Improved Gradient-Based Micro Sensor Routing Protocol with Node Sleep Scheduling in Wireless Sensor Networks

In this paper, we propose an improved gradient-based micro sensor routing protocol (GMSRP) using a node sleep scheduling mechanism, to save energy for sensor nodes, called the GMSRP-SLE. This algorithm takes into account the characteristic of most applications in WSNs, i.e.,the sensor nodes are deployed randomly with some areas covered by many sensor nodes at same time. During network initialization, each sensor node in GMSRP-SLE can learn its gradient information, which is the minimal number of hops away from the sink node. Sensor nodes with the same gradients in the same layer can form a cluster according to the requirement of minimal sensing coverage ratio. One sensor node in the cluster is selected to be a cluster head, and the rest will go to sleep. Additionally, in order to balance the energy consumption and the lifetime of sensor nodes in a cluster, each sensor node will take turn to become the cluster head. Our NS-2 simulation results show that the GMSRP-SLE algorithm can work efficiently to keep some nodes sleeping in order to save more energy.