VBF: Vector-Based Forwarding Protocol for Underwater Sensor Networks

In this paper, we tackle one fundamental problem in Underwater Sensor Networks (UWSNs): robust, scalable and energy efficient routing. UWSNs are significantly different from terrestrial sensor networks in the following aspects: low bandwidth, high latency, node float mobility (resulting in high network dynamics), high error probability, and 3-dimensional space. These new features bring many challenges to the network protocol design of UWSNs. In this paper, we propose a novel routing protocol, called vector-based forwarding (VBF), aiming to provide robust, scalable and energy efficient routing. VBF is essentially a location-based routing approach. No state information is required on the sensor nodes and only a small fraction of the nodes are involved in routing. Moreover, packets are forwarded in redundant and interleaved paths, which add robustness to VBF. Further, we develop a localized and distributed self-adaptation algorithm, which helps to enhance the performance of VBF. The self-adaptation algorithm allows the nodes to weigh the benefit to forward packets and reduce energy consumption by discarding the low benefit packets. We evaluate the performance of VBF through extensive simulations. Our experiment results show that for networks with small or medium node mobility (1 m/s-3 m/s), VBF can effectively accomplish the goals of robustness, energy efficiency, and high success of data delivery.