JP2018195928A - Radio communication system, movable base station, control station, and movable sensor - Google Patents

Abstract

To quickly make base station deployment appropriate or optimize it in a radio communication system.SOLUTION: A radio communication system may include a movable base station 20 and a movable sensor 30. The movable base station 20 and the movable sensor 30 can independently move. The movable sensor 30 can measure and collect information indicating a radio wave environment around its current position. The movable base station 20 may move to a position corresponding to a sensing result of the movable sensor 30.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a radio communication system, a mobile base station, a control station, and a mobile sensor.

  With the rapid increase in mobile traffic in recent years, base stations in mobile communication are not limited to guaranteeing a coverage area (may be referred to as coverage), and are required to be installed so as to ensure an expected communication speed. .

  For example, a small cell having a smaller coverage than the macro cell may be arranged in an area where terminals exist in the macro cell at a high density for traffic offloading.

  However, places with a lot of traffic are affected by the time of day and the presence or absence of events. On the other hand, in addition to the cost of the equipment itself, the installation of a small cell requires costs such as location selection, securing, and site survey of the installation location. Can cause waste.

  Therefore, for example, a base station configured to be movable (hereinafter sometimes referred to as a “mobile base station”) senses surrounding traffic while moving, and moves to a place where there is a lot of traffic. It can be considered to achieve dispersion.

JP-A-7-87011 JP 2004-363156 A

  However, there are cases where the base station is heavy due to the mounted wireless device or the like and cannot be moved quickly. Therefore, it takes time for the base station to move to the target position, and there is a possibility that the optimization or optimization of the base station arrangement for traffic distribution or the like is delayed.

  On the other hand, if a base station equipped with a sensor function is to be realized with a small configuration capable of high-speed movement, the function, configuration, and performance inherently expected as a base station are sacrificed, such as limiting radio transmission power. Can be.

  In one aspect, one of the objects of the present invention is to enable appropriate optimization or optimization of base station arrangement in a wireless communication system.

  In one aspect, the wireless communication system may include a mobile sensor and a mobile base station. The movement sensor may be configured to be movable, and may be capable of sensing information indicating a radio wave environment around the current position. The mobile base station can move independently of the movement sensor and may move to a position corresponding to the sensing result of the movement sensor.

  In one aspect, the mobile base station is configured to be movable and may include a receiving unit and a control unit. The receiving unit may receive an instruction regarding a moving position. The control unit may control movement to the position. The position may be a position determined based on a sensing result by a mobile sensor capable of moving independently of the mobile base station and sensing information indicating a radio wave environment around the current position. .

  Further, in one aspect, the control station may include a reception unit, a determination unit, and a transmission unit. The receiving unit may receive a sensing result from the movement sensor. The movement sensor can move independently of a mobile base station configured to be movable, and can sense information indicating a radio wave environment around the current position. The determination unit may determine the position of the mobile base station based on the sensing result. The transmission unit may transmit an instruction to move to the determined position to the mobile base station.

  In one aspect, the movement sensor is configured to be movable, and may include a sensing unit, a reception unit, and a transmission unit. The sensing unit may sense information indicating a radio wave environment around the current position. The receiving unit may receive an instruction regarding a position where the information is sensed. The transmission unit may transmit a sensing result at the position moved according to the instruction to a device that determines the position of the mobile base station.

  As one aspect, it becomes possible to promptly optimize or optimize the base station arrangement in the wireless communication system.

It is a block diagram which shows the structural example of the radio | wireless communications system which concerns on one Embodiment. FIG. 2 is a schematic diagram for explaining an operation example of the wireless communication system illustrated in FIG. 1. FIG. 3 is a sequence diagram illustrating an operation example of the wireless communication system illustrated in FIG. 1. 3 is a flowchart illustrating an operation example of the movement sensor illustrated in FIG. 1. FIG. 2 is a diagram illustrating a format example of a sensing instruction transmitted from a control station to a mobile sensor in the wireless communication system illustrated in FIG. 1. It is a figure which shows the example of a format of the sensing result report transmitted to a control station from a mobile sensor in the radio | wireless communications system illustrated in FIG. It is a figure which shows an example of the electromagnetic wave environment information management table produced | generated based on the sensing result report received from the mobile sensor in the control station illustrated in FIG. FIG. 2 is a diagram illustrating a format example of a movement instruction transmitted from a control station to a mobile base station in the wireless communication system illustrated in FIG. 1. It is a block diagram which shows the structural example of the mobile base station illustrated in FIG. FIG. 2 is a block diagram illustrating a configuration example of a movement sensor illustrated in FIG. 1. It is a block diagram which shows the structural example of the control station illustrated in FIG. It is a sequence diagram which shows the operation example of the radio | wireless communications system which concerns on the modification of one Embodiment. It is a figure which shows the variation of the function sharing of the radio | wireless communications system which concerns on the modification of one Embodiment. It is a schematic diagram which shows the example which a mobile base station and a mobile sensor unite in the radio | wireless communications system illustrated in FIG. It is a block diagram which shows the structural example of a mobile base station and a mobile sensor corresponding to the example of FIG. FIG. 15 is a schematic diagram showing that an SMA (Sub Miniature Type A) connector is applicable for the combination illustrated in FIG. 14. FIG. 15 is a block diagram illustrating an example of an analog beam forming configuration at the time of merging illustrated in FIG. 14. It is a block diagram which shows an example of the digital beam forming structure at the time of the unification illustrated in FIG.

  Hereinafter, embodiments will be described with reference to the drawings. However, the embodiment described below is merely an example, and there is no intention to exclude various modifications and technical applications that are not explicitly described below. Various exemplary embodiments described below may be implemented in combination as appropriate. Note that, in the drawings used in the following embodiments, portions denoted by the same reference numerals represent the same or similar portions unless otherwise specified.

  FIG. 1 is a block diagram illustrating a configuration example of a wireless communication system according to an embodiment. The wireless communication system 1 illustrated in FIG. 1 may include, for example, a terminal 10, a base station 20, a sensor 30, and a control station 40. Two or more of the terminal 10, the base station 20, the sensor 30, and the control station 40 may be provided in the wireless communication system 1.

  The terminal 10 can perform wireless communication with the base station 20 in a wireless area formed or provided by the base station 20. The “terminal” may be referred to as “wireless device”, “wireless device”, “terminal device”, or the like. The “wireless area” may be referred to as “cell”, “coverage area”, “communication area”, “service area”, and the like.

  The terminal 10 may be a fixed terminal whose position does not change, or may be a mobile terminal (which may be referred to as a “mobile device”) whose position changes. Non-limiting examples of mobile terminals include mobile phones, smartphones, tablet terminals, and other UEs. “UE” is an abbreviation for “User Equipment”.

  As a non-limiting example of the fixed terminal, a UE such as a sensor device or a meter (measuring instrument) having a wireless communication function, which forms a sensor network, can be cited. In other words, the UE 10 that can connect to the base station 20 and perform wireless communication is not limited to a mobile phone, a smartphone, or a tablet terminal, and may include a sensor device, a meter, and the like.

  A sensor device or meter having a wireless communication function is sometimes referred to as an MTC terminal or an MTC device, etc., as distinguished from a UE such as a mobile phone or a smartphone. “MTC” is an abbreviation for “machine type communications”.

  Note that, by IoT (Internet of Things), a wireless communication function can be mounted on various “things” without being limited to sensor devices and meters. Therefore, various “things” (may be referred to as “IoT devices”) equipped with a wireless communication function may correspond to MTC terminals.

  The base station 20 forms or provides a cell that enables radio communication with the UE 10. The “cell” may include a “macro cell” and a “small cell” having a smaller coverage than the “macro cell”.

  The “small cell” may have a different name depending on the coverage area. For example, the small cell may be referred to as “femtocell”, “picocell”, “microcell”, “nanocell”, “metrocell”, “homecell”, and the like.

  The term “cell” means an individual geographical area in which the base station 20 provides a radio service, and communication managed by the base station 20 in order to communicate with the terminal 10 in the individual geographical area. It may also mean part of the function.

  The base station 20 may be, for example, an “eNB” compliant with 3rd generation partnership project (3GPP) long term evolution (LTE) or LTE-Advanced (hereinafter collectively referred to as “LTE”). “ENB” is an abbreviation for “evolved Node B”.

  A communication point called RRH (Remote Radio Head), which is separated from the base station main body and arranged in a remote place, may be regarded as corresponding to the base station 20. RRH may be referred to as RRU (Remote Radio Unit) or RRE (Remote Radio Equipment).

  In the present embodiment, the base station 20 may be configured to be movable. Hereinafter, the mobile base station 20 may be referred to as a “mobile base station 20” for convenience. For example, the mobile base station 20 may be provided with a drive unit 23 (described later in FIG. 9) including a motor, wheels, screws, and the like.

  Depending on the driving of the driving unit 23, the mobile base station 20 may be able to move on the ground, underground, water, and the like. For example, the mobile base station 20 may be configured as a robot apparatus that can move on the ground, underground, water, and the like.

  Alternatively, the mobile base station 20 may be movable by being mounted on a mobile body such as a vehicle. In other words, a drive unit provided in a moving body such as a vehicle may correspond to the drive unit 23 for moving the mobile base station 20.

  The range in which the mobile base station 20 may move (hereinafter, may be abbreviated as “movable range”) may be determined depending on the moving speed according to the driving capability of the driving unit 23. For example, the movable range of the mobile base station 20 may be determined so that the area of the moving range is proportional to the speed according to the moving speed.

  The sensor 30 is exemplarily configured to be movable, and can sense information indicating a radio wave environment around the current position (hereinafter sometimes abbreviated as “radio wave environment information”). Hereinafter, the movable sensor 30 may be referred to as a “movement sensor” for convenience.

  The movement sensor 30 can move independently of the mobile base station 20 to a position where a part or all of the movable range of the mobile base station 20 can be sensed. The range in which the movement sensor 30 may move may also be abbreviated as “movable range” and may be determined depending on the moving speed. Note that “sensing” by the movement sensor 30 may be rephrased as “measurement”, “detection”, “investigation”, “scan”, or the like.

  The mobile sensor 30 may be realized by a small device that is smaller in size, weight, etc. than the mobile base station 20 and can move at a higher speed than the mobile base station 20. For example, the movement sensor 30 may be able to move in the air by being mounted on a flying object such as a drone. However, the movement sensor 30 is not limited to being in the air, and may be configured as a robot apparatus that can move on the ground, underground, water, and the like.

  The mobile sensor 30 may be managed in association with any mobile base station 20. The management may be performed by the control station 40, for example. The correspondence between the mobile sensor 30 and the mobile base station 20 may be one-to-one, one-to-many, or many-to-one.

  For example, the movement sensor 30 may sense radio wave environment information by moving in an area determined by the movable range of one mobile base station 20, and is formed by the movable ranges of two or more mobile base stations 20. Radio wave environment information may be sensed by moving the entire area. Alternatively, two or more movement sensors 30 may move in a movable range of one mobile base station 20 and sense radio wave environment information in a cooperative and distributed manner.

  The radio wave environment information may include, for example, any one or more of reception power, channel estimation value, and propagation loss between the terminal 10 and the mobile sensor 30. Therefore, the movement sensor 30 may be, for example, a radio wave sensor having one or more antennas.

  The radio wave environment information is not limited to information that explicitly or directly indicates the radio wave environment around the current position of the mobile sensor 30 such as received power, channel estimation value, propagation loss, etc., but the radio wave environment is implied or indirect. It may be the information shown.

  For example, by applying image processing such as image recognition and image analysis to image data captured by an imaging device such as a camera mounted on the movement sensor 30, the number and density of people (users) existing in the imaging range can be reduced. Can be estimated. Therefore, the number and density of the terminals 10 located around the sensor 30 can be estimated.

  If the number and density of the terminals 10 located around the movement sensor 30 can be estimated, the radio wave environment around the current position of the movement sensor 30 can be estimated. Therefore, the image data captured by the movement sensor 30 or the data obtained by image processing of the image data can be positioned as an example of information that indirectly indicates the radio wave environment around the current position of the movement sensor 30.

  For example, the mobile base station 20 and the mobile sensor 30 may be communicably connected to the control station 40 via a backhaul (BH) line in a wireless or wired manner. For example, the control station 40 may be provided in a backbone network (NW) including a core network. Note that the backbone NW may be illustratively connected to the Internet including an information processing apparatus such as a server.

  The control station 40 may communicate with the movement sensor 30 through the BH line to control movement (in other words, position) of the movement sensor 30 or acquire radio wave environment information obtained by the movement sensor 30. it can. Further, the control station 40 can control the movement (in other words, the position) of the mobile base station 20 by communicating with the mobile base station 20 through the BH line.

  Therefore, for example, the control station 40 optimizes the position (or arrangement) of the mobile base station 20 based on the radio wave environment information acquired by moving the movement sensor 30, and moves the mobile base station 20 to the optimized position. It is possible to make it. In other words, the control station 40 is an example of an apparatus that can determine the position of the mobile base station 20 based on the sensing result of the mobile sensor 30.

  The control station 40 may be communicably connected to the core network, for example, in the backbone NW. The control station 40 transmits a signal (for example, user data) received from the core network to the terminal 10 to any one or more mobile base stations 20 via a BH line (also referred to as “transfer”). Good.)

(Operation example)
Hereinafter, an operation example of the wireless communication system 1 of the present embodiment will be described with reference to FIGS.

  In order to determine the position of the mobile base station 20, the control station 40 transmits an instruction regarding the position where the control station 40 wants to acquire radio wave environment information to the mobile sensor 30 via the BH line (process 2001 in FIG. 2). , Processing 3001 in FIG. This instruction may be referred to as a “sensing instruction” for convenience.

  The “position where the control station 40 wants to acquire radio wave environment information” may be referred to as “a position where radio wave environment information is sensed”. Further, the “position to be sensed” may be referred to as a “sensing position” or a “target position”.

  The information indicating the target position (hereinafter sometimes abbreviated as “target position information”) may be indicated by latitude and longitude or latitude, longitude, and altitude, for example. Alternatively, the target position information is a combination of coordinates indicating the moving direction and moving distance from the origin in a two-dimensional (xy) or three-dimensional (xyz) coordinate system in which the current position of the movement sensor 30 is the reference position (origin). May be shown. Further, for example, when the mobile base station 20 is configured to be movable only in one direction along the guide rail, the target position information may be indicated by the movement distance alone.

  In the sensing instruction, as illustrated in FIG. 5, information may be set with the control station 40 as the transmission source and the instruction target movement sensor 30 as the destination. For example, the identification information (ID) of the control station 40 and the ID of the movement sensor 30 may be used for the transmission source information and the destination information of the sensing instruction, respectively.

  In the case where there are a plurality of movement sensors 30, the control station 40 may give a sensing instruction to one or more movement sensors 30 in which the position where the radio wave environment information is desired is included in the movable range.

  The movement sensor 30 confirms whether a sensing instruction addressed to the movement sensor 30 is received from the control station 40 (NO in the process 4001 in FIG. 4).

  When reception of the sensing instruction is confirmed (YES in process 4001), the movement sensor 30 moves to the sensing position indicated by the target position information in the received sensing instruction (process 4002 in FIG. 4).

  2 schematically illustrates the movement sensor 30 moving from the current position A to the sensing position B in response to a sensing instruction from the control station 40. In FIG. 2, an area centered on the position B (may be referred to as “area B” for convenience) is an area centered on the position A (referred to as “area A” for convenience). It is assumed that there are more terminals 10 than.

  When the movement sensor 30 moves to the sensing position B (or with movement toward the sensing position B), the movement sensor 30 may sense the surrounding radio wave environment (process 3002 in FIG. 3 and process 4003 in FIG. 4).

  As a non-limiting example, the radio wave environment information to be sensed may be received power from the terminal 10 or information (channel estimation value) indicating a DL channel state from the mobile sensor 30 to the terminal 10. The received power from the terminal 10 may be, for example, the received power of an uplink (uplink, UL) reference signal. The “reference signal” may be referred to as a “pilot signal”.

  The DL channel estimation value is received from the terminal 10 because, for example, in the time division duplex (TDD) based wireless communication system 1, there is channel reciprocity between uplink and downlink (downlink, DL). It may be estimated based on the UL reference signal.

  In other words, in TDD, a UL channel estimated based on a UL reference signal may be treated as a DL channel. Therefore, the base station can acquire a channel estimation value for DL beamforming based on the UL reference signal.

  Therefore, the mobile sensor 30 uses a DL channel estimation value, which is an example of radio characteristics when it is assumed that the mobile base station 20 is located at the current position, based on a UL reference signal received from the terminal 10. Can be obtained.

  Upon completion of sensing, the mobile sensor 30 may transmit the sensing result to the control station 40 through, for example, a BH line (processing 2003 in FIG. 2, processing 3003 in FIG. 3, and processing 4004 in FIG. 4).

  “Transmission” of radio wave environment information from the mobile sensor 30 to the control station 40 may be rephrased as “report” or “notification”. As illustrated in FIG. 6, the sensing result report may include sensed radio wave environment information and information indicating a position where the radio wave environment information is sensed. The information indicating the sensed position may be in the same format as the information indicating the sensing position instructed from the control station 40. Further, the IDs of the mobile sensor 30 and the control station 40 may be used as the transmission source and the destination of the sensing result report, respectively.

  The control station 40 may store the radio wave environment information reported from the movement sensor 30 in a storage device such as a memory. The storage format of the radio wave environment information is not particularly limited, but may be, for example, a table format as shown in FIG. The radio wave environment information stored in the table format may be referred to as a “radio wave environment information management table” for convenience.

  In the radio wave environment information management table, for example, radio wave environment information (reception power in the example of FIG. 7) regarding each terminal 10 is provided for each different position information (for example, latitude and longitude) indicating the sensing position. It may be registered and managed.

  The received power for each terminal 10 can be obtained from the received reference signal, for example. For example, the radio resource used by the terminal 10 for transmitting the reference signal may be allocated for each terminal 10 by the mobile base station 20. Assigning radio resources to terminal 10 may be referred to as “scheduling”.

  The radio resource may be divided into two dimensions of time and frequency (or band, the same in the following), or three dimensions of time, frequency and power (or code).

  For example, the control station 40 notifies the mobile sensor 30 of information on the radio resource allocated to each terminal 10, so that the mobile sensor 30 demodulates the radio resource for which the reference signal is received for each terminal 10. Thus, the power of the received reference signal can be obtained.

  For example, assuming that different frequencies f1 and f2 are assigned to the terminals # 1 and # 2, respectively, the mobile sensor 30 performs a demodulation process on the received signals of the frequencies f1 and f2, and thereby the terminal # 1. And # 2 can be obtained.

  For example, every time the control station 40 receives the radio wave environment information reported from the mobile sensor 30 (process 3004 in FIG. 3), the control station 40 checks whether or not sensing has been completed at all scheduled sensing positions. (Process 3005 in FIG. 3).

  If the sensing at all sensing positions is not completed (NO in process 3005), the control station 40 may repeat until it is completed and transmit a sensing instruction for the new sensing position to the mobile sensor 30.

  If sensing at all sensing positions is completed (YES in processing 3005), the control station 40 calculates the optimal or suitable position of the mobile base station 20 based on the radio wave environment information obtained at each sensing position. (Process 3006).

  The optimal or suitable position of the mobile base station 20 may be, for example, a position where the DL throughput is maximized or a position where the propagation loss is minimized within the movable range of the movement sensor 30. Alternatively, it may be a position where the number of connected terminals estimated based on received power for each position, or the amount of traffic that can be estimated based on the estimated number of connected terminals is leveled.

  For example, the control station 40 estimates the throughput T (p) at the position p from the channel estimation value h (p) when the mobile base station 20 exists at a certain position p within the movable range of the movement sensor 30. it can. Therefore, for example, the control station 40 may determine the position p at which the throughput T (p) is maximum within the movable range of the movement sensor 30 as the position of the mobile base station 20.

  In the example of FIG. 2, since the number of terminals in area B is larger than the number of terminals in area A, it can be determined that the improvement in throughput can be expected if the base station 20 is arranged at the position B rather than the position A. Therefore, the control station 40 may determine the position B as the position of the mobile base station 20.

  Note that the throughput can be calculated by the same procedure when there are a plurality of mobile base stations 20. Even if there are a plurality of mobile base stations 20, it is not necessary to have a plurality of mobile sensors 30.

For example, the control station 40 acquires the channel information h (p) at the position p for the range in which the mobile sensor 30 includes all of the movable ranges of the mobile base stations 20, so that the base station #i at the position p _i Throughput T (p ₁ , p ₂ ,..., P _N ) can be calculated.

Therefore, the control station 40 obtains the optimum position Pc = (p ₁ , p ₂ ,..., P _N ) of the mobile base station 20 based on the throughput T (p ₁ , p ₂ ,..., P _N ). Can do.

As a non-limiting example of how to obtain the optimum position, for example, the throughput T (p ₁ , p ₂ ,..., P _N ) is calculated for all possible patterns, and the optimum pattern is selected from the pattern set. For example, selecting a combination of positions.

  In addition, even if there is a single mobile base station 20, by providing a plurality of mobile sensors 30, the sensing range can be shared by the plurality of mobile sensors 30, and the acquisition of sensing results can be completed more quickly.

  The number of mobile sensors 30 may be determined without depending on the number of mobile base stations 20. The number of the movement sensors 30 may be determined based on the relationship between the speed at which the information acquisition for determining the position of the mobile base station 20 is completed and the allowable cost.

  The control station 40 estimates the number of terminals 10 connected to the base station 20 when the base station 20 is arranged at each position based on the received power at each position as illustrated in FIG. It's okay. Then, for example, the control station 40 may determine the position of the mobile base station 20 so that the difference in the estimated number of connected terminals between the base stations 20 is minimized (in other words, leveled).

  Further, for example, the control station 40 may determine the position of the mobile base station 20 using information indicating the coverage of each mobile base station 20 as an index so that the coverages are as equal as possible. Information indicating the coverage of the mobile base station 20 may be estimated based on, for example, received power at the mobile sensor 30 of a signal transmitted by the terminal 10.

  Further, as described above, when an imaging device such as a camera is mounted on the movement sensor 30, the terminal density estimated by performing image processing on the image data is used as an index for determining the position of the mobile base station 20. Also good. For example, the control station 40 may determine the position of the mobile base station 20 so that the mobile base station 20 is preferentially arranged in an area where the terminal density is relatively high.

  The information that can be estimated by performing image processing on the image data is not limited to the terminal density in the sensing range by the sensor 30. For example, information such as the gender and age group of users located around the sensor 30 (may be referred to as “user information” for convenience) may be estimated by image processing.

  Even if the terminal density is high in a certain area, depending on the gender and age group of the user, it can be estimated that the communication amount by the terminal 10 is small. Conversely, even if the terminal density is low, the communication amount by the terminal 10 is large. Can be estimated.

  Therefore, the control station 40 may perform correction such as weighting the position of the mobile base station 20 using user information obtained by image processing.

  When the position of the mobile base station 20 is determined, the control station 40 may instruct the mobile base station 20 to be moved to the determined position (process 2004 in FIG. 2 and process 3007 in FIG. 3).

  In the movement instruction for the mobile base station 20, information indicating the determined position (in other words, information indicating the target position to which the mobile base station 20 moves) may be set as illustrated in FIG.

  The information indicating the target position may be indicated by the latitude and longitude, or the latitude, longitude, and altitude, similarly to the target position information in the sensing instruction, or by the moving direction and moving distance from the current position of the mobile base station 20 May be shown.

  In the movement instruction, for example, information having the control station 40 as a transmission source and the instruction target mobile base station 20 as a destination may be set. For example, the ID of the control station 40 and the ID of the mobile base station 20 may be used for the source information and destination information of the movement instruction, respectively.

  When receiving the movement instruction addressed to the mobile base station 20 from the control station 40 (process 3008 in FIG. 3), the mobile base station 20 moves to the position indicated in the received movement instruction (process 3009 in FIG. 3).

  As described above, according to the above-described embodiment, the position of the mobile base station 20 is determined by the control station 40 based on the sensing result of the radio wave environment by the mobile sensor 30, and the movement of the mobile base station 20 is controlled according to the determination. Is done.

  Since the radio wave environment is sensed by the mobile sensor 30 that is separate from the mobile base station 20 and capable of moving at a higher speed than the mobile base station 20, the mobile base station 20 is more mobile than the mobile base station 20 that moves and performs sensing. The position of the station 20 can be determined quickly.

  For example, by realizing the movement sensor 30 using a small device such as a drone that can move at high speed, the mobile base station 20 can quickly sense the radio wave environment in an area where the mobile base station 20 can move. Twenty positions can be quickly determined.

  In addition, since the mobile base station 20 does not need to move and sense, the mobile base station 20 does not need to have a sensing function. Therefore, it is easy to reduce the size and speed of movement of the mobile base station 20 without restricting the function, configuration, and performance of the base station 20.

  As a result, the mobile base station 20 can be quickly moved to a position determined based on the sensing result. Therefore, for example, communication traffic between the mobile base station 20 and the terminal 10 can be quickly distributed or the throughput can be improved according to the density of the terminal 10 in a certain area.

(Configuration example)
Next, configuration examples of the mobile base station 20, the mobile sensor 30, and the control station 40 in the above-described embodiment will be described with reference to FIGS.

(Mobile base station 20)
FIG. 9 is a block diagram illustrating a configuration example of the mobile base station 20 according to an embodiment.
As shown in FIG. 9, the mobile base station 20 may include an antenna 21, a communication unit 22, a drive unit 23, and a drive control unit 24, for example. For example, the communication unit 22 may include a wireless transmission / reception circuit 221 and a signal processing unit 222.

  The communication unit 22 may be regarded as one of the functions (base station function unit) normally provided in the base station. The communication unit 22 illustratively transmits / receives a signal to / from the terminal 10 via the antenna 21, receives user data transmitted from the control station 40 via the BH line, and is transmitted from the control station 40. A movement instruction is received.

  For example, the radio transmission / reception circuit 221 performs transmission processing of a DL signal transmitted to the terminal 10, reception processing of a UL signal transmitted from the terminal 10, and reception processing of a signal transmitted from the control station 40.

  The DL signal transmission processing may include, for example, baseband (BB) signal digital-analog (DA) conversion, up-conversion, and the like.

  The reception process of the UL signal and the reception process of the signal transmitted by the control station 40 may include, for example, down conversion of the radio signal, analog-digital (AD) conversion, and the like.

  The wireless transmission / reception circuit 221 is an example of a movement instruction receiving unit that receives a movement instruction from the control station 40.

  The antenna 21 may be shared for transmission and reception or may be individual for transmission and reception. The antenna 21 may be an array antenna having a plurality of antenna elements. MIMO (multiple-input and multiple-output) communication and beam forming may be performed by the array antenna.

  For example, the signal processing unit 222 performs signal processing of a transmission signal and a reception signal. The signal processing may include, for example, channel estimation, transmission signal encoding and modulation, reception signal demodulation and decoding, and the like.

  In addition, the signal processing may include, for example, processing related to sensing equivalent to the movement sensor 30. For example, processing for acquiring radio wave environment information including any one or more of received power, channel estimation value, and propagation loss may be performed by the signal processing unit 222.

  The drive part 23 has drive sources, such as a motor and a wheel for enabling the movement of the mobile base station 20 exemplarily.

  For example, the drive control unit 24 controls the drive unit 23 based on a movement instruction from the control station 40 obtained by the signal processing unit 222. Controlling the drive unit 23 may include, for example, a process of converting target position information in the movement instruction into a rotation amount of the motor or the like. Thereby, the mobile base station 20 moves to the target position instructed from the control station 40.

  Therefore, the drive control unit 24 is an example of a control unit that controls the movement of the mobile base station 20 in accordance with the movement instruction received from the control station 40.

(Movement sensor 30)
FIG. 10 is a block diagram illustrating a configuration example of the movement sensor 30 according to an embodiment.
As illustrated in FIG. 10, the movement sensor 30 may include an antenna 31, a sensor function unit 32, a drive unit 33, and a drive control unit 34, for example.

  For example, the sensor function unit 32 may include a wireless transmission / reception circuit 321, a signal processing unit 322, and a sensor information generation unit 323. The movement sensor 30 may be provided with an imaging device 35 such as a camera. The imaging device 35 may be connected to the sensor function unit 32 (for example, the signal processing unit 322).

  For example, the sensor function unit 32 senses the surrounding radio wave environment, generates radio wave environment information (which may be referred to as “sensor information”) as a sensing result, transmits sensor information, via the antenna 31. A sensing instruction is received from the control station 40. The sensor function unit 32 may be referred to as a “sensing unit”.

  For example, the wireless transmission / reception circuit 321 performs processing for receiving a reference signal transmitted from the terminal 10, processing for transmitting (reporting) sensor information to the control station 40, and processing for receiving a sensing instruction from the control station 40.

  The reference signal reception processing may include, for example, down conversion of a radio signal, analog-digital (AD) conversion, and the like.

  The sensor information transmission (report) processing to the control station 40 may include, for example, DA conversion of the BB signal, up-conversion, and the like. The reception process of the sensing instruction from the control station 40 may include down conversion and AD conversion, for example.

  The wireless transmission / reception circuit 321 is an example of a sensing instruction receiving unit that receives a sensing instruction from the control station 40. The wireless transmission / reception circuit 321 is also an example of a sensing result transmission unit that transmits a sensing result at a position moved according to a sensing instruction to the control station 40.

  The antenna 31 may be shared for transmission and reception or may be individual for transmission and reception. The antenna 31 may be an array antenna having a plurality of antenna elements.

  For example, the signal processing unit 322 performs signal processing of a transmission signal and a reception signal. For example, the signal processing may include processing for acquiring radio wave environment information including any one or more of received power, channel estimation value, and propagation loss.

  The sensor information generation unit 323 illustratively generates a sensing result (radio wave environment information) to be reported to the control station 40. When the imaging device 35 is provided, the sensing result may include image data obtained by the imaging device 35 or data obtained by performing image processing on the image data by the signal processing unit 322, for example.

  The drive unit 33 exemplarily includes a drive source such as a motor and wheels for enabling the movement sensor 30 to move. In the case of a device that can be moved in the air, such as a drone, a motor, a propeller, and the like may be provided as a drive source. In the case of a device that is movable on the water, a motor, a screw, and the like may be provided as a drive source. .

  For example, the drive control unit 34 controls the drive unit 33 based on a sensing instruction from the control station 40 obtained by the signal processing unit 322. Controlling the drive unit 33 may include, for example, a process of converting target position information in the sensing instruction into a rotation amount of the motor or the like. Thereby, the movement sensor 30 moves to the target position instructed from the control station 40.

(Control station 40)
FIG. 11 is a block diagram illustrating a configuration example of the control station 40 according to an embodiment.
As shown in FIG. 11, the control station 40 illustratively includes an antenna 41, a communication unit 42, a sensor information processing unit 43, a sensor / base station position control unit 44, a storage device 45, and a core network connection interface (IF ) 46 may be provided. For example, the communication unit 42 may include a wireless transmission / reception circuit 421 and a signal processing unit 422.

  For example, the communication unit 42 transmits instructions to the mobile base station 20 and the mobile sensor 30, transfers user data via the BH line to the mobile base station 20, and receives sensor information from the mobile sensor 30. Do.

  For example, the radio transmission / reception circuit 421 performs a transmission process of a signal addressed to the mobile base station 20 and a signal addressed to the mobile sensor 30 and a reception process of a signal from the mobile sensor 30.

  The transmission process may include, for example, DA conversion of the BB signal, up-conversion, and the like. For example, the reception process may include down-conversion of radio signals, AD conversion, and the like.

  The wireless transmission / reception circuit 421 is an example of a sensing result receiving unit that receives a sensing result from the movement sensor 30. The wireless transmission / reception circuit 421 is also an example of a movement instruction transmission unit that transmits a movement instruction to a position determined based on a sensing result to the mobile base station 20.

  The antenna 41 may be shared for transmission and reception or may be individual for transmission and reception. The antenna 41 may be an array antenna having a plurality of antenna elements.

  The sensor information processing unit 43 illustratively performs a process of collecting sensor information received from the movement sensor 30. In the process of aggregating sensor information, for example, a radio wave environment information management table (see FIG. 7) is generated and stored in the storage device 45, and information is registered (recorded) in the radio wave environment information management table. Processing may be included.

  The sensor / base station position control unit 44 is an example of a determination unit that determines the position of the mobile base station 20 based on the radio wave environment information management table stored in the storage device 45. Further, the sensor / base station position control unit 44 exemplarily determines the sensing position by the movement sensor 30 based on the information about the position and area where the radio wave environment information is sensed and stored in the storage device 45.

  Information indicating the position determined by the sensor / base station position control unit 44 (target position information) is set in the signal processing unit 422 as a movement instruction addressed to the mobile base station 20 or a sensing instruction addressed to the mobile sensor 30. Good.

  The storage device 45 exemplarily stores the above-described radio wave environment information management table and information on the position and area where the radio wave environment information is acquired.

  The sensor information processing unit 43 and the sensor / base station position control unit 44 may be regarded as corresponding to a controller provided in the control station 40. The storage device 45 may be provided either inside or outside the controller, and only needs to be connected to the controller so as to be accessible for writing and reading from the controller.

  For example, the core network connection IF 46 provides a connection IF with the core network, and transmits and receives user data through the core network. The user data addressed to the terminal 10 connected to the mobile base station 20 received from the core network is illustratively transmitted from the radio transmission / reception circuit 421 to the mobile base station 20 via the BH line. Therefore, the radio transmission / reception circuit 421 is an example of a terminal-addressed signal transmission unit that transmits a signal addressed to the terminal 10 received from the core network to the mobile base station 20.

  Note that the configuration examples illustrated in FIGS. 9 to 11 are merely examples, and functions and hardware may be increased or decreased appropriately for each of the mobile base station 20, the mobile sensor 30, and the control station 40. .

  For example, addition, deletion, division, and combination of one or more functional blocks and hardware blocks are performed as necessary for each of the mobile base station 20, the mobile sensor 30, and the control station 40. Good.

(Modification)
In the embodiment described above, the possibility that there is an error in the radio wave environment information acquired by the movement sensor 30 is not considered. The radio wave environment information acquired by the movement sensor 30 may not accurately represent the radio wave environment that the mobile base station 20 actually experiences at the position after movement due to some error factor. As an error factor, for example, it is conceivable that there is a difference between the sensing position by the mobile sensor 30 and the position after the mobile base station 20 has moved.

  Therefore, after the mobile base station 20 moves according to the movement instruction of the control station 40, the mobile base station 20 may acquire the radio wave environment information at that position and report it to the control station 40. The control station 40 may update the radio wave environment information table based on the reported radio wave environment information and recalculate the position of the mobile base station 20 again.

  FIG. 12 shows an example of a sequence diagram according to the modification. FIG. 12 corresponds to an example in which processes 3010 to 3014 are added as post-processes of processes 3001 to 3009 illustrated in FIG. 3.

  As described with reference to FIG. 3, the mobile base station 20 moves to the target position in accordance with the movement instruction from the control station 40, and then acquires the radio wave environment information at that position (processing 3010). It may be transmitted (reported) to the control station 40 (process 3011).

  When the control station 40 receives the radio wave environment information transmitted from the mobile base station 20 (process 3012), the control station 40 updates the radio wave environment information table with the radio wave environment information, and the mobile base station 20 based on the updated radio wave environment information table. May be recalculated (process 3013).

  Then, the control station 40 may confirm whether or not the recalculated position has changed with respect to the previously determined position (processing 3014).

  As a result of the confirmation, if there is a change in position (YES in process 3014), the control station 40 may instruct the mobile base station 20 to move to the recalculated position (process 3007). The instruction may be performed in the same format as illustrated in FIG.

  If there is no change in the recalculated position (NO in process 3014), the control station 40 does not have to give a movement instruction to the mobile base station 20 again.

  Through the above processing, the control station 40 can correct the position of the mobile base station 20 based on information indicating the radio wave environment that the mobile base station 20 actually experiences at the position after moving. Therefore, compared with the above-described embodiment, further optimization of communication performance such as communication traffic distribution and throughput improvement can be achieved.

  In the embodiment including the above-described modification, the base station function is provided in the mobile base station 20 and the sensor function for sensing the surrounding radio wave environment is the mobile sensor as illustrated in item No. 1 in FIG. 30 is provided. In addition, the control station 40 has a function of collecting sensor information and determining the positions of the mobile sensor 30 and the mobile base station 20.

  However, the sharing of various functions with respect to the mobile base station 20, the mobile sensor 30, and the control station 40 is not limited to the above-described embodiment, and variations are conceivable. Examples of possible function sharing variations are shown in item numbers 2 to 5 in FIG.

  The item number 2 in FIG. 13 differs from the item number 1 in that the mobile base station 20 has a sensor function in addition to the base station function. For example, the mobile base station 20 can use a part of the sensor function in addition to the base station function by using the antenna 21 and the wireless transmission / reception circuit 221 as sensors. In the function sharing example of item number 2, the efficiency of sensing can be improved by the mobile base station 20 and the mobile sensor 30 performing sensing together.

  The item number 3 in FIG. 13 differs from the item number 1 in that the mobile sensor 30 has a function of determining the position of the mobile base station 20 instead of the control station 40. For example, the mobile sensor 30 can determine the position of the mobile base station 20 without using the control station 40 based on the acquired sensing result. Further, the movement sensor 30 may autonomously determine the position of the movement sensor 30 based on the acquired sensing result.

  When the position of the mobile base station 20 is determined, the movement sensor 30 can give a movement instruction including information indicating the determined position to the target mobile base station 20. In this case, the control station 40 does not have to collect the sensor information and determine the position of the mobile base station 20, and only needs to be able to transmit / receive user data to / from the mobile base station 20 via the BH line.

  In other words, the control station 40 of item number 3 is connected to the core network and provides a function as a BH line that distributes a signal addressed to each terminal 10 to one of the mobile base stations 20.

  Item No. 4 in FIG. 13 differs from item No. 1 in that the control station 40 additionally has a base station function as a non-moving base station (hereinafter referred to as “fixed base station”). In this case, the terminal 10 can connect to both the mobile base station 20 and the control station 40 and perform wireless communication. Item number 4 can be said to be a configuration example in which the mobile base station 20 not connected to the core network and the fixed base station 40 connected to the core network are mixed.

  Item No. 5 in FIG. 13 differs from item No. 1 in that the mobile sensor 30 additionally has a part of the base station function. For example, the movement sensor 30 can assume a part of the base station function using the wireless transmission / reception circuit 321 used for sensing.

  The mobile sensor 30 can operate as a base station while maintaining the mobility as a sensor, for example, by weakening the output power of the mobile base station 20.

  Thereby, for example, the movement sensor 30 can operate as the base station 20 at a time when it does not need to operate as a sensor (in other words, a time when the sensor function can be disabled), such as after the end of sensing. . Therefore, useless waiting time of the movement sensor 30 can be reduced.

  In addition, the example of item number 5 is a configuration example in which various types of mobile base stations 20 are mixed, such as a lightweight mobile base station 20 that emphasizes mobility and a slightly large mobile base station 20 that emphasizes radio performance. I can say.

  The base station function includes functions such as transmission / reception of signals with the terminal 10, transmission / reception of control information, and scheduling of the connected terminals 10 including modulation / demodulation of radio signals.

  As in the example of item number 5, when the mobile sensor 30 has a part of the base station function, various forms can be considered depending on which base station function it has. For example, the mobile sensor 30 is in charge of transmission / reception of user data, and the mobile base station 20 is in charge of transmission / reception and scheduling of various control information.

  In this case, the terminal 10 can be connected (dual connect) to both the mobile base station 20 and the mobile sensor 30. For example, the terminal 10 can receive user data via the mobile sensor 30, and can perform transmission / reception of user data transmission / reception timing and related control signals with the mobile base station 20.

  Note that the wireless communication system 1 may be configured using two or more types of devices having different ratios between the sensor function and the base station function without being limited to the two types of the mobile sensor 30 and the mobile base station 20.

  As a configuration example similar to item number 5 in FIG. 13, as schematically illustrated in FIG. 14, the mobile sensor 30 is configured to be able to be combined and separated with respect to any mobile base station 20. Good.

  By combining the mobile sensor 30 with the mobile base station 20 at a time when it does not need to operate as a sensor, the number of antennas of the mobile base station 20 can be increased, and the radio characteristics (for example, throughput performance) of the mobile base station 20 are improved. can do.

  Therefore, even in the case of the mobile sensor 30 having no room for mounting the base station function due to device and physical restrictions, it is possible to reduce useless waiting time such as time when sensing is unnecessary.

  FIG. 15 shows a configuration example of the mobile base station 20 and the mobile sensor 30 that can be combined and separated. As illustrated in FIG. 14, the mobile base station 20 is different from FIG. 9 in that a connector 25 is additionally provided. On the other hand, the movement sensor 30 is different from that of FIG. 10 in that it includes a connector 36 and a switch 37.

  With the connectors 25 and 36, the mobile base station 20 and the mobile sensor 30 may be combined to establish an electrical connection. Therefore, the connectors 25 and 36 are an example of an interface for connecting the mobile base station 20 and the mobile sensor 30. As a non-limiting example, SMA connectors used for connection of wireless signals may be applied to the connectors 25 and 36.

  The SMA connectors 25 and 36 are aligned with each other, and one or both of them are rotated and screwed, so that the mobile sensor 30 can be mechanically fixed and combined with the mobile base station 20. Further, the mobile sensor 30 can be mechanically separated from the mobile base station 20 by reversely rotating one or both of the SMA connectors 25 and 36. Bi-directional rotation of one or both of the SMA connectors 25 and 36 may be automated by way of example by a drive source such as a motor.

  As schematically illustrated in FIG. 16, when the mobile base station 20 is configured as a robot apparatus, the connector 25 may be provided at the top of the robot apparatus as a non-limiting example. On the other hand, when the movement sensor 30 is configured as “drone”, the connector 36 may be provided on the bottom surface of the drone.

  Thereby, the drone as the movement sensor 30 can be united and separated using the top of the robot apparatus as the mobile base station 20 as a takeoff / landing point.

  In the mobile base station 20, the connector 25 may be electrically connected to the wireless transmission / reception circuit 221 exemplarily. In the movement sensor 30, the connector 36 may be electrically connected to a switch 37 that is electrically connected to the antenna 31, for example.

  The switch 37 switches whether to electrically connect to the mobile base station 20 (wireless transmission / reception circuit 221) or to electrically connect to the wireless transmission / reception circuit 321 of the movement sensor 30 through the connector 36.

  For example, when the mobile base station 20 and the mobile sensor 30 are combined, the switch 37 is switched to the connector 36 side. Thereby, an electrical connection is established between the radio transmission / reception circuit 221 of the mobile base station 20 and the antenna 31 of the mobile sensor 30.

  Thereby, the mobile sensor 30 can transmit the wireless signal transmitted from the wireless transmission / reception circuit 221 of the mobile base station 20 from the antenna 31 via the switch 37. In addition, the mobile base station 20 can receive a radio signal received by the antenna 31 of the mobile sensor 30 by the radio transmission / reception circuit 221.

  Therefore, the mobile base station 20 can transmit and receive radio signals using the antenna 31 of the mobile sensor 30 in addition to the antenna 21 by combining with the mobile sensor 30. In other words, the number of antennas of the mobile base station 20 can be substantially increased by combining with the mobile sensor 30.

  When the mobile base station 20 and the mobile sensor 30 are combined, both antennas 21 and 31 may be used for BF (Beamforming). The BF may be an analog BF or a digital BF.

  In analog BF, the directivity of a beam is controlled by controlling one or both of the phase and amplitude of an analog radio signal with a phase shifter or the like. On the other hand, in the digital BF, an analog radio signal is down-converted into a BB signal, and then AD conversion is performed. By controlling one or both of the phase and amplitude by digital signal processing, the beam directivity is controlled.

  FIG. 17 schematically illustrates a configuration example of the analog BF, and FIG. 18 schematically illustrates a configuration example of the digital BF. In the examples of FIGS. 17 and 18, it is assumed that the mobile base station 20 has one antenna 21 and the mobile sensor 30 has one antenna 31. However, if it is sufficient that BF is possible when the mobile base station 20 and the mobile sensor 30 are combined, the number of each antenna may be one or more.

  Further, as illustrated in FIG. 15, the mobile base station 20 may include a power supply circuit 26 for charging the mobile sensor 30 when the mobile base station 20 is combined with the mobile sensor 30. For example, the power supply circuit 26 can charge the power supply circuit 38 of the movement sensor 30 through the connector 36 of the movement sensor 30 by supplying power to the connector 25. Thereby, since the operation time after the movement sensor 30 isolate | separates from the base station 20 can be extended, the movable distance and sensing time of the movement sensor 30 can be extended.

  When there are a plurality of mobile base stations 20, any mobile base station 20 may be the target to which the mobile sensor 30 is combined to receive charging. The movement sensor 30 can extend the movable distance and the sensing possible time by appropriately charging any one or more of the plurality of mobile base stations 20 as a charging point.

  Note that the combination of the mobile base station 20 and the mobile sensor 30 does not necessarily have to be in physical contact. For example, the movement sensor 30 may be connected wirelessly in a state of being in close contact with the mobile base station 20 in a non-contact manner. For wireless connection, NFC (Near Field Communication), Bluetooth (registered trademark), or the like may be applied.

  In other words, the term “union” is not limited to a single device in physical contact, but is functionally combined even if physically separated in a non-contact state. You can think of it as a concept that also includes.

1 wireless communication system 10 terminal 20 base station (mobile base station)
DESCRIPTION OF SYMBOLS 21 Antenna 22 Communication part 221 Wireless transmission / reception circuit 222 Signal processing part 23 Drive part 24 Drive control part 25 Connector 26 Power supply circuit 30 Sensor (movement sensor)
DESCRIPTION OF SYMBOLS 31 Antenna 32 Sensor function part 321 Wireless transmission / reception circuit 322 Signal processing part 323 Sensor information generation part 33 Drive part 34 Drive control part 35 Imaging device 36 Connector 37 Switch 38 Power supply circuit 40 Control station 41 Antenna 42 Communication part 421 Wireless transmission / reception circuit 422 Signal Processing unit 43 Sensor information processing unit 44 Sensor / base station position control unit 45 Storage device 46 Core network connection interface (IF)

Claims (17)

A movable sensor configured to be movable and capable of sensing information indicating a radio wave environment around the current position;
A mobile base station that can move independently of the movement sensor and moves to a position according to a sensing result of the movement sensor;
A wireless communication system comprising: The movement sensor includes a sensing instruction receiving unit that receives the instruction from a control station that instructs a sensing position of the information;
A sensing result transmitting unit that transmits the sensing result at the position moved according to the instruction to the control station; and
The control station
A sensing result receiving unit for receiving the sensing result from the movement sensor;
A determination unit that determines the position of the mobile base station based on the sensing result;
A movement instruction transmission unit that transmits a movement instruction to the determined position to the mobile base station, and
The mobile base station
A movement instruction receiving unit for receiving the movement instruction from the control station;
A control unit for controlling movement of the mobile base station according to the movement instruction;
The wireless communication system according to claim 1, comprising:   The wireless communication system according to claim 1, wherein the movement sensor moves to a position where at least a part of a range in which the mobile base station may move can be sensed.   The wireless communication system according to claim 1, wherein the movement sensor is mounted on a flying object that can move in the air.   The information indicating the radio wave environment includes received power of a signal received by the mobile sensor from a terminal that can be connected to the mobile base station, a channel estimation value obtained based on the signal, and a propagation obtained based on the signal. The wireless communication system according to claim 1, wherein the wireless communication system is one or more of losses.   The information indicating the radio wave environment includes information indirectly indicating the radio wave environment obtained by processing image data obtained by an imaging device provided in the movement sensor. The wireless communication system according to item 1. A mobile base station configured to be movable,
A receiving unit for receiving an instruction regarding a moving position;
A control unit for controlling movement to the position,
The position is a position determined based on a sensing result by a movement sensor that can move independently of the mobile base station and can sense information indicating a radio wave environment around the current position. base station. An interface for connecting to the movement sensor;
The mobile base station according to claim 7, wherein a transmission signal is output to an antenna provided in the mobile sensor through the interface in a state where the mobile sensor is connected to the mobile sensor through the interface.   The mobile base station according to claim 8, further comprising a power supply circuit that supplies power to the mobile sensor through the interface. A receiving unit that receives a sensing result by a mobile sensor that can move independently of a mobile base station configured to be movable and can sense information indicating a radio wave environment around the current position;
A determination unit that determines the position of the mobile base station based on the sensing result;
A transmission unit for transmitting a movement instruction to the determined position to the mobile base station;
With a control station.   The information indicating the radio wave environment includes received power of a signal received by the mobile sensor from a terminal that can be connected to the mobile base station, a channel estimation value obtained based on the signal, and a propagation obtained based on the signal. The control station of claim 10, wherein the control station is one or more of the losses.   The control station according to claim 10, wherein the information indicating the radio wave environment includes information indirectly indicating the radio wave environment obtained by processing image data obtained by an imaging device provided in the movement sensor. . The determination unit is
Based on the sensing result, estimate the radio characteristics when the mobile base station is located at the position where the sensing result was obtained, and based on the estimated radio characteristics, the position of the mobile base station The control station according to claim 10, wherein: A movement sensor configured to be movable,
A sensing unit that senses information indicating the radio wave environment around the current location;
A receiving unit for receiving an instruction regarding a position to sense the information;
A transmission unit for transmitting a sensing result at the position moved according to the instruction to a device for determining the position of the mobile base station;
A movement sensor.   The movement sensor according to claim 14, wherein the movement sensor is mounted on a flying object that can move in the air. An interface for connecting to the mobile base station;
The mobile sensor according to claim 14, further comprising: an antenna that transmits a transmission signal of the mobile base station received through the interface in a state of being connected to the mobile base station through the interface.   The movement sensor according to claim 16, further comprising a power supply circuit that receives power supply from the mobile base station through the interface.