KR102516194B1 - System for monitoring, analyzing, and identifying maritime microwave dataling integrity inhibitors, and control method thereof - Google Patents

Abstract

Disclosed is a control method of a control station for monitoring datalink integrity inhibitors of a very-high-frequency band data exchange system of a coastal station which makes communications with one or more ships. The control method includes the steps of: receiving a datalink message from the very-high-frequency band data exchange system of the coastal station; based on a header of a datalink message packet, classifying and storing the datalink message according to the type of receiving device, whether the coast station performs transmission and reception, and channel information; reconstructing the classified and stored datalink messages into a column family of a dataset matched to a plurality of different judgment criteria; and identifying datalink integrity inhibitors based on the reconstructed column family. The presence of the integrity inhibitors can be systematically and automatically identified.

Description

Maritime microwave data link integrity impediment monitoring/analysis/identification system and its control method

The present disclosure relates to a safety management system for a ship, and more particularly, to a system for monitoring data link integrity deterioration factors in communication between ships or coast stations.

The International Maritime Organization (IMO), through the International Convention for the Safety of Life at Sea (SOLAS), since July 2002, ships with a gross tonnage of 300 tons or more engaged in international voyages and international voyages It stipulates the phased mandatory installation of AIS (Automatic Identification System) for cargo ships of 500 tons or more and all passenger ships not engaged in

The purpose of introduction of the automatic identification system is for ship collision avoidance, ship and cargo information collection, and ship traffic management. It was the only technology that could communicate, so various application equipment and services using this automatic identification system technology appeared one after another.

The automatic identification system, which has been in operation for more than 20 years since its initial introduction, has been used to the extent that the original purpose of introduction of the automatic identification system has faded in major ports of several countries, including Korea, the United States, and Japan, due to various application equipment and services that increase every year. Resource utilization has reached a saturation point, and the International Maritime Organization revives the original purpose of introducing such an automatic identification system and provides a digital communication service with a faster transmission speed even at sea. It was decided to introduce a next-generation maritime digital wireless communication technology with a data transmission speed that is at least 2 times (19.2 kbps) and up to 32 times (307.2 kbps) faster than

This next-generation maritime digital wireless communication technology, named VDES (VHF Data Exchange System), provides static information (name of ship, ship type, identification code, etc.) and dynamic information (speed over ground, course on ground, latitude, longitude, etc.), AIS messages that provide or request information necessary for safe navigation of ships, or are remotely controlled for data link management purposes, and ASM messages (application-specific messages) for use in internationally or regionally defined application services. In addition, two existing AIS frequency channels (AIS 1 and AIS 2) and long-distance AIS frequency 2 are used to transmit VDE messages, which are a means of providing Maritime Service classified into 16 types and commercial services using low-orbit satellites in the future. 2 channels of ASM frequencies (ASM 1 and ASM 2) additionally assigned to channels (75 and 76), 12 channels of VDE frequencies (1024, 1084, 1025, 1085, 1026, 1086, 2024, 2084, 2025, 2085 , 2026, 2086), it provides simplex or duplex data communication between ship-to-ship, ship-to-shore, coast-to-ship, ship-to-satellite, and satellite-to-ship using a total of 18 frequency channels.

Conventional maritime communication technology transmits a data payload of 168 bits for a unit time (26.667 ms) by using a GMSK (Gaussian Minimum Shift Keying) modulation method that can reduce the bandwidth of a signal while removing abrupt changes in binary data. However, multi-level modulation schemes such as pi/4 QPSK, 8PSK, and 16QAM, channel coding techniques, and multiple channel bandwidths are integrated. The microwave band data exchange system that can be used in this way can transmit data payloads of as little as 352 bits and as much as 5,584 bits during the same time, thereby achieving the main purpose of the automatic identification system by increasing the efficiency of radio wave resources. In addition, it enables smooth provision of various maritime information services, including Maritime Safety Information (MSI), which requires a large amount of data.

However, despite the many advantages of the next-generation maritime digital wireless communication technology, there are concerns that it is complicated to systematically and efficiently utilize the increased resources, and that it may be more vulnerable to the effects of data link interference.

The present disclosure provides a system operated based on a solution capable of effectively monitoring and analyzing data link interference.

The objects of the present disclosure are not limited to the above-mentioned objects, and other objects and advantages of the present disclosure not mentioned above can be understood by the following description and will be more clearly understood by the embodiments of the present disclosure. Further, it will be readily apparent that the objects and advantages of the present disclosure may be realized by means of the instrumentalities and combinations indicated in the claims.

According to an embodiment of the present disclosure, a control method of a control station for monitoring data link integrity impediments of a VHF data exchange system of a coast station communicating with one or more ships includes: Receiving a data link message, classifying and storing the data link message according to the type of receiving device, transmission/reception status of the coast station, and channel information based on the header of the data link message packet, the classified and stored data Reconstructing the link message into a column family of a dataset that matches a plurality of different criterion, respectively, and identifying a data link integrity impediment based on the reconstructed column family.

In the step of classifying and storing the data link message, information on the reception time of the message, the first slot number used to transmit the message, the electric field strength of the message, and the signal-to-noise ratio of the message is added, and the frame including the message is added. Information on the average noise level value of the previous frame of can be added.

The step of identifying the data link integrity impediment may include identifying a control message among messages transmitted or received by a coast station managed by the control station, and including a number, identification code, latitude, and longitude of the control message. When the identification code of the control message does not match the identification code of the coast station by analyzing the column family composed of the data set, the identification code of the control message matches the identification code of the coast station, but the coast station When there is no history of transmitting a control message, when the identification code of the control message overlaps with the coast station managed by the control station and the communication coverage area does not match the identification code of another coast station under the management of another control station It may be determined whether at least one of: , and a case where the identification code of the control message matches the identification code of the other coast station but there is no history of transmitting the control message from the other coast station.

The step of identifying the data link integrity impediment may include analyzing a column family composed of control setting information of a message transmitted or received by a coast station managed by the control station to exceed a parameter allocation limit setting or for future use. When the reserved setting is used, when the recommended value for the increment is not met, when the number of consecutive slots in the reserved block exceeds a certain number, when the timeout setting is decreased by 1 or not renewed, when the geographic area boundaries It can be determined whether at least one of the cases in which the intersection points of is exceeded 3, the bulletin board version does not match, the validity period exceeds a certain period, and the TDMA frame size does not correspond to the recommended value. In this case, the control setting information may include message number, slot offset, slot increment, number of slots, timeout, geographical area, radio station class, vessel type, reporting interval, bulletin board version, and version validity.

The step of identifying the data link integrity impediment may include analyzing a column family composed of control setting information of a message transmitted or received by one or more coast stations managed by the control station, so that two or more adjacent coast stations are located in the same geographical area. If the transmit/receive modes set for the same geographic area are conflicting, or if the transmit power strengths set by two or more adjacent coast stations for the same geographic area are conflicting, the radio station class or vessel type set by two or more adjacent coast stations in the same geographic area In the case of conflicting transmission/reception modes, when two or more adjacent coast stations have conflicting reporting intervals set for radio station classes or ship types in the same geographic area, and when two or more adjacent coast stations have radio station classes or ship types in the same geographical area. It may be determined whether the silence time set for . corresponds to at least one of contradictory cases. In this case, the control setting information may include message number, geographic area, transmission/reception mode, transmission power intensity, radio station class, ship type, reporting interval, and silence time.

The step of identifying the data link integrity impediment may include analyzing a column family composed of communication state information of a message transmitted or received within a communication coverage area of a coast station managed by the control station, and reporting a data link first access vessel. If the message is not AIS message No. 3, if the data link first access vessel does not report while calculating or updating the slot increment, the data link first access vessel sets the slot increment as 0 and reports it as AIS message No. 1 in the next transmission It is possible to determine whether at least one of the following cases is not applicable, and the case where the report message of the ship designated as the allocation mode by AIS messages 16 and 23 of the coast station is not 2. At this time, the communication state information includes message number, synchronization state, slot timeout, number of other ships receiving the message, slot number, UTC time, slot offset, slot increment, number of consecutive slots, and allocation maintenance flag. can include

The step of identifying the data link integrity impediment may include a column family including a reception time of a message transmitted or received within a communication coverage area of a coast station managed by the control station and a first slot number used to transmit the message. is analyzed, if the time identified to the third decimal place of the reception time of the message transmitted through a single slot is greater than the value calculated based on the first slot number and slot clock cycle by a certain time or more, and consecutive slots It is possible to determine whether at least one of the cases in which the reception time of the message transmitted through the 3rd decimal place is greater than the value calculated based on the first slot number and the slot clock cycle by a predetermined time or more. there is.

The step of identifying the data link integrity impediment may include identifying a dynamic information message or a static information message transmitted or received within a communication coverage area of a coast station managed by the control station, and the dynamic information message or the static information message. By analyzing the column family including number, channel number, radio station class, maritime mobile service identification code, navigation status, ground speed, and ground course, the nominal reporting interval according to the dynamic status of each class of vessel It is possible to determine whether or not at least one of the cases where the ship has not been reported as , and the case where the ship that has made a static report does not report at a predetermined reporting interval.

The step of identifying the data link integrity impediment may include identifying an inquiry message and a response message transmitted or received within a communication coverage area of the coast station managed by the control station, and transmitting the inquiry message number and the inquiry message. Obtain query response request information including the maritime mobile service identification code of one vessel, the maritime mobile service identification code of the query target of the query message, the request message number, and the slot offset, and the number of the response message, the channel number, the Obtain query response information including the maritime mobile service identification code of the ship that sent the response message and the maritime mobile service identification code of the response target of the response message, and obtain a column family including the query response request information and the query response It is possible to determine whether there is no response message to the query message by analyzing a column family including information.

The step of identifying the data link integrity impediment may include identifying a dynamic information message, a static information message, and an application-specific message transmitted or received within a communication coverage area of a coast station managed by the control station, and the dynamic information message , By analyzing the column family including the channel number, the message number, and the maritime mobile service identification code of each of the static information message and the application-specific message, the dynamic information message of the ship having the same maritime mobile service identification code is obtained. When not transmitted across two channels, static information messages of ships with the same maritime mobile service identification code are not transmitted across two channels, and application-specific messages from ships with the same maritime mobile service identification code It is possible to determine whether at least one of the cases in which is not transmitted while crossing two channels.

The step of identifying the data link integrity impediment may include identifying a dynamic information message transmitted or received within a communication coverage area of a coast station managed by the control station, a number of the dynamic information message, a maritime mobile service identification code, By analyzing a column family including speed over ground, course over ground, latitude, longitude, turn rate, heading, and altitude, it is possible to determine whether a peripheral device is not installed or has a poor connection.

The step of identifying the data link integrity impediment may include identifying a safety-related message transmitted or received within a communication coverage area of the coast station managed by the control station, the number of the safety-related message, a maritime mobile service identification code, and 6-bit-ASCII character contents, and by analyzing a column family, it is possible to determine whether text suggesting a distress situation is included in the safety-related message.

The step of identifying the data link integrity impediment may include identifying a location correction message transmitted or received by a coast station managed by the control station, and determining the number, maritime mobile service identification code, latitude, and longitude of the location correction message. When the identification code of the location correction message does not match the identification code of the coast station by analyzing the column family including the location correction message, the identification code of the location correction message matches the identification code of the coast station, but the coast station does not match the identification code of the coast station. When there is no history of transmitting the positioning correction message, and the identification code of the positioning correction message overlaps with the coast station and the communication coverage area and matches the identification code of another coast station under the management of another control station, but the other coast station It is possible to determine whether at least one of the cases where there is no history of transmitting the location correction message is applicable.

The step of identifying the data link integrity impediment may include identifying a dynamic information message or a static information message transmitted or received within a communication coverage area of a coast station managed by the control station, and the dynamic information message or the static information message. By analyzing the column family including the number, maritime mobile service identification code, voyage status, and destination information, if the position of the ship temporarily indicates a point outside the communication coverage area of the coast station, the ship sailing at a constant speed It may be determined whether at least one of a case in which the voyage state indicates another state such as mooring, anchoring, anchoring, or stranding, and a case in which the spelling of the destination is misspelled or partially omitted.

The step of identifying the data link integrity impediment may include a column including a number of a dynamic information message transmitted or received within a communication coverage area of a coast station managed by the control station, a maritime mobile service identification code, latitude, and longitude. After analyzing the family, at least one of a case where there is a radio station transmitting a location report with an unregistered maritime mobile service identification code and a case where there are two or more radio stations transmitting different location information with a registered maritime mobile service identification code. It can be determined whether one is applicable.

The step of identifying the data link integrity impediment may include, at the start of each frame, information about a channel number included in a frame summary of AIS reception (FSR) sentence provided from a receiving device and an average noise level value of a previous frame. By analyzing the included column family, it is possible to determine whether a large number of intentional or malicious broadcast messages in frame units exist.

According to the present disclosure, a system, a control station, or a control method for monitoring integrity-compromising elements systematically and automatically identifies the existence of integrity-compromising elements by classifying data according to message packets and constructing a column family that meets each criterion. can do.

1 is a view showing a ship station, a coast station, a control station, and a situation control room based on Korean waters;
2 is a diagram showing the configuration of a system for monitoring, analyzing, and identifying maritime microwave data link integrity impediments according to an embodiment of the present disclosure;
3 is a diagram showing a distributed data processing method of a system for monitoring, analyzing, and identifying maritime microwave data link integrity impediments according to an embodiment of the present disclosure; and
4 is a diagram illustrating a data link access algorithm of a Class A vessel using an automatic identification system (AIS) according to an embodiment of the present disclosure.

Prior to a detailed description of the present disclosure, the method of describing the present specification and drawings will be described.

First, terms used in the present specification and claims are general terms in consideration of functions in various embodiments of the present disclosure. However, these terms may vary depending on the intention of a technician working in the art, legal or technical interpretation, and the emergence of new technologies. In addition, some terms are arbitrarily selected by the applicant. These terms may be interpreted as the meanings defined in this specification, and if there is no specific term definition, they may be interpreted based on the overall content of this specification and common technical knowledge in the art.

In addition, the same reference numerals or numerals in each drawing attached to this specification indicate parts or components that perform substantially the same function. For convenience of description and understanding, the same reference numerals or symbols are used in different embodiments. That is, even if all components having the same reference numerals are shown in a plurality of drawings, the plurality of drawings do not mean one embodiment.

Also, in the present specification and claims, terms including ordinal numbers such as “first” and “second” may be used to distinguish between elements. These ordinal numbers are used to distinguish the same or similar components from each other, and the meaning of the term should not be construed as being limited due to the use of these ordinal numbers. For example, the order of use or arrangement of elements associated with such ordinal numbers should not be limited by the number. If necessary, each ordinal number may be used interchangeably.

In this specification, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, the terms "comprise" or "consist of" are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other It should be understood that the presence or addition of features, numbers, steps, operations, components, parts, or combinations thereof is not precluded.

In the embodiments of the present disclosure, terms such as “module,” “unit,” and “part” are terms used to refer to components that perform at least one function or operation, and these components are hardware or software. It may be implemented or implemented as a combination of hardware and software. In addition, a plurality of "modules", "units", "parts", etc. are integrated into at least one module or chip, except for cases where each of them needs to be implemented with separate specific hardware, so that at least one processor can be implemented as

Also, in an embodiment of the present disclosure, when a part is said to be connected to another part, this includes not only a direct connection but also an indirect connection through another medium. In addition, the meaning that a certain part includes a certain component means that it may further include other components without excluding other components unless otherwise stated.

Hereinafter, various embodiments of the present invention will be described in detail using the accompanying drawings.

1 is a diagram showing a ship station, a coast station, a control station, and a situation control room based on the sea area of Korea.

Vessels (100-1, 2, 3, …) are operating, anchored or moored in conjunction with the Automatic Identification System (AIS) or VDES (Very Short Band Data Exchange System) according to international agreements, and communicate with various external devices It may be referred to as a ship station, including a device or system for doing so.

The coast station 200 corresponds to a device or system that receives information of ship stations within its jurisdiction or transmits information to ship stations.

The control station (300. Operation Center) corresponds to a device or system that controls and manages safe navigation, including the amount of traffic of coast stations and ship stations within its jurisdiction. The control station may be provided for each region in the country.

The situation control room 400 corresponds to a device or system that collects information from control stations in charge of each region nationwide and monitors the information in an integrated manner.

As shown in FIG. 1, the situation control room 400 has jurisdiction over one or more control stations, and each control station has jurisdiction over one or more coast stations, and each coast station exchanges information with ship stations within a communication coverage area. to target Each coast station is installed to have a communication coverage area that partially overlaps between two adjacent coast stations. This is to eliminate shadows that may occur at the boundary of communication coverage for continuous and stable maritime traffic control and to reduce the non-receipt rate due to the effect of garbling (propagation and time resource collision). In addition, each coast station may be implemented to ensure continuity of information collection through line redundancy using a communication device composed of a main device and a spare device, a dedicated line, and a commercial LTE mobile communication network.

Referring to FIG. 1 , each communication coverage area of a coast station is shown, and a ship (ship station) within the coverage area and a ship (ship station) outside the communication coverage area are respectively shown.

In addition, circles indicated by dotted lines represent the communication coverage area of each ship station, and other ships within the communication coverage area of each ship station, other ships outside the communication coverage area of each ship station, and the like are respectively shown.

In the example of FIG. 1, the ship 100-1 refers to a harmless ship that is not affected or not affected by the data link, and the ship 100-2 refers to a ship that includes one or more types of data link impairing elements, The ship 100-3 is within the communication coverage area of the ship (ex. 100-2) including any one or more types of data link impediments and is damaged by the data link.

2 is a diagram showing the configuration of a system for monitoring, analyzing, and identifying maritime microwave data link integrity impediments according to an embodiment of the present disclosure.

The microwave band data exchange system (11, 12, ...) for coast stations receives information from other radio stations (ex. other ship stations) inside the communication coverage area within its jurisdiction or provides periodic coast station information or control/management services. It plays the role of sending information for the purpose of

According to the present disclosure, the system 20 for monitoring/analyzing/identifying data link integrity streams the information of other radio stations received from the VHF data exchange system for coast stations by type of receiving device (AIS, ASM, VDE-TER). After processing, it is stored in distributed storage, and the stream of continuous data with time continuity is divided into appropriate units to identify 7 types of data link integrity impediments. After processing the distributed data constituting the mart, it is possible to derive the result value by identifying and analyzing whether it corresponds to the judgment criteria for each type.

Conventionally, the types that can threaten the integrity of the VDL could be listed as 7 types as follows, but unlike the conventional rules that only listed 7 types, the present system 20 specifically analyzes / There is a feature that utilizes an algorithm for identification.

- Type 1: Transmission of unauthorized data link control signals

- Type 2: Failure of at least one device to international performance standards

- Type 3: Incorrect configuration and installation of at least one device

- Type 4: Whether or not service messages from unauthorized coast stations are transmitted or received.

- Type 5: Whether spoofing (stealing) messages are sent or received

- Type 6: Whether to send or receive DOS (Denial of Service Attack) messages

- Type 7: Abuse of the protocol

Each of the components 21, 22, 23, 24, and 25 constituting the system 20, which will be described later, may be included in at least one control station. In this case, the control station can monitor and analyze the integrity of the data link using the corresponding configurations. In addition, each of the components 21, 22, 23, 24, and 25 constituting the system 20 may be provided in at least one of a situation control room, a control station, and a coast station.

In the system 20, the distributed stream processing module 21 converts each message based on the formatter and channel code included in the header part of the received data link message packet, to the type of receiving device (AIS, ASM, VDE-TER), coast station transmission/reception status, used channel information, and the original text of each data link message is stored in the corresponding distributed storage 22. When processing distributed streams, using the information included in the header part of the message packet, the data payload section in the message packet is converted into a 6-bit binary field and can be split into bits according to the message structure and reconstructed quickly without going through a complicated parsing process. and accurately classify messages.

In addition, when the original text of each data link message is stored in the distributed storage 22 through distributed stream processing, each message included in a VDL signal information (VSI) sentence provided in a pair with every received message is received from the receiving device. Information on the time (hhmmss.sss), the first slot number used to transmit the message, the electric field strength of the received message, and the signal-to-noise ratio (SNR) are added, and the FSR provided from the receiving device at the start of each frame ( Frame summary of AIS reception) adds information about the average noise level value of the previous frame included in the sentence. This is a time-series data alignment that cannot be clearly distinguished only by the information contained in the data payload in the data link message packet, and the presence or absence of data link integrity deterioration factors due to background noise or garbling of the communication channel. used as a basis

The original data link message stored in the distributed storage 22 is converted into a 6-bit binary field through the AIS/ASM/VDE message parser in the distributed data processing process of the distributed data processing module 23, and the bits according to each different message structure After being broken down into units, it is composed of key/value pairs for parameters and corresponding values, which identifies 7 types of data link integrity impediments again in 1-minute intervals, which are the basic unit of TDMA frame synchronization. It is a collection of datasets that are easy to analyze whether or not the 16 types of criteria defined for It is reconstructed and stored in the data mart 24.

The 16 types of criteria defined to identify 7 types of data link integrity impediments are as follows.

- Criterion 1: Origin and authenticity of AIS control messages and positioning messages;

- criterion 2: origin and authenticity of VDE-TER control messages;

- criterion 3: adequacy of the content and validity period of the control message;

- criterion 4: existence of conflicting control messages;

- Criterion 5: compliance with data link access regulations;

- Criterion 6: compliance with slot access regulations;

- Criterion 7: compliance with reporting intervals;

- Criterion 8: Response to specific message, compliance with Re-action function,

- Criterion 9: compliance with cross-channel transmission;

- Criterion 10: Peripheral devices such as sensors and satellite navigation receivers are not installed or are not properly connected;

- Criterion 11: Origin and authenticity of safety-related messages;

- Criterion 12: Origin and authenticity of geolocation messages;

- Criterion 13: Inclusion of dynamic, static and voyage-related data, including unintentional misinformation;

- Criterion 14: Inclusion of dynamic, static or voyage-related data that is deliberately false;

- Criterion 15: Existence of intentional and malicious broadcast messages,

- Criterion 16: Existence of protocol abuse

For example, criteria 1 to 4 may be specific procedures for the above-described type 1 determination, criteria 5 to 9 may be specific procedures for the above-described type 2 determination, and criterion 10 may be the above-described type 3 can be a specific process for the determination, criteria 11 and 12 can be a specific process for the above-described type 4 determination, and criteria 13 and 14 can be a specific process for the above-described type 5 determination and criterion 15 can be a specific process for determining the above-mentioned type 6.

In the method for analyzing whether the criterion 1 and criterion 2 are applicable,

AIS message no. 16 (assignment mode command), message no. 20 (data link management), message no. 22 (channel management) to no. 23 (group assignment command) and VDE-TER (terrestrial VDE) message no. 0 (media access control) , Message Nos. 20 to 22 (bulletin board) correspond to coast station-only messages defined to be used to control the data link within the coast station's communication coverage area.

Here, the control station, through the system 20,

Parsing the data payload section of the data link message corresponding to the control message among the messages sent from the coast station managed by the control station (VDO or EDO sentence) or messages received from unspecified numbers (VDM or EDM sentence) It is possible to determine whether or not the approved coast station control message corresponds to the value of the parameter obtained through the above process. That is, by parsing AIS message no. 16, message no. 20, message no. 22 to 23 and VDE-TER message no. 0, message no. 20 to 22 transmitted or received by the coast station managed by the control station, the message in the data mart Through key/value analysis of the column family reconstructed into a dataset including static information such as number, MMSI, latitude, and longitude, whether or not at least one of the following cases is applicable can be derived as a result. can

- If it does not match the identification code of the coast station managed by the control station,

- If the communication coverage area managed by the control station adjacent to the control station does not match the overlapping coast station identification code (ex. the first coast station of the first control station (: the corresponding control station) and the second control station In a state where the communication coverage area overlaps between the second coast stations, if the message does not match the identification code of the second coast station),

- If it matches the coast station identification code managed by the control station, but there is no transmission history from the coast station managed by the control station, or other parameter values such as location information of the coast station do not match,

- Although the communication coverage area managed by the control station adjacent to the control station matches the overlapping coast station identification code, there is no transmission history from the coast station managed by the actual adjacent control station, or other parameter values such as location information of the coast station If they don't match,

In the method for analyzing whether criterion 3 is applicable, the control station, through the system 20,

AIS message no. 16, message no. 20, message no. 22 to 23 and VDE-TEST message no. 0, message no. 20 to 22 sent or received by the coast station managed by the control station are parsed and the message number in the data mart, Dataset containing control setting information such as slot offset, slot increment, number of slots, timeout, geographical area (north-south-west coordinates), station class, vessel type, reporting interval, bulletin board version, and version validity. Through the key/value analysis of the column family reconstructed as , whether or not at least one of the following cases is applicable can be derived as a result.

- exceeding parameter assignment limit settings or using settings reserved for future use;

- recommended values for increments (2, 3, 5, 6, 9, 10, 15, 18, 25, 30, 45, 50, 75, 90, 125, 150, 225, 250, 375, 450, 750, 1125), if none of them apply,

- If the number of consecutive slots in the reserved block exceeds 5,

- If the timeout setting is decreased by 1 or not renewed,

- if there are more than three points of intersection of the boundaries of a geographical area;

- If the bulletin board version does not match or the validity period exceeds 45 days,

- If the TDMA frame size does not correspond to any of the recommended values (2, 3, 5, 6, 9, 10, 15)

In the method for analyzing whether criterion 4 is applicable, the control station, through the system 20,

AIS messages 22 and 23 are parsed to obtain control setting information such as message number within the data mart, individual addressing or geographic area, transmit/receive mode, transmit power strength, radio station class, vessel type, report interval, and silence time. Through key/value analysis of the column family reconstructed into the dataset, whether or not at least one of the following cases is applicable may be derived.

If two or more adjacent coast stations have conflicting maritime mobile service identification codes assigned to individual addresses using AIS message No. 22 or transmission/reception modes set for the same geographical area,

If two or more adjacent coast stations have conflicting maritime mobile service identification codes assigned to individual addresses using AIS message No. 22 or the strength of transmit power set for the same geographical area,

If two or more adjacent coast stations have conflicting transmission/reception modes set for the radio station class or ship type in the same geographical area using AIS message No. 23,

If two or more adjacent coast stations have conflicting reporting intervals set for radio station class or ship type in the same geographic area using AIS message No. 23,

If two or more adjacent coast stations have conflicting silence times set for radio station classes or ship types in the same geographic area using AIS message No. 23,

Whether or not any one of them is applicable can be derived as a result.

In the method for analyzing whether criterion 5 is applicable, whether or not data link access regulations are observed is determined as follows.

The control station parses the dynamic information message of the mobile station using RATDMA (random access time division multiple access), ITDMA, or SOTDMA access schemes such as AIS message No. 1 to No. 3 to obtain message number, synchronization status, slot timeout, Communication State, such as the number of other radio stations received (number of other ships that received the message), slot number, UTC time, slot offset, slot increment, number of consecutive slots, allocation keep flag Through key/value analysis of a column family reconstructed into a dataset including information, whether or not at least one of the following cases is applicable may be derived as a result.

- If the report message of the first data link access vessel is not AIS message No. 3,

- If the first data link access vessel does not report while calculating/updating the slot increment among the communication status information through AIS message No. 3 for one minute,

- In the case where the ship that designated the slot increment as '0' among the communication status information in AIS message No. 3 did not report it in AIS message No. 1 in the next transmission,

- If the report message of the vessel designated as the allocation mode by AIS message No. 16 and message No. 23 of the coast station is not AIS message No. 2

In the method for analyzing whether criterion 6 is applicable, whether or not the slot access regulation is observed is determined as follows.

The control station determines the reception time of each message and the first slot number used to transmit the message included in the VDL signal information (VSI) sentence provided as a pair with each transmitted/received message from the coast station device for all received messages. Through information analysis on , whether or not at least one of the following cases is applicable may be derived as a result.

- The second unit (ss.sss) including the third decimal place of the message reception time transmitted using a single slot is {(the first slot number used to transmit the message + 1) x slot clock period (1/37.5 ms)} is significantly larger (tens of ms or more) than the calculated value,

- The second unit (ss.sss) including the third decimal place of the message reception time transmitted using consecutive slots is {(the first slot number used to transmit the message + the number of consecutive slots - 1) x slot clock cycle (1/37.5 ms)} significantly (tens of ms or more) larger than the calculated value

Table 1 is a table showing the automatic identification system reporting interval according to the dynamic state of the wireless station using the automatic identification system, the reporting rate converted based on the automatic identification system, the slot increment, and the candidate slot selection range. The international standard stipulates that the reporting interval of a ship is to report dynamic information at a minimum interval of 2 seconds to a maximum of 3 minutes depending on the sailing condition, speed, and course change of the ship, and report static information every 6 minutes. 10 seconds is the default setting for the reporting interval of search and rescue aircraft using the automatic identification system.

4 is a diagram illustrating a data link access algorithm of a Class A vessel using an automatic identification system (AIS) according to an embodiment of the present disclosure.

The automatic identification system monitors the datalink for 1 minute before accessing the datalink, and after 1 minute elapses, it randomly selects the Nominal Start Slot between Current Slot and Nominal Increment for datalink access. Slot). The nominal start slot for initial access has the same value as the nominal slot, and if the selection interval based on this nominal slot is determined, four or more free states suitable for the candidate slot selection conditions are determined within the selection interval. Determines whether or not there is an empty slot, randomly selects a nominal transmission slot among them, calculates and stores the increment for the next nominal transmission slot (the offset from the slot to be used for this transmission to the slot to be used for the next transmission) do. In this way, if the nominal transmission slot for the first data link access is determined, the nominal transmission slot and the next transmission slot are continuously assigned/calculated during the first frame phase of 1 minute, and message 3 (special location report) is transmitted, and if all allocations are made after one frame, the slot increment is set to 0 in the last transmission to indicate that no more allocations are made, and then the continuous operation step is entered. The continuous operation phase is maintained until the automatic identification system terminates, enters allocation mode, or changes the reporting interval, and transmits message #1 using the SOTDMA (autonomous time division multiple access) access scheme. Message No. 2 is used when operating in the allocation mode by the coast station's allocation mode command or group allocation command.

The composition of the dynamic information report message (AIS messages 1 to 3) of a Class A vessel using the automatic identification system is listed in Table 2, and the communication status of the message using the ITDMA access system and the SOTDMA access system The communication states of messages using are listed in Table 3 and Table 4, respectively. Table 5 is a table explaining types and contents of submessages according to slot timeout numbers among communication states of messages using the SOTDMA access scheme.

In the method for analyzing whether criterion 7 is applicable, whether or not the reporting interval is observed is determined as follows.

The control station parses dynamic information messages such as message 1, message 4, message 9, message 18, and message 21 of the AIS and static information messages such as message 5 and message 24 to obtain messages in the data mart. A family of columns reconstructed into datasets containing information such as number, channel number, station class, maritime mobile service identification, navigational status, speed over ground, and corse over ground. Through key/value analysis, whether or not at least one of the following cases is applicable may be derived as a result.

- If a station that made a dynamic report using AIS message No. 1, message No. 4, message No. 9, message No. 18, or message No. 21 does not report at the nominal reporting interval according to the dynamic status of each station class shown in Table 1,

- In the case where a station that made a static report using AIS message No. 5 and message No. 24 did not report within a reporting interval of 6 minutes

The automatic identification system can request UTC information (hour/minute/second) and date information (year/month/day) from other wireless stations by using AIS message No. 10. Message No. 4) is specified to respond. In addition, the dynamic/static information of other radio stations can be queried using Message No. 15, and the radio station receiving the query transmits the dynamic or static message requested by the other radio stations through the same channel as the channel on which the query was received using the designated slot offset information. are required to respond. However, Class B devices and AtoN devices cannot query other stations.

In the method for analyzing whether criterion 8 is applicable, whether a response to a specific message and a reaction function are observed is determined as follows.

The control station parses query messages such as AIS message No. 10 and message No. 15 to request a query response such as the message number, the maritime mobile service identification code of the own ship, the maritime mobile service identification code of the query target, the request message number, and the slot offset. Query response such as message number, channel number, maritime mobile service identification code of the ship, and maritime mobile service identification code of the response target by parsing the key/value of the column family reconstructed as a data set including information and the corresponding response message. Whether or not at least one of the following cases is applicable may be derived as a result through key/value analysis of the reconstructed column family with a data set including information.

- If there is no response message to the UTC information (hour/minute/second) and date information (year/month/day) query message,

- If there is no response message to the dynamic/static information query message,

The dynamic information message and the static information message of the automatic identification system stipulate that the message be transmitted while crossing two channels, unless otherwise specified through a query or individual/group assignment or channel management message. Application Specific Messages (ASM) also stipulate that messages be transmitted while crossing two channels. However, the static information messages 24A and 24B of the B class device must be transmitted on the same channel, and chain transmission using the MITDMA (multiple incremental time division multiple access) access scheme among the application specific messages (ASM) of the microwave band data exchange system. In this case, they must be transmitted on the same channel.

In the method for analyzing whether criterion 9 is applicable, whether cross-channel transmission is compliant is determined as follows.

The control station transmits dynamic and static information messages such as AIS message Nos. 1 to 5, message No. 9, message No. 18, message No. 21, and message No. 24, and ASM message No. 0, message No. 2, message No. 4, and message 6. Through key/value analysis of column families reconstructed into a dataset including network access information and static information such as channel number, message number, and maritime mobile service identification code by parsing application-specific messages such as Whether or not at least one is applicable can be derived as a result.

- when the dynamic information message of a ship with the same maritime mobile service identification code is not transmitted across the two channels;

- when static information messages from ships with the same maritime mobile service identification code are not transmitted across the two channels;

- When application-specific messages from ships with the same maritime mobile service identification code are not transmitted while crossing two channels

In the method for analyzing whether criterion 10 is applicable, whether a peripheral device such as a sensor or a satellite navigation receiver is not installed or has a poor connection can be determined as follows.

The control station parses dynamic information messages such as AIS message Nos. 1 to 4, message No. 9, and message No. 18 to parse the message number, maritime mobile service identification code, speed over ground, course over ground, latitude, longitude, rate of turn, and heading. Through key/value analysis of a column family reconstructed into a dataset including sensing information such as , altitude, whether or not at least one of the following cases is applicable may be derived as a result.

- If the ground speed is 1,023,

- If the ground course is 3,600,

- If the latitude is 91,

- If the longitude is 181,

- If the turn rate is -128,

- If the forward defense is 511,

- If the altitude is 4,095

The automatic identification system can designate the maritime mobile service identification code of a specific radio station using AIS message 12 and message 14 or transmit safety-related messages with a length of 1 to 5 slots through broadcasting, and can transmit individually designated maritime mobile service A radio station whose identification code matches its own maritime mobile service identification code can transmit an acknowledgment (ACK) to the safety-related message using message #13. The main content of the safety-related message uses a text format consisting of 6-bit-ASCII characters.

In the method for analyzing whether criterion 11 is applicable, the origin and authenticity of the safety-related message can be determined as follows.

The control station parses AIS message No. 12 and message No. 14 and analyzes the key/value of the column family reconstructed into a data set including the message number, maritime mobile service identification code, and 6-bit-ASCII text contents, in the following cases. Whether or not it is applicable can be derived as a result.

- Among the contents of 6bit-ASCII characters, if the text implying a distress situation such as “MAYDAY”, “SOS”, “DISTRESS”, “CRASH”, “AGROUND”, “FIRE”, “FLOOD” is included

In the method for analyzing whether the criterion 12 is applicable,

AIS message No. 17 (binary GNSS broadcasting) is a coastal station-only message that can be used to provide location correction information to other wireless stations within the coastal station's communication coverage area. The control station controls the data payload section of the data link message corresponding to the position correction message among the messages (VDO or EDO sentence) transmitted from the coast station managed by the control station or the messages (VDM or EDM sentence) received from many unspecified persons. It is possible to determine whether or not the approved coast station service message corresponds to a parameter value obtained by parsing . That is, AIS message No. 17 transmitted or received by the coast station managed by the control station is parsed and reconstructed into a dataset including dynamic and static information such as message number in the data mart, maritime mobile service identification code, latitude, and longitude. Through key/value analysis of the column family, whether or not at least one of the following cases is applicable may be derived as a result.

- If it does not match the identification code of the coast station managed by the control station,

- If the communication coverage area managed by the control station adjacent to the control station does not match the overlapping coast station identification code,

- If it matches the coast station identification code managed by the control station, but there is no transmission history from the coast station managed by the control station, or other parameter values such as location information of the coast station do not match,

- Although the communication coverage area managed by the control station adjacent to the control station matches the overlapping coast station identification code, there is no transmission history from the coast station managed by the actual adjacent control station, or other parameter values such as location information of the coast station In case of mismatch

In the method for analyzing whether criterion 13 is applicable, whether or not dynamic, static, and voyage-related data including unintentional erroneous information are included can be determined as follows.

The control station parses mobile station dynamic/static information messages such as AIS message Nos. 1 to 3 and message 5 so that users such as message number, maritime mobile service identification code, navigational status, and destination information are MKD ( Through the key/value analysis of the column family reconstructed as a dataset that includes dynamic and navigation-related information that can be mistyped through Minimum Keyboard Display), whether or not at least one of the following cases is applicable is derived as a result.

- if the position of the vessel represents a point temporarily outside the area of communication coverage of the coast station;

- If the sailing condition of a vessel sailing at a constant speed indicates another condition, such as mooring, anchoring, anchoring, or aground;

- If the destination is misspelled or partially missing

In the method for analyzing whether criterion 14 is applicable, it is determined as follows whether or not dynamic, static, and voyage-related data decorated with intentional falsehood are included.

The control station parses dynamic information messages such as AIS message Nos. 1 to 3 and message No. 18 and reconstructs a column family key into a dataset including information such as message number, maritime mobile service identification code, latitude, and longitude. / Through value analysis, whether or not at least one of the following cases is applicable is derived as a result.

- if there is a station transmitting position reports with an unregistered maritime mobile service identification code;

- When there are two or more radio stations transmitting different location information with registered maritime mobile service identification codes

In the method for analyzing whether criterion 15 is applicable, the presence or absence of intentional or malicious broadcast messages is determined as follows.

Specifically, the control station reconstructs the channel number included in the frame summary of AIS reception (FSR) sentence provided from the receiving device at the start of each frame into a dataset including information on the average noise level value of the previous frame. Through the key/value analysis of the column family, it is possible to derive a result of whether a large number of intentional or malicious broadcast messages exist in frame units.

In the method for analyzing whether or not the criterion 16 is applicable, in the process of determining whether there is a case of protocol abuse, the control station calculates whether the standard 1 to criterion 3, criterion 10, criterion 12, and criterion 14 are applicable to the protocol abuse case. results can be derived.

Meanwhile, the above-described processes for identifying data link integrity impediments may be performed under certain conditions.

As a specific example, when the signal-to-noise ratio of the data link message is greater than or equal to the critical value, the control station can identify the data link integrity impairing factor based on the column family in which the data link message is reconstructed as described above.

Here, the threshold value may be preset and may be updated according to a predetermined period. For example, it may be set lower as the average noise level of the previous frame is higher and higher as the average noise level of the previous frame is lower, but is not limited thereto.

On the other hand, if the signal-to-noise ratio of the data link message is less than the critical value, the control station can identify the data link integrity impediment based on the column family in which the data link message received in the next frame of the frame in which the data link message is received is reconstructed. there is.

However, if the signal-to-noise ratios of one or more data link messages transmitted and received within a certain number of consecutive frames are all less than the critical value, the control station determines that the signal-to-noise ratio of one or more data link messages included in the consecutive frames is the largest. Based on the column family from which the message is reconstructed, data link integrity impediments may be identified.

Here, the above-described predetermined number may be periodically updated according to the frequency at which integrity-compromising elements are discovered during the recent period. For example, the above-described predetermined number may be updated/set smaller as the frequency at which integrity-compromising elements are found is higher. As a result, frequent verification can be performed even for data link messages having a poor signal-to-noise ratio.

Meanwhile, as long as the various embodiments described above do not conflict with each other, two or more embodiments may be implemented together.

Meanwhile, various embodiments described above may be implemented in a recording medium readable by a computer or a similar device using software, hardware, or a combination thereof.

According to the hardware implementation, the embodiments described in this disclosure are application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), and field programmable gate arrays (FPGAs). ), processors, controllers, micro-controllers, microprocessors, and electrical units for performing other functions.

In some cases, the embodiments described herein may be implemented by a processor itself. According to software implementation, embodiments such as procedures and functions described in this specification may be implemented as separate software modules. Each of the software modules described above may perform one or more functions and operations described herein.

Meanwhile, computer instructions for performing processing operations of a server or a terminal according to various embodiments of the present disclosure described above may be stored in a non-transitory computer-readable medium. Computer instructions stored in such a non-transitory computer readable medium, when executed by a processor of a specific device, cause the above-described device to perform processing operations of the electronic device according to the various embodiments described above.

A non-transitory readable medium is not a medium that stores data for a short moment, such as a register, cache, or memory, but a medium that stores data semi-permanently and can be read by a device. Specifically, the various applications or programs described above may be stored and provided in non-transitory readable media such as CD, DVD, hard disk, Blu-ray disk, USB, memory card, ROM, and the like.

In addition, although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific embodiments described above, and the technical field to which the present invention belongs without departing from the gist of the present invention claimed in the claims. Of course, various modifications are possible by those skilled in the art, and these modifications should not be individually understood from the technical spirit or prospect of the present invention.

100: ship (ship station) 200: coast station
300: control station 400: central control room

Claims (9)

A control method of a control station for monitoring data link integrity impediments of a microwave band data exchange system of a coast station communicating with one or more ships, the method comprising:
receiving a data link message from a very high frequency band data exchange system of the coast station;
Classifying and storing the data link message according to a type of receiving device, transmission/reception status of a coast station, and channel information based on a header of a data link message packet;
reconstructing the classified and stored data link messages into column families of a dataset each matching a plurality of different decision criteria; and
A control method of a control station comprising: identifying a data link integrity impediment based on the reconstructed column family. According to claim 1,
The step of classifying and storing the data link message,
adding information about the time of reception of the message, the number of the first slot used to transmit the message, the electric field strength of the message, and the signal-to-noise ratio of the message;
A control method of a control station that adds information about an average noise level value of a frame previous to a frame including the message. According to claim 1,
The step of identifying the data link integrity impediment,
identify whether an unauthorized data link control signal is transmitted;
In the step of identifying the data link integrity impediment, in identifying whether an unauthorized data link control signal is transmitted,
Identifying a control message among messages transmitted or received by a coast station managed by the control station;
Identification of the control message when the identification code of the control message does not match the identification code of the coast station by analyzing a column family composed of a data set including the number, identification code, latitude, and longitude of the control message If the code matches the identification code of the coast station but there is no history of transmitting the control message from the coast station, the identification code of the control message overlaps the coast station managed by the control station and the communication coverage area, and another control message When the identification code of the control message does not match the identification code of another coast station under the management of the station, and when the identification code of the control message matches the identification code of the other coast station but there is no history of transmitting the control message from the other coast station. determine whether at least one of the
In the step of identifying the data link integrity impediment, in identifying whether an unauthorized data link control signal is transmitted,
By analyzing the column family consisting of the control setting information of messages transmitted or received by coast stations managed by the control station, recommendations for incremental if parameter assignment limit settings are exceeded or settings reserved for future use are used. When the number of consecutive slots in the reserved block exceeds a certain number, when the timeout setting is decreased by 1 or not updated, when the intersection of geographical area boundaries exceeds three, the bulletin board version It is determined whether the correctness also corresponds to one of the case that does not match or the validity period exceeds a certain period, and the case that the TDMA frame size does not correspond to the recommended value;
The control setting information,
number of messages, slot offset, slot increment, number of slots, timeout, geographic area, station class, vessel type, reporting interval, bulletin board version, and validity of the version;
In the step of identifying the data link integrity impediment, in identifying whether an unauthorized data link control signal is transmitted,
By analyzing a column family composed of control setting information of messages transmitted or received by one or more coast stations managed by the control station, if the transmission/reception modes set by two or more adjacent coast stations for the same geographical area are conflicting, two adjacent coast stations When the transmit power strengths set by two or more coast stations for the same geographical area are conflicting, When the transmission/reception modes set by two or more adjacent shore stations for radio station classes or ship types in the same geographical area are conflicting, or two or more adjacent shore stations At least if the reporting intervals established by stations for radio station classes or ship types in the same geographic area are conflicting, and if two or more adjacent coast stations have conflicting silence times established for radio station classes or vessel types in the same geographic area. determine if one of the
The control setting information,
A control method of a control station, including number of messages, geographic area, transmission/reception mode, strength of transmission power, radio station class, vessel type, reporting interval, and silence time. According to claim 1,
The step of identifying the data link integrity impediment,
identify whether at least one device does not meet international performance standards;
In the step of identifying the data link integrity impediment, in identifying whether or not the at least one device does not meet the international performance standard,
By analyzing the column family consisting of the communication state information of the message transmitted or received within the communication coverage area of the coast station managed by the control station, if the report message of the ship that first accessed the data link is not AIS message No. 3, the data link If the first access vessel does not report while calculating or updating the slot increment, if the data link first access vessel does not report AIS message No. 1 in the next transmission after designating the slot increment as 0, and the coast station AIS message No. 16 Determining whether at least one of the cases where the report message of the ship designated as the allocation mode by No. 23 is not No. 2,
The communication state information,
number of messages, synchronization status, slot timeout, number of other ships receiving messages, slot number, UTC time minutes, slot offset, slot increment, number of consecutive slots, and allocation hold flag;
In the step of identifying the data link integrity impediment, in identifying whether or not the at least one device does not meet the international performance standard,
By analyzing the column family including the reception time of the message transmitted or received within the communication coverage area of the coast station managed by the control station and the first slot number used to transmit the message, If the time identified to the third decimal place of the reception time is greater than the value calculated based on the first slot number and the slot clock cycle, and the reception time of the message transmitted through consecutive slots is the third decimal place Determining whether at least one of the cases where the time identified up to the digit or less is greater than a value calculated based on the first slot number and the slot clock cycle by a predetermined time or more;
In the step of identifying the data link integrity impediment, in identifying whether or not the at least one device does not meet the international performance standard,
Identifying a dynamic information message or a static information message transmitted or received within a communication coverage area of a coast station managed by the control station;
By analyzing the column family including number, channel number, radio station class, maritime mobile service identification code, voyage status, ground speed, and ground course of the dynamic information message or the static information message, the ship making the dynamic report Determining whether at least one of the case where the report was not reported at the nominal reporting interval according to the dynamic status of each class and the case where the ship that made the static report did not report at the preset reporting interval was determined;
In the step of identifying the data link integrity impediment, in identifying whether or not the at least one device does not meet the international performance standard,
Identifying an inquiry message and a response message transmitted or received within a communication coverage area of a coast station managed by the control station;
Obtain query response request information including the number of the query message, a maritime mobile service identification code of a ship that sent the query message, a maritime mobile service identification code of a query target of the query message, a request message number, and a slot offset; ,
obtaining query response information including a number of the response message, a channel number, a maritime mobile service identification code of a ship that transmitted the response message, and a maritime mobile service identification code of a response target of the response message;
determining whether there is no response message to the query message by analyzing a column family including the query response request information and a column family including the query response information;
In the step of identifying the data link integrity impediment, in identifying whether or not the at least one device does not meet the international performance standard,
Identify dynamic information messages, static information messages, and application-specific messages transmitted or received within a communication coverage area of a coast station managed by the control station;
By analyzing a column family including a channel number, a message number, and a maritime mobile service identification code of each of the dynamic information message, the static information message, and the application-specific message, a ship having the same maritime mobile service identification code is analyzed. When dynamic information messages are not transmitted across two channels, static information messages of ships with the same maritime mobile service identification code are not transmitted across two channels, and ships with the same maritime mobile service identification code A control method of a control station, which determines whether at least one of the cases in which the application-specific message is not transmitted while crossing two channels. According to claim 1,
The step of identifying the data link integrity impediment,
identify misconfiguration and installation of at least one device;
In the step of identifying the data link integrity impairing element, in identifying incorrect configuration and installation of at least one device,
Identifying a dynamic information message transmitted or received within a communication coverage area of a coast station managed by the control station;
By analyzing the column family including the number of the dynamic information message, maritime mobile service identification code, ground speed, ground course, latitude, longitude, turn rate, heading, and altitude, determining whether peripheral devices are not installed or connection is defective, The control method of the control station. According to claim 1,
The step of identifying the data link integrity impediment,
identify whether unauthorized coast station service messages have been sent or received;
In the step of identifying the data link integrity impediment, in identifying whether an unauthorized coast station service message is transmitted or received,
Identifying a safety-related message transmitted or received within a communication coverage area of a coast station managed by the control station;
By analyzing a column family including the number of the safety-related message, a maritime mobile service identification code, and 6-bit-ASCII text content, it is determined whether the safety-related message includes text implying a distress situation,
In the step of identifying the data link integrity impediment, in identifying whether an unauthorized coast station service message is transmitted or received,
Identifying a position correction message transmitted or received by a coast station managed by the control station;
The positioning message number, maritime mobile service identification code, latitude, and longitude of the positioning message are analyzed, and when the identification code of the positioning message does not match the identification code of the coast station, the positioning message If the identification code of matches the identification code of the coast station, but the coast station has no history of transmitting the location correction message, and the identification code of the location correction message overlaps the coast station and the communication coverage area, and other control A control method of a control station, which determines whether at least one of cases matching the identification code of another coast station under the control of the station but having no history of transmitting the location correction message from the other coast station is applicable. According to claim 1,
The step of identifying the data link integrity impediment,
identify whether a spoof message was sent or received;
In the step of identifying the data link integrity impediment, in identifying whether a spoofing message is transmitted or received,
Identifying a dynamic information message or a static information message transmitted or received within a communication coverage area of a coast station managed by the control station;
By analyzing the column family including the number, maritime mobile service identification code, voyage status, and destination information of the dynamic information message or the static information message, the location of the vessel indicates a point temporarily outside the communication coverage area of the coast station. In this case, determining whether at least one of the cases where the sailing state of the ship sailing at a certain speed indicates another state such as mooring, anchoring, anchoring, or stranding, and the case where the destination is misspelled or partially omitted,
In the step of identifying the data link integrity impediment, in identifying whether a spoofing message is transmitted or received,
Unregistered maritime mobile services are identified by analyzing column families including number, maritime mobile service identification code, latitude, and longitude of a dynamic information message transmitted or received within the communication coverage area of the coast station managed by the control station. Control of the control station for determining whether at least one of the case where there is a radio station that transmits a location report with a code and the case where there are two or more radio stations that transmit different location information with a registered maritime mobile service identification code exists method. According to claim 1,
The step of identifying the data link integrity impediment,
identify whether a denial-of-service attack message was sent or received;
In the step of identifying the data link integrity impairing element, in identifying whether a denial of service attack message is transmitted or received,
At the start of each frame, the channel number included in the frame summary of AIS reception (FSR) sentence provided from the receiving device and the column family including information on the average noise level value of the previous frame are analyzed, and the intentional Alternatively, a control method of a control station determining whether a large number of malicious broadcast messages exist. According to claim 2,
The step of identifying the data link integrity impediment,
When the signal-to-noise ratio of the data link message is greater than or equal to a critical value, a data link integrity impediment is identified based on the reconstructed column family;
When the signal-to-noise ratio of the data link message is less than the threshold value, a data link integrity impediment is identified based on a column family in which a data link message received in a frame next to a frame in which the data link message is received is reconstructed,
The control method,
When the signal-to-noise ratios of one or more data link messages transmitted and received within a certain number of consecutive frames are all less than the threshold value, the data link message having the largest signal-to-noise ratio among the one or more data link messages included in the consecutive frames is reconstructed. A control method of a control station that identifies data link integrity impediments based on the identified column family.

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