KR20150023138A - Transfer route setting method for configurating network between vessels, communication route configuration method and data communication method - Google Patents

Abstract

Disclosed are a method for setting a transmission path for configuration of a network between ships, a method for configuring a communications channel of ships, and a data communications method thereof. The method for setting a transmission path for configuration of a network between ships comprises the following steps: a base station periodically transmits transmission path request messages to adjacent nodes; each of the nodes increases a hop count by one, inserts its own information in the transmission path request message, and broadcasts the message to the surrounding nodes; each of the nodes determines an optimal path from the base station by analyzing the transmission path request messages transmitted directly from the base station or broadcasted; each of the nodes transmits a transmission path request response message to the base station through the optimal path; the base station updates an optimal path information table storing the optimal paths to the nodes according to the received transmission path request response message; and each of the nodes updates a path table by receiving a path setting message from the base station.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission route setting method for a ship,

The present invention relates to a transmission path setting method, a communication path setting method, and a data communication method for a ship-to-ship network configuration.

Communication between existing ships, ships, and ships does not constitute a network but transmits only important data using carrier frequencies such as MF (Medium Frequency), HF (High Frequency) and VHF (Very High Frequency) .

In this case, since the wireless communication can not be performed when the mobile terminal is far from the land, expensive satellite communication is often used.

Therefore, multi-hop communication method using MANET (Mobile ad-hoc network) method is being studied in inter-ship communication, ship-to-ship communication, and the like.

1 is a diagram illustrating a structure of a periodic communication network and a mobile ad-hoc network.

Mobile communication, ethernet, WLAN, Wi-Fi, etc. have a centralized infrastructure network structure as shown in FIG. 1 (a) Lt; / RTI > communication.

Therefore, research on MANET, which is a distributed ad-hoc network structure as shown in FIG. 1 (b) is underway.

The routing protocols of various MANETs proposed previously adopt a method of establishing a path from a node to a gateway or a sink node to establish a path.

This is because MANETs are often fixed sensors in which the nodes do not move. In this case, when a new node exists, the new node performs a path setting step to find a transmission path from itself to the sink.

However, in the case of a node moving like a ship, there is a case where communication is impossible with a predetermined transmission path since a previously generated path is changed. In order to prevent such a case, a new transmission path setting method is needed.

Korean Patent Laid-Open No. 10-2009-0121258 discloses a marine wireless mesh network device, a system thereof, and a network configuration method thereof. However, only a mention is made that a mesh network is constituted, It is not disclosed whether or not to perform communication.

Korean Patent Laid-Open No. 10-2009-0121258

The present invention relates to a network configuration between vessels, such as a moving ship, in which a transmission path from a sink node to a moving node is set in an environment in which a communication path on the network is frequently changed, A transmission path setting method, a communication path setting method of a ship, and a data communication method.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide a ship capable of reducing communication waste and communication delay time by preventing unnecessary data transmission operations from being performed by a ship outside the communication area, A method of setting a communication path of a ship, and a data communication method.

Other objects of the present invention will become readily apparent from the following description.

According to an aspect of the present invention, there is provided a transmission path setting method for a network configuration between vessels, comprising the steps of: (a) periodically transmitting a transmission path request message to neighboring nodes in a base station; (b) each of the nodes increases its hop count by 1, and broadcasts its transmission path request message to surrounding nodes by including its own information; (c) each of the nodes analyzing the broadcast transmission path request message transmitted directly from the base station and determining an optimal path from the base station; (d) each of the nodes transmitting a transmission path request response message to the base station along the optimal path; (e) updating the optimal path information table up to the nodes according to the received transmission path request response message; And (f) receiving, from each of the nodes, a routing message from the base station and updating the routing table.

Each of the nodes may be a mobile node corresponding to ships located in the sea.

In the step (c), each of the nodes may determine an optimal path from the base station in a minimum hopping manner based on the hop count.

According to another aspect of the present invention, there is provided a method of establishing a communication path in a ship, which is a mobile node, comprising the steps of: (a) determining whether a path setting message is received from a base station; (b) if the path setup message is received, determining that the communication path setup is successful, and selecting the optimal path included in the path setup message to complete data transmission / reception preparation; And (c) if the path setting message is not received, determining that the communication path setting has failed and switching to the receiving mode.

In step (c), the ship only receives the routing message in the reception mode, and can wait without transmitting even if there is data to be transmitted to the base station.

In the step (c), the ship may receive the route setting message in the reception mode and resume RF communication when the communication path setting is completed, thereby performing data communication.

According to another aspect of the present invention, there is provided a data communication method in a ship that is a mobile node, the method comprising the steps of: (a) when there is data to be transmitted to a base station, Determining whether or not a predetermined value exists; (b) if the RF communication path exists, transmitting the corresponding path data; And (c) terminating the communication or using the satellite communication according to the importance of the data when the RF communication path does not exist.

Wherein step (b) comprises: (b1) attempting to transmit data using the RF communication path information; (b2) determining whether the communication is successful according to whether the response message is received or not; (b3) completing data communication when transmission is successful, and attempting retransmission if transmission is unsuccessful.

(C1) incrementing the retransmission count by 1 if the transmission fails in step (b3); (c2) determining whether a retransmission count has been performed a predetermined number of times and recognizing that the data transmission has failed if the retransmission count is reached; (c3) if the communication end retransmission count has not been reached, determining whether the RF communication path setting has been changed according to the periodic update from the base station, and attempting retransmission through the RF communication path or the newly updated RF communication path . ≪ / RTI >

Other aspects, features, and advantages will become apparent from the following drawings, claims, and detailed description of the invention.

According to the embodiment of the present invention, it is possible to establish a transmission path from a sink node to a moving node in an environment where a communication path on the network is frequently changed, such as a moving node, such as a ship, .

In addition, it is possible to prevent unnecessary data transmission operations from being carried out by a ship outside the communication area, thereby suppressing power waste, and in the case of a high possibility of communication failure, communication is not attempted, thereby reducing communication cost and communication delay time have.

1 is a diagram illustrating a structure of a periodic communication network and a mobile ad-hoc network,
FIGS. 2 and 3 are diagrams for explaining a transmission path setting method between a base station on land and marine vessels;
4 is a view showing a case where the ship A is moved and the optimum path is changed,
5 is a view showing a case where the ship A is further moved out of the network,
FIG. 6 is a flowchart of a transmission path setting method for a network configuration between ships according to an embodiment of the present invention; FIG.
7 is a diagram illustrating a transmission path setting method for a network configuration between ships according to an embodiment of the present invention;
8 is an exemplary diagram illustrating an optimal path information table with each node in the base station and a path table included in each node,
FIG. 9 is a flowchart of a communication path setting method in a ship when vessels moving in the vicinity are located outside the RF communication area,
10 is a flowchart of a data communication method in an existing mobile node,
11 is a flowchart of a data communication method in a mobile node according to an embodiment of the present invention.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It is to be understood, however, that the invention is not to be limited to the specific embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, components, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

The terms first, second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

Also, the term "part" or the like, as described in the specification, means a unit for processing at least one function or operation, and may be implemented by hardware, software, or a combination of hardware and software.

It is to be understood that the components of the embodiments described with reference to the drawings are not limited to the embodiments and may be embodied in other embodiments without departing from the spirit of the invention. It is to be understood that although the description is omitted, multiple embodiments may be implemented again in one integrated embodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

In the conventional ad-hoc routing scheme, only a communication path from the corresponding node to the sink node exists. This is because sensors are usually fixed and existing network paths are rarely changed.

However, when the nodes move, an environment in which the communication path on the network is frequently changed is created, and there is a case where communication is impossible with the established path. However, since the countermeasures against this problem are insufficient, It is necessary.

In the case where a node moves, a transmission path from a sink node to a moving node (mobile node) is more suitable than a method of setting a transmission path from a node to a sink node according to an embodiment of the present invention.

Hereinafter, a method of setting an optimal path is described on the assumption of a minimum hop, but this is merely an example, and in some cases, various schemes such as a metric may be applied.

Here, it is assumed that the path information is stored in the cache of the base station and each node, and that the base station and each node use the stored path information as a data communication path.

First, an existing path setting method will be described with reference to FIG. 2 and FIG.

FIGS. 2 and 3 are views for explaining a transmission path setting method between a base station on the land and marine vessels.

Each ship corresponding to the nodes constituting the network transmits a message informing that it is possible to transmit to other ships adjacent to the ship.

(See FIG. 2 (a)) in the case of the ship A and to the adjacent ships A, C and D in the case of the ship B (see FIG. In the case of vessel D, it is transmitted to vessels A, B, C and F (see Fig. 2 (c)). D, E and F in the case of the ship C (see FIG. 3 (a)) and in the case of the ship F to the ships C, D, E and the base station (See Fig. 3 (b)), and in the case of the ship E, to the ships C, F and the base station (see Fig. 3 (c)).

Thus, the path from each node to the sink node (here, the base station) is set.

The base station determines the minimum hop from each node based on the transmitted path information, and sets a path corresponding to the minimum hop as an optimal path from each node to the base station. For example, in the case of ship A, there are a plurality of paths to the base station, and the optimal path (minimum hop) to the base station is 'A → D → F → base station'.

Then, the base station transmits information on the minimum hop to each node, so that each node establishes a minimum hop path with the base station.

In this case, problems that may occur when the node is a mobile node will be described with reference to the related drawings.

FIG. 4 is a view showing a case where the ship A is moved and the optimal path is changed, and FIG. 5 is a diagram showing a case where the ship A moves further and leaves the network.

Referring to FIG. 4, it is assumed that the ship A is moved and communication with the ship D is impossible.

In this case also, the ship A tries to communicate with the previously stored path of "A → D → F → base station".

Since the ship A is far from the ship D and communication is impossible, the ship A eventually fails in communication and performs a procedure for setting a new route as shown in FIGS. 2 and 3.

There is a problem that a lot of delay time is required for data transmission since a new path setting is attempted for communication.

If ship A moves, it would have been possible to carry out data transmission without delay time if the path of 'A → B → C → E → base station' is secured in advance.

Referring to FIG. 5, it is assumed that the ship A moves further so that it is impossible to communicate with the ship B as well as the ship D, that is, out of the network.

Ship A will try to communicate with the existing route of 'A → B → C → E → base station'. However, since the response to the data transmission is not received, it is confirmed that the transmission has failed.

After the data transmission failure, it is recognized that it is located outside the communicable area through the process shown in FIG. 2 and FIG. Thereafter, the ship A periodically sends a message for setting the transmission path, and data transmission is possible when the path setting is completed.

However, at this time, since the ship A periodically transmits the route setting message until the new route setting is completed, unnecessary transmission power is wasted.

Therefore, in order to solve these problems, a transmission path setting method for a network configuration between a mobile node and a ship will be described with reference to the related drawings.

FIG. 6 is a flowchart of a transmission path setting method for a network configuration between ships according to an embodiment of the present invention, FIG. 7 is a diagram illustrating a transmission path setting method for a network configuration between ships according to an embodiment of the present invention 8 is an exemplary diagram illustrating an optimal path information table with each node and a path table included in each node.

Referring to FIG. 6, contrary to FIG. 2 and FIG. 3, as shown in FIG. 7, a base station periodically transmits a transmission path request message to peripheral nodes to set up a transmission path (Step S100).

The nodes receiving the transmission route request message increase the hop count by 1 (step S110), and broadcast the broadcasting route to neighboring nodes by including their own address information (step S120).

Each node analyzes the transmission path request message and determines an optimal path from the base station (step S130). Here, each node determines the path with the minimum hop count as the optimal path.

Then, each node sends a transmission path request response message to the base station (step S140). The transmission path request response message may include information on an optimal path from the base station of each node.

The base station receives and analyzes the transmission path request response message transmitted from each node, and updates the optimal path information table indicating the optimal path with each node as shown in FIG. 8 (a) (step S150 ). Then, the base station transmits data using the optimal path information table.

In addition, each node receives the routing message including the optimal route from the base station and periodically updates the route table to the base station as shown in FIG. 8B (step S160). Such a path table may be changed by a path setting periodically performed when the corresponding node moves or a node existing on the path moves.

The moving nodes perform data communication with the base station using the latest path table.

If it is assumed that the ship A moves as shown in FIG. 4, the route information from the base station to the ship A can be changed through the route information periodically updated according to the present embodiment. That is, the path from the base station to the ship A is changed from 'base station → F → D → A' to 'base station → E → C → B → A'.

The data is transmitted through the changed path information, so that the data transmission failure and delay due to the path change can be prevented.

Also, assuming that the ship A is out of the network as shown in FIG. 5, in this case, the ship A can not receive the periodically updated route information message transmitted from the base station.

Accordingly, the ship A recognizes that it is outside the network area of the base station itself, and can stop the data communication until the transmission path is formed. After the path information is updated to generate the path information, the data communication can be resumed.

That is, a ship located outside the network can prevent unnecessary communication attempts, thereby preventing unnecessary transmission power from being wasted.

The operation of the mobile node will be described in more detail with reference to the related drawings.

9 is a flowchart of a communication path setting method in a ship when vessels moving in the vicinity are located outside the RF communication area.

Referring to FIG. 9, when communication path setting is started (step S200), the mobile node determines whether it has received a routing message from the base station (step S210).

When the path setting message is received, the optimum communication path is selected (step S220), it is determined that the communication path setting is successful (step S230), and preparation for data transmission / reception through the communication path is completed (step S240) The setting can be completed (step S250).

However, if the path setting message is not received, it is determined that the communication path setting has failed (step S260), and the mode is switched to the receiving mode (step S270).

In the reception mode, only the communication route setting message is received, and even when there is data to be transmitted to the base station, the transmission is not performed.

This means that the ship moving in the vicinity is located outside the RF communication area. In this case, since the node attempting to communicate is located outside the communication area, communication can not be performed, so that RF communication is stopped and unnecessary data transmission power is not wasted It is for this reason.

That is, RF communication is stopped and only important data is transmitted using satellite communication.

When the path setting message is received and the communication path setting is completed, the RF communication is restarted to perform data communication (steps S220 to S250).

FIG. 10 is a flowchart of a data communication method in a conventional mobile node, and FIG. 11 is a flowchart of a data communication method in a mobile node according to an embodiment of the present invention.

Referring to FIG. 10, in the existing data communication method, when there is data to be transmitted regardless of the routing information, an attempt is made to transmit using the RF module (step S310).

In step S320, it is determined whether the communication is successful according to whether a response message (Ack) is received or not (step S320). If the transmission is successful, the data transmission process is completed (step S330).

If the transmission fails, the retransmission count is incremented by 1 (step S340), and it is determined whether the retransmission has been performed a predetermined number of times, that is, the communication end retransmission count has been reached (step S350).

If the communication end retransmission count has not been reached, the process returns to step S310 to retry the data transmission. If the communication end retransmission count is reached, it is recognized that the data transmission has failed (step S360).

Thereafter, the same process is carried out when other data are transmitted.

In this case, irrespective of the path setting state, if there is data to be transmitted, it is unconditionally transmitted, and unnecessary operations are repeated until it is determined that the data transmission is failed. This wastes transmission power for data transmission.

In addition, in the case of important data, data may be transmitted through another communication method such as satellite communication. However, data transmission delay may occur due to use of RF communication.

Therefore, in order to solve such a problem, a data communication method in a mobile node according to an embodiment of the present invention utilizes communication path information, and the method is the same as that shown in FIG.

If there is data to be transmitted from the mobile node to the base station, data communication is started (step S400).

First, it is determined whether an RF communication path exists (step S410), and if there is an RF communication path, data is transmitted to the path (step S430 and subsequent steps).

However, if the RF communication path does not exist, it is transmitted using another communication method such as satellite communication in the case of important data, and if it is not important data, the communication is determined to be in failure and the communication is terminated (step S420).

If there is an RF communication path, data transmission is attempted using the communication path information (step S430). It is determined whether or not communication is successful according to whether a response message (Ack) is received (step S440) And completes the communication (step S510).

If the communication fails, the retransmission count is incremented by 1 (step S450), and it is determined whether the retransmission has been performed a predetermined number of times, that is, the communication end retransmission count has been reached (step S460).

When the communication end retransmission count is reached, it is recognized that the data transmission has failed (step S460).

If the communication end retransmission count has not been reached, the communication path setting is again compared (step S480) without retrying the data transmission immediately.

If it is determined through periodic update from the base station that the communication path has changed in the meantime, the flow advances to step S500 to try retransmission to the updated new path. If there is no change in the communication path, .

In the conventional method shown in FIG. 10, if there is data to be transmitted, the data is transmitted immediately. If the data is failed, the data is retransmitted up to the maximum number of retransmissions.

However, according to the present embodiment shown in FIG. 11, if there is data to be transmitted, the path setting information is checked first, and if it exists, the path setting information is transmitted through the path information. If there is no route information, it is transmitted using another communication method without using the RF module, or the communication is terminated.

In addition, when there is a high possibility that the RF communication fails, that is, when there is no routing information, the communication is not attempted, thereby reducing the communication cost and reducing the communication area time.

According to this embodiment, a network can be formed smoothly between a fixed base station located on the land or a lighthouse and a ship located in the offshore, and a low-cost radio wave (MF, HF, VHF, etc.) So that data transmission can be used.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the following claims And changes may be made without departing from the spirit and scope of the invention.

A, B, C, D, E, F: Ship (mobile node)

Claims (9)

A transmission path setting method for a network configuration between ships,
(a) periodically transmitting a transmission path request message to neighboring nodes in a base station;
(b) each of the nodes increases its hop count by 1, and broadcasts its transmission path request message to surrounding nodes by including its own information;
(c) each of the nodes analyzing the broadcast transmission path request message transmitted directly from the base station and determining an optimal path from the base station;
(d) each of the nodes transmitting a transmission path request response message to the base station along the optimal path;
(e) updating the optimal path information table up to the nodes according to the received transmission path request response message; And
(f) receiving, by each of the nodes, a route setup message from the base station and updating the route table. The method according to claim 1,
Wherein each of the nodes is a mobile node corresponding to maritime vessels. The method according to claim 1,
Wherein, in step (c), each of the nodes determines an optimal path from the base station in a minimum hopping manner based on the hop count. A communication path setting method in a ship which is a mobile node,
(a) determining whether a routing message including an optimal communication path from the base station to the ship has been received;
(b) if the path setup message is received, determining that the communication path setup is successful, and selecting the optimal path included in the path setup message to complete data transmission / reception preparation; And
(c) if the path setting message is not received, determining that the communication path setting has failed and switching to the receiving mode. 5. The method of claim 4,
Wherein, in the step (c), the ship receives only the route setting message in the reception mode and waits without transmitting even if there is data to be transmitted to the base station. 6. The method of claim 5,
Wherein, in the step (c), the ship receives the route setting message in the receiving mode and resumes RF communication when the communication path setting is completed, thereby performing data communication. A method of data communication in a ship, which is a mobile node,
(a) if there is data to be transmitted to the base station, determining whether there is an RF communication path to the base station set according to the periodic update from the base station;
(b) if the RF communication path exists, transmitting the corresponding path data; And
(c) using the satellite communication or terminating communication according to the importance of the data if the RF communication path does not exist. 8. The method of claim 7,
Wherein step (b) comprises:
(b1) attempting to transmit data using the RF communication path information;
(b2) determining whether the communication is successful according to whether the response message is received or not;
(b3) completing the data communication when the transmission is successful, and attempting retransmission if the transmission is unsuccessful. 9. The method of claim 8,
If the transmission fails in the step (b3)
(c1) incrementing the retransmission count by one;
(c2) determining whether a retransmission count has been performed a predetermined number of times and recognizing that the data transmission has failed if the retransmission count is reached;
(c3) if the communication end retransmission count is not reached, determining whether the RF communication path setting has been changed according to the periodic update from the base station, and attempting retransmission through the RF communication path or the newly updated RF communication path And a data communication method in a ship.

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