Automated Sensor Web Adaptation to Sensor Networks

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This thesis investigates the notion of a dynamic Sensor Web Language (SWL). As nodes appear and disappear in a Wireless Sensor Network (WSN), the protocols acting in the physical layer adapt dynamically to the new network structure. SWL is an extensible, object-oriented language and is especially useful for information transmission from the sensor nodes in the network to the web applications. A dynamic web architecture was extended from a mesh structure to provide automated web based response to changes in WSN. Two new message types, RequestAnnounce and Announce are added to the SWL grammar to support this adaptation. All software layers, including sensor nodes, gateway, base station (including the database) and the web applications were updated. Two web applications were implemented to display dynamic adaptation on the web clearly. A test network was established using 6 sensor nodes and 10 sensors (6 battery voltage sensors, 2 air temperature sensors and 2 solar radiation sensors), and 1 gateway. Each node was added one by one over 4 hours in the network, then removed one by one from the network over 4 hours. Testing indicates appearance of a node in the web application within seconds of being added to the WSN.