An efficient scalable scheduling mac protocol for underwater sensor networks

Underwater Sensor Networks (UWSNs) utilise acoustic waves with comparatively lower loss and longer range than those of electromagnetic waves. However, energy remains a challenging issue in addition to long latency, high bit error rate, and limited bandwidth. Thus, collision and retransmission should be efficiently handled at Medium Access Control (MAC) layer in order to reduce the energy cost and also to improve the throughput and fairness across the network. In this paper, we propose a new reservation-based distributed MAC protocol called ED-MAC, which employs a duty cycle mechanism to address the spatial-temporal uncertainty and the hidden node problem to effectively avoid collisions and retransmissions. ED-MAC is a conflict-free protocol, where each sensor schedules itself independently using local information. Hence, ED-MAC can guarantee conflict-free transmissions and receptions of data packets. Compared with other conflict-free MAC protocols, ED-MAC is distributed and more reliable, i.e., it schedules according to the priority of sensor nodes which based on their depth in the network. We then evaluate design choices and protocol performance through extensive simulation to study the load effects and network scalability in each protocol. The results show that ED-MAC outperforms the contention-based MAC protocols and achieves a significant improvement in terms of successful delivery ratio, throughput, energy consumption, and fairness under varying offered traffic and number of nodes

Enhanced hop-by-hop routing algorithms for underwater acoustic sensor networks

Underwater Acoustic Sensor Network (UW-ASN) is a wireless network infrastructure applicable in deep ocean to sense, collect and transmit information to seashore data collector. Underwater sensor network consists of sensor nodes disposed in different depths, equipped with a low bandwidth acoustic modem and acts collaboratively to route the packet from one node to another. Underwater routing protocols provide route information to underwater sensor nodes to transmit collected information efficiently using an optimal path. Routing protocol related to UW-ASN is identified with the issues of low energy consumption, high end-to-end delay and shorter network lifetime. These are due to the distribution of unnecessary information packet flooding in route establishment, improper selection of next hop neighbour and inefficient routing path generation. This research develops a routing protocol that will be able to control flooding of hello packet at information distribution phase, to calculate link quality and composite metric cost for next hop selection and to regularly update the energy status in order to achieve optimum balance in routing path. The developed protocol is called Distance based Reliable and Energy Efficient (DREE) consists of three schemes. The first scheme is called distance calculation and information distribution scheme that calculates the distance between potential neighbours and distribute the local information in an energy efficient manner. The second scheme is route planning and data forwarding scheme in which a node calculates the link quality towards its neighbours and selects a path based on physical distance, link quality and node energy information. Finally, the third scheme is energy balancing scheme that provides each node with new energy status of its neighbours on regular basis. DREE is compared with a Reliable and Energy Efficient routing protocol (R-ERP2R) and Depth based Routing (DBR) protocol. Simulation shows that DREE reducing energy consumption in the information distribution phase by 187% and 179% compared to R-ERP2R in random and grid topology respectively. DREE achieves higher packet delivery ratio of 96% with a similar end-to-end delay as R-ERP2R. DREE improves packet delivery ratio by 7% and 13% over R-ERP2R and DBR, with 9.3% and 201% less energy consumption respectively in data forwarding phase. Finally, DREE improves network lifetime by 18% and 74.5% compared to R-ERP2R and DBR protocols

Design, Analysis, and Performance Evaluation for Handshaking Based MAC Protocols in Underwater Acoustic Networks

Ph.DDOCTOR OF PHILOSOPH

TIME DOMAIN MEDIUM ACCESS CONTROL PROTOCOLS FOR UNDERWATER ACOUSTIC NETWORKS

Ph.DDOCTOR OF PHILOSOPH

Internet of Underwater Things and Big Marine Data Analytics -- A Comprehensive Survey

The Internet of Underwater Things (IoUT) is an emerging communication ecosystem developed for connecting underwater objects in maritime and underwater environments. The IoUT technology is intricately linked with intelligent boats and ships, smart shores and oceans, automatic marine transportations, positioning and navigation, underwater exploration, disaster prediction and prevention, as well as with intelligent monitoring and security. The IoUT has an influence at various scales ranging from a small scientific observatory, to a midsized harbor, and to covering global oceanic trade. The network architecture of IoUT is intrinsically heterogeneous and should be sufficiently resilient to operate in harsh environments. This creates major challenges in terms of underwater communications, whilst relying on limited energy resources. Additionally, the volume, velocity, and variety of data produced by sensors, hydrophones, and cameras in IoUT is enormous, giving rise to the concept of Big Marine Data (BMD), which has its own processing challenges. Hence, conventional data processing techniques will falter, and bespoke Machine Learning (ML) solutions have to be employed for automatically learning the specific BMD behavior and features facilitating knowledge extraction and decision support. The motivation of this paper is to comprehensively survey the IoUT, BMD, and their synthesis. It also aims for exploring the nexus of BMD with ML. We set out from underwater data collection and then discuss the family of IoUT data communication techniques with an emphasis on the state-of-the-art research challenges. We then review the suite of ML solutions suitable for BMD handling and analytics. We treat the subject deductively from an educational perspective, critically appraising the material surveyed.Comment: 54 pages, 11 figures, 19 tables, IEEE Communications Surveys & Tutorials, peer-reviewed academic journa

An Overview of MOOS-IvP and a Users Guide to the IvP Helm - Release 4.2.1

This document describes the IvP Helm - an Open Source behavior-based autonomy application for unmanned vehicles. IvP is short for interval programming - a technique for representing and solving multi-objective optimizations problems. Behaviors in the IvP Helm are reconciled using multi-objective optimization when in competition with each other for influence of the vehicle. The IvP Helm is written as a MOOS application where MOOS is a set of Open Source publish-subscribe autonomy middleware tools. This document describes the configuration and use of the IvP Helm, provides examples of simple missions and information on how to download and build the software from the MOOS-IvP server at www.moos-ivp.org.United States. Office of Naval Research (Code 311

Redes de transmissão de dados em meios submarinos

Dissertação de Mestrado, Engenharia Eletrica e Eletrónica, Instituto Superior de Engenharia, Universidade do Algarve, 2015Há um crescente interesse nas comunicações submarinas e aos dados oceanográficos nos últimos anos, devido à importância dos oceanos para o ser humano. As redes acústicas submarinas têm grande potencial para suportar uma grande variedade de aplicações, monitorização ambiental, vigilância submarina, prevenção de catástrofes, exploração de petróleo e monitorização de poluição. Apesar da comunicação acústica submarina ter sido estudada durante várias décadas, trabalhos em redes acústicas submarinos, projectos de implementação de protocolos de acesso ao meio (MAC) e protocolos de encaminhamento apenas estão numa fase inicial como campo de pesquisa devido ao elevado custo dos nós e dos navios de distribuição. Neste âmbito, a simulação torna-se como uma ferramenta fundamental para avaliação do desempenho da rede e um grande auxiliar no projecto de implementação dos protocolos em aplicações onde os cenários são complexos, devido ao elevado custo e inviabilidade em pôr na prática. Neste sentido, tendo como objectivo proporcionar um ambiente fiável de simulação de redes acústicas submarinas, optámos pelo simulador de rede WOSS (World Ocean Simulation System) de forma a fornecer uma reprodução mais detalhada da propagação acústica. O Objectivo central desta dissertação consiste na implementação de um protocolo de acesso ao meio DACAP (Distance Aware Collision Avoidance Protocol) para redes ad-hoc acústica submarina -caracterizadas por longos atrasos de propagação e diferentes requisitos de potência de Transmissão/Receção- e de seguida testá-lo no referido simulador de rede. Os resultados são mostrados fazendo comparação do desempenho da rede acústica submarina para diversos parâmetros, entre o protocolo DACAP e diversos mecanismos de acesso ao meio existentes no simulador de rede, para um conjunto de topologias diferentes e para diferentes tamanhos de tramas

Decentralized task allocation for dynamic, time-sensitive tasks

Thesis: S.M., Massachusetts Institute of Technology, Department of Mechanical Engineering, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 103-110).In time-sensitive and dynamic missions, autonomous vehicles must respond quickly to new information and objectives. In the case of dynamic task allocation, a team of agents are presented with a new, unknown task that must be allocated with their original allocations. This is exacerbated further in decentralized settings where agents are limited to utilizing local information during the allocation process. This thesis presents a fully decentralized, dynamic task allocation algorithm that extends the Consensus-Based Bundle Algorithm (CBBA) to allow for allocating new tasks. Whereas static CBBA requires a full resetting of previous allocations, CBBA with Partial Replanning (CBBA-PR) enables the agents to only partially reset their allocations to efficiently and quickly allocate a new task. By varying the number of existing tasks that are reset during replan, the team can trade-off convergence speed with amount of coordination. By specifically choosing the lowest bid tasks for resetting, CBBA-PR is shown to converge linearly with the number of tasks reset and the network diameter of the team. In addition, limited replanning methods are presented for scenarios without sufficient replanning time. These include a single reset bidding procedure for agents at capacity, a no-replanning heuristic that can identify scenarios that does not require replanning, and a subteam formation algorithm for reducing the network diameter. Finally, this thesis describes hardware and simulation experiments used to explore the effects of ad-hoc, decentralized communication on consensus algorithms and to validate the performance of CBBA-PR.by Noam Buckman.S.M

MOOS-IvP Autonomy Tools Users Manual Release 4.2.1

This document describes 19 MOOS-IvP autonomy tools. uHelmScope provides a run-time scoping window into the state of an active IvP Helm executing its mission. pMarineViewer is a geo-based GUI tool for rendering marine vehicles and geometric data in their operational area. uXMS is a terminal based tool for scoping on a MOOSDB process. uTermCommand is a terminal based tool for poking a MOOSDB with a set of MOOS file pre-defined variable-value pairs selectable with aliases from the command-line. pEchoVar provides a way of echoing a post to one MOOS variable with a new post having the same value to a different variable. uProcessWatch monitors the presence or absence of a set of MOOS processes and summarizes the collective status in a single MOOS variable. uPokeDB provides a way of poking the MOOSDB from the command line with one or more variable-value pairs without any pre-existing configuration of a MOOS file. uTimerScript will execute a pre-defined timed pausable script of poking variable-value pairs to a MOOSDB. pNodeReporter summarizes a platforms critical information into a single node report string for sharing beyond the vehicle. pBasicContactMgr provides a basic contact management service with the ability to generate range-dependent configurable alerts. uSimMarine provides a simple marine vehicle simulator. uSimBeaconRange and uSimContactRange provide further simulation for range-only sensors. The Alog Toolbox is a set of offline tools for analyzing and manipulating log files in the .alog format

An Overview of MOOS-IvP and a Users Guide to the IvP Helm Autonomy Software

This document describes the IvP Helm -- an Open Source behavior-based autonomy application for unmanned vehicles. IvP is short for interval programming -- a technique for representing and solving multi-objective optimizations problems. Behaviors in the IvP Helm are reconciled using multi-objective optimization when in competition with each other for influence of the vehicle. The IvP Helm is written as a MOOS application where MOOS is a set of Open Source publish-subscribe autonomy middleware tools. This document describes the configuration and use of the IvP Helm, provides examples of simple missions and information on how to download and build the software from the MOOS-IvP server at www.moosivp.org