Channel replay-based performance evaluation of protocols for underwater routing

The paper presents a comparative performance evaluation of two routing protocols for underwater wireless sensor networks (UWSNs). The two protocols are the Channel-Aware Routing Protocol (CARP), exemplary of a cross layer approach to underwater routing, and a simple variation of common flooding, called EFlood, where performance is enhanced by introducing random re-transmission times. The scenarios we consider are obtained via simulations and from trials at sea performed under a collaboration agreement between the University of Roma “La Sapienza” and the NATO Science and Technology Organization Centre for Maritime Research and Experimentation (STO CMRE). Two sets of simulations results are shown where the physical layer is modeled by a ray-traced channel as well as by replaying real channel traces, under the same network configuration. Results are also reported from campaigns of experiments at sea. Comparing all results shows how channel replay mimics faithfully actual channel dynamics with respect to what is achievable through a simulated channel model, thus demonstrating the effectiveness of this technique for a fair and repeatable performance comparison of solutions for UWSNs.