KR20090099217A - Method for hierarchical configuration of wireless sensor networks and device thereof - Google Patents

Abstract

A method for configuring a hierarchical wireless sensor network and a device thereof are provided to operate a dynamic network and a standardized network by hierarchically operating a network, thereby configuring a flexible and expanded network. The first transceiver(10) communicates with one or more nodes of an upper network. The second transceiver(20) communicates with one or more nodes of a lower network. A controller(30) separates and operates the upper and lower networks into independent networks based on a signal communicated through the first and second transceivers. The controller includes an allocation unit and a network management unit.

Description

Method for hierarchical configuration of wireless sensor networks and device

The present invention relates to a wireless sensor network, and more particularly, to a method and apparatus for constructing a hierarchical wireless sensor network.

A wireless sensor network is a network that senses recognition information about an object or surrounding environment information through a sensor node sensor and processes the information by connecting it to the outside. For example, it can remotely detect and manage various status and environmental information such as temperature, humidity, light intensity, and pressure. In particular, it can be useful for the management of areas or objects that are difficult to access or require constant measurement, monitoring and control.

The wireless sensor network uses one channel and one personal area network identifier (PAN ID) in one personal area network. That is, different personal area networks use different channels or different personal area network identifiers. At this time, any node searches for neighboring nodes by channel or personal area network identifier to join the network, and when joining nodes are found, it joins the network of the first discovered node.

However, this method uses the same channel in one personal area network, so orphan nodes may occur. For example, when the number of child nodes in the network topology is limited, if the sensor nodes do not participate in the sink node's network that they need to join, but participate in another sink node in close proximity, this node's child node capacity Can be saturated. Accordingly, there is a problem in that the sensor node to be participated in becomes an orphan node because it cannot participate in the sink node. In addition, there is a problem in that the participation of sensor nodes in a specific sink node or an unbalanced atypical network topology is formed so that network traffic can be abnormally concentrated in a specific area.

Accordingly, an object of the present invention is to provide a method and apparatus for constructing a hierarchical wireless sensor network which is flexible and scalable, which is devised to solve the above-mentioned problems of the related art.

To achieve the above object, the present invention proposes a method and apparatus for constructing a hierarchical wireless sensor network.

More specifically, according to an aspect of the present invention, the above object is achieved through a first transceiver for communicating with a node of a higher network, a second transceiver for communicating with a node of a lower network, and a first transceiver and a second transceiver. It is achieved by a sink node in a wireless sensor network including a control unit for separating and operating the upper network and lower network as independent networks based on the communication signal.

Meanwhile, according to another aspect of the present invention, an object of the present invention is to communicate with a node of a first upper network and a node of a first lower network through two transceivers, respectively. A second sink node communicating with the node and a node of the second lower network, respectively, wherein the upper network of the first sink node and the lower network of the second sink node form the same wireless network that can communicate with each other, The lower network may configure the same wireless network that can communicate with the upper network of the second sink node. With n sink nodes having this feature, a large wireless network in which n different networks can communicate with each other can be achieved.

On the other hand, according to another aspect of the present invention, the above object, the at least one upper node of the upper network and at least one lower node of the lower network to communicate with each other to distinguish the at least one upper node and at least one lower node, Allocating or receiving group information to at least one divided upper node and at least one lower node, and making a network connection or allowing access to each node of the upper network or the lower network through the assigned group information. This is also achieved by a method of constructing a wireless sensor network of a sync node.

As described above, according to the present invention, a method and apparatus for constructing a hierarchical wireless sensor network are provided.

As a result, by operating the network hierarchically as the upper network and the lower network, it is possible to operate the network as well as the dynamic network, thereby enabling flexible and expanded network configuration. This prevents the occurrence of orphans and enables a balanced network topology to efficiently manage the network. In addition, it is possible to prevent traffic from abnormally concentrating on a specific node and maximize the life of the sensor node as a low power design is possible through a flexible network configuration.

Hereinafter, with reference to the accompanying drawings will be described a preferred embodiment of the present invention; In the following description of the present invention, if it is determined that a detailed description of related known functions or operations may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. In addition, terms to be described below are terms defined in consideration of functions in the present invention, which may vary according to intention or custom of a user or an operator. Therefore, the definition should be made based on the contents throughout the specification.

1 is a block diagram of a wireless sensor network according to an embodiment of the present invention.

Referring to FIG. 1, the wireless sensor network includes a sink node 1, a sensor node 2, and a base station 3.

The wireless sensor network is a network that supports various services such as measurement, remote management, maintenance, and monitoring through wireless communication between nodes. Wireless sensor network technologies may include Zigbee, Bluetooth, and Radio Frequency IDentification (RFID). In particular, the wireless sensor network according to an embodiment of the present invention can be usefully used in the Zigbee technology.

ZigBee technology, one of the IEEE 802.15.4 standards supporting near field communication, can maximize the life of sensor nodes with low power design, and can be manufactured at low cost and maximize the ability to accept and resolve network shape changes. Its use is great. Hereinafter, a method and a device for configuring a hierarchical wireless sensor network will be described in detail with reference to Zigbee technology, which is one of wireless sensor network technologies. However, this is for ease of explanation and other wireless sensor network technologies may be implemented.

The wireless sensor network according to an embodiment of the present invention detects recognition information about an object or a person or surrounding environment information in real time through a sensor of the sensor node 2. There may be a plurality of sensor nodes 2. The sink node 1 receives the information sensed through the sensor node 2 and routes it, and transmits it to the broadband communication network through the base station 3. For example, in the case of a wireless sensor network for vehicle detection, in order to detect a vehicle on a road, the sensor node 2 may sense a vehicle by using a change in a sensing value of a sensor installed and embedded in the road surface or inside the road. Can be.

At this time, the sink node 2 collects various data sent from the sensor node 1 and relays it to other sink nodes as needed, and the base station 3 collects data from the sensor node 2 and the sink node 1. It can manage the entire Telematics Sensor Network (TSN) or act as a gateway between the existing infrastructure and the TSN. The existing infrastructure includes wired networks such as serial communication, wired LAN, ADSL, and optical communication, and wireless networks such as satellite communication, wireless LAN, CDMA, and GSM.

Meanwhile, the sync node 1 according to an embodiment of the present invention includes two radio transmitters. One transceiver unit communicates with a parent node which is an upper node included in the upper network of the sink node 1, and the other transceiver unit is a child node that is a lower node included in the lower network of the sink node 1. child node). At this time, the upper and lower networks can be separated into hierarchical groups to form a wireless sensor network, and if necessary, the two transceivers can be connected to each other to exchange the access information of the upper node and the access information of the lower node. You can also allow connections. This enables flexible and scalable hierarchical network configurations.

Hereinafter, the configuration of the sink node 1 constituting a network hierarchically by embedding two transceivers will be described in detail with reference to FIGS. 2 and 3.

2 is a block diagram of a sink node 1 according to an embodiment of the present invention.

2, the sink node 1 includes a first transceiver 10, a first antenna 12, a second transceiver 20, a second antenna 22, and a controller 30.

The first transceiver 10 communicates with a node of the upper network of the sink node 1 through the first antenna 12, and the upper network is a base station that is a parent node, a coordinator managing another node, or another node. A sink node may be included. The second transceiver 20 communicates with lower network nodes of the sink node 1 through the second antenna 22, and the lower network includes sensor nodes that are child nodes. The first transceiving unit 10 and the second transceiving unit 20 may be connected to each other through an internal or external interface to check a state of each other or to transmit and receive a message.

The controller 30 classifies the upper node connected to the first transceiver 10 and the lower node connected to the second transceiver 20 and allocates group information to the lower node, and accesses the upper network through the assigned group information. Allow network access for each node in the subnetwork. The group information may be channel or personal area network identifier information for distinguishing an upper node and a lower node.

Accordingly, the upper network and the lower network of the sink node 1 may be operated as separate networks separated into different groups. The controller 30 analyzes the frame structure of the data transmitted and received through the first transceiver 10 or the second transceiver 20 to approve a frame or detect an error and determine whether to retransmit and access the network of a higher node. Or allow subnodes to access the network. In this case, the controller 30 may configure a route request, route reply, route error, leave, and the like for an upper node of a higher network or a lower node of a lower network when an independent network is configured. Manage reserved, etc.

In more detail, the controller 30 may be configured as a hierarchical network by dividing a lower node of an upper node or a lower network of an upper network, and connecting two transceivers to each other as necessary to connect the access information of the upper node and the lower node. It can also be configured as a network that allows interconnection by exchanging access information.

3 is a detailed block diagram of the control unit 30 of the sink node 1 of FIG. 2 according to an embodiment of the present invention.

Referring to FIG. 3, the controller 30 includes an allocator 300 and a network manager 310.

The allocator 300 classifies the upper node connected to the first transceiver and the lower node connected to the second transceiver and receives group information or allocates the group information to each node. The group information may be a channel or personal area network identifier as information for distinguishing an upper network and a lower network into independent networks.

The network manager 310 requests network access to an upper network through group information allocated through the allocator 300 or allows network access of each node of a lower network. That is, the network manager 310 may configure a hierarchical network according to a request or allow for a network connection by dividing an upper node of a higher network or a lower node of a lower network, respectively.

In more detail, the network manager 310 manages network participation or departure of sensor nodes included in the lower network of the sink node 1 through the second transceiver, and separates it from the upper network. In order to provide such a function, the sink node 1 has a table with information for the purpose of managing and maintaining the network. The information stored in the table includes the maximum number of child nodes, the maximum depth of the network tree, the maximum number of routers that a child node can have, the information related to broadcast transmissions, a table containing information of neighbor nodes, a route table, Contains security related information. The network layer uses this information and fixed values, called network constants, to manage and maintain the network. The route table contains information used when searching for routes to transfer data from a multihop network to a destination.

4 and 5 are diagrams illustrating a wireless sensor network configuration of a sync node when the wireless sensor network includes a plurality of sync nodes.

Referring to FIG. 4, sink nodes of a wireless sensor network operate independently by separating a lower network and an upper network from two sink nodes including two transceivers. For example, as shown in FIG. 4, the first sink node 1a communicates with the nodes of the first upper network and the nodes of the first lower network through two transceivers 10a and 20a, respectively. The second sink node 1b communicates with the nodes of the second upper network and the nodes of the second lower network through two transceivers 10b and 20b, respectively. In this case, the first sink node 1a and the second sink node 1b may be connected with the coordinator 4 of the upper network coordinating them, and the coordinator 4 is connected with the base station 3 of the upper network.

Meanwhile, the first sink node 1a or the second sink node 1b may separate and operate the lower network from the upper network through different channels. For example, as shown in FIG. 4, the first sink node 1a may operate by separating the upper network and the lower network into CH1 and CH2, respectively. In addition, the second sink node 1b may also operate by separating the upper network and the lower network into CH1 and CH3, respectively. Furthermore, the first sink node 1a may separate and operate the lower network as an independent network that does not overlap with the lower network of the other sink node 1b. For example, as shown in FIG. 4, the lower network of the first sink node 1a and the lower network of the second sink node 1b may be separated from each other through different channels.

Furthermore, the sink node 1 may separate and operate the lower network through a personal area network identifier (PAN ID) different from the upper network as shown in FIG. 5. For example, as illustrated in FIG. 5, the first sink node 1a may divide the upper network and the lower network into PAN ID 1 and PAN ID 2, respectively. In addition, the first sink node 1a may separate and operate the lower network as an independent network through different PAN IDs so as not to overlap the lower network of the other sink node 1b.

6 is an exemplary diagram illustrating a wireless sensor network configuration using a channel of a sink node according to an embodiment of the present invention.

Referring to FIG. 6, the sink node may separate an upper network and a lower network through different channels. For example, as illustrated in FIG. 6, the sink nodes 1c and 1d may form an independent network composed of CH1 from the base station 3. At this time, the sink nodes 1c and 1d participate in an independent upper network composed of CH1 using a signal received through one of the two transceivers of the sink nodes 1c and 1d. In contrast, the sink nodes 1c and 1d may configure independent sub-networks consisting of CH2 and CH3, respectively, with sensor nodes of the sub-network through another transceiver.

Accordingly, when a network is configured through only one conventional transceiver, it is possible to prevent a phenomenon caused by using the same channel in one personal area network. For example, if the number of child nodes in the network topology is limited and the sensor nodes do not participate in the sink node's network to which they should participate, and if they participate in another sink node in close proximity, the number of child nodes in that sink node will be The sensor node that is full and cannot participate in this sink node can become an orphaned node. However, since the sink node according to an embodiment of the present invention includes two transceivers in a balanced manner, the sink node can be prevented from generating an orphan node in advance. In addition, it is possible to distribute the traffic evenly among sink nodes by establishing a structured system when forming a large network.

Meanwhile, the sink node according to an embodiment of the present invention may operate as a sink node including one transceiver as needed. That is, by connecting two transceivers of the sink node to each other, the interconnection information may be allowed by exchanging the access information of the upper node and the access information of the lower node according to a situation.

7 is a diagram illustrating a wireless sensor network configuration using a personal area identifier of a sink node according to an embodiment of the present invention.

Referring to FIG. 7, an upper network and a lower network may be hierarchically separated through different personal area network identifiers (PAN IDs). For example, as shown in FIG. 7, two sink nodes 1e and 1f may be placed below a B node in order to distribute traffic concentrated in the A node in FIG. 6. At this time, the two sink nodes 1e and 1f use the same channel as CH1, but the lower sink nodes 1g and 1h of the two sink nodes 1e and 1f have different personal area network identifiers (PANID1 and PANID2). You can distribute the traffic by configuring the network as an independent network. Configuring the network in this way allows a tiered system to form a large network, so that traffic can be distributed evenly among the sink nodes. Meanwhile, the sink node may operate as a sink node including one transceiver by allowing access to each other by exchanging connection information between an upper node and a lower node as necessary. This enables flexible and scalable network configuration according to the situation.

8 is a flowchart illustrating a wireless sensor network configuration of a sink node according to an embodiment of the present invention.

Referring to FIG. 8, the sink node first communicates with an upper node of an upper network and a lower node of a lower network (S100). At this time, one transceiver of the sink node communicates with a node of a higher network, and the other transceiver communicates with lower network nodes. The upper network may include a base station that is the parent node of the sink node, a coordinator managing the sink node, or another sink node. The lower network includes sink nodes or sensor nodes that are child nodes of the sink node. Each transceiver may be interconnected through an internal or external interface to check each other's status or to transmit and receive messages.

Subsequently, the upper node of the upper network connected to each transmitter and the lower node of the lower network are distinguished (S110). The group information is requested or assigned to the separated upper node and lower node (S120). The group information may be a channel or personal area network identifier for distinguishing an upper node and a lower node. In this way, a hierarchical network configuration in which upper nodes of upper networks and lower nodes of lower networks are divided into different groups is possible.

Subsequently, access to the upper network through the group information or allow network access of each node of the lower network (S130). At this time, the data frame structure transmitted / received through the two transceivers is analyzed to approve the frame, detect an error, determine whether to retransmit, and process packet routing. When the packet routing process is connected to a node of a higher network through one transceiver, the sink node is operated as an end device or a router, and when connected to nodes of a lower network through another transceiver, the sink node is operated as a coordinator node.

In this case, the upper node of the upper network or the lower node of the lower network may be divided to form a layered network. The two transceivers may be connected to each other to exchange access information of the upper node and access information of the lower node to allow interconnection. It may be.

In summary, the sink node according to an embodiment of the present invention enables flexible and expanded network configuration by operating a network hierarchically as an upper network and a lower network. This prevents the occurrence of orphaned nodes and enables a balanced network topology configuration, enabling efficient network management. Furthermore, the flexible network configuration enables low-power design, maximizing the life of the sensor node.

Meanwhile, the method and apparatus for constructing a hierarchical wireless sensor network according to an embodiment of the present invention include traffic control, parking guidance, indoor and outdoor location recognition, handicapped service, anti-lost, shopping guide, floating population statistics, public transportation, street lamp control, and the like. Applicable to the location-based sensor network. It can also be applied to disaster prevention sensor networks such as wildfires, floods, falling rocks, building fires, and lifesavings. It can also be applied to security, medical, and home networks.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

1 is a block diagram of a wireless sensor network according to an embodiment of the present invention;

2 is a block diagram of a sink node according to an embodiment of the present invention;

3 is a detailed configuration diagram of a sink node according to an embodiment of the present invention;

4 is an exemplary view showing a wireless sensor network configuration of a sink node according to an embodiment of the present invention;

5 is an exemplary diagram illustrating a wireless sensor network configuration of a sink node according to an embodiment of the present invention;

6 is an exemplary diagram illustrating a wireless sensor network configuration using a channel of a sink node according to an embodiment of the present invention;

7 is an exemplary diagram showing a wireless sensor network configuration using a personal area identifier of a sink node according to an embodiment of the present invention;

8 is a flowchart illustrating a wireless sensor network configuration of a sink node according to an embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

1: Sink node 2: Sensor node

3: base station 4: coordinator node

10: first transceiver 12: first antenna

20: second transceiver 22: second antenna

30 control unit 300 allocation unit

310: network management unit

Claims (11)

A first transceiver for communicating with at least one node of a higher network; A second transceiver for communicating with at least one node of a lower network; And And a controller configured to separate and operate the upper network and the lower network into independent networks based on signals communicated through the first transceiver and the second transceiver. The method of claim 1, The control unit may include: an allocator configured to allocate at least one upper node connected to the first transceiver and at least one lower node connected to the second transceiver to allocate group information to each node of a lower network; And And a network manager configured to access the upper network or allow network access of each node of the lower network through the assigned group information. The method of claim 1, The sink node is a sink node in a wireless sensor network operated as an end device or a router connected to at least one higher node through the first transceiver. The method of claim 1, The sink node of the wireless sensor network operated as a coordinator node connected to at least one lower node through the second transceiver. The method of claim 1, The control unit is a sink node in a wireless sensor network for separating and operating the lower network as an independent network that does not overlap with a lower network of another sink node. The method of claim 1, The control unit is a sink node in a wireless sensor network for separating and operating the lower network through a different channel from the lower network of the other sink node. The method of claim 1, The control unit is a sink node in a wireless sensor network for separating and operating the lower network through a different personal area network identifier from the lower network of the other sink node. The method of claim 1, The first node and the second transceiver is a sink node in a wireless sensor network connected to the internal or external interface. A first sink node communicating with at least one node of the first upper network and at least one node of the first lower network through two transceivers; And A second sink node communicating with at least one node of the second upper network and at least one node of the second lower network through two transceivers, The first sink node separates and operates the first sub-network into a different network from the second sub-network. The method of claim 9, And the second sink node separates through different channels or different personal area network identifiers when separating into the other networks. (a) distinguishing an upper at least one upper node from the at least one lower node by communicating with at least one upper node of the upper network and at least one lower node of the lower network; (b) receiving group information from the divided at least one upper node or allocating group information to the at least one lower node; And (c) requesting and allowing a network connection of each node of the upper network or the lower network through the assigned or allocated group information.

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