Terminal and Communication Method

Abstract

A terminal according to an aspect of this disclosure attempts to connect to a first network after a timer is stopped and includes: a reception unit that receives, from a second network, a connection allowance signal indicating allowance for connection to the first network; and a control unit that, when receiving the connection allowance signal, stops the timer in operation.

Description

[Technical Field]

[0001] The present disclosure relates to a terminal and a communication method. [Background technology]

[0002] The 3GPP (3rd Generation Partnership Project) has developed specifications for 5G (5th generation mobile communication system, also known as NR (New Radio) or NG (Next Generation)), and is also working on specifications for the next generation, known as Beyond 5G, 5G Evolution, or 6G.

[0003] In NR, a network architecture is being considered that includes a 5G core network (5GC: 5G Core Network) that corresponds to EPC (Evolved Packet Core), which is a core network in the network architecture of LTE (Long Term Evolution), and an NG-RAN (Next Generation - Radio Access Network) that corresponds to E-UTRAN (Evolved Universal Terrestrial Radio Access Network), which is a radio access network (RAN: Radio Access Network) in the network architecture of LTE (see Non-Patent Document 1). Note that 5GC and EPC may also be referred to as a core network or a network.

[0004] In the current 3GPP standard specifications, when the 5GC receives a registration request from a terminal (also referred to as a UE (User Equipment)) without a 5GC contract, it sends a Registration Reject signal to the terminal to allow it to camp only on the EPC side. In addition, the 5GC notifies the terminal of Cause #27 indicating the reason for the registration rejection (see Non-Patent Document 2). Cause #27 (N1 mode not allowed) is information indicating that "the N1 mode (5GC Capability) is not allowed". Note that "allowed" may be read as "permitted".

[0005] Upon receiving the Registration Reject signal (Cause #27), the terminal disables the N1 mode (5GC Capability), starts a timer, and connects to the EPC.

[0006] After that, when a 5GC contract is newly granted to the terminal, the terminal becomes connectable to the 5GC.

[0007] However, if the 5GC contract is granted during the timer countdown, the terminal cannot move to a cell under the 5GC until the timer expires and stops, or until the power is turned off and then turned on again.

[0008] As a solution to this problem, in order to accelerate the transition of the terminal to the 5GC cell, shortening the timer value or the 5GC instructing the timer value to the terminal has been proposed (see Non-Patent Document 3).

Prior Art Documents

Non-Patent Documents

[0009]

Non-Patent Document 1

Non-Patent Document 2

Non-Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0010] However, if the timer value is shortened, even when the terminal does not have a 5GC contract, the terminal will frequently attempt to connect to the 5GC. Also, since the EPC cannot predict when the 5GC contract will be granted to the terminal, it is difficult for the EPC to instruct the terminal of the timer value.

[0011] Also, in the case of a module type located in a remote area, etc., depending on the type of the terminal, it is difficult to manually turn off and on the power.

[0012] In view of the above, one aspect of the present disclosure provides a terminal and its communication method that can transition from a state where the terminal cannot connect to the 5GC (first network) to a state where it can connect, to the 5GC (first network) from the EPC (second network) at an appropriate timing.

Means for Solving the Problems

[0013] A terminal according to one aspect of the present disclosure is a terminal that attempts to connect to a first network after stopping a timer, and includes a receiving unit that receives a connection permission signal indicating permission to connect to the first network from a second network, and a control unit that stops the timer that is running when the connection permission signal is received.

[0014] A communication method according to one aspect of the present disclosure is a communication method of a terminal that attempts to connect to a first network after stopping a timer, and starts the timer when the connection to the first network is rejected, and stops the timer that is running when a connection permission signal indicating permission to connect to the first network is received from the second network. [Brief explanation of the drawings]

[0015] [Figure 1] A figure showing an example of an operation for transitioning a UE from 5GC to EPC when the UE cannot connect to 5GC. [Diagram 2] A figure showing an example of operation for a UE to transition from EPC to 5GC in accordance with an embodiment. [Figure 3] A figure showing an example of operation for a UE to transition from EPC to 5GC in accordance with an embodiment. [Figure 4] A figure showing an example of an operation in which a UE is caused to transition from 5GC to EPC when the UE cannot connect to 5GC, according to an embodiment. [Figure 5] A figure showing an example of operation for a UE to transition from EPC to 5GC in accordance with an embodiment. [Figure 6] FIG. 2 is a block diagram showing an example of a configuration of a terminal according to an embodiment. [Figure 7] FIG. 2 is a diagram illustrating an example of a hardware configuration of a terminal according to an embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment according to one aspect of the present disclosure will be described with reference to the drawings.

[0017] (Mobile communication system) As shown in FIGS. 1 to 5, the mobile communication system includes a terminal (hereinafter referred to as “UE”) 10, a 5GC 20, and an EPC 30.

[0018] The UE 10 connects to the 5GC 20 via the NG-RAN and connects to the EPC 30 via the E-UTRAN. In the NG-RAN, for example, a base station gNB for the 5GS (5G System) is arranged. In the E-UTRAN, for example, a base station eNB for the EPF (Evolved Packet System) is arranged.

[0019] 5GC20 includes, for example, an AMF (Access and Mobility Management Function), a UPF (User Plane Function), an SMF (Session Management Function), a PCF (Policy Control Function), and a UDM (Unified Data Management).

[0020] In the EPC 30, for example, an MME (Mobility Management Entity), an SGW (Serving Gateway), a PGW (Packet Data Network Gateway), a PCRF (Policy and Charging Rules Function), an HSS (Home Subscriber Server), etc. are arranged.

[0021] (operation) Below, an example of the operation of this embodiment will be described in which UE10 transitions from EPC30 to 5GC20 when it changes from a state where it cannot connect to 5GC20 to a state where it can connect. Note that "connection" may be read as "access." Furthermore, communication between UE10 and 5GC20 or EPC30 described below is performed via a base station, but to avoid redundant explanation, the base station and its operation will be omitted.

[0022] (Prerequisites) First, the operation of UE 10 that wishes to connect to 5GC and does not have a 5GC contract until it connects to EPC 30 will be described with reference to FIG. 1.

[0023] In step S101, the UE 10 transmits a registration request signal to the 5GC 20.

[0024] In step S102, the 5GC20 checks the contract details of the UE10, for example, by inquiring of a contract DB (Database).

[0025] If the confirmation result in step S102 shows that the 5GC contract has not been granted to the UE 10, in step S103, the 5GC 20 transmits a registration rejection signal (Registration Reject) to the UE 10. In addition, the 5GC notifies the terminal of Cause #27 indicating the reason for the registration rejection.

[0026] Upon receiving the registration rejection signal, UE10 disables the N1 mode (5GC capability) in step S104. Here, "disabling the N1 mode" may mean "turning off (the function of) the N1 mode." Conversely, "enabling the N1 mode" may mean "turning on (the function of) the N1 mode."

[0027] Next, in step S105, the UE 10 starts an implementation-dependent timer to keep the N1 mode disabled for a certain period of time.

[0028] In addition, in step S106, the UE 10 transmits an attach request signal to the EPC 30.

[0029] In step S107, the EPC 30 transmits an Attach Accept signal to the UE 10. Upon receiving the Attach Accept signal, the UE 10 transitions from the 5GC 20 to the EPC 30.

[0030] (Operations related to the present disclosure) Next, an example of operation according to the present disclosure will be described in which UE 10 transitions from EPC 30 to 5GC 20 when it changes from a state in which it cannot connect to 5GC 20 to a state in which it can connect.

[0031] (Example 1) Operation Example 1 is an example of introducing a new feature on the EPC30 side. In Operation Example 1, as described with reference to FIG. 1, it is assumed that the UE10 has started to deactivate the N1 mode triggered by the reception of Cause #27 (the timer is running). Hereinafter, Operation Example 1 will be described with reference to FIG. 2.

[0032] After step S107 in FIG. 1, in step S201, the EPC30 checks the grant of the 5GC contract for the UE10. This check may be performed, for example, by the EPC30 periodically polling the contract DB, or by the contract DB notifying the EPC30 of the grant of the 5GC contract when the 5GC contract is granted to the UE10.

[0033] When the EPC30 confirms that the 5GC contract has been granted to the UE10, in step S202, it transmits to the UE10 an N1 mode connection permission signal indicating that the connection of the UE10 to the 5GC20, which is a new feature, is permitted.

[0034] When the UE10 receives the N1 mode connection permission signal, in step S203, it stops the timer.

[0035] After that, the UE10 activates the N1 mode and attempts to connect to the 5GC20.

[0036] In this way, in Operation Example 1, after the EPC30 confirms that the 5GC contract has been granted to the UE10, that is, after the UE10 is in a state where it can connect to the 5GC20, the UE10 stops the timer in response to the reception of the N1 mode connection permission signal. As a result, the UE10 can transition from the EPC30 to the 5GC20 more timely without frequently attempting to connect to the 5GC20.

[0037] (Operation Example 2) Operation Example 2 is an example that extends Operation Example 1. Therefore, also in Operation Example 2, it is assumed that, as described with reference to FIG. 1, UE 10 has started to invalidate the N1 mode triggered by the reception of Cause #27 (N1 mode not allowed) (the timer is running). Hereinafter, Operation Example 2 will be described with reference to FIG. 3.

[0038] After step S107 in FIG. 1, in step S201, EPC 30 confirms the grant of a 5GC contract to UE 10.

[0039] Next, in step S301, EPC 30 confirms that UE 10 is present within a specific area based on information such as the location of UE 10 reported from UE 10, the capabilities of UE 10, and the slice used by UE 10. Note that the specific area may mean the area of a cell under 5GC or a narrower area within this area.

[0040] When it is confirmed that a 5GC contract has been granted to UE 10 and that UE 10 is present within the specific area, EPC 30 transmits an N1 mode connection permission signal to UE 10 in step S202.

[0041] When UE 10 receives the N1 mode connection permission signal, it stops the timer in step S203.

[0042] When the timer stops, UE 10 activates the N1 mode and attempts to connect to 5GC 20.

[0043] Thus, in Operation Example 2, after it is confirmed in the EPC 30 that a 5GC contract has been granted to the UE 10, that is, after the UE 10 has become capable of connecting to the 5GC 20, and after it is confirmed that the UE 10 is present within a specific area, the timer is stopped in response to the reception of the N1-mode connection permission signal. Thereby, the UE 10 does not need to perform an unnecessary search for a cell under the 5GC, and can transition from the EPC 30 to the 5GC 20 more timely without causing a significant increase in power consumption.

[0044] (Operation Example 3) Operation Example 3 is an example in which new features are introduced not on the EPC 30 side but on the UE 10 and 5GC 20 sides. In Operation Example 3, criteria for enabling the N1 mode are provided in advance when the UE 10 is in a state where it cannot connect to the 5GC 20 and is located in the EPC 30. The criteria are associated with existing elements of the EPC 30. For example, the criteria may be the case where the UE 10 receives a specific existing signal of the EPC 30, and the existing signal may be, for example, a Detach Request signal, but is not limited thereto. Note that the criteria may be read as standards, conditions, etc.

[0045] First, an operation example of causing the UE 10 to transition from the 5GC 20 to the EPC 30 when the UE 10 is in a state where it cannot connect to the 5GC 20, including the setting of criteria in the UE 10, will be described with reference to FIG. 4.

[0046] In step S101, the UE 10 transmits a registration request signal to the 5GC 20. In step S102, the 5GC 20 checks the contract details of the UE 10.

[0047] If the confirmation result in step S102 shows that the 5GC contract has not been granted to the UE 10, the 5GC 20 transmits a registration rejection signal with Cause #27 (N1 mode not allowed) together with the criteria to the UE 10 in step S103a. As a result, the criteria is set in the UE 10.

[0048] In response to receiving the registration rejection signal, the UE 10 disables the N1 mode in step S104, and starts a timer in step S105.

[0049] In addition, in step S106, UE 10 transmits an attach request signal to EPC 30. In step S107, EPC 30 transmits an attach accept signal to UE 10. As a result, UE 10 transitions from 5GC 20 to EPC 30.

[0050] Next, an example of operation for enabling the N1 mode when the criteria are met will be described with reference to Fig. 5. This example of operation is based on the premise that the UE 10 has transitioned from the 5GC 20 to the EPC 30 in accordance with the example of operation in Fig. 4 described above.

[0051] After step S107 in FIG. 4, in step S201, EPC30 confirms the granting of a 5GC contract to UE10.

[0052] After confirming that a 5GC contract has been granted to UE10, in step S401, EPC30 transmits an existing signal to UE10.

[0053] When the UE 10 receives the existing signal, the UE 10 confirms whether the existing signal meets the criteria in step S402. For example, if the criteria is that the UE 10 receives a detach request signal from the EPC 30, and the existing signal received by the UE 10 is a detach request signal, the UE 10 determines that the existing signal meets the criteria.

[0054] When it is confirmed that the existing signal meets the criteria, that is, when the criteria are satisfied, the UE 10 stops the timer in step S203.

[0055] When the timer stops, the UE 10 activates the N1 mode and performs a connection attempt to the 5GC 20.

[0056] Thus, in operation example 3, after it is confirmed that a 5GC contract has been granted to the UE 10, that is, after the UE 10 becomes capable of connecting to the 5GC 20, the UE 10 stops the timer. As a result, the UE 10 can transition from the EPC 30 to the 5GC 20 more timely without frequently performing connection attempts to the 5GC 20.

[0057] Note that the criteria are not limited to the above examples. For example, the criteria may be that a specific message, a specific value, a specific area, etc. are respectively a message received by the UE 10 from the EPC 30, a set value of an information element (IE) in the message received by the UE 10 from the EPC 30, the location registration area where the message received by the UE 10 from the EPC 30 is received, etc., or a combination thereof.

[0058] (Device Configuration) Next, a functional configuration example of the terminal 10 that executes the processes and operations described so far will be described. The terminal 10 includes the functions described in the above examples. However, the terminal 10 may include only some of the functions described in the above examples.

[0059] <Terminal 10> FIG. 6 is a diagram showing an example of the functional configuration of the terminal 10 according to an embodiment of the present disclosure. As shown in FIG. 6, the terminal 10 includes a transmission unit 510, a reception unit 520, a setting unit 530, and a control unit 540. The functional configuration shown in FIG. 6 is merely an example. As long as the operations according to the embodiments of the present disclosure can be executed, the functional divisions and the names of the functional units may be any.

[0060] The transmitting unit 510 generates a transmission signal from the transmission data and wirelessly transmits the generated transmission signal. For example, the transmitting unit 510 transmits a registration request signal, an attach request signal, etc. The receiving unit 520 wirelessly receives various signals and acquires signals of a higher layer from the received physical layer signals. For example, the receiving unit 520 receives a registration rejection signal, an attach acceptance signal, an N1 mode connection permission signal, a detach request signal, etc.

[0061] The setting unit 530 stores various setting information received from the base station by the receiving unit 520 in a storage device (storage unit), and reads out the setting information from the storage device as necessary. Also, the setting unit 530 stores preset pre-setting information in the storage device. Note that the setting unit 530 may be included in the control unit 540.

[0062] The control unit 540 controls the entire terminal 10. The control unit 540 performs control related to communication related to switching between 5GC and EPC, for example. A functional unit related to signal transmission in the control unit 540 may be included in the transmitting unit 510, and a functional unit related to signal reception in the control unit 540 may be included in the receiving unit 520.

[0063] (Hardware Configuration) Note that the block diagrams used in the description of the above embodiments show blocks of functional units. These functional blocks (components) are realized by any combination of at least one of hardware and software. Also, the method of realizing each functional block is not particularly limited. That is, each functional block may be realized using one physically or logically combined device, or two or more physically or logically separated devices may be directly or indirectly connected (for example, using wired, wireless, etc.), and realized using these multiple devices. The functional block may be realized by combining software with the above one device or the above multiple devices.

[0064] Functions include, but are not limited to, judgment, determination, judgment, calculation, computation, processing, derivation, investigation, search, confirmation, reception, transmission, output, access, resolution, selection, election, establishment, comparison, assumption, expectation, consideration, broadcasting, notifying, communicating, forwarding, configuring, reconfiguring, allocation, mapping, and assignment. For example, a functional block (component) that performs transmission is called a transmitting unit or transmitter. As mentioned above, there are no particular limitations on how these functions are implemented.

[0065] For example, a terminal according to an embodiment of the present disclosure may function as a computer that performs processing of the wireless communication method of the present disclosure. Fig. 7 is a diagram illustrating an example of the hardware configuration of a terminal according to an embodiment of the present disclosure. The terminal 10 described above may be physically configured as a computer device including a processor 1001, a memory 1002, a storage 1003, a communication device 1004, an input device 1005, an output device 1006, a bus 1007, etc.

[0066] In the following description, the term "device" can be interpreted as a circuit, a device, a unit, etc. The hardware configuration of the terminal 10 may be configured to include one or more of the devices shown in the drawings, or may be configured to exclude some of the devices.

[0067] Each function of the terminal 10 is realized by loading predetermined software (programs) onto hardware such as the processor 1001 and memory 1002, causing the processor 1001 to perform calculations, control communication by the communication device 1004, and control at least one of reading and writing data in the memory 1002 and storage 1003.

[0068] Processor 1001 controls the entire computer by operating, for example, an operating system. Processor 1001 may be constituted by a central processing unit (CPU: Central Processing Unit) including an interface with peripheral devices, a control device, an arithmetic device, registers, and the like. For example, the above-described control unit 540 and the like may be realized by Processor 1001.

[0069] Further, Processor 1001 reads a program (program code), software module, data, etc. from at least one of Storage 1003 and Communication Device 1004 into Memory 1002, and executes various processes according to these. As the program, a program for causing a computer to execute at least a part of the operations described in the above-described embodiments is used. For example, the control unit 540 of Terminal 10 may be realized by a control program stored in Memory 1002 and operating in Processor 1001, and other functional blocks may be realized in the same manner. Although it has been described that the above-described various processes are executed by one Processor 1001, they may be executed simultaneously or sequentially by two or more Processors 1001. Processor 1001 may be implemented by one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

[0070] Memory 1002 is a computer-readable recording medium, and may be constituted by, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), and the like. Memory 1002 may be referred to as a register, a cache, a main memory (main storage device), and the like. Memory 1002 can store a program (program code), a software module, etc. executable for implementing the wireless communication method according to an embodiment of the present disclosure.

[0071] Storage 1003 is a computer-readable recording medium, and may be composed of at least one of, for example, an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (e.g., a compact disk, a digital versatile disk, a Blu-ray disc), a smart card, a flash memory (e.g., a card, a stick, a key drive), a floppy disk, a magnetic strip, etc. Storage 1003 may also be referred to as an auxiliary storage device. The above-mentioned storage medium may be, for example, a database, a server, or other appropriate medium including at least one of memory 1002 and storage 1003.

[0072] The communication device 1004 is hardware (transmission / reception device) for communicating between computers via at least one of a wired network and a wireless network, and is also referred to as, for example, a network device, a network controller, a network card, or a communication module. The communication device 1004 may be configured to include a high-frequency switch, a duplexer, a filter, a frequency synthesizer, etc. to realize at least one of frequency division duplex (FDD) and time division duplex (TDD). For example, the above-mentioned transmitter 710, transmitter 810, transmitter 910, receiver 720, receiver 820, and receiver 920 may be realized by the communication device 1004.

[0073] The input device 1005 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, etc.) that receives input from the outside. The output device 1006 is an output device (for example, a display, a speaker, an LED lamp, etc.) that outputs to the outside. The input device 1005 and the output device 1006 may be integrated into one device (for example, a touch panel).

[0074] Also, each device such as the processor 1001 and the memory 1002 is connected by a bus 1007 for communicating information. The bus 1007 may be configured using a single bus or may be configured using different buses for each device.

[0075] Also, the terminal 10 may be configured to include hardware such as a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), or a field programmable gate array (FPGA), and some or all of the functional blocks may be realized by the hardware. For example, the processor 1001 may be implemented using at least one of these hardware components.

[0076] (Notification of Information, Signaling) The notification of information is not limited to the aspects / embodiments described in the present disclosure, and other methods may be used. For example, the notification of information may be performed by physical layer signaling (e.g., downlink control information (DCI), uplink control information (UCI)), upper layer signaling (e.g., radio resource control (RRC) signaling, medium access control (MAC) signaling, notification information (master information block (MIB), system information block (SIB))), other signals, or a combination thereof. Also, the RRC signaling may be referred to as an RRC message and may be, for example, an RRC connection setup message, an RRC connection reconfiguration message, etc.

[0077] (Applicable System) Each aspect / embodiment described in the present disclosure may be applicable to at least one of systems using LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G (4th generation mobile communication system), 5G (5th generation mobile communication system), FRA (Future Radio Access), NR (New Radio), W-CDMA (registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi (registered trademark)), IEEE 802.16 (WiMAX (registered trademark)), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), and other suitable systems, as well as next-generation systems extended based on these. Further, a plurality of systems may be combined (e.g., a combination of at least one of LTE and LTE-A and 5G, etc.) and applied.

[0078] (Processing procedures, etc.) The processing procedures, sequences, flowcharts, etc. of each aspect / embodiment described in the present disclosure may be rearranged as long as there is no contradiction. For example, for the methods described in the present disclosure, the elements of various steps are presented using an exemplary order and are not limited to the specific order presented.

[0079] (Base station operation) Certain operations assumed to be performed by a base station in the present disclosure may, in some cases, be performed by its upper node. In a network consisting of one or more network nodes having a base station, various operations performed for communication with a terminal can clearly be performed by at least one of the base station and other network nodes other than the base station (for example, but not limited to, MME or S-GW, etc.). Although the case where there is one other network node other than the base station has been exemplified above, a combination of a plurality of other network nodes (for example, MME and S-GW) may also be possible.

[0080] (Input / output direction) Information, etc. (see the item "Information, Signal") can be output from an upper layer (or lower layer) to a lower layer (or upper layer). It may also be input and output via a plurality of network nodes.

[0081] (Handling of input / output information, etc.) The input / output information, etc. may be stored in a specific location (for example, memory) or may be managed using a management table. The input / output information, etc. can be overwritten, updated, or appended. The output information, etc. may be deleted. The input information, etc. may be transmitted to other devices.

[0082] (Determination method) The determination may be made by a value represented by 1 bit (0 or 1), may be made by a Boolean value (true or false), or may be made by a numerical comparison (for example, comparison with a predetermined value).

[0083] (Software) 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.

[0084] 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.

[0085] (information, signals) 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.

[0086] 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. For example, at least one of a channel and a symbol may be a signal (signaling). Furthermore, a signal may be a message. Furthermore, a component carrier (CC) may be called a carrier frequency, a cell, a frequency carrier, etc.

[0087] ("System", "Network") As used in this disclosure, the terms "system" and "network" are used interchangeably.

[0088] (parameter, channel name) Furthermore, the information, parameters, etc. described in the present disclosure may be expressed using absolute values, may be expressed using relative values from a predetermined value, or may be expressed using other corresponding information. For example, a radio resource may be indicated by an index.

[0089] The names used for the above-described parameters are not intended to be limiting in any way. Furthermore, the mathematical expressions using these parameters may differ from those explicitly disclosed in this disclosure. The various channels (e.g., PUCCH, PDCCH, etc.) and information elements may be identified by any suitable names, and therefore the various names assigned to these various channels and information elements are not intended to be limiting in any way.

[0090] (Base station (wireless base station)) In this disclosure, terms such as "base station (BS)," "radio base station," "fixed station," "NodeB," "eNodeB (eNB)," "gNodeB (gNB)," "access point," "transmission point," "reception point," "transmission / reception point," "cell," "sector," "cell group," "carrier," and "component carrier" may be used interchangeably. Base stations may also be referred to by terms such as macrocell, small cell, femtocell, and picocell.

[0091] A base station can accommodate one or more (e.g., three) cells. When the base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, and each smaller area can also provide communication services by a base station subsystem (e.g., a small indoor base station (RRH: Remote Radio Head)). The term "cell" or "sector" refers to a part or the whole of the coverage area of at least one of the base station and the base station subsystem that provides communication services in this coverage.

[0092] (Terminal) In this disclosure, terms such as "Mobile Station (MS)", "user terminal", "User Equipment (UE)", "terminal", etc. can be used interchangeably.

[0093] A mobile station may also be called by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terms.

[0094] (Base station / Mobile station) At least one of the base station and the mobile station may be called a transmitting device, a receiving device, a communication device, etc. Note that at least one of the base station and the mobile station may also be a device mounted on a moving body, the moving body itself, etc. The moving body may be a vehicle (e.g., a car, an airplane, etc.), a moving body that moves without a driver (e.g., a drone, an autonomous vehicle, etc.), or a robot (humanoid or non-humanoid). Note that at least one of the base station and the mobile station also includes a device that does not necessarily move during communication operations. For example, at least one of the base station and the mobile station may be an IoT (Internet of Things) device such as a sensor.

[0095] In addition, the base station in the present disclosure may be replaced by a user terminal. For example, for a configuration in which communication between a base station and a user terminal is replaced with communication between a plurality of user terminals (which may be referred to as, for example, D2D (Device-to-Device), V2X (Vehicle-to-Everything), etc.), each aspect / embodiment of the present disclosure may be applied. In this case, the functions of the base station may be configured to be possessed by the terminal 10. Also, terms such as "uplink" and "downlink" may be replaced with terms corresponding to inter-terminal communication (for example, "side"). For example, an uplink channel, a downlink channel, etc. may be replaced with a side channel.

[0096] Similarly, the terminal in the present disclosure may be replaced by a base station. In this case, the functions of the above-described terminal 10 may be configured to be possessed by the base station.

[0097] (Meaning and Interpretation of Terms) As used in this disclosure, the terms "determining" and "determining" may encompass a wide variety of actions. "Determining" and "determining" may include, for example, judging, calculating, computing, processing, deriving, investigating, looking up, searching, inquiring (e.g., searching in a table, database, or other data structure), ascertaining, and the like. "Determining" and "determining" may also include receiving (e.g., receiving information), transmitting (e.g., sending information), input, output, accessing (e.g., accessing data in memory), and the like. Furthermore, "judgment" and "decision" can include regarding resolving, selecting, choosing, establishing, comparing, etc. as having been "judged" or "decided." In other words, "judgment" and "decision" can include regarding some action as having been "judged" or "decided." Furthermore, "judgment (decision)" can be interpreted as "assuming," "expecting," "considering," etc.

[0098] The terms "connected" and "coupled," or any variations thereof, mean any direct or indirect connection or coupling between two or more elements and can include the presence of one or more intermediate elements between two elements that are "connected" or "coupled" to each other. The coupling or connection between elements can be physical, logical, or a combination thereof. For example, "connected" may be read as "accessed." As used in this disclosure, two elements can be considered to be "connected" or "coupled" to each other using at least one of one or more wires, cables, and printed electrical connections, as well as, by way of some non-limiting and non-exhaustive examples, electromagnetic energy having wavelengths in the radio frequency region, microwave region, and optical (both visible and invisible) region.

[0099] (Reference signal) The reference signal can also be abbreviated as RS (Reference Signal) and may be called a Pilot depending on the applicable standard.

[0100] (Meaning of "based on") As used in this disclosure, the recitation "based on" does not mean "based solely on" unless otherwise specified. In other words, the recitation "based on" means both "based solely on" and "based at least in part on."

[0101] (First, second) Any reference to an element using the designations "first," "second," etc. as used in this disclosure does not generally limit the quantity or order of those elements. These designations can be used in this disclosure as a convenient way to distinguish between two or more elements. Thus, a reference to a first and a second element does not mean that only two elements can be employed or that the first element must precede the second element in any way.

[0102] (Means) In the configuration of each of the above devices, the "section" may be replaced with "means", "circuit", "device", etc.

[0103] (Open format) In the present disclosure, when terms such as "include", "including" and their variants are used, these terms are intended to be inclusive, similar to the term "comprising". Further, the term "or" used in the present disclosure is not intended to be an exclusive disjunction.

[0104] (Time units such as TTI, frequency units such as RB, radio frame configuration) A radio frame may be composed of one or more frames in the time domain. Each of the one or more frames in the time domain may be called a subframe. A subframe may further be composed of one or more slots in the time domain. A subframe may have a fixed time length (e.g., 1 ms) independent of numerology.

[0105] Numerology may be a communication parameter applied to at least one of transmission and reception of a certain signal or channel. Numerology may indicate, for example, at least one of subcarrier spacing (SCS), bandwidth, symbol length, cyclic prefix length, transmission time interval (TTI), number of symbols per TTI, radio frame configuration, specific filtering processing performed by a transceiver in the frequency domain, specific windowing processing performed by a transceiver in the time domain, etc.

[0106] A slot may be composed of one or more symbols (such as an Orthogonal Frequency Division Multiplexing (OFDM) symbol or a Single Carrier Frequency Division Multiple Access (SC-FDMA) symbol) in the time domain. A slot may be a time unit based on numerology.

[0107] A slot may include multiple minislots. Each minislot may consist of one or multiple symbols in the time domain. A minislot may also be called a subslot. A minislot may consist of fewer symbols than a slot. A PDSCH (or PUSCH) transmitted in a time unit larger than a minislot may be called PDSCH (or PUSCH) mapping type A. A PDSCH (or PUSCH) transmitted using a minislot may be called PDSCH (or PUSCH) mapping type B.

[0108] The radio frame, subframe, slot, minislot, and symbol all represent time units for transmitting signals, and may be referred to by other names corresponding to the radio frame, subframe, slot, minislot, and symbol.

[0109] For example, one subframe may be called a transmission time interval (TTI), multiple consecutive subframes may be called a TTI, or one slot or one minislot may be called a TTI. That is, at least one of the subframe and the TTI may be a subframe (1 ms) in existing LTE, a period shorter than 1 ms (for example, 1-13 symbols), or a period longer than 1 ms. Note that the unit representing the TTI may be called a slot, minislot, etc. instead of a subframe.

[0110] Here, TTI refers to, for example, the smallest time unit for scheduling in wireless communication. For example, in an LTE system, a base station performs scheduling to allocate radio resources (such as frequency bandwidth and transmission power that can be used by each user terminal) to each user terminal in TTI units. However, the definition of TTI is not limited to this.

[0111] The TTI may be a transmission time unit for a channel-encoded data packet (transport block), a code block, a code word, etc., or may be a processing unit for scheduling, link adaptation, etc. When a TTI is given, the time interval (e.g., the number of symbols) to which a transport block, a code block, a code word, etc. is actually mapped may be shorter than the TTI.

[0112] When one slot or one minislot is called a TTI, one or more TTIs (i.e., one or more slots or one or more minislots) may be the minimum time unit for scheduling. Also, the number of slots (minislots) constituting the minimum time unit for scheduling may be controlled.

[0113] A TTI having a time length of 1 ms may be called a regular TTI (TTI in LTE Rel. 8-12), normal TTI, long TTI, regular subframe, normal subframe, long subframe, slot, etc. A TTI shorter than a regular TTI may be called a shortened TTI, short TTI, partial or fractional TTI, shortened subframe, short subframe, minislot, subslot, slot, etc.

[0114] In addition, a long TTI (e.g., a normal TTI, a subframe, etc.) may be interpreted as a TTI having a time length of more than 1 ms, and a short TTI (e.g., a shortened TTI, etc.) may be interpreted as a TTI having a TTI length shorter than the TTI length of a long TTI and equal to or greater than 1 ms.

[0115] A resource block (RB) is a resource allocation unit in the time domain and frequency domain, and may include one or more consecutive subcarriers in the frequency domain. The number of subcarriers included in an RB may be the same regardless of numerology, for example, 12. The number of subcarriers included in an RB may also be determined based on numerology.

[0116] The time domain of an RB may include one or more symbols and may have a length of one slot, one minislot, one subframe, or one TTI. One TTI, one subframe, etc. may each be composed of one or more resource blocks.

[0117] Note that one or more RBs may also be called a physical resource block (PRB), a sub-carrier group (SCG), a resource element group (REG), a PRB pair, an RB pair, or the like.

[0118] Furthermore, a resource block may be composed of one or more resource elements (REs). For example, one RE may be a radio resource region of one subcarrier and one symbol.

[0119] A Bandwidth Part (BWP) (which may also be referred to as a fractional bandwidth) may represent a subset of contiguous common resource blocks (RBs) for a given numerology on a given carrier, where the common RBs may be identified by their index relative to a common reference point of the carrier. PRBs may be defined in a given BWP and numbered within that BWP.

[0120] The BWP may include a BWP for UL (UL BWP) and a BWP for DL (DL BWP). One or more BWPs may be configured for a UE within one carrier.

[0121] At least one of the configured BWPs may be active, and the UE may not expect to transmit or receive a given signal / channel outside the active BWP. Note that the terms "cell," "carrier," etc. in this disclosure may be read as "BWP."

[0122] The above-described structures of radio frames, subframes, slots, minislots, symbols, etc. are merely examples. For example, the number of subframes included in a radio frame, the number of slots per subframe or radio frame, the number of minislots included in a slot, the number of symbols and RBs included in a slot or minislot, the number of subcarriers included in an RB, the number of symbols in a TTI, the symbol length, the cyclic prefix (CP) length, etc. may be changed in various ways.

[0123] 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.

[0124] 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."

[0125] (Variations of form, etc.) Each aspect / embodiment described in this disclosure may be used alone, in combination, or switched depending on the implementation. Furthermore, notification of predetermined information (e.g., notification that "X is true") is not limited to being done explicitly, but may be done implicitly (e.g., by not notifying the predetermined information).

[0126] As described in detail above, it is obvious to those skilled in the art that the present disclosure is not limited to the embodiments described in the present disclosure. The present disclosure can be implemented in modified and changed forms without departing from the spirit and scope of the present disclosure as defined by the claims. Therefore, the description of the present disclosure is for illustrative purposes and has no restrictive meaning for the present disclosure.

Industrial Applicability

[0127] One aspect of the present disclosure is useful for a wireless communication system.

Description of Reference Numerals

[0128] 10 UE 20 5GC 30 EPC 510 Transmitter 520 Receiver 530 Setting Unit 540 Control Unit

Claims

1. A terminal that attempts to connect to a first network after the timer stops, a receiving unit that receives a connection permission signal indicating permission to connect to the first network from a second network; a control unit that stops the timer that is counting when the connection permission signal is received; comprising: wherein the connection permission signal is transmitted from the second network due to a contract with the first network being granted to the terminal; Terminal.

2. When the control unit receives the connection permission signal, it activates the ability to connect to the first network. The terminal according to claim 1.

3. The connection permission signal is transmitted from the second network due to a contract with the first network being granted to the terminal and the terminal being present in the area of a cell under the first network. The terminal according to claim 1.

4. A terminal that attempts to connect to a first network after the timer stops, a receiving unit that receives information indicating criteria when connection to the first network is rejected from the first network and receives an existing signal when connection to the first network is permitted from a second network; a control unit that starts the timer when connection to the first network is rejected and stops the timer that is counting when it is confirmed that the existing signal meets the criteria; comprising: wherein the connection permission signal is transmitted from the second network due to a contract with the first network being granted to the terminal; Terminal.

5. A communication method for a terminal that attempts to connect to a first network after stopping a timer, starting the timer when connection to the first network is rejected; stopping the timer that is counting when a connection permission signal indicating permission to connect to the first network is received from a second network; wherein the connection permission signal is transmitted from the second network due to a contract with the first network being granted to the terminal; Communication method.

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