KR20190062921A - Underwater communication apparatus using seamless DTN (Delay Tolerant Network) protocol and method thereof - Google Patents

Abstract

The present invention relates to an underwater communication apparatus using a seamless delay tolerant network (S-DTN) protocol, which uses the S-DTN protocol to realize seamless underwater communications among divers in the water; and a communication method thereof. According to the present invention, the underwater communication apparatus using an S-DTN protocol, which is worn by each diver and forms a diver network (DN), comprises a data link abstraction layer connected to a lower data link tier to provide an interface with an external device, and an S-DTN layer. The S-DTN layer comprises: a DTN function unit storing data in a buffer, which is transmitted to perform a DTN function for underwater communications, and storing and retransmitting the data until reception confirmation; a network topology formation/management unit performing a function for forming and managing an underwater mobile ad-hoc network (MANET)-based DN topology; a surrounding situation information collection/management unit collecting and managing surrounding situation information formed by periodically analyzing packets received through overhearing with respect to multiple communication media; a surrounding situation information storage unit storing the collected and managed surrounding situation information; and a data link layer selection/operation unit selecting a multi-data link layer and establishing an operation policy through machine learning preset based on the surrounding situation information collected and stored by the surrounding situation collection/management unit and the surrounding situation storage unit.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater communication apparatus using a seamless DTN protocol,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an underwater communication apparatus and method, and more particularly, to an underwater communication apparatus and method using a seamless DTN (Delay Tolerant Network) protocol to enable seamless underwater communication among divers Communication apparatus and its underwater communication method.

Generally, diver is working and activities in poor underwater environment, so underwater communication between each other is as important as wet suit. In the diver network, real-time and reliable communication between the diver is indispensable since safety problems due to water depths, algae, floats, etc. can occur from time to time.

In the past, when divers are active in the water, it is difficult to obtain a watch due to underwater turbidity, and it is possible to move to a dangerous area according to the tide. Therefore, it may cause a safety accident because it does not recognize the state or emergency situation of a fellow diver in a timely manner. .

In addition, there is a problem that communication between divers is often hand-held, and conversation among divers is limited.

Accordingly, there is a need in the art to develop a technique that enables real-time and reliable underwater communication by forming a diver network for safe underwater activities of divers in the water.

Korean Patent No. 10-1296744 Korean Patent No. 10-1475926 Korean Patent Publication No. 10-2013-0030970

The present invention provides an underwater communication device capable of supporting real-time and reliable communication while supporting diver mobility in a diver network through a seamless DTN protocol in an underwater environment in response to the problems of the related art and the demand for technology development, And a communication method therefor.

In addition, the present invention provides an underwater communication device using a seamless DTN protocol that enables seamless communication by providing a P2P-based handover suitable for an underwater environment in order to ensure diversity of mobility, There is another purpose in providing a method.

The present invention also provides an underwater communication apparatus and method for minimizing overhead and communication traffic through a compression scheme applying a lightweight extension header and an address scheme for a seamless DTN protocol to a header of an existing underwater communication protocol, There is another purpose.

The underwater communication device using the seamless DTN protocol according to the embodiment of the present invention is a submersible communication device that is installed in each of a plurality of divers and constitutes a diver network DN, A data link abstraction layer providing an interface of the data link; DTN function to store transmitted data in a buffer to perform DTN function for underwater communication and to store and retransmit until receiving acknowledgment; formation of a network topology that forms and manages DN topology based on underwater MANET; A management unit, a surrounding information collecting and managing unit for collecting and managing peripheral information that periodically analyzes the received packets through overhearing of multiple communication media, a surrounding information collecting and managing unit for collecting and managing the surrounding information, A data link layer for selecting a plurality of data link layers and establishing an operation policy through predetermined machine learning based on peripheral information collected and stored in the information storage unit, the surrounding information collection and management unit, and the peripheral situation information storage unit And an S-DTN layer including an operation part; .

In the present invention, the data link abstraction layer is a data link layer common interface in which a communication protocol operated in the diver network (DN) provides a unified common standard interface for accessing multiple interfaces for multiple communication media; A data link layer common function unit for providing redundant functions of the protocol of the data link layer for the multiple communication media as a common function; And a data link layer adapter for supporting access to multiple communication media through the data link layer.

In the present invention, when the S-DTN layer receives a data transmission request from a predetermined external device, the data link layer selection and operation unit may select a multi- Selects a communication medium, and transmits the data transmission request to the data link abstraction layer through the selected multiple communication medium.

In the present invention, when the data link abstraction layer receives the data transmission request, the data link abstraction layer generates a packet suited to the selected multiple communication medium and transmits the packet to the external device.

In the present invention, the S-DTN layer performs fragmentation when the size of the data is larger than a maximum transmission size (MTU) of the selected multiple communication medium, and then transmits the fragmented data transmission request to the data Link abstraction layer, and the data link abstraction layer generates a packet suited to the selected multiple communication medium according to the fragmented data and transmits the packet to the external device.

In the present invention, when the S-DTN layer receives the packet from the outside, the fragmented data included in the packet is reassembled to restore the original data.

In the present invention, the peripheral situation information collecting and managing unit may collect the number of received packets, error information of packets, reception rate and error rate information of various frequency bands for the same communication medium, Information of the diver network (DN) is collected through the context information extension header, and is stored and updated in the context information storage unit.

In the present invention, the S-DTN layer performs a compressing and restoring function of a lightweight address system suitable for a cluster head selecting unit or a diver network (DN) for selecting cluster heads in a plurality of clusters when forming the DN topology. And a lightweight address system compression and decompression unit.

In the present invention, the lightweight address system compression / decompression unit provides an inter-compatible address system between underwater and terrestrial IoTs for interworking between the underwater IoT (IoUT) and the ground IoT.

In the present invention, the S-STN layer has a lightweight P2P-based handover function in which a handover function is performed such that seamless communication between the diver in the first cluster and the second cluster is possible in the diver network (DN) And the like.

In addition, an underwater communication method using a seamless DTN protocol according to an embodiment of the present invention includes: configuring a diver network (DN) including a gateway and a plurality of divers in a cluster at an S-DTN layer; Collecting and storing a plurality of peripheral situation information through the data link abstraction layer; Selecting a multiple communication medium capable of satisfying a real time restriction on transmission of the emergency message based on the stored surrounding information when receiving a request for transmission of an emergency message according to the risk detection from an external device in the S-DTN layer; Forwarding a request for transmission of the emergency message to the data link abstraction layer at the S-DTN layer; And generating a packet corresponding to the selected multiple communication medium in response to the emergency message in the data link abstraction layer and transmitting the generated packet to the outside through the multiple communication medium; .

In the present invention, the step of collecting and storing the circumstance information may include: receiving a packet number, a packet error information, a reception rate and an error rate information for various frequency bands in the case of the same communication medium, Information of the diver network (DN) is collected through the piggybacked peripheral situation information extension header, and is stored and updated in the peripheral situation information storage unit.

Further, an underwater communication method using a seamless DTN protocol according to another embodiment of the present invention includes: configuring a diver network (DN) including a gateway and a plurality of divers in a cluster at an S-DTN layer; Collecting and storing a plurality of peripheral situation information through the data link abstraction layer; Selecting a multiple communication medium capable of reliable transmission according to transmission of the photo / image based on the stored surrounding information when receiving a request to transmit a photo / image from an external device at the S-DTN layer; Performing fragmentation of the photo / image by comparing the maximum transmission size (MTU) of the selected multiple communication medium with the size of the photo / image at the S-DTN layer; Transferring the fragmented picture / video transmission request to the data link abstraction layer at the S-DTN layer; And generating a packet corresponding to the selected multiple communication medium corresponding to the fragmented photo / image in the data link abstraction layer and transmitting the generated packet to an external device via the multiple communication medium.

In the present invention, the fragmentation is performed when the size of the photo / image is larger than the MTU of the selected multiple communication medium.

In the present invention, when the packet is received from the external device after the step of transmitting the packet to the external device, the fragmented photo / image included in the packet is reassembled at the S-DTN layer of the external device, / ≪ / RTI > image.

Further, an underwater communication method using a seamless DTN protocol according to another embodiment of the present invention includes: configuring a diver network (DN) including a gateway and a plurality of divers in a cluster at an S-DTN layer; Collecting and storing a plurality of peripheral situation information through the data link abstraction layer; Performing communication with other divers in a first cluster at a data link abstraction layer of an underwater communication device mounted on a first diver; As the first diver moves from the first cluster to the second cluster during the communication, communication disconnection between the first cluster head of the first cluster and the second cluster of the second cluster in the data link abstraction layer Detecting movement between the first and second clusters through communication start with the head; Notifying reception information through the first and second cluster movement detection and communication initiation from the data link abstraction layer to the S-DTN layer; Storing the reported reception information in the S-DTN layer, and recognizing information of a second cluster in which the first diver is currently moving based on the neighboring situation information stored in the neighboring situation information storage unit; Transmitting a join request for the second cluster from the S-DTN layer to the second cluster head; Notifying the second cluster head of a cluster information update to a DN gateway corresponding to the second cluster head and transmitting a join approval of the second cluster to the S-DTN layer; And the first diver comprises performing communication with the other diver in the second cluster.

The present invention enables real-time and reliable underwater communication in a network between underwater active divers to ensure divers safety.

In addition, according to the present invention, it is possible to reliably perform underwater communication between divers, thereby greatly contributing to activation of a related market.

In addition, according to the present invention, it is possible to mitigate and overcome the risks and the constraints of activities that the diver can experience in the water through the provision of the real-time reliability of the seamless DTN protocol and the mobility function.

Furthermore, according to the present invention, the seamless DTN protocol is applied to the underwater IoT environment, thereby enabling activation of various application domains.

1 is a block diagram of a seamless DTN-based diver network according to an embodiment of the present invention,
2 is a block diagram of an underwater communication device using a seamless DTN protocol according to an embodiment of the present invention;
FIG. 3 is a flowchart illustrating an underwater communication method using a seamless DTN protocol according to an embodiment of the present invention;
FIG. 4 is a flowchart illustrating an underwater communication method using a seamless DTN protocol according to another embodiment of the present invention;
5 is a flow chart illustrating a method of underwater communication using a seamless DTN protocol according to another embodiment of the present invention.

Hereinafter, some embodiments of the present invention will be described in detail with reference to exemplary drawings. It should be noted that, in adding reference numerals to the constituent elements of the drawings, the same constituent elements are denoted by the same reference symbols as possible even if they are shown in different drawings. In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the difference that the embodiments of the present invention are not conclusive.

In describing the components of the embodiment of the present invention, terms such as first, second, A, B, (a), and (b) may be used. These terms are intended to distinguish the constituent elements from other constituent elements, and the terms do not limit the nature, order or order of the constituent elements. When a component is described as being "connected", "coupled", or "connected" to another component, the component may be directly connected or connected to the other component, May be "connected," "coupled, " or" connected. &Quot;

1 is a block diagram of a seamless DTN-based diver network according to an embodiment of the present invention. Referring to FIG. 1, a seamless DTN-based diver network (DN) includes a plurality of divers 10, a plurality of gateways 20, a communication network 30, and a DN service management server 40 . At this time, the diver 10 may be an underwater robot such as an Autonomous Underwater Vehicle (AUV) or a Remotely Operated Vehicle (ROV) as a subject that performs activities and works while moving in water. It also means a device that performs various functions while attaching or wearing substantially a diver, a diver, or the like. In the present embodiment, these are collectively referred to as a diver for convenience of explanation.

The DN network according to the present invention is preferably formed as a cluster-based structured diver network topology as illustrated in the figure. In the drawing, for example, some clusters are shown in the DN topology, but the number thereof is changeable.

Some of the divers 10 that underwater communicate with each other form a DN cluster 11. In each of the clusters 11, there is a cluster head 10a. The cluster head 10a is set to one of the plurality of divers 10 included in the cluster 11. The cluster head 10a communicates with the other divers 10 while receiving data and transmits data to the upper DN gateway 20 through in-water communication.

Each gateway 20 corresponds to at least one cluster 11. That is, data is received from at least one cluster head 10a and transmitted to the DN service management server 40 on the ground via the communication network 30. [ The DN service management server 40 processes and manages data received from each of the divers 40 on the ground.

Each of the divers 10 is guaranteed to have mobility. Thus, it may move from its original DN cluster 11 to another DN cluster 11, as indicated by 'move' in the figure. The figure shows an example in which a diver # 1.1.4 moves from a DN cluster # 1.1 to a DN cluster # 1.2 and then to a DN cluster # 2.1.

Here, the diver 40 includes an underwater communication device for data transmission / reception through underwater communication. These underwater communication devices transmit and receive data between each other and the DN gateway 20 using a seamless DTN protocol. At this time, the underwater communication apparatus according to the present invention is capable of real-time and reliable underwater communication seamlessly without data transmission. The underwater communication used in this embodiment uses various multiple communication media. For example, a communication medium such as a sound wave, a visible light, a magnetic field, or a low frequency is applied.

2 is a block diagram of an underwater communication device using a seamless DTN protocol according to an embodiment of the present invention. 2, an underwater communication device 100 using a seamless DTN protocol according to the present invention includes a data link abstraction layer 110, a network layer 120, a transport layer 130, ), An S-DTN layer 140, and an intersection layer interface 150.

The underwater communication device 100 is connected to the lower data link layer 210 and the data link layer 210 is responsible for communication with the ground / underwater communication model 220. Such communication modems may include sonic waves, visible light, low frequency, magnetic field modems, and the like. In addition, the underwater communication device 100 is connected to an upper application layer 230 of a diver network (DN).

The data link abstraction layer 110 includes a data link layer common interface 111, a data link layer common function module 112, and a data link layer 110. The data link layer common interface 111 is a layer that provides an interface with the lower data link layer 210, And an adapter 113. The data link layer common interface 111 is a common interface for a communication protocol operated in the diver network DN to access various multiple interfaces for multiple communication media (e.g., sound waves, visible light, magnetic field, low frequency, etc.) standard interface. The data link layer common function unit 112 minimizes resource waste by providing redundant functions of protocols of the data link layer 210 for the various communication media as common functions. The data link layer adapter 113 supports access to various media through the data link layer 210.

The network layer 120 may be selectively applied to a lightweight network layer suitable for an underwater diver network (DN) and may include only minimal basic functionality or delegate functionality to the S-DTN layer 140.

The transport layer 130 may also be selectively applied to a lightweight network layer suitable for the DN and may include only minimal basic functionality or delegate functionality to the S-DTN layer 140.

The S-DTN layer 140 includes a DTN functional unit 141, a network topology formation and management unit 142, a cluster head selection unit 143, a lightweight address system compression and restoration unit 144, 145, a surrounding situation information storage unit 146, a data link layer selecting and operating unit 147, and a lightweight P2P based handover function unit 148.

The DTN function unit 141 performs a lightweight DTN function for ensuring communication in an underwater environment. The DTN function unit 141 stores and transmits a message transmitted from a transmitter using a Store and Forward mechanism, etc., .

The network topology formation and management unit 142 is responsible for overhead and resource allocation and management for adopting and operating individual topologies for underwater mobile ad hoc networks (MANETs) at the data link layer 210, the network layer 120, the transport layer 130, In order to minimize the waste, the S-DTN layer 140 forms and manages DN topology based on underwater MANET.

The cluster head selection unit 143 functions to select a cluster head in each cluster when a cluster-based DN topology is formed.

The lightweight address system compression and restoration unit 144 is a structure for performing compression and restoration of a lightweight address system suitable for a diver network DN. The lightweight address system compression / And ground-based IoT. In case of IPv6 system used in terrestrial IOT, it is impossible to apply address system to underwater environment. Of course, the compression scheme for IPv6 addressing scheme is applied on the ground to operate in a constrained environment such as 6LoWPAN, but this also has a limitation to be directly applied to the underwater environment.

In order to overcome this problem, it is necessary to omit unnecessary parts and reduce the number of bits of the field by reflecting environment factors (eg, number of divers in the cluster, identifier length, topology structure, etc.) suitable for the diver network (DN) based on the compression technique of 6LoWPAN So as to further improve the compression efficiency.

The surrounding situation information collection and management unit 145 collects, manages, and stores the surrounding situation information that periodically analyzes the received packets through overhearing of multiple communication media in the water. (Link Quality Indicator) information such as the number of received packets, the error information of the packet, the reception ratio and the error rate for various frequency bands in the same medium, and collects it in the surrounding situation information storage unit 146 Store and update. (E.g., cluster, cluster head, diver, etc.) related to the diversity network (DN) through the surrounding information extension header piggybacked on the received packet, and also stores and updates the information on the surrounding situation information storage unit 146 .

The data link layer selection and operation unit 147 generates a real-time and reliable data link layer through machine learning based on the surrounding situation information collected, stored and updated in the neighboring situation information collecting and managing unit 145 and the neighboring situation information storing unit 146 It selects the appropriate multiple data link layer for underwater communication and establishes the operation policy. The machine learning may employ a deep learning algorithm, for example.

In addition, the data link layer selection and operation unit 147 may analyze the latest peripheral information in the case of real-time emergency communication to select multiple data link layers and multiple frequency bands that can satisfy the real-time constraint to perform communication .

In addition, in the case of reliable communication, the data link layer selection and operation unit 147 can perform communication by selecting multiple data link layers and multiple frequency bands capable of reliable data transmission by analyzing the latest peripheral information .

In addition, the data link layer selection and operation unit 147 performs fragmentation of data in consideration of the maximum transmission unit (MTU) size of the multiple data link layer at the transmitting side when data division is required, So that transmission to the medium can be performed. Therefore, even if some packet loss occurs on the receiving side, reliable communication can be realized by reassembling using packets received from other media.

The lightweight P2P based handover function unit 148 performs a lightweight P2P based handover function suitable for a diver network (DN). This is to perform a handover function to enable seamless underwater communication even if a diver belonging to a specific cluster in the DN moves to another cluster.

In addition, the lightweight P2P-based handover function unit 148 is configured to perform a lightweight P2P-based handover when a lightweight P2P-based overlay network, i.e., a diver network DN is formed in the network topology formation and management unit 142, do.

In the case of a diver moving from a specific cluster to another cluster, the neighboring situation information collection and management unit 145 may use the surrounding information of the piggybacked extension header of a plurality of received packets received through the multiple communication medium to move Clusters are recognized and handover is performed.

Meanwhile, the S-DTN layer 140 can receive messages or data from external devices such as various sensors, cameras, smart devices, and the like. Such a message or data may be an urgent message or urgent data, preferably informing the diver's risk. That is, in this embodiment, the danger may be detected through various sensors to detect an emergency situation or an emergency, and the emergency scene may be photographed and transmitted through a camera.

When the underwater communication device 100 mounted on the diver is added to the diver network DN to enter a specific cluster, the network topology formation and management unit 142 transmits the underwater communication device 100, The diver network forming process is performed. The surrounding situation information collection and management unit 145 continuously collects, analyzes, and updates various peripheral situation information collected through the data link abstraction layer 110.

At this time, when a danger is detected in a predetermined external device installed in a specific diver or a photo / image is photographed, the S-DTN layer 140 is requested to transmit a danger detection emergency message or a photo / image transmission. In response to the transmission request, the data link layer selection and operation unit 142 selects a multiple communication medium capable of satisfying real-time constraints for urgent messages or picture / video transmission based on the surrounding information. And requests an urgent message or picture / image transmission to the data link abstraction layer 110 via the selected multiple communication media.

Here, if the object to be transmitted is a picture / video, the S-DTN layer 140 may perform fragmentation of a picture / image considering the MTU of the selected multiple communication medium as described above. Then, the transfer request of the photo / image is a request to transfer the fragmented photo / image data.

The data link abstraction layer 110 generates a packet suited to the selected multiple communication medium and transmits the packet to the cluster head or other divers underwater communication apparatus 100 through the selected multiple communication medium. This transmission can be carried out by broadcasting. The underwater communication device 100 of another diver is adapted to receive the packet through the data link abstraction layer 110.

Accordingly, the data link abstraction layer 110 outputs an alert through an external device or the like mounted on the diver as soon as the received packet is received, thereby informing the diver of the occurrence of the emergency situation and informing of the support request. As soon as the cluster head receives the packet, the cluster head selects the neighboring diver, cluster head, and / or DN gateway to be propagated using the surrounding information, and transmits the packet to the selected destination.

In the case of receiving a packet including the fragmented photo / image data, the fragmented photo / image data is reassembled into the original photo / image and restored in the S-DTN layer 140, By sending a video, the diver is informed of the support request.

3 is a flowchart illustrating an underwater communication method using a seamless DTN protocol according to an embodiment of the present invention. Referring to FIG. 3, in an underwater communication method using a seamless DTN protocol according to an exemplary embodiment of the present invention, a real-time and reliable packet transmission process is provided to notify a neighboring diver when a danger is detected in a specific diver.

First, a process of forming a diver network DN is performed between the DN gateway 20 and a plurality of diver 10 in a cluster (S101). The DN formation process is performed in the network topology formation and management unit 142 of the divers underwater communication device 100. In the DN formation process, for example, a plurality of diver belonging to a cluster, a cluster head among a plurality of divers, and a DN gateway corresponding to a cluster are determined.

Subsequently, various underwater environment information collected through the data link abstraction layer 110 in the underwater environment information collection and management unit 145 is continuously collected, analyzed, and updated (S103). The analysis result and the update result are stored in the surrounding situation information storage unit 146.

Thereafter, when a danger of a diver from an external device (for example, a danger detection sensor) mounted on the diver is sensed (S105), the external device transmits a transmission request of the danger detection emergency message to the S-DTN layer 140 (S107). The S-DTN layer 140 selects a suitable multiple communication medium that can satisfy the real-time restriction on the transmission of the emergency message based on the surrounding information (S109). Then, the emergency message transmission request is transmitted to the data link abstraction layer 110 through the selected multiple communication media (S111).

Then, the data link abstraction layer 110 generates a packet matching the selected multiple communication medium (S113), and transmits the packet to the underwater communication device 100 and the cluster head of the other divers (S115). This transmission may be broadcast, and the packet is transmitted to the S-DTN layer 140 via the data link abstraction layer 110 of the underwater communication device 100 (S117). Then, the S-DTN layer 140 transmits it again to the external device (S119). The external device outputs an alarm in response to the received packet (S121). These alerts enable the diver to detect and provide support for neighboring divers.

In addition, when the cluster head receives the packet as described above, the cluster head selects a neighboring diver, a cluster head, or a DN gateway to which the packet is to be transmitted based on the surrounding information (S123), and transmits the packet to the selected object S125).

In this way, if a diver is in a dangerous situation, it is possible to seamlessly transmit packets notifying dangerous situations to other divers, cluster heads, and DN gateways in real time.

4 is a flowchart illustrating an underwater communication method using a seamless DTN protocol according to another embodiment of the present invention. Referring to FIG. 4, in the underwater communication method using the seamless DTN protocol according to another embodiment of the present invention, when a dangerous photograph or image is photographed in a specific diver, a real-time and reliable packet transmission process .

3, a process of forming a diver network DN is performed between the DN gateway 20 and a plurality of diver 10 in the cluster (S201). Subsequently, various underwater environment information collected through the data link abstraction layer 110 is continuously collected, analyzed and updated in the underwater environment information collection and management unit 145 (S203). The analysis result and the update result are stored in the surrounding situation information storage unit 146.

Thereafter, when a photograph or an image (photograph / image) is photographed from an external device (for example, a camera) mounted on the diver (S205), the external device transmits a request for transmission of the photographed photograph / image to the underwater communication device 100 To the S-DTN layer 140 in step S207. The S-DTN layer 140 selects multiple communication media that can reliably transmit pictures / images based on the surrounding information (S209). Then, in step S213, a request for transmission of a photo / image is transmitted to the data link abstraction layer 110 through the selected multiple communication media.

At this time, if necessary, the image / image data fragmentation operation may be optionally performed prior to the transmission of the photo / image after step S209 (S211). This is done when the size of the photo / image data is larger by comparing the maximum transmission size (MTU) of the multiple communication medium and the size of the photo / image data in step S209. This is because if the picture / image size is larger than the MTU of multiple communication media, it can not be sent all at once. This is because, in an emergency situation, when only a part of a photograph / image is transmitted or data is broken, the emergency situation may not be notified properly. Accordingly, in another embodiment, if the fragmentation operation is performed as in step S211, the fragmented photo / image transmission request is transmitted to the data link abstraction layer 110 in step S213.

Thereafter, the data link abstraction layer 110 generates a packet matching the selected multiple communication medium (S215), and transmits the packet to the underwater communication device 100 of another diver (S217). Such transmissions may be broadcast. Subsequently, the photo / image is transmitted to the S-DTN layer 140 through the data link abstraction layer 110 of the other divers's underwater communication device 100 (S219). The S-DTN layer 140 transmits this to the external device again (S223). Accordingly, the external device can output the photo / video corresponding to the received packet, and can also output the alarm together with the alarm. The other diver identifies these pictures / videos so that the neighboring diver can detect and support the danger.

At this time, if the S-DTN layer 140 receives a packet including a fragmented picture / image as in the other embodiments, the S-DTN layer 140 transmits a packet to the external device in step S223, (S221), and transfers the assembled original image to an external device (S223).

In addition, when the cluster head receives a packet as described above, the cluster head may select a neighboring diver, a cluster head, or a DN gateway to which the packet is to be transmitted based on the surrounding information, as described above, and transmit the packet to the selected target.

In this way, if a diver is in danger, other divers, cluster heads, and DN gateways will be able to seamlessly transmit packets informing of a dangerous situation in real time.

5 is a flowchart illustrating a method of underwater communication using a seamless DTN protocol according to another embodiment of the present invention. Referring to FIG. 5, in the underwater communication method using the seamless DTN protocol according to another embodiment of the present invention, when the first diver moves from the first cluster to another second cluster as illustrated in FIG. 1, And shows the communication process between the underwater communication devices for handover.

3 and 4, a process of forming a diver network DN is performed between the DN gateway 20 and a plurality of diver 10 in the cluster (S301). Then, various underwater environment information collected through the data link abstraction layer 110 is continuously collected, analyzed and updated in the underwater environment information collection and management unit 145 (S303). The analysis result and the update result are stored in the surrounding situation information storage unit 146.

While performing communication with other divers in the first cluster in the data link abstraction layer 110 of the underwater communication device 100 mounted on the first diver (S305), the first diver is in the first cluster, The data link abstraction layer 110 detects the movement of the cluster by the disconnection of the first cluster head and the reception of the information of the second cluster head (S307).

The data link abstraction layer 110 notifies the S-DTN layer 140 of the reception information through the detection of the inter-cluster movement and the start of communication (S309). The surrounding situation information collection and management unit 145 of the S-DTN layer 140 stores the notified reception information in the surrounding situation information storage unit 146 (S311), and the lightweight P2P based handover function unit 148 The first diver recognizes the information of the second cluster currently moved based on the surrounding information stored in the surrounding information storage unit 146 at step S313.

Then, the S-DTN layer 140 of the first diver's underwater communication device 100 transmits a cluster join request to the second cluster head of the second cluster (S315). Then, the second cluster head notifies cluster information update to the DN gateway corresponding to itself (S317), and transmits the cluster join acknowledgment to the S-DTN layer 140 (S319). This causes the first diver to communicate with the other diver in the second cluster.

Then, the first cluster head notifies the corresponding cluster information update to the S-DTN layer 140 of the second diver (S321), and the first diver moving to the second cluster communicates with the other diver in the second cluster (S323).

As described above, the present invention provides an underwater communication protocol that enables real-time and reliable communication by forming a diver network (DN) for safe underwater activities among divers in the water, and performs underwater communication based on the protocol And a communication method therefor. In particular, according to the present invention, a seamless real-time message transmission method, a real-time reliable message transmission method, and a communication method for handing over a diver are provided, thereby enabling seamless underwater communication between divers in the water.

While the present invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not limited to the disclosed embodiments. That is, within the scope of the present invention, all of the components may be selectively coupled to one or more of them. Furthermore, the terms "comprises", "comprising", or "having" described above mean that a component can be implanted unless otherwise specifically stated, But should be construed as including other elements. All terms, including technical and scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used terms, such as predefined terms, should be interpreted to be consistent with the contextual meanings of the related art, and are not to be construed as ideal or overly formal, unless expressly defined to the contrary.

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be construed according to the following claims, and all technical ideas within the scope of equivalents should be construed as falling within the scope of the present invention.

10: Diver
10a: cluster head
11: Cluster
20: DN gateway
30: Network
40: DN Service Management Server
110: Data Link Abstract Layer
111: Data link layer common interface
112: Data Link Layer Common Function
113: Data Link Layer Adapters
120: Network layer
130: Transport layer
140: S-DTN layer
141: DTN function section
142: Network topology formation and management section
143: Cluster head selection section
144: Lightweight address system compression and decompression unit
145: Surrounding situation information collection and management unit
146: Ambient situation information storage unit
150: Cross-layer interface
210: Data link layer
220: ground / underwater communication modem
230: Diver Network Application Layer

Claims (16)

1. An underwater communication device mounted on a plurality of divers and constituting a diver network (DN)
A data link abstraction layer connected to a lower data link layer to provide an interface with an external device; And
A DTN function section for storing the transmitted data in the buffer to perform the DTN function for underwater communication and then storing and retransmitting the data until receipt confirmation, and a network topology forming and managing section for forming and managing the DN topology based on the underwater MANET A peripheral status information collection and management unit for collecting and managing peripheral status information that periodically analyzes packets received through overhearing of multiple communication media, a peripheral status information collection and management unit for storing the peripheral status information collected and managed, A data link layer selecting unit for selecting a plurality of data link layers through predetermined machine learning based on peripheral information collected and stored in the storage unit, the surrounding information collection and management unit, and the surrounding information storage unit, An S-DTN layer including an operation part; Wherein the at least one of the at least two DTN protocols is a DTN protocol. 2. The method of claim 1, wherein the data link abstraction layer comprises:
A data link layer common interface for providing a unified common standard interface for accessing multiple interfaces for multiple communication media by a communication protocol operated in the diver network (DN);
A data link layer common function unit for providing redundant functions of the protocol of the data link layer for the multiple communication media as a common function; And
And a data link layer adapter for supporting access to multiple communication media through the data link layer. 2. The method of claim 1, wherein when the S-DTN layer receives a data transmission request from a predetermined external device, the data link layer selection and operation unit satisfies a real- And transmitting the data transmission request to the data link abstraction layer through the selected multiple communication medium. 4. The underwater communication device according to claim 3, wherein the data link abstraction layer generates a packet corresponding to the selected multiple communication medium when the data transmission request is received and transmits the packet to the outside. 5. The method of claim 4, wherein the S-DTN layer performs fragmentation when the size of the data is larger than a maximum transmission size (MTU) of the selected multiple communication medium, and then transmits the fragmented data transmission request Link layer to the data link abstraction layer, and the data link abstraction layer generates a packet suited to the selected multiple communication medium according to the fragmented data, and transmits the generated packet to the outside, and uses the seamless DTN protocol. 6. The underwater communication device of claim 5, wherein the S-DTN layer reassembles the fragmented data included in the packet when the packet is received from the outside and restores the original data. 2. The method of claim 1, wherein the surrounding information collecting and managing unit receives information on the number of received packets, error information on packets, reception rate and error rate information of various frequency bands for the same communication medium, (DTN) protocol that collects information of a diver network (DN) through a surrounding information extension header and stores and updates the information in the surrounding information storage unit. 2. The method of claim 1, wherein the S-DTN layer includes a compression and restoration function of a lightweight address system suitable for a cluster head selection unit or a diver network (DN) for selecting cluster heads in a plurality of clusters when forming the divers topology And a lightweight address system compression and decompression unit that performs a lightweight address system compression and decompression unit that performs a lightweight address system compression and decompression unit that performs a lightweight address system compression and decompression unit. 9. The underwater communication device according to claim 8, wherein the lightweight address system compression / decompression unit provides a compatible address system between underwater and terrestrial IoT for interworking between underwater IoT (IoUT) and ground IoT. 10. The method of claim 9, wherein the S-STN layer is a lightweight P2P-based handheld device that performs a handover function in a diver network (DN) such that diver in the first cluster is seamlessly in- And an over function section. Configuring a diver network (DN) comprising a gateway and a plurality of divers in the cluster at the S-DTN layer;
Collecting and storing a plurality of peripheral situation information through the data link abstraction layer;
Selecting a multiple communication medium capable of satisfying a real time restriction on transmission of the emergency message based on the stored surrounding information when receiving a request for transmission of an emergency message according to the risk detection from an external device in the S-DTN layer;
Forwarding a request for transmission of the emergency message to the data link abstraction layer at the S-DTN layer; And
Generating a packet corresponding to the selected multiple communication medium in response to the emergency message in the data link abstraction layer and transmitting the generated packet to the outside through the multiple communication medium; The method comprising the steps < RTI ID = 0.0 > of: < / RTI > 12. The method of claim 11, wherein the collecting and storing of the surrounding information comprises:
The number of received packets, the error information of packets, the reception ratio and error rate information of various frequency bands in the case of the same communication medium, and the surrounding information information extension header piggybacked on the received packet, A method of underwater communication using a seamless DTN protocol for collecting and storing information in an environment information storage unit. Configuring a diver network (DN) comprising a gateway and a plurality of divers in the cluster at the S-DTN layer;
Collecting and storing a plurality of peripheral situation information through the data link abstraction layer;
Selecting a multiple communication medium capable of reliable transmission according to transmission of the photo / image based on the stored surrounding information when receiving a request to transmit a photo / image from an external device at the S-DTN layer;
Performing fragmentation of the photo / image by comparing the maximum transmission size (MTU) of the selected multiple communication medium with the size of the photo / image at the S-DTN layer;
Transferring the fragmented picture / video transmission request to the data link abstraction layer at the S-DTN layer; And
Generating a packet corresponding to the selected multiple communication medium corresponding to the fragmented photo / image in the data link abstraction layer and transmitting the generated packet to an external device via the multiple communication medium; The method comprising the steps < RTI ID = 0.0 > of: < / RTI > 14. The method of claim 13, wherein the fragmentation is performed when the size of the photo / image is larger than the MTU of the selected multiple communication medium. 14. The method of claim 13, further comprising: after transmitting the packet to an external device,
Receiving the packet from the external device, reconstructing the fragmented photo / image included in the packet at the S-DTN layer of the external device, and restoring the original photo / image to the original, using the seamless DTN protocol Communication method. Configuring a diver network (DN) comprising a gateway and a plurality of divers in the cluster at the S-DTN layer;
Collecting and storing a plurality of peripheral situation information through the data link abstraction layer;
Performing communication with other divers in a first cluster at a data link abstraction layer of an underwater communication device mounted on a first diver;
As the first diver moves from the first cluster to the second cluster during the communication, communication disconnection between the first cluster head of the first cluster and the second cluster of the second cluster in the data link abstraction layer Detecting movement between the first and second clusters through communication start with the head;
Notifying reception information through the first and second cluster movement detection and communication initiation from the data link abstraction layer to the S-DTN layer;
Storing the reported reception information in the S-DTN layer, and recognizing information of a second cluster in which the first diver is currently moving based on the neighboring situation information stored in the neighboring situation information storage unit;
Transmitting a join request for the second cluster from the S-DTN layer to the second cluster head;
Notifying the second cluster head of a cluster information update to a DN gateway corresponding to the second cluster head and transmitting a join approval of the second cluster to the S-DTN layer; And
Wherein the first diver comprises communicating with other divers in the second cluster.

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