2. DATA AGGREGATION RELATED ISSUES IN WIRELESS SENSOR NETWORKS AND THE NEW SECTORAL SWEEPER SCHEME Ayhan ERDOĞAN, 2003

Keywords :  Wireless Sensor networks, Data Aggregation, Received Signal Strength Indicator, Task Dissemination, Directional Antenna, Sectoral Sweeper.  

In this thesis, we review the data aggregation related issues in Wireless Sensor Networks to gain a global view of current research areas and hot topics. The sectoral sweeper scheme is also introduced where a central node that has a directional antenna broadcasts tasks, after supplying a basic technical background about the components of the new scheme. Nodes which receive a task start sensing and generating reports. Hence nodes at a specified region can be activated or deactivated at any time. Tasks are also associated with a unique identification for each region. Sensor nodes include related task identifications and received signal strength indicator in their messages. By using this data, the location of the sensor nodes can be estimated with a resolution high enough for many applications. Since our scheme does not require any additional software or hardware for node management and location estimation in sensor nodes, the deficiencies of tiny sensors are effectively eliminated. Our scheme also reduces energy consumption considerably and provides immediate task dissemination.