KR20100074410A - Overlay interlocking architecture and system thereof for sharing sensor network - Google Patents

Abstract

PURPOSE: An overlay-based coupling architecture for sharing a sensor network is provided to search various sensor networks by enabling access of an external network to a sensor network through a sync node and the data transmission of a heterogeneous sensor network through a peer to peer service. CONSTITUTION: An overlay network integrates sensor networks. A sensor peer to peer is embodied in the overlay network. The sensor network is united with the sensor peer to peer. A user terminal joins the sensor peer to peer as a peer. The user terminal searches the sensor network. The user terminal obtains sensing information from the sensor network.

Description

OVERLAY INTERLOCKING ARCHITECTURE AND SYSTEM THEREOF FOR SHARING SENSOR NETWORK}

The present invention relates to an overlay-based interworking architecture and a device for sharing a sensor network, and more particularly, an overlay for sharing a sensor network in which a user terminal can find a desired sensor network regardless of geographical location and utilize the sensing information. It relates to an underlying interworking architecture and its apparatus.

With the advent of ubiquitous societies, networks have become so large that they can't be bound. Beyond the existing network where users became members of the virtual society by accessing the network through the Internet, the network now exists in the user's environment and the user has crossed the physical and virtual society without knowing the existence of the network. .

In Korea, under the U-Society plan, a project to build a national-led sensor network is underway. In addition, several universities in Korea are constructing sensor network systems of various sizes for research purposes. The sensor network pilot projects that have been conducted in Korea so far focus on the functions of management / monitoring such as water quality monitoring, weather / ocean observation, bridge safety, and cultural property management, and the planned projects also focus on similar functions.

These sensor networks are currently simply collecting and transferring data from the various sensors installed within the environment. In addition, the use of the data has been shown to be accessed and used only by the party who established the network. As a result, data to be processed into various services is not widely used due to the closedness of the sensor network.

Next, a sensor network and an internet interworking technology will be described to help understanding of the present invention.

(1) Gateway (Proxy) based interworking

Gateway (Proxy) based interworking is a method of placing a proxy or gateway that performs a protocol conversion function between the sensor network and the Internet (see Fig. 1). This method can be applied by implementing only a gateway (proxy) that is responsible for packet conversion. Proxy server can be implemented in relay or front-end format. The former is a method of receiving and recording information on data of interest from a user and transferring the data received from the sensor network to the corresponding user. The latter stores the data received from the sensor in a database in the proxy and the user can request that information by sending a query such as SQL. However, it has the disadvantage of not being able to request data or send a command directly to a specific sensor network from an external network. In addition, among gateway-based internet linkage techniques, there is a technique using a Delay Tolerant Network (DTN) gateway (see FIG. 2).

(2) Overlay based interlocking

TCP / IC Overlay Network

The combination of the WSN (Wireless Sensor Network) and the Internet using the TCP / IC Overlay technique is a method of constructing an overlay network using IP on the WSN. This technique implements an IP protocol stack and assigns an IP address to sensor nodes on WSN to form an overlay network that sends and receives data through IP packets. In this case, since it is impossible to upload IP to all sensor nodes due to resource constraints, the IP protocol is uploaded to some nodes that can be processed (see FIG. 3). This method allows some selected nodes to have an IP stack that allows direct communication with a host on the Internet, but has the problem of address assignment and significant overhead on the sensor network.

(B) Overlay Sensor Network

This technique is to configure the overlay sensor network using the sensor network stack to interface with the WSN to the host located on the Internet. In this method, underlying Internet protocols provide an overlay service so that a user terminal of the Internet may be a sensor network node (see FIG. 4). That is, in this method, the data-oriented sensor network routing scheme is extended to the application layer overlay sensor network on the Internet to interwork the internet and sensor network. This method enables communication between the sensor node and the Internet host, but the protocol overhead can be large for the virtual sensor node.

Next, the sensor network and P2P network technology will be described.

In general, the model of implementing P2P network in sensor network is classified as follows.

a. P2P network composed of sensor network (see Fig. 5)

b. P2P network consisting of sensor nodes (see Figure 6)

c. P2P network consisting of sensor network and sensor node

 a indicates that a sink or gateway representing the sensor network functions as one peer on the P2P network. Sink nodes have more computing power and resources than general sensor nodes, so that the functions of P2P networks used on the Internet can be used as they are.

b configures the P2P network by operating the sensor nodes inside the sensor network as one peer. Depending on the sensor network protocol and the computing power of the sensor node, the P2P network used may differ. In general, it is difficult to build a P2P network such as Structured P2P using a hash function because the sensor node has a lower capability than the sink node.

c is a network consisting of a mixture of a and b. In each case, a and b can participate in the P2P network, so each sensor node must have a unique ID of the entire P2P unit.

Next, the P2P based sensor network service will be described.

The sensor network can be fixed or mobile locally or remotely and the user can also be a static terminal or a dynamic terminal. Therefore, there is a need for a method for making sensor network information available to a user regardless of location. In addition, as sensor and network types are diversified, methods for finding sensor services and communication protocols must be flexible and support various types of sensors and services.

(1) Sharing Sensor Networks

This method is a P2P model utilizing the Universal Plug and Play (UPnP) standard for sharing sensor network information (see FIG. 7). This model consists of P2P Bridge, P2P UPnP Gateway, P2P Substrate, and UPnP Proxy. The P2P Bridge acts as a gateway between the sensor network and the Internet and as a peer node of the P2P model. That is, the received sensing data is analyzed and organized into attribute data of a sensor node capable of providing P2P service. Peer node can find desired sensor node by requesting Discovery Query to P2P Substrate. P2P UPnP Gateway provides an interface for users to access sensor information through P2P service. That is, in this model, user application services cannot send queries directly to sensor peer nodes, but are serviced through UPnP Proxy. Therefore, clients that do not use UPnP cannot receive services. The UPnP Proxy is indicated by the UPnP Gateway for each type of sensing service.

(2) PIAX-based Sensor P2P Model

PIAX was developed to handle information from ubiquitous devices. PIAX works in conjunction with P2P networks and agents. Agents are injected into the P2P network and may be copied and moved to other peer nodes. PIAX simultaneously places multiple P2P overlay networks and selects the P2P overlay network that best suits the user's needs (see Figure 8). Therefore, P2P overlays are provided for each type of sensing data and service type (eg, video streaming, temperature information, etc.), and P2P is selected and sent according to the user's request. This property is called Multi-Overlay. This model requires the construction of multiple overlay networks, which requires a lot of resources with technical complexity.

The present invention provides an overlay-based interworking architecture and apparatus for sharing a sensor network that enables a user terminal to find a desired sensor network regardless of geographic location and utilize sensing information through sensor data sharing to overcome limitations of the conventional sensor network. To provide.

The present invention provides a sensor network, an overlay network for integrating the sensor network, a sensor P2P implemented in the overlay network and joining the sensor network, and participating in the sensor P2P as a peer to search for a sensor network. An overlay-based interworking architecture for sharing a sensor network, comprising: a user terminal for acquiring sensing information from a corresponding sensor network.

The sink node of the sensor network may include a sink module for analyzing and processing sensing information received as a gateway, extracting data information corresponding to a user request, and storing the data information in a database, and an overlay node module for configuring an overlay network; And a sensor P2P node module for providing sensing information to a user terminal according to a request of the sensor P2P node.

In addition, the user terminal peer node includes a Pastry module that provides a P2P overlay service, a Scribe that provides peer-to-peer interaction, authentication, retrieval, and multicasting of real-time data on the overlay, and a PAST that supports non-real-time data. An overlay based interworking architecture for sensor network sharing, comprising: a.

The present invention is implemented based on the map so that the user can easily know the geographic location of the sensor network including the user, the web application portion including a communication unit for loading an open API and get information from the user GUI; A communication unit for querying Pastry or transferring information to the web application unit based on the information input through the information input through the user GUI interface, and a graphic unit for displaying real-time data and non-real-time data based on a search result. An overlay-based interworking architecture device for sensor network sharing, characterized by consisting of JAVA parts.

The corresponding sensor load of the Pastry has the region, organization, node type, sensing data type, GPS information of the sensor node overlay-based interworking architecture device for sharing the sensor network.

According to the present invention, an external network accesses a sensor network through a sink node, and data of a heterogeneous sensor network is transmitted through a P2P service on an overlay network, so that various sensor networks can be easily searched for and used by the sensing information. There is.

Hereinafter, with reference to the accompanying drawings will be described in detail the preferred embodiment of the overlay-based interlocking architecture and apparatus for sharing the sensor network according to the present invention.

9 is a schematic diagram of an overlay-based interworking architecture for sensor network sharing in accordance with the present invention.

Referring to the figure, various types of sensor networks, which are installed for various purposes in the ubiquitous society, are integrated on the overlay network, and the user can sense sensor information of each sensor network from the peer node in the overlay network. You can get services through the network. The sensor network portion of the P2P USN targets a variety of physical sensor networks, with each node's sink node participating in the sensor P2P on the overlay as a peer node. The user terminal participates in the sensor P2P as a user node and becomes a subject requesting an application service.

That is, as shown in FIG. 10, the user requests the P2P USN to obtain information, and the P2P USN analyzes the requested information to connect the user to the sensor network that matches the information.

Here, the P2P structure is based on Pastry (Ref. A. Rowstron and P. Druschel, "Pastry: Scalable, decentralized object location and routing for large-scale peer-to-peer systems". IFIP / ACM International Conference on Distributed Systems Platforms (Middleware), Heidelberg, Germany, pages 329-350, November, 2001.)

Next, the implementation of the architecture will be described.

In general, sensor networks can use a variety of network structures and protocol stacks, depending on their implementation purposes. In the present invention proposed for integrating these heterogeneous sensor networks, the overlay sensor network interworking method and the P2P network method composed of the sensor network described above were used. The sink node of each sensor network participates in the overlay network as a gateway of the corresponding sensor network.

Here, each sink node has a different hardware structure according to the characteristics of the corresponding network. Therefore, the sink node must be implemented independently of hardware, and its structure is shown in FIG.

In the figure, the sink module analyzes / processes the received sensing information, extracts information corresponding to a user request, and stores the information in a database. It also performs sink node functions of general USN such as sensor node management in the sensor network. 12 shows an execution screen of the sink module.

The overlay node module is software for configuring an overlay network and the Sensor P2P node module is P2P node software for configuring a P2P sensor framework (see FIG. 13).

The application service module receives the sensing information from the database or directly according to the request of the P2P node and provides it to the P2P user.

In the present invention, the sink node processes the sensing information into real-time data and non-real-time data. In the case of real-time data, it is delivered directly to the P2P module for real-time service, but in the case of non-real-time data, a file is created for sharing of sensing information and delivered to the P2P module by request. The message structure of the real time data is as shown in Figs. 14A and 14B, for example.

GPS info is the physical location of the network and location is the name of the organization. The file name of the non-real-time data is shown in FIG. 15 as an example. In the case of non-real-time GPS information indicating the physical location of the network is stored in the header of the file. The configuration and management program of the sink node implemented based on this is shown in FIG. 16 as an example.

Subsequently, the overlay P2P network will be described.

There are two types of service methods of P2P networks, Unstructured P2P and Structured P2P. Unlike Unstructured P2P, where all network information is managed by all nodes or by one node, Structured P2P maintains and maintains information about each node's part of the entire network. This is a distributed hash table (DHT) that provides distributed indexing, and uses a distributed-content-addressing-based data storage scheme where content storage and retrieval are performed by mapping content and peer information into a common single address space. The main algorithms of DHT are Chord, Pastry, and CAN. In the present invention, Pastry is applied. In a Pastry-based P2P architecture, users who want to share sensor networks join as peers of a Pastry P2P system and form an overlay network on Pastry between them. Each user computer on the Internet joins this overlay network as one Pastry peer node to share data. The stack structure of each peer node is shown in FIG. 17 as an example.

PSN (P2P Sensor) including detailed modules such as Pastry module which provides P2P overlay network service, Scribe which provides peer interaction, authentication, search, and multicast of real-time data on overlay and PAST supporting non-real time data. Net) module is a key part of the overlay P2P network implementation.

Due to the routing function by the content provided by Pastry, each Pastry node can be considered connected on the Pastry ring, and each node has a 128-bit node ID generated by the hash function given by Pastry ( 18).

Next, a service apparatus of an architecture implemented as described above will be described.

The existing USN application service used a method of processing only the information provided by the corresponding sensor network and delivering it to the user, so the scope of the service was limited. Currently, the USN application service shown in the national pilot project deals only with the information of the specific sensor network that is established, and the user is provided with only passive services such as monitoring of the sensor network. In this way, the sensor P2P application was implemented to share the data of various sensor networks already established and to use it as a resource of application service.

When sensor P2P can be used to share data from heterogeneous sensor networks, it is possible to build active application services that other sensor networks can respond to based on the information provided by specific sensor networks. As a result, the sensor P2P application can be used to lay the foundation for active application services.

The sensor P2P application enables the USN application service by using the sensing information desired by the terminal and searching for various types of sensor networks regardless of the sensor network and the geographical location of the user.

In the figure, the web application part was written using JavaScript and Ajax and implemented based on a map so that users can easily know the geographical location of the sensor network including themselves.

The web map uses the Google Maps Open API, which supports GPS coordinates WGS-84. The marker indicating the specific position and the information window of each sensor network are the details of the graphic part. The communication part that loads the open API and retrieves information from the user GUI is also part of the web application. The JAVA (SWT / Applet) part consists of a communication unit that queries Pastry based on the information entered by the user through the GUI interface or delivers the information to a web application, and a graphic unit that displays real-time and non-real-time data based on the search results. It became.

Each sensor node has topic information. A topic is an identifier of a unique sensor node that contains information such as region, organization, node type, sensing data type, and GPS information of the sensor node.

The sensor node displays its information as a topic, and creates a unique broadcasting group to transmit sensing data in real time to the connected P2P peer.

20 is a main screen when executing implemented Map-Based sensor network search application software. The left side is the web application part and the right side is the JAVA (SWT / Applet) part. The user enters details about his location and sensor search in the GUI Sensor Search tab on the right and starts the search. 21 is a search result screen (a is a map, b is a list).

As a result of search, your location and searched sensor network are displayed on the map with markers. If you click the mark, detail window will appear with Zoom-In. For a list of search results, see the Text-based search tab. The user can know the detailed information of a specific sensor network, such as the number and type of sensor nodes, based on the search results.

The user can select real-time / non-real-time data characteristics with the selection of the sensor node and type of the selected sensor network (see FIG. 22). In the case of real-time data transmission, as shown in FIG. 23, a graph according to the data value is drawn on the top, and the raw data value of the corresponding data is displayed on the bottom.

Accordingly, regardless of the geographic location of the sensor network and the user, the terminal can find various types of sensor networks and utilize desired sensing information.

The above description is not limited to the present invention as an embodiment according to the present invention, it is to be understood that it can be carried out in various ways within the scope of the technical idea described in the claims of the present invention.

1 to 8 is a reference diagram for helping the understanding of the present invention,

9 to 23 are explanatory diagrams according to the present invention.

Claims (5)

Sensor network, An overlay network for integrating the sensor network; A sensor P2P implemented in the overlay network and joined by the sensor network; An overlay-based interworking architecture for sensor network sharing, comprising: a user terminal for participating in the sensor P2P as a peer, searching for a sensor network, and obtaining sensing information from the sensor network. The method of claim 1, The sink node of the sensor network analyzes and processes sensing information received as a gateway to extract data information corresponding to a user's request and store it in a database, an overlay node module for configuring an overlay network, and a sensor P2P. An overlay-based interworking architecture for sensor network sharing comprising a sensor P2P node module for providing sensing information to a user terminal according to a node's request. The method of claim 1, The user terminal peer node includes a Pastry module that provides a P2P overlay service, a Scribe that provides peer-to-peer interaction, authentication, retrieval, and multicasting of real-time data on the overlay, and a PAST that supports non-real-time data. Features an overlay-based interlocking architecture for sensor network sharing. A web application part that is implemented based on a map so that a user can easily know the geographical location of the sensor network including the user, and includes a communication unit that loads an open API and retrieves information from the user GUI; A communication unit for querying Pastry or transferring information to the web application unit based on the information input through the information input through the user GUI interface, and a graphic unit for displaying real-time data and non-real-time data based on a search result. An overlay-based interworking architecture device for sensor network sharing, characterized by consisting of JAVA parts. The method of claim 4, wherein The Pastry-based sensor load has an area, organization, node type, sensing data type, and GPS information of a sensor node.

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