KR101293951B1 - Appratus and method for managing sensor nodes in wireless sensor network - Google Patents

Abstract

The present invention relates to an apparatus and a method for managing a sensor node in a wireless sensor network. An apparatus for managing a sensor node provided in a header node in a wireless sensor network according to an embodiment of the present invention includes the header node itself from a satellite. GPS receiving unit for receiving the position data of the communication unit and a wireless sensor network including a plurality of heterogeneous communication module and communicates with the sensor node using any one of the communication module and receives the information detected by the sensor node and the position data of the sensor node It includes a processing unit for selecting any one of the plurality of heterogeneous communication modules in consideration of the network connection state of the network and managing the sensor nodes connected to the header node in a cluster unit.

Description

Apparatus and method for managing sensor nodes in wireless sensor network

The present invention relates to a technique for managing a sensor node in a wireless sensor network, and more particularly, in a wireless sensor network, a header node communicates with sensor nodes, forms a cluster, and includes location information and network of sensor nodes included in the cluster. An apparatus, a method for managing formation information, and a recording medium recording the method.

Recently, with the rapid development of wireless communication, a smart sensor node that consumes less power, can be produced at a lower cost, and has a smaller size has been realized. These sensor nodes are used to measure environmental factors such as temperature, humidity and illuminance from the environment. In addition, sensor nodes may process measured data and exchange data through communication between the sensor nodes.

When a plurality of such sensor nodes are collected, a wireless sensor network (WSN) having a self-organizing ability can be established without human support. Thus, a plurality of sensor nodes may be deployed randomly from an airplane or helicopter, and each wireless node can establish a wireless sensor network using its own wireless communication means. These wireless sensor networks can be widely used in monitoring applications for different purposes in various areas such as science, medicine, military and natural disaster prevention.

Meanwhile, the wireless sensor network may use an ad-hoc network that is autonomously configured by nodes for communication between respective sensor nodes. Ad hoc networks do not require specific network connection rules or underlying network devices such as base stations or access points to configure and maintain the network. Ad-hoc nodes communicate with each other using the air interface, overcome the limitations of communication distance of the air interface by the multi-hop routing function, and the network topology changes dynamically because the nodes are free to move. There is a characteristic.

Knowing the location of each sensor arranged in the wireless sensor network environment as described above is one of the most basic and important problems in the sensor network. In this regard, the non-patent literature cited below describes a position measurement technique using an RF transmission level in a wireless sensor network. However, RF (radio frequency) communication has been pointed out that the distance between the communication is flexible depending on the power, the reliability is not very high even in a short distance, and the actual communication coverage is not large.

Therefore, when considering the various applications of the wireless sensor network, and also to improve the efficiency of management of the respective sensor nodes, it is necessary to be able to accurately and quickly locate the position of the sensor nodes.

 Position Measurement Techniques Using RF Transmission Level in Wireless Sensor Networks, Sang Yoon Chae, Joo Sun Han, Haran, Korea Information Science Society, 2007.

The technical problem to be solved by the present invention is to solve the problem that the communication performance between the sensors in the wireless sensor network using the conventional RF communication changes in accordance with the power, and the limitation of low reliability and narrow communication coverage of RF communication In order to overcome the problem, unnecessary power is wasted due to sending and receiving messages through a plurality of sensors and RF communication to determine the location of the sensors.

In order to solve the above technical problem, an apparatus provided in a header node and managing a sensor node in a wireless sensor network according to an embodiment of the present invention receives position data of the header node itself from a satellite. A global positioning system (GPS) receiver; A communication unit including a plurality of heterogeneous communication modules, communicating with the sensor node using any one of the communication modules, and receiving information sensed by the sensor node and position data of the sensor node; And a processor configured to select any one of the plurality of heterogeneous communication modules in consideration of a network connection state of the wireless sensor network and to manage sensor nodes connected to the header node in a cluster unit.

In the above-described embodiment, the processor may further include a location map of sensor nodes constituting the cluster based on the location data of the sensor node received through the communication unit and the location data of the header node received through the GPS receiver. Is generated and added to the cluster management information.

The processor attempts to communicate with the sensor node by sequentially activating the plurality of communication modules in a set order in consideration of the arrangement or position of the sensor node. In addition, in the above-described embodiment, each of the sensor nodes and the header node constituting the one cluster may perform communication through at least one communication module.

In the above-described embodiment, when each of the sensor nodes and the header node constituting the cluster to communicate through at least two communication modules, the processing unit, the heterogeneous standard received through the heterogeneous communication module It is possible to provide a heterogeneous data conversion means for converting the data according to the data according to a single standard.

In one embodiment described above, the plurality of communication modules are communication means capable of relatively long distance communication rather than radio frequency (RF) communication.

In the above embodiment, the header node further comprises a sensing unit for sensing information, the communication unit of the header node for communication with the first communication channel and another header node for communication with the sensor nodes. The communication is performed according to a cross layer scheme supporting at least two communication channels of the second communication channel.

In order to solve the above technical problem, a method of managing a sensor node by a header node in a wireless sensor network according to an embodiment of the present invention includes: receiving position data of the header node itself from a satellite using a GPS receiver; ; Selecting one of a plurality of heterogeneous communication modules to communicate with the sensor node in consideration of a network connection state of the wireless sensor network, and receiving information sensed by the sensor node and position data of the sensor node; And managing the sensor nodes connected to the header node in a cluster unit.

In the above-described embodiment, the method of the header node to manage the sensor node, the position of the sensor node constituting the cluster based on the position data of the sensor node and the position data of the header node received through the GPS receiver. Generating a map and adding to the cluster management information.

Meanwhile, the following provides a computer-readable recording medium having recorded thereon a program for executing a method of managing a sensor node by a header node in a wireless sensor network described above.

Embodiments of the present invention overcome the limitations of low reliability and narrow communication coverage by performing inter-node communication using a communication means capable of relatively long-distance communication rather than RF communication, and the sensor node and the header node directly position information from the GPS satellites. By detecting the position of each of the sensors can be quickly obtained accurate position information without additional communication, thereby reducing the power consumption used for unnecessary communication.

1 is a diagram illustrating a structure of a sensor network in which embodiments of the present invention are implemented and components constituting the same.
2 is a block diagram illustrating an apparatus for managing a sensor node in a wireless sensor network according to an embodiment of the present invention.
3 is a block diagram illustrating a method of communicating with each sensor node and a gateway through heterogeneous communication modules in the sensor node management apparatus of FIG. 2 according to an embodiment of the present invention.
4 is a flowchart illustrating a method of managing sensor nodes in a wireless sensor network according to an embodiment of the present invention.

Before describing the embodiments of the present invention, the environment in which the embodiments are implemented will be briefly described, and the basic idea that the embodiments are commonly employed will be presented.

As introduced earlier, the sensor node has a small form-factor, so it can only have a small battery size, which results in limited energy supply. Therefore, in order to increase the duration of a network composed of many sensor nodes, it is necessary to efficiently use limited energy resources. In other words, to achieve longer network durations, data transfer protocols need to be designed to minimize energy consumption throughout the entire network.

In the existing wireless sensor network, the sensors focused on the limitation of power supply due to battery use, and RF communication was mainly used to increase the sensor's own life by prioritizing savings in the communication module that consumes the most power in the sensor module. I have used However, RF communication has been pointed out as a problem that the distance between communication is flexible according to the power, not only the reliability is very high even in a short distance, but also the actual communication distance is not very long. In addition, in order to use RF communication, there has been a waste of injecting a large number of sensors insignificantly, and there are many defects in transmitting a large amount of data due to reliability problems.

Accordingly, embodiments according to the present invention configure a plurality of sensor nodes and one or more header nodes into one cluster using communication means having a longer reach and more reliable communication than RF communication in various installation environments, and the clusters are wireless. Configure the sensor network. In particular, embodiments of the present invention utilize the GPS information to configure the cluster, to more accurately and quickly identify and manage the location of each sensor node. That is, each sensor node and header node has a GPS receiver, and receives its location information from the GPS satellites and transmits it to the header node, thereby providing a location map that accurately represents the positional relationship of member nodes constituting a cluster. Can be generated. To this end, the header node preferably stores the connection and management information of the detected sensor node by adding location information of the sensor node (which may be raw data including coordinate information received through GPS satellites). .

Furthermore, embodiments according to the present invention allow for multiple heterogeneous communication schemes, not just a single communication scheme. To this end, the header node includes a communication protocol switching means that can provide compatibility between heterogeneous communication methods, and can flexibly select a communication method according to network conditions, thereby improving usability and communication performance. Accordingly, the header node should be able to ensure the interconnectivity and compatibility even when the communication between the sensor nodes and the communication between the clusters is performed in accordance with heterogeneous standards as well as the role of the sink node of the conventional wireless sensor network.

Accordingly, embodiments of the present invention described below improve the communication performance of the sensor node and the network by introducing at least three generations or more of communication means and methods to the sensor node, thereby improving overall network maintenance and management of the network or cluster. It is easy to achieve. In addition, a plurality of heterogeneous communication schemes can be introduced by adopting three or more generation communication schemes in the conventional RF communication one-way communication scheme, thereby providing a technical means for communication compatibility between respective sensor nodes, clusters, or networks. Furthermore, by receiving the location information directly from the GPS satellites, the location information of the cluster formed by the sensor node and the header node can be intuitively and accurately managed.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings in order to clarify a solution of the technical problem of the present invention. However, in describing the present invention, when it is determined that the description of the related known technology may make the gist of the present invention unclear, the description thereof will be omitted.

1 is a diagram illustrating a structure of a sensor network in which embodiments of the present invention are implemented and components constituting the sensor network, including a sensor node 100, a header node 200, a gateway 400, and a server 500. . The wireless sensor network of FIG. 1 is generally used on the ground, but may be flexibly applied in water or in various other environments. In addition, the wireless sensor network configures one cluster 310, 320 as a plurality of sensor nodes 100 and at least one header node 200.

The sensor node 100 collects arbitrary information according to a purpose, and detects various information such as temperature, wind direction, salinity, water pressure, etc. by using one or more sensors or one or more kinds of sensors, and detects the sensed information. Transmission to the header node 200.

The header node 200 collects information from the sensor node and relays communication between the sensor nodes. At this time, the header node 200 stores and maintains connection information, management information, and location information of the sensor nodes 100 forming the cluster 310. In addition, in the embodiments of the present invention, the header node 200 may also include one or more sensors or one or more types of sensors, such as the conventional sensor node 100, and through this, it is possible to detect information such as the sensor node 100. Can play a role.

Then, each of the clusters 310 and 320 formed is connected to the gateway 400 for interaction or information collection, and at a higher level, to the management server 500. That is, the gateway 400 serves to transfer the sensing information collected by the header node 200 to the outside, and the server 500 serves to monitor, use, and manage the above components. In this case, the gateway 400 and the server 500 may transmit and receive data to each other through radio wave communication, for example, a CDMA network.

As described above, in the wireless sensor network of FIG. 1, the sensor node 100 transmits and receives data to and from the header node 200 through a high-speed telecommunication means, and each sensor node centers around these header nodes 200. The networks 100 are configured in such a way that the fields 100 form clusters 310 and 320. The header node 200 may serve as a relay between a plurality of communication modules so as to support a plurality of heterogeneous communication methods, and it is preferable to take a cross layer communication method to perform a role as a general sensor node. Do. The header node 200 also plays a role of transmitting and receiving data with the gateway 400, but does not directly perform the role of the gateway 400 itself because the role of the sensor node 100 is difficult to be implemented in a typical wired communication network. to be. Therefore, it may be substantially implemented in the form of two gateways on the wireless sensor network.

2 is a block diagram illustrating an apparatus for managing a sensor node in a wireless sensor network according to an embodiment of the present invention, which is implemented in the header node 200. Therefore, it is obvious that the present device managing the sensor node may include a normal configuration (for example, may be a power module for supplying power) constituting the header node. Accordingly, a power management function may be performed to maintain communication with the plurality of sensor nodes and to maintain the network connection state and the lifespan (meaning duration time) of the header node as long as possible. For example, the activation and deactivation intervals for the sensor nodes may be set, and accordingly, an operation of not only performing on / off of the corresponding module but also maintaining a minimum power for the module to operate may be performed. However, since these common configurations correspond to the configurations that are somewhat far from the essence to be emphasized through the embodiments of the present disclosure, detailed descriptions of these configurations will be omitted herein.

The GPS (global positioning system) receiving unit 10 receives the position data of the header node itself from the satellite. In this case, the position data may be raw data or coordinate data received from a GPS satellite.

Typically, GPS calculates the distance between the GPS satellites and the GPS receiver to obtain coordinates. If we can pinpoint the location and distance of the GPS satellites, we can get the exact location with only three GPS satellites. This is because we live on the earth's surface, which is roughly a three-dimensional sphere. If it is one-dimensional, such as a straight line, it is easy to determine the location by knowing two reference points and their respective distance values. In a two-dimensional world, you need to know three reference points and their distance values. This is because the point where the three circles meet when the reference point is the center of the circle and the distance value is the radius is the corresponding position. Similarly, in three dimensions, you can find the location where four spheres overlap. However, since the earth's surface itself acts as a sphere, three GPS satellites can, in principle, determine its position.

 However, this alone does not actually calculate distance correctly. The distance between the GPS satellites and the GPS receiver is calculated based on the arrival time of the radio waves sent by the satellite, because an error occurs because the clock mounted on the satellite and the clock mounted on the receiver do not coincide. Therefore, it is necessary to receive radio waves from four or more GPS satellites to determine the exact location. Recently emerging GPS receivers can receive signals from 20 satellites and calculate their position accurately.

By using the above methods, the header node 200 according to the present embodiment can specify its own location. Of course, the present embodiment focuses on the header node 200, but the same configuration (GPS information reception and location specification) can be implemented through the sensor node 100 as a matter of course. Therefore, the communication unit 20 of the header node 200 to be described later receives the position information of the corresponding sensor node from the sensor node 100. Of course, such position information corresponds to the position information of the sensor node directly received from the GPS satellite by the GPS receiving means provided in the sensor node.

The communication unit 20 includes a plurality of heterogeneous communication modules, and communicates with the sensor node 100 using any one of the communication modules. In addition, the communication unit 20 detects the information detected by the sensor node 100 (means specific sensing information detected according to the unique role of the sensor node) and the position data of the sensor node 100 (as described above). Receives location information received through GPS satellites.).

In terms of implementation, the communication modules of the communication unit 20 may be equipped with various communication modules according to the situation, and may be implemented as communication modules corresponding to the communication network so that the existing 3G to 4G communication networks can be used as they are. . Therefore, the header node 200 according to the embodiment of the present invention can exchange data with each other through the sensor node or the header node to which these modules are organically attached.

The processor 30 selects one of the plurality of heterogeneous communication modules in consideration of a network connection state of the wireless sensor network, and clusters the sensor nodes 100 connected to the header node 200 in cluster units. Manage with. At this time, the processing unit 30 is based on the position data of the sensor node received through the communication unit 20 and the position data of the header node received through the GPS receiver, to the sensor nodes constituting the cluster. A location map may be generated and stored in the storage unit 50 in addition to the cluster management information.

In view of controlling the communication unit 20, the processor 30 attempts to communicate with the sensor node by sequentially activating the plurality of communication modules in a predetermined order in consideration of the arrangement or position of the sensor node. can do. Here, the consideration of the placement or location of the sensor node means that the physical environment factors or variables are considered for the communication between the sensor node and the header node. For example, when the environment where the sensor node is disposed and installed is an underwater environment, a sound wave may be a more suitable communication means than a normal communication module. In another case, if there is severe interference in a specific frequency band in the arrangement and installation of sensor nodes, it may be desirable to select a communication module that does not use the frequency band.

As described above, the processing unit 30 may examine the characteristics of the environment in advance in the installation step of the sensor node, and then sequentially operate the communication modules according to the utilization order of the communication module set by the administrator. If a response signal is detected by the operation of the corresponding communication module, communication with the sensor node may be performed through the corresponding communication module. On the other hand, if the response signal is not detected, or if the strength of the response signal is determined to be less than a certain threshold unsuitable for communication, it may attempt to communicate by operating the next highest communication module. This is because, if a weak signal is detected such that normal data transmission and reception are impossible, a communication attempt to detect such a signal may cause unnecessary power consumption.

On the other hand, the header node 200 according to the present embodiment may further include a sensing unit 40 for sensing information as in a conventional sensor node. In this case, the communication unit 20 of the header node 200 supports at least two communication channels of a first communication channel for communication with the sensor nodes and a second communication channel for communication with another header node. It is preferable to perform communication according to a cross layer scheme. Through such a cross-layer method, the header node 200 can secure independent communication channels without disturbing or confusion of communication.

The storage unit 50 stores management information of the wireless sensor network, sensor node connection information, and GPS location information generated by the processor 30, and in particular, is generated from the GPS location information in connection information of member nodes forming a cluster. By adding and storing the location map, the usability of the sensor nodes can be improved. Therefore, the storage unit 50 records the identifier of the sensor node 100 included in the response message received from the sensor node 100 and the location information added thereto in response to the request message of the header node 200. Could be.

3 is a block diagram illustrating a method of communicating with each sensor node and a gateway through heterogeneous communication modules in the sensor node management apparatus of FIG. 2 according to an embodiment of the present invention.

As briefly described above, in the wireless sensor network according to the present embodiment, each of the sensor nodes and the header node constituting the one cluster perform communication through at least one communication module. Therefore, when each of the sensor nodes constituting the cluster and the header node communicate with each other through at least two communication modules, the processor 30 according to the heterogeneous standard received through the heterogeneous communication module. It is preferable to have heterogeneous data conversion means for converting data into data according to a single standard. This data conversion means corresponds to a kind of data bridge or converter, and converts and transfers data items having the same attributes to the format of data defined in each protocol according to two communication protocols. . Therefore, such heterogeneous data conversion means may be designed to be suitable according to a self-implementation environment and communication protocols utilized by those skilled in the art.

On the other hand, the plurality of communication modules implemented through the communication unit 20 is preferably a communication means capable of relatively long-distance communication than RF (radio frequency) communication. For example, the plurality of communication modules may include WiFi, code division multiple access (CDMA), wideband code division multiple access (WCDMA), long term evolution (LTE), high speed downlink packet access (HSDPA), and wireless broadband (WiBro). internet), and in addition to these communication modules, a communication module specialized for the environment may be adopted in consideration of the implementation environment of the wireless sensor network.

In FIG. 3, the communication module 1 is connected to the sensor node 1 110 and the sensor node 2 120, the communication module 2 is connected to the gateway 400, and the communication module N is the sensor node 3 130. You can see that you have a connection with). That is, the header node 200 communicates with the sensor node 1 110 and the sensor node 2 120 according to the first communication protocol, and the header node 200 according to the gateway 400 and the second communication protocol. In this case, the sensor node 3 130 communicates with the sensor node 3 130 according to the Nth communication protocol.

4 is a flowchart illustrating a method of managing a sensor node in a wireless sensor network according to an embodiment of the present invention. Each performing step includes individual components of the header node 200 of FIGS. 2 and 3 described above. As it corresponds to the process to be performed, only an outline of this is briefly described.

In step 410, a header node (or a sensor node management device implemented in the header node) receives position data of the header node itself from a satellite using a GPS receiver.

In step 420, the header node selects any one of a plurality of heterogeneous communication modules to communicate with the sensor node in consideration of a network connection state of a wireless sensor network, and detects the information sensed by the sensor node and location data of the sensor node. Receive. In addition, the header node may attempt to communicate with the sensor node by sequentially activating the plurality of communication modules in a set order in consideration of the arrangement or position of the sensor node.

In this way, each of the sensor nodes and the header node constituting one cluster may perform communication through at least one communication module. In addition, when each of the sensor nodes constituting a cluster and the header node communicate with each other through at least two communication modules, the header node receives data according to the heterogeneous standard received through the heterogeneous communication module. It is preferable to have a heterogeneous data converting means for converting the data into data.

Furthermore, the plurality of communication modules are preferably communication means capable of relatively long distance communication, rather than radio frequency (RF) communication, and the plurality of communication modules include WiFi, code division multiple access (CDMA), and wideband code (WCDMA). division multiple access (LTE), long term evolution (LTE), high speed downlink packet access (HSDPA), and wireless broadband internet (WBro).

In step 430, the header node manages sensor nodes connected to the header node in cluster units.

In operation 440, the header node generates a location map of the sensor nodes constituting the cluster based on the location data of the sensor node and the location data of the header node received through the GPS receiver, and generates the location map for the cluster management information. Can be added. This process is to manage the location information of the sensor node more efficiently, and may be selectively and repeatedly performed as necessary.

Meanwhile, the header node or sensor node management apparatus according to the embodiments of the present invention may be implemented by a system on chip technology on a microprocessor such as a microcontroller unit (MCU). If the present invention is implemented in a microprocessor, the size of various systems can be reduced, the assembly process can be simplified, and manufacturing costs can be reduced.

In addition, the embodiments of the present invention can be embodied as computer readable program codes on a computer readable recording medium. When the present invention is executed through software, the constituent means of the present invention are code segments for performing necessary tasks. In addition, the program or code segments may be stored in a computer readable medium of a computer or transmitted as a computer data signal coupled with a carrier via a transmission medium or a communication network.

Computer-readable recording media include all kinds of recording devices for storing data that can be read by a computer system. For example, the computer-readable recording medium may include a ROM, a RAM, a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer can store and execute the code that is readable.

As described above, according to embodiments of the present invention, by performing communication between nodes using a communication means that can be relatively long-distance communication than RF communication, overcomes the limitations of low reliability and narrow communication coverage, sensor node and header By receiving the location information directly from the GPS satellites, the node can quickly obtain accurate location information without additional communication in order to locate each sensor, thereby reducing power consumption for unnecessary communication.

So far, the present invention has been described with reference to the embodiments. However, one of ordinary skill in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential technical spirit of the present invention. Therefore, the above-described embodiments should be considered in descriptive sense only and not for purposes of limitation. That is, the true technical scope of the present invention is indicated in the appended claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

100, 110, 120, 130: sensor node 200: header node
310, 320: Cluster 400: Gateway
500: Server
10: GPS receiver 20: communication unit
30: processing unit 40: sensing unit
50: storage unit

Claims (9)

An apparatus for managing the sensor node in a wireless sensor network comprising a sensor node for sensing information and a header node for collecting the information from the sensor node.
The apparatus is provided in the header node,
A global positioning system (GPS) receiver configured to receive position data of the header node itself from a satellite;
A communication unit including a plurality of heterogeneous communication modules, communicating with the sensor node using any one of the communication modules, and receiving information sensed by the sensor node and position data of the sensor node; And
A processor configured to select any one of the plurality of heterogeneous communication modules in consideration of a network connection state of the wireless sensor network and manage sensor nodes connected to the header node in a cluster unit;
And each of the sensor nodes and the header node constituting the cluster perform communication through at least one communication module. The method of claim 1,
Wherein,
Generating a location map for the sensor nodes constituting the cluster based on the location data of the sensor node received through the communication unit and the location data of the header node received through the GPS receiver, and adding the location map to the cluster management information; Characterized in that the device. The method of claim 1,
Wherein,
And attempting to communicate with the sensor node by sequentially activating the plurality of communication modules in a set order in consideration of the arrangement or position of the sensor node. delete The method of claim 1,
When each of the sensor nodes constituting the one cluster and the header node communicate with each other through at least two communication modules, the processing unit,
And heterogeneous data converting means for converting the data according to the heterogeneous standard received through the heterogeneous communication module into the data according to a single standard. The method of claim 1,
The plurality of communication modules, characterized in that the communication means capable of relatively long-distance communication than radio frequency (RF) communication. The method of claim 1,
The plurality of communication modules may include at least one of WiFi, code division multiple access (CDMA), wideband code division multiple access (WCDMA), long term evolution (LTE), high speed downlink packet access (HSDPA), and wireless broadband internet (WBro). Apparatus comprising one. The method of claim 1,
The header node further includes a sensing unit for sensing information,
The communication unit of the header node supports a cross layer scheme supporting at least two communication channels of a first communication channel for communication with the sensor nodes and a second communication channel for communication with another header node. And accordingly perform communication. The method of claim 1,
Wherein,
By providing a communication protocol switching means capable of providing compatibility between heterogeneous communication schemes to ensure interconnectivity and compatibility when the communication between the sensor nodes and the communication between the clusters are performed according to heterogeneous standards. Device characterized in that.

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