Date Added: Aug 2009
Answering queries with a low selectivity in wireless sensor networks is a challenging problem. A simple tree-based data collection is communication-intensive and costly in terms of energy. Prior work has addressed the problem by approximating query results based on models of sensor readings. This cuts communication effort if the accuracy requirements are loose, e.g., if the temperature is required within ?0.5◦C. For more accuracy, the models need frequent updates, and the communication costs quickly increase.