JP2020156014A - Control device, communication system including the same, program, and computer-readable recording medium on which program is recorded - Google Patents

Abstract

To provide a control device that controls to increase the number of cluster members accommodated in a cluster.SOLUTION: Calculation means 504 executes a first arithmetic process of calculating the number of accommodations which are the number of cluster members that a candidate cluster head can accommodate, and dividing the number of accommodations by the amount of a first wireless resource that the candidate cluster head can use for wireless communication with a base station to calculate the accommodation efficiency of cluster members, for a plurality of candidate cluster heads. Selection means 503 selects the candidate cluster head having the maximum accommodating efficiency detected from the calculated accommodating efficiencies as the cluster head. Control means 502 controls the candidate cluster heads selected by the selection means 503 to form a cluster.SELECTED DRAWING: Figure 2

Description

The present invention relates to a control device, a communication system including the control device, a program, and a computer-readable recording medium on which the program is recorded.

Conventionally, a hierarchical network has been known that efficiently exchanges a large amount of information such as map data with a huge number of moving bodies moving at a low speed without delay (Non-Patent Documents 1 and 2).

This hierarchical network includes an information server, a control server, a base station (or AP: Access Point), and a plurality of mobile units. Multiple moving objects form a cluster. Then, one of the plurality of moving bodies is a cluster head, and the other moving bodies are cluster members.

The information server holds data downloaded by a plurality of moving objects. The data downloaded by multiple mobiles from the information server is the same for each other.

The control server allocates channels for wireless communication within the cluster. More specifically, the control server receives cluster information including the number of mobile bodies included in the cluster from the mobile bodies of the cluster head, and uses the cluster information to equalize the number of mobile bodies for each channel. Assign channels to the cluster so that. Then, the control server transmits information indicating the assigned channels to the moving bodies of the corresponding cluster heads. For example, if the number of available channels is 10 and there are 20 clusters containing similar numbers of mobiles, the control server will ensure that the number of mobiles using each channel is more even. , Assign one channel for every two clusters.

The cluster head mobile unit receives the channel assigned by the control server from the control server via the base station (or AP), and wirelessly communicates with the cluster member mobile unit in the cluster using the received channel. ..

The cluster head mobile body downloads data from the information server via the base station (or AP), and transmits the downloaded data to the cluster member mobile body using the channel received from the control server. Then, each moving body of the cluster member receives data from the moving body of the cluster head.

In this way, the hierarchical network disclosed in Non-Patent Documents 1 and 2 includes wide-area wireless communication for the mobile cluster head to download data from the information server, and movement of the mobile cluster head and cluster members. It is a network that performs wireless communication in the near range that sends and receives data to and from the body.

Rui Teng, Kazuto Yano, and Tomoaki Kumagai, “A Distributed Clustering Scheme for Local Information Sharing in Hierarchical Robotic Wireless Networks,” IEICE-2018-Generalcon. Rui Teng, Kazuto Yano, and Tomoaki Kumagai, “Efficient Acquisition of Map Information using Local Data Sharing over Hierarchical Wireless Network for Service Robots,” APMC2018.

However, it is difficult to increase the number of cluster members accommodated in the cluster by the cluster configuration method disclosed in Non-Patent Documents 1 and 2.

Therefore, according to the embodiment of the present invention, there is provided a control device that controls so as to increase the number of cluster members accommodated in the cluster.

Further, according to the embodiment of the present invention, there is provided a communication system including a control device for controlling so as to increase the number of cluster members accommodated in the cluster.

Further, according to an embodiment of the present invention, there is provided a program for causing a computer to perform control for increasing the number of cluster members accommodated in the cluster.

Further, according to an embodiment of the present invention, there is provided a computer-readable recording medium on which a program for causing a computer to execute control for increasing the number of cluster members accommodated in the cluster is recorded.

(Structure 1)
According to the embodiment of the present invention, the control device is a control device that selects a cluster head from a plurality of moving bodies and periodically controls the cluster head so that the selected cluster head constitutes a cluster. , A calculation means, a selection means, and a control means. The calculation means calculates the number of cluster members that can be accommodated by the candidate cluster head, which is a candidate for the cluster head, and is the first amount of wireless resources that the candidate cluster head can use for wireless communication with the base station. The first arithmetic process for calculating the accommodation efficiency of the cluster members in the candidate cluster heads by dividing the number of accommodations is executed for the plurality of candidate cluster heads. The selection means detects the maximum accommodating efficiency from the plurality of accommodating efficiencies calculated for the plurality of candidate cluster heads, and selects the candidate cluster head having the detected maximum accommodating efficiency as the cluster head. The control means controls the candidate cluster heads selected by the selection means so as to form a cluster.

(Structure 2)
In configuration 1, the amount of free radio resources in one channel is set as the maximum amount of radio resources that the candidate cluster head can use for wireless communication with the cluster members. The calculation means executes a second calculation process for a plurality of cluster members to calculate the amount of the second radio resource by dividing the data capacity of the data acquired by the cluster member by the communication rate between the candidate cluster head and the cluster member. Based on the plurality of second radio resource amounts calculated for the plurality of cluster members, the number of the second radio resource amounts whose sum is smaller than the maximum radio resource amount is calculated as the accommodation number.

(Structure 3)
In the configuration 2, when the calculation means executes the second calculation process for one cluster member to calculate the second radio resource amount, the calculated second radio resource amount is subtracted from the maximum radio resource amount and subtracted. When the result is positive, the process of increasing the number of accommodations by "1" is repeatedly executed, and the count value of the number of accommodations when the subtraction result becomes zero or less is calculated as the number of accommodations.

(Structure 4)
In configuration 2 or 3, the control device further comprises search means. The search means searches for the amount of free radio resources for each of the plurality of channels. The calculation means calculates the number of accommodations by using one free radio resource amount selected from a plurality of free radio resource amounts corresponding to the plurality of channels as the maximum radio resource amount.

(Structure 5)
In the configuration 4, the calculation means calculates the number of accommodations by using the maximum free radio resource amount as the maximum radio resource amount among the plurality of free radio resource amounts.

(Structure 6)
In the configuration 4, the calculation means calculates the number of accommodations by using one free radio resource amount arbitrarily selected from the plurality of free radio resource amounts as the maximum radio resource amount.

(Structure 7)
In any of the configurations 1 to 6, the arithmetic means is the data capacity of the data downloaded by each of the plurality of moving objects constituting the cluster by the area of the circle having the first radius centered on the position of the candidate cluster head. When the total data capacity of the data downloaded from the information server by the candidate cluster head is represented by the area of the circle having the second radius, which is an integral multiple of the first radius, centered on the position of the candidate cluster head. The first radio resource amount is calculated by dividing the total data capacity by the communication rate between the candidate cluster head and the base station.

(Structure 8)
Further, according to the embodiment of the present invention, the communication system receives the control device according to any one of the configurations 1 to 7, the plurality of mobile bodies constituting the cluster, and the data downloaded by the plurality of mobile bodies. It has an information server to hold it. Multiple moving objects include a cluster head and a cluster member. The cluster head consists of candidate cluster heads, and constitutes a cluster according to the control by the control device. The cluster members perform wireless communication with the cluster head. Then, the cluster head downloads the data of the cluster head and the cluster member from the information server, and sends the data of the cluster member to the cluster member.

(Structure 9)
Further, according to an embodiment of the present invention, the program selects a cluster head from a plurality of moving bodies and causes a computer to periodically control the cluster head so that the selected cluster head constitutes a cluster. Program for
The calculation means calculates the number of cluster members that can be accommodated by the candidate cluster head, which is a candidate for the cluster head, and the amount of the first radio resource that the candidate cluster head can use for wireless communication with the base station. The first step of executing the first arithmetic processing for calculating the accommodation efficiency of the cluster members in the candidate cluster heads by dividing the number of accommodations for a plurality of candidate cluster heads, and
A second step in which the selection means detects the maximum accommodation efficiency from the plurality of accommodation efficiencies calculated for the plurality of candidate cluster heads and selects the candidate cluster head having the detected maximum accommodation efficiency as the cluster head.
The control means is a program for causing the computer to perform a third step of controlling the candidate cluster heads selected by the selection means to form a cluster.

(Structure 10)
In configuration 9, the amount of free radio resources in one channel is set as the maximum amount of radio resources that the candidate cluster head can use for wireless communication with the cluster members. In the first step, the calculation means performs a plurality of second calculation processes for calculating the amount of the second radio resource by dividing the data capacity of the data acquired by the cluster member by the communication rate between the candidate cluster head and the cluster member. Based on the plurality of second radio resource amounts calculated for the plurality of cluster members, the number of the second radio resource amounts whose sum is smaller than the maximum radio resource amount is calculated as the accommodated number. To do.

(Structure 11)
In the configuration 10, when the calculation means executes the second calculation process for one cluster member to calculate the second radio resource amount in the first step, the calculated second radio resource amount is maximized by the radio. When the subtraction result subtracted from the resource amount is positive, the process of increasing the number of accommodations by "1" is repeatedly executed, and the count value of the number of accommodations when the subtraction result becomes zero or less is calculated as the number of accommodations. To do.

(Structure 12)
In configuration 10 or 11, the program causes the search means to further perform a fourth step of searching for the amount of free radio resources for each of the plurality of channels. Then, in the first step, the calculation means uses one vacant radio resource amount selected from a plurality of vacant radio resource amounts corresponding to the plurality of channels as the maximum radio resource amount to determine the number of accommodations. Calculate.

(Structure 13)
In the configuration 12, in the first step, the calculation means calculates the number of accommodations by using the maximum free radio resource amount among the plurality of free radio resource amounts as the maximum radio resource amount.

(Structure 14)
In the configuration 12, in the first step, the calculation means calculates the number of accommodations by using one free radio resource amount arbitrarily selected from the plurality of free radio resource amounts as the maximum radio resource amount.

(Structure 15)
In any of configurations 9 through 14, the computing means in the first step is that each of the plurality of moving objects forming the cluster by the area of a circle centered on the position of the candidate cluster head and having a first radius. Represents the data capacity of the data to be downloaded, centered on the position of the candidate cluster head, and the total data of the data downloaded by the candidate cluster head from the information server by the area of the circle having the second radius which is an integral multiple of the first radius. When the capacity is expressed, the total data capacity is divided by the communication rate between the candidate cluster head and the base station to calculate the first radio resource amount.

(Structure 16)
Further, according to an embodiment of the present invention, the recording medium is a computer-readable recording medium on which the program according to any one of configurations 9 to 15 is recorded.

The number of cluster members accommodated in the cluster can be increased.

It is the schematic of the communication system by embodiment of this invention. It is the schematic of the control device shown in FIG. It is the schematic of the correspondence table which shows the correspondence relationship between the received signal strength and the communication rate. It is a schematic diagram of the correspondence table which shows the correspondence relationship between a channel and the amount of available radio resources. It is the schematic of the correspondence table which shows the correspondence relation of the identifier, the position, the received signal strength and the number of connections of a moving body. It is the schematic for demonstrating the data capacity in embodiment of this invention. It is a figure for demonstrating the method of selecting a cluster head. It is a figure for demonstrating the preferable calculation method of the accommodation number N_hus. It is the schematic of the moving body shown in FIG. It is a flowchart for demonstrating operation of the communication system shown in FIG. It is a flowchart for demonstrating the detailed operation of step S2 of FIG. It is a flowchart for demonstrating the detailed operation of step S21 of FIG. It is a flowchart for demonstrating the detailed operation of step S3 of FIG. It is a flowchart for demonstrating the detailed operation of step S4 of FIG. It is a figure for demonstrating the method of obtaining the total data capacity D_total. It is a figure for demonstrating another method to obtain the total data capacity D_total.

Embodiments of the present invention will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals and the description is not repeated.

FIG. 1 is a schematic diagram of a communication system according to an embodiment of the present invention. With reference to FIG. 1, the communication system 100 according to the embodiment of the present invention includes mobile units 1 to 10, AP20, LTE (Long Time Evolution) base station 30, network 40, control device 50, and information. It includes a server 60.

Each of the moving bodies 1 to 10 may be a device that moves autonomously, and may be, for example, mobility such as an electric wheelchair, an entertainment robot, a transportation robot, or the like.

The moving bodies 1 to 10 form a cluster including a cluster head and a cluster member by a method described later. Then, the cluster head downloads the data of the cluster head and the cluster member from the information server 60 via the AP 20 (or LTE base station 30), and transmits the data of the cluster member to the cluster member.

Further, the mobile body (any of the mobile bodies 1 to 10) that does not form a cluster downloads its own data from the information server 60 via the AP 20 (or LTE base station 30).

The AP 20 mediates communication between the mobile bodies 1 to 10 and the control device 50 or the information server 60. The LTE base station 30 mediates communication between the mobile units 1 to 10 and the control device 50 or the information server 60.

The control device 50 selects a cluster head from the candidate cluster head CH_CAD (a part of the moving bodies 1 to 10) which is a candidate for the cluster head CH by the method described later, and the selected cluster head is a cluster. Is controlled to configure.

The information server 60 holds data D1 to D10 downloaded by the moving bodies 1 to 10, respectively. Each of the data D1 to D10 is, for example, map data. The data D1~D10 has the same data capacity _{D C.}

FIG. 2 is a schematic view of the control device 50 shown in FIG. With reference to FIG. 2, the control device 50 includes a communication means 501, a control means 502, a selection means 503, a calculation means 504, a search means 505, and a database 506.

The communication means 501 receives the Hello packet from the mobile bodies 1 to 10 via the AP 20 (or LTE base station 30) and the network 40, and outputs the received Hello packet to the control means 502.

Further, the communication means 501 receives the control information IF_CTL from the control means 502, and receives the received control information IF_CTL to the mobile body (any of the mobile bodies 1 to 10) selected as the cluster head to the network 40 and the AP20 (or AP20). It is transmitted via the LTE base station 30).

Control means 502 receives a Hello packet from the communication unit 501, an identifier _Add i (i = _1~n) of the mobile from the received Hello packet, the position _{[x i, y i],} the received signal strength RSSI1, the received signal The intensity RSSI2 and the number of connections N_CN_i are detected. Here, the received signal strength RSSI1 is the received signal strength between the base station (AP20 or LTE base station 30) and the candidate cluster head CH_CAD, and the received signal strength RSSI2 is the candidate cluster head CH_CAD and the candidate cluster member CM_CAD. It is the received signal strength between, and the number of connections N_CN_i is the number of moving bodies to which each moving body is connected to itself by a wireless link.

Control means 502, the identifier Add _i, the position _{[x i, y i],} when detecting the received signal strength RSSIi and connections N_CN_i identifier Add _i, the position _{[x i, y i],} the received signal strength RSSI1, the received signal The strength RSSI2 and the number of connections N_CN_i are associated with each other and stored in the database 506.

The control means 502 has a built-in timer, and with reference to the timer, the number N_hus of cluster member CMs that one moving body can accommodate in the cluster as the cluster head CH is determined by the candidate cluster heads CH_CAD and AP20 (or LTE). The calculation means 504 is periodically controlled so that the accommodation efficiency EFF_hus divided by the amount of radio resources between the base station 30) and the base station 30) is calculated for the plurality of candidate cluster heads CH_CAD.

Control means 502, and maximum accommodation efficiency EFF_hus_max, the identifier _Add i _CH_S candidate cluster head CH_CAD_S selected as the cluster head CH, the channel CHN_max when the maximum of the accommodation efficiency EFF_hus_max is obtained, housed in the candidate cluster head CH_CAD_S When the plurality of identifiers Add _i _CM_S of the plurality of candidate cluster members CM_CAD are received from the selection means 503, the selection information IF_CH indicating that the candidate cluster head CH_CAD_S having the identifier Add _i _CH_S is selected as the cluster head CH is generated. To do. Then, the control unit 502, outputs the selection information IF_CH, a channel CHN_max, the plurality of identifiers _Add i generates control information IF_CTL including the _CM_S, control information IF_CTL identifier _Add i _CH_S and the communication means 501 that generates and controls the communication unit 501 to transmit control information IF_CTL to a mobile identifier _Add i _CH_S.

Selection means 503, a plurality of candidate cluster members respectively corresponding a plurality of accommodation efficiency EFF_hus, a plurality of identifiers _Add i _CH plurality of candidate cluster head CH_CAD corresponding to the plurality of accommodation efficiency EFF_hus, a plurality of accommodation efficiency EFF_hus a plurality of identifiers _Add i _CM of CM_CAD, receiving a plurality of channels CHN_max corresponding to the plurality of accommodation efficiency EFF_hus from the arithmetic unit 504 selects the maximum accommodation efficiency EFF_hus a plurality of accommodation efficiency EFF_hus thereof received. The selecting unit 503, and maximum accommodation efficiency EFF_hus, the identifier _Add i _CH_S corresponding to the maximum of the accommodation efficiency EFF_hus, a plurality of identifiers _Add i _CM_S corresponding to the maximum of the accommodation efficiency EFF_hus, the maximum accommodation efficiency EFF_hus The corresponding channel CHN_max is output to the control means 502.

The calculation means 504 calculates the accommodation efficiency EFF_hus for the plurality of candidate cluster heads CH_CAD according to the method described later according to the control from the control means 502. The arithmetic unit 504, a plurality of candidates corresponding respective plurality of accommodation efficiency EFF_hus, a plurality of identifiers _Add i _CH plurality of candidate cluster head CH_CAD corresponding to the plurality of accommodation efficiency EFF_hus, a plurality of accommodation efficiency EFF_hus outputting a plurality of identifiers _Add i _CM cluster members CM_CAD, and a plurality of channels CHN_max corresponding to the plurality of accommodation efficiency EFF_hus to selection means 503.

The search means 505 searches for the amount of available radio resources (= the amount of free radio resources) for each of the plurality of channels CHN1 to CHNq (q is an integer of 2 or more), and the searched available radios. The resource amount is stored in the database 506 in association with the channel CHNq. In this case, the search means 505 searches for the ratio of the sum of the free time to the observation time of one channel as the amount of available radio resources. The search means 505 periodically searches for the amount of available radio resources, and stores the search result in the database 506.

The database 506 contains a correspondence table between the received signal strength and the communication rate, a correspondence table between the channel and the amount of radio resources available, the identifier of the moving body, the position of the moving body, the received signal strength of the moving body, and the like. Stores the correspondence table with the number of connected mobile devices.

FIG. 3 is a schematic diagram of a correspondence table showing the correspondence relationship between the received signal strength and the communication rate. With reference to FIG. 3, the correspondence table TBL1 includes the received signal strength and the communication rate. Received signal strength and communication rate are associated with each other.

A received signal strength of less than -82 [dBm] is associated with a communication rate of 6 [Mbps], and a received signal strength of -82 [dBm] or more and less than -81 [dBm] is associated with a communication rate of 9 [Mbps]. The received signal strength of -81 [dBm] or more and less than -79 [dBm] is associated with the communication rate of 12 [Mbps], and the received signal strength of -79 [dBm] or more and less than -77 [dBm]. Is associated with a communication rate of 18 [Mbps]. Further, the received signal strength of -77 [dBm] or more and less than -74 [dBm] is associated with the communication rate of 24 [Mbps], and the received signal strength of -74 [dBm] or more and less than -70 [dBm] is A received signal strength of -70 [dBm] or more and less than -66 [dBm] associated with a communication rate of 36 [Mbps] is associated with a communication rate of 48 [Mbps] and received at -66 [dBm] or more. The signal strength is associated with a communication rate of 54 [Mbps].

In general, the correspondence between the received signal strength and the communication rate in the correspondence table TBL1 is different for each wireless system. Therefore, for example, LTE and wireless LAN (Local Area Network) use different correspondence tables. May be good.

FIG. 4 is a schematic diagram of a correspondence table showing the correspondence between the channel and the available radio resource amount ACOR.

With reference to FIG. 4, correspondence table TBL2 includes channels and available radio resource amount ACOR. Channel and radio resource volume ACORs are associated with each other. Channels CHN1 to CHNq are associated with radio resource amounts ACOR of 0.9, 0.8, 0.6, ..., 0.5, respectively. Then, the channels CHN1 to CHNq are stored in the correspondence table TBL2 in descending order of the available radio resource amount ACOR, for example.

FIG. 5 is a schematic diagram of a correspondence table showing the correspondence between the identifiers, positions, received signal strengths, and the number of connections of the moving bodies 1 to 10.

With reference to FIG. 5, correspondence table TBL3 includes identifiers, positions, received signal strength 1, received signal strength 2 and number of connections for moving objects 1-10. The identifier, position, received signal strength 1, received signal strength 2, and number of connections are associated with each other.

Identifier consists IP address Add _i of the mobile, the position is, for example, x-y coordinate _{[x i, y} i] is represented by. The received signal strength 1 is composed of the received goods strength RSSI _{AP-m_i} between the AP 20 (or LTE base station 30) and the mobile body m, and the received signal strength 2 is between the mobile body mi and the mobile body mj. Received signal strength of RSSI _{mi-mj_i} . Note that j is equal to the number of connections N_CN_i. Therefore, in FIG. 5, one received signal strength RSSI _{mi-mj_i} is stored for each identifier Addi, but in reality, j (j is 1 ≦ j ≦ N_CN_i) for each identifier Addi. The received signal strength (an integer that satisfies) is stored. The number of connections N_CN_i consists of one mobile body and the number of mobile bodies having a wireless link.

FIG. 6 is a schematic diagram for explaining the data capacity in the embodiment of the present invention. With reference to FIG. 6, a circle CIR1 centered on the position of the candidate cluster head CH_CAD and having a radius r (for example, 10 m) from the center represents data of each of the candidate cluster head CH_CAD and the cluster member CM.

Then, the cluster member CM whose position is inside the circle CIR1 and on the circumference of the circle CIR is set as a proximity moving body close to the candidate cluster head CH_CAD. In the embodiment of the present invention, the cluster is composed of a cluster head CH and a proximity moving body of the cluster head CH.

When the position of the cluster member CM exists on the circumference of the circle CIR1, the data of the cluster member CM is represented by the circle CIR2. Further, when the position of the cluster member CM exists inside the circle CIR1, the data of the cluster member CM is represented by the circle CIR3.

Here, assuming a circle CIR_total with a radius of 2r (= 20 m) centered on the position of the candidate cluster head CH_CAD, the circle representing the data of the cluster member CM always exists in the region represented by the circle CIR_total. This is because the position of the cluster member CM exists in the region represented by the circle CIR1.

Since the data capacity Dc of one data is represented by the area of the circle CIR1, the data capacity of the data represented by the circle CIR_total is (4πr ² / πr ² ) × Dc = 4Dc.

The cluster head CH (= candidate cluster head CH_CAD selected as the cluster head CH) downloads its own data and the data of the cluster member CM from the information server 60. In this case, the cluster head CH (= candidate cluster head CH_CAD selected as the cluster head CH) downloads data having a data capacity of 4Dc represented by the circle CIR_total from the information server 60.

In the embodiment of the present invention, the circle CIR_total is not limited to twice the radius r of the circle CIR1, but generally may be an integral multiple of the radius r of the circle CIR1.

FIG. 7 is a diagram for explaining a method of selecting a cluster head. Referring to FIG. 7, the control unit 502 refers to the correspondence table TBL3 stored in the database 506, the position of each mobile 1~10 _{[x i, y} i] on the basis of the mobile 10 Recognize the distribution state of. Then, the control means 502 extracts a mobile body having a number of connections N_CN_i'that is equal to or greater than the threshold value as a candidate cluster head CH_CAD based on the number of connections N_CN_i in the correspondence table TBL3. As a result, the set SET_CH of the candidate cluster head CH_CAD and the set SET_CM of the candidate cluster member CM_CAD shown in FIG. 7 are obtained. The set SET_CM is composed of moving bodies other than the candidate cluster head CH_CAD.

In the example shown in FIG. 7, the moving bodies 2, 6 and 9 are selected as the candidate cluster head CH_CAD, and the moving bodies 1, 3, 4, 5, 7, 8 and 10 are selected as the candidate cluster members CM_CAD.

Then, the control means 502 includes the identifiers Add ₂ , Add ₆ , and Ad ₉ of the candidate cluster head CH_CAD (= mobile bodies ₂ , ₆ , ₉₎ and the candidate cluster member CM_CAD (= mobile bodies 1, 3, 4, 5, 7). , 8, 10) identifiers Add ₁ , Add ₃ , Add ₄ , Add ₅ , Add ₇ , Add ₈ , and Add ₁₀ are output to the calculation means 504. In this case, the control means 502 calculates the accommodation efficiency EFF_hus by referring to the correspondence table TBL2 and using the radio resource amount corresponding to the channel having the maximum available radio resource amount ACOR as the maximum radio resource amount. It controls the arithmetic means 504. The control means 502 is a calculation means so as to select an arbitrary channel with reference to the correspondence table TBL2 and calculate the accommodation efficiency EFF_hus by using the amount of radio resources corresponding to the selected channel as the maximum amount of radio resources. 504 may be controlled. Further, the control means 502 may include another candidate cluster head CH_CAD in the candidate cluster member CM when actually calculating the accommodation efficiency EFF_hus.

The calculation means 504 includes identifiers of candidate cluster head CH_CAD (= mobile bodies ₂ , ₆ , ₉ ), Add ₂ , Add ₆ , and Add ₉ , and candidate cluster member CM_CAD (= mobile bodies 1, 3, 4, 5, 7, 8). , 10) identifiers Add ₁ , Add ₃ , Add ₄ , Add ₅ , Add ₇ , Add ₈ , Add ₁₀ are received from the control means 502.

Then, the calculation means 504 refers to the correspondence table TBL2, selects the radio resource amount (= 0.9) corresponding to the channel CHN1 having the maximum available radio resource amount, and selects the selected radio resource amount (= 0.9). = 0.9) is set to A_COR_initial.

Further, the calculation means 504 refers to the correspondence table TBL3, and the received signal strength between the moving body 2 and the moving body 1,3,4,5,7,8,10 RSSI2-1, RSSI2-3. RSSI2-4, RSSI2-5, RSSI2-7, RSSI2-8, RSSI2-10 are detected, and then, referring to the correspondence table TBL1, the detected received signal strength RSSI2-1, RSSI2-3, RSSI2-4 , RSSI2-5, RSSI2-7, RSSI2-8, communication rate _R 1 respectively corresponding to _{RSSI2-10, R 3,} R _4, detects the _{R 5, R 7, R 8} , R 10. The arithmetic unit 504, the communication rate _{R 1, R 3, R 4} , R 5, and _{R 7, R 8, R 10} , respectively, the moving body 2 mobile 1,3,4,5,7,8 Communication rates between R _{CH_CAD (2) -CM_CAD (1)} , R _{CH_CAD (2) -CM_CAD (3)} , R _{CH_CAD (2) -CM_CAD (4)} , R _{CH_CAD (2) -CM_CAD (5) )} , R _{CH_CAD (2) -CM_CAD (7)} R _{CH_CAD (2) -CM_CAD (8)} R _{CH_CAD (2) -CM_CAD (10)} .

After that, the calculation means 504 _substitutes the data capacity Dc of one data, the communication rate R _{CH_CAD (2) -CM_CAD (1),} and the cycle length Td for downloading the data into the following equation, and substitutes the candidate cluster head CH_CAD (mobile body 2). ) And the candidate cluster member CM_CAD (mobile body 1), the amount of radio resources COR (1) is calculated.

The denominator on the right side of the equation (1) is the communication rate R _{CH_CAD (2) -CM_CAD (1)} multiplied by the cycle length Td, and has a unit of [bit]. Further, since the data Dc also has a unit of [bit], the radio resource amount COR (k) of the equation (1) is a dimensionless unit.

Then, the calculation means 504 substitutes the radio resource amount COR (1) into the COR (k) of the following equation to calculate the total radio resource amount CM_COR_total.

When the total amount of radio resources CM_COR_total is first calculated, CM_COR_total on the right side of the equation (2) is set to "0".

Subsequently, the calculation means 504 calculates the available radio resource amount A_COR by substituting the calculated total radio resource amount CM_COR_total into the following equation.

As described above, A_COR_initial of the formula (3) is a dimensionless unit because it consists of the amount of radio resources available in the correspondence table TBL2. The total radio resource amount CM_COR_total is the sum of the radio resource amount COT (k), and the radio resource amount COR (k) is a dimensionless unit as described above. Therefore, the available radio resource amount A_COR is a dimensionless unit.

Then, the calculation means 504 determines whether or not the available radio resource amount A_COR is larger than zero. Then, when it is determined that the available radio resource amount A_COR is larger than zero, the calculation means 504 increments the accommodation number N_hus of the candidate cluster member CM_CAD by "1".

After that, the calculation means 504 substitutes the data capacity Dc, the communication rate R _{CH_CAD (2) -CM_CAD (3)} between the moving body 2 and the moving body 3, and the cycle length Td into the equation (1) to form a candidate cluster. The radio resource amount COR (3) between the head CH_CAD (mobile body 2) and the candidate cluster member CM_CAD (mobile body 3) is calculated.

Then, the calculation means 504 substitutes the radio resource amount COR (3) into the equation (2) to calculate the total radio resource amount CM_COR_total. In this case, the total radio resource amount CM_COR_total is the sum of the radio resource amount COR (1) and the radio resource amount COR (3).

Subsequently, the calculation means 504 calculates the available radio resource amount A_COR by substituting the calculated total radio resource amount CM_COR_total into the equation (3).

Then, the calculation means 504 determines whether or not the available radio resource amount A_COR is larger than zero, and when it is determined that the available radio resource amount A_COR is larger than zero, the accommodation number N_hus is set to "1". "Increment only.

The calculation means 504 repeatedly executes the above operation until the available radio resource amount A_COR becomes less than zero (that is, until the available radio resource amount A_COR becomes zero or less). Then, the calculation means 504 sets the count value of N_hus when the available radio resource amount A_COR is no more than zero (that is, when the available radio resource amount A_COR becomes zero or less) as the candidate cluster head CH_CAD. The number of units that can be accommodated by (moving body 2).

When the calculation means 504 calculates the accommodation number N_hus that can be accommodated by the candidate cluster head CH_CAD (mobile body 2), the calculation means 504 refers to the correspondence table TBL3 and refers to the AP20 (or LTE base station 30) and the candidate cluster head CH_CAD (mobile body 2). ) detects the received signal strength _{RSSI AP-m} _2 between, by referring to the correspondence table TBL1, detects the communication rate _{R AP-2} corresponding to the received signal strength _{RSSI AP-m} _2. Then, the calculation means 504 sets the communication rate R _AP-2 to the communication rate R _{AP-CH_CAD (2)} between the AP 20 (or LTE base station 30) and the candidate cluster head CH_CAD (mobile body 2).

Then, the calculation means 504 divides the data capacity 4Dc of the data downloaded from the information server 60 by the communication rate R _{AP-CH_CAD (2)} to _AP20 (or LTE base station 30) and the candidate cluster head CH_CAD (mobile body 2). _{Calculate the} amount of radio resource COR _{AP-CH_CAD (2)} between and. Then, the calculation means 504 divides the accommodation number N_hus by the radio resource amount COR _AP- CH_CAD (2) to calculate the accommodation efficiency EFF_hus (2) of the candidate cluster head CH_CAD (mobile body 2).

The calculation means 504 repeatedly executes the above-described operation to calculate the accommodation efficiency EFF_hus (6) of the candidate cluster head CH_CAD (moving body 6) and the accommodation efficiency EFF_hus (9) of the candidate cluster head CH_CAD (moving body 9).

Then, the calculation means 504 includes the accommodation efficiencies EFF_hus (2), EFF_hus (6), EFF_hus (9), the identifiers Add ₂ , Add ₆ , Add _9, and the accommodating efficiencies EFF_hus (2), EFF_hus (6), EFF_hus ( Channels CHN_EFF_hus (2), CHN6_EFF_hus (6), CHN9_EFF_hus (9) when 9) was obtained, and candidate cluster members when the accommodation efficiencies EFF_hus (2), EFF_hus (6), EFF_hus (9) were obtained. outputting a plurality of identifiers _Add i _CM of CM_CAD the selecting means 503.

The selection means 503 includes accommodation efficiencies EFF_hus (2), EFF_hus (6), EFF_hus (9), identifiers Add ₂ , Add ₆ , Add ₉ , and accommodation efficiencies EFF_hus (2), EFF_hus (6), EFF_hus (9). CHN_EFF_hus (2), CHN6_EFF_hus (6), CHN9_EFF_hus (9) and candidate cluster members CM_CAD when the accommodating efficiencies EFF_hus (2), EFF_hus (6), EFF_hus (9) were obtained. receiving a plurality of identifiers _Add i _CM from the arithmetic unit 504. Then, the selection means 503 selects the maximum accommodation efficiency EFF_hus_max from the accommodation efficiencies EFF_hus (2), EFF_hus (6), and EFF_hus (9), and selects the maximum accommodating efficiency EFF_hus_max and the maximum accommodating efficiency EFF_hus_max. the identifier _Add i _CH_S candidate cluster head CH_CAD_S the resulting plurality of identifiers Add _i of the plurality of candidate cluster members CM_CAD when the channel CHN_max when the maximum of the accommodation efficiency EFF_hus_max is obtained, the maximum accommodation efficiency EFF_hus_max obtained _CM_S is output to the control means 502.

Control means 502, and maximum accommodation efficiency EFF_hus_max, a channel CHN_max when the maximum accommodation efficiency EFF_hus_max identifier in the candidate cluster head CH_CAD_S which is obtained _Add i _CH_S, the maximum accommodation efficiency EFF_hus_max obtained, the maximum accommodation efficiency EFF_hus_max receives from a plurality of candidate cluster members CM_CAD multiple identifiers _Add i _CM_S and the selection means 503 when obtained.

Then, the control unit 502, the identifier _Add i _CH_S mobile and cluster head CH having generates control information IF_CTL described above, the generated control information IF_CTL identifier _Add i communication to the mobile unit having a _CH_S 501 Send via. In this case, it is assumed that the control information IF_CTL is transmitted to the moving body 6, for example.

Mobile 6 receives control information IF_CTL, based on the received control information IF_CTL, transmits to the mobile, each having a plurality of identifiers _Add i _CM_S generates a cluster head declaration DEC_CH. In this case, it is assumed that the moving body 6 transmits the cluster head declaration DEC_CH to the moving bodies 1, 3, 7, and 10.

The moving bodies 1, 3, 7, and 10 receive the cluster head declaration DEC_CH from the moving body 6 and recognize that the moving body 6 is the cluster head CH. Then, each of the moving bodies 1, 3, 7, and 10 generates cluster member information IF_CM indicating that the moving body is a cluster member CM, and among the other moving bodies (moving bodies 1, 3, 6, 7, and 10). Send to other moving objects). The mobile body that has received the cluster member information IF_CM recognizes that the mobile bodies 1, 3, 7, and 10 are cluster member CMs. As a result, a cluster consisting of a cluster head (= moving body 6) and a cluster member (= moving body 1, 3, 7, 10) is formed.

FIG. 8 is a diagram for explaining a preferable calculation method of the accommodation number N_hus. With reference to FIG. 8A, the amount of radio resources COR between the mobile body 2 which is the candidate cluster head and the mobile bodies 1,3,4,5,7,8,10 which are the candidate cluster members ( 1), COR (3), COR (4), COR (5), COR (7), COR (8), COR (10) are 0.3, 0.5, 0.2, 0, respectively. It is assumed that it is 7, 0.4, 0.6, 0.1. Further, it is assumed that A_COR_initial in the formula (3) is 0.9.

In this case, the amount of radio resources COR (1), COR (3), COR (4), COR in the order of moving body 1, moving body 3, moving body 4, moving body 5, moving body 7, moving body 8 and 10. By substituting (5), COR (7), COR (8), and COR (10) into the equation (2), the total radio resource amount CM_COR_total is calculated, and the calculated total radio resource amount CM_COR_total is calculated by the equation (3). ) To calculate the available radio resource amount A_COR, the radio resource amount of the mobile body 1 (= 0.3), the radio resource amount of the mobile body 3 (= 0.5), and the radio resource of the mobile body 4. When the amount (0.2) is added by the equation (2), the total amount of radio resources CM_COR_total becomes "1.0", which is larger than A_COR_initial (= 0.9). That is, when the amount of radio resources of the mobile body 1 (= 0.3), the amount of radio resources of the mobile body 3 (= 0.5), and the amount of radio resources of the mobile body 4 (0.2) are added, the equation ( The available radio resource amount A_COR calculated by 3) becomes negative (-0.1), and the accommodated number N_hus becomes "2".

On the other hand, as shown in FIG. 8B, when the radio resource amount COR (k) is arranged in ascending order, the radio resource amount of the mobile body 10 (= 0.1) and the radio resource amount of the mobile body 4 (=). 0.2), the total amount of radio resources CM_COR_total becomes "1.0" when the amount of radio resources of the mobile body 1 (= 0.3) and the amount of radio resources of the mobile body 7 (0.4) are added. Therefore, the amount of available radio resources A_COR becomes negative (-0.1). As a result, the number of accommodations N_hus becomes "3".

In this way, the accommodation number N_hus can be increased by arranging the radio resource amount COR (k) in ascending order and counting the accommodation number N_hus. Therefore, in the embodiment of the present invention, the arithmetic means 504 preferably arranges the radio resource amount COR (k) in ascending order and counts the number of accommodated N_hus.

FIG. 9 is a schematic view of the moving body 1 shown in FIG. With reference to FIG. 9, the mobile body 1 includes a communication means 11, a cluster configuration means 12, and a data acquisition means 13.

The communication means 11 includes wireless modules 111 and 112. The wireless module 111 is a wide-area wireless module that communicates with the control device 50 or the information server 60 via the AP 20 (or LTE base station 30). The wireless module 112 is a near-range wireless module that performs wireless communication within the cluster.

The wireless module 111 receives the control information IF_CTL from the control device 50 via the AP 20 (or LTE base station 30), and outputs the received control information IF_CTL to the cluster configuration means 12.

Further, when the wireless module 111 receives a packet from the AP 20 (or LTE base station 30), it detects the received signal strength RSSI _BS at the time of receiving the packet, and transfers the detected received signal strength RSSI _BS to the cluster forming means 12. Output.

Further, the radio module 111 receives a Hello packet including the identifier Add ₁ , the position [x ₁ , y ₁ ] of the mobile body 1, the received signal strength RSSI ₁ , and the number of connections N_CN_1 from the cluster configuration means 12, and receives the received Hello packet. It is transmitted to the control device 50 via the AP 20 (or LTE base station 30).

Further, when the mobile body 1 is the cluster head CH, the wireless module 111 receives data from the AP 20 (or LTE base station 30) and outputs the received data to the data acquisition means 13.

Further, when the mobile body 1 is a mobile body that does not form a cluster, the wireless module 111 receives data from the AP 20 (or LTE base station 30) and outputs the received data to the data acquisition means 13.

Furthermore, the wireless module 111, the position of the moving body _{1 [x i, y i]} , identifier Add _i, receives a Hello packet that includes the received signal strength RSSIi and connections N_CN_i from the cluster configuration unit 12, the received Hello packet It is transmitted to the control device 50 via the AP 20 (or LTE base station 30).

The wireless module 112 receives a beacon from another mobile body before the mobile body 1 forms a cluster, and detects the received signal strength RSSI _BC when the beacon is received. Then, the wireless module 112 outputs the beacon and the received signal strength RSSI _BC to the cluster forming means 12. When the radio module 112 receives a beacon including the identifier of the mobile body 1 from the cluster forming means 12, the radio module 112 transmits the received beacon to another mobile body.

Further, the radio module 112 receives the channel CHN_max from the cluster forming means 12 when the moving body 1 forms a cluster. Then, when the wireless module 112 receives the cluster head declaration DEC_CH from the cluster configuration means 12, the radio module 112 transmits the received cluster head declaration DEC_CH to another mobile body on the channel CHN_max.

Further, when the wireless module 112 receives the cluster head declaration DEC_CH from another mobile on the channel CHN_max, the wireless module 112 outputs the received cluster head declaration DEC_CH to the cluster configuration means 12. When the wireless module 112 receives the cluster member information IF_CM from another mobile on the channel CHN_max, the wireless module 112 outputs the received cluster member information IF_CM to the cluster configuration means 12. When the wireless module 112 receives the cluster member information IF_CM (information indicating that the mobile body 1 is a cluster member) from the cluster configuration means 12, the wireless module 112 transmits the received cluster member information IF_CM to another mobile unit via the channel CHN_max. ..

Further, when the wireless module 112 receives data other than the data of the mobile body 1 from the data acquisition means 13, the wireless module 112 transmits the received data to another mobile body via the channel CHN_max.

Further, when the mobile body 1 is a cluster member CM, the wireless module 112 receives the data of the mobile body 1 from the mobile body of the cluster head CH on the channel CHN_max, and outputs the received data to the data acquisition means 13.

The cluster configuration means 12 receives the beacon and the received signal strength RSSI _BC (= received signal strength RSSI _mi- mj_i included in the correspondence table TBL3 of FIG. 5) from the radio module 112. Then, the cluster configuration means 12, the received signal strength RSSI _BC is equal to or greater than or equal to the threshold value, when the received signal strength RSSI _BC is smaller than the threshold, discards the beacon having a received signal strength RSSI _BC.

On the other hand, the cluster configuration means 12, when the received signal strength RSSI _BC is equal to or greater than the threshold, the received identifier Add _i contained in the beacon, to detect the position _{[x i, y} i] and the received signal strength RSSI _BC. The cluster configuration means 12 performs this process for all beacons received from the wireless module 112, counts the number of beacons having a received signal strength RSSI _BC equal to or higher than the threshold value, and obtains the number of connections N_CN_i.

Further, the cluster forming means 12 receives the received signal strength RSSI _BS (= received signal strength RSSI _AP- m_i included in the correspondence table TBL3 of FIG. 5) from the wireless module 111.

Further, the cluster forming means 12 detects the position [x ₁ , y ₁ ] of the moving body 1 by, for example, GPS (Global Positioning System).

Then, the cluster configuration means 12, the position of the moving body _{1 [x i, y i]} , identifier Add _i, the received signal strength _{RSSI mi-mj} _i, Hello packet that includes the received signal strength _{RSSI AP-m} _i and connections N_CN_i Is generated, and the generated Hello packet is output to the radio module 111.

Cluster configuration unit 12 receives the control information IF_CTL from the wireless module 111, the control information selected from IF_CTL information IF_CH, channel CHN_max, detects a plurality of identifiers _Add i _CM_S. Then, the cluster configuration means 12 outputs the channel CHN_max to the wireless module 112.

Also, the cluster configuration means 12 based on the selection information IF_CH, generates a cluster head declaration DEC_CH, a plurality of moving bodies each having a plurality of identifiers _Add i _CM_S cluster head declaration DEC_CH that the generated via the wireless module 112 Send to. Then, the cluster configuration means 12 outputs the selection information IF_CH to the data acquisition means 13.

Further, when the cluster configuration means 12 receives the cluster head declaration DEC_CH received from another mobile body from the wireless module 112, it generates cluster member information IF_CM and outputs the cluster member information IF_CM to the data acquisition means 13 and the wireless module 112.

The data acquisition means 13 recognizes that the moving body 1 is the cluster head CH based on the selection information IF_CH received from the cluster configuration means 12. Then, the data acquisition means 13 transmits a data acquisition request for the cluster head CH and the cluster member CM to the information server 60 via the wireless module 111.

Further, the data acquisition means 13 recognizes that the moving body 1 is a cluster member CM based on the cluster member information IF_CM received from the cluster configuration means 12. Then, the data acquisition means 13 transmits a data acquisition request of the mobile body 1 to the mobile body of the cluster head CH via the wireless module 112.

When the data acquisition means 13 receives the data of the cluster head CH and the cluster member CM from the wireless module 111, the data acquisition means 13 extracts the data of the mobile body 1 and acquires the data of the mobile body 1. Then, the data acquisition means 13 outputs the data of the other mobile body to the wireless module 112.

Each of the moving bodies 2 to 10 shown in FIG. 1 has the same configuration as that of the moving body 1 shown in FIG.

FIG. 10 is a flowchart for explaining the operation of the communication system 100 shown in FIG.

With reference to FIG. 10, when the operation of the communication system 100 is started, the control device 50 determines whether or not the cycle T has arrived by the built-in timer (step S1). Then, when it is determined that the period T has arrived, the control device 50 selects the candidate cluster head CH_CAD having the maximum accommodation efficiency EFF_hus, and controls the selected candidate cluster head CH_CAD to form a cluster (step). S2).

The selected candidate cluster heads CH_CAD among the moving bodies 1 to 10 form a cluster according to the control from the control device 50 (step S3).

Then, the cluster head CH accesses the information server 60 via the AP20 (or LTE base station 30) and the network 40 by the wireless module (wide area) 111, and receives its own data and the data of the cluster member CM from the information server 60. Download (step S4). That is, the cluster head CH downloads data from the information server 60 by the wireless module (wide area) 111.

After that, the cluster head CH acquires its own data from the downloaded data, and transmits the data of the cluster member CM to the cluster member CM on the channel CHN_max by the wireless module (near area) 112 (step S5). That is, the cluster head CH transmits data to the cluster member CM by the wireless module (near range) 112.

In this way, the cluster head CH and the cluster member CM acquire data by a hierarchical network using the wireless module (wide area) 111 and the wireless module (near area) 112.

Then, after step S5, the series of operations shifts to step S1, and the above-mentioned steps S1 to S5 are repeatedly executed. As a result, the cluster head CH is selected, the cluster is configured by the selected cluster head CH, and the data is downloaded from the information server 60 periodically.

FIG. 11 is a flowchart for explaining the detailed operation of step S2 of FIG. With reference to FIG. 11, when it is determined in step S1 of FIG. 10 that the period T has arrived, the calculation means 504 of the control device 50 calculates the accommodation efficiency EFF_hus of the candidate cluster head CH_CAD (step S21). The calculated accommodation efficiency EFF_hus is output to the selection means 503.

The selection means 503 receives the accommodation efficiency EFF_hus from the calculation means 504, and ranks the received accommodation efficiency EFF_hus (step S22). Then, the selection means 503 selects the candidate cluster head CH_CAD having the maximum accommodation efficiency (step S23), and outputs the selected candidate cluster head CH_CAD to the control means 502.

The control means 502 receives the selected candidate cluster head CH_CAD_S from the selection means 503, and controls the candidate cluster head CH_CAD_S so that the received candidate cluster head CH_CAD_S constitutes a cluster (step S24).

Then, the control means 502 updates the set of the candidate cluster head CH_CAD and the candidate cluster member CM_CAD to be clustered (step S25).

Then, the control means 502 determines whether or not the selection of the candidate cluster head CH_CAD is completed (step S26). The control means 502 determines that the selection of the candidate cluster head CH_CAD is completed when all of the mobile bodies 1 to 10 are clustered or when the available radio resource amount A_COR becomes zero or less, and the mobile body 1 When all of 10 to 10 are not clustered, or when the available radio resource amount A_COR is larger than zero, it is determined that the selection of the candidate cluster head CH_CAD is not completed.

When it is determined in step S26 that the selection of the candidate cluster head CH_CAD is not completed, the series of operations proceeds to step S21 until it is determined in step S26 that the selection of the candidate cluster head CH_CAD is not completed. ~ Step S26 is repeatedly executed. Then, when it is determined in step S26 that the selection of the candidate cluster head CH_CAD is completed, the series of operations shifts to step S3 of FIG.

FIG. 12 is a flowchart for explaining the detailed operation of step S21 of FIG.

With reference to FIG. 12, when it is determined in step S1 of FIG. 10 that the period T has arrived, the calculation means 504 of the control device 50 sets h = 1 (step S211). In addition, h = 1 to H, and H is the total number of candidate cluster heads CH_CAD.

After step S211 the arithmetic means 50 accepts the data capacity Dc, the data download cycle length Td, the number of proximity moving bodies N_CN, and the communication rate R _{CH_CAD-CM_CAD} between the candidate cluster head CH_CAD and the candidate cluster member CM_CAD ( Step S212).

Then, the calculation means 504 detects the maximum available radio resource amount from the correspondence table TBL2, determines the channel CHN corresponding to the detected maximum available radio resource amount as the channel CHN_max, and determines the maximum available radio resource amount. Set the amount of radio resources in A_COR_initial. That is, the calculation means 504 determines the channel CHN_max and sets A_COR_initial = maximum available radio resource amount (step S213). In step S213, the calculation means 504 may determine any channel CHNq in the correspondence table TBL2 as channel CHN_max, and set the amount of available radio resources corresponding to any channel CHNq to A_COR_initial.

After that, the calculation means 504 sets the accommodation number N_hus = 0 (step S214), sets the total radio resource amount CM_COR_total = 0 (step S215), and sets k = 1 (step S216). In addition, k = 1 to K, where K is the total number of candidate cluster members CM_CAD.

After step S216, the calculation means 504 calculates COR (k) = Dc / (R _{CH_CAD-CM_CAD (k)} · Td) (step S217).

Then, the calculation means 504 adds the radio resource amount COR (k) calculated in step S217 to the total radio resource amount CM_COR_total, and sets the addition result as the total radio resource amount CM_COR_total (step S218).

After that, the calculation means 504 calculates the available radio resource amount A_COR by the equation (3) (step S219).

Then, the calculation means 504 determines whether or not the available radio resource amount A_COR is larger than zero (= 0) (step S220).

When it is determined in step S220 that the available radio resource amount A_COR is larger than zero (= 0), the calculation means 504 increments the accommodation number N_hus by "1" (step S221). Then, the calculation means 504 sets k = k + 1 (step S222).

After that, the series of operations proceeds to step S217, and steps S217 to S222 are repeatedly executed until it is determined in step S220 that the available radio resource amount A_COR is zero (= 0) or less.

Then, in step S220, when it is determined that the available radio resource amount A_COR is zero (= 0) or less, the arithmetic means 504 sets the base station (AP20 or LTE base station 30) and the candidate cluster head CH_CAD. The accommodation efficiency EFF_hus is calculated by dividing the accommodation number N_hus by the amount of radio resources in between (step S223).

After that, the calculation means 504 determines whether or not h = H (step S224). When it is determined in step S224 that h = H, the calculation means 504 sets h = h + 1 (step S225). Then, the series of operations proceeds to step S212, and steps S212 to S225 are repeatedly executed until it is determined in step S224 that h = H. Then, when it is determined in step S224 that h = H, the series of operations shifts to step S22 in FIG.

Steps S217 to S222 are steps in which the number of accommodated N_hus is counted up until the available radio resource amount A_COR becomes zero (= 0) or less. Then, in step S220, the sum (=) from the radio resource amount COR (1) of the first candidate cluster member CM_CAD (1) to the radio resource amount COR (k + 1) of the k + 1th candidate cluster member CM_CAD (k + 1). When it is determined that the available radio resource amount A_COR when CM_COR_total) is subtracted from A_COR_intial is zero (= 0) or less, the radio resource amount COR (1) of the first candidate cluster member CM_CAD (1). ) To the kth candidate cluster member CM_CAD (k) to the radio resource amount COR (k) (= CM_COR_total) is subtracted from A_COR_intial, the number N_hus that can be accommodated can be accommodated by one candidate cluster head CH_CAD. The final capacity is N_hus.

When steps S217 to S222 are repeatedly executed, preferably, as shown in FIG. 8B, the radio resource amount COR (k) is arranged in ascending order and steps S217 to S222 are repeatedly executed. As a result, the final number of accommodated N_hus can be increased, and more candidate cluster member CM_CAD can be accommodated in the cluster as a cluster member CM.

Then, in step S220, repeating steps S217 to S222 until it is determined that the available radio resource amount A_COR is zero (= 0) or less is a candidate cluster head that is a candidate for the cluster head CH. It corresponds to calculating the accommodating number N_hus, which is the number of cluster member CMs accommodating by CH_CAD.

Further, in step S224, repeating step S223 until it is determined that h = H means that the candidate cluster head CH_CAD can be used for wireless communication with the base station (AP20 or LTE base station 30). The first calculation for calculating the accommodation efficiency EFF_hus of the cluster member CM in the candidate cluster head CH_CAD by dividing the accommodation number N_hus by the radio resource amount of 1 (“radio resource amount between AP and CH_CAD” in step S223 of FIG. 12). This corresponds to executing the process for a plurality of candidate cluster heads (H candidate cluster heads CH_CAD).

Further, in step S213, setting A_COR_initial = the maximum amount of available radio resources means that "the amount of free radio resources in one channel (= the amount of available radio resources in FIG. 4) is a candidate cluster head CH_CAD. Is the maximum amount of wireless resources that can be used for wireless communication with the cluster member CM. "

Further, in step S220, the cluster member (= candidate cluster member CM_CAD) acquires that the cluster member (= candidate cluster member CM_CAD) repeatedly executes step S217 until it is determined that the available radio resource amount A_COR is not larger than zero (= 0). A plurality of cluster members perform a second arithmetic process for calculating the second radio resource amount COR (k) by dividing the data capacity Dc of the data by the communication rate between the candidate cluster head and the cluster member (= candidate cluster member CM_CAD). (= Multiple candidate cluster members CM_CAD) is equivalent to execution.

Further, in step S220, repeating step S221 until it is determined that the available radio resource amount A_COR is not larger than zero (= 0) may be a plurality of cluster members (= a plurality of candidate cluster members CM_CAD). The number of second radio resource amounts COR (k) in which the sum total CM_COR_total is smaller than the maximum radio resource amount A_COR_initial based on the plurality of second radio resource amounts (= plurality of COR (k)) calculated for). Is calculated as the number of accommodated N_hus.

Further, repeating steps S220 and S221 until it is determined in step S220 that the amount of available radio resources A_COR is not greater than zero (= 0) is a second arithmetic process for one cluster member. Is executed to calculate the second radio resource amount COR (k), and the calculated second radio resource amount COR (k) is subtracted from the maximum radio resource amount A_COR_initial. When the subtraction result A_COR is positive, the number of accommodations is accommodated. It corresponds to repeatedly executing the process of increasing the count value of N_hus by "1" and calculating the count value of the number of N_hus accommodated when the subtraction result A_COR becomes zero or less as the number of accommodated items.

FIG. 13 is a flowchart for explaining the detailed operation of step S3 of FIG.

With reference to FIG. 13, after step S2 of FIG. 10, the candidate cluster head CH_CAD_S selected as the cluster head CH receives the control information IF_CTL from the control device 50 (step S31).

The candidate cluster head CH_CAD_S is, (a plurality of identifiers of a plurality of candidate cluster members CM_CAD when = candidate cluster head CH_CAD_S is selected as the cluster head) control information selected from IF_CTL information IF_CH, channel CHN_max and a plurality of identifiers _Add i Is detected (step S32).

After that, the candidate cluster head CH_CAD_S generates the cluster head declaration DEC_CH based on the selection information IF_CH (step S33), and the generated cluster head declaration DEC_CH is used as the candidate cluster member CM_CAD_S (= candidate cluster head CH_CAD_S is the cluster head) on the channel CHN_max. Is transmitted to a plurality of candidate cluster members CM_CAD) when selected as (step S34).

Subsequently, the candidate cluster member CM_CAD_S (= a plurality of candidate cluster member CM_CAD when the candidate cluster head CH_CAD_S is selected as the cluster head) receives the cluster head declaration DEC_CH on the channel CHN_max (step S35).

Then, the candidate cluster member CM_CAD_S (= a plurality of candidate cluster member CM_CAD when the candidate cluster head CH_CAD_S is selected as the cluster head) generates the cluster member information IF_CM, and the generated cluster member information IF_CM is a candidate in the channel CHN_max. It is transmitted to the cluster head CH_CAD_S (step S36).

Then, the candidate cluster head CH_CAD_S receives the cluster member information IF_CM on the channel CHN_max (step S37). As a result, a cluster is formed, and the series of operations shifts to step S4 of FIG.

FIG. 14 is a flowchart for explaining the detailed operation of step S4 of FIG.

With reference to FIG. 14, after step S3 of FIG. 10, the cluster member CM transmits a data acquisition request to the cluster head CH on the channel CHN_max (step S41).

Then, the cluster head CH receives the data acquisition request on the channel CHN_max (step S42).

Then, the cluster head CH accesses the information server 60 via the base station (AP20 or LTE base station 30), and downloads the data of the cluster head CH and the cluster member CM from the information server 60 (step S43). After that, the series of operations proceeds to step S5 of FIG.

In the embodiment of the present invention, the operation of the control device 50 may be realized by software. In this case, the control device 50 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). Then, the ROM stores a program Prog_A including each step of the flowchart shown in FIG. 11 (including the flowchart shown in FIG. 12).

The CPU reads the program Prog_A from the ROM, executes the read program Prog_A, selects the cluster head CH from the candidate cluster head CH_CAD so that the accommodation efficiency EFF_hus is maximized, and the selected cluster head CH sets the cluster. Control to configure. The RAM temporarily stores the radio resource amount COR (k), the total radio resource amount CM_COR_total, the maximum radio resource amount A_COR_initial, the number of accommodations N_hus, and the accommodation efficiency EFF_hus.

Further, the program Prog_A may be recorded on a recording medium such as a CD or DVD and distributed. When the recording medium on which the program Prog_A is recorded is attached to the computer, the computer reads and executes the program Prog_A from the recording medium, selects the cluster head CH from the candidate cluster head CH_CAD so as to maximize the accommodation efficiency EFF_hus, and selects the cluster head CH from the candidate cluster head CH_CAD. The selected cluster head CH is controlled to form a cluster.

Therefore, the recording medium on which the program Prog_A is recorded is a computer-readable recording medium.

In the embodiment of the present invention, the total data capacity D_total of the data of the candidate cluster head CH_CAD and the data of the candidate cluster member CM_CAD may be calculated by the method described below.

FIG. 15 is a diagram for explaining a method of obtaining the total data capacity D_total. With reference to FIG. 15, the radius of the circle indicating each of the data D_CH and D_CM is r, the center of the data D_CH is the point A, and the intersection of the data D_CH and D_CM is the points B and C. Let the angle ∠BAC be θ. Arc BC, the area _{S FS} fan-shaped formed by the sides AB and side AC is expressed by the following equation.

Then, the length h of the perpendicular line drawn from the point A to the line segment BC is expressed by the following equation.

Assuming that the intersection of the line segment BC and the perpendicular line from the point A is the point D, the length of the line segment CD is represented by rsin (θ / 2), so that the points A, C, and D are the vertices. The area _STG1 of the triangle is expressed by the following equation.

Then, the area _STG of the triangle having the points A, B, and C as vertices is expressed by the following equation.

As a result, the area _{S ARC} of the portion surrounded by the line segment BC and the arc BC _is equal to S FS _{-S TG,} represented by the following equation.

Therefore, the area _{S DUP} of the overlapped portion of the data D_CH and data D_CM is because it is 2 × _{S ARC,} represented by the following equation.

Since each data capacity of the data D_CH and D_CM is Dc, the data capacity D _DUP of the overlapping portion between the data D_CH and the data D_CM is expressed by the following equation.

The total data capacity D_total when the two data D_CH and D_CM are collectively downloaded from the information server 60 is the data of the overlapping portion of the data D_CH and the data D_CM from the sum of the data capacities of the two data D_CH and D_CM 2 × Dc. It is obtained by subtracting the capacity D _DUP . Therefore, the total data capacity D_total is expressed by the following equation.

As shown in FIG. 6, the data of the cluster head CH (represented by the circle CIR1) partially overlaps with the data of the cluster member CM (represented by the circle CIR2 or the circle CIR3). Therefore, assuming that the total number of data in the cluster head CH and data in the cluster member CM is m (m is an integer of 2 or more), the total data capacity D_total (m) of m data is expressed by the following equation. To.

The overlapping portion of the data of the cluster head CH and the m-1 data of the m-1 cluster member CM is m-1, and one D _DUP (p) is the data capacity of one overlapping portion. since representative of, by subtracting the sum of the data capacity of the m-1 pieces of the overlapped portion from the m × _{D C,} the total data capacity D_total (m) is obtained.

The distance (= 2h) between the cluster head CH and the cluster member CM is calculated from the position of the cluster head CH and the position of the cluster member CM, h is calculated from the distance (= 2h), and h and the radius r (= known (for example, for example)). Since the angle θ can be calculated from the cosine theorem (cos (θ / 2) = h / r) from 10m)), the total data capacity D_total (m) can be calculated. Then, if the overlapping portion of the two data D_CH and D_CM becomes large, the D _DUP (p) of the equation (12) becomes large, so that the total data capacity D_total (m) becomes small. On the other hand, if the overlapping portion of the two data D_CH and D_CM becomes smaller, the D _DUP (p) of the equation (12) becomes smaller, so that the total data capacity D_total (m) becomes larger.

FIG. 16 is a diagram for explaining another method for obtaining the total data capacity D_total. With reference to FIG. 16, a mesh is provided in the arrangement area of the two data D_CH and D_CM, and the total area of the mesh (the mesh represented by the diagonal line) in which the two data D_CH and D_CM are arranged is obtained. Then, the total data capacity D_total may be obtained by D_total = Dc × (total area) / πr ² .

In this case, if the overlapping portion of the two data D_CH and D_CM becomes large, the total area becomes small, so that the total data capacity D_total becomes small. On the other hand, if the overlapping portion of the two data D_CH and D_CM becomes smaller, the total area becomes larger, so that the total data capacity D_total becomes larger. Therefore, the total data capacity D_total (m) of m pieces of data may be calculated by the method shown in FIG.
The total data capacity D_total (m) calculated by the method shown in FIG. 15 or FIG. 16 is used to calculate the “amount of radio resources between AP and CH_CAD” in step S223 of FIG. Then, the "amount of radio resources between AP and CH_CAD" is calculated by dividing the total data capacity D_total (m) by the communication rate R _{AP-CH_CAD} between _{AP and CH_CAD} .

According to the above-described embodiment, the control device according to the embodiment of the present invention selects a cluster head from a plurality of moving bodies, and periodically controls the cluster head so that the selected cluster head constitutes a cluster. It is a control device that
The number of cluster members that can be accommodated by the candidate cluster head, which is a candidate for the cluster head, is calculated, and the number of accommodations is calculated by the amount of the first radio resource that the candidate cluster head can use for wireless communication with the base station. An arithmetic means for executing the first arithmetic processing for calculating the accommodation efficiency of cluster members in the candidate cluster heads for a plurality of candidate cluster heads by dividing them.
A selection means for detecting the maximum accommodating efficiency from a plurality of accommodating efficiencies calculated for a plurality of candidate cluster heads and selecting the candidate cluster head having the detected maximum accommodating efficiency as a cluster head.
It suffices to provide a control means for controlling the candidate cluster heads selected by the selection means so as to form a cluster.

Further, the communication system according to the embodiment of the present invention includes a control device according to the embodiment of the present invention, a plurality of mobile bodies constituting a cluster, and an information server that holds data downloaded by the plurality of mobile bodies. ,
Multiple moving objects
It consists of candidate cluster heads and includes cluster heads that form a cluster under the control of a control device and cluster members that perform wireless communication with the cluster heads.
The cluster head may download the data of the cluster head and the cluster member from the information server and send the data of the cluster member to the cluster member.

Further, the program according to the embodiment of the present invention is a program for selecting a cluster head from a plurality of moving bodies and causing a computer to periodically control the cluster head so that the selected cluster head constitutes a cluster. And
The calculation means calculates the number of cluster members that can be accommodated by the candidate cluster head, which is a candidate for the cluster head, and the amount of the first radio resource that the candidate cluster head can use for wireless communication with the base station. The first step of executing the first arithmetic processing for calculating the accommodation efficiency of the cluster members in the candidate cluster heads by dividing the number of accommodations for a plurality of candidate cluster heads, and
A second step in which the selection means detects the maximum accommodation efficiency from the plurality of accommodation efficiencies calculated for the plurality of candidate cluster heads and selects the candidate cluster head having the detected maximum accommodation efficiency as the cluster head.
The control means may cause the computer to perform a third step of controlling the candidate cluster heads selected by the selection means to form a cluster.

It should be considered that the embodiments disclosed this time are exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the embodiment described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

The present invention applies to control devices, communication systems equipped with them, programs and computer-readable recording media on which programs are recorded.

1-10 mobiles, 11,501 communication means, 12 cluster configuration means, 13 data acquisition means, 20 APs, 30 LTE base stations, 40 networks, 50 controllers, 60 information servers, 100 communication systems, 111 wireless modules (wide area) ) 112 wireless module (near range), 502 control means, 503 selection means, 504 arithmetic means, 505 search means, 506 database.

Claims (16)

A control device that selects a cluster head from a plurality of moving bodies and periodically controls the cluster head so that the selected cluster head constitutes a cluster.
The number of cluster members that can be accommodated by the candidate cluster head, which is a candidate for the cluster head, is calculated, and the amount of the first radio resource that the candidate cluster head can use for wireless communication with the base station is used to accommodate the candidate cluster head. A calculation means for executing a first calculation process for calculating the accommodation efficiency of the cluster members in the candidate cluster heads by dividing the number of the candidate cluster heads for the plurality of candidate cluster heads.
A selection means for detecting the maximum accommodating efficiency from a plurality of accommodating efficiencies calculated for the plurality of candidate cluster heads and selecting the candidate cluster head having the detected maximum accommodating efficiency as a cluster head.
A control device including a control means for controlling a candidate cluster head selected by the selection means so as to form a cluster. The amount of wireless resources available in one channel is defined as the maximum amount of wireless resources that the candidate cluster head can use for wireless communication with the cluster members.
The calculation means performs a second calculation process for calculating the amount of the second radio resource by dividing the data capacity of the data acquired by the cluster member by the communication rate between the candidate cluster head and the cluster member. The number of the second radio resources whose sum is smaller than the maximum radio resource amount based on the plurality of second radio resource amounts calculated for the members and calculated for the plurality of cluster members is the number of accommodated numbers. The control device according to claim 1, wherein the control device is calculated as. When the calculation means executes the second calculation process for one cluster member to calculate the second radio resource amount, the calculated second radio resource amount is subtracted from the maximum radio resource amount and subtracted. When the result is positive, the process of increasing the count value of the number of accommodations by "1" is repeatedly executed, and the count value of the number of accommodations when the subtraction result becomes zero or less is calculated as the number of accommodations. The control device according to claim 2. Further equipped with a search means for searching for the amount of free radio resources for each of a plurality of channels.
The calculation means calculates the number of accommodations by using one free radio resource amount selected from a plurality of free radio resource amounts corresponding to the plurality of channels as the maximum radio resource amount. The control device according to claim 2 or 3. The control device according to claim 4, wherein the calculation means calculates the number of accommodations by using the maximum free radio resource amount among the plurality of free radio resource amounts as the maximum radio resource amount. The calculation means according to claim 4, wherein the accommodating number is calculated by using one vacant radio resource amount arbitrarily selected from the plurality of vacant radio resource amounts as the maximum radio resource amount. Control device. The calculation means represents the data capacity of data to be downloaded by each of a plurality of moving bodies constituting the cluster by the area of a circle having a first radius centered on the position of the candidate cluster head, and represents the data capacity of the candidate cluster head. When the total data capacity of the data downloaded from the information server by the candidate cluster head is represented by the area of a circle having a second radius that is an integral multiple of the first radius and is centered on the position, the total data capacity is calculated. The control device according to any one of claims 1 to 6, wherein the amount of the first radio resource is calculated by dividing by the communication rate between the candidate cluster head and the base station. The control device according to any one of claims 1 to 7.
Multiple moving objects that make up a cluster,
It is provided with an information server that holds data downloaded by the plurality of moving objects.
The plurality of moving bodies
A cluster head composed of the candidate cluster heads and forming a cluster under the control of the control device,
Including the cluster head and a cluster member that performs wireless communication
The cluster head is a communication system that downloads data of the cluster head and the cluster member from the information server and transmits the data of the cluster member to the cluster member. A program for selecting a cluster head from a plurality of moving bodies and causing a computer to periodically control the cluster head so that the selected cluster head constitutes a cluster.
The computing means calculates the number of cluster members that can be accommodated by the candidate cluster head that is a candidate for the cluster head, and the candidate cluster head is a first wireless resource that can be used for wireless communication with the base station. A first step of executing a first arithmetic process for calculating the accommodation efficiency of the cluster members in the candidate cluster head by dividing the number of accommodations by the quantity for the plurality of candidate cluster heads.
The second step is that the selection means detects the maximum accommodating efficiency from the plurality of accommodating efficiencies calculated for the plurality of candidate cluster heads, and selects the candidate cluster head having the detected maximum accommodating efficiency as the cluster head. ,
A program for causing a computer to perform a third step in which the control means controls a candidate cluster head selected by the selection means to form a cluster. The amount of wireless resources available in one channel is defined as the maximum amount of wireless resources that the candidate cluster head can use for wireless communication with the cluster members.
In the first step, the calculation means divides the data capacity of the data acquired by the cluster member by the communication rate between the candidate cluster head and the cluster member to calculate the amount of the second radio resource. Is executed for a plurality of cluster members, and the total sum is smaller than the maximum radio resource amount based on the plurality of second radio resource amounts calculated for the plurality of cluster members. The program for causing the computer according to claim 9, which calculates the number of quantities as the accommodation quantity. When the calculation means executes the second calculation process for one cluster member to calculate the second radio resource amount in the first step, the calculated second radio resource amount is maximized. When the subtraction result subtracted from the amount of radio resources is positive, the process of increasing the count value of the accommodation number by "1" is repeatedly executed, and the count value of the accommodation number when the subtraction result becomes zero or less is calculated. The program for being executed by the computer according to claim 10, which is calculated as the number of stored items. The search means causes the computer to further perform a fourth step of searching for the amount of free radio resources for each of the plurality of channels.
In the first step, the calculation means uses one free radio resource amount selected from a plurality of free radio resource amounts corresponding to the plurality of channels as the maximum radio resource amount. The program for causing the computer according to claim 10 or 11, to calculate the number of stored pieces. The calculation means claims that in the first step, the accommodation number is calculated by using the maximum free radio resource amount among the plurality of free radio resource amounts as the maximum radio resource amount. A program for causing the computer according to 12. In the first step, the calculation means calculates the number of accommodations by using one free radio resource amount arbitrarily selected from the plurality of free radio resource amounts as the maximum radio resource amount. , The program for causing the computer according to claim 12 to execute. In the first step, the calculation means determines the data capacity of the data downloaded by each of the plurality of moving bodies constituting the cluster by the area of the circle having the first radius centered on the position of the candidate cluster head. The total data capacity of the data downloaded from the information server by the candidate cluster head is represented by the area of a circle having a second radius that is an integral multiple of the first radius and is centered on the position of the candidate cluster head. The computer according to any one of claims 9 to 14, wherein the total data capacity is divided by the communication rate between the candidate cluster head and the base station to calculate the amount of the first radio resource. A program to run. A computer-readable recording medium on which the program according to any one of claims 9 to 15 is recorded.

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