Real-Time Communication Support for Underwater Acoustic Sensor Networks

Abstract

Underwater sensor networks represent an important and promising field of research due to the large diversity of underwater ubiquitous applications that can be supported by these networks, e.g., systems that deliver tsunami and oil spill warnings, or monitor submarine ecosystems. Most of these monitoring and warning systems require real-time communication in wide area networks that have a low density of nodes. The underwater communication medium involved in these networks is very harsh and imposes strong restrictions to the communication process. In this scenario, the real-time transmission of information is done mainly using acoustic signals, since the network nodes are not physically close. The features of the communication scenario and the requirements of the communication process represent major challenges for designers of both, communication protocols and monitoring and warning systems. The lack of models to represent these networks is the main stumbling block for the proliferation of underwater ubiquitous systems. This paper presents a real-time communication model for underwater acoustic sensor networks (UW-ASN) that are designed to cover wide areas with a low density of nodes, using any-to-any communication. This model is analytic, considers two solution approaches for scheduling the real-time messages, and provides a time-constraint analysis for the network performance. Using this model, the designers of protocols and underwater ubiquitous systems can quickly prototype and evaluate their solutions in an evolving way, in order to determine the best solution to the problem being addressed. The suitability of the proposal is illustrated with a case study that shows the performance of a UW-ASN under several initial conditions. This is the first analytic model for representing real-time communication in this type of network, and therefore, it opens the door for the development of underwater ubiquitous systems for several application scenarios.

A Glider-Assisted Link Disruption Restoration Mechanism in Underwater Acoustic Sensor Networks

“…The technology to improve connectivity and reliability of sensor networks is a hot topic nowadays. There are several kinds of methods aiming to improve connectivity and reliability to meet the requirement of applications, such as the algorithms for the routing layer and MAC layer [ 12 , 13 , 14 , 15 , 16 ], the nodes complement about dynamic nodes and static nodes [ 17 , 18 , 19 ] and so on. In this section, we provide a review on research works on this topic.…”

“…This is because the disruption of communication in two nodes is not only caused by the increase of communication distance, so merely increasing the transmission power not only causes a large energy overhead but also easily causes interference to other nodes and reduces the channel capacity. For sparse networks, the authors in [ 16 ] propose a network analytic model and designed an any-to-any communication scheme. The model considers the problem of real-time message-delivery which is solved by integer linear programming and heuristics.…”

“…The model considers the problem of real-time message-delivery which is solved by integer linear programming and heuristics. The model proposed in [ 16 ] can reduce the complexity and improve the efficiency of networks and it is helpful for network simulation. With distributed beacons, the authors in [ 13 ] propose a novel cooperative opportunistic routing (OVAR) scheme for UASNs and build a contiguity graph at each hop and select a forwarding set that maintains the best balance between reliability and energy efficiency.…”

Underwater Optical Wireless Communications: Overview

“…Extensive studies are conducted to improve the performance of the acoustic communication channels [3][4][5][6][7]. Nevertheless, its performance is linked to the physical nature that limits the bandwidth, causes high latency, produces high transmission losses, time varying multi-path propagation and Doppler's spread [8][9][10][11][12][13]. These limitations do not allow autonomous underwater vehicles (AUV) to transmit real-time video in high definition via acoustic communication.…”

ABS-FishCount: An Agent-Based Simulator of Underwater Sensors for Measuring the Amount of Fish

“…In this context, these sensors usually communicate among each other for conforming underwater sensor networks [ 2 ], the acoustic networks being the most common ones. Acoustic underwater sensor networks are useful for real-time communications even in networks with a low density of nodes [ 3 ]. Simulation tools can be useful for testing and analyzing certain approaches of underwater sensor networks in the early stages without needing the high costs of deploying an actual underwater sensor network [ 4 ].…”