Abstract
In wireless sensor networks, sensor nodes send event data to sink nodes. However, when several neighboring nodes sensed the same event and send the sensed data to a sink node, the nodes on the path from the event region to the sink node have to forward many similar data packets, and unnecessary energy costs are introduced. In this thesis, data packets are collected by local collection nodes. Each local collection node sends its collected data to a globally-known index node after it received the event data. When a sink needs to obtain some event data, it sends a query packet to the index node. The query packet will be forwarded to the local collection node which has the request data. Then the local collection node transfers event data to the sink node. Data packets are forwarded to the local collection nodes based on the attraction value of nodes, which can be computed by an attraction function. When a node want to forward its sensed data packet to the local collection node, it uses the attraction function to compute the attraction value of neighboring nodes and forwards data packets to the neighboring node with the highest value. Simulation results show that our proposed scheme has a superior performance in control overhead and number of data packet forwards to previous work.