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Claudio M. de Farias 1 and Luci Pirmez 1 and Luiz F. R. C. Carmo 1, 2 and Davidson Boccardo 2 and Flavia C. Delicato 1 and Igor L. dos Santos 1 and Renato Pinheiro 1 and Rafael O. Costa 1
Academic Editor:Raffaele Gravina
1, Programa de Pos-Graduação em Informatica, Instituto Tercio Pacitti de Aplicações e Pesquisas Computacionais, Instituto de Matematica, Universidade Federal do Rio de Janeiro, 21941-901 Rio de Janeiro, RJ, Brazil
2, Instituto Nacional de Metrologia, Qualidade e Tecnologia, 25250-020 Duque de Caxias, RJ, Brazil
Received 11 June 2015; Accepted 17 September 2015; 15 November 2015
This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
1. Introduction
Recent advances in microelectromechanical systems and wireless communication technologies have enabled the building of low-cost and small-sized sensors nodes, which are capable of sensing, processing, and communicating through wireless links. Wireless Sensor Networks (WSNs) are composed of tens, hundreds, or even thousands of sensor nodes [1, 2]. Nodes in WSNs commonly rely on nonrechargeable batteries as their energy sources, and the replacement of depleted batteries is not always feasible or desirable. Therefore, a major challenge in the design of WSNs is how to save energy in order to extend the network operational lifetime. Wireless Sensor Networks are commonly used to monitor a wide range of environmental variables, such as temperature, humidity, acceleration, and light among others [3]. These networks can thus be regarded as the interface between the physical world and the world of electrical/electronic devices, as computers and domestic appliances [4]. WSNs communicate the information collected by their sensing devices through their wireless links, thus enabling interaction between people or computers and the surrounding environment [5]. The data gathered by the different nodes is transmitted to one or more sink nodes. Sink nodes are devices endowed with high processing power and with no energy constraints. Such nodes act as the entry points for application requests and also as the gathering points of sensor-collected data [1]. The WSN technology can also encompass the use of wireless actuators, originating the concept of Wireless Sensor and Actuator Networks (WSANs) [5]. Besides the inherent sensing capabilities of the...