RECAR: Robust and efficient collision-avoiding routing for 3D underwater named data networking

Internet of Underwater Things (IoUT) has important application prospects in fields of both scientific research and commercial business. As a future network architecture, Named Data Networking (NDN) is starting to be applied to IoUT. Although Underwater Named Data Networking (UNDN) has unique advantages in dealing with bandwidth usage, multi-path forwarding, and node mobility, there is still no specific routing protocol for UNDN. The existing underwater routing protocols are either difficult to combine with NDN, or are limited by channel collision and redundant forwarding, especially broadcast suppression routing. In this paper, we propose a routing method named Robust and Efficient Collision-Avoiding Routing (RECAR) for 3D UNDN. RECAR consists of three combined forwarding modes: Directive Mode (DM), Directive Flooding Mode (DFM), and Flooding Mode (FM). In DFM, we propose Segmentation Suppression for Optimal Position (SSOP), an elaborate waiting time algorithm of broadcast suppression which can effectively reduce channel collisions and redundant forwarding. For DM, failure path recovery and unreliable path elimination are proposed to address failure paths. Additionally, several forwarding efficient mechanisms are designed including flexible mode shift, unified data forwarding and scope control. Simulation results show that RECAR has excellent and robust performance, even in the cases of node failure and void hole. Compared with a recent underwater routing method (adaptive location-based routing protocol), RECAR improves the average interest satisfied rate by 19.57% while reducing the request time, collisions, redundant forwarding, total traffic, and energy consumption by 19.5%, 91.7%, 71.4%, 78.4%, and 27.3%, respectively.