UAV-Assisted Underwater Sensor Networks Using RF and Optical Wireless Links

Underwater sensor networks (UWSNs) are of interest to gather data from underwater nodes (SNs) and deliver information a terrestrial access point (AP) in the uplink transmission, transfer AP SNs downlink transmission. In this paper, we investigate triple-hop UWSN which autonomous vehicle (AUV) unmanned aerial (UAV) relays enable end-to-end communications between AP. It is assumed that SN–AUV, AUV–UAV, UAV–AP links deployed by optical communication (UWOC), free-space optic (FSO), radio frequency (RF) technologies, respectively. Two scenarios proposed for FSO transmissions AUV UAV, subject water-to-air air-to-water interface impacts; direct transmission scenario (DTS) retro-reflection (RRS). After providing channel models their statistics, UWSN's outage probability average bit error rate (BER) computed. Besides, tracking procedure set up reliable stable AUV– UAV communications. Through numerical results, it concluded RSS scheme outperforms DTS one with about 200% (32%) 80% (17%) better (average BER) downlink, also shown provides on 480% 170% improvements network's BER, respectively, compared poorly aligned conditions. The results verified applying Monte-Carlo simulations.