On the deployment of large-scale wireless sensor networks considering the energy hole problem

Heterogeneous sensor networks have been proposed to address some fundamental limits and performance issues present in homogeneous Wireless Sensor Networks (WSNs). Questions such as the number of high-end sensors should be used, and how to deploy them, need proper assessment. In this work, we propose a novel model capable of representing a wide variety of scenarios, from totally random to planned stochastic node deployment in both homogeneous and heterogeneous sensor networks. In particular, this model encompasses networks with the characteristics of small-world networks. Using only about 3% of high-end sensors, and deploying nodes by using the slightly attractive model defined herein, we observe improved characteristics of the network topology, such as: (i) low average path length, (ii) high clustering coefficient, and (iii) improved relay task distribution among sensors. We also provide a guide for deploying nodes in order to improve the network lifetime, showing that the aforementioned model can be used to diminish the energy hole effect. Moreover, we evaluate a topological metric, namely Sink Betweenness, suitable for characterizing the relay task of a node.