Energy-efficient data dissemination using beamforming in wireless sensor networks

Energy conservation is essential in Wireless Sensor Networks (WSNs) because of limited energy in nodes' batteries. Collaborative beamforming uses multiple transmitters to form antenna arrays; the electromagnetic waves from these antenna arrays can create constructive interferences at the receiver and increase the transmission distance. Each transmitter can use lower power and save energy, since the energy consumption is spread over multiple transmitters. Each beamforming transmission requires multiple collaborative transmitters. Repetitively using the same transmitters will deplete their energy and create coverage holes in the sensing area. To prevent holes, energy should be balanced by using different transmitters. This article investigates the factors that can affect the energy consumption and network lifetime when using beamforming. We present an algorithm for selecting the transmitters in order to prolong the network lifetime. Compared with an existing beamforming transmitters scheduling algorithm, our algorithm doubles the network lifetime. When compared with direct transmission or multihop transmissions towards a receiver far away from the sensing area, our approach can increase the network's lifetime substantially.