Data Aggregation Algorithms for Wireless Sensor Network: A Review Abstract   In recent years, wireless sensor network (WSN) is one of the rapidly growing area in various domains such as disaster relief operation, military applications, health applications, etc. In WSN, to eliminate the redundant information from the gathered data, data aggregation is a prime approach by which we can considerably reduce the energy consumption of each node. This reduction supports the achievement of the higher lifetime of WSN. In this paper, we have endeavored to introduce a review of various existing data aggregation algorithms in the literature. We have also tried to summarize all these existing data aggregation algorithms on the basis of different performance metrics such as energy consumption, network lifetime, delay, energy cost, etc. Finally, this paper supports the reader an idea to select the data aggregation algorithm for the desired application.

Data Exchange in Cluster Structure for Longevity of IoT In the Internet of Things (IoT), the scope of wireless sensor nodes is extended to things deployed in a pervasive world. For various IoT service applications, things can gather and share their information with each other through selfdecisionmaking. Therefore, we cannot apply the existing information aggregation methods of wireless sensor networks to the IoT environment, which aim to transmit the collected data to only a sink node or a central server. Moreover, since the existing methods involve all the sensor nodes in the process of data exchange, they can cause an increase in the network traffic, delay of data transmission, and amount of energy consumed by things. In this paper, we propose a clusteringpropertybased data exchange method for efficient energy consumption in IoT networks. First, the proposed method assigns properties to each thing according to the characteristics of the obtained data. Second, it constructs a cluster network considering the location of things and their energy consumption. Finally, the things in a cluster communicate with other things in a different cluster based on their properties. In the experiment, the proposed method exhibits a better performance than the existing method. Owing to the energysaving effect, we demonstrate that the proposed method results in a more reliable network and improves the longevity of IoT networks.