IDFR: Intelligent directional flooding-based routing protocols for underwater sensor networks

In deep waters, both the natural acoustic systems (such as marine mammals) and artificial acoustic systems (like underwater sensor networks (UWSNs) and sonar users) use acoustic signals for communication, echolocation, sensing, and detection. This makes the channel spectrum, heavily shared by UWSNs posing several salient features such as narrow bandwidth, long propagation delay, and high packet loss caused by acoustic channel. Flooding of data packets in such environment, therefore, is known to be a more appropriate mechanism. Hence, many researchers proposed flooding-based routing protocols for UWSNs such as VBF and HH-VBF. Nevertheless, these known protocols maximize overhead within network due to their dependency on additional parameters such as routing vector. To deviate this overhead and control the flooding, we previously proposed a Directional Flooding Routing (DFR) protocol, which controls the flooding area based on link quality. However, DFR lacks to deal with dynamic changes under the shores due to fixed system parameters throughout the network communications. In this paper, we therefore propose two new DFR protocols, called QA-DFR-AA (QoS-Aware DFR with Angle Adaption) and QA-DFR-TA (QoS-Aware DFR with Threshold Adaption) to reflect QoS dynamically. In addition, we also aid our current DFR with holding time technique to avoid packet collision and redundant packet transmission. Through NS-2 simulations, we found that our new intelligent DFR (iDFR) and two new versions of DFR outperforms the current version of the DFR.