Base station control device, control method for base station control device, and control program for base station control device

Abstract

This base station control device relating to a wireless communication system in which a first base station and a second base station coordinate to communicate wirelessly with a terminal comprises: a storage unit that stores base station information including the locations of a plurality of base stations; a propagation path condition information acquisition unit that acquires propagation path information indicating the condition of a propagation path transmitted from the terminal when a coordination action by the first base station and the second base station has been configured; a change information acquisition unit that acquires change information relating to a change in a communication condition of the terminal due to the coordination action; a location estimation unit that estimates the location of the terminal; a generation unit that performs training on the relationship between the propagation path information, the change information, and the location of the terminal, and generates a trained model for outputting information about a base station that coordinates with a prescribed base station to communicate wirelessly with a prediction target terminal, said prediction target terminal communicating wirelessly with the prescribed base station; and a selection unit that selects a base station as the second base station on the basis of the trained model.

Description

Base station control device, control method for base station control device, and control program for base station control device

[0001] The present invention relates to a base station control device, a control method for the base station control device, and a control program for the base station control device.

[0002] Conventionally, when executing cooperative technologies such as carrier aggregation (CA: Carrier Aggregation) or coordinated multi-point transmission technology (CoMP: Coordinated Multi Point transmission) between base stations, based on the geographical conditions of the base stations or through radio wave propagation simulations, etc., an optimal base station is selected. (For example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2010-258612

[0004] A base station control device according to an embodiment of the present invention is a base station control device related to a wireless communication system in which a first base station and a second base station cooperate to perform wireless communication with a terminal, and includes a storage unit that stores base station information including the positions of a plurality of base stations including the first base station and the second base station, a propagation path state information acquisition unit that acquires propagation path information indicating the state of the propagation path transmitted from the terminal when a cooperative operation between the first base station and the second base station is set, a change information acquisition unit that acquires change information regarding a change in the communication state of the terminal due to the cooperative operation, a position estimation unit that estimates the positions of the terminal with respect to the first base station and the second base station based on signals transmitted from the terminal to the first base station and the second base station, a generation unit that learns the relationship between the propagation path information, the change information, and the position of the terminal, and generates a learning model that outputs information on a base station that performs wireless communication in cooperation with a predetermined base station for a terminal to be predicted that performs wireless communication with the predetermined base station, and a selection unit that selects, as the second base station, a base station that performs wireless communication in cooperation with the first base station for a terminal to be predicted that performs wireless communication with the first base station at a predetermined position based on the learning model.

[0005] In the base station control device according to an embodiment of the present invention, the change information acquisition unit may acquire, as the change information, the change in the communication speed before and after the start of the cooperative operation.

[0006] In a base station control device according to one embodiment of the present invention, the propagation path state information acquisition unit may acquire at least one of CQI (Channel Quality Indicator) and CSI (Channel State Information) as propagation path information.

[0007] In a base station control device according to one embodiment of the present invention, the propagation path status information acquisition unit may acquire at least the terminal handover history as propagation path information.

[0008] A base station control device according to one embodiment of the present invention may further include a setting unit that, based on a learning model, sets base stations that should not cooperate with the first base station in relation to a target terminal that communicates wirelessly with the first base station and is located at a predetermined position.

[0009] A control method for a base station control device according to one embodiment of the present invention is a control method for a base station control device relating to a wireless communication system in which a first base station and a second base station cooperate to perform wireless communication with a terminal, which includes the steps of: storing base station information including the locations of a plurality of base stations, including the first base station and the second base station, in a predetermined storage unit; acquiring propagation path information indicating the state of the propagation path transmitted from the terminal when cooperative operation between the first base station and the second base station is set; acquiring change information acquisition unit that acquires change information regarding changes in the communication state of the terminal due to cooperative operation; estimating the position of the terminal relative to the first base station and the second base station based on signals transmitted from the terminal to the first base station and the second base station; generating a learning model that learns the relationship between propagation path information, change information and the position of the terminal, and outputs information of a base station that cooperates with a predetermined base station to perform wireless communication with a predicted terminal that performs wireless communication with a predetermined base station; and selecting a base station as a second base station that cooperates with the first base station to perform wireless communication with a predicted terminal that is located at a predetermined location, based on the learning model.

[0010] A control program for a base station control device according to one embodiment of the present invention provides a base station control device for a wireless communication system in which a first base station and a second base station cooperate to perform wireless communication with a terminal, and includes the following functions: a function to store base station information including the locations of a plurality of base stations, including the first base station and the second base station, in a predetermined storage unit; a function to acquire propagation path information indicating the state of the propagation path transmitted from the terminal when cooperative operation between the first base station and the second base station is set; a change information acquisition unit that acquires change information regarding changes in the communication state of the terminal due to cooperative operation; a function to estimate the position of the terminal relative to the first base station and the second base station based on signals transmitted from the terminal to the first base station and the second base station; a function to learn the relationship between propagation path information, change information, and the position of the terminal, and generate a learning model that outputs information of a base station that cooperates with a predetermined base station to perform wireless communication with a predicted terminal that performs wireless communication with a predetermined base station; and a function to select a base station as the second base station that cooperates with the first base station to perform wireless communication with a predicted terminal that is located at a predetermined location and performs wireless communication with the first base station, based on the learning model.

[0011] Figure 1 shows an example of a base station control system configuration according to one embodiment of the present invention. Figure 2 shows an example of a sequence diagram related to setting up coordinated operation by a base station. Figure 3 is a schematic diagram of the functional block configuration of a base station control device according to one embodiment of the present invention. Figure 4 is a flowchart of an example of a control method for a base station control device according to one embodiment of the present invention.

[0012] Hereafter, an embodiment of the invention described herein (also referred to as the present invention) will be explained using the figures. Note that the figures are examples only, and the present invention is not limited to those shown in the figures. For example, the illustrated base station control device (server), terminal (wireless communication terminal), sequence diagram, flowchart, etc., are examples only, and the present invention is not limited to these.

[0013] As mentioned above, conventionally, when implementing cooperative technologies such as Co-MP (Cooperative Transmission Platform) and Carrier Aggregation (CA) between base stations, the optimal base station is selected based on the geographical conditions of the base stations or through radio wave propagation simulations. However, especially in urban areas, buildings are densely packed, making it difficult for radio wave propagation to proceed as simulated. Therefore, even if cooperative technologies are applied between base stations based on simulation results, the maximum effect may not be achieved if the combination of base stations is not optimal. Furthermore, conventional methods did not allow for dynamic changes to the optimal combination of base stations in response to changes in traffic volume over time.

[0014] In contrast, according to one embodiment of the present invention, based on information related to wireless communication measured by a terminal (UE: User Equipment) (signal strength, transmission power, movement speed, movement direction, handover history, channel quality indicator (CQI), channel state information (CSI), etc.), the most efficient combination of base stations for cooperative technology is determined by artificial intelligence (AI). Furthermore, according to one embodiment of the present invention, base stations that can be recognized by the terminal but are not recommended for wireless communication using cooperative technology from an efficiency standpoint may be determined. Note that "channel" may also be referred to as "propagation path" in this context.

[0015] <System Configuration> Figure 1 shows an example configuration of a base station control system according to one embodiment of the present invention. The base station control system 600 includes a wireless communication terminal (also referred to as "terminal") 300, a wireless access network RAN ​​(Radio Access Network) 400, and a core network CN. The RAN 400 includes a plurality of base stations 200 (200A, 200B, 200C, ...) and a base station control device 100. In this embodiment, a 5G (fifth generation) mobile communication system is assumed, and the RAN 400 may be a RAN to which the specifications defined by the industry group O-RAN Alliance (Open Radio Access Network Alliance) are applied. Furthermore, the base stations 200 may include RU (Radio Unit), DU (Distribution Unit), and CU (Central Unit). Furthermore, CU / DU may be implemented using vRAN (virtual RAN), which implements each function using software on general-purpose hardware.

[0016] The base station control device 100 may implement a RIC (RAN Intelligent Controller), which is defined in O-RAN as a logical node for automating and optimizing the parameter design, setting, and operation of the base station. The base station control device 100 and the base station 200 are connected to each other via a network for communication. The base station 200 may also have the functions of the base station control device 100. Furthermore, the base station control device 100 may be installed in the core network CN.

[0017] Although only one base station control device 100 is shown in Figure 1, it is not limited to this. In other words, each function described as being provided by the base station control device 100 may be realized by multiple base station control devices. Furthermore, the base station control device 100 may be a distributed system that operates cooperatively by communicating over a network, for example, or it may be a so-called cloud device. In other words, the base station control device 100 is not limited to a physical base station control device, but may also include a virtual base station control device provided by software.

[0018] The base station 200 communicates wirelessly with the connected terminal 300. In Figure 1, three base stations 200 (200A, 200B, 200C) are shown, but the number is not limited to these, and if there is no need to distinguish between them, they are simply referred to as base station 200. Multiple base stations 200 may cooperate to communicate wirelessly with the terminal 300. For example, in the example in Figure 1, base stations 200A and 200B cooperate to communicate wirelessly with the terminal 300. In Figure 1, only one terminal 300 is shown, but there may be more. In other words, the number of base stations 200 and terminals 300 is not limited to those shown.

[0019] Furthermore, the present invention is not limited to 5G, and may be applicable to LTE, LTE-Advanced, Beyond 5G, 6G (sixth generation) and later mobile communication systems. It may also be applicable to wireless communication systems that use 5G as part of a wireless communication system.

[0020] <Outline of the Invention> The outline of the present invention will be explained using Figure 2. Figure 2 is an example of a sequence between a terminal 300 and base stations A (first base station) 200A and B (second base station) 200B that perform cooperative wireless communication with the terminal 300.

[0021] First, it is assumed that the first base station 200A and the terminal 300 are transmitting and receiving data via wireless communication (step S1). The terminal 300 may transmit channel status information, channel quality information, etc., as information related to wireless communication measured by its own terminal. In addition, the signals transmitted from the terminal 300 to the first base station 200A may include a broadband sounding reference signal (SRS). Furthermore, the information transmitted from the terminal 300 to the first base station 200A may include handover history.

[0022] The first base station 200A may select the second base station 200B as the base station for cooperative operation based on the location of the terminal 300 (relative position to the first base station 200A) and information about other base stations 200 recognized by the terminal 300 (for example, the second base station 200B) (step S2). The location (relative position) of the terminal 300 relative to the base station 200 may be estimated using the transmission power and signal strength of the uplink signal (PUSCH) from the terminal 300, the transmission timing (TA: Timing Advance), the direction of movement, and the speed of movement. For example, the greater the communication distance between the terminal 300 and the base station 200, the stronger the power the terminal 300 sends the signal; therefore, the transmission power and signal strength can be used to estimate the distance between the terminal 300 and the base station 200. Existing propagation models may be used to estimate the distance. Furthermore, TA is an index used to adjust the timing at which terminal 300 transmits data based on the distance between base station 200 and terminal 300, and is specified by base station 200. Therefore, the relative position of terminal 300 with respect to base station 200 can be estimated using TA. In addition, the direction and speed of movement may be estimated from the direction and time of arrival of the signal, changes in signal strength, etc. Furthermore, information about base station 200 that terminal 300 can recognize may be handover history, channel quality index (CQI), etc.

[0023] The first base station 200A may transmit a request for coordinated operation to the second base station 200B via the backhaul link (step S3). The second base station 200B may respond to the request (here, an ACK: acknowledgment) (step S4) and perform settings for coordinated operation, such as allocating a resource block for coordinated operation to the terminal 300 (step S5). Then, a message may be transmitted to the terminal 300 indicating that the first base station 200A and the second base station 200B will perform wireless communication in cooperation (step S6). The terminal 300 may perform settings to support the coordinated operation between the first base station 200A and the second base station 200B (step S7). After that, the first base station 200A and the second base station 200B may cooperate to send and receive data to the terminal 300 (steps S8, S9).

[0024] Terminal 300 may measure changes in the communication state caused by the coordinated operation of base station 200 (step S10). Changes in the communication state may be changes in parameters indicating the communication state before and after the start of coordinated operation. For example, terminal 300 may measure changes in communication speed and communication efficiency before and after the start of coordinated operation. Terminal 300 may transmit information regarding changes in the communication state to the first base station 200A (step S11). The first base station 200A may transmit learning data containing information regarding changes in the communication state to a base station control device 100 (described later), which is not shown (step S12). The learning data may include the location information of terminal 300 and propagation path information indicating the propagation path state transmitted from terminal 300 before and after coordinated operation. The learning data may also be transmitted from the second base station 200B.

[0025] According to one embodiment of the present invention, the base station control device 100 may learn information relating to wireless communication between the base station 200 and the terminal 300 before and after the start of cooperative operation from the base station that performs cooperative operation. For example, if the communication speed of the terminal 300 decreases as a result of the cooperative operation, or if the improvement in communication speed does not exceed a predetermined threshold, these may be learned as cooperative operation failure data. Then, a learning model may be generated that outputs information about the base station that performs wireless communication in cooperation with the predetermined base station to a target terminal that performs wireless communication with the predetermined base station.

[0026] Next, the configuration of the base station control device will be explained using Figure 3.

[0027] <Hardware configuration of base station control device> The base station control device (server) 100 may include a control unit 110, a communication unit 120, an input / output unit 130, and a storage unit 170.

[0028] The control unit 110 is typically a processor, and may include a central processing unit (CPU), a microprocessing unit (GPU), a graphics processing unit (GPU), a microprocessor, etc., and may be implemented by logic circuits (hardware) or dedicated circuits formed on an integrated circuit (IC (Integrated Circuit) chip, LSI (Large Scale Integration)), etc.

[0029] The communication unit 120 may be implemented as hardware such as a NIC (Network Interface Card), a network adapter, communication software, or a combination thereof. The communication unit 120 may transmit and receive various types of data with the base station 200.

[0030] The input / output unit 130 may include an input device for inputting various operations to the base station control device 100, and an output device for outputting processing results processed by the base station control device 100. The input device may include, for example, hardware keys such as a touch panel, touch display, or keyboard, a pointing device such as a mouse, a camera, or a microphone. The output device may output processing results processed by the control unit 110. The output device may include, for example, a display, touch panel, or speaker.

[0031] The storage unit 170 stores various programs and data necessary for the operation of the base station control device 100. For example, the storage unit 170 may store base station information, including the locations of multiple base stations 200, including the first base station 200A and the second base station 200B. The storage unit 170 may include, for example, an HDD (Hard Disk Drive), an SSD (Solid State Drive), flash memory, etc. The storage unit 170 may also include memory that provides a working area for the control unit 110.

[0032] <Functional Configuration of Base Station Control Device> The base station control device 100 may include a propagation path status information acquisition unit 111, a change information acquisition unit 112, a position estimation unit 113, a generation unit (learning unit) 114, a selection unit 115, and a setting unit 116.

[0033] The propagation path status information acquisition unit 111 may acquire propagation path information indicating the state of the propagation path transmitted from the terminal 300 when cooperative operation between the first base station 200A and the second base station 200B is set. For example, the propagation path status information acquisition unit 111 may acquire at least one of CQI (Channel Quality Indicator) and CSI (Channel State Information) as propagation path information. Alternatively, the propagation path status information acquisition unit 111 may acquire at least the handover history of the terminal 300 as propagation path information.

[0034] The change information acquisition unit 112 may acquire change information relating to changes in the communication state of the terminal 300 due to cooperative operation. Here, the change information acquisition unit 112 may acquire changes in communication speed before and after the start of cooperative operation as change information.

[0035] The position estimation unit 113 may estimate the position of terminal 300 relative to the first base station 200A and the second base station 200B based on signals transmitted from terminal 300 to the first base station 200A and the second base station 200B. The generation unit 114 may learn the relationship between propagation path information, change information, and the position of terminal 300, and generate a learning model that outputs information of a base station that performs wireless communication in cooperation with a predetermined base station to a terminal to be predicted to perform wireless communication with a predetermined base station. The selection unit 115 may select a base station as a second base station that performs wireless communication in cooperation with the first base station 200A to a terminal to be predicted to perform wireless communication with the first base station 200A, which is located at a predetermined position, based on the learning model.

[0036] The setting unit 116 may, based on the learning model, set up base stations that should not cooperate with the first base station 200A in relation to a target terminal that is performing wireless communication with the first base station 200A at a predetermined location. This can be obtained by learning cases where the communication speed decreases or other improvements in communication performance are not observed due to cooperative operation.

[0037] Furthermore, the generation of the learning model may be performed for each base station 200 based on information obtained from multiple terminals 300. In other words, the learning model may differ for each base station 200.

[0038] Furthermore, the accuracy of the learning model may be improved through reinforcement learning using real data such as changes in communication performance obtained when communication is performed through coordinated operation between base stations configured based on the learning model.

[0039] <Control Flowchart of the Base Station Control Device> The control method of the base station control device 100 described above will be explained using the flowchart in Figure 4. First, base station information, including the locations of multiple base stations, including the first base station and the second base station, is stored in the storage unit 170 (step S11). Next, the propagation path state information acquisition unit 111 acquires propagation path information indicating the state of the propagation path transmitted from the terminal when cooperative operation between the first base station and the second base station is set (step S12). The change information acquisition unit 112 acquires change information regarding the change in the communication state of the terminal due to the cooperative operation (step S13). The position estimation unit 113 estimates the position of the terminal relative to the first base station and the second base station based on the signals transmitted from the terminal to the first base station and the second base station (step S14). The generation unit 114 learns the relationship between the propagation path state, the change information, and the position of the terminal, and generates a learning model that outputs information of a base station that performs wireless communication in cooperation with a predetermined base station to a terminal that is a target for prediction to perform wireless communication with a predetermined base station (step S15). Based on the learning model, the selection unit 115 selects a base station to be used as a second base station, which will cooperate with the first base station to perform wireless communication with a target terminal located at a predetermined position that is performing wireless communication with the first base station (step S16).

[0040] While the present invention has been described based on various drawings and embodiments, it should be noted that those skilled in the art will find it easy to make various modifications and alterations based on this disclosure. Therefore, it should be noted that these modifications and alterations are within the scope of the present invention. For example, the functions included in each component, step, etc., can be rearranged in a logically consistent manner, and multiple components or steps, etc., can be combined into one or divided. Furthermore, the configurations shown in the above embodiments may be combined as appropriate. For example, each component described as being provided by the base station control device 100 may be implemented by distributing them among multiple base station control devices.

[0041] Furthermore, the training data used to generate the learning model is not limited to what is described above; it may be less or more. For example, information such as traffic volume, time, construction status, and presence or absence of obstacles may also be learned.

[0042] The programs of each embodiment of this disclosure may be provided stored in a storage medium readable by the information processing device. The storage medium is a "non-temporary tangible medium" capable of storing programs. The programs include, for example, software programs and information processing device programs. When each functional unit of the base station control device 100 as an information processing device is implemented by software, the base station control device 100 functions as a propagation path state information acquisition unit 111, a change information acquisition unit 112, a position estimation unit 113, a generation unit (learning unit) 114, a selection unit 115, and a setting unit 116 by having the processor execute a program loaded into memory.

[0043] When appropriate, the memory medium can include one or more semiconductor-based or other integrated circuits (ICs) (e.g., field programmable gate arrays (FPGAs), application specific ICs (ASICs), etc.), hard disk drives (HDDs), hybrid hard drives (HHDs), optical disks, optical disk drives (ODDs), magneto-optical disks, magneto-optical drives, floppy disks, floppy disk drives (FDDs), magnetic tapes, solid state drives (SSDs), RAM drives, secure digital cards or drives, any other appropriate memory medium, or any suitable combination of two or more of these. The memory medium can be volatile, non-volatile, or a combination of volatile and non-volatile when appropriate.

[0044] In addition, the program of the present disclosure may be provided to the base station control device 100 via any transmission medium (such as a communication network or a broadcast wave) capable of transmitting the program.

[0045] In addition, each embodiment of the present disclosure can also be realized in the form of a data signal embedded in a carrier wave, in which the program is embodied by electronic transmission. Note that the program of the present disclosure may be implemented using, for example, script languages such as JavaScript (registered trademark), Python (registered trademark), etc., C language, Go language, Swift (registered trademark), Kotlin (registered trademark), Java (registered trademark), etc.

[0046] According to each aspect of the present disclosure described above, since a technology for improving communication quality is provided, it can contribute to the achievement of Sustainable Development Goal (SDG) 9, "Build the infrastructure for industry and innovation".

[0047] 100 Base station control device (server) 110 Control unit 111 Propagation path state information acquisition unit 112 Change information acquisition unit 113 Position estimation unit 114 Generation unit (learning unit) 115 Selection unit 116 Setting unit 120 Communication unit 130 Input / output unit 170 Memory unit 200 Base station 300 Wireless communication terminal 400 RAN 600 Base station control system CN Core network

Claims

1. A base station control device for a wireless communication system in which a first base station and a second base station cooperate to perform wireless communication with a terminal, comprising: a storage unit that stores base station information including the locations of a plurality of base stations, including the first base station and the second base station; a propagation path state information acquisition unit that acquires propagation path information indicating the state of the propagation path transmitted from the terminal when cooperative operation between the first base station and the second base station is set; a change information acquisition unit that acquires change information relating to the change in the communication state of the terminal due to the cooperative operation; a position estimation unit that estimates the position of the terminal relative to the first base station and the second base station based on signals transmitted from the terminal to the first base station and the second base station; a generation unit that learns the relationship between the propagation path information, the change information and the position of the terminal and generates a learning model that outputs information of a base station that cooperates with a predetermined base station to perform wireless communication with a predicted terminal that performs wireless communication with a predetermined base station; and a selection unit that selects a base station as the second base station that cooperates with the first base station to perform wireless communication with a predicted terminal that is located at a predetermined location.

2. The base station control device according to claim 1, wherein the change information acquisition unit acquires the change in communication speed before and after the start of the cooperative operation as the change information.

3. The base station control device according to claim 1, wherein the propagation path state information acquisition unit acquires at least one of CQI (Channel Quality Indicator) and CSI (Channel State Information) as the propagation path information.

4. The base station control device according to claim 1, wherein the propagation path status information acquisition unit acquires at least the handover history of the terminal as the propagation path information.

5. The base station control device according to claim 1, further comprising a setting unit that sets base stations that should not cooperate with the first base station in relation to a terminal to be predicted that is located at a predetermined position and performs wireless communication with the first base station, based on the learning model.

6. A control method for a base station control device relating to a wireless communication system in which a first base station and a second base station cooperate to perform wireless communication with a terminal, comprising the steps of: storing base station information including the locations of a plurality of base stations, including the first base station and the second base station, in a predetermined storage unit; acquiring propagation path information indicating the state of the propagation path transmitted from the terminal when cooperative operation between the first base station and the second base station is set; acquiring change information regarding the change in the communication state of the terminal due to the cooperative operation; estimating the position of the terminal relative to the first base station and the second base station based on signals transmitted from the terminal to the first base station and the second base station; generating a learning model that learns the relationship between the propagation path information, the change information, and the position of the terminal, and outputs information of a base station that cooperates with the predetermined base station to perform wireless communication with a terminal to be predicted to perform wireless communication with the predetermined base station; and selecting a base station as the second base station that cooperates with the first base station to perform wireless communication with a terminal to be predicted to perform wireless communication with the first base station, located at a predetermined location, based on the learning model.

7. A control program for a base station control device relating to a wireless communication system in which a first base station and a second base station cooperate to perform wireless communication with a terminal, comprising: a function to store base station information including the locations of a plurality of base stations, including the first base station and the second base station, in a predetermined storage unit; a function to acquire propagation path information indicating the state of the propagation path transmitted from the terminal when cooperative operation between the first base station and the second base station is set; a change information acquisition unit that acquires change information relating to the change in the communication state of the terminal due to the cooperative operation; a function to estimate the position of the terminal relative to the first base station and the second base station based on signals transmitted from the terminal to the first base station and the second base station; a function to learn the relationship between the propagation path information, the change information, and the position of the terminal, and generate a learning model that outputs information of a base station that cooperates with the predetermined base station to perform wireless communication with a terminal to be predicted to perform wireless communication with the predetermined base station; and a function to select a base station as the second base station that cooperates with the first base station to perform wireless communication with a terminal to be predicted to perform wireless communication with the first base station, located at a predetermined position, based on the learning model.

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