In Network Processing and Data Aggregation in

Figure 3. Aggregation tree is a reverse multicast treeThe plan for the remainder of this paper is as follows: In Section 2, we present themain networking issues of the wireless sensor networks and also the data-centric routing.In section 3 we discuss the data aggregation problem and distinguish the different typesof aggregates that may be computed over a WSN. In section 4 we make a taxonomy ofthe current aggregation techniques that are widely accepted. In section 5 we review themain trade-offs resulting from the use of data aggregation. Section 6 consists of the finalsolution of the paper.