Base station device, terminal device, and communication method

Abstract

The present invention extends the time for transmitting and receiving data. This base station device comprises a wireless communication unit and a control unit. The wireless communication unit of the base station device performs wireless communication with a terminal device via a first antenna and a second antenna. The control unit of the base station device performs: control for registering (Registration) the terminal device in a core network using wireless communication via the first antenna; and control, after the registration, of wireless communication with the terminal device via the second antenna.

Description

Base station device, terminal device, and communication method

[0001] The present disclosure relates to a base station device, a terminal device, and a communication method.

[0002] In recent years, 5G mobile communication systems have become widespread (see, for example, Patent Document 1). 5G has features such as low latency, high-speed, large-capacity communication, and the ability to connect multiple devices simultaneously, and is also applied to private networks, etc. Here, a private network provides cellular communication services in a limited area, such as a factory, office, studio, hospital, or university. Unlike ordinary public cellular communication services, communication services are limited to a specific area.

[0003] JP 2023-164085 A

[0004] However, in a 5G private network, the service coverage area may be relatively narrow. In such cases, a problem may arise in that a terminal device connected to the network does not have enough time to transmit and receive data. In particular, when the service coverage area is relatively narrow and the terminal device moves at high speed, the time spent in the service area is shortened, resulting in a problem of insufficient time for transmitting and receiving data.

[0005] Therefore, the present disclosure proposes a base station that extends the time for transmitting and receiving data.

[0006] The base station device of the present disclosure has a wireless communication unit that performs wireless communication with a terminal device via a first antenna and a second antenna, and a control unit that controls registration of the terminal device to a core network using wireless communication via the first antenna and controls wireless communication with the terminal device via the second antenna after the registration.

[0007] 1 is a diagram illustrating an example of a private network. A diagram illustrating a configuration of a network architecture of a 5G system. A diagram illustrating a configuration example of a base station device according to an embodiment of the present disclosure. A block diagram illustrating a configuration example of a terminal device according to an embodiment of the present disclosure. A diagram illustrating a configuration example of a base station device according to a first embodiment of the present disclosure. A diagram illustrating a configuration example of a conventional network system. A diagram illustrating a configuration example of a conventional network system. A diagram illustrating a configuration example of a base station device according to a first embodiment of the present disclosure. A diagram illustrating a configuration example of a network system according to a first embodiment of the present disclosure. A diagram illustrating an example of a processing procedure of communication processing according to the first embodiment of the present disclosure. A diagram illustrating an example of communication processing according to the first embodiment. A diagram illustrating a configuration example of a base station device according to a second embodiment of the present disclosure. A diagram illustrating an example of communication processing according to a third embodiment of the present disclosure. A diagram illustrating a configuration example of a conventional network system. A diagram illustrating a configuration example of a conventional network system. A diagram illustrating an example of a configuration of a conventional network system. A diagram illustrating an example of a configuration of a conventional network system. A diagram illustrating an example of power between cells in a conventional network system. A diagram illustrating an example of power between cells in a conventional network system. A diagram illustrating an example of a configuration of a base station device according to a fourth embodiment of the present disclosure. A diagram illustrating an example of a handover trigger according to a fourth embodiment of the present disclosure. A diagram illustrating an example of antenna arrangement according to a fourth embodiment of the present disclosure. A diagram illustrating an example of handover trigger according to a fourth embodiment of the present disclosure. A diagram illustrating an example of communication processing according to a fourth embodiment of the present disclosure. 10A and 10B are diagrams illustrating a configuration example of a base station device according to a fifth embodiment of the present disclosure;FIGS. 11A and 11B are diagrams illustrating a configuration example of a base station device according to a sixth embodiment of the present disclosure;FIGS.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The description will be given in the following order. Note that in the following embodiments, the same components will be assigned the same reference numerals to avoid redundant description. 1. Overview 2. Example of a communication system configuration 3. First embodiment 4. Second embodiment 5. Third embodiment 6. Fourth embodiment 7. Fifth embodiment 8. Sixth embodiment

[0009] (1. Overview) (1-1. Local 5G / Private 5G) Local 5G and private 5G are cellular communication services that are available in limited areas such as factories, offices, studios, hospitals, universities, etc. By limiting the provision of services to local areas, local 5G and private 5G have the advantage of being able to provide customized cellular services.

[0010] In this embodiment, private 5G and local 5G may be referred to as a 4G / 5G private network, a private network, a 4G / 5G local network, a local network, a 4G / 5G virtual private network, or a virtual private network.

[0011] It should be noted that the private network is not limited to a 4G / 5G private network. In the following description, the private network may be referred to as a non-public cellular network, a non-public cellular closed network, or simply a closed network.

[0012] Security is a key consideration in many use cases that use private networks. Examples include production lines in factories that handle highly confidential technology. Hospitals also handle a lot of personal information related to patients' privacy, making them a use case requiring high confidentiality. Universities and offices also often handle personal information, and communications related to that personal information require a high level of confidentiality.

[0013] (1-2. Characteristics of a Private Network) Before describing the outline of this embodiment, the characteristics of a private network will be described.

[0014] Fig. 1 is a diagram illustrating an example of a private network. The 4G / 5G private network shown in Fig. 1 includes a user equipment (UE), a base station (BS), a core network control plane (CN-C), a core network user plane (CN-U), and an application function (AF).

[0015] Here, the UE and BS may be located on-premises in a facility such as a factory, office, or home, or in a local area network (LAN). The CN-C, CN-U, and AF may be located on a cloud such as a data center.

[0016] (1) Characteristics of a Closed Network In a private network, a LAN and a cloud are connected within a closed network. An example of a closed network is a virtual private network (VPN).

[0017] In a closed network, a base station device located in a LAN (or within a facility) and a core network located in the cloud are connected using a private IP address, without using a public IP address.

[0018] Communications limited to within a closed network are resistant to eavesdropping from outside. Communications limited to within a closed network can be configured to completely block access from outside the closed network. Communications limited to within a closed network can also be configured to send packets from within the closed network to the outside, with only the responses being allowed into the closed network. Normally, a device outside the closed network cannot trigger an access to a device inside the closed network (devices including UE). In this way, closed networks can be said to have a high level of confidentiality.

[0019] Communications limited to a closed network do not require conversion between private IP addresses and global IP addresses, so UDP (User Datagram Protocol) communications can be easily used for communications limited to a closed network.

[0020] TCP (Transmission Control Protocol) is usually used for communications that require conversion between private IP addresses and global IP addresses. On the other hand, the ease of use of UDP communication makes it attractive for applications that use UDP communication, as it offers advantages such as low latency.

[0021] (2) IP Addresses Assigned to Terminal Devices When a terminal device is attached to a network, it is assigned an IP address from the core network. Typically, a private IP address is assigned to the terminal device.

[0022] In a public network, a public IP address may be directly assigned to a terminal device, whereas in a 4G / 5G private network, which is a non-public network, a private IP address is usually assigned to a terminal device.

[0023] Therefore, for packets sent from the closed network to an external network, network address translation is performed to convert the private IP address into a public IP address.

[0024] The AF can obtain information indicating what IP address has been assigned to the terminal device from the core network. In 5G, an API (Application Program Interface) called SBI (Service Based Interface) is provided to obtain the IP address of the terminal device. Even in 4G, the AF can obtain the IP address of the terminal device in the same way as in 5G by accessing a subscriber file that stores the IP address of each terminal device.

[0025] In a closed network, the AF may be able to send IP packets directly to the terminal device (ie, network initiated message push) by holding the IP address of the terminal device.

[0026] (2. Configuration Example of Communication System) (2.1. Network Architecture of 5G System) A communication system according to an embodiment of the present disclosure is, for example, a 5G system. Here, an example of the network architecture of a 5G system, which is the communication system according to the present embodiment, will be described with reference to FIG. 2 .

[0027] 2 is a diagram showing the configuration of the network architecture of a 5G system, which will be abbreviated as 5GS (5G System) hereinafter.

[0028] 5GS includes a terminal device (UE: User Equipment) 10, a base station ((R)AN) 20, and a 5GC (5G Core) 30. 5GC is also referred to as an NGC (NG CORE) or a core network. 5GC will also be referred to as a core network below. The term (R)AN refers to a base station device including a RAN (Radio Access Network) and an AN (Access Network). The base station device will also be referred to as a base station below.

[0029] An application server (AS) 40 that processes applications is connected to 5GS via the Internet, enabling the terminal device 10 to use applications via 5G services.

[0030] When an entity that provides an application, for example, a service provider, has a contract such as a service level agreement (SLA) with a public land mobile network (PLMN) operator that provides 5G services, the application server 40 is arranged in the 5GC 30 as the DN 340. Alternatively, the application server 40 can be connected to the DN 340 via a dedicated line or a virtual private network (VPN).

[0031] The application server 40 is also called a cloud server, or may be provided in the form of an edge server.

[0032] The 5GS control plane functions include an Access and Mobility Management Function (AMF) 301, a Network Exposure Function (NEF) 302, and a Network Repository Function (NRF) 303. The control plane functions also include a Network Slice Selection Function (NSSF) 304, a Policy Control Function (PCF) 305, a Session Management Function (SMF) 306, and a Unified Data Management Function (UDM) 307. The control plane functions include an Application Function (AF) 308, an Authentication Server Function (AUSF) 309, and a UE radio Capability Management Function (UCMF) 310. The control plane functions also include a Location Management Function (LMF) 311 and a Network Slice Access Control Function (NSACF) 312. In this way, the control plane functions are configured by a plurality of Network Functions (NFs).

[0033] Here, the AF 308 can operate as a NF that processes the control plane of the application server 40. The AF 308 may be implemented in the same physical device as the application server 40, that is, as an entity logically different from the application server 40. The AF 308 may also operate as a NF that processes the control plane for a 5GS application and be located in the 5GC 30.

[0034] A service provider that manages and operates the application server 40 can obtain information from each NF of the 5G system via the NEF 302 within the scope of the SLA with the PLMN operator. The NEF 302 can securely secure and disclose the capabilities and events of each NF to the service provider.

[0035] The UDM 307 includes a UDR (Unified Data Repository) that stores and manages the contracting party information, and an FE (Front End) unit that processes the contracting party information.

[0036] The AMF 301 performs mobility management. Detailed operations of the AMF 301 related to this embodiment will be described later. The SMF 306 performs session management.

[0037] The PCF 305 provides a unified policy framework for governing network operations, provides policy rules to each network function in the control plane, and accesses subscriber information from the UDR for policy decisions.

[0038] The UCMF 310 holds UE Radio Capability Information corresponding to all UE Radio Capability IDs in a PLMN, and is responsible for assigning each PLMN-assigned UE Radio Capability ID.

[0039] In the UE-Based mode, the LMF 311 provides assistance data for positioning to the terminal device 10. The terminal device 10 can perform measurements related to the Global Navigation Satellite System (GNSS) and calculate its position using the assistance data acquired from the LMF 311. The terminal device 10 can use, for example, a widely known technique called Assisted-GNSS.

[0040] In the UE-Assisted mode, the LMF 311 acquires GNSS-related measurement values ​​such as Code Phase, Doppler, and Carrier Phase from the terminal device 10 equipped with a GNSS receiver, and calculates the position of the terminal device 10 .

[0041] Furthermore, for terminal devices 10 that are equipped with a GNSS receiver but cannot receive signals from the GNSS, or that are not equipped with a GNSS, the LMF 311 acquires information relating to the location of the terminal device 10 using positioning techniques called: -OTDOA (Observed Time Difference Of Arrival) -Multi-RTT (Round Trip Time) -DL AoD (Downlink Angle-of-Departure) -DL TDOA (Downlink Time Difference Of Arrival) -UL TDOA (Uplink Time Difference Of Arrival) -UL AoA (Angle of Arrival).

[0042] NSACF 312 monitors and controls the number of terminal devices 10 registered for each network slice, the number of established PDU sessions, and the number of terminal devices 10 establishing one or more PDU sessions. This allows NSACF 312 to apply admission control to prevent congestion in each network slice. NSACF 312 also supports notification and reporting of the status of network slices in response to events to each NF.

[0043] One of the requirements for network slices is to ensure isolation between them. In particular, when multiple network slices are supported within limited radio resources, admission control is applied to prevent congestion in each network slice so as not to affect other network slices.

[0044] The NSSF 304 will be described later.

[0045] Namf is a service-based interface provided by the AMF 301. Nsmf is a service-based interface provided by the SMF 306. Nnef is a service-based interface provided by the NEF 302.

[0046] Npcf is a service-based interface provided by the PCF 305. Nudm is a service-based interface provided by the UDM 307. Naf is a service-based interface provided by the AF 308. Nnrf is a service-based interface provided by the NRF 303.

[0047] Nnssf is a service-based interface provided by the NSSF 304. Nausf is a service-based interface provided by the AUSF 309. Nucmf is a service-based interface provided by the UCMF 310.

[0048] Nlmf is a service-based interface provided by the LMF 311. Nnsacf is a service-based interface provided by the NSACF 312.

[0049] Each NF can request or subscribe to a service provided by another network function and receive a response or notification from the service. That is, each NF exchanges information with other NFs by means of a request / response or a subscribe / notification via each service-based interface.

[0050] A UPF (User Plane Function) 330 has a function of processing the user plane. A DN (Data Network) 340 has a function of enabling connection to a mobile network operator (MNO)'s (Mobile Network Operator) proprietary service, the Internet, and a third-party service.

[0051] The UPF 330 functions as a forwarding processing unit for user plane data processed by the application server 40. The UPF 330 also functions as a gateway connected to the base station device 20.

[0052] Here, 5GS can configure each NF of 5GC 30 using virtualization or a container and implement it on a cloud server. Furthermore, 5GS can set each NF dynamically and reconfigurably using SDN (Software Defined Network).

[0053] The base station device 20 has a function that enables connection to a RAN and connection to an AN other than the RAN. The base station device 20 includes a base station device called a gNB or ng-eNB. The RAN is sometimes called an NG (Next Generation)-RAN.

[0054] The functions of the base station device 20 are divided into a CU (Central Unit) that processes L2 / L3 functions above the PDCP (Packet Data Convergence Protocol) sublayer, and a DU (Distributed Unit) that processes L2 / L1 functions below the RLC (Radio Link Control) sublayer. The functions of the base station device 20 can be distributed and arranged via an F1 interface.

[0055] Furthermore, the functions of the DU are divided into an RU (Radio Unit) that processes the LOW PHY sublayer and radio section, and a DU that processes the RLC, MAC (Medium Access Control) and HIGH PHY sublayers.

[0056] The RU functionality may be distributed over, for example, an evolved Common Public Radio Interface (eCPRI) compliant fronthaul.

[0057] Here, 5GS can configure the functions of the CU and / or DU using virtualization or containers and implement them on a cloud server. Furthermore, 5GS can use SDN to dynamically and reconfigure the functions of the CU and / or DU.

[0058] Between the terminal device 10 and the AMF 301, information is exchanged via a reference point N1. Between the base station device 20 and the AMF 301, information is exchanged via a reference point N2. Between the SMF 306 and the UPF 330, information is exchanged via a reference point N4.

[0059] (2.2. Configuration Example of Base Station Device) Next, the base station device 20 will be described. The base station device 20 is a communication device that operates a cell and provides wireless communication services to one or more terminal devices 10 located within the coverage of the cell. The cell is operated according to any wireless communication method, for example, LTE or NR. The base station device 20 is connected to a core network 30. The core network 30 is connected to a packet data network via a gateway device. In addition, the base station device 20 operates beams that can be identified by SSB (Synchronization Signal / PBCH Block), and transmits and receives data to and from one or more terminal devices 10 via one or more beams.

[0060] The base station device 20 may be configured as a collection of multiple physical or logical devices. For example, in an embodiment of the present disclosure, the base station device 20 may be divided into multiple devices, a baseband unit (BBU) and a radio unit (RU), and may be interpreted as a collection of these multiple devices. Additionally or alternatively, in an embodiment of the present disclosure, the base station device 20 may be either or both of a BBU and an RU. The BBU and the RU may be connected via a predetermined interface (e.g., eCPRI). Additionally or alternatively, the RU may be referred to as an RRU (Remote Radio Unit) or an RD (Radio DoT). Additionally or alternatively, the RU may correspond to a gNB-DU (gNB-CU) (described later). Additionally or alternatively, the BBU may correspond to a gNB-CU (gNB-CU) (described later). Alternatively, the RU may be connected to a gNB-DU (gNB-DU). Furthermore, the BBU may correspond to a combination of a gNB-CU and a gNB-DU (gNB-DU) (described later). Additionally or alternatively, the RU may be a device integrally formed with an antenna. The antenna of the base station device 20 (e.g., an antenna integrally formed with the RU) may employ an Advanced Antenna System and support MIMO (e.g., FD-MIMO) and beamforming. In the Advanced Antenna System, the antenna of the base station device 20 (e.g., an antenna integrally formed with the RU) may have, for example, 64 transmitting antenna ports and 64 receiving antenna ports.

[0061] Furthermore, multiple base station devices 20 may be connected to each other. One or more base station devices 20 may be included in a Radio Access Network (RAN). That is, the base station device 20 may simply be referred to as a RAN, a RAN node, an Access Network (AN), and an AN node. The RAN in LTE is called an Enhanced Universal Terrestrial RAN (EUTRAN). The RAN in NR is called an NGRAN. The RAN in W-CDMA (UMTS) is called a UTRAN. The base station device 20 in LTE is called an Evolved Node B (eNodeB) or eNB. That is, the EUTRAN includes one or more eNodeBs (eNBs). Furthermore, the base station device 20 in NR is called a gNodeB or gNB. That is, the NGRAN includes one or more gNBs. Furthermore, the EUTRAN may include a gNB (en-gNB) connected to a core network (EPC) in an LTE communication system (EPS). Similarly, the NGRAN may include an ng-eNB connected to a core network 5GC in a 5G communication system (5GS). Additionally or alternatively, if the base station device 20 is an eNB, gNB, or the like, it may be referred to as 3GPP Access. Additionally or alternatively, if the base station device 20 is a wireless access point (e.g., a Wi-Fi (registered trademark) access point), it may be referred to as Non-3GPP Access. Additionally or alternatively, the base station device 20 may be an optical extension device called an RRH (Remote Radio Head). Additionally or alternatively, when the base station device 20 is a gNB, the base station device 20 may be referred to as a combination of the above-mentioned gNB CU (Central Unit) and gNB DU (Distributed Unit), or as either of them. The gNB CU (Central Unit) hosts multiple upper layers (e.g., RRC, SDAP, PDCP) of the Access Stratum for communication with the terminal device 10.On the other hand, the gNB-DU hosts multiple lower layers (e.g., RLC, MAC, PHY) of the Access Stratum. That is, among the messages and information described below, RRC signaling (e.g., MIB, various SIBs including SIB1, RRCSetup message, RRCReconfiguration message) is generated in the gNB CU, while DCI and various physical channels (e.g., PDCCH, PBCH) described below may be generated in the gNB DU. Alternatively, some configuration (setting information) of the RRC signaling, such as IE:cellGroupConfig, may be generated in the gNB-DU, and the remaining configuration may be generated in the gNB-CU. These configurations (setting information) may be transmitted and received via an F1 interface, which will be described later. A base station device 20 may be configured to be able to communicate with other base station devices 20. For example, when multiple base station devices 20 are eNBs or a combination of an eNB and an en-gNB, the base station devices 20 may be connected to each other via an X2 interface. Additionally or alternatively, when multiple base station devices 20 are gNBs or a combination of an ng-eNB and a gNB, the devices may be connected to each other via an Xn interface. Additionally or alternatively, when multiple base station devices 20 are a combination of a gNB CU and a gNB DU, the devices may be connected via the F1 interface described above. Messages and information (RRC signaling or DCI information, Physical Channel) described below may be communicated between multiple base station devices 20 (e.g., via the X2, Xn, and F1 interfaces).

[0062] Furthermore, as described above, the base station device 20 may be configured to manage multiple cells. A cell provided by the base station device 20 is called a serving cell. The serving cell includes a PCell (Primary Cell) and an SCell (Secondary Cell). When dual connectivity (e.g., EUTRA-EUTRA Dual Connectivity, EUTRA-NR Dual Connectivity (ENDC), EUTRA-NR Dual Connectivity with 5GC, NR-EUTRA Dual Connectivity (NEDC), NR-NR Dual Connectivity) is provided to a terminal device (e.g., terminal device 10), the PCell and zero or more SCell(s) provided by the MN (Master Node) are called a Master Cell Group. Furthermore, the serving cell may include a PSCell (Primary Secondary Cell or Primary SCG Cell). That is, when Dual Connectivity is provided to the terminal device 10, the PSCell and zero or one or more SCell(s) provided by the SN (Secondary Node) are called an SCG (Secondary Cell Group). Unless special configuration (for example, PUCCH on SCell) is performed, the Physical Uplink Control Channel (PUCCH) is transmitted by the PCell and PSCell, but not by the SCell. Also, Radio Link Failure is detected by the PCell and PSCell, but not by the SCell (it does not need to be detected). As such, the PCell and PSCell have special roles among the Serving Cell(s), and are therefore also called SpCells (Special Cells). One cell may be associated with one downlink component carrier and one uplink component carrier. Furthermore, the system bandwidth corresponding to one cell may be divided into multiple bandwidth parts (BWPs).In this case, one or more BWPs may be configured in the terminal device 10, and one BWP may be used as an Active BWP by the terminal device 10. Furthermore, radio resources (for example, frequency band, numerology (subcarrier spacing), slot format (Slot configuration)) that the terminal device 10 can use may differ for each cell, each component carrier, or each BWP.

[0063] 3 is a diagram illustrating a configuration example of a base station device according to an embodiment of the present disclosure. The base station device 20 is a communication device (wireless system) that wirelessly communicates with the terminal device 10. The base station device 20 is a type of information processing device.

[0064] The base station device 20 includes a communication unit 21, a storage unit 22, a network communication unit 23, and a control unit 24. Note that the configuration shown in FIG. 3 is a functional configuration, and the hardware configuration may be different. Furthermore, the functions of the base station device 20 may be distributed and implemented in multiple physically separated devices. For example, as described above, the functions of the base station device 20 may be distributed to a CU and a DU, or to a CU, a DU, and a RU.

[0065] The communication unit 21 is a wireless communication interface (signal processing unit) that communicates wirelessly with other communication devices (for example, the terminal device 10 and other base station devices 20). The communication unit 21 is a wireless transceiver that operates under the control of the control unit 24. The communication unit 21 may be compatible with multiple wireless access methods. For example, the communication unit 21 may be compatible with both NR and LTE. The communication unit 21 may be compatible with other cellular communication methods such as W-CDMA and cdma2000. Furthermore, the communication unit 21 may be compatible with a wireless LAN communication method in addition to the cellular communication method. Of course, the communication unit 21 may only be compatible with one wireless access method.

[0066] The communication unit 21 includes a reception processing unit 211, a transmission processing unit 212, and an antenna 213. The communication unit 21 may include a plurality of reception processing units 211, a plurality of transmission processing units 212, and a plurality of antennas 213. Note that, when the communication unit 21 supports a plurality of radio access methods, each unit of the communication unit 21 may be configured individually for each radio access method. For example, when the base station device 20 supports NR and LTE, the reception processing unit 211 and the transmission processing unit 212 may be configured individually for NR and LTE.

[0067] The reception processing unit 211 processes an uplink signal received via the antenna 213. The reception processing unit 211 includes a radio reception unit 211a, a demultiplexing unit 211b, a demodulation unit 211c, and a decoding unit 211d.

[0068] The radio receiving unit 211a performs down-conversion, removal of unnecessary frequency components, control of amplification level, quadrature demodulation, conversion to a digital signal, removal of guard intervals, and extraction of frequency domain signals by fast Fourier transform on the uplink signal. For example, assume that the radio access method of the base station device 20 is a cellular communication method such as LTE. In this case, the demultiplexing unit 211b separates uplink channels such as PUSCH (Physical Uplink Shared Channel) and PUCCH (Physical Uplink Control Channel) and uplink reference signals from the signal output from the radio receiving unit 211a. The demodulating unit 211c demodulates the received signal using a modulation method such as BPSK (Binary Phase Shift Keying) and QPSK (Quadrature Phase Shift Keying) for the modulation symbols of the uplink channel. The modulation scheme used by the demodulator 211c may be multi-level QAM such as 16QAM (Quadrature Amplitude Modulation), 64QAM, or 256QAM. The decoder 211d performs decoding processing on the coded bits of the demodulated uplink channel. The decoded uplink data and uplink control information are output to the controller 24.

[0069] The transmission processing unit 212 performs processing for transmitting downlink control information and downlink data, and includes an encoding unit 212a, a modulation unit 212b, a multiplexing unit 212c, and a radio transmission unit 212d.

[0070] The encoder 212a encodes the downlink control information and downlink data input from the controller 24 using a coding method such as block coding, convolutional coding, or turbo coding. Here, the encoding may be performed using polar codes or low-density parity check codes (LDPC codes). The modulator 212b modulates the coded bits output from the encoder 212a using a predetermined modulation method such as BPSK, QPSK, 16QAM, 64QAM, or 256QAM. The multiplexer 212c multiplexes the modulation symbols of each channel and the downlink reference signal and allocates the multiplexed symbols to predetermined resource elements. The radio transmitter 212d performs various signal processing on the signal from the multiplexer 212c. For example, the radio transmitter 212d performs processing such as conversion to the time domain using fast Fourier transform, addition of guard intervals, generation of baseband digital signals, conversion to analog signals, quadrature modulation, upconversion, removal of unnecessary frequency components, and power amplification. The signal generated by the transmission processing unit 212 is transmitted from an antenna 213 .

[0071] The storage unit 22 is a data readable / writable storage device such as a DRAM, an SRAM, a flash memory, a hard disk, etc. The storage unit 22 functions as a storage means of the base station device 20.

[0072] The network communication unit 23 is a communication interface for communicating with other devices (e.g., other base station devices 20). For example, the network communication unit 23 is a LAN interface such as a NIC. The network communication unit 23 may be a USB interface configured with a USB host controller, a USB port, etc. The network communication unit 23 may also be a wired interface or a wireless interface. The network communication unit 23 functions as a network communication means of the base station device 20. The network communication unit 23 communicates with other devices under the control of the control unit 24.

[0073] The control unit 24 is a controller that controls each unit of the base station device 20. The control unit 24 is realized by a processor such as a CPU, an MPU, or a GPU. For example, the control unit 24 is realized by a processor executing various programs stored in a storage device inside the base station device 20 using RAM or the like as a working area. The control unit 24 may also be realized by an integrated circuit such as an ASIC or an FPGA. The CPU, MPU, GPU, ASIC, and FPGA can all be considered as controllers.

[0074] (2.3. Configuration Example of Terminal Device) Fig. 4 is a block diagram showing a configuration example of a terminal device according to an embodiment of the present disclosure. The configuration example of the terminal device 10 according to an embodiment of the present disclosure will be described with reference to Fig. 4 .

[0075] The terminal device 10 is a wireless communication device that, for example, wirelessly communicates with the base station device 20. The terminal device 10 is, for example, a mobile phone, a smart device (smartphone or tablet), a PDA (Personal Digital Assistant), or a personal computer. The terminal device 10 may also be a wearable device such as a head-mounted display, VR goggles, or smart glasses that has a function of wirelessly transmitting and receiving data.

[0076] The terminal device 10 may also be capable of sidelink communication with other terminal devices 10. The terminal device 10 may use an automatic retransmission technique such as HARQ (Hybrid Automatic Repeat reQuest) when performing sidelink communication. The terminal device 10 may also be capable of NOMA (Non Orthogonal Multiple Access) communication with the base station device 20. The terminal device 10 may also be capable of NOMA communication in communication (sidelink) with other terminal devices 10. The terminal device 10 may also be capable of LPWA (Low Power Wide Area) communication with other communication devices (e.g., base station device 20 and other terminal devices 10). Alternatively, the wireless communication used by the terminal device 10 may be wireless communication using millimeter waves. The wireless communication (including sidelink communication) used by the terminal device 10 may be wireless communication using radio waves or wireless communication using infrared or visible light (optical wireless).

[0077] The terminal device 10 may simultaneously connect to multiple base station devices 20 or multiple cells to perform communication. For example, if one base station device 20 can provide multiple cells, the terminal device 10 can perform carrier aggregation by using one cell as a pCell and another cell as an sCell. Furthermore, if multiple base station devices 20 can each provide one or multiple cells, the terminal device 10 can realize DC (Dual Connectivity) by using one or multiple cells managed by one base station device 20 (MN (e.g., MeNB or MgNB)) as a pCell, or a pCell (PSCell) and sCell(s) and using one or multiple cells managed by the other base station device 20 (SN (e.g., SeNB or SgNB)) as a pCell (PSCell), or a pCell (PSCell) and sCell(s). DC may also be referred to as MC (Multi Connectivity).

[0078] When a communication area is supported via cells of different base station devices 20 (multiple cells having different cell identifiers or the same cell identifier), the multiple cells can be bundled together using carrier aggregation (CA), dual connectivity (DC), or multi-connectivity (MC) technology to enable communication between the base station device 20 and the terminal device 10. Alternatively, the terminal device 10 can communicate with the multiple base station devices 20 via the cells of the different base station devices 20 using coordinated multi-point transmission and reception (CoMP) technology.

[0079] The terminal device 10 includes a communication unit 11, a storage unit 12, a network communication unit 13, an input / output unit 14, and a control unit 15. Note that the configuration shown in Fig. 4 is a functional configuration, and the hardware configuration may be different from this. Furthermore, the functions of the terminal device 10 may be distributed and implemented in multiple physically separated components.

[0080] The communication unit 11 is a signal processing unit for wireless communication with other wireless communication devices (for example, a base station device 20 and another terminal device 10). The communication unit 11 operates under the control of the control unit 15. The communication unit 11 may be a wireless transceiver compatible with one or more wireless access methods. For example, the communication unit 11 is compatible with both NR and LTE. The communication unit 11 may be compatible with W-CDMA and cdma2000 in addition to NR and LTE. The communication unit 11 may also be compatible with communication using NOMA.

[0081] The communication unit 11 includes a reception processing unit 111, a transmission processing unit 112, and an antenna 113. The communication unit 11 may include a plurality of reception processing units 111, a plurality of transmission processing units 112, and a plurality of antennas 113. The configurations of the communication unit 11, the reception processing units 111, the transmission processing units 112, and the antennas 113 are similar to those of the communication unit 21, the reception processing units 211, the transmission processing units 212, and the antennas 214 of the base station device 20.

[0082] The storage unit 12 is a data readable / writable storage device such as a DRAM, an SRAM, a flash memory, a hard disk, etc. The storage unit 12 functions as a storage means of the terminal device 10.

[0083] The network communication unit 13 is a communication interface for communicating with other devices connected via a network. For example, the network communication unit 13 is a LAN interface such as a NIC. The network communication unit 13 may be a wired interface or a wireless interface. The network communication unit 13 functions as a network communication means of the terminal device 10. The network communication unit 13 communicates with other devices under the control of the control unit 15.

[0084] The input / output unit 14 is a user interface for exchanging information with the user. For example, the input / output unit 14 is an operating device such as a keyboard, a mouse, operation keys, or a touch panel that allows the user to perform various operations. Alternatively, the input / output unit 14 is a display device such as a liquid crystal display (LCD) or an organic electroluminescence display (OLED). The input / output unit 14 may be an audio device such as a microphone, a speaker, or a buzzer. The input / output unit 14 may also be a lighting device such as an LED (Light Emitting Diode) lamp. The input / output unit 14 functions as input / output means (input means, output means, operating means, or notification means) of the terminal device 10. For example, if the terminal device 10 is a sensor or the like, the input / output unit 14 may be omitted.

[0085] The control unit 15 is a controller that controls each unit of the terminal device 10. The control unit 15 is realized by a processor such as a CPU, an MPU, or a GPU. For example, the control unit 15 is realized by a processor executing various programs stored in a storage device inside the terminal device 10 using RAM or the like as a work area. The control unit 15 may also be realized by an integrated circuit such as an ASIC or an FPGA. The CPU, MPU, GPU, ASIC, and FPGA can all be considered as controllers.

[0086] (3. First Embodiment) A cellular system according to an embodiment of the present disclosure will be described. The cellular system includes a core network and a base station device 20. The core network manages a plurality of base station devices 20. This core network may be deployed in the cloud. The base station device 20 controls and manages overall wireless communication, such as managing frequency resources and time resources for wireless communication. The base station device 20 may be implemented separately as the BBU and RRH described above. The configuration of this base station device 20 will be described using FIG. 5.

[0087] Fig. 5 is a diagram showing a configuration example of a base station device according to the first embodiment of the present disclosure. Similar to Fig. 3, Fig. 5 is a diagram showing a configuration example of a base station device 20. The base station device 20 in Fig. 5 includes a BBU 220 and an RRH 230. The BBU 220 includes a reception processing unit 211, a transmission processing unit 212, and a control unit 24. The RRH 230 includes a radio reception unit 211a and a radio transmission unit 212d. In this manner, most of the signal processing units are implemented in the BBU 220. Furthermore, the RRH 230 includes an analog unit that handles RF (Radio Frequency), an antenna, and the like.

[0088] The BBU 220 and the RRH 230 are connected by, for example, a cable or an optical fiber. By adopting such a configuration, the RRH 230 equipped with an antenna can be made smaller, and installation costs can also be reduced. Transmission and reception between the BBU 220 and the RRH 230 is performed based on the Common Public Radio Interface (CPRI) standard. The BBU 220 may be located on the cloud side or on the local area network side. The core network may also be located on the cloud side or on the local area network side.

[0089] FIG. 6A is a diagram showing an example of the configuration of a conventional network system. The network system in the figure corresponds to a private network and is a system that operates a cell 200 formed on a part of a route 2. Route 2 is, for example, a road or a railway. Route 2 in the figure is assumed to be a road. The network system in the figure includes a base station device 20 equipped with an antenna 213. The cell 200 is limited to a narrow range of route 2. The terminal device 10 is, for example, owned by a user traveling along route 2. The terminal device 10 can transmit and receive only when it enters the range of the cell 200. For example, there is a use case in which stored data is to be uploaded at high speed. Or, there is also a case in which high-speed downloading is desired.

[0090] However, in the case of a non-public network, it is necessary to minimize unnecessary radiation outside the user's own property. Furthermore, since cells are not contiguous and a single cell suddenly appears, there may not be enough time for registration and high-speed transmission when the terminal device 10 is moving. In the case of a single cell as shown in Figure 6A, the terminal device 10 approaches while detached from the network, so a registration procedure is required instead of a handover. This registration is a procedure by which the base station device 20 obtains an IP address from the network, and may take from several seconds to approximately 30 seconds.

[0091] 6B is a diagram showing an example of the configuration of a conventional network system. The network system shown in the figure includes a directional antenna 215. Even in such a system, if a user travels at high speed in a vehicle such as a car, there is insufficient time for registration and high-speed transmission, and the user ends up going outside the range of cell 200.

[0092] [Configuration of Base Station Device] Fig. 7 is a diagram illustrating a configuration example of a base station device according to the first embodiment of the present disclosure. The figure is a block diagram illustrating a configuration example of a base station device 20. The base station device 20 in the figure includes a BBU 220, an RRH 230, a branching unit 240, an antenna 260, and an antenna 250.

[0093] Antenna 260 is an antenna for SISO (Single Input Single Output) communication. The antenna 260 in FIG. 7 is a leaky coaxial cable antenna. A leaky coaxial cable is an antenna that uses radio waves leaking from gaps called slits formed at regular intervals in a coaxial cable. In other words, the coaxial cable itself is used as an antenna. This antenna is suitable for situations where a certain level of communication quality must be maintained in a linear area, such as inside a tunnel. The black circles on antenna 260 in FIG. 7 represent slits 261. The signals leaking from multiple slits are the same. Therefore, multiple transmission / reception points can be used for transmission / reception with the same base station device 20 having the same cell ID. Therefore, when moving between multiple transmission / reception points leaking from multiple slits, procedures such as handover to change base station devices are not required. This is because each transmission / reception point is connected to only one base station device 20. This leaky coaxial cable antenna enables cell coverage to be extended linearly over a very long range.

[0094] The antenna 250 is an antenna for MIMO (Multiple Input Multiple Output) communication. The antenna 250 is configured with multiple antennas. For example, the antenna 250 can be configured with eight antennas. Beamforming is performed by these multiple antennas, enabling high-speed transmission.

[0095] Branching unit 240 branches the signal from antenna 260 and one of antennas 250. Branching unit 240 is a device that can split one input signal into two antennas and output the two input signals as one output signal.

[0096] The control unit 24 included in the BBU 220 controls the registration of the terminal device 10 to the core network using wireless communication via the antenna 260, and controls wireless communication between the terminal device 10 and the antenna 250 after the registration. The control unit 54 associates the antenna 250 and the antenna 260 with the same cell ID. Note that a description of the RRH 230 will be omitted. Note that the antenna 260 is an example of a "first antenna" in the present disclosure. The antenna 250 is an example of a "second antenna" in the present disclosure.

[0097] [Configuration of Network System] Fig. 8 is a diagram showing an example configuration of a network system according to the first embodiment of the present disclosure. As shown in the figure, the antenna 260 is arranged along a route 2 from near the edge of the cell of the antenna 250. The base station device 20 attaches to the network when the terminal device 10 approaches the antenna 260. While maintaining this state with the antenna 260, data is transmitted and received using the subsequent antenna 250, which is capable of high-speed transmission.

[0098] In this way, the registration process of the base station device 20 is performed using the antenna 260 arranged along the route 2 from near the edge of the cell of the antenna 250. After that, when the base station device 20 reaches the cell of the antenna 250, the base station device 20 communicates with the terminal device 10 using the antenna 250. This makes it possible to extend the period of wireless communication via the antenna 250.

[0099] When using the antenna 250, the base station device 20 needs to acquire propagation path information for the antenna 250. Furthermore, the base station device 20 needs to perform beamforming of the antenna 250. This procedure can be performed as follows. First, the base station device 20 transmits a propagation path information reference signal (CSI-RS) to the terminal device 10. The terminal device 10 receives the CSI-RS, performs measurements, generates a measurement report, and transmits it to the base station device 20. The base station device 20 acquires propagation path information based on the measurement report. Furthermore, the base station device 20 performs beamforming of the antenna 250 based on the measurement report.

[0100] Furthermore, the terminal device 10 may transmit a sounding reference signal (SRS) to the base station device 20, and the base station device 20 may acquire propagation path information and perform beamforming based on the SRS.

[0101] The process of acquiring the propagation path information can be performed within a predetermined period after the registration of the terminal device 10. The period for performing the process of acquiring the propagation path information is specified in advance in the base station device 20 and the terminal device 10. This allows the base station device 20 and the terminal device 10 to secure frequency resources and time resources for acquiring the propagation path information. The process of acquiring the propagation path information can be performed with priority, and the period leading up to the acquisition of the propagation path information can be shortened. This allows the period of wireless communication by the antenna 250 to be further extended.

[0102] This predetermined period can be transmitted from the base station device 20 to the terminal device 10 by a 5G identifier (5QI) of quality of service (QoS) in a protocol data unit (PDU) session established between the terminal device 10 and the core network 30. Specifically, the control unit 24 performs control to include information about the predetermined period in the 5QI and transmit it to the terminal device 10. The predetermined period can start from the establishment of the PDU session, for example. Furthermore, the predetermined period can be expressed by, for example, the number of frames or the number of slots.

[0103] [Communication Processing] Fig. 9 is a diagram showing an example of a processing procedure of communication processing according to the first embodiment of the present disclosure. The figure is a diagram explaining an outline of communication processing in the base station device 20 and the terminal device 10. Of the processing in the figure, steps S101 to S104 are performed in a low-speed transmission region, i.e., a communication region using the antenna 260. Furthermore, steps S105 to S107 are performed in a high-speed transmission region, i.e., a communication region using the antenna 250.

[0104] First, the base station device 20 starts a registration process (step S101). The terminal device 10 performs measurements for CSI (Channel Status Information) in a low-speed region and determines an optimal MCS (Modulation Coding Scheme) (step S102). Next, low-speed transmission (UL / DL) is started in the terminal device 10 and the base station device 20 (step S103). Next, a client-side application in the terminal device 10 accesses a server-side application on the network (step S104). Next, the terminal device 10 performs measurements for CSI in a high-speed region and determines an optimal MIMO layer and MCS (step S105). Next, high-speed transmission (UL / DL) is started in the terminal device 10 and the base station device 20 (step S106). After that, the client-side application in the terminal device 10 gradually increases the data transfer rate (step S107).

[0105] FIG. 10 is a diagram illustrating an example of communication processing according to the first embodiment of the present disclosure. This diagram illustrates communication processing in a network system. The diagram illustrates a terminal device 10, a base station device 20, and a core network 30. First, the base station device 20 transmits a CSI-RS (CSI-RS) to the terminal device 10 using the antenna 260 (step S131). Having received the CSI-RS, the terminal device 10 performs measurements (step S132) and transmits a measurement report to the base station device 20 (step S133). Next, the terminal device 10 transmits a registration request to the base station device 20 (step S141). The base station device 20 transmits the registration request of the terminal device 10 to the core network 30 (step S142). The core network performs registration processing and notifies the base station device 20 of registration acceptance (step S143). The base station device 20 notifies the terminal device 10 of registration acceptance (step S144).

[0106] Next, the terminal device 10 transmits a protocol data unit (PDU) session request to the base station device 20 (step S151). Next, the base station device 20 transmits the PDU session request to the core network 30 (step S152). Thereafter, a PDU session is established (step S153). At this time, the base station device 20 transmits information about the above-mentioned predetermined period to the terminal device 10.

[0107] The base station device 20 transmits the CSI-RS to the terminal device 10 after a predetermined period (71 in FIG. 10) has elapsed (step S161). The terminal device 10 that has received the CSI-RS performs measurements (step S162) and generates a measurement report. Next, the terminal device 10 transmits the measurement report to the base station device 20 (step S163). As a result, the base station device 20 acquires propagation path information and performs beamforming of the antenna 250.

[0108] The terminal device 10 transmits the SRS to the base station device 20 after a predetermined period (72 in FIG. 10 ) has elapsed (step S171). The base station device 20 acquires propagation path information based on the received SRS and performs beamforming of the antenna 250.

[0109] Either the process of acquiring propagation path information using CSI-RS in steps S161 to S163 or the process of acquiring propagation path information in step S171 can be performed.

[0110] In this way, the base station device 20 according to the first embodiment of the present disclosure includes the antenna 260 and the antenna 250, performs the registration process for the terminal device 10 using the antenna 260, and performs wireless communication after registration using the antenna 250. This allows the registration process to be performed in advance, and the time for normal wireless communication using the antenna 250 can be extended.

[0111] (4. Second Embodiment) The base station device 20 of the first embodiment described above includes the antenna 260 and performs the registration process of the terminal device 10 in advance. In contrast, the base station device 20 of the second embodiment of the present disclosure differs from the first embodiment described above in that it detects the time it takes for the terminal device 10 to reach the cell of the antenna 250 after registration.

[0112] [Configuration of base station device] Fig. 11 is a diagram showing a configuration example of a base station device according to the second embodiment of the present disclosure. Similar to Fig. 7, Fig. 11 is a block diagram showing a configuration example of a base station device 20. The base station device 20 in Fig. 11 differs from the base station device 20 in Fig. 7 in that it further includes a detection unit 270.

[0113] The detection unit 270 detects the terminal device 10. For example, a camera or radar can be applied to this detection unit 270. The detection unit 270 detects a vehicle or the like carrying the user of the terminal device 10 traveling along the route 2, and outputs the detection result to the control unit 24. The control unit 24 detects the time at which the terminal device 10 reaches the cell of the antenna 250 based on the detection result. Next, the control unit 24 can allocate frequency resources and time resources for acquiring propagation path information to the detected time. That is, the control unit 24 controls the acquisition of propagation path information during a predetermined period starting from the detection of the terminal device 10 by the detection unit 270. This allows the process of acquiring propagation path information to be performed with priority.

[0114] The detection unit 270 can also be configured to receive an RF tag that can acquire the vehicle ID. Furthermore, by using a camera that can acquire the vehicle's image ID or vehicle license plate number as an image in the detection unit 270, it becomes possible to link the IDs of the vehicle and the terminal device 10. In this case, it becomes possible to calculate the measurement time required for a specific vehicle.

[0115] The configuration of the base station device other than that described above is the same as the configuration of the base station device in the first embodiment of the present disclosure, and therefore description thereof will be omitted.

[0116] As described above, the base station device according to the second embodiment of the present disclosure includes the detection unit 270, and detects the time it takes for the terminal device 10, after the registration process, to reach the cell of the antenna 250. This makes it possible to extend the period of wireless communication in the cell of the antenna 250.

[0117] (5. Third Embodiment) The base station device of the above-described first embodiment includes the antenna 260 and performs in advance the registration process of the terminal device 10. In contrast, the base station device of the third embodiment of the present disclosure differs from the above-described first embodiment in that it transmits information about the terminal device 10 to an application.

[0118] The application and cellular communication are separate layers, and the application layer cannot recognize the communication speed of the cellular communication in the lower layer. For this reason, the application layer gradually increases the amount of packets in the application layer, and gradually reduces the amount of packets if there is no response such as an ACK from the other application. In addition, the application gradually increases the amount of packets if the packet transmission is successful. In other words, the application layer and the communication layer do not cooperate with each other and operate as separate layers.

[0119] There is a technology that observes the amount of packets that can be sent at the application layer, predicts future packet volumes, and increases or decreases the amount of packets at the application layer based on the prediction. However, this technology merely predicts the future based on past changes in communication volume, and does not link the application layer and the cellular communication layer. In a single-cell use case such as the network system disclosed herein, the communication environment changes dramatically. That is, the channel environment changes dramatically when the terminal device 10 enters the area of ​​the antenna 260 and when the terminal device 10 enters the high-speed communication area provided by the antenna 250. Therefore, it is difficult to predict the throughput that cellular communication can provide based on past communication volume, etc.

[0120] Therefore, when the base station device 20 detects that the terminal device 10 has been registered, it notifies the application that communication to the terminal device 10 will occur. Thereafter, the base station device 20 detects the time when the terminal device 10 will enter a high-speed communication area using the antenna 250. The base station device 20 then notifies the application of the time when the terminal device 10 will enter the high-speed communication area, and increases the amount of packets in the application layer according to that time. Note that a configuration in which the core network 30 notifies the application may also be adopted. Note that the time when the high-speed communication area will be entered is an example of "transmission speed information" in the present disclosure.

[0121] The time when the terminal device 10 enters the high-speed communication area using the antenna 250 can be detected using, for example, the detection unit 270 in FIG.

[0122] [Communication Processing] Fig. 12 is a diagram showing an example of communication processing according to the third embodiment of the present disclosure. Similar to Fig. 10, this figure shows communication processing in a network system. This figure also shows an application server 40 on which an application is deployed.

[0123] After transmitting the registration acceptance to the terminal device 10, the base station device 20 notifies the application of the application server 40 (step S181). After acquiring the propagation path information of the antenna 250, the base station device 20 transmits the transmission rate information to the application of the application server 40 (step S182).

[0124] The configuration of the base station device other than that described above is the same as the configuration of the base station device in the first embodiment of the present disclosure, and therefore description thereof will be omitted.

[0125] In this way, the base station device according to the third embodiment of the present disclosure transmits information about the terminal device 10 to the application. This allows the application layer of the terminal device 10 to cooperate with the application of the application server 40, enabling high-speed data communication.

[0126] (6. Fourth Embodiment) A private network system uses a network system in which multiple antennas are arranged along a predetermined route to form cells shaped along the route. In this network system, multiple transmission points are grouped. By combining multiple transmission locations, any desired coverage area shape can be formed. Each transmission point transmits radio waves at low power. As an example of this network system, a train radio system has been proposed in which multiple zones, which are radio areas corresponding to the running route of a train carrying mobile stations, are set, and radio communication is performed between the base station included in each zone and the mobile station via a leaky coaxial cable (for example, JP 2013-160806 A).

[0127] When a plurality of these network systems are deployed, a cell ID is assigned to each network system, and a handover procedure is required when switching to a cell of a different network system due to movement of the terminal device 10.

[0128] It is also possible to assign the same cell ID to network systems arranged along the entire path. However, since transmission and reception points with the same cell ID are connected to a single base station (BBU), the throughput of the entire system is limited by the maximum throughput of a single base station device, which affects performance. Therefore, if you want to obtain so-called cell splitting gain, you need to prepare network systems with different cell IDs.

[0129] However, in a private network system, handover becomes difficult due to the low power consumption of each transmitting and receiving point.

[0130] Therefore, we propose a network system that facilitates handover.

[0131] [Conventional Network System] Fig. 13A is a diagram showing an example of the configuration of a conventional network system. The network system in the figure shows base station devices 20a and 20b each having a plurality of antennas 213 arranged along a path 2. A linear cell can be formed by the plurality of antennas 213. The cell of base station device 20a and the cell of base station device 20b are adjacent to each other, and a handover is required when a terminal device 10 crosses the boundary between them (indicated by the dashed dotted line in the figure).

[0132] 13B is a diagram showing an example of the configuration of a conventional network system. The network system shown in the figure shows base station devices 20a and 20b each having a leaky coaxial cable type antenna 260 arranged along path 2. In the network system shown in the figure, handover is also required at the boundary of adjacent cells.

[0133] In any of the above network systems, handover is difficult because the power of the antenna 213 and the like is small.

[0134] 14 is a diagram showing an example of the configuration of a conventional network system, which shows base station devices 20a and 20b having a normal antenna 213 for comparison.

[0135] Figures 15A and 15B are diagrams showing an example of power between cells in a conventional network system. Figure 15A shows power in the network system of Figure 14. Figure 15B shows power in the network systems of Figures 13A and 13B. The vertical axis in the figure represents power, and the horizontal axis represents position.

[0136] In Fig. 15A, the power of antenna 213 is high, so the power is relatively high even at the boundary between the cell of base station device 20a and the cell of base station device 20b. In contrast, in Fig. 15B, the power of antenna 213 and the like is low, so the power is low at the boundary between the cell of base station device 20a and the cell of base station device 20b. This makes handover difficult.

[0137] 16 is a diagram illustrating a configuration example of a base station device according to a fourth embodiment of the present disclosure. The figure is a block diagram illustrating a configuration example of a base station device 20. The base station devices 20a and 20b in the figure include a BBU 220, an RRH 230, and an antenna 260.

[0138] As shown in the figure, the antennas 260 of adjacent base station devices 20a and 20b are arranged along path 2 in a partially overlapping manner, thereby reducing power loss at the ends of the antennas 260 and facilitating handover.

[0139] The trigger that triggers handover will be described.

[0140] Fig. 17 is a diagram showing an example of a handover trigger according to the fourth embodiment of the present disclosure. The diagram shows events A1 to A6 that trigger handover as defined by 3GPP (registered trademark). In the network system of Fig. 16, event A4 can be applied as a condition for handover. Note that the length of the section where antennas 260 overlap shown in Fig. 16 needs to satisfy the following condition: section length / speed of moving body<time required for handover procedure

[0141] In addition, in event A4, when a new cell is found, a handover is made to that cell, so if route 2 is curved, there is a problem that the handover to the adjacent cell may not be performed appropriately.

[0142] 18 is a diagram illustrating an example of an arrangement of antennas according to the fourth embodiment of the present disclosure. The diagram illustrates three antennas 260a, 260b, and 260c arranged on a curved path 2. The diagram also shows the cell IDs of the cells of the respective antennas 260. In this manner, the cell IDs can be assigned in ascending order according to the direction of movement of a vehicle or the like.

[0143] Furthermore, the event trigger shown in FIG. 19 is introduced.

[0144] FIG. 19 is a diagram showing an example of a handover trigger according to the fourth embodiment of the present disclosure. This figure shows new event 1 and new event 2 that trigger handover. New event 1 is when the ID of a neighboring cell is greater than the current cell ID (Neighbor Cell ID is greater than current Cell ID). New event 2 is when the ID of a neighboring cell is one bigger than the current cell ID (Neighbor Cell ID is one bigger number than current Cell ID), or when the ID of a neighboring cell is greater than the current cell ID by a predetermined value or more, except for the above case (Neighbor Cell ID is bigger number than current Cell ID with amount offset except for the above case). Note that new event 1 is an example of a "first event" in the present disclosure. New event 2 is an example of a "second event" in the present disclosure.

[0145] As described above, by assigning cell IDs to neighboring cells that increase by one each time and using the new event 1 in Fig. 19, it is possible to reduce the possibility of handover to a cell in a direction different from the direction of travel. However, there is still a possibility of handover from cell ID "10" to cell ID "12".

[0146] In this case, new event 2 in FIG. 19 is used. A trigger is activated immediately for a cell ID with a number one higher, but a trigger is not activated for a number one or higher unless the number is equal to or greater than the threshold. Note that if the upper limit for cell IDs is reached, the number returns to "0." By using this new event 2, handover between base station devices 20 equipped with antennas 260 arranged in a curved, overlapping configuration can be performed smoothly.

[0147] The control unit 24 of the base station device 20 can notify the terminal device 10 of event trigger information related to either new event 1 or new event 2. Upon receiving this notification, the control unit 15 of the terminal device 10 can start a handover procedure based on new event 1 or new event 2.

[0148] The configuration of the new event is not limited to this example. For example, a new event can be generated when the ID of an adjacent cell differs from the current cell ID by one.

[0149] The configuration of the base station device other than that described above is the same as the configuration of the base station device in the first embodiment of the present disclosure, and therefore description thereof will be omitted.

[0150] 20 is a diagram illustrating an example of communication processing according to the fourth embodiment of the present disclosure. The diagram illustrates communication processing in a network system. The diagram illustrates a terminal device 10, a base station device 20a, a base station device 20b, a core network 30, and an application server 40.

[0151] First, the base station device 20a notifies the terminal device 10 of the setting of an event trigger including New Event (step S201). Next, the terminal device 10 hits the trigger condition (step S202). Next, the terminal device 10 transmits a measurement report to the base station device 20a (step S203). Next, the base station device 20a outputs a handover request to the base station device 20b (step S204). The base station device 20b transmits a handover acknowledgement to the base station device 20a (step S205). Next, the base station device 20a transmits an RRC configuration to the terminal device 10 (step S206). Next, the terminal device 10 performs random access between the base station device 20b and the terminal device 10 (step S207). Next, the terminal device 10 notifies the base station device 20b of the completion of the RRC configuration (step S208). Next, the terminal device 10 performs random access with the application server 40 (step S209).

[0152] As described above, the base station device according to the fourth embodiment of the present disclosure includes the leaky coaxial cable type antenna 260. This antenna 260 is arranged in a shape that partially overlaps with the antenna 260 of another adjacent base station device 20. This makes it possible to easily perform handover.

[0153] (7. Fifth Embodiment) The base station device of the above-described fourth embodiment includes the leaky coaxial cable antenna 260. In contrast, the base station device of the fifth embodiment of the present disclosure differs from the above-described fourth embodiment in that it further includes a normal antenna.

[0154] [Configuration of base station device] Fig. 21 is a diagram showing a configuration example of a base station device according to the fifth embodiment of the present disclosure. Similar to Fig. 16, Fig. 21 is a block diagram showing a configuration example of a base station device 20. The base station devices 20a and 20b in Fig. 21 differ from the base station device 20 in Fig. 16 in that they further include an antenna 215.

[0155] Antenna 215 is a normal antenna with a relatively large cell range. This antenna 215 is placed at the end of antenna 260. The cell range of antenna 215 is larger than the cell range caused by radio waves leaking from the slits of a leaky coaxial cable type antenna. Therefore, it is easy to form an overlapping section between adjacent cells with different cell IDs. The figure shows an example in which antenna 215 is placed at the end (end in the direction of travel) of antenna 260. This makes it easy to maintain the connection between the terminal device 10 and the cell until handover is complete.

[0156] In this case, there is a possibility that unwanted radiation outside the owner's land will increase at the location where antenna 215 is installed. In this case, antenna 215 can be made directional so that unwanted radiation outside the owner's land will not increase. By directing this directivity toward the next antenna 260, unwanted radiation outside the owner's land can be reduced.

[0157] The configuration of the base station device other than that described above is the same as the configuration of the base station device in the fourth embodiment of the present disclosure, and therefore description thereof will be omitted.

[0158] In this way, the base station device 20 according to the fifth embodiment of the present disclosure places the antenna 215 near the end of the antenna 260. This makes it possible to form a cell that overlaps with the cell of an adjacent base station device 20, facilitating handover.

[0159] (8. Sixth Embodiment) The base station device of the above-described fifth embodiment includes the leaky coaxial cable type antenna 260. In contrast, the base station device of the fifth embodiment of the present disclosure differs from the above-described fourth embodiment in that it includes multiple antennas.

[0160] [Configuration of base station device] Fig. 22 is a diagram illustrating a configuration example of a base station device according to the sixth embodiment of the present disclosure. Similar to Fig. 21, the figure is a block diagram illustrating a configuration example of a base station device 20. The base station devices 20a and 20b in the figure differ from the base station device 20 in Fig. 21 in that they include multiple antennas 213 instead of the antenna 260.

[0161] The multiple antennas 213 are arranged so that their cells overlap. Furthermore, the antenna 215 arranged at the end is configured so as to overlap with the cell of an adjacent base station device 20.

[0162] The configuration of the base station device 20 is not limited to this example. For example, the antenna 215 may be arranged on the left side of the group of antennas 213.

[0163] The configuration of the base station device other than that described above is the same as the configuration of the base station device in the fourth embodiment of the present disclosure, and therefore description thereof will be omitted.

[0164] In this way, the base station device 20 according to the sixth embodiment of the present disclosure places the antenna 215 near the end of the group of antennas 213. This makes it possible to form a cell that overlaps with the cell of an adjacent base station device 20, facilitating handover.

[0165] The configuration of the fourth embodiment of the present disclosure can be applied to other embodiments. Specifically, new event 1 and new event 2 that trigger handover in FIG. 19 can be applied to the first to third embodiments of the present disclosure. In this case, the control unit 24 of the base station device 20 notifies the terminal device 10 of event trigger information related to either new event 1 or new event 2.

[0166] (Other Modifications) In this embodiment, the control device that controls the terminal device 10 and the base station device 20 may be realized by a dedicated computer system or a general-purpose computer system.

[0167] For example, a communication program for executing the above-described operations is stored on a computer-readable recording medium such as an optical disk, a semiconductor memory, a magnetic tape, or a flexible disk and distributed. Then, for example, the program is installed on a computer and the above-described processing is executed to configure a control device. In this case, the control device may be a device external to the terminal device 10 or the base station device 20 (for example, a personal computer). Alternatively, the control device may be a device internal to the terminal device 10 or the base station device 20 (for example, the control unit 15 or the control unit 24).

[0168] The communication program may also be stored in a disk device provided in a server device on a network such as the Internet, and may be downloaded to a computer. The above-described functions may also be realized by a combination of an operating system (OS) and application software. In this case, the components other than the OS may be stored on a medium and distributed, or may be stored in a server device and downloaded to a computer.

[0169] Furthermore, among the processes described in the above embodiments, all or part of the processes described as being performed automatically can be performed manually, or all or part of the processes described as being performed manually can be performed automatically using a known method. In addition, the information including the processing procedures, specific names, various data, and parameters shown in the above documents and drawings can be changed as desired unless otherwise specified. For example, the various information shown in each drawing is not limited to the information shown in the drawings.

[0170] Furthermore, the components of each device shown in the figure are conceptual functional units and do not necessarily have to be physically configured as shown. In other words, the specific form of distribution and integration of each device is not limited to that shown in the figure, and all or part of the devices can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc. Note that this distribution and integration configuration may also be performed dynamically.

[0171] The above-described embodiments can be combined as appropriate within the scope of the present invention without causing any inconsistency in the processing content. The order of the steps shown in the flowcharts of the above-described embodiments can be changed as appropriate.

[0172] Furthermore, for example, the present embodiment can also be implemented as any configuration that constitutes an apparatus or system, such as a processor as a system LSI (Large Scale Integration), a module using multiple processors, a unit using multiple modules, a set in which other functions are added to a unit, or the like (i.e., a configuration of a part of an apparatus).

[0173] In this embodiment, a system refers to a collection of multiple components (devices, modules (components), etc.), regardless of whether all of the components are in the same housing. Therefore, multiple devices housed in separate housings and connected via a network, and a single device in which multiple modules are housed in a single housing, are both systems.

[0174] Furthermore, for example, this embodiment can have a cloud computing configuration in which one function is shared and processed jointly by a plurality of devices via a network.

[0175] Although the embodiments of the present disclosure have been described above, the technical scope of the present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the gist of the present disclosure. Furthermore, components of different embodiments and modifications may be combined as appropriate.

[0176] The series of processes performed by each device described in this specification may be realized using software, hardware, or a combination of software and hardware. The programs constituting the software are stored in advance, for example, in a storage medium (non-transitory medium) provided inside or outside each device. Then, each program is loaded into RAM when executed by a computer, and executed by a processor such as a CPU.

[0177] Furthermore, the processes described herein using flowcharts and sequence diagrams do not necessarily have to be performed in the order shown. Some process steps may be performed in parallel. Furthermore, additional process steps may be employed, and some process steps may be omitted.

[0178] The effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0179] The present technology may also be configured as follows: (1) A base station apparatus including: a wireless communication unit that performs wireless communication with a terminal device via a first antenna and a second antenna; and a control unit that controls registration of the terminal device with a core network using wireless communication via the first antenna and controls wireless communication with the terminal device via the second antenna after the registration. (2) The base station apparatus according to (1), in which the first antenna and the second antenna are associated with the same cell ID. (3) The base station apparatus according to (1), in which the control unit notifies the terminal device of event trigger information related to either a first event or a second event, in which the first event is that an ID of a neighboring cell is greater than an ID of a current cell, and the second event is that the ID of the neighboring cell is greater than the ID of the current cell by 1 or greater than the ID of the current cell by a predetermined value or more. (4) The base station apparatus according to (1), in which the first antenna is an antenna for SISO communication. (5) The base station device according to (2), wherein the first antenna is configured by a leaky coaxial cable antenna. (6) The base station device according to any one of (1) to (5), wherein the second antenna is configured by a plurality of antennas for MIMO communication. (7) The base station device according to any one of (1) to (6), wherein the control unit further controls acquisition of propagation path information during a predetermined period after the registration. (8) The base station device according to (7), wherein the control unit controls transmission of a propagation path information reference signal (CSI-RS) as the control for acquiring the propagation path information. (9) The base station device according to (7), wherein the control unit controls reception of a sounding reference signal (SRS) as the control for acquiring the propagation path information. (10) The base station device according to (7), wherein the control unit includes information about the predetermined period in a 5G identifier (5QI) of a quality of service (QoS) in a protocol data unit (PDU) session established between the terminal device and the core network.(11) The base station device according to (7), further comprising a detection unit that detects the terminal device, wherein the control unit controls acquisition of propagation path information during the predetermined period starting from the detection of the terminal device by the detection unit. (12) The base station device according to (7), wherein the control unit further controls transmission of transmission rate information to an application used by the terminal device that is located in a server of the core network after acquiring the propagation path information. (13) A base station device comprising: a wireless communication unit that performs wireless communication via a leaky coaxial cable antenna arranged along a predetermined path; and a control unit that controls wireless communication of the wireless communication unit, wherein the antenna is arranged in a shape that partially overlaps with a leaky coaxial cable antenna of another base station device that is arranged along the predetermined path. (14) A base station device comprising: a wireless communication unit that performs wireless communication via a first leaky coaxial cable antenna arranged along the predetermined path and a second antenna arranged near an end of the first antenna, and a control unit that controls wireless communication of the wireless communication unit. (15) A base station device comprising: a wireless communication unit that performs wireless communication via a plurality of antennas arranged along a predetermined path; and a control unit that controls the wireless communication of the wireless communication unit, wherein a terminal antenna of the plurality of antennas is adjusted to have directivity toward an antenna of another base station device arranged along the predetermined path. (16) A terminal device comprising: a control unit that controls receiving information for a predetermined period from a base station device when registering the terminal device with a core network, and controls acquiring propagation path information for the predetermined period after the registration. (17) The terminal device according to (16), wherein the control unit controls receiving a propagation path information reference signal (CSI-RS) as the control for acquiring the propagation path information. (18) The terminal device according to (16), wherein the control unit controls transmitting a sounding reference signal (SRS) as the control for acquiring the propagation path information. (19) A terminal device comprising: a control unit that controls starting a handover procedure between two base station devices, each having a cell ID set, based on the cell ID.(20) The terminal device according to (19), wherein the control unit initiates the handover procedure based on event trigger information of either a first event or a second event, wherein the first event is that an ID of a neighboring cell is greater than a current cell ID, and the second event is that the ID of the neighboring cell is greater than the current cell ID by 1, or the ID of the neighboring cell is greater than the current cell ID by a predetermined value or more. (21) A communication method comprising: registering a terminal device with a core network using wireless communication via a first antenna; and performing wireless communication with the terminal device via a second antenna after the registration. (22) A communication method comprising: receiving information for a predetermined period from a base station device when registering its own terminal device with a core network; and acquiring propagation path information for the predetermined period after the registration.

[0180] 2 Path 10 Terminal device 15, 24 Control unit 20, 20a, 20b Base station device 21 Communication unit 30 Core network 40 Application server 213 to 215, 250, 260, 260a Antenna 270 Detection unit

Claims

1. A base station device having a wireless communication unit that performs wireless communication with a terminal device via a first antenna and a second antenna, and a control unit that controls registration of the terminal device to a core network using wireless communication via the first antenna and controls wireless communication with the terminal device via the second antenna after the registration.

2. The base station device according to claim 1, wherein the first antenna and the second antenna are associated with the same cell ID.

3. The base station device according to claim 1, wherein the control unit notifies the terminal device of event trigger information relating to either a first event or a second event, wherein the first event is that the ID of the adjacent cell is greater than the current cell ID, and the second event is that the ID of the adjacent cell is greater than the current cell ID by 1 or is greater than the current cell ID by a predetermined value or more.

4. The base station apparatus according to claim 1, wherein the first antenna is an antenna for SISO communication.

5. The base station device according to claim 1, wherein the first antenna is configured as a leaky coaxial cable type antenna.

6. The base station apparatus according to claim 1, wherein the second antenna is configured with a plurality of antennas for MIMO communication.

7. The base station device according to claim 1, wherein the control unit further performs control to acquire propagation path information during a predetermined period after the registration.

8. The base station device according to claim 7, wherein the control unit controls transmission of a communication signal information reference signal (CSI-RS) as control for acquiring the communication signal information.

9. The base station device according to claim 7, wherein the control unit controls reception of a sounding reference signal (SRS) as control for acquiring the propagation path information.

10. The base station device according to claim 7, wherein the control unit includes information about the predetermined period in a 5G identifier (5QI) of quality of service (QoS) in a protocol data unit (PDU) session established between the terminal device and the core network.

11. The base station device according to claim 7, further comprising a detection unit that detects the terminal device, wherein the control unit controls the acquisition of propagation path information during the predetermined period starting from the detection of the terminal device by the detection unit.

12. The base station device according to claim 7, wherein the control unit further controls transmission of transmission rate information to an application used by the terminal device located in a server of the core network after acquiring the propagation path information.

13. A terminal device having a control unit that controls receiving information from a base station device for a predetermined period when registering the terminal device with a core network, and controls acquiring propagation path information for the predetermined period after the registration.

14. The terminal device according to claim 13, wherein the control unit controls reception of a communication signal information reference signal (CSI-RS) as control for acquiring the communication signal information.

15. The terminal device according to claim 13, wherein the control unit controls transmission of a sounding reference signal (SRS) as control for acquiring the propagation path information.

16. A communication method comprising: registering a terminal device with a core network using wireless communication via a first antenna; and, after said registration, conducting wireless communication with the terminal device via a second antenna.

17. A communication method comprising: receiving information for a predetermined period from a base station device when registering a terminal device to a core network; and acquiring propagation path information for the predetermined period after the registration.

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