JP2018056796A - Base station, communication terminal, drone and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a base station which can determine an optimal handover destination of a flying drone.SOLUTION: The base station, which determines the handover destination of a flying drone, includes: a data reception and transmission unit which receives a communication quality value which is the communication quality value, measured by the drone, for each of a plurality of cells located within a predetermined distance range from the drone; a filter processing unit which, based on a filter which includes a weight value, which is determined based on relative position relation with the cell of interest, and a calculation rule, filter-processes the communication quality value of each of the plurality of cells located within the predetermined distance range from the drone; and a handover destination determination unit which determines the handover destination of the drone, on the basis of the filter-processed communication quality value of the plurality of cells.SELECTED DRAWING: Figure 5

Description

  The present invention relates to a base station that determines a handover destination of a drone in flight, a communication terminal that executes a handover to the determined handover destination, a drone, and a program.

  A drone is also called an unmanned aerial vehicle (Unmanned Aerial Vehicle, Uninhabited Aerial Vehicle, UAV), and is a general term for an aircraft that can fly unmanned by remote control or automatic control. A drone (unmanned aerial vehicle) can be made to fly by remote control or autopilot among airplanes that can be used by air, rotary wing aircraft, gliders, airships, and other devices that cannot be ridden structurally It is a term that refers to all things. Drones include aircraft of various sizes and shapes. Military drones have many large aircraft, and commercial drones are small to medium sized, with many rotary wing aircraft (multicopters).

  It has been studied to install a communication terminal in a drone or add a function as a communication terminal to a drone and perform communication between the drone and a base station using an existing mobile communication network (Non-patent Document 1). ).

NTT DoCoMo, “Press Release (Notification) Start of Demonstration Experiment for Mobile Phone Use in Drone”, September 9, 2016, NTT DoCoMo, [Search September 14, 2016], Internet <URL : https: //www.nttdocomo.co.jp/info/news_release/notice/2016/09/09_00.html>

  In the base station, the directivity of radio waves is designed so that the communication quality is high when used on the ground. Therefore, when using a mobile communication network in the sky, the distribution of radio waves is different from the case of using it on the ground, and it may be non-uniform. Further, since the reflected waves from the ground are used in the sky, it is easy for remote capture to occur, and communication may not be stable.

  Hereinafter, with reference to FIGS. 1 to 3, an example of remote capture in a drone in flight will be described. FIG. 1 is a diagram showing an example of cell arrangement and an example of a drone flight route. Symbols A to T are given to the cells appearing in the following description. Assume that each cell covers each cell. For example, a base station covering cell A is referred to as a base station 92A, a base station covering cell B is referred to as a base station 92B,. When a sector antenna is used for the base station, one base station covers a plurality of cells. Therefore, for example, the base station 92A, the base station 92B, the base station 92C, etc. may actually be realized as a single base station. In this specification, even in such a case, for convenience, the base station corresponding to each cell is referred to according to the rules described above.

  In this example, it is assumed that the drone 91 is flying on the route indicated by the thick broken line in FIG. It is assumed that the circle symbols with reference signs T1, T2, T3, and T4 represent the positions of the drone 91 at times T1, T2, T3, and T4, respectively.

  From the flight route of the drone 91 shown in FIG. 1, the drone 91 is located in the cell F at the times T1 to T2, and is located in the cell G at the times T3 to T4. It is considered preferable to use 92F and hand over to the base station 92G at some timing from T2 to T4. When the communication terminal moves on the same route near the ground surface, there is a high possibility that the handover (F → G) as described above is actually executed.

  Next, an example of communication quality of each base station (each cell) measured by the sky drone 91 at each time (T1, T2, T3, T4) in the example of FIG. 1 will be described with reference to FIG. Each row in the table of FIG. 2 means each base station (each cell). Each column in the table of FIG. 2 means each time. The numerical values in the table are values obtained by normalizing the measurement values obtained by measuring the communication quality of each cell at each time and making them unitless, and the larger the value, the higher the communication quality. Accordingly, the base station 92Q (cell Q) is a high-quality base station (cell) at time T1, the base station 92I (cell I) is a high-quality base station (cell) at time T2, and the base station 92E (cell E) is a high-quality base station (cell), and at time T4, the base station 92T (cell T) is a high-quality base station (cell). You can see that this is the situation.

  Conventionally, a method in which handover is sequentially performed to a cell having the highest communication quality is common. Therefore, in the case of the above example, in the conventional handover method, handover may be executed in the order of cell Q → cell I → cell E → cell T (see the shaded portion in FIG. 2 and FIG. 3).

  In this way, when a terminal (drone) is handed over to a distant cell rather than a cell in which the terminal (drone) is actually located, this is referred to as remote capture. However, a phenomenon in which the communication quality of a distant cell becomes high is often caused by local and unstable factors such as reflection in a high-rise building. Therefore, as the terminal (drone) moves or the time elapses, the communication quality of the distant cell, which should have been high quality, may rapidly deteriorate. In this case, handovers occur frequently and communication becomes unstable. As described above, it has been assumed that with the spread of drones, distant capture frequently occurs in the sky, but a specific method for solving this has not been known.

  Therefore, an object of the present invention is to provide a base station that can determine an optimum handover destination for a drone in flight.

  The base station of the present invention is a base station that determines a handover destination of a drone in flight, and includes a data transmission / reception unit, a filter processing unit, and a handover destination determination unit.

  The data transmission / reception unit receives communication quality values of a plurality of cells within a predetermined distance from the drone and measured by the drone. The filter processing unit communicates with each of a plurality of cells within a predetermined distance from the drone based on a filter composed of a weight value determined based on a relative positional relationship with the cell of interest and a calculation rule. Filter quality values. The handover destination determining unit determines the handover destination of the drone based on the communication quality values of the plurality of filtered cells.

  According to the base station of the present invention, it is possible to determine an optimum handover destination for a drone in flight.

The figure which shows the example of arrangement | positioning of a cell, and the flight route of drone. The figure which shows the example of the communication quality value of each cell which the drone in flight measured at each time. The figure which shows the example of a far-field capture in the drone in flight. 1 is a diagram illustrating a schematic configuration of a communication system according to a first embodiment. 1 is a block diagram illustrating a configuration of each device included in a communication system according to a first embodiment. FIG. 3 is a sequence diagram illustrating operations of devices included in the communication system according to the first embodiment. The figure which illustrates the filter which weights a communication quality value. The figure which illustrates the filter which weights a communication quality value. The figure which illustrates the hand-over destination which the base station of a present Example determined. The figure which compares the example of the flight destination of the hand-over destination determined by the base station of a present Example, and the flight route of a drone. The block diagram which shows the structural example of the general purpose system or computer device which can be used in order to implement | achieve the base station, the communication terminal, and drone which are described in an Example.

  Hereinafter, embodiments of the present invention will be described in detail. In addition, the same number is attached | subjected to the structure part which has the same function, and duplication description is abbreviate | omitted.

  The schematic configuration of the communication system according to the first embodiment will be described below with reference to FIG. As shown in FIG. 4, the communication system 1 of the present embodiment is configured to include one or more drones 11 and one or more base stations 12. In the example of FIG. 4, only one drone 11 to be noted in the description is shown. In the example of FIG. 4, it is assumed that there are a plurality of base stations 12, and are referred to as base station 12A, base station 12B,..., Base station 12T,. Note that the base stations 12A to 12T correspond to the cells A to T that have appeared in the description of FIG.

  The drone 11 may be a device having a communication function based on a cellular communication system, or the drone 11 itself may not have the same function, but instead may be equipped with a communication terminal having the same function. In the following description, the drone 11 itself is described as including the same function. However, when the drone 11 itself does not have the same function, “drone 11” appearing in the following description is replaced with “communication terminal 11”.

  Hereinafter, the configuration of each device included in the communication system 1 of the present embodiment will be described with reference to FIG. As shown in FIG. 5, the drone 11 (communication terminal 11) includes a data transmission / reception unit 111, a cell quality measurement unit 112, a cell quality storage unit 112A, and a handover execution unit 113. The base station 12 includes a data transmission / reception unit 121, a filter processing unit 122, a filter storage unit 122A, and a handover destination determination unit 123.

  Hereinafter, the operation of each device included in the communication system 1 according to the present embodiment will be described with reference to FIG. In the following sequence diagram, it is assumed that LTE is used, and the operation starts from the LTE connected communication state. However, the communication system 1 of the present embodiment is not limited to the LTE communication method, and can be realized by any other communication method. It is assumed that the drone 11 (communication terminal 11) is flying over the sky.

  The data transmitter / receiver 121 of the base station 12 transmits a communication quality measurement request to the drone 11 (communication terminal 11) (S121A). The communication quality measurement request here corresponds to RRC Connection Recofiguration in the case of LTE described above. In general, RRC Connection Recofiguration defines conditions for reporting communication quality.

  The data transmitter / receiver 111 of the drone 11 (communication terminal 11) receives a communication quality measurement request (in the case of LTE, RRC Connection Recofiguration) from the base station 12 (S111A). The cell quality measurement unit 112 of the drone 11 (communication terminal 11), based on a communication quality measurement request (in the case of LTE, RRC Connection Recofiguration), the communication quality of each of a plurality of cells within a predetermined distance from the own device. A value (for example, reception quality) is measured (S112). The distance between the own device and the corresponding cell may be, for example, the length of a line segment that projects a line segment connecting the own device and the center of the corresponding cell onto the ground surface. Alternatively, the length of the line segment projected on the ground surface may be the line segment connecting the own device and the base station location coordinates of the corresponding cell. Alternatively, the length of the line segment projected on the ground surface may be the line segment connecting the own device and the antenna location coordinates of the corresponding base station. In addition to this, connect the line segment that connects your cell and the cell center, the line that connects your cell and the base station location coordinates of the cell, or the cell and the coordinates of the tip of the antenna of the cell. The line segment may be used as a distance as it is without being projected onto the ground surface. The measured communication quality value is stored in the cell quality storage unit 112A. The data transmitter / receiver 111 of the drone 11 (communication terminal 11) transmits the measured communication quality value to the base station 12 (S111B). In the case of LTE, the measured communication quality value (for example, reception quality) is transmitted in a report. This report is called Measurement Report.

  The data transmitter / receiver 121 of the base station 12 receives the communication quality value measured from the drone 11 (communication terminal 11) (S121B). The filter processing unit 122 of the base station 12 filters the communication quality values of each of a plurality of cells within a predetermined distance from the drone 11 (communication terminal 11) using the filter stored in the filter storage unit 122A. Process (S122). The handover destination determining unit 123 of the base station 12 determines the handover destination of the drone 11 (communication terminal 11) based on the communication quality values of the plurality of cells subjected to the filter processing (S123). Details of steps S122 and S123 will be described later.

  The data transmitter / receiver 121 of the base station 12 transmits the handover destination determined in step S123 to the drone 11 (communication terminal 11) (S121C). The data transmission / reception unit 111 of the drone 11 (communication terminal 11) receives the handover destination of the own device from the base station 12 (S111C). The handover execution unit 113 of the drone 11 (communication terminal 11) executes the handover based on the received handover destination (S113).

<Filter processing (S122)>
Hereinafter, step S122 will be described in detail. For example, it is assumed that a filter as illustrated in FIG. 7 is stored in advance in the filter storage unit 122A. The filter used in the present embodiment is defined as “a filter composed of a weight value determined based on a relative positional relationship with a focused cell and an operation rule”.

  For example, a filter for image processing may be expressed as a matrix of weight values (for example, a matrix of 3 rows × 3 columns, 5 rows × 5 columns) when digitally processed, but is used in this embodiment. The concept of the filter to be applied is similar to the above matrix. However, the filter used in this embodiment is a matrix simulating the cell structure. The filter used in the present embodiment has a special matrix structure of seven weight values (center weight value and six weight values adjacent thereto) as shown in FIG. 7, for example. For example, the filter 81 in the figure weights the communication quality value of the center cell of interest by 100% and gives the communication quality values of six cells adjacent to the center cell by 20%. This is a filter for setting the value obtained by addition (the calculation rule of this filter is “weighting + addition”) as the communication quality value of a new cell of interest. The filter 81 is a filter having a function similar to a Gaussian filter in image processing, but is not adjusted so that the sum of weight values becomes 1.

  The filter 82 is a filter having a function similar to that of the moving average filter in image processing, and is a filter adjusted so that the sum of weight values becomes 1. In the case of the filter 82, a value obtained by reducing the communication quality value of the central cell of interest to 1/7 and a value obtained by reducing each of the communication quality values of the six cells adjacent thereto by 1/7 are added. (The calculation rule of this filter is also “weighting + addition”), and the communication quality value of the new cell of interest is used.

  The filter 83 is a filter having a function similar to that of a Gaussian filter in image processing, and is a filter adjusted so that the sum of weight values becomes 1. In the case of the filter 83, the value obtained by dividing the communication quality value of the central cell of interest by half and the value obtained by reducing each of the communication quality values of the six cells adjacent thereto by a factor of two are added. The communication quality value of the new cell of interest

  The filter 84 is a filter having a function similar to a median filter in image processing. In the case of the filter 84, the communication quality values (represented as a, b, c, d, e, f, g in this case) of the target cell and the neighboring cells are rearranged in ascending or descending order, and the median value is newly renewed. The cell communication quality value. In the case of the filter 84, the weight value 1 is assigned to the cell corresponding to the median value, the weight value 0 is assigned to the other cells, and the calculation rule “weighting + addition” similar to the above is executed. Also good. Alternatively, the weight value for the communication quality value of the cell of interest and the neighboring cells may be set to 1, and an algorithm of “select a median value and assign it to the cell of interest” as an operation rule may be defined.

  For example, as shown in FIG. 8, it is good also as a filter containing the weight value with respect to the cell which is not adjacent to an attention cell. The filter 85 is a filter having a function similar to a moving average filter in image processing, and is a filter composed of a matrix of 19 weight values including 12 cells not adjacent to the target cell. The filter 86 is a filter having a function similar to a Gaussian filter in image processing, and is a filter composed of a matrix of 19 weight values including 12 cells not adjacent to the target cell.

  7 and 8 exemplify various filters, but the requirements for the filters differed in comparison with the communication quality values of the surrounding cells and the communication quality values of the surrounding cells. It has a function of smoothing the value. For example, in FIG. 2, considering that it is a problem that a cell (for example, cell Q) whose quality value deviated from surrounding cells due to some factor is captured is a problem, such a protrusion is used as a filter. It is only necessary to have a function of smoothing the value and the deviation value. Since the divergence value and the salient value can be said to be a concept similar to high-frequency noise of an image, it is possible to use a filter having a function similar to a low-pass filter in image processing. In the above description, it is assumed that a filter process using one type of filter is performed. However, the present invention is not limited to this, and the filter process using a plurality of types of filters may be executed a plurality of times. For example, after the communication quality value is filtered by a filter similar to the Gaussian filter (for example, the filters 81, 83, 86), the communication quality value is further filtered by a filter similar to the median filter (for example, the filter 84). Also good. Or you may perform the filter process which combined the filter of the time direction with said filter of the spatial direction.

<Determination of handover destination (S123)>
Hereinafter, step S123 will be described in detail. As a result of executing the filtering process by the filter 81 of FIG. 7 on the communication quality value at each cell / time in FIG. 2, the communication quality value at each cell / time as shown in FIG. 9 is obtained. The handover destination determining unit 123 of the base station 12 sets a cell having the highest communication quality as the new handover destination for the communication quality value after the filter processing, as in the conventional case. Therefore, as highlighted by shading in FIG. 9, cell F is selected as the handover destination at times T1 and T2, and cell G is selected as the handover destination at times T3 and T4 (see FIG. 10).

  As described above, in the communication system 1, the drone 11 (communication terminal 11), and the base station 12 according to the present embodiment, communication is performed using a filter having a function of smoothing a deviation value or a protruding value of a communication quality value that causes a remote capture. Since the quality value is filtered, the handover destination is determined based on the filtered communication quality value, and the handover is performed based on the determined handover destination, the drone 11 in flight (communication terminal 11) Therefore, it is possible to determine an optimum handover destination.

<Hardware configuration>
In addition, the block diagram used for description of the said embodiment (Example) has shown the block of the functional unit. These functional blocks (components) are realized by any combination of hardware and / or software. Further, the means for realizing each functional block is not particularly limited. That is, each functional block may be realized by one device physically and / or logically coupled, and two or more devices physically and / or logically separated may be directly and / or indirectly. (For example, wired and / or wireless) and may be realized by these plural devices.

  For example, the drone 11 (communication terminal 11), the base station 12, and the like in the embodiment of the present invention may function as a computer that executes the communication method of the present invention. FIG. 11 is a diagram illustrating an example of a hardware configuration of the drone 11 (communication terminal 11) and the base station 12 according to the embodiment of the present invention. The drone 11 (communication terminal 11) and the base station 12 described above are physically configured as a computer device including a processor 11000, a memory 12000, a storage 13000, a communication device 14000, an input device 15000, an output device 16000, a bus 17000, and the like. May be.

  In the following description, the term “apparatus” can be read as a circuit, a device, a unit, or the like. The hardware configuration of the drone 11 (communication terminal 11) and the base station 12 may be configured to include one or a plurality of the devices illustrated in the figure, or may be configured not to include some devices. Good.

  The functions of the drone 11 (communication terminal 11) and the base station 12 are carried out by causing the processor 11000 to perform calculations by reading predetermined software (programs) on hardware such as the processor 11000 and the memory 12000. This is realized by controlling communication and reading and / or writing of data in the memory 12000 and the storage 13000.

  For example, the processor 11000 controls the entire computer by operating an operating system. The processor 11000 may be configured by a central processing unit (CPU) including an interface with peripheral devices, a control device, an arithmetic device, a register, and the like. For example, the data transmission / reception unit 111, the cell quality measurement unit 112, the handover execution unit 113, the data transmission / reception unit 121, the filter processing unit 122, the handover destination determination unit 123, and the like described above may be realized by the processor 11000.

  Further, the processor 11000 reads programs (program codes), software modules, and data from the storage 13000 and / or the communication device 14000 to the memory 12000, and executes various processes according to these. As the program, a program that causes a computer to execute at least a part of the operations described in the above embodiments is used. For example, the data transmission / reception unit 111, the cell quality measurement unit 112, the handover execution unit 113, the data transmission / reception unit 121, the filter processing unit 122, and the handover destination determination unit 123 described above are stored in the memory 12000 and operate on the processor 11000. It may be realized by a control program, and may be realized similarly for other functional blocks. Although the above-described various processes have been described as being executed by one processor 11000, they may be executed simultaneously or sequentially by two or more processors 11000. The processor 11000 may be implemented with one or more chips. Note that the program may be transmitted from a network via a telecommunication line.

  The memory 12000 is a computer-readable recording medium and includes, for example, at least one of ROM (Read Only Memory), EPROM (Erasable Programmable ROM), EEPROM (Electrically Erasable Programmable ROM), RAM (Random Access Memory), and the like. May be. The memory 12000 may be called a register, a cache, a main memory (main storage device), or the like. The memory 12000 can store a program (program code), a software module, and the like that can be executed to execute the communication method according to the embodiment of the present invention.

  The storage 13000 is a computer-readable recording medium such as an optical disk such as a CD-ROM (Compact Disc ROM), a hard disk drive, a flexible disk, a magneto-optical disk (for example, a compact disk, a digital versatile disk, a Blu-ray). (Registered trademark) disk, smart card, flash memory (for example, card, stick, key drive), floppy (registered trademark) disk, magnetic strip, and the like. The storage 13000 may be referred to as an auxiliary storage device. The storage medium described above may be, for example, a database including a memory 12000 and / or storage 13000, a server, or other suitable medium.

  The communication device 14000 is hardware (transmission / reception device) for performing communication between computers via a wired and / or wireless network, and is also referred to as a network device, a network controller, a network card, a communication module, or the like. For example, the transmission / reception antenna, amplifier unit, transmission / reception unit, transmission path interface, and the like included in the above-described drone 11 (communication terminal 11), base station 12, and the like may be realized by the communication device 14000.

  The input device 15000 is an input device (for example, a keyboard, a mouse, a microphone, a switch, a button, a sensor, or the like) that receives input from the outside. The output device 16000 is an output device (for example, a display, a speaker, an LED lamp, etc.) that performs output to the outside. Note that the input device 15000 and the output device 16000 may have an integrated configuration (for example, a touch panel).

  Each device such as the processor 11000 and the memory 12000 is connected by a bus 17000 for communicating information. The bus 17000 may be composed of a single bus or may be composed of different buses between devices.

  In addition, the drone 11 (communication terminal 11) and the base station 12 include a microprocessor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a programmable logic device (PLD), and a field programmable gate array (FPGA). ) Etc., and a part or all of each functional block may be realized by the hardware. For example, the processor 11000 may be implemented with at least one of these hardware.

<Information notification, signaling>
The notification of information is not limited to the aspect / embodiment described in the present specification, and may be performed by other methods. For example, information notification includes physical layer signaling (for example, DCI (Downlink Control Information), UCI (Uplink Control Information)), upper layer signaling (for example, RRC (Radio Resource Control) signaling, MAC (Medium Access Control) signaling), It may be implemented by broadcast information (MIB (Master Information Block), SIB (System Information Block))), other signals, or a combination thereof. Further, the RRC signaling may be called an RRC message, and may be, for example, an RRC connection setup message, an RRC connection reconfiguration message, or the like.

<Applicable system>
Each aspect / embodiment described herein includes LTE (Long Term Evolution), LTE-A (LTE-Advanced), SUPER 3G, IMT-Advanced, 4G, 5G, FRA (Future Radio Access), and W-CDMA. (Registered trademark), GSM (registered trademark), CDMA2000, UMB (Ultra Mobile Broadband), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, UWB (Ultra-WideBand), Bluetooth (registered trademark), The present invention may be applied to a system using another appropriate system and / or a next generation system extended based on the system.

<Processing procedure>
As long as there is no contradiction, the order of the processing procedures, sequences, flowcharts, and the like of each aspect / embodiment described in this specification may be changed. For example, the methods described herein present the elements of the various steps in an exemplary order and are not limited to the specific order presented.

<Operation of base station>
The specific operation assumed to be performed by the base station in this specification may be performed by its upper node in some cases. In a network composed of one or more network nodes having a base station, various operations performed for communication with a terminal may be performed by the base station and / or other network nodes other than the base station (e.g., Obviously, this can be done by MME or S-GW, but not limited to these. Although the case where there is one network node other than the base station in the above is illustrated, a combination of a plurality of other network nodes (for example, MME and S-GW) may be used.

<Input / output direction>
Information or the like (* see “Information, Signal” item) can be output from the upper layer (or lower layer) to the lower layer (or upper layer). Input / output may be performed via a plurality of network nodes.

<Handling of input / output information, etc.>
Input / output information and the like may be stored in a specific location (for example, a memory) or may be managed by a management table. Input / output information and the like can be overwritten, updated, or additionally written. The output information or the like may be deleted. The input information or the like may be transmitted to another device.

<Judgment method>
The determination may be performed by a value represented by 1 bit (0 or 1), may be performed by a true / false value (Boolean: true or false), or may be performed by comparing numerical values (for example, a predetermined value) Comparison with the value).

<Aspect variations>
Each aspect / embodiment described in this specification may be used independently, may be used in combination, or may be switched according to execution. Further, notification of predetermined information (for example, notification of “being X”) is not limited to explicitly performed, but is performed implicitly (for example, without notification of the predetermined information). Also good.

  Although the present invention has been described in detail above, it will be apparent to those skilled in the art that the present invention is not limited to the embodiments described herein. The present invention can be implemented as modified and changed modes without departing from the spirit and scope of the present invention defined by the description of the scope of claims. Therefore, the description of the present specification is for illustrative purposes and does not have any limiting meaning to the present invention.

<Meaning and interpretation of terms>
1) Software Software, whether it is called software, firmware, middleware, microcode, hardware description language, or another name, is an instruction, instruction set, code, code segment, program code, program, subprogram Software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc. should be interpreted broadly.

  Also, software, instructions, etc. may be transmitted / received via a transmission medium. For example, software may use websites, servers, or other devices using wired technology such as coaxial cable, fiber optic cable, twisted pair and digital subscriber line (DSL) and / or wireless technology such as infrared, wireless and microwave. When transmitted from a remote source, these wired and / or wireless technologies are included within the definition of a transmission medium.

2) Information, signals The information, signals, etc. described herein may be represented using any of a variety of different technologies. For example, data, commands, commands, information, signals, bits, symbols, chips, etc. that may be referred to throughout the above description are voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, light fields or photons, or any of these May be represented by a combination of

  Note that the terms described in this specification and / or terms necessary for understanding this specification may be replaced with terms having the same or similar meaning. For example, the channel and / or symbol may be a signal. The signal may be a message. In addition, the component carrier (CC) may be called a carrier frequency, a cell, or the like.

3) “System”, “Network”
As used herein, the terms “system” and “network” are used interchangeably.

4) Names of parameters and channels The information and parameters described in this specification may be expressed as absolute values, relative values from predetermined values, or other corresponding values. It may be represented by information. For example, the radio resource may be indicated by an index.

  The names used for the parameters described above are not limiting in any way. Further, mathematical formulas and the like that use these parameters may differ from those explicitly disclosed herein. Since various channels (eg, PUCCH, PDCCH, etc.) and information elements (eg, TPC, etc.) can be identified by any suitable name, the various names assigned to these various channels and information elements are However, it is not limited.

5) Base station A base station may accommodate one or multiple (eg, three) cells (also referred to as sectors). When a base station accommodates multiple cells, the entire coverage area of the base station can be divided into multiple smaller areas, each smaller area being divided into a base station subsystem (eg, an indoor small base station RRH: Remote Radio Head) can also provide communication services. The term “cell” or “sector” refers to part or all of the coverage area of a base station and / or base station subsystem that provides communication services in this coverage. Further, the terms “base station”, “eNB”, “cell”, and “sector” may be used interchangeably herein. A base station may also be referred to in terms such as a fixed station, NodeB, eNodeB (eNB), access point, femtocell, small cell and the like.

6) Mobile station A mobile station is defined by those skilled in the art as a subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal, It may also be called mobile terminal, wireless terminal, remote terminal, handset, user agent, mobile client, client, or some other appropriate terminology.

7) Other terms "Judgment", "Decision"
As used herein, the terms “determining” and “determining” may encompass a wide variety of actions. “Judgment” and “determination” are, for example, judgment, calculation, calculation, processing, derivation, investigating, looking up (eg, table , Searching in a database or another data structure), considering ascertaining as “determining”, “deciding”, and the like. In addition, “determination” and “determination” include receiving (for example, receiving information), transmitting (for example, transmitting information), input (input), output (output), and access. (accessing) (e.g., accessing data in a memory) may be considered as "determined" or "determined". In addition, “determination” and “decision” means that “resolving”, “selecting”, “choosing”, “establishing”, and “comparing” are regarded as “determining” and “deciding”. May be included. In other words, “determination” and “determination” may include considering some operation as “determination” and “determination”.

2. "Connected", "coupled"
The terms “connected”, “coupled”, or any variation thereof, means any direct or indirect connection or coupling between two or more elements and It can include the presence of one or more intermediate elements between two “connected” or “coupled” elements. The coupling or connection between the elements may be physical, logical, or a combination thereof. As used herein, the two elements are radio frequency by using one or more wires, cables and / or printed electrical connections, as well as some non-limiting and non-inclusive examples. By using electromagnetic energy, such as electromagnetic energy having wavelengths in the region, the microwave region and the light (both visible and invisible) region can be considered “connected” or “coupled” to each other.

3. "On the basis of the"
As used herein, the phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” means both “based only on” and “based at least on.”

4). "Including", "or"
As long as “including” and variations thereof are used herein or in the claims, these terms are intended to be inclusive, as well as the term “comprising”. Furthermore, the term “or” as used herein or in the claims is not intended to be an exclusive OR.

5. Articles Throughout this disclosure, if articles are added by translation, for example, a, an, and the in English, these articles must be clearly indicated by the context , Including multiple items.

Claims (10)

A base station that determines the handover destination of a drone in flight,
A communication quality value for each of a plurality of cells within a predetermined distance from the drone, and a data transmission / reception unit that receives the communication quality value measured by the drone,
Filter communication quality values of each of a plurality of cells within a predetermined distance from the drone based on a filter comprising weight values determined based on the relative positional relationship with the cell of interest and calculation rules. A filter processing unit to process;
A base station including a handover destination determining unit that determines a handover destination of the drone based on communication quality values of the plurality of cells subjected to the filtering process. The base station according to claim 1, wherein
The filter is
Among the communication quality values of a plurality of cells, this is a filter having a function of smoothing out a value that protrudes compared to the communication quality value of surrounding cells and a value that deviates from the communication quality value of surrounding cells. base station. The base station according to claim 2, wherein
The filter is
A base station that is a filter whose weight value for a cell of interest is larger than the weight values for other cells. A communication terminal that receives a handover destination from a base station during flight,
A cell quality measurement unit for measuring communication quality values of each of a plurality of cells within a predetermined distance from the own device;
A data transmission / reception unit for transmitting the measured communication quality value to the base station and receiving a handover destination of the own device from the base station;
A handover execution unit that executes a handover based on the received handover destination;
The received handover destination is determined based on a filter consisting of a weight value determined based on a relative positional relationship with the cell of interest and a calculation rule. A communication terminal that is a handover destination that has been subjected to filter processing on the communication quality values of each of a plurality of cells in the base station and that has been determined by the base station based on the communication quality values of the plurality of cells subjected to the filter processing. The communication terminal according to claim 4, wherein
The filter is
Among the communication quality values of a plurality of cells, this is a filter having a function of smoothing out a value that protrudes compared to the communication quality value of surrounding cells and a value that deviates from the communication quality value of surrounding cells. Communication terminal. The communication terminal according to claim 5, wherein
The filter is
A communication terminal that is a filter in which a weight value for a cell of interest is larger than weight values for other cells. A drone that receives a handover destination from a base station during flight,
A cell quality measurement unit for measuring communication quality values of each of a plurality of cells within a predetermined distance from the own device;
A data transmission / reception unit for transmitting the measured communication quality value to the base station and receiving a handover destination of the own device from the base station;
A handover execution unit that executes a handover based on the received handover destination;
The received handover destination is determined based on a filter consisting of a weight value determined based on a relative positional relationship with the cell of interest and a calculation rule. A drone that is a handover destination that is obtained by filtering the communication quality values of each of the plurality of cells in the base station, and determined by the base station based on the communication quality values of the plurality of filtered cells.   The program for functioning a computer as a control part of the base station in any one of Claim 1 to 3.   The program for functioning a computer as a communication terminal in any one of Claim 4 to 6.   The program for functioning a computer as a control part of the drone of Claim 7.

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