An Efficient Gradient Mechanism of Directed Diffusion in Wireless Sensor Network

In wireless sensor network (WSN), sensor node is limited in energy, thus energy efficiency is an important concern in routing protocol design. And some applications in sensor networks have the requirement of timely delivery, real-time also become needed for routing. Directed diffusion (DD) is a data centric dissemination protocol for sensor networks, but DD cannot support time-sensitive traffic nor perform balance of energy consumption to increase network lifetime. To solve this issue, we design a new kind of gradient mechanism, which considers residual energy of node and the number of hops from the sink to an intermediate node synchronously. It can find a best-effort optimal path in sensor networks for data transfer. Simulation results show that our proposed method achieves more globally energy balancing and lower delay for data transfer than originally DD. It prolongs the lifetime of network efficiently.