KR20140001312A - Method for supproting mobility of sensor network - Google Patents

Abstract

When a layer identifier of a sensor node is changed as the sensor node moves from a first network area to a second network area in a sensor network, the sensor node receives a renewal request of the layer identifier and transmits the request to a server. The server stores a profile of the sensor node by using the layer identifier as a key and supports the mobility of the sensor node by renewing the layer identifier of the sensor node according to the renewal request of the layer identifier of the sensor node. [Reference numerals] (100a,100b) Sensor node; (200a,200b) PAN coordinator; (300) Gateway; (400) Server; (500) Profile database

Description

How to Support Mobility in Sensor Networks {METHOD FOR SUPPROTING MOBILITY OF SENSOR NETWORK}

The present invention relates to a method for supporting mobility of a sensor network, and more particularly, to a method for supporting mobility of a mobile sensor node in a sensor network.

The sensor network system generally consists of a mobile sensor node with a built-in sensor, a personal area network (PAN) coordinator that manages the home network of the mobile sensor node, and a gateway for delivering actual data to a server through communication between the mobile sensor node. . In the sensor network system, the mobile sensor nodes and the PAN coordinator have a hierarchical structure.

Mobility support in sensor network systems has been recognized as an important technology. As the mobile sensor node moves out of the home network and moves into a new network, the network topology changes. Therefore, when the mobile sensor node moves from the home network to the new network, the mobile sensor node needs to register its profile with the server. Since the profile is large, network traffic due to profile registration of the mobile sensor node is increased. .

The technical problem to be solved by the present invention is to provide a mobility support method of the sensor network that can minimize the increase in network traffic due to mobility support.

According to an embodiment of the present invention, a method for supporting mobility of a sensor node in a sensor network is provided. In the mobility support method of a sensor node, when the layer identifier of the sensor node is changed as the sensor node moves from the first network region to the second network region, receiving a request for updating the layer identifier from the sensor node, and the request Delivering to the server. At this time, the server stores the profile of the sensor node with the layer identifier as a key, and updates the layer identifier of the sensor node according to the request, wherein the layer identifier is a value of the upper layer resource of the sensor node in the second network area. It may be generated using a local identifier and a local identifier of the sensor node.

According to an embodiment of the present invention, an increase in network traffic due to profile registration of a sensor node can be minimized by updating a layer identifier of a sensor network resource.

In addition, it is possible to support mobile location tracking services while minimizing network traffic by updating layer identifiers of sensor nodes of the sensor network.

1 is a diagram illustrating a sensor network environment according to an exemplary embodiment of the present invention.
2 is a diagram illustrating an example of an identifier hierarchy structure of a sensor network resource according to an embodiment of the present invention.
3 is a diagram illustrating a method of updating a layer identifier of a sensor node in a sensor network according to an embodiment of the present invention.
4 is a diagram illustrating a location tracking method of a sensor node in a sensor network according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention. In order to clearly illustrate the present invention, parts not related to the description are omitted, and similar parts are denoted by like reference characters throughout the specification.

Throughout the specification and claims, when a section is referred to as "including " an element, it is understood that it does not exclude other elements, but may include other elements, unless specifically stated otherwise.

Now, a method for supporting mobility of a sensor network according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a diagram illustrating a sensor network environment according to an exemplary embodiment of the present invention.

Referring to FIG. 1, a sensor network includes a plurality of mobile sensor nodes (hereinafter, referred to as “sensor nodes”) 100a and 100b, PAN coordinators 200a and 200b, a gateway 300, a server 400, and a profile database ( 500).

The gateway 300 and the server 400 may be connected to an IP-based network, and the PAN coordinators 200a and 200b may be mounted to the gateway 300.

Sensor nodes 100a and 100b may include at least one sensor 110 and / or actuator 120. The sensor 110 wirelessly senses environmental information such as ambient temperature, light, acceleration, or the like, for example, physical state information and recognition information about the actuator 120, depending on the type. The actuator 120 has a function of operating a predetermined device or turning on or off a predetermined device.

The sensor nodes 100a and 100b may transmit data sensed by the sensor 110 to the PAN coordinators 200a and 200b, respectively, and control the operation of the actuator 120. In this case, data of the sensor nodes 100a and 100b may be transferred to the PAN coordinators 200a and 200b through multi-hops, respectively.

The PAN coordinators 200a and 200b manage the sensor nodes 100a and 100b in their networks 20a and 20b and receive data from the sensor nodes 100a and 100b in their networks 20a and 20b. To the gateway 300.

The gateway 300 transmits the sensing data received through the PAN coordinators 200a and 200b to the server 400. The gateway 300 supports a multimode-multichannel communication protocol for connection of the server 400 and the sensor nodes 100a and 100b.

The server 400 stores and manages sensing data received from the gateway 300.

In addition, the server 400 registers and registers profiles of all resources of the sensor network, for example, the sensor nodes 100a and 100b, the PAN coordinators 200a and 200b, and the gateway 300. The registration order of the profile may be performed in order of the gateway 300, the PAN coordinators 200a and 200b, and the sensor nodes 100a and 100b.

The profile may include a resource management application programming interface (API) and additional information. The resource management API provides functions such as initializing access to a resource, activating a resource, setting a deactivation cycle, and monitoring a resource. The additional information may include a local identifier of a resource, a universal identifier and a layer identifier, a type of resource, a unit of resource, a type of sensing data, and the like.

The sensor nodes 100a and 100b, the PAN coordinators 200a and 200b and the gateway 300 store and manage their own profiles. The sensor nodes 100a and 100b, the PAN coordinators 200a and 200b, and the gateway 300 may store and manage their own profiles in a nonvolatile memory.

The sensor nodes 100a and 100b, the PAN coordinators 200a and 200b and the gateway 300 transmit the profile to the server 400 when the local identifier is changed or connected to a new network.

The server 400 stores and manages a resource profile of the sensor network in the profile database 500. In particular, the server 400 may define hierarchical identifiers and universal identifiers of the sensor nodes 100a and 100b as search keys and store the profiles of the sensor nodes 100a and 100b in the profile database 500. Therefore, the server 400 may track the moving object to which the sensor nodes 100a and 100b are attached using the profile of the sensor nodes 100a and 100b.

The profile database 500 stores resource profiles of the sensor network. The profile database 500 may be implemented in the server 400.

 2 is a diagram illustrating an example of an identifier hierarchy structure of a sensor network resource according to an embodiment of the present invention.

In FIG. 2, only one sensor node 100a, one sensor 110, and one actuator 120 are illustrated for convenience of description.

As shown in FIG. 2, the server 400, the gateway 300, the PAN coordinator 200a, the sensor node 100a, and the sensor 110 and / or the actuator 120 may have a local identifier (LID). Has

The LIDs of the server 400 and the gateway 300 are allocated according to an International Mobile Station Identity (IMSI) or Internet Protocol (IP) address system, which is a number system of a mobile communication network.

The PAN coordinator 200a, the sensor node 100a, the sensor 110, and / or the actuator 120 may be assigned by a user or according to a self-identification scheme defined in a sensor network such as Zigbee, Bluetooth, or PAN. .

On the other hand, when the sensor node 100a is attached to the moving object to be tracked, the sensor node 100a may have a global IDentifier (GID) as well as an LID. GIDs are assigned according to globally uniquely identified address systems, such as IPv6 addresses or Mobile Station International Subscriber Directory Numbers (MSISDNs).

In addition, the gateway 300, the PAN coordinator 200a, the sensor node 100a, the sensor 110, and / or the actuator 120 may provide a hierarchical ReSourCe IDentifier (RSCID) indicating location information on a resource. Have

That is, the sensor network has a hierarchical structure in order of the gateway 300, the PAN coordinator 200a, the sensor node 100a, the sensor 110, and / or the actuator 120. Accordingly, RSCIDs of the gateway 300, the PAN coordinator 200a, the sensor node 100a, the sensor 110, and / or the actuator 120 each represent their hierarchical location information.

Specifically, since the gateway 300 is a top layer, the RSCID of the gateway 300 may be set to the LID of the gateway 300. Since the PAN coordinator 200a is located below the gateway 300, the RSCID of the PAN coordinator 200a may be set by combining the LID of the gateway 300 and the LID of the PAN coordinator 200a. In this manner, the RSCID of the sensor node 100a may be set by combining the LID of the gateway 300 with the LID of the PAN coordinator 200a and the LID of the sensor node 100a. In addition, the RSCID of the sensor 110 may be set by combining the LID of the gateway 300 and the LID of the PAN coordinator 200a, the LID of the sensor node 100a, and the LID of the sensor 110, and the The RSCID may be set by combining the LID of the gateway 300, the LID of the PAN coordinator 200a, the LID of the sensor node 100a, and the LID of the actuator 120.

For example, as shown in FIG. 2, the LID of the gateway 300 is www.gw.com, the LID of the PAN coordinator 200a is 1, the LID of the sensor node 100a is 1, and the sensor ( When the LID of 110 is 1, the RSCID of the gateway 300 may be set to www.gw.com, the RSCID of the PAN coordinator 200a may be set to www.gw.com/1, and the sensor node ( RSCID of 100a) may be set to www.gw.com/1/1, and RSCID of sensor 110 may be set to www.gw.com/1/1/1.

The sensor node 100a transmits its profile to the server 400 when its LID is changed or connected to a new network. The server 400 uses the RSCID and the GID of the sensor node 100a as a search key. Update the profile of node 100a.

3 is a diagram illustrating a method of updating a layer identifier of a sensor node in a sensor network according to an embodiment of the present invention. In FIG. 3, the gateway 300 is omitted for convenience of description, but the communication between the PAN coordinator 200b and the server 400 is performed through the gateway 300.

The update of the layer identifier of the sensor node 100a occurs when the sensor node 100a needs to newly search and connect to the network. For example, this occurs when the LID of the sensor node 100a is changed or connected to a new network.

Referring to FIG. 3, if communication with the network to which the sensor node 100a is connected is not possible, the sensor node 100a searches for a new network and accesses the new network (S310).

The sensor node 100a transmits an ancestor profile request message to the PAN coordinator 200b of the new network (S320).

The PAN coordinator 200b transmits the LIDs of the PAN coordinator 200b and the gateway 300 to the sensor node 100a through an ancestor profile response message (S330).

The sensor node 100a obtains the LID of the upper layer resources, that is, the PAN coordinator 200b and the gateway 300, in the new network through an ancestor profile response message. Alternatively, the sensor node 100a may acquire the LIDs of the PAN coordinator 200b and the gateway 300 through a beacon message periodically broadcasted by the PAN coordinator 200b mounted on the gateway 300. have. Of course, in this case, the beacon message includes the LIDs of the PAN coordinator 200b and the gateway 300.

Next, the sensor node 100a generates an RSCID of the sensor node 100a using the LID of the sensor node 100a, the acquired PAN coordinator 200b, and the LID of the gateway 300 (S340). In this case, the LID of the sensor node 100a may be newly assigned by the PAN coordinator 200b.

When the sensor node 100a differs from the most recently maintained RSCID (A) and the newly generated RSCID (B) value (S350), the sensor node 100a receives the RSCID (A, B) through the layer identifier notification message (RscIdUpdateNotification). 200b), the PAN coordinator 200b transmits a layer identifier notification message (RscIdUpdateNotification) to the server 400 (S370). In this case, the sensor node 100a may request the server 400 to update the RSCID through the layer identifier update request (RscIdUpdateReqeust) message through the PAN coordinator 200b.

When the server 400 receives the layer identifier notification message RscIdUpdateNotification, the server 400 updates the RSCID (A) to the RSCID (B) in the profile database 500. That is, the server 400 retrieves RSCID (A) from the profile database 500 and updates RSCID (A) with RSCID (B).

In addition, the server 400 extracts the LID of the gateway 300 from the RSCID (A) as needed and provides the extracted gateway 300 with the address of the sensor node corresponding to the LID of the sensor node constituting the RSCID (A). It may be required to recover.

That is, when the sensor node 100a is connected to a new network, the sensor node 100a transmits the changed RSCID of the sensor node 100a to the server 400 unlike the conventional method. Then, the server 400 updates only the RSCID of the sensor node 100a in the profile database 500. In this way, an increase in network traffic due to profile registration of the sensor node 100a can be minimized.

Next, a method of tracking the sensor node 100a in the server 400 will be described. In this case, it is assumed that the sensor node 100a is connected to the network area of the PAN coordinator 200b.

4 is a diagram illustrating a location tracking method of a sensor node in a sensor network according to an exemplary embodiment of the present invention. In FIG. 4, the gateway 300 is omitted for convenience of description, but the communication between the PAN coordinator 200b and the server 400 is performed through the gateway 300.

Referring to FIG. 4, the server 400 searches the RSCID corresponding to the GID of the sensor node 100a from the profile database 500 using the GID of the sensor node 100a to be tracked.

The server 400 transmits the sensor node 100a to the sensor node 100a through the PAN coordinator 200b using a sensor node trace request message including the retrieved RSCID (S410 to S420), and tracks the position of the sensor node 100a. To indicate.

The server 400 refers to the mapping information of the GID of the sensor node 100a and the LID of the gateway 300 to which the sensor node 100a belongs in the profile database 500, and the gateway 300 refers to the sensor node 100a. By maintaining the mapping information of the GID of the LID / LID of the sensor node (100a) of the PAN coordinator (200b), to transmit only the GID through the SensorNodeTraceRequest message between the server 400 and the gateway 300 You may. This reduces the packet size of the SensorNodeTraceRequest message, which in turn reduces network traffic.

When the sensor node 100a receives a SensorNodeTraceRequest message, the sensor node 100a receives GID and location information, for example, RSCID, Global Positioning System (GPS) value, and RSSI (Received) using a SensorNodeTraceResponse message. Signal Strength Indication) value and the like are transmitted to the server 400 through the PAN coordinator 200b and the gateway 300 (S430 to S440). In this case, a SensorNodeTraceNotification message may be used instead of a SensorNodeTraceResponse message.

The server 400 may store and manage location information transmitted by the sensor node 100a and provide a movement path tracking service using the location information transmitted by the sensor node 100a.

That is, when the RSCID is defined for the sensor nodes 100a and 100b in the sensor network, and the local identifier or the RSCID is changed according to the movement of the sensor nodes 100a and 100b, the server 400 in the sensor node 100a and 100b. By updating the profile of), the location tracking service of the moving object to which the sensor nodes 100a and 100b are attached can be enabled.

The embodiments of the present invention are not limited to the above-described apparatuses and / or methods, but may be implemented through a program for realizing functions corresponding to the configuration of the embodiment of the present invention or a recording medium on which the program is recorded, Such an embodiment can be readily implemented by those skilled in the art from the description of the embodiments described above.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

Claims (1)

As a method of supporting the mobility of sensor nodes in a sensor network,
When the layer identifier of the sensor node is changed as the sensor node moves from the first network region to the second network region, requesting an update of the layer identifier from the sensor node; and
Forwarding the request to a server,
The server stores a profile of the sensor node using a layer identifier as a key, and updates the layer identifier of the sensor node according to the request.
And the layer identifier is generated using a local identifier of a higher layer resource of the sensor node and a local identifier of the sensor node in the second network area.

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