A ship-shore information service exchange method for autonomous traffic tasks

Abstract

The present invention proposes a ship-shore information service exchange method for autonomous traffic tasks, which realizes efficient and reliable information exchange between ships and shores through an autonomous traffic task system; the method includes splitting message information according to information importance, selecting the optimal communication link using multi-attribute decision analysis, and setting a preset time threshold to monitor the transmission process. Through precise data splitting and transmission strategies, the present invention improves the efficiency and reliability of data transmission and reduces the risk of data loss and delay; the method can adapt to changes in the communication environment in real time, optimize resource utilization, and improve user experience and management efficiency, which is of great significance for promoting the development of autonomous traffic tasks.

Description

Technical Field

[0001] The present invention relates to the technical field of water ship-shore information service exchange, and in particular to a ship-shore information service exchange method oriented to autonomous traffic tasks. Background Art

[0002] Currently, ship-shore information service exchange mainly relies on traditional communication methods, such as wireless VHF (Very High Frequency) and satellite communications. However, due to factors such as signal transmission distance, weather, and the complexity and uncertainty of the marine environment, communications may be interfered with during transmission, resulting in information distortion or loss. Therefore, the selection of communication links and the splitting and sending of data have become technical means to improve the accuracy of information exchange.

[0003] In autonomous transportation missions, the exchange of ship-to-shore information services is a key link in ensuring effective communication between ships and shore systems. In existing ship-to-shore communication systems, link selection is typically based on fixed priorities or simple link quality assessments. These methods often fail to comprehensively consider multiple real-time parameters such as link stability, bandwidth, latency, and packet loss rate, making it impossible to accurately select the optimal communication link. Furthermore, as the ship's navigation environment changes, the real-time status of the link will also change, and traditional link selection methods cannot adapt to these changes in a timely manner.

[0004] For large amounts of data, traditional transmission methods typically use a wholesale method. However, this method fails to consider the importance and urgency of the data, as well as the bandwidth limitations of the communication link. When the data volume is large, wholesale transmission can easily lead to low transmission efficiency and may even cause data loss or transmission delays. Furthermore, for urgent or important data, wholesale transmission cannot guarantee the timeliness and reliability of the data.

[0005] Due to the lack of effective link quality assessment and data splitting transmission mechanism, the existing ship-shore information service exchange method is prone to data loss or transmission delay when facing an unstable communication environment. This risk is particularly prominent in urgent or important data exchanges. Summary of the Invention

[0006] The present invention aims at solving the above technical problems and provides a method for exchanging ship-shore information services for autonomous transportation tasks.

[0007] In order to achieve the above-mentioned purpose of the present invention, the present invention adopts the following technical solutions:

[0008] The autonomous traffic mission system is used to complete the ship-shore information service exchange, and the autonomous traffic mission system includes a ship-borne terminal, a shore-side system and multiple preset communication links.

[0009] The ship-shore information service exchange method for autonomous transportation tasks includes the following steps:

[0010] Step S1: The shipborne terminal receives the first message information edited by the user, where the first message information includes data information and an information importance tag.

[0011] Step S2: Based on the information importance tag, the shipborne terminal splits the first message information according to content or structure to form second message information, where the second message information includes multiple short message information packets and a short message directory packet.

[0012] Furthermore, the information importance label is divided into three levels: urgent, important, and general. When the information importance label is urgent or important, the shipborne terminal splits the first message information according to content. When the information importance label is general, the shipborne terminal splits the first message information according to structure.

[0013] Furthermore, the shipborne terminal splits the first message information according to the structure, including determining the hierarchy and substructure of the first message information, dividing the first message information into different hierarchies, each containing at least one specific information directory, and determining one or more substructures in each hierarchy, wherein the substructure represents a specific amount of information, packaging each hierarchy into a short message information package, and packaging the specific information directory into a short message directory package.

[0014] The shipborne terminal splits the first message information according to the content, including identifying keywords, phrases or sentences in the first message information as key information fragments, splitting the first message information according to the identified key information fragments, ensuring that each short message information packet contains at least one complete key information fragment; and packaging the key information fragments into a short message directory package.

[0015] Step S3: The shipborne terminal evaluates the real-time parameters of the current multiple preset communication links based on a multi-attribute decision analysis method and determines the target communication link.

[0016] Furthermore, the real-time parameters include the stability S of the i-th link i Bandwidth B i , delay D i and packet loss rate L i , assign a weight value W to each real-time parameter i , calculate the comprehensive score of each link i , the calculation formula for the comprehensive score is:

[0017]

[0018] Among them, w s +wB +w D +w L =1,w s , w B , w D , w L are the weights of stability, bandwidth, delay and packet loss rate respectively; S i The value range is [S min , S max ], D max is the maximum delay value of the i-th link in the last n communications, n ≥ 20.

[0019] The link stability S of the i-th link i The calculation formula is:

[0020] S i =F av / (1+aF ji +F er )

[0021] Among them, F av is the link availability, which indicates the proportion of time the link is available in the past period of time; F ji is the link jitter value, which represents the difference between the maximum and minimum time intervals for data packet delivery. a is a normalization constant, 1<a≤5; F er is the error rate, which indicates the frequency of errors during data transmission.

[0022] Furthermore, the current comprehensive scores of all links are calculated: Score1, Score2, ..., Score m , m is the total number of communication links, then the maximum value of the comprehensive score Max(Score1, Score2, ..., Score m ) is the target communication link.

[0023] Step S4: The shipborne terminal sends the short message directory package in the second message information to the shore system through the target communication link.

[0024] Furthermore, after the shipborne terminal sends the short message directory package in the second message information to the shore system through the target communication link, the shore system automatically verifies the integrity of the short message directory package. If the verification passes, a confirmation notification is sent to the shipborne terminal through the target communication link. If the verification fails, no operation is performed.

[0025] Step S5: If the shipborne terminal receives a confirmation notification returned by the shore system within the first preset time, the shipborne terminal sends multiple short message packets in the second message information to the shore system through the target communication link; otherwise, the shipborne terminal returns to step S3 to reselect the communication link.

[0026] Step S6: If multiple short message information packets are received from the ship end within the second preset time and completely match the short message directory packet, it indicates that the first message information is sent successfully; otherwise, the shore-side system initiates an active inquiry to the ship-borne terminal.

[0027] Furthermore, if the shore-side system fails to receive multiple short message information packets from the ship-side within the preset second time, or does not completely match the short message directory packet, the shore-side system initiates an active inquiry to the ship-borne terminal, and the inquiry data format includes at least: an inquiry header, a timestamp, a missing information identifier, and a checksum.

[0028] The inquiry header includes the inquiry type, shore system identifier, and shipboard terminal identifier; the timestamp is the specific time when the inquiry is initiated, which is used for data synchronization and log recording; the missing information identifier is the identifier of the short message information packet that does not match the short message directory packet; the checksum is used to verify the entire inquiry data packet to ensure the integrity and accuracy of the data during transmission.

[0029] Furthermore, in step S6, if multiple short message packets are received from the ship within the second preset time, the shore system performs the following steps:

[0030] In step S61, the shore-side system generates an actually received short message directory packet based on the received multiple short message information packets.

[0031] Step S62: Compare the short message directory package actually received with the short message directory package sent by the shore system to confirm whether the two are completely matched.

[0032] Step S63: If the two are completely matched, it indicates that the first message information is sent successfully. The shore system records the sending success information and processes the received short message information packet.

[0033] In step S64, if the two do not completely match, the shore system records the error information and generates an active query instruction to send to the shipborne terminal, requesting the shipborne terminal to resend the unsuccessfully received short message information packet or send a retransmission request for the entire first message information.

[0034] Furthermore, the first preset time T1 is 5 seconds to 10 seconds, and the second preset time is dynamically set based on the number of key information segments or information directories in the short message information packet.

[0035] Furthermore, the second preset time T2 is dynamically set based on the number N of key information segments or information directories in the short message information packet: T2=T base +N×T u , where T base The basic time is the waiting time from when the shore system sends a confirmation notification to the shipboard terminal through the target communication link to when the shipboard terminal sends the second message information. u The benchmark time required to transmit each key information fragment or information directory.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] The present invention realizes dynamic selection of communication links, accurate data splitting and efficient transmission by introducing a multi-attribute decision analysis method and a split transmission strategy based on data importance; by splitting message information into multiple short message information packets and a short message directory packet according to the importance label of the data, accurate data splitting is achieved. This splitting method can reasonably arrange the transmission order and priority of the data according to the bandwidth limit of the link and the urgency of the data, thereby improving the overall efficiency of data transmission; by evaluating the real-time parameters of multiple current preset communication links through the multi-attribute decision analysis method, the optimal communication link is selected for data transmission. The method of the present invention can adapt to changes in the communication environment in real time and improve the stability and reliability of data transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a flow chart of a ship-shore information service exchange method for autonomous transportation tasks according to the present invention. DETAILED DESCRIPTION

[0039] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention are described clearly and completely below. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0040] like Figure 1 As shown, it is a flow chart of a method for exchanging ship-shore information services for autonomous traffic tasks according to the present invention. The method uses an autonomous traffic task system to complete the exchange of ship-shore information services. The autonomous traffic task system includes a ship-borne terminal, a shore system, and multiple preset communication links.

[0041] The shipboard terminal, serving as the vessel's information collection and transmission device, receives user-edited messages and processes them based on their importance. The shipboard terminal exchanges information with the shore-based system via a pre-set communication link. The shore-based system, located onshore, receives and processes messages sent by the shipboard terminal. The shore-based system can send confirmation notifications or proactive inquiries to the shipboard terminal to ensure accurate information transmission. The pre-set communication links, which include multiple links with varying quality, stability, and bandwidth, are used for information transmission between the shipboard terminal and the shore-based system.

[0042] Commonly used ship-to-shore communication links include: 4G or 5G mobile networks, which are mainly suitable for inland and coastal shipping, as stable mobile network signals are more easily available in these areas; broadband satellite communications, which are particularly suitable for ocean-going vessels because satellite communications can cover vast ocean areas; narrowband satellite communications, which are suitable for situations requiring emergency communications or short information transmission; AIS (Automatic Identification System) communication links, which are ship automatic identification systems used for automatic identification, collision avoidance, and communication between ships; VHF (Very High Frequency) communication links, and Navtex (Navigational Telex) navigation telegraph systems.

[0043] The ship-shore information service exchange method for autonomous transportation tasks includes the following steps:

[0044] Step S1: The shipborne terminal receives the first message information edited by the user, where the first message information includes data information and an information importance tag.

[0045] Example 1: The first short message is: "Vessel A, position 123.456, N, 789.012, E, speed 20 knots, heading 180 degrees, cargo XXX loaded", and the information importance label is: "General".

[0046] Step S2: Based on the information importance tag, the shipborne terminal splits the first message information according to content or structure to form second message information, where the second message information includes multiple short message information packets and a short message directory packet.

[0047] The information importance label is divided into three levels: urgent, important, and general. When the information importance label is urgent or important, the shipborne terminal splits the first message information according to content. When the information importance label is general, the shipborne terminal splits the first message information according to structure.

[0048] The shipborne terminal splits the first message information according to the structure, including determining the hierarchy and substructure of the first message information, dividing the first message information into different hierarchies, each containing at least one specific information directory, and determining one or more substructures in each hierarchy, wherein the substructures represent a specific amount of information, packaging each hierarchy into a short message information package, and packaging the specific information directory into a short message directory package.

[0049] The first short message in Example 1 is split according to the structure. The shipborne terminal determines the hierarchy and substructure of the first message. In this example, the message can be divided into several main hierarchies, such as ship identification, location information, navigation status, and cargo status. The shipborne terminal divides the first message into different hierarchies, each of which contains at least one specific information directory:

[0050] Ship identification: Ship A;

[0051] Location information: 123.456,N,789.012,E;

[0052] Navigation status: speed 20 knots, heading 180 degrees;

[0053] Cargo status: Cargo XXX has been loaded.

[0054] In each level, the shipborne terminal will further determine one or more substructures, which represent specific amounts of information. For example, location information can be further divided into two substructures: longitude and latitude, and navigation status can be divided into two substructures: speed and heading. Finally, the shipborne terminal packages each level into a short message information package, and packages the specific information directory into a short message directory package. The short message information package will contain the specific data of each level, and the short message directory package will contain the index and description of each short message information package, so that the shore system can correctly reorganize and parse the information.

[0055] In this way, the shipborne terminal can effectively split the first message information according to the structure and send it to the shore system in the form of multiple short message information packets and short message directory packets, thereby improving the efficiency and reliability of ship-shore information service exchange.

[0056] The shipborne terminal splits the first message information according to the content, including identifying keywords, phrases or sentences in the first message information as key information fragments, splitting the first message information according to the identified key information fragments, ensuring that each short message information packet contains at least one complete key information fragment; and packaging the key information fragments into a short message directory package.

[0057] Example 2: “Ship B, encountering strong winds, requests immediate change of course to 120.345, N, 678.901, E, requests immediate shore rescue”, and the information importance label is marked as “important”.

[0058] According to this requirement, the shipboard terminal will split the message according to the content to ensure that each short message packet contains at least one complete key information fragment. The shipboard terminal will first identify the key words, phrases or sentences in the message as key information fragments. In Example 2, the key information fragments include: "encountering strong winds", "immediately change route", "emergency rescue"

[0059] Split the message according to key information fragments: The shipborne terminal will split the message into multiple short message packets based on the identified key information fragments. Each short message packet should contain at least one complete key information fragment to ensure the integrity and importance of the information. The splitting method is as follows:

[0060] Short message packet 1: "Ship B, encountering strong winds"

[0061] Short message packet 2: "Requesting immediate change of route to 120.345, N, 678.901, E"

[0062] Short message packet 3: "Request for immediate rescue from shore"

[0063] The shipborne terminal will also package the above key information fragments into a short message directory package. This directory package will contain the index and description of each short message information package so that the shore system can accurately understand and reorganize this information. The short message directory package: "Encountering strong winds, immediately change the route, emergency rescue"; in this way, the shipborne terminal can ensure that even in poor network conditions or unstable communication links, the most important information fragments can be transmitted first, thereby improving the efficiency of ship-shore information service exchange and the response speed in emergency situations.

[0064] Step S3: The shipborne terminal evaluates the real-time parameters of the current multiple preset communication links based on a multi-attribute decision analysis method and determines the target communication link.

[0065] The real-time parameters include the stability S of the i-th link i Bandwidth B i , delay D i and packet loss rate L i , assign a weight value W to each real-time parameter i , calculate the comprehensive score of each link i , the calculation formula for the comprehensive score is:

[0066]

[0067] Among them, w s +w B +w D +w L =1,w s , w B , w D , w L are the weights of stability, bandwidth, delay and packet loss rate respectively; S i The value range is [S min , S max ], D max is the maximum delay value of the i-th link in the last n communications, n ≥ 20.

[0068] The link stability S of the i-th link i The calculation formula is:

[0069] S i =F av / (1+aF ji +F er )

[0070] Among them, F av is the link availability, which indicates the proportion of time the link is available in the past period of time; F ji is the link jitter value, which represents the difference between the maximum and minimum time intervals for data packet delivery. a is a normalization constant, 1<a≤5; F er is the error rate, which indicates the frequency of errors during data transmission.

[0071] Furthermore, the current comprehensive scores of all links are calculated: Score1, Score2, ..., Score m , m is the total number of communication links, then the maximum value of the comprehensive score Max(Score1, Score2, ..., Score m ) is the target communication link.

[0072] For example: Link 1: stability 0.92, bandwidth 10 Mbps, delay 50ms, packet loss rate 0.01; Link 2: stability 0.89, bandwidth 20 Mbps, delay 100ms, packet loss rate 0.02; Link 3: stability 0.97, bandwidth 15 Mbps, delay 75ms, packet loss rate 0.015. Weight: w s =0.3, w B =0.2, w D =0.3, w L =0.2.

[0073] After calculation, the comprehensive score of link 1 is 0.28, the comprehensive score of link 2 is 0.21, and the comprehensive score of link 3 is 0.29. Determining the target communication link Since link 3 has the highest comprehensive score (0.29), link 3 is determined as the target communication link.

[0074] Step S4: The shipborne terminal sends the short message directory package in the second message information to the shore system through the target communication link.

[0075] After the shipborne terminal sends the short message directory package in the second message information to the shore system through the target communication link, the shore system automatically verifies the integrity of the short message directory package. If the verification passes, a confirmation notification is sent to the shipborne terminal through the target communication link. If the verification fails, no operation is performed.

[0076] Step S5: If the shipborne terminal receives a confirmation notification returned by the shore system within the first preset time, the shipborne terminal sends multiple short message packets in the second message information to the shore system through the target communication link; otherwise, the shipborne terminal returns to step S3 to reselect the communication link.

[0077] Step S6: If multiple short message information packets are received from the ship end within the second preset time and completely match the short message directory packet, it indicates that the first message information is sent successfully; otherwise, the shore-side system initiates an active inquiry to the ship-borne terminal.

[0078] If the shore-side system fails to receive multiple short message information packets from the ship-side within the preset second time, or does not completely match the short message directory packet, the shore-side system initiates an active inquiry to the ship-borne terminal, and the inquiry data format includes at least: an inquiry header, a timestamp, a missing information identifier and a checksum.

[0079] The inquiry header includes the inquiry type, shore system identifier, and shipboard terminal identifier; the timestamp is the specific time when the inquiry is initiated, which is used for data synchronization and log recording; the missing information identifier is the identifier of the short message information packet that does not match the short message directory packet; the checksum is used to verify the entire inquiry data packet to ensure the integrity and accuracy of the data during transmission.

[0080] In step S6, if multiple short message packets are received from the ship within the second preset time, the shore system performs the following steps:

[0081] In step S61, the shore-side system generates an actually received short message directory packet based on the received multiple short message information packets.

[0082] Step S62: Compare the short message directory package actually received with the short message directory package sent by the shore system to confirm whether the two are completely matched.

[0083] Step S63: If the two are completely matched, it indicates that the first message information is sent successfully. The shore system records the sending success information and processes the received short message information packet.

[0084] In step S64, if the two do not completely match, the shore system records the error information and generates an active query instruction to send to the shipborne terminal, requesting the shipborne terminal to resend the unsuccessfully received short message information packet or send a retransmission request for the entire first message information.

[0085] The first preset time T1 is 5 seconds to 10 seconds, and the second preset time is dynamically set based on the number of key information segments or information directories in the short message information packet.

[0086] The second preset time T2 is dynamically set based on the number N of key information segments or information directories in the short message information packet: T2=T base +N×T u , where T base The basic time is the waiting time from when the shore system sends a confirmation notification to the shipboard terminal through the target communication link to when the shipboard terminal sends the second message information. u The benchmark time required to transmit each key information fragment or information directory.

[0087] The specific implementation methods described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific implementation method of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for exchanging ship-shore information services for autonomous traffic tasks, characterized in that: The ship-shore information service exchange is completed by using an autonomous traffic task system, the autonomous traffic task system includes a ship-borne terminal, a shore system and a plurality of preset communication links; the ship-shore information service exchange method includes the following steps: Step S1: The shipborne terminal receives first message information edited by a user, wherein the first message information includes data information and an information importance label; Step S2: According to the information importance label, the shipborne terminal splits the first message information according to content or structure to form second message information, where the second message information includes a plurality of short message information packets and a short message directory packet; The information importance label is divided into three levels: urgent, important, and general. When the information importance label is urgent or important, the shipboard terminal splits the first message information according to the content; when the information importance label is general, the shipboard terminal splits the first message information according to the structure; Step S3: the shipborne terminal evaluates the real-time parameters of multiple current preset communication links based on a multi-attribute decision analysis method to determine a target communication link; The real-time parameters include the stability S of the i-th link i Bandwidth B i , delay D i and packet loss rate L i , assign a weight value W to each real-time parameter i , calculate the comprehensive score of each link i , the calculation formula of comprehensive score is: Among them, w s +w B +w D +w L =1,w s ,w B ,w D ,w L are the weights of stability, bandwidth, delay and packet loss rate; S i The value range is [S min ,S max ], D max is the maximum delay value of the ith link in the last n communications, n ≥ 20; The link stability S of the i-th link i The calculation formula is: S i =F av / (1+aF ji +F er ) Among them, F av is the link availability, which indicates the proportion of time the link is available in the past period of time; F ji is the link jitter value, which indicates the difference between the maximum time interval and the minimum time interval for data packet delivery. a is a normalization constant, 1 <a≤5;F er is the error rate, which indicates the frequency of errors that occur during data transmission; Calculate the current comprehensive score of all links: Score1, Score2, ..., Score m , m is the total number of communication links, then the maximum value of the comprehensive score Max(Score1, Score2, ..., Score m ) The link corresponding to is the target communication link; Step S4: the shipborne terminal sends the short message directory package in the second message information to the shore system through the target communication link; Step S5: If the shipborne terminal receives a confirmation notification returned by the shore system within the first preset time, the shipborne terminal sends the multiple short message packets in the second message information to the shore system through the target communication link; otherwise, the shipborne terminal returns to step S3 to reselect the communication link; Step S6: If multiple short message information packets are received from the ship end within the second preset time and completely match the short message directory packet, it indicates that the first message information is sent successfully; otherwise, the shore system initiates an active inquiry to the ship-borne terminal.

2. A method for exchanging ship-shore information services for autonomous traffic tasks according to claim 1, characterized in that: If the shore system fails to receive multiple short message information packets from the ship within the preset second time, or does not completely match the short message directory packet, the shore system initiates an active inquiry to the ship-borne terminal, and the inquiry data format at least includes: an inquiry header, a timestamp, a missing information identifier, and a checksum; The inquiry header contains the inquiry type, shore system identifier, and shipboard terminal identifier; the timestamp is the specific time when the inquiry is initiated, which is used for data synchronization and log recording; the missing information identifier is the identifier of the short message information packet that does not match the short message directory packet; the checksum is used to verify the entire inquiry data packet to ensure the integrity and accuracy of the data during transmission.

3. A method for exchanging ship-shore information services for autonomous traffic tasks according to claim 2, characterized in that: The shipborne terminal splits the first message information according to the structure, including determining the level and substructure of the first message information, dividing the first message information into different levels, each of which contains at least one specific information directory, and further determining one or more substructures in each level, wherein the substructure represents a specific amount of information, packaging each level into a short message information package, and packaging the specific information directory into a short message directory package; The shipborne terminal splits the first message information according to the content, including identifying keywords, phrases or sentences in the first message information as key information fragments, splitting the first message information according to the identified key information fragments, ensuring that each short message information packet contains at least one complete key information fragment; and packaging the key information fragments into a short message directory package.

4. A method for exchanging ship-shore information services for autonomous traffic tasks according to claim 3, characterized in that: After the shipborne terminal sends the short message directory package in the second message information to the shore system through the target communication link, the shore system automatically verifies the integrity of the short message directory package. If the verification passes, a confirmation notification is sent to the shipborne terminal through the target communication link. If the verification fails, no operation is performed.

5. A method for exchanging ship-shore information services for autonomous traffic tasks according to claim 4, characterized in that: In step S6, if multiple short message packets are received from the ship within the second preset time, the shore system performs the following steps: Step S61, the shore-side system generates an actually received short message directory package according to the received multiple short message information packets; Step S62, comparing the short message directory package actually received with the short message directory package sent by the shore system to confirm whether the two completely match; Step S63: If the two completely match, it indicates that the first message information is sent successfully, and the shore system records the sending success information and processes the received short message information packet; Step S64, if the two do not completely match, the shore system records the error information and generates an active inquiry instruction to send to the shipborne terminal, requesting the shipborne terminal to resend the short message information packet that was not successfully received or send a retransmission request for the entire first message information.

6. A method for exchanging ship-shore information services for autonomous traffic tasks according to claim 5, characterized in that: The first preset time T1 is 5 seconds to 10 seconds, and the second preset time is dynamically set based on the number of key information fragments or information directories in the short message information packet.

7. A method for exchanging ship-shore information services for autonomous traffic tasks according to claim 6, characterized in that: The second preset time T2 is dynamically set based on the number N of key information segments or information directories in the short message information packet: T2=T base +N×T u , where T base is the basic time, which means the waiting time from the shore system sending a confirmation notification to the shipboard terminal through the target communication link to the shipboard terminal sending the second message information, T u The benchmark time required to transmit each key information fragment or information directory.

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