Date Added: Jun 2011
Top-k query is a very useful and important query in Wireless Sensor Networks (WSNs), aiming to find the k nodes with highest readings among the sensor nodes. In WSNs, there are generally two kinds of networks: Always-On WSNs (AO-WSNs) in which sensors always keep awake and Duty-Cycled WSNs (DCWSNs) where sensors dynamically sleep and wake. To the best of the authors' knowledge, there are a lot of work about top-k query in AOWSNs but little research has been done regarding top-k query in DC-WSNs. However, DC-WSN is a very practical network model in which energy consumption can be greatly saved.