Directed Flooding with Self-Pruning in Wireless Sensor Networks

In wireless sensor networks, nodes commonly rely on each other to route messages to the sink node. In this paper, we introduce a highly efficient directed flooding protocol with self-pruning. In directed flooding, a node broadcasts messages, but only the nodes within a limited aperture can forward these messages. However, it is difficult to decide the size of the aperture. If the aperture is small, there exists high probability of adjusting the aperture. Conversely, more than one node will forward the messages if the aperture is large, and this will consume limited energy and bandwidth. We present an approach to avoid many nodes forwarding the message simultaneously. When a node receives the data packet, it waits for a random period to listen to other nodes´ acknowledge messages. The node forwards the received packet only if it have not received the acknowledge messages. In this way the network can optimize the overhead and correspondingly reduce the bandwidth and energy used. Simulation results show that our protocol achieves much higher performance compared with the directed flooding without self-pruning.