KR100925044B1 - A Clustering Topology Control Method using Second Order Formation with 2 Level Transmission Power in USN - Google Patents

Abstract

The present invention provides a method for managing a sensor clustering topology of sensor nodes having a dual transmission range. In a method of configuring a sensor network in a USN environment, a cluster is formed using a transmission power variable node having a dual transmission range. Making a first step; And a second step of grouping adjacent node sets having the same hop count level into a cluster after the first step; and configuring a network around nodes having two transmission ranges to reduce load on each node. Energy efficiency can be improved while maintaining connectivity between the network and the entire network.

USN, cluster, topology, transmission range, sensor node

Description

A Clustering Topology Control Method using Second Order Formation with 2 Level Transmission Power in USN}

The present invention relates to a technique for constructing a sensor network in a USN (Ubiquitous Sensor Network). In particular, a network is constructed around nodes having two transmission ranges, thereby reducing the load of each node and maintaining the connectivity of the entire network. The present invention relates to a method for managing a sensor clustering topology of sensor nodes having a dual transmission range, which is suitable for improving efficiency.

In general, USN (Ubiquitous Sensor Network) is a technology aimed at realizing a ubiquitous environment using a sensor network. Recently, the USN environment has been developed as an IP-USN using IP (Internet Protocol). IP-USN is a technology for supporting an ALL IP network.

In wireless ubiquitous environment, various methods for forming a sensor network, which is a sensor-to-sensor connection, have been proposed. These various sensor network systems are studied in terms of how to construct a sensor network in a local form or a small form, and how to construct an entire network in a wide area form. The wireless ad-hoc or IP network system The method is partially applied.

Structural tree forms are common in the method of sending data to a desired node by combining sensors with limited functions and limited power into a network. This structured tree form spreads and distributes sensor nodes to the desired application area to identify the number of upper and lower nodes, sets intermediate nodes between 'parent-child', and each 'child' is a lower 'child'. It is linked with and gives a logical ID to each node and manages it. Such an example uses the IEEE 802.15.4 standard and may be considered to have partial logic.

However, this conventional structural tree type is suitable for managing a limited area or a small number of nodes, and when a large number of nodes are arranged in all directions, transmission collisions between many nodes may cause IDs or beacon cycles and mutual IDs. There was a problem that was difficult to set the duty time.

Other methods of forming a wireless ubiquitous network include a peer-to-peer method and a star method.

There is also a lot of research on how to connect the sensors into a group and operate as a cluster. Basically, most clusters internally elect the cluster head to operate the cluster network around the cluster head, and select the cluster head properly, connect the adjacent cluster nodes, avoid duplication, transmit range and location management, etc. There is research.

However, such a conventional method adopts a method of forming a cluster through inter-node communication in a regional scope and transmitting information to neighbor nodes or adjacent clusters. There was a problem in that logical management such as transmission collision avoidance was difficult.

In addition, if the transmission power of the nodes forming the cluster is operated in various forms, there is a disadvantage in that it is difficult to operate the network for a long time due to the characteristics of the sensor node that reduces energy efficiency when the transmission power is varied. 'S research is insufficient.

In order to construct a unit-wide regional sensor network, a central node for collecting and managing data or a sink node for collecting data is required, and such a central node mainly plays a role of a base station or an access point. In order to activate the sensor network, a central node, a forwarding node, and a general node are required, each of which performs data sensing and network communication. Some conventional methods form a network by varying the transmission range in order to allow a small sensor node to communicate with a node other than the basic transmission range, but such a technique is difficult to arbitrarily vary the transmission range, The amount of power consumed when the variable is variable, there is a problem that comes to the sensor node.

Therefore, the present invention has been proposed to solve the above-mentioned conventional problems, and an object of the present invention is to configure a network centered on nodes having two transmission ranges to reduce the load of each node and maintain connectivity of the entire network. The present invention provides a method for managing a sensor clustering topology of sensor nodes having a dual transmission range capable of improving energy efficiency.

In addition, another object of the present invention is to propose an efficient topology formation and management method in a wireless sensor network environment, to manage logical clusters using neighbor node information, to minimize mutual collisions in local clusters, and to manage energy of clusters and general nodes. It improves node's active time through network and secures connectivity of wide area network.

1 is a conceptual diagram illustrating a configuration of a sensor network in a general USN environment, and FIG. 2 is a flowchart illustrating a method for managing a sensor clustering topology of sensor nodes having a dual transmission range according to an embodiment of the present invention.

As shown here, a method for constructing a sensor network in a USN environment, comprising: a first step (ST1) of forming a cluster using a transmission power variable node having a dual transmission range; And a second step ST2 of grouping adjacent node sets having the same hop count level into a cluster after the first step.

The sensor clustering topology management method of the sensor nodes having the dual transmission range may further include a third step (ST3) of managing information flow between nodes after the first step.

The sensor clustering topology management method of the sensor nodes having the dual transmission range may further include a fourth step (ST4) of managing the topology after the first step.

The sensor clustering topology management method of the sensor nodes having the dual transmission range may further include a fifth step (ST5) of performing a cluster registration process for each new or mobile node after the first step. .

Sensor clustering topology management method of the sensor nodes having a dual transmission range according to an embodiment of the present invention, as shown in Figure 2, in the method for configuring a sensor network in the USN environment, the transmission having a dual transmission range A first step ST1 of forming a cluster using a power variable node; A second step (ST2) of grouping adjacent sets of adjacent nodes of the same hop number level into a cluster after the first step; A third step ST3 of managing information flow between nodes after the first step; A fourth step (ST4) of managing a topology after the first step; And a fifth step (ST5) of performing a cluster registration process for each layer of the new or mobile node after the first step.

3 is a detailed flowchart illustrating a first step of forming a cluster using a variable transmission power node having a dual transmission range in FIG. 2, and FIG. 4 is a conceptual diagram illustrating an example of forming a primary cluster network in FIG. 3. 5 is a conceptual diagram illustrating an example of forming a secondary cluster network in FIG. 3.

As shown therein, the first step includes: an eleventh step (ST11) of forming a primary cluster network in consideration of a transmission range between a cluster head or a forwarding node based on a center node as a start node; And a twelfth step (ST12) of forming a secondary cluster network in consideration of the transmission range between the corresponding general nodes based on the cluster head node or the forwarding node after the eleventh step.

The eleventh step is characterized in that the primary cluster network is formed for a cluster head or a forwarding node having a transmission range of more than twice the general node.

In the second step, nodes having the same transmission range and the same number of hops have a logical tree structure from the top node, and overlap with neighboring nodes when forming a cluster around any node. When this occurs, it is characterized by grouping adjacent node sets of the same hop number level into a cluster.

FIG. 6 is a detailed flowchart of a second step of grouping adjacent node sets of the same hop number level into clusters in FIG. 2.

As shown therein, the second step includes: a twenty-first step (ST21) of calculating a set of adjacent nodes based on each node having the same hop number level and forming a cluster using the set; A twenty-second step (ST22) such that each node within the duplicate hop number after the twenty-first step has the same transmission range, each node has a unique ID, and the ID has a logical sequential value; After the twenty-second step, the upper node uses the information received from the lower node to know neighboring neighbor nodes and neighbor information of the lower nodes, and sequentially arranges adjacent nodes based on the information (ST23). )Wow; A twenty-fourth step (ST24) for forming a cluster around the center node of the sequential last set after the twenty-third step (cluster head); A twenty-fifth step ST25 for forming a cluster around the center node of the cluster having the last element of the set of primary clusters as an initial element after the twenty-fourth step; It is characterized by performing.

FIG. 7 is a detailed flowchart of a third step of managing information flow between nodes in FIG. 2.

As shown therein, the third step includes: a thirty first step (ST31) of performing acquisition processing of basic node information after the first step; A thirty-second step (ST32) of performing a selection process of an upper node when the next higher node overlaps after the first step; A thirty-third step (ST33) of performing information acquisition processing between the cluster head node or the forwarding node after the first step; And a thirty-fourth step (ST34) of performing information acquisition processing between the cluster head node and the general node after the first step.

FIG. 8 is a conceptual diagram illustrating an example of obtaining and processing basic node information in FIG. 7.

As shown in the drawing, in the thirty-first step, in order to form a network between cluster head nodes, each head node collects information of lower nodes using transmission power having a large transmission range.

In the thirty-second step, when two or more second-order nodes overlap at an arbitrary hop number level, the corresponding node selects a next-order node based on a predetermined criterion according to application service characteristics of the entire system and transmits the information.

The criterion preset in the thirty-second step is that the upper node having a large amount of power to be selected is selected.

The criterion preset in the thirty-second step is that a node having a small number of holding cluster nodes is selected.

In the step 32, the preset criterion is that a node designating a specific quality of service (QoS) is selected.

The criterion preset in the thirty-second step is that the upper node is randomly selected.

The criterion preset in the thirty-second step is characterized in that the node is sequentially selected to cycle.

In the step 32, the preset criterion is that a node having a relatively high or low ID is selected.

In the thirty-third step, the upper node broadcasts its own node ID information and cumulative hop number information from the highest node (initial number of hops is 0) to the next lower node, and the lower node acquires the broadcasting information of the upper node. It is characterized in that to transmit its ID to the upper node.

In the thirty-third step, the next higher node manages node information received from the lower node as a table, and the table has hop number information and ID of each lower node and adjacent node information of the lower node.

In the thirty-third step, the lower node adds 1, its level hop number, to the number of hops received from the next higher node, stores it in a table, and broadcasts this information to discover the next lower node.

In the thirty-third step, each node ignores the received information packet when it receives information having a hop number lower than the accumulated hop number.

FIG. 9 is a conceptual diagram illustrating an example of information exchange between nodes in an information acquisition process between a cluster head node or a forwarding node in FIG. 7.

As shown in FIG. 33, the 33rd step includes ID information, cumulative hop number information, upper node information, lower node information, function information, data factor information, and retained power in the information content of the nodes at the 1-hop level. Characterized in that one or more of the information is included.

In the thirty-fourth step, the general node constituting the cluster may receive topology information from an upper cluster head node to form a regional cluster.

In the thirty-fourth step, the clusterhead node may broadcast an initial command including its ID information to the neighboring nodes using a transmission power having a transmission range smaller than that of the first configured clusterhead transmission range.

In the thirty-fourth step, the general nodes analyze a command packet broadcast by the cluster head and then send a cluster participation request command including their ID and information on neighbor nodes to participate in the cluster.

In the thirty-fourth step, the clusterhead analyzes and organizes the participation request packets of the general nodes, and then broadcasts the beacon periods and the duty time of the general nodes included in its cluster.

In the thirty-fourth step, the general nodes of the local cluster operate in a transmission / reception mode at their duty time, and wait for a sleep state other than the duty time.

FIG. 10 is a conceptual diagram illustrating an example of information exchange content during information acquisition processing between a cluster head node and a general node in FIG. 7.

As shown in FIG. 34, in the step 34, when information is exchanged between the cluster head node and the general node, when the cluster head node transmits the information to the general node, ID information, cumulative hop number information, upper node information, neighbor head information, cluster Including at least one of node duty time information, function information, attribute information, data factor information, and reserved power information, the general node transmits information including ID information, cumulative hop count information, And at least one of head node information, neighbor node information, node duty time information, function information, attribute information, data factor information, and retained power amount information.

FIG. 11 is a detailed flowchart illustrating an example of managing a topology in FIG. 2, and FIG. 12 is a conceptual diagram illustrating a topology management step of FIG. 11.

As shown in FIG. 4, the fourth step includes a step 41 of calculating the amount of power of the sensors after the sensors are installed globally, and assigning the role of the cluster head and the transfer node or determining the role of the general node. ; Step 42, after the step 41, each node waits to receive a TP_INIT ₁ (topology initialization) command signal from an upper node; A 43rd step (ST43) of receiving each TP_INIT ₁ (topology initialization) command signal 2 or 3 times after step 42 and transmitting a TP_REP ₁ (topology response) command signal to a higher node; In step 44, the upper node receiving the TP_REP ₁ (Topology Response) command signal transmits the TP_ADV ₁ (Topology Notification) command signal to each node that sends the TP_REP ₁ (Topology Response) command signal. ; A step 45 (ST45) in which each cluster receiving the TP_ADV ₁ (topology notification) command signal after the step 44 checks the clustering with respect to the head and then exchanges data with each other; After clustering from the upper node after the 45th step, the primary clusters transmit and receive normal communication, and the lower node lowers the transmission power value to reduce the transmission range to implement the secondary clustering configuration for the general nodes within the corresponding range. 46 steps (ST46); characterized in that performed.

The signal data in the 43rd step is characterized by applying the transmission method in IEEE 802.11 Mac.

In step 44, the TP_ADV ₁ (topology notification) command signal data includes cluster unit information, logical ID, and cluster head information of corresponding nodes.

In the fourth step, after the 46th step, the TP_REP ₂ (Topology Response) command signal is transmitted from the lower node to the upper node, and the upper node is sent to the secondary cluster nodes using the TP_ADV ₂ (Topology Notification) command signal data. And 47 th step of transmitting information (ST47).

In the fourth step, after the 47th step, the upper node configures clustering using TP_INIT _n (topology initialization), TP_REP _n (topology response), and TP_ADV _n (topology notification) command signals according to each layer. After the TP_REP _n (Topology Response) command signal does not occur, the upper node finally sends a TP_CONF (Topology Confirmation) command signal to complete the clustering configuration (ST48).

FIG. 13 is a detailed flowchart of a fifth step of performing a layer cluster registration process of a new or mobile node in FIG. 2.

As shown in FIG. 5, the fifth step includes: a 51 st step (ST51) of periodically transmitting a TP_REP (Topology Response) command signal to a neighbor node as a beacon signal after a predetermined time; A 52nd step (ST52) of receiving a beacon-shaped signal by the cluster head node or the forwarding node within the transmission distance after the 51st step and newly registering the signal; After the 52nd step, the clusterhead processes the newly registered node information locally, transmits the new node information added when transmitting topology information to the upper node, and adjusts the beacon period and duty time to reconfigure the internal node of the cluster. And updating the information in step 53 to adjust time scheduling (ST53).

The sensor clustering topology management method of the sensor nodes having the dual transmission range according to the present invention forms a network around nodes having two transmission ranges to reduce the load of each node and maintain the connectivity of the entire network. There is an effect that can be improved.

In addition, the present invention proposes an efficient topology formation and management method in a wireless sensor network environment, manages a logical cluster using neighbor node information, minimizes mutual collisions in a local cluster, and manages nodes through energy management of a cluster and a general node. It improves the activity time of the network, and has the effect of securing the connectivity of the wide area network.

A preferred embodiment of a method for managing a sensor clustering topology of sensor nodes having a dual transmission range according to the present invention configured as described above will be described in detail with reference to the accompanying drawings. In the following description of the present invention, detailed descriptions of well-known functions or configurations will be omitted if it is determined that the detailed description of the present invention may unnecessarily obscure the subject matter of the present invention. 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 precedent of a user or an operator, and thus, the meaning of each term should be interpreted based on the contents throughout the present specification. will be.

First, the present invention aims to improve energy efficiency while constructing a network around nodes having two transmission ranges while reducing load of each node and maintaining connectivity of the entire network.

In addition, the present invention relates to a method for forming a cluster using nodes having two transmission ranges in a hierarchical cluster structure, which is a method for configuring a sensor network. In the sensor network environment in which the general node, the cluster head, and the forwarding node are mixed, the transmission power of the node acting as a cluster head or a forwarding node having a value greater than or equal to the transmission power that determines the transmission distance of the general node is used. First, we construct a primary cluster network based on the forwarding node (or clusterhead), and secondly, cluster between common nodes in the corresponding transmission range around the forwarding node (or clusterhead) configured first. Configure the sensor network. Here, two transmission ranges are a transmission range of a general node, and the other transmission range is a transmission range of a cluster head or a transmission node having a value twice or more of a transmission power for determining a transmission distance of the general node. Therefore, rather than forming a network through multi-level tree structure or mutual negotiation with neighboring nodes, the method of forming and managing hierarchical clusters improves the overall network construction speed, energy efficiency, and life-time of the entire network. You can.

And the meaning of the terms used in the present invention are first defined as follows.

Network Node: A device connected to a network having a wired / wireless communication function and a data processing function. A mobile node (MS), a personal digital assistant (PDA), a sensor node, a sink node, a gateway, a base station ( Base station (BS)).

-Sensor Node: A device that has a sensing function and a communication function for observing and sensing a physical phenomenon, and is a basic component of a sensor network.

-Sink Node: A Sink Node that performs interworking with the external network and manages sensor nodes among the sensor nodes constituting the sensor network.

Cluster: A small group of sensor nodes consisting of a cluster head and a general node.

Cluster head node: A node that manages topology and data communication in a cluster, performs communication between adjacent cluster heads, and manages its location information, IDs of each node in the cluster, and power consumption.

-Forwarding node: A node that can recognize its own ID and amount of power, plays a role of cluster head according to the method of selecting a head in a cluster, is located in an area adjacent to the cluster head, and plays an intermediate transmission role for communication between clusters. to be.

-Normal Node: A general element of sensor network, and a lower level sensor node constituting a cluster. Communication is performed by adjacent forwarding node (boundary node) that plays an intermediate transmission role.

-Top Node: A central node that manages the data collection or the topology of the entire network. It is called the start node of topology formation. The cumulative hop number is 0 as the initial value for topology formation.

-Next higher node: A node located one level above any node level, based on the cumulative number of hops from the top node.

Subordinate Nodes: Nodes located one level below any node level, based on the cumulative number of hops from the top node.

-TP_INITn (Topology Initialization): This is the topology initial beacon command signal transmitted by the upper node in the initial stage of configuring the topology.

-TP_REPn (Topology Response): Each node that receives the TP_INIT signal sends its ID, adjacent node information of the same level, and the amount of power retained.

-TP_ADVn (Topology Notification): This is a command signal that the parent node that receives the topology response sends topology information to the node as part of the overall topology formation.

TP_REQn (Topology Request): A request command signal for a new or mobile node to join a topology.

-TP_CONFn (Topology Confirmation): As a command signal for final notification of information related to cluster formation at each stage, each node performs internal clustering and total communication in a cycle and method defined in TP_CONF.

1 is a conceptual diagram showing the configuration of a sensor network in the USN environment to which the present invention is applied.

Here, reference numeral 100 is a sensor network, 110 is a cluster, 120 is a sensor node, 200 is a public network, 300 is a USN server, and 400 is a user terminal.

The sensor network 100 is composed of a plurality of sensor nodes 120 for sensing the information of the physical space to transmit the sensing information. A node that performs interworking with external networks and manages other sensor nodes among the sensor nodes is called a sink node, and a node that performs sensing and transfers sensing information of another sensor node to the sink node is also called a relay node. .

The public network 200 is composed of an internet network or a mobile communication network and connected to the sensor network 100 to provide various public network services.

The USN server 300 manages the sensor node 120 and sensing information and provides various services to the user 400. In order to provide the location-based service, the USN server 300 should be able to efficiently manage a large amount of sensing information and location information. The user 400 connected to the USN server 300 through a wired / wireless network is a target for using the sensing information, and receives various services according to characteristics of the user through the USN server 300.

The user 400 may be in the form of a personal computer (PC), a personal digital assistant (PDA), a mobile communication terminal, or an application server or system for performing a specific task.

2 is a flowchart illustrating a method for managing a sensor clustering topology of sensor nodes having a dual transmission range according to an embodiment of the present invention.

Therefore, in the first step ST1, a cluster is formed by using a transmission power variable node having a dual transmission range.

In the second step ST2, a set of adjacent nodes of the same hop number level is grouped into a cluster.

In the third step ST3, information flow between nodes is managed.

In the fourth step ST4, the topology is managed.

In a fifth step ST5, the cluster registration process for each new or mobile node is performed.

FIG. 3 is a detailed flowchart of a first step of forming a cluster by using a transmission power variable node having a dual transmission range in FIG. 2.

Therefore, in the eleventh step (ST11), the primary cluster network considering the transmission range between the cluster head or the forwarding node is formed on the basis of the center node as the start node.

4 is a conceptual diagram illustrating an example of forming a primary cluster network in FIG. 3.

In FIG. 4, reference numeral 111 is a primary cluster, and 121 is a clusterhead node.

Therefore, a primary cluster network is formed for a cluster head or a forwarding node having a transmission range twice as large as that of a general node.

In FIG. 4, [Level 0, 1, 2, ...] represents the number of hops from the start node, and is named as the hop number level for convenience, and the hop number difference between the lower level and the lower level is 1.

In addition, in the twelfth step ST12, a secondary cluster network considering the transmission range between the corresponding general nodes is formed based on the cluster head node or the forwarding node.

FIG. 5 is a conceptual diagram illustrating an example of forming a secondary cluster network in FIG. 3.

Here, reference numeral 111 is a primary cluster, 112 is a secondary cluster, 121 is a cluster head node, 122 is a forwarding node, and 123 is a general node.

Therefore, a partial cluster is composed of general nodes within a corresponding transmission range around a cluster head node or a forwarding node configured as a primary.

In the example of FIG. 5, a local cluster is formed around CH ₁ , ₁ , which is a level 1 clusterhead node.

FIG. 6 is a detailed flowchart of a second step of grouping adjacent node sets of the same hop number level into clusters in FIG. 2.

Therefore, if the number of hops from the upper node is located at the same level and the cluster formation for nodes with overlapping transmission ranges is necessary, the following rules are applied to form a cluster.

-Nodes with the same size of transmission range and the same number of hops have a logical tree structure from the top node, and the same number of hops when overlapping with neighboring nodes occurs when forming a cluster around any node Group sets of adjacent nodes in the level into clusters.

A set of adjacent nodes is calculated based on each node having the same hop number level, and a cluster is formed using the set (ST21).

The transmission range of each node in the duplicate hop number is the same, and each node has a unique ID, and this ID has a logical sequential value (ST22).

-The upper node uses the information received from the lower node to know neighboring neighboring nodes and neighboring neighboring information between the lower nodes, and sequentially arranges neighboring nodes based on this information (ST23). That is, the set of adjacent nodes f (n _i ) centering on any node n _i is expressed as follows.

f (n _i ) = [n ₀ , n ₁ , n ₂ , n ₃ , ......, n _e ]

Where node n ₀ is the logical initial element (node) of the set and n _e is the logical last element (node) of the set.

The primary cluster C1 (n _i ) forms a cluster around the center (cluster head) of n _i nodes, which are the central nodes of f (n _i ), which is the last sequential set having n ₀ as an element (ST24).

C1 (n _i ) = [central node of the last set f (n _i ) with n _i | n ₀ as element]

The secondary cluster C2 (n _j ) at the same hop level is the central node of f (n _j ), which is the initial element with the last element n _e of f (n _i ), the set of primary clusters C1 (n _i ) A cluster is formed around the n _j nodes (clusterhead) (ST25).

C2 (n _i ) = [central node of set f (n _j ) with n _j | n _e as initial element]

Cluster configuration methods after the same level tertiary cluster C3 (n _j ) are the same as the second cluster configuration method.

FIG. 7 is a detailed flowchart of a third step of managing information flow between nodes in FIG. 2.

This is the 31st step (ST31) of performing the acquisition process of the basic node information, the 32nd step (ST32) of performing the selection process of the upper node when the next higher node overlaps, the acquisition process of the information between the cluster head node or the forwarding node And the thirty-third step (ST33), the thirty-fourth step (ST34) for performing the process of obtaining information between the cluster head node and the general node.

FIG. 8 is a conceptual diagram illustrating an example of obtaining and processing basic node information in FIG. 7.

Therefore, in order to form a network between cluster head nodes, each head node collects information of the lower nodes in the same manner as in the flow ① of FIG. 8 using a transmission power having a large transmission range.

Also, when the next higher node is duplicated, the upper node selection method is as follows.

If two or more second-order nodes overlap at any hop level, the node selects the next-order node and transmits information based on one of the following methods according to the application service characteristics of the entire system.

-Select the parent node with a large amount of power

-Select nodes with fewer cluster nodes

Select nodes that specify a specific quality of service

-Randomly selects parent nodes

-Select nodes by cycling sequentially

-Select nodes with relatively high or low ID

In addition, the process and contents of obtaining information between cluster head nodes or forwarding nodes are as follows.

-The upper node broadcasts its own node ID information and accumulated hop number information from the highest node (initial number of hops is 0) to the next node, and the lower node acquires its ID after obtaining the broadcasting information of the upper node. Pass to the parent node.

-The next higher node manages the node information received from the lower node as a table, and the table has hop number information and ID of each lower node and adjacent node information of the lower node.

-The lower node adds its level hop number 1 to the hops received from the next higher node, stores it in the table, and broadcasts this information to find the next lower node.

Each node ignores the received information packet when it receives information with a hop count lower than the accumulated hop count.

FIG. 9 is a conceptual diagram illustrating an example of information exchange between nodes in an information acquisition process between a cluster head node or a forwarding node in FIG. 7.

The key information between nodes of one hop level is shown in FIG. Therefore, the information content between the nodes at the 1-hop level includes at least one of ID information, cumulative hop number information, upper node information, lower node information, function information, data factor information, and retained power information.

In addition, the information acquisition process and contents between the cluster head node and the general node are as follows.

-The general node constituting the cluster receives the topology information from the upper cluster head node to form a local cluster.

-The cluster head node broadcasts an initial command including its ID information to neighboring nodes using transmission power having a transmission range smaller than that of the first configured cluster head.

-Normal nodes analyze the command packet broadcast by clusterhead and send cluster join request command including their ID and information about neighbor node to join cluster.

-The clusterhead analyzes and organizes the participation request packets of the general nodes and broadcasts the beacon period and the duty time of the general nodes included in its cluster.

-Normal nodes of the local cluster operate in the transmit / receive mode at their duty time and sleep in the sleep state except the duty time.

FIG. 10 is a conceptual diagram illustrating an example of information exchange content during information acquisition processing between a cluster head node and a general node in FIG. 7.

Therefore, when information is exchanged between the cluster head node and the general node, the cluster head node transmits the information to the general node such as ID information, cumulative hop count information, upper node information, neighbor head information, cluster node duty time information, function information, attribute information, It transmits including one or more of data factor information and reserved power amount information, the general node when transmitting information to the cluster head node, ID information, cumulative hop number information, head node information, neighbor node information, node duty time It includes one or more of information, function information, attribute information, data factor information, data retention information, and the like.

In addition, the main command procedures and methods for managing the cluster topology are as follows.

FIG. 11 is a detailed flowchart illustrating an example of managing a topology in FIG. 2, and FIG. 12 is a conceptual diagram illustrating a topology management step of FIG. 11. Thus, the clustering configuration procedure for each layer according to the transmission range is shown in FIG. 12, and the detailed steps and contents thereof are shown in FIG.

Therefore, the sensors are installed in a global manner, respectively, to calculate its own power amount, and assigned the role of the cluster head and the transfer node or determine the role of the general node (ST41).

Each node waits to receive a TP_INIT ₁ (topology initialization) command signal from an upper node (ST42).

Each node receives the TP_INIT ₁ (topology initialization) command signal two or three times and transmits a TP_REP ₁ (topology response) command signal to the upper node (ST43). This signal data is based on the IEEE 802.11 Mac transfer method.

The upper node receiving the TP_REP ₁ (Topology Response) command signal transmits the TP_ADV ₁ (Topology Notification) command signal to each node that has sent the TP_REP ₁ (Topology Response) command signal (ST44). The TP_ADV ₁ (topology notification) command signal data includes cluster unit information, logical ID, and cluster head information of corresponding nodes.

Each cluster that receives the TP_ADV ₁ (Topology Notification) command signal checks the clustering around the head and exchanges data with each other (ST45).

The primary clusters that have completed clustering from the upper node receive normal communication, and the upper node reduces the transmission range by lowering the transmission power value and performs the secondary clustering configuration for the general nodes within the corresponding range (ST46).

Secondary clustering configuration is similar to that of ST43 above. The TP_REP ₂ (Topology Response) command signal is sent by the lower node to the upper node, and the upper node uses the TP_ADV ₂ (Topology Notification) command signal data. Information is transmitted to the primary cluster nodes (ST47).

Depending on each layer, the parent node configures clustering using the TP_INIT _n (topology initialization) and TP_REP _n (topology response) and TP_ADV _n (topology notification) command signals, and after a certain time, the TP_REP _n (topology response) command signal occurs. Otherwise, the upper node finally sends a TP_CONF (Topology Confirmation) command signal to complete the clustering configuration (ST48).

FIG. 13 is a detailed flowchart of a fifth step of performing a layer cluster registration process of a new or mobile node in FIG. 2.

Generally, clustering is configured using the TP_INIT, TP_REP, and TP_ADV command signals to form a clustering topology in an open environment, but it cannot receive command signals related to topology formation, in part due to node-to-node collisions or geographic interference. Or a partial error can result in a node not participating in clustering.

Similarly, new nodes do not immediately enter clusters within the existing topology.

The new or mobile node periodically transmits a TP_REP (Topology Response) command signal to a neighbor node as a beacon signal (ST51).

The cluster head node or the forwarding node within the transmission distance receives the transmitted beacon-shaped signal and performs new registration (ST52).

In addition, the clusterhead recognized as a new node processes the newly registered node information locally, and transmits the new node information including the new node information added when the topology information is transmitted to the upper node. In addition, the beacon period and duty time are readjusted to update information in the cluster internal node to adjust time scheduling (ST53).

As described above, the present invention configures a network around nodes having two transmission ranges, thereby improving energy efficiency while reducing load of each node and maintaining connectivity of the entire network.

Although the above has been described as being limited to the preferred embodiment of the present invention, the present invention is not limited thereto and various changes, modifications, and equivalents may be used. Therefore, the present invention can be applied by appropriately modifying the above embodiments, it will be obvious that such application also belongs to the scope of the present invention based on the technical idea described in the claims below.

1 is a conceptual diagram showing the configuration of a sensor network in the USN environment to which the present invention is applied.

2 is a flowchart illustrating a method for managing a sensor clustering topology of sensor nodes having a dual transmission range according to an embodiment of the present invention.

FIG. 3 is a detailed flowchart of a first step of forming a cluster by using a transmission power variable node having a dual transmission range in FIG. 2.

4 is a conceptual diagram illustrating an example of forming a primary cluster network in FIG. 3.

FIG. 5 is a conceptual diagram illustrating an example of forming a secondary cluster network in FIG. 3.

FIG. 6 is a detailed flowchart of a second step of grouping adjacent node sets of the same hop number level into clusters in FIG. 2.

FIG. 7 is a detailed flowchart of a third step of managing information flow between nodes in FIG. 2.

FIG. 8 is a conceptual diagram illustrating an example of obtaining and processing basic node information in FIG. 7.

FIG. 9 is a conceptual diagram illustrating an example of information exchange between nodes in an information acquisition process between a cluster head node or a forwarding node in FIG. 7.

FIG. 10 is a conceptual diagram illustrating an example of information exchange content during information acquisition processing between a cluster head node and a general node in FIG. 7.

FIG. 11 is a detailed flowchart illustrating an example of managing a topology in FIG. 2.

FIG. 12 is a conceptual diagram illustrating the topology management step of FIG. 11.

FIG. 13 is a detailed flowchart of a fifth step of performing a layer cluster registration process of a new or mobile node in FIG. 2.

Explanation of symbols on the main parts of the drawings

100: sensor network

110: cluster

111: primary cluster

112: secondary cluster

120: sensor node

121: clusterhead node

122: forwarding node

123: general node

200: public network

300: USN Server

400: user terminal

Claims (35)

A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, Forming a cluster using a transmission power variable node having a dual transmission range; A second step of grouping adjacent sets of adjacent nodes of the same hop number level into a cluster after the first step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed. The method according to claim 1, Sensor clustering topology management method of the sensor nodes having the dual transmission range, A third step of managing information flow between nodes after the first step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that it further comprises. The method according to claim 1, Sensor clustering topology management method of the sensor nodes having the dual transmission range, A fourth step of managing a topology after the first step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that it further comprises. The method according to claim 1, Sensor clustering topology management method of the sensor nodes having the dual transmission range, A fifth step of performing a cluster registration process for each new or mobile node after the first step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that it further comprises. A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, Forming a cluster using a transmission power variable node having a dual transmission range; A second step of grouping adjacent sets of adjacent nodes of the same hop number level into a cluster after the first step; A third step of managing information flow between nodes after the first step; A fourth step of managing a topology after the first step; A fifth step of performing a cluster registration process for each new or mobile node after the first step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed. The method according to claim 1 or 5, The first step is, An eleventh step of forming a primary cluster network in consideration of a transmission range between a cluster head or a forwarding node based on a center node as a start node; A twelfth step of forming a secondary cluster network in consideration of a transmission range between general nodes based on a cluster head node or a forwarding node of the primary cluster network formed after the eleventh step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed. The method according to claim 6, The eleventh step, A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, wherein the primary cluster network is formed for a cluster head or a forwarding node having a transmission range of more than twice the general node. The method according to claim 1 or 5, The second step, Nodes with the same transmission range and the same number of hops have a tree structure from the top node, and when a cluster is formed around any node, if overlapping with neighboring nodes occurs, the neighbors of the same hop level A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, characterized by grouping a node set into a cluster. The method according to claim 8, The second step, A twenty-first step of calculating a set of adjacent nodes based on each node having the same hop level and forming a cluster using the set; A twenty-second step of allowing each node to have the same transmission range after the twenty-first step so that each node has the same ID, and each node has a unique ID; A twenty-third step in which the upper node uses the information received from the lower node to know neighboring neighbor nodes and neighboring neighbor information between the lower nodes, and sequentially arranges adjacent nodes based on the neighbor information; A twenty-fourth step of forming a cluster around the center node of the sequential last set after the twenty-third step; A twenty-fifth step of forming a cluster around the center node of the cluster having the last element of the set of primary clusters as an initial element after the twenty-fourth level of the second cluster; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed. The method according to claim 2 or 5, The third step, A thirty first step of performing acquisition processing of basic node information after the first step; A thirty-second step of performing a selection process of an upper node when the next higher node overlaps after the first step; A thirty-third step of performing information acquisition process between the cluster head node or the forwarding node after the first step; A thirty-fourth step of performing information acquisition process between the cluster head node and the general node after the first step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed. The method according to claim 10, The thirty first step is A method for managing a cluster cluster topology of sensor nodes having dual transmission ranges, wherein each head node collects information of lower nodes using transmission power having a large transmission range in order to form a network between cluster head nodes. The method according to claim 10, The thirty-second step is When two or more second-order nodes overlap at an arbitrary hop level, the duplicated node selects a next-order node according to a predetermined criterion according to the application service characteristics of the entire system and transmits information. How to manage sensor clustering topology of nodes. The method according to claim 12, The criterion preset in the 32nd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, wherein an upper node having a large amount of power is selected. The method according to claim 12, The criterion preset in the 32nd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, characterized in that a node having a small number of holding cluster nodes is selected. The method according to claim 12, The criterion preset in the 32nd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, characterized in that selecting a node to designate a specific QoS. The method according to claim 12, The criterion preset in the 32nd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, wherein the upper node is selected at random. The method according to claim 12, The criterion preset in the 32nd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, characterized in that the node is sequentially selected to rotate. The method according to claim 12, The criterion preset in the 32nd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range, characterized by selecting a node having a relatively high or low ID. The method according to claim 10, In the 33rd step, The upper node broadcasts its own node ID information and cumulative hop count information from the highest node to the next lower node, and the lower node acquires the broadcasting information of the upper node and transmits its ID to the upper node. A method for managing sensor clustering topology of sensor nodes having a transmission range. The method according to claim 10, In the 33rd step, The next higher node manages the node information received from the lower node as a table, and the table includes the hop number information and ID of each lower node and adjacent node information of the lower node. How to manage your topology. The method according to claim 10, In the 33rd step, The lower node adds its level hop number 1 to the number of hops received from the next higher node, stores it in the table, and broadcasts the information stored in the table to discover the next lower node. To manage their sensor clustering topology. The method according to claim 10, In the 33rd step, And each node ignores the received information packet when receiving information having a hop number lower than the accumulated hop number stored in the node. The method according to claim 10, In the 33rd step, The inter-node information content of the 1-hop level includes a dual transmission range comprising at least one of ID information, cumulative hop count information, upper node information, lower node information, function information, data factor information, and power amount information. A method for managing sensor clustering topology of sensor nodes. The method according to claim 10, The 34th step is The general node constituting the cluster receives the topology information from the upper cluster head node to form a regional cluster. The method according to claim 10, The 34th step is The cluster head node broadcasts an initial command including its ID information to neighboring nodes using a transmission power having a transmission range smaller than that of the primary cluster head. How to manage a sensor clustering topology. The method according to claim 10, The 34th step is The general nodes analyze the command packet broadcast by the clusterhead and send a cluster join request command including their ID and information about the neighbor node to join the cluster. How to manage a sensor clustering topology. The method according to claim 10, The 34th step is The clusterhead manages the sensor clustering topology of the sensor nodes having a dual transmission range after analyzing and arranging the participation request packets of the general nodes and broadcasting by allocating beacon periods and duty times of the general nodes included in the cluster. Way. The method according to claim 10, The 34th step, A method of managing a cluster cluster topology of sensor nodes having a dual transmission range, wherein the general nodes of the regional cluster operate in a transmission / reception mode at their duty time and wait for a sleep state other than the duty time. The method according to claim 10, The 34th step is When information is exchanged between the cluster head node and the general node, the cluster head node transmits the information to the general node with ID information, cumulative hop count information, higher node information, neighbor head information, cluster node duty time information, function information, attribute information, and data. It includes one or more of the factor information and the amount of power information, and the general node transmits the information to the cluster head node, ID information, cumulative hop information, head node information, neighbor node information, node duty time information, function information And at least one of attribute information, data factor information, and reserved power amount information, and transmitting the sensor clustering topology of the sensor nodes having a dual transmission range. The method according to claim 3 or 5, The fourth step, The sensors may be configured to calculate their own power amount after being installed globally, and may be assigned a cluster head and a transfer node role or determine a general node role; Step 42, after each step 41, the node waits to receive a TP_INIT ₁ (topology initialization) command signal from an upper node; Step 43, after the step 42, each node receives the TP_INIT ₁ (topology initialization) command signal two or three times and transmits a TP_REP ₁ (topology response) command signal to a higher node; A 44th step in which the upper node receiving the TP_REP ₁ (topology response) command signal transmits a TP_ADV ₁ (topology notification) command signal to each node that has sent the TP_REP ₁ (topology response) command signal after the 43rd step; A forty-fifth step in which each cluster receiving the TP_ADV ₁ (Topology Notification) command signal after the 44th step checks clustering around the head and then exchanges data with each other; After clustering from the upper node after the 45th step, the primary clusters send and receive normal communication, and the upper node reduces the transmission range by lowering the transmission power value to implement the secondary clustering configuration for the general nodes within the reduced transmission range. A forty sixth step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed. The method of claim 30, The signal data in the 43rd step is A method for managing a sensor clustering topology of sensor nodes having a dual transmission range characterized by applying a transmission method in IEEE 802.11 Mac. The method of claim 30, In step 44, the TP_ADV ₁ (topology notification) command signal data includes: A method for managing a sensor clustering topology of sensor nodes having dual transmission ranges, comprising cluster unit information of nodes and information of ID and cluster head. The method of claim 30, The fourth step, After the 46th step, the TP_REP ₂ (Topology Response) command signal is transmitted from the lower node to the upper node, and the upper node transmits information to the secondary cluster nodes using the TP_ADV ₂ (Topology Notification) command signal data. step; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that it further comprises. The method according to claim 33, The fourth step, The second step 47 after configuring clustering Dara parent node in each layer using TP_INIT _n (topology initialization) and TP_REP _n (topology response) and TP_ADV _n (topology notification) command signal, and after a predetermined time TP_REP _n ( Step 48), if the command signal does not occur, the upper node finally sends a TP_CONF (Topology Confirmation) command signal to complete the clustering configuration; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that it further comprises. The method according to claim 4 or 5, The fifth step, A new or mobile node periodically transmits a TP_REP (Topology Response) command signal to a neighbor node as a beacon signal after a predetermined time; A 52nd step of receiving, after the 51st step, a cluster head node or a forwarding node within the transmission distance by receiving a transmitted beacon signal; After the 52nd step, the clusterhead processes the newly registered node information locally, transmits the new node information added when transmitting topology information to the upper node, and adjusts the beacon period and duty time to reconfigure the internal node of the cluster. A fifty-seventh step of adjusting time scheduling by updating information in the second information; Sensor clustering topology management method of the sensor nodes having a dual transmission range, characterized in that performed.

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