KR101309742B1 - System and method for energy management for sensor network - Google Patents

Abstract

The present invention relates to a method and system for energy management in a sensor network environment.

An energy management method in a sensor network environment according to an embodiment of the present invention may include: connecting a link so that a closed loop is not formed between the nodes in a predetermined area in which a plurality of nodes are arbitrarily distributed; Checking the energy remaining amount of the node according to energy consumption due to data transmission at each link connection update period; And updating the link connection formed between the nodes based on the energy remaining of the nodes to have a minimum cost extension tree based on the node having the smallest remaining energy.

PEGASIS, PEDAP, PEDAP-PA, LEACH

Description

Energy management method and system in sensor network environment {SYSTEM AND METHOD FOR ENERGY MANAGEMENT FOR SENSOR NETWORK}

1 is a view showing an energy management system to which an energy management method according to an embodiment of the present invention is applied;

2 is a view showing a system for explaining an energy management method according to a first embodiment of the present invention;

3 to 7 is a view showing a link connection according to the energy management method according to a first embodiment of the present invention,

8 is a diagram illustrating a system for explaining an energy management method according to a second embodiment of the present invention;

9 to 13 is a view showing a link connection according to the energy management method according to a second embodiment of the present invention,

14 is a graph comparing a lifespan between a system to which an energy management method is applied according to an embodiment of the present invention and a conventional system;

FIG. 15 is a graph illustrating a lifespan of a system to which an energy management method is applied according to a change of a link connection update cycle. FIG.

The present invention relates to a method and a system for managing energy in a sensor network environment, and to a method for managing energy in a sensor network environment that can uniformly use energy of each sensor in a sensor network connecting sensors distributed in a certain area by a link. It is about the system.

A sensor network is a technology that can be used to accurately identify characteristics of a certain area, for example, temperature and location of an earthquake, and remote meter reading. A plurality of sensors are distributed in a certain area, Information is collected and analyzed to extract desired data.

In the case of using the sensor as a limited resource, for example, as a battery, it is necessary to distribute the sensors in consideration of the energy efficiency of the sensors or connect the distributed sensors. Although placing a specific sensor in a certain area to be uniform and having a certain distance is an average of the above-described energy efficiency, in practice, in the process of applying the sensors, it is impossible to keep all the distances between the sensors constant. Do. In addition, in order to transfer information collected by a plurality of sensors to an information collecting device, for example, a base station (BS), a method of transmitting information to the other sensors to a specific sensor in consideration of energy efficiency is efficient. Various methods have been proposed for energy optimization according to the above-described characteristics of sensor distribution and information transfer between sensors.

In more detail, the conventional sensor link connection scheme for energy optimization configures the link connection by reflecting only the initial energy of the initially arranged sensors, and operates until the energy of the specific sensors of the sensor network is exhausted. That is, in the conventional sensor link connection method, in the sensors that use energy differently according to distance, when energy of specific sensors is consumed faster than other sensors, the link connection of the sensor network is terminated. Except for the new configuration. In this case, except for the dead sensor, the newly formed link connection may have a link having a longer distance than the existing link connection, and as a result, the lifespan of the sensors may be reduced at a faster rate. In addition, in the conventional sensor link connection method, due to the dead sensors, there is a disadvantage that the reliability of the data is sharply lowered.

Therefore, the present invention was devised to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a method and system for energy management in a sensor network environment that enables the energy of sensors to be used evenly.

Energy management method in a sensor network environment according to an embodiment of the present invention for achieving the above object, in a region where a plurality of nodes are randomly distributed, connecting the link so that the closed loop is not formed between the nodes step; Checking the energy remaining amount of the node according to energy consumption due to data transmission at each link connection update period; And updating the link connection formed between the nodes based on the energy remaining of the nodes to have a minimum cost extension tree based on the node having the smallest remaining energy.

An energy management system in a sensor network environment according to an embodiment of the present invention for achieving the above objects is a link connection update period and link link so that a closed loop is not formed in a predetermined area in which a plurality of nodes are arbitrarily distributed. Nodes for updating the connected link every time; And collecting data from the nodes, inspecting the remaining amount of energy of the node according to energy consumption due to data transmission at each link connection update period, and based on the inspected remaining amount of energy, energy of the link connection formed between the nodes. And a base station that calculates to have a minimum cost extension tree based on the node having the smallest remaining amount, and delivers the calculated value to the node.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, only parts necessary for understanding the operation according to the embodiment of the present invention will be described, and the description of other parts will be omitted so as not to disturb the gist of the present invention.

The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and the inventor is not limited to the meaning of the terms in order to describe his invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention. Therefore, the embodiments described in the present specification and the configurations shown in the drawings are merely the most preferred embodiments of the present invention, and not all of the technical ideas of the present invention are described. Therefore, It is to be understood that equivalents and modifications are possible.

The sensor network energy management method and system described in the present invention includes a plurality of sensor nodes distributed for collecting a certain area of information, and energy in a sensor network area connected by a link between sensor nodes for information transfer between the sensor nodes. It relates to a management method and system. In the sensor network of the present invention, various sensors such as seismic measurement sensors, temperature sensors, humidity sensors, microbial measurement sensors, CBR sensors, and the like may be applied.

In addition, the protocol to which the energy management method and system of the present invention may be applied may be various protocols such as LEACH, PEGASIS, PEDAP, and PEDAP-PA.

LEACH is a routing algorithm with the first hierarchical structure. The sensor area is divided into clusters and the cluster header is designated as the responsible node to communicate with the BS. Among the sensor nodes, the responsible node is determined in a probabilistic manner. When the responsible node is determined, the selected responsible nodes designate neighboring sensor nodes close to themselves as members of their cluster.

PEGASIS connects all the sensor nodes in a chain form, selects only one node in charge, and the node takes place sequentially according to the chain sequence formed by the BS. In the case of PEGASIS, if the sensor node is depleted during operation, the routing path is broken, so the routing path is restored by connecting two neighboring sensor nodes that can communicate directly with the depleted sensor node in the chain.

PEDAP selects the sensor node closest to the BS as the responsible node, and the routing path uses the spanning tree that requires the least energy when transmitting, so the routing path length and average transmission energy are the lowest compared to other routing algorithms. PEDAP proposed PEDAP-PA, a variation of PEDAP, to maintain the remaining energy of sensor nodes at a similar level. In this case, we changed the additional amount of energy to consider when constructing the spanning tree.

1 is a diagram illustrating a network system to which a link connection according to an embodiment of the present invention is applied.

Prior to the description, the sensor network system of the present invention has a power source in which a sensor node is not recharged, and a base station (BS) is assumed to assume a general environment of a sensor network having infinite power source. It is assumed that a specific node in charge periodically receives and processes data of other sensor nodes and transmits the data to the BS. In addition, it is assumed that the BS and the sensor node do not move, and all sensor nodes determine transmission energy according to link length. In this environment, the BS periodically checks the remaining energy of the sensor nodes in the sensor network, and updates the link connection between the sensor nodes distributed in the sensor network at regular intervals to adjust the energy usage of each sensor node. In this case, the dead time of the entire sensor is induced to be uniform.

Referring to FIG. 1, a network system according to an exemplary embodiment of the present invention has a distributed sensor node 10 having a link connection formed by preferentially connecting a link having a plurality of closed loops in a predetermined area and having a cost not to form a closed loop. The sensor network 50 formed by the distribution of the sensor nodes 10 and the information collected by the sensor network 50 are received from a specific sensor node, and the remaining energy of the sensor nodes 10 and the sensor node 10 are received. It includes a base station (BS) 30 for periodically updating the link connection in consideration of the transmission energy according to the distance between them.

The sensor node 10 receives a sensor node 10 that collects information and a responsible node 10a that collects information and receives information collected from other sensor nodes 10 and delivers the information to the BS 30. It is configured to include. The link connection of the sensor nodes 10 forms a link connection by applying a method in which each sensor node does not form a closed loop and uses a minimum spanning tree.

The sensor network 50 defines an area in which the sensor nodes 10 connected to the link are distributed. The sensor network 50 transmits the information collected by the plurality of connected sensor nodes 10 to the external BS 30.

The BS 30 receives information collected by each sensor node 10 included in the sensor network 50 and analyzes the information. The BS 30 connects a link with the responsible node 10a among the sensor nodes 10 included in the sensor network 50 in consideration of energy efficiency, and collects information from the connected responsible node 10a. In this case, the responsible node 10a receives information from other sensor nodes connected to the responsible node 10a through a link, compresses the information, and delivers the information to the BS 30. On the other hand, the BS 30 determines a predetermined period, for example, a time for consuming 10% of the sensor node having the lowest energy remaining among all the sensor nodes 10 as one period, and the sensor node 10 according to the corresponding period. Update the link connection according to the remaining energy. At this time, the BS 30 receives the information on the remaining energy from the sensor nodes 10, performs a calculation necessary for linking the sensor nodes 10 based on the information on the remaining energy, and calculated By passing the link connection to each sensor node 10, the link connection can be updated.

In the above, the configuration of the network system according to an embodiment of the present invention has been described. Hereinafter, an energy management method of the sensor nodes 10 constituting the sensor network 50 of the network system according to the embodiment of the present invention will be described.

2 to 7 are diagrams illustrating an example for explaining an energy management method in a sensor network according to the first embodiment of the present invention.

Prior to the description, in the energy management method according to the first embodiment of the present invention, it is assumed that the initial energy of each sensor node is uniform, and the energy consumption is assumed to be consumed in proportion to the transmission energy. In addition, it is assumed that the maximum link tolerance of each sensor node is set to 2, and each sensor node transmits data through a link that requires the least cost. Meanwhile, in the energy management method according to the first embodiment of the present invention, the data transmission period of each sensor node and the link connection update period for updating the entire link connection are similarly described, but the present invention is not limited thereto. . That is, the energy management method according to the first embodiment of the present invention is preferably set to 1/5 ~ 1/15 of the lifetime of all sensor nodes, regardless of the data transmission cycle, the information on the life of the entire sensor network If present, it is preferable to set the link connection update period as a time length corresponding to 1/10 of the total sensor network life. This link connection update cycle is difficult to distribute the remaining energy between sensor nodes if the link connection update is repeated only within about 5 times during the lifetime of the sensor network. Since the additional energy required for resetting becomes too large, it becomes undesirable, and therefore it is preferable to set it under the conditions as described above. In addition, in the energy management method of the present invention, the lengths of the link connection update periods may not all have the same length, but may be similarly set and applied within a predetermined range experimentally.

In addition, in the energy management method according to an embodiment of the present invention, it is preferable that the BS 30 capable of using infinite resources is assumed to perform calculation for link connection of each sensor node.

Referring to FIG. 2, the energy management method according to an embodiment of the present invention includes a BS 30 and four sensor nodes 1, 2, 3, and 4, and sensor nodes 1, 2, and 3. 4 denotes the number of the sensor node, the solid line between the sensor node 1, 2, 3, 4 or between BS 30 and the sensor node 1, 2, 3, 4 is a link. The numbers listed above indicate the transmission energy used to transmit data, and the numbers listed near each sensor node represent the remaining energy of the sensor node since energy was consumed from the previous energy remaining. For example, in the energy management method of the present invention, the transmission energy between the BS 30 and the first sensor node 1 is 10, the transmission energy between the BS 30 and the second sensor node 2 is 13, and the BS 30 ) And the transmission energy between the third sensor node 3 is 14, the transmission energy between the first sensor node 1 and the second sensor node 2 is 5, the first sensor node 1 and the third sensor node 3 It is assumed that the transmission energy between) is formed as In addition, it is assumed that the energy remaining amount of each sensor node (1, 2, 3, 4) has all 100 initially.

In the sensor network as shown in FIG. 2, the energy management method of the present invention has a transmission energy between the BS 30 and the first sensor node 1 as shown in FIG. 3. Since it is formed lower than the third sensor node 3, it is preferable that the first sensor node 1 is selected as the responsible node 10a, and each of the other sensor nodes does not form a closed loop. It is preferably formed to constitute a Minimum Spanning Tree). Accordingly, in the energy management method of the present invention, the second sensor node 2 and the third sensor node 3 transmit data to the fourth sensor node 4, respectively, and the fourth sensor node 4 is in charge of the node. Data is transmitted to the first sensor node 1, which is 10a, and the first sensor node 1 compresses the collected data and transmits the data to the BS 30. On the other hand, each of the sensor nodes (1, 2, 3, 4) is a state in which the energy remaining is reduced by a certain amount as shown for reasons such as data transmission.

Next, as shown in FIG. 4, in the energy management method of the present invention, the second sensor node 2 having the highest energy remaining and relatively low transmission energy with the BS 30 is determined as the responsible node 10a. Accordingly, the first sensor node 1 is a link connection for transmitting data to the second sensor node 2, and the third sensor node 3 is a link connection for transmitting data to the fourth sensor node 4. And the fourth sensor node 4 form a link connection for transmitting data to the second sensor node 2.

Next, when the link connection update period is reached, the BS 30 collects information on energy remaining from each sensor node 1, 2, 3, and 4, and the collected energy remaining information is shown in FIG. When distributed as described above, the third sensor node 3 having a relatively high energy remaining and having high transmission energy with the BS 30 is designated as the responsible node 10a, and a link connection update as shown in FIG. In order to perform, the sensor node 1, 2, 3, and 4 transmits the information related to the link connection update. That is, in the energy management method of the present invention shown in FIG. 5, the third sensor node 3 is configured as the responsible node 10a, and the first sensor node 1 and the second sensor node 2 are each a fourth one. Link connection for transmitting data to the sensor node 4, the fourth sensor node 4 forms a link connection for transmitting data to the third sensor node (3).

Subsequently, when the next link connection update period is reached, the BS 30 collects energy remaining amount information distributed to each sensor node 1, 2, 3, and 4 from the sensor nodes, and then, based on this, FIG. Control to form a link connection as shown. In detail, in the energy management method of the present invention illustrated in FIG. 6, the fourth sensor node 4 is designated as the responsible node 10a, and the first sensor node 1 is connected to the third sensor node 3. Link connection for transmitting data, third sensor node (3) is the link connection for transmitting data to the fourth sensor node (4) and second sensor node (2) for transmitting data to the fourth sensor node (4) Form a link connection.

Next, when the next link connection update period is reached, the energy management method of the present invention forms a link connection in which the first sensor node 1 is the responsible node 10a, as shown in FIG. The sensor node 2 is a link connection for transmitting data to the fourth sensor node 4, the fourth sensor node 4 is a link connection for transmitting data to the third sensor node 3, the third sensor node 3 ) Forms a link connection that transmits data to the first sensor node 1. In this link connection configuration, the first sensor node 1 has a link connection different from the link connection designated as the responsible node 10a.

As described above, the energy management method according to the first embodiment of the present invention compares the remaining energy of each sensor node (1, 2, 3, 4) with the transmission energy, so that the BS 30 By configuring the link connection with the responsible node 10a in accordance with the link connection update period that is specified, the entire sensor node is used with a relatively uniform energy use distribution.

8 is a view showing an energy management method according to a second embodiment of the present invention.

Referring to FIG. 8, the energy management method according to the second embodiment of the present invention transmits data to a BS 30, a responsible node 10a transmitting data to the BS 30, and a responsible node 10a. It is formed of a plurality of sensor nodes 1, 2, 3, 4, 5, 6. In FIG. 8, the solid line represents the link connection between each sensor node 1, 2, 3, 4, 5, 6 and between BS 30 and the sensor node 1, 2, 3, 4, 5, 6. The numbers above indicate the transmission energy, and the numbers described in the sensor nodes 1, 2, 3, 4, 5, and 6 respectively indicate the index numbers of the sensor nodes 1, 2, 3, 4, 5, and 6, respectively.

Hereinafter, an initial chain forming method and chain update of the present invention will be described with reference to the drawings.

9 to 11, it is assumed that the first chain forming method in the energy management method of the present invention has a link structure connected by one chain, and the initial chain configuration is preferential on a sensor network in which a plurality of sensor nodes are distributed. Therefore, a link having a minimum cost is formed as a subchain, and when an area in which a link overlaps another link occurs in the subchain, the transmission energy between sensor nodes is minimized, that is, the maximum length that can be formed between sensor nodes. Choose the connection between sensor nodes to minimize.

In detail, as shown in FIG. 9, in the energy management method according to the second embodiment of the present invention, the initial chain formation first forms a subchain by first connecting a link having a minimum transmission energy cost. That is, the fourth sensor node 4 and the sixth sensor node 6 form a link, and the fourth sensor node 4 and the third sensor node 3 form a link. Next, as shown in FIG. 10, in the initial chain formation, a link is formed between the third sensor node 3 and the fifth sensor node 5, and the first sensor node 1 and the second sensor node 2 are formed. A link is formed between them. Next, as shown in FIG. 11, a link is formed between the second sensor node 2 and the fifth sensor node 5.

On the other hand, the chain connection structure shown in FIG. 11 is a link connection update cycle designated by the BS 30, for example, a time when 10% of the energy of the sensor node having the lowest energy remaining among the sensor nodes included in the entire sensor network is consumed. After this elapses, energy consumption occurs in accordance with the data transmission, respectively, to have the remaining energy as indicated by the numbers described in the vicinity of the sensor node. In FIG. 11, an initial energy of each sensor node 1, 2, 3, 4, 5, and 6 is assumed to be 100, and energy is consumed according to transmission energy, and consideration of the responsible node 10a is excluded for convenience of description. Let's do it.

After the above-described link connection update period occurs, considering the remaining energy of each sensor node (1, 2, 3, 4, 5, 6), each link connection has a minimum transmission energy of the sensor node having the smallest remaining energy. Update the link connection so that the link with In other words, as shown in FIG. 12, the fifth sensor node 5 preferentially forms a link connection with the third sensor node 3, and the second sensor node 2 is connected to the third sensor node 3. ) And form a link connection.

Next, as shown in FIG. 13, the second sensor node 2 forms a link connection with the first sensor node 1, and the sixth sensor node 6 links with the fourth sensor node 4. The chain is formed to form a chain as a whole.

Through the chain configuration according to the energy management method according to the second embodiment of the present invention, each sensor node forms a chain, while remaining the energy remaining relatively uniform, thereby, the life of the entire sensor network It can be extended and increase the reliability of the data as the sensors are not killed during the life of the sensor network.

Meanwhile, the link connection protocol in which the sensor node of the present invention has a link order and the sensor node has a link order and is configured to have a chain has been described. In each embodiment, a few sensors are provided. Although the node has been described as an example, the optimal link connection according to each link-to-link and link connection update period may be calculated by the BS 30 and transmitted to each sensor node.

14 and 15 are diagrams showing experimentally measuring the effects of the case of applying the energy management method according to an embodiment of the present invention, and the case of applying a different protocol.

14 and 15, the sensor node has an initial energy of 0.25J, and the sensor network assumes that 100 sensor nodes are randomly distributed in a square shape of 50m on one side, and the BS is 125m away from the center point. do. The energy used here is a value obtained by considering only transmission energy.

FIG. 14 shows the number of sensor nodes operating normally in each cycle as a result of performing 10 link connection updates during the life of the sensor network to which LEACH, PEGASIS, PEDAP, PEDAP-PA and the energy management method according to the present invention are applied. Indicated.

As shown in FIG. 14, it can be seen that the sensor nodes have almost similar lifespans, and also by calculating the average lifespan of the sensor nodes according to the present invention, it can be seen that they have an extended life expectancy than all other methods. In other words, the system to which the energy management method according to the present invention is applied maintains the best data quality of the sensor network by reducing the case where the sensor node dies in advance, and at the same time, the sensor network can be operated for the most false.

FIG. 15 shows the calculated life cycles of sensor nodes in units of cycles as a result of performing link connection updates 5, 10 and 15 during the lifetime of the sensor network using the chain algorithm to which the energy management method of the present invention is applied. will be. As shown in the figure, the lifespan becomes more apparent in the 10th cycle than in the 5th cycle, while the 10th and 15th cycles have almost similar life distributions. That is, it can be seen that the link connection update is preferably 10 times in the energy management method to which the present invention is applied. However, as the size of the sensor network grows, the distribution of sensor node life spreads, so the life distribution can be stabilized after 10 or more reconfigurations. However, if substantial energy is required in the actual reconstruction, it may be desirable to limit the number of reconstructions to 10 or less.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and similarities. Therefore, the scope of the present invention should not be limited by the illustrated embodiments, but should be determined by the scope of the appended claims and equivalents thereof.

As described above, according to the energy management method and system in the sensor network environment of the present invention proposed by the present invention, the energy of all the sensor nodes by newly updating the link connection for connecting the sensor nodes distributed in a certain area at regular intervals. By equalizing consumption, it is possible to maximize the life of the sensor network and improve the reliability of data collected from each sensor node.

Claims (14)

In a certain area where a plurality of nodes are randomly distributed, Connecting a link such that a closed loop is not formed between the nodes; Checking the energy remaining amount of the node according to energy consumption due to data transmission at each link connection update period; And And updating a link connection formed between the nodes based on the energy remaining of the nodes to have a minimum cost extension tree based on the node having the smallest remaining energy. The update step The base station calculates the link connection so that the remaining energy of each node is uniformly distributed, delivering the calculation result to each node and the node updating the link connection with the neighboring node according to the calculation result Energy management method in sensor network environment. The method of claim 1, The link connection is And connecting each node to form a minimum cost extension tree between the nodes having a link tolerance degree. The method of claim 1, The link connection is A chain is formed to connect the plurality of nodes by a link, and two end nodes are formed, and a chain is formed by forming a wireless link so that the transmission energy has the minimum new equipment regardless of link connection and non-connection between the nodes. Energy management method in a sensor network environment, characterized in that. The method of claim 3, The link connection is Forming a sub-chain subchain constituting the minimum cost extension tree; And And configuring each node as a chain having a minimum cost extension tree so as not to form a closed loop. The method of claim 1, The link connection update cycle The energy management method of the sensor network environment, characterized in that the time unit takes 10% of the energy of the node with the least energy remaining among the nodes. The method of claim 1, The link connection update period is Energy management method in a sensor network environment, characterized in that having a length equal to 1/5 ~ 1/15 of the life of the sensor network. The method according to claim 6, The link connection update period is And a time period in which the life span of the sensor network is divided into ten equal parts. delete In a certain area where a plurality of nodes are randomly distributed, Nodes that link the links so that a closed loop is not formed and update the linked links every link connection update period; And Collecting data from the nodes, and checks the remaining energy of the node according to the energy consumption due to data transmission for each link connection update period, and based on the inspected remaining energy, the remaining link energy between the link connection formed between the nodes A base station that calculates to have a minimum cost extension tree based on the minimum node and delivers the calculated value to the node; The base station Calculate the link connection so that the energy balance of each node is uniformly distributed and transmit the calculation result to each node, The node is The energy management system in the sensor network environment for updating the link connection with the peripheral node according to the calculation result. 10. The method of claim 9, The link connection update cycle Energy management system in the sensor network environment, characterized in that the time unit takes 10% of the energy of the node with the least energy remaining among the nodes. 10. The method of claim 9, The link connection update period is Energy management system in a sensor network environment, characterized in that having a length equal to 1/5 ~ 1/15 of the life of the sensor network. 10. The method of claim 9, The link connection update period is Energy management system in a sensor network environment, characterized in that having a time period divided by the life of the sensor network 10 times. 10. The method of claim 9, The link connection is Connecting each node to form a minimum cost extension tree between the nodes having a link tolerance order. 10. The method of claim 9, The link connection is A chain is formed to connect the plurality of nodes by a link, and two end nodes are formed, and a chain is formed by forming a wireless link so that the transmission energy has a minimum elongation cost regardless of link connection or non-connection between the nodes. Energy management system in the sensor network environment, characterized in that.

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