KR20220055304A - Method for determining ttl of messages in information-centric networking based on delay tolerant networking, recording medium and device for performing the method - Google Patents

Abstract

A method of determining TTL of a message in an information-centered network based on a delay-tolerance network includes the following steps of: when a node receives a message, determining a capacity value about a destination node of the node, based on a residual buffer ratio, a residual battery power ratio and a prediction rate of transmission to the destination node; setting an initial time-to-live (TTL) value depending on whether the node is a data mule and general node; when the node comes in contact with a counterpart node, determining whether a message transmission condition to the counterpart node is satisfied, based on the prediction rate of transmission; and when the message transmission condition is satisfied, determining a TTL value about the message in accordance with a node type of the counterpart node. Accordingly, the method is capable of properly setting a TTL value on each node through a TTL determination considering characteristics of a transmission node, thereby effectively improving network performance.

Description

METHOD FOR DETERMINING TTL OF MESSAGES IN INFORMATION-CENTRIC NETWORKING BASED ON DELAY TOLERANT NETWORKING, RECORDING MEDIUM AND DEVICE FOR PERFORMING THE METHOD}

The present invention relates to a method for determining TTL of a message in a delay-tolerant network-based information-centric network, a recording medium and an apparatus for performing the same, and more particularly, to a delay-tolerant network-based information-centric network through TTL determination in consideration of the characteristics of a forwarding node. It relates to a technology that aims to improve the performance of

Information-centric networking (ICN) is a network that performs routing based on the name of a content and is known to have superior performance compared to the existing communication method for routing based on the address of a destination.

A delay tolerant network (DTN) is a technology used to effectively deliver messages in an environment where connectivity between a source node and a destination node is not guaranteed. The delay-tolerant network uses the store-carry and forward method, in which a mobile relay node stores, forwards, and transports the message to deliver the message to the final destination node.

The delay-tolerant network-based information-centric network must provide an information-centric network that performs name-based routing in a delay-tolerant network where connectivity between nodes is not guaranteed. There are many problems to be solved compared to the method of transferring interest and data. Interest and data are delivered through the store-carry-forward method in the delay-tolerant network, and through this, an information-centric network can be provided.

In an information-centric network based on a delay-tolerant network, interest and data are transmitted through transmission when contacting neighboring nodes, and can be transmitted to the final destination node through a series of transmission procedures. When two nodes come into contact, there is a limit in sufficiently delivering the message stored in the buffer due to the fast relative movement speed of the two nodes and the limited transmission speed.

As one of the methods for overcoming this limitation, a time-to-live (TTL) having an initially set fixed value is usually used in a delay-tolerant network-based information-centric network. Interest and Data have TTL, and this value decreases with time. Finally, when the value of this TTL becomes 0, it is removed from the node's buffer.

However, when the TTL value is set large, if the buffer size is not sufficient, a buffer overflow occurs frequently, and messages are frequently deleted, thereby reducing the message delivery rate. On the other hand, if the TTL is set to be small, even if the buffer size is sufficient, the message is not properly delivered to the destination node and is deleted midway, resulting in a decrease in the delivery rate.

The method using the fixed TTL as described above does not properly consider the characteristics of the forwarding node, which have different values depending on the forwarding node, such as the forwarding node's buffer usage, battery power consumption, and delivery prediction rate to the destination node, so it is effective for message delivery. There is a problem that is not there.

KR 10-1471276 B1 KR 10-1654039 B1 KR 10-0628479 B1

Accordingly, it is an object of the present invention to provide a method for determining TTL of a message in an information-centric network based on a delay tolerant network.

Another object of the present invention is to provide a recording medium in which a computer program is recorded for performing the method for determining TTL of a message in the delay-tolerant network-based information-centric network.

Another object of the present invention is to provide an apparatus for performing a method for determining TTL of a message in the delay-tolerant network-based information-centric network.

In a method for determining TTL of a message in an information-centric network based on a delay tolerant network according to an embodiment for realizing the object of the present invention, when a node receives a message, the remaining buffer ratio, the remaining battery power ratio and the destination node are determining a capacity value for the destination node of the node based on the forward prediction rate of ; setting an initial time-to-live (TTL) value according to whether the node is a data mule or a normal node; determining whether a message delivery condition to the counterpart node is satisfied based on a delivery prediction rate when the node contacts the counterpart node; and determining a TTL value for the message according to the node type of the counterpart node when the message delivery condition is satisfied.

In an embodiment of the present invention, the step of determining the capacity value for the destination node of the node includes: a ratio of the remaining buffer remaining unused among the total buffers of the node, unused among the total battery power of the node The capacity value may be determined as a weighted sum obtained by applying weights to the remaining battery power ratio and the prediction rate of delivery to the destination node defined by the PRoPHET protocol.

In an embodiment of the present invention, the step of setting the initial TTL value includes, when the node is a data mule, a TTL _max defined as a fixed value for Interest and Data received when receiving a message from a content requester or a content provider setting the value to an initial TTL value; and when the node is a normal node, setting the initial TTL value as a TTL _default value having a value smaller than the TTL _max value for interest and data received when receiving a message from a content requester or a content provider. can

In an embodiment of the present invention, the step of determining the TTL value for the message includes: when the node and the counterpart node are normal nodes, the destination node of the counterpart node with respect to the capability value of the node to the TTL value of the node setting the TTL value as a value obtained by multiplying the ratio of the capability value with respect to .

In an embodiment of the present invention, the determining of the TTL value for the message may further include determining the TTL value as a smaller value among a set TTL value and the TTL _default value.

In an embodiment of the present invention, in the step of determining the TTL value for the message, when the node is a normal node and the counterpart node is a data mule, the TTL _max value by the ratio of the TTL _default value to the TTL value of the node and setting the TTL value by correcting the .

In an embodiment of the present invention, the determining of the TTL value for the message may further include determining the TTL value as a smaller value among a set TTL value and the TTL _max value.

In an embodiment of the present invention, the step of determining the TTL value for the message includes: when the node is a data mule and the counterpart node is a normal node, calculating a ratio of the TTL value of the node to the TTL _default value ; converting the TTL value to a normal node by multiplying the TTL _default value by the ratio of the TTL value of the node to the TTL _default value; and multiplying the converted TTL value by a capacity value for the destination node of the counterpart node to set a corrected TTL value by the capacity value of the counterpart node.

In an embodiment of the present invention, the determining of the TTL value for the message may further include determining the TTL value as a smaller value among a set TTL value and the TTL _default value.

In an embodiment of the present invention, the step of determining the TTL value for the message includes: when the node and the counterpart node are data mules, the TTL value of the node corresponds to a capacity value for the destination node setting the TTL value as a value obtained by multiplying the ratio of the capacity value with the destination node of the counterpart node.

In an embodiment of the present invention, the determining of the TTL value for the message may further include determining the TTL value as a smaller value among a set TTL value and the TTL _max value.

In an embodiment of the present invention, the determining of the TTL value for the message may include determining the TTL value as a TTL _max value when the counterpart node is a data mule.

In a computer-readable storage medium according to an embodiment for realizing the other object of the present invention, a computer program for performing a method for determining TTL of a message in the delay-tolerant network-based information-centric network is recorded.

The apparatus for determining TTL of a message in a delay tolerant network-based information-centric network according to an embodiment for realizing another object of the present invention, when a node receives the message, the remaining buffer ratio, the remaining battery power ratio, and the destination a capability value determining unit that determines a capacity value of the node based on the prediction rate of delivery to the node; an initial TTL setting unit configured to set an initial time-to-live (TTL) value according to whether the node is a data mule or a normal node; a delivery determining unit configured to determine whether a message delivery condition to the counterpart node is satisfied based on a delivery prediction rate when the node contacts the counterpart node; and a TTL determining unit that determines a TTL value for the message according to the node type of the counterpart node when the message delivery condition is satisfied.

In an embodiment of the present invention, the capability value determining unit is configured to determine the ratio of the remaining unused buffer among the total buffers of the node, the ratio of the remaining battery power remaining unused among the total battery power of the node, and the PRoPHET protocol. The capacity value may be determined as a weighted sum in which weights are given respectively to the prediction rates of delivery to the destination node defined by .

In an embodiment of the present invention, when the node is a data mule, the initial TTL setting unit sets a TTL _max value defined as a fixed value for Interest and Data received when receiving a message from a content requester or a content provider to the initial TTL value, and if the node is a normal node, it can be set as the initial TTL value as the TTL _default value having a value smaller than the TTL _max value for the interest and data received when receiving a message from the content requester or content provider there is.

In an embodiment of the present invention, when the node and the counterpart node are normal nodes, the TTL determination unit calculates the ratio of the capability value of the node to the capability value of the node to the capability value of the destination node to the TTL value of the node. sets the TTL value as a multiplied value, and sets the TTL value by correcting the TTL _max value by the ratio of the TTL _default value to the TTL value of the node when the node is a normal node and the counterpart node is a data mule, When the node is a data mule and the counterpart node is a normal node, the ratio of the TTL value of the node to the TTL _default value is calculated, and the ratio of the TTL value of the node to the TTL _default value is multiplied by the TTL _default value. converts to a TTL value of , multiplies the converted TTL value by a capacity value for a destination node of the counterpart node to set a corrected TTL value by the capacity value of the counterpart node, and the node and the counterpart node In the case of a data mule, the TTL value may be set as a value obtained by multiplying the TTL value of the node by the ratio of the capacity value for the destination node of the node to the capacity value for the destination node of the counterpart node.

In an embodiment of the present invention, when the node is a normal node, the TTL determiner may determine the TTL value as a smaller value among a set TTL value and the TTL _max value.

In an embodiment of the present invention, when the node is a data mule, the TTL determiner may determine the TTL value as a smaller value among a set TTL value and the TTL _default value.

In an embodiment of the present invention, when the counterpart node is a data mule, the TTL determiner may determine a TTL value as a TTL _max value.

According to the method of determining the TTL of a message in such a delay-tolerant network-based information-centric network, network performance can be effectively improved by appropriately setting the TTL value in each node through the TTL determination in consideration of the characteristics of the forwarding node.

1 is a diagram for explaining a delay-tolerant network-based information-centric network environment including a data mule and a general node of the present invention.
2 is a block diagram of an apparatus for determining TTL of a message in an information-centric network based on a delay tolerant network according to an embodiment of the present invention.
3 is a diagram for explaining TTL determination according to types of nodes and counterpart nodes according to the present invention.
4 is a flowchart of a method for determining TTL of a message in an information-centric network based on a delay tolerant network according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0012] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS [0010] Reference is made to the accompanying drawings, which show by way of illustration specific embodiments in which the present invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the present invention. It should be understood that the various embodiments of the present invention are different but need not be mutually exclusive. For example, certain shapes, structures, and characteristics described herein with respect to one embodiment may be implemented in other embodiments without departing from the spirit and scope of the invention. In addition, it should be understood that the location or arrangement of individual components within each disclosed embodiment may be changed without departing from the spirit and scope of the present invention. Accordingly, the detailed description set forth below is not intended to be taken in a limiting sense, and the scope of the present invention, if properly described, is limited only by the appended claims, along with all scope equivalents as those claimed. Like reference numerals in the drawings refer to the same or similar functions throughout the various aspects.

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

1 is a diagram for explaining a delay-tolerant network-based information-centric network environment including a data mule and a general node of the present invention.

The present invention is based on a delay-tolerant network-based information-centric network environment (1) composed of moving nodes, that is, pedestrians, cars, trams, etc. as shown in FIG. 1 .

The node considered in the delay-tolerant network environment of the present invention is a data mule with sufficient buffer size, battery power, etc., such as a general node such as a pedestrian who has a smart phone, etc. with a limited buffer size and battery power, and a vehicle and tram. ) is assumed to be composed of

In the delay-tolerant network-based information-centric network, the content requester transmits an interest message based on the name of the content to the neighboring nodes in order to download the content they want. Thereafter, the content provider receiving this message or the node storing the corresponding content in its CS (Content Store) returns the requested content, Data, to the content requester.

In the delay-tolerant network-based information-centric network, since the connectivity between nodes is not guaranteed, it cannot operate like the interest and data transfer method in the existing information-centric network using CS, PIT, and FIB. -Interest and data must be transferred in a forward method.

In other words, in the environment where the existing connectivity is guaranteed, data cannot be transmitted to the requesting node in the opposite path through which the interest is transmitted using the PIT information, and the data can be transmitted more effectively to the content requester by using the opportunistic contact with neighboring nodes. Data should be delivered to the content requester by delivering data to a node that can deliver it and repeating this process.

When delivering messages such as interest and data, in a node that has a message, it is recommended to effectively set the TTL (time-to-live) corresponding to the lifetime of the message according to the characteristics of the node due to resource constraints such as limited buffer size and battery power. need.

In the present invention, a delay-tolerant network composed of a data mule and a normal node is assumed, and the data mule is a node having a sufficiently large buffer size and battery power, whereas a general node corresponds to a node having a limited buffer size and battery power.

Therefore, for effective data transfer, it is necessary to determine the appropriate TTL according to the characteristics of the node. That is, in the case of a data mule with sufficient resources, since there are no restrictions on buffer capacity and battery power, the TTL is set large to increase message delivery to the destination node.

On the other hand, since general nodes have limitations in buffer capacity and battery power, each node considers its own buffer capacity, battery power remaining, and delivery prediction rate to the destination node, and sets the TTL value appropriately to improve overall network performance. want to do

2 is a block diagram of an apparatus for determining TTL of a message in an information-centric network based on a delay tolerant network according to an embodiment of the present invention.

In the delay-tolerant network-based information-centric network according to the present invention, the TTL determination device (10, hereinafter device) of a message automatically determines whether the API call is legitimate based on constraints when making an API call during software coding. It is an editor that verifies.

Referring to FIG. 2 , the apparatus 10 according to the present invention includes a capability value determining unit 110 , an initial TTL setting unit 130 , a delivery determining unit 150 , and a TTL determining unit 170 . The device 10 of the present invention may be some modules of a general node and a data mule constituting a delay tolerant network-based information-centric network, or may be included in each node.

In the device 10 of the present invention, software (application) for determining the TTL of a message in a delay tolerant network-based information-centric network may be installed and executed, and the capability value determination unit 110, the initial TTL setting unit ( 130), the configuration of the delivery determining unit 150 and the TTL determining unit 170 to be controlled by software for determining the TTL of a message in the delay-tolerant network-based information-centric network running in the device 10 can

The device 10 may be a separate terminal or may be a part of a module of the terminal. In addition, the configuration of the capability value determining unit 110 , the initial TTL setting unit 130 , the delivery determining unit 150 , and the TTL determining unit 170 may be formed as an integrated module or may be composed of one or more modules. can However, on the contrary, each configuration may be formed of a separate module.

The apparatus 10 may have mobility, and the apparatus 10 may include a device, an apparatus, a terminal, a user equipment (UE), a mobile station (MS), and a wireless device. ), a handheld device, and the like.

The device 10 may execute or manufacture various software based on an operating system (OS), that is, the system. The operating system is a system program for software to use the hardware of the device, and is a mobile computer operating system such as Android OS, iOS, Windows Mobile OS, Bada OS, Symbian OS, Blackberry OS and Windows series, Linux series, Unix series, It can include all computer operating systems such as MAC, AIX, and HP-UX.

When the node receives the message, the capability determiner 110 determines a capacity value of the node for the destination node based on the remaining buffer ratio, the remaining battery power ratio, and the delivery prediction rate to the destination node. do.

It is assumed that the content provider who initially created the data sets the TTL to infinity by default in order to provide the content they want to provide for as long as they want. On the other hand, data mule and general nodes, which are relay nodes used to deliver content, must set TTL appropriately to prevent network load.

In the present invention, when a normal node A receives a message m from which the destination node is D, its residual buffer ratio, residual battery power ratio, and delivery prediction rate to the destination node (detailed definition related to the delivery prediction rate is defined in IRTF RFC 6693 PRoPHET protocol) ), the capacity value of the node A for the destination node D is defined as a weighted sum as shown in Equation 1 below.

[Equation 1]

Capacity(A,D) = W _B *B(A) + W _E *E(A) + W _P *P(A,D)

W _B + W _E + W _P = 1

0 ≤ Capacity(A) ≤ 1

B(A) is the percentage of the remaining unused buffer among the total buffers of node A, E(A) is the percentage of the remaining unused battery power among the total battery power of the node A, and P(A,D) is PRoPHET The predicted delivery rate of node A to the destination node D defined by the protocol, W _B corresponds to the weight of the remaining buffer ratio, W _E is the weight of the remaining battery power ratio, and W _P corresponds to the weight of the delivery prediction rate. At this time, it is assumed that the sum of these weights is 1, and accordingly, the capacity value of node A has a value between 0 and 1.

The initial TTL setting unit 130 sets an initial time-to-live (TTL) value according to whether the node is a data mule or a normal node.

In relation to TTL setting, in the present invention, first, TTL _max and TTL _default values defined as fixed values are defined. When the data mule directly receives messages such as interest or data from the content requester or content provider, respectively, it sets the initial TTL value to TTL _max , which has a sufficiently large value for the received interest and data, and then sets the TTL value as time elapses. will decrease.

On the other hand, when a normal node directly receives a message such as Interest or Data from a content requestor or a content provider, respectively, the initial TTL value is set to TTL _default with a value smaller than TTL _max , and the TTL value decreases as time passes. do.

When the node contacts the counterpart node, the delivery determination unit 150 determines whether a message delivery condition to the counterpart node is satisfied based on a delivery prediction rate.

When a data mule with a message or a normal node A delivers a message m with a destination D to another data mule or normal node B, depending on the node type of the sending node and the receiving node, the receiving node B sends a message m with a destination D. The TTL is determined.

In this case, various conditions may be assumed for the conditions for the node A to transmit the message to the node B. For example, the message may be delivered from node A to node B if the predicted delivery rate of node B to destination node D is greater than the predicted delivery rate of node A to destination node D.

Alternatively, it may be assumed that the message passing between normal nodes occurs only when the delivery prediction rate is higher, and that the message is always delivered when the contact node is a data mule with sufficient capability. Also, it can be assumed that the message is transmitted only when the contact node is a node with a larger capability value.

When the message delivery condition is satisfied, the TTL determining unit 170 determines a TTL value for the message according to the node type of the counterpart node.

In the present invention, a message can be delivered to a contact node according to various conditions as described above, and the TTL value of the transmitted message can be determined as follows.

1) Case 1: When transmitting from normal node A -> normal node B, the TTL value can be determined as shown in Equation 2 below.

[Equation 2]

TTL(B,D) = min(TTL _default , TTL(A,D) * Capacity(B,D)/Capacity(A,D))

When transmitted from normal node A to normal node B, the TTL (B ,D) is set.

That is, if the capability value of Node B is larger, the TTL value is increased, otherwise, the TTL value is decreased. However, in this case, since the maximum value of the TTL value of the normal node must not exceed the TTL _default , the TTL value may be set to a smaller value among the determined value and the TTL _default value.

2) Case 2: When transmitting to a normal node A -> data mule B, the TTL value can be determined as shown in Equation 2 below.

[Equation 3]

TTL(B,D) = min(TTL _max , TTL _max * TTL(A,D)/ TTL _default )

When data is transmitted from normal node A to data mule B, the TTL _max value is corrected and set by the ratio of the current TTL(A,D) value to the TTL _default value. However, in this case, since the maximum value should not exceed TTL _max , the TTL value may be set to a smaller value among the determined value and the TTL _max value.

3) Case 3: When data mule A -> normal node B is transmitted, the TTL value can be determined as shown in Equation 4 below.

[Equation 4]

TTL(B,D) = min(TTL _default , TTL(A,D)/ TTL _max * TTL _default * Capacity(B,D)/Capacity-threshold)

Here, Capacity-threshold is defined as a value between 0 and 1. When data is transmitted from mule A to normal node B, find the ratio of the TTL(A,D) value in the current data mule A to the TTL _max value, and multiply this value by the TTL _default value to convert it to the TTL value to the general node After that, it is multiplied by the Capacity(B,D) value and corrected as much as the capacity value of Node B.

However, at this time, by defining the capacity-threshold value defined as a value between 0 and 1 and adjusting this value appropriately, the TTL value corrected by the capability value of Node B can be appropriately and additionally corrected. Alternatively, by default, the value of Capacity-threshold can be set to 1. However, in this case, since the maximum value of the TTL value of the normal node must not exceed the TTL _default , the TTL value may be set to a smaller value among the determined value and the TTL _default value.

4) Case 4: When data mule A -> data mule B is transmitted, the TTL value can be determined as in Equation 5 below.

[Equation 5]

TTL(B,D) = min(TTL _max , TTL(A,D)* Capacity(B,D)/Capacity(A,D))

When transmitted from data mule A to data mule B, the TTL (B) ,D) is set. That is, if the capability value of Node B is larger, the TTL value is increased, otherwise, the TTL value is decreased.

However, in this case, since the maximum value of the TTL value of the normal node must not exceed the TTL _max , the TTL value may be set to a smaller value among the determined value and the TTL _max value.

As described above, in the present invention, the TTL value is determined in consideration of the characteristics of the forwarding node, and the process of determining the TTL value for each case is illustrated in FIG. 3 . Accordingly, in the present invention, when transmitting messages such as interest and data, TTL (time-to-live) corresponding to the lifetime of the message due to resource constraints such as limited buffer size and battery power in the node having the message is calculated as the characteristic of the node. to improve the network performance.

As another example, in Cases 1, 2, 3, and 4, the min operation was used to prevent TTL _default from normal nodes and TTL max values from being set to a value greater than the TTL _max value for data mules, but by releasing this, Cases 1, 2, 3 , it is also possible to set the TTL value to the value determined in 4 (the value corresponding to y in min(x,y)).

In another embodiment, when the data transfer rate is very high, the buffer size and battery power of the data mule are not limited, and the overall traffic load of the network is not large, in Cases 2 and 4, the data mule receives the message, Equation 6 below It is also possible to set the TTL value to the maximum value, TTL _max .

[Equation 6]

* Case 2 (normal node A -> data transfer to mule B): TTL(B) = TTL _max

* Case 4 (data mule A -> data mule B transfer): TTL(B) = TTL _max

Accordingly, the present invention can effectively improve network performance by appropriately setting the TTL value in each node through TTL determination in consideration of the characteristics of the forwarding node.

4 is a flowchart of a method for determining TTL of a message in an information-centric network based on a delay tolerant network according to an embodiment of the present invention.

The method for determining the TTL of a message in the information-centric network based on the delay tolerant network according to the present embodiment may proceed in substantially the same configuration as the network environment 1 of FIG. 1 and the apparatus 10 of FIG. 2 . Accordingly, the same components as the network environment 1 of FIG. 1 and the device 10 of FIG. 2 are given the same reference numerals, and repeated descriptions are omitted.

In addition, the method for determining the TTL of a message in the delay-tolerant network-based information-centric network according to the present embodiment may be executed by software (application) for determining the TTL of a message in the delay-tolerant network-based information-centric network.

4, in the method for determining TTL of a message in a delay tolerant network-based information-centric network according to the present embodiment, when a node receives a message (step S10), the remaining buffer ratio, the remaining battery power ratio, and the destination node Based on the forward prediction rate of , a capacity value of the node for the destination node is determined (step S20).

The step of determining the capacity value of the node for the destination node (step S20) includes the ratio of the remaining buffer remaining unused among the total buffers of the node, and the remaining unused among the total battery power of the node. The capacity value may be determined as a weighted sum obtained by applying weights to the residual battery power ratio and the prediction rate of delivery to the destination node defined by the PRoPHET protocol. Here, the capacity may have a value between 0 and 1.

An initial time-to-live (TTL) value is set according to whether the node is a data mule or a normal node (step S30).

In the step of setting the initial TTL value (step S30), when the node is a data mule, a TTL _max value defined as a fixed value for Interest and Data received when receiving a message from a content requester or a content provider is initialized Set as TTL value.

On the other hand, when the node is a normal node, the TTL _default value having a value smaller than the TTL _max value for the interest and data received when receiving a message from the content requester or the content provider is set as the initial TTL value.

When the node contacts the counterpart node (step S40), it is determined whether a message delivery condition to the counterpart node is satisfied based on the delivery prediction rate (step S40).

For example, a condition for node A to transmit a message to node B may assume various conditions. For example, the message may be delivered from node A to node B if the predicted delivery rate of node B to destination node D is greater than the predicted delivery rate of node A to destination node D.

Alternatively, it may be assumed that the message passing between normal nodes occurs only when the delivery prediction rate is higher, and that the message is always delivered when the contact node is a data mule with sufficient capability. Also, it can be assumed that the message is transmitted only when the contact node is a node with a larger capability value.

When the message delivery condition is satisfied, a TTL value for the message is determined according to the node type of the counterpart node (step S60).

In the step of determining the TTL value for the message (step S60), when the node and the counterpart node are normal nodes, the ability of the counterpart node to the destination node with respect to the node's capability value to the TTL value of the node You can set the TTL value by multiplying the ratio of the values. In this case, the TTL value may be determined as the smaller of the set TTL value and the TTL _default value.

When the node is a normal node and the counterpart node is a data mule, the TTL value may be set by correcting the TTL _max value by the ratio of the TTL _default value to the TTL value of the node. In this case, the TTL value may be determined as the smaller of the set TTL value and the TTL _max value.

When the node is a data mule and the counterpart node is a normal node, the ratio of the TTL value of the node to the TTL _default value is calculated, and the ratio of the TTL value of the node to the TTL _default value is multiplied by the TTL _default value. Convert to TTL value to normal node. Thereafter, the TTL value corrected by the capacity value of the counterpart node may be set by multiplying the converted TTL value by the capacity value of the counterpart node for the destination node. In this case, the TTL value may be determined as the smaller of the set TTL value and the TTL _default value.

When the node and the counterpart node are data mules, the TTL value of the node is multiplied by the ratio of the capacity value for the destination node to the capacity value for the destination node of the node multiplied by the value. You can set the TTL value. In this case, the TTL value may be determined as the smaller of the set TTL value and the TTL _max value.

In another embodiment, in the step of determining the TTL value for the message (step S60 ), when the counterpart node is a data mule, the TTL value may be determined as a TTL _max value.

Therefore, according to the method for determining the TTL of a message in the delay-tolerant network-based information-centric network of the present invention, network performance can be effectively improved by appropriately setting the TTL value at each node through the TTL determination in consideration of the characteristics of the forwarding node.

In such a delay-tolerant network-based information-centric network, the TTL determination method of a message may be implemented as an application or implemented in the form of program instructions that may be executed through various computer components and recorded in a computer-readable recording medium. The computer-readable recording medium may include program instructions, data files, data structures, etc. alone or in combination.

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

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

Examples of program instructions include not only machine language codes such as those generated by a compiler, but also high-level language codes 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 carrying out the processing according to the present invention, and vice versa.

Although the above has been described with reference to the embodiments, those skilled in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below you will understand

The present invention can effectively improve network performance by appropriately setting the TTL value in each node through TTL determination in consideration of the characteristics of the forwarding node in a general delay-tolerant network environment composed of general nodes in which connectivity is not guaranteed. Accordingly, since a message can be transmitted effectively even in an environment where connectivity between nodes is not guaranteed, it can be usefully applied to information communication fields requiring data transmission.

1: Latency-tolerant network-based information-centric network environment
10: TTL determination device of the message
110: ability value determination unit
130: initial TTL setting unit
150: delivery decision unit
170: TTL decision unit

Claims (20)

when the node receives the message, determining a capacity value of the node for the destination node based on the remaining buffer ratio, the remaining battery power ratio, and the forwarding prediction rate to the destination node;
setting an initial time-to-live (TTL) value according to whether the node is a data mule or a normal node;
determining whether a message delivery condition to the counterpart node is satisfied based on a delivery prediction rate when the node contacts the counterpart node; and
and determining a TTL value for the message according to the node type of the counterpart node when the message delivery condition is satisfied.
The method of claim 1, wherein determining a capacity value for a destination node of the node comprises:
The ratio of the remaining unused buffer among the total buffers of the node, the ratio of the remaining unused battery power among the total battery power of the node, and the prediction rate of delivery to the destination node defined by the PRoPHET protocol are weighted, respectively A method for determining TTL of a message in a delay-tolerant network-based information-centric network, wherein the capacity value is determined by a weighted sum of the values.
The method of claim 1, wherein the setting of the initial TTL value comprises:
when the node is a data mule, setting a TTL _max value defined as a fixed value for Interest and Data received when receiving a message from a content requester or a content provider as an initial TTL value; and
When the node is a normal node, setting the initial TTL value as a TTL _default value having a value smaller than the TTL _max value for interest and data received when receiving a message from a content requester or a content provider, A method for determining the TTL of a message in a delay-tolerant network-based information-centric network.
4. The method of claim 3, wherein determining the TTL value for the message comprises:
When the node and the counterpart node are normal nodes, setting the TTL value to a value obtained by multiplying the TTL value of the node by the ratio of the capability value of the node to the capability value of the counterpart node to the destination node; includes; A method for determining the TTL of a message in a delay-tolerant network-based information-centric network.
5. The method of claim 4, wherein determining a TTL value for the message comprises:
Determining the TTL value as a smaller value among the set TTL value and the TTL _default value; further comprising, a method for determining TTL of a message in a delay-tolerant network-based information-centric network.
4. The method of claim 3, wherein determining the TTL value for the message comprises:
When the node is a normal node and the counterpart node is a data mule, setting the TTL value by correcting the TTL _max value by the ratio of the TTL _default value to the TTL value of the node to the TTL default value; A method for determining the TTL of a message in a central network.
7. The method of claim 6, wherein determining a TTL value for the message comprises:
Determining the TTL value as the smaller of the set TTL value and the TTL _max value; further comprising, a method for determining TTL of a message in a delay-tolerant network-based information-centric network.
4. The method of claim 3, wherein determining the TTL value for the message comprises:
calculating a ratio of the TTL value of the node to the TTL _default value when the node is a data mule and the counterpart node is a normal node;
converting the TTL value to a normal node by multiplying the TTL _default value by the ratio of the TTL value of the node to the TTL _default value; and
Setting the TTL value corrected by the capacity value of the counterpart node by multiplying the converted TTL value by the capacity value for the destination node of the counterpart node; How to determine TTL.
The method of claim 8, wherein determining the TTL value for the message comprises:
Determining the TTL value as a smaller value among the set TTL value and the TTL _default value; further comprising, a method for determining TTL of a message in a delay-tolerant network-based information-centric network.
4. The method of claim 3, wherein determining the TTL value for the message comprises:
When the node and the counterpart node are data mules, the TTL value of the node is multiplied by the ratio of the capacity value for the destination node to the capacity value for the destination node of the node multiplied by the value. A method of determining TTL of a message in a delay-tolerant network-based information-centric network, comprising: setting a TTL value.
11. The method of claim 10, wherein determining the TTL value for the message comprises:
Determining the TTL value as the smaller of the set TTL value and the TTL _max value; further comprising, a method for determining TTL of a message in a delay-tolerant network-based information-centric network.
The method of claim 1, wherein determining a TTL value for the message comprises:
When the counterpart node is a data mule, determining a TTL value as a TTL _max value.
A computer-readable storage medium having recorded thereon a computer program for performing the method for determining TTL of a message in the delay-tolerant network-based information-centric network according to claim 1 .
When the node receives the message, based on the remaining buffer ratio, the remaining battery power ratio, and the prediction rate of delivery to the destination node, a capability value determination unit for determining a capacity value for the destination node of the node;
an initial TTL setting unit for setting an initial time-to-live (TTL) value according to whether the node is a data mule or a normal node;
a delivery determining unit that determines whether or not a message delivery condition to the counterpart node is satisfied based on a delivery prediction rate when the node contacts the counterpart node; and
and a TTL determination unit for determining a TTL value for the message according to a node type of the counterpart node when the message delivery condition is satisfied.
15. The method of claim 14, wherein the ability value determining unit,
The ratio of the remaining unused buffer among the total buffers of the node, the ratio of the remaining unused battery power among the total battery power of the node, and the prediction rate of delivery to the destination node defined by the PRoPHET protocol are weighted, respectively A device for determining the TTL of a message in a delay-tolerant network-based information-centric network, which determines the capacity value by a weighted sum of .
The method of claim 14, wherein the initial TTL setting unit,
When the node is a data mule, the TTL _max value defined as a fixed value for the interest and data received when receiving a message from the content requester or content provider is set as the initial TTL value,
When the node is a normal node, a TTL _default value having a value smaller than the TTL _max value for interest and data received when receiving a message from a content requester or a content provider is set as an initial TTL value, delay-tolerant network-based A device for determining the TTL of a message in an information-centric network.
The method of claim 16, wherein the TTL determining unit,
When the node and the counterpart node are normal nodes, the TTL value is set as a value obtained by multiplying the TTL value of the node by the ratio of the capability value of the node to the capability value of the counterpart node to the destination node;
When the node is a normal node and the counterpart node is a data mule, the TTL value is set by correcting the TTL _max value by the ratio of the TTL _default value to the TTL value of the node,
When the node is a data mule and the counterpart node is a normal node, the ratio of the TTL value of the node to the TTL _default value is calculated, and the ratio of the TTL value of the node to the TTL _default value is multiplied by the TTL _default value. converting the TTL value to the node, multiplying the converted TTL value by the capacity value for the destination node of the counterpart node, and setting the corrected TTL value by the capacity value of the counterpart node,
When the node and the counterpart node are data mules, the TTL value of the node is multiplied by the ratio of the capacity value for the destination node to the capacity value for the destination node of the node multiplied by the value. A device for determining the TTL of a message in a delay-tolerant network-based information-centric network, which sets the TTL value.
The method of claim 17, wherein the TTL determining unit,
When the node is a normal node, the TTL value is determined as the smaller of the set TTL value and the TTL _max value, the TTL determination apparatus for a message in a delay-tolerant network-based information-centric network.
The method of claim 17, wherein the TTL determining unit,
When the node is a data mule, the TTL value is determined as a smaller value among a set TTL value and the TTL _default value, a TTL determination apparatus for a message in a delay tolerant network-based information-centric network.
The method of claim 16, wherein the TTL determining unit,
When the counterpart node is a data mule, a TTL value is determined as a TTL _max value as a TTL value.

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