KR100957740B1 - Energy-Efficient Topology Control Method based on Location Awareness for Wireless Sensor Networks - Google Patents

Abstract

A location recognition based power control method for a wireless sensor network is provided. Location-based power control method for a wireless sensor network according to an embodiment of the present invention comprises the steps of calculating the node density of all the FFD nodes on the network; A second step of dividing the transmission range of the FFD node into a border area and a core area by using node density; Calculating a maximum angle and a minimum angle between nodes of the border area; A fourth step of comparing an maximum angle and a minimum angle with a lower bound to determine an algorithm coverage; A fifth step of reconfiguring the border area and the core area of the FFD node; And a sixth step of selecting a node whose state is to be changed to FFDState among the nodes of the reconstructed border area.

802.15.4, LR-WPAN, Wireless Sensor Networks, Topology, Non-Beacon Mode, Control

Description

Energy-Efficient Topology Control Method based on Location Awareness for Wireless Sensor Networks}

The present invention relates to an energy-efficient topology control method for an IEEE 802.15.4 based wireless sensor network. More particularly, the present invention relates to a method for controlling the number of nodes actually linked by finding overlapping ranges in a transmission range of a node. The present invention relates to a location-based power control method for a wireless sensor network that minimizes interference.

The Wireless Sensor Network, which consists of a number of devices with limited energy and resources, has become possible to construct low-cost sensor networks with recent advances in wireless communication technology.

In general, wireless sensor networks can be used in a variety of applications, including location tracking, home monitoring, fire reporting, earthquake detection and reporting, surveillance, health care, mobile conferencing, and home networking.

For example, the IEEE 802.15.4 “Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for Low Rate Wireless Personal Area Networks (LR-WPAN)” refers to Wireless Personal Area Network (WPAN) and Wireless Sensor Network (WSN). As a standard, it enables most of the above mentioned fields at low cost.

The goal of the 802.15.4 standard is to enable low cost, low power communication while maintaining a simple and flexible protocol.

Recently, many studies have been conducted to overcome energy limitations in wireless sensor networks and especially 802.15.4 based networks, and it is still of great interest to minimize the energy consumption of nodes and to increase the operating time of the network. These studies have proposed various methods such as energy-efficient topology control algorithms, wake-up scheduling, energy-efficient routing algorithms, and activity management.

However, because these methods depend on the electrical characteristics of the 802.15.4 RF transmission medium and can only be applied to specific scenarios, the problem of energy efficiency in wireless sensor networks remains a challenge.

In addition, if the nodes are densely packed in the wireless network, the possibility of collision and congestion increases, resulting in increased energy consumption, delayed message delivery, and shorter operating time for the entire network. Therefore, algorithms and protocols are needed to reduce energy consumption. .

Therefore, in the wireless sensor network, there is a need for a new method to reduce the energy consumption of the device to increase the life of the network and to extend the operating time.

SUMMARY OF THE INVENTION The present invention provides a low power topology control method based on location recognition for a wireless sensor network that finds overlapping ranges in a transmission range of a node, thereby reducing the number of nodes actually linked, thereby minimizing interference of neighboring nodes. To provide.

The objects of the present invention are not limited to the above-mentioned objects, and other objects which are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the above object, a location-aware power control method for a wireless sensor network according to an embodiment of the present invention includes a first step of calculating the node density of all the FFD nodes on the network; A second step of dividing the transmission range of the FFD node into a border area and a core area by using node density; Calculating a maximum angle and a minimum angle between nodes of the border area; A fourth step of comparing an maximum angle and a minimum angle with a lower bound to determine an algorithm coverage; A fifth step of reconfiguring the border area and the core area of the FFD node; And a sixth step of selecting a node whose state is to be changed to FFDState among the nodes of the reconstructed border area.

According to the location-aware low power topology control algorithm for the wireless sensor network of the present invention as described above, not only does it increase energy efficiency in a dense network, but also does not cause additional overhead or energy consumption according to the algorithm. Thus, the energy consumption of the entire network can be reduced.

In addition, since the number of interconnected nodes is smaller than the number of nodes actually present in the network, there are additional advantages such as reducing collisions and congestion to maintain or increase the packet transmission rate of the network.

Specific details of other embodiments are included in the detailed description and the drawings.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the present embodiments merely make the disclosure of the present invention complete, and are common in the art to which the present invention pertains. It is provided to inform those skilled in the art to the fullest extent of the invention, the invention being defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

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

In the IEEE 802.15.4 standard, specifications of the physical layer and the medium access control (MAC) layer are defined. The physical layer uses methods such as operation management of the transmission medium, energy verification of the PAN, link health verification, and clear channel assessment (CCA) to improve energy efficiency.

The MAC protocol of IEEE 802.15.4 can operate in beacon mode or non-beacon mode. At this time, the non-beacon mode uses the unslotted CSMA-CA, the device can transmit data to the coordinator at any time.

According to IEEE 802.15.4, device types participating in a network include a full function device (FFD) and a reduced function device (RFD).

Here, the FFD may operate in three modes: a PAN coordinator, a coordinator, or a device.

Also, FFDs can exchange messages with both RFDs and FFDs, while RFDs can only exchange messages with FFDs. RFDs are designed for simple applications such as light switches, eliminating the need to transmit large amounts of data. You can exchange packets with only one FFD node at a time, allowing you to operate on a network using less resources and less memory.

All devices operating in a PAN have a 64-bit address (MAC address) for direct communication with all other devices. When a device joins a PAN, it is assigned a 16-bit address (network address) from the PAN coordinator, which is then used instead of the 64-bit address.

According to the needs of the application layer, the 802.15.4 LR-WPAN operates in two topologies, a star topology and a mesh topology.

1 is an exemplary diagram illustrating a topology of 802.15.4.

First, referring to the star topology of FIG. 1 (a), first, one FFD is operated, and then a PAN coordinator generates a network. All star topologies operate independently of the other star topologies currently in operation. Therefore, such a star topology can be distinguished using a PAN ID that is not currently used by other coordinators even if they are in the same transmission range.

Once the PAN ID is selected, the PAN coordinator can join other devices to its network.

Secondly, FIG. 1B is a peer-to-peer topology such as a mesh topology, which is more complicated than a star topology. This peer-to-peer topology can be used for applications such as industrial control and monitoring using wireless sensor networks.

In a peer-to-peer topology each device can communicate with other devices within its transmission range. One of those devices will act as the PAN coordinator for the entire network.

FIG. 1C is a cluster tree network illustrating an example of using a peer-to-peer topology. Cluster tree networks are a special case of a peer-to-peer topology where most nodes are FFD nodes.

At this time, since the RFD node cannot have other nodes as child nodes, the RFD node is connected to the cluster tree as an end device.

On the other hand, every FFD node can operate as a coordinator, and the coordinator can provide synchronization services to other devices or coordinators. Among them, one coordinator having more energy and resources than any other device in the PAN becomes a PAN coordinator that manages the entire PAN.

In the 802.15.4 standard, data transmission can be defined as three types, first of all, a type of transmission from a device to a coordinator, a second type of transmission from a coordinator to a device, and finally a type of transmission between two devices. Can be.

In star topologies, data is only transferred between the coordinator and the device, so only the first and second types are used, whereas in peer-to-peer topologies, all three types are available because messages can be sent between any node in the network. Do.

In addition, the algorithm for each transmission type may vary depending on whether the network is in beacon mode or non-beacon mode. If the network requires synchronization or supports low-latency, it may operate in beacon mode, otherwise it may operate in non-beacon mode.

2 is a sequence diagram illustrating data transmission in a coordinator.

First, when the device needs to transmit data to the coordinator in the beacon mode, the device first waits until it receives a beacon from the coordinator.

Once the device receives the beacon, it synchronizes with the coordinator according to the superframe structure, and during the active period of the superframe, the device transmits data to the coordinator using the slotted CSMA-CA. At this time, the coordinator may notify the device that the data has been successfully received by sending an ACK.

On the other hand, when the device attempts to transmit data in the non-beacon mode, the device may transmit data directly to the coordinator using an unslotted CSMA-CA algorithm. The coordinator then informs of successful data reception by sending an ACK. This sequence diagram is shown in Fig. 2B.

For example, when a coordinator wants to transmit data to a device in a beacon mode network, the coordinator transmits a beacon to inform the device that there is data to transmit.

Then, the device receives a beacon from the coordinator through the network. If the data is waiting, the device sends a MAC command frame requesting data to the coordinator using the slotted CSMA-CA.

The coordinator receiving the MAC command frame requesting the data indicates that the reception was successful by sending an ACK, and then waiting data may be transmitted using the slotted CSMA-CA or immediately after receiving the ACK.

3 is a sequence diagram illustrating a process of transmitting data to a coordinator.

3 (a) shows a data transmission process in a beacon mode. Referring to this, the device may transmit an ACK to the coordinator to indicate that data has been successfully received. Also, when the data transmission is completed, the message of the beacon is completed. You can delete queued messages from the waiting list.

On the other hand, Figure 3 (b) shows a data transmission process in the non-beacon mode.

As shown in FIG. 3B, a location-aware low power topology control algorithm for a wireless sensor network according to an embodiment of the present invention may be used by a coordinator to transmit data to a device in a non-beacon mode network. The coordinator stores the data until the device requests it, and then the device sends a MAC command frame requesting data using the unslotted CSMA-CA, and the coordinator sends an ACK to request the data. Notify the device that it has arrived.

If there is data to be sent to the coordinator, the coordinator transmits the data to the device using an unslotted CSMA-CA. If there is no data to be sent, the coordinator receives the data request frame and then includes the fact in the ACK packet. Notifies or notifies by sending a packet with the payload field set to zero.

In addition, when the coordinator requests the ACK, the device may inform the successful reception of data by sending an ACK.

Every node in a peer-to-peer network can communicate with all other nodes in the transport area. In order to do this effectively, nodes that want to communicate need to continuously receive messages or synchronize with other nodes. In the former case, the node can only transmit data using unslotted CSMA-CA, and in the latter case, another method is needed to perform synchronization.

A location-aware low power topology control algorithm (hereinafter, referred to as DRpi algorithm) for a wireless sensor network according to an embodiment of the present invention is a wake-up algorithm for reducing the number of coordinators operating at the same time.

In other words, the DualRing parent initiated (DRpi) algorithm can reduce the overlapping range while preserving the transmission range of the entire network. Here, the overlapping range indicates a range which has already been transmitted by the transmission range of two or more nodes.

4 is an exemplary diagram illustrating a network in which a plurality of nodes are configured in overlapping ranges.

As shown in Fig. 4, nodes 2, 3, and 4 are located within the transmission range of node 1, and nodes 5 and 6 are located within the transmission range of node 2 or node 3. However, the transmission range of node 4 is already included in the range that can be transmitted by nodes 1, 2, and 3. All nodes within the transmission range of node 4 can send and receive messages to or from node 2 or node 3 directly.

The DRpi algorithm according to an embodiment of the present invention focuses on an 802.15.4 peer-to-peer topology network operating in non-beacon mode.

For example, all nodes in a network know their location information through trilateration, triangulation, and fingerprinting, and do not waste or consume resources to calculate their location. Also, it is assumed that there is no error with incorrect location information and so on, and for the performance evaluation of the DRpi algorithm, a network having an ideal transmission range that all nodes can represent as a perfect circle is used.

5 is an exemplary diagram illustrating a node applied to a core and a border area.

As shown in FIG. 5, the DRpi algorithm according to an embodiment of the present invention may divide a transmission range of an FFD node into a border region and a core region according to node density.

Here, the core region is a circle smaller than the transmission range of the node and represents an area divided by a radius calculated according to the density, and the border region represents an area surrounded by the transmission range of the FFD node and the radius of the core area. The DRpi algorithm according to an embodiment of the present invention is to be applied between nodes closest to each other located in the border region of one node.

The DRpi algorithm according to an embodiment of the present invention adds a new frame control type to the 802.15.4 MAC layer to transmit control messages and HELLO messages.

Here, the control message indicates a message requesting status update and current status information of the FFD nodes. In contrast, the HELLO message is optional and does not need to be added if overhearing is possible.

These two new frames can use the MAC header defined in the 802.15.4 standard just like any other control message. At this time, it may be preferable to extend the location information.

Since the DRpi algorithm is an 802.15.4 MAC layer, it is independent of the routing algorithm used above the MAC layer. In other words, by using an energy-efficient routing algorithm, the performance of the network can be improved independently of the DRpi algorithm in terms of energy efficiency.

The 802.15.4 MAC has a neighbor table for special purposes. All FFD nodes in the network have 1-hop information, their neighbor ID (network address or MAC address), their location information, their status information (if they are FFD nodes), their relationships (parent, child, neighbors). Node) and device type (FFD or RFD) in the neighbor table, which is used to calculate the DRpi algorithm.

In the DRpi algorithm according to an embodiment of the present invention, the FFD node may maintain one of FFDState and RFDState.

6 shows a state diagram of an FFD node. An FFD node, which is an FFDState, can operate like an FFD node defined in the 802.15.4 standard, and an FFD node, which is an RFDState, can operate like an RFD node defined in the 802.15.4 standard. .

The initial state of all FFD nodes except the PAN coordinator is RFDState. RFDState changes to FFDState during the sleep backoff timer interval or upon receipt of a StateUpdate command frame from the coordinator. The FFDState may be changed to RFDState by receiving a StateUpdate command frame from the PAN coordinator after there is no child node of the node or after the wakeup backoff timer interval.

7 is a sequence diagram illustrating the change of an FFD node from RFDState to FFDState.

Referring to FIG. 7, when the FFD node is an RFDState, the node transmits an FFDState.req message to the coordinator in a sleep backoff timer interval. The coordinator sends back an ACK and checks the current state of the node that sent FFDState.req in the neighbor table. The coordinator sends FFDState.upd message to the node that is RFDState with state information. The RFDState node receives the FFDState.upd message, sends back an ACK, and checks whether a state change has occurred. If the RFDState node changes to FFDState, it is possible for other nodes to join the network and do not send FFDState.req messages again during the wakeup backoff timer interval.

8 is a sequence diagram showing the change of the FFD node from FFDState to RFDState.

Referring to FIG. 8, when the FFD node is an FFDState, the node transmits an FFDState.req message to the wakeup backoff timer interval. The coordinator sends an ACK again and checks the state of the node requesting FFDState.req from the neighbor table. After that, the coordinator sends the state information obtained from the neighbor table of the FFD node in the FFDState.upd message. The FFD node receives the FFDState.upd message, sends back an ACK, and the coordinator checks to see if the node's state has changed. If the node changes to RFDState, the node acts as an RFD node and does not send back an FFDState.req message during the sleep backoff timer interval.

The DRpi algorithm according to an embodiment of the present invention is applicable to all FFD nodes that are FFDStates in a network, and may also be composed of six steps to be described later.

First, step 1 calculates node density within the transmission range. To do this, all FFD nodes in the network use HELLO messages or overhearing to calculate node density. Nodes also provide their location information to the network. At this time, the delay for the topology configuration using the HELLO message can be reduced, while the overhead due to the control message can be increased.

9 is a diagram showing that the two stages of the DRpi algorithm are divided by width and radius.

Referring to FIG. 9, the DRpi algorithm according to an embodiment of the present invention may represent two cases of division by width and division by radius. In other words, the second step of the DRpi algorithm is to divide the transmission range of the FFD node into a border region and a core region.

At this time, which division method is selected is determined according to the DRpi algorithm threshold value of the first step. If the density of nodes is greater than the threshold value, the core region will be calculated according to the width as shown in Fig. 9 (a), otherwise it will be calculated according to the radius as shown in Fig. 9 (b). .

FIG. 10 is an exemplary diagram illustrating a maximum angle α _max and a minimum angle α _min between border region nodes.

Step 3 calculates the maximum angle (α _max ) and the minimum angle (α _max ) between nodes in the border area. At this time, the DRpi algorithm preferably has location information of each node. The maximum angle α _max and the minimum angle α _min can be calculated using a vector algebra.

Step 4 is to calculate the lower bound (α _LB ).

Lower Bound (α _LB ) is a value that is calculated between nodes to apply the DRpi algorithm of the border area and is a criterion for determining whether to apply it or not. If α _min ≧ α _{LB, the} DRpi algorithm will not be applied among the nodes of the PAN, and all nodes will maintain FFDState. This means that the density of PAN is low. In addition, if α _min <α _LB <α _max , the DRpi algorithm will be applied only in certain zones, and if α _max ≤α _LB , the DRpi algorithm will be applied throughout the PAN.

11 is an exemplary diagram illustrating a method of calculating the DRpi algorithm Lower Bound (α _LB ), and the following Equation 1 is for calculating this value.

[Equation 1]

In the above equation, r is a radius value of the transmission area, and d ₁₂ and d ₁₃ are distances between the coordinator (node 1) and nodes 2 and 3 in the two border areas, respectively.

Lower Bound (α _LB ) is the maximum applicable angle of the algorithm of the node to be applied to the border area. Referring to FIG. When A is the point where the boundary of the range meets each other, the angle formed by the nodes 2 and 3 becomes α _LB.

Step 5 is to divide the transmission range of FFD node into border area and core area (second step).

This step is performed on a regular basis, because node density can continue to change due to energy depletion of the nodes. In this step, the radius of the core region is calculated based on the maximum angle α _max already calculated between the nodes of the border region.

[Formula 2] to [Formula 5] show the formulas for this process.

[Equation 2]

[Equation 3]

[Equation 4]

[Equation 5]

Where r is the radius of the transmission zone, d _ij is the distance between node i and j, and Δr is the radius of the core zone. At this stage, the scope of the core area is the size at which nodes with no additional transmission range are located. In other words, the transmission range of a node located in the core area is a range that can already be transmitted by other nodes.

Step 6 is to select the FFD node state.

13 shows a process of selecting a node to be changed to FFDState. As shown in (a) of FIG. 13, after the new core region radius is calculated, all FFD nodes within the transmission range stay in the RFDState from the coordinator. And among the nodes in the border area, the node whose state will be changed to FFDState is selected.

Node 1 is a coordinator to which the DRpi algorithm can be applied. First, FFDState node 2 is selected as FFDState. It will then move clockwise by the maximum angle α _max to find the next FFDState coordinator and draw a straight line as shown. Node 3 closest to the line segment becomes the new FFDState FFD node. This same rule would apply to nodes 4 and 6. However, there is more than one node between node 5 and node 6. To determine the status of this node, additional checks are needed at nodes 1, 4, 5, and 6 for the transmission range. Equation 6 below is for this test.

[Equation 6]

In Equation 6, Ai (i = 1, 2, 3, 4, 5, 6) represents a transmission range for node i. If this equation holds, node 5 will be FFDState from coordinator (node 1), otherwise it will be RFDState.

In order to show the performance of the DRpi algorithm according to an embodiment of the present invention, the conventional standard 802.15.4 MAC algorithm and the DRpi algorithm are compared through simulation. The simulation was carried out in NS-2 2.31, and the values used are shown in Table 1.

TABLE 1

 Parameter  Value Simulation Area, m ²  50x50, 60x60, 70x70, 80x80, 90x90, 100x100  Average Node Degree (with respect to Simulation Area)  45, 32.5, 25, 19.5, 15.5, 13  Simulation Time, s  1300  Traffic Type  Poisson  Traffic Rate, pps  0.2, 0.5, 1, 5, 10  Packet Size, byte  90

Since the simulation of the DRpi algorithm according to the embodiment of the present invention is performed based on the standard 802.15.4 MAC algorithm, the standard 802.15.4 MAC protocol and the DRpi algorithm can be compared.

At this time, AODV routing protocol was used as a routing protocol, and 221 nodes (210 FFD nodes, 10 RFD nodes, and 1 PAN coordinator) were used to evaluate performance by varying the number of nodes. The constant bit rate (CBR) traffic, which is commonly used in simulations, was too fixed in wireless sensor networks, not mobile, so that all of the simulations used Poisson traffic, which was performed 20 times for each simulation. The PAN coordinator is located at the center of the simulation area and randomly placed the source node and the destination node among 10 RFD nodes so that all packets pass through other nodes before arriving at the destination node.

The DRpi algorithm compares the following values for performance evaluation with standard 802.15.4 MAC protocol.

 Remaining Energy: The sum of the remaining energy of all nodes in the network at any given time.

Number of surviving nodes: Number of nodes with energy remaining at any given time

-Packet transmission rate: the number of data packets transmitted to the destination node / the number of data packets to be transmitted to the destination node

14 is a graph showing the remaining energy of the entire network.

This compares the energy remaining throughout the network with the standard 802.15.4 MAC and DRpi algorithms. It also compares the energy remaining in both the 802.15.4 standard and the DRpi algorithm for networks with different densities in the same algorithm.

Referring to FIG. 14, it can be seen that the DRpi algorithm reduces energy consumption. In a standard 802.15.4 MAC, every node consumes all of its energy in about 600 seconds, but increases to about 1100 seconds in the DRpi algorithm. In the figure above, there is a slight change in the curve curve of the DRpi algorithm around 600 seconds due to the reconfiguration of the network topology. The nodes already linked at this time consume all the energy, but the other nodes relink to form a network.

15 is a graph showing the number of nodes with energy remaining.

Referring to FIG. 15, it can be seen that more than 80% of the nodes can maintain energy during the network operation time using the DRpi algorithm than the standard 802.15.4 MAC protocol.

In addition, the graph shows that the topology is reconfigured in about 590 seconds and 1050 seconds. As the density of nodes increases, the number of surviving nodes increases. The size of the network is not important because the performance of this algorithm does not change with the size of the network but with the density of the nodes.

16 and 17 are graphs illustrating packet transmission rates of the DRpi algorithm and the standard 802.15.4 algorithm for different network densities and respective traffic loads.

As shown in Figure 16 and 17, the DRpi algorithm according to an embodiment of the present invention can also increase the packet transmission rate.

Such a low power topology control algorithm (DRpi algorithm) based on location recognition for a wireless sensor network according to an embodiment of the present invention calculates the number of nodes within the transmission range of one node, and transmits the transmission range to the border region. It is possible to reduce the number of nodes connected to the conventional network by identifying nodes overlapping among the nodes in the border area by dividing them into the core area and selecting nodes to be connected to each other using them.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention belongs may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. You will understand that. Therefore, the embodiments described above are to be understood in all respects as illustrative and not restrictive.

1 is an exemplary diagram illustrating a topology of 802.15.4.

2 is a sequence diagram illustrating data transmission in the coordinator of the DRpi algorithm according to an embodiment of the present invention.

3 is a sequence diagram illustrating a process of transmitting data to a coordinator.

4 is an exemplary diagram illustrating a network in which a plurality of nodes are configured in overlapping ranges.

5 is an exemplary diagram illustrating a node applied to a core and a border area.

6 is a diagram illustrating a state of an FFD node.

7 is a sequence diagram illustrating a change of an FFD node from RFDstate to FFDState.

8 is a sequence diagram showing the change of the FFD node from FFDState to RFDState.

9 is a diagram showing that the two stages of the DRpi algorithm are divided by width and radius.

FIG. 10 is an exemplary diagram illustrating a maximum angle α _max and a minimum angle α _min between border region nodes.

11 is an exemplary diagram illustrating a method of calculating a DRpi algorithm lower bound.

12 is an exemplary view illustrating a radius calculation method of a DRpi core region.

13 is an exemplary diagram illustrating a state selection process of an FFD node.

14 is a graph showing the remaining energy of the entire network.

15 is a graph showing the number of nodes with energy remaining.

16 is a graph showing packet transmission rates of the DRpi algorithm and the standard 802.15.4 algorithm in different traffic loads.

17 is a graph showing packet transmission rates of DRpi algorithm and standard 802.15.4 algorithm of different network density.

Claims (8)

Calculating a node density of all FFD nodes on the network; A second step of dividing a transmission range of an FFD node into a border area and a core area by using the node density; Calculating a maximum angle and a minimum angle between nodes of the border area; A fourth step of determining an application range of the algorithm by comparing the maximum angle and the minimum angle with a lower bound; A fifth step of reconfiguring a border region and a core region of the FFD node; And And a sixth step of selecting a node whose state is to be changed to FFDState among the nodes of the reconstructed border area. The method of claim 1, The node density is calculated based on the node's own location information and the HELLO message or the OVERHEARING provided from the node. The method of claim 1, And the border area and the core area are divided into a division method by a width and a division method by a radius. The method of claim 3, wherein The core region is calculated by the division method by the area if the node density is greater than the threshold value, If the node density is smaller than the threshold value, the location-based power control method for a wireless sensor network, characterized in that calculated by the division method by the radius. The method of claim 1, The maximum angle and the minimum angle is calculated using a vector (algebra) position recognition based power control method for a wireless sensor network. The method of claim 1, Wherein the lower bound satisfies Equation 1 below. [Equation 1]

(Where r is the radius of the transmission area and d _ij is the distance between node i and node j (i = 1,2,3,…, j = 1,2,3,…)) The method of claim 1, The radius of the core region to be reconfigured in the fifth step satisfies the following [Equation 2] to [Equation 5]. [Equation 2]

&Quot; (3) &quot;

[Equation 4]

[Equation 5]

(Where r is the radius of the transmission region, d _ij is the distance between nodes i and j (i = 1,2,3,…, j = 1,2,3,…), Δr is the radius of the core region) delete

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