KR20100083622A - Method and device for deploying relay node, computer recordable medium - Google Patents

Abstract

PURPOSE: A method and a device for arranging relay nodes, and a computer recordable medium thereof are provided to efficiently and rapidly calculate an arrangement location of a relay node. CONSTITUTION: A memory(230) stores location information of a sensor node included in a list of sensor nodes to be connected and a relay node included in a list of arranged relay nodes. A control unit(220) performs a relay node arrangement method using information stored in the memory. A data receiving unit(240) receives information related to the sensor nodes included in the list of the sensor nodes which will be connected.

Description

Relay node placement method, relay node placement device and computer readable recording medium {METHOD AND DEVICE FOR DEPLOYING RELAY NODE, COMPUTER RECORDABLE MEDIUM}

The present invention relates to a relay node arrangement method and relay node arrangement apparatus for interconnecting sensor networks in a sensor network.

In operating a wireless sensor network, extending the life of a wireless sensor network is one of the important challenges. One method for extending the life of a wireless sensor network is to detect environmental variables that serve as sensor nodes (SNs) with various constraints (eg, power, processing, network throughput). It is limited to the basic functions of transmitting the detected data.

Therefore, the wireless sensor network needs a set of relay nodes (RNs) capable of delivering sensing data transmitted to a base station (including a router).

 Double-tier architecture (DTA), where the lower layer is responsible for detecting each sensor node and all events, and the upper node is responsible for transmitting data to the base station (BS). It means network structure. In a double-layer structure, relay nodes should be placed so that each sensor node can find at least one relay node within one hop distance.

In the double layer structure, it is desirable to minimize the number of relay nodes. In other words, consideration should be given to relay node placement (RNPDTA) in an efficient dual layer structure.

The present invention is to quickly and efficiently calculate the arrangement position of the relay node for the relay node to function effectively in installing the sensor network.

In addition, the present invention is to be able to quickly calculate the arrangement position of the relay node even with a device having a small computing power.

The relay node arrangement method according to the embodiment of the present invention for realizing the above object is (a) at the closest distance from any sensor node and any sensor node included in the list of sensor nodes to be connected. Selecting another sensor node that is located, (b) calculating the position of any relay node using location information of the arbitrary sensor node and the other sensor node, and (c) the arbitrary sensor node; Deleting another sensor node from the list of sensor nodes to be connected, and adding the any relay node to the list of deployed relay nodes.

In an aspect of the present disclosure, the method may further include receiving information related to sensor nodes included in the list of sensor nodes to be connected.

In another aspect of the invention, (d) by using the position information of the relay node included in the list of the relay node arranged and the sensor node included in the list of sensor nodes to be connected, the (a) to (c And repeating the steps).

In yet another aspect of the present invention, the step (d) comprises: (d1) a sensor-relay node composed of a sensor node arbitrarily selected from the list of sensor nodes to be connected and a relay node arbitrarily selected from the list of arranged relay nodes. Searching for a sensor-relay node pair closest to each other among the pairs; (d2) calculating a position of a new relay node using a distance between a sensor node and a relay node constituting the found sensor-relay node pair; (d3) adding the new relay node to the list of deployed relay nodes.

In another aspect of the invention, the step (b), (b1) comparing the distance between the arbitrary sensor node and another sensor node and 2r (r means the maximum transmittable distance of the sensor node) It may include.

In another aspect of the present invention, the step (b), (b21) a line segment connecting the arbitrary sensor node and the other sensor node when the length between the arbitrary sensor node and another sensor node is greater than 2r. Comprising any of the points present above, a point r apart from any sensor node as the position of any relay node.

In another aspect of the invention, the step (b), (b31) if the length between the arbitrary sensor node and the other sensor node is less than or equal to 2r, and greater than r, the arbitrary sensor node and other Computing the point r apart from all the sensor nodes to the location of any relay node.

In another aspect of the present invention, the relay node arrangement method may be used in a dual-layer sensor network.

A memory for storing location information of a sensor node included in a list of sensor nodes to be connected or a relay node included in a list of arranged relay nodes;

Relay node arrangement apparatus according to another embodiment of the present invention for realizing the above object comprises a control unit for performing a relay node arrangement method using the information stored in the memory, the relay node arrangement method, ( a) selecting any sensor node included in the list of sensor nodes to be connected and another sensor node located at a closest distance from the any sensor node, and (b) the other sensor node and the other Calculating a position of an arbitrary relay node using the position information of the sensor node; and (c) deleting the arbitrary relay node from the list of sensor nodes to which the arbitrary sensor node is connected to another sensor node, and removing the arbitrary relay node from the deployed relay. Adding to the list of nodes.

In another aspect of the present invention, the method may further include a data receiver configured to receive information related to sensor nodes included in the list of sensor nodes to be connected.

In another aspect of the present invention, the sensor node included in the list of sensor nodes to be connected may further include a display unit for displaying the position information of the relay node included in the list of relay nodes arranged.

In a computer-readable recording medium related to another embodiment of the present invention for realizing the above object, a relay node arrangement program for performing the relay node arrangement method may be recorded.

Relay node arrangement method, arrangement and recording medium according to an embodiment of the present invention associated with the above problem, by arranging a relatively small number of relay nodes to calculate the placement position of the relay node that can connect the sensor node, A wireless sensor network including a relay node can be efficiently implemented.

In addition, the relay node arrangement method, the arrangement device and the recording medium according to an embodiment of the present invention, by calculating the placement position of the relay node using a relatively low complexity operation, even relay devices having a relatively low calculation capability The placement of nodes can be calculated.

In addition, the relay node arrangement method, the arrangement apparatus and the recording medium according to an embodiment of the present invention, it is possible to quickly calculate the arrangement position of the relay node by calculating the arrangement position of the relay node using a relatively low complexity operation. have.

Hereinafter, a relay node arrangement method, a relay node arrangement device and a computer-readable recording medium for performing the relay node placement method according to the present invention will be described in more detail with reference to the accompanying drawings. The suffixes "module" and "unit" for components used in the following description are given or used in consideration of ease of specification, and do not have distinct meanings or roles from each other.

Since the description of the disclosed technology is only an embodiment for structural or functional description, the scope of the disclosed technology should not be construed as limited by the embodiments described herein. That is, the embodiments may be variously modified and may have various forms, and thus the scope of the disclosed technology should be understood to include equivalents capable of realizing the technical idea.

On the other hand, the meaning of the terms described in the present application should be understood as follows.

The terms “first”, “second”, etc. are intended to distinguish one component from another, and the scope of rights shall not be limited by these terms. For example, the first component may be named a second component, and similarly, the second component may also be named a first component.

The term “and / or” should be understood to include all combinations that can be suggested from one or more related items. For example, the meaning of “first item, second item and / or third item” means from two or more of the first, second or third items as well as the first, second or third items. It means any combination of items that can be presented.

When a component is referred to as being "connected" to another component, it should be understood that there may be other components in between, although it may be directly connected to the other component. On the other hand, when an element is referred to as being "directly connected" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions describing the relationship between the components, such as "between" and "immediately between" or "neighboring to" and "directly neighboring", should be interpreted as well.

Singular expressions should be understood to include plural expressions unless the context clearly indicates otherwise, and terms such as "include" or "have" refer to features, numbers, steps, operations, components, parts, or parts thereof described. It is to be understood that the combination is intended to be present and does not exclude in advance the possibility of the presence or addition of one or more other features or numbers, steps, actions, components, parts or combinations thereof.

BS, SN, and RN may represent a base station, a sensor node, and a relay node, respectively. If t is a point, the position can be assumed to be pt with Cartesian coordinates (xt, yt). If t1 and t2 are two points on a two-dimensional plane, the line connecting t1 and t2 is represented by [t1, t2], and the Euclidean distance is || t1, t2 ||, || pt1, pt2 || Or || (xt1, yt1), (xt2, yt2) ||.

Relay Node Placement in double-tier architecture (RNPDTA) can be described as follows. For the set of sensor nodes S = {s1, s2, ..., sn} included in the list of sensor nodes to be connected, the corresponding positions are {ps1, ps2, ..., psn} and each transmission range of SN and RN Suppose r and R (R> = r). The goal of this problem is to provide a set of relay nodes R = {r1, r2, ..., rn} to ensure connectivity between all sensor nodes (except source and destination sensor nodes) via the RN-RN path. To deploy.

Communication range and connectivity may be defined as follows. If psi, prj || <= r, sensor node si may communicate with relay node rj. Similarly, if || pri, prj || <= R, two relay nodes ri and rj can communicate.

Covered and Uncovered Sensor Nodes can be described as follows. It is assumed that si is a sensor node having a position psi, and R = {r1, r2, ..., rm} is a set of relay nodes having positions {pr1, pr2, ..., prm}. Ps _i , pr _j || If rj satisfying <= r is present in R, si may be said to be covered or connected. That is, if any s _i satisfies Equation 1 below, s _i may be said to be covered or connected.

If any si does not satisfy the following equation, si is said to be uncovered or broken. That is, if any s _i satisfies Equation 2 below, si is said to be uncovered or cut off.

The number of RN required to connect a SN may be defined as follows. It is assumed that SNi is a sensor node having a transmission range r, and RNj is a relay node having a transmission range R (R> = r). When SNi is to be connected to RNi through at least one RN present on the line connecting SNi and RNi (in other words, the RNs are arranged such that SNi, RNi, and RNs connecting SNi and RNi are located in a straight line). The minimum number of required RNs is shown in Equation 3 below.

Cover factor may be defined as follows. The cover factor αα is one of the properties of a location that indicates the number of broken SNs that should be covered by the RN at that location in a particular step of the PGA (Polynomial-time Greedy Approximation) algorithm. The value calculated by the cover factor αα has an integer value.

For example, let q be the position in the deployment region where n sensor nodes are deployed. The cover factor ααq of q can be calculated by the following equation (4).

Cumulative distance may be defined as follows. The cumulative distance is defined as the sum of the distances from the relay node to all broken sense nodes. If? J is the cumulative distance of the relay node rj, the cumulative distance? J can be calculated by the following equation (5).

Convex and Non-convex Deployment Regions may be defined as follows. If the proposition "if any two points are selected points in the area, all points present on the line connecting said two points are in area" is true for all points present in said area, said area Is the convex area. The reason for the assumption of the convex region is that any point calculated by the PGA algorithm may exist outside the boundary for the non-convex configuration region. However, the realistic placement area may be non-convex.

The effect of the existence of base-stations in DTA in a double layer structure (DTA) is described as follows. The function of the base station is naturally a superset of the function of the relay node. Therefore, the transmission range of the base station is equal to the transmission range R of the relay node.

Each step may occur differently from the stated order unless the context clearly dictates the specific order. That is, each step may occur in the same order as specified, may be performed substantially simultaneously, or may be performed in the reverse order.

 All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art unless otherwise defined. Terms defined in commonly used dictionaries should be interpreted to be consistent with meaning in the context of the relevant art and can not be construed as having ideal or overly formal meaning unless expressly defined in the present application.

To simplify the problem definition, it is assumed that the layout area is convex, and the problem can be defined as follows.

 S = {s1, s2, ..., sn} is a set of sensor nodes, the position of the sensor node is defined as {ps1, ps2, ..., psn}. The positions {ps1, ps2, ..., psn} of the sensor nodes are all located within a finite convex region, and r (r> 0) is assumed to be a transmission range of each sensor node. In addition, it is assumed that R (R> = r) is a transmission range of the relay node. If the following two conditions are met, relay node placement in a double layer structure may be solved.

1A to 1E are diagrams for describing a relay node arrangement method according to an embodiment of the disclosed technology. 1A-1E relate to scenarios that may occur while executing the algorithm described in FIG. 6.

<Scenario 1>: || RN, SN || if <= r.

Scenario 1 describes a situation where a disconnected sensor node (disconnected SN) is within a distance r from any relay node (RN). In scenario 1, according to the algorithm, no further relay node RN is deployed. In addition, the sensor node SN is considered to be connected and is excluded from the list of sensor nodes to be connected.

<Scenario 2>: r <|| RN, SN || if <= r + R.

이기 때문이다.It is assumed that the relay node RN and the sensor node SN are separated from each other by r + δδ (0 <δδ <R). One relay node is needed to cover the sensor node SN. because

Because it is.

As shown in FIG. 1A, a relay node RN at any position within the shaded area a may cover a sensor node SN that is in communication with a previously deployed relay node RN. have.

It is assumed that there are other sensor nodes to be covered other than the sensor node SN shown in FIG. 1A. When the relay node RN is disposed on the transmission boundary of the relay node RN (including the points corresponding to the outermost areas of the relay nodes within the transmission distance), the probability of covering the other sensor nodes is increased. You can.

 When arranging any relay node RN, in order to check the possibility that other sensor nodes are covered, when calculating the likelihood that the other sensor nodes are covered for every point located in the shaded area a, It takes a lot of time.

Thus, in this algorithm, in order to keep the time complexity low, the other sensor node coverage probability of the relay node RN is calculated for only three positions.

Two points (b, c) of the three positions are points separated from the relay node (RN) and the sensor node (SN) by R and r, respectively, and the remaining points (d) on the [RN, SN] line It may mean a point separated by R from the relay node RN.

Among the three points b, c, and d, one point that is most advantageous for the other disconnected sensor node SN may be selected. Two parameters are considered to measure the degree of benefit. The first criterion is the cover factor (ie the maximum number of sensor nodes SN covered by the relay node RN at that location), and the second criterion is that of the relay node RN at that location. Cumulative distance. As a result of applying the first criterion, when the plurality of relay nodes RN are selected, the second criterion is applied. This deployment is called intelligent deployment.

<Scenario 3>: r <|| RN, SN || <r + R and R> 2r

As shown in FIG. 1B, if || pRN, pSN || If <R-2r, the two circles may not intersect each other. In order to obtain the intersection points, instead of R, the transmittable length of the relay node RN, the center of the relay node RN is used as the center point, and intelligent placement is applied by using a circle having a radius of || pRN and pSN ||. can do.

That is, Scenario 1 using a circle having the position of the relay node RN as the center point, a circle having the radius || pRN and pSN ||, a circle having the position of the sensor node SN as the center point, and the radius r being the radius. Intelligent placement can be applied as

 Radius || pRN, pSN || from relay node RN and sensor node SN respectively. Apply intelligent placement using and r.

<Scenario 4>: || RN, SN || > r + R

As shown in FIG. 1C, the distance between the existing relay node RN and the target sensor node SN may be greater than R + r. In this case, in order to connect the target sensor node SN, it is necessary to arrange a plurality of relay nodes RN1 and RN2. All but the last relay node RN3 may be placed on a straight line [RN, SN] from the relay node RN and the last relay node RN using existing intelligent arrangements.

Scenario 5: Avoiding too close deployment of relay nodes.

A general strategy for limiting the placement of unnecessary relay nodes RN is to maintain a minimum distance between any pair of relay nodes. In some cases, this strategy may be violated by intelligent deployment. For example, as shown in FIG. 1D, any sensor node SNi may be one hop away from two existing relay nodes RN (ie, RNi and RNk).

When calculating a position to place a new relay node RN using the intelligent arrangement using the arbitrary sensor node SNi and any relay node RNi, select a position that is too close to another relay node RNk. It is possible to.

In such a case, any possible location RNa with a distance less than r from any other relay node RN may be disqualified in the intelligent placement calculation. That is, the point where the disqualified is eliminated may be excluded in calculating a position to place a new relay node (RN).

The remaining positions RNb and RNc among the other positions may be selected as positions where new relay nodes are to be placed by intelligent placement.

|| RN, SN || If <r it is possible that all three of these positions are within a distance r from any other relay node. In this case, the new relay node RN may be located at the same position as the sensor node SNi. If it is impossible to arrange a plurality of nodes at the same position, the point closest to SNj among the points existing on the line [RNi, RNk] may be selected. Thus intelligent placement always supports a strategy of maintaining the minimum distance r between any pair of relay nodes.

<Scenario 6>: shrink strategy.

As shown in FIG. 1E, during placement of any relay node RN, the estimated position may be located outside the boundary of the placement area. In this case, a shrinking operation is used to replace the calculated position RNi (xi, yi) with the position RNj (xj, yj) on the placement region boundary closest to RNi. If the layout area is called a rectangle, the lower left corner coordinate of the area is (Xmin, Ymin) and the upper right corner coordinate of the area is (Xmax, Ymax), then the reduction operation calculates RNj (xj, yj) as Can be.

Each relay node RN outside of the placement area is arranged to cover any sensor node SN in the shaded area. Even after shrinking, the algorithm covers the shadowed area, so it does not lose its generality.

2 is a block diagram showing a relay node arrangement according to an embodiment of the present invention.

The relay node arrangement apparatus 200 may include a display 210, a controller 220, a memory 230, and a data receiver 240. The components shown in FIG. 2 are not essential, so that a mobile terminal having more or fewer components may be implemented.

Hereinafter, the components will be described in order.

The display unit 210 displays (outputs) information processed by the relay node arrangement device 200. For example, location information of a sensor node included in a list of sensor nodes to be connected or a relay node included in a list of arranged relay nodes may be displayed.

The display unit 151 includes a liquid crystal display (LCD), a thin film transistor-liquid crystal display (TFT LCD), an organic light-emitting diode (OLED), and a flexible display (flexible). and at least one of a 3D display.

Some of these displays can be configured to be transparent or light transmissive so that they can be seen from the outside. This may be referred to as a transparent display. A representative example of the transparent display is TOLED (Transparant OLED).

The controller 220 may control the overall operation of the relay node arrangement device 200. The controller 220 may perform a PGA (Polynomail-time Greedy Approximation) algorithm described with reference to FIGS. 3 to 6.

The memory 230 may store a program for the operation of the controller 220 and may temporarily store input / output data.

The memory 230 may store location information of the sensor node included in the list of sensor nodes to be connected or the relay node included in the list of arranged relay nodes.

The memory 230 may be a flash memory type, a hard disk type, a multimedia card micro type, a card type memory (for example, SD or XD memory), RAM (Random Access Memory, RAM), Static Random Access Memory (SRAM), Read-Only Memory (ROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), Programmable Read-Only Memory (PROM), Magnetic Memory, Magnetic It may include a storage medium of at least one type of disk, optical disk. The mobile terminal 100 may operate in connection with a web storage that performs a storage function of the memory 160 on the Internet.

The data receiver 240 may receive information related to sensor nodes included in the list of sensor nodes to be connected.

The data receiver 240 receives information related to sensor nodes included in the list of sensor nodes to be connected through wired / wireless communication from an external device or a network, or connects the data from a user of the relay node arrangement apparatus 200. Information related to sensor nodes included in the list of sensor nodes may be received.

When the data receiver 240 receives information related to sensor nodes included in the list of sensor nodes to be connected from the user of the relay node arrangement apparatus 200, the data receiver 240 is a user input unit 240. Can function. The user input unit 240 may include a keypad, a keyboard, a mouse, a joystick, and the like. Alternatively, the user input unit 240 may be implemented in the form of a touch screen in which a touch pad is coupled to the display unit 210.

According to a hardware implementation, the embodiments described herein include application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs), field programmable gate arrays (FPGAs), and the like. It may be implemented using at least one of processors, controllers, micro-controllers, microprocessors, and electrical units for performing other functions. The described embodiments may be implemented by the controller 220 itself.

According to the software implementation, embodiments such as the procedures and functions described herein may be implemented as separate software modules. Each of the software modules may perform one or more functions and operations described herein. Software code may be implemented in software applications written in a suitable programming language. The software code may be stored in the memory 230 and executed by the controller 220.

4 is a flowchart illustrating a relay node arrangement method according to an embodiment of the present invention.

As shown in FIG. 4, the relay node arrangement apparatus 200 receives information related to sensor nodes included in a list of sensor nodes to be connected (S = {S1, S2, S3, ..., Sn}). Can be (S10). The information may include location information of the sensor nodes (S10). The sensor nodes may be arranged in the Euclidean plane.

The relay node arranging apparatus 200 selects any sensor node St among the list of sensor nodes S, and selects another sensor node located closest to the selected sensor node St. (Su) may be performed (S20).

The relay node arrangement apparatus 200 may calculate the position Pr1 of the arbitrary relay node r1 based on the position of the arbitrary sensor node St and the other sensor node Su (S30). The intelligent placement algorithm may be used in the calculation process.

The relay node arrangement device 200 may delete the arbitrary sensor node St and the other sensor node Su, which are connected, from the list S of sensor nodes to be connected (S40).

The relay node arranging apparatus 200 may add an arbitrary relay node r1 to the collection of arranged relay nodes TREE (S50). The relay node arrangement apparatus 200 may calculate a distance between other sensor nodes included in a list S of sensor nodes to be connected to an arbitrary relay node r1.

The relay node arrangement apparatus 200 may repeat the steps S10 to S50 based on the set S of sensor nodes and the set TREE of relay nodes arranged (S60).

5A and 5B are diagrams for describing a relay node arrangement process by the relay node arrangement system.

 In the case of FIG. 5A, the relay node arrangement system 200 displays a set S of sensor nodes received from a user. In FIG. 5B, the relay node arrangement system 200 is based on a set S of sensor nodes. Display the relay nodes that are placed into.

6A and 6B are flowcharts illustrating a relay node placement method according to an embodiment of the disclosed technology.

 The PGA algorithm described in FIGS. 6A and 6B may be described in two parts. The first part describes the process of finding the first relay node (RN), and the next part describes the process of searching the sequential relay nodes (subsequent RNs) necessary to cover all the sensor nodes (SNs).

 The input of the PGA algorithm is (1) the set of N sensor nodes SNs in the Euclidean plane S = s1, s2, ..., sn, the corresponding positions of the sensor nodes SNs. Are two integers r and R (R> = r), which are ps1, ps2, ..., psn in the convex region and (2) indicate the transmission ranges of the sensor node SN and the relay node RN, respectively. It includes.

The output of the PGA algorithm is a collection of deployed relay nodes (TREE), and the collection of deployed relay nodes (TREE) is also present in the convex region.

 In the first stage, the relay node placement system 200 is a bottom-right SN st (xt, yt) of the set S = s1, s2, ..., sn of the given sensor nodes SNs. And find the closest sensor node su (xu, yu) from the first sensor node st.

 Using the positions of these two sensor nodes st and su, the relay node placement system calculates the position of the first relay node RN pr1 (x, y). There are two possibilities at this stage. The first is when the distance between two sensor nodes (st, su) is greater than 2r (ie || pst, psu ||> 2r), and the second is the distance between two sensor nodes (st, su) Is less than or equal to 2r (ie || pst, psu || <= 2r).

 In the first case, the relay node placement system 200 finds a position (x, y) away from st on the line [st, su]. The equation for the straight line (ie y = mx + c, m is the slope, c is a constant) is used to find the position.

 In the second case, three probable positions are calculated, two of which are r apart from both sensor nodes (st, su). The position of these two points is calculated using the following two equations.

(1) r2 = (x-xt) ² + (y-yt) ²

(2) r2 = (x-xu) ² + (y-yu) ²

 The position of the third point is r apart from st on the straight line [st, su]. One of these three points is selected as the first relay node r1 based on the criteria described in Intelligent Deployment Strategy. After determining the location of the first relay node r1, the relay node placement system 200 marks st and su as connected and deletes st and su from the list of sensor nodes SNs. Next, the relay node arrangement system 200 adds the first relay node r1 to the collection of deployed relay nodes TREE and the distance of all disconnected sensor nodes from the first relay node r1. Calculate

 The second part of the PGA algorithm finds the closest sensor node and relay node pair (SN-RN pair) from a given set of sensor nodes (S) and a set of relay nodes arranged (TREE), and the target sensor node (target SN). According to the scenario described above, a new relay node is arranged based on the distance between the sensor node and the relay node, and the newly repeated relay nodes are included in the set of arranged relay nodes (TREE).

 The disclosed technique may have the following effects. It is to be understood, however, that the scope of the disclosed technology is not to be construed as limited thereby, as it is not meant to imply that a particular embodiment should include all of the following effects or only the following effects.

 The relay node arrangement system according to an embodiment may efficiently arrange a relay node based on the received information about the sensor nodes. For example, a relay node placement system can connect all of the sensor nodes using as few relay nodes as possible.

 Relay node arrangement system according to an embodiment can be efficiently used in a dual-layer sensor network.

In addition, according to an embodiment of the present invention, the above-described method may be implemented as code that can be read by a processor in a medium in which a program is recorded. Examples of processor-readable media include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like, and may be implemented in the form of a carrier wave (for example, transmission over the Internet). Include.

The relay node arrangement method, the relay node arrangement device, and the computer-readable recording medium described above are not limited to the configuration and method of the above-described embodiments, but the embodiments may be modified in various ways. All or part of each of the embodiments may be configured to be selectively combined so that.

1A to 1E are diagrams for describing a relay node arrangement method according to an embodiment of the disclosed technology.

2 is a block diagram illustrating a relay node arrangement apparatus according to an embodiment of the disclosed technology.

3 is a table for explaining a relay node arrangement method according to an embodiment of the disclosed technology.

4 is a flowchart illustrating a relay node arrangement method according to an embodiment of the disclosed technology.

5A and 5B are diagrams for explaining a relay node arrangement process by the relay node arrangement system.

6A and 6B are flowcharts illustrating a relay node arrangement method according to an embodiment of the disclosed technology.

Claims (17)

(a) selecting any sensor node among the sensor nodes included in the list of sensor nodes to be connected with another sensor node located closest to the arbitrary sensor node; (b) calculating a position of any relay node using location information of the arbitrary sensor node and the other sensor node; and (c) deleting the sensor node from a list of sensor nodes to be connected to another sensor node and adding the relay node to the list of deployed relay nodes. According to claim 1, And receiving information related to sensor nodes included in the list of sensor nodes to be connected. According to claim 1, (d) repeating steps (a) to (c) by using the position information of the relay node included in the list of the arranged relay nodes and the sensor node included in the list of sensor nodes to be connected. Relay node placement method comprising. The method of claim 3, In step (d), (d1) searching for a sensor-relay node pair closest to the distance among a sensor-relay node pair consisting of a sensor node arbitrarily selected from the list of sensor nodes to be connected and a relay node arbitrarily selected from the list of arranged relay nodes; (d2) calculating a position of a new relay node using a distance between a sensor node and a relay node constituting the retrieved sensor-relay node pair; and (d3) adding the new relay node to the list of deployed relay nodes. According to claim 1, In step (b), (b1) comparing the distance between the arbitrary sensor node and another sensor node and 2r (r means the maximum transmittable distance of the sensor node). 6. The method of claim 5, Step (b) is (b21) If the length between the arbitrary sensor node and the other sensor node is greater than 2r, any point existing at the line segment connecting the arbitrary sensor node and the other sensor node, And calculating a point a distance r from said any sensor node as a location of any relay node. 6. The method of claim 5, In step (b), (b31) when the length between the arbitrary sensor node and the other sensor node is less than or equal to 2r and larger than r, And calculating a point r apart from both the sensor node and the other sensor node as the position of the relay node. According to claim 1, The relay node arrangement method is a relay node arrangement method used in a dual-layer sensor network. A memory for storing location information of a sensor node included in a list of sensor nodes to be connected or a relay node included in a list of arranged relay nodes; And a controller for performing a relay node arrangement method using the information stored in the memory. The relay node arrangement method, (a) selecting any sensor node among the sensor nodes included in the list of sensor nodes to be connected with another sensor node located closest to the arbitrary sensor node; (b) calculating a position of any relay node using location information of the arbitrary sensor node and the other sensor node; and (c) deleting from the list of sensor nodes to connect the sensor node to another sensor node, and adding the any relay node to the list of deployed relay nodes. The method of claim 9, And a data receiver configured to receive information related to sensor nodes included in the list of sensor nodes to be connected. The method of claim 9, And a display unit configured to display location information of a sensor node included in a list of sensor nodes to be connected or a relay node included in a list of arranged relay nodes. The method of claim 9, Relay node arrangement method performed by the control unit, (d) repeating steps (a) to (c) by using the position information of the relay node included in the list of the arranged relay nodes and the sensor node included in the list of sensor nodes to be connected. Relay node arrangement comprising. The method of claim 12, In step (d), (d1) a sensor node arbitrarily selected from the list of sensor nodes to be connected; Retrieving the closest sensor-relay node pair among the sensor-relay node pairs composed of a relay node arbitrarily selected from the list of arranged relay nodes; (d2) a sensor node and a relay node constituting the retrieved sensor-relay node pair. Calculating the position of the new relay node using the distance between the nodes; and (d3) adding the new relay node to the list of deployed relay nodes; Relay node arrangement comprising a step. The method of claim 9, In step (b), (b1) comparing the distance between the arbitrary sensor node and another sensor node and 2r (r means the maximum transmittable distance of the sensor node). 15. The method of claim 14, Step (b) is (b21) If the length between the arbitrary sensor node and the other sensor node is greater than 2r, any point existing at the line segment connecting the arbitrary sensor node and the other sensor node, And calculating a point a distance r from the sensor node as the position of the relay node. 15. The method of claim 14, In step (b), (b31) when the length between the arbitrary sensor node and the other sensor node is less than or equal to 2r and larger than r, And calculating a point r apart from both the sensor node and the other sensor node as the position of the relay node. A computer-readable recording medium in which a relay node arrangement program for performing the relay node arrangement method of any one of claims 1 to 8 is recorded.

Images