iAMCTD: Improved Adaptive Mobility of Courier Nodes in Threshold-Optimized DBR Protocol for Underwater Wireless Sensor Networks

Abstract

We propose forwarding-function ( ) based routing protocol for underwater sensor networks (UWSNs): improved adaptive mobility of courier nodes in threshold-optimized depth-based-routing (iAMCTD). Unlike existing depth-based acoustic protocols, the proposed protocol exploits network density for time-critical applications. In order to tackle flooding, path loss, and propagation latency, we calculate optimal holding time ( ) and use routing metrics: localization-free signal-to-noise ratio (LSNR), signal quality index (SQI), energy cost function (ECF), and depth-dependent function (DDF). Our proposal provides on-demand routing by formulating hard threshold ( th ), soft threshold ( th ), and prime energy limit ( prime ). Simulation results verify effectiveness and efficiency of the proposed iAMCTD. BackgroundUnderwater acoustic sensor networks (UASNs), as a subclass of wireless sensor networks (WSNs), are specifically used for monitoring purposes in aqueous environment. The acoustic wireless sensors along with sink(s), distributed under water, constitute the basic body of UASN, where acoustic sensors gather the information of interest and then following a routing strategy forward these data to the end station. WHOI Micro-Modem [1] and Crossbow Mica2 [2] are among the commercially available sensors for underwater environments. Sink is generally supposed to have no power constraint, whereas the acoustic sensors are equipped with limited battery power. These networks provide diversified range of applications like pollution monitoring, ocean current detection, submarine discovery, deep sea explorations, and seabed management.Due to the nature of aqueous environment, improving energy efficiency at routing layer is a challenging task. Moreover, as there are major differences between terrestrial and underwater conditions, hence the basic concepts of terrestrial routing can not be implemented in UWSNs. To tackle these problems, researchers exercise the role of low speed acoustic signals for aqueous communication and sea navigation systems, leading to high propagation delay and transmission losses. High shipping activity, thermal noise, and turbulent noise also increase the error rate. Authors in [3] design the underwater acoustic channel to descriptively analyze the total noise density and path loss. On the other hand [4], it investigates diverse routing architectures for 2-dimensional and 3-dimensional UWSNs. Fundamental analyses of aqueous conditions show that reactive routing is more challenging than the proactive one. Battery replacement and efficient routing are among the solutions to overcome the

A Routing Protocol Based on Received Signal Strength for Underwater Wireless Sensor Networks (UWSNs)

“…However, the movement of courier nodes makes AMCTD unsuitable for data-sensitive applications during the instability phase. So Javaid et al proposed i-AMCTD in [20]. i-AMCTD precedes AMCTD by introducing both hard and soft thresholds.…”

“…Here, h is the distance from the receiving node B to RSS vector. For clarity, let ∆ = ( + + ), according to the Qinjiushao-Helen formula, the area of the triangle ABS, denoted by A, can be calculated as in Equation (20).…”

A Recent Study on Routing Protocols in UWSNs

“…AMCTD'S performance is far better than EEDBR and DBR, however it had deficiency which further removed by an Improved Adaptive Mobility of Courier Nodes in Threshold-Optimized DBR Protocol (iAMCTD) which is routing protocol overcome to AMCTD uses forwarded function for time critical applications for UWSN [17]. iAMCTD exploits network density to tackle the problem of path loss, flooding and latency propagation.…”

“…iAMCTD exploits network density to tackle the problem of path loss, flooding and latency propagation. In sparse condition the energy consumption is decreases of low depth nodes and minimizes end-to-end delay due to courier nodes of efficient node [17]. In terms of distance and frequency the acoustic link channel is described in iAMCTD, faced transmission of redundant data which further resulted in major energy consumption…”

DSM: Dynamic Sink Mobility Equipped DBR for Underwater WSNs

“…Another reactive routing protocol, improved Adaptive Mobility of Courier nodes in Threshold-optimized Depthbased-routing (iAMCTD) 10 increases the network throughput and largely minimizes packet drop ratio by using its formulated Forwarding Functions FFs. To reduce network lifetime, mobile courier nodes are utilized in UWSNs.…”