A cooperative protocol for pervasive underwater acoustic networks

The novel Underwater Wireless Sensor Network (UWSN) can contribute to monitor and explore aquatic environments. But, communicating in these environments is still hard and has many challenges. For example, optical and electromagnetic waves deteriorate from high-attenuation. Moreover, acoustic communication has a large packet error rate and low throughput. A large number of solutions to improve aquatic communication refers to routing protocols, medium access control protocols, and designing acoustic modems. Cooperative communication explores the broadcast nature of wireless transmission and enhances its performance. However, cooperative communication has not been fully explored in UWSNs. In this work, we present COPPER, a Cooperative Protocol for Pervasive Underwater Acoustic Networks. COPPER considers LLC and MAC sub-layers and operates synchronously or asynchronously over Time Division Multiple Access using a selective repeat ARQ scheme. COPPER exploits the broadcast nature of wireless communication and, sensor nodes that are idle can operate as a relay, enhancing communication by space diversity. Simulation results show that COPPER improves network performance. For example, the network goodput improves by 17% and the packet error rate decreases by 65%.