KR20220032823A - Method for selecting mobile sink path in solar-powered wireless sensor networks, recording medium and device for performing the method - Google Patents

Abstract

The present invention relates to a method for selecting a mobile sync path in a solar energy-collecting wireless sensor network environment, which includes the following steps of: setting a search area constituted by two lines with a predetermined width (w) in the middle in the entire area set in a solar energy-collecting wireless sensor network; selecting at least one anchor node based on the amount of residual energy of nodes in the search area; collecting energy by visiting an anchor node selected in the search area by a mobile sync; resetting the search area by moving the two lines by the predetermined width (w) in directions away from each other in each period of mobile sync-based energy collection; collecting energy by visiting an anchor node selected along a path in the search area set for each period by the mobile sync; and sending a line release message informing of release of the two lines in order to restart energy collection in a case where energy collection is completed in the entire area. According to the present invention, a node life problem can be solved and network energy imbalance can be mitigated using a solar energy-collecting wireless sensor node.

Description

Method for selecting a mobile sink movement path in a solar energy-collecting wireless sensor network environment, and a recording medium and device for performing the same

The present invention relates to a method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment, a recording medium and an apparatus for performing the same, and more particularly, an area-based anchor node for solving an energy imbalance problem in a wireless sensor network It relates to selection and mobile sync movement path selection technology.

A wireless sensor network (WSN) consists of several sensor nodes and exchanges data through multi-hop communication. In general, wireless sensor networks are used to collect environmental data in areas that are difficult to access by humans, such as ecological monitoring or military facilities.

Since the sensor node has a limited energy resource, techniques for maximizing the lifespan of the WSN by using the minimum energy for data collection have been proposed in the existing WSN research. However, due to the fundamental constraint of limited energy, the performance improvement was limited. In order to solve this problem, research on an energy collection type sensor node that collects ambient energy to charge a battery has started.

Among them, solar energy has a higher energy density than other energy sources and has the advantage that it can be collected periodically. , SP-WSN) is being studied most actively.

On the other hand, most wireless sensor networks are operated by sending the data collected by the sensor node to a fixed sink node. In this method, energy consumption of the sink node and nodes in the vicinity of the sink node becomes relatively large. Such an area is called an energy hotspot.

Energy imbalance problem occurs centered on energy hotspots, and this energy imbalance problem is the biggest factor that reduces the lifespan of WSNs. In order to solve this problem, a technique of distributing energy overhead in a hotspot area to the entire network using a mobile sink has been recently proposed.

If the mobile sink directly moves to the data area and collects data, the data transmission energy of the data relay nodes between the sensor node and the sink node can be reduced. In addition, it is possible to alleviate to some extent the problem of energy hotspots around the sink that occurs when data is transmitted toward a fixed sink across the WSN.

However, a caveat here is that mobile sinks such as drones cannot visit all nodes in the network to collect data due to their limited battery (amount of energy). For this, it is necessary to limit the moving distance of the mobile sink. In recent studies, many methods are used to temporarily collect sensing data from a specific node called an anchor, and a mobile sink visits only these anchor nodes to collect data more efficiently.

Many studies have been conducted for efficient anchor node selection. Among them, Line-Based Data Dissemination (LBDD), a region-based anchor node selection technique [Non-Patent Document 1 of the prior art document], is a region (line-based data dissemination) that vertically crosses the network. ) and select nodes within the region as anchor nodes to transmit the data collected from each sensor node in the direction of the line.

Accordingly, it is easy for the sensor node to find a path through which data is transmitted to the anchor node, and the movement path of the mobile sink is simplified. However, since it is designed for a battery-based node rather than a solar energy collection node, it operates in a direction to minimize the energy use of the node.

In SP-WSN, each node should be designed to make the most of the collected energy rather than focusing on minimizing energy use because it can receive sufficient amount of energy for the node to operate and also periodically.

For example, if the nodes of SP-WSN use energy sparingly, the remaining energy can exceed the capacity of the rechargeable battery due to the charged energy, and the excess energy is inevitably thrown away.

In addition, even in the case of a solar energy collecting sensor, there is a problem that the nodes in the energy hotspot area may be in a blackout state until the energy is depleted and the energy is charged again.

KR 10-2020-0028645 A KR 10-1948447 B1 KR 10-1957728 B1

E. Ben Hamida and G. Chelius, "A line-based data dissemination protocol for wireless sensor networks with mobile sink", IEEE Int. Conf. on Communications 2008. ICC'08., pp. 2201-2205, 2008.

Accordingly, it is an object of the present invention to provide a method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment in order to increase energy efficiency.

Another object of the present invention is to provide a recording medium in which a computer program for performing a method of selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment is recorded.

Another object of the present invention is to provide an apparatus for performing a mobile sink movement path selection method in the solar energy collection type wireless sensor network environment.

In the method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment according to an embodiment for realizing the object of the present invention, a predetermined width (w ) setting a search area consisting of two lines with selecting at least one anchor node based on residual energy of nodes existing in the search region; collecting energy by visiting an anchor node selected in the search area by a mobile sink; resetting the search area by moving the two lines by a predetermined width (w) in a direction away from each other at every cycle in which energy is collected by the mobile sink; collecting energy by visiting a selected anchor node along a movement path within a search area set by the mobile sink for each period; and sending a line release message indicating release of the two lines in order to restart energy collection when all energy collection has been performed in the entire area.

In an embodiment of the present invention, the step of selecting at least one anchor node based on the residual energy of the nodes existing in the search area comprises setting a search area composed of two lines having a predetermined width w to a predetermined height g ) dividing into vertical lines having; and selecting one anchor node for each region divided by a vertical line.

In an embodiment of the present invention, in the step of selecting one anchor node for each region divided by the vertical line, a node with the largest amount of residual energy among nodes existing in each divided region may be selected as the anchor node. .

In an embodiment of the present invention, the movement path of the mobile sink may be one of a round trip path, a clockwise traversal path, and a counterclockwise traversal path within the search area of the corresponding period.

In an embodiment of the present invention, in the method for selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment, after the step of sending the line release message, it has a predetermined width w again in the center of the entire area The method may further include a step of resetting a search area composed of two lines.

In an embodiment of the present invention, in the method for selecting a mobile sync movement path in the solar energy collection type wireless sensor network environment, after the step of sending the line release message, the two lines are drawn near each other by a predetermined width (w ) to reset the search area by moving it; may further include.

In an embodiment of the present invention, the step of collecting energy by visiting an anchor node selected in the search area by the mobile sink includes: broadcasting an anchor node search message in the search area; and visiting the anchor node according to a response message transmitted by the anchor node receiving the discovery message.

In an embodiment of the present invention, in the method of selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment, when an anchor node is selected for each period, each sensor node transmits data in the direction of the closest line among the two lines. It may further include; transmitting the.

In an embodiment of the present invention, in the method for selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment, when an anchor node is selected for each cycle, the sensor nodes transmit data to the center of the network in the current cycle, and The method may further include; in the cycles, nodes that were inline nodes or anchor nodes transmit data in a direction opposite to the center of the network.

In an embodiment of the present invention, the method for selecting a movement path for a mobile sink in the solar energy collection type wireless sensor network environment further includes: when nodes receive a line release message, transmitting data to the network center again in the next cycle can do.

In a computer-readable storage medium according to an embodiment for realizing another object of the present invention, a computer program for performing a method of selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment is recorded. .

A mobile sink movement path selection device in a solar energy collection type wireless sensor network environment according to an embodiment for realizing another object of the present invention has a predetermined width in the center in the entire area set in the solar energy collection type wireless sensor network a line configuration unit for setting a search area composed of two lines having (w); an anchor node selection unit for selecting at least one anchor node based on residual energy of nodes existing in the search region; a line shifting unit configured to reset the search area by moving the two lines in a direction away from each other by a predetermined width (w) at each cycle in which energy is collected by visiting the anchor node selected in the search area by the mobile sink; and a line release unit that transmits a line release message informing that the two lines are released to start energy collection again when energy collection is performed in the entire area by the mobile sink.

According to the mobile sink movement path selection method in such a solar energy collection type wireless sensor network environment, a solar energy collection type sensorless sensor node is used to solve the lifespan problem of the node, and an anchor node is selected through the use of extra energy, so the power failure node reduce the time of In addition, since the multi-line and the line move, it is possible to reduce the time of the power failure node and increase the data collection amount.

1 is a block diagram of an apparatus for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment according to an embodiment of the present invention.
2 is a view for explaining the overall process of selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment proposed by the present invention.
3 is a diagram for explaining a line configuration proposed by the present invention.
4 is a diagram for explaining a line shift proposed by the present invention.
5 is a diagram for explaining line release proposed by the present invention.
6 is a diagram for explaining a data transmission direction of sensor nodes and data collection of a mobile sink in the present invention.
7 is a graph showing the total power outage time according to the number of nodes to verify the performance of the present invention.
8 is a graph showing the total data collection amount according to the number of nodes in order to verify the performance of the present invention.
9 is a flowchart of a method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment 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 block diagram of an apparatus for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment according to an embodiment of the present invention. 2 is a diagram for explaining the overall process of selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment proposed by the present invention.

In the solar energy collection type wireless sensor network environment according to the present invention, the mobile sink movement path selection device (10, hereinafter device) is based on LBDD (Line-Based Data Dissemination) based on the energy restriction problem (limited lifespan) of the sensor node and the fixed To solve the energy hotspot problem of the anchor node and the nodes around the line, we propose a technique for area-based anchor selection and mobile sink movement path selection.

Referring to FIG. 1 , the device 10 according to the present invention includes a line configuration unit 110 , an anchor node selection unit 130 , a line shift unit 150 , and a line release unit 170 .

In the device 10 of the present invention, software (application) for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment may be installed and executed, and the line configuration unit 110 and the anchor node selection unit 130, the configuration of the line shift unit 150 and the line release unit 170 is software for selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment executed in the device 10. can be controlled by

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 line configuration unit 110 , the anchor node selection unit 130 , the line shift unit 150 , and the line release unit 170 may be formed as an integrated module, or may consist of one or more modules. there is. However, on the contrary, each configuration may be formed of a separate module.

The device 10 may be movable or stationary. The apparatus 10 may be in the form of a server or an engine, and may be a device, an application, a terminal, a user equipment (UE), a mobile station (MS), or a wireless device. (wireless device), may be called other terms such as a handheld device (handheld device).

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.

Referring to FIG. 2 , the present invention operates two anchor lines by maximally utilizing the collected energy using the energy model of the solar energy collection type sensor node. In the solar energy collection type wireless sensor network environment of the present invention, there are a general sensor node, an inline node and an anchor node in the search area.

In the present invention, two lines (areas) are established to maximize the utilization of solar energy collected by each node and alleviate the energy hotspot problem, and anchor nodes are selected along these lines. The mobile sink takes these two lines as a round trip path for data collection and visits the anchor nodes within the line.

In the present invention, it is attempted to minimize the blackout time of the nodes in the energy hotspot area by operating Line-Based Data Dissemination (LBDD) by fully utilizing the solar energy collected by each node. This has the same meaning as minimizing the energy imbalance problem of nodes in the energy hotspot area.

The line configuration unit 110 sets a search area composed of two lines having a predetermined width w in the center in the entire area set in the solar energy collection type wireless sensor network.

Referring to FIG. 3 , the line configuration unit 110 divides the LBDD line into two lines L11 and L21 in the next round, starting from the center of the network, and moves the two lines to both sides by the same distance every round thereafter. .

According to the shift of the line in FIG. 2 , the search area is moved in the order of A → B1 & B2 → C1 & C2. In each line, nodes with sufficient energy are selected to become anchor nodes, and each sensor node transmits data in the direction of these two lines (refer to the routing path in FIG. 2), causing the anchor node to temporarily collect data.

In each round, the mobile sink visits anchor nodes in the line by selecting these two lines as a round trip path (refer to the mobile sink path in FIG. 2). The present invention alleviates energy hotspots of anchor nodes and neighboring nodes by periodically moving lines. As a result, the power outage time of the node can be reduced and the amount of collected data can be increased.

The multi-line data collection technique is based on The best utilization of harvested energy (maximizing utilization of harvested solar energy by selecting nodes with sufficient energy in two lines as anchor nodes), Relieve the energy-imabalance problem (two lines It is possible to reduce the overhead of the energy hotspot area by maintaining By solving the imbalance problem, the power outage time of nodes is minimized, which increases the amount of sensed data, and as a result, the amount of data collected by the mobile sink increases).

The anchor node selector 130 selects at least one anchor node based on the amount of residual energy of the nodes existing in the search area.

In the present invention, an energy threshold as shown in Equation 1 below is used to determine whether the current remaining energy amount of a node is sufficient to perform a basic operation used for data collection and transmission.

[Equation 1]

는 시스템 에너지 소모율,

는 에너지 수집률, C는 배터리 용량을 나타낸다. 노드의 잔여 에너지의 양이 문턱값

보다 크다면 노드가 정전되지 않으며 기본 동작을 수행하는데 충분하다고 생각되어 추가적인 일을 수행해도 된다는 의미이다.

is the system energy consumption rate,

is the energy collection rate, and C is the battery capacity. The amount of residual energy in the node is the threshold

If it is greater than that, it means that the node is not out of power and is considered sufficient to perform basic operations and can perform additional work.

이상의 에너지들을 사용함으로써 수집된 에너지의 양을 최대로 활용할 수 있다. If no additional work is done, the amount of energy in the rechargeable battery increases, and eventually the battery is fully charged and energy charged later is wasted.

By using the above energies, the amount of collected energy can be used to the maximum.

가 항상

보다 작도록 초기 세팅을 하여야 한다. In the present invention, this extra energy is used to operate as an anchor node. However, if the energy consumption rate is greater than the collection rate, the threshold value becomes larger than the battery capacity of the node, so that the given task cannot be operated. Therefore, when performing the basic operation of the node through duty-cycle control or sensing-rate control of the node,

is always

The initial setting should be made smaller.

Referring to FIG. 3 , a virtual line having a horizontal size of w is created in a network space like LBDD, and the line is divided into a vertical size of g. These two variables w and g may be determined in consideration of the communication range of the sensor node.

The initial lines L11 and L21 are located in the middle of the network as shown in FIG. 3 . Each node uses its own location information to determine whether it exists within the line, and the nodes in the line are called inline nodes, and the other nodes are called general nodes.

A node satisfying Equation 2 below is selected as an anchor node among inline nodes existing in an area in which this line is divided by a vertical size of g.

[Equation 2]

는 노드 i의 현재 잔여 에너지량이다. 만약, 수학식 2를 만족하는 노드들이 여러 개일 경우에는 만족하는 노드 중에서 잔여 에너지가 가장 많은 노드를 선택하여 앵커 노드로 설정한다. here,

is the current residual energy amount of node i. If there are multiple nodes satisfying Equation 2, a node having the most residual energy is selected from among the satisfied nodes and set as an anchor node.

Conversely, even when there is no node satisfying Equation 2, one node having a large amount of residual energy among nodes in the region must be selected as the anchor node. Otherwise, data transmitted to that area cannot be collected.

The line shift unit 150 resets the search area by moving the two lines in a direction away from each other by a certain width (w) at every cycle that visits the anchor node selected in the search area by the mobile sync and collects energy. do.

A round means a period in which the mobile sink visits anchor nodes in the current line to collect energy. After one round, it is divided into left and right sides based on the current line, and a new line is formed by moving the size of the line on both sides, that is, by w.

At this time, the anchor nodes of the current round inform nodes located in the direction in which the line moves, the starting point and the ending point of the line of the next round, so that each node can determine that it is an inline node of the next round. .

Referring to FIG. 4 , it is a view showing the state in which the lines are moved twice in FIG. 3 ( L13 and L23 ). The line L11 of FIG. 3 moved to L12 and then to L13 in the next cycle. Similarly, the L21 line moved to L22 and then to L23 in the next cycle.

After each line moves, among inline nodes belonging to each line, nodes satisfying Equation 2 are selected as anchor nodes. Since there must be one anchor node in the horizontal w and vertical g regions, even if there is no node with sufficient energy to operate as an anchor node among inline nodes, the node with the most residual energy is selected as the anchor node.

The line release unit 170 transmits a line release message informing the release of the two lines in order to restart energy collection when all energy collection is performed in the entire area by the mobile sink.

Referring to FIG. 5 , when the lines L14 and L24 come into contact with the end region of the network and can no longer move, the lines disappear, and the lines L15 and L25 for the next round are re-created in the center.

To release a line and create a new line in the center, the current anchor nodes send a message to release the line in the direction of the center of the network. When nodes belonging to the middle line receive these messages, they know that they are inline nodes, select anchors in each area, and take charge of data collection for the next round.

As another embodiment, when the anchor line reaches the end of the network, a method of moving the anchor line toward the center of the network again may be selected, instead of releasing the line and re-creating the line from the center. In this case, the anchor line is not released and goes back and forth between the center and the end of the network.

However, this method may not give enough time for the hotspot area nodes in or around the line to recharge their energy, for example, nodes in the vicinity of the network line changing direction become inline nodes again within a short time. They are more likely to be included in the energy hotspot area around them, so they may not have enough time to recover their energy.

Referring to FIG. 6 , a sensor node that needs to transmit data needs to know in which direction to send data. In the present invention, nodes that acted as normal nodes in the current round transmit data to the center of the network, and nodes that were inline nodes or anchor nodes in previous rounds transmit data in the opposite direction to the center of the network.

If the nodes receive a line release message, they send data back to the network center in the next round. This technique is very effective in that each node can determine the data transmission direction very easily, and the amount of relayed data can be distributed in a balanced way.

Since the mobile sync already knows that the line moves by w for each round, it can calculate the position of the moved line to determine the position of the changed line in the next round. Then, it traverses the identified line and collects data from the anchor node.

In this way, although the mobile sink knows the position of the line, it broadcasts an anchor node discovery message after arriving at the line because it does not have information on who is the anchor among the nodes in the line, that is, the anchor node. After receiving the discovery message, the anchor node transmits a response message informing the mobile sink that it is an anchor node so that the mobile node can visit itself.

Hereinafter, simulation results for comparing the present invention with the conventional LBDD will be described for performance evaluation of the present invention.

For the simulation, 800, 1000, and 1200 nodes were placed in a field area of 75 m X 75 m, and a drone was used for the mobile sink. The simulation was conducted for a total of 720 rounds, and the total power outage time and total data collection amount of the node were measured for each technique. The detailed experimental environment is described in Table 1 below.

[Table 1]

Referring to FIG. 7 , it is a graph showing the total power outage time of nodes according to the present invention and LBDD arranged nodes. In the case of LBDD, it can be seen that the power outage time of the node is relatively large compared to the present invention. This is because, by operating only one fixed line, the data that nodes belonging to the line must receive has increased.

On the other hand, it was confirmed that the total power outage time of the node was smaller by showing more distributed energy consumption than LBDD by moving and operating the two lines with the present invention.

Referring to FIG. 7 , it is a graph showing the total amount of data collection according to the present invention and LBDD nodes. The present invention showed a larger collection amount as the two lines were moved and operated.

On the other hand, LBDD showed a lower collection amount compared to the present invention. This appears to be influenced by the results of the previous experiment, measuring the total outage time of the node. That is, in LBDD, many nodes were out of power compared to the present invention, which results in data communication failure and less data sensing, which is expected to show the same results.

Together with this, it can be confirmed that the present invention has a larger increase in the total data collection amount compared to LBDD. Although the present invention achieves distribution of energy consumption of nodes by moving two lines even if the number of deployed nodes increases, LBDD does not solve the energy imbalance problem as it operates only one fixed line, so this result appears to come out.

A method of collecting data using a mobile sink can solve the energy imbalance problem of WSN nodes to some extent. However, for mobile syncs such as drones, a moving distance is inevitably suggested due to a limited battery.

Therefore, the present invention proposes an area-based anchor selection method and a mobile sink movement path selection method for a solar energy-based sensor network. In the present invention, two lines (regions) were set to maximize the utilization of solar energy collected by each node and alleviate the energy hotspot problem, and nodes with a lot of energy within these lines were selected as anchor nodes.

The mobile sink easily collects data by taking these two lines as a round-trip path for data collection. The present invention showed more even energy consumption than in LBDD, so that the power outage time of the node was reduced and the amount of data collection increased, which was confirmed to be more effective.

9 is a flowchart of a method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment according to an embodiment of the present invention.

The method for selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment according to the present embodiment may proceed in substantially the same configuration as the device 10 of FIG. 1 .

Accordingly, the same components as those of the device 10 of FIG. 1 are given the same reference numerals, and repeated descriptions are omitted. Also, the method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment according to the present embodiment may be executed by software (application) for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment.

The present invention is based on LBDD (Line-Based Data Dissemination) to solve the energy constraint problem (limited lifespan) of the sensor node and the energy hotspot problem of the fixed anchor node and the node around the line. Suggests techniques for selection.

The present invention operates two anchor lines by maximally utilizing the collected energy using the energy model of the solar energy collection type sensor node.

In other words, the present invention sets two lines (areas) to maximize the utilization of solar energy collected by each node and alleviate the energy hotspot problem, and anchor nodes are selected along these lines. The mobile sink takes these two lines as a round trip path for data collection and visits the anchor nodes within the line.

In the present invention, it is attempted to minimize the blackout time of the nodes in the energy hotspot area by operating Line-Based Data Dissemination (LBDD) by fully utilizing the solar energy collected by each node.

Referring to FIG. 9 , in the method of selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment according to this embodiment, first, having a predetermined width w in the center in the entire area set in the solar energy collection type wireless sensor network A search area composed of two lines (L11 and L21 in Fig. 3) is set (step S10).

At least one anchor node is selected based on the residual energy of nodes existing in the search region (step S20).

Anchor node selection DMS A search area consisting of two lines with a certain width (w) is divided into a vertical line with a certain height (g) (see Fig. 3), and one anchor node for each area divided by a vertical line to select The anchor node selects a node with the largest amount of residual energy among nodes existing in each divided region as the anchor node.

When an anchor node is selected for each period, each sensor node transmits data in the direction of the closest line among the two lines. For example, if an anchor node is selected for each cycle, sensor nodes in the current cycle transmit data to the center of the network, and nodes that were inline nodes or anchor nodes in previous cycles can transmit data in the opposite direction of the network center. there is. However, when the nodes receive the line release message, data can be transmitted to the network center again in the next cycle.

Energy is collected by visiting an anchor node selected in the search area by the mobile sink (step S30). The moving path of the mobile sink may be one of a round trip path, a clockwise traversal path, and a counterclockwise traversal path within the search area of the corresponding period.

The mobile sink may broadcast an anchor node discovery message in the search region of the corresponding cycle, and visit the anchor node according to a response message transmitted by the anchor node receiving the discovery message.

The search area is reset by moving the two lines by a predetermined width w in the direction away from each other at every cycle in which energy is collected by the mobile sink (step S40). Energy is collected by visiting the anchor node selected along the movement path within the search area set by the mobile sink for each period.

When all energy collection is performed in the entire area (step S50), a line release message is sent to inform the release of the two lines to start energy collection again (step S60).

In an embodiment, after the sending of the line release message, the search area composed of two lines having a predetermined width w may be re-established in the center of the entire area.

In another embodiment, after sending the line release message, the search area may be reset by moving the two lines by a predetermined width w in a direction to approach each other.

The present invention solves the lifespan problem of a node by using a solar energy collection type Mussen sensor node, and selects an anchor node through the utilization of extra energy, thereby reducing the time of the power failure node. In addition, since multi-lines and lines are moved, it is possible to reduce the time of the power failure node and increase the amount of data collection.

In such a solar energy collection type wireless sensor network environment, the mobile sink movement path selection method 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 shows more even energy consumption than in LBDD, so the power outage time of the node is reduced and the data collection amount is increased, which is more effective, and thus can be usefully utilized in the field of solar energy-based wireless sensor networks.

10: Mobile sink movement path selection device
110: line configuration part
130: anchor node selection unit
150: line shift unit
170: line release unit

Claims (12)

Setting a search area consisting of two lines having a predetermined width (w) in the center in the entire area set in the solar energy collection type wireless sensor network;
selecting at least one anchor node based on the residual energy of nodes existing in the search region;
collecting energy by visiting an anchor node selected in the search area by a mobile sink;
resetting the search area by moving the two lines by a predetermined width (w) in a direction away from each other at every cycle in which energy is collected by the mobile sink;
collecting energy by visiting a selected anchor node along a movement path within a search area set by the mobile sink for each period; and
When all energy collection is performed in the entire area, sending a line release message informing of the release of the two lines to restart energy collection; moving mobile sinks in a solar energy collection type wireless sensor network environment, including: How to choose a route.
The method of claim 1, wherein the selecting of at least one anchor node based on residual energy of nodes existing in the search region comprises:
dividing a search area composed of two lines having a predetermined width w into vertical lines having a predetermined height g; and
A method of selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment, including; selecting one anchor node for each area divided by a vertical line.
The method of claim 2, wherein the step of selecting one anchor node for each region divided by the vertical line comprises:
A method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment, in which a node with the largest amount of residual energy among nodes existing in each divided area is selected as an anchor node.
According to claim 1,
The method of selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment, wherein the movement path of the mobile sink is one of a round trip path, a clockwise traversal path, and a counterclockwise traversal path within a search area of a corresponding period.
According to claim 1,
After sending the line release message, resetting the search area consisting of two lines having a predetermined width w again in the center of the entire area; further comprising, a solar energy collection type wireless sensor network environment How to choose the mobile sink breadcrumbs in.
According to claim 1,
After sending the line release message, moving the two lines in a direction closer to each other by a predetermined width (w) to reset the search area; In a solar energy collection type wireless sensor network environment, further comprising How to choose a mobile sink breadcrumb path.
The method of claim 1, wherein the collecting energy by visiting an anchor node selected in the search area by the mobile sink comprises:
broadcasting an anchor node discovery message in the search region; and
Visiting the anchor node according to a response message transmitted by the anchor node that has received the discovery message; A method for selecting a movement path for a mobile sink in a solar energy collection type wireless sensor network environment, comprising: a.
According to claim 1,
When an anchor node is selected for each cycle, each sensor node transmits data in the direction of a line closest in distance among the two lines; Method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment further comprising the .
According to claim 1,
When an anchor node is selected for each cycle, sensor nodes in the current cycle transmit data to the center of the network, and nodes that were inline nodes or anchor nodes in previous cycles transmit data in the opposite direction to the center of the network; further Including, a method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment.
According to claim 1,
When the nodes receive the line release message, transmitting data back to the network center in the next cycle; The method for selecting a mobile sink movement path in a solar energy collection type wireless sensor network environment, further comprising a.
According to claim 1,
A computer-readable storage medium having recorded thereon a computer program for performing a method for selecting a mobile sink movement path in the solar energy collection type wireless sensor network environment.
A line configuration unit for setting a search area consisting of two lines having a predetermined width (w) in the center in the entire area set in the solar energy collection type wireless sensor network;
an anchor node selection unit for selecting at least one anchor node based on residual energy of nodes existing in the search region;
a line shifting unit configured to reset the search area by moving the two lines in a direction away from each other by a predetermined width (w) at each cycle in which energy is collected by visiting an anchor node selected in the search area by the mobile sink; and
When all energy collection is performed in the entire area by the mobile sink, a line release unit that sends a line release message informing the release of the two lines to start energy collection again; Solar energy collection type wireless sensor including Mobile sink breadcrumb path selection device in network environment.

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