Efficient target coverage in WSNs with bidirectional communication

Several applications in wireless sensor networks require a bidirectional communication between the sensing nodes and the sink. A number of relay nodes is used to achieve this bidirectional communication. The relay nodes adjust their communication range in order to consume less energy, constructing an asymmetric network with unidirectional links. In this paper, we examine the case where a bidirectional path must be established between the sensing nodes and the sink, focusing on the extension of the network lifetime. We propose an efficient heuristic that establishes two unidirectional paths in order to distribute the communication cost among the nodes. Our evaluation shows an over 20% improvement in some cases compared to the commonly used approach where a single bidirectional path is used.