.

[0009] FIG. 1 is a diagram illustrating an example of a schematic configuration of a system according to an embodiment of the present disclosure. FIG. 2 is a diagram illustrating an example of a schematic functional configuration of each device according to an embodiment of the present disclosure. FIG. 3 is a diagram illustrating an example of a schematic hardware configuration of each device according to an embodiment of the present disclosure. FIG. 4 is a diagram illustrating an example of slice switching caused by an instruction from an app according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating an example of a first control flow of slice switching according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating an example of a second control flow of slice switching according to an embodiment of the present disclosure.

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

[0011] In the present disclosure, a word enclosed in "( )" in a sentence may indicate an explanation of the word immediately preceding it (for example, an explanation of spelling), a paraphrase, a specific example, a supplementary explanation, etc. Also, in the present disclosure, a word enclosed in "[ ]" in a sentence may be interpreted including the word in the meaning of the entire sentence, or may be interpreted excluding the word in the meaning of the entire sentence (ignoring the word in the meaning of the entire sentence). Note that "( )" and "[ ]" may also be used for purposes / meanings other than those mentioned above.

[0012] In the present disclosure, "A / B" and "at least one of A and B" may be interpreted interchangeably. Also, in the present disclosure, "A / B / C" may mean "at least one of A, B, and C."

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

[0014] Slice replacement is introduced in the current 3GPP standard Rel. 18. For example, multiple slices are prepared for a UE, and when the UE moves out of the service area of ​​a slice currently in use, the UE switches to a spare slice, or the slice is switched at the timing of a handover message.

[0015] However, in the current 3GPP standard, a service provider's application communicating with a UE cannot select a slice for the UE's communication from outside the core network, even via the NEF. In other words, slice switching triggered by the application is not possible. If the application cannot dynamically specify a network slice, the communication quality between the UE and the application may deteriorate, communication throughput may decrease, or the throughput of the entire system may not be improved. In this case, it may be difficult for the service provider to provide appropriate services.

[0016] Therefore, the present inventors came up with the idea of ​​a control system and method for dynamically selecting an appropriate slice from the application side.

[0017] 1 is a diagram illustrating an example of a schematic configuration of a system according to an embodiment of the present disclosure. The 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 user equipment (UE) 40. The system 1 may also be referred to as a wireless communication system, an information communication system, or the like.

[0018] In the present disclosure, the NF may include, for example, at least one of 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), etc. Note that these are merely examples, and it is naturally understood that NFs other than these are also covered in the present disclosure.

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

[0020] Note that system 1 is not limited to this example, and may include systems that use 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), and other wireless communication methods, as well as next-generation systems that are extended, modified, created, or defined based on these.

[0021] In other words, terms related to 5G in the present disclosure can be replaced with terms of other technologies / systems. In addition, when this replacement is made, it is naturally understood by those skilled in the art that, for example, NF can be replaced with a function similar to NF of 5G.

[0022] In system 1, the communication link going to (receiving from) BS 30 / going out (transmitting from) UE 40 may be referred to as uplink (UL), and the communication link going out (transmitting from) BS 30 / going out (receiving from) UE 40 may be referred to as downlink (DL).

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

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

[0025] The API server 21 provides an API for externally accessing 5GC services (NFs, particularly control NFs). For example, when a service provider that is not a telecommunications carrier provides a service related to a UE 40 using communication, the API can be used to request and acquire information about the location / status of the UE 40, or to specify the service quality (such as communication speed) for the UE 40. The API server 21 may correspond to the above-mentioned NEF defined for 5GC. In the present disclosure, the API server 21 and the NEF are interchangeable.

[0026] The NF server 22 provides at least one of the above-described NF functions. In Fig. 1, an NF server 22 connected to the BS 30 and providing an AMF, an NF server 22 providing an SMF, and an NF server 22 connected to the BS 30, the SMF, and an AF (in a more specific example, via a DN) and providing a UPF are shown. In the present disclosure, the NF server 22 and an NF (other than an NEF, for example, an AMF, an NSSF, a PCF, an SMF, etc.) can be read as interchangeable terms.

[0027] In this disclosure, for the sake of convenience, the API server 21 is distinguished from the NF server 22, but it is well known that the NEF is also one of the NFs, and the API server 21 can be included in the NF server 22. In other words, the API server 21 and one or more NF servers 22 may correspond to a single server.

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

[0029] 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 5GC via an NG interface. BS 30 may also 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 a radio access network in the above-mentioned 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 (e.g., a vehicle) that is a movable object, or may be the moving object itself.

[0031] 1 may be referred to as a network node, a node, a [wired / wireless] communication device, an information processing device, etc. The lines between devices in FIG. 1 indicate logical connections and do not necessarily have to be physically connected directly (they may be connected indirectly 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] 2 is a diagram illustrating an example of a 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, the NF server 22, the BS 30, and the UE 40 may also have similar functional configurations. For this reason, in Fig. 2, the symbols of the functional blocks corresponding to each device are also shown by replacing the highest digit of the symbol indicating each device (for example, for the BS 30, the highest digit of "30" is "3") with "1". The following describes the functional blocks related to the application server 10, but it will be understood that the same description applies to the other devices.

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

[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. The control unit 110 may also acquire information necessary for processing based on 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 communication. The communication unit 120 may obtain information from a received signal and output it to the control unit 110, or may convert information input from the control unit 110 into a signal and transmit it. The communication unit 120 may also be called a transmitting unit, a receiving unit, a transmitting / receiving unit, etc.

[0038] The input / output unit 130 may include an input unit that accepts input through human operation. The input unit may be connected to a predetermined device, storage medium, etc., and may accept data input. The input unit may output the input result to the control unit 110, for example.

[0039] The input / output unit 130 may also include an output unit that outputs data, content, etc. in a format that can be perceived by humans. The output unit may include a display unit that displays images, an audio output unit that outputs audio, etc.

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

[0041] 3 is a diagram illustrating 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] 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 to exclude some of the elements. For example, UE 40 may not have network interface 540.

[0043] The antenna 510 converts signals into radio waves and radiates the radio waves into space. The antenna 510 also receives radio waves in space and converts the radio waves into signals. Multiple antennas 510 may be installed, may include a transmitting antenna and a receiving antenna, or may include a single antenna for transmitting and receiving. The antenna 510 may include a directional antenna or may include multiple antenna elements.

[0044] The RF circuitry 520 performs analog processing of signals transmitted and received via the antenna 510. The RF circuitry 520 may include filters (e.g., high frequency filters, low pass filters), amplifiers, modulators, frequency synthesizers, analog-to-digital conversion circuits, digital-to-analog conversion circuits, Fast Fourier Transform (FFT)) / Inverse Fast Fourier Transform (IFFT)) processing circuits, and the like.

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

[0046] The processor 530 may control the entire device. The processor 530 may read programs (program codes), software (software modules), data, etc. from the storage 570 into the memory 560 and execute various processes in accordance with these. For example, the processor 503 may execute a program of an operating system (OS) loaded into the memory 560 to perform control.

[0047] The processor 530 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, a register, etc. The processor 530 may also 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 circuitry 520. The digital processing may include physical layer processing (e.g., processing of functions higher than the physical layer), processing of the Medium Access Control (MAC) layer or higher, modulation, demodulation, encoding, decoding, scrambling, etc. The processor 530 also processes signals transmitted and received via the network interface 540.

[0049] The processor 530 may include multiple processors or may be a single processor, which may include a baseband processor that performs the 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 via a wired connection to send and receive signals.

[0051] The RF circuit 520, the baseband processor, and the network interface 540 may be integrated into one unit. The RF circuit 520, the baseband processor, and the network interface 540 may be called a network controller, a network card, a communication module, or the like.

[0052] The input device / output device 550 includes input devices that accept input from the outside (e.g., keyboards, mice, microphones, switches, buttons, sensors, etc.), output devices that output to the outside (e.g., displays, speakers, Light Emitting Diode (LED) lamps, etc.), and devices that combine these (e.g., touch panels).

[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 a read-only memory (ROM), an erasable programmable ROM (EPROM), an electrically programmable read-only memory (EEPROM), a random access memory (RAM), and a flash memory. All or a part of the memory 560 may be included within the processor 530. The memory 560 may also be called a register, a cache, a main memory, etc.

[0054] Storage 570 is a computer-readable non-transitory recording medium and stores various information. Storage 570 may include, for example, at least one of a flexible disk, a floppy (registered trademark) disk, a magneto-optical disk (e.g., a compact disc ROM (CD-ROM)), a digital versatile disc, a Blu-ray (registered trademark) disc), a removable disk, a hard disc drive (HDD), a smart card, a flash memory device (e.g., a solid state drive (SSD)), and the like. Storage 570 may also be referred to as an auxiliary storage device.

[0055] Furthermore, 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 between the devices.

[0056] The control unit X10 (X=1, 2, 3, 4; the same applies below) 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] The BS 30 may be separated into three elements: a radio unit (RU), a distributed unit (DU), and a central unit (CU). The RU performs RF processing and lower-level functions of the physical layer. The DU performs higher-level functions of the physical layer, MAC layer functions, and Radio Link Control (RLC) layer functions. The CU performs Packet Data Convergence Protocol (PDCP) layer, Service Data Adaptation Protocol (SDAP), and Radio Resource Control (RRC) layer functions.

[0058] In the present disclosure, BS 30 may include one device that implements all of the functions of the RU, DU, and CU, or may include multiple devices that each implement some of the functions of the RU, DU, and CU.

[0059] Other devices in the present disclosure may also be implemented by multiple devices that are physically separated from one another. Conversely, multiple different devices in the present disclosure (e.g., two or more of the API server 21, the NF server 22, and the BS 30) may be implemented as a single device.

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

[0061] In the following description of the present disclosure, reference numerals may be omitted. For example, UE in the following description may refer to UE 40.

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

[0063] <<Slice Switching Due to an Instruction from an Application>> In one embodiment of the present disclosure, 5GC dynamically switches a slice accommodating traffic between a UE and an application server (AF) based on an instruction from an application running on the AF, thereby allowing the application side to dynamically select an appropriate slice.

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

[0065] In the following description, a slice may refer to a slice accommodating traffic between a UE and an AF, a slice used for communication between a UE and an AF, etc. Note that this traffic may be communicated via at least one of a BS, a UPF, a DN, etc. In the present disclosure, terms such as switch, re-accommodation, update, replace, modify, transfer / migrate, etc. may be read as interchangeable terms.

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

[0067] 4 is a diagram illustrating an example of slice switching caused by an instruction from an application according to an embodiment of the present disclosure. This example illustrates an example of switching from an original slice (which may be referred to as a default slice, original slice, base slice, or the like) to a slice (premium slice) with better communication quality / higher speed. In the present disclosure, the terms "communication quality / speed / delay" may be interchangeably referred to as "communication performance."

[0068] In step S101, the AF monitors (determines) whether a condition for slice switching is satisfied, and if satisfied, proceeds to step S102. The condition may be defined based on at least one of time, area, quality, UE position / velocity, information notified from 5GC, information notified from the UE, and the like.

[0069] The above conditions may include, for example, one or more of the following conditions: - A specific time has arrived or is within a specific time period; - The UE has entered, left, 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 still images / video images uploaded from the UE has deteriorated); - The fluctuations in the UE's position / speed / acceleration are below a threshold (in other words, for example, the mobile object containing the UE is hardly moving); - Specific information is sent from the UE (for example, a mobile object containing the UE transfers a message via the UE that autonomous driving is difficult); - A specific operation is performed in the app (for example, a specific button / menu is operated).

[0070] The specified 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 the specified time], etc. The time may be expressed in units of, for example, seconds, minutes, hours, etc.

[0071] The specific area may be indicated by at least one of a latitude / longitude range [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 / app. The specific area may be determined based on at least one of a reference point, a latitude / longitude range [from a reference point], a distance [from a 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 (ID) predefined in the AF / app, etc. The reference point may be predefined in the AF / app, or may be the UE's current location.

[0072] The condition being satisfied may mean that the condition is satisfied once, or may mean that the condition is satisfied over a certain period of time / a certain number of times. For example, the AF may have a counter, and when the condition is satisfied once at a certain timing, the AF may increment the counter each time the condition is satisfied at a specific interval, and if the counter exceeds a threshold within a certain period of time from the certain timing, the AF may proceed to step S102, and if not, the AF may reset the counter (or set it to 0).

[0073] The AF may determine whether the above conditions are satisfied based on information acquired from the 5GC [NEF] / application. For example, the AF may acquire (receive) information about the UE / communication quality via APIs for services such as Nnef_EventExposure and Nnef_AnalyticsExposure of the NEF, and determine whether the above conditions are satisfied based on the 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 in a geographical area, etc. Nnef_AnalyticsExposure is a service for notifying network statistics. For example, the statistics include at least one of performance information, quality of service (QoS) information, congestion information, etc.

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

[0076] In step S102, the AF may transmit a slice switching instruction to the NEF of the 5GC if 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, the AF may invoke the specific service operation, update the request (information included in the request), and transmit the request to the NEF. This request may correspond to the slice switching instruction. In the present disclosure, terms such as instruction, designation, and request may be interchangeable.

[0077] In the present disclosure, the terms service operation, API [for service operation], interface [for service operation], etc. may be read interchangeably.

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

[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 to); - Information indicating the slice after switching (the slice to be switched to); - Information indicating the UE [that uses the slice to be switched to] (which may also be called UE identification information, UE information, etc.); - Information regarding the timing of switching the slice (which may also 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), and the information indicating the slice after switching may be, for example, Alternative S-NSSAI.

[0081] 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 in the allowed NSSAI, which 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 replacing "when the S-NSSAI is unavailable or congested" in the above definition with "when the S-NSSAI is unavailable or congested, or is designated [via the NEF] to be switched." The alternative S-NSSAI in the present disclosure may be referred to as an indicated S-NSSAI, etc.

[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] If the UE information is an external (unique) ID different from the 3GPP domain (under 5GS management) ID (e.g., GPSI), the AF / NEF may have information on the mapping (correspondence) between the 3GPP domain ID and the external ID. The UE information below may be interchangeable with the UE information converted into the 3GPP domain ID by the NEF or another NF.

[0084] The timing information may indicate, for example, one or more of the following: - Switch immediately; - Switch at a specific time (or for a specific time); - Switch when the UE enters, leaves, or is within a specific area.

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

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

[0087] 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 of switching slices may correspond to the timing when all of the time / area conditions indicated by the timing information are satisfied. As described above for step S101, satisfaction of the conditions may mean that the conditions are satisfied once, or may mean that the conditions are satisfied over a certain period of time / a certain number of times.

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

[0090] The AF may determine at least one of the slice after switching, the timing of switching the slice, etc., based on information acquired from the 5GC [NEF] / application to generate the slice switching instruction. The acquisition of the information may be similar to that described above in step S101. For example, the AF may acquire information regarding the [alternative] S-NSSAI and the performance (e.g., communication speed, quality, etc.) of the slice corresponding to the [alternative] S-NSSAI.

[0091] The AF may set / notify / store information about available S-NSSAIs (or permitted NSSAIs) in advance. For example, the information may be set / notified by a 5GC carrier. The AF may select an alternative S-NSSAI indicating a slice after switching from among the available S-NSSAIs (or permitted NSSAIs).

[0092] In step S103, the NEF transmits information about slice switching to the nodes involved in the slice (instructs the slice switching). The information about slice switching may include one or more pieces of information included in the slice switching instruction. In step S104, the nodes control the slice switching based on the information about slice switching. Note that the NEF / node may determine the start timing of the slice switching process (e.g., information transmission to another node) based on the time / area indicated by the timing information, and start the process at the determined start timing. This allows the slice switching process to be performed based on the time / area desired by the AF.

[0093] Although not shown in the figure, in step S105, the node may transmit a report on the result of the slice switching (success, failure, etc.) to the NEF. In step S106, the NEF may transmit a report on the result of the slice switching to the AF.

[0094] After the slice is switched, if a condition is met, the node may perform control to return to the original slice (default slice). The condition may be, for example, that a certain time has elapsed since the switch. The condition may also be that the AF transmits an instruction to the 5GC [NEF] to return the switched slice. Whether or not to transmit the instruction to return the switched slice may be determined in the same manner as the condition for slice switching in step S101 (but using a different rule).

[0095] 4 shows an example in which the switching destination slice has better communication quality / speed than the original slice, but the switching destination slice does not have to have better communication quality / speed than the original slice. For example, if the communication quality / throughput between a certain UE and an AF is sufficiently good for controlling / monitoring the UE or a mobile body carrying a person carrying the UE (or on which the UE is mounted), switching to a slice with lower but acceptable quality / speed may be controlled. In this case, it is possible to provide a margin for network resources in consideration of a case in which a new UE requiring higher quality / speed communication starts communication.

[0096] According to the slice switching procedure described above, an appropriate slice can be dynamically / explicitly selected from the application side. For example, in a case where a UE normally in an autonomously driving vehicle uploads (streams) video captured by a camera around the vehicle to an AF, and in an emergency, the vehicle enters a remote control (remote driving) mode, and a person remotely controls the vehicle while watching the video on an application in the AF, the AF can specify switching to a premium slice based on deterioration of communication quality, thereby enabling stable remote control (reducing human operation errors).

[0097] In addition, in the above case, the UE uploads data using the default slice during autonomous driving, and the AF can specify a switch so that the UE uploads data using the premium slice when autonomous driving is difficult, allowing for stable remote operation (reducing human operating errors).

[0098] Furthermore, when an application streams video to a UE, the AF can specify switching to a premium slice based on deterioration in communication quality, thereby enabling stable delivery of high-quality video to the UE.

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

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

[0101] In step S202 (corresponding to step S103), the NEF transmits information (notification) about 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), based on the information (notification) regarding the slice switching, the AMF / NSSF / PCF performs control to switch the slice accommodating 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 (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 an S-NSSAI with an alternative S-NSSAI, which is described in the current Rel. 18 3GPP standard (e.g., §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 becomes unavailable or congested), network slice replacement is triggered by sending a predetermined notification (such as a "Network Slice Availability Notification" or "Access and Mobility Related Policy Notification") to the AMF. The predetermined notification may include an alternative S-NSSAI that can be used to replace the S-NSSAI.

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

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

[0107] The AMF may also provide both the S-NSSAI and the alternative S-NSSAI to the SMF (e.g., 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 with the alternative S-NSSAI, the AMF may, after sending the mapping to the UE, send an update to the SMF indicating that the PDU session will be transferred to the slice associated with the alternative S-NSSAI. The SMF may control the transfer of PDU sessions 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 to the SMF of the PDU session associated with the S-NSSAI, including the SM Context ID, S-NSSAI, an alternative S-NSSAI, etc. The SMF may send an N4 Session Modification request message to the UPF indicating that the S-NSSAI is to be replaced with the alternative S-NSSAI. The SMF may also send a PDU Session Modification command to the UE (via the AMF and the BS) including at least one of the alternative S-NSSAI and a cause value indicating that the S-NSSAI of the PDU session is to be replaced with the alternative S-NSSAI (or PDU session re-establishment at the alternative S-NSSAI is requested).

[0109] In addition, a PDU session may refer to an association between a UE and a DN that provides a PDU connection service.

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

[0111] In step S204 (corresponding to step S105), the AMF / NSSF / PCF transmits a report on the result of the slice switching (success, failure, etc.) to the NEF. In step S205 (corresponding to step S106), the NEF transmits a report on the result of the slice switching to the AF. The reports on the results of the slice switching in steps S204 and S205 may be different (may contain different content) or may be the same. The report on the result of the slice switching in step S205 may be a response to Nnef_ServiceParameter_Update.

[0112] According to the first control flow described above, control based on a slice switching instruction from an application can be performed in accordance with existing network slice replacement procedures.

[0113] <<Second Control Flow of Slice Switching>> FIG. 6 is a diagram illustrating 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, and therefore will not be described repeatedly.

[0115] Steps S302 and S304 may be the same as steps S202 and S204, respectively, with AMF / NSSF / PCF replaced with SMF, and therefore the description will not be repeated.

[0116] In step S303, based on the information (notification) regarding the slice switching from the NEF, the SMF performs control to switch the slices accommodating traffic between the UE indicated by the UE information and the AF from the slices associated with the S-NSSAI to the slices associated with the 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 (for example, §4.3.3 PDU Session Modification in Non-Patent Document 2).

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

[0119] In addition, the SMF may report the subscribed events to the PCF [by performing the SM policy association modification procedure].

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

[0121] <<Cases where the specified destination slice is unavailable>> If the 5GC [node] determines that the destination slice (alternative S-NSSAI) desired by the AF is unavailable, it may propose / use another destination slice (which may be referred to as an additional alternative S-NSSAI, another alternative S-NSSAI, etc.) as the destination slice. Note that "unavailable" may be interchangeably read as "unavailable, unauthorized to use, or congested." In addition, in the above-mentioned network slice replacement procedure, PDU session modification procedure, etc., a report indicating "switching failed (unable to switch)" being sent to any NF node may also be considered "unavailable."

[0122] The slice of the additional alternative S-NSSAI may have performance equal to or less than the slice of the alternative S-NSSAI, and may have performance equal to or greater than the slice of the original S-NSSAI.

[0123] For example, when the NEF, in cooperation with the NSSF / PCF, etc., determines that the alternative S-NSSAI indicated in the instruction / request received in the above-mentioned steps S102 / S201 / S301 is unavailable, it may skip the steps and send a report indicating that the alternative S-NSSAI is unavailable to the AF in the above-mentioned steps S106 / S205 / S305. Note that, when the NEF, in cooperation with the NSSF / PCF, etc., determines that the alternative S-NSSAI is unavailable but an additional alternative S-NSSAI is found, it may notify the AF of the additional alternative S-NSSAI in the above-mentioned report.

[0124] If the AMF / NSSF / PCF / SMF determines that the alternative S-NSSAI indicated by the information / notification received in the above-mentioned steps S103 / S202 / S302 is unavailable, the AMF / NSSF / PCF / SMF may skip the steps and send a report indicating that the alternative S-NSSAI is unavailable to the NEF in the above-mentioned steps S105 / S204 / S304. Note that if the alternative S-NSSAI is unavailable but an additional alternative S-NSSAI is found, the AMF / NSSF / PCF / SMF may notify the additional alternative S-NSSAI in the above-mentioned report. The NEF may send a report indicating that the alternative S-NSSAI is unavailable to the AF.

[0125] When the AF receives a report indicating the additional alternative S-NSSAI in steps S106 / S205 / S305, the AF may set the additional alternative S-NSSAI to the slice (alternative S-NSSAI) to which the AF is switching, and may again transmit the instruction / request in steps S102 / S201 / S301 to the NEF. Note that the report may also include a list (candidates) of additional alternative S-NSSAIs. In this case, the AF may select one additional alternative S-NSSAI from the list, set the selected additional alternative S-NSSAI to the slice (alternative S-NSSAI) to which the AF is switching, and again transmit the instruction / request in steps S102 / S201 / S301 to the NEF.

[0126] For example, the NEF may work in cooperation with the NSSF / PCF, etc. to determine that the alternative S-NSSAI indicated in the instruction / request received in the above-mentioned steps S102 / S201 / S301 is not available, and discover (determine) an additional alternative S-NSSAI.

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

[0128] If an additional alternative S-NSSAI is found, the subsequent steps may be performed by replacing the above-mentioned alternative S-NSSAI with the additional alternative S-NSSAI. Note that the NEF may send a report to the AF in steps S106 / S205 / S305 indicating that the alternative S-NSSAI was not available [and therefore switched to the slice of the additional alternative S-NSSAI].

[0129] According to the example described above, even if the designated switching destination slice is unavailable, control based on a slice switching instruction from an application can be performed based on another switching destination slice.

[0130] <Supplementary Information> In the above-described embodiments, slice switching is instructed / controlled, but the scope of the present disclosure is not limited to this. The slice in the above-described embodiments may be interchangeably read as a network slice instance (NSI) / network slice subnet instance (NSSI). In this case, the S-NSSAI (including S-NSSAI such as an alternative S-NSSAI) in the above-described embodiments may be interchangeably read as an NSI ID, an NSSI ID, or the like. In other words, the present disclosure may cover switching on a slice instance / slice subnet instance basis.

[0131] <Supplementary Notes> The following inventions are supplemented with respect to one embodiment of the present disclosure. [Supplementary Note 1] A communication device (e.g., an application server 10) that communicates with a terminal (e.g., a UE 40), comprising: a control unit that determines whether a condition for switching a logical network (e.g., a slice) between the terminal and the communication device is satisfied; and a communication unit that, when the condition is satisfied, transmits an instruction (e.g., a slice switching instruction) to switch the logical network to another logical network (e.g., another slice) to a second communication device (e.g., an API server 21) that exposes a network function (Network Function (NF)) of a physical network (e.g., 5GC) corresponding to the logical network to the outside. [Supplementary Note 2] The communication device according to Supplementary Note 1, wherein the condition includes being met at a specific time or during a specific time period. [Supplementary Note 3] The communication device according to Supplementary Note 1 or Supplementary Note 2, wherein the condition includes being met when the terminal enters a specific area, leaves the specific area, or is within the specific area. [Supplementary Note 4] The communication device according to any one of Supplementary Notes 1 to 3, wherein the communication unit receives, from the second communication device, information indicating another available logical network (e.g., an additional alternative S-NSSAI) when the other logical network is unavailable after transmitting the instruction. [Supplementary Note 5] The communication device according to any one of Supplementary Notes 1 to 4, wherein the instruction includes information (e.g., timing information) regarding timing for switching the logical network slice to the other logical network. [Supplementary Note 6] A communication device (e.g., API server 21), comprising: 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., UE 40) and a second communication device (e.g., application server 10) to another logical network (e.g., another slice); and a transmitting unit that transmits the information indicating the other logical network (e.g., an alternative S-NSSAI) to a third communication device (e.g., AMF / NSSF / PCF / SMF).[Supplementary Note 7] The communication device according to Supplementary Note 6, wherein the third communication device triggers a network slice replacement procedure (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 communication device according to Supplementary Note 6 or Supplementary Note 7, wherein the third communication device 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 for a communication device that communicates with a terminal, comprising: determining whether a condition for switching the logical network between the terminal and the communication device is satisfied; and, if the condition is satisfied, transmitting an instruction to switch the logical network to the other logical network to a second communication device that exposes a network function (NF) of a physical network corresponding to the logical network to the outside. [Supplementary Note 10] A terminal (e.g., UE 40) that communicates with a communication device (e.g., application server 10), the terminal having: a communication unit that transmits specific information (e.g., a message indicating that autonomous driving of a moving body including UE 40 is difficult), and a control unit that controls communication with the communication device using another logical network (e.g., another slice) instead of the logical network when a condition for switching a logical network (e.g., slice) between the terminal and the communication device based on the specific information is satisfied. [Supplementary Note 11] A communication system including the communication device described in any of Supplementary Notes 1 to 8 and the terminal described in Supplementary Note 10.

[0132] <Modifications> Note that terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings.

[0133] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be read interchangeably.

[0134] The information, parameters, etc. described in the present disclosure may be expressed using absolute values, relative values ​​from a predetermined value, or other corresponding information. For example, a radio resource may be indicated by a predetermined index.

[0135] The names used for parameters and the like in this disclosure are not limiting in any way, and furthermore, the mathematical formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure.

[0136] The information, signals, etc. described in this disclosure may be represented using any of a variety of 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 voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, optical fields or photons, or any combination thereof.

[0137] Input and output information, signals, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. Input and output information, signals, etc. may be overwritten, updated, or added. Output information, signals, etc. may be deleted. Input information, signals, etc. may be transmitted to another device.

[0138] Any information described in the present disclosure (e.g., information related to any parameter / variable) may be communicated between any devices in the present disclosure. Furthermore, in the present disclosure, communication of information is not limited to the aspects / embodiments described in the present disclosure, and may be performed using other methods.

[0139] Furthermore, notification of specified information (e.g., notification that "it is X") is not limited to explicit notification, but may be made implicitly (e.g., by not notifying the specified information or by notifying other information).

[0140] Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

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

[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 this disclosure, the terms "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, device, transmitting device, receiving device, wireless communication device, information processing device, etc., and these terms may be interchangeable. Any device in the present disclosure may be a device mounted on a moving object, which is a movable object, a device contained within the moving object (held by a person riding the moving object), or the moving object itself. Examples of such moving objects include, but are not limited to, vehicles, transport vehicles, automobiles, motorcycles, bicycles, connected cars, excavators, bulldozers, wheel loaders, dump trucks, forklifts, trains, buses, handcarts, rickshaws, ships and other watercraft, airplanes, rockets, satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. Furthermore, such moving objects may be autonomous / automatically driven. Note that the term "moving object" in the present disclosure may be interchangeable with a non-moving object (e.g., a non-moving object that a person can ride on).

[0145] Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, the order of the processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in this disclosure may be changed unless inconsistent. For example, the methods described in this disclosure present elements of various steps using an example order, and are not limited to the particular order presented.

[0146] As used in this disclosure, the phrase "based on" does not mean "based only on," unless expressly stated otherwise. In other words, the phrase "based on" means both "based only on" and "based at least on."

[0147] As used in this disclosure, any reference to an element using a designation such as "first," "second," etc. does not generally limit the quantity or order of those elements. These designations may be used in this disclosure as a convenient method of distinguishing between two or more elements. Thus, a reference to a first and a second element does not imply that only two elements may be employed or that the first element must in some way precede the second element.

[0148] As used in this disclosure, the terms "connected," "coupled," or any variation thereof, refer to any direct or indirect connection or coupling between two or more elements, and may include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements may be physical, logical, or a combination thereof. The coupling or connection between elements may be via wired and / or wireless connections.

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

[0150] When the terms "include," "including," and variations thereof are used in this disclosure, these terms are intended to be inclusive, similar to the term "comprising." Furthermore, when the term "or" is used in this disclosure, it is not intended to be an exclusive or.

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

[0152] In the present disclosure, terms such as "decide," "judge," "determine," "select," "calculate," "calculate," "process," "derive," "search," "confirm," "assume," and "expect" may be read interchangeably.

[0153] In the present disclosure, terms such as "less than or equal to," "less than," "greater than," "more than," "equal to," etc. may be interchangeable. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative. Furthermore, in the present disclosure, terms meaning "good," "bad," "big," "small," "high," "low," "fast," "slow," "wide," "narrow," etc. may be interchangeable, not limited to the positive, comparative, and superlative, as expressions with "i-th" (i is an arbitrary integer) attached (for example, "highest" may be interchangeable with "i-th highest").

[0154] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0155] Although the invention according to the present disclosure has been described in detail above, it is clear 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 only and does not impose any limiting meaning on the invention according to the present disclosure.

[0156] This application is based on Japanese Patent Application No. 2023-220630, filed December 27, 2023, the contents of which are incorporated herein in their entirety.

Claims

1. A communication device that communicates with a terminal, the communication device comprising: 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 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.

2. The communication device according to claim 1, wherein the condition includes that a specific time has come 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, comprising: 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; and a transmitting unit that transmits information indicating the other logical network to a third communication device.

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, the method comprising: determining whether a condition for switching a logical network between the terminal and the communication device is satisfied; and when the condition is satisfied, sending an instruction to switch the logical network to another logical network to a second communication device for exposing a network function (Network Function (NF)) of a physical network corresponding to the logical network to the outside.

10. A terminal that communicates with a communication device, the terminal comprising: a communication unit that transmits specific information; and a control unit that controls to communicate with the communication device using another logical network instead of the logical network when a condition for switching the logical network between the terminal and the communication device based on the specific information is satisfied.

11. A communication system including the communication device according to claim 1 and the terminal according to claim 10.

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