Data Aggregation in Wireless Sensor Networks: A Multifaceted Perspective

Wireless sensor network applications usually do not require knowledge of each individual sensor measurement at the sinks; rather, an overall aggregate of the data monitored by different sensor nodes could be sufficient. Dealing with aggregated data is potentially highly convenient in the network perspective because it leads to a reduction in the overall energy consumption, even if the needed processing involves resource consumption. The reason is that through aggregation the unnecessary packets overhead is avoided and the waste of energy and bandwidth resources are reduced. Moreover, since during in-network data aggregation some pre-elaboration of the data can be made, several wireless sensor network applications may benefit from having this pre-elaborated data and may be facilitated in handling and processing the sensor measurements. Thus, data aggregation is a promising approach for improving the performance of sensor networks and has recently attracted the interest of researchers. In this chapter we provide a survey of the main approaches at data aggregation recently proposed and compare different potential perspectives for a data aggregation taxonomy in wireless sensor networks. Then, we introduce a more comprehensive classification which allows to embrace the existing ones and to incorporate the different phases of the data aggregation process: information description, propagation and preservation.