KR101534527B1 - Method of message delivery based on history of node residence in delay tolerant network, recording medium and apparatus for performing the method - Google Patents

Abstract

Provided is a method for forwarding a message based on a retention history of a node in delay tolerant networks, which comprises the steps of: obtaining information on a maximum retention cell of a node on a grid cell formed by dividing a network area into a predetermined size; exchanging the information on the maximum retention cell of the nod with the other node in case that the node is contacted with the other node; confirming whether or not the number of copied messages included in the node is a spray phase of ′n′ number (n is a natural number which is greater than 1); and differentially controlling the number of the copied messages forwarded to the other node by comparing information on the maximum retention cell of a destination nod of the message with information on the maximum retention cell of the other node in case that the node is in the spray phase. Accordingly, the entire message transfer rate can be increased by using information on the maximum retention grid cell according to periodicity of the nod in a spray and wait protocol in order to appropriately control the number of the copied messages.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a message delivery method based on a retention history of a node in a delay-allowed network, a recording medium and an apparatus for performing the message delivery method,

The present invention relates to a message delivery method based on a retention history of a node in a delay-allowed network, and a recording medium and an apparatus for performing the same. More particularly, And more particularly, to a message delivery method for efficiently delivering a message to a corresponding node based on a predetermined criterion when a user makes contact with the node, and a recording medium and an apparatus for performing the message delivery method.

Recently, a study on a Delay Tolerant Network (DTN) in which a connection between a calling node and a called node is not ensured is being actively researched. Since the end-to-end connection is not guaranteed in DTN, existing routing protocols that perform routing routines are not suitable, and new routing protocols based on Store-Carry-Forward are needed. In the DTN, each node stores a message to be transmitted in a buffer, and when it encounters another node, it forwards the message to the final destination by forwarding the stored message.

The DTN routing protocol is classified into a deterministic protocol applied in an environment that predicts changing network information and a dynamic protocol applied in an environment in which network information can not be predicted in advance. Among them, Epidemic routing protocol based on flooding scheme, PRoPHET routing protocol for performing probabilistic transmission using cumulative contact information of each node, and Spray step for performing retransmission with redundancy in a copy of message And a Spray and Wait protocol consisting of a Wait step that does not perform transmission until the destination node is reached using both the copy and the copy.

The epidemic routing protocol exchanges the index information of the messages with each other when the nodes that make up the network contact with each other, And a packet loss may occur due to an increase in the probability of a wireless access collision.

The PRoPHET routing protocol transmits a message to a node with a high probability of delivery success probability based on the stored contact information when each node in the network contacts another node. It has a disadvantage that diffusion is slow and transmission rate is low.

The Spray and Wait protocol sets the L, which is the size of the maximum number of copies of the message, to the first message originating node and sends the message to the first connected node. The node that receives the message determines the value of the message copy count within the range of L, which is the number of copying times of the message, according to the determined transmission policy when connecting to another node, and performs message transmission to the other node . At this time, the value of L, which is the size of the message copying number that has been initially set, has not yet been exhausted, so that the state of performing the retransmission is referred to as a spraying step and the node having the message has only one copy, A state in which retransmission is no longer performed until a node is encountered is called a weighting phase.

The Spray and Wait protocol has been proposed in various ways according to the distribution method of the message copy. In addition to the normal Spray and Wait, which conveys one copy to the contact node, the Binary Spray and Wait which conveys the half of the copy to the contact node Recently, there have been techniques for transferring copies in consideration of position prediction, Quality of Node (QoN), direction information, and moving speed.

Since the Spray and Wait protocol performs retransmission only for a fixed L, it reduces the number of message transmissions throughout the network, so that the load is constant and the transmission success rate is good. However, in the existing Spray and Wait protocol, the success rate and the delay time may be lowered due to the mobility of the node due to the limited number of copies, and the extension range of the packet is limited. In particular, when a node is applied to an environment having a more periodic mobility, a message may not be spread quickly because the number of nodes contacting the node is less than the environment having random mobility.

KR 10-2013-0046612 A KR 10-2014-0054886 A

  T. Spyropoulos, K. Psounis, C. S. Raghavendra, "Spray and Wait: an efficient routing scheme for intermittently connected mobile networks ", ACM SIGCOMM Workshop on Delay Tolerant Networking, Aug. 2005.   F. Ekman, A. Keranen, J. Karvo, and J. Ott. Working day movement model. In Proc. of Mobility Models, pp. 33-40, 2008.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a message delivery method for adaptively determining an amount of message transmission in each node of a delay-

Another object of the present invention is to provide a recording medium for performing a message delivery method for adaptively determining the amount of message transmission at each node of the delay admission network.

It is still another object of the present invention to provide a message delivery device provided at each node of a delay-allowed network to adaptively determine the amount of message transmission reflecting the residence history of the node.

According to another aspect of the present invention, there is provided a message delivery method for adaptively determining an amount of message transmission in each node of a delay-allowed network, the method comprising: acquiring information of a longest staying cell of the node on a grid cell; Exchanging information of the longest staying cell with the other node when the node contacts the other node; Confirming that the number of copies of the message held by the node is a personal spray state of n (n is a natural number greater than 1); And comparing the information of the longest stay cell of the destination node of the message with the information of the longest stay cell of the other node to differentially adjust the number of message copies to be transmitted to the other node when the node is in the spray state .

In an embodiment of the present invention, exchanging information of the other node and the longest stay cell may exchange information of the longest stay cell of another node held by the node.

In the embodiment of the present invention, the step of differentially adjusting the number of message copies to be transmitted to the other node includes: checking whether the other node holds information of the longest staying cell of the destination node of the message; And when the other node holds the information of the longest stay cell of the destination node of the message, a message copy of the message to be transmitted to the other node according to the distance between the longest stay cell of the destination node of the message and the longest stay cell of the other node And determining the number.

In an embodiment of the present invention, the step of differentially adjusting the number of message copies to be transmitted to the other node may further comprise the steps of: if the other node does not hold information of the longest staying cell of the destination node of the message, And < / RTI > determining to deliver a copy of the message.

In the exemplary embodiment of the present invention, the step of determining the number of message copies to be transmitted to the other node may include: when the longest stay cell of the destination node of the message matches the longest stay cell of the other node, And determining to deliver a copy of the message.

In the exemplary embodiment of the present invention, the step of determining the number of message copies to be transmitted to the other node may include: if the longest stay cell of the destination node of the message does not match the longest stay cell of the other node, Determining to deliver the n first rate message copies to the other node if the longest cell of the first node is within the first peripheral zone of the longest stay cell of the other node.

In the embodiment of the present invention, the step of determining the number of message copies to be transmitted to the other node may include: when the longest staying cell of the destination node of the message is within the second peripheral zone of the longest staying cell of the other node, Further comprising determining to deliver a message copy of n second ratios to the node, wherein the second peripheral zone is farther from the first stay zone of the other node than the first peripheral zone, 1 ratio.

In the embodiment of the present invention, the step of determining the number of message copies to be transmitted to the other node may include the step of, when the longest stay cell of the destination node of the message is not within the neighboring zone of the longest stay cell of the other node, And determining to deliver one copy of the message.

In the embodiment of the present invention, the step of acquiring the information of the longest staying cell of the node on the grid cell formed by dividing the area of the network into the predetermined size may include the step of confirming the position of the node with GPS coordinates ; Converting the GPS coordinates into the grid cell units; Measuring the residence time in the cell before the change or measuring the residence time in the current cell according to whether the residence cell in which the node is located is changed; And comparing the measured residence time to update the longest stay cell in which the node is located the longest.

In an embodiment of the invention, if the node is in a wait phase with a single copy of the message, the node can carry the message without forwarding it until it encounters the destination node of the message have.

According to another aspect of the present invention, there is provided a computer-readable storage medium storing a computer program for performing a message delivery method for adaptively determining the amount of message transmission at each node of the above- Is recorded.

According to another aspect of the present invention, there is provided a message delivery apparatus provided at each node of a delay-allowed network for adaptively determining an amount of message transmission, the apparatus comprising: An information obtaining unit obtaining information of a longest stay cell of the node on a formed grid cell; An information exchange unit for exchanging information between the other node and the longest stay cell when the node makes contact with another node; A status verifying unit for verifying whether the number of copies of the message held by the node is a personal spray state n (n is a natural number exceeding 1); A controller for differentially adjusting the number of message copies to be transmitted to the other node according to a distance between a longest stay cell of a destination node of the message and a longest stay cell of the other node when the node is in a spray state; And a message delivery unit for delivering to the other node a message copy corresponding to the number of message copies determined in the message copy.

In an embodiment of the present invention, the information obtaining unit may include: a coordinate identifying unit that identifies the position of the node with GPS coordinates at regular intervals; A cell transform unit for transforming the GPS coordinates into the grid cell units; A residence time measuring unit for measuring a residence time in the cell before the change or measuring the residence time in the current cell according to whether the residence cell in which the node is located is changed; And a comparison unit for comparing the measured residence time and updating the longest staying cell in which the node is located the longest.

A node moves to a Working Day Movement model in which a daily life pattern of people is implemented in a delay tolerant network operating in a Spray and Wait protocol. The node moves to a grid cell in which the node moves for the longest time And the number of message copies is adjusted according to how close the grid cell of the node in contact with the lattice cell in which the destination node of the contacted node stays for the longest time is. Accordingly, it is advantageous to increase the overall message transmission rate by appropriately adjusting the number of copies of messages by utilizing the information on the grid cells staying the longest according to the periodicity of the nodes in the spray and weight protocol.

1 is a block diagram of a message delivery device based on a residence history of nodes in a delay-tolerant network according to an embodiment of the present invention.
2 is a block diagram of the information obtaining unit of FIG.
3 is an illustration of a grid cell utilized in the information obtaining unit of FIG.
4 is an illustration of an information list stored in the storage unit of FIG.
5 and 6 are flowcharts of a message delivery method based on a residence history of nodes in a delay-allowed network according to an embodiment of the present invention.

The following detailed description of the invention refers to the accompanying drawings, which illustrate, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention. It should be understood that the various embodiments of the present invention are different, but need not be mutually exclusive. For example, certain features, structures, and characteristics described herein may be implemented in other embodiments without departing from the spirit and scope of the invention in connection with an embodiment. It is also to be understood that the position or arrangement of the individual components within each disclosed embodiment may be varied without departing from the spirit and scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is to be limited only by the appended claims, along with the full scope of equivalents to which such claims are entitled, if properly explained. In the drawings, like reference numerals refer to the same or similar functions throughout the several views.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the drawings.

1 is a block diagram of a message delivery device based on a residence history of nodes in a delay-tolerant network according to an embodiment of the present invention. 2 is a block diagram of the information obtaining unit of FIG.

In the present invention, in the Delay Tolerant Network (DTN) including a plurality of nodes, the message delivery device 10 is provided in each node and adaptively determines the amount of message transmission based on the retention history of the node. In the delay tolerant network, each node stores a message to be transmitted in a message storage unit in a way that the connection between the source node and the destination node is not guaranteed. When the node meets another node, .

The present invention is characterized in that L (L is a natural number equal to or greater than 1) value, which is a maximum number of copies of a message, is generated by a node that generated the first message among delay tolerant networks, and L copies are generated, It is based on the Spray and Wait protocol.

When a message is delivered to another node, it is divided into a spray phase and a wait phase. In the spray state, the nodes remaining in the communication range are limited to the number of remaining messages n, If a message is delivered as many as the number of copies, and the message is delivered to the final destination even after the message has been delivered by the limited number of copies in the weighted state, even if another node approaches within the range, Until the final destination node is encountered. When the relay node contacts another node, the relay node delivers the copy within the range of L according to each transmission policy.

1, the message delivery apparatus 10 includes an information obtaining unit 110, an information exchanging unit 130, a status checking unit 150, a controller 170, and a message transmitting unit 190. [ .

The message delivery device 10 includes a memory (not shown) and stores programs and data required for the operation of the message delivery device 10 and data generated during the operation of the message delivery device 10 It can be stored in memory. For example, a message to be transmitted to another node, a list of stored messages, and the like may be stored in the memory. The message and message list stored in the memory may be exchanged when in contact with another node.

The information obtaining unit 110 obtains information on the longest staying cell of the node on a grid cell formed by dividing the area of the network into a predetermined size. 2, the information obtaining unit 110 may include a coordinate checking unit 111, a cell converting unit 113, a residence time measuring unit 115, and a comparing unit 117.

The coordinate confirmation unit 111 identifies the position of the node as GPS coordinates at regular intervals. The period may be set in units of seconds, minutes, etc., as needed. For example, the node can identify its coordinates in 1 second increments.

The cell transforming unit 113 transforms the GPS coordinates into the grid cell units.

Referring to FIG. 3, an example of a grid cell formed by dividing an area of the network into predetermined sizes is shown. The cell converting unit 113 maps the GPS coordinates received from the coordinate confirming unit 111 to corresponding lattice cells to acquire position information of the corresponding cell.

The residence time measuring unit 115 measures the residence time in the cell before the change or measures the residence time in the current cell according to whether the residence cell where the node is located is changed. Specifically, when the position of the node is not changed, the residence time in the current cell is obtained, and when the position of the node is changed, the residence time in the cell before the change is obtained.

If the position of the node is not changed, the residence time in the current cell can be obtained by the following equation (1).

[Equation 1]

Current cell residence time

= Current residence time in cell + (current time - latest update time)

Also, when the position of the node is changed, the residence time in the cell before the change can be obtained by the following equation (2).

&Quot; (2) "

Retention time in cell before change

= Residence time in cell before change + (current time - latest update time)

The comparing unit 117 compares the residence time of each cell acquired by the residence time measuring unit 115 to acquire the longest staying cell having the longest stay of the node and continuously updates it.

The information obtaining unit 110 may further include a storage unit 119 for storing information on the obtained longest stay cell. The storage unit 119 receives and stores not only the information of the longest stay cell of the node itself but also the information of the contacted longest stay cell of the other node and information of the longest stay cell of another node held by the other node .

FIG. 4 shows an example of information of the longest staying cell of each node stored in the storage unit 119. FIG.

Referring to FIG. 4, an ID capable of distinguishing each node, information of the longest stay cell corresponding thereto, and update time of information are stored as a list. The list compares the update time with each time the information of the longest stay cell of the other node is received, and updates it to the latest updated information and is constantly updated.

When the node contacts the other node, the information exchanging unit 130 exchanges information of the other node and the longest stay cell. That is, the node transmits information on its longest stay cell to the other node, and receives information on the longest stay cell of the other node.

In this case, information on the longest stay cell of another node held by the other node is received together, and the node also transmits information on the longest stay cell of another node held by the node to the other node. The exchange of information of the longest staying cell can be performed together with exchanging messages and message lists stored in each node in contact with another node.

When the node is in the spray state, the controller 170 controls the number of message copies to be transmitted to the other node by differentially adjusting the distances between the longest stay cell of the destination node and the longest stay cell of the other node .

First, it is determined whether the number of copies of the message held by the node itself is n (n is a natural number exceeding 1) spray phase. If the node is in a wait phase with a single copy of the message, the node carries the message without forwarding it until it encounters the destination node of the message. Also in this case, the information of the other node in contact with the longest staying cell is exchanged.

When the number of copies of the message held by the node itself is n sprayed, the information of the longest stay cell of the destination node of the message is compared with the information of the longest stay cell of the other node, The number of copies of the message is differentially adjusted.

The control unit 170 checks whether the other node has information on the longest stay cell of the destination node of the message and if the other node does not hold information of the longest stay cell of the destination node of the message, And to forward only one copy of the message to the node.

On the other hand, when the other node holds the information of the longest stay cell of the destination node of the message, the controller 170 determines whether the longest stay cell of the destination node of the message and the longest stay cell of the other node Determine the number of message copies to send to the other node.

The number of message copies to be transmitted to the other node may be inversely proportional to the distance between the longest staying cell of the destination node and the longest staying cell of the other node of the message. That is, the closer the distance between the two cells, the more message copies can be transmitted.

More specifically, if the longest stay cell of the destination node of the message is closer to the longest stay cell of the other node, it may transmit more copies of the message, and if the longest stay cell of the destination node of the message is the longest stay cell of the other node If you are far away, you can send a smaller copy of the message.

For example, when the longest stay cell of the destination node of the message and the longest stay cell of the other node coincide with each other (region A of FIG. 3), the controller 170 transmits all n copies of the message to the other node .

If the longest stay cell of the destination node of the message does not match the longest stay cell of the other node, the longest stay cell of the destination node of the message is located in the first peripheral zone of the longest stay cell of the other node , It may decide to deliver n copies of the first rate message to the other node.

Also, even if the longest stay cell of the destination node of the message does not exist in the first peripheral zone of the longest stay cell of the other node, the longest stay cell of the destination node of the message is located at the second nearest If it is in a zone (C area of FIG. 3), the controller 170 may decide to deliver n copies of the second rate message to the other node.

At this time, the second ratio is smaller than the first ratio. For example, if the longest cell of the destination node of the message is within the zone B of FIG. 3, the first rate is set to 0.75, and the longest cell of the destination node of the message is within the C- If present, the second ratio may be set to 0.5. If the number of message copies determined according to the ratio is a real number other than a natural number, the natural number rounded down to a decimal point can be determined as the number of message copies.

In the present embodiment, the number of message copies is adjusted according to the distance of the longest staying cell of the destination node of the message based on the longest staying cell of the other node. However, It is of course possible to adjust the number of message copies according to the distance of the longest staying cell of the other node.

The message transfer unit 190 transfers a copy of a message corresponding to the number of message copies determined by the controller 170 to the other node.

The present invention is based on the Working Day Movement model environment rather than the Random Waypoint Movement model utilized in the conventional technique. The Working Day Movement model is a combination of mobility submodels with different node motions. It is the main activity to stay at home, work, or often meet friends in the evening, and is repeated periodically on a daily basis.

Each node forms a community and social network by doing the same activity in the same area at the same time. For example, nodes in the same house form a family member, and nodes in the same office form a peer member.

For example, each node starts daily activities from home when it is morning, and each node wakes up the same time each morning during the entire simulation. During the wake-up time, each node leaves the house and travels to the office using different modes of transportation (walking, car or bus).

The working hours are configurable, and the node determines if it will return home at the end of the day or evening activity, and is performed according to a defined submodel. Nodes performing evening activities stay in their respective groups and places.

The present invention can improve the message transmission rate by adjusting the number of message copies according to the degree of matching using periodic long-term location information such as home, office, etc. using the environment having such periodicity.

5 and 6 are flowcharts of a message delivery method based on a residence history of nodes in a delay-allowed network according to an embodiment of the present invention.

The message delivery method according to the present embodiment can be performed in substantially the same configuration as the message delivery device 10 of FIG. Therefore, the same components as those of the message delivery device 10 of FIG. 1 are denoted by the same reference numerals, and repeated descriptions are omitted.

Referring to FIG. 5, the message delivery method according to the present embodiment adaptively determines the amount of message transmission based on the retention history of each node in the delay grant network including a plurality of nodes.

To do this, each cell first divides the area of the network into a predetermined size and obtains the information of the longest staying cell of the node on a grid cell (step S10).

6, step (step S10) of acquiring information on the longest staying cell of the node will be described in detail.

The node checks its position with GPS coordinates at regular intervals (step S11). The period may be set in units of seconds, minutes, etc., as needed. For example, the node can identify its coordinates in 1 second increments.

Upon obtaining the GPS coordinates, the GPS coordinates are converted into the grid cell units (step S13). That is, the GPS coordinates are mapped to corresponding grid cells to obtain position information of the corresponding cells. An example of a grid cell formed by dividing the area of the network into a predetermined size is shown in FIG.

(Step S15), the residence time in the cell before the change or the residence time in the current cell is measured according to whether the residence cell in which the node is located is changed (step S15). Specifically, if the position of the node is not changed, the residence time in the current cell is obtained (step S16), and if the position of the node is changed, the residence time in the cell before the change is obtained (step S17) .

If the position of the node is not changed in step S16, the residence time in the current cell can be obtained by the following equation (1).

[Equation 1]

Current cell residence time

= Current residence time in cell + (current time - latest update time)

In addition, when the position of the node is changed in step S17, the residence time in the cell before the change can be obtained by the following equation (2).

&Quot; (2) "

Retention time in cell before change

= Residence time in cell before change + (current time - latest update time)

The measured residence time is compared, and the longest staying cell in which the node is located the longest is acquired and continuously updated (step S19).

If the node makes contact with another node (step S20), the other node in contact with the node exchanges a message and a message list stored therein, and exchanges the information of the longest cell stored in each node (step S40 ).

That is, the node transmits information on its longest stay cell to the other node, and receives information on the longest stay cell of the other node. Also, the information on the longest stay cell of another node held by the other node is received together, and the node can also transmit the information on the longest stay cell of another node held by the node to the other node.

In addition, the node checks whether the number of copies of the message it holds is a personal spray state (n is a natural number exceeding 1) (step S50).

If the node is in a wait phase with the number of copies of the message being one, the node carries the message without delivering the message until it encounters the destination node of the message (step S60). Also in this case, the information of the other node in contact with the longest staying cell is exchanged.

When the number of copies of the message held by the node itself is n sprayed, the information of the longest stay cell of the destination node of the message is compared with the information of the longest stay cell of the other node, The number of copies of the message is differentially adjusted.

In step S71, if the other node does not hold the information of the longest stay cell of the destination node of the message, it is checked whether the other node holds the information of the longest stay cell of the destination node of the message Only one copy of the message is delivered to the node (step S91).

On the other hand, when the other node holds the information of the longest stay cell of the destination node of the message, a copy of the message to be transmitted to the other node according to the distance between the longest stay cell of the destination node of the message and the longest stay cell of the other node . ≪ / RTI >

The number of message copies to be transmitted to the other node may be inversely proportional to the distance between the longest staying cell of the destination node and the longest staying cell of the other node of the message. That is, the closer the distance between the two cells, the more message copies can be transmitted.

More specifically, if the longest stay cell of the destination node of the message is closer to the longest stay cell of the other node, it may transmit more copies of the message, and if the longest stay cell of the destination node of the message is the longest stay cell of the other node If you are far away, you can send a smaller copy of the message.

For example, if the longest stay cell of the destination node of the message matches the longest stay cell of the other node (region A in FIG. 3) (step S73), all n copies of the message may be delivered to the other node (Step S93).

If the longest stay cell of the destination node of the message does not match the longest stay cell of the other node, the longest stay cell of the destination node of the message is located in the first peripheral zone of the longest stay cell of the other node (Step S75), n copies of the first rate message can be delivered to the other node (step S95).

Also, even if the longest stay cell of the destination node of the message does not exist in the first peripheral zone of the longest stay cell of the other node, the longest stay cell of the destination node of the message is located at the second nearest If it is within the zone (area C in Fig. 3) (step S77), n copies of the second rate message can be delivered to the other node (step S97).

At this time, the second ratio is smaller than the first ratio. For example, if the longest cell of the destination node of the message is within the zone B of FIG. 3, the first rate is set to 0.75, and the longest cell of the destination node of the message is within the C- If present, the second ratio may be set to 0.5. If the number of message copies determined according to the ratio is a real number other than a natural number, the natural number rounded down to a decimal point can be determined as the number of message copies.

If the longest stay cell of the destination node of the message is not present in a certain peripheral zone of the longest stay cell of the other node, it may decide to deliver only one message copy to the other node (step S99).

The present invention can improve the message transmission rate by adjusting the number of message copies according to the degree of matching using periodic long-term location information such as home, office, etc. using the environment having such periodicity.

The message transfer method based on the residence history of the nodes in the delay admission network according to the present invention can be implemented in the form of program instructions that can be executed through various computer components and recorded on a computer readable recording medium. The computer-readable recording medium may include program commands, data files, data structures, and the like, alone or in combination.

The program instructions recorded on the computer-readable recording medium may be ones that are specially designed and configured for the present invention and are known and available to those skilled in the art of computer software.

Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tape, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floptical disks, media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like.

Examples of program instructions include machine language code such as those generated by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules for performing the processing according to the present invention, and vice versa.

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 present invention as defined by the following claims. You will understand.

The message delivery method according to the present invention divides an entire network area into a certain range of grid cells, and stores each cell's cell information for a long period of time such as an office or a house, And determines the number of copies of the message to be different according to whether the longest staying cell of the node in contact with the destination node of the message is matched. In the present invention, since the actual life pattern is taken into consideration, compared to the existing Random Waypoint Movement model, the location where each node is frequently located can be identified and the overall message transmission rate can be increased.

10: message delivery device 110: information acquisition unit
111: coordinate confirmation unit 113:
115: residence time measuring unit 117: comparing unit
119: storage unit 130: information exchange unit
150: status check unit 170:
190:

Claims (13)

A message delivery method for adaptively determining an amount of message transmission at each node of a delay-
Obtaining information of a longest staying cell of the node on a grid cell formed by dividing an area of the network into a predetermined size;
Exchanging information of the longest staying cell with information of the other node and information of the longest staying cell of another node held by the node when the node makes contact with another node;
Confirming that the number of copies of the message held by the node is a personal spray state of n (n is a natural number greater than 1); And
Comparing the information of the longest stay cell of the destination node of the message with the information of the longest stay cell of the other node to differentially adjust the number of message copies to be transmitted to the other node when the node is in the spray state Message delivery method.
delete The method as claimed in claim 1, wherein the step of differentially adjusting the number of message copies to be transmitted to the other node comprises:
Confirming whether the other node retains information of a longest staying cell of a destination node of the message; And
The number of message copies to be transmitted to the other node according to the distance between the longest stay cell of the destination node of the message and the longest stay cell of the other node when the other node holds information of the longest stay cell of the destination node of the message The method comprising the steps of:
4. The method of claim 3, wherein the step of differentially adjusting the number of message copies to be transmitted to the other node comprises:
Further comprising determining to deliver one copy of the message to the other node if the other node does not retain information of the longest stay cell of the destination node of the message.
4. The method of claim 3, wherein determining the number of message copies to be sent to the other node comprises:
Determining to deliver n copies of the message to the other node if the longest stay cell of the destination node of the message matches the longest stay cell of the other node.
4. The method of claim 3, wherein determining the number of message copies to be sent to the other node comprises:
When the longest stay cell of the destination node of the message does not match the longest stay cell of the other node and the longest stay cell of the destination node of the message is within the first neighboring zone of the longest stay cell of the other node, Determining to deliver n first rate copies of the message to the other node.
Claim 7 has been abandoned due to the setting registration fee. 7. The method of claim 6, wherein determining the number of message copies to be sent to the other node comprises:
Further comprising determining to deliver n second rate message copies to the other node if the longest stay cell of the destination node of the message is within a second peripheral zone of the longest stay cell of the other node,
Wherein the second peripheral zone is further away from the first peripheral zone from the longest stay cell of the other node and the second rate is less than the first rate.
4. The method of claim 3, wherein determining the number of message copies to be sent to the other node comprises:
Determining to deliver one copy of the message to the other node if the longest stay cell of the destination node of the message is not within the neighborhood of the longest stay cell of the other node.
2. The method of claim 1, wherein obtaining the information of the longest staying cell of the node on a grid cell formed by dividing an area of the network into a predetermined size comprises:
The node identifying its position as GPS coordinates at regular intervals;
Converting the GPS coordinates into the grid cell units;
Measuring the residence time in the cell before the change or measuring the residence time in the current cell according to whether the residence cell in which the node is located is changed; And
And comparing the measured residence time to update the longest stay cell in which the node is located the longest.
The method according to claim 1,
If the node is in a wait phase with a single copy of the message, the node carries the message without forwarding until it encounters a destination node of the message.
A computer program for performing a message delivery method for adaptively determining the amount of message transmission at each node of the delay tolerant network according to any one of claims 1 and 3 to 10, Possible recording medium.
1. A message delivery apparatus provided in each node of a delay-allowed network for adaptively determining an amount of message transmission,
An information obtaining unit for obtaining information on a longest staying cell of the node on a grid cell formed by dividing an area of the network into a predetermined size;
An information exchange unit for exchanging information between the other node and the longest stay cell when the node makes contact with another node;
A status verifying unit for verifying whether the number of copies of the message held by the node is a personal spray state n (n is a natural number exceeding 1);
A controller for differentially adjusting the number of message copies to be transmitted to the other node according to a distance between a longest stay cell of a destination node of the message and a longest stay cell of the other node when the node is in a spray state; And
And a message delivery unit for delivering, to the other node, a message copy corresponding to the number of message copies determined in the message copy,
The information obtaining unit obtains,
A coordinate confirming unit for confirming the position of the node with GPS coordinates at regular intervals;
A cell transform unit for transforming the GPS coordinates into the grid cell units;
A residence time measuring unit for measuring a residence time in the cell before the change or measuring the residence time in the current cell according to whether the residence cell in which the node is located is changed; And
And a comparison unit comparing the measured residence time to update the longest stay cell in which the node is located the longest.
delete

Images