Data Aggregation in Wireless Sensor Networks

Recent advancements in wireless communication and electronics have led to the development of low-cost wireless sensor networks (WSNs). A wireless sensor network consists of a large deployment of sensor nodes across a geographical area. When radio applications are considered, the sensor nodes sense the data and broadcast the sensed data to the destination or access point. In most applications, the sensor nodes are powered using batteries which are not rechargeable. In remote applications, it is even impossible to replace the batteries. Hence it is important to extend the network lifetime by minimizing the energy consumption of sensor nodes. It is essential to develop energy-efficient strategies to minimize the usage of battery power. Cooperative Multiple-Input-Multiple-Output (CMIMO) is a technique which is adopted in cluster-based WSN to bring in cooperation among the sensor nodes in a particular cluster. This technique exploits the multiple antennas present and cooperatively transmits the data to access point, thereby reducing the transmission energy. Data Aggregation is a technique which is combined with CMIMO to reduce the energy cost further by reducing the amount of data in transit. It is believed that closely spaced sensor nodes sense data that are spatially correlated. Thus redundancy exists in the data, which can be removed by data aggregation. The amount of data transmitted to the access point is thus reduced and the transmission cost is also reduced.