WO2022054267A1

WO2022054267A1 - Terminal, base station, communication method, and program

Info

Publication number: WO2022054267A1
Application number: PCT/JP2020/034666
Authority: WO
Inventors: 克成上村
Original assignee: ソフトバンク株式会社
Priority date: 2020-09-14
Filing date: 2020-09-14
Publication date: 2022-03-17

Abstract

Provided is a terminal having: an acquisition unit for acquiring slice information indicating a network slice that can be provided by a cell; and a control unit for performing, on the basis of the slice information, a cell selection or a cell reselection of a cell to be camped on, from among cells capable of providing a network slice supported by the terminal.

Description

Terminals, base stations, communication methods and programs

The present invention relates to terminals, base stations, communication methods and programs.

The 3GPP (3rd Generation Partnership Project), an international standardization organization, is studying the 5G system (5GS: 5G System), which is a 5th generation (5G) cellular system.

For example, network slicing is being studied as a technology for operating an optimal network for 5G services. Network slicing is a technology for constructing multiple virtualized logical networks on a physical network in order to support the service requirements of a certain communication service. Each of the plurality of virtualized logical networks is referred to as a network slice or simply a slice (Non-Patent Document 1).

According to the specifications currently under consideration in 3GPP, the terminal registers with the network by transmitting information indicating the network slice desired to be registered to the cell selected by the cell selection process or the cell reselection process. Perform processing. If the network cannot provide the specified network slice from the terminal, registration to the specified network slice will be refused.

However, according to the current specifications, the terminal determines whether or not the network slice desired to be registered is provided unless the cell selected by the cell selection process or the cell reselection process is registered in the network. Since it cannot be known, there is a possibility that wireless resources related to the registration process to the network will be wasted.

Therefore, an object of the present invention is to provide a technique that enables cell selection or cell reselection in consideration of network slices.

The terminal according to one aspect of the present invention is a camp from an acquisition unit that acquires slice information indicating a network slice that can be provided by a cell and a cell that can provide a network slice supported by the terminal based on the slice information. It has a control unit for selecting or reselecting a cell to be turned on.

According to the present invention, it is possible to provide a technique that enables cell selection or cell reselection in consideration of network slices.

It is a figure which shows an example of the outline of the wireless communication system which concerns on this embodiment. It is a figure for demonstrating network slicing and network slicing. It is a figure explaining the conventional processing procedure when a terminal is registered in a network. It is a figure which shows the bit composition of S-NSSAI. It is a definition of SST value (SST Value). It is a figure which shows an example of the hardware composition of a terminal and a base station. It is a figure which shows the functional block composition example of a terminal. It is a figure which shows an example of the functional block composition of a base station. It is a flowchart which shows an example of the processing procedure when a terminal performs cell selection or cell reselection.

An embodiment of the present invention will be described with reference to the accompanying drawings. In each figure, those with the same reference numerals have the same or similar configurations.

<System configuration>
The wireless communication system according to the present embodiment targets, but is limited to, a 5G system (5G system: 5GS) including a radio access network (RAN), a core network (CN), and a terminal. Not done. For example, it is also applicable to a wireless communication system that employs LTE and LTE-Advanced. Further, the radio access network may operate with a plurality of RATs (multi-RATs) including LTE and / or LTE-Advanced and NR, or may operate with any one RAT (Radio Access Technology). good. LTE and / or LTE-Advanced are also referred to as EUTRA (Evolved Universal Terrestrial Radio Access). 5G is also called NR (New Radio Access). This embodiment can be applied to any wireless communication system including at least a terminal, a base station, and a core network.

FIG. 1 is a diagram showing an example of an outline of the wireless communication system 1 according to the present embodiment. As shown in FIG. 1, the wireless communication system 1 includes a terminal 10, base stations 20A to 20B, and a core network 30. When the base stations 20A to 20B and the cells C1 to C2 are not distinguished, they are collectively referred to as the base station 20 and the cell C, respectively. Further, the numbers of the terminals 10 and the base station 20 shown in FIG. 1 are merely examples, and are not limited to the numbers shown.

The terminal 10 is a predetermined terminal or device such as a smartphone, a personal computer, an in-vehicle terminal, an in-vehicle device and a stationary device. The terminal 10 may be referred to as a user equipment (UE). The terminal 10 may be a mobile type or a fixed type. The terminal 10 can communicate with, for example, a RAT that employs at least one of EUTRA and NR.

As the base station 20, a base station for EUTRA (Evolved Universal Terrestrial Radio Access), a base station for NR, or a base station that supports both EUTRA and NR can be used. The base station 20 for EUTRA is called eNB (evolved NodeB), and the base station 20 for NR is called gNB (g-NodeB).

The base station 20 includes ng-eNB, gNodeB (gNB), en-gNB, Next Generation-Radio Access Network (NG-RAN) node, Donor eNodeB (DeNB), Donor node, Central Unit (CU), and low power node ( low-power node), pico eNB, Home eNB (HeNB), Distributed Unit (DU), gNB-DU, Remote Radio Head (RRH), or Integrated Access and Backhaul / Backhauling (IAB) node, etc. good.

Base station 20 forms one or more cells C. Cell C is a serving cell, carrier, component carrier (CC), primary cell (PrimaryCell: PCell), secondary cell (SecondaryCell: SCell), primary secondary cell (PrimarySCell), special cell (SpecialCell), etc. May be paraphrased as. In FIG. 1, the

base stations

20A and 20B form cells C1 and C2, respectively, but the present invention is not limited to this, and each base station may form a plurality of cells C. Further, the plurality of base stations 20 may be connected to each other by a predetermined interface (for example, X2 or Xn interface).

The core network 30 is, for example, a core network corresponding to EUTRA (Evolved Packet Core: EPC) or a core network corresponding to NR (5G Core Network: 5GC). The core network 30 includes a plurality of entities (entities) such as AMF (Access and Mobility Management Function), SMF (Session Management Function), UPF (User Plane Function) and NSSF (Network Slice Selection Function) (shown). figure). These entities are implemented in one or more physical or logical devices. For example, each slice may contain AMF, SMF, UPF respectively, or may share a part or all.

In the wireless communication system 1, the terminal 10 can communicate with one or more base stations 20. For example, in FIG. 1, the terminal 10 can communicate by means of dual connectivity (DC) connected to two cell groups including one or more cells C, respectively. When two cell groups use different RATs, the DC may be referred to as a Multi-RAT DC (MR-DC). Further, the terminal 10 can also perform communication by using carrier aggregation (CA) that integrates a plurality of cells C.

FIG. 2 is a diagram for explaining network slicing and network slicing. By network slicing, resources of the entire network or a part of the network including the radio access network (RAN) 2 composed of a plurality of base stations 20 and the core network 30 are virtually divided as network slices. The core network 30 and the base station 20 may be prepared individually for each network slice, or may be partially or wholly shared between different network slices. Network slicing typically divides the core network 30 logically / virtually, but may also physically / logically / virtually divide the radio access network 2. For example, the base station 20 allocates radio resources to the terminal 10 (scheduling), and various types related to layer 1 (physical layer), layer 2 (MAC layer, RLC layer, PDCP layer) and layer 3 (RRC layer). By performing the processing for each slice, network slicing can be realized in the wireless access network 2.

In the example of FIG. 2, the core network 30 is a core network (eMBB (enhanced Mobile Broadband)) 30-1 for high-capacity high-speed communication and a core network (URLLC (Ultra Reliable Low Latency Communication)) 30- for low latency. It has a function to virtually realize at least three different networks of 2 and the core network (MIoT (massiveIoT)) 30-3 for IoT terminals, and can be operated as slice 1, slice 2, and slice 3, respectively. Indicates that. Terminals with different service requirements, such as terminals 10-1 used as game consoles, terminals 10-2 mounted on vehicles and used as IoT devices, have their respective service requirements. It belongs to Slice 1, Slice 2 and Slice 3 to fill.

In this case, the communication performed by the terminal 10-1 is processed by the core network (eMBB) 30-1. Further, the communication performed by the terminal 10-2 is processed by the core network (URLLC) 30-2. The communication performed by the terminal 10-3 is processed by the core network (MIoT) 30-3. In this way, by using the network slice, it is possible to perform communication processing suitable for the characteristics of the service required for the terminal 10.

FIG. 3 is a diagram illustrating a conventional processing procedure when the terminal 10 is registered in the network. In FIG. 3, the radio access network 2 including at least one base station 20 and the core network 30 are collectively referred to as “network”. Further, it is assumed that the core network 30 knows in advance which base station 20 (cell) supports which network slice.

First, the state of the terminal 10 will be described. The state of the terminal 10 includes an idle state, an inactive state, and a connected state. The idle state is a state in which the terminal 10 has not established an RRC connection with the base station 20, and is also called an RRC_IDLE state, an idle mode, or the like.

The idle terminal 10 receives the system information (System Information) of the cell C (S10), and camps on the cell C selected by cell selection or cell reselection (S11). "Camping on to cell C" may be paraphrased as "being in cell C".

Cell selection is to select cell C (also referred to as an appropriate cell "suitable cell") that satisfies a predetermined criterion (Cell Selection Criteria).

Cell reselection is to find (detect) and camp on a cell C (more suiteable cell) that is more suitable than the cell C that is currently camping on according to a predetermined criterion (CellReselectionCriteria). Cell reselection includes reselection of cell C having the same carrier frequency as cell C to camp on (intra-frequency cell selection), and reselection of cell C having a carrier frequency different from that of cell C to camp on. (Inter-frequency cell selection), reselection of cell C having a carrier frequency different from that of cell C to camp on (inter-RAT cell selection) is included.

Next, the terminal 10 uses the radio resource notified in advance by the system information to transmit a signal called a random access preamble to the base station 20 (step S12). The random access preamble is also called message 1 (Msg1). Upon receiving the random access preamble, the base station 20 transmits a random access response message (RandomAccessresponse) to the terminal 10 (step S13). The random access response message is also referred to as message 2 (Msg2). Subsequently, the terminal 10 transmits an RRC message including an RRC Setup Request (RRCSetupRequest) to the base station 20 (step S14). The RRC setup request message contains at least information (Establishment Cause) indicating the reason for establishing the RRC. The message containing the RRC setup request is also referred to as message 3 (Msg3).

Subsequently, the base station 20 transmits an RRC message including an RRC setup (RRCSetup) to the terminal 10 (step S15). The RRC message containing the RRC setup is also referred to as message 4 (Msg4). Subsequently, the terminal 10 transmits an RRC message including the RRC Setup Complete to the terminal 10 (step S16). The RRC message containing the RRC setup complete is also referred to as message 5 (Msg5). When the transmission of the message 5 is completed, the RRC connection is established, and the idle terminal 10 transitions to the connected state.

When the terminal 10 wishes to register in the network slice, the terminal 10 piggybacks the registration request including the ID that uniquely identifies the network slice requesting registration with the RRCSetupComplete message to the base station 20. Send. The ID that uniquely identifies the network slice is called S-NSSAI (Single Network Slice Selection Assistance Information). Further, a list of a plurality of S-NSSAIs is called NSSAI (Network Slice Selection Assistance Information). Hereinafter, S-NSSAI will be described as including NSSAI.

When the registration request (Registration Request) including S-NSSAI is notified by the message 5, the base station 20 selects the core network 30 (AMF) for registering the terminal information, and the base station 20 selects the registration request (Registration) to the selected core network 30. Request) is forwarded. The core network 30 (AMF) is a requested network slice based on a network slice supported by the base station 20 (or cell) receiving the registration request and a network slice supported by the core network 30. It is determined whether or not it is possible to accept the registration in, and the determination result is notified to the base station 20. The base station 20 supports the information (Allowed NSSAI) indicating that the requested S-NSSAI is supported or the requested S-NSSAI in the RRC reconfiguration message (RRCReconfiguration) or the downlink information transfer message (DLInformationTransfer). It is transmitted to the terminal 10 including the information (Rejected NSSAI) indicating that the information is not performed (step S17).

FIG. 4 is a diagram illustrating the configuration of S-NSSAI specified in the 3GPP specifications. FIG. 4A shows the bit configuration of S-NSSAI. S-NSSAI is composed of SST (Slice / Service Type) indicating the type of network slice and SD (Slice Differentiator) which is information for distinguishing network slices belonging to the same SST. For example, the SST may be composed of 8 bits and the SD may be composed of 24 bits. Since SD is optional information, it does not necessarily have to be included in S-NSSAI. That is, S-NSSAI is an information bit composed of 8 bits or 32 bits.

FIG. 4B is a definition of the SST value (SST Value). SST values = 1, 2, 3 and 4 indicate that the service types (or slice types) provided by the network slice are eMBB, URLLC, MioT and V2X (Vehicle-to-Everything), respectively. The definition of the SST value is not limited to FIG. 4B in the future, and a new SST value may be added.

According to the conventional processing procedure described above, when the terminal 10 wishes to be registered in a predetermined network slice, the terminal 10 executes a random access procedure in the camp-on cell by cell selection or cell reselection, and registers in the network. It is not possible to know if a given network slice is supported without processing. If the network does not support the network slice that the terminal 10 wants to register, the random access procedure and the registration process to the network (that is, the processing procedure of steps S12 to S17 in FIG. 3) become useless. ..

Therefore, in the present embodiment, the system information transmitted by each base station 20 includes information indicating a network slice that can be provided by the cell C formed by each base station 20, and the terminal 10 selects the cell. Alternatively, when the cell is reselected, the cell that can provide the network slice supported by the terminal 10 (or wishes to be registered) is preferentially camp-on.

<Hardware configuration>
FIG. 5 is a diagram showing an example of the hardware configuration of the terminal 10 and the base station 20. The terminal 10 and the base station 20 include a processor 11, a memory 12, a storage device 13, a communication device 14 for wired or wireless communication, an input device 15 for receiving input operations, an output device 16 for outputting information, and an antenna 17.

The processor 11 is, for example, a CPU (Central Processing Unit) and controls a terminal 10 or a base station 20.

The memory 12 is composed of, for example, a ROM (ReadOnlyMemory), an EPROM (ErasableProgrammableROM), an EEPROM (ElectricallyErasableProgrammableROM), and / or a RAM (RandomAccessMemory).

The storage device 13 is composed of storage such as HDD (Hard Disk Drive), SSD (Solid State Drive) and / or eMMC (embedded MultiMediaCard), for example.

The communication device 14 is a device that communicates via a wired and / or wireless network, and is, for example, a network card, a communication module, or the like. Further, the communication device 14 may include an amplifier, an RF (Radio Frequency) device that performs processing related to radio signals, and a BB (BaseBand) device that performs baseband signal processing.

The RF device generates a radio signal transmitted from the antenna 17 by performing D / A conversion, modulation, frequency conversion, power amplification, etc. on the digital baseband signal received from the BB device, for example. Further, the RF device generates a digital baseband signal by performing frequency conversion, demodulation, A / D conversion, etc. on the radio signal received from the antenna 17, and transmits the digital baseband signal to the BB device. The BB apparatus performs a process of converting a digital baseband signal into an IP packet and a process of converting an IP packet into a digital baseband signal.

The input device 15 is, for example, a keyboard, a touch panel, a mouse and / or a microphone. The output device 16 is, for example, a display and / or a speaker.

<Functional block configuration>
(Terminal)
FIG. 6 is a diagram showing an example of a functional block configuration of the terminal 10. The terminal 10 includes a storage unit 100, a reception unit 101, a transmission unit 102, an acquisition unit 103, and a control unit 104. Note that FIG. 6 shows a functional block required in this embodiment. The storage unit 100 may be realized by using the memory 12 and / or the storage device 13 included in the terminal 10. The receiving unit 101 and the transmitting unit 102 may be realized, for example, by the communication device 14, or may be realized by the processor 11 executing the program stored in the storage device 13 in addition to the communication device 14. .. The acquisition unit 103 and the control unit 104 may be realized by the processor 11 of the terminal 10 executing a program stored in the storage device 13. Further, the program can be stored in a storage medium. The storage medium in which the program is stored may be a non-transitory computer readable medium. The non-temporary storage medium is not particularly limited, but may be, for example, a storage medium such as a USB memory or a CD-ROM.

The storage unit 100 stores information (S-NSSAI or NSSAI) indicating one or more network slices supported by the terminal 10.

The receiving unit 101 receives a downlink (DownLink) signal from the base station 20. The transmission unit 102 generates an uplink (UPLink) signal and transmits it to the base station 20.

The acquisition unit 103 acquires information indicating a network slice that can be provided in the cell (hereinafter, referred to as "slice information"). The "network slices that can be provided by the cell" are "network slices that can be provided by the cell", "network slices that can be registered in the area including the cell", and "network slices that can be provided by the base station 20 (or network)". It may be read as "a network slice supported by the base station 20 (or a network)" or "a network slice that can be registered in an area including the base station 20 (or a network)". The acquisition unit 103 acquires slice information from the RRC message (system information, RRC reset message, etc.) received from the base station 20.

Based on the slice information acquired by the acquisition unit 103, the control unit 104 selects (cell selection) or reselects (cell selection) the cell to camp on from the cells that can provide the network slice supported by the terminal 10. Select). "Network slices supported by terminal 10" should be read as "network slices used by terminal 10", "network slices desired by terminal 10", or "network slices desired by terminal 10 to be registered". May be good. Further, the "network slice used by the terminal 10", the "network slice desired by the terminal 10", or the "network slice desired by the terminal 10" are among the network slices supported by the terminal 10. It may mean the slice / service type or S-NSSAI used by the terminal 10. In the present embodiment, the expressions "used by the terminal 10", "desired to be used by the terminal 10", and "desired to be registered by the terminal 10" can be interchanged with each other.

(base station)
FIG. 7 is a diagram showing an example of a functional block configuration of the base station 20. The base station 20 includes a storage unit 200, a reception unit 201, and a transmission unit 202. Note that FIG. 7 shows a functional block required in this embodiment. The storage unit 200 may be realized by using the memory 12 and / or the storage device 13 included in the base station 20. The receiving unit 201 and the transmitting unit 202 may be realized, for example, by the communication device 14, or may be realized by the processor 11 executing the program stored in the storage device 13 in addition to the communication device 14. .. Further, the program can be stored in a storage medium. The storage medium in which the program is stored may be a non-temporary storage medium that can be read by a computer. The non-temporary storage medium is not particularly limited, but may be, for example, a storage medium such as a USB memory or a CD-ROM.

The receiving unit 201 receives the uplink signal from the terminal 10. The transmission unit 202 generates a downlink signal and transmits it to the terminal 10. Further, the transmission unit 202 transmits an RRC message (system information, RRC reset message, etc.) including slice information. Further, the receiving unit 201 and the transmitting unit 202 correspond to a random access procedure, an RRC connection establishment process (for example, reception of an RRCSetupComplete message including desired slice information), and transmission / reception of other RRC messages with the terminal 10. Perform the processing to be performed. Further, the receiving unit 201 and the transmitting unit 202 transmit and receive a message (NAS message) with and from the core network 30.

Further, the transmission unit 202 includes the slice information indicating the network slice that can be provided by the cell in the system information and transmits the slice information. Further, the receiving unit 201 selects a cell to camp on from among the cells capable of providing the network slice supported by the terminal 10 (or used by the terminal 10) to the terminal 10 based on the slice information. The cell reselection is executed, and the information of the network slice used by the terminal 10 is received from the terminal 10.

<Processing procedure>
Subsequently, the processing procedure performed by the wireless communication system 1 according to the present embodiment will be specifically described.

FIG. 8 is a flowchart showing an example of a processing procedure when the terminal 10 performs cell selection or cell reselection.

In step S100, the acquisition unit 103 searches for peripheral cells of the terminal 10 itself, and acquires system information including slice information in the detected cells to acquire slice information and information necessary for camp-on. Alternatively, the acquisition unit 103 acquires slice information about peripheral cells in advance by receiving an RRC message (for example, RRC Reconfiguration, RRC Release, etc.) or an upper layer message (for example, NAS message) other than the system information from the base station 20 in advance. You may do it. The slice information may be provided in a bitmap format in which bits corresponding to the supported slices are set, in a list format in which the supported slices are listed, or an SST value may be notified.

In step S101, when cell selection or cell reselection is performed, the control unit 104 has acquired information indicating the slices supported by the terminal 10 itself and the presence or absence of appropriate cells capable of providing slices supported by the terminal 10 itself. Judgment is based on system information. The information indicating the slices supported by the terminal 10 itself may be stored in the storage unit 100 in advance, or may be stored in the SIM (Subscriber Identity Module). If the cell is found, the control unit 104 proceeds to the processing procedure of step S102, and if not found, the control unit 104 proceeds to the processing procedure of step S103. The "appropriate cell" in the processing procedure of step S101 may mean a cell C that satisfies a predetermined criterion (Cell Selection Criteria) at the time of cell selection. In addition, "appropriate cell" means a cell C (more suiteable cell) that is found according to a predetermined criterion (CellReselectionCriteria) and is more appropriate than the cell C currently camping on at the time of cell reselection. You may do it.

The terminal 10 may be capable of supporting a plurality of network slices. For example, a terminal 10 or the like that supports both a slice whose slice / service type is URLLC and a slice whose service type is V2X is assumed.

For example, the terminal 10 supports both a slice that is a URLLC and a slice that is a V2X, and whether it operates as a URLLC terminal or a V2X terminal according to a user's instruction or an operator (PLMN) contract or the like. It may be switchable. In this case, when making a cell selection, the terminal 10 is asked to select an appropriate cell that can provide slices supported by the terminal 10 itself (that is, a cell that supports at least both URLLC and V2X) as a cell to camp on. You may do it. Alternatively, when the terminal 10 performs cell selection, if the slice used by the terminal 10 itself is URLLC (that is, when the terminal 10 operates as a URLLC terminal), at least an appropriate cell capable of providing a slice of URLLC is selected. It may be selected as the cell to camp on.

Further, in the processing procedure of step S101, the "appropriate cell capable of providing the slice supported by the terminal 10 itself" may be replaced with the "appropriate cell supporting the slice supported by the terminal 10 itself".

Further, in the processing procedure of step S100 and the processing procedure of step S101, the terminal 10 may determine whether or not it is possible to provide a network slice to be supported after determining that the cell satisfies a predetermined criterion. However, it may be determined whether or not it is possible to provide a network slice that supports it regardless of whether or not it meets a predetermined criterion.

In step S102, the control unit 104 of the terminal 10 camps on the cell found in step S101 and returns to the processing procedure of step S100 to search for a cell more suitable than the camp-on cell. do.

In step S103, when the control unit 104 of the terminal 10 ends the cell selection or cell reselection process (for example, when the power of the terminal 10 is turned off) (step S103-YES), the process procedure shown in FIG. 8 ends. .. If it does not end (step S103-NO), the process returns to the processing procedure of step S100.

Subsequently, a plurality of modified examples will be described for the processing procedure of step S100. The following modification examples can be combined arbitrarily.

(Modification 1)
An "appropriate cell" may be defined as a cell capable of providing a network slice supported by the terminal 10 and satisfying a predetermined criterion. Here, the predetermined criterion may be "Cell Selection Criteria" in the case of cell selection and "Cell Reselection Criteria" in the case of cell reselection.

(Modification 2)
In the second modification, the cell capable of providing the network slice supported by the terminal 10 by adding the offset value related to the corresponding network slice to the predetermined selection criterion (Cell Selection Criteria) used at the time of cell selection is ". It may be included in the "appropriate cell".

More specifically, the control unit 104 may select a cell for detecting an appropriate cell, and the appropriate cell may be a cell that satisfies at least a predetermined selection criterion. Further, the predetermined selection criterion may be that the reception level and / or the reception quality calculated based on the predetermined formula exceeds a predetermined value. Further, the predetermined calculation formula may be a calculation formula defined so that the reception level or the reception quality is equal to or less than the predetermined value for the cells that cannot provide the network slice supported by the terminal 10. ..

Specifically, the predetermined calculation formula may be the formula shown below. That is, the predetermined selection criterion described above may be that the reception level (Srxlev) and the reception quality (Squal) calculated based on the following equation exceed the predetermined values (0). According to the following formula, if the measured cell is a cell that cannot provide the network slice supported by the terminal 10, the Qoffset slice is set to infinity. Therefore, since the reception level (Srxlev) and the reception quality (Squal) are both equal to or less than the predetermined value (0), the predetermined selection criteria are not satisfied.

Here, Srxlev indicates the reception level (Cell selection RX level value) at the time of cell selection, and Squal indicates the reception quality (Cell selection quality value) at the time of cell selection. Qrxlevmeas indicates the received level (RSRP) of the measured cell, and Qqualmeas indicates the received quality (RSRQ) of the measured cell. Qrxlevmin indicates the minimum reception level of the required cell, and Qqualmin indicates the minimum reception quality of the required cell. Qrxlevminoffset is the offset value applied to Qrxlevmin, and Qqualminoffset is the offset value applied to Qqualmin. Pcompensation is a value determined by whether the frequency is in the FR1 range or the FR2 range. Qoffsettemp is a temporary offset value applied to the cell.

Qoffsetslice can be set to an infinite value if the measured cell is not capable of providing a network slice supported by terminal 10, and the detected cell can provide a network slice supported by terminal 10. In the case of a cell, it may be set to 0. Qoffsetslice also sets the measured cell to a positive value (ie, a value that lowers the Srxlev and Squal calculation results) indicated in the system information if the measured cell is not capable of providing the network slices supported by the terminal 10. If the set and detected cell is a cell capable of providing the network slice supported by the terminal 10, it may be set to 0. Qoffsetslice is also set to 0 if the measured cell is not capable of providing network slices supported by terminal 10, and the detected cells can provide network slices supported by terminal 10. In the case of a cell, it may be set to a negative value indicated by system information (that is, a value that raises the calculation result of Srxlev and Squal). Also, Qoffset slice may be applied to only one of Srxlev and Squal.

(Modification 3)
In the case where one cell can provide one or more network slices, the terminal 10 can provide all the one or more network slices supported by the terminal 10 when performing cell selection or cell reselection. The cell may be selected as the cell to camp on.

More specifically, the slice information included in the system information indicates one or more network slices that can be provided by the cell, and the control unit 104 sets the one or more network slices supported by the terminal 10. Cell selection or cell reselection may be performed from all available cells.

For example, if there is a terminal 10 that supports both a slice that is URLLC and a slice that is V2X, the terminal 10 uses a cell that can provide both a slice that is URLLC and a slice that is V2X as an appropriate cell. You may consider it as a camp on.

(Modification example 4)
In the case where one cell can provide one or more network slices, the terminal 10 prefers at least one or more network slices supported by the terminal 10 when performing cell selection or cell reselection. The cell that can provide the network slice with the highest degree may be selected as the cell to camp on. The network slice having the highest priority may be preset in the storage unit 100, the SIM card, or the like. Alternatively, the network slice with the highest priority may be the slice desired to be registered at the time of the latest RRC connection.

More specifically, the slice information indicates one or more network slices that can be provided in the cell, and the control unit 104 tells the terminal 10 among the one or more network slices supported by the terminal 10. Cell selection or cell reselection may be performed from among the cells that can provide the set highest priority network slice.

For example, it is assumed that there is a terminal 10 that supports both a slice that is URLLC and a slice that is V2X and has the highest priority of URLLC. Further, it is assumed that the terminal 10 has found a cell capable of providing a slice that is URLLC and a cell that can provide a slice that is V2X. In this case, the terminal 10 may camp on by regarding a cell capable of providing a slice that is URLLC as an appropriate cell.

Further, the modified example 3 and the modified example 4 may be combined. For example, the control unit 104 performs cell selection or cell reselection from cells capable of providing all one or a plurality of network slices supported by the terminal 10, and a cell capable of providing all the plurality of network slices is available. If it does not exist, cell selection or cell reselection may be performed from the cells that can provide the highest priority network slice set in the terminal 10.

(Modification 5)
The slice information may indicate a network slice that can be provided in the cell by storing information about the network slice that is not provided in the cell. Further, the control unit 104 of the terminal 10 may consider the network slice not stored in the slice information to be the network slice provided by the cell. That is, the slice information may be so-called blacklist format information.

(Modification 6)
The system information may include information (for example, a bit of 0 or 1) indicating whether or not the terminal 10 is to execute the cell selection or cell reselection process in consideration of the network slice. Further, the terminal 10 is based on the system information including "information indicating whether or not the process of performing cell selection or cell reselection in consideration of the network slice is permitted" from the cells detected by the terminal 10. Selection or cell reselection may be performed.

Specifically, the acquisition unit 103 acquires system information including information indicating whether or not the process of cell selection or cell reselection is permitted from the cells that can provide the network slice supported by the terminal 10. You may try to do it. The information may be included in the system information of all cells belonging to the same PLMN, for example. Further, the control unit 104 selects a cell or a cell from the cells capable of providing the network slice supported by the terminal 10 based on the slice information acquired by the acquisition unit 103 when the processing is permitted. You may want to reselect. Further, the control unit 104 causes cell selection or cell reselection when the processing is not allowed, regardless of whether the detected cell is a cell capable of providing the network slice supported by the terminal 10. You may do it. That is, if the processing is not allowed, the terminal 10 may perform cell selection or cell reselection according to the conventional processing procedure described with reference to FIG.

As a result, when a situation occurs in which it becomes difficult to provide a part or all of the network slices, for example, in the event of a disaster, the base station 20 performs cell selection or cell reselection processing in consideration of the network slices on the terminal 10. By transmitting information to prevent execution via system information, it is possible to quickly prevent the terminal 10 from falling into a state in which communication is not possible. Further, the terminal 10 is regarded as a "conventional base station 20 that does not support this function" and performs a conventional processing procedure, or "a base station 20 that supports this function but cannot provide a network slice (that is, a network slice). This information can also be used to determine whether to perform the processing by regarding it as a base station 20) connected to a core network that does not support.

(Modification 7)
When the terminal 10 cannot camp on without considering the detected cell as an appropriate cell when the terminal 10 selects a cell because there is no cell capable of providing the network slice supported by the terminal 10, the terminal 10 communicates. You will not be able to. Therefore, the system information may include information that allows camping on when there is no appropriate cell to camp on.

More specifically, in cell selection, the acquisition unit 103 acquires system information including information indicating a cell that is allowed to camp on when there is no cell that can provide a network slice supported by the terminal 10. You may try to do it. Further, in the cell selection, if there is no cell capable of providing the network slice supported by the terminal 10, the control unit 104 camps on the cell that is allowed to camp on, which is indicated by the system information at the time of cell selection. You may try to do it. As a result, the terminal 10 camps on the cell in which the information is transmitted in the system information, so that communication can be performed even if there is no cell capable of providing the network slice supported by the terminal 10. become.

(Modification 8)
Slice information may be defined for each PLMN (mobile network). Specifically, the slice information included in the system information may indicate a network slice that can be provided in a cell for each PLMN (mobile network). Further, the control unit 104 performs cell selection or cell reselection based on the slice information from the cells of the mobile network selected by the terminal 10 and which can provide the network slice supported by the terminal 10. You may do so. This makes it possible to set different slice information for each PLMN when RAN sharing that shares a radio access network is performed among a plurality of PLMNs.

<Summary>
According to the embodiment described above, the terminal 10 camps on a cell capable of providing a network slice supported by the terminal 10 itself based on the slice information included in the system information or the like. This makes it possible to provide a technique that enables cell selection or cell reselection in consideration of network slices.

The embodiments described above are for facilitating the understanding of the present invention, and are not for limiting the interpretation of the present invention. The flowcharts, sequences, elements included in the embodiments, arrangements, materials, conditions, shapes, sizes, and the like described in the embodiments are not limited to those exemplified, and can be appropriately changed. Further, it is possible to partially replace or combine the configurations shown in different embodiments.

1 ... wireless communication system, 10 ... terminal, 11 ... processor, 12 ... memory, 13 ... storage device, 14 ... communication device, 15 ... input device, 16 ... output device, 17 ... antenna, 20 ... base station, 30 ... core Network, 100 ... storage unit, 101 ... reception unit, 102 ... transmission unit, 103 ... acquisition unit, 104 ... control unit, 200 ... storage unit, 201 ... reception unit, 202 ... transmission unit

Claims

It ’s a terminal,
An acquisition unit that acquires slice information indicating network slices that can be provided in a cell,
Based on the slice information, a control unit that selects or reselects the cell to camp on from the cells that can provide the network slice supported by the terminal.
Terminal with.
The control unit performs the cell selection or the cell reselection by detecting an appropriate cell, and then performs the cell selection or the cell reselection.
The suitable cell is a cell capable of providing a network slice supported by the terminal and includes a cell satisfying a predetermined criterion.
The terminal according to claim 1.
The control unit selects an appropriate cell by detecting the appropriate cell, and then selects the cell.
The appropriate cell is a cell that meets at least a predetermined selection criterion.
The predetermined selection criterion is that the reception level and reception quality calculated based on the predetermined formula exceed the predetermined values.
The predetermined calculation formula is defined so that the reception level or the reception quality is equal to or less than the predetermined value for cells that cannot provide the network slice supported by the terminal.
The terminal according to claim 1.
The slice information indicates one or more network slices that can be provided in the cell.
The control unit performs cell selection or cell reselection from cells capable of providing all one or a plurality of network slices supported by the terminal.
The terminal according to any one of claims 1 to 3.
The slice information indicates one or more network slices that can be provided in the cell.
The control unit selects or reselects the cell from among the cells that can provide the network slice with the highest priority set in the terminal among one or a plurality of network slices supported by the terminal. conduct,
The terminal according to any one of claims 1 to 3.
The slice information indicates a network slice that can be provided in the cell by storing information about the network slice that is not provided in the cell.
The control unit considers the network slice not stored in the slice information to be the network slice provided by the cell.
The terminal according to any one of claims 1 to 5.
The acquisition unit acquires system information including information indicating whether or not the process of performing the cell selection or the cell reselection is permitted from the cells that can provide the network slice supported by the terminal.
When the processing is permitted, the control unit selects the cell or reselects the cell from the cells that can provide the network slice supported by the terminal based on the slice information.
The terminal according to any one of claims 1 to 6.
The acquisition unit acquires system information including information indicating cells that are allowed to camp on when there is no cell capable of providing a network slice supported by the terminal in the cell selection.
In the cell selection, if there is no cell capable of providing the network slice supported by the terminal, the control unit camps on the cell that allows the camp-on indicated in the system information.
The terminal according to any one of claims 1 to 7.
The slice information indicates the network slice that can be provided in the cell for each mobile network.
Based on the slice information, the control unit selects or reselects the cell from the cells of the mobile network selected by the terminal and capable of providing the network slice supported by the terminal. ,
The terminal according to any one of claims 1 to 8.
A base station that communicates with terminals
A transmitter that includes slice information indicating network slices that can be provided in a cell in system information and sends it.
Based on the slice information, the terminal is made to execute cell selection or cell reselection of the cell to camp on from the cells that can provide the network slice supported by the terminal, and the terminal wants to use it. A receiver that receives network slice information from the terminal,
Base station with.
It is a communication method performed by the terminal.
Steps to get slice information indicating the network slices that can be provided in the cell,
Based on the slice information, a step of selecting or reselecting a cell to camp on from among cells that can provide a network slice supported by the terminal.
Communication methods including.
On the computer
Steps to get slice information indicating the network slices that can be provided in the cell,
Based on the slice information, a step of selecting or reselecting a cell to camp on from among cells that can provide a network slice supported by the computer.
A program to execute.