Energy-Efficient Routing in Wireless Sensor Networks with Improved Network Life

Nowadays maintaining neighbourhood information for packet forwarding can achieve a high efficiency in geographic routing, but may not be appropriate for wireless sensor networks in highly dynamic scenarios where network topology changes frequently due to nodes mobility and availability. Geographic routing is an attractive localized routing scheme for wireless sensor networks (WSNs) due to its desirable scalability and efficiency. We propose an online routing scheme, which can provide loop-free, fully stateless, energy-efficient and beaconless sensor-to-sink routing at a low communication overhead without the help of prior neighbourhood knowledge. In this algorithm, each node first calculates its ideal next-hop relay position on the straight line toward the sink based on the energy-optimal forwarding distance, and each forwarder selects the neighbour closest to its ideal next-hop relay position as the next-hop relay using the Request-To-Send/Clear-To-Send (RTS/CTS) handshaking mechanism. At the same time, we also estimate the energy level of that particular node which will be the best next hop relay, whether it has sufficient energy to transmit or not.