Robust Spatial Reuse Scheduling in Underwater Acoustic Communication Networks

Abstract

Abstract-In this paper we address the problem of spatialreuse scheduling for underwater acoustic communication (UWAC) networks that support high traffic broadcast communication and require robustness to inaccurate topology information. To this end, we derive a broadcast scheduling algorithm that combines topology-transparent and topology-dependent scheduling methodologies to achieve high-throughput in static and dynamic topology scenarios. While we focus on scheduling in UWAC networks, our approach can also be adopted for broadcast scheduling for radio ad-hoc network if robustness to topology uncertainties is desired. Simulation results for typical UWAC scenarios demonstrate that our protocol achieves high throughput and provides robustness to outdated topology information in dynamic topologies.Index Terms-Underwater acoustic communication (UWAC), broadcast scheduling problem (BSP), spatial-reuse scheduling, topology-transparent scheduling.

Underwater Acoustic Sensor Node Scheduling using an Evolutionary Memetic Algorithm

“…The largest size of the expected propagation delay experienced underwater is reduced by using propagation estimation to stagger transmission [23]. HSR-TDMA presented in [17] overcomes the above conflicts and increases the number of node transmissions, but a few nodes within the network suffered from a long turnaround wait time for their subsequent transmissions. As the size of UWASN increases, the HSR-TDMA frame length also increases, which shows that a few nodes in the network suffer from very long turnaround times for their subsequent transmissions also, which means they will be the cause of the lowest successful packet transmission rate (STR) for those few nodes, which affects the overall network throughput [17].…”

“…All proposals have major issues in broadcast scheduling. In [17] hybrid spatial reuse TDMA (HSR-TDMA), the problem of broadcast scheduling has been solved using the hybrid spread spectrum method, but the hidden and exposed terminal issues have not been addressed effectively. The other drawback in HSR-TDMA is that few nodes in the network suffer from very long schedules for its subsequent transmissions, which directly affects the overall throughput.…”

Asymmetric Propagation Delay-Aware TDMA MAC Protocol for Mobile Underwater Acoustic Sensor Networks

“…In high traffic scenarios, packet collisions of MUASNs not only severely degrade network throughput, but also cause intolerably long latency due to uncertain number of retransmissions. On the other hand, contention-free MAC protocols [22][23][24][25][26][27][28][29][30][31][32][33][34][35][36][37] are significantly superior to contention-based ones in high traffic scenarios because the medium is orthogonalized in a certain domain.…”

“…However, this large propagation delay is being re-interpreted rather positively, and TDMA approaches in MUASN are considered to be one of the most efficient MAC protocols. In particular, spatial reuse MACs [28][29][30][31][32][33][34][35][36][37] take advantage of a large propagation delay for concurrent transmissions without collisions at receivers by considering possible interferences from neighbor nodes.…”

“…Spatial reuse MACs that operate in a distributed manner [29][30][31][32][33][34] make concurrent multiple connections as frequently as possible, and show significantly improved throughput. However, it is not easy to operate these distributed methods in a centralized manner without sacrificing performance.…”