KR101143510B1 - Apparatus and method for message transmission in delay tolerant network using communication infrastructure - Google Patents

Abstract

Disclosed are a message transmission apparatus and method of a delay-tolerant network using a communication infrastructure. In a transmitting node for transmitting a message among a plurality of mobile nodes included in the mobile network, the storage unit stores a message to be transmitted to a destination. The transmission unit transmits a copy of the message generated from the message stored in the storage unit to a transmission node for transmitting a message among a plurality of mobile nodes included in the mobile network, or a communication device connected to the fixed network. When the connection with the forwarding node is detected, the controller determines the transmission amount of the message copy to be transmitted to the forwarding node within the maximum amount of the set copy of the message, and when the connection with the communication device is detected, the communication device is based on the type of the network to which the destination belongs. Determines the amount of copy of the message to be sent. According to the present invention, a message is transmitted to a communication device connected to a fixed network, so that the message can be delivered to the final destination, so that the message delivery range can be efficiently increased even when the distribution density of the node is low, thereby improving the success rate of delivery. And shorten the propagation delay time.

Description

Apparatus and method for message transmission in delay tolerant network using communication infrastructure}

The present invention relates to a message transmission apparatus and method of a delay-tolerant network using a communication infrastructure, and more particularly, to retransmit a message to another node and a communication infrastructure in a delay-tolerant network in which a connection between an originating node and a destination node is not guaranteed. An apparatus and method are provided.

Delay Tolerant Network (DTN) is a network in which the connection between the originating node and the destination node is not guaranteed. In the DTN, each node stores a message to be sent in a buffer and forwards the stored message when it encounters another node. Deliver the message to its destination.

The DTN routing protocol is classified into a deterministic protocol applied in an environment capable of predicting changing network information and a dynamic protocol applied in an environment in which network information cannot be predicted in advance. A copy of a message is an example of a dynamic protocol applied in a general environment. There is a Spray and Wait protocol that consists of a Spray stage that performs redundancy and a Wait stage that does not perform transmission until the destination node is met by using both copies and a copy.

In the Spray and Wait protocol, the originating node sets the size L of the maximum copy of the message and sends the message to the first forwarding node. Then, when the forwarding node contacts another node, the forwarding node forwards the message copy by setting the number of message copies within the range of L according to the transmission policy. Various techniques to improve the Spray and Wait protocol have been proposed. Among them, Binary Spray and Wait technique is the method that always delivers L / 2 copies to the contact nodes.

In addition, in the vehicle network environment, each node knows its mobility information and transmits the maximum size L of the copy by giving priority to the node moving in the other direction and the node far from the destination, and There is a technique in which each node recognizes the mobility model of the node and efficiently resizes and retransmits L.

The techniques described above are for efficiently increasing the message delivery range in consideration of the directionality or mobility model in the Spray and Wait protocol that performs retransmission by L. FIG. However, the Spray and Wait protocol can reduce the network load by retransmitting a message by a limited L basically, but there is a problem in that the message delivery range is limited, thereby degrading the success rate of the message.

The present invention is to provide a message transmission apparatus and method for a delay-tolerant network using a communication infrastructure that can increase the success rate of the message transmission and reduce the transmission delay time in a delay-tolerant network having a low density distribution of nodes. have.

Another technical problem to be solved by the present invention is to execute a message transmission method of a delay-tolerant network using a communication infrastructure that can increase the success rate of a message transmission and reduce the transmission delay time in a delay-tolerant network having a low density distribution of nodes. The present invention provides a computer-readable recording medium having recorded thereon a program.

In order to achieve the above technical problem, a message transmission apparatus of a delay-tolerant network using a communication infrastructure according to the present invention is provided in a transmitting node for transmitting a message among a plurality of mobile nodes included in a mobile network, and transmitted to a destination. A storage unit in which a message is stored; A transmitter for transmitting a copy of a message generated from a message stored in the storage unit to a forwarding node for transmitting a message among a plurality of mobile nodes included in the mobile network, or a communication device connected to a fixed network; And determining a transmission amount of a message copy to be transmitted to the forwarding node within a range of the maximum amount of the set copy of the message when the connection with the forwarding node is detected, and based on the type of the network to which the destination belongs when the connection with the communication device is detected. And a controller for determining a transmission amount of a message copy to be transmitted to the communication device.

In order to achieve the above technical problem, a message transmission device of a delay-tolerant network using a communication infrastructure according to the present invention is provided in a first communication device connected to a fixed network, and transmits a message from a plurality of mobile nodes included in a mobile network. A receiving unit for receiving a message to be transmitted from a transmitting node to a destination; And a transmitter configured to transmit the message to the destination when the destination belongs to the fixed network, and to transmit the message to a second communication device connected to the fixed network when the destination belongs to the mobile network. do.

In order to achieve the above technical problem, a message transmission method of a delay-tolerant network using a communication infrastructure according to the present invention includes transmitting a message to be transmitted to a destination from a transmitting node transmitting a message among a plurality of mobile nodes included in the mobile network. (A) determining a transmission amount of a copy of a message to be transmitted to a forwarding node for delivering a message among a plurality of mobile nodes included in the mobile network, or a communication device connected to a fixed network, from among the copy of the message generated from the message; ; And (b) transmitting the copy of the message to the forwarding node or the communication device. In step (a), if a connection with the forwarding node is detected, the message is transmitted within the maximum amount of the set copy of the message. The transmission amount of the message copy to be transmitted to the node is determined, and when the connection with the communication device is detected, the transmission amount of the message copy to be transmitted to the communication device is determined based on the type of the network to which the destination belongs.

In order to achieve the above technical problem, a message transmission method of a delay-tolerant network using a communication infrastructure according to the present invention is for transmitting a message to be transmitted to a destination from a first communication device connected to a fixed network, and (a) moving. Receiving the message from a transmitting node transmitting a message among a plurality of mobile nodes included in a network; And (b) transmitting the message to the destination if the destination belongs to the fixed network, and transmitting the message to a second communication device connected to the fixed network if the destination belongs to the mobile network. Has

According to an apparatus and method for transmitting a message in a delay-tolerant network using a communication infrastructure according to the present invention, a message is transmitted to a communication device connected to a fixed network so that a message can be delivered to a final destination, even when the distribution density of nodes is low. The range of delivery of messages can be effectively increased, which improves the success rate of delivery and shortens the delivery delay time.

1 is a diagram illustrating a network configuration to which a message transmission apparatus of a delay-tolerant network using a communication infrastructure according to the present invention is applied;
Figure 2 is a block diagram showing the configuration of a preferred embodiment for a message transmission device provided in each of the mobile node and communication equipment,
3 is a flowchart illustrating a preferred embodiment of a method for transmitting a message from a mobile node to a communication device, and
4 is a flowchart illustrating a preferred embodiment of a method for delivering a message to a destination after receiving a message from a communication device.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the message transmission apparatus and method of a delay-tolerant network using a communication infrastructure according to the present invention.

First, FIG. 1 is a diagram illustrating a network configuration to which a message transmission apparatus of a delay-tolerant network using a communication infrastructure according to the present invention is applied. Referring to FIG. 1, the apparatus for transmitting a message according to the present invention is provided in a plurality of mobile nodes 101, 102, 103, hereinafter referred to as '100' constituting a mobile network, or in a fixed network 300 such as an IP network. It may be provided in each of the communication equipment 201, 202, 203, hereinafter '200' is connected and wired to each other.

The example shown in FIG. 1 is a case in which vehicles driving constitute a mobile network, and the message transmission apparatus according to the present invention is applicable to other delay-tolerant networks. In addition, in FIG. 1, the fixed network 300 is composed of fixed nodes 400. For convenience of description, one fixed node 400 is illustrated separately from the fixed network 300.

As described above, the spray and wait routing protocol in a delay-tolerant network delivers only a limited number of L copies of messages to other nodes, thereby limiting the range of message delivery, thereby reducing the message transmission success rate. . This decrease in transmission success rate is more problematic when the density of nodes constituting the network is low and the movement is frequent.

Therefore, the apparatus for transmitting a message according to the present invention may transfer the message to the destination by using the communication device 200 connected to the fixed network as well as other mobile nodes belonging to the same network as the mobile node 100 of the delay-allowed network to transmit the message to the destination. To improve the transmission rate of the message.

2 is a block diagram showing the configuration of a preferred embodiment of a message transmission device provided in each of the mobile node 100 and the communication device 200.

Referring to FIG. 2, first, a message transmission device provided in the mobile node 100 includes a storage unit 110, a first transmission unit 120, and a control unit 130, and a message provided in the communication device 200. The transmission device includes a receiver 210 and a second transmitter 220. Hereinafter, for convenience of description, the message transmission device provided in the mobile node 100 is defined as the mobile node 100 and the message transmission device provided in the communication device 200 as the communication device 200.

In addition, the mobile node 100 operates as a delivery node that receives a message from a transmitting node or a transmitting node which transmits a message to a destination, and delivers a message back to the destination, and the communication device 200 communicates with the mobile node 100 or another communication. It receives the message from the device 200 and performs the operation of delivering back toward the destination.

A message to be transmitted to a destination is stored in the storage 110 of the transmitting node of the mobile node 100, and the first transmitter 120 transmits a copy of the message generated from the message stored in the storage 110 to the forwarding node or the communication. Send to the equipment 200. That is, when the connection between the transmitting node and the transmitting node is detected, the first transmitting unit 120 transmits a message to the transmitting node. When the connection between the transmitting node and the communication device 200 is detected, the first transmitting unit 120 transmits the message. Send a message to the communication device (200).

The control unit 130 of the transmitting node determines the amount of transmission of the copy of the message to be transmitted to the transfer node or communication equipment. In this case, the message transmission from the transmitting node to the transmitting node may be performed using the existing Spray and Wait routing protocol. In one embodiment, the message transmission from the transmitting node to the delivery node may be performed by a Binary Spray and Wait technique, and if the maximum size of the preset copy of the message is L, the controller 130 may transmit the message to the first transmitter 120. Sends L / 2 copies of the message to the forwarding node.

On the other hand, when the transmitting node that is moving enters the transmission range of the communication device 200 and the connection with the communication device 200 is detected, the controller 130 determines the amount of transmission of the message copy to the communication device 200. The amount of transmission of a copy of a message to be transmitted to the communication device 200 depends on the type of network to which the destination of the message belongs. For example, the controller 130 may transmit the first transmission unit 120 when the destination of the message to be transmitted is one of the fixed nodes 400 constituting the fixed network 300 connected to the communication device 200. Transmits all of the generated message copies to the communication device 200, and when the destination is one of the other mobile nodes 100 of the mobile network, the first transmitter 120 transmits a part of the generated message copies. Transmission to the communication equipment 200.

When the first transmission unit 120 transmits all of the copy of the message to the communication device 200, the control unit 130 changes the state of the transmission node to the standby mode by changing the L value set for the transmission node to 0. .

On the other hand, when the first transmission unit 120 transmits only a part of the message copy to the communication device 200, the transmission amount is determined according to a preset ratio. That is, when the constant d is set in advance, and the transmitting node to transmit the message to one of the other mobile nodes 100 enters the transmission range of the communication device 200, the controller 130 may transmit the first transmission unit 120. The L / d to send a copy of the message to the communication device (200).

Meanwhile, the communication device 200 that receives the message from the first transmitting unit 120 of the transmitting node also operates differently according to the type of the network to which the destination belongs. Referring back to FIG. 2, the receiver 210 of the communication device 200 receives a copy of the message transmitted by the transmitting node, and the second transmitter 220 corresponds to the type of the network to which the destination of the received message belongs. Send a message to the destination or other communication device (200).

When the destination of the message transmitted from the transmitting node is one of the fixed nodes 400 of the fixed network, the second transmitter 220 receives the final destination of the message because the communication device 200 is connected to the fixed network. The sent message. However, when the destination of the message is one of the mobile nodes 100 of the mobile network, the mobile node 100 as the destination within the transmission range of the corresponding communication device 200 is transmitted by transmitting the message to one of the other communication devices 200. When entered, the message can be delivered. For convenience of explanation, hereinafter, the communication device 200 receiving a message from a transmitting node is referred to as a first communication device, and the communication device 200 receiving a message from the first communication device is referred to as a second communication device.

When the second communication device receives a message to be transmitted from the first communication device to the mobile node 100 as the destination, the second communication device sets a reference time to transmit the message to the mobile node 100 as the destination. When the mobile node 100 as the destination enters the transmission range of the second communication device within the set reference time, the second transmitter 220 of the second communication device transmits a message to the corresponding destination. However, if the mobile node 100 as the destination does not enter the transmission range of the second communication device within the reference time, the stored message is discarded to prevent the overflow of the buffer.

Referring to Figure 1 with reference to the message transfer process between the mobile node 100 and the communication device 200 as follows. In FIG. 1, the mobile node 101 located within the transmission range of the communication device 201 may transmit its message to the communication device 201. However, the mobile node 102, which is not located within the transmission range of the communication device 200, cannot transmit a message to the communication device 200, but enters its own transmission range and sends a message to another mobile node 103 in which a connection is detected. Can be transmitted. In this case, message transmission is performed by the existing Binary Spray and Wait routing protocol.

The transmitting node 101, which is one of the mobile nodes 100 shown in FIG. 1, transmits a message to the first communication device 201 in which a connection is detected, and the receiving node 103, which is one of the other mobile nodes 100. FIG. Or a case in which a message is transmitted to a fixed node 400 belonging to the fixed network 300.

In the case of first transmitting a message to the receiving node 103, the first transmitting unit 120 of the transmitting node 101 detects a connection with the first communication device 201 and transmits a copy of the message to the first communication device 201. send. In this case, the transmission amount of the message copy is set by the controller 130 as a part of the entire message copy. Next, the second transmitter 220 of the first communication device 201 transfers the message to the second communication device 202 through the wired network since the destination of the message is the reception node 103 belonging to the mobile network.

The second communication device 202 transmits a message to the receiving node 103 when the receiving node 103 moves within the preset reference time to enter its transmission range, and the receiving node 103 transmits within the reference time. If no range is entered, the message is discarded.

When transmitting a message to the fixed node 400, the first transmitting unit 120 of the transmitting node 101 transmits a copy of the message to the first communication device 201 when the connection with the first communication device 201 is detected. However, the control unit 130 transmits the entire copy of the message to the first communication device 201 because the destination is the fixed node 400 and switches the state of the transmitting node 101 to the standby mode. The first communication device 201 receiving the message transmits the message to the fixed node 400 through the connected fixed network 300.

3 is a flowchart illustrating a preferred embodiment of the method for transmitting a message from the mobile node 100 to the communication device 200.

Referring to FIG. 3, if the connection with the communication device 200 is not detected (S310), the mobile node 100 transmits half of the entire message copy to another mobile node based on the existing Binary Spray and Wait routing protocol (S310). S320). However, the transmission amount of the message copy to another mobile node may be determined to be half of the entire message copy according to the Binary Spray and Wait routing protocol, or may be determined to be different according to the existing Spray and Wait routing protocol.

However, when the connection with the communication device 200 is detected (S310), a copy of the message whose transmission amount is determined according to the type of the network to which the destination belongs is transmitted. That is, when the destination is one of the other mobile nodes 100 belonging to the mobile network (S330), a part of the message copy set by the controller 130 is transmitted to the communication device 200 (S340). However, when the destination is one of the fixed nodes 400 belonging to the fixed network, all of the copy of the message is transmitted to the communication device 200 (S350), and the mobile node 100 switches to the standby mode.

4 is a flowchart illustrating a preferred embodiment of a method for delivering a message to a destination after receiving a message from the communication device 200.

Referring to FIG. 4, the communication device 200 receives a message (S410), and checks the destination of the message. If the message is received from the mobile node 100 (S420), the message is transmitted to different places according to the type of the network to which the destination of the message belongs. That is, if the destination is a mobile node (100) (S430) transmits a message to another communication device 200 connected through a wired network (S440), if the destination is a fixed node (400) transmits a message to a destination through a connected fixed network. (S450).

On the other hand, if the message is received from the other communication device 200 determines the connection with the mobile node 100 as a destination within the reference time by setting a reference time (S460), the mobile node (destination) within the reference time ( When 100) enters the transmission range, it transmits a message to the destination (S450). However, if the mobile node 100 as the destination does not enter the transmission range within the reference time, the received message is discarded (S470).

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. The computer-readable recording medium includes all kinds of recording devices in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like, and may be implemented in the form of a carrier wave (for example, transmission via the Internet) . The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

Although the preferred embodiments of the present invention have been shown and described above, the present invention is not limited to the specific preferred embodiments described above, and the present invention belongs to the present invention without departing from the gist of the present invention as claimed in the claims. Various modifications can be made by those skilled in the art, and such changes are within the scope of the claims.

100 (101, 102, 103)-mobile node
110-storage
120-first transmitter
130-control unit
200 (201, 202)-communication equipment
210-receiver
220-second transmitter
300-fixed network
400-Fixed Node

Claims (15)

In the message transmission apparatus provided in the transmitting node for transmitting a message among a plurality of mobile nodes included in the mobile network,
A storage unit for storing a message to be sent to a destination;
A transmitter for transmitting a copy of a message generated from a message stored in the storage unit to a forwarding node for transmitting a message among a plurality of mobile nodes included in the mobile network, or a communication device connected to a fixed network; And
When the connection with the forwarding node is detected, the transmission amount of the message copy to be transmitted to the forwarding node is determined within the maximum amount of the set copy of the message, and when the connection with the communication device is detected, based on the type of the network to which the destination belongs. And a controller configured to determine a transmission amount of a message copy to be transmitted to the communication device. The method of claim 1,
If the destination belongs to the fixed network, the controller determines all of the message copies generated from the messages stored in the storage unit as the transmission amount of the message copies to be transmitted to the communication device, and if the destination belongs to the mobile network, And a transmission amount of a message copy to be transmitted to the communication device, the amount corresponding to a preset ratio among the message copies. The method of claim 2,
And the controller switches the state of the transmitting node to a standby mode after all of the copy of the message is transmitted to the communication device. 4. The method according to any one of claims 1 to 3,
And a different area address is assigned to the destination according to the type of the network to which the destination belongs. In the message transmission device provided in the first communication device connected to the fixed network,
A receiving unit which receives a message to be transmitted to a destination from a transmitting node transmitting a message among a plurality of mobile nodes included in the mobile network; And
A transmission unit transmitting the message to the destination when the destination belongs to the fixed network, and transmitting the message to a second communication device connected to the fixed network when the destination belongs to the mobile network. Message transmission apparatus, characterized in that. 6. The method of claim 5,
And the second communication device transmits a message received from the transmitter to the destination when the connection with the destination is detected within a preset reference time. The method of claim 6,
And the second communication device discards the message received from the transmitter if the connection with the destination is not detected within the reference time. A message transmitting method for transmitting a message to be transmitted from a transmitting node transmitting a message among a plurality of mobile nodes included in a mobile network to a destination,
(a) determining a transmission amount of a message copy to be transmitted to a forwarding node for transmitting a message among a plurality of mobile nodes included in the mobile network, or a communication device connected to a fixed network, from among the message copies generated from the message; And
(b) sending a copy of the message to the forwarding node or the communication device;
In the step (a), if the connection with the forwarding node is detected, the transmission amount of the message copy to be transmitted to the forwarding node is determined within the range of the maximum amount of the set message copy, and if the connection with the communication device is detected, the destination is determined. And determining a transmission amount of a copy of the message to be transmitted to the communication device based on the type of the network to which the network belongs. The method of claim 8,
In the step (a), if the destination belongs to the fixed network, all of the message copies generated from the messages stored in the storage unit are determined as the transmission amount of the message copies to be transmitted to the communication device, and the destination is the mobile network. In the case of belonging to the message transmission method, characterized in that the amount of the message copy to be transmitted to the communication device to determine the amount corresponding to a preset ratio of the message copy. The method of claim 9,
(c) transitioning a state of the transmitting node to a standby mode after all of the copy of the message is transmitted to the communication equipment. The method of claim 8,
And a different area address is assigned to the destination according to the type of the network to which the destination belongs. In the message transmission method for transmitting a message to be transmitted to a destination from a first communication device connected to a fixed network,
(a) receiving the message from a transmitting node transmitting a message among a plurality of mobile nodes included in the mobile network; And
(b) transmitting the message to the destination if the destination belongs to the fixed network, and transmitting the message to a second communication device connected to the fixed network if the destination belongs to the mobile network; Message transmission method comprising the. The method of claim 12,
And when the connection with the destination is detected within a preset reference time, the second communication device transmits the message received in step (b) to the destination. The method of claim 13,
And if the connection with the destination is not detected within the reference time, the second communication device discards the message received in step (b). A computer-readable recording medium having recorded thereon a program for executing the message transmission method according to any one of claims 8 to 14.

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