Power-aware data dissemination protocol for grid-based wireless sensor networks with mobile sinks

In wireless sensor networks (WSNs), sink mobility has been drawing more and more attention in recent years. Some approaches suggest that mobile sinks repeatedly propagate packets to notify the potential sources of their latest location information. As a result, frequent location updates from multiple sinks introduce both increased transmission traffic and rapid power expenditure. In order to reduce power consumption and minimise the overhead of frequently propagating packets, the authors propose a power-aware data dissemination (PADD) protocol for grid-based WSNs with mobile sinks. Rather than propagate the query messages from each sink to all sensor nodes to establish data forwarding information, a source constructs a grid structure beforehand so that only the dissemination nodes located at grid points need to acquire forwarding information. A properly grid cell size is determined to ensure that a dissemination node can directly communicate each other with its eight neighbouring dissemination nodes. As a result, a message can traverse not only vertically or horizontally but diagonally as well. Besides, dissemination nodes with the most residual energy are selected for forwarding query and disseminating data to evenly distribute energy load in the sensor field. Simulation results demonstrate the effectiveness of PADD in reducing the energy consumption and prolonging the network lifetime.