JP6597111B2 - COMMUNICATION CONTROL PROGRAM, COMMUNICATION CONTROL METHOD, AND COMMUNICATION CONTROL DEVICE - Google Patents

Description

  The present invention relates to a communication control program, a communication control method, and a communication control apparatus.

  Conventionally, a short wave having a frequency of 3 MHz to 30 MHz and a wavelength of 10 m to 100 m is used for communication between a land base station and a ship such as a fishing boat on the sea. Communication using short waves is performed using reflection by the ionosphere. For example, when confirming the safety of a fishing boat, when a base station such as a fishing port transmits a message, the message reflected by the ionosphere is received by a radio device mounted on the ship. Thereafter, when the wireless device transmits a response message for the message, the response message reflected by the ionosphere is received by the base station. In this way, the base station confirms the safety of the fishing boat.

JP-A-10-294690

  However, short-wave communication is affected by natural phenomena because the bandwidth of the frequency that can be occupied is narrow and the reflection of the ionosphere is used. For this reason, when the land base station sends a telegram and when the ship sends a response, the ionosphere may have a different impact range, and even if a telegram from the base station arrives at the ship, The response may not reach the base station. Therefore, until the response is received, the base station may retransmit the message to the ship that has received the message, and unnecessary communication occurs. This problem is not limited to ships, but there is a similar problem in areas where communication is difficult, such as deserts, mountainous areas, and depopulated areas. For example, there is a similar problem when confirming the safety of people or livestock in such difficult communication areas.

  In one aspect, an object is to provide a communication control program, a communication control method, and a communication control apparatus that can collect a large amount of response information with a small amount of communication.

  In the first plan, the communication control program causes the computer to execute a process of transmitting a response transmission request that causes the ship to respond with at least ship identification information. When the communication control program receives a response to the response transmission request from the ship to the computer, the other ship mounted on the ship transmits to at least one or more of the ship identification information included in the response. A process for transmitting a command for transmitting the identification information of the other ship is executed with reference to a storage unit that stores a response to the response transmission request. The communication control program causes a computer to execute a process of receiving information on the other ship from the at least one ship.

  According to one embodiment, a large amount of response information can be collected with a small amount of communication.

FIG. 1 is a functional block diagram illustrating the configuration of the system according to the first embodiment. FIG. 2 is an explanatory diagram showing an example of a message format. FIG. 3 is a diagram illustrating an example of an ionosphere map. FIG. 4 is a diagram illustrating an example of area information. FIG. 5 is a diagram illustrating an example of information stored in the reception status DB. FIG. 6 is a diagram illustrating an example of the sea information map. FIG. 7 is a sequence diagram showing the flow of processing. FIG. 8 is a diagram for explaining a format example of a message. FIG. 9 is a diagram illustrating a transmission example of a broadcast message from the base station. FIG. 10 is a diagram illustrating a transmission example of an ACK message from each ship. FIG. 11 is a diagram illustrating an ACK proxy example. FIG. 12 is an explanatory diagram illustrating an example of a computer that executes a communication control program.

  Hereinafter, embodiments of a communication control program, a communication control method, and a communication control device according to the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

[overall structure]
FIG. 1 is a functional block diagram illustrating the configuration of the system according to the first embodiment. The management system illustrated in FIG. 1 includes a management server 2, a plurality of ships 10, and a plurality of base stations 100. Note that the number of ships and base stations is not limited and can be arbitrarily changed.

  The communication terminals 11 and the plurality of base stations 100 included in each ship are connected to each other so as to be able to communicate with each other by short-wave waves using the reflection of the ionosphere L. Further, the base stations 100 and the management server 2 are connected via a network N so that they can communicate with each other. For such a network N, any kind of communication network such as the Internet (Internet), LAN (Local Area Network), VPN (Virtual Private Network), etc. can be adopted regardless of wired or wireless.

  Here, the system according to the first embodiment will be described. In the following description, a fishing boat will be described as an example of a ship. In the management system, for example, the communication terminal 11 is installed in a ship 10 such as a fishing boat that operates in the ocean, at least 200 nautical miles away from the coast. Each base station 100 is installed in a fishery radio association or the like provided in the vicinity of a fishing port. In addition, the management system is provided with a management server 2 on a cloud such as a data center, for example, and is connected to each base station 100 via a network N. Moreover, in the example of FIG. 1, a certain base station is installed in Hokkaido, for example, and another base station is installed in Okinawa, for example. In addition, in FIG. 1, although the case where the base station 100 was installed in the fishery radio association was shown, it is not limited to this. Base station 100 may be installed alone or in another fishery radio association.

  For example, each base station 100 may be assigned a marine area to be managed. Each base station 100 is also installed in a coastal station or the like in the Fisheries Radio Association, and can also hold a list of ship IDs that identify ships to be managed. The ship ID is an example of ship identification information.

  The management server 2 periodically collects the position information of the fishing boat via each base station 100 and generates a position map indicating the position of each fishing boat. In addition, the management server 2 collects the radio wave intensity when radio communication is performed between the fishing boats via the base stations 100, and the radio wave intensity between positions during radio communication using the ionosphere at sea. An ionosphere map showing is generated. For example, the management server 2 generates an ionosphere map for each combination of season, frequency, and time zone. The management server 2 can generate an ionosphere map in any combination such as an ionosphere map for each season and an ionosphere map for each combination of season and frequency.

  The management server 2 stores the position map and ionosphere map on a disk that can be shared with each base station 100. By doing in this way, each base station 100 can read a position map and an ionosphere map, and can preserve | save it in an own apparatus. The management server 2 updates the position map and ionosphere map each time information is received from the base station 100.

  Note that examples of situations in which reception is difficult include interference due to a fading phenomenon or the like, and occurrence of some errors. The fading phenomenon includes coherent fading, polarization fading, jump fading, absorptive fading, selective fading, and K-type fading. Coherent fading is fading caused by a path difference when there are a plurality of paths through which radio communication radio waves reach. Polarization fading is fading that occurs when the plane of polarization changes when radio waves are reflected on the ionosphere. Jumping fading is fading that occurs when radio waves are reflected by the ionosphere or penetrate through the ionosphere due to variations in the density of the ionosphere. Selective fading is fading that occurs when a band and an attenuation amount that are attenuated by a frequency selective medium in a radio wave transmission path vary with time. K-type fading is fading that occurs when the equivalent radius coefficient (K) of the earth fluctuates due to weather conditions or the like, and the bending of the radio wave transmission path fluctuates.

[Function configuration]
Next, functional configurations of the communication terminal 11 and each base station 100 included in the ship 10 illustrated in FIG. 1 will be described.

(Functional configuration of communication terminal 11)
As illustrated in FIG. 1, the communication terminal 11 includes a wireless unit 12, a storage unit 13, and a control unit 14, and is installed on the ship 10. Note that the communication terminal 11 may include various functional units included in known computers, for example, functional units such as various input devices and audio output devices, in addition to the functional units illustrated in FIG. 1. As an example of the communication terminal 11, a tablet terminal, a portable personal computer, or the like can be employed. The communication terminal 11 is a transmitter that transmits management information such as position information and radio wave intensity using short waves.

  The radio unit 12 is realized by, for example, a medium wave to short wave or ultra high frequency band radio device. The wireless unit 12 is wirelessly connected to any one or more of the plurality of base stations 100 via the ionosphere L, and performs communication of information with the management server 2 via the base station 100 and the network N. Interface. The radio unit 12 transmits the management information input from the control unit 14 toward the base station 100. The wireless unit 12 receives radio waves transmitted from the base station 100 and acquires various types of information.

  The radio unit 12 is one of at least one of a 2 MHz band, a 4 MHz band, an 8 MHz band, a 12 MHz band, a 16 MHz band, a 30 MHz band, and a 50 MHz band or more as a radio wave of medium to short wave or ultra high frequency band. A frequency band can be used. For example, the radio unit 12 uses a frequency band selected by the operator of the communication terminal 11 according to the distance from the land and the time zone. This is because the propagation state of radio waves in the medium wave, short wave band, and ultra short wave band is affected by the ionosphere, which varies in state depending on solar activity and day and night. In addition, the selection of the frequency calculates the distance to the representative base station 100 based on the position information obtained by positioning with a positioning sensor or the like, and weights each frequency according to the calculated distance, season and time. It is possible to select a frequency with higher reachability. The frequency is selected in consideration of the band characteristics of each frequency band.

  The radio unit 12 can use digital modulation such as PSK (Phase Shift Keying) and FSK (Frequency Shift Keying) as a modulation method. In addition, the radio unit 12 can use a modulation scheme such as PSK31 in a low frequency band. For example, PSK31 has a low communication speed of 31 baud but has a narrow exclusive band and is suitable for data communication in a short wave band for mainly communicating text data. Note that the wireless unit 12 uses, for example, serial communication using RS-232C for control of the wireless unit 12 as a connection method with the control unit 14, and voice input / output for data exchange such as management information. A modulation signal can be input and output using a terminal.

  In addition, when using the existing radio device mounted on the ship 10, it is possible to separately install a modulation device for performing digital modulation in a short wave frequency band. In this case, when the digital information output from the control unit 14 is acquired, the digital information is modulated into an analog waveform and output to the wireless device. In addition, as the wireless unit 12, an existing wireless device mounted on a ship can be used.

  The storage unit 13 is realized by, for example, a semiconductor memory device such as a random access memory (RAM) or a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 13 stores various information included in the management information, information used for processing in the control unit 14, and the like.

  The storage unit 13 stores position information obtained by positioning, radio wave intensity measured when a radio signal is transmitted / received to / from another communication terminal 11, and the like. The storage unit 13 can also store various signals and various maps transmitted from the base station 100. Moreover, the memory | storage part 13 can also memorize | store response signals, such as ACK received from the communication terminal of another ship, for the predetermined time.

  The control unit 14 is realized, for example, by executing a program stored in an internal storage device using a RAM as a work area by a CPU (Central Processing Unit), an MPU (Micro Processing Unit), or the like. The control unit 14 may be realized by an integrated circuit such as an application specific integrated circuit (ASIC) or a field programmable gate array (FPGA).

  The control unit 14 controls the entire communication terminal 11. The control unit 14 includes a position measurement unit 15, a response unit 16, and a proxy processing unit 17.

  The position measurement unit 15 is a processing unit that receives a signal of the satellite positioning system. The position measuring unit 15 performs positioning by receiving signals from a global navigation satellite system such as GPS (Global Positioning System), GLONASS (Global Navigation Satellite System), Galileo, and a compass as a satellite positioning system. The position measuring unit 15 performs positioning when positioning is requested from the control unit 14, and outputs the positioning result as position information based on a geodetic system such as a WGS (World Geodetic System) 84. In addition, when the position measurement unit 15 is requested by the control unit 14 to continue positioning, the position measurement unit 15 continuously performs positioning and continues to output position information until the control unit 14 requests to stop. The position measurement unit 15 receives a signal from a quasi-zenith satellite system, an Indian regional navigation satellite system, DORIS (Doppler Orbitography and Radio-positioning Integrated by Satellite), and a regional navigation satellite system such as Hokuto as a satellite positioning system. May be.

  The response unit 16 is a processing unit that transmits various responses when a broadcast telegram is received from the base station 100. For example, when the response unit 16 receives a broadcast message such as a safety confirmation from the base station 100, the response unit 16 responds to the base station 100 with an ACK message including the ship ID of the ship 10 on which the communication terminal 11 as its own device is mounted.

  The proxy processing unit 17 is a processing unit that executes a response corresponding to a broadcast telegram from the base station 100 on behalf of another ship. For example, when the proxy processing unit 17 receives an ACK message transmitted from a communication terminal of another ship in response to a broadcast message from the base station 100, the proxy processing unit 17 stores the ACK message in the storage unit 13.

  In such a state, when the proxy processing unit 17 receives a request message requesting a proxy response from the base station 100, the proxy processing unit 17 generates an ACK proxy message including ACKs of other ships stored in the storage unit 13. Then, the proxy processing unit 17 transmits an ACK proxy message to the base station 100 that is the transmission source of the request message.

  For example, when the message received from the base station 100 includes an identifier indicating that it is a request message, the proxy processing unit 17 indicates that the vessel ID of the vessel 10 on which the device is installed is the designated vessel. If it is included as an ID, it is determined that a proxy message has been received. Then, the proxy processing unit 17 extracts the other ship ID that specifies the ship ID of the ship that has been received by the base station 100 from the received proxy message.

  And the proxy process part 17 extracts each ACK message from the other ship which has been received from the memory | storage part 13, and extracts ship ID from each extracted ACK message. Subsequently, the proxy processing unit 17 specifies a ship ID other than the other ship ID from the extracted ship IDs. Thereafter, the proxy processing unit 17 transmits an ACK proxy message including the identified ship ID as an additional ship to the base station 100.

  Further, the control unit 14 periodically reads position information, radio wave intensity, and the like from the storage unit 13, generates management information including these pieces of information, and transmits the management information to the base station 100 via the wireless unit 12. .

  FIG. 2 is an explanatory diagram showing an example of a message format. As shown in FIG. 2, for example, the message format 21 includes “Char code”, “format ver”, “Message Type”, “name of a vessel”, “Call Sign”, “nationality”, “prefectures”, “Geographic”. It has items such as “Point Location” and “Parity”. In the message format 21 of FIG. 2, for example, one cell is one byte. Further, the length of the message format 21 shown in FIG. 2 is 104 bytes as an example, but is not limited to this, and can be an arbitrary length. Further, the message format 21 may include, as items, a wireless association code to be forwarded, a position information mask level indicating a level for masking a part of position information, that is, an encryption level, and the like.

  “Char code” indicates a character code system. “Format ver” indicates the version of the message format 21 and is an item for responding to the format change. “Message Type” indicates a message type, for example, a message type such as automatic, manual, request transmission, or emergency. “Name of a vessel” represents the name or identification information of the fishing boat on which the communication terminal 11 is installed. Note that “name of a vessel” may represent the name and identification information of a fishing boat if the number of characters is sufficient. “Call Sign” represents the call sign of the radio station for reliable identification. “Nationality” is an abbreviation of “nationality registration” and represents a country of registration of a vessel. “Prefectures” represents the prefecture to which the affiliation belongs. “Geographic Point Location” indicates location information, and represents, for example, a positioning system, latitude, and longitude. “Parity” is a parity for confirming complete reception of the message.

  Further, the control unit 14 may use TCG (Trusted Computing Group) technology to make it possible to verify the authenticity of the information and to implement secure information transmission. Here, an example of the TCG technique will be described.

  Terminals and devices that communicate with the outside are always exposed to security threats, and unexpected modifications may be made to the software structure that constitutes the platform due to viruses, spyware, other malicious scripts, unauthorized access, and the like. For such risks, TCG realizes a safe computing environment by ensuring the reliability of the platform. Here, the platform indicates hardware, OS, application, and the like.

  For example, there is a limit to conventional security measures that depend on software against the threat of software tampering. For this reason, TCG embeds a TPM (Trusted Platform Module) chip (not shown) in the platform, and uses this TPM chip as a root of trust to construct a reliable computing environment that is extremely difficult to falsify. Further, by using the TPM chip, hardware-based data / certificate protection and a secure cryptographic processing environment can be realized.

  Next, the TPM chip will be described. The TPM chip is a birdware chip bound to an electronic device (for example, the communication terminal 11) and has tamper resistance. The TPM chip is physically bound to the main components of the electronic device so that it cannot be removed from the electronic device. For example, the component parts of the electronic device correspond to a motherboard or the like. Since the TPM chip is designed with the functions, memory area, and processor power to be suppressed as much as possible, it can be manufactured at low cost and can be applied to various electronic devices and platforms.

  For example, the functions of the TPM include a function for generating and storing an RSA (Rivest Shamir Adleman) secret key, and a function for signing, encrypting, and decrypting with an RSA secret key. In RSA, a pair of a private key and a public key is created. In addition, the functions of the TPM include a function for performing a hash calculation of SHA-1 (Secure Hash Algorithm 1) and a function for holding environment information of the electronic device. When the bound electronic device is activated, the TPM measures the software code in the boot process to the BIOS, OSloader, and OS kernel, hashs the measured software code, and registers it in a register inside the TPM. Further, the TPM collects hardware information of the bound electronic device, hashes the hardware information, and registers the hashed information in a register in the TPM.

  In the TCG technology, a software stack and a software interface are defined in order to use a TPM chip that is a hardware device from a higher-level application or library. This software stack is called TSS (TCG Software Stack), and is composed of software modules that store the functions of TPM chips whose resources are limited. The application of the electronic device can access the function of the TPM chip described above using the interface provided by the TSS. The TPM chip ensures the validity of hash value collection by managing the rules for collecting hash values with the TPM chip on the customer system side by hashing and adding a signature. Moreover, the TPM chip proves the non-falsification of the rule by checking the current rule and signature as necessary. In other words, it is possible to verify the authenticity of the processing and information relating to the control unit 14. As a result, the TPM chip ensures that there is no falsification in the rules for collecting hash values by referring to the rules that have been proven to be non-falsified on the TPM chip side.

  In addition, the control unit 14 may insert information that has been hashed and signed by the TPM chip into a message format to generate a message that is management information. In this case, it is possible to verify the authenticity of processing and information related to the control unit 14 in the device (for example, a device in the Fishery Radio Association to which the ship belongs) that has received the generated electronic message.

(Functional configuration of base station 100)
As shown in FIG. 1, the base station 100 includes a communication unit 101, a storage unit 102, and a control unit 110, and is installed in a coastal station or the like. Note that the base station 100 may include various functional units included in known computers, for example, functional units such as various input devices and audio output devices, in addition to the functional units illustrated in FIG. The base station 100 has, for example, a radio for each frequency band, and an antenna (not shown) is connected to each radio, and communicates with the communication terminals 11 installed on a plurality of fishing boats simultaneously in each frequency band. Can do.

  The communication unit 101 is realized by, for example, a medium wave, short wave, or ultra high frequency band radio device. The communication unit 101 is realized by, for example, a NIC (Network Interface Card) in order to communicate with the management server 2 via the network N. The communication unit 101 is wirelessly connected to any one or more of the plurality of communication terminals 11 via the ionosphere L, and is connected to the management server 2 via the network N. That is, the communication unit 101 is a communication interface that manages information communication between the communication terminal 11 and the base station 100 and between the base station 100 and the management server 2. That is, the base station 100 relays communication between the communication terminal 11 and the management server 2. The communication unit 101 connects to the network N by wire or wireless.

  The communication unit 101 is, for example, a plurality of wireless devices, for example, 2 MHz band, 4 MHz band, 8 MHz band, 12 MHz band, 16 MHz band, 30 MHz band, and 50 MHz band or more, as a radio wave of medium to short wave or ultra high frequency band. The radio waves transmitted from the communication terminal 11 are received using seven wireless devices corresponding to the ultra high frequency band. The communication unit 101 receives radio signals transmitted from the plurality of communication terminals 11 using radio waves having different frequencies, with a plurality of radio devices having corresponding frequencies. In addition, the frequency band to be used is determined according to any one or more of the position and time slot | zone of the fishing boat in which the communication terminal 11 is installed. Further, the communication unit 101 uses the same modulation scheme as the radio unit 12 of the communication terminal 11 as the modulation scheme. In addition, the communication unit 101 can use the serial communication using RS-232C and the data communication using the voice input / output terminal similarly to the communication terminal 11 for connection to the control unit 110. When using an existing radio installed in the base station, it is possible to separately install a modulation device for performing digital modulation in a short wave frequency band. In this case, when the analog waveform received by the wireless device is acquired, the analog waveform is converted into digital information and output to the control unit 110.

  The communication unit 101 extracts management information from the received radio wave, that is, a message, and outputs the management information to the control unit 110. The communication unit 101 transmits the extracted management information to the management server 2 via the network N using the NIC.

  The storage unit 102 is realized by, for example, a semiconductor memory device such as a RAM or a flash memory, or a storage device such as a hard disk or an optical disk. The storage unit 102 stores information and the like used for processing in the control unit 110, and stores an ionosphere map DB 103, a reception status DB 104, and a sea information map 105. Moreover, the memory | storage part 102 memorize | stores the positional information received regularly from the communication terminal 11 of each ship in time series. That is, it is possible to estimate the current position of a ship by specifying the position information stored in the storage unit 102 in time series. Also, the ionosphere map is updated by storing the data (logs) recorded during the voyage (including communications of other ships) in the DB of the management server or the like via a memory or by high-speed communication such as a mobile phone when calling at the port. it can.

  The ionosphere map DB 103 is a database that stores an ionosphere map for each combination of a season, a frequency, and a time zone. Each ionosphere map is generated by the management server 2, and is read from the management server 2 by the control unit 110 and stored in the ionosphere map DB 103. That is, the ionosphere map DB 103 stores an ionosphere map of each region that is managed by the base station 100.

  FIG. 3 is a diagram illustrating an example of an ionosphere map. The ionosphere map shown in FIG. 3 is generated based on the results measured when the season is S, the frequency is fa, and the time zone is 00:00 to 01:00.

  In the example of FIG. From "001003" to Area No. Indicates that the radio wave intensity is “0.62” in the wireless communication between “001002”. That is, when the season is S and the time zone is from 00:00 to 01:00, a message is transmitted and received between the ship located at “001003” and the ship located at “001002” using the frequency fa. It shows that the radio wave intensity was “0.62.” Note that there are communication from “001003” to “001002” and communication from “001002” to “001003”, and either one is adopted here. Also, the average value of both radio field intensities can be adopted.

  In the example of FIG. 3, an example is shown in which the higher the numerical value, the better the radio wave intensity. However, the present invention is not limited to this, and various indexes can be adopted. For example, the success rate and error rate of wireless communication, and the average values of the past several times can also be employed. That is, various indexes indicating the stability of wireless communication using the ionosphere can be employed.

  The ionosphere map DB 103 also stores area information in which the ionosphere map area and the actual position are associated with each other. FIG. 4 is a diagram illustrating an example of area information. As shown in FIG. 4, the ionosphere map DB 103 stores “Area No.” that specifies an area in the chart and “center position” that indicates the center of the area in association with each other. In the example of FIG. Indicates that the region identified by “001001” is within a circle having a radius of 10 km centered on “N12 ° 14 ′ 36 ″, E139 ° 32 ′ 45 ″”.

  Here, an example in which regions are distinguished by circles has been described, but the present invention is not limited to this. For example, each area may be associated with four positions, and each area may be an area surrounded by four points. Alternatively, two areas may be associated with each area, and each area may be a region surrounded by a circle having a diameter of two points.

  The reception status DB 104 is a database that stores the reception status of broadcast telegrams transmitted by the base station 100. That is, the reception status DB 104 stores information indicating whether or not each ship under the management of the base station 100 has been received for each broadcast message transmitted by the base station 100.

  FIG. 5 is a diagram illustrating an example of information stored in the reception status DB 104. As shown in FIG. 5, the reception status DB 104 stores “broadcast ID, ship ID, reception result, reception intensity (base, ship), time, position information, frequency” in association with each other.

  The “broadcast ID” stored here is an identifier for identifying a broadcast telegram, and the “ship ID” is an identifier for identifying a ship. The “reception result” indicates the reception status of the broadcast message, and “OK” is set when the broadcast message is received normally, and “NG” is set when the message cannot be received within a predetermined time. “Reception strength (base, ship)” indicates the downlink reception intensity from the base station 100 to the ship and the uplink reception intensity from the ship to the base station 100. “Time” indicates the time when the response message (ACK) is received from the ship, “Position information” is information indicating the position of the ship included in the response message, and “Frequency” indicates transmission of the broadcast message Indicates the frequency used.

  The example of FIG. 5 is the reception status of the broadcast message with the broadcast ID “B01” distributed using the frequency “8 MHz”. The ship with the ship ID “S01” is normally received and the ship ID is “S02”. Indicates that no response message has been received from the ship. Further, from the ship with the ship ID “S01”, a response message including the reception intensity (5, 5) and the position information (N12 ° 14 ′ 36 ″, E139 ° 32 ′ 45 ″) is “10:00: "00" indicates that it has been received.

  The sea information map 105 is a sea position map showing the position of the ship and the state of the sea. The information stored here is generated based on the ship position information periodically acquired by the base station 100 and the ship position information stored in the reception status DB 104 by the update unit 114 or the like described later. FIG. 6 is a diagram illustrating an example of the sea information map. As shown in FIG. 6, the sea information map 105 is information indicating the positions of the respective base stations “A point”, “B point”, “C point”, “D point”, and the position of each ship. It is. It is also possible to further illustrate the wave height, the direction of the wind, the traveling direction of each ship, and the like.

  The control unit 110 is realized by executing a program stored in an internal storage device using the RAM as a work area by a CPU, an MPU, or the like. The control unit 110 may be realized by an integrated circuit such as an ASIC or FPGA, for example. The control unit 110 includes a message transmission / reception unit 111, an ACK detection unit 112, a proxy instruction unit 113, and an update unit 114, and realizes or executes functions and operations of information processing described below. Note that the internal configuration of the control unit 110 is not limited to the configuration illustrated in FIG. 1, and may be another configuration as long as the information processing described below is performed.

  The message transmission / reception unit 111 is a processing unit that transmits a message such as a broadcast message to each ship and receives a response of the message from each ship. Then, the message transmission / reception unit 111 stores information in the reception status DB 104 according to the reception status.

  For example, the message transmission / reception unit 111 assigns a broadcast ID “B01” to a broadcast message for confirming safety. Then, the telegram transmitting / receiving unit 111 transmits the broadcast telegram having the broadcast ID “B01” by broadcast using the frequency “8 MHz”. After that, when receiving a response message from the ship with the ship ID “S01” at 10:00: 00 within a predetermined time such as 10 minutes, the message transmission / reception unit 111 receives the received strength (5, 5) from the response message. The position information (XXX) is extracted. The message transmission / reception unit 111 then associates the broadcast ID “B01” with “ship ID: S01, reception result: OK, reception intensity: 5, 5, position information: XXX, time: 10:00:00, frequency. : 8 MHz "is stored in the reception status DB 104.

  In addition, when the message transmission / reception unit 111 cannot receive a response message from the ship with the ship ID “S02” within a predetermined time such as 10 minutes, for example, the message transmission / reception unit 111 associates the broadcast ID “B01” with “ship ID: S02, reception”. “Result: NG, Frequency: 8 MHz” is stored in the reception status DB 104.

  The ACK detection unit 112 is a processing unit that detects the reception status of an ACK message for a broadcast message transmitted from the base station 100. Specifically, for each broadcast message, the ACK detection unit 112 refers to the reception status DB 104 to detect a ship that has received an ACK message and a ship that has not received an ACK message.

  For example, it is assumed that “S01” to “S05” are included as destinations of the broadcast ID “B01”. The ACK detection unit 112 refers to the reception status DB 104 for the broadcast ID “B01”, and detects the ship IDs “S01, S02, S05” in which “OK” is set in the reception result as ACK-received ships. Further, the ACK detection unit 112 refers to the reception status DB 104 for the broadcast ID “B01”, and detects the ship IDs “S03” and “S04” in which “NG” is set as the reception result as ACK unreceived ships.

  Then, the ACK detection unit 112 outputs “S01, S02, S05” to the proxy instruction unit 113 as the ship ID of the ship that has received the ACK for the broadcast ID “B01”. Similarly, the ACK detection unit 112 outputs “S03” and “S04” to the proxy instruction unit 113 as the ship ID of the ship that has not received ACK for the broadcast ID “B01”. Then, the ACK detection unit 112 requests the proxy instruction unit 113 to request a proxy response.

  The proxy instruction unit 113 is a processing unit that instructs the ACK-received ship to perform proxy transmission of the ACK message of the ACK-unreceived ship. Specifically, the proxy instruction unit 113 identifies at least one ship among the ACK-received ships notified from the ACK detection unit 112, and the specified ACK-received ship is notified from the ACK detection unit 112. Request proxy transmission of ACK messages for ships that have not received ACK. Further, when receiving a response from the ship that has requested proxy transmission, the proxy instruction unit 113 updates the reception status DB 104 according to the response.

  Explaining in the above example, the proxy instruction unit 113 determines “S01” as the proxy request destination among the ship IDs “S01, S02, S05” for which ACK has been received. Then, the proxy instruction unit 113 sets “B01” as the broadcast ID, sets “S01, S02, S05” as the other ship IDs indicating the ACK-received ships, and sets “S01” as the designated ship ID indicating the proxy request destination. Request message with "" set. Then, the proxy instruction unit 113 transmits the generated request message to the communication terminal mounted on the ship with the ship ID “S01” as the request destination.

  Here, an example of selecting a proxy request destination will be described. For example, the proxy instructing unit 113 can determine the ship having the highest reception intensity among the ACK-received ships as the proxy request destination. Specifically, the proxy instruction unit 113 acquires the reception status of each ACK-received vessel from the reception status DB 104, and determines the vessel having the highest received strength (ship) as the proxy request destination. The reception strength (ship) is the reception strength when a message is transmitted from the ship to the base station, that is, the reception strength when an ACK message is received.

  As another method, the proxy instruction unit 113 can also make a determination based on the ionosphere map. Specifically, the proxy instruction unit 113 extracts the latest position information of the ACK-unreceived ship from the position information of each ship stored in the storage unit 102. Further, the proxy instruction unit 113 refers to the reception status DB 104 and extracts position information of each ACK-received ship. And the proxy instruction | indication part 113 pinpoints the area in which each ship is located from the positional information on the specified ACK unreceived ship and ACK received ship according to the area information memorize | stored in ionosphere map DB103.

  After that, the proxy instruction unit 113 reads from the ionosphere map DB 103 an ionosphere map that matches the season, time zone, and frequency at which the target message “B01” is distributed. And the proxy instruction | indication part 113 pinpoints an area with the highest radio field intensity with the area where an ACK non-reception ship is located among the areas where each ACK reception ship is located according to an ionosphere map. Thereafter, the proxy instruction unit 113 specifies the ACK-received ship located in the specified area as the proxy request destination.

  For example, in FIG. 3, it is assumed that the area where the ACK-unreceived ship is located is “001005” and the areas where the ACK-received ship is located are “001001”, “001002”, and “001004”. In this case, the proxy instructing unit 113 determines that the radio field intensity between “001005” and “001001” is “0.63”, and the radio field intensity between “001005” and “001002” is “0.89” and “001005”. And “001004” is specified as “0.95”. As a result, the proxy instruction unit 113 determines the ACK-received ship located at “001004” having the highest radio wave intensity as the request destination.

  Here, the proxy instructing unit 113 can estimate the position of the ACK-unreceived ship using various methods. For example, the proxy instructing unit 113 specifies the speed of the ACK-unreceived ship from the latest position information of the ACK-unreceived ship and the previous position information. And the proxy instruction | indication part 113 can also estimate the present position of an ACK non-reception ship from the speed of a ACK non-reception ship, and the newest position information of an ACK non-reception ship.

  Further, the proxy instruction unit 113 specifies the traveling direction of the ACK-unreceived ship from the latest position information of the ACK-unreceived ship and the previous position information. Further, the proxy instruction unit 113 calculates a time difference from the current time and the time when the latest position information of the ACK-unreceived ship is acquired. Further, the proxy instructing unit 113 specifies a movement distance indicating how much the vehicle moves with the calculated time difference from the past position information of the ACK-unreceived ship. And the proxy instruction | indication part 113 can also estimate the position advanced only the movement distance from the newest position information of the ACK non-reception ship in the advancing direction of the ACK non-reception ship as the current position of the ACK non-reception ship.

  The proxy instruction unit 113 can also estimate the current position of the ACK-unreceived ship using both the speed and the traveling direction of the ACK-unreceived ship. In addition, the proxy instruction unit 113 can use two pieces of position information at different times instead of the latest position information and the previous position information. In this case, the proxy instruction unit 113 can also estimate the speed and the like from the time difference and the moving distance.

  The update unit 114 is a processing unit that updates the sea information map 105 according to the position information received from each ship and the reception status stored in the reception status DB 104. For example, the update unit 114 reflects the latest position of each ship in the sea information map 105 according to the received position information, and reflects the dead zone and the sensitive band in the sea information map 105 according to the reception status DB 104.

[Sequence Diagram]
Next, a processing sequence executed by the management system shown in FIG. 1 will be described. FIG. 7 is a sequence diagram showing the flow of processing. Here, as an example, the management targets of the base station 100 are ship A (ship ID = S01), ship B (ship ID = S02), ship C (ship ID = S03), ship D (ship ID = S04). And Moreover, although each ship has the communication terminal 11 demonstrated in FIG. 1, a code | symbol may be abbreviate | omitted and described here. Further, it is assumed that the base station 100 has already acquired the ionosphere map generated by the management server 2.

  As shown in FIG. 7, the telegram transmitting / receiving unit 111 of the base station 100 generates a broadcast telegram and transmits it to the ship A, the ship B, the ship C, and the ship D (S101 and S102). At this time, the broadcast telegram is received by each ship.

  Thereafter, the communication terminal of the ship A that has received the broadcast message transmits an ACK message to the base station 100 (S103 and S104). Note that the ACK message transmitted from the ship A reaches the ship B and the ship C and is also received by these ships (S105 and S106).

  Similarly, the communication terminal of the ship B that has received the broadcast message transmits an ACK message to the base station 100 (S107 and S108). Note that the ACK message transmitted from the ship B reaches the ship C and the ship D and is also received by these ships (S109 and S110).

  The communication terminal of the ship C that has received the broadcast message transmits an ACK message to the base station 100, but does not reach the base station 100 (S111 and S112). That is, since the influence of the ionosphere when the base station 100 transmits a broadcast message differs from the influence of the ionosphere when the ship C responds with an ACK message, there is a situation where the ACK message does not arrive even if the broadcast message arrives. appear. Note that the ACK message transmitted from the ship C reaches the ship B and the ship D, and is normally received by these ships (S113 and S114).

  Similarly, the communication terminal of the ship D that has received the broadcast message transmits an ACK message to the base station 100, but does not reach the base station 100 (S115 and S116). That is, since the influence of the ionosphere when the base station 100 transmits a broadcast message differs from the influence of the ionosphere when the ship D responds with an ACK message, there is a situation where the ACK message does not reach even if the broadcast message arrives. appear. Note that the ACK message transmitted from the ship D reaches the ship B and the ship C and is normally received by these ships (S117 and S118).

  Thereafter, the telegram transmitting / receiving unit 111 of the base station 100 receives an ACK telegram from each of the ship A and the ship B (S119). At this time, the message transmission / reception unit 111 stores the reception status in the reception status DB 104.

  Subsequently, the ACK detection unit 112 of the base station 100 identifies the ship C and the ship D as ACK-unreceived ships according to the reception status of the ACK message (S120). And the proxy instruction | indication part 113 of the base station 100 specifies the ship B as a proxy request destination using the receiving strength between the ship A and the base station 100, the receiving strength between the ship B and the base station 100, etc. ( S121).

  Subsequently, the proxy instructing unit 113 generates a proxy request message in which the ship B is set as the proxy request destination and the ship A is set as the other ship ID indicating the ship that has received the ACK message (S122). And the proxy instruction | indication part 113 transmits a request message toward the ship B (S123 and S124).

  Thereafter, the communication terminal of the ship B receives the request message transmitted from the base station 100 (S125). Then, the communication terminal of the ship B specifies a ship other than the received ship included in the request message among the ships of the ACK message received by itself, and generates an ACK proxy message including the ship ID of the ship. (S125), it transmits toward the requesting base station 100 (S126 and S127).

  Thereafter, the proxy instructing unit 113 of the base station 100 extracts the ACK of the ACK-unreceived ship from the ACK proxy message received from the ship B, and when it determines that the end condition is satisfied, sends the request end message to the ship B. Transmit (S128 and S129). The termination condition includes whether the number of retransmissions exceeds a threshold, whether the time for performing this processing is outside a specified time, or whether the number of ACK responses from the ship is equal to or greater than the threshold.

  Here, examples of formats of various messages exchanged in the processing sequence shown in FIG. 7 will be described. FIG. 8 is a diagram for explaining a format example of a message.

  As shown in FIG. 8, the broadcast telegram transmitted from the base station 100 in S101 has “communication format information, base station ID, broadcast ID, broadcast information”. In the example of FIG. 8, the base station 100 indicates that the broadcast telegram with the broadcast ID “B03” has been broadcast to each ship.

  Here, the “communication format information” is information indicating, for example, a character code system, a message format version, a message type, and the like. The “base station ID” is an identifier that identifies the source base station. “Broadcast ID” is an identifier for identifying a broadcast telegram. “Broadcast information” is the content of a broadcast message.

  In addition, the ACK message transmitted from the ship A or the ship B in S103 or S107 has “communication format information, base station ID, broadcast ID, ship ID, ACKID”. The example of FIG. 8 indicates that the communication terminal of the ship B whose ship ID is “S02” responded to the base station 100 with an ACK message for the broadcast message with the broadcast ID “B03”.

  Here, “communication format information”, “base station ID”, and “broadcast ID” have the same meanings as broadcast telegrams, and thus will not be described in detail. The “base station ID” is an identifier indicating the transmission destination of the ACK message, that is, the base station that is the transmission source of the broadcast message, and corresponds to the base station ID in the broadcast message. “Broadcast ID” is an identifier that indicates which broadcast message the ACK message corresponds to and identifies the corresponding broadcast message. The broadcast ID in the broadcast telegram is used for this broadcast ID. The “ship ID” is an identifier for identifying the ship where the communication terminal that has transmitted the ACK message is installed. “ACKID” is, for example, a number indicating the number of ACK messages for a broadcast message with a certain broadcast ID. That is, for example, the ACKID is incremented by one every time a broadcast message having the same content is retransmitted and an ACK message is transmitted. Moreover, ACKID is good also as a number which shows how many times it is ACK message | telegram within one day, for example. In addition to these, the number of character errors occurring in the broadcast message when receiving the broadcast message corresponding to the Ack message, that is, the “number of error characters” that is information indicating the number of error characters can be included. .

  Further, the request message transmitted from the base station 100 to the ship B in S124 has “communication format information, base station ID, broadcast ID, designated ship ID, other ship ID”. Since “communication format information, base station ID, broadcast ID” has been described above, a detailed description thereof will be omitted. The “broadcast ID” is used to specify which broadcast message is requested for an ACK message. Further, the “designated ship ID” designates the ship ID of the ship on which the requested communication terminal requesting transmission of the proxy message is mounted. In “other ship ID”, a ship ID of a ship that has already received an ACK message is designated.

  That is, the example in FIG. 8 is an example of a request message of an ACK message for a broadcast message with a broadcast ID “B03”. In the example of FIG. 8, the base station 100 whose base station ID is “BB” has already received an ACK message from the ship A with the ship ID “S01”, and performs proxy transmission of ACK messages from other ships. A request is made to the ship B having the ship ID “S02”.

  In addition, the ACK proxy message transmitted from the ship B in S126 has “communication format information, base station ID, broadcast ID, ship ID, additional ship, ACKID”. Since “communication format information, base station ID, broadcast ID, ACKID” has been described above, a detailed description thereof will be omitted. “Ship ID” is the ship ID of the sender ship that transmitted the ACK proxy message, and is the transmission destination of the request message of the base station 100. The “additional ship” is a ship ID to which the proxy requesting ship responds by proxy to ACK.

  Explaining in the above example, the communication terminal of the ship B that has been requested to act on the proxy has received the designation specified by the request message among “S01, S03, S04” that is the ship ID of the sender of the ACK message received by itself. A ship ID “S03, S04” other than the ship ID “S01” of the ship is extracted. Then, the communication terminal of the ship B generates an ACK proxy message in which the ship ID “S03, S04” is set as an additional ship, and transmits it to the base station 100.

  Thereafter, the request end message transmitted from the base station 100 in S128 has “communication format information, base station ID, broadcast ID, proxy end declaration code”. Since “communication format information, base station ID, broadcast ID” has been described above, a detailed description thereof will be omitted. The “proxy end declaration code” is set to indicate the end of proxy transmission. The base station 100 transmits a request end message when the reception status of the ACK message or the ACK proxy message satisfies the end condition. In the example of FIG. 8, the base station 100 broadcasts a message including the proxy end declaration code “SSS” as the broadcast ID “B04”. The communication terminal of each ship that has received this message ends the proxy transmission because the proxy end declaration code “SSS” is included.

[Concrete example]
Next, a specific example will be described with reference to the charts of FIGS. FIG. 9 is a diagram illustrating an example of transmission of a broadcast message from the base station, FIG. 10 is a diagram illustrating an example of transmission of an ACK message from each ship, and FIG. 11 is a diagram illustrating an example of proxy for ACK. is there.

  As shown in FIG. 9, base stations 100 are installed at points A, B, C, and D, respectively. Each base station 100 transmits the same broadcast telegram while suppressing interference using different frequencies. For example, the base station 100 at the point A transmits a broadcast signal to each ship including the ship A, the ship B, the ship C, and the ship D.

  Subsequently, as illustrated in FIG. 10, the communication terminals of the ship A and the ship B respond to the base station 100 with an ACK message for the broadcast message. Here, the ACK message transmitted from the communication terminal of the ship C does not reach the base station 100, but is received by the communication terminal of the ship B. Similarly, the ACK message transmitted from the communication terminal of the ship D does not reach the base station 100 but is received by the communication terminal of the ship B.

  After that, as shown in FIG. 11, the base station 100 has received the ACK message from the ship A and the ship B, but has not received from the ship C and the ship D. To do. The requested communication terminal of the ship B generates an ACK proxy message including the already received ACK of the ship C and the ACK of the ship D, and responds to the requesting base station 100.

[effect]
As described above, when the base station 100 receives the response of the distributed message from the ship B, the base station 100 can also request the ship B to transmit the response information of the other ship stored in the ship B. For this reason, the base station 100 can collect response information that does not reach the base station 100 directly, and can collect a lot of response information with less communication.

  In addition, since retransmission due to broadcast telegrams can be suppressed, congestion and interference in the network can be suppressed. In addition, since congestion and interference are suppressed, the degree of influence on transmission of other telegrams can be reduced, and errors due to interference and the like can also be reduced.

  Although the embodiments of the present invention have been described so far, the present invention may be implemented in various different forms other than the embodiments described above.

  Moreover, in the said Example, although the antenna connected to the communication part 101 of the base station 100 was each connected for every radio | wireless machine, it is not limited to this. For example, a multi-band antenna or an antenna tuner may be used. Further, different frequencies may be used for transmission from the ship to the land and transmission from the land to the ship. Thereby, the conditions of the antenna installation location are eased.

  Moreover, in the said Example, although PSK31 was mentioned as an example of digital modulation, it is not limited to this. For example, narrowband digital modulation that can be used in a short wave band such as RTTY (Radioteletype), packet communication, and SSTV may be used. Accordingly, communication with a larger amount of data can be performed in a high frequency band in the short wave band.

  Further, in the above example, the description has been given by taking the sea as an example. However, the present invention is not limited to this. it can. In addition, the present invention can be similarly applied to communication difficult areas such as deserts, mountainous areas, and depopulated areas.

  For example, a wireless device is arranged in a private house or livestock existing in an area where communication is difficult. When the base station 100 receives the response of the distributed message from the first radio device, the base station 100 can also request the first radio device to transmit response information of other radio devices stored in the first radio device. . For this reason, the base station 100 can collect response information that does not reach the base station 100 directly, and can collect a lot of response information with less communication.

[Request method]
In the above embodiment, when a request message is transmitted, it can be transmitted at the same frequency as the broadcast message transmitted first, or can be transmitted at a different frequency. In this case, the base station 100 can determine the requested ship using the ionosphere map corresponding to the changed frequency. In addition, the base station 100 inquires of the communication terminal of each ship that has received the ACK message whether the proxy process can be executed, and requests one communication terminal from among the communication terminals of the ship that has responded that execution is possible. It can also be selected as the destination.

  In the above-described embodiment, an example in which the proxy request destination is one has been described. However, the present invention is not limited to this. For example, the base station 100 can transmit the request message to the communication terminal of each ship that has received the ACK message. In addition, when there are three ACK unreceived ships, the base station 100 can determine a request destination for each ACK unreceived ship. For example, the base station 100 determines a ship having a high radio wave intensity as a request destination for each ACK-unreceived ship.

[system]
In addition, each component of each part illustrated does not necessarily need to be physically configured as illustrated. In other words, the specific form of distribution / integration of each unit is not limited to that shown in the figure, and all or a part thereof may be functionally or physically distributed / integrated in arbitrary units according to various loads or usage conditions. Can be configured. Furthermore, various processing functions performed by each device may be executed entirely or arbitrarily on a CPU (or a microcomputer such as an MPU or MCU (Micro Controller Unit)). In addition, various processing functions may be executed in whole or in any part on a program that is analyzed and executed by a CPU (or a microcomputer such as an MPU or MCU) or on hardware based on wired logic. Needless to say, it is good.

[hardware]
The various processes described in the above embodiments can be realized by executing a prepared program on a computer. Therefore, in the following, an example of a computer that executes a program having the same function as in the above embodiment will be described. FIG. 12 is an explanatory diagram illustrating an example of a computer that executes a communication control program.

  As illustrated in FIG. 12, the computer 200 includes a CPU 201 that executes various arithmetic processes, an input device 202 that receives data input, and a monitor 203. The computer 200 also includes a medium reading device 204 that reads a program and the like from a storage medium, an interface device 205 for connecting to various devices, and a communication device 206 for connecting to other information processing devices and the like by wire or wirelessly. Have The computer 200 also includes a RAM 207 that temporarily stores various types of information and a hard disk device 208. Each device 201 to 208 is connected to a bus 209.

  The hard disk device 208 stores a communication control program having the same functions as the processing units of the message transmission / reception unit 111, the ACK detection unit 112, the proxy instruction unit 113, and the update unit 114 shown in FIG. Also, the hard disk device 208 stores an ionosphere map DB 103, a reception status DB 104, a sea information map 105, and various data for realizing a communication control program. The input device 202 receives input of various information such as operation information from the administrator of the computer 200, for example. The monitor 203 displays various screens for the administrator of the computer 200, for example. The interface device 205 is connected to, for example, a printing device. The communication device 206 has the same function as the communication unit 101 illustrated in FIG. 1 and is connected to the network N, for example.

  The CPU 201 reads out each program stored in the hard disk device 208, develops it in the RAM 207, and executes it to perform various processes. In addition, these programs can cause the computer 200 to function as the message transmission / reception unit 111, the ACK detection unit 112, the proxy instruction unit 113, and the update unit 114 illustrated in FIG.

  Note that the above-described communication control program is not necessarily stored in the hard disk device 208. For example, the computer 200 may read and execute a program stored in a storage medium readable by the computer 200. The storage medium readable by the computer 200 corresponds to, for example, a portable recording medium such as a CD-ROM, a DVD disk, a USB (Universal Serial Bus) memory, a semiconductor memory such as a flash memory, a hard disk drive, and the like. Alternatively, the communication control program may be stored in a device connected to a public line, the Internet, a LAN, or the like, and the computer 200 may read out and execute the management program therefrom.

2 management server 10 ship 11 communication terminal 12 wireless unit 13 storage unit 14 control unit 15 position measurement unit 16 response unit 17 proxy processing unit 100 base station 101 communication unit 102 storage unit 103 ionosphere map DB
104 Reception status DB
105 Sea information map 110 Control unit 111 Message transmission / reception unit 112 ACK detection unit 113 Proxy instruction unit 114 Update unit

Claims (6)

Deliver telegrams to each ship by the first communication using radio waves in the medium to short wave or ultra high frequency band ,
When receiving a reception result indicating that the electronic message has been normally received from the ship by the second communication using the radio wave, which is a response by the first communication, the response corresponding to the transmission source of the reception result has been completed. At least one or more responding ships among the ships are caused to transmit the reception result of the unresponsive ship that is received from the other ship by the second communication and that is not included in the transmission source of the reception result . Send instructions,
The communication control program for executing a process of receiving the reception result of the unanswered vessels from at least one or more acknowledged ship computer. Process of transmitting the instructions, when receiving the pre Ki応 answers from multiple vessels, claim 1, characterized in that selecting the highest the acknowledged vessel receiving intensity of the plurality of vessels The communication control program described in 1. The computer further executes processing for periodically acquiring and holding the position information of each ship,
The process of transmitting the instruction before when receiving Ki応 answers from multiple vessels, according ionosphere maps showing the radio wave strength among the positions at sea, the plurality of vessels each latest position held The position where the radio field intensity is the strongest with the latest position of the non-responding ship to be held is specified, and the command is transmitted to the responded ship at the specified position. The communication control program according to claim 1. Deliver telegrams to each ship by the first communication using radio waves in the medium to short wave or ultra high frequency band ,
When receiving a reception result indicating that the electronic message has been normally received from the ship by the second communication using the radio wave, which is a response by the first communication, the response corresponding to the transmission source of the reception result has been completed. At least one or more responding ships among the ships are caused to transmit the reception result of the unresponsive ship that is received from the other ship by the second communication and that is not included in the transmission source of the reception result . Send instructions,
Communication control method wherein at least one or more of the process of receiving the reception result of the unanswered vessels from acknowledged ship computer executes. A first transmission unit that distributes a message to each ship by first communication using radio waves in a medium wave, a short wave, or an ultra-short wave band ;
When receiving a reception result indicating that the electronic message has been normally received from the ship by the second communication using the radio wave, which is a response by the first communication, the response corresponding to the transmission source of the reception result has been completed. At least one or more responding ships among the ships are caused to transmit the reception result of the unresponsive ship that is received from the other ship by the second communication and that is not included in the transmission source of the reception result . A second transmitter for transmitting the command;
Communication control apparatus characterized by having a receiving section for receiving the reception result of the unacknowledged vessels from the at least one or more acknowledged vessels. Deliver telegrams to each communication device through first communication using medium to short-wave or ultra-short-wave radio waves ,
When the communication device receives a reception result indicating that the electronic message has been normally received by the second communication using the radio wave, which is a response by the first communication, the response corresponding to the transmission source of the reception result is completed. The reception result of an unanswered device that is not included in the transmission source of the reception result, which is received from the other communication device by the second communication by the responded device, is transmitted to at least one of the responded devices. Send a command to
A communication control program for the executing the process of receiving the reception result unanswered device to the computer from the at least one or more acknowledged apparatus.

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