Management device and method

Abstract

To appropriately suppress waste of network (NW) resources and appropriately reduce throughput degradation, when a plurality of NWs are available.SOLUTION: A management device according to an aspect of the present disclosure includes a communication unit that communicates with at least one of a first cellular network (NW) and a second cellular NW, and a control unit that performs control to release management information about the first cellular NW related to a terminal when the terminal that has been communicating with the first cellular NW starts communicating with the second cellular NW before a normal termination process of the communication is performed.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a management apparatus and method in a mobile communication system. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP (registered trademark)), a standardization project for mobile communication systems, has established standards for 5th generation mobile communication systems (5G), which stipulate cooperation between different networks (Networks (NW)).

[0003] For example, Non-Patent Documents 1 and 2 specify handover between Evolved Packet System (EPS) and 5G System (5GS), handover of Protocol Data Unit (PDU) sessions between 3GPP access and non-3GPP access, and the like, as switching of communications between different networks. [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] 3GPP TS 23.501 V18.3.0 (2023-09) “System architecture for the 5G System (5GS); Stage 2 (Release 18)” [Non-patent document 2] 3GPP TS 23.502 V18.3.0 (2023-09) “Procedures for the 5G System (5GS); Stage 2 (Release 18)” Summary of the Invention [Problem to be solved by the invention]

[0005] When handover between different networks is performed properly, resources for communication in the network before switching are released properly.

[0006] However, in the current 3GPP standard, for example, when a user equipment (UE) communicating on a certain network experiences a communication problem (e.g., the user equipment is unable to connect due to a failure) and switches to communication on another network, the resources for communication on the certain network are not released. In this case, there is a risk that the resources will be wasted and that the throughput of the entire system will not be improved.

[0007] Therefore, one of the objects of the present disclosure is to provide a management device and method that can appropriately suppress waste of network resources and appropriately suppress a decrease in throughput when multiple networks are available. [Means for solving the problem]

[0008] A management device according to one embodiment of the present disclosure includes a communication unit that communicates with at least one of a first cellular network (Network (NW)) and a second cellular NW, and a control unit that performs control to release management information about the first cellular NW related to a terminal that has been communicating with the first cellular NW when the terminal starts communicating with the second cellular NW before the normal termination process of the communication is performed. [Effects of the Invention]

[0009] According to one aspect of the present disclosure, when multiple networks are available, it is possible to appropriately suppress waste of network resources and appropriately suppress a decrease in throughput. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a diagram illustrating an example of a schematic configuration of a system according to an embodiment of the present disclosure. [Figure 2] FIG. 2 is a diagram illustrating an example of a schematic functional configuration of each device according to an embodiment of the present disclosure. [Figure 3] FIG. 3 is a diagram illustrating an example of a schematic hardware configuration of each device according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a diagram illustrating an example of deleting unnecessary management information when switching networks according to an embodiment of the present disclosure. [Figure 5] FIG. 5 is a diagram illustrating an example of a control procedure related to the deletion of MA PDU session information of a pre-switching NW according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0011] 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.

[0012] <Explanation of replacement> In this disclosure, words enclosed in "()" in a sentence may indicate an explanation of the immediately preceding wording (for example, an explanation of spelling), a paraphrase, a specific example, a supplementary explanation, etc. Also, in this disclosure, words enclosed in "[ ]" in a sentence may be interpreted including the meaning of the entire sentence, or may be interpreted excluding the meaning of the entire sentence (ignoring the meaning of the entire sentence). Note that "()" and "[ ]" may also be used for purposes / meanings other than those mentioned above.

[0013] 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."

[0014] In the present disclosure, the NF may, for example, include at least one of the following: Application Function (AF) (e.g., a function that realizes an application server outside the 5G Core Network (5GC)), Access and Mobility management Function (AMF) (e.g., functions to manage UE registration, location, etc.), Data Network (DN) (e.g., the function to realize a data network outside 5GC), Location Management Function (LMF) (e.g., communication control function related to location-based services), Non-3GPP Inter-Working Function (N3IWF) (e.g., function connecting untrusted non-3GPP access networks with 5GC), Network Exposure Function (NEF) (e.g., a function that provides an application interface for 5GC NF services to the outside world), Network Slice Selection Function (NSSF) (e.g., the function that selects the network slice), Network Data Analytics Function (NWDAF) (e.g., a function for analyzing network data), Operation, Administration and Maintenance (Management) (OAM) (e.g., functions that provide the means for operation, maintenance and management), Policy Control Function (PCF) (e.g., a function that controls the quality of data transfer paths, policies, etc.), Session Management Function (SMF) (e.g., a function that manages a session), Trusted Non-3GPP Gateway Function (TNGF) (e.g., a function that connects trusted non-3GPP access networks with 5GC), Trusted WLAN Interworking Function (TWIF) (e.g., for non-5G UEs, connecting trusted non-3GPP access networks with 5G via a Wireless Local Area Network (LAN)), (Radio) Access Network ((R)AN) (e.g., the functionality that provides the radio access network), User Equipment (UE) (e.g., user access to network services over the radio interface), Unified Data Management (UDM) (e.g., the ability to store and manage subscriber information, UE authentication information, etc.), Unified Data Repository (UDR) (e.g., the ability to manage authentication / authorization based on subscriber information), User Plane Function (UPF) (e.g., the function that carries packets of user data).

[0015] It should be understood that these are merely examples and that other NFs are also covered by the present disclosure.

[0016] In this disclosure, terms such as switch, relocation, update, replace, modify, transfer / migrate, etc. may be read interchangeably.

[0017] <Task analysis> As described above, in the current 3GPP standard, for example, when a UE communicating on one network switches to communication on another network, resources for communication on the one network may not be released. In this case, resources may be wasted and the throughput of the entire system may not be improved.

[0018] Therefore, the present inventors have conceived a management device and method for appropriately releasing resources in the above case.

[0019] <System configuration> 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 a management device 10, a network function (NF) server 20, a base station (BS) 30, user equipment (UE) 40, and an access point (AP) 50. The system 1 may also be referred to as a wireless communication system, an information communication system, or the like.

[0020] 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).

[0021] Note that system 1 is not limited to this example, and may also 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.

[0022] In other words, terms related to 5G in this 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 that of 5G NF (or a device having a similar function).

[0023] In the system 1, a UE 40 receives wireless communication services using a Home Public Land Mobile Network (HPLMN) 1000, a Visited PLMN (VPLMN) 2000 / 2001, and the like.

[0024] The VPLMNs 2000 and 2001 each correspond to a cellular network to which a UE managed by the management device 10 can connect. Hereinafter, the VPLMNs 2000 and 2001 are also referred to as the first cellular network and the second cellular network, respectively. Note that the communications carrier (which may also be referred to as an operator, carrier, administrator, etc.) of the second cellular network may be different from or the same as the communications carrier of the first cellular network.

[0025] The HPLMN 1000 corresponds to a network separate from the first cellular network and the second cellular network. Hereinafter, the HPLMN 1000 is also referred to as the third network. The third network may include a cellular network or a non-cellular network. If the third network includes a cellular network, its telecommunications carrier may be the telecommunications carrier of the first cellular network / second cellular network, or may be a different carrier from either of them (for example, a mobile virtual network operator (MVNO)) that provides services using the communication lines of the telecommunications carrier of the first cellular network / second cellular network). In the latter case, the MVNO may correspond to a full MVNO. In this disclosure, the term HPLMN may be interchangeable with the term Equivalent HPLMN (EHPLMN).

[0026] It should be noted that the HPLMN 1000, VPLMN 2000, and VPLMN 2001 in this disclosure do not necessarily correspond to HPLMN / VPLMN, and may be replaced with networks of any name / function.

[0027] In this disclosure, the cellular network may be interchangeably read as a mobile network, a wireless communication network, a 5G core network (5G Core Network (5GC)), a 3GPP access network, etc. The 5GC may include, for example, an optical fiber network. In this disclosure, the non-cellular network may be interchangeably read as a non-3GPP access network.

[0028] In system 1, the communication link going to (receiving from) BS30 (AP50) / going out (transmitting from) UE40 may be referred to as the uplink (UL), and the communication link going out (transmitting from) BS30 (AP50) / going out (receiving from) UE40 may be referred to as the downlink (DL).

[0029] The management device 10 may manage the mobility, sessions, authentication, contracts, communication control, etc. of the UE 40, and may also manage information related thereto (for example, parameters, logs). For example, the management device 10 may perform control related to management information (described later) about the first cellular NW / second cellular NW / third NW related to the UE 40. The management device 10 may be operated / managed by at least one of the telecommunications carriers of the first cellular NW / second cellular NW / third NW. The management device 10 may be configured (stored) in advance with information about the UE 40 to be managed.

[0030] The management device 10 may correspond to the above-mentioned PCF / UDM / UDR, etc., defined for 5GC. Although shown separately in FIG. 1 for convenience of explanation, the management device 10 and one or more NF servers 20 (for example, SMF / AMF / UPF) may correspond to a single server. Furthermore, the management device 10 may be a device capable of transmitting instructions to the PCF / UDM / UDR / SMF / AMF / UPF, etc., to perform control related to management information.

[0031] 1, the management device 10 is located within the HPLMN 1000, but is not limited to this. For example, the management device 10 may be located within the VPLMN 2000 / VPLMN 2001, or may be located in a network outside the HPLMN 1000, VPLMN 2000, and VPLMN 2001.

[0032] The NF server 20 provides at least one function of the above-mentioned NF. In FIG. 1, an NF server 20 that provides an AMF, an NF server 20 that provides an SMF, an NF server 20 that provides a UPF, etc. are shown. Note that other NF servers 20 may be included in each NW. In the present disclosure, the NF server 20 and the NF (e.g., AMF, SMF, UPF, etc.) are interchangeable.

[0033] In the present disclosure, some or all of the NF servers 20 that are normally present in a certain network may be present outside the network. Also, the NF servers 20 present outside a certain network (e.g., VPLMN 2000 or VPLMN 2001) may provide NF / wireless communication services in the network by communicating with the NF servers 20 in the network.

[0034] Note that the NFs in the HPLMN 1000 may be referred to as H-NFs (e.g., H-SMF, H-UPF, H-PCF), and the NFs in the VPLMNs 2000 and 2001 may be referred to as V-NFs (e.g., V-SMF, V-UPF, V-PCF). The H-NFs and V-NFs may be connected to transmit signals. For example, a signal transmitted from the UE 40 may be transmitted to the DN via the BS 30, the V-UPF of the VPLMN 2000, and the H-UPF of the HPLMN 2000.

[0035] 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 this disclosure, the terms BS and (Radio) Access Network ((R)AN) may be interpreted as interchangeable.

[0036] 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).

[0037] The AP 50 performs non-cellular NW communication with the UE 40. In the present disclosure, the non-cellular NW may include, for example, a wireless local area network (LAN) such as Wi-Fi (registered trademark) or Bluetooth (registered trademark).

[0038] If the AP 50 provides untrusted non-3GPP access, the AP 50 may connect to the AMF of the HPLMN 1000 via the N3IWF.

[0039] If the AP 50 corresponds to a trusted non-3GPP AP (Trusted Non-3GPP Access Point), it may cooperate with a TNGF or TWIF node to provide a trusted non-3GPP access (Trusted Non-3GPP Access Network (TNAN)). In this case, the AP 50 may be connected to the AMF of the HPLMN 1000 via the node. The AP 50 may also include the node.

[0040] The UE 40 connects to the above-mentioned RAN / non-cellular NW. 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, may be the moving object itself, or may be a device included in the moving object (held by a person riding in the moving object).

[0041] The UE 40 may be able to use (or may be equipped with) separate Subscriber Identity Modules (SIMs) / Embedded SIMs (eSIMs) for the respective carriers of the first cellular network, the second cellular network, and / or the third network. The UE 40 may also switch its connection to different networks by switching an Access Point Name (APN) configuration profile.

[0042] 1 may be called a network node, a node, a server, 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).

[0043] <Configuration of each device> An example of the configuration of each device (the management device 10, the NF server 20, the BS 30, the UE 40, and the AP 50) according to an embodiment of the present disclosure will be described.

[0044] <<Function configuration>> 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 management device 10 includes a control unit 110, a communication unit 120, an input / output unit 130, and a storage unit 140.

[0045] Note that the NF server 20, BS 30, UE 40, and AP 50 may also have similar functional configurations. For this reason, in Fig. 2, the reference numerals of the functional blocks corresponding to each device are also shown in which the highest digit of the reference numeral representing each device (for example, for BS 30, the highest digit of "30" is "3") is replaced with "1". Below, the functional blocks relating to the management device 10 will be described, but it will be understood that the same description applies to other devices.

[0046] 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.

[0047] The control unit 110 controls the management device 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.

[0048] 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.

[0049] 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 input of data. The input unit may output the input result to the control unit 110, for example.

[0050] 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 be configured to include a display unit that displays images, an audio output unit that outputs audio, etc.

[0051] The storage unit 140 stores (holds) various pieces of information used in the processing by the management device 10. The control unit 110 may instruct the storage unit 140 to read and write data.

[0052] <<Hardware configuration>> 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 910, a radio frequency (RF) circuit 920, a processor 930, a network interface 940, an input device / output device 950, a memory 960, and a storage 970.

[0053] For example, the above-mentioned control unit X10 (X=1, 2, 3, 4, 5; the same applies below) may be implemented by the processor 930. The communication unit X20 may be implemented by the antenna 910 / RF circuit 920 / network interface 940. The input / output unit X30 may be implemented by the input device / output device 950. The storage unit X40 may be implemented by the memory 960 / storage 970.

[0054] 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 940.

[0055] The antenna 910 converts signals into radio waves and radiates the radio waves into space. The antenna 910 also receives radio waves in space and converts the radio waves into signals. Multiple antennas 910 may be installed, may include a transmitting antenna and a receiving antenna, or may include a single antenna for both transmission and reception. The antenna 910 may include a directional antenna or may include multiple antenna elements.

[0056] The RF circuitry 920 performs analog processing of signals transmitted and received via the antenna 910. The RF circuitry 920 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, etc.

[0057] The RF circuit 920 may perform amplification, filtering, demodulation to a baseband signal, etc. on the received radio frequency band signal, and output the signal to the processor 930. The RF circuit 920 may perform modulation to a radio frequency band, filtering, amplification, etc. on the baseband signal input from the processor 930, and transmit the radio frequency band signal via the transmitting / receiving antenna 910. Note that the RF circuit 920 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.

[0058] The processor 930 may control the entire device. The processor 930 may read programs (program codes), software (software modules), data, etc. from the storage 970 into the memory 960 and execute various processes in accordance with these. For example, the processor 930 may execute a program of an operating system (OS) loaded into the memory 960 to perform control.

[0059] The processor 930 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control unit, an arithmetic unit, registers, etc. The processor 930 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.

[0060] The processor 930 may perform digital processing of signals transmitted and received via the antenna 910 and the RF circuitry 920. 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 930 also processes signals transmitted and received via the network interface 940.

[0061] Processor 930 may include multiple processors or may be a single processor, which may include a baseband processor that performs the digital processing described above and one or more processors that perform other processing (e.g., overall control).

[0062] The network interface 940 may be, for example, a network adapter, which is connected to an external network via a wired connection and may transmit and receive signals.

[0063] The RF circuit 920, the baseband processor, and the network interface 940 may be integrated into one unit, and may be called a network controller, a network card, a communication module, or the like.

[0064] The input device / output device 950 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).

[0065] The memory 960 is a computer-readable non-transitory recording medium that stores programs executed by the processor 930, parameters related to the programs, and various other information. The memory 960 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 portion of the memory 960 may be included within the processor 930. The memory 960 may also be called a register, a cache, a main memory, etc.

[0066] Storage 970 is a computer-readable non-transitory recording medium that stores various information. Storage 970 may include, for example, at least one of a flexible disk, a floppy 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 disk drive (HDD), a smart card, a flash memory device (e.g., a solid state drive (SSD)), and the like. Storage 970 may also be referred to as an auxiliary storage device.

[0067] Furthermore, each device such as the processor 930, the memory 960, etc. 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.

[0068] 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), Service Data Adaptation Protocol (SDAP), and Radio Resource Control (RRC) layer functions.

[0069] In the present disclosure, BS30 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.

[0070] 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 management device 10, the NF server 20, the BS 30, and the AP 50) may be implemented as a single device.

[0071] Furthermore, some or all of the devices disclosed herein may refer to logical devices realized by virtual machines, containers, Docker, etc., or physical devices that operate the logical devices.

[0072] <Example of operation> 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.

[0073] In the following description of the present disclosure, reference numerals may be omitted. For example, the UE in the following description may refer to the UE 40.

[0074] Each device / function in the following description may be mutually replaced with one or more functional blocks (e.g., control unit 110, communication unit 120) or hardware configurations (e.g., RF circuit 920, processor 930) within the device / function.

[0075] <<Deletion of Unnecessary Management Information during NW Switching>> FIG. 4 is a diagram showing an example of deletion of unnecessary management information during NW switching according to an embodiment of the present disclosure. In this example, in the above-described system 1, a case where the UE switches from communication with the first cellular NW to communication with the second cellular NW will be described. Note that FIG. 4 is described with some of the devices of the system 1 shown in FIG. 1 omitted.

[0076] In step S101, the UE that is the management target of the management device starts communication in the first cellular NW.

[0077] In the present disclosure, the start of communication may mean that at least one of the following is performed: · Registration / re-registration (which may also be called registration update) of the UE, · Transition from an idle (which may also be called Idle, RRC IDLE, etc.) / inactive (which may also be called Inactive, RRC INACTIVE, etc.) state to an active (which may also be called Active) / connected (which may also be called Connected, RRC CONNECTED, etc.) state, · Connection establishment (e.g., PDU session establishment, etc.), · Connection modification (e.g., PDU session modification, etc.).

[0078] In step S102, the management device stores management information about the first cellular NW for the UE of step S101. Step S102 may be included in the start procedure of step S101.

[0079] The management information in the present disclosure may be information related to at least one of mobility, session, authentication, contract, communication control, log, etc., and may include, for example, session information, authentication information, contract information, Quality of Service (QoS) information, slice information, etc. Note that the management information may be stored in, for example, PCF / UDM / UDR / SMF / UPF / AMF / RAN.

[0080] In the present disclosure, the terms session, PDU session, Multi-Access (MA) PDU session, etc. may be interchangeable. Note that a PDU session may refer to an association between a UE and a DN that provides a PDU connection service. Also, an MA PDU session may refer to a PDU session having user plane resources in two networks. Here, the two networks may be two access networks, one access network and one non-access network, or two non-access networks. The MA PDU session may be related to Access Traffic Steering, Switching and Splitting (ATSSS).

[0081] The session information may include at least one of a session identifier (ID), a session type, a context associated with the session (e.g., context information associated with a particular NF, such as RAN / AMF / SMF / UPF), etc.

[0082] The authentication information / contract information may also be, for example, information regarding the authentication / contract of a subscriber managed by the UDM.

[0083] The QoS information may also include at least one of information about the QoS flow, information about the bearer, a 5G QoS Identifier (5QI), a QoS Class Identifier (QCI), and the like.

[0084] Furthermore, the slice information may be an identifier related to the slice, and may include, for example, at least one of Single Network Slice Selection Assistance Information (S-NSSAI), Slice and Service Type (SST), Dedicated Core Network ID (DCN ID), etc. The slice in the present disclosure may be interchangeably read as a Network Slice Instance (NSI) / Network Slice Subnets Instance (NSSI). In this case, the S-NSSAI may be interchangeably read as an NSI ID, an NSSI ID, etc.

[0085] The management information may be stored / managed in association with information for identifying the UE to be managed (which may be called UE information), information for identifying the cellular network to be managed (which may be called NW identification information), etc.

[0086] 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, Information about the SIM / eSIM used by (or installed in) the UE (e.g., Integrated Circuit Card Identifier (ICCID), Embedded Identity Document (EID)), Any other identifier for identifying the UE (for example, the UE's telephone number itself or information related to the telephone number (for example, Mobile Station International Subscriber Directory Number (MSISDN))).

[0087] The NW specific information may include at least one of the following: Serving NW information (e.g., PLMN-ID, Network ID (NID)), Information on the SIM / eSIM used by (or installed in) the UE (e.g., ICCID, EID).

[0088] The management information in the present disclosure may be used for, for example, UE contract and policy information in UDM / PCF, for access / mobility management in AMF, or for session establishment / modification in SMF. In the present disclosure, the management information may be interchangeably read as a resource related to the management information.

[0089] In step S103, the UE starts communication through a second cellular network different from the first cellular network.

[0090] Step S103 may be performed when a normal termination process of communication is not performed (or before the normal termination process is performed) for the first cellular network. Here, the normal termination process may mean that one or more of the following are performed: UE deregistration, transitions from an active / connected state to an idle / inactive state, Connection termination / resource release (e.g. PDU Session release).

[0091] For example, the UE may be performing a process of switching to communication via the second cellular network in step S103 when the communication via the first cellular network becomes unsuccessful (for example, the connection cannot be established due to a communication failure). In the present disclosure, the term "determined that the communication has become unsuccessful (or is likely to become unsuccessful)" may be interpreted interchangeably as "determined that a switch is necessary." The UE may determine that the communication has become unsuccessful.

[0092] For example, if communication (response) from a BS in a first cellular network is not detected for a certain time / a certain number of times [despite uplink transmission to the BS], the UE may determine that communication with the BS has malfunctioned. Also, if the received power / reception quality of a signal (e.g., a specific reference signal) from a BS in the first cellular network is below a threshold for a certain time / a certain number of times, the UE may determine that communication with the BS has malfunctioned. Also, if specific information (e.g., information indicating that a communication failure has occurred or is about to occur, information indicating the need to switch networks, etc.) is notified [via the first cellular network / third network], the UE may determine that communication via the first cellular network has malfunctioned.

[0093] In step S104, the management device stores management information about the second cellular network for the UE. Step S104 may be included in the start procedure in step S103.

[0094] In step S104, if management information for the first cellular NW remains, the management information for the second cellular NW may be determined (applied) based on the management information for the first cellular NW. In other words, the management information for the first cellular NW may be applied to communication of the second cellular NW. This allows old management information to be applied (reused) to new management information, reducing the load on the management device involved in generating / determining the management information and speeding up the generation / determination of the management information. For example, at least a portion of the management information for the second cellular NW may be the same as at least a portion of the management information for the first cellular NW (e.g., using the same values), or may be derived by expanding / modifying / changing / scaling at least a portion of the management information.

[0095] In step S104, the management device may reflect the management information about the first cellular network in the contract / policy information (UDM / PCF) of the UE in the second cellular network, or in the session establishment / modification (SMF).

[0096] In the present disclosure, the fact that management information remains may mean that the management information is stored (retained) in any NF of the first cellular network / second cellular network / third network.

[0097] In step S105, if management information about the first cellular network remains for the UE, the management device may perform control to release the management information (e.g., processing the release, sending an instruction to release, etc.).

[0098] In step S105, the management device may release the management information stored in any NF (or the management device itself) in the third NW. In the present disclosure, the management device may transmit an instruction to the NFs in the first cellular NW / second cellular NW in addition to / instead of the NFs in the third NW (or the management device itself) to cause them to perform control related to the above management information (control for release / establishment (or re-establishment) as described above), and cause them to perform the control. In the present disclosure, "releasing management information of a certain NW," "sending an instruction to a device (such as an NF) in a certain NW to release management information," etc. may be read interchangeably.

[0099] Like step S103, step S105 may be performed when normal termination processing of communication is not performed (or before it is performed) for the first cellular network. Furthermore, for example, there may be a restriction that the first cellular network and the second cellular network are not used simultaneously for the UE. In this case, the management device may release the management information for the first cellular network upon storing the management information for the second cellular network in step S104.

[0100] In addition, the management device may determine that management information regarding the first cellular network remains for the UE, for example, by detecting that specific information (e.g., information indicating a cellular network switch) is included in a request for connection establishment (e.g., PDU session establishment) from the V-SMF of the second cellular network, and may release the management information.

[0101] In step S105, the management device may release management information related to communication using the first cellular network and the third network (note that this communication has started before step S103) for the UE. For example, the communication may be communication according to at least one of ATSSS, carrier aggregation, dual connectivity, etc.

[0102] In the present disclosure, the release of management information for a certain network related to a certain UE may mean the release of all of the management information, or may mean the release of only a part of the management information (e.g., mobility / session information). Furthermore, the release of management information for a certain network related to a certain UE may mean the release of the management information in all NFs / management devices in the network (or related to the network), or may mean the release of the management information in some NFs / management devices in the network (related to the network).

[0103] In step S105, for example, the management device may release, for the UE, MA PDU session information related to the first cellular NW and the third NW. The management device may perform control for releasing the MA PDU session across the first cellular NW and the third NW (e.g., invoking a service operation of Session Management (SM) context update for the PDU session (in the case of the management device as an AMF) or releasing the MA PDU session (in the case of the management device as an SMF)) for the UE.

[0104] In this disclosure, the release of an MA PDU session across the first cellular network and the third network may be interpreted as the complete release of the MA PDU session, or as the release of the MA PDU session on the first cellular network (single access). In the latter case, the MA PDU session on the third network may be maintained.

[0105] In step S105, control may be performed to establish (or re - establish) a MA PDU session spanning the second cellular NW and the third NW for the above - mentioned UE. For example, a management device (or PCF / UDM) may perform control to establish (or re - establish) a MA PDU session spanning the second cellular NW and the third NW for the above - mentioned UE (for example, trigger the establishment (or re - establishment)), send information / instructions for performing the above - mentioned control to the SMF, and the SMF may perform the above - mentioned control.

[0106] Note that in steps S103 to S105, for example, if an irregular event such as an accident occurs (for example, the start of communication with the second cellular NW in step S103 fails), the management device may release the management information regarding the first cellular NW if such management information remains for the above - mentioned UE.

[0107] According to the operation examples described above, for example, even if normal termination processing of communication is not performed in a certain cellular NW, resources regarding the cellular NW can be appropriately released with the start of communication with another cellular NW, and the network resources can be made to have a margin. Also, according to the above - mentioned operation examples, it is possible to preferably suppress the situation where the remaining management information in the NW before switching (where normal termination processing of communication was not performed) has an unfavorable influence on a specific communication function (for example, ATSSS (MA PDU session) described later).

[0108] <<Control Procedure for Deletion of MA PDU Session Information>> As a more specific example of the deletion of unnecessary management information during the above - mentioned NW switching, the control procedure for the deletion of the MA PDU session information of the NW before switching in the system configuration of FIG. 1 will be shown below.

[0109] 5 is a diagram illustrating an example of a control procedure related to deletion of MA PDU session information of a pre-switching network according to an embodiment of the present disclosure. Fig. 5 is an excerpt of the first eight steps of Figure 4.3.2.2.2-1: UE-requested PDU Session Establishment for home-routed roaming scenarios in Non-Patent Document 2.

[0110] First, the establishment of a normal PDU session shown in Figure 5 will be described. In step 1, a PDU session establishment request including a PDU session ID etc. is sent from the UE to the AMF. In step 6, the V-SMF sends a PDU session creation request (Nsmf_PDUSession_Create Request) to the H-SMF. In step 7, if the session management subscription data corresponding to the information included in the request (e.g., SUPI) is not available, the H-SMF may obtain this data from the UDM ( / UDR). In step 8, a second authentication / authorization may be performed.

[0111] The MA PDU session establishment procedure is performed in a slightly modified manner from the normal PDU session establishment procedure. For example, in step 1, the UE provides a request type of "MA PDU Request" in the PDU session establishment request. In step 6, the V-SMF sends a request for creating an MA PDU session to the H-SMF (a request for creating a PDU session containing "MA PDU Request").

[0112] Now, let's return to the explanation of deleting unnecessary management information when switching networks. As a step for deleting MA PDU session information of the network before switching, after step 6 (for example, between steps 6 and 7), the H-SMF / H-PCF may determine whether or not MA PDU session information remains for a cellular network other than the cellular network corresponding to the request for the UE that is the target of the request for creating an MA PDU session, and if so, release the MA PDU session information. Note that the above deletion step may be located before / after / during another step in the procedure for establishing an MA PDU session.

[0113] For example, consider a case where a UE is connected to a first cellular network (VPLMN 2000 in FIG. 1) and a third network (HPLMN 1000 in FIG. 1), and an MA PDU session has already been established across the first cellular network and the third network, but communication across the second cellular network is started without normal termination processing for the first cellular network. In this case, the VPLMN in FIG. 5 corresponds to the second cellular network (VPLMN 2001) in FIG. 1, and the HPLMN in FIG. 5 corresponds to the third network (HPLMN 1000) in FIG. 1. In this case, in the deletion step, the MA PDU session information across the first cellular network and the third network is released.

[0114] Furthermore, according to the MA PDU session establishment procedure that includes the above-mentioned deletion step, even if the management information of the first cellular network is not released when registering the UE to the second cellular network, the management information can be suitably released when the MA PDU session establishment procedure is performed.

[0115] According to the control procedure for deleting MA PDU session information described above, even if, for example, normal termination processing of an ATSSS (MA PDU session) using a certain cellular network is not performed, an ATSSS (MA PDU session) using another cellular network can be established.

[0116] In the existing ATSSS mechanism, only one MA PDU session can be used for one 3GPP access and one non-3GPP access, and if an MA PDU session remains before switching, the MA PDU session after switching cannot be used. According to the release of management information shown in this disclosure, even if switching occurs between networks of multiple communication operators, ATSSS with non-3GPP can be continued (or re-established), thereby achieving communication stability, high throughput, etc.

[0117] <Additional Notes> The following inventions are added regarding one embodiment of the present disclosure. [Appendix 1] a communication unit that communicates with at least one of a first cellular network (Network (NW)) and a second cellular network (NW); A management device having a control unit that performs control to release management information about the first cellular network related to a terminal when the terminal that was communicating on the first cellular network starts communicating on the second cellular network before the normal termination processing of the communication is performed. [Appendix 2] A management device according to Supplementary Note 1, wherein the management information about the first cellular network is information related to at least one of mobility, session, authentication, contract, and communication control. [Appendix 3] The management device according to claim 1 or 2, wherein the normal termination process includes deregistration of the terminal. [Appendix 4] A management device described in any one of Supplementary Note 1 to Supplementary Note 3, wherein the control unit determines management information for the second cellular network based on the management information for the first cellular network. [Appendix 5] A management device according to any one of Supplementary Note 1 to Supplementary Note 4, wherein the management information about the first cellular network includes information about a Multi-Access Protocol Data Unit (MA PDU) session. [Appendix 6] Communicating with at least one of a first cellular network (NW) and a second cellular network (NW); A method of a management device comprising: when a terminal that was communicating on the first cellular network starts communicating on the second cellular network before the communication is normally terminated, the method comprises a step of performing control to release management information about the first cellular network related to the terminal. [Appendix 7] The method described in Appendix 6, wherein the management information about the first cellular network is information related to at least one of mobility, session, authentication, contract, and communication control. [Appendix 8] 8. The method according to claim 6 or 7, wherein the normal termination process includes deregistration of the terminal. [Appendix 9] A method according to any one of Supplementary Notes 6 to 8, comprising a step of determining management information for the second cellular network based on the management information for the first cellular network. [Appendix 10] A method according to any one of Supplementary Note 6 to Supplementary Note 9, wherein the management information about the first cellular network includes information about a Multi-Access Protocol Data Unit (MA PDU) session.

[0118] <Modification> In addition, terms explained in this disclosure and terms necessary for understanding this disclosure may be replaced with terms having the same or similar meanings.

[0119] In the present disclosure, the terms apparatus, circuit, device, section, unit, etc. may be read interchangeably.

[0120] 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.

[0121] The names used for parameters and the like in this disclosure are not limiting in any way, and furthermore, the formulas and the like using these parameters may differ from those explicitly disclosed in this disclosure.

[0122] 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.

[0123] 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.

[0124] 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.

[0125] 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).

[0126] 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.

[0127] 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), then these wired and / or wireless technologies are included within the definition of transmission media.

[0128] 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.

[0129] In this disclosure, the terms "Mobile Station (MS)," "user terminal," "User Equipment (UE)," "terminal," etc. may be used interchangeably.

[0130] 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 body, 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, artificial satellites, drones, multicopters, quadcopters, balloons, and objects mounted thereon. The moving object may also be autonomous / automatically driven. Note that the term "moving object" in the present disclosure may be interchangeable with a non-moving object (e.g., an object that does not move but can be ridden by a person).

[0131] 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 specific order presented.

[0132] 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."

[0133] 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.

[0134] 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.

[0135] 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."

[0136] When used in this disclosure, the terms "include," "including," and variations thereof are intended to be inclusive, similar to the term "comprising." Furthermore, when used in this disclosure, the term "or" is not intended to be an exclusive or.

[0137] 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.

[0138] In the present disclosure, terms such as "decide," "judge," "determine," "select," "calculate," "calculate," "process," "derive," "search," "confirm," "assume," and "expect" may be read interchangeably.

[0139] 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 the prefix "i-th" (i is any integer) (for example, "highest" may be interchangeable as "i-th highest").

[0140] In this disclosure, the terms "of," "for," "regarding," "related to," "associated with," etc. may be read interchangeably.

[0141] 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.

Claims

1. a communication unit that communicates with at least one of a first cellular network (Network (NW)) and a second cellular network (NW); A management device having a control unit that performs control to release management information about the first cellular network related to a terminal when the terminal that was communicating on the first cellular network starts communicating on the second cellular network before the normal termination processing of the communication is performed.

2. The management device according to claim 1 , wherein the management information about the first cellular network is information related to at least one of mobility, session, authentication, contract, and communication control.

3. The management device according to claim 1 , wherein the normal termination process includes deregistration of the terminal.

4. The management device according to claim 1 , wherein the control unit determines management information for the second cellular network based on the management information for the first cellular network.

5. The management device according to claim 1 , wherein the management information about the first cellular network includes information about a Multi-Access Protocol Data Unit (MA PDU) session.

6. Communicating with at least one of a first cellular network (NW) and a second cellular network (NW); A method of a management device comprising: when a terminal that was communicating on the first cellular network starts communicating on the second cellular network before the communication is normally terminated, the method comprises a step of performing control to release management information about the first cellular network related to the terminal.

7. The method of claim 6 , wherein the management information about the first cellular network is information related to at least one of mobility, session, authentication, contract, and communication control.

8. The method of claim 6 , wherein the graceful termination process includes de-registration of the terminal.

9. The method of claim 6 , further comprising determining management information for the second cellular network based on the management information for the first cellular network.

10. The method according to any one of claims 6 to 9, wherein the management information for the first cellular network includes information of a Multi-Access Protocol Data Unit (MA PDU) session.

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