Base station control device, base station control method, base station, and setting control method

Abstract

Provided is a base station control device comprising a control unit that controls base stations which communicate with a terminal device moving between a plurality of base stations, wherein the control unit acquires terminal position information pertaining to the position of the terminal device, and, on the basis of the acquired terminal position information, executes optimization processing for optimizing communication between the terminal device and the base stations.

Description

Base station control device, base station control method, base station and setting control method

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

[0002] Conventionally, there has been known an in-vehicle communication unit that communicates with a server terminal that provides a service via a mobile communication network (see, for example, Patent Document 1). The in-vehicle communication unit includes a communication module that communicates with the mobile communication network, and resets the operating state of the communication module when communication for receiving the service is not possible.

[0003] Japanese Patent Application Laid-Open No. 2015-192356

[0004] Meanwhile, a terminal device such as the in-vehicle communication unit of Patent Document 1 communicates with a base station that constitutes a communication network. The base station may be restarted due to a change in frequency settings, etc. When the base station is restarted, it takes time to communicate with the terminal device, which causes an interruption of communication services to users.

[0005] Therefore, the present disclosure proposes a base station control device, a base station control method, a base station, and a setting control method that can optimize communications according to the location of a terminal device while maintaining communication services.

[0006] In order to solve the above problems, the base station control device of the present disclosure is a base station control device that includes a control unit that controls a base station that communicates with a terminal device that moves between multiple base stations, and the control unit acquires terminal location information, which is information regarding the location of the terminal device, and performs an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information.

[0007] 1 is a diagram illustrating an example of a private network. FIG. 2 is a diagram illustrating an example configuration of a communication system. FIG. 3 is a diagram illustrating a base station. FIG. 4 is a diagram illustrating an example of restarting a base station. FIG. 5 is a diagram relating to radio wave interference on own land and other's land. FIG. 6 is a diagram illustrating an example configuration of a base station control device according to the first embodiment of the present disclosure. FIG. 7 is a diagram illustrating an example configuration of a base station according to the first embodiment of the present disclosure. FIG. 8 is a diagram illustrating an example configuration of a communication system according to the first embodiment of the present disclosure. FIG. 9 is a diagram illustrating an example control of a communication system according to the second embodiment of the present disclosure. FIG. 10 is a diagram illustrating an example control of a communication system according to the second embodiment of the present disclosure. FIG. 11 is a diagram illustrating an example of system information. FIG. 12 is a diagram illustrating an example control of a communication system according to the second embodiment of the present disclosure. FIG. 13 is a diagram illustrating an example control of a communication system according to the second embodiment of the present disclosure.

[0008] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. In the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0009] The present disclosure will be described in the following order of items: 1. Overview 1-1. Local 5G / Private 5G 1-2. BBU and RRH 1-3. Service Continuity 1-4. Changing base station settings 1-5. Suppression of unwanted radio waves outside own land 1-6. Overview of proposed technology 2. Configuration example of communication system of first embodiment 2-1. Overall configuration example of communication system 2-2. Configuration example of base station control device 2-3. Configuration example of base station 3. Operation example of communication system of first embodiment 3-1. Overview of operation of communication system 3-2. Method of grasping position of terminal device 3-3. First operation example 3-4. Second operation example 3-5. Third operation example 3-6. Fourth operation example 3-7. Fifth operation example 3-8. Sixth operation example 3-9. Effects 4. Configuration example of communication system of second embodiment 5. Operation example of communication system of second embodiment 5-1. Overview of operation of communication system 5-2. Operation mode of base station 5-3. First operation example 5-4. Second operation example 5-5. Third operation example 5-6. Effects 6. Other embodiments 7. Effects of base station control device, base station control method, base station, and setting control method according to the present disclosure 8. Hardware configuration

[0010] <<1. Overview>> <1-1. Local 5G / Private 5G> Local 5G / Private 5G is a cellular communication service that is available in limited areas such as factories, offices, studios, hospitals, universities, etc. By limiting the provision of services to local areas, it has the advantage of being able to provide customized cellular services.

[0011] In this embodiment, the private 5G and local 5G may be referred to as a 4G / 5G private network or simply as a private network.

[0012] 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 closed network or simply as a closed network.

[0013] Before describing the outline of this embodiment, the characteristics of a private network will be described. Fig. 1 is a diagram showing an example of a private network. The predetermined 4G / 5G private network shown in Fig. 1 includes a UE (User Equipment), a base station (BS), a core network control plane (CN-C), a core network user plane (CN-U), and an application function (AF).

[0014] The UE and BS are located on-premises in a facility such as a factory, office, or home, or in a local area network (LAN), while the CN-C, CN-U, and AF are located on a cloud such as a data center.

[0015] In a typical public cellular network, it is not easy to change the settings of a base station. This is because many users communicate (connect) with the base station in the public cellular network. Therefore, it is not easy to make a setting change that requires interrupting communication (connection) with users in a base station of a public cellular network that communicates (connects) with many users.

[0016] On the other hand, in a private network, the number of users (terminal devices) communicating (connecting) with base stations is smaller than in a public cellular network. Therefore, it is easier to change the settings of base stations in a private network than in a public cellular network. Therefore, if the operator of the private network deems it necessary, the settings of the base station can be changed to suit the service, for example.

[0017] For example, when optimizing cellular communication services based on services provided in a local area such as within a facility, changes to the settings of the base station may be made that have a significant impact on communication performance.

[0018] Therefore, with private 5G, it is expected that there will be an increased number of opportunities for configuration changes that require base stations to be restarted.

[0019] Here, the base station settings that are subject to change to optimize the cellular communication service include, for example, at least one of the following: - TDD (Time Division Multiplexing) Configuration - Frequency band - Frequency bandwidth

[0020] For example, depending on the service within the private network, there may be more uplink traffic or more downlink traffic. In other words, the ratio of uplink to downlink traffic varies depending on the service. By changing the TDD Configuration setting described above according to this ratio, the cellular communication service can be optimized.

[0021] Another example of optimizing services is changing the setting of a frequency band or frequency bandwidth depending on the state of radio wave interference.

[0022] <1-2. BBU and RRH> A cellular system is divided into a Core Network (CN) and a Radio Access Network (RAN). The CN manages multiple base stations. The CN manages subscriber information for each UE (terminal device) and manages sessions for each UE. The CN can be located on a cloud, for example.

[0023] A base station (RAN) controls and manages all aspects of wireless communication, including frequency and time resources for wireless communication. A base station is often implemented as a separate unit consisting of a base band unit (BBU) and a remote radio head (RRH).

[0024] The BBU may be equipped with most of the signal processing units that perform signal processing of the base station. The RRH may be equipped with an analog unit that handles RF (Radio Frequency), an antenna, and the like. The RRH and the BBU are connected by, for example, a cable or optical fiber. The length of the cable connecting the RRH and the BBU may be, for example, about 10 km. Note that in private 5G, the length is considered to be 1 km or less in most cases.

[0025] As described above, separating the base station into the BBU and the RRH has the advantage of reducing the size of the RRH equipped with the antenna, which reduces the installation cost of the RRH.

[0026] Communication between the RRH and the BBU is performed in accordance with a standard called CPRI (Common Public Radio Interface). In this standard, I and Q channels of digital data are packed into a box called a container and transmitted and received between the RRH and the BBU. In this way, digital signals are transmitted and received between the RRH and the BBU.

[0027] Fig. 2 is a diagram showing an example of the configuration of a communication system, and Fig. 3 is a diagram showing a base station. The communication system shown in Fig. 2 and Fig. 3 includes a core network 20, a base station 30, a terminal device 400, and an application server 60.

[0028] The core network 20 provides a cellular communication service to the terminal device 400 via, for example, the base station 30. The core network 20 may be located on the cloud side or on the LAN side (see FIG. 1 ).

[0029] 3 includes a BBU 310 and an RRH 320 having an antenna 313. The BBU 310 may be located on the cloud side or on the LAN side.

[0030] The placement of the core network 20 and the BBU 310 may be determined depending on the use case. Also, all functions of the core network 20 do not have to be placed in the same location. For example, some functions of the core network 20 may be placed on the cloud side, and the remaining functions may be placed on the LAN side.

[0031] In the example of Fig. 3, the BBU 310 and the RRH 320 are connected by an optical fiber. The BBU 310 and the RRH 320 can be located apart by up to 10 km. A single-mode optical fiber can usually be used for the connection between the BBU 310 and the RRH 320. In communication between the BBU 310 and the RRH 320, digital signals are transmitted and received in a format conforming to the CPRI standard.

[0032] The BBU 310 may be configured with a CU (Central Unit) and a DU (Distributed Unit). The RRH is also called an RU (Radio Unit).

[0033] The terminal device 400 includes an application client 50. The application client 50 communicates with an application server 60, for example, via a private network. The application client 50, together with the application server 60, provides an application service to a user of the terminal device 400.

[0034] The application server 60 communicates with the application client 50 via, for example, a private network. The application server 60, together with the application client 50, provides application services to users of the terminal devices 400, for example.

[0035] <1-3. Service Continuity> Conventionally, service continuity has been studied in 3GPP (registered trademark). The service continuity studied here is called session and service continuity. This service continuity is specified in, for example, 3GPP TS38.501 Section 5.6.9.

[0036] The Service Continuity defined here is a mechanism for continuing service even when the UE moves, i.e., when the UE moves. Here, for example, the following three modes are defined:

[0037] The first mode is when the IP address remains the same even when the UE moves, the second mode is when the IP address changes when the UE moves, and the third mode is when the UE has two IP addresses and two connections when it moves.

[0038] Generally, when an IP address is changed, the service provided by the application is temporarily interrupted. 3GPP TS38.501 Section 5.6.9 specifies a mode that includes the case where the IP address is changed.

[0039] However, conventional Service Continuity does not consider interruption of services due to restarting the base station 30. Even when the settings of the base station 30 are changed and the base station 30 is restarted, it is desirable that services be provided to the terminal device 400 without interruption.

[0040] <1-4. Changing the Settings of the Base Station> Here, changing the settings of the base station 30 will be described.

[0041] Various settings are made in the base station 30. For example, basic design includes setting a frequency, setting a frequency width, etc. These settings determine, for example, which frequency the base station 30 will use to perform communication.

[0042] In a public cellular network, the settings of the base station 30 are rarely changed. On the other hand, in a private 5G network, the settings of the base station 30 may be frequently changed at the discretion of the operator (administrator).

[0043] When the setting related to the frequency is changed, it is necessary to restart the base station 30. Furthermore, this setting change may require resynchronization of the clocks of the BBU 310 and the RRH 320. The resynchronization may take a certain amount of time in order to synchronize the clocks used by the BBU 310 and the RRH 320 with high precision.

[0044] There are setting changes that do not require restarting the base station 30. For example, the base station 30 is restarted in response to a setting change of the center frequency, a setting change of the frequency bandwidth, a setting change of the TDD configuration, etc. On the other hand, the base station 30 is not restarted in response to a setting change of the transmission power of the base station 30, a setting change related to a handover instruction to the terminal device 400, etc.

[0045] Furthermore, clock resynchronization (clock resynchronization of CPRI) of the BBU 310 and the RRH 320 may be required due to a change in the setting of the center frequency and the setting of the frequency bandwidth. On the other hand, clock resynchronization of CPRI is not required for a change in the setting of the TDD configuration, a change in the setting of the transmission power of the base station 30, a change in the setting related to a handover instruction to the terminal device 400, etc.

[0046] Here, "restart" generally means restarting the OS (Operating System) or the base station 30. In this case, the transmission of control signals to analog units and the like controlled by the base station 30 is also temporarily stopped. Therefore, restarting the base station 30 also temporarily stops the emission of radio waves.

[0047] In this embodiment, in addition to or instead of the general restart described above, a temporary disconnection of the connection between the base station 30 and the terminal device 400 is also included in the restart.

[0048] For example, changing the settings of the TDD configuration described above may not necessarily require restarting the OS or software of the base station 30. Even in this case, when the settings of the TDD configuration are changed, the connection between the base station 30 and the terminal device 400 is temporarily interrupted. Specifically, communication between the terminal device 400 and the base station 30 is interrupted until radio waves are output from the base station 30 in accordance with the newly set TDD configuration. In this embodiment, such an interruption of communication that is not due to a restart of the OS or software is also defined as a "restart."

[0049] In the case of CPRI clock synchronization, it takes time for the clocks of the BBU 310 and the RRH 320 to be synchronized with high precision. In such a case, radio waves from the base station 30 must be temporarily stopped.

[0050] Therefore, clock synchronization (resynchronization) of the CPRI is also classified as a case in which the base station 30 is restarted. For example, when a change in the frequency bandwidth setting is made, which involves a change in the sampling rate, the clock resynchronization of the CPRI is required.

[0051] Fig. 4 is a diagram showing an example of restarting the base station 30. As shown in Fig. 4, in restarting the base station 30, first the BBU 310 is reset, then the software of the BBU 310 is started up and the preparation of the BBU 310 is completed. Next, the RRH 320 synchronizes with the clock of the BBU 310 and becomes ready, and the UE attach procedure is performed, and the UE attach (connection) is completed.

[0052] It takes about 10 seconds for the software to start up after the BBU 310 is reset, T1, and then about 30 seconds for the RRH 320 to synchronize with the clock of the BBU 310 and become operational, T2.

[0053] It should be noted that the time T2 required for the RRH 320 to become operable is less than one second when clock synchronization is not required between the RRH 320 and the BBU 310. An example of a case where clock synchronization is required between the RRH 320 and the BBU 310 is when a setting change in the base station 30 is made, which involves a change in the sampling rate.

[0054] When the preparation of the RRH 320 is completed and radio waves are output from the RRH 320, the UE (terminal device 400) attaches to the core network 20 via the reset (restarted) base station 30. A time T3 from the completion of preparation of the RRH 320 to the completion of attachment of the UE is approximately 30 seconds or more.

[0055] In this way, it may take about one to two minutes for the base station 30 to perform a restart accompanied by CPRI clock synchronization and for the UE to complete attach, that is, for the UE to be able to perform communication after the restart of the base station 30. Furthermore, even if CPRI clock synchronization is not accompanied, it may take 30 seconds or more for the UE to be able to perform communication after the restart of the base station 30.

[0056] During this time, the UE cannot receive services provided via the base station 30. This interruption of services may occur in all UEs connected to the base station 30 that performs the setting change.

[0057] In this way, when the base station 30 is restarted due to a setting change, there is a problem that the service of an application operating at a protocol layer is interrupted in the UE that was using the base station 30. This interruption may significantly deteriorate the user experience of the user using the UE.

[0058] <1-5. Suppression of Unwanted Radio Waves Outside One's Land> Figure 5 is a diagram showing radio wave interference between one's own land and other people's land. As shown in Figure 5, non-public cellular communications such as private 5G are communication systems intended to provide communication services within one's own land. For this reason, this communication system is required to keep radio wave leakage outside one's own land below a certain level.

[0059] For example, when using a 100 MHz frequency band, radio wave leakage is set to -91 dBm or less. This is intended to reduce interference with other communication systems used on other land. If interference with other communication systems on other land increases, the throughput of the other communication systems will decrease. In a communication system such as a road where communication is performed between a UE installed in a vehicle and a base station located on the side of the road, communication between the UE and the base station does not occur when no vehicles are passing. Even in such cases, control signals or synchronization signals are constantly transmitted in the downlink from the base station, which becomes an interference component for other land. Therefore, it is desirable to suppress unnecessary radio waves to other land when no vehicles are passing.

[0060] When considering the amount of radio wave interference on other people's land, it is common to focus on the amount of interference from the base station and not consider interference from the UE, because the UE's transmission power is several tens of dB lower than that of the base station.

[0061] <1-6. Overview of Proposed Technology> A base station status controller according to the proposed technology of the present disclosure executes an optimization process for optimizing communication between a terminal device (UE) 400 and a base station (BS) 30. As shown in FIG. 2 , the base station status controller 10 is a device connected to a core network 20. The base station status controller 10 may be a device included in the core network 20.

[0062] The base station control device 10 includes a control unit. The control unit acquires terminal location information, which is information relating to the location of the terminal device 400. Then, the control unit executes an optimization process for optimizing communication between the terminal device 400 and the base station 30 based on the acquired terminal location information. Here, the terminal location information is information indicating which base station 30 the terminal device 400 belongs to, and is exemplified in the following embodiment.

[0063] Here, the optimization process includes a process executed when the base station is restarted in <1-4. Changing the base station settings>, and a process executed when the base station suppresses unwanted radio waves in <1-5. Suppressing unwanted radio waves outside the base station's own land>. The process executed when the base station is restarted will be described in the first embodiment, and the process executed when the base station suppresses unwanted radio waves will be described in the second embodiment.

[0064] <<2. Configuration Example of Communication System According to First Embodiment>> First, a configuration example of a communication system according to the first embodiment will be described. Note that both the communication system according to the first embodiment and the communication system according to the second embodiment have the configuration shown in FIG. 2.

[0065] In the first embodiment, when the base station 30 is restarted, radio waves from the base station 30 are temporarily stopped. It takes several tens of seconds for the base station 30 to start transmitting radio waves again, and it also takes several tens of seconds for the terminal device 400 to attach to the network via the base station 30. As a result, communication between the terminal device 400 and the application server 60 on the network side is temporarily interrupted, and communication services between the application server 60 on the network side and the client installed in the terminal device 400 are interrupted.

[0066] Such interruptions in service are undesirable, and continuity of communication services is important. Therefore, a method is required for restarting the base station 30 in response to a change in the settings of the base station 30, without stopping the application services being performed between the terminal device 400 and the network side at the time of restart.

[0067] <2-1. Example of Overall Configuration of Communication System> In this communication system, it is assumed that base stations 30 are placed on a road, for example, at intervals of 1 km. In this case, it is assumed that the traffic volume on the road is such that several cars pass every few minutes to several tens of minutes. Furthermore, in this communication system, it is assumed that the terminal device 400 is mounted on a vehicle. In other words, it is a communication system in which the terminal device 400 moves between multiple base stations 30. In such a communication system, interruptions in communication services can be avoided by restarting the base station 30 in response to a setting change when there are no cars present.

[0068] 2, the communication system includes a base station control device 10, a core network 20, a plurality of base stations 30, terminal devices 400, and an application server 60. The core network 20, the base stations 30, the terminal devices 400, and the application server 60 are the same as those described above.

[0069] <2-2. Configuration Example of Base Station Control Device> Fig. 6 is a diagram showing a configuration example of a base station control device according to the first embodiment of the present disclosure. The base station control device 10 includes a communication unit 11, a storage unit 12, and a control unit 13. Note that the configuration shown in Fig. 6 is a functional configuration, and the hardware configuration may be different. Furthermore, the functions of the base station control device 10 may be statically or dynamically distributed and implemented in multiple physically separated configurations. For example, the base station control device 10 may be configured by multiple server devices.

[0070] The communication unit 11 is a communication interface for communicating with other devices. The communication unit 11 may be a network interface or a device connection interface. For example, the communication unit 11 may be a LAN (Local Area Network) interface such as a NIC (Network Interface Card), or a USB (Universal Serial Bus) interface configured with a USB host controller, a USB port, etc. The communication unit 11 may also be a wired interface or a wireless interface. The communication unit 11 functions as a communication means of the base station control device 10. The communication unit 11 communicates with the core network 20, the base station 30, etc. under the control of the control unit 13.

[0071] The storage unit 12 is a data readable / writable storage device such as a dynamic random access memory (DRAM), a static random access memory (SRAM), a flash memory, a hard disk, etc. The storage unit 12 functions as a storage means of the base station control device 10.

[0072] The control unit 13 is a controller that controls each unit of the base station control device 10. The control unit 13 executes various processes, which will be described later.

[0073] The control unit 13 is realized by a processor such as a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or a GPU (Graphics Processing Unit). For example, the control unit 13 is realized by a processor executing various programs stored in a storage device inside the base station control device 10 using a RAM (Random Access Memory) or the like as a working area. The control unit 13 may also be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The CPU, MPU, GPU, ASIC, and FPGA can all be considered as controllers.

[0074] 2-3. Configuration Example of Base Station> Fig. 7 is a diagram showing a configuration example of a base station according to the first embodiment of the present disclosure. The base station 30 includes a wireless communication unit 31, a storage unit 32, and a control unit 33. Note that the configuration shown in Fig. 7 is a functional configuration, and the hardware configuration may be different. Furthermore, the functions of the base station 30 may be distributed and implemented in multiple physically separated configurations.

[0075] The wireless communication unit 31 is a signal processing unit for wireless communication with other wireless communication devices (e.g., terminal device 400). The wireless communication unit 31 includes the above-mentioned antenna 313 and operates under the control of the control unit 33. The wireless communication unit 31 supports one or more wireless access methods and performs transmission and reception processing. For example, the wireless communication unit 31 supports both NR and LTE. In addition to NR and LTE, the wireless communication unit 31 may also support W-CDMA (Wideband-Code Division Multiple Access) and cdma2000. Furthermore, the wireless communication unit 31 may also support automatic retransmission techniques such as HARQ (Hybrid Automatic Repeat reQuest).

[0076] The storage unit 32 is a data readable / writable storage device such as a DRAM, an SRAM, a flash memory, a hard disk, etc. The storage unit 32 functions as a storage means of the base station 30.

[0077] The control unit 33 is a controller that controls each unit of the base station 30. The control unit 33 is realized by a processor such as a CPU or an MPU. For example, the control unit 33 is realized by a processor executing various programs stored in a storage device inside the base station 30 using RAM or the like as a work area. The control unit 33 may also be realized by an integrated circuit such as an ASIC or an FPGA. A CPU, an MPU, an ASIC, and an FPGA can all be considered as controllers. The control unit 33 may also be realized by a GPU in addition to or instead of a CPU.

[0078] <<3. Example of Operation of Communication System of First Embodiment>> <3-1. Overview of Operation of Communication System> In the above communication system, the control unit 13 of the base station control device 10 acquires terminal location information, which is information relating to the location of the terminal device 400. Then, as an optimization process, the control unit 13 outputs, to the base station 30, a restart signal that restarts the base station 30 that is not communicating with the terminal device, based on the acquired terminal location information.

[0079] <3-2. Method of determining the position of the terminal device> Here, a method of determining the position of the terminal device 400 will be described. One method of determining the position of the terminal device 400 is to determine the position of the terminal device 400 using GPS (Global Positioning System). That is, the terminal position information is GPS information acquired by the terminal device 400. In this method, the GPS information acquired by the terminal device 400 is transmitted to the base station 30 by private 5G. Note that in this case, it is necessary that the base station 30 is able to communicate with the terminal device 400 in private 5G.

[0080] On the other hand, if a separate terminal device is provided that transmits GPS information to the base station control device 10 via a public cellular network, it becomes possible to constantly grasp the location of the terminal device 400. In this case, even if the terminal device 400 is in a state where it cannot communicate with the base station 30 (idle mode), it is possible to transmit the location of the terminal device 400 to the base station control device 10.

[0081] Another method for determining the location of the terminal device 400 is to determine the location of the terminal device 400 using the RAN-UE-ID. The RAN-UE-ID is registered in the base station 30 when the terminal device 400 and the base station 30 establish a communication connection. In other words, the terminal location information is terminal identification information that identifies the terminal device 400 registered in the base station 30. The RAN-UE-ID is linked on the core network 20 side to the subscriber ID (IMSI (International Mobile Subscriber Identity), SUPI (Subscription Permanent Identifier), etc.) of the terminal device 400 or the IP address of the terminal device 400. For this reason, the base station control device 10 can identify which terminal device 400 is connected to the base station 30 using the API (Application Programming Interface) of the base station 30. In other words, the base station control device 10 can determine which terminal device 400 is located near which base station 30.

[0082] Note that, when the terminal device 400 is not in a state (connected mode) in which it is communicating with the base station 30, the base station control device 10 cannot acquire the RAN-UE-ID from the base station 30. For this reason, the terminal device 400 needs to be in connected mode and be able to communicate with the base station 30.

[0083] <3-3. First Operation Example> A first operation example of the communication system according to the first embodiment will be described with reference to Fig. 8 to Fig. 10. Fig. 8 is a diagram showing a configuration example of the communication system according to the first embodiment of the present disclosure. Fig. 9 is a diagram showing a control example of the communication system according to the first embodiment of the present disclosure. Fig. 10 is a flowchart showing an example of control of the base station control device according to the first embodiment of the present disclosure.

[0084] In the first embodiment, a base station 30 that is not communicating with the terminal device 400 is restarted based on terminal location information of the terminal device 400. As shown in Fig. 8 , a plurality of base stations 30 are arranged side by side along a predetermined route such as a road, with the base stations 30 arranged at intervals of 1 km, and the terminal device 400 moves along the predetermined route. Therefore, the terminal device 400 passes through the coverage (communication area) of the base stations 30 sequentially along the predetermined route.

[0085] The base station control device 10 calculates the arrival time (Y seconds) of the terminal device 400 to reach the edge of the coverage of the base station 30 to be restarted, based on the terminal location information of the terminal device 400. For example, if the terminal device 400 is located at a location where the arrival time (Y seconds) is farther than X seconds, e.g., 120 seconds, it is possible to complete the restart associated with a setting change of the base station 30 in approximately 60 seconds. In other words, the time (X seconds) is the time required to execute the restart of the target base station 30. In the first embodiment, the base station control device 10 determines whether or not to restart the base station 30 based solely on the location of the terminal device 400.

[0086] When the terminal device 400 moves in both directions along a predetermined route, the positions of the terminal device 400 in both directions are taken into consideration.

[0087] Assuming that the moving speed of the terminal device 400 is 80 km / h and the coverage area of ​​the base station 30 is 1 km square, the arrival time (Y seconds) required to reach a point 1 km from the position of the base station 30 is calculated, and if the arrival time (Y seconds) is greater than the time (X seconds), the base station 30 is restarted in accordance with a setting change.

[0088] 9 and 10, a base station control method executed by the base station control device 10 will be described. As shown in Fig. 10, in the base station control method, first, the base station control device 10 acquires terminal location information of the terminal device 400 (step S1). In this method, the RAN-UE-ID is used as the terminal location information, and the base station control device 10 acquires the RAN-UE-ID registered in the base station 30.

[0089] As shown in FIG. 9 , the base station control device 10 calculates the arrival time (Y seconds) to the edge of the coverage of the target base station 30 based on the acquired terminal location information, assuming that the terminal device 400 is moving at a speed of 80 km / h (step S2). The base station control device 10 then determines whether the calculated arrival time (Y seconds) is greater than the time (X seconds) required to restart the target base station 30 (step S3). If the base station control device 10 determines in step S3 that the arrival time (Y seconds) is greater than the time (X seconds) (step S3: Yes), it outputs a restart signal to the target base station 30 to restart the base station 30 (step S4). On the other hand, if the base station control device 10 determines in step S3 that the arrival time (Y seconds) is less than or equal to the time (X seconds) (step S3: No), it does not restart the base station 30 and ends the series of steps shown in FIG. 10 . The steps shown in FIG. 10 are repeatedly executed.

[0090] The arrival time (Y seconds) may be calculated by adding a margin that takes into account, for example, a speed change of ±10 km / h, assuming that the movement speed of the terminal device 400 changes. Furthermore, the arrival time (Y seconds) may be calculated by taking into account the occurrence of a movement delay in the terminal device 400 due to traffic congestion, etc. In this case, it is assumed that only some of the terminal devices 400 experiencing a movement delay will communicate using a base station 30 on a predetermined route.

[0091] 3-4. Second Operation Example FIG. 11 is a flowchart showing an example of control of a base station control device according to the first embodiment of the present disclosure. In the first operation example, the base station control device 10 calculates the arrival time (Y seconds) based on terminal location information and movement speed. Meanwhile, when the terminal device 400 is in Connected mode, the base station control device 10 can identify the connected base station 30 by observing parameters such as the RAN-UE-ID. Therefore, as shown in FIG. 11, if the base station control device 10 determines based on the RAN-UE-ID that the terminal device 400 is not present in X neighboring base stations 30, it may restart the X neighboring base stations 30. For example, if the transit time of the terminal device 400 passing through the coverage of one base station 30 is 60 seconds, and if the terminal device 400 is not present in two neighboring base stations 30, it can be estimated that it will take 120 seconds for the terminal device 400 to reach the coverage of the target base station 30.

[0092] As shown in FIG. 11 , the base station control device 10 acquires the RAN-UE-ID registered in the base station 30 as terminal location information (step S11). Based on the acquired terminal location information, the base station control device 10 calculates the transit time required to pass through the coverage area of ​​one base station 30, and determines the number (X) of neighboring base stations 30 based on the calculated transit time (step S12). The base station control device 10 then determines whether the terminal device 400 is present among the determined X number of neighboring base stations 30 (step S13). In step S13, if the base station control device 10 determines that the terminal device 400 is not present (step S13: Yes), it outputs a restart signal to the target base station 30 to restart the base station 30 (step S14). On the other hand, if the base station control device 10 determines that the terminal device 400 is present (step S13: No), it does not restart the base station 30 and ends the series of steps shown in FIG. 11 . Note that the flow shown in FIG. 11 is repeatedly executed.

[0093] <3-5. Third Operation Example> In the first operation example, if the arrival time (Y seconds) is greater than the time (X seconds), the target base station 30 is restarted, but if the arrival time (Y seconds) is equal to or less than the time (X seconds), the base station 30 is not restarted. In the base station control method of the third operation example, if the arrival time (Y seconds) is equal to or less than the time (X seconds), or even if the terminal device 400 is within the coverage of the base station 30, the target base station 30 is restarted if the terminal device 400 is in idle mode.

[0094] In step S3 of FIG. 10, if the base station control device 10 determines that the arrival time (Y seconds) is equal to or less than the time (X seconds), or if it determines that the terminal device 400 is within the coverage of the base station 30, it determines whether the terminal device 400 is in idle mode or connected mode.

[0095] When the base station control device 10 determines that the terminal device 400 is in the idle mode, it restarts the base station 30. In this way, when the terminal device 400 is in the idle mode, there is no data transmission or reception, so the base station 30 may be restarted.

[0096] <3-6. Fourth Operation Example> In the third operation example, if the arrival time (Y seconds) is equal to or less than the time (X seconds) and the terminal device 400 is in the idle mode, that is, if the terminal device 400 is in a state in which no communication with the base station 30 is permitted, the target base station 30 is restarted. In this base station control method, the target base station 30 is restarted even if the arrival time (Y seconds) is equal to or less than the time (X seconds) and the terminal device 400 is in the connected mode.

[0097] When the base station control device 10 determines that the arrival time (Y seconds) is equal to or less than the time (X seconds) and that the terminal device 400 is in Connected mode, it determines whether the QoS identifier 5QI used in the QoS control executed in the communication between the terminal device 400 and the base station 30 is a QoS identifier that allows service interruption. When it determines that the QoS identifier is a QoS identifier that allows service interruption, the base station control device 10 restarts the base station 30. Note that restarting of the base station 30 is also allowed when the terminal device 400 is in Idle mode.

[0098] In this base station control method, if a QoS identifier that allows service interruption is suddenly used, service interruption does not have to be handled. Also, by referring to the communication history of the terminal device 400, if only 5QI identifiers that allow service interruption have been used within the past hour, the terminal device 400 may be recognized as a terminal device 400 that allows service interruption. In this case, service interruption is allowed even if a QoS identifier that allows service interruption is suddenly used.

[0099] Here, as the QoS identifier that allows service interruption, among the conventional 5QIs, a 5QI that is not used for video transmission may be considered as the 5QI that allows service interruption. Also, a new 5QI QoS identifier may be newly defined and introduced into the 5G system.

[0100] <3-7. Fifth Operation Example> In this base station control method, even if the arrival time (Y seconds) is less than the time (X seconds), the target base station 30 is restarted.

[0101] If the arrival time (Y seconds) is equal to or less than the time (X seconds) and if the application layer has been notified that an application that does not tolerate service interruption is not running in the terminal device 400, the base station control device 10 prevents service interruption, that is, does not restart the base station 30. In other words, if the arrival time (Y seconds) is equal to or less than the time (X seconds) and an application that does not tolerate service interruption is not being used in the terminal device 400, that is, if a state in which no communication with the base station 30 is tolerated, the base station control device 10 restarts the base station 30.

[0102] If the base station control device 10 determines that the arrival time (Y seconds) is equal to or less than the time (X seconds), it determines whether an application that does not tolerate service interruption is being used in the application layer of the terminal device 400, or whether there is a plan to use an application that does not tolerate service interruption. If the base station control device 10 determines that an application that does not tolerate service interruption is not being used, it restarts the base station 30.

[0103] Information regarding application usage is provided as a report to a server managing the terminal device 400, and the base station control device 10 uses the report information to determine whether the application is being used. Furthermore, for a plan to use an application that does not tolerate service interruptions, the terminal device 400 may report a scheduled activation time to the base station control device 10 in advance. In this case, it is possible to deal with sudden activation of an application that does not tolerate service interruptions. For example, assume that the terminal device 400 is moving within the coverage of the base station 30, the scheduled activation time of the application that does not tolerate service interruptions is Y minutes from now, and the terminal device 400 will move out of the coverage range of the base station 30 in X minutes. In this case, if the base station control device 10 determines that Y > X is true, it determines that the application is not being activated within the coverage range of the base station 30 and restarts the base station 30.

[0104] <3-8. Sixth Operation Example> Next, a sixth operation example of the communication system according to the first embodiment will be described with reference to Fig. 12. Fig. 12 is a diagram showing a configuration example of the communication system according to the first embodiment of the present disclosure.

[0105] In the first to fifth operation examples, the base station 30 is restarted when the terminal device 400 is not within the coverage of the base station 30 or does not reach the coverage range of the base station 30. Furthermore, even when the terminal device 400 is within the coverage of the base station 30, the base station 30 is restarted when interruption of communication with the base station 30 is acceptable.

[0106] Here, if there are several hundred base stations 30 and it is necessary to restart all of the base stations 30, it would take a very long time to restart each and every base station 30 that can be restarted.

[0107] For this reason, in the sixth operation example, the plurality of base stations 30 are divided into several groups, and each group is restarted for each base station 30. As shown in Fig. 12, in this communication system, the plurality of base stations 30 are divided into several groups, and are arranged side by side along a predetermined route.

[0108] The base station control device 10 identifies the number of terminal devices 400 present in the coverage area covered by the group based on the terminal location information. Then, the base station control device 10 determines the group with the fewest number of terminal devices 400 present among the multiple groups. The base station control device 10 then restarts the base station 30 included in the group with the fewest number of terminal devices 400. Furthermore, starting from the group with the fewest number of terminal devices, the base station control device 10 sequentially restarts the base stations 30 included in the other groups along a predetermined route. That is, the base station control device 10 restarts the base stations 30 for each group sequentially along the predetermined route. Therefore, the group of base stations 30 to be restarted moves at a speed equivalent to the movement speed of the terminal devices 400, minimizing the number of terminal devices 400 affected by the restart, and the base stations 30 are restarted at the same speed as the movement speed of the terminal devices 400. Therefore, for example, if a given route is a road with a total length of 80 km, assuming that a car equipped with terminal device 400 travels at a speed of 80 km per hour, restarting of base stations 30 in the entire 80 km area will be completed in one hour.

[0109] Furthermore, the base station control device 10 outputs a notification to the terminal device 400 communicating with the base station 30 that the target base station 30 will be restarted. In this way, the base station control device 10 can prevent the terminal device 400 from encountering an unexpected interruption of service by transmitting information about the restart plan to the terminal device 400.

[0110] <3-9. Effects> As described above, according to the first embodiment, it is possible to maintain communication between the terminal device 400 and the base station 30, and therefore it is possible to restart the base station 30 while suppressing the impact on communication services. Therefore, it is possible to prevent the services of applications installed in the terminal device 400 from being affected.

[0111] Furthermore, according to the first embodiment, even if there are several hundred base stations 30, the time required for restarting the base stations 30 can be reduced by restarting the base stations 30 on a group-by-group basis, and the impact on communication services can also be minimized.

[0112] <<4. Configuration Example of Communication System According to Second Embodiment>> Next, a configuration example of a communication system according to the second embodiment will be described. As described above, the communication system according to the second embodiment has the same configuration as the communication system according to the first embodiment, as shown in FIG. 2 .

[0113] In the second embodiment, when a base station 30 arranged along a predetermined route and a terminal device 400 moving along the route communicate using private 5G, there is a need to prevent radio waves on the predetermined route, which is the user's own land, from interfering with other users' land outside the predetermined route. For example, it may be required to limit the transmission power of radio waves to less than -91 dBm in a 100 MHz bandwidth.

[0114] On the other hand, it is not desirable to completely stop the transmission of radio waves from the base station 30. When the terminal device 400 changes from a power-off state to a power-on state, if the terminal device 400 attempts to connect to the base station 30, and no radio waves are emitted from the base station 30, the terminal device 400 cannot attach to the network. More specifically, "attach" means that the terminal device 400 communicates with the core network 20 via the base station 30, and is ready to communicate.

[0115] When the terminal device 400 enters coverage where it cannot communicate with the base station 30 at all, the terminal device 400 may recognize that it has gone out of range (out of coverage range) and transition to a detached state. If the terminal device 400 enters a detached state, it may not be able to connect to the network when it re-enters coverage. This is because if the correct detach procedure is not followed and the terminal device is not detached, a discrepancy will occur between the state on the network side and the state on the terminal side. Therefore, it is necessary to prevent the base station 30 from creating an out-of-range state.

[0116] Furthermore, if the terminal device 400 can maintain an attached state to the base station 30, when data is sent from the network side to the terminal device 400, the terminal device 400 transitions from idle mode to connected mode and can return to a state in which it can connect to the network. On the other hand, for a terminal device 400 that is out of range, it is not possible to perform an operation to return to a state in which it can connect to the network, which makes it difficult to use when using an application. For this reason, the communication system of the second embodiment executes the following operations.

[0117] <<5. Example of Operation of Communication System of Second Embodiment>> <5-1. Overview of Operation of Communication System> In the communication system of the second embodiment, the control unit 13 of the base station control device 10 acquires terminal location information, which is information relating to the location of the terminal device 400. Then, as an optimization process, the control unit 13 executes mode switching of the operation mode of the base station 30 based on the acquired terminal location information.

[0118] <5-2. Operation Modes of Base Station> Here, the operation modes of the base station 30 include an active mode, an idle mode, and a stop mode.

[0119] The active mode is the normal state of the base station 30, in which radio waves are transmitted and received.

[0120] The idle mode is a state in which the base station 30 is operated with lower transmission power than the base station 30 in active mode so that the terminal device 400 does not go out of range, that is, is capable of communicating with the terminal device 400. Therefore, the base station 30 in idle mode can maintain the attached state of the terminal device 400 so that the terminal device 400 does not detach.

[0121] The transmission power of the base station 30 in idle mode is determined taking into consideration propagation loss characteristics so that the received power at the outermost part of the coverage where radio waves are weak is, for example, -110 dBm in a 30 kHz bandwidth. For example, the transmission power of the base station 30 in active mode is 40 dBm, and the transmission power of the base station 30 in idle mode is 10 dBm.

[0122] Even when the base station 30 is in idle mode, communication is possible if the coding rate is small and the coding is QPSK (Quadrature Phase Shift Keying) such as MCS1, but large amounts of user data cannot be sent on the downlink. On the other hand, the uplink is determined by the transmission power of the terminal device 400. Therefore, since the transmission power of the terminal device 400 is normally a maximum of 23 dBm, the uplink throughput is not affected even in idle mode. In addition, the transmission power setting of the base station 30 can be changed without restarting the base station 30.

[0123] The stop mode is a state in which radio wave transmission from the base station 30 is completely stopped. Therefore, a base station 30 in the stop mode is completely unable to transmit or receive either uplink or downlink. This is because an uplink cannot be transmitted if it cannot receive a downlink control signal. In this state, the terminal device 400 is out of range and also gives up the IP address assigned by the network. Therefore, it is desirable to execute the stop mode when the terminal device 400 is completely absent from the vicinity of the base station 30.

[0124] As described above, the base station 30 acquires a control signal for switching the operation mode from the base station control device 10, and executes a setting control method for switching to one of the operation modes of the active mode, the idle mode, and the restart mode based on the acquired control signal.

[0125] <5-3. First Operation Example> A first operation example of the communication system according to the second embodiment will be described with reference to Fig. 13 to Fig. 15. Fig. 13 is a diagram showing a configuration example of the communication system according to the second embodiment of the present disclosure. Fig. 14 is a diagram showing a control example of the communication system according to the second embodiment of the present disclosure. Fig. 15 is a flowchart showing an example of control of the base station control device according to the second embodiment of the present disclosure.

[0126] In the second embodiment, based on the terminal location information, it is determined whether the base station 30 is communicating with the terminal device 400, and a control signal is output to the base station 30 that is not communicating with the terminal device 400 to put the base station 30 into idle mode.

[0127] The base station control device 10 uses the RAN-UE-ID as terminal location information. In order for the base station control device 10 to acquire the RAN-UE-ID, the terminal device 400 must be in Connected mode. For this reason, the base station control device 10 puts all terminal devices 400 known from the network side into Connected mode by continuously outputting pings at predetermined intervals (for example, one second). This allows the base station control device 10 to know the locations of all terminal devices 400. In other words, all terminal devices 400 are in Connected mode, and the base station 30 has terminal location information for all terminal devices 400.

[0128] As shown in FIG. 13, the base station control device 10 sets a total of five base stations 30, including the base station 30 where the terminal device 400 is located and two adjacent base stations 30 on the front and rear sides of this base station 30, to active mode, and sets the other base stations 30 to idle mode.

[0129] For this reason, even a terminal device 400 that has been powered on can attach to the core network 20. Even in this case, a total of five base stations 30, including the base station 30 where the powered-on terminal device 400 is located and two adjacent base stations 30 on the front and rear sides of this base station 30, are in active mode. Then, when the terminal device 400 moves, the base station control device 10 follows the movement of the terminal device 400 and switches the base stations 30 to active mode.

[0130] 14 and 15, a base station control method executed by the base station control device 10 will be described. As shown in Fig. 15, in the base station control method, first, the base station control device 10 sets all base stations 30 to idle mode (step S21). Next, the base station control device 10 outputs pings to all terminal devices 400 via the core network 20, thereby transitioning all terminal devices 400 to connected mode, and determines the locations of all terminal devices 400 from the APIs (Application Programming Interfaces) of the base stations 30 connected to the terminal devices 400 (step S22).

[0131] Then, the base station control device 10 determines that a total of five base stations 30, including the base station 30 where the terminal device 400 is located and two adjacent base stations 30 on the front and rear sides of this base station 30, should be placed in active mode, and transitions the base stations 30 determined to be in active mode to active mode (step S23).

[0132] The number of terminal devices 400 that transition to the active mode may be changed depending on the mode of movement. For example, the number of base stations that transition to the active mode may be increased (for example, 2) in the direction of travel of the moving terminal device 400, and the number of base stations that transition to the active mode may be decreased (for example, 1) in the direction of travel of the moving terminal device 400.

[0133] <5-4. Second Operation Example> Next, a second operation example of the communication system according to the second embodiment will be described with reference to Fig. 16 and Fig. 17. Fig. 16 is a diagram showing an example of system information. Fig. 17 is a diagram showing a control example of the communication system according to the second embodiment of the present disclosure.

[0134] In the first operation example, all of the terminal devices 400 are set to connected mode, so that the base station control device 10 knows the locations of all of the terminal devices 400. In the base station control method of the second operation example, the terminal devices 400 communicate with the base station 30, and when the terminal devices 400 change from idle mode to connected mode, the base station control device 10 knows the locations of the terminal devices 400.

[0135] Furthermore, when the terminal device 400 in Connected mode transitions to Idle mode, thereby interrupting communication between the terminal device 400 and the base station 30, the base station control device 10 causes the base station 30 to maintain active mode for a predetermined period of time (for example, approximately 30 seconds). Therefore, even if the terminal device 400 returns to Connected mode within 30 seconds from Idle mode, the operation mode of the base station 30 is not switched. In this way, by maintaining the active mode of the base station 30 even when the base station 30 meets the conditions for transitioning from active mode to idle mode, the response of the communication connection with the terminal device 400 can be improved.

[0136] Here, the base station control device 10 may notify the terminal device 400 of the definition of the idle mode of the base station 30 and the conditions for transitioning to the idle mode by using the system information shown in Fig. 16. The system information shown in Fig. 16 notifies the terminal device 400 of whether the operation mode of the base station 30 is the active mode or the idle mode, and also notifies information that the base station 30 will transition from the active mode to the idle mode after a predetermined time has elapsed.

[0137] A base station control method executed by the base station control device 10 will be described with reference to Fig. 17. As shown in Fig. 17, in the base station control method, first, the base station control device 10 sets all base stations 30 to idle mode. Next, when the terminal device 400 transitions from idle mode to connected mode, the base station control device 10 grasps the location of the terminal device 400 that has transitioned to connected mode from an API (Application Programming Interface) of the base station 30 connected to the terminal device 400 via the core network 20.

[0138] The base station control device 10 then determines that a total of five base stations 30, including the base station 30 where the terminal device 400 is located and the two adjacent base stations 30 on the front and rear sides of this base station 30, should be placed in active mode, and transitions the base stations 30 determined to be in active mode to active mode. Note that even when the terminal device 400 transitions from connected mode to idle mode, the base station control device 10 maintains the base stations 30 in active mode for a predetermined time.

[0139] <5-5. Third Operation Example> Next, a third operation example of the communication system according to the second embodiment will be described with reference to Fig. 18. Fig. 18 is a diagram showing a control example of the communication system according to the second embodiment of the present disclosure.

[0140] In the first operation example, all of the terminal devices 400 are set to Connected mode, so that the base station control device 10 knows the positions of all of the terminal devices 400. In the base station control method of the third operation example, position coordinate information such as GPS information acquired by an application in the terminal device 400 is transmitted from the terminal device 400 to the base station control device 10 as terminal position information, so that the base station control device 10 knows the positions of the terminal devices 400. Note that, when the base station control device 10 is incorporated in the core network 20, the terminal position information may be acquired as NAS (Non Access Stratum) signaling between the core network 20 and the terminal device 400.

[0141] The location coordinate information transmitted from the terminal device 400 to the base station control device 10 includes current location coordinate information as well as future planned location coordinate information. The location coordinate information may also be transmitted from another terminal device to the base station control device 10 via a public cellular network.

[0142] A base station control method executed by the base station control device 10 will be described with reference to Fig. 18. As shown in Fig. 18, in the base station control method, first, the base station control device 10 sets all base stations 30 to idle mode. Next, the terminal device 400 transmits terminal location information acquired by an application from the terminal device 400 to the base station control device 10, whereby the base station control device 10 acquires the terminal location information of the terminal device 400 via the core network 20 and ascertains the location of the terminal device 400.

[0143] Then, the base station control device 10 determines that a total of five base stations 30, including the base station 30 where the terminal device 400 is located and two adjacent base stations 30 on the front and rear sides of this base station 30, should be placed in active mode, and transitions the base stations 30 determined to be in active mode to active mode.

[0144] <5-6. Effects> As described above, according to the second embodiment, it is possible to suppress unnecessary radio waves to other land without affecting communication services on one's own land, and therefore it is possible to prevent a decrease in communication throughput on both one's own land and other land.

[0145] <<6. Other Embodiments>> The processing according to each of the above-described embodiments may be implemented in various different forms other than the above-described embodiments.

[0146] For example, 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. Furthermore, 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.

[0147] Furthermore, the components of each device shown in the figure are conceptual functional components and do not necessarily have to be physically configured as shown in the figure. 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 them can be functionally or physically distributed and integrated in any unit depending on various loads, usage conditions, etc.

[0148] Furthermore, the above-described embodiments and modifications can be combined as appropriate within the scope of not causing any contradiction in the processing content.

[0149] Furthermore, the effects described in this specification are merely examples and are not limiting, and other effects may also be present.

[0150] <<7. Effects of the base station control device, base station control method, base station, and setting control method according to the present disclosure>> As described above, the base station control device according to the present disclosure (base station control device 10 in the embodiment) is a base station control device including a control unit (control unit 13 in the embodiment) that controls a base station that communicates with a terminal device (terminal device 400 in the embodiment) that moves between a plurality of base stations (base stations 30 in the embodiment), and the control unit acquires terminal location information that is information related to the location of the terminal device, and executes an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information.

[0151] In this way, the base station control device according to the present disclosure can perform optimization processing based on the location of the terminal device, thereby optimizing communication according to the location of the terminal device while maintaining communication services.

[0152] Furthermore, in the base station control device, the control unit restarts the base station that is not communicating with the terminal device based on the terminal location information as the optimization process.

[0153] In this way, the base station control device restarts the base station that is not communicating with the terminal device, without restarting the base station that is communicating with the terminal device, so that communication between the terminal device and the base station is not interrupted and communication services can be continued.

[0154] Furthermore, in the base station control device, the control unit calculates the arrival time of the terminal device to reach the communication area (coverage in this embodiment) of the base station that is the target of the optimization process based on the terminal location information, and if the arrival time is longer than the time required to restart the target base station, restarts the target base station.

[0155] In this way, the base station control device restarts the base station where the terminal device does not reach the communication area, and does not restart the base station that communicates with the terminal device, so communication between the terminal device and the base station is not interrupted and communication services can be continued.

[0156] Furthermore, in the base station control device, the control unit calculates the transit time of the terminal device passing through the communication area of ​​the base station communicating with the terminal device based on the terminal location information, determines whether the terminal device will arrive at the target base station by the transit time, and if it determines that the terminal device will not arrive, restarts the target base station.

[0157] In this way, the base station control device can determine whether the terminal device will reach the target base station based on the time it takes to pass through the communication area, and can target the base station whose communication area the terminal device will not reach for restart.

[0158] In addition, in the base station control device, the control unit determines whether the terminal device is present in the communication area of ​​the base station based on the terminal location information, and restarts the base station if the terminal device present in the communication area is not communicating with the base station.

[0159] In this way, even if a terminal device is present in the communication area, the base station control device can restart the base station if the terminal device is not communicating with the base station, thereby minimizing the impact of restarting the base station.

[0160] In addition, in the base station control device, the control unit determines whether the terminal device is present in the communication area covered by the base station based on the terminal location information, and restarts the base station if the terminal device present in the communication area tolerates a non-communication state with the base station.

[0161] In this way, even if a terminal device is present in the communication area, the base station control device can restart the base station if the terminal device allows a non-communication state with the base station, thereby minimizing the impact of restarting the base station.

[0162] In addition, in the base station control device, the multiple base stations are divided into multiple groups each including one or more of the base stations, and as the optimization process, the control unit identifies the number of terminal devices present in the communication area covered by the group based on the terminal location information, determines the group with the smallest number of terminal devices present in the multiple groups, and restarts the base station included in the group with the smallest number of terminal devices.

[0163] In this way, the base station control device can restart the base station in the group with the fewest number of terminal devices, thereby minimizing the impact of restarting the base station.

[0164] In addition, in the base station control device, the control unit outputs a notification to the terminal device communicating with the base station to the effect that the base station to be targeted will be restarted.

[0165] In this way, the base station control device can notify the terminal device of the base station to be restarted, thereby making it possible to prompt the terminal device to reduce the impact of restarting the base station.

[0166] Further, in the base station control device, the base station performs mode switching of the operating mode, and the operating mode includes an active mode in which communication is performed with the terminal device, and an idle mode in which communication is performed with the terminal device by reducing the transmission power of communication compared to the active mode, and the control unit, as the optimization process, determines whether the base station is communicating with the terminal device based on the terminal location information, and switches the base station that is not communicating with the terminal device to the idle mode.

[0167] In this way, the base station control device can put a base station that is not communicating with a terminal device into idle mode, thereby reducing the base station's transmission power and suppressing unnecessary radio waves from the base station.

[0168] In addition, in the base station control device, the control unit sets at least the base station communicating with the terminal device and the base station adjacent to the base station communicating with the terminal device to the active mode.

[0169] In this way, the base station control device can set the base station where the terminal device is located and the base station near the terminal device to active mode, so that communication between the terminal device and the base station is not interrupted and communication services can be continued.

[0170] In addition, in the base station control device, when the terminal device is communicatively connected to the base station that is in the idle mode, the control unit puts the base station to which the terminal device is communicatively connected into the active mode.

[0171] In this way, when a terminal device is communicatively connected to the base station, the base station control device can return the base station from the idle mode to the active mode.

[0172] In addition, in the base station control device, the control unit causes the base station in the active mode to maintain the active mode for a predetermined period of time when communication with the terminal device is interrupted.

[0173] In this way, the base station control device can preferably establish a communication connection between the terminal device and the base station without changing the operating mode of the base station, even if the terminal device becomes able to communicate again.

[0174] In addition, in the base station control device, the control unit notifies the terminal device of the operation mode of the base station and the conditions under which the base station enters the idle mode.

[0175] In this way, the base station control device can allow the terminal device to easily grasp the status of the base station, thereby improving throughput.

[0176] In addition, in the base station control device, the terminal location information is terminal identification information (RAN-UE-ID in the embodiment) that identifies the terminal device registered in the base station.

[0177] In this way, the base station control device can use the terminal identification information registered in the base station, and therefore can grasp the location of the terminal device even when not communicating with the terminal device.

[0178] In addition, in the base station control device, the terminal location information is GPS information acquired by the terminal device.

[0179] In this way, the base station control device can use GPS information, and therefore can accurately grasp the position of the terminal device.

[0180] In addition, the base station control method of the present disclosure is a base station control method executed by a base station control device that has a control unit that controls a base station that communicates with a terminal device that moves between multiple base stations, and the control unit acquires terminal location information, which is information regarding the location of the terminal device, and executes an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information.

[0181] In this way, the base station control method of the present disclosure can perform optimization processing based on the location of the terminal device, thereby optimizing communication according to the location of the terminal device while maintaining communication services.

[0182] In addition, the base station according to the present disclosure is a base station that is controlled by a base station control device and communicates with a terminal device, and is equipped with a control unit (in the embodiment, a control unit 33) that performs mode switching of the operation mode, the operation modes including an active mode in which communication is performed with the terminal device, an idle mode in which transmission power is reduced compared to the active mode so as to be able to communicate with the terminal device, and a restart mode in which restart is performed, and the control unit acquires a control signal from the base station control device, and performs mode switching to one of the operation modes, the active mode, the idle mode, and the restart mode, based on the acquired control signal.

[0183] In this way, the base station according to the present disclosure can be set to an operation mode appropriate for communication with a terminal device by being switched to any one of the operation modes of the active mode, the idle mode, and the restart mode by the base station control device, thereby optimizing communication between the base station and the terminal device while maintaining communication services for the terminal device.

[0184] In addition, the setting control method according to the present disclosure is a setting control method controlled by a base station control device and executed by a base station that communicates with a terminal device, wherein the base station is provided with a control unit that performs mode switching of operation modes, and the operation modes include an active mode in which communication is performed with the terminal device, an idle mode in which transmission power is reduced compared to the active mode so as to be able to communicate with the terminal device, and a restart mode in which restart is performed, and the control unit acquires a control signal from the base station control device, and performs mode switching to one of the operation modes, the active mode, the idle mode, and the restart mode, based on the acquired control signal.

[0185] In this way, the setting control method according to the present disclosure can switch the operation mode to any one of the active mode, idle mode, and restart mode by the base station control device, thereby making it possible to set the operation mode appropriate for communication with the terminal device. This makes it possible to optimize communication between the base station and the terminal device while maintaining communication services for the terminal device.

[0186] <<8. Hardware Configuration>> Information devices such as the base station control device 10 according to each of the above-described embodiments are realized by a computer 1000 having a configuration as shown in FIG. 19, for example. The base station control device 10 according to the embodiments will be described below as an example. FIG. 19 is a hardware configuration diagram showing an example of a computer 1000 that realizes the functions of the base station control device 10. The computer 1000 has a CPU 1100, a RAM 1200, a ROM (Read Only Memory) 1300, a HDD (Hard Disk Drive) 1400, a communication interface 1500, and an input / output interface 1600. The various components of the computer 1000 are connected by a bus 1050.

[0187] The CPU 1100 operates and controls each component based on programs stored in the ROM 1300 or the HDD 1400. For example, the CPU 1100 loads the programs stored in the ROM 1300 or the HDD 1400 into the RAM 1200 and executes processing corresponding to the various programs.

[0188] The ROM 1300 stores boot programs such as a Basic Input Output System (BIOS) that is executed by the CPU 1100 when the computer 1000 is started, and programs that depend on the hardware of the computer 1000 .

[0189] HDD 1400 is a computer-readable recording medium that non-temporarily records programs executed by CPU 1100 and data used by such programs. Specifically, HDD 1400 is a recording medium that records a base station control program, which is an example of program data 1450.

[0190] The communication interface 1500 is an interface for connecting the computer 1000 to an external network 1550 (e.g., the Internet). For example, the CPU 1100 receives data from other devices and transmits data generated by the CPU 1100 to other devices via the communication interface 1500.

[0191] The input / output interface 1600 is an interface for connecting the input / output device 1650 and the computer 1000. For example, the CPU 1100 receives data from an input device such as a keyboard or a mouse via the input / output interface 1600. The CPU 1100 also transmits data to an output device such as a display, a speaker, or a printer via the input / output interface 1600. The input / output interface 1600 may also function as a media interface for reading programs and the like recorded on a predetermined recording medium. Examples of media include optical recording media such as a DVD (Digital Versatile Disc) or a PD (Phase Change Rewritable Disc), magneto-optical recording media such as an MO (Magneto-Optical Disk), tape media, magnetic recording media, and semiconductor memories.

[0192] For example, when the computer 1000 functions as the base station control device 10 according to the embodiment, the CPU 1100 of the computer 1000 executes a base station control program loaded onto the RAM 1200 to realize functions such as the control unit 13. The HDD 1400 stores various programs used by the base station control device 10 according to the present disclosure and data in the storage unit 12. The CPU 1100 reads and executes program data 1450 from the HDD 1400, but as another example, the CPU 1100 may obtain these programs from another device via an external network 1550.

[0193] As described above, the present disclosure can also have the following configurations. (1) A base station control device including a control unit that controls a base station that communicates with a terminal device that moves between multiple base stations, wherein the control unit acquires terminal location information that is information about the location of the terminal device, and executes an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information. (2) The base station control device described in (1), wherein the control unit restarts the base station that is not communicating with the terminal device based on the terminal location information as part of the optimization process. (3) The base station control device described in (2), wherein the control unit calculates, based on the terminal location information, an arrival time for the terminal device to arrive at a communication area of ​​the base station that is a target of the optimization process, and if the arrival time is longer than the time required to restart the target base station, restarts the target base station. (4) The base station control device according to (2) or (3), wherein the control unit calculates, based on the terminal location information, a transit time of the terminal device passing through a communication area of ​​the base station communicating with the terminal device, determines whether the terminal device will arrive at the target base station by the transit time, and restarts the target base station if it is determined that the terminal device will not arrive. (5) The base station control device according to any one of (2) to (4), wherein the control unit determines, based on the terminal location information, whether the terminal device is present in a communication area of ​​the base station, and restarts the base station if the terminal device present in the communication area is not communicating with the base station. (6) The base station control device according to any one of (2) to (5), wherein the control unit determines, based on the terminal location information, whether the terminal device is present in a communication area covered by the base station, and restarts the base station if the terminal device present in the communication area tolerates a non-communication state with the base station.(7) The base station control device according to (1), wherein the plurality of base stations are divided into a plurality of groups, each group including one or more of the base stations, and the control unit, as the optimization processing, identifies the number of terminal devices present in a communication area covered by the group based on the terminal location information, determines the group with the fewest number of terminal devices present in the plurality of groups, and restarts the base station included in the group with the fewest number of terminal devices. (8) The base station control device according to (7), wherein the control unit outputs a notification to the terminal devices communicating with the base station to restart the target base station. (9) The base station performs mode switching of an operation mode, and the operation modes include an active mode in which the base station communicates with the terminal device, and an idle mode in which the base station communicates with the terminal device with communication transmission power reduced compared to the active mode, and the control unit, as the optimization processing, determines whether the base station is communicating with the terminal device based on the terminal location information, and switches the base station not communicating with the terminal device to the idle mode. (10) The base station control device according to (9), wherein the control unit sets at least the base station communicating with the terminal device and the base station adjacent to the base station communicating with the terminal device to the active mode. (11) The base station control device according to (9) or (10), wherein the control unit, when the terminal device is connected to the base station that is set to the idle mode, sets the base station to which the terminal device is connected to the active mode. (12) The base station control device according to any one of (9) to (11), wherein the control unit, when communication with the terminal device is interrupted, causes the base station that is set to the active mode to maintain the active mode for a predetermined time. (13) The base station control device according to any one of (9) to (12), wherein the control unit notifies the terminal device of the operation mode of the base station and the conditions under which the base station is set to the idle mode.(14) The base station control device according to any one of (1) to (13), wherein the terminal location information is terminal identification information that identifies the terminal device registered at the base station. (15) The base station control device according to any one of (1) to (13), wherein the terminal location information is GPS information acquired by the terminal device. (16) A base station control method executed by a base station control device including a control unit that controls a base station that communicates with a terminal device that moves between a plurality of base stations, wherein the control unit acquires terminal location information that is information about a location of the terminal device, and executes an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information. (17) A base station controlled by a base station control device and communicating with a terminal device, comprising: a control unit that executes mode switching of an operation mode, wherein the operation modes include an active mode for communicating with the terminal device, an idle mode in which transmission power is reduced compared to the active mode so as to be able to communicate with the terminal device, and a restart mode for restarting, wherein the control unit acquires a control signal from the base station control device, and executes mode switching to any of the operation modes of the active mode, the idle mode, and the restart mode based on the acquired control signal. (18) A setting control method executed by a base station controlled by a base station control device and communicating with a terminal device, wherein the base station comprises: a control unit that executes mode switching of an operation mode, wherein the operation modes include an active mode for communicating with the terminal device, an idle mode in which transmission power is reduced compared to the active mode so as to be able to communicate with the terminal device, and the restart mode for restarting, wherein the control unit acquires a control signal from the base station control device, and executes mode switching to any of the operation modes of the active mode, the idle mode, and the restart mode based on the acquired control signal.

[0194] REFERENCE SIGNS LIST 10 base station control device 13 control unit 20 core network 30 base station 33 control unit 400 terminal device 60 application server

Claims

1. A base station control device comprising a control unit that controls a base station that communicates with a terminal device that moves between multiple base stations, wherein the control unit acquires terminal location information, which is information about the location of the terminal device, and executes an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information.

2. The base station control device according to claim 1, wherein the control unit, as the optimization process, restarts the base station that is not communicating with the terminal device based on the terminal location information.

3. The base station control device according to claim 2, wherein the control unit calculates the arrival time of the terminal device for arriving at the communication area of ​​the base station that is the target of the optimization process based on the terminal location information, and restarts the target base station if the arrival time is longer than the time required to restart the target base station.

4. The base station control device according to claim 2, wherein the control unit calculates the transit time of the terminal device passing through the communication area of ​​the base station communicating with the terminal device based on the terminal location information, determines whether the terminal device will arrive at the target base station by the transit time, and restarts the target base station if it is determined that the terminal device will not arrive.

5. The base station control device according to claim 2, wherein the control unit determines whether the terminal device is present in the communication area of ​​the base station based on the terminal location information, and restarts the base station if the terminal device present in the communication area is not communicating with the base station.

6. The base station control device according to claim 2, wherein the control unit determines whether the terminal device is present in the communication area covered by the base station based on the terminal location information, and restarts the base station if the terminal device present in the communication area tolerates a non-communication state with the base station.

7. A base station control device according to claim 1, wherein the plurality of base stations are divided into a plurality of groups each including one or more of the base stations, and the control unit, as the optimization process, identifies the number of terminal devices present in the communication area covered by the group based on the terminal location information, determines the group with the fewest number of terminal devices present in the plurality of groups, and restarts the base station included in the group with the fewest number of terminal devices.

8. The base station control device according to claim 7, wherein the control unit outputs a notification to the terminal device communicating with the base station to the effect that the target base station will be restarted.

9. The base station control device according to claim 1, wherein the base station performs mode switching of operation modes, the operation modes including an active mode in which communication is performed with the terminal device, and an idle mode in which communication is performed with the terminal device with a reduced transmission power for communication compared to the active mode, and the control unit, as the optimization process, determines whether the base station is communicating with the terminal device based on the terminal location information, and switches the base station that is not communicating with the terminal device to the idle mode.

10. The base station control device according to claim 9, wherein the control unit sets at least the base station communicating with the terminal device and the base station adjacent to the base station communicating with the terminal device to the active mode.

11. The base station control device according to claim 9, wherein the control unit, when the terminal device is connected to the base station in the idle mode, switches the base station to which the terminal device is connected to the active mode.

12. The base station control device according to claim 9, wherein the control unit causes the base station in the active mode to maintain the active mode for a predetermined period of time when communication with the terminal device is interrupted.

13. The base station control device according to claim 9, wherein the control unit notifies the terminal device of the operation mode of the base station and the conditions under which the base station enters the idle mode.

14. The base station control device according to claim 1, wherein the terminal location information is terminal identification information that identifies the terminal device registered in the base station.

15. The base station control device according to claim 1, wherein the terminal location information is GPS information acquired by the terminal device.

16. A base station control method executed by a base station control device having a control unit that controls a base station that communicates with a terminal device that moves between multiple base stations, wherein the control unit acquires terminal location information that is information about the location of the terminal device, and executes an optimization process that optimizes communication between the terminal device and the base station based on the acquired terminal location information.

17. A base station controlled by a base station control device and communicating with a terminal device, comprising a control unit that executes mode switching of operation modes, wherein the operation modes include an active mode in which communication is performed with the terminal device, an idle mode in which transmission power is reduced compared to the active mode so as to be able to communicate with the terminal device, and a restart mode in which restart is performed, wherein the control unit acquires a control signal from the base station control device, and executes mode switching to one of the operation modes of the active mode, the idle mode, and the restart mode based on the acquired control signal.

18. A setting control method executed by a base station controlled by a base station control device and communicating with a terminal device, wherein the base station has a control unit that executes mode switching of operation modes, the operation modes including an active mode for communicating with the terminal device, an idle mode in which transmission power is reduced compared to the active mode so as to be able to communicate with the terminal device, and a restart mode for restarting, the control unit acquiring a control signal from the base station control device, and executing mode switching to one of the operation modes of the active mode, the idle mode, and the restart mode based on the acquired control signal.

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